--- /dev/null
+/*
+ * Copyright (C) 2007 Oracle. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+#include <linux/sched.h>
+#include <linux/pagemap.h>
+#include <linux/writeback.h>
+#include <linux/blkdev.h>
+#include <linux/sort.h>
+#include <linux/rcupdate.h>
+#include <linux/kthread.h>
+#include <linux/slab.h>
+#include <linux/ratelimit.h>
+#include <linux/percpu_counter.h>
+#include "hash.h"
+#include "tree-log.h"
+#include "disk-io.h"
+#include "print-tree.h"
+#include "volumes.h"
+#include "raid56.h"
+#include "locking.h"
+#include "free-space-cache.h"
+#include "math.h"
+#include "sysfs.h"
+#include "qgroup.h"
+
+#undef SCRAMBLE_DELAYED_REFS
+
+/*
+ * control flags for do_chunk_alloc's force field
+ * CHUNK_ALLOC_NO_FORCE means to only allocate a chunk
+ * if we really need one.
+ *
+ * CHUNK_ALLOC_LIMITED means to only try and allocate one
+ * if we have very few chunks already allocated. This is
+ * used as part of the clustering code to help make sure
+ * we have a good pool of storage to cluster in, without
+ * filling the FS with empty chunks
+ *
+ * CHUNK_ALLOC_FORCE means it must try to allocate one
+ *
+ */
+enum {
+ CHUNK_ALLOC_NO_FORCE = 0,
+ CHUNK_ALLOC_LIMITED = 1,
+ CHUNK_ALLOC_FORCE = 2,
+};
+
+/*
+ * Control how reservations are dealt with.
+ *
+ * RESERVE_FREE - freeing a reservation.
+ * RESERVE_ALLOC - allocating space and we need to update bytes_may_use for
+ * ENOSPC accounting
+ * RESERVE_ALLOC_NO_ACCOUNT - allocating space and we should not update
+ * bytes_may_use as the ENOSPC accounting is done elsewhere
+ */
+enum {
+ RESERVE_FREE = 0,
+ RESERVE_ALLOC = 1,
+ RESERVE_ALLOC_NO_ACCOUNT = 2,
+};
+
+static int update_block_group(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, u64 bytenr,
+ u64 num_bytes, int alloc);
+static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ u64 bytenr, u64 num_bytes, u64 parent,
+ u64 root_objectid, u64 owner_objectid,
+ u64 owner_offset, int refs_to_drop,
+ struct btrfs_delayed_extent_op *extra_op,
+ int no_quota);
+static void __run_delayed_extent_op(struct btrfs_delayed_extent_op *extent_op,
+ struct extent_buffer *leaf,
+ struct btrfs_extent_item *ei);
+static int alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ u64 parent, u64 root_objectid,
+ u64 flags, u64 owner, u64 offset,
+ struct btrfs_key *ins, int ref_mod);
+static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ u64 parent, u64 root_objectid,
+ u64 flags, struct btrfs_disk_key *key,
+ int level, struct btrfs_key *ins,
+ int no_quota);
+static int do_chunk_alloc(struct btrfs_trans_handle *trans,
+ struct btrfs_root *extent_root, u64 flags,
+ int force);
+static int find_next_key(struct btrfs_path *path, int level,
+ struct btrfs_key *key);
+static void dump_space_info(struct btrfs_space_info *info, u64 bytes,
+ int dump_block_groups);
+static int btrfs_update_reserved_bytes(struct btrfs_block_group_cache *cache,
+ u64 num_bytes, int reserve,
+ int delalloc);
+static int block_rsv_use_bytes(struct btrfs_block_rsv *block_rsv,
+ u64 num_bytes);
+int btrfs_pin_extent(struct btrfs_root *root,
+ u64 bytenr, u64 num_bytes, int reserved);
+
+static noinline int
+block_group_cache_done(struct btrfs_block_group_cache *cache)
+{
+ smp_mb();
+ return cache->cached == BTRFS_CACHE_FINISHED ||
+ cache->cached == BTRFS_CACHE_ERROR;
+}
+
+static int block_group_bits(struct btrfs_block_group_cache *cache, u64 bits)
+{
+ return (cache->flags & bits) == bits;
+}
+
+static void btrfs_get_block_group(struct btrfs_block_group_cache *cache)
+{
+ atomic_inc(&cache->count);
+}
+
+void btrfs_put_block_group(struct btrfs_block_group_cache *cache)
+{
+ if (atomic_dec_and_test(&cache->count)) {
+ WARN_ON(cache->pinned > 0);
+ WARN_ON(cache->reserved > 0);
+ kfree(cache->free_space_ctl);
+ kfree(cache);
+ }
+}
+
+/*
+ * this adds the block group to the fs_info rb tree for the block group
+ * cache
+ */
+static int btrfs_add_block_group_cache(struct btrfs_fs_info *info,
+ struct btrfs_block_group_cache *block_group)
+{
+ struct rb_node **p;
+ struct rb_node *parent = NULL;
+ struct btrfs_block_group_cache *cache;
+
+ spin_lock(&info->block_group_cache_lock);
+ p = &info->block_group_cache_tree.rb_node;
+
+ while (*p) {
+ parent = *p;
+ cache = rb_entry(parent, struct btrfs_block_group_cache,
+ cache_node);
+ if (block_group->key.objectid < cache->key.objectid) {
+ p = &(*p)->rb_left;
+ } else if (block_group->key.objectid > cache->key.objectid) {
+ p = &(*p)->rb_right;
+ } else {
+ spin_unlock(&info->block_group_cache_lock);
+ return -EEXIST;
+ }
+ }
+
+ rb_link_node(&block_group->cache_node, parent, p);
+ rb_insert_color(&block_group->cache_node,
+ &info->block_group_cache_tree);
+
+ if (info->first_logical_byte > block_group->key.objectid)
+ info->first_logical_byte = block_group->key.objectid;
+
+ spin_unlock(&info->block_group_cache_lock);
+
+ return 0;
+}
+
+/*
+ * This will return the block group at or after bytenr if contains is 0, else
+ * it will return the block group that contains the bytenr
+ */
+static struct btrfs_block_group_cache *
+block_group_cache_tree_search(struct btrfs_fs_info *info, u64 bytenr,
+ int contains)
+{
+ struct btrfs_block_group_cache *cache, *ret = NULL;
+ struct rb_node *n;
+ u64 end, start;
+
+ spin_lock(&info->block_group_cache_lock);
+ n = info->block_group_cache_tree.rb_node;
+
+ while (n) {
+ cache = rb_entry(n, struct btrfs_block_group_cache,
+ cache_node);
+ end = cache->key.objectid + cache->key.offset - 1;
+ start = cache->key.objectid;
+
+ if (bytenr < start) {
+ if (!contains && (!ret || start < ret->key.objectid))
+ ret = cache;
+ n = n->rb_left;
+ } else if (bytenr > start) {
+ if (contains && bytenr <= end) {
+ ret = cache;
+ break;
+ }
+ n = n->rb_right;
+ } else {
+ ret = cache;
+ break;
+ }
+ }
+ if (ret) {
+ btrfs_get_block_group(ret);
+ if (bytenr == 0 && info->first_logical_byte > ret->key.objectid)
+ info->first_logical_byte = ret->key.objectid;
+ }
+ spin_unlock(&info->block_group_cache_lock);
+
+ return ret;
+}
+
+static int add_excluded_extent(struct btrfs_root *root,
+ u64 start, u64 num_bytes)
+{
+ u64 end = start + num_bytes - 1;
+ set_extent_bits(&root->fs_info->freed_extents[0],
+ start, end, EXTENT_UPTODATE, GFP_NOFS);
+ set_extent_bits(&root->fs_info->freed_extents[1],
+ start, end, EXTENT_UPTODATE, GFP_NOFS);
+ return 0;
+}
+
+static void free_excluded_extents(struct btrfs_root *root,
+ struct btrfs_block_group_cache *cache)
+{
+ u64 start, end;
+
+ start = cache->key.objectid;
+ end = start + cache->key.offset - 1;
+
+ clear_extent_bits(&root->fs_info->freed_extents[0],
+ start, end, EXTENT_UPTODATE, GFP_NOFS);
+ clear_extent_bits(&root->fs_info->freed_extents[1],
+ start, end, EXTENT_UPTODATE, GFP_NOFS);
+}
+
+static int exclude_super_stripes(struct btrfs_root *root,
+ struct btrfs_block_group_cache *cache)
+{
+ u64 bytenr;
+ u64 *logical;
+ int stripe_len;
+ int i, nr, ret;
+
+ if (cache->key.objectid < BTRFS_SUPER_INFO_OFFSET) {
+ stripe_len = BTRFS_SUPER_INFO_OFFSET - cache->key.objectid;
+ cache->bytes_super += stripe_len;
+ ret = add_excluded_extent(root, cache->key.objectid,
+ stripe_len);
+ if (ret)
+ return ret;
+ }
+
+ for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
+ bytenr = btrfs_sb_offset(i);
+ ret = btrfs_rmap_block(&root->fs_info->mapping_tree,
+ cache->key.objectid, bytenr,
+ 0, &logical, &nr, &stripe_len);
+ if (ret)
+ return ret;
+
+ while (nr--) {
+ u64 start, len;
+
+ if (logical[nr] > cache->key.objectid +
+ cache->key.offset)
+ continue;
+
+ if (logical[nr] + stripe_len <= cache->key.objectid)
+ continue;
+
+ start = logical[nr];
+ if (start < cache->key.objectid) {
+ start = cache->key.objectid;
+ len = (logical[nr] + stripe_len) - start;
+ } else {
+ len = min_t(u64, stripe_len,
+ cache->key.objectid +
+ cache->key.offset - start);
+ }
+
+ cache->bytes_super += len;
+ ret = add_excluded_extent(root, start, len);
+ if (ret) {
+ kfree(logical);
+ return ret;
+ }
+ }
+
+ kfree(logical);
+ }
+ return 0;
+}
+
+static struct btrfs_caching_control *
+get_caching_control(struct btrfs_block_group_cache *cache)
+{
+ struct btrfs_caching_control *ctl;
+
+ spin_lock(&cache->lock);
+ if (!cache->caching_ctl) {
+ spin_unlock(&cache->lock);
+ return NULL;
+ }
+
+ ctl = cache->caching_ctl;
+ atomic_inc(&ctl->count);
+ spin_unlock(&cache->lock);
+ return ctl;
+}
+
+static void put_caching_control(struct btrfs_caching_control *ctl)
+{
+ if (atomic_dec_and_test(&ctl->count))
+ kfree(ctl);
+}
+
+/*
+ * this is only called by cache_block_group, since we could have freed extents
+ * we need to check the pinned_extents for any extents that can't be used yet
+ * since their free space will be released as soon as the transaction commits.
+ */
+static u64 add_new_free_space(struct btrfs_block_group_cache *block_group,
+ struct btrfs_fs_info *info, u64 start, u64 end)
+{
+ u64 extent_start, extent_end, size, total_added = 0;
+ int ret;
+
+ while (start < end) {
+ ret = find_first_extent_bit(info->pinned_extents, start,
+ &extent_start, &extent_end,
+ EXTENT_DIRTY | EXTENT_UPTODATE,
+ NULL);
+ if (ret)
+ break;
+
+ if (extent_start <= start) {
+ start = extent_end + 1;
+ } else if (extent_start > start && extent_start < end) {
+ size = extent_start - start;
+ total_added += size;
+ ret = btrfs_add_free_space(block_group, start,
+ size);
+ BUG_ON(ret); /* -ENOMEM or logic error */
+ start = extent_end + 1;
+ } else {
+ break;
+ }
+ }
+
+ if (start < end) {
+ size = end - start;
+ total_added += size;
+ ret = btrfs_add_free_space(block_group, start, size);
+ BUG_ON(ret); /* -ENOMEM or logic error */
+ }
+
+ return total_added;
+}
+
+static noinline void caching_thread(struct btrfs_work *work)
+{
+ struct btrfs_block_group_cache *block_group;
+ struct btrfs_fs_info *fs_info;
+ struct btrfs_caching_control *caching_ctl;
+ struct btrfs_root *extent_root;
+ struct btrfs_path *path;
+ struct extent_buffer *leaf;
+ struct btrfs_key key;
+ u64 total_found = 0;
+ u64 last = 0;
+ u32 nritems;
+ int ret = -ENOMEM;
+
+ caching_ctl = container_of(work, struct btrfs_caching_control, work);
+ block_group = caching_ctl->block_group;
+ fs_info = block_group->fs_info;
+ extent_root = fs_info->extent_root;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ goto out;
+
+ last = max_t(u64, block_group->key.objectid, BTRFS_SUPER_INFO_OFFSET);
+
+ /*
+ * We don't want to deadlock with somebody trying to allocate a new
+ * extent for the extent root while also trying to search the extent
+ * root to add free space. So we skip locking and search the commit
+ * root, since its read-only
+ */
+ path->skip_locking = 1;
+ path->search_commit_root = 1;
+ path->reada = 1;
+
+ key.objectid = last;
+ key.offset = 0;
+ key.type = BTRFS_EXTENT_ITEM_KEY;
+again:
+ mutex_lock(&caching_ctl->mutex);
+ /* need to make sure the commit_root doesn't disappear */
+ down_read(&fs_info->commit_root_sem);
+
+next:
+ ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
+ if (ret < 0)
+ goto err;
+
+ leaf = path->nodes[0];
+ nritems = btrfs_header_nritems(leaf);
+
+ while (1) {
+ if (btrfs_fs_closing(fs_info) > 1) {
+ last = (u64)-1;
+ break;
+ }
+
+ if (path->slots[0] < nritems) {
+ btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
+ } else {
+ ret = find_next_key(path, 0, &key);
+ if (ret)
+ break;
+
+ if (need_resched() ||
+ rwsem_is_contended(&fs_info->commit_root_sem)) {
+ caching_ctl->progress = last;
+ btrfs_release_path(path);
+ up_read(&fs_info->commit_root_sem);
+ mutex_unlock(&caching_ctl->mutex);
+ cond_resched();
+ goto again;
+ }
+
+ ret = btrfs_next_leaf(extent_root, path);
+ if (ret < 0)
+ goto err;
+ if (ret)
+ break;
+ leaf = path->nodes[0];
+ nritems = btrfs_header_nritems(leaf);
+ continue;
+ }
+
+ if (key.objectid < last) {
+ key.objectid = last;
+ key.offset = 0;
+ key.type = BTRFS_EXTENT_ITEM_KEY;
+
+ caching_ctl->progress = last;
+ btrfs_release_path(path);
+ goto next;
+ }
+
+ if (key.objectid < block_group->key.objectid) {
+ path->slots[0]++;
+ continue;
+ }
+
+ if (key.objectid >= block_group->key.objectid +
+ block_group->key.offset)
+ break;
+
+ if (key.type == BTRFS_EXTENT_ITEM_KEY ||
+ key.type == BTRFS_METADATA_ITEM_KEY) {
+ total_found += add_new_free_space(block_group,
+ fs_info, last,
+ key.objectid);
+ if (key.type == BTRFS_METADATA_ITEM_KEY)
+ last = key.objectid +
+ fs_info->tree_root->nodesize;
+ else
+ last = key.objectid + key.offset;
+
+ if (total_found > (1024 * 1024 * 2)) {
+ total_found = 0;
+ wake_up(&caching_ctl->wait);
+ }
+ }
+ path->slots[0]++;
+ }
+ ret = 0;
+
+ total_found += add_new_free_space(block_group, fs_info, last,
+ block_group->key.objectid +
+ block_group->key.offset);
+ caching_ctl->progress = (u64)-1;
+
+ spin_lock(&block_group->lock);
+ block_group->caching_ctl = NULL;
+ block_group->cached = BTRFS_CACHE_FINISHED;
+ spin_unlock(&block_group->lock);
+
+err:
+ btrfs_free_path(path);
+ up_read(&fs_info->commit_root_sem);
+
+ free_excluded_extents(extent_root, block_group);
+
+ mutex_unlock(&caching_ctl->mutex);
+out:
+ if (ret) {
+ spin_lock(&block_group->lock);
+ block_group->caching_ctl = NULL;
+ block_group->cached = BTRFS_CACHE_ERROR;
+ spin_unlock(&block_group->lock);
+ }
+ wake_up(&caching_ctl->wait);
+
+ put_caching_control(caching_ctl);
+ btrfs_put_block_group(block_group);
+}
+
+static int cache_block_group(struct btrfs_block_group_cache *cache,
+ int load_cache_only)
+{
+ DEFINE_WAIT(wait);
+ struct btrfs_fs_info *fs_info = cache->fs_info;
+ struct btrfs_caching_control *caching_ctl;
+ int ret = 0;
+
+ caching_ctl = kzalloc(sizeof(*caching_ctl), GFP_NOFS);
+ if (!caching_ctl)
+ return -ENOMEM;
+
+ INIT_LIST_HEAD(&caching_ctl->list);
+ mutex_init(&caching_ctl->mutex);
+ init_waitqueue_head(&caching_ctl->wait);
+ caching_ctl->block_group = cache;
+ caching_ctl->progress = cache->key.objectid;
+ atomic_set(&caching_ctl->count, 1);
+ btrfs_init_work(&caching_ctl->work, btrfs_cache_helper,
+ caching_thread, NULL, NULL);
+
+ spin_lock(&cache->lock);
+ /*
+ * This should be a rare occasion, but this could happen I think in the
+ * case where one thread starts to load the space cache info, and then
+ * some other thread starts a transaction commit which tries to do an
+ * allocation while the other thread is still loading the space cache
+ * info. The previous loop should have kept us from choosing this block
+ * group, but if we've moved to the state where we will wait on caching
+ * block groups we need to first check if we're doing a fast load here,
+ * so we can wait for it to finish, otherwise we could end up allocating
+ * from a block group who's cache gets evicted for one reason or
+ * another.
+ */
+ while (cache->cached == BTRFS_CACHE_FAST) {
+ struct btrfs_caching_control *ctl;
+
+ ctl = cache->caching_ctl;
+ atomic_inc(&ctl->count);
+ prepare_to_wait(&ctl->wait, &wait, TASK_UNINTERRUPTIBLE);
+ spin_unlock(&cache->lock);
+
+ schedule();
+
+ finish_wait(&ctl->wait, &wait);
+ put_caching_control(ctl);
+ spin_lock(&cache->lock);
+ }
+
+ if (cache->cached != BTRFS_CACHE_NO) {
+ spin_unlock(&cache->lock);
+ kfree(caching_ctl);
+ return 0;
+ }
+ WARN_ON(cache->caching_ctl);
+ cache->caching_ctl = caching_ctl;
+ cache->cached = BTRFS_CACHE_FAST;
+ spin_unlock(&cache->lock);
+
+ if (fs_info->mount_opt & BTRFS_MOUNT_SPACE_CACHE) {
+ mutex_lock(&caching_ctl->mutex);
+ ret = load_free_space_cache(fs_info, cache);
+
+ spin_lock(&cache->lock);
+ if (ret == 1) {
+ cache->caching_ctl = NULL;
+ cache->cached = BTRFS_CACHE_FINISHED;
+ cache->last_byte_to_unpin = (u64)-1;
+ caching_ctl->progress = (u64)-1;
+ } else {
+ if (load_cache_only) {
+ cache->caching_ctl = NULL;
+ cache->cached = BTRFS_CACHE_NO;
+ } else {
+ cache->cached = BTRFS_CACHE_STARTED;
+ cache->has_caching_ctl = 1;
+ }
+ }
+ spin_unlock(&cache->lock);
+ mutex_unlock(&caching_ctl->mutex);
+
+ wake_up(&caching_ctl->wait);
+ if (ret == 1) {
+ put_caching_control(caching_ctl);
+ free_excluded_extents(fs_info->extent_root, cache);
+ return 0;
+ }
+ } else {
+ /*
+ * We are not going to do the fast caching, set cached to the
+ * appropriate value and wakeup any waiters.
+ */
+ spin_lock(&cache->lock);
+ if (load_cache_only) {
+ cache->caching_ctl = NULL;
+ cache->cached = BTRFS_CACHE_NO;
+ } else {
+ cache->cached = BTRFS_CACHE_STARTED;
+ cache->has_caching_ctl = 1;
+ }
+ spin_unlock(&cache->lock);
+ wake_up(&caching_ctl->wait);
+ }
+
+ if (load_cache_only) {
+ put_caching_control(caching_ctl);
+ return 0;
+ }
+
+ down_write(&fs_info->commit_root_sem);
+ atomic_inc(&caching_ctl->count);
+ list_add_tail(&caching_ctl->list, &fs_info->caching_block_groups);
+ up_write(&fs_info->commit_root_sem);
+
+ btrfs_get_block_group(cache);
+
+ btrfs_queue_work(fs_info->caching_workers, &caching_ctl->work);
+
+ return ret;
+}
+
+/*
+ * return the block group that starts at or after bytenr
+ */
+static struct btrfs_block_group_cache *
+btrfs_lookup_first_block_group(struct btrfs_fs_info *info, u64 bytenr)
+{
+ struct btrfs_block_group_cache *cache;
+
+ cache = block_group_cache_tree_search(info, bytenr, 0);
+
+ return cache;
+}
+
+/*
+ * return the block group that contains the given bytenr
+ */
+struct btrfs_block_group_cache *btrfs_lookup_block_group(
+ struct btrfs_fs_info *info,
+ u64 bytenr)
+{
+ struct btrfs_block_group_cache *cache;
+
+ cache = block_group_cache_tree_search(info, bytenr, 1);
+
+ return cache;
+}
+
+static struct btrfs_space_info *__find_space_info(struct btrfs_fs_info *info,
+ u64 flags)
+{
+ struct list_head *head = &info->space_info;
+ struct btrfs_space_info *found;
+
+ flags &= BTRFS_BLOCK_GROUP_TYPE_MASK;
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(found, head, list) {
+ if (found->flags & flags) {
+ rcu_read_unlock();
+ return found;
+ }
+ }
+ rcu_read_unlock();
+ return NULL;
+}
+
+/*
+ * after adding space to the filesystem, we need to clear the full flags
+ * on all the space infos.
+ */
+void btrfs_clear_space_info_full(struct btrfs_fs_info *info)
+{
+ struct list_head *head = &info->space_info;
+ struct btrfs_space_info *found;
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(found, head, list)
+ found->full = 0;
+ rcu_read_unlock();
+}
+
+/* simple helper to search for an existing data extent at a given offset */
+int btrfs_lookup_data_extent(struct btrfs_root *root, u64 start, u64 len)
+{
+ int ret;
+ struct btrfs_key key;
+ struct btrfs_path *path;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ key.objectid = start;
+ key.offset = len;
+ key.type = BTRFS_EXTENT_ITEM_KEY;
+ ret = btrfs_search_slot(NULL, root->fs_info->extent_root, &key, path,
+ 0, 0);
+ btrfs_free_path(path);
+ return ret;
+}
+
+/*
+ * helper function to lookup reference count and flags of a tree block.
+ *
+ * the head node for delayed ref is used to store the sum of all the
+ * reference count modifications queued up in the rbtree. the head
+ * node may also store the extent flags to set. This way you can check
+ * to see what the reference count and extent flags would be if all of
+ * the delayed refs are not processed.
+ */
+int btrfs_lookup_extent_info(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, u64 bytenr,
+ u64 offset, int metadata, u64 *refs, u64 *flags)
+{
+ struct btrfs_delayed_ref_head *head;
+ struct btrfs_delayed_ref_root *delayed_refs;
+ struct btrfs_path *path;
+ struct btrfs_extent_item *ei;
+ struct extent_buffer *leaf;
+ struct btrfs_key key;
+ u32 item_size;
+ u64 num_refs;
+ u64 extent_flags;
+ int ret;
+
+ /*
+ * If we don't have skinny metadata, don't bother doing anything
+ * different
+ */
+ if (metadata && !btrfs_fs_incompat(root->fs_info, SKINNY_METADATA)) {
+ offset = root->nodesize;
+ metadata = 0;
+ }
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ if (!trans) {
+ path->skip_locking = 1;
+ path->search_commit_root = 1;
+ }
+
+search_again:
+ key.objectid = bytenr;
+ key.offset = offset;
+ if (metadata)
+ key.type = BTRFS_METADATA_ITEM_KEY;
+ else
+ key.type = BTRFS_EXTENT_ITEM_KEY;
+
+ ret = btrfs_search_slot(trans, root->fs_info->extent_root,
+ &key, path, 0, 0);
+ if (ret < 0)
+ goto out_free;
+
+ if (ret > 0 && metadata && key.type == BTRFS_METADATA_ITEM_KEY) {
+ if (path->slots[0]) {
+ path->slots[0]--;
+ btrfs_item_key_to_cpu(path->nodes[0], &key,
+ path->slots[0]);
+ if (key.objectid == bytenr &&
+ key.type == BTRFS_EXTENT_ITEM_KEY &&
+ key.offset == root->nodesize)
+ ret = 0;
+ }
+ }
+
+ if (ret == 0) {
+ leaf = path->nodes[0];
+ item_size = btrfs_item_size_nr(leaf, path->slots[0]);
+ if (item_size >= sizeof(*ei)) {
+ ei = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_extent_item);
+ num_refs = btrfs_extent_refs(leaf, ei);
+ extent_flags = btrfs_extent_flags(leaf, ei);
+ } else {
+#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
+ struct btrfs_extent_item_v0 *ei0;
+ BUG_ON(item_size != sizeof(*ei0));
+ ei0 = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_extent_item_v0);
+ num_refs = btrfs_extent_refs_v0(leaf, ei0);
+ /* FIXME: this isn't correct for data */
+ extent_flags = BTRFS_BLOCK_FLAG_FULL_BACKREF;
+#else
+ BUG();
+#endif
+ }
+ BUG_ON(num_refs == 0);
+ } else {
+ num_refs = 0;
+ extent_flags = 0;
+ ret = 0;
+ }
+
+ if (!trans)
+ goto out;
+
+ delayed_refs = &trans->transaction->delayed_refs;
+ spin_lock(&delayed_refs->lock);
+ head = btrfs_find_delayed_ref_head(trans, bytenr);
+ if (head) {
+ if (!mutex_trylock(&head->mutex)) {
+ atomic_inc(&head->node.refs);
+ spin_unlock(&delayed_refs->lock);
+
+ btrfs_release_path(path);
+
+ /*
+ * Mutex was contended, block until it's released and try
+ * again
+ */
+ mutex_lock(&head->mutex);
+ mutex_unlock(&head->mutex);
+ btrfs_put_delayed_ref(&head->node);
+ goto search_again;
+ }
+ spin_lock(&head->lock);
+ if (head->extent_op && head->extent_op->update_flags)
+ extent_flags |= head->extent_op->flags_to_set;
+ else
+ BUG_ON(num_refs == 0);
+
+ num_refs += head->node.ref_mod;
+ spin_unlock(&head->lock);
+ mutex_unlock(&head->mutex);
+ }
+ spin_unlock(&delayed_refs->lock);
+out:
+ WARN_ON(num_refs == 0);
+ if (refs)
+ *refs = num_refs;
+ if (flags)
+ *flags = extent_flags;
+out_free:
+ btrfs_free_path(path);
+ return ret;
+}
+
+/*
+ * Back reference rules. Back refs have three main goals:
+ *
+ * 1) differentiate between all holders of references to an extent so that
+ * when a reference is dropped we can make sure it was a valid reference
+ * before freeing the extent.
+ *
+ * 2) Provide enough information to quickly find the holders of an extent
+ * if we notice a given block is corrupted or bad.
+ *
+ * 3) Make it easy to migrate blocks for FS shrinking or storage pool
+ * maintenance. This is actually the same as #2, but with a slightly
+ * different use case.
+ *
+ * There are two kinds of back refs. The implicit back refs is optimized
+ * for pointers in non-shared tree blocks. For a given pointer in a block,
+ * back refs of this kind provide information about the block's owner tree
+ * and the pointer's key. These information allow us to find the block by
+ * b-tree searching. The full back refs is for pointers in tree blocks not
+ * referenced by their owner trees. The location of tree block is recorded
+ * in the back refs. Actually the full back refs is generic, and can be
+ * used in all cases the implicit back refs is used. The major shortcoming
+ * of the full back refs is its overhead. Every time a tree block gets
+ * COWed, we have to update back refs entry for all pointers in it.
+ *
+ * For a newly allocated tree block, we use implicit back refs for
+ * pointers in it. This means most tree related operations only involve
+ * implicit back refs. For a tree block created in old transaction, the
+ * only way to drop a reference to it is COW it. So we can detect the
+ * event that tree block loses its owner tree's reference and do the
+ * back refs conversion.
+ *
+ * When a tree block is COW'd through a tree, there are four cases:
+ *
+ * The reference count of the block is one and the tree is the block's
+ * owner tree. Nothing to do in this case.
+ *
+ * The reference count of the block is one and the tree is not the
+ * block's owner tree. In this case, full back refs is used for pointers
+ * in the block. Remove these full back refs, add implicit back refs for
+ * every pointers in the new block.
+ *
+ * The reference count of the block is greater than one and the tree is
+ * the block's owner tree. In this case, implicit back refs is used for
+ * pointers in the block. Add full back refs for every pointers in the
+ * block, increase lower level extents' reference counts. The original
+ * implicit back refs are entailed to the new block.
+ *
+ * The reference count of the block is greater than one and the tree is
+ * not the block's owner tree. Add implicit back refs for every pointer in
+ * the new block, increase lower level extents' reference count.
+ *
+ * Back Reference Key composing:
+ *
+ * The key objectid corresponds to the first byte in the extent,
+ * The key type is used to differentiate between types of back refs.
+ * There are different meanings of the key offset for different types
+ * of back refs.
+ *
+ * File extents can be referenced by:
+ *
+ * - multiple snapshots, subvolumes, or different generations in one subvol
+ * - different files inside a single subvolume
+ * - different offsets inside a file (bookend extents in file.c)
+ *
+ * The extent ref structure for the implicit back refs has fields for:
+ *
+ * - Objectid of the subvolume root
+ * - objectid of the file holding the reference
+ * - original offset in the file
+ * - how many bookend extents
+ *
+ * The key offset for the implicit back refs is hash of the first
+ * three fields.
+ *
+ * The extent ref structure for the full back refs has field for:
+ *
+ * - number of pointers in the tree leaf
+ *
+ * The key offset for the implicit back refs is the first byte of
+ * the tree leaf
+ *
+ * When a file extent is allocated, The implicit back refs is used.
+ * the fields are filled in:
+ *
+ * (root_key.objectid, inode objectid, offset in file, 1)
+ *
+ * When a file extent is removed file truncation, we find the
+ * corresponding implicit back refs and check the following fields:
+ *
+ * (btrfs_header_owner(leaf), inode objectid, offset in file)
+ *
+ * Btree extents can be referenced by:
+ *
+ * - Different subvolumes
+ *
+ * Both the implicit back refs and the full back refs for tree blocks
+ * only consist of key. The key offset for the implicit back refs is
+ * objectid of block's owner tree. The key offset for the full back refs
+ * is the first byte of parent block.
+ *
+ * When implicit back refs is used, information about the lowest key and
+ * level of the tree block are required. These information are stored in
+ * tree block info structure.
+ */
+
+#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
+static int convert_extent_item_v0(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ u64 owner, u32 extra_size)
+{
+ struct btrfs_extent_item *item;
+ struct btrfs_extent_item_v0 *ei0;
+ struct btrfs_extent_ref_v0 *ref0;
+ struct btrfs_tree_block_info *bi;
+ struct extent_buffer *leaf;
+ struct btrfs_key key;
+ struct btrfs_key found_key;
+ u32 new_size = sizeof(*item);
+ u64 refs;
+ int ret;
+
+ leaf = path->nodes[0];
+ BUG_ON(btrfs_item_size_nr(leaf, path->slots[0]) != sizeof(*ei0));
+
+ btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
+ ei0 = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_extent_item_v0);
+ refs = btrfs_extent_refs_v0(leaf, ei0);
+
+ if (owner == (u64)-1) {
+ while (1) {
+ if (path->slots[0] >= btrfs_header_nritems(leaf)) {
+ ret = btrfs_next_leaf(root, path);
+ if (ret < 0)
+ return ret;
+ BUG_ON(ret > 0); /* Corruption */
+ leaf = path->nodes[0];
+ }
+ btrfs_item_key_to_cpu(leaf, &found_key,
+ path->slots[0]);
+ BUG_ON(key.objectid != found_key.objectid);
+ if (found_key.type != BTRFS_EXTENT_REF_V0_KEY) {
+ path->slots[0]++;
+ continue;
+ }
+ ref0 = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_extent_ref_v0);
+ owner = btrfs_ref_objectid_v0(leaf, ref0);
+ break;
+ }
+ }
+ btrfs_release_path(path);
+
+ if (owner < BTRFS_FIRST_FREE_OBJECTID)
+ new_size += sizeof(*bi);
+
+ new_size -= sizeof(*ei0);
+ ret = btrfs_search_slot(trans, root, &key, path,
+ new_size + extra_size, 1);
+ if (ret < 0)
+ return ret;
+ BUG_ON(ret); /* Corruption */
+
+ btrfs_extend_item(root, path, new_size);
+
+ leaf = path->nodes[0];
+ item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
+ btrfs_set_extent_refs(leaf, item, refs);
+ /* FIXME: get real generation */
+ btrfs_set_extent_generation(leaf, item, 0);
+ if (owner < BTRFS_FIRST_FREE_OBJECTID) {
+ btrfs_set_extent_flags(leaf, item,
+ BTRFS_EXTENT_FLAG_TREE_BLOCK |
+ BTRFS_BLOCK_FLAG_FULL_BACKREF);
+ bi = (struct btrfs_tree_block_info *)(item + 1);
+ /* FIXME: get first key of the block */
+ memset_extent_buffer(leaf, 0, (unsigned long)bi, sizeof(*bi));
+ btrfs_set_tree_block_level(leaf, bi, (int)owner);
+ } else {
+ btrfs_set_extent_flags(leaf, item, BTRFS_EXTENT_FLAG_DATA);
+ }
+ btrfs_mark_buffer_dirty(leaf);
+ return 0;
+}
+#endif
+
+static u64 hash_extent_data_ref(u64 root_objectid, u64 owner, u64 offset)
+{
+ u32 high_crc = ~(u32)0;
+ u32 low_crc = ~(u32)0;
+ __le64 lenum;
+
+ lenum = cpu_to_le64(root_objectid);
+ high_crc = btrfs_crc32c(high_crc, &lenum, sizeof(lenum));
+ lenum = cpu_to_le64(owner);
+ low_crc = btrfs_crc32c(low_crc, &lenum, sizeof(lenum));
+ lenum = cpu_to_le64(offset);
+ low_crc = btrfs_crc32c(low_crc, &lenum, sizeof(lenum));
+
+ return ((u64)high_crc << 31) ^ (u64)low_crc;
+}
+
+static u64 hash_extent_data_ref_item(struct extent_buffer *leaf,
+ struct btrfs_extent_data_ref *ref)
+{
+ return hash_extent_data_ref(btrfs_extent_data_ref_root(leaf, ref),
+ btrfs_extent_data_ref_objectid(leaf, ref),
+ btrfs_extent_data_ref_offset(leaf, ref));
+}
+
+static int match_extent_data_ref(struct extent_buffer *leaf,
+ struct btrfs_extent_data_ref *ref,
+ u64 root_objectid, u64 owner, u64 offset)
+{
+ if (btrfs_extent_data_ref_root(leaf, ref) != root_objectid ||
+ btrfs_extent_data_ref_objectid(leaf, ref) != owner ||
+ btrfs_extent_data_ref_offset(leaf, ref) != offset)
+ return 0;
+ return 1;
+}
+
+static noinline int lookup_extent_data_ref(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ u64 bytenr, u64 parent,
+ u64 root_objectid,
+ u64 owner, u64 offset)
+{
+ struct btrfs_key key;
+ struct btrfs_extent_data_ref *ref;
+ struct extent_buffer *leaf;
+ u32 nritems;
+ int ret;
+ int recow;
+ int err = -ENOENT;
+
+ key.objectid = bytenr;
+ if (parent) {
+ key.type = BTRFS_SHARED_DATA_REF_KEY;
+ key.offset = parent;
+ } else {
+ key.type = BTRFS_EXTENT_DATA_REF_KEY;
+ key.offset = hash_extent_data_ref(root_objectid,
+ owner, offset);
+ }
+again:
+ recow = 0;
+ ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
+ if (ret < 0) {
+ err = ret;
+ goto fail;
+ }
+
+ if (parent) {
+ if (!ret)
+ return 0;
+#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
+ key.type = BTRFS_EXTENT_REF_V0_KEY;
+ btrfs_release_path(path);
+ ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
+ if (ret < 0) {
+ err = ret;
+ goto fail;
+ }
+ if (!ret)
+ return 0;
+#endif
+ goto fail;
+ }
+
+ leaf = path->nodes[0];
+ nritems = btrfs_header_nritems(leaf);
+ while (1) {
+ if (path->slots[0] >= nritems) {
+ ret = btrfs_next_leaf(root, path);
+ if (ret < 0)
+ err = ret;
+ if (ret)
+ goto fail;
+
+ leaf = path->nodes[0];
+ nritems = btrfs_header_nritems(leaf);
+ recow = 1;
+ }
+
+ btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
+ if (key.objectid != bytenr ||
+ key.type != BTRFS_EXTENT_DATA_REF_KEY)
+ goto fail;
+
+ ref = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_extent_data_ref);
+
+ if (match_extent_data_ref(leaf, ref, root_objectid,
+ owner, offset)) {
+ if (recow) {
+ btrfs_release_path(path);
+ goto again;
+ }
+ err = 0;
+ break;
+ }
+ path->slots[0]++;
+ }
+fail:
+ return err;
+}
+
+static noinline int insert_extent_data_ref(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ u64 bytenr, u64 parent,
+ u64 root_objectid, u64 owner,
+ u64 offset, int refs_to_add)
+{
+ struct btrfs_key key;
+ struct extent_buffer *leaf;
+ u32 size;
+ u32 num_refs;
+ int ret;
+
+ key.objectid = bytenr;
+ if (parent) {
+ key.type = BTRFS_SHARED_DATA_REF_KEY;
+ key.offset = parent;
+ size = sizeof(struct btrfs_shared_data_ref);
+ } else {
+ key.type = BTRFS_EXTENT_DATA_REF_KEY;
+ key.offset = hash_extent_data_ref(root_objectid,
+ owner, offset);
+ size = sizeof(struct btrfs_extent_data_ref);
+ }
+
+ ret = btrfs_insert_empty_item(trans, root, path, &key, size);
+ if (ret && ret != -EEXIST)
+ goto fail;
+
+ leaf = path->nodes[0];
+ if (parent) {
+ struct btrfs_shared_data_ref *ref;
+ ref = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_shared_data_ref);
+ if (ret == 0) {
+ btrfs_set_shared_data_ref_count(leaf, ref, refs_to_add);
+ } else {
+ num_refs = btrfs_shared_data_ref_count(leaf, ref);
+ num_refs += refs_to_add;
+ btrfs_set_shared_data_ref_count(leaf, ref, num_refs);
+ }
+ } else {
+ struct btrfs_extent_data_ref *ref;
+ while (ret == -EEXIST) {
+ ref = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_extent_data_ref);
+ if (match_extent_data_ref(leaf, ref, root_objectid,
+ owner, offset))
+ break;
+ btrfs_release_path(path);
+ key.offset++;
+ ret = btrfs_insert_empty_item(trans, root, path, &key,
+ size);
+ if (ret && ret != -EEXIST)
+ goto fail;
+
+ leaf = path->nodes[0];
+ }
+ ref = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_extent_data_ref);
+ if (ret == 0) {
+ btrfs_set_extent_data_ref_root(leaf, ref,
+ root_objectid);
+ btrfs_set_extent_data_ref_objectid(leaf, ref, owner);
+ btrfs_set_extent_data_ref_offset(leaf, ref, offset);
+ btrfs_set_extent_data_ref_count(leaf, ref, refs_to_add);
+ } else {
+ num_refs = btrfs_extent_data_ref_count(leaf, ref);
+ num_refs += refs_to_add;
+ btrfs_set_extent_data_ref_count(leaf, ref, num_refs);
+ }
+ }
+ btrfs_mark_buffer_dirty(leaf);
+ ret = 0;
+fail:
+ btrfs_release_path(path);
+ return ret;
+}
+
+static noinline int remove_extent_data_ref(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ int refs_to_drop, int *last_ref)
+{
+ struct btrfs_key key;
+ struct btrfs_extent_data_ref *ref1 = NULL;
+ struct btrfs_shared_data_ref *ref2 = NULL;
+ struct extent_buffer *leaf;
+ u32 num_refs = 0;
+ int ret = 0;
+
+ leaf = path->nodes[0];
+ btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
+
+ if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
+ ref1 = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_extent_data_ref);
+ num_refs = btrfs_extent_data_ref_count(leaf, ref1);
+ } else if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
+ ref2 = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_shared_data_ref);
+ num_refs = btrfs_shared_data_ref_count(leaf, ref2);
+#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
+ } else if (key.type == BTRFS_EXTENT_REF_V0_KEY) {
+ struct btrfs_extent_ref_v0 *ref0;
+ ref0 = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_extent_ref_v0);
+ num_refs = btrfs_ref_count_v0(leaf, ref0);
+#endif
+ } else {
+ BUG();
+ }
+
+ BUG_ON(num_refs < refs_to_drop);
+ num_refs -= refs_to_drop;
+
+ if (num_refs == 0) {
+ ret = btrfs_del_item(trans, root, path);
+ *last_ref = 1;
+ } else {
+ if (key.type == BTRFS_EXTENT_DATA_REF_KEY)
+ btrfs_set_extent_data_ref_count(leaf, ref1, num_refs);
+ else if (key.type == BTRFS_SHARED_DATA_REF_KEY)
+ btrfs_set_shared_data_ref_count(leaf, ref2, num_refs);
+#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
+ else {
+ struct btrfs_extent_ref_v0 *ref0;
+ ref0 = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_extent_ref_v0);
+ btrfs_set_ref_count_v0(leaf, ref0, num_refs);
+ }
+#endif
+ btrfs_mark_buffer_dirty(leaf);
+ }
+ return ret;
+}
+
+static noinline u32 extent_data_ref_count(struct btrfs_root *root,
+ struct btrfs_path *path,
+ struct btrfs_extent_inline_ref *iref)
+{
+ struct btrfs_key key;
+ struct extent_buffer *leaf;
+ struct btrfs_extent_data_ref *ref1;
+ struct btrfs_shared_data_ref *ref2;
+ u32 num_refs = 0;
+
+ leaf = path->nodes[0];
+ btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
+ if (iref) {
+ if (btrfs_extent_inline_ref_type(leaf, iref) ==
+ BTRFS_EXTENT_DATA_REF_KEY) {
+ ref1 = (struct btrfs_extent_data_ref *)(&iref->offset);
+ num_refs = btrfs_extent_data_ref_count(leaf, ref1);
+ } else {
+ ref2 = (struct btrfs_shared_data_ref *)(iref + 1);
+ num_refs = btrfs_shared_data_ref_count(leaf, ref2);
+ }
+ } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
+ ref1 = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_extent_data_ref);
+ num_refs = btrfs_extent_data_ref_count(leaf, ref1);
+ } else if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
+ ref2 = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_shared_data_ref);
+ num_refs = btrfs_shared_data_ref_count(leaf, ref2);
+#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
+ } else if (key.type == BTRFS_EXTENT_REF_V0_KEY) {
+ struct btrfs_extent_ref_v0 *ref0;
+ ref0 = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_extent_ref_v0);
+ num_refs = btrfs_ref_count_v0(leaf, ref0);
+#endif
+ } else {
+ WARN_ON(1);
+ }
+ return num_refs;
+}
+
+static noinline int lookup_tree_block_ref(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ u64 bytenr, u64 parent,
+ u64 root_objectid)
+{
+ struct btrfs_key key;
+ int ret;
+
+ key.objectid = bytenr;
+ if (parent) {
+ key.type = BTRFS_SHARED_BLOCK_REF_KEY;
+ key.offset = parent;
+ } else {
+ key.type = BTRFS_TREE_BLOCK_REF_KEY;
+ key.offset = root_objectid;
+ }
+
+ ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
+ if (ret > 0)
+ ret = -ENOENT;
+#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
+ if (ret == -ENOENT && parent) {
+ btrfs_release_path(path);
+ key.type = BTRFS_EXTENT_REF_V0_KEY;
+ ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
+ if (ret > 0)
+ ret = -ENOENT;
+ }
+#endif
+ return ret;
+}
+
+static noinline int insert_tree_block_ref(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ u64 bytenr, u64 parent,
+ u64 root_objectid)
+{
+ struct btrfs_key key;
+ int ret;
+
+ key.objectid = bytenr;
+ if (parent) {
+ key.type = BTRFS_SHARED_BLOCK_REF_KEY;
+ key.offset = parent;
+ } else {
+ key.type = BTRFS_TREE_BLOCK_REF_KEY;
+ key.offset = root_objectid;
+ }
+
+ ret = btrfs_insert_empty_item(trans, root, path, &key, 0);
+ btrfs_release_path(path);
+ return ret;
+}
+
+static inline int extent_ref_type(u64 parent, u64 owner)
+{
+ int type;
+ if (owner < BTRFS_FIRST_FREE_OBJECTID) {
+ if (parent > 0)
+ type = BTRFS_SHARED_BLOCK_REF_KEY;
+ else
+ type = BTRFS_TREE_BLOCK_REF_KEY;
+ } else {
+ if (parent > 0)
+ type = BTRFS_SHARED_DATA_REF_KEY;
+ else
+ type = BTRFS_EXTENT_DATA_REF_KEY;
+ }
+ return type;
+}
+
+static int find_next_key(struct btrfs_path *path, int level,
+ struct btrfs_key *key)
+
+{
+ for (; level < BTRFS_MAX_LEVEL; level++) {
+ if (!path->nodes[level])
+ break;
+ if (path->slots[level] + 1 >=
+ btrfs_header_nritems(path->nodes[level]))
+ continue;
+ if (level == 0)
+ btrfs_item_key_to_cpu(path->nodes[level], key,
+ path->slots[level] + 1);
+ else
+ btrfs_node_key_to_cpu(path->nodes[level], key,
+ path->slots[level] + 1);
+ return 0;
+ }
+ return 1;
+}
+
+/*
+ * look for inline back ref. if back ref is found, *ref_ret is set
+ * to the address of inline back ref, and 0 is returned.
+ *
+ * if back ref isn't found, *ref_ret is set to the address where it
+ * should be inserted, and -ENOENT is returned.
+ *
+ * if insert is true and there are too many inline back refs, the path
+ * points to the extent item, and -EAGAIN is returned.
+ *
+ * NOTE: inline back refs are ordered in the same way that back ref
+ * items in the tree are ordered.
+ */
+static noinline_for_stack
+int lookup_inline_extent_backref(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ struct btrfs_extent_inline_ref **ref_ret,
+ u64 bytenr, u64 num_bytes,
+ u64 parent, u64 root_objectid,
+ u64 owner, u64 offset, int insert)
+{
+ struct btrfs_key key;
+ struct extent_buffer *leaf;
+ struct btrfs_extent_item *ei;
+ struct btrfs_extent_inline_ref *iref;
+ u64 flags;
+ u64 item_size;
+ unsigned long ptr;
+ unsigned long end;
+ int extra_size;
+ int type;
+ int want;
+ int ret;
+ int err = 0;
+ bool skinny_metadata = btrfs_fs_incompat(root->fs_info,
+ SKINNY_METADATA);
+
+ key.objectid = bytenr;
+ key.type = BTRFS_EXTENT_ITEM_KEY;
+ key.offset = num_bytes;
+
+ want = extent_ref_type(parent, owner);
+ if (insert) {
+ extra_size = btrfs_extent_inline_ref_size(want);
+ path->keep_locks = 1;
+ } else
+ extra_size = -1;
+
+ /*
+ * Owner is our parent level, so we can just add one to get the level
+ * for the block we are interested in.
+ */
+ if (skinny_metadata && owner < BTRFS_FIRST_FREE_OBJECTID) {
+ key.type = BTRFS_METADATA_ITEM_KEY;
+ key.offset = owner;
+ }
+
+again:
+ ret = btrfs_search_slot(trans, root, &key, path, extra_size, 1);
+ if (ret < 0) {
+ err = ret;
+ goto out;
+ }
+
+ /*
+ * We may be a newly converted file system which still has the old fat
+ * extent entries for metadata, so try and see if we have one of those.
+ */
+ if (ret > 0 && skinny_metadata) {
+ skinny_metadata = false;
+ if (path->slots[0]) {
+ path->slots[0]--;
+ btrfs_item_key_to_cpu(path->nodes[0], &key,
+ path->slots[0]);
+ if (key.objectid == bytenr &&
+ key.type == BTRFS_EXTENT_ITEM_KEY &&
+ key.offset == num_bytes)
+ ret = 0;
+ }
+ if (ret) {
+ key.objectid = bytenr;
+ key.type = BTRFS_EXTENT_ITEM_KEY;
+ key.offset = num_bytes;
+ btrfs_release_path(path);
+ goto again;
+ }
+ }
+
+ if (ret && !insert) {
+ err = -ENOENT;
+ goto out;
+ } else if (WARN_ON(ret)) {
+ err = -EIO;
+ goto out;
+ }
+
+ leaf = path->nodes[0];
+ item_size = btrfs_item_size_nr(leaf, path->slots[0]);
+#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
+ if (item_size < sizeof(*ei)) {
+ if (!insert) {
+ err = -ENOENT;
+ goto out;
+ }
+ ret = convert_extent_item_v0(trans, root, path, owner,
+ extra_size);
+ if (ret < 0) {
+ err = ret;
+ goto out;
+ }
+ leaf = path->nodes[0];
+ item_size = btrfs_item_size_nr(leaf, path->slots[0]);
+ }
+#endif
+ BUG_ON(item_size < sizeof(*ei));
+
+ ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
+ flags = btrfs_extent_flags(leaf, ei);
+
+ ptr = (unsigned long)(ei + 1);
+ end = (unsigned long)ei + item_size;
+
+ if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK && !skinny_metadata) {
+ ptr += sizeof(struct btrfs_tree_block_info);
+ BUG_ON(ptr > end);
+ }
+
+ err = -ENOENT;
+ while (1) {
+ if (ptr >= end) {
+ WARN_ON(ptr > end);
+ break;
+ }
+ iref = (struct btrfs_extent_inline_ref *)ptr;
+ type = btrfs_extent_inline_ref_type(leaf, iref);
+ if (want < type)
+ break;
+ if (want > type) {
+ ptr += btrfs_extent_inline_ref_size(type);
+ continue;
+ }
+
+ if (type == BTRFS_EXTENT_DATA_REF_KEY) {
+ struct btrfs_extent_data_ref *dref;
+ dref = (struct btrfs_extent_data_ref *)(&iref->offset);
+ if (match_extent_data_ref(leaf, dref, root_objectid,
+ owner, offset)) {
+ err = 0;
+ break;
+ }
+ if (hash_extent_data_ref_item(leaf, dref) <
+ hash_extent_data_ref(root_objectid, owner, offset))
+ break;
+ } else {
+ u64 ref_offset;
+ ref_offset = btrfs_extent_inline_ref_offset(leaf, iref);
+ if (parent > 0) {
+ if (parent == ref_offset) {
+ err = 0;
+ break;
+ }
+ if (ref_offset < parent)
+ break;
+ } else {
+ if (root_objectid == ref_offset) {
+ err = 0;
+ break;
+ }
+ if (ref_offset < root_objectid)
+ break;
+ }
+ }
+ ptr += btrfs_extent_inline_ref_size(type);
+ }
+ if (err == -ENOENT && insert) {
+ if (item_size + extra_size >=
+ BTRFS_MAX_EXTENT_ITEM_SIZE(root)) {
+ err = -EAGAIN;
+ goto out;
+ }
+ /*
+ * To add new inline back ref, we have to make sure
+ * there is no corresponding back ref item.
+ * For simplicity, we just do not add new inline back
+ * ref if there is any kind of item for this block
+ */
+ if (find_next_key(path, 0, &key) == 0 &&
+ key.objectid == bytenr &&
+ key.type < BTRFS_BLOCK_GROUP_ITEM_KEY) {
+ err = -EAGAIN;
+ goto out;
+ }
+ }
+ *ref_ret = (struct btrfs_extent_inline_ref *)ptr;
+out:
+ if (insert) {
+ path->keep_locks = 0;
+ btrfs_unlock_up_safe(path, 1);
+ }
+ return err;
+}
+
+/*
+ * helper to add new inline back ref
+ */
+static noinline_for_stack
+void setup_inline_extent_backref(struct btrfs_root *root,
+ struct btrfs_path *path,
+ struct btrfs_extent_inline_ref *iref,
+ u64 parent, u64 root_objectid,
+ u64 owner, u64 offset, int refs_to_add,
+ struct btrfs_delayed_extent_op *extent_op)
+{
+ struct extent_buffer *leaf;
+ struct btrfs_extent_item *ei;
+ unsigned long ptr;
+ unsigned long end;
+ unsigned long item_offset;
+ u64 refs;
+ int size;
+ int type;
+
+ leaf = path->nodes[0];
+ ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
+ item_offset = (unsigned long)iref - (unsigned long)ei;
+
+ type = extent_ref_type(parent, owner);
+ size = btrfs_extent_inline_ref_size(type);
+
+ btrfs_extend_item(root, path, size);
+
+ ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
+ refs = btrfs_extent_refs(leaf, ei);
+ refs += refs_to_add;
+ btrfs_set_extent_refs(leaf, ei, refs);
+ if (extent_op)
+ __run_delayed_extent_op(extent_op, leaf, ei);
+
+ ptr = (unsigned long)ei + item_offset;
+ end = (unsigned long)ei + btrfs_item_size_nr(leaf, path->slots[0]);
+ if (ptr < end - size)
+ memmove_extent_buffer(leaf, ptr + size, ptr,
+ end - size - ptr);
+
+ iref = (struct btrfs_extent_inline_ref *)ptr;
+ btrfs_set_extent_inline_ref_type(leaf, iref, type);
+ if (type == BTRFS_EXTENT_DATA_REF_KEY) {
+ struct btrfs_extent_data_ref *dref;
+ dref = (struct btrfs_extent_data_ref *)(&iref->offset);
+ btrfs_set_extent_data_ref_root(leaf, dref, root_objectid);
+ btrfs_set_extent_data_ref_objectid(leaf, dref, owner);
+ btrfs_set_extent_data_ref_offset(leaf, dref, offset);
+ btrfs_set_extent_data_ref_count(leaf, dref, refs_to_add);
+ } else if (type == BTRFS_SHARED_DATA_REF_KEY) {
+ struct btrfs_shared_data_ref *sref;
+ sref = (struct btrfs_shared_data_ref *)(iref + 1);
+ btrfs_set_shared_data_ref_count(leaf, sref, refs_to_add);
+ btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
+ } else if (type == BTRFS_SHARED_BLOCK_REF_KEY) {
+ btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
+ } else {
+ btrfs_set_extent_inline_ref_offset(leaf, iref, root_objectid);
+ }
+ btrfs_mark_buffer_dirty(leaf);
+}
+
+static int lookup_extent_backref(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ struct btrfs_extent_inline_ref **ref_ret,
+ u64 bytenr, u64 num_bytes, u64 parent,
+ u64 root_objectid, u64 owner, u64 offset)
+{
+ int ret;
+
+ ret = lookup_inline_extent_backref(trans, root, path, ref_ret,
+ bytenr, num_bytes, parent,
+ root_objectid, owner, offset, 0);
+ if (ret != -ENOENT)
+ return ret;
+
+ btrfs_release_path(path);
+ *ref_ret = NULL;
+
+ if (owner < BTRFS_FIRST_FREE_OBJECTID) {
+ ret = lookup_tree_block_ref(trans, root, path, bytenr, parent,
+ root_objectid);
+ } else {
+ ret = lookup_extent_data_ref(trans, root, path, bytenr, parent,
+ root_objectid, owner, offset);
+ }
+ return ret;
+}
+
+/*
+ * helper to update/remove inline back ref
+ */
+static noinline_for_stack
+void update_inline_extent_backref(struct btrfs_root *root,
+ struct btrfs_path *path,
+ struct btrfs_extent_inline_ref *iref,
+ int refs_to_mod,
+ struct btrfs_delayed_extent_op *extent_op,
+ int *last_ref)
+{
+ struct extent_buffer *leaf;
+ struct btrfs_extent_item *ei;
+ struct btrfs_extent_data_ref *dref = NULL;
+ struct btrfs_shared_data_ref *sref = NULL;
+ unsigned long ptr;
+ unsigned long end;
+ u32 item_size;
+ int size;
+ int type;
+ u64 refs;
+
+ leaf = path->nodes[0];
+ ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
+ refs = btrfs_extent_refs(leaf, ei);
+ WARN_ON(refs_to_mod < 0 && refs + refs_to_mod <= 0);
+ refs += refs_to_mod;
+ btrfs_set_extent_refs(leaf, ei, refs);
+ if (extent_op)
+ __run_delayed_extent_op(extent_op, leaf, ei);
+
+ type = btrfs_extent_inline_ref_type(leaf, iref);
+
+ if (type == BTRFS_EXTENT_DATA_REF_KEY) {
+ dref = (struct btrfs_extent_data_ref *)(&iref->offset);
+ refs = btrfs_extent_data_ref_count(leaf, dref);
+ } else if (type == BTRFS_SHARED_DATA_REF_KEY) {
+ sref = (struct btrfs_shared_data_ref *)(iref + 1);
+ refs = btrfs_shared_data_ref_count(leaf, sref);
+ } else {
+ refs = 1;
+ BUG_ON(refs_to_mod != -1);
+ }
+
+ BUG_ON(refs_to_mod < 0 && refs < -refs_to_mod);
+ refs += refs_to_mod;
+
+ if (refs > 0) {
+ if (type == BTRFS_EXTENT_DATA_REF_KEY)
+ btrfs_set_extent_data_ref_count(leaf, dref, refs);
+ else
+ btrfs_set_shared_data_ref_count(leaf, sref, refs);
+ } else {
+ *last_ref = 1;
+ size = btrfs_extent_inline_ref_size(type);
+ item_size = btrfs_item_size_nr(leaf, path->slots[0]);
+ ptr = (unsigned long)iref;
+ end = (unsigned long)ei + item_size;
+ if (ptr + size < end)
+ memmove_extent_buffer(leaf, ptr, ptr + size,
+ end - ptr - size);
+ item_size -= size;
+ btrfs_truncate_item(root, path, item_size, 1);
+ }
+ btrfs_mark_buffer_dirty(leaf);
+}
+
+static noinline_for_stack
+int insert_inline_extent_backref(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ u64 bytenr, u64 num_bytes, u64 parent,
+ u64 root_objectid, u64 owner,
+ u64 offset, int refs_to_add,
+ struct btrfs_delayed_extent_op *extent_op)
+{
+ struct btrfs_extent_inline_ref *iref;
+ int ret;
+
+ ret = lookup_inline_extent_backref(trans, root, path, &iref,
+ bytenr, num_bytes, parent,
+ root_objectid, owner, offset, 1);
+ if (ret == 0) {
+ BUG_ON(owner < BTRFS_FIRST_FREE_OBJECTID);
+ update_inline_extent_backref(root, path, iref,
+ refs_to_add, extent_op, NULL);
+ } else if (ret == -ENOENT) {
+ setup_inline_extent_backref(root, path, iref, parent,
+ root_objectid, owner, offset,
+ refs_to_add, extent_op);
+ ret = 0;
+ }
+ return ret;
+}
+
+static int insert_extent_backref(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ u64 bytenr, u64 parent, u64 root_objectid,
+ u64 owner, u64 offset, int refs_to_add)
+{
+ int ret;
+ if (owner < BTRFS_FIRST_FREE_OBJECTID) {
+ BUG_ON(refs_to_add != 1);
+ ret = insert_tree_block_ref(trans, root, path, bytenr,
+ parent, root_objectid);
+ } else {
+ ret = insert_extent_data_ref(trans, root, path, bytenr,
+ parent, root_objectid,
+ owner, offset, refs_to_add);
+ }
+ return ret;
+}
+
+static int remove_extent_backref(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ struct btrfs_extent_inline_ref *iref,
+ int refs_to_drop, int is_data, int *last_ref)
+{
+ int ret = 0;
+
+ BUG_ON(!is_data && refs_to_drop != 1);
+ if (iref) {
+ update_inline_extent_backref(root, path, iref,
+ -refs_to_drop, NULL, last_ref);
+ } else if (is_data) {
+ ret = remove_extent_data_ref(trans, root, path, refs_to_drop,
+ last_ref);
+ } else {
+ *last_ref = 1;
+ ret = btrfs_del_item(trans, root, path);
+ }
+ return ret;
+}
+
+static int btrfs_issue_discard(struct block_device *bdev,
+ u64 start, u64 len)
+{
+ return blkdev_issue_discard(bdev, start >> 9, len >> 9, GFP_NOFS, 0);
+}
+
+int btrfs_discard_extent(struct btrfs_root *root, u64 bytenr,
+ u64 num_bytes, u64 *actual_bytes)
+{
+ int ret;
+ u64 discarded_bytes = 0;
+ struct btrfs_bio *bbio = NULL;
+
+
+ /* Tell the block device(s) that the sectors can be discarded */
+ ret = btrfs_map_block(root->fs_info, REQ_DISCARD,
+ bytenr, &num_bytes, &bbio, 0);
+ /* Error condition is -ENOMEM */
+ if (!ret) {
+ struct btrfs_bio_stripe *stripe = bbio->stripes;
+ int i;
+
+
+ for (i = 0; i < bbio->num_stripes; i++, stripe++) {
+ if (!stripe->dev->can_discard)
+ continue;
+
+ ret = btrfs_issue_discard(stripe->dev->bdev,
+ stripe->physical,
+ stripe->length);
+ if (!ret)
+ discarded_bytes += stripe->length;
+ else if (ret != -EOPNOTSUPP)
+ break; /* Logic errors or -ENOMEM, or -EIO but I don't know how that could happen JDM */
+
+ /*
+ * Just in case we get back EOPNOTSUPP for some reason,
+ * just ignore the return value so we don't screw up
+ * people calling discard_extent.
+ */
+ ret = 0;
+ }
+ btrfs_put_bbio(bbio);
+ }
+
+ if (actual_bytes)
+ *actual_bytes = discarded_bytes;
+
+
+ if (ret == -EOPNOTSUPP)
+ ret = 0;
+ return ret;
+}
+
+/* Can return -ENOMEM */
+int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ u64 bytenr, u64 num_bytes, u64 parent,
+ u64 root_objectid, u64 owner, u64 offset,
+ int no_quota)
+{
+ int ret;
+ struct btrfs_fs_info *fs_info = root->fs_info;
+
+ BUG_ON(owner < BTRFS_FIRST_FREE_OBJECTID &&
+ root_objectid == BTRFS_TREE_LOG_OBJECTID);
+
+ if (owner < BTRFS_FIRST_FREE_OBJECTID) {
+ ret = btrfs_add_delayed_tree_ref(fs_info, trans, bytenr,
+ num_bytes,
+ parent, root_objectid, (int)owner,
+ BTRFS_ADD_DELAYED_REF, NULL, no_quota);
+ } else {
+ ret = btrfs_add_delayed_data_ref(fs_info, trans, bytenr,
+ num_bytes,
+ parent, root_objectid, owner, offset,
+ BTRFS_ADD_DELAYED_REF, NULL, no_quota);
+ }
+ return ret;
+}
+
+static int __btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ u64 bytenr, u64 num_bytes,
+ u64 parent, u64 root_objectid,
+ u64 owner, u64 offset, int refs_to_add,
+ int no_quota,
+ struct btrfs_delayed_extent_op *extent_op)
+{
+ struct btrfs_fs_info *fs_info = root->fs_info;
+ struct btrfs_path *path;
+ struct extent_buffer *leaf;
+ struct btrfs_extent_item *item;
+ struct btrfs_key key;
+ u64 refs;
+ int ret;
+ enum btrfs_qgroup_operation_type type = BTRFS_QGROUP_OPER_ADD_EXCL;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ if (!is_fstree(root_objectid) || !root->fs_info->quota_enabled)
+ no_quota = 1;
+
+ path->reada = 1;
+ path->leave_spinning = 1;
+ /* this will setup the path even if it fails to insert the back ref */
+ ret = insert_inline_extent_backref(trans, fs_info->extent_root, path,
+ bytenr, num_bytes, parent,
+ root_objectid, owner, offset,
+ refs_to_add, extent_op);
+ if ((ret < 0 && ret != -EAGAIN) || (!ret && no_quota))
+ goto out;
+ /*
+ * Ok we were able to insert an inline extent and it appears to be a new
+ * reference, deal with the qgroup accounting.
+ */
+ if (!ret && !no_quota) {
+ ASSERT(root->fs_info->quota_enabled);
+ leaf = path->nodes[0];
+ btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
+ item = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_extent_item);
+ if (btrfs_extent_refs(leaf, item) > (u64)refs_to_add)
+ type = BTRFS_QGROUP_OPER_ADD_SHARED;
+ btrfs_release_path(path);
+
+ ret = btrfs_qgroup_record_ref(trans, fs_info, root_objectid,
+ bytenr, num_bytes, type, 0);
+ goto out;
+ }
+
+ /*
+ * Ok we had -EAGAIN which means we didn't have space to insert and
+ * inline extent ref, so just update the reference count and add a
+ * normal backref.
+ */
+ leaf = path->nodes[0];
+ btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
+ item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
+ refs = btrfs_extent_refs(leaf, item);
+ if (refs)
+ type = BTRFS_QGROUP_OPER_ADD_SHARED;
+ btrfs_set_extent_refs(leaf, item, refs + refs_to_add);
+ if (extent_op)
+ __run_delayed_extent_op(extent_op, leaf, item);
+
+ btrfs_mark_buffer_dirty(leaf);
+ btrfs_release_path(path);
+
+ if (!no_quota) {
+ ret = btrfs_qgroup_record_ref(trans, fs_info, root_objectid,
+ bytenr, num_bytes, type, 0);
+ if (ret)
+ goto out;
+ }
+
+ path->reada = 1;
+ path->leave_spinning = 1;
+ /* now insert the actual backref */
+ ret = insert_extent_backref(trans, root->fs_info->extent_root,
+ path, bytenr, parent, root_objectid,
+ owner, offset, refs_to_add);
+ if (ret)
+ btrfs_abort_transaction(trans, root, ret);
+out:
+ btrfs_free_path(path);
+ return ret;
+}
+
+static int run_delayed_data_ref(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_delayed_ref_node *node,
+ struct btrfs_delayed_extent_op *extent_op,
+ int insert_reserved)
+{
+ int ret = 0;
+ struct btrfs_delayed_data_ref *ref;
+ struct btrfs_key ins;
+ u64 parent = 0;
+ u64 ref_root = 0;
+ u64 flags = 0;
+
+ ins.objectid = node->bytenr;
+ ins.offset = node->num_bytes;
+ ins.type = BTRFS_EXTENT_ITEM_KEY;
+
+ ref = btrfs_delayed_node_to_data_ref(node);
+ trace_run_delayed_data_ref(node, ref, node->action);
+
+ if (node->type == BTRFS_SHARED_DATA_REF_KEY)
+ parent = ref->parent;
+ ref_root = ref->root;
+
+ if (node->action == BTRFS_ADD_DELAYED_REF && insert_reserved) {
+ if (extent_op)
+ flags |= extent_op->flags_to_set;
+ ret = alloc_reserved_file_extent(trans, root,
+ parent, ref_root, flags,
+ ref->objectid, ref->offset,
+ &ins, node->ref_mod);
+ } else if (node->action == BTRFS_ADD_DELAYED_REF) {
+ ret = __btrfs_inc_extent_ref(trans, root, node->bytenr,
+ node->num_bytes, parent,
+ ref_root, ref->objectid,
+ ref->offset, node->ref_mod,
+ node->no_quota, extent_op);
+ } else if (node->action == BTRFS_DROP_DELAYED_REF) {
+ ret = __btrfs_free_extent(trans, root, node->bytenr,
+ node->num_bytes, parent,
+ ref_root, ref->objectid,
+ ref->offset, node->ref_mod,
+ extent_op, node->no_quota);
+ } else {
+ BUG();
+ }
+ return ret;
+}
+
+static void __run_delayed_extent_op(struct btrfs_delayed_extent_op *extent_op,
+ struct extent_buffer *leaf,
+ struct btrfs_extent_item *ei)
+{
+ u64 flags = btrfs_extent_flags(leaf, ei);
+ if (extent_op->update_flags) {
+ flags |= extent_op->flags_to_set;
+ btrfs_set_extent_flags(leaf, ei, flags);
+ }
+
+ if (extent_op->update_key) {
+ struct btrfs_tree_block_info *bi;
+ BUG_ON(!(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK));
+ bi = (struct btrfs_tree_block_info *)(ei + 1);
+ btrfs_set_tree_block_key(leaf, bi, &extent_op->key);
+ }
+}
+
+static int run_delayed_extent_op(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_delayed_ref_node *node,
+ struct btrfs_delayed_extent_op *extent_op)
+{
+ struct btrfs_key key;
+ struct btrfs_path *path;
+ struct btrfs_extent_item *ei;
+ struct extent_buffer *leaf;
+ u32 item_size;
+ int ret;
+ int err = 0;
+ int metadata = !extent_op->is_data;
+
+ if (trans->aborted)
+ return 0;
+
+ if (metadata && !btrfs_fs_incompat(root->fs_info, SKINNY_METADATA))
+ metadata = 0;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ key.objectid = node->bytenr;
+
+ if (metadata) {
+ key.type = BTRFS_METADATA_ITEM_KEY;
+ key.offset = extent_op->level;
+ } else {
+ key.type = BTRFS_EXTENT_ITEM_KEY;
+ key.offset = node->num_bytes;
+ }
+
+again:
+ path->reada = 1;
+ path->leave_spinning = 1;
+ ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key,
+ path, 0, 1);
+ if (ret < 0) {
+ err = ret;
+ goto out;
+ }
+ if (ret > 0) {
+ if (metadata) {
+ if (path->slots[0] > 0) {
+ path->slots[0]--;
+ btrfs_item_key_to_cpu(path->nodes[0], &key,
+ path->slots[0]);
+ if (key.objectid == node->bytenr &&
+ key.type == BTRFS_EXTENT_ITEM_KEY &&
+ key.offset == node->num_bytes)
+ ret = 0;
+ }
+ if (ret > 0) {
+ btrfs_release_path(path);
+ metadata = 0;
+
+ key.objectid = node->bytenr;
+ key.offset = node->num_bytes;
+ key.type = BTRFS_EXTENT_ITEM_KEY;
+ goto again;
+ }
+ } else {
+ err = -EIO;
+ goto out;
+ }
+ }
+
+ leaf = path->nodes[0];
+ item_size = btrfs_item_size_nr(leaf, path->slots[0]);
+#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
+ if (item_size < sizeof(*ei)) {
+ ret = convert_extent_item_v0(trans, root->fs_info->extent_root,
+ path, (u64)-1, 0);
+ if (ret < 0) {
+ err = ret;
+ goto out;
+ }
+ leaf = path->nodes[0];
+ item_size = btrfs_item_size_nr(leaf, path->slots[0]);
+ }
+#endif
+ BUG_ON(item_size < sizeof(*ei));
+ ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
+ __run_delayed_extent_op(extent_op, leaf, ei);
+
+ btrfs_mark_buffer_dirty(leaf);
+out:
+ btrfs_free_path(path);
+ return err;
+}
+
+static int run_delayed_tree_ref(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_delayed_ref_node *node,
+ struct btrfs_delayed_extent_op *extent_op,
+ int insert_reserved)
+{
+ int ret = 0;
+ struct btrfs_delayed_tree_ref *ref;
+ struct btrfs_key ins;
+ u64 parent = 0;
+ u64 ref_root = 0;
+ bool skinny_metadata = btrfs_fs_incompat(root->fs_info,
+ SKINNY_METADATA);
+
+ ref = btrfs_delayed_node_to_tree_ref(node);
+ trace_run_delayed_tree_ref(node, ref, node->action);
+
+ if (node->type == BTRFS_SHARED_BLOCK_REF_KEY)
+ parent = ref->parent;
+ ref_root = ref->root;
+
+ ins.objectid = node->bytenr;
+ if (skinny_metadata) {
+ ins.offset = ref->level;
+ ins.type = BTRFS_METADATA_ITEM_KEY;
+ } else {
+ ins.offset = node->num_bytes;
+ ins.type = BTRFS_EXTENT_ITEM_KEY;
+ }
+
+ BUG_ON(node->ref_mod != 1);
+ if (node->action == BTRFS_ADD_DELAYED_REF && insert_reserved) {
+ BUG_ON(!extent_op || !extent_op->update_flags);
+ ret = alloc_reserved_tree_block(trans, root,
+ parent, ref_root,
+ extent_op->flags_to_set,
+ &extent_op->key,
+ ref->level, &ins,
+ node->no_quota);
+ } else if (node->action == BTRFS_ADD_DELAYED_REF) {
+ ret = __btrfs_inc_extent_ref(trans, root, node->bytenr,
+ node->num_bytes, parent, ref_root,
+ ref->level, 0, 1, node->no_quota,
+ extent_op);
+ } else if (node->action == BTRFS_DROP_DELAYED_REF) {
+ ret = __btrfs_free_extent(trans, root, node->bytenr,
+ node->num_bytes, parent, ref_root,
+ ref->level, 0, 1, extent_op,
+ node->no_quota);
+ } else {
+ BUG();
+ }
+ return ret;
+}
+
+/* helper function to actually process a single delayed ref entry */
+static int run_one_delayed_ref(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_delayed_ref_node *node,
+ struct btrfs_delayed_extent_op *extent_op,
+ int insert_reserved)
+{
+ int ret = 0;
+
+ if (trans->aborted) {
+ if (insert_reserved)
+ btrfs_pin_extent(root, node->bytenr,
+ node->num_bytes, 1);
+ return 0;
+ }
+
+ if (btrfs_delayed_ref_is_head(node)) {
+ struct btrfs_delayed_ref_head *head;
+ /*
+ * we've hit the end of the chain and we were supposed
+ * to insert this extent into the tree. But, it got
+ * deleted before we ever needed to insert it, so all
+ * we have to do is clean up the accounting
+ */
+ BUG_ON(extent_op);
+ head = btrfs_delayed_node_to_head(node);
+ trace_run_delayed_ref_head(node, head, node->action);
+
+ if (insert_reserved) {
+ btrfs_pin_extent(root, node->bytenr,
+ node->num_bytes, 1);
+ if (head->is_data) {
+ ret = btrfs_del_csums(trans, root,
+ node->bytenr,
+ node->num_bytes);
+ }
+ }
+ return ret;
+ }
+
+ if (node->type == BTRFS_TREE_BLOCK_REF_KEY ||
+ node->type == BTRFS_SHARED_BLOCK_REF_KEY)
+ ret = run_delayed_tree_ref(trans, root, node, extent_op,
+ insert_reserved);
+ else if (node->type == BTRFS_EXTENT_DATA_REF_KEY ||
+ node->type == BTRFS_SHARED_DATA_REF_KEY)
+ ret = run_delayed_data_ref(trans, root, node, extent_op,
+ insert_reserved);
+ else
+ BUG();
+ return ret;
+}
+
+static noinline struct btrfs_delayed_ref_node *
+select_delayed_ref(struct btrfs_delayed_ref_head *head)
+{
+ struct rb_node *node;
+ struct btrfs_delayed_ref_node *ref, *last = NULL;;
+
+ /*
+ * select delayed ref of type BTRFS_ADD_DELAYED_REF first.
+ * this prevents ref count from going down to zero when
+ * there still are pending delayed ref.
+ */
+ node = rb_first(&head->ref_root);
+ while (node) {
+ ref = rb_entry(node, struct btrfs_delayed_ref_node,
+ rb_node);
+ if (ref->action == BTRFS_ADD_DELAYED_REF)
+ return ref;
+ else if (last == NULL)
+ last = ref;
+ node = rb_next(node);
+ }
+ return last;
+}
+
+/*
+ * Returns 0 on success or if called with an already aborted transaction.
+ * Returns -ENOMEM or -EIO on failure and will abort the transaction.
+ */
+static noinline int __btrfs_run_delayed_refs(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ unsigned long nr)
+{
+ struct btrfs_delayed_ref_root *delayed_refs;
+ struct btrfs_delayed_ref_node *ref;
+ struct btrfs_delayed_ref_head *locked_ref = NULL;
+ struct btrfs_delayed_extent_op *extent_op;
+ struct btrfs_fs_info *fs_info = root->fs_info;
+ ktime_t start = ktime_get();
+ int ret;
+ unsigned long count = 0;
+ unsigned long actual_count = 0;
+ int must_insert_reserved = 0;
+
+ delayed_refs = &trans->transaction->delayed_refs;
+ while (1) {
+ if (!locked_ref) {
+ if (count >= nr)
+ break;
+
+ spin_lock(&delayed_refs->lock);
+ locked_ref = btrfs_select_ref_head(trans);
+ if (!locked_ref) {
+ spin_unlock(&delayed_refs->lock);
+ break;
+ }
+
+ /* grab the lock that says we are going to process
+ * all the refs for this head */
+ ret = btrfs_delayed_ref_lock(trans, locked_ref);
+ spin_unlock(&delayed_refs->lock);
+ /*
+ * we may have dropped the spin lock to get the head
+ * mutex lock, and that might have given someone else
+ * time to free the head. If that's true, it has been
+ * removed from our list and we can move on.
+ */
+ if (ret == -EAGAIN) {
+ locked_ref = NULL;
+ count++;
+ continue;
+ }
+ }
+
+ /*
+ * We need to try and merge add/drops of the same ref since we
+ * can run into issues with relocate dropping the implicit ref
+ * and then it being added back again before the drop can
+ * finish. If we merged anything we need to re-loop so we can
+ * get a good ref.
+ */
+ spin_lock(&locked_ref->lock);
+ btrfs_merge_delayed_refs(trans, fs_info, delayed_refs,
+ locked_ref);
+
+ /*
+ * locked_ref is the head node, so we have to go one
+ * node back for any delayed ref updates
+ */
+ ref = select_delayed_ref(locked_ref);
+
+ if (ref && ref->seq &&
+ btrfs_check_delayed_seq(fs_info, delayed_refs, ref->seq)) {
+ spin_unlock(&locked_ref->lock);
+ btrfs_delayed_ref_unlock(locked_ref);
+ spin_lock(&delayed_refs->lock);
+ locked_ref->processing = 0;
+ delayed_refs->num_heads_ready++;
+ spin_unlock(&delayed_refs->lock);
+ locked_ref = NULL;
+ cond_resched();
+ count++;
+ continue;
+ }
+
+ /*
+ * record the must insert reserved flag before we
+ * drop the spin lock.
+ */
+ must_insert_reserved = locked_ref->must_insert_reserved;
+ locked_ref->must_insert_reserved = 0;
+
+ extent_op = locked_ref->extent_op;
+ locked_ref->extent_op = NULL;
+
+ if (!ref) {
+
+
+ /* All delayed refs have been processed, Go ahead
+ * and send the head node to run_one_delayed_ref,
+ * so that any accounting fixes can happen
+ */
+ ref = &locked_ref->node;
+
+ if (extent_op && must_insert_reserved) {
+ btrfs_free_delayed_extent_op(extent_op);
+ extent_op = NULL;
+ }
+
+ if (extent_op) {
+ spin_unlock(&locked_ref->lock);
+ ret = run_delayed_extent_op(trans, root,
+ ref, extent_op);
+ btrfs_free_delayed_extent_op(extent_op);
+
+ if (ret) {
+ /*
+ * Need to reset must_insert_reserved if
+ * there was an error so the abort stuff
+ * can cleanup the reserved space
+ * properly.
+ */
+ if (must_insert_reserved)
+ locked_ref->must_insert_reserved = 1;
+ locked_ref->processing = 0;
+ btrfs_debug(fs_info, "run_delayed_extent_op returned %d", ret);
+ btrfs_delayed_ref_unlock(locked_ref);
+ return ret;
+ }
+ continue;
+ }
+
+ /*
+ * Need to drop our head ref lock and re-aqcuire the
+ * delayed ref lock and then re-check to make sure
+ * nobody got added.
+ */
+ spin_unlock(&locked_ref->lock);
+ spin_lock(&delayed_refs->lock);
+ spin_lock(&locked_ref->lock);
+ if (rb_first(&locked_ref->ref_root) ||
+ locked_ref->extent_op) {
+ spin_unlock(&locked_ref->lock);
+ spin_unlock(&delayed_refs->lock);
+ continue;
+ }
+ ref->in_tree = 0;
+ delayed_refs->num_heads--;
+ rb_erase(&locked_ref->href_node,
+ &delayed_refs->href_root);
+ spin_unlock(&delayed_refs->lock);
+ } else {
+ actual_count++;
+ ref->in_tree = 0;
+ rb_erase(&ref->rb_node, &locked_ref->ref_root);
+ }
+ atomic_dec(&delayed_refs->num_entries);
+
+ if (!btrfs_delayed_ref_is_head(ref)) {
+ /*
+ * when we play the delayed ref, also correct the
+ * ref_mod on head
+ */
+ switch (ref->action) {
+ case BTRFS_ADD_DELAYED_REF:
+ case BTRFS_ADD_DELAYED_EXTENT:
+ locked_ref->node.ref_mod -= ref->ref_mod;
+ break;
+ case BTRFS_DROP_DELAYED_REF:
+ locked_ref->node.ref_mod += ref->ref_mod;
+ break;
+ default:
+ WARN_ON(1);
+ }
+ }
+ spin_unlock(&locked_ref->lock);
+
+ ret = run_one_delayed_ref(trans, root, ref, extent_op,
+ must_insert_reserved);
+
+ btrfs_free_delayed_extent_op(extent_op);
+ if (ret) {
+ locked_ref->processing = 0;
+ btrfs_delayed_ref_unlock(locked_ref);
+ btrfs_put_delayed_ref(ref);
+ btrfs_debug(fs_info, "run_one_delayed_ref returned %d", ret);
+ return ret;
+ }
+
+ /*
+ * If this node is a head, that means all the refs in this head
+ * have been dealt with, and we will pick the next head to deal
+ * with, so we must unlock the head and drop it from the cluster
+ * list before we release it.
+ */
+ if (btrfs_delayed_ref_is_head(ref)) {
+ if (locked_ref->is_data &&
+ locked_ref->total_ref_mod < 0) {
+ spin_lock(&delayed_refs->lock);
+ delayed_refs->pending_csums -= ref->num_bytes;
+ spin_unlock(&delayed_refs->lock);
+ }
+ btrfs_delayed_ref_unlock(locked_ref);
+ locked_ref = NULL;
+ }
+ btrfs_put_delayed_ref(ref);
+ count++;
+ cond_resched();
+ }
+
+ /*
+ * We don't want to include ref heads since we can have empty ref heads
+ * and those will drastically skew our runtime down since we just do
+ * accounting, no actual extent tree updates.
+ */
+ if (actual_count > 0) {
+ u64 runtime = ktime_to_ns(ktime_sub(ktime_get(), start));
+ u64 avg;
+
+ /*
+ * We weigh the current average higher than our current runtime
+ * to avoid large swings in the average.
+ */
+ spin_lock(&delayed_refs->lock);
+ avg = fs_info->avg_delayed_ref_runtime * 3 + runtime;
+ fs_info->avg_delayed_ref_runtime = avg >> 2; /* div by 4 */
+ spin_unlock(&delayed_refs->lock);
+ }
+ return 0;
+}
+
+#ifdef SCRAMBLE_DELAYED_REFS
+/*
+ * Normally delayed refs get processed in ascending bytenr order. This
+ * correlates in most cases to the order added. To expose dependencies on this
+ * order, we start to process the tree in the middle instead of the beginning
+ */
+static u64 find_middle(struct rb_root *root)
+{
+ struct rb_node *n = root->rb_node;
+ struct btrfs_delayed_ref_node *entry;
+ int alt = 1;
+ u64 middle;
+ u64 first = 0, last = 0;
+
+ n = rb_first(root);
+ if (n) {
+ entry = rb_entry(n, struct btrfs_delayed_ref_node, rb_node);
+ first = entry->bytenr;
+ }
+ n = rb_last(root);
+ if (n) {
+ entry = rb_entry(n, struct btrfs_delayed_ref_node, rb_node);
+ last = entry->bytenr;
+ }
+ n = root->rb_node;
+
+ while (n) {
+ entry = rb_entry(n, struct btrfs_delayed_ref_node, rb_node);
+ WARN_ON(!entry->in_tree);
+
+ middle = entry->bytenr;
+
+ if (alt)
+ n = n->rb_left;
+ else
+ n = n->rb_right;
+
+ alt = 1 - alt;
+ }
+ return middle;
+}
+#endif
+
+static inline u64 heads_to_leaves(struct btrfs_root *root, u64 heads)
+{
+ u64 num_bytes;
+
+ num_bytes = heads * (sizeof(struct btrfs_extent_item) +
+ sizeof(struct btrfs_extent_inline_ref));
+ if (!btrfs_fs_incompat(root->fs_info, SKINNY_METADATA))
+ num_bytes += heads * sizeof(struct btrfs_tree_block_info);
+
+ /*
+ * We don't ever fill up leaves all the way so multiply by 2 just to be
+ * closer to what we're really going to want to ouse.
+ */
+ return div_u64(num_bytes, BTRFS_LEAF_DATA_SIZE(root));
+}
+
+/*
+ * Takes the number of bytes to be csumm'ed and figures out how many leaves it
+ * would require to store the csums for that many bytes.
+ */
+u64 btrfs_csum_bytes_to_leaves(struct btrfs_root *root, u64 csum_bytes)
+{
+ u64 csum_size;
+ u64 num_csums_per_leaf;
+ u64 num_csums;
+
+ csum_size = BTRFS_LEAF_DATA_SIZE(root) - sizeof(struct btrfs_item);
+ num_csums_per_leaf = div64_u64(csum_size,
+ (u64)btrfs_super_csum_size(root->fs_info->super_copy));
+ num_csums = div64_u64(csum_bytes, root->sectorsize);
+ num_csums += num_csums_per_leaf - 1;
+ num_csums = div64_u64(num_csums, num_csums_per_leaf);
+ return num_csums;
+}
+
+int btrfs_check_space_for_delayed_refs(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root)
+{
+ struct btrfs_block_rsv *global_rsv;
+ u64 num_heads = trans->transaction->delayed_refs.num_heads_ready;
+ u64 csum_bytes = trans->transaction->delayed_refs.pending_csums;
+ u64 num_dirty_bgs = trans->transaction->num_dirty_bgs;
+ u64 num_bytes, num_dirty_bgs_bytes;
+ int ret = 0;
+
+ num_bytes = btrfs_calc_trans_metadata_size(root, 1);
+ num_heads = heads_to_leaves(root, num_heads);
+ if (num_heads > 1)
+ num_bytes += (num_heads - 1) * root->nodesize;
+ num_bytes <<= 1;
+ num_bytes += btrfs_csum_bytes_to_leaves(root, csum_bytes) * root->nodesize;
+ num_dirty_bgs_bytes = btrfs_calc_trans_metadata_size(root,
+ num_dirty_bgs);
+ global_rsv = &root->fs_info->global_block_rsv;
+
+ /*
+ * If we can't allocate any more chunks lets make sure we have _lots_ of
+ * wiggle room since running delayed refs can create more delayed refs.
+ */
+ if (global_rsv->space_info->full) {
+ num_dirty_bgs_bytes <<= 1;
+ num_bytes <<= 1;
+ }
+
+ spin_lock(&global_rsv->lock);
+ if (global_rsv->reserved <= num_bytes + num_dirty_bgs_bytes)
+ ret = 1;
+ spin_unlock(&global_rsv->lock);
+ return ret;
+}
+
+int btrfs_should_throttle_delayed_refs(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root)
+{
+ struct btrfs_fs_info *fs_info = root->fs_info;
+ u64 num_entries =
+ atomic_read(&trans->transaction->delayed_refs.num_entries);
+ u64 avg_runtime;
+ u64 val;
+
+ smp_mb();
+ avg_runtime = fs_info->avg_delayed_ref_runtime;
+ val = num_entries * avg_runtime;
+ if (num_entries * avg_runtime >= NSEC_PER_SEC)
+ return 1;
+ if (val >= NSEC_PER_SEC / 2)
+ return 2;
+
+ return btrfs_check_space_for_delayed_refs(trans, root);
+}
+
+struct async_delayed_refs {
+ struct btrfs_root *root;
+ int count;
+ int error;
+ int sync;
+ struct completion wait;
+ struct btrfs_work work;
+};
+
+static void delayed_ref_async_start(struct btrfs_work *work)
+{
+ struct async_delayed_refs *async;
+ struct btrfs_trans_handle *trans;
+ int ret;
+
+ async = container_of(work, struct async_delayed_refs, work);
+
+ trans = btrfs_join_transaction(async->root);
+ if (IS_ERR(trans)) {
+ async->error = PTR_ERR(trans);
+ goto done;
+ }
+
+ /*
+ * trans->sync means that when we call end_transaciton, we won't
+ * wait on delayed refs
+ */
+ trans->sync = true;
+ ret = btrfs_run_delayed_refs(trans, async->root, async->count);
+ if (ret)
+ async->error = ret;
+
+ ret = btrfs_end_transaction(trans, async->root);
+ if (ret && !async->error)
+ async->error = ret;
+done:
+ if (async->sync)
+ complete(&async->wait);
+ else
+ kfree(async);
+}
+
+int btrfs_async_run_delayed_refs(struct btrfs_root *root,
+ unsigned long count, int wait)
+{
+ struct async_delayed_refs *async;
+ int ret;
+
+ async = kmalloc(sizeof(*async), GFP_NOFS);
+ if (!async)
+ return -ENOMEM;
+
+ async->root = root->fs_info->tree_root;
+ async->count = count;
+ async->error = 0;
+ if (wait)
+ async->sync = 1;
+ else
+ async->sync = 0;
+ init_completion(&async->wait);
+
+ btrfs_init_work(&async->work, btrfs_extent_refs_helper,
+ delayed_ref_async_start, NULL, NULL);
+
+ btrfs_queue_work(root->fs_info->extent_workers, &async->work);
+
+ if (wait) {
+ wait_for_completion(&async->wait);
+ ret = async->error;
+ kfree(async);
+ return ret;
+ }
+ return 0;
+}
+
+/*
+ * this starts processing the delayed reference count updates and
+ * extent insertions we have queued up so far. count can be
+ * 0, which means to process everything in the tree at the start
+ * of the run (but not newly added entries), or it can be some target
+ * number you'd like to process.
+ *
+ * Returns 0 on success or if called with an aborted transaction
+ * Returns <0 on error and aborts the transaction
+ */
+int btrfs_run_delayed_refs(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, unsigned long count)
+{
+ struct rb_node *node;
+ struct btrfs_delayed_ref_root *delayed_refs;
+ struct btrfs_delayed_ref_head *head;
+ int ret;
+ int run_all = count == (unsigned long)-1;
+
+ /* We'll clean this up in btrfs_cleanup_transaction */
+ if (trans->aborted)
+ return 0;
+
+ if (root == root->fs_info->extent_root)
+ root = root->fs_info->tree_root;
+
+ delayed_refs = &trans->transaction->delayed_refs;
+ if (count == 0)
+ count = atomic_read(&delayed_refs->num_entries) * 2;
+
+again:
+#ifdef SCRAMBLE_DELAYED_REFS
+ delayed_refs->run_delayed_start = find_middle(&delayed_refs->root);
+#endif
+ ret = __btrfs_run_delayed_refs(trans, root, count);
+ if (ret < 0) {
+ btrfs_abort_transaction(trans, root, ret);
+ return ret;
+ }
+
+ if (run_all) {
+ if (!list_empty(&trans->new_bgs))
+ btrfs_create_pending_block_groups(trans, root);
+
+ spin_lock(&delayed_refs->lock);
+ node = rb_first(&delayed_refs->href_root);
+ if (!node) {
+ spin_unlock(&delayed_refs->lock);
+ goto out;
+ }
+ count = (unsigned long)-1;
+
+ while (node) {
+ head = rb_entry(node, struct btrfs_delayed_ref_head,
+ href_node);
+ if (btrfs_delayed_ref_is_head(&head->node)) {
+ struct btrfs_delayed_ref_node *ref;
+
+ ref = &head->node;
+ atomic_inc(&ref->refs);
+
+ spin_unlock(&delayed_refs->lock);
+ /*
+ * Mutex was contended, block until it's
+ * released and try again
+ */
+ mutex_lock(&head->mutex);
+ mutex_unlock(&head->mutex);
+
+ btrfs_put_delayed_ref(ref);
+ cond_resched();
+ goto again;
+ } else {
+ WARN_ON(1);
+ }
+ node = rb_next(node);
+ }
+ spin_unlock(&delayed_refs->lock);
+ cond_resched();
+ goto again;
+ }
+out:
+ ret = btrfs_delayed_qgroup_accounting(trans, root->fs_info);
+ if (ret)
+ return ret;
+ assert_qgroups_uptodate(trans);
+ return 0;
+}
+
+int btrfs_set_disk_extent_flags(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ u64 bytenr, u64 num_bytes, u64 flags,
+ int level, int is_data)
+{
+ struct btrfs_delayed_extent_op *extent_op;
+ int ret;
+
+ extent_op = btrfs_alloc_delayed_extent_op();
+ if (!extent_op)
+ return -ENOMEM;
+
+ extent_op->flags_to_set = flags;
+ extent_op->update_flags = 1;
+ extent_op->update_key = 0;
+ extent_op->is_data = is_data ? 1 : 0;
+ extent_op->level = level;
+
+ ret = btrfs_add_delayed_extent_op(root->fs_info, trans, bytenr,
+ num_bytes, extent_op);
+ if (ret)
+ btrfs_free_delayed_extent_op(extent_op);
+ return ret;
+}
+
+static noinline int check_delayed_ref(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ u64 objectid, u64 offset, u64 bytenr)
+{
+ struct btrfs_delayed_ref_head *head;
+ struct btrfs_delayed_ref_node *ref;
+ struct btrfs_delayed_data_ref *data_ref;
+ struct btrfs_delayed_ref_root *delayed_refs;
+ struct rb_node *node;
+ int ret = 0;
+
+ delayed_refs = &trans->transaction->delayed_refs;
+ spin_lock(&delayed_refs->lock);
+ head = btrfs_find_delayed_ref_head(trans, bytenr);
+ if (!head) {
+ spin_unlock(&delayed_refs->lock);
+ return 0;
+ }
+
+ if (!mutex_trylock(&head->mutex)) {
+ atomic_inc(&head->node.refs);
+ spin_unlock(&delayed_refs->lock);
+
+ btrfs_release_path(path);
+
+ /*
+ * Mutex was contended, block until it's released and let
+ * caller try again
+ */
+ mutex_lock(&head->mutex);
+ mutex_unlock(&head->mutex);
+ btrfs_put_delayed_ref(&head->node);
+ return -EAGAIN;
+ }
+ spin_unlock(&delayed_refs->lock);
+
+ spin_lock(&head->lock);
+ node = rb_first(&head->ref_root);
+ while (node) {
+ ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
+ node = rb_next(node);
+
+ /* If it's a shared ref we know a cross reference exists */
+ if (ref->type != BTRFS_EXTENT_DATA_REF_KEY) {
+ ret = 1;
+ break;
+ }
+
+ data_ref = btrfs_delayed_node_to_data_ref(ref);
+
+ /*
+ * If our ref doesn't match the one we're currently looking at
+ * then we have a cross reference.
+ */
+ if (data_ref->root != root->root_key.objectid ||
+ data_ref->objectid != objectid ||
+ data_ref->offset != offset) {
+ ret = 1;
+ break;
+ }
+ }
+ spin_unlock(&head->lock);
+ mutex_unlock(&head->mutex);
+ return ret;
+}
+
+static noinline int check_committed_ref(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ u64 objectid, u64 offset, u64 bytenr)
+{
+ struct btrfs_root *extent_root = root->fs_info->extent_root;
+ struct extent_buffer *leaf;
+ struct btrfs_extent_data_ref *ref;
+ struct btrfs_extent_inline_ref *iref;
+ struct btrfs_extent_item *ei;
+ struct btrfs_key key;
+ u32 item_size;
+ int ret;
+
+ key.objectid = bytenr;
+ key.offset = (u64)-1;
+ key.type = BTRFS_EXTENT_ITEM_KEY;
+
+ ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
+ if (ret < 0)
+ goto out;
+ BUG_ON(ret == 0); /* Corruption */
+
+ ret = -ENOENT;
+ if (path->slots[0] == 0)
+ goto out;
+
+ path->slots[0]--;
+ leaf = path->nodes[0];
+ btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
+
+ if (key.objectid != bytenr || key.type != BTRFS_EXTENT_ITEM_KEY)
+ goto out;
+
+ ret = 1;
+ item_size = btrfs_item_size_nr(leaf, path->slots[0]);
+#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
+ if (item_size < sizeof(*ei)) {
+ WARN_ON(item_size != sizeof(struct btrfs_extent_item_v0));
+ goto out;
+ }
+#endif
+ ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
+
+ if (item_size != sizeof(*ei) +
+ btrfs_extent_inline_ref_size(BTRFS_EXTENT_DATA_REF_KEY))
+ goto out;
+
+ if (btrfs_extent_generation(leaf, ei) <=
+ btrfs_root_last_snapshot(&root->root_item))
+ goto out;
+
+ iref = (struct btrfs_extent_inline_ref *)(ei + 1);
+ if (btrfs_extent_inline_ref_type(leaf, iref) !=
+ BTRFS_EXTENT_DATA_REF_KEY)
+ goto out;
+
+ ref = (struct btrfs_extent_data_ref *)(&iref->offset);
+ if (btrfs_extent_refs(leaf, ei) !=
+ btrfs_extent_data_ref_count(leaf, ref) ||
+ btrfs_extent_data_ref_root(leaf, ref) !=
+ root->root_key.objectid ||
+ btrfs_extent_data_ref_objectid(leaf, ref) != objectid ||
+ btrfs_extent_data_ref_offset(leaf, ref) != offset)
+ goto out;
+
+ ret = 0;
+out:
+ return ret;
+}
+
+int btrfs_cross_ref_exist(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ u64 objectid, u64 offset, u64 bytenr)
+{
+ struct btrfs_path *path;
+ int ret;
+ int ret2;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOENT;
+
+ do {
+ ret = check_committed_ref(trans, root, path, objectid,
+ offset, bytenr);
+ if (ret && ret != -ENOENT)
+ goto out;
+
+ ret2 = check_delayed_ref(trans, root, path, objectid,
+ offset, bytenr);
+ } while (ret2 == -EAGAIN);
+
+ if (ret2 && ret2 != -ENOENT) {
+ ret = ret2;
+ goto out;
+ }
+
+ if (ret != -ENOENT || ret2 != -ENOENT)
+ ret = 0;
+out:
+ btrfs_free_path(path);
+ if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
+ WARN_ON(ret > 0);
+ return ret;
+}
+
+static int __btrfs_mod_ref(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct extent_buffer *buf,
+ int full_backref, int inc)
+{
+ u64 bytenr;
+ u64 num_bytes;
+ u64 parent;
+ u64 ref_root;
+ u32 nritems;
+ struct btrfs_key key;
+ struct btrfs_file_extent_item *fi;
+ int i;
+ int level;
+ int ret = 0;
+ int (*process_func)(struct btrfs_trans_handle *, struct btrfs_root *,
+ u64, u64, u64, u64, u64, u64, int);
+
+
+ if (btrfs_test_is_dummy_root(root))
+ return 0;
+
+ ref_root = btrfs_header_owner(buf);
+ nritems = btrfs_header_nritems(buf);
+ level = btrfs_header_level(buf);
+
+ if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state) && level == 0)
+ return 0;
+
+ if (inc)
+ process_func = btrfs_inc_extent_ref;
+ else
+ process_func = btrfs_free_extent;
+
+ if (full_backref)
+ parent = buf->start;
+ else
+ parent = 0;
+
+ for (i = 0; i < nritems; i++) {
+ if (level == 0) {
+ btrfs_item_key_to_cpu(buf, &key, i);
+ if (key.type != BTRFS_EXTENT_DATA_KEY)
+ continue;
+ fi = btrfs_item_ptr(buf, i,
+ struct btrfs_file_extent_item);
+ if (btrfs_file_extent_type(buf, fi) ==
+ BTRFS_FILE_EXTENT_INLINE)
+ continue;
+ bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
+ if (bytenr == 0)
+ continue;
+
+ num_bytes = btrfs_file_extent_disk_num_bytes(buf, fi);
+ key.offset -= btrfs_file_extent_offset(buf, fi);
+ ret = process_func(trans, root, bytenr, num_bytes,
+ parent, ref_root, key.objectid,
+ key.offset, 1);
+ if (ret)
+ goto fail;
+ } else {
+ bytenr = btrfs_node_blockptr(buf, i);
+ num_bytes = root->nodesize;
+ ret = process_func(trans, root, bytenr, num_bytes,
+ parent, ref_root, level - 1, 0,
+ 1);
+ if (ret)
+ goto fail;
+ }
+ }
+ return 0;
+fail:
+ return ret;
+}
+
+int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
+ struct extent_buffer *buf, int full_backref)
+{
+ return __btrfs_mod_ref(trans, root, buf, full_backref, 1);
+}
+
+int btrfs_dec_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
+ struct extent_buffer *buf, int full_backref)
+{
+ return __btrfs_mod_ref(trans, root, buf, full_backref, 0);
+}
+
+static int write_one_cache_group(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ struct btrfs_block_group_cache *cache)
+{
+ int ret;
+ struct btrfs_root *extent_root = root->fs_info->extent_root;
+ unsigned long bi;
+ struct extent_buffer *leaf;
+
+ ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1);
+ if (ret) {
+ if (ret > 0)
+ ret = -ENOENT;
+ goto fail;
+ }
+
+ leaf = path->nodes[0];
+ bi = btrfs_item_ptr_offset(leaf, path->slots[0]);
+ write_extent_buffer(leaf, &cache->item, bi, sizeof(cache->item));
+ btrfs_mark_buffer_dirty(leaf);
+fail:
+ btrfs_release_path(path);
+ return ret;
+
+}
+
+static struct btrfs_block_group_cache *
+next_block_group(struct btrfs_root *root,
+ struct btrfs_block_group_cache *cache)
+{
+ struct rb_node *node;
+
+ spin_lock(&root->fs_info->block_group_cache_lock);
+
+ /* If our block group was removed, we need a full search. */
+ if (RB_EMPTY_NODE(&cache->cache_node)) {
+ const u64 next_bytenr = cache->key.objectid + cache->key.offset;
+
+ spin_unlock(&root->fs_info->block_group_cache_lock);
+ btrfs_put_block_group(cache);
+ cache = btrfs_lookup_first_block_group(root->fs_info,
+ next_bytenr);
+ return cache;
+ }
+ node = rb_next(&cache->cache_node);
+ btrfs_put_block_group(cache);
+ if (node) {
+ cache = rb_entry(node, struct btrfs_block_group_cache,
+ cache_node);
+ btrfs_get_block_group(cache);
+ } else
+ cache = NULL;
+ spin_unlock(&root->fs_info->block_group_cache_lock);
+ return cache;
+}
+
+static int cache_save_setup(struct btrfs_block_group_cache *block_group,
+ struct btrfs_trans_handle *trans,
+ struct btrfs_path *path)
+{
+ struct btrfs_root *root = block_group->fs_info->tree_root;
+ struct inode *inode = NULL;
+ u64 alloc_hint = 0;
+ int dcs = BTRFS_DC_ERROR;
+ u64 num_pages = 0;
+ int retries = 0;
+ int ret = 0;
+
+ /*
+ * If this block group is smaller than 100 megs don't bother caching the
+ * block group.
+ */
+ if (block_group->key.offset < (100 * 1024 * 1024)) {
+ spin_lock(&block_group->lock);
+ block_group->disk_cache_state = BTRFS_DC_WRITTEN;
+ spin_unlock(&block_group->lock);
+ return 0;
+ }
+
+ if (trans->aborted)
+ return 0;
+again:
+ inode = lookup_free_space_inode(root, block_group, path);
+ if (IS_ERR(inode) && PTR_ERR(inode) != -ENOENT) {
+ ret = PTR_ERR(inode);
+ btrfs_release_path(path);
+ goto out;
+ }
+
+ if (IS_ERR(inode)) {
+ BUG_ON(retries);
+ retries++;
+
+ if (block_group->ro)
+ goto out_free;
+
+ ret = create_free_space_inode(root, trans, block_group, path);
+ if (ret)
+ goto out_free;
+ goto again;
+ }
+
+ /* We've already setup this transaction, go ahead and exit */
+ if (block_group->cache_generation == trans->transid &&
+ i_size_read(inode)) {
+ dcs = BTRFS_DC_SETUP;
+ goto out_put;
+ }
+
+ /*
+ * We want to set the generation to 0, that way if anything goes wrong
+ * from here on out we know not to trust this cache when we load up next
+ * time.
+ */
+ BTRFS_I(inode)->generation = 0;
+ ret = btrfs_update_inode(trans, root, inode);
+ if (ret) {
+ /*
+ * So theoretically we could recover from this, simply set the
+ * super cache generation to 0 so we know to invalidate the
+ * cache, but then we'd have to keep track of the block groups
+ * that fail this way so we know we _have_ to reset this cache
+ * before the next commit or risk reading stale cache. So to
+ * limit our exposure to horrible edge cases lets just abort the
+ * transaction, this only happens in really bad situations
+ * anyway.
+ */
+ btrfs_abort_transaction(trans, root, ret);
+ goto out_put;
+ }
+ WARN_ON(ret);
+
+ if (i_size_read(inode) > 0) {
+ ret = btrfs_check_trunc_cache_free_space(root,
+ &root->fs_info->global_block_rsv);
+ if (ret)
+ goto out_put;
+
+ ret = btrfs_truncate_free_space_cache(root, trans, NULL, inode);
+ if (ret)
+ goto out_put;
+ }
+
+ spin_lock(&block_group->lock);
+ if (block_group->cached != BTRFS_CACHE_FINISHED ||
+ !btrfs_test_opt(root, SPACE_CACHE)) {
+ /*
+ * don't bother trying to write stuff out _if_
+ * a) we're not cached,
+ * b) we're with nospace_cache mount option.
+ */
+ dcs = BTRFS_DC_WRITTEN;
+ spin_unlock(&block_group->lock);
+ goto out_put;
+ }
+ spin_unlock(&block_group->lock);
+
+ /*
+ * Try to preallocate enough space based on how big the block group is.
+ * Keep in mind this has to include any pinned space which could end up
+ * taking up quite a bit since it's not folded into the other space
+ * cache.
+ */
+ num_pages = div_u64(block_group->key.offset, 256 * 1024 * 1024);
+ if (!num_pages)
+ num_pages = 1;
+
+ num_pages *= 16;
+ num_pages *= PAGE_CACHE_SIZE;
+
+ ret = btrfs_check_data_free_space(inode, num_pages, num_pages);
+ if (ret)
+ goto out_put;
+
+ ret = btrfs_prealloc_file_range_trans(inode, trans, 0, 0, num_pages,
+ num_pages, num_pages,
+ &alloc_hint);
+ if (!ret)
+ dcs = BTRFS_DC_SETUP;
+ btrfs_free_reserved_data_space(inode, num_pages);
+
+out_put:
+ iput(inode);
+out_free:
+ btrfs_release_path(path);
+out:
+ spin_lock(&block_group->lock);
+ if (!ret && dcs == BTRFS_DC_SETUP)
+ block_group->cache_generation = trans->transid;
+ block_group->disk_cache_state = dcs;
+ spin_unlock(&block_group->lock);
+
+ return ret;
+}
+
+int btrfs_setup_space_cache(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root)
+{
+ struct btrfs_block_group_cache *cache, *tmp;
+ struct btrfs_transaction *cur_trans = trans->transaction;
+ struct btrfs_path *path;
+
+ if (list_empty(&cur_trans->dirty_bgs) ||
+ !btrfs_test_opt(root, SPACE_CACHE))
+ return 0;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ /* Could add new block groups, use _safe just in case */
+ list_for_each_entry_safe(cache, tmp, &cur_trans->dirty_bgs,
+ dirty_list) {
+ if (cache->disk_cache_state == BTRFS_DC_CLEAR)
+ cache_save_setup(cache, trans, path);
+ }
+
+ btrfs_free_path(path);
+ return 0;
+}
+
+/*
+ * transaction commit does final block group cache writeback during a
+ * critical section where nothing is allowed to change the FS. This is
+ * required in order for the cache to actually match the block group,
+ * but can introduce a lot of latency into the commit.
+ *
+ * So, btrfs_start_dirty_block_groups is here to kick off block group
+ * cache IO. There's a chance we'll have to redo some of it if the
+ * block group changes again during the commit, but it greatly reduces
+ * the commit latency by getting rid of the easy block groups while
+ * we're still allowing others to join the commit.
+ */
+int btrfs_start_dirty_block_groups(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root)
+{
+ struct btrfs_block_group_cache *cache;
+ struct btrfs_transaction *cur_trans = trans->transaction;
+ int ret = 0;
+ int should_put;
+ struct btrfs_path *path = NULL;
+ LIST_HEAD(dirty);
+ struct list_head *io = &cur_trans->io_bgs;
+ int num_started = 0;
+ int loops = 0;
+
+ spin_lock(&cur_trans->dirty_bgs_lock);
+ if (list_empty(&cur_trans->dirty_bgs)) {
+ spin_unlock(&cur_trans->dirty_bgs_lock);
+ return 0;
+ }
+ list_splice_init(&cur_trans->dirty_bgs, &dirty);
+ spin_unlock(&cur_trans->dirty_bgs_lock);
+
+again:
+ /*
+ * make sure all the block groups on our dirty list actually
+ * exist
+ */
+ btrfs_create_pending_block_groups(trans, root);
+
+ if (!path) {
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+ }
+
+ /*
+ * cache_write_mutex is here only to save us from balance or automatic
+ * removal of empty block groups deleting this block group while we are
+ * writing out the cache
+ */
+ mutex_lock(&trans->transaction->cache_write_mutex);
+ while (!list_empty(&dirty)) {
+ cache = list_first_entry(&dirty,
+ struct btrfs_block_group_cache,
+ dirty_list);
+ /*
+ * this can happen if something re-dirties a block
+ * group that is already under IO. Just wait for it to
+ * finish and then do it all again
+ */
+ if (!list_empty(&cache->io_list)) {
+ list_del_init(&cache->io_list);
+ btrfs_wait_cache_io(root, trans, cache,
+ &cache->io_ctl, path,
+ cache->key.objectid);
+ btrfs_put_block_group(cache);
+ }
+
+
+ /*
+ * btrfs_wait_cache_io uses the cache->dirty_list to decide
+ * if it should update the cache_state. Don't delete
+ * until after we wait.
+ *
+ * Since we're not running in the commit critical section
+ * we need the dirty_bgs_lock to protect from update_block_group
+ */
+ spin_lock(&cur_trans->dirty_bgs_lock);
+ list_del_init(&cache->dirty_list);
+ spin_unlock(&cur_trans->dirty_bgs_lock);
+
+ should_put = 1;
+
+ cache_save_setup(cache, trans, path);
+
+ if (cache->disk_cache_state == BTRFS_DC_SETUP) {
+ cache->io_ctl.inode = NULL;
+ ret = btrfs_write_out_cache(root, trans, cache, path);
+ if (ret == 0 && cache->io_ctl.inode) {
+ num_started++;
+ should_put = 0;
+
+ /*
+ * the cache_write_mutex is protecting
+ * the io_list
+ */
+ list_add_tail(&cache->io_list, io);
+ } else {
+ /*
+ * if we failed to write the cache, the
+ * generation will be bad and life goes on
+ */
+ ret = 0;
+ }
+ }
+ if (!ret) {
+ ret = write_one_cache_group(trans, root, path, cache);
+ /*
+ * Our block group might still be attached to the list
+ * of new block groups in the transaction handle of some
+ * other task (struct btrfs_trans_handle->new_bgs). This
+ * means its block group item isn't yet in the extent
+ * tree. If this happens ignore the error, as we will
+ * try again later in the critical section of the
+ * transaction commit.
+ */
+ if (ret == -ENOENT) {
+ ret = 0;
+ spin_lock(&cur_trans->dirty_bgs_lock);
+ if (list_empty(&cache->dirty_list)) {
+ list_add_tail(&cache->dirty_list,
+ &cur_trans->dirty_bgs);
+ btrfs_get_block_group(cache);
+ }
+ spin_unlock(&cur_trans->dirty_bgs_lock);
+ } else if (ret) {
+ btrfs_abort_transaction(trans, root, ret);
+ }
+ }
+
+ /* if its not on the io list, we need to put the block group */
+ if (should_put)
+ btrfs_put_block_group(cache);
+
+ if (ret)
+ break;
+
+ /*
+ * Avoid blocking other tasks for too long. It might even save
+ * us from writing caches for block groups that are going to be
+ * removed.
+ */
+ mutex_unlock(&trans->transaction->cache_write_mutex);
+ mutex_lock(&trans->transaction->cache_write_mutex);
+ }
+ mutex_unlock(&trans->transaction->cache_write_mutex);
+
+ /*
+ * go through delayed refs for all the stuff we've just kicked off
+ * and then loop back (just once)
+ */
+ ret = btrfs_run_delayed_refs(trans, root, 0);
+ if (!ret && loops == 0) {
+ loops++;
+ spin_lock(&cur_trans->dirty_bgs_lock);
+ list_splice_init(&cur_trans->dirty_bgs, &dirty);
+ /*
+ * dirty_bgs_lock protects us from concurrent block group
+ * deletes too (not just cache_write_mutex).
+ */
+ if (!list_empty(&dirty)) {
+ spin_unlock(&cur_trans->dirty_bgs_lock);
+ goto again;
+ }
+ spin_unlock(&cur_trans->dirty_bgs_lock);
+ }
+
+ btrfs_free_path(path);
+ return ret;
+}
+
+int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root)
+{
+ struct btrfs_block_group_cache *cache;
+ struct btrfs_transaction *cur_trans = trans->transaction;
+ int ret = 0;
+ int should_put;
+ struct btrfs_path *path;
+ struct list_head *io = &cur_trans->io_bgs;
+ int num_started = 0;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ /*
+ * We don't need the lock here since we are protected by the transaction
+ * commit. We want to do the cache_save_setup first and then run the
+ * delayed refs to make sure we have the best chance at doing this all
+ * in one shot.
+ */
+ while (!list_empty(&cur_trans->dirty_bgs)) {
+ cache = list_first_entry(&cur_trans->dirty_bgs,
+ struct btrfs_block_group_cache,
+ dirty_list);
+
+ /*
+ * this can happen if cache_save_setup re-dirties a block
+ * group that is already under IO. Just wait for it to
+ * finish and then do it all again
+ */
+ if (!list_empty(&cache->io_list)) {
+ list_del_init(&cache->io_list);
+ btrfs_wait_cache_io(root, trans, cache,
+ &cache->io_ctl, path,
+ cache->key.objectid);
+ btrfs_put_block_group(cache);
+ }
+
+ /*
+ * don't remove from the dirty list until after we've waited
+ * on any pending IO
+ */
+ list_del_init(&cache->dirty_list);
+ should_put = 1;
+
+ cache_save_setup(cache, trans, path);
+
+ if (!ret)
+ ret = btrfs_run_delayed_refs(trans, root, (unsigned long) -1);
+
+ if (!ret && cache->disk_cache_state == BTRFS_DC_SETUP) {
+ cache->io_ctl.inode = NULL;
+ ret = btrfs_write_out_cache(root, trans, cache, path);
+ if (ret == 0 && cache->io_ctl.inode) {
+ num_started++;
+ should_put = 0;
+ list_add_tail(&cache->io_list, io);
+ } else {
+ /*
+ * if we failed to write the cache, the
+ * generation will be bad and life goes on
+ */
+ ret = 0;
+ }
+ }
+ if (!ret) {
+ ret = write_one_cache_group(trans, root, path, cache);
+ if (ret)
+ btrfs_abort_transaction(trans, root, ret);
+ }
+
+ /* if its not on the io list, we need to put the block group */
+ if (should_put)
+ btrfs_put_block_group(cache);
+ }
+
+ while (!list_empty(io)) {
+ cache = list_first_entry(io, struct btrfs_block_group_cache,
+ io_list);
+ list_del_init(&cache->io_list);
+ btrfs_wait_cache_io(root, trans, cache,
+ &cache->io_ctl, path, cache->key.objectid);
+ btrfs_put_block_group(cache);
+ }
+
+ btrfs_free_path(path);
+ return ret;
+}
+
+int btrfs_extent_readonly(struct btrfs_root *root, u64 bytenr)
+{
+ struct btrfs_block_group_cache *block_group;
+ int readonly = 0;
+
+ block_group = btrfs_lookup_block_group(root->fs_info, bytenr);
+ if (!block_group || block_group->ro)
+ readonly = 1;
+ if (block_group)
+ btrfs_put_block_group(block_group);
+ return readonly;
+}
+
+static const char *alloc_name(u64 flags)
+{
+ switch (flags) {
+ case BTRFS_BLOCK_GROUP_METADATA|BTRFS_BLOCK_GROUP_DATA:
+ return "mixed";
+ case BTRFS_BLOCK_GROUP_METADATA:
+ return "metadata";
+ case BTRFS_BLOCK_GROUP_DATA:
+ return "data";
+ case BTRFS_BLOCK_GROUP_SYSTEM:
+ return "system";
+ default:
+ WARN_ON(1);
+ return "invalid-combination";
+ };
+}
+
+static int update_space_info(struct btrfs_fs_info *info, u64 flags,
+ u64 total_bytes, u64 bytes_used,
+ struct btrfs_space_info **space_info)
+{
+ struct btrfs_space_info *found;
+ int i;
+ int factor;
+ int ret;
+
+ if (flags & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1 |
+ BTRFS_BLOCK_GROUP_RAID10))
+ factor = 2;
+ else
+ factor = 1;
+
+ found = __find_space_info(info, flags);
+ if (found) {
+ spin_lock(&found->lock);
+ found->total_bytes += total_bytes;
+ found->disk_total += total_bytes * factor;
+ found->bytes_used += bytes_used;
+ found->disk_used += bytes_used * factor;
+ found->full = 0;
+ spin_unlock(&found->lock);
+ *space_info = found;
+ return 0;
+ }
+ found = kzalloc(sizeof(*found), GFP_NOFS);
+ if (!found)
+ return -ENOMEM;
+
+ ret = percpu_counter_init(&found->total_bytes_pinned, 0, GFP_KERNEL);
+ if (ret) {
+ kfree(found);
+ return ret;
+ }
+
+ for (i = 0; i < BTRFS_NR_RAID_TYPES; i++)
+ INIT_LIST_HEAD(&found->block_groups[i]);
+ init_rwsem(&found->groups_sem);
+ spin_lock_init(&found->lock);
+ found->flags = flags & BTRFS_BLOCK_GROUP_TYPE_MASK;
+ found->total_bytes = total_bytes;
+ found->disk_total = total_bytes * factor;
+ found->bytes_used = bytes_used;
+ found->disk_used = bytes_used * factor;
+ found->bytes_pinned = 0;
+ found->bytes_reserved = 0;
+ found->bytes_readonly = 0;
+ found->bytes_may_use = 0;
+ found->full = 0;
+ found->force_alloc = CHUNK_ALLOC_NO_FORCE;
+ found->chunk_alloc = 0;
+ found->flush = 0;
+ init_waitqueue_head(&found->wait);
+ INIT_LIST_HEAD(&found->ro_bgs);
+
+ ret = kobject_init_and_add(&found->kobj, &space_info_ktype,
+ info->space_info_kobj, "%s",
+ alloc_name(found->flags));
+ if (ret) {
+ kfree(found);
+ return ret;
+ }
+
+ *space_info = found;
+ list_add_rcu(&found->list, &info->space_info);
+ if (flags & BTRFS_BLOCK_GROUP_DATA)
+ info->data_sinfo = found;
+
+ return ret;
+}
+
+static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
+{
+ u64 extra_flags = chunk_to_extended(flags) &
+ BTRFS_EXTENDED_PROFILE_MASK;
+
+ write_seqlock(&fs_info->profiles_lock);
+ if (flags & BTRFS_BLOCK_GROUP_DATA)
+ fs_info->avail_data_alloc_bits |= extra_flags;
+ if (flags & BTRFS_BLOCK_GROUP_METADATA)
+ fs_info->avail_metadata_alloc_bits |= extra_flags;
+ if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
+ fs_info->avail_system_alloc_bits |= extra_flags;
+ write_sequnlock(&fs_info->profiles_lock);
+}
+
+/*
+ * returns target flags in extended format or 0 if restripe for this
+ * chunk_type is not in progress
+ *
+ * should be called with either volume_mutex or balance_lock held
+ */
+static u64 get_restripe_target(struct btrfs_fs_info *fs_info, u64 flags)
+{
+ struct btrfs_balance_control *bctl = fs_info->balance_ctl;
+ u64 target = 0;
+
+ if (!bctl)
+ return 0;
+
+ if (flags & BTRFS_BLOCK_GROUP_DATA &&
+ bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) {
+ target = BTRFS_BLOCK_GROUP_DATA | bctl->data.target;
+ } else if (flags & BTRFS_BLOCK_GROUP_SYSTEM &&
+ bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) {
+ target = BTRFS_BLOCK_GROUP_SYSTEM | bctl->sys.target;
+ } else if (flags & BTRFS_BLOCK_GROUP_METADATA &&
+ bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) {
+ target = BTRFS_BLOCK_GROUP_METADATA | bctl->meta.target;
+ }
+
+ return target;
+}
+
+/*
+ * @flags: available profiles in extended format (see ctree.h)
+ *
+ * Returns reduced profile in chunk format. If profile changing is in
+ * progress (either running or paused) picks the target profile (if it's
+ * already available), otherwise falls back to plain reducing.
+ */
+static u64 btrfs_reduce_alloc_profile(struct btrfs_root *root, u64 flags)
+{
+ u64 num_devices = root->fs_info->fs_devices->rw_devices;
+ u64 target;
+ u64 tmp;
+
+ /*
+ * see if restripe for this chunk_type is in progress, if so
+ * try to reduce to the target profile
+ */
+ spin_lock(&root->fs_info->balance_lock);
+ target = get_restripe_target(root->fs_info, flags);
+ if (target) {
+ /* pick target profile only if it's already available */
+ if ((flags & target) & BTRFS_EXTENDED_PROFILE_MASK) {
+ spin_unlock(&root->fs_info->balance_lock);
+ return extended_to_chunk(target);
+ }
+ }
+ spin_unlock(&root->fs_info->balance_lock);
+
+ /* First, mask out the RAID levels which aren't possible */
+ if (num_devices == 1)
+ flags &= ~(BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID0 |
+ BTRFS_BLOCK_GROUP_RAID5);
+ if (num_devices < 3)
+ flags &= ~BTRFS_BLOCK_GROUP_RAID6;
+ if (num_devices < 4)
+ flags &= ~BTRFS_BLOCK_GROUP_RAID10;
+
+ tmp = flags & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID0 |
+ BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID5 |
+ BTRFS_BLOCK_GROUP_RAID6 | BTRFS_BLOCK_GROUP_RAID10);
+ flags &= ~tmp;
+
+ if (tmp & BTRFS_BLOCK_GROUP_RAID6)
+ tmp = BTRFS_BLOCK_GROUP_RAID6;
+ else if (tmp & BTRFS_BLOCK_GROUP_RAID5)
+ tmp = BTRFS_BLOCK_GROUP_RAID5;
+ else if (tmp & BTRFS_BLOCK_GROUP_RAID10)
+ tmp = BTRFS_BLOCK_GROUP_RAID10;
+ else if (tmp & BTRFS_BLOCK_GROUP_RAID1)
+ tmp = BTRFS_BLOCK_GROUP_RAID1;
+ else if (tmp & BTRFS_BLOCK_GROUP_RAID0)
+ tmp = BTRFS_BLOCK_GROUP_RAID0;
+
+ return extended_to_chunk(flags | tmp);
+}
+
+static u64 get_alloc_profile(struct btrfs_root *root, u64 orig_flags)
+{
+ unsigned seq;
+ u64 flags;
+
+ do {
+ flags = orig_flags;
+ seq = read_seqbegin(&root->fs_info->profiles_lock);
+
+ if (flags & BTRFS_BLOCK_GROUP_DATA)
+ flags |= root->fs_info->avail_data_alloc_bits;
+ else if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
+ flags |= root->fs_info->avail_system_alloc_bits;
+ else if (flags & BTRFS_BLOCK_GROUP_METADATA)
+ flags |= root->fs_info->avail_metadata_alloc_bits;
+ } while (read_seqretry(&root->fs_info->profiles_lock, seq));
+
+ return btrfs_reduce_alloc_profile(root, flags);
+}
+
+u64 btrfs_get_alloc_profile(struct btrfs_root *root, int data)
+{
+ u64 flags;
+ u64 ret;
+
+ if (data)
+ flags = BTRFS_BLOCK_GROUP_DATA;
+ else if (root == root->fs_info->chunk_root)
+ flags = BTRFS_BLOCK_GROUP_SYSTEM;
+ else
+ flags = BTRFS_BLOCK_GROUP_METADATA;
+
+ ret = get_alloc_profile(root, flags);
+ return ret;
+}
+
+/*
+ * This will check the space that the inode allocates from to make sure we have
+ * enough space for bytes.
+ */
+int btrfs_check_data_free_space(struct inode *inode, u64 bytes, u64 write_bytes)
+{
+ struct btrfs_space_info *data_sinfo;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_fs_info *fs_info = root->fs_info;
+ u64 used;
+ int ret = 0;
+ int need_commit = 2;
+ int have_pinned_space;
+
+ /* make sure bytes are sectorsize aligned */
+ bytes = ALIGN(bytes, root->sectorsize);
+
+ if (btrfs_is_free_space_inode(inode)) {
+ need_commit = 0;
+ ASSERT(current->journal_info);
+ }
+
+ data_sinfo = fs_info->data_sinfo;
+ if (!data_sinfo)
+ goto alloc;
+
+again:
+ /* make sure we have enough space to handle the data first */
+ spin_lock(&data_sinfo->lock);
+ used = data_sinfo->bytes_used + data_sinfo->bytes_reserved +
+ data_sinfo->bytes_pinned + data_sinfo->bytes_readonly +
+ data_sinfo->bytes_may_use;
+
+ if (used + bytes > data_sinfo->total_bytes) {
+ struct btrfs_trans_handle *trans;
+
+ /*
+ * if we don't have enough free bytes in this space then we need
+ * to alloc a new chunk.
+ */
+ if (!data_sinfo->full) {
+ u64 alloc_target;
+
+ data_sinfo->force_alloc = CHUNK_ALLOC_FORCE;
+ spin_unlock(&data_sinfo->lock);
+alloc:
+ alloc_target = btrfs_get_alloc_profile(root, 1);
+ /*
+ * It is ugly that we don't call nolock join
+ * transaction for the free space inode case here.
+ * But it is safe because we only do the data space
+ * reservation for the free space cache in the
+ * transaction context, the common join transaction
+ * just increase the counter of the current transaction
+ * handler, doesn't try to acquire the trans_lock of
+ * the fs.
+ */
+ trans = btrfs_join_transaction(root);
+ if (IS_ERR(trans))
+ return PTR_ERR(trans);
+
+ ret = do_chunk_alloc(trans, root->fs_info->extent_root,
+ alloc_target,
+ CHUNK_ALLOC_NO_FORCE);
+ btrfs_end_transaction(trans, root);
+ if (ret < 0) {
+ if (ret != -ENOSPC)
+ return ret;
+ else {
+ have_pinned_space = 1;
+ goto commit_trans;
+ }
+ }
+
+ if (!data_sinfo)
+ data_sinfo = fs_info->data_sinfo;
+
+ goto again;
+ }
+
+ /*
+ * If we don't have enough pinned space to deal with this
+ * allocation, and no removed chunk in current transaction,
+ * don't bother committing the transaction.
+ */
+ have_pinned_space = percpu_counter_compare(
+ &data_sinfo->total_bytes_pinned,
+ used + bytes - data_sinfo->total_bytes);
+ spin_unlock(&data_sinfo->lock);
+
+ /* commit the current transaction and try again */
+commit_trans:
+ if (need_commit &&
+ !atomic_read(&root->fs_info->open_ioctl_trans)) {
+ need_commit--;
+
+ trans = btrfs_join_transaction(root);
+ if (IS_ERR(trans))
+ return PTR_ERR(trans);
+ if (have_pinned_space >= 0 ||
+ trans->transaction->have_free_bgs ||
+ need_commit > 0) {
+ ret = btrfs_commit_transaction(trans, root);
+ if (ret)
+ return ret;
+ /*
+ * make sure that all running delayed iput are
+ * done
+ */
+ down_write(&root->fs_info->delayed_iput_sem);
+ up_write(&root->fs_info->delayed_iput_sem);
+ goto again;
+ } else {
+ btrfs_end_transaction(trans, root);
+ }
+ }
+
+ trace_btrfs_space_reservation(root->fs_info,
+ "space_info:enospc",
+ data_sinfo->flags, bytes, 1);
+ return -ENOSPC;
+ }
+ ret = btrfs_qgroup_reserve(root, write_bytes);
+ if (ret)
+ goto out;
+ data_sinfo->bytes_may_use += bytes;
+ trace_btrfs_space_reservation(root->fs_info, "space_info",
+ data_sinfo->flags, bytes, 1);
+out:
+ spin_unlock(&data_sinfo->lock);
+
+ return ret;
+}
+
+/*
+ * Called if we need to clear a data reservation for this inode.
+ */
+void btrfs_free_reserved_data_space(struct inode *inode, u64 bytes)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_space_info *data_sinfo;
+
+ /* make sure bytes are sectorsize aligned */
+ bytes = ALIGN(bytes, root->sectorsize);
+
+ data_sinfo = root->fs_info->data_sinfo;
+ spin_lock(&data_sinfo->lock);
+ WARN_ON(data_sinfo->bytes_may_use < bytes);
+ data_sinfo->bytes_may_use -= bytes;
+ trace_btrfs_space_reservation(root->fs_info, "space_info",
+ data_sinfo->flags, bytes, 0);
+ spin_unlock(&data_sinfo->lock);
+}
+
+static void force_metadata_allocation(struct btrfs_fs_info *info)
+{
+ struct list_head *head = &info->space_info;
+ struct btrfs_space_info *found;
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(found, head, list) {
+ if (found->flags & BTRFS_BLOCK_GROUP_METADATA)
+ found->force_alloc = CHUNK_ALLOC_FORCE;
+ }
+ rcu_read_unlock();
+}
+
+static inline u64 calc_global_rsv_need_space(struct btrfs_block_rsv *global)
+{
+ return (global->size << 1);
+}
+
+static int should_alloc_chunk(struct btrfs_root *root,
+ struct btrfs_space_info *sinfo, int force)
+{
+ struct btrfs_block_rsv *global_rsv = &root->fs_info->global_block_rsv;
+ u64 num_bytes = sinfo->total_bytes - sinfo->bytes_readonly;
+ u64 num_allocated = sinfo->bytes_used + sinfo->bytes_reserved;
+ u64 thresh;
+
+ if (force == CHUNK_ALLOC_FORCE)
+ return 1;
+
+ /*
+ * We need to take into account the global rsv because for all intents
+ * and purposes it's used space. Don't worry about locking the
+ * global_rsv, it doesn't change except when the transaction commits.
+ */
+ if (sinfo->flags & BTRFS_BLOCK_GROUP_METADATA)
+ num_allocated += calc_global_rsv_need_space(global_rsv);
+
+ /*
+ * in limited mode, we want to have some free space up to
+ * about 1% of the FS size.
+ */
+ if (force == CHUNK_ALLOC_LIMITED) {
+ thresh = btrfs_super_total_bytes(root->fs_info->super_copy);
+ thresh = max_t(u64, 64 * 1024 * 1024,
+ div_factor_fine(thresh, 1));
+
+ if (num_bytes - num_allocated < thresh)
+ return 1;
+ }
+
+ if (num_allocated + 2 * 1024 * 1024 < div_factor(num_bytes, 8))
+ return 0;
+ return 1;
+}
+
+static u64 get_system_chunk_thresh(struct btrfs_root *root, u64 type)
+{
+ u64 num_dev;
+
+ if (type & (BTRFS_BLOCK_GROUP_RAID10 |
+ BTRFS_BLOCK_GROUP_RAID0 |
+ BTRFS_BLOCK_GROUP_RAID5 |
+ BTRFS_BLOCK_GROUP_RAID6))
+ num_dev = root->fs_info->fs_devices->rw_devices;
+ else if (type & BTRFS_BLOCK_GROUP_RAID1)
+ num_dev = 2;
+ else
+ num_dev = 1; /* DUP or single */
+
+ /* metadata for updaing devices and chunk tree */
+ return btrfs_calc_trans_metadata_size(root, num_dev + 1);
+}
+
+static void check_system_chunk(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, u64 type)
+{
+ struct btrfs_space_info *info;
+ u64 left;
+ u64 thresh;
+
+ info = __find_space_info(root->fs_info, BTRFS_BLOCK_GROUP_SYSTEM);
+ spin_lock(&info->lock);
+ left = info->total_bytes - info->bytes_used - info->bytes_pinned -
+ info->bytes_reserved - info->bytes_readonly;
+ spin_unlock(&info->lock);
+
+ thresh = get_system_chunk_thresh(root, type);
+ if (left < thresh && btrfs_test_opt(root, ENOSPC_DEBUG)) {
+ btrfs_info(root->fs_info, "left=%llu, need=%llu, flags=%llu",
+ left, thresh, type);
+ dump_space_info(info, 0, 0);
+ }
+
+ if (left < thresh) {
+ u64 flags;
+
+ flags = btrfs_get_alloc_profile(root->fs_info->chunk_root, 0);
+ btrfs_alloc_chunk(trans, root, flags);
+ }
+}
+
+static int do_chunk_alloc(struct btrfs_trans_handle *trans,
+ struct btrfs_root *extent_root, u64 flags, int force)
+{
+ struct btrfs_space_info *space_info;
+ struct btrfs_fs_info *fs_info = extent_root->fs_info;
+ int wait_for_alloc = 0;
+ int ret = 0;
+
+ /* Don't re-enter if we're already allocating a chunk */
+ if (trans->allocating_chunk)
+ return -ENOSPC;
+
+ space_info = __find_space_info(extent_root->fs_info, flags);
+ if (!space_info) {
+ ret = update_space_info(extent_root->fs_info, flags,
+ 0, 0, &space_info);
+ BUG_ON(ret); /* -ENOMEM */
+ }
+ BUG_ON(!space_info); /* Logic error */
+
+again:
+ spin_lock(&space_info->lock);
+ if (force < space_info->force_alloc)
+ force = space_info->force_alloc;
+ if (space_info->full) {
+ if (should_alloc_chunk(extent_root, space_info, force))
+ ret = -ENOSPC;
+ else
+ ret = 0;
+ spin_unlock(&space_info->lock);
+ return ret;
+ }
+
+ if (!should_alloc_chunk(extent_root, space_info, force)) {
+ spin_unlock(&space_info->lock);
+ return 0;
+ } else if (space_info->chunk_alloc) {
+ wait_for_alloc = 1;
+ } else {
+ space_info->chunk_alloc = 1;
+ }
+
+ spin_unlock(&space_info->lock);
+
+ mutex_lock(&fs_info->chunk_mutex);
+
+ /*
+ * The chunk_mutex is held throughout the entirety of a chunk
+ * allocation, so once we've acquired the chunk_mutex we know that the
+ * other guy is done and we need to recheck and see if we should
+ * allocate.
+ */
+ if (wait_for_alloc) {
+ mutex_unlock(&fs_info->chunk_mutex);
+ wait_for_alloc = 0;
+ goto again;
+ }
+
+ trans->allocating_chunk = true;
+
+ /*
+ * If we have mixed data/metadata chunks we want to make sure we keep
+ * allocating mixed chunks instead of individual chunks.
+ */
+ if (btrfs_mixed_space_info(space_info))
+ flags |= (BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA);
+
+ /*
+ * if we're doing a data chunk, go ahead and make sure that
+ * we keep a reasonable number of metadata chunks allocated in the
+ * FS as well.
+ */
+ if (flags & BTRFS_BLOCK_GROUP_DATA && fs_info->metadata_ratio) {
+ fs_info->data_chunk_allocations++;
+ if (!(fs_info->data_chunk_allocations %
+ fs_info->metadata_ratio))
+ force_metadata_allocation(fs_info);
+ }
+
+ /*
+ * Check if we have enough space in SYSTEM chunk because we may need
+ * to update devices.
+ */
+ check_system_chunk(trans, extent_root, flags);
+
+ ret = btrfs_alloc_chunk(trans, extent_root, flags);
+ trans->allocating_chunk = false;
+
+ spin_lock(&space_info->lock);
+ if (ret < 0 && ret != -ENOSPC)
+ goto out;
+ if (ret)
+ space_info->full = 1;
+ else
+ ret = 1;
+
+ space_info->force_alloc = CHUNK_ALLOC_NO_FORCE;
+out:
+ space_info->chunk_alloc = 0;
+ spin_unlock(&space_info->lock);
+ mutex_unlock(&fs_info->chunk_mutex);
+ return ret;
+}
+
+static int can_overcommit(struct btrfs_root *root,
+ struct btrfs_space_info *space_info, u64 bytes,
+ enum btrfs_reserve_flush_enum flush)
+{
+ struct btrfs_block_rsv *global_rsv = &root->fs_info->global_block_rsv;
+ u64 profile = btrfs_get_alloc_profile(root, 0);
+ u64 space_size;
+ u64 avail;
+ u64 used;
+
+ used = space_info->bytes_used + space_info->bytes_reserved +
+ space_info->bytes_pinned + space_info->bytes_readonly;
+
+ /*
+ * We only want to allow over committing if we have lots of actual space
+ * free, but if we don't have enough space to handle the global reserve
+ * space then we could end up having a real enospc problem when trying
+ * to allocate a chunk or some other such important allocation.
+ */
+ spin_lock(&global_rsv->lock);
+ space_size = calc_global_rsv_need_space(global_rsv);
+ spin_unlock(&global_rsv->lock);
+ if (used + space_size >= space_info->total_bytes)
+ return 0;
+
+ used += space_info->bytes_may_use;
+
+ spin_lock(&root->fs_info->free_chunk_lock);
+ avail = root->fs_info->free_chunk_space;
+ spin_unlock(&root->fs_info->free_chunk_lock);
+
+ /*
+ * If we have dup, raid1 or raid10 then only half of the free
+ * space is actually useable. For raid56, the space info used
+ * doesn't include the parity drive, so we don't have to
+ * change the math
+ */
+ if (profile & (BTRFS_BLOCK_GROUP_DUP |
+ BTRFS_BLOCK_GROUP_RAID1 |
+ BTRFS_BLOCK_GROUP_RAID10))
+ avail >>= 1;
+
+ /*
+ * If we aren't flushing all things, let us overcommit up to
+ * 1/2th of the space. If we can flush, don't let us overcommit
+ * too much, let it overcommit up to 1/8 of the space.
+ */
+ if (flush == BTRFS_RESERVE_FLUSH_ALL)
+ avail >>= 3;
+ else
+ avail >>= 1;
+
+ if (used + bytes < space_info->total_bytes + avail)
+ return 1;
+ return 0;
+}
+
+static void btrfs_writeback_inodes_sb_nr(struct btrfs_root *root,
+ unsigned long nr_pages, int nr_items)
+{
+ struct super_block *sb = root->fs_info->sb;
+
+ if (down_read_trylock(&sb->s_umount)) {
+ writeback_inodes_sb_nr(sb, nr_pages, WB_REASON_FS_FREE_SPACE);
+ up_read(&sb->s_umount);
+ } else {
+ /*
+ * We needn't worry the filesystem going from r/w to r/o though
+ * we don't acquire ->s_umount mutex, because the filesystem
+ * should guarantee the delalloc inodes list be empty after
+ * the filesystem is readonly(all dirty pages are written to
+ * the disk).
+ */
+ btrfs_start_delalloc_roots(root->fs_info, 0, nr_items);
+ if (!current->journal_info)
+ btrfs_wait_ordered_roots(root->fs_info, nr_items);
+ }
+}
+
+static inline int calc_reclaim_items_nr(struct btrfs_root *root, u64 to_reclaim)
+{
+ u64 bytes;
+ int nr;
+
+ bytes = btrfs_calc_trans_metadata_size(root, 1);
+ nr = (int)div64_u64(to_reclaim, bytes);
+ if (!nr)
+ nr = 1;
+ return nr;
+}
+
+#define EXTENT_SIZE_PER_ITEM (256 * 1024)
+
+/*
+ * shrink metadata reservation for delalloc
+ */
+static void shrink_delalloc(struct btrfs_root *root, u64 to_reclaim, u64 orig,
+ bool wait_ordered)
+{
+ struct btrfs_block_rsv *block_rsv;
+ struct btrfs_space_info *space_info;
+ struct btrfs_trans_handle *trans;
+ u64 delalloc_bytes;
+ u64 max_reclaim;
+ long time_left;
+ unsigned long nr_pages;
+ int loops;
+ int items;
+ enum btrfs_reserve_flush_enum flush;
+
+ /* Calc the number of the pages we need flush for space reservation */
+ items = calc_reclaim_items_nr(root, to_reclaim);
+ to_reclaim = items * EXTENT_SIZE_PER_ITEM;
+
+ trans = (struct btrfs_trans_handle *)current->journal_info;
+ block_rsv = &root->fs_info->delalloc_block_rsv;
+ space_info = block_rsv->space_info;
+
+ delalloc_bytes = percpu_counter_sum_positive(
+ &root->fs_info->delalloc_bytes);
+ if (delalloc_bytes == 0) {
+ if (trans)
+ return;
+ if (wait_ordered)
+ btrfs_wait_ordered_roots(root->fs_info, items);
+ return;
+ }
+
+ loops = 0;
+ while (delalloc_bytes && loops < 3) {
+ max_reclaim = min(delalloc_bytes, to_reclaim);
+ nr_pages = max_reclaim >> PAGE_CACHE_SHIFT;
+ btrfs_writeback_inodes_sb_nr(root, nr_pages, items);
+ /*
+ * We need to wait for the async pages to actually start before
+ * we do anything.
+ */
+ max_reclaim = atomic_read(&root->fs_info->async_delalloc_pages);
+ if (!max_reclaim)
+ goto skip_async;
+
+ if (max_reclaim <= nr_pages)
+ max_reclaim = 0;
+ else
+ max_reclaim -= nr_pages;
+
+ wait_event(root->fs_info->async_submit_wait,
+ atomic_read(&root->fs_info->async_delalloc_pages) <=
+ (int)max_reclaim);
+skip_async:
+ if (!trans)
+ flush = BTRFS_RESERVE_FLUSH_ALL;
+ else
+ flush = BTRFS_RESERVE_NO_FLUSH;
+ spin_lock(&space_info->lock);
+ if (can_overcommit(root, space_info, orig, flush)) {
+ spin_unlock(&space_info->lock);
+ break;
+ }
+ spin_unlock(&space_info->lock);
+
+ loops++;
+ if (wait_ordered && !trans) {
+ btrfs_wait_ordered_roots(root->fs_info, items);
+ } else {
+ time_left = schedule_timeout_killable(1);
+ if (time_left)
+ break;
+ }
+ delalloc_bytes = percpu_counter_sum_positive(
+ &root->fs_info->delalloc_bytes);
+ }
+}
+
+/**
+ * maybe_commit_transaction - possibly commit the transaction if its ok to
+ * @root - the root we're allocating for
+ * @bytes - the number of bytes we want to reserve
+ * @force - force the commit
+ *
+ * This will check to make sure that committing the transaction will actually
+ * get us somewhere and then commit the transaction if it does. Otherwise it
+ * will return -ENOSPC.
+ */
+static int may_commit_transaction(struct btrfs_root *root,
+ struct btrfs_space_info *space_info,
+ u64 bytes, int force)
+{
+ struct btrfs_block_rsv *delayed_rsv = &root->fs_info->delayed_block_rsv;
+ struct btrfs_trans_handle *trans;
+
+ trans = (struct btrfs_trans_handle *)current->journal_info;
+ if (trans)
+ return -EAGAIN;
+
+ if (force)
+ goto commit;
+
+ /* See if there is enough pinned space to make this reservation */
+ if (percpu_counter_compare(&space_info->total_bytes_pinned,
+ bytes) >= 0)
+ goto commit;
+
+ /*
+ * See if there is some space in the delayed insertion reservation for
+ * this reservation.
+ */
+ if (space_info != delayed_rsv->space_info)
+ return -ENOSPC;
+
+ spin_lock(&delayed_rsv->lock);
+ if (percpu_counter_compare(&space_info->total_bytes_pinned,
+ bytes - delayed_rsv->size) >= 0) {
+ spin_unlock(&delayed_rsv->lock);
+ return -ENOSPC;
+ }
+ spin_unlock(&delayed_rsv->lock);
+
+commit:
+ trans = btrfs_join_transaction(root);
+ if (IS_ERR(trans))
+ return -ENOSPC;
+
+ return btrfs_commit_transaction(trans, root);
+}
+
+enum flush_state {
+ FLUSH_DELAYED_ITEMS_NR = 1,
+ FLUSH_DELAYED_ITEMS = 2,
+ FLUSH_DELALLOC = 3,
+ FLUSH_DELALLOC_WAIT = 4,
+ ALLOC_CHUNK = 5,
+ COMMIT_TRANS = 6,
+};
+
+static int flush_space(struct btrfs_root *root,
+ struct btrfs_space_info *space_info, u64 num_bytes,
+ u64 orig_bytes, int state)
+{
+ struct btrfs_trans_handle *trans;
+ int nr;
+ int ret = 0;
+
+ switch (state) {
+ case FLUSH_DELAYED_ITEMS_NR:
+ case FLUSH_DELAYED_ITEMS:
+ if (state == FLUSH_DELAYED_ITEMS_NR)
+ nr = calc_reclaim_items_nr(root, num_bytes) * 2;
+ else
+ nr = -1;
+
+ trans = btrfs_join_transaction(root);
+ if (IS_ERR(trans)) {
+ ret = PTR_ERR(trans);
+ break;
+ }
+ ret = btrfs_run_delayed_items_nr(trans, root, nr);
+ btrfs_end_transaction(trans, root);
+ break;
+ case FLUSH_DELALLOC:
+ case FLUSH_DELALLOC_WAIT:
+ shrink_delalloc(root, num_bytes * 2, orig_bytes,
+ state == FLUSH_DELALLOC_WAIT);
+ break;
+ case ALLOC_CHUNK:
+ trans = btrfs_join_transaction(root);
+ if (IS_ERR(trans)) {
+ ret = PTR_ERR(trans);
+ break;
+ }
+ ret = do_chunk_alloc(trans, root->fs_info->extent_root,
+ btrfs_get_alloc_profile(root, 0),
+ CHUNK_ALLOC_NO_FORCE);
+ btrfs_end_transaction(trans, root);
+ if (ret == -ENOSPC)
+ ret = 0;
+ break;
+ case COMMIT_TRANS:
+ ret = may_commit_transaction(root, space_info, orig_bytes, 0);
+ break;
+ default:
+ ret = -ENOSPC;
+ break;
+ }
+
+ return ret;
+}
+
+static inline u64
+btrfs_calc_reclaim_metadata_size(struct btrfs_root *root,
+ struct btrfs_space_info *space_info)
+{
+ u64 used;
+ u64 expected;
+ u64 to_reclaim;
+
+ to_reclaim = min_t(u64, num_online_cpus() * 1024 * 1024,
+ 16 * 1024 * 1024);
+ spin_lock(&space_info->lock);
+ if (can_overcommit(root, space_info, to_reclaim,
+ BTRFS_RESERVE_FLUSH_ALL)) {
+ to_reclaim = 0;
+ goto out;
+ }
+
+ used = space_info->bytes_used + space_info->bytes_reserved +
+ space_info->bytes_pinned + space_info->bytes_readonly +
+ space_info->bytes_may_use;
+ if (can_overcommit(root, space_info, 1024 * 1024,
+ BTRFS_RESERVE_FLUSH_ALL))
+ expected = div_factor_fine(space_info->total_bytes, 95);
+ else
+ expected = div_factor_fine(space_info->total_bytes, 90);
+
+ if (used > expected)
+ to_reclaim = used - expected;
+ else
+ to_reclaim = 0;
+ to_reclaim = min(to_reclaim, space_info->bytes_may_use +
+ space_info->bytes_reserved);
+out:
+ spin_unlock(&space_info->lock);
+
+ return to_reclaim;
+}
+
+static inline int need_do_async_reclaim(struct btrfs_space_info *space_info,
+ struct btrfs_fs_info *fs_info, u64 used)
+{
+ u64 thresh = div_factor_fine(space_info->total_bytes, 98);
+
+ /* If we're just plain full then async reclaim just slows us down. */
+ if (space_info->bytes_used >= thresh)
+ return 0;
+
+ return (used >= thresh && !btrfs_fs_closing(fs_info) &&
+ !test_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state));
+}
+
+static int btrfs_need_do_async_reclaim(struct btrfs_space_info *space_info,
+ struct btrfs_fs_info *fs_info,
+ int flush_state)
+{
+ u64 used;
+
+ spin_lock(&space_info->lock);
+ /*
+ * We run out of space and have not got any free space via flush_space,
+ * so don't bother doing async reclaim.
+ */
+ if (flush_state > COMMIT_TRANS && space_info->full) {
+ spin_unlock(&space_info->lock);
+ return 0;
+ }
+
+ used = space_info->bytes_used + space_info->bytes_reserved +
+ space_info->bytes_pinned + space_info->bytes_readonly +
+ space_info->bytes_may_use;
+ if (need_do_async_reclaim(space_info, fs_info, used)) {
+ spin_unlock(&space_info->lock);
+ return 1;
+ }
+ spin_unlock(&space_info->lock);
+
+ return 0;
+}
+
+static void btrfs_async_reclaim_metadata_space(struct work_struct *work)
+{
+ struct btrfs_fs_info *fs_info;
+ struct btrfs_space_info *space_info;
+ u64 to_reclaim;
+ int flush_state;
+
+ fs_info = container_of(work, struct btrfs_fs_info, async_reclaim_work);
+ space_info = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA);
+
+ to_reclaim = btrfs_calc_reclaim_metadata_size(fs_info->fs_root,
+ space_info);
+ if (!to_reclaim)
+ return;
+
+ flush_state = FLUSH_DELAYED_ITEMS_NR;
+ do {
+ flush_space(fs_info->fs_root, space_info, to_reclaim,
+ to_reclaim, flush_state);
+ flush_state++;
+ if (!btrfs_need_do_async_reclaim(space_info, fs_info,
+ flush_state))
+ return;
+ } while (flush_state < COMMIT_TRANS);
+}
+
+void btrfs_init_async_reclaim_work(struct work_struct *work)
+{
+ INIT_WORK(work, btrfs_async_reclaim_metadata_space);
+}
+
+/**
+ * reserve_metadata_bytes - try to reserve bytes from the block_rsv's space
+ * @root - the root we're allocating for
+ * @block_rsv - the block_rsv we're allocating for
+ * @orig_bytes - the number of bytes we want
+ * @flush - whether or not we can flush to make our reservation
+ *
+ * This will reserve orgi_bytes number of bytes from the space info associated
+ * with the block_rsv. If there is not enough space it will make an attempt to
+ * flush out space to make room. It will do this by flushing delalloc if
+ * possible or committing the transaction. If flush is 0 then no attempts to
+ * regain reservations will be made and this will fail if there is not enough
+ * space already.
+ */
+static int reserve_metadata_bytes(struct btrfs_root *root,
+ struct btrfs_block_rsv *block_rsv,
+ u64 orig_bytes,
+ enum btrfs_reserve_flush_enum flush)
+{
+ struct btrfs_space_info *space_info = block_rsv->space_info;
+ u64 used;
+ u64 num_bytes = orig_bytes;
+ int flush_state = FLUSH_DELAYED_ITEMS_NR;
+ int ret = 0;
+ bool flushing = false;
+
+again:
+ ret = 0;
+ spin_lock(&space_info->lock);
+ /*
+ * We only want to wait if somebody other than us is flushing and we
+ * are actually allowed to flush all things.
+ */
+ while (flush == BTRFS_RESERVE_FLUSH_ALL && !flushing &&
+ space_info->flush) {
+ spin_unlock(&space_info->lock);
+ /*
+ * If we have a trans handle we can't wait because the flusher
+ * may have to commit the transaction, which would mean we would
+ * deadlock since we are waiting for the flusher to finish, but
+ * hold the current transaction open.
+ */
+ if (current->journal_info)
+ return -EAGAIN;
+ ret = wait_event_killable(space_info->wait, !space_info->flush);
+ /* Must have been killed, return */
+ if (ret)
+ return -EINTR;
+
+ spin_lock(&space_info->lock);
+ }
+
+ ret = -ENOSPC;
+ used = space_info->bytes_used + space_info->bytes_reserved +
+ space_info->bytes_pinned + space_info->bytes_readonly +
+ space_info->bytes_may_use;
+
+ /*
+ * The idea here is that we've not already over-reserved the block group
+ * then we can go ahead and save our reservation first and then start
+ * flushing if we need to. Otherwise if we've already overcommitted
+ * lets start flushing stuff first and then come back and try to make
+ * our reservation.
+ */
+ if (used <= space_info->total_bytes) {
+ if (used + orig_bytes <= space_info->total_bytes) {
+ space_info->bytes_may_use += orig_bytes;
+ trace_btrfs_space_reservation(root->fs_info,
+ "space_info", space_info->flags, orig_bytes, 1);
+ ret = 0;
+ } else {
+ /*
+ * Ok set num_bytes to orig_bytes since we aren't
+ * overocmmitted, this way we only try and reclaim what
+ * we need.
+ */
+ num_bytes = orig_bytes;
+ }
+ } else {
+ /*
+ * Ok we're over committed, set num_bytes to the overcommitted
+ * amount plus the amount of bytes that we need for this
+ * reservation.
+ */
+ num_bytes = used - space_info->total_bytes +
+ (orig_bytes * 2);
+ }
+
+ if (ret && can_overcommit(root, space_info, orig_bytes, flush)) {
+ space_info->bytes_may_use += orig_bytes;
+ trace_btrfs_space_reservation(root->fs_info, "space_info",
+ space_info->flags, orig_bytes,
+ 1);
+ ret = 0;
+ }
+
+ /*
+ * Couldn't make our reservation, save our place so while we're trying
+ * to reclaim space we can actually use it instead of somebody else
+ * stealing it from us.
+ *
+ * We make the other tasks wait for the flush only when we can flush
+ * all things.
+ */
+ if (ret && flush != BTRFS_RESERVE_NO_FLUSH) {
+ flushing = true;
+ space_info->flush = 1;
+ } else if (!ret && space_info->flags & BTRFS_BLOCK_GROUP_METADATA) {
+ used += orig_bytes;
+ /*
+ * We will do the space reservation dance during log replay,
+ * which means we won't have fs_info->fs_root set, so don't do
+ * the async reclaim as we will panic.
+ */
+ if (!root->fs_info->log_root_recovering &&
+ need_do_async_reclaim(space_info, root->fs_info, used) &&
+ !work_busy(&root->fs_info->async_reclaim_work))
+ queue_work(system_unbound_wq,
+ &root->fs_info->async_reclaim_work);
+ }
+ spin_unlock(&space_info->lock);
+
+ if (!ret || flush == BTRFS_RESERVE_NO_FLUSH)
+ goto out;
+
+ ret = flush_space(root, space_info, num_bytes, orig_bytes,
+ flush_state);
+ flush_state++;
+
+ /*
+ * If we are FLUSH_LIMIT, we can not flush delalloc, or the deadlock
+ * would happen. So skip delalloc flush.
+ */
+ if (flush == BTRFS_RESERVE_FLUSH_LIMIT &&
+ (flush_state == FLUSH_DELALLOC ||
+ flush_state == FLUSH_DELALLOC_WAIT))
+ flush_state = ALLOC_CHUNK;
+
+ if (!ret)
+ goto again;
+ else if (flush == BTRFS_RESERVE_FLUSH_LIMIT &&
+ flush_state < COMMIT_TRANS)
+ goto again;
+ else if (flush == BTRFS_RESERVE_FLUSH_ALL &&
+ flush_state <= COMMIT_TRANS)
+ goto again;
+
+out:
+ if (ret == -ENOSPC &&
+ unlikely(root->orphan_cleanup_state == ORPHAN_CLEANUP_STARTED)) {
+ struct btrfs_block_rsv *global_rsv =
+ &root->fs_info->global_block_rsv;
+
+ if (block_rsv != global_rsv &&
+ !block_rsv_use_bytes(global_rsv, orig_bytes))
+ ret = 0;
+ }
+ if (ret == -ENOSPC)
+ trace_btrfs_space_reservation(root->fs_info,
+ "space_info:enospc",
+ space_info->flags, orig_bytes, 1);
+ if (flushing) {
+ spin_lock(&space_info->lock);
+ space_info->flush = 0;
+ wake_up_all(&space_info->wait);
+ spin_unlock(&space_info->lock);
+ }
+ return ret;
+}
+
+static struct btrfs_block_rsv *get_block_rsv(
+ const struct btrfs_trans_handle *trans,
+ const struct btrfs_root *root)
+{
+ struct btrfs_block_rsv *block_rsv = NULL;
+
+ if (test_bit(BTRFS_ROOT_REF_COWS, &root->state))
+ block_rsv = trans->block_rsv;
+
+ if (root == root->fs_info->csum_root && trans->adding_csums)
+ block_rsv = trans->block_rsv;
+
+ if (root == root->fs_info->uuid_root)
+ block_rsv = trans->block_rsv;
+
+ if (!block_rsv)
+ block_rsv = root->block_rsv;
+
+ if (!block_rsv)
+ block_rsv = &root->fs_info->empty_block_rsv;
+
+ return block_rsv;
+}
+
+static int block_rsv_use_bytes(struct btrfs_block_rsv *block_rsv,
+ u64 num_bytes)
+{
+ int ret = -ENOSPC;
+ spin_lock(&block_rsv->lock);
+ if (block_rsv->reserved >= num_bytes) {
+ block_rsv->reserved -= num_bytes;
+ if (block_rsv->reserved < block_rsv->size)
+ block_rsv->full = 0;
+ ret = 0;
+ }
+ spin_unlock(&block_rsv->lock);
+ return ret;
+}
+
+static void block_rsv_add_bytes(struct btrfs_block_rsv *block_rsv,
+ u64 num_bytes, int update_size)
+{
+ spin_lock(&block_rsv->lock);
+ block_rsv->reserved += num_bytes;
+ if (update_size)
+ block_rsv->size += num_bytes;
+ else if (block_rsv->reserved >= block_rsv->size)
+ block_rsv->full = 1;
+ spin_unlock(&block_rsv->lock);
+}
+
+int btrfs_cond_migrate_bytes(struct btrfs_fs_info *fs_info,
+ struct btrfs_block_rsv *dest, u64 num_bytes,
+ int min_factor)
+{
+ struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
+ u64 min_bytes;
+
+ if (global_rsv->space_info != dest->space_info)
+ return -ENOSPC;
+
+ spin_lock(&global_rsv->lock);
+ min_bytes = div_factor(global_rsv->size, min_factor);
+ if (global_rsv->reserved < min_bytes + num_bytes) {
+ spin_unlock(&global_rsv->lock);
+ return -ENOSPC;
+ }
+ global_rsv->reserved -= num_bytes;
+ if (global_rsv->reserved < global_rsv->size)
+ global_rsv->full = 0;
+ spin_unlock(&global_rsv->lock);
+
+ block_rsv_add_bytes(dest, num_bytes, 1);
+ return 0;
+}
+
+static void block_rsv_release_bytes(struct btrfs_fs_info *fs_info,
+ struct btrfs_block_rsv *block_rsv,
+ struct btrfs_block_rsv *dest, u64 num_bytes)
+{
+ struct btrfs_space_info *space_info = block_rsv->space_info;
+
+ spin_lock(&block_rsv->lock);
+ if (num_bytes == (u64)-1)
+ num_bytes = block_rsv->size;
+ block_rsv->size -= num_bytes;
+ if (block_rsv->reserved >= block_rsv->size) {
+ num_bytes = block_rsv->reserved - block_rsv->size;
+ block_rsv->reserved = block_rsv->size;
+ block_rsv->full = 1;
+ } else {
+ num_bytes = 0;
+ }
+ spin_unlock(&block_rsv->lock);
+
+ if (num_bytes > 0) {
+ if (dest) {
+ spin_lock(&dest->lock);
+ if (!dest->full) {
+ u64 bytes_to_add;
+
+ bytes_to_add = dest->size - dest->reserved;
+ bytes_to_add = min(num_bytes, bytes_to_add);
+ dest->reserved += bytes_to_add;
+ if (dest->reserved >= dest->size)
+ dest->full = 1;
+ num_bytes -= bytes_to_add;
+ }
+ spin_unlock(&dest->lock);
+ }
+ if (num_bytes) {
+ spin_lock(&space_info->lock);
+ space_info->bytes_may_use -= num_bytes;
+ trace_btrfs_space_reservation(fs_info, "space_info",
+ space_info->flags, num_bytes, 0);
+ spin_unlock(&space_info->lock);
+ }
+ }
+}
+
+static int block_rsv_migrate_bytes(struct btrfs_block_rsv *src,
+ struct btrfs_block_rsv *dst, u64 num_bytes)
+{
+ int ret;
+
+ ret = block_rsv_use_bytes(src, num_bytes);
+ if (ret)
+ return ret;
+
+ block_rsv_add_bytes(dst, num_bytes, 1);
+ return 0;
+}
+
+void btrfs_init_block_rsv(struct btrfs_block_rsv *rsv, unsigned short type)
+{
+ memset(rsv, 0, sizeof(*rsv));
+ spin_lock_init(&rsv->lock);
+ rsv->type = type;
+}
+
+struct btrfs_block_rsv *btrfs_alloc_block_rsv(struct btrfs_root *root,
+ unsigned short type)
+{
+ struct btrfs_block_rsv *block_rsv;
+ struct btrfs_fs_info *fs_info = root->fs_info;
+
+ block_rsv = kmalloc(sizeof(*block_rsv), GFP_NOFS);
+ if (!block_rsv)
+ return NULL;
+
+ btrfs_init_block_rsv(block_rsv, type);
+ block_rsv->space_info = __find_space_info(fs_info,
+ BTRFS_BLOCK_GROUP_METADATA);
+ return block_rsv;
+}
+
+void btrfs_free_block_rsv(struct btrfs_root *root,
+ struct btrfs_block_rsv *rsv)
+{
+ if (!rsv)
+ return;
+ btrfs_block_rsv_release(root, rsv, (u64)-1);
+ kfree(rsv);
+}
+
+void __btrfs_free_block_rsv(struct btrfs_block_rsv *rsv)
+{
+ kfree(rsv);
+}
+
+int btrfs_block_rsv_add(struct btrfs_root *root,
+ struct btrfs_block_rsv *block_rsv, u64 num_bytes,
+ enum btrfs_reserve_flush_enum flush)
+{
+ int ret;
+
+ if (num_bytes == 0)
+ return 0;
+
+ ret = reserve_metadata_bytes(root, block_rsv, num_bytes, flush);
+ if (!ret) {
+ block_rsv_add_bytes(block_rsv, num_bytes, 1);
+ return 0;
+ }
+
+ return ret;
+}
+
+int btrfs_block_rsv_check(struct btrfs_root *root,
+ struct btrfs_block_rsv *block_rsv, int min_factor)
+{
+ u64 num_bytes = 0;
+ int ret = -ENOSPC;
+
+ if (!block_rsv)
+ return 0;
+
+ spin_lock(&block_rsv->lock);
+ num_bytes = div_factor(block_rsv->size, min_factor);
+ if (block_rsv->reserved >= num_bytes)
+ ret = 0;
+ spin_unlock(&block_rsv->lock);
+
+ return ret;
+}
+
+int btrfs_block_rsv_refill(struct btrfs_root *root,
+ struct btrfs_block_rsv *block_rsv, u64 min_reserved,
+ enum btrfs_reserve_flush_enum flush)
+{
+ u64 num_bytes = 0;
+ int ret = -ENOSPC;
+
+ if (!block_rsv)
+ return 0;
+
+ spin_lock(&block_rsv->lock);
+ num_bytes = min_reserved;
+ if (block_rsv->reserved >= num_bytes)
+ ret = 0;
+ else
+ num_bytes -= block_rsv->reserved;
+ spin_unlock(&block_rsv->lock);
+
+ if (!ret)
+ return 0;
+
+ ret = reserve_metadata_bytes(root, block_rsv, num_bytes, flush);
+ if (!ret) {
+ block_rsv_add_bytes(block_rsv, num_bytes, 0);
+ return 0;
+ }
+
+ return ret;
+}
+
+int btrfs_block_rsv_migrate(struct btrfs_block_rsv *src_rsv,
+ struct btrfs_block_rsv *dst_rsv,
+ u64 num_bytes)
+{
+ return block_rsv_migrate_bytes(src_rsv, dst_rsv, num_bytes);
+}
+
+void btrfs_block_rsv_release(struct btrfs_root *root,
+ struct btrfs_block_rsv *block_rsv,
+ u64 num_bytes)
+{
+ struct btrfs_block_rsv *global_rsv = &root->fs_info->global_block_rsv;
+ if (global_rsv == block_rsv ||
+ block_rsv->space_info != global_rsv->space_info)
+ global_rsv = NULL;
+ block_rsv_release_bytes(root->fs_info, block_rsv, global_rsv,
+ num_bytes);
+}
+
+/*
+ * helper to calculate size of global block reservation.
+ * the desired value is sum of space used by extent tree,
+ * checksum tree and root tree
+ */
+static u64 calc_global_metadata_size(struct btrfs_fs_info *fs_info)
+{
+ struct btrfs_space_info *sinfo;
+ u64 num_bytes;
+ u64 meta_used;
+ u64 data_used;
+ int csum_size = btrfs_super_csum_size(fs_info->super_copy);
+
+ sinfo = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_DATA);
+ spin_lock(&sinfo->lock);
+ data_used = sinfo->bytes_used;
+ spin_unlock(&sinfo->lock);
+
+ sinfo = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA);
+ spin_lock(&sinfo->lock);
+ if (sinfo->flags & BTRFS_BLOCK_GROUP_DATA)
+ data_used = 0;
+ meta_used = sinfo->bytes_used;
+ spin_unlock(&sinfo->lock);
+
+ num_bytes = (data_used >> fs_info->sb->s_blocksize_bits) *
+ csum_size * 2;
+ num_bytes += div_u64(data_used + meta_used, 50);
+
+ if (num_bytes * 3 > meta_used)
+ num_bytes = div_u64(meta_used, 3);
+
+ return ALIGN(num_bytes, fs_info->extent_root->nodesize << 10);
+}
+
+static void update_global_block_rsv(struct btrfs_fs_info *fs_info)
+{
+ struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
+ struct btrfs_space_info *sinfo = block_rsv->space_info;
+ u64 num_bytes;
+
+ num_bytes = calc_global_metadata_size(fs_info);
+
+ spin_lock(&sinfo->lock);
+ spin_lock(&block_rsv->lock);
+
+ block_rsv->size = min_t(u64, num_bytes, 512 * 1024 * 1024);
+
+ num_bytes = sinfo->bytes_used + sinfo->bytes_pinned +
+ sinfo->bytes_reserved + sinfo->bytes_readonly +
+ sinfo->bytes_may_use;
+
+ if (sinfo->total_bytes > num_bytes) {
+ num_bytes = sinfo->total_bytes - num_bytes;
+ block_rsv->reserved += num_bytes;
+ sinfo->bytes_may_use += num_bytes;
+ trace_btrfs_space_reservation(fs_info, "space_info",
+ sinfo->flags, num_bytes, 1);
+ }
+
+ if (block_rsv->reserved >= block_rsv->size) {
+ num_bytes = block_rsv->reserved - block_rsv->size;
+ sinfo->bytes_may_use -= num_bytes;
+ trace_btrfs_space_reservation(fs_info, "space_info",
+ sinfo->flags, num_bytes, 0);
+ block_rsv->reserved = block_rsv->size;
+ block_rsv->full = 1;
+ }
+
+ spin_unlock(&block_rsv->lock);
+ spin_unlock(&sinfo->lock);
+}
+
+static void init_global_block_rsv(struct btrfs_fs_info *fs_info)
+{
+ struct btrfs_space_info *space_info;
+
+ space_info = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_SYSTEM);
+ fs_info->chunk_block_rsv.space_info = space_info;
+
+ space_info = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA);
+ fs_info->global_block_rsv.space_info = space_info;
+ fs_info->delalloc_block_rsv.space_info = space_info;
+ fs_info->trans_block_rsv.space_info = space_info;
+ fs_info->empty_block_rsv.space_info = space_info;
+ fs_info->delayed_block_rsv.space_info = space_info;
+
+ fs_info->extent_root->block_rsv = &fs_info->global_block_rsv;
+ fs_info->csum_root->block_rsv = &fs_info->global_block_rsv;
+ fs_info->dev_root->block_rsv = &fs_info->global_block_rsv;
+ fs_info->tree_root->block_rsv = &fs_info->global_block_rsv;
+ if (fs_info->quota_root)
+ fs_info->quota_root->block_rsv = &fs_info->global_block_rsv;
+ fs_info->chunk_root->block_rsv = &fs_info->chunk_block_rsv;
+
+ update_global_block_rsv(fs_info);
+}
+
+static void release_global_block_rsv(struct btrfs_fs_info *fs_info)
+{
+ block_rsv_release_bytes(fs_info, &fs_info->global_block_rsv, NULL,
+ (u64)-1);
+ WARN_ON(fs_info->delalloc_block_rsv.size > 0);
+ WARN_ON(fs_info->delalloc_block_rsv.reserved > 0);
+ WARN_ON(fs_info->trans_block_rsv.size > 0);
+ WARN_ON(fs_info->trans_block_rsv.reserved > 0);
+ WARN_ON(fs_info->chunk_block_rsv.size > 0);
+ WARN_ON(fs_info->chunk_block_rsv.reserved > 0);
+ WARN_ON(fs_info->delayed_block_rsv.size > 0);
+ WARN_ON(fs_info->delayed_block_rsv.reserved > 0);
+}
+
+void btrfs_trans_release_metadata(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root)
+{
+ if (!trans->block_rsv)
+ return;
+
+ if (!trans->bytes_reserved)
+ return;
+
+ trace_btrfs_space_reservation(root->fs_info, "transaction",
+ trans->transid, trans->bytes_reserved, 0);
+ btrfs_block_rsv_release(root, trans->block_rsv, trans->bytes_reserved);
+ trans->bytes_reserved = 0;
+}
+
+/* Can only return 0 or -ENOSPC */
+int btrfs_orphan_reserve_metadata(struct btrfs_trans_handle *trans,
+ struct inode *inode)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_block_rsv *src_rsv = get_block_rsv(trans, root);
+ struct btrfs_block_rsv *dst_rsv = root->orphan_block_rsv;
+
+ /*
+ * We need to hold space in order to delete our orphan item once we've
+ * added it, so this takes the reservation so we can release it later
+ * when we are truly done with the orphan item.
+ */
+ u64 num_bytes = btrfs_calc_trans_metadata_size(root, 1);
+ trace_btrfs_space_reservation(root->fs_info, "orphan",
+ btrfs_ino(inode), num_bytes, 1);
+ return block_rsv_migrate_bytes(src_rsv, dst_rsv, num_bytes);
+}
+
+void btrfs_orphan_release_metadata(struct inode *inode)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ u64 num_bytes = btrfs_calc_trans_metadata_size(root, 1);
+ trace_btrfs_space_reservation(root->fs_info, "orphan",
+ btrfs_ino(inode), num_bytes, 0);
+ btrfs_block_rsv_release(root, root->orphan_block_rsv, num_bytes);
+}
+
+/*
+ * btrfs_subvolume_reserve_metadata() - reserve space for subvolume operation
+ * root: the root of the parent directory
+ * rsv: block reservation
+ * items: the number of items that we need do reservation
+ * qgroup_reserved: used to return the reserved size in qgroup
+ *
+ * This function is used to reserve the space for snapshot/subvolume
+ * creation and deletion. Those operations are different with the
+ * common file/directory operations, they change two fs/file trees
+ * and root tree, the number of items that the qgroup reserves is
+ * different with the free space reservation. So we can not use
+ * the space reseravtion mechanism in start_transaction().
+ */
+int btrfs_subvolume_reserve_metadata(struct btrfs_root *root,
+ struct btrfs_block_rsv *rsv,
+ int items,
+ u64 *qgroup_reserved,
+ bool use_global_rsv)
+{
+ u64 num_bytes;
+ int ret;
+ struct btrfs_block_rsv *global_rsv = &root->fs_info->global_block_rsv;
+
+ if (root->fs_info->quota_enabled) {
+ /* One for parent inode, two for dir entries */
+ num_bytes = 3 * root->nodesize;
+ ret = btrfs_qgroup_reserve(root, num_bytes);
+ if (ret)
+ return ret;
+ } else {
+ num_bytes = 0;
+ }
+
+ *qgroup_reserved = num_bytes;
+
+ num_bytes = btrfs_calc_trans_metadata_size(root, items);
+ rsv->space_info = __find_space_info(root->fs_info,
+ BTRFS_BLOCK_GROUP_METADATA);
+ ret = btrfs_block_rsv_add(root, rsv, num_bytes,
+ BTRFS_RESERVE_FLUSH_ALL);
+
+ if (ret == -ENOSPC && use_global_rsv)
+ ret = btrfs_block_rsv_migrate(global_rsv, rsv, num_bytes);
+
+ if (ret) {
+ if (*qgroup_reserved)
+ btrfs_qgroup_free(root, *qgroup_reserved);
+ }
+
+ return ret;
+}
+
+void btrfs_subvolume_release_metadata(struct btrfs_root *root,
+ struct btrfs_block_rsv *rsv,
+ u64 qgroup_reserved)
+{
+ btrfs_block_rsv_release(root, rsv, (u64)-1);
+}
+
+/**
+ * drop_outstanding_extent - drop an outstanding extent
+ * @inode: the inode we're dropping the extent for
+ * @num_bytes: the number of bytes we're relaseing.
+ *
+ * This is called when we are freeing up an outstanding extent, either called
+ * after an error or after an extent is written. This will return the number of
+ * reserved extents that need to be freed. This must be called with
+ * BTRFS_I(inode)->lock held.
+ */
+static unsigned drop_outstanding_extent(struct inode *inode, u64 num_bytes)
+{
+ unsigned drop_inode_space = 0;
+ unsigned dropped_extents = 0;
+ unsigned num_extents = 0;
+
+ num_extents = (unsigned)div64_u64(num_bytes +
+ BTRFS_MAX_EXTENT_SIZE - 1,
+ BTRFS_MAX_EXTENT_SIZE);
+ ASSERT(num_extents);
+ ASSERT(BTRFS_I(inode)->outstanding_extents >= num_extents);
+ BTRFS_I(inode)->outstanding_extents -= num_extents;
+
+ if (BTRFS_I(inode)->outstanding_extents == 0 &&
+ test_and_clear_bit(BTRFS_INODE_DELALLOC_META_RESERVED,
+ &BTRFS_I(inode)->runtime_flags))
+ drop_inode_space = 1;
+
+ /*
+ * If we have more or the same amount of outsanding extents than we have
+ * reserved then we need to leave the reserved extents count alone.
+ */
+ if (BTRFS_I(inode)->outstanding_extents >=
+ BTRFS_I(inode)->reserved_extents)
+ return drop_inode_space;
+
+ dropped_extents = BTRFS_I(inode)->reserved_extents -
+ BTRFS_I(inode)->outstanding_extents;
+ BTRFS_I(inode)->reserved_extents -= dropped_extents;
+ return dropped_extents + drop_inode_space;
+}
+
+/**
+ * calc_csum_metadata_size - return the amount of metada space that must be
+ * reserved/free'd for the given bytes.
+ * @inode: the inode we're manipulating
+ * @num_bytes: the number of bytes in question
+ * @reserve: 1 if we are reserving space, 0 if we are freeing space
+ *
+ * This adjusts the number of csum_bytes in the inode and then returns the
+ * correct amount of metadata that must either be reserved or freed. We
+ * calculate how many checksums we can fit into one leaf and then divide the
+ * number of bytes that will need to be checksumed by this value to figure out
+ * how many checksums will be required. If we are adding bytes then the number
+ * may go up and we will return the number of additional bytes that must be
+ * reserved. If it is going down we will return the number of bytes that must
+ * be freed.
+ *
+ * This must be called with BTRFS_I(inode)->lock held.
+ */
+static u64 calc_csum_metadata_size(struct inode *inode, u64 num_bytes,
+ int reserve)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ u64 old_csums, num_csums;
+
+ if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM &&
+ BTRFS_I(inode)->csum_bytes == 0)
+ return 0;
+
+ old_csums = btrfs_csum_bytes_to_leaves(root, BTRFS_I(inode)->csum_bytes);
+ if (reserve)
+ BTRFS_I(inode)->csum_bytes += num_bytes;
+ else
+ BTRFS_I(inode)->csum_bytes -= num_bytes;
+ num_csums = btrfs_csum_bytes_to_leaves(root, BTRFS_I(inode)->csum_bytes);
+
+ /* No change, no need to reserve more */
+ if (old_csums == num_csums)
+ return 0;
+
+ if (reserve)
+ return btrfs_calc_trans_metadata_size(root,
+ num_csums - old_csums);
+
+ return btrfs_calc_trans_metadata_size(root, old_csums - num_csums);
+}
+
+int btrfs_delalloc_reserve_metadata(struct inode *inode, u64 num_bytes)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_block_rsv *block_rsv = &root->fs_info->delalloc_block_rsv;
+ u64 to_reserve = 0;
+ u64 csum_bytes;
+ unsigned nr_extents = 0;
+ int extra_reserve = 0;
+ enum btrfs_reserve_flush_enum flush = BTRFS_RESERVE_FLUSH_ALL;
+ int ret = 0;
+ bool delalloc_lock = true;
+ u64 to_free = 0;
+ unsigned dropped;
+
+ /* If we are a free space inode we need to not flush since we will be in
+ * the middle of a transaction commit. We also don't need the delalloc
+ * mutex since we won't race with anybody. We need this mostly to make
+ * lockdep shut its filthy mouth.
+ */
+ if (btrfs_is_free_space_inode(inode)) {
+ flush = BTRFS_RESERVE_NO_FLUSH;
+ delalloc_lock = false;
+ }
+
+ if (flush != BTRFS_RESERVE_NO_FLUSH &&
+ btrfs_transaction_in_commit(root->fs_info))
+ schedule_timeout(1);
+
+ if (delalloc_lock)
+ mutex_lock(&BTRFS_I(inode)->delalloc_mutex);
+
+ num_bytes = ALIGN(num_bytes, root->sectorsize);
+
+ spin_lock(&BTRFS_I(inode)->lock);
+ nr_extents = (unsigned)div64_u64(num_bytes +
+ BTRFS_MAX_EXTENT_SIZE - 1,
+ BTRFS_MAX_EXTENT_SIZE);
+ BTRFS_I(inode)->outstanding_extents += nr_extents;
+ nr_extents = 0;
+
+ if (BTRFS_I(inode)->outstanding_extents >
+ BTRFS_I(inode)->reserved_extents)
+ nr_extents = BTRFS_I(inode)->outstanding_extents -
+ BTRFS_I(inode)->reserved_extents;
+
+ /*
+ * Add an item to reserve for updating the inode when we complete the
+ * delalloc io.
+ */
+ if (!test_bit(BTRFS_INODE_DELALLOC_META_RESERVED,
+ &BTRFS_I(inode)->runtime_flags)) {
+ nr_extents++;
+ extra_reserve = 1;
+ }
+
+ to_reserve = btrfs_calc_trans_metadata_size(root, nr_extents);
+ to_reserve += calc_csum_metadata_size(inode, num_bytes, 1);
+ csum_bytes = BTRFS_I(inode)->csum_bytes;
+ spin_unlock(&BTRFS_I(inode)->lock);
+
+ if (root->fs_info->quota_enabled) {
+ ret = btrfs_qgroup_reserve(root, nr_extents * root->nodesize);
+ if (ret)
+ goto out_fail;
+ }
+
+ ret = reserve_metadata_bytes(root, block_rsv, to_reserve, flush);
+ if (unlikely(ret)) {
+ if (root->fs_info->quota_enabled)
+ btrfs_qgroup_free(root, nr_extents * root->nodesize);
+ goto out_fail;
+ }
+
+ spin_lock(&BTRFS_I(inode)->lock);
+ if (extra_reserve) {
+ set_bit(BTRFS_INODE_DELALLOC_META_RESERVED,
+ &BTRFS_I(inode)->runtime_flags);
+ nr_extents--;
+ }
+ BTRFS_I(inode)->reserved_extents += nr_extents;
+ spin_unlock(&BTRFS_I(inode)->lock);
+
+ if (delalloc_lock)
+ mutex_unlock(&BTRFS_I(inode)->delalloc_mutex);
+
+ if (to_reserve)
+ trace_btrfs_space_reservation(root->fs_info, "delalloc",
+ btrfs_ino(inode), to_reserve, 1);
+ block_rsv_add_bytes(block_rsv, to_reserve, 1);
+
+ return 0;
+
+out_fail:
+ spin_lock(&BTRFS_I(inode)->lock);
+ dropped = drop_outstanding_extent(inode, num_bytes);
+ /*
+ * If the inodes csum_bytes is the same as the original
+ * csum_bytes then we know we haven't raced with any free()ers
+ * so we can just reduce our inodes csum bytes and carry on.
+ */
+ if (BTRFS_I(inode)->csum_bytes == csum_bytes) {
+ calc_csum_metadata_size(inode, num_bytes, 0);
+ } else {
+ u64 orig_csum_bytes = BTRFS_I(inode)->csum_bytes;
+ u64 bytes;
+
+ /*
+ * This is tricky, but first we need to figure out how much we
+ * free'd from any free-ers that occured during this
+ * reservation, so we reset ->csum_bytes to the csum_bytes
+ * before we dropped our lock, and then call the free for the
+ * number of bytes that were freed while we were trying our
+ * reservation.
+ */
+ bytes = csum_bytes - BTRFS_I(inode)->csum_bytes;
+ BTRFS_I(inode)->csum_bytes = csum_bytes;
+ to_free = calc_csum_metadata_size(inode, bytes, 0);
+
+
+ /*
+ * Now we need to see how much we would have freed had we not
+ * been making this reservation and our ->csum_bytes were not
+ * artificially inflated.
+ */
+ BTRFS_I(inode)->csum_bytes = csum_bytes - num_bytes;
+ bytes = csum_bytes - orig_csum_bytes;
+ bytes = calc_csum_metadata_size(inode, bytes, 0);
+
+ /*
+ * Now reset ->csum_bytes to what it should be. If bytes is
+ * more than to_free then we would have free'd more space had we
+ * not had an artificially high ->csum_bytes, so we need to free
+ * the remainder. If bytes is the same or less then we don't
+ * need to do anything, the other free-ers did the correct
+ * thing.
+ */
+ BTRFS_I(inode)->csum_bytes = orig_csum_bytes - num_bytes;
+ if (bytes > to_free)
+ to_free = bytes - to_free;
+ else
+ to_free = 0;
+ }
+ spin_unlock(&BTRFS_I(inode)->lock);
+ if (dropped)
+ to_free += btrfs_calc_trans_metadata_size(root, dropped);
+
+ if (to_free) {
+ btrfs_block_rsv_release(root, block_rsv, to_free);
+ trace_btrfs_space_reservation(root->fs_info, "delalloc",
+ btrfs_ino(inode), to_free, 0);
+ }
+ if (delalloc_lock)
+ mutex_unlock(&BTRFS_I(inode)->delalloc_mutex);
+ return ret;
+}
+
+/**
+ * btrfs_delalloc_release_metadata - release a metadata reservation for an inode
+ * @inode: the inode to release the reservation for
+ * @num_bytes: the number of bytes we're releasing
+ *
+ * This will release the metadata reservation for an inode. This can be called
+ * once we complete IO for a given set of bytes to release their metadata
+ * reservations.
+ */
+void btrfs_delalloc_release_metadata(struct inode *inode, u64 num_bytes)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ u64 to_free = 0;
+ unsigned dropped;
+
+ num_bytes = ALIGN(num_bytes, root->sectorsize);
+ spin_lock(&BTRFS_I(inode)->lock);
+ dropped = drop_outstanding_extent(inode, num_bytes);
+
+ if (num_bytes)
+ to_free = calc_csum_metadata_size(inode, num_bytes, 0);
+ spin_unlock(&BTRFS_I(inode)->lock);
+ if (dropped > 0)
+ to_free += btrfs_calc_trans_metadata_size(root, dropped);
+
+ if (btrfs_test_is_dummy_root(root))
+ return;
+
+ trace_btrfs_space_reservation(root->fs_info, "delalloc",
+ btrfs_ino(inode), to_free, 0);
+
+ btrfs_block_rsv_release(root, &root->fs_info->delalloc_block_rsv,
+ to_free);
+}
+
+/**
+ * btrfs_delalloc_reserve_space - reserve data and metadata space for delalloc
+ * @inode: inode we're writing to
+ * @num_bytes: the number of bytes we want to allocate
+ *
+ * This will do the following things
+ *
+ * o reserve space in the data space info for num_bytes
+ * o reserve space in the metadata space info based on number of outstanding
+ * extents and how much csums will be needed
+ * o add to the inodes ->delalloc_bytes
+ * o add it to the fs_info's delalloc inodes list.
+ *
+ * This will return 0 for success and -ENOSPC if there is no space left.
+ */
+int btrfs_delalloc_reserve_space(struct inode *inode, u64 num_bytes)
+{
+ int ret;
+
+ ret = btrfs_check_data_free_space(inode, num_bytes, num_bytes);
+ if (ret)
+ return ret;
+
+ ret = btrfs_delalloc_reserve_metadata(inode, num_bytes);
+ if (ret) {
+ btrfs_free_reserved_data_space(inode, num_bytes);
+ return ret;
+ }
+
+ return 0;
+}
+
+/**
+ * btrfs_delalloc_release_space - release data and metadata space for delalloc
+ * @inode: inode we're releasing space for
+ * @num_bytes: the number of bytes we want to free up
+ *
+ * This must be matched with a call to btrfs_delalloc_reserve_space. This is
+ * called in the case that we don't need the metadata AND data reservations
+ * anymore. So if there is an error or we insert an inline extent.
+ *
+ * This function will release the metadata space that was not used and will
+ * decrement ->delalloc_bytes and remove it from the fs_info delalloc_inodes
+ * list if there are no delalloc bytes left.
+ */
+void btrfs_delalloc_release_space(struct inode *inode, u64 num_bytes)
+{
+ btrfs_delalloc_release_metadata(inode, num_bytes);
+ btrfs_free_reserved_data_space(inode, num_bytes);
+}
+
+static int update_block_group(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, u64 bytenr,
+ u64 num_bytes, int alloc)
+{
+ struct btrfs_block_group_cache *cache = NULL;
+ struct btrfs_fs_info *info = root->fs_info;
+ u64 total = num_bytes;
+ u64 old_val;
+ u64 byte_in_group;
+ int factor;
+
+ /* block accounting for super block */
+ spin_lock(&info->delalloc_root_lock);
+ old_val = btrfs_super_bytes_used(info->super_copy);
+ if (alloc)
+ old_val += num_bytes;
+ else
+ old_val -= num_bytes;
+ btrfs_set_super_bytes_used(info->super_copy, old_val);
+ spin_unlock(&info->delalloc_root_lock);
+
+ while (total) {
+ cache = btrfs_lookup_block_group(info, bytenr);
+ if (!cache)
+ return -ENOENT;
+ if (cache->flags & (BTRFS_BLOCK_GROUP_DUP |
+ BTRFS_BLOCK_GROUP_RAID1 |
+ BTRFS_BLOCK_GROUP_RAID10))
+ factor = 2;
+ else
+ factor = 1;
+ /*
+ * If this block group has free space cache written out, we
+ * need to make sure to load it if we are removing space. This
+ * is because we need the unpinning stage to actually add the
+ * space back to the block group, otherwise we will leak space.
+ */
+ if (!alloc && cache->cached == BTRFS_CACHE_NO)
+ cache_block_group(cache, 1);
+
+ byte_in_group = bytenr - cache->key.objectid;
+ WARN_ON(byte_in_group > cache->key.offset);
+
+ spin_lock(&cache->space_info->lock);
+ spin_lock(&cache->lock);
+
+ if (btrfs_test_opt(root, SPACE_CACHE) &&
+ cache->disk_cache_state < BTRFS_DC_CLEAR)
+ cache->disk_cache_state = BTRFS_DC_CLEAR;
+
+ old_val = btrfs_block_group_used(&cache->item);
+ num_bytes = min(total, cache->key.offset - byte_in_group);
+ if (alloc) {
+ old_val += num_bytes;
+ btrfs_set_block_group_used(&cache->item, old_val);
+ cache->reserved -= num_bytes;
+ cache->space_info->bytes_reserved -= num_bytes;
+ cache->space_info->bytes_used += num_bytes;
+ cache->space_info->disk_used += num_bytes * factor;
+ spin_unlock(&cache->lock);
+ spin_unlock(&cache->space_info->lock);
+ } else {
+ old_val -= num_bytes;
+ btrfs_set_block_group_used(&cache->item, old_val);
+ cache->pinned += num_bytes;
+ cache->space_info->bytes_pinned += num_bytes;
+ cache->space_info->bytes_used -= num_bytes;
+ cache->space_info->disk_used -= num_bytes * factor;
+ spin_unlock(&cache->lock);
+ spin_unlock(&cache->space_info->lock);
+
+ set_extent_dirty(info->pinned_extents,
+ bytenr, bytenr + num_bytes - 1,
+ GFP_NOFS | __GFP_NOFAIL);
+ /*
+ * No longer have used bytes in this block group, queue
+ * it for deletion.
+ */
+ if (old_val == 0) {
+ spin_lock(&info->unused_bgs_lock);
+ if (list_empty(&cache->bg_list)) {
+ btrfs_get_block_group(cache);
+ list_add_tail(&cache->bg_list,
+ &info->unused_bgs);
+ }
+ spin_unlock(&info->unused_bgs_lock);
+ }
+ }
+
+ spin_lock(&trans->transaction->dirty_bgs_lock);
+ if (list_empty(&cache->dirty_list)) {
+ list_add_tail(&cache->dirty_list,
+ &trans->transaction->dirty_bgs);
+ trans->transaction->num_dirty_bgs++;
+ btrfs_get_block_group(cache);
+ }
+ spin_unlock(&trans->transaction->dirty_bgs_lock);
+
+ btrfs_put_block_group(cache);
+ total -= num_bytes;
+ bytenr += num_bytes;
+ }
+ return 0;
+}
+
+static u64 first_logical_byte(struct btrfs_root *root, u64 search_start)
+{
+ struct btrfs_block_group_cache *cache;
+ u64 bytenr;
+
+ spin_lock(&root->fs_info->block_group_cache_lock);
+ bytenr = root->fs_info->first_logical_byte;
+ spin_unlock(&root->fs_info->block_group_cache_lock);
+
+ if (bytenr < (u64)-1)
+ return bytenr;
+
+ cache = btrfs_lookup_first_block_group(root->fs_info, search_start);
+ if (!cache)
+ return 0;
+
+ bytenr = cache->key.objectid;
+ btrfs_put_block_group(cache);
+
+ return bytenr;
+}
+
+static int pin_down_extent(struct btrfs_root *root,
+ struct btrfs_block_group_cache *cache,
+ u64 bytenr, u64 num_bytes, int reserved)
+{
+ spin_lock(&cache->space_info->lock);
+ spin_lock(&cache->lock);
+ cache->pinned += num_bytes;
+ cache->space_info->bytes_pinned += num_bytes;
+ if (reserved) {
+ cache->reserved -= num_bytes;
+ cache->space_info->bytes_reserved -= num_bytes;
+ }
+ spin_unlock(&cache->lock);
+ spin_unlock(&cache->space_info->lock);
+
+ set_extent_dirty(root->fs_info->pinned_extents, bytenr,
+ bytenr + num_bytes - 1, GFP_NOFS | __GFP_NOFAIL);
+ if (reserved)
+ trace_btrfs_reserved_extent_free(root, bytenr, num_bytes);
+ return 0;
+}
+
+/*
+ * this function must be called within transaction
+ */
+int btrfs_pin_extent(struct btrfs_root *root,
+ u64 bytenr, u64 num_bytes, int reserved)
+{
+ struct btrfs_block_group_cache *cache;
+
+ cache = btrfs_lookup_block_group(root->fs_info, bytenr);
+ BUG_ON(!cache); /* Logic error */
+
+ pin_down_extent(root, cache, bytenr, num_bytes, reserved);
+
+ btrfs_put_block_group(cache);
+ return 0;
+}
+
+/*
+ * this function must be called within transaction
+ */
+int btrfs_pin_extent_for_log_replay(struct btrfs_root *root,
+ u64 bytenr, u64 num_bytes)
+{
+ struct btrfs_block_group_cache *cache;
+ int ret;
+
+ cache = btrfs_lookup_block_group(root->fs_info, bytenr);
+ if (!cache)
+ return -EINVAL;
+
+ /*
+ * pull in the free space cache (if any) so that our pin
+ * removes the free space from the cache. We have load_only set
+ * to one because the slow code to read in the free extents does check
+ * the pinned extents.
+ */
+ cache_block_group(cache, 1);
+
+ pin_down_extent(root, cache, bytenr, num_bytes, 0);
+
+ /* remove us from the free space cache (if we're there at all) */
+ ret = btrfs_remove_free_space(cache, bytenr, num_bytes);
+ btrfs_put_block_group(cache);
+ return ret;
+}
+
+static int __exclude_logged_extent(struct btrfs_root *root, u64 start, u64 num_bytes)
+{
+ int ret;
+ struct btrfs_block_group_cache *block_group;
+ struct btrfs_caching_control *caching_ctl;
+
+ block_group = btrfs_lookup_block_group(root->fs_info, start);
+ if (!block_group)
+ return -EINVAL;
+
+ cache_block_group(block_group, 0);
+ caching_ctl = get_caching_control(block_group);
+
+ if (!caching_ctl) {
+ /* Logic error */
+ BUG_ON(!block_group_cache_done(block_group));
+ ret = btrfs_remove_free_space(block_group, start, num_bytes);
+ } else {
+ mutex_lock(&caching_ctl->mutex);
+
+ if (start >= caching_ctl->progress) {
+ ret = add_excluded_extent(root, start, num_bytes);
+ } else if (start + num_bytes <= caching_ctl->progress) {
+ ret = btrfs_remove_free_space(block_group,
+ start, num_bytes);
+ } else {
+ num_bytes = caching_ctl->progress - start;
+ ret = btrfs_remove_free_space(block_group,
+ start, num_bytes);
+ if (ret)
+ goto out_lock;
+
+ num_bytes = (start + num_bytes) -
+ caching_ctl->progress;
+ start = caching_ctl->progress;
+ ret = add_excluded_extent(root, start, num_bytes);
+ }
+out_lock:
+ mutex_unlock(&caching_ctl->mutex);
+ put_caching_control(caching_ctl);
+ }
+ btrfs_put_block_group(block_group);
+ return ret;
+}
+
+int btrfs_exclude_logged_extents(struct btrfs_root *log,
+ struct extent_buffer *eb)
+{
+ struct btrfs_file_extent_item *item;
+ struct btrfs_key key;
+ int found_type;
+ int i;
+
+ if (!btrfs_fs_incompat(log->fs_info, MIXED_GROUPS))
+ return 0;
+
+ for (i = 0; i < btrfs_header_nritems(eb); i++) {
+ btrfs_item_key_to_cpu(eb, &key, i);
+ if (key.type != BTRFS_EXTENT_DATA_KEY)
+ continue;
+ item = btrfs_item_ptr(eb, i, struct btrfs_file_extent_item);
+ found_type = btrfs_file_extent_type(eb, item);
+ if (found_type == BTRFS_FILE_EXTENT_INLINE)
+ continue;
+ if (btrfs_file_extent_disk_bytenr(eb, item) == 0)
+ continue;
+ key.objectid = btrfs_file_extent_disk_bytenr(eb, item);
+ key.offset = btrfs_file_extent_disk_num_bytes(eb, item);
+ __exclude_logged_extent(log, key.objectid, key.offset);
+ }
+
+ return 0;
+}
+
+/**
+ * btrfs_update_reserved_bytes - update the block_group and space info counters
+ * @cache: The cache we are manipulating
+ * @num_bytes: The number of bytes in question
+ * @reserve: One of the reservation enums
+ * @delalloc: The blocks are allocated for the delalloc write
+ *
+ * This is called by the allocator when it reserves space, or by somebody who is
+ * freeing space that was never actually used on disk. For example if you
+ * reserve some space for a new leaf in transaction A and before transaction A
+ * commits you free that leaf, you call this with reserve set to 0 in order to
+ * clear the reservation.
+ *
+ * Metadata reservations should be called with RESERVE_ALLOC so we do the proper
+ * ENOSPC accounting. For data we handle the reservation through clearing the
+ * delalloc bits in the io_tree. We have to do this since we could end up
+ * allocating less disk space for the amount of data we have reserved in the
+ * case of compression.
+ *
+ * If this is a reservation and the block group has become read only we cannot
+ * make the reservation and return -EAGAIN, otherwise this function always
+ * succeeds.
+ */
+static int btrfs_update_reserved_bytes(struct btrfs_block_group_cache *cache,
+ u64 num_bytes, int reserve, int delalloc)
+{
+ struct btrfs_space_info *space_info = cache->space_info;
+ int ret = 0;
+
+ spin_lock(&space_info->lock);
+ spin_lock(&cache->lock);
+ if (reserve != RESERVE_FREE) {
+ if (cache->ro) {
+ ret = -EAGAIN;
+ } else {
+ cache->reserved += num_bytes;
+ space_info->bytes_reserved += num_bytes;
+ if (reserve == RESERVE_ALLOC) {
+ trace_btrfs_space_reservation(cache->fs_info,
+ "space_info", space_info->flags,
+ num_bytes, 0);
+ space_info->bytes_may_use -= num_bytes;
+ }
+
+ if (delalloc)
+ cache->delalloc_bytes += num_bytes;
+ }
+ } else {
+ if (cache->ro)
+ space_info->bytes_readonly += num_bytes;
+ cache->reserved -= num_bytes;
+ space_info->bytes_reserved -= num_bytes;
+
+ if (delalloc)
+ cache->delalloc_bytes -= num_bytes;
+ }
+ spin_unlock(&cache->lock);
+ spin_unlock(&space_info->lock);
+ return ret;
+}
+
+void btrfs_prepare_extent_commit(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root)
+{
+ struct btrfs_fs_info *fs_info = root->fs_info;
+ struct btrfs_caching_control *next;
+ struct btrfs_caching_control *caching_ctl;
+ struct btrfs_block_group_cache *cache;
+
+ down_write(&fs_info->commit_root_sem);
+
+ list_for_each_entry_safe(caching_ctl, next,
+ &fs_info->caching_block_groups, list) {
+ cache = caching_ctl->block_group;
+ if (block_group_cache_done(cache)) {
+ cache->last_byte_to_unpin = (u64)-1;
+ list_del_init(&caching_ctl->list);
+ put_caching_control(caching_ctl);
+ } else {
+ cache->last_byte_to_unpin = caching_ctl->progress;
+ }
+ }
+
+ if (fs_info->pinned_extents == &fs_info->freed_extents[0])
+ fs_info->pinned_extents = &fs_info->freed_extents[1];
+ else
+ fs_info->pinned_extents = &fs_info->freed_extents[0];
+
+ up_write(&fs_info->commit_root_sem);
+
+ update_global_block_rsv(fs_info);
+}
+
+static int unpin_extent_range(struct btrfs_root *root, u64 start, u64 end,
+ const bool return_free_space)
+{
+ struct btrfs_fs_info *fs_info = root->fs_info;
+ struct btrfs_block_group_cache *cache = NULL;
+ struct btrfs_space_info *space_info;
+ struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
+ u64 len;
+ bool readonly;
+
+ while (start <= end) {
+ readonly = false;
+ if (!cache ||
+ start >= cache->key.objectid + cache->key.offset) {
+ if (cache)
+ btrfs_put_block_group(cache);
+ cache = btrfs_lookup_block_group(fs_info, start);
+ BUG_ON(!cache); /* Logic error */
+ }
+
+ len = cache->key.objectid + cache->key.offset - start;
+ len = min(len, end + 1 - start);
+
+ if (start < cache->last_byte_to_unpin) {
+ len = min(len, cache->last_byte_to_unpin - start);
+ if (return_free_space)
+ btrfs_add_free_space(cache, start, len);
+ }
+
+ start += len;
+ space_info = cache->space_info;
+
+ spin_lock(&space_info->lock);
+ spin_lock(&cache->lock);
+ cache->pinned -= len;
+ space_info->bytes_pinned -= len;
+ percpu_counter_add(&space_info->total_bytes_pinned, -len);
+ if (cache->ro) {
+ space_info->bytes_readonly += len;
+ readonly = true;
+ }
+ spin_unlock(&cache->lock);
+ if (!readonly && global_rsv->space_info == space_info) {
+ spin_lock(&global_rsv->lock);
+ if (!global_rsv->full) {
+ len = min(len, global_rsv->size -
+ global_rsv->reserved);
+ global_rsv->reserved += len;
+ space_info->bytes_may_use += len;
+ if (global_rsv->reserved >= global_rsv->size)
+ global_rsv->full = 1;
+ }
+ spin_unlock(&global_rsv->lock);
+ }
+ spin_unlock(&space_info->lock);
+ }
+
+ if (cache)
+ btrfs_put_block_group(cache);
+ return 0;
+}
+
+int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root)
+{
+ struct btrfs_fs_info *fs_info = root->fs_info;
+ struct extent_io_tree *unpin;
+ u64 start;
+ u64 end;
+ int ret;
+
+ if (trans->aborted)
+ return 0;
+
+ if (fs_info->pinned_extents == &fs_info->freed_extents[0])
+ unpin = &fs_info->freed_extents[1];
+ else
+ unpin = &fs_info->freed_extents[0];
+
+ while (1) {
+ mutex_lock(&fs_info->unused_bg_unpin_mutex);
+ ret = find_first_extent_bit(unpin, 0, &start, &end,
+ EXTENT_DIRTY, NULL);
+ if (ret) {
+ mutex_unlock(&fs_info->unused_bg_unpin_mutex);
+ break;
+ }
+
+ if (btrfs_test_opt(root, DISCARD))
+ ret = btrfs_discard_extent(root, start,
+ end + 1 - start, NULL);
+
+ clear_extent_dirty(unpin, start, end, GFP_NOFS);
+ unpin_extent_range(root, start, end, true);
+ mutex_unlock(&fs_info->unused_bg_unpin_mutex);
+ cond_resched();
+ }
+
+ return 0;
+}
+
+static void add_pinned_bytes(struct btrfs_fs_info *fs_info, u64 num_bytes,
+ u64 owner, u64 root_objectid)
+{
+ struct btrfs_space_info *space_info;
+ u64 flags;
+
+ if (owner < BTRFS_FIRST_FREE_OBJECTID) {
+ if (root_objectid == BTRFS_CHUNK_TREE_OBJECTID)
+ flags = BTRFS_BLOCK_GROUP_SYSTEM;
+ else
+ flags = BTRFS_BLOCK_GROUP_METADATA;
+ } else {
+ flags = BTRFS_BLOCK_GROUP_DATA;
+ }
+
+ space_info = __find_space_info(fs_info, flags);
+ BUG_ON(!space_info); /* Logic bug */
+ percpu_counter_add(&space_info->total_bytes_pinned, num_bytes);
+}
+
+
+static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ u64 bytenr, u64 num_bytes, u64 parent,
+ u64 root_objectid, u64 owner_objectid,
+ u64 owner_offset, int refs_to_drop,
+ struct btrfs_delayed_extent_op *extent_op,
+ int no_quota)
+{
+ struct btrfs_key key;
+ struct btrfs_path *path;
+ struct btrfs_fs_info *info = root->fs_info;
+ struct btrfs_root *extent_root = info->extent_root;
+ struct extent_buffer *leaf;
+ struct btrfs_extent_item *ei;
+ struct btrfs_extent_inline_ref *iref;
+ int ret;
+ int is_data;
+ int extent_slot = 0;
+ int found_extent = 0;
+ int num_to_del = 1;
+ u32 item_size;
+ u64 refs;
+ int last_ref = 0;
+ enum btrfs_qgroup_operation_type type = BTRFS_QGROUP_OPER_SUB_EXCL;
+ bool skinny_metadata = btrfs_fs_incompat(root->fs_info,
+ SKINNY_METADATA);
+
+ if (!info->quota_enabled || !is_fstree(root_objectid))
+ no_quota = 1;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ path->reada = 1;
+ path->leave_spinning = 1;
+
+ is_data = owner_objectid >= BTRFS_FIRST_FREE_OBJECTID;
+ BUG_ON(!is_data && refs_to_drop != 1);
+
+ if (is_data)
+ skinny_metadata = 0;
+
+ ret = lookup_extent_backref(trans, extent_root, path, &iref,
+ bytenr, num_bytes, parent,
+ root_objectid, owner_objectid,
+ owner_offset);
+ if (ret == 0) {
+ extent_slot = path->slots[0];
+ while (extent_slot >= 0) {
+ btrfs_item_key_to_cpu(path->nodes[0], &key,
+ extent_slot);
+ if (key.objectid != bytenr)
+ break;
+ if (key.type == BTRFS_EXTENT_ITEM_KEY &&
+ key.offset == num_bytes) {
+ found_extent = 1;
+ break;
+ }
+ if (key.type == BTRFS_METADATA_ITEM_KEY &&
+ key.offset == owner_objectid) {
+ found_extent = 1;
+ break;
+ }
+ if (path->slots[0] - extent_slot > 5)
+ break;
+ extent_slot--;
+ }
+#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
+ item_size = btrfs_item_size_nr(path->nodes[0], extent_slot);
+ if (found_extent && item_size < sizeof(*ei))
+ found_extent = 0;
+#endif
+ if (!found_extent) {
+ BUG_ON(iref);
+ ret = remove_extent_backref(trans, extent_root, path,
+ NULL, refs_to_drop,
+ is_data, &last_ref);
+ if (ret) {
+ btrfs_abort_transaction(trans, extent_root, ret);
+ goto out;
+ }
+ btrfs_release_path(path);
+ path->leave_spinning = 1;
+
+ key.objectid = bytenr;
+ key.type = BTRFS_EXTENT_ITEM_KEY;
+ key.offset = num_bytes;
+
+ if (!is_data && skinny_metadata) {
+ key.type = BTRFS_METADATA_ITEM_KEY;
+ key.offset = owner_objectid;
+ }
+
+ ret = btrfs_search_slot(trans, extent_root,
+ &key, path, -1, 1);
+ if (ret > 0 && skinny_metadata && path->slots[0]) {
+ /*
+ * Couldn't find our skinny metadata item,
+ * see if we have ye olde extent item.
+ */
+ path->slots[0]--;
+ btrfs_item_key_to_cpu(path->nodes[0], &key,
+ path->slots[0]);
+ if (key.objectid == bytenr &&
+ key.type == BTRFS_EXTENT_ITEM_KEY &&
+ key.offset == num_bytes)
+ ret = 0;
+ }
+
+ if (ret > 0 && skinny_metadata) {
+ skinny_metadata = false;
+ key.objectid = bytenr;
+ key.type = BTRFS_EXTENT_ITEM_KEY;
+ key.offset = num_bytes;
+ btrfs_release_path(path);
+ ret = btrfs_search_slot(trans, extent_root,
+ &key, path, -1, 1);
+ }
+
+ if (ret) {
+ btrfs_err(info, "umm, got %d back from search, was looking for %llu",
+ ret, bytenr);
+ if (ret > 0)
+ btrfs_print_leaf(extent_root,
+ path->nodes[0]);
+ }
+ if (ret < 0) {
+ btrfs_abort_transaction(trans, extent_root, ret);
+ goto out;
+ }
+ extent_slot = path->slots[0];
+ }
+ } else if (WARN_ON(ret == -ENOENT)) {
+ btrfs_print_leaf(extent_root, path->nodes[0]);
+ btrfs_err(info,
+ "unable to find ref byte nr %llu parent %llu root %llu owner %llu offset %llu",
+ bytenr, parent, root_objectid, owner_objectid,
+ owner_offset);
+ btrfs_abort_transaction(trans, extent_root, ret);
+ goto out;
+ } else {
+ btrfs_abort_transaction(trans, extent_root, ret);
+ goto out;
+ }
+
+ leaf = path->nodes[0];
+ item_size = btrfs_item_size_nr(leaf, extent_slot);
+#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
+ if (item_size < sizeof(*ei)) {
+ BUG_ON(found_extent || extent_slot != path->slots[0]);
+ ret = convert_extent_item_v0(trans, extent_root, path,
+ owner_objectid, 0);
+ if (ret < 0) {
+ btrfs_abort_transaction(trans, extent_root, ret);
+ goto out;
+ }
+
+ btrfs_release_path(path);
+ path->leave_spinning = 1;
+
+ key.objectid = bytenr;
+ key.type = BTRFS_EXTENT_ITEM_KEY;
+ key.offset = num_bytes;
+
+ ret = btrfs_search_slot(trans, extent_root, &key, path,
+ -1, 1);
+ if (ret) {
+ btrfs_err(info, "umm, got %d back from search, was looking for %llu",
+ ret, bytenr);
+ btrfs_print_leaf(extent_root, path->nodes[0]);
+ }
+ if (ret < 0) {
+ btrfs_abort_transaction(trans, extent_root, ret);
+ goto out;
+ }
+
+ extent_slot = path->slots[0];
+ leaf = path->nodes[0];
+ item_size = btrfs_item_size_nr(leaf, extent_slot);
+ }
+#endif
+ BUG_ON(item_size < sizeof(*ei));
+ ei = btrfs_item_ptr(leaf, extent_slot,
+ struct btrfs_extent_item);
+ if (owner_objectid < BTRFS_FIRST_FREE_OBJECTID &&
+ key.type == BTRFS_EXTENT_ITEM_KEY) {
+ struct btrfs_tree_block_info *bi;
+ BUG_ON(item_size < sizeof(*ei) + sizeof(*bi));
+ bi = (struct btrfs_tree_block_info *)(ei + 1);
+ WARN_ON(owner_objectid != btrfs_tree_block_level(leaf, bi));
+ }
+
+ refs = btrfs_extent_refs(leaf, ei);
+ if (refs < refs_to_drop) {
+ btrfs_err(info, "trying to drop %d refs but we only have %Lu "
+ "for bytenr %Lu", refs_to_drop, refs, bytenr);
+ ret = -EINVAL;
+ btrfs_abort_transaction(trans, extent_root, ret);
+ goto out;
+ }
+ refs -= refs_to_drop;
+
+ if (refs > 0) {
+ type = BTRFS_QGROUP_OPER_SUB_SHARED;
+ if (extent_op)
+ __run_delayed_extent_op(extent_op, leaf, ei);
+ /*
+ * In the case of inline back ref, reference count will
+ * be updated by remove_extent_backref
+ */
+ if (iref) {
+ BUG_ON(!found_extent);
+ } else {
+ btrfs_set_extent_refs(leaf, ei, refs);
+ btrfs_mark_buffer_dirty(leaf);
+ }
+ if (found_extent) {
+ ret = remove_extent_backref(trans, extent_root, path,
+ iref, refs_to_drop,
+ is_data, &last_ref);
+ if (ret) {
+ btrfs_abort_transaction(trans, extent_root, ret);
+ goto out;
+ }
+ }
+ add_pinned_bytes(root->fs_info, -num_bytes, owner_objectid,
+ root_objectid);
+ } else {
+ if (found_extent) {
+ BUG_ON(is_data && refs_to_drop !=
+ extent_data_ref_count(root, path, iref));
+ if (iref) {
+ BUG_ON(path->slots[0] != extent_slot);
+ } else {
+ BUG_ON(path->slots[0] != extent_slot + 1);
+ path->slots[0] = extent_slot;
+ num_to_del = 2;
+ }
+ }
+
+ last_ref = 1;
+ ret = btrfs_del_items(trans, extent_root, path, path->slots[0],
+ num_to_del);
+ if (ret) {
+ btrfs_abort_transaction(trans, extent_root, ret);
+ goto out;
+ }
+ btrfs_release_path(path);
+
+ if (is_data) {
+ ret = btrfs_del_csums(trans, root, bytenr, num_bytes);
+ if (ret) {
+ btrfs_abort_transaction(trans, extent_root, ret);
+ goto out;
+ }
+ }
+
+ ret = update_block_group(trans, root, bytenr, num_bytes, 0);
+ if (ret) {
+ btrfs_abort_transaction(trans, extent_root, ret);
+ goto out;
+ }
+ }
+ btrfs_release_path(path);
+
+ /* Deal with the quota accounting */
+ if (!ret && last_ref && !no_quota) {
+ int mod_seq = 0;
+
+ if (owner_objectid >= BTRFS_FIRST_FREE_OBJECTID &&
+ type == BTRFS_QGROUP_OPER_SUB_SHARED)
+ mod_seq = 1;
+
+ ret = btrfs_qgroup_record_ref(trans, info, root_objectid,
+ bytenr, num_bytes, type,
+ mod_seq);
+ }
+out:
+ btrfs_free_path(path);
+ return ret;
+}
+
+/*
+ * when we free an block, it is possible (and likely) that we free the last
+ * delayed ref for that extent as well. This searches the delayed ref tree for
+ * a given extent, and if there are no other delayed refs to be processed, it
+ * removes it from the tree.
+ */
+static noinline int check_ref_cleanup(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, u64 bytenr)
+{
+ struct btrfs_delayed_ref_head *head;
+ struct btrfs_delayed_ref_root *delayed_refs;
+ int ret = 0;
+
+ delayed_refs = &trans->transaction->delayed_refs;
+ spin_lock(&delayed_refs->lock);
+ head = btrfs_find_delayed_ref_head(trans, bytenr);
+ if (!head)
+ goto out_delayed_unlock;
+
+ spin_lock(&head->lock);
+ if (rb_first(&head->ref_root))
+ goto out;
+
+ if (head->extent_op) {
+ if (!head->must_insert_reserved)
+ goto out;
+ btrfs_free_delayed_extent_op(head->extent_op);
+ head->extent_op = NULL;
+ }
+
+ /*
+ * waiting for the lock here would deadlock. If someone else has it
+ * locked they are already in the process of dropping it anyway
+ */
+ if (!mutex_trylock(&head->mutex))
+ goto out;
+
+ /*
+ * at this point we have a head with no other entries. Go
+ * ahead and process it.
+ */
+ head->node.in_tree = 0;
+ rb_erase(&head->href_node, &delayed_refs->href_root);
+
+ atomic_dec(&delayed_refs->num_entries);
+
+ /*
+ * we don't take a ref on the node because we're removing it from the
+ * tree, so we just steal the ref the tree was holding.
+ */
+ delayed_refs->num_heads--;
+ if (head->processing == 0)
+ delayed_refs->num_heads_ready--;
+ head->processing = 0;
+ spin_unlock(&head->lock);
+ spin_unlock(&delayed_refs->lock);
+
+ BUG_ON(head->extent_op);
+ if (head->must_insert_reserved)
+ ret = 1;
+
+ mutex_unlock(&head->mutex);
+ btrfs_put_delayed_ref(&head->node);
+ return ret;
+out:
+ spin_unlock(&head->lock);
+
+out_delayed_unlock:
+ spin_unlock(&delayed_refs->lock);
+ return 0;
+}
+
+void btrfs_free_tree_block(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct extent_buffer *buf,
+ u64 parent, int last_ref)
+{
+ int pin = 1;
+ int ret;
+
+ if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
+ ret = btrfs_add_delayed_tree_ref(root->fs_info, trans,
+ buf->start, buf->len,
+ parent, root->root_key.objectid,
+ btrfs_header_level(buf),
+ BTRFS_DROP_DELAYED_REF, NULL, 0);
+ BUG_ON(ret); /* -ENOMEM */
+ }
+
+ if (!last_ref)
+ return;
+
+ if (btrfs_header_generation(buf) == trans->transid) {
+ struct btrfs_block_group_cache *cache;
+
+ if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
+ ret = check_ref_cleanup(trans, root, buf->start);
+ if (!ret)
+ goto out;
+ }
+
+ cache = btrfs_lookup_block_group(root->fs_info, buf->start);
+
+ if (btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) {
+ pin_down_extent(root, cache, buf->start, buf->len, 1);
+ btrfs_put_block_group(cache);
+ goto out;
+ }
+
+ WARN_ON(test_bit(EXTENT_BUFFER_DIRTY, &buf->bflags));
+
+ btrfs_add_free_space(cache, buf->start, buf->len);
+ btrfs_update_reserved_bytes(cache, buf->len, RESERVE_FREE, 0);
+ btrfs_put_block_group(cache);
+ trace_btrfs_reserved_extent_free(root, buf->start, buf->len);
+ pin = 0;
+ }
+out:
+ if (pin)
+ add_pinned_bytes(root->fs_info, buf->len,
+ btrfs_header_level(buf),
+ root->root_key.objectid);
+
+ /*
+ * Deleting the buffer, clear the corrupt flag since it doesn't matter
+ * anymore.
+ */
+ clear_bit(EXTENT_BUFFER_CORRUPT, &buf->bflags);
+}
+
+/* Can return -ENOMEM */
+int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root *root,
+ u64 bytenr, u64 num_bytes, u64 parent, u64 root_objectid,
+ u64 owner, u64 offset, int no_quota)
+{
+ int ret;
+ struct btrfs_fs_info *fs_info = root->fs_info;
+
+ if (btrfs_test_is_dummy_root(root))
+ return 0;
+
+ add_pinned_bytes(root->fs_info, num_bytes, owner, root_objectid);
+
+ /*
+ * tree log blocks never actually go into the extent allocation
+ * tree, just update pinning info and exit early.
+ */
+ if (root_objectid == BTRFS_TREE_LOG_OBJECTID) {
+ WARN_ON(owner >= BTRFS_FIRST_FREE_OBJECTID);
+ /* unlocks the pinned mutex */
+ btrfs_pin_extent(root, bytenr, num_bytes, 1);
+ ret = 0;
+ } else if (owner < BTRFS_FIRST_FREE_OBJECTID) {
+ ret = btrfs_add_delayed_tree_ref(fs_info, trans, bytenr,
+ num_bytes,
+ parent, root_objectid, (int)owner,
+ BTRFS_DROP_DELAYED_REF, NULL, no_quota);
+ } else {
+ ret = btrfs_add_delayed_data_ref(fs_info, trans, bytenr,
+ num_bytes,
+ parent, root_objectid, owner,
+ offset, BTRFS_DROP_DELAYED_REF,
+ NULL, no_quota);
+ }
+ return ret;
+}
+
+/*
+ * when we wait for progress in the block group caching, its because
+ * our allocation attempt failed at least once. So, we must sleep
+ * and let some progress happen before we try again.
+ *
+ * This function will sleep at least once waiting for new free space to
+ * show up, and then it will check the block group free space numbers
+ * for our min num_bytes. Another option is to have it go ahead
+ * and look in the rbtree for a free extent of a given size, but this
+ * is a good start.
+ *
+ * Callers of this must check if cache->cached == BTRFS_CACHE_ERROR before using
+ * any of the information in this block group.
+ */
+static noinline void
+wait_block_group_cache_progress(struct btrfs_block_group_cache *cache,
+ u64 num_bytes)
+{
+ struct btrfs_caching_control *caching_ctl;
+
+ caching_ctl = get_caching_control(cache);
+ if (!caching_ctl)
+ return;
+
+ wait_event(caching_ctl->wait, block_group_cache_done(cache) ||
+ (cache->free_space_ctl->free_space >= num_bytes));
+
+ put_caching_control(caching_ctl);
+}
+
+static noinline int
+wait_block_group_cache_done(struct btrfs_block_group_cache *cache)
+{
+ struct btrfs_caching_control *caching_ctl;
+ int ret = 0;
+
+ caching_ctl = get_caching_control(cache);
+ if (!caching_ctl)
+ return (cache->cached == BTRFS_CACHE_ERROR) ? -EIO : 0;
+
+ wait_event(caching_ctl->wait, block_group_cache_done(cache));
+ if (cache->cached == BTRFS_CACHE_ERROR)
+ ret = -EIO;
+ put_caching_control(caching_ctl);
+ return ret;
+}
+
+int __get_raid_index(u64 flags)
+{
+ if (flags & BTRFS_BLOCK_GROUP_RAID10)
+ return BTRFS_RAID_RAID10;
+ else if (flags & BTRFS_BLOCK_GROUP_RAID1)
+ return BTRFS_RAID_RAID1;
+ else if (flags & BTRFS_BLOCK_GROUP_DUP)
+ return BTRFS_RAID_DUP;
+ else if (flags & BTRFS_BLOCK_GROUP_RAID0)
+ return BTRFS_RAID_RAID0;
+ else if (flags & BTRFS_BLOCK_GROUP_RAID5)
+ return BTRFS_RAID_RAID5;
+ else if (flags & BTRFS_BLOCK_GROUP_RAID6)
+ return BTRFS_RAID_RAID6;
+
+ return BTRFS_RAID_SINGLE; /* BTRFS_BLOCK_GROUP_SINGLE */
+}
+
+int get_block_group_index(struct btrfs_block_group_cache *cache)
+{
+ return __get_raid_index(cache->flags);
+}
+
+static const char *btrfs_raid_type_names[BTRFS_NR_RAID_TYPES] = {
+ [BTRFS_RAID_RAID10] = "raid10",
+ [BTRFS_RAID_RAID1] = "raid1",
+ [BTRFS_RAID_DUP] = "dup",
+ [BTRFS_RAID_RAID0] = "raid0",
+ [BTRFS_RAID_SINGLE] = "single",
+ [BTRFS_RAID_RAID5] = "raid5",
+ [BTRFS_RAID_RAID6] = "raid6",
+};
+
+static const char *get_raid_name(enum btrfs_raid_types type)
+{
+ if (type >= BTRFS_NR_RAID_TYPES)
+ return NULL;
+
+ return btrfs_raid_type_names[type];
+}
+
+enum btrfs_loop_type {
+ LOOP_CACHING_NOWAIT = 0,
+ LOOP_CACHING_WAIT = 1,
+ LOOP_ALLOC_CHUNK = 2,
+ LOOP_NO_EMPTY_SIZE = 3,
+};
+
+static inline void
+btrfs_lock_block_group(struct btrfs_block_group_cache *cache,
+ int delalloc)
+{
+ if (delalloc)
+ down_read(&cache->data_rwsem);
+}
+
+static inline void
+btrfs_grab_block_group(struct btrfs_block_group_cache *cache,
+ int delalloc)
+{
+ btrfs_get_block_group(cache);
+ if (delalloc)
+ down_read(&cache->data_rwsem);
+}
+
+static struct btrfs_block_group_cache *
+btrfs_lock_cluster(struct btrfs_block_group_cache *block_group,
+ struct btrfs_free_cluster *cluster,
+ int delalloc)
+{
+ struct btrfs_block_group_cache *used_bg;
+ bool locked = false;
+again:
+ spin_lock(&cluster->refill_lock);
+ if (locked) {
+ if (used_bg == cluster->block_group)
+ return used_bg;
+
+ up_read(&used_bg->data_rwsem);
+ btrfs_put_block_group(used_bg);
+ }
+
+ used_bg = cluster->block_group;
+ if (!used_bg)
+ return NULL;
+
+ if (used_bg == block_group)
+ return used_bg;
+
+ btrfs_get_block_group(used_bg);
+
+ if (!delalloc)
+ return used_bg;
+
+ if (down_read_trylock(&used_bg->data_rwsem))
+ return used_bg;
+
+ spin_unlock(&cluster->refill_lock);
+ down_read(&used_bg->data_rwsem);
+ locked = true;
+ goto again;
+}
+
+static inline void
+btrfs_release_block_group(struct btrfs_block_group_cache *cache,
+ int delalloc)
+{
+ if (delalloc)
+ up_read(&cache->data_rwsem);
+ btrfs_put_block_group(cache);
+}
+
+/*
+ * walks the btree of allocated extents and find a hole of a given size.
+ * The key ins is changed to record the hole:
+ * ins->objectid == start position
+ * ins->flags = BTRFS_EXTENT_ITEM_KEY
+ * ins->offset == the size of the hole.
+ * Any available blocks before search_start are skipped.
+ *
+ * If there is no suitable free space, we will record the max size of
+ * the free space extent currently.
+ */
+static noinline int find_free_extent(struct btrfs_root *orig_root,
+ u64 num_bytes, u64 empty_size,
+ u64 hint_byte, struct btrfs_key *ins,
+ u64 flags, int delalloc)
+{
+ int ret = 0;
+ struct btrfs_root *root = orig_root->fs_info->extent_root;
+ struct btrfs_free_cluster *last_ptr = NULL;
+ struct btrfs_block_group_cache *block_group = NULL;
+ u64 search_start = 0;
+ u64 max_extent_size = 0;
+ int empty_cluster = 2 * 1024 * 1024;
+ struct btrfs_space_info *space_info;
+ int loop = 0;
+ int index = __get_raid_index(flags);
+ int alloc_type = (flags & BTRFS_BLOCK_GROUP_DATA) ?
+ RESERVE_ALLOC_NO_ACCOUNT : RESERVE_ALLOC;
+ bool failed_cluster_refill = false;
+ bool failed_alloc = false;
+ bool use_cluster = true;
+ bool have_caching_bg = false;
+
+ WARN_ON(num_bytes < root->sectorsize);
+ ins->type = BTRFS_EXTENT_ITEM_KEY;
+ ins->objectid = 0;
+ ins->offset = 0;
+
+ trace_find_free_extent(orig_root, num_bytes, empty_size, flags);
+
+ space_info = __find_space_info(root->fs_info, flags);
+ if (!space_info) {
+ btrfs_err(root->fs_info, "No space info for %llu", flags);
+ return -ENOSPC;
+ }
+
+ /*
+ * If the space info is for both data and metadata it means we have a
+ * small filesystem and we can't use the clustering stuff.
+ */
+ if (btrfs_mixed_space_info(space_info))
+ use_cluster = false;
+
+ if (flags & BTRFS_BLOCK_GROUP_METADATA && use_cluster) {
+ last_ptr = &root->fs_info->meta_alloc_cluster;
+ if (!btrfs_test_opt(root, SSD))
+ empty_cluster = 64 * 1024;
+ }
+
+ if ((flags & BTRFS_BLOCK_GROUP_DATA) && use_cluster &&
+ btrfs_test_opt(root, SSD)) {
+ last_ptr = &root->fs_info->data_alloc_cluster;
+ }
+
+ if (last_ptr) {
+ spin_lock(&last_ptr->lock);
+ if (last_ptr->block_group)
+ hint_byte = last_ptr->window_start;
+ spin_unlock(&last_ptr->lock);
+ }
+
+ search_start = max(search_start, first_logical_byte(root, 0));
+ search_start = max(search_start, hint_byte);
+
+ if (!last_ptr)
+ empty_cluster = 0;
+
+ if (search_start == hint_byte) {
+ block_group = btrfs_lookup_block_group(root->fs_info,
+ search_start);
+ /*
+ * we don't want to use the block group if it doesn't match our
+ * allocation bits, or if its not cached.
+ *
+ * However if we are re-searching with an ideal block group
+ * picked out then we don't care that the block group is cached.
+ */
+ if (block_group && block_group_bits(block_group, flags) &&
+ block_group->cached != BTRFS_CACHE_NO) {
+ down_read(&space_info->groups_sem);
+ if (list_empty(&block_group->list) ||
+ block_group->ro) {
+ /*
+ * someone is removing this block group,
+ * we can't jump into the have_block_group
+ * target because our list pointers are not
+ * valid
+ */
+ btrfs_put_block_group(block_group);
+ up_read(&space_info->groups_sem);
+ } else {
+ index = get_block_group_index(block_group);
+ btrfs_lock_block_group(block_group, delalloc);
+ goto have_block_group;
+ }
+ } else if (block_group) {
+ btrfs_put_block_group(block_group);
+ }
+ }
+search:
+ have_caching_bg = false;
+ down_read(&space_info->groups_sem);
+ list_for_each_entry(block_group, &space_info->block_groups[index],
+ list) {
+ u64 offset;
+ int cached;
+
+ btrfs_grab_block_group(block_group, delalloc);
+ search_start = block_group->key.objectid;
+
+ /*
+ * this can happen if we end up cycling through all the
+ * raid types, but we want to make sure we only allocate
+ * for the proper type.
+ */
+ if (!block_group_bits(block_group, flags)) {
+ u64 extra = BTRFS_BLOCK_GROUP_DUP |
+ BTRFS_BLOCK_GROUP_RAID1 |
+ BTRFS_BLOCK_GROUP_RAID5 |
+ BTRFS_BLOCK_GROUP_RAID6 |
+ BTRFS_BLOCK_GROUP_RAID10;
+
+ /*
+ * if they asked for extra copies and this block group
+ * doesn't provide them, bail. This does allow us to
+ * fill raid0 from raid1.
+ */
+ if ((flags & extra) && !(block_group->flags & extra))
+ goto loop;
+ }
+
+have_block_group:
+ cached = block_group_cache_done(block_group);
+ if (unlikely(!cached)) {
+ ret = cache_block_group(block_group, 0);
+ BUG_ON(ret < 0);
+ ret = 0;
+ }
+
+ if (unlikely(block_group->cached == BTRFS_CACHE_ERROR))
+ goto loop;
+ if (unlikely(block_group->ro))
+ goto loop;
+
+ /*
+ * Ok we want to try and use the cluster allocator, so
+ * lets look there
+ */
+ if (last_ptr) {
+ struct btrfs_block_group_cache *used_block_group;
+ unsigned long aligned_cluster;
+ /*
+ * the refill lock keeps out other
+ * people trying to start a new cluster
+ */
+ used_block_group = btrfs_lock_cluster(block_group,
+ last_ptr,
+ delalloc);
+ if (!used_block_group)
+ goto refill_cluster;
+
+ if (used_block_group != block_group &&
+ (used_block_group->ro ||
+ !block_group_bits(used_block_group, flags)))
+ goto release_cluster;
+
+ offset = btrfs_alloc_from_cluster(used_block_group,
+ last_ptr,
+ num_bytes,
+ used_block_group->key.objectid,
+ &max_extent_size);
+ if (offset) {
+ /* we have a block, we're done */
+ spin_unlock(&last_ptr->refill_lock);
+ trace_btrfs_reserve_extent_cluster(root,
+ used_block_group,
+ search_start, num_bytes);
+ if (used_block_group != block_group) {
+ btrfs_release_block_group(block_group,
+ delalloc);
+ block_group = used_block_group;
+ }
+ goto checks;
+ }
+
+ WARN_ON(last_ptr->block_group != used_block_group);
+release_cluster:
+ /* If we are on LOOP_NO_EMPTY_SIZE, we can't
+ * set up a new clusters, so lets just skip it
+ * and let the allocator find whatever block
+ * it can find. If we reach this point, we
+ * will have tried the cluster allocator
+ * plenty of times and not have found
+ * anything, so we are likely way too
+ * fragmented for the clustering stuff to find
+ * anything.
+ *
+ * However, if the cluster is taken from the
+ * current block group, release the cluster
+ * first, so that we stand a better chance of
+ * succeeding in the unclustered
+ * allocation. */
+ if (loop >= LOOP_NO_EMPTY_SIZE &&
+ used_block_group != block_group) {
+ spin_unlock(&last_ptr->refill_lock);
+ btrfs_release_block_group(used_block_group,
+ delalloc);
+ goto unclustered_alloc;
+ }
+
+ /*
+ * this cluster didn't work out, free it and
+ * start over
+ */
+ btrfs_return_cluster_to_free_space(NULL, last_ptr);
+
+ if (used_block_group != block_group)
+ btrfs_release_block_group(used_block_group,
+ delalloc);
+refill_cluster:
+ if (loop >= LOOP_NO_EMPTY_SIZE) {
+ spin_unlock(&last_ptr->refill_lock);
+ goto unclustered_alloc;
+ }
+
+ aligned_cluster = max_t(unsigned long,
+ empty_cluster + empty_size,
+ block_group->full_stripe_len);
+
+ /* allocate a cluster in this block group */
+ ret = btrfs_find_space_cluster(root, block_group,
+ last_ptr, search_start,
+ num_bytes,
+ aligned_cluster);
+ if (ret == 0) {
+ /*
+ * now pull our allocation out of this
+ * cluster
+ */
+ offset = btrfs_alloc_from_cluster(block_group,
+ last_ptr,
+ num_bytes,
+ search_start,
+ &max_extent_size);
+ if (offset) {
+ /* we found one, proceed */
+ spin_unlock(&last_ptr->refill_lock);
+ trace_btrfs_reserve_extent_cluster(root,
+ block_group, search_start,
+ num_bytes);
+ goto checks;
+ }
+ } else if (!cached && loop > LOOP_CACHING_NOWAIT
+ && !failed_cluster_refill) {
+ spin_unlock(&last_ptr->refill_lock);
+
+ failed_cluster_refill = true;
+ wait_block_group_cache_progress(block_group,
+ num_bytes + empty_cluster + empty_size);
+ goto have_block_group;
+ }
+
+ /*
+ * at this point we either didn't find a cluster
+ * or we weren't able to allocate a block from our
+ * cluster. Free the cluster we've been trying
+ * to use, and go to the next block group
+ */
+ btrfs_return_cluster_to_free_space(NULL, last_ptr);
+ spin_unlock(&last_ptr->refill_lock);
+ goto loop;
+ }
+
+unclustered_alloc:
+ spin_lock(&block_group->free_space_ctl->tree_lock);
+ if (cached &&
+ block_group->free_space_ctl->free_space <
+ num_bytes + empty_cluster + empty_size) {
+ if (block_group->free_space_ctl->free_space >
+ max_extent_size)
+ max_extent_size =
+ block_group->free_space_ctl->free_space;
+ spin_unlock(&block_group->free_space_ctl->tree_lock);
+ goto loop;
+ }
+ spin_unlock(&block_group->free_space_ctl->tree_lock);
+
+ offset = btrfs_find_space_for_alloc(block_group, search_start,
+ num_bytes, empty_size,
+ &max_extent_size);
+ /*
+ * If we didn't find a chunk, and we haven't failed on this
+ * block group before, and this block group is in the middle of
+ * caching and we are ok with waiting, then go ahead and wait
+ * for progress to be made, and set failed_alloc to true.
+ *
+ * If failed_alloc is true then we've already waited on this
+ * block group once and should move on to the next block group.
+ */
+ if (!offset && !failed_alloc && !cached &&
+ loop > LOOP_CACHING_NOWAIT) {
+ wait_block_group_cache_progress(block_group,
+ num_bytes + empty_size);
+ failed_alloc = true;
+ goto have_block_group;
+ } else if (!offset) {
+ if (!cached)
+ have_caching_bg = true;
+ goto loop;
+ }
+checks:
+ search_start = ALIGN(offset, root->stripesize);
+
+ /* move on to the next group */
+ if (search_start + num_bytes >
+ block_group->key.objectid + block_group->key.offset) {
+ btrfs_add_free_space(block_group, offset, num_bytes);
+ goto loop;
+ }
+
+ if (offset < search_start)
+ btrfs_add_free_space(block_group, offset,
+ search_start - offset);
+ BUG_ON(offset > search_start);
+
+ ret = btrfs_update_reserved_bytes(block_group, num_bytes,
+ alloc_type, delalloc);
+ if (ret == -EAGAIN) {
+ btrfs_add_free_space(block_group, offset, num_bytes);
+ goto loop;
+ }
+
+ /* we are all good, lets return */
+ ins->objectid = search_start;
+ ins->offset = num_bytes;
+
+ trace_btrfs_reserve_extent(orig_root, block_group,
+ search_start, num_bytes);
+ btrfs_release_block_group(block_group, delalloc);
+ break;
+loop:
+ failed_cluster_refill = false;
+ failed_alloc = false;
+ BUG_ON(index != get_block_group_index(block_group));
+ btrfs_release_block_group(block_group, delalloc);
+ }
+ up_read(&space_info->groups_sem);
+
+ if (!ins->objectid && loop >= LOOP_CACHING_WAIT && have_caching_bg)
+ goto search;
+
+ if (!ins->objectid && ++index < BTRFS_NR_RAID_TYPES)
+ goto search;
+
+ /*
+ * LOOP_CACHING_NOWAIT, search partially cached block groups, kicking
+ * caching kthreads as we move along
+ * LOOP_CACHING_WAIT, search everything, and wait if our bg is caching
+ * LOOP_ALLOC_CHUNK, force a chunk allocation and try again
+ * LOOP_NO_EMPTY_SIZE, set empty_size and empty_cluster to 0 and try
+ * again
+ */
+ if (!ins->objectid && loop < LOOP_NO_EMPTY_SIZE) {
+ index = 0;
+ loop++;
+ if (loop == LOOP_ALLOC_CHUNK) {
+ struct btrfs_trans_handle *trans;
+ int exist = 0;
+
+ trans = current->journal_info;
+ if (trans)
+ exist = 1;
+ else
+ trans = btrfs_join_transaction(root);
+
+ if (IS_ERR(trans)) {
+ ret = PTR_ERR(trans);
+ goto out;
+ }
+
+ ret = do_chunk_alloc(trans, root, flags,
+ CHUNK_ALLOC_FORCE);
+ /*
+ * Do not bail out on ENOSPC since we
+ * can do more things.
+ */
+ if (ret < 0 && ret != -ENOSPC)
+ btrfs_abort_transaction(trans,
+ root, ret);
+ else
+ ret = 0;
+ if (!exist)
+ btrfs_end_transaction(trans, root);
+ if (ret)
+ goto out;
+ }
+
+ if (loop == LOOP_NO_EMPTY_SIZE) {
+ empty_size = 0;
+ empty_cluster = 0;
+ }
+
+ goto search;
+ } else if (!ins->objectid) {
+ ret = -ENOSPC;
+ } else if (ins->objectid) {
+ ret = 0;
+ }
+out:
+ if (ret == -ENOSPC)
+ ins->offset = max_extent_size;
+ return ret;
+}
+
+static void dump_space_info(struct btrfs_space_info *info, u64 bytes,
+ int dump_block_groups)
+{
+ struct btrfs_block_group_cache *cache;
+ int index = 0;
+
+ spin_lock(&info->lock);
+ printk(KERN_INFO "BTRFS: space_info %llu has %llu free, is %sfull\n",
+ info->flags,
+ info->total_bytes - info->bytes_used - info->bytes_pinned -
+ info->bytes_reserved - info->bytes_readonly,
+ (info->full) ? "" : "not ");
+ printk(KERN_INFO "BTRFS: space_info total=%llu, used=%llu, pinned=%llu, "
+ "reserved=%llu, may_use=%llu, readonly=%llu\n",
+ info->total_bytes, info->bytes_used, info->bytes_pinned,
+ info->bytes_reserved, info->bytes_may_use,
+ info->bytes_readonly);
+ spin_unlock(&info->lock);
+
+ if (!dump_block_groups)
+ return;
+
+ down_read(&info->groups_sem);
+again:
+ list_for_each_entry(cache, &info->block_groups[index], list) {
+ spin_lock(&cache->lock);
+ printk(KERN_INFO "BTRFS: "
+ "block group %llu has %llu bytes, "
+ "%llu used %llu pinned %llu reserved %s\n",
+ cache->key.objectid, cache->key.offset,
+ btrfs_block_group_used(&cache->item), cache->pinned,
+ cache->reserved, cache->ro ? "[readonly]" : "");
+ btrfs_dump_free_space(cache, bytes);
+ spin_unlock(&cache->lock);
+ }
+ if (++index < BTRFS_NR_RAID_TYPES)
+ goto again;
+ up_read(&info->groups_sem);
+}
+
+int btrfs_reserve_extent(struct btrfs_root *root,
+ u64 num_bytes, u64 min_alloc_size,
+ u64 empty_size, u64 hint_byte,
+ struct btrfs_key *ins, int is_data, int delalloc)
+{
+ bool final_tried = false;
+ u64 flags;
+ int ret;
+
+ flags = btrfs_get_alloc_profile(root, is_data);
+again:
+ WARN_ON(num_bytes < root->sectorsize);
+ ret = find_free_extent(root, num_bytes, empty_size, hint_byte, ins,
+ flags, delalloc);
+
+ if (ret == -ENOSPC) {
+ if (!final_tried && ins->offset) {
+ num_bytes = min(num_bytes >> 1, ins->offset);
+ num_bytes = round_down(num_bytes, root->sectorsize);
+ num_bytes = max(num_bytes, min_alloc_size);
+ if (num_bytes == min_alloc_size)
+ final_tried = true;
+ goto again;
+ } else if (btrfs_test_opt(root, ENOSPC_DEBUG)) {
+ struct btrfs_space_info *sinfo;
+
+ sinfo = __find_space_info(root->fs_info, flags);
+ btrfs_err(root->fs_info, "allocation failed flags %llu, wanted %llu",
+ flags, num_bytes);
+ if (sinfo)
+ dump_space_info(sinfo, num_bytes, 1);
+ }
+ }
+
+ return ret;
+}
+
+static int __btrfs_free_reserved_extent(struct btrfs_root *root,
+ u64 start, u64 len,
+ int pin, int delalloc)
+{
+ struct btrfs_block_group_cache *cache;
+ int ret = 0;
+
+ cache = btrfs_lookup_block_group(root->fs_info, start);
+ if (!cache) {
+ btrfs_err(root->fs_info, "Unable to find block group for %llu",
+ start);
+ return -ENOSPC;
+ }
+
+ if (pin)
+ pin_down_extent(root, cache, start, len, 1);
+ else {
+ if (btrfs_test_opt(root, DISCARD))
+ ret = btrfs_discard_extent(root, start, len, NULL);
+ btrfs_add_free_space(cache, start, len);
+ btrfs_update_reserved_bytes(cache, len, RESERVE_FREE, delalloc);
+ }
+
+ btrfs_put_block_group(cache);
+
+ trace_btrfs_reserved_extent_free(root, start, len);
+
+ return ret;
+}
+
+int btrfs_free_reserved_extent(struct btrfs_root *root,
+ u64 start, u64 len, int delalloc)
+{
+ return __btrfs_free_reserved_extent(root, start, len, 0, delalloc);
+}
+
+int btrfs_free_and_pin_reserved_extent(struct btrfs_root *root,
+ u64 start, u64 len)
+{
+ return __btrfs_free_reserved_extent(root, start, len, 1, 0);
+}
+
+static int alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ u64 parent, u64 root_objectid,
+ u64 flags, u64 owner, u64 offset,
+ struct btrfs_key *ins, int ref_mod)
+{
+ int ret;
+ struct btrfs_fs_info *fs_info = root->fs_info;
+ struct btrfs_extent_item *extent_item;
+ struct btrfs_extent_inline_ref *iref;
+ struct btrfs_path *path;
+ struct extent_buffer *leaf;
+ int type;
+ u32 size;
+
+ if (parent > 0)
+ type = BTRFS_SHARED_DATA_REF_KEY;
+ else
+ type = BTRFS_EXTENT_DATA_REF_KEY;
+
+ size = sizeof(*extent_item) + btrfs_extent_inline_ref_size(type);
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ path->leave_spinning = 1;
+ ret = btrfs_insert_empty_item(trans, fs_info->extent_root, path,
+ ins, size);
+ if (ret) {
+ btrfs_free_path(path);
+ return ret;
+ }
+
+ leaf = path->nodes[0];
+ extent_item = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_extent_item);
+ btrfs_set_extent_refs(leaf, extent_item, ref_mod);
+ btrfs_set_extent_generation(leaf, extent_item, trans->transid);
+ btrfs_set_extent_flags(leaf, extent_item,
+ flags | BTRFS_EXTENT_FLAG_DATA);
+
+ iref = (struct btrfs_extent_inline_ref *)(extent_item + 1);
+ btrfs_set_extent_inline_ref_type(leaf, iref, type);
+ if (parent > 0) {
+ struct btrfs_shared_data_ref *ref;
+ ref = (struct btrfs_shared_data_ref *)(iref + 1);
+ btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
+ btrfs_set_shared_data_ref_count(leaf, ref, ref_mod);
+ } else {
+ struct btrfs_extent_data_ref *ref;
+ ref = (struct btrfs_extent_data_ref *)(&iref->offset);
+ btrfs_set_extent_data_ref_root(leaf, ref, root_objectid);
+ btrfs_set_extent_data_ref_objectid(leaf, ref, owner);
+ btrfs_set_extent_data_ref_offset(leaf, ref, offset);
+ btrfs_set_extent_data_ref_count(leaf, ref, ref_mod);
+ }
+
+ btrfs_mark_buffer_dirty(path->nodes[0]);
+ btrfs_free_path(path);
+
+ /* Always set parent to 0 here since its exclusive anyway. */
+ ret = btrfs_qgroup_record_ref(trans, fs_info, root_objectid,
+ ins->objectid, ins->offset,
+ BTRFS_QGROUP_OPER_ADD_EXCL, 0);
+ if (ret)
+ return ret;
+
+ ret = update_block_group(trans, root, ins->objectid, ins->offset, 1);
+ if (ret) { /* -ENOENT, logic error */
+ btrfs_err(fs_info, "update block group failed for %llu %llu",
+ ins->objectid, ins->offset);
+ BUG();
+ }
+ trace_btrfs_reserved_extent_alloc(root, ins->objectid, ins->offset);
+ return ret;
+}
+
+static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ u64 parent, u64 root_objectid,
+ u64 flags, struct btrfs_disk_key *key,
+ int level, struct btrfs_key *ins,
+ int no_quota)
+{
+ int ret;
+ struct btrfs_fs_info *fs_info = root->fs_info;
+ struct btrfs_extent_item *extent_item;
+ struct btrfs_tree_block_info *block_info;
+ struct btrfs_extent_inline_ref *iref;
+ struct btrfs_path *path;
+ struct extent_buffer *leaf;
+ u32 size = sizeof(*extent_item) + sizeof(*iref);
+ u64 num_bytes = ins->offset;
+ bool skinny_metadata = btrfs_fs_incompat(root->fs_info,
+ SKINNY_METADATA);
+
+ if (!skinny_metadata)
+ size += sizeof(*block_info);
+
+ path = btrfs_alloc_path();
+ if (!path) {
+ btrfs_free_and_pin_reserved_extent(root, ins->objectid,
+ root->nodesize);
+ return -ENOMEM;
+ }
+
+ path->leave_spinning = 1;
+ ret = btrfs_insert_empty_item(trans, fs_info->extent_root, path,
+ ins, size);
+ if (ret) {
+ btrfs_free_path(path);
+ btrfs_free_and_pin_reserved_extent(root, ins->objectid,
+ root->nodesize);
+ return ret;
+ }
+
+ leaf = path->nodes[0];
+ extent_item = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_extent_item);
+ btrfs_set_extent_refs(leaf, extent_item, 1);
+ btrfs_set_extent_generation(leaf, extent_item, trans->transid);
+ btrfs_set_extent_flags(leaf, extent_item,
+ flags | BTRFS_EXTENT_FLAG_TREE_BLOCK);
+
+ if (skinny_metadata) {
+ iref = (struct btrfs_extent_inline_ref *)(extent_item + 1);
+ num_bytes = root->nodesize;
+ } else {
+ block_info = (struct btrfs_tree_block_info *)(extent_item + 1);
+ btrfs_set_tree_block_key(leaf, block_info, key);
+ btrfs_set_tree_block_level(leaf, block_info, level);
+ iref = (struct btrfs_extent_inline_ref *)(block_info + 1);
+ }
+
+ if (parent > 0) {
+ BUG_ON(!(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF));
+ btrfs_set_extent_inline_ref_type(leaf, iref,
+ BTRFS_SHARED_BLOCK_REF_KEY);
+ btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
+ } else {
+ btrfs_set_extent_inline_ref_type(leaf, iref,
+ BTRFS_TREE_BLOCK_REF_KEY);
+ btrfs_set_extent_inline_ref_offset(leaf, iref, root_objectid);
+ }
+
+ btrfs_mark_buffer_dirty(leaf);
+ btrfs_free_path(path);
+
+ if (!no_quota) {
+ ret = btrfs_qgroup_record_ref(trans, fs_info, root_objectid,
+ ins->objectid, num_bytes,
+ BTRFS_QGROUP_OPER_ADD_EXCL, 0);
+ if (ret)
+ return ret;
+ }
+
+ ret = update_block_group(trans, root, ins->objectid, root->nodesize,
+ 1);
+ if (ret) { /* -ENOENT, logic error */
+ btrfs_err(fs_info, "update block group failed for %llu %llu",
+ ins->objectid, ins->offset);
+ BUG();
+ }
+
+ trace_btrfs_reserved_extent_alloc(root, ins->objectid, root->nodesize);
+ return ret;
+}
+
+int btrfs_alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ u64 root_objectid, u64 owner,
+ u64 offset, struct btrfs_key *ins)
+{
+ int ret;
+
+ BUG_ON(root_objectid == BTRFS_TREE_LOG_OBJECTID);
+
+ ret = btrfs_add_delayed_data_ref(root->fs_info, trans, ins->objectid,
+ ins->offset, 0,
+ root_objectid, owner, offset,
+ BTRFS_ADD_DELAYED_EXTENT, NULL, 0);
+ return ret;
+}
+
+/*
+ * this is used by the tree logging recovery code. It records that
+ * an extent has been allocated and makes sure to clear the free
+ * space cache bits as well
+ */
+int btrfs_alloc_logged_file_extent(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ u64 root_objectid, u64 owner, u64 offset,
+ struct btrfs_key *ins)
+{
+ int ret;
+ struct btrfs_block_group_cache *block_group;
+
+ /*
+ * Mixed block groups will exclude before processing the log so we only
+ * need to do the exlude dance if this fs isn't mixed.
+ */
+ if (!btrfs_fs_incompat(root->fs_info, MIXED_GROUPS)) {
+ ret = __exclude_logged_extent(root, ins->objectid, ins->offset);
+ if (ret)
+ return ret;
+ }
+
+ block_group = btrfs_lookup_block_group(root->fs_info, ins->objectid);
+ if (!block_group)
+ return -EINVAL;
+
+ ret = btrfs_update_reserved_bytes(block_group, ins->offset,
+ RESERVE_ALLOC_NO_ACCOUNT, 0);
+ BUG_ON(ret); /* logic error */
+ ret = alloc_reserved_file_extent(trans, root, 0, root_objectid,
+ 0, owner, offset, ins, 1);
+ btrfs_put_block_group(block_group);
+ return ret;
+}
+
+static struct extent_buffer *
+btrfs_init_new_buffer(struct btrfs_trans_handle *trans, struct btrfs_root *root,
+ u64 bytenr, int level)
+{
+ struct extent_buffer *buf;
+
+ buf = btrfs_find_create_tree_block(root, bytenr);
+ if (!buf)
+ return ERR_PTR(-ENOMEM);
+ btrfs_set_header_generation(buf, trans->transid);
+ btrfs_set_buffer_lockdep_class(root->root_key.objectid, buf, level);
+ btrfs_tree_lock(buf);
+ clean_tree_block(trans, root->fs_info, buf);
+ clear_bit(EXTENT_BUFFER_STALE, &buf->bflags);
+
+ btrfs_set_lock_blocking(buf);
+ btrfs_set_buffer_uptodate(buf);
+
+ if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
+ buf->log_index = root->log_transid % 2;
+ /*
+ * we allow two log transactions at a time, use different
+ * EXENT bit to differentiate dirty pages.
+ */
+ if (buf->log_index == 0)
+ set_extent_dirty(&root->dirty_log_pages, buf->start,
+ buf->start + buf->len - 1, GFP_NOFS);
+ else
+ set_extent_new(&root->dirty_log_pages, buf->start,
+ buf->start + buf->len - 1, GFP_NOFS);
+ } else {
+ buf->log_index = -1;
+ set_extent_dirty(&trans->transaction->dirty_pages, buf->start,
+ buf->start + buf->len - 1, GFP_NOFS);
+ }
+ trans->blocks_used++;
+ /* this returns a buffer locked for blocking */
+ return buf;
+}
+
+static struct btrfs_block_rsv *
+use_block_rsv(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, u32 blocksize)
+{
+ struct btrfs_block_rsv *block_rsv;
+ struct btrfs_block_rsv *global_rsv = &root->fs_info->global_block_rsv;
+ int ret;
+ bool global_updated = false;
+
+ block_rsv = get_block_rsv(trans, root);
+
+ if (unlikely(block_rsv->size == 0))
+ goto try_reserve;
+again:
+ ret = block_rsv_use_bytes(block_rsv, blocksize);
+ if (!ret)
+ return block_rsv;
+
+ if (block_rsv->failfast)
+ return ERR_PTR(ret);
+
+ if (block_rsv->type == BTRFS_BLOCK_RSV_GLOBAL && !global_updated) {
+ global_updated = true;
+ update_global_block_rsv(root->fs_info);
+ goto again;
+ }
+
+ if (btrfs_test_opt(root, ENOSPC_DEBUG)) {
+ static DEFINE_RATELIMIT_STATE(_rs,
+ DEFAULT_RATELIMIT_INTERVAL * 10,
+ /*DEFAULT_RATELIMIT_BURST*/ 1);
+ if (__ratelimit(&_rs))
+ WARN(1, KERN_DEBUG
+ "BTRFS: block rsv returned %d\n", ret);
+ }
+try_reserve:
+ ret = reserve_metadata_bytes(root, block_rsv, blocksize,
+ BTRFS_RESERVE_NO_FLUSH);
+ if (!ret)
+ return block_rsv;
+ /*
+ * If we couldn't reserve metadata bytes try and use some from
+ * the global reserve if its space type is the same as the global
+ * reservation.
+ */
+ if (block_rsv->type != BTRFS_BLOCK_RSV_GLOBAL &&
+ block_rsv->space_info == global_rsv->space_info) {
+ ret = block_rsv_use_bytes(global_rsv, blocksize);
+ if (!ret)
+ return global_rsv;
+ }
+ return ERR_PTR(ret);
+}
+
+static void unuse_block_rsv(struct btrfs_fs_info *fs_info,
+ struct btrfs_block_rsv *block_rsv, u32 blocksize)
+{
+ block_rsv_add_bytes(block_rsv, blocksize, 0);
+ block_rsv_release_bytes(fs_info, block_rsv, NULL, 0);
+}
+
+/*
+ * finds a free extent and does all the dirty work required for allocation
+ * returns the key for the extent through ins, and a tree buffer for
+ * the first block of the extent through buf.
+ *
+ * returns the tree buffer or an ERR_PTR on error.
+ */
+struct extent_buffer *btrfs_alloc_tree_block(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ u64 parent, u64 root_objectid,
+ struct btrfs_disk_key *key, int level,
+ u64 hint, u64 empty_size)
+{
+ struct btrfs_key ins;
+ struct btrfs_block_rsv *block_rsv;
+ struct extent_buffer *buf;
+ struct btrfs_delayed_extent_op *extent_op;
+ u64 flags = 0;
+ int ret;
+ u32 blocksize = root->nodesize;
+ bool skinny_metadata = btrfs_fs_incompat(root->fs_info,
+ SKINNY_METADATA);
+
+ if (btrfs_test_is_dummy_root(root)) {
+ buf = btrfs_init_new_buffer(trans, root, root->alloc_bytenr,
+ level);
+ if (!IS_ERR(buf))
+ root->alloc_bytenr += blocksize;
+ return buf;
+ }
+
+ block_rsv = use_block_rsv(trans, root, blocksize);
+ if (IS_ERR(block_rsv))
+ return ERR_CAST(block_rsv);
+
+ ret = btrfs_reserve_extent(root, blocksize, blocksize,
+ empty_size, hint, &ins, 0, 0);
+ if (ret)
+ goto out_unuse;
+
+ buf = btrfs_init_new_buffer(trans, root, ins.objectid, level);
+ if (IS_ERR(buf)) {
+ ret = PTR_ERR(buf);
+ goto out_free_reserved;
+ }
+
+ if (root_objectid == BTRFS_TREE_RELOC_OBJECTID) {
+ if (parent == 0)
+ parent = ins.objectid;
+ flags |= BTRFS_BLOCK_FLAG_FULL_BACKREF;
+ } else
+ BUG_ON(parent > 0);
+
+ if (root_objectid != BTRFS_TREE_LOG_OBJECTID) {
+ extent_op = btrfs_alloc_delayed_extent_op();
+ if (!extent_op) {
+ ret = -ENOMEM;
+ goto out_free_buf;
+ }
+ if (key)
+ memcpy(&extent_op->key, key, sizeof(extent_op->key));
+ else
+ memset(&extent_op->key, 0, sizeof(extent_op->key));
+ extent_op->flags_to_set = flags;
+ if (skinny_metadata)
+ extent_op->update_key = 0;
+ else
+ extent_op->update_key = 1;
+ extent_op->update_flags = 1;
+ extent_op->is_data = 0;
+ extent_op->level = level;
+
+ ret = btrfs_add_delayed_tree_ref(root->fs_info, trans,
+ ins.objectid, ins.offset,
+ parent, root_objectid, level,
+ BTRFS_ADD_DELAYED_EXTENT,
+ extent_op, 0);
+ if (ret)
+ goto out_free_delayed;
+ }
+ return buf;
+
+out_free_delayed:
+ btrfs_free_delayed_extent_op(extent_op);
+out_free_buf:
+ free_extent_buffer(buf);
+out_free_reserved:
+ btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 0);
+out_unuse:
+ unuse_block_rsv(root->fs_info, block_rsv, blocksize);
+ return ERR_PTR(ret);
+}
+
+struct walk_control {
+ u64 refs[BTRFS_MAX_LEVEL];
+ u64 flags[BTRFS_MAX_LEVEL];
+ struct btrfs_key update_progress;
+ int stage;
+ int level;
+ int shared_level;
+ int update_ref;
+ int keep_locks;
+ int reada_slot;
+ int reada_count;
+ int for_reloc;
+};
+
+#define DROP_REFERENCE 1
+#define UPDATE_BACKREF 2
+
+static noinline void reada_walk_down(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct walk_control *wc,
+ struct btrfs_path *path)
+{
+ u64 bytenr;
+ u64 generation;
+ u64 refs;
+ u64 flags;
+ u32 nritems;
+ u32 blocksize;
+ struct btrfs_key key;
+ struct extent_buffer *eb;
+ int ret;
+ int slot;
+ int nread = 0;
+
+ if (path->slots[wc->level] < wc->reada_slot) {
+ wc->reada_count = wc->reada_count * 2 / 3;
+ wc->reada_count = max(wc->reada_count, 2);
+ } else {
+ wc->reada_count = wc->reada_count * 3 / 2;
+ wc->reada_count = min_t(int, wc->reada_count,
+ BTRFS_NODEPTRS_PER_BLOCK(root));
+ }
+
+ eb = path->nodes[wc->level];
+ nritems = btrfs_header_nritems(eb);
+ blocksize = root->nodesize;
+
+ for (slot = path->slots[wc->level]; slot < nritems; slot++) {
+ if (nread >= wc->reada_count)
+ break;
+
+ cond_resched();
+ bytenr = btrfs_node_blockptr(eb, slot);
+ generation = btrfs_node_ptr_generation(eb, slot);
+
+ if (slot == path->slots[wc->level])
+ goto reada;
+
+ if (wc->stage == UPDATE_BACKREF &&
+ generation <= root->root_key.offset)
+ continue;
+
+ /* We don't lock the tree block, it's OK to be racy here */
+ ret = btrfs_lookup_extent_info(trans, root, bytenr,
+ wc->level - 1, 1, &refs,
+ &flags);
+ /* We don't care about errors in readahead. */
+ if (ret < 0)
+ continue;
+ BUG_ON(refs == 0);
+
+ if (wc->stage == DROP_REFERENCE) {
+ if (refs == 1)
+ goto reada;
+
+ if (wc->level == 1 &&
+ (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF))
+ continue;
+ if (!wc->update_ref ||
+ generation <= root->root_key.offset)
+ continue;
+ btrfs_node_key_to_cpu(eb, &key, slot);
+ ret = btrfs_comp_cpu_keys(&key,
+ &wc->update_progress);
+ if (ret < 0)
+ continue;
+ } else {
+ if (wc->level == 1 &&
+ (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF))
+ continue;
+ }
+reada:
+ readahead_tree_block(root, bytenr);
+ nread++;
+ }
+ wc->reada_slot = slot;
+}
+
+static int account_leaf_items(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct extent_buffer *eb)
+{
+ int nr = btrfs_header_nritems(eb);
+ int i, extent_type, ret;
+ struct btrfs_key key;
+ struct btrfs_file_extent_item *fi;
+ u64 bytenr, num_bytes;
+
+ for (i = 0; i < nr; i++) {
+ btrfs_item_key_to_cpu(eb, &key, i);
+
+ if (key.type != BTRFS_EXTENT_DATA_KEY)
+ continue;
+
+ fi = btrfs_item_ptr(eb, i, struct btrfs_file_extent_item);
+ /* filter out non qgroup-accountable extents */
+ extent_type = btrfs_file_extent_type(eb, fi);
+
+ if (extent_type == BTRFS_FILE_EXTENT_INLINE)
+ continue;
+
+ bytenr = btrfs_file_extent_disk_bytenr(eb, fi);
+ if (!bytenr)
+ continue;
+
+ num_bytes = btrfs_file_extent_disk_num_bytes(eb, fi);
+
+ ret = btrfs_qgroup_record_ref(trans, root->fs_info,
+ root->objectid,
+ bytenr, num_bytes,
+ BTRFS_QGROUP_OPER_SUB_SUBTREE, 0);
+ if (ret)
+ return ret;
+ }
+ return 0;
+}
+
+/*
+ * Walk up the tree from the bottom, freeing leaves and any interior
+ * nodes which have had all slots visited. If a node (leaf or
+ * interior) is freed, the node above it will have it's slot
+ * incremented. The root node will never be freed.
+ *
+ * At the end of this function, we should have a path which has all
+ * slots incremented to the next position for a search. If we need to
+ * read a new node it will be NULL and the node above it will have the
+ * correct slot selected for a later read.
+ *
+ * If we increment the root nodes slot counter past the number of
+ * elements, 1 is returned to signal completion of the search.
+ */
+static int adjust_slots_upwards(struct btrfs_root *root,
+ struct btrfs_path *path, int root_level)
+{
+ int level = 0;
+ int nr, slot;
+ struct extent_buffer *eb;
+
+ if (root_level == 0)
+ return 1;
+
+ while (level <= root_level) {
+ eb = path->nodes[level];
+ nr = btrfs_header_nritems(eb);
+ path->slots[level]++;
+ slot = path->slots[level];
+ if (slot >= nr || level == 0) {
+ /*
+ * Don't free the root - we will detect this
+ * condition after our loop and return a
+ * positive value for caller to stop walking the tree.
+ */
+ if (level != root_level) {
+ btrfs_tree_unlock_rw(eb, path->locks[level]);
+ path->locks[level] = 0;
+
+ free_extent_buffer(eb);
+ path->nodes[level] = NULL;
+ path->slots[level] = 0;
+ }
+ } else {
+ /*
+ * We have a valid slot to walk back down
+ * from. Stop here so caller can process these
+ * new nodes.
+ */
+ break;
+ }
+
+ level++;
+ }
+
+ eb = path->nodes[root_level];
+ if (path->slots[root_level] >= btrfs_header_nritems(eb))
+ return 1;
+
+ return 0;
+}
+
+/*
+ * root_eb is the subtree root and is locked before this function is called.
+ */
+static int account_shared_subtree(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct extent_buffer *root_eb,
+ u64 root_gen,
+ int root_level)
+{
+ int ret = 0;
+ int level;
+ struct extent_buffer *eb = root_eb;
+ struct btrfs_path *path = NULL;
+
+ BUG_ON(root_level < 0 || root_level > BTRFS_MAX_LEVEL);
+ BUG_ON(root_eb == NULL);
+
+ if (!root->fs_info->quota_enabled)
+ return 0;
+
+ if (!extent_buffer_uptodate(root_eb)) {
+ ret = btrfs_read_buffer(root_eb, root_gen);
+ if (ret)
+ goto out;
+ }
+
+ if (root_level == 0) {
+ ret = account_leaf_items(trans, root, root_eb);
+ goto out;
+ }
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ /*
+ * Walk down the tree. Missing extent blocks are filled in as
+ * we go. Metadata is accounted every time we read a new
+ * extent block.
+ *
+ * When we reach a leaf, we account for file extent items in it,
+ * walk back up the tree (adjusting slot pointers as we go)
+ * and restart the search process.
+ */
+ extent_buffer_get(root_eb); /* For path */
+ path->nodes[root_level] = root_eb;
+ path->slots[root_level] = 0;
+ path->locks[root_level] = 0; /* so release_path doesn't try to unlock */
+walk_down:
+ level = root_level;
+ while (level >= 0) {
+ if (path->nodes[level] == NULL) {
+ int parent_slot;
+ u64 child_gen;
+ u64 child_bytenr;
+
+ /* We need to get child blockptr/gen from
+ * parent before we can read it. */
+ eb = path->nodes[level + 1];
+ parent_slot = path->slots[level + 1];
+ child_bytenr = btrfs_node_blockptr(eb, parent_slot);
+ child_gen = btrfs_node_ptr_generation(eb, parent_slot);
+
+ eb = read_tree_block(root, child_bytenr, child_gen);
+ if (!eb || !extent_buffer_uptodate(eb)) {
+ ret = -EIO;
+ goto out;
+ }
+
+ path->nodes[level] = eb;
+ path->slots[level] = 0;
+
+ btrfs_tree_read_lock(eb);
+ btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK);
+ path->locks[level] = BTRFS_READ_LOCK_BLOCKING;
+
+ ret = btrfs_qgroup_record_ref(trans, root->fs_info,
+ root->objectid,
+ child_bytenr,
+ root->nodesize,
+ BTRFS_QGROUP_OPER_SUB_SUBTREE,
+ 0);
+ if (ret)
+ goto out;
+
+ }
+
+ if (level == 0) {
+ ret = account_leaf_items(trans, root, path->nodes[level]);
+ if (ret)
+ goto out;
+
+ /* Nonzero return here means we completed our search */
+ ret = adjust_slots_upwards(root, path, root_level);
+ if (ret)
+ break;
+
+ /* Restart search with new slots */
+ goto walk_down;
+ }
+
+ level--;
+ }
+
+ ret = 0;
+out:
+ btrfs_free_path(path);
+
+ return ret;
+}
+
+/*
+ * helper to process tree block while walking down the tree.
+ *
+ * when wc->stage == UPDATE_BACKREF, this function updates
+ * back refs for pointers in the block.
+ *
+ * NOTE: return value 1 means we should stop walking down.
+ */
+static noinline int walk_down_proc(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ struct walk_control *wc, int lookup_info)
+{
+ int level = wc->level;
+ struct extent_buffer *eb = path->nodes[level];
+ u64 flag = BTRFS_BLOCK_FLAG_FULL_BACKREF;
+ int ret;
+
+ if (wc->stage == UPDATE_BACKREF &&
+ btrfs_header_owner(eb) != root->root_key.objectid)
+ return 1;
+
+ /*
+ * when reference count of tree block is 1, it won't increase
+ * again. once full backref flag is set, we never clear it.
+ */
+ if (lookup_info &&
+ ((wc->stage == DROP_REFERENCE && wc->refs[level] != 1) ||
+ (wc->stage == UPDATE_BACKREF && !(wc->flags[level] & flag)))) {
+ BUG_ON(!path->locks[level]);
+ ret = btrfs_lookup_extent_info(trans, root,
+ eb->start, level, 1,
+ &wc->refs[level],
+ &wc->flags[level]);
+ BUG_ON(ret == -ENOMEM);
+ if (ret)
+ return ret;
+ BUG_ON(wc->refs[level] == 0);
+ }
+
+ if (wc->stage == DROP_REFERENCE) {
+ if (wc->refs[level] > 1)
+ return 1;
+
+ if (path->locks[level] && !wc->keep_locks) {
+ btrfs_tree_unlock_rw(eb, path->locks[level]);
+ path->locks[level] = 0;
+ }
+ return 0;
+ }
+
+ /* wc->stage == UPDATE_BACKREF */
+ if (!(wc->flags[level] & flag)) {
+ BUG_ON(!path->locks[level]);
+ ret = btrfs_inc_ref(trans, root, eb, 1);
+ BUG_ON(ret); /* -ENOMEM */
+ ret = btrfs_dec_ref(trans, root, eb, 0);
+ BUG_ON(ret); /* -ENOMEM */
+ ret = btrfs_set_disk_extent_flags(trans, root, eb->start,
+ eb->len, flag,
+ btrfs_header_level(eb), 0);
+ BUG_ON(ret); /* -ENOMEM */
+ wc->flags[level] |= flag;
+ }
+
+ /*
+ * the block is shared by multiple trees, so it's not good to
+ * keep the tree lock
+ */
+ if (path->locks[level] && level > 0) {
+ btrfs_tree_unlock_rw(eb, path->locks[level]);
+ path->locks[level] = 0;
+ }
+ return 0;
+}
+
+/*
+ * helper to process tree block pointer.
+ *
+ * when wc->stage == DROP_REFERENCE, this function checks
+ * reference count of the block pointed to. if the block
+ * is shared and we need update back refs for the subtree
+ * rooted at the block, this function changes wc->stage to
+ * UPDATE_BACKREF. if the block is shared and there is no
+ * need to update back, this function drops the reference
+ * to the block.
+ *
+ * NOTE: return value 1 means we should stop walking down.
+ */
+static noinline int do_walk_down(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ struct walk_control *wc, int *lookup_info)
+{
+ u64 bytenr;
+ u64 generation;
+ u64 parent;
+ u32 blocksize;
+ struct btrfs_key key;
+ struct extent_buffer *next;
+ int level = wc->level;
+ int reada = 0;
+ int ret = 0;
+ bool need_account = false;
+
+ generation = btrfs_node_ptr_generation(path->nodes[level],
+ path->slots[level]);
+ /*
+ * if the lower level block was created before the snapshot
+ * was created, we know there is no need to update back refs
+ * for the subtree
+ */
+ if (wc->stage == UPDATE_BACKREF &&
+ generation <= root->root_key.offset) {
+ *lookup_info = 1;
+ return 1;
+ }
+
+ bytenr = btrfs_node_blockptr(path->nodes[level], path->slots[level]);
+ blocksize = root->nodesize;
+
+ next = btrfs_find_tree_block(root->fs_info, bytenr);
+ if (!next) {
+ next = btrfs_find_create_tree_block(root, bytenr);
+ if (!next)
+ return -ENOMEM;
+ btrfs_set_buffer_lockdep_class(root->root_key.objectid, next,
+ level - 1);
+ reada = 1;
+ }
+ btrfs_tree_lock(next);
+ btrfs_set_lock_blocking(next);
+
+ ret = btrfs_lookup_extent_info(trans, root, bytenr, level - 1, 1,
+ &wc->refs[level - 1],
+ &wc->flags[level - 1]);
+ if (ret < 0) {
+ btrfs_tree_unlock(next);
+ return ret;
+ }
+
+ if (unlikely(wc->refs[level - 1] == 0)) {
+ btrfs_err(root->fs_info, "Missing references.");
+ BUG();
+ }
+ *lookup_info = 0;
+
+ if (wc->stage == DROP_REFERENCE) {
+ if (wc->refs[level - 1] > 1) {
+ need_account = true;
+ if (level == 1 &&
+ (wc->flags[0] & BTRFS_BLOCK_FLAG_FULL_BACKREF))
+ goto skip;
+
+ if (!wc->update_ref ||
+ generation <= root->root_key.offset)
+ goto skip;
+
+ btrfs_node_key_to_cpu(path->nodes[level], &key,
+ path->slots[level]);
+ ret = btrfs_comp_cpu_keys(&key, &wc->update_progress);
+ if (ret < 0)
+ goto skip;
+
+ wc->stage = UPDATE_BACKREF;
+ wc->shared_level = level - 1;
+ }
+ } else {
+ if (level == 1 &&
+ (wc->flags[0] & BTRFS_BLOCK_FLAG_FULL_BACKREF))
+ goto skip;
+ }
+
+ if (!btrfs_buffer_uptodate(next, generation, 0)) {
+ btrfs_tree_unlock(next);
+ free_extent_buffer(next);
+ next = NULL;
+ *lookup_info = 1;
+ }
+
+ if (!next) {
+ if (reada && level == 1)
+ reada_walk_down(trans, root, wc, path);
+ next = read_tree_block(root, bytenr, generation);
+ if (!next || !extent_buffer_uptodate(next)) {
+ free_extent_buffer(next);
+ return -EIO;
+ }
+ btrfs_tree_lock(next);
+ btrfs_set_lock_blocking(next);
+ }
+
+ level--;
+ BUG_ON(level != btrfs_header_level(next));
+ path->nodes[level] = next;
+ path->slots[level] = 0;
+ path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
+ wc->level = level;
+ if (wc->level == 1)
+ wc->reada_slot = 0;
+ return 0;
+skip:
+ wc->refs[level - 1] = 0;
+ wc->flags[level - 1] = 0;
+ if (wc->stage == DROP_REFERENCE) {
+ if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF) {
+ parent = path->nodes[level]->start;
+ } else {
+ BUG_ON(root->root_key.objectid !=
+ btrfs_header_owner(path->nodes[level]));
+ parent = 0;
+ }
+
+ if (need_account) {
+ ret = account_shared_subtree(trans, root, next,
+ generation, level - 1);
+ if (ret) {
+ printk_ratelimited(KERN_ERR "BTRFS: %s Error "
+ "%d accounting shared subtree. Quota "
+ "is out of sync, rescan required.\n",
+ root->fs_info->sb->s_id, ret);
+ }
+ }
+ ret = btrfs_free_extent(trans, root, bytenr, blocksize, parent,
+ root->root_key.objectid, level - 1, 0, 0);
+ BUG_ON(ret); /* -ENOMEM */
+ }
+ btrfs_tree_unlock(next);
+ free_extent_buffer(next);
+ *lookup_info = 1;
+ return 1;
+}
+
+/*
+ * helper to process tree block while walking up the tree.
+ *
+ * when wc->stage == DROP_REFERENCE, this function drops
+ * reference count on the block.
+ *
+ * when wc->stage == UPDATE_BACKREF, this function changes
+ * wc->stage back to DROP_REFERENCE if we changed wc->stage
+ * to UPDATE_BACKREF previously while processing the block.
+ *
+ * NOTE: return value 1 means we should stop walking up.
+ */
+static noinline int walk_up_proc(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ struct walk_control *wc)
+{
+ int ret;
+ int level = wc->level;
+ struct extent_buffer *eb = path->nodes[level];
+ u64 parent = 0;
+
+ if (wc->stage == UPDATE_BACKREF) {
+ BUG_ON(wc->shared_level < level);
+ if (level < wc->shared_level)
+ goto out;
+
+ ret = find_next_key(path, level + 1, &wc->update_progress);
+ if (ret > 0)
+ wc->update_ref = 0;
+
+ wc->stage = DROP_REFERENCE;
+ wc->shared_level = -1;
+ path->slots[level] = 0;
+
+ /*
+ * check reference count again if the block isn't locked.
+ * we should start walking down the tree again if reference
+ * count is one.
+ */
+ if (!path->locks[level]) {
+ BUG_ON(level == 0);
+ btrfs_tree_lock(eb);
+ btrfs_set_lock_blocking(eb);
+ path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
+
+ ret = btrfs_lookup_extent_info(trans, root,
+ eb->start, level, 1,
+ &wc->refs[level],
+ &wc->flags[level]);
+ if (ret < 0) {
+ btrfs_tree_unlock_rw(eb, path->locks[level]);
+ path->locks[level] = 0;
+ return ret;
+ }
+ BUG_ON(wc->refs[level] == 0);
+ if (wc->refs[level] == 1) {
+ btrfs_tree_unlock_rw(eb, path->locks[level]);
+ path->locks[level] = 0;
+ return 1;
+ }
+ }
+ }
+
+ /* wc->stage == DROP_REFERENCE */
+ BUG_ON(wc->refs[level] > 1 && !path->locks[level]);
+
+ if (wc->refs[level] == 1) {
+ if (level == 0) {
+ if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
+ ret = btrfs_dec_ref(trans, root, eb, 1);
+ else
+ ret = btrfs_dec_ref(trans, root, eb, 0);
+ BUG_ON(ret); /* -ENOMEM */
+ ret = account_leaf_items(trans, root, eb);
+ if (ret) {
+ printk_ratelimited(KERN_ERR "BTRFS: %s Error "
+ "%d accounting leaf items. Quota "
+ "is out of sync, rescan required.\n",
+ root->fs_info->sb->s_id, ret);
+ }
+ }
+ /* make block locked assertion in clean_tree_block happy */
+ if (!path->locks[level] &&
+ btrfs_header_generation(eb) == trans->transid) {
+ btrfs_tree_lock(eb);
+ btrfs_set_lock_blocking(eb);
+ path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
+ }
+ clean_tree_block(trans, root->fs_info, eb);
+ }
+
+ if (eb == root->node) {
+ if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
+ parent = eb->start;
+ else
+ BUG_ON(root->root_key.objectid !=
+ btrfs_header_owner(eb));
+ } else {
+ if (wc->flags[level + 1] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
+ parent = path->nodes[level + 1]->start;
+ else
+ BUG_ON(root->root_key.objectid !=
+ btrfs_header_owner(path->nodes[level + 1]));
+ }
+
+ btrfs_free_tree_block(trans, root, eb, parent, wc->refs[level] == 1);
+out:
+ wc->refs[level] = 0;
+ wc->flags[level] = 0;
+ return 0;
+}
+
+static noinline int walk_down_tree(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ struct walk_control *wc)
+{
+ int level = wc->level;
+ int lookup_info = 1;
+ int ret;
+
+ while (level >= 0) {
+ ret = walk_down_proc(trans, root, path, wc, lookup_info);
+ if (ret > 0)
+ break;
+
+ if (level == 0)
+ break;
+
+ if (path->slots[level] >=
+ btrfs_header_nritems(path->nodes[level]))
+ break;
+
+ ret = do_walk_down(trans, root, path, wc, &lookup_info);
+ if (ret > 0) {
+ path->slots[level]++;
+ continue;
+ } else if (ret < 0)
+ return ret;
+ level = wc->level;
+ }
+ return 0;
+}
+
+static noinline int walk_up_tree(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ struct walk_control *wc, int max_level)
+{
+ int level = wc->level;
+ int ret;
+
+ path->slots[level] = btrfs_header_nritems(path->nodes[level]);
+ while (level < max_level && path->nodes[level]) {
+ wc->level = level;
+ if (path->slots[level] + 1 <
+ btrfs_header_nritems(path->nodes[level])) {
+ path->slots[level]++;
+ return 0;
+ } else {
+ ret = walk_up_proc(trans, root, path, wc);
+ if (ret > 0)
+ return 0;
+
+ if (path->locks[level]) {
+ btrfs_tree_unlock_rw(path->nodes[level],
+ path->locks[level]);
+ path->locks[level] = 0;
+ }
+ free_extent_buffer(path->nodes[level]);
+ path->nodes[level] = NULL;
+ level++;
+ }
+ }
+ return 1;
+}
+
+/*
+ * drop a subvolume tree.
+ *
+ * this function traverses the tree freeing any blocks that only
+ * referenced by the tree.
+ *
+ * when a shared tree block is found. this function decreases its
+ * reference count by one. if update_ref is true, this function
+ * also make sure backrefs for the shared block and all lower level
+ * blocks are properly updated.
+ *
+ * If called with for_reloc == 0, may exit early with -EAGAIN
+ */
+int btrfs_drop_snapshot(struct btrfs_root *root,
+ struct btrfs_block_rsv *block_rsv, int update_ref,
+ int for_reloc)
+{
+ struct btrfs_path *path;
+ struct btrfs_trans_handle *trans;
+ struct btrfs_root *tree_root = root->fs_info->tree_root;
+ struct btrfs_root_item *root_item = &root->root_item;
+ struct walk_control *wc;
+ struct btrfs_key key;
+ int err = 0;
+ int ret;
+ int level;
+ bool root_dropped = false;
+
+ btrfs_debug(root->fs_info, "Drop subvolume %llu", root->objectid);
+
+ path = btrfs_alloc_path();
+ if (!path) {
+ err = -ENOMEM;
+ goto out;
+ }
+
+ wc = kzalloc(sizeof(*wc), GFP_NOFS);
+ if (!wc) {
+ btrfs_free_path(path);
+ err = -ENOMEM;
+ goto out;
+ }
+
+ trans = btrfs_start_transaction(tree_root, 0);
+ if (IS_ERR(trans)) {
+ err = PTR_ERR(trans);
+ goto out_free;
+ }
+
+ if (block_rsv)
+ trans->block_rsv = block_rsv;
+
+ if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
+ level = btrfs_header_level(root->node);
+ path->nodes[level] = btrfs_lock_root_node(root);
+ btrfs_set_lock_blocking(path->nodes[level]);
+ path->slots[level] = 0;
+ path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
+ memset(&wc->update_progress, 0,
+ sizeof(wc->update_progress));
+ } else {
+ btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
+ memcpy(&wc->update_progress, &key,
+ sizeof(wc->update_progress));
+
+ level = root_item->drop_level;
+ BUG_ON(level == 0);
+ path->lowest_level = level;
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ path->lowest_level = 0;
+ if (ret < 0) {
+ err = ret;
+ goto out_end_trans;
+ }
+ WARN_ON(ret > 0);
+
+ /*
+ * unlock our path, this is safe because only this
+ * function is allowed to delete this snapshot
+ */
+ btrfs_unlock_up_safe(path, 0);
+
+ level = btrfs_header_level(root->node);
+ while (1) {
+ btrfs_tree_lock(path->nodes[level]);
+ btrfs_set_lock_blocking(path->nodes[level]);
+ path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
+
+ ret = btrfs_lookup_extent_info(trans, root,
+ path->nodes[level]->start,
+ level, 1, &wc->refs[level],
+ &wc->flags[level]);
+ if (ret < 0) {
+ err = ret;
+ goto out_end_trans;
+ }
+ BUG_ON(wc->refs[level] == 0);
+
+ if (level == root_item->drop_level)
+ break;
+
+ btrfs_tree_unlock(path->nodes[level]);
+ path->locks[level] = 0;
+ WARN_ON(wc->refs[level] != 1);
+ level--;
+ }
+ }
+
+ wc->level = level;
+ wc->shared_level = -1;
+ wc->stage = DROP_REFERENCE;
+ wc->update_ref = update_ref;
+ wc->keep_locks = 0;
+ wc->for_reloc = for_reloc;
+ wc->reada_count = BTRFS_NODEPTRS_PER_BLOCK(root);
+
+ while (1) {
+
+ ret = walk_down_tree(trans, root, path, wc);
+ if (ret < 0) {
+ err = ret;
+ break;
+ }
+
+ ret = walk_up_tree(trans, root, path, wc, BTRFS_MAX_LEVEL);
+ if (ret < 0) {
+ err = ret;
+ break;
+ }
+
+ if (ret > 0) {
+ BUG_ON(wc->stage != DROP_REFERENCE);
+ break;
+ }
+
+ if (wc->stage == DROP_REFERENCE) {
+ level = wc->level;
+ btrfs_node_key(path->nodes[level],
+ &root_item->drop_progress,
+ path->slots[level]);
+ root_item->drop_level = level;
+ }
+
+ BUG_ON(wc->level == 0);
+ if (btrfs_should_end_transaction(trans, tree_root) ||
+ (!for_reloc && btrfs_need_cleaner_sleep(root))) {
+ ret = btrfs_update_root(trans, tree_root,
+ &root->root_key,
+ root_item);
+ if (ret) {
+ btrfs_abort_transaction(trans, tree_root, ret);
+ err = ret;
+ goto out_end_trans;
+ }
+
+ /*
+ * Qgroup update accounting is run from
+ * delayed ref handling. This usually works
+ * out because delayed refs are normally the
+ * only way qgroup updates are added. However,
+ * we may have added updates during our tree
+ * walk so run qgroups here to make sure we
+ * don't lose any updates.
+ */
+ ret = btrfs_delayed_qgroup_accounting(trans,
+ root->fs_info);
+ if (ret)
+ printk_ratelimited(KERN_ERR "BTRFS: Failure %d "
+ "running qgroup updates "
+ "during snapshot delete. "
+ "Quota is out of sync, "
+ "rescan required.\n", ret);
+
+ btrfs_end_transaction_throttle(trans, tree_root);
+ if (!for_reloc && btrfs_need_cleaner_sleep(root)) {
+ pr_debug("BTRFS: drop snapshot early exit\n");
+ err = -EAGAIN;
+ goto out_free;
+ }
+
+ trans = btrfs_start_transaction(tree_root, 0);
+ if (IS_ERR(trans)) {
+ err = PTR_ERR(trans);
+ goto out_free;
+ }
+ if (block_rsv)
+ trans->block_rsv = block_rsv;
+ }
+ }
+ btrfs_release_path(path);
+ if (err)
+ goto out_end_trans;
+
+ ret = btrfs_del_root(trans, tree_root, &root->root_key);
+ if (ret) {
+ btrfs_abort_transaction(trans, tree_root, ret);
+ goto out_end_trans;
+ }
+
+ if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) {
+ ret = btrfs_find_root(tree_root, &root->root_key, path,
+ NULL, NULL);
+ if (ret < 0) {
+ btrfs_abort_transaction(trans, tree_root, ret);
+ err = ret;
+ goto out_end_trans;
+ } else if (ret > 0) {
+ /* if we fail to delete the orphan item this time
+ * around, it'll get picked up the next time.
+ *
+ * The most common failure here is just -ENOENT.
+ */
+ btrfs_del_orphan_item(trans, tree_root,
+ root->root_key.objectid);
+ }
+ }
+
+ if (test_bit(BTRFS_ROOT_IN_RADIX, &root->state)) {
+ btrfs_drop_and_free_fs_root(tree_root->fs_info, root);
+ } else {
+ free_extent_buffer(root->node);
+ free_extent_buffer(root->commit_root);
+ btrfs_put_fs_root(root);
+ }
+ root_dropped = true;
+out_end_trans:
+ ret = btrfs_delayed_qgroup_accounting(trans, tree_root->fs_info);
+ if (ret)
+ printk_ratelimited(KERN_ERR "BTRFS: Failure %d "
+ "running qgroup updates "
+ "during snapshot delete. "
+ "Quota is out of sync, "
+ "rescan required.\n", ret);
+
+ btrfs_end_transaction_throttle(trans, tree_root);
+out_free:
+ kfree(wc);
+ btrfs_free_path(path);
+out:
+ /*
+ * So if we need to stop dropping the snapshot for whatever reason we
+ * need to make sure to add it back to the dead root list so that we
+ * keep trying to do the work later. This also cleans up roots if we
+ * don't have it in the radix (like when we recover after a power fail
+ * or unmount) so we don't leak memory.
+ */
+ if (!for_reloc && root_dropped == false)
+ btrfs_add_dead_root(root);
+ if (err && err != -EAGAIN)
+ btrfs_std_error(root->fs_info, err);
+ return err;
+}
+
+/*
+ * drop subtree rooted at tree block 'node'.
+ *
+ * NOTE: this function will unlock and release tree block 'node'
+ * only used by relocation code
+ */
+int btrfs_drop_subtree(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct extent_buffer *node,
+ struct extent_buffer *parent)
+{
+ struct btrfs_path *path;
+ struct walk_control *wc;
+ int level;
+ int parent_level;
+ int ret = 0;
+ int wret;
+
+ BUG_ON(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ wc = kzalloc(sizeof(*wc), GFP_NOFS);
+ if (!wc) {
+ btrfs_free_path(path);
+ return -ENOMEM;
+ }
+
+ btrfs_assert_tree_locked(parent);
+ parent_level = btrfs_header_level(parent);
+ extent_buffer_get(parent);
+ path->nodes[parent_level] = parent;
+ path->slots[parent_level] = btrfs_header_nritems(parent);
+
+ btrfs_assert_tree_locked(node);
+ level = btrfs_header_level(node);
+ path->nodes[level] = node;
+ path->slots[level] = 0;
+ path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
+
+ wc->refs[parent_level] = 1;
+ wc->flags[parent_level] = BTRFS_BLOCK_FLAG_FULL_BACKREF;
+ wc->level = level;
+ wc->shared_level = -1;
+ wc->stage = DROP_REFERENCE;
+ wc->update_ref = 0;
+ wc->keep_locks = 1;
+ wc->for_reloc = 1;
+ wc->reada_count = BTRFS_NODEPTRS_PER_BLOCK(root);
+
+ while (1) {
+ wret = walk_down_tree(trans, root, path, wc);
+ if (wret < 0) {
+ ret = wret;
+ break;
+ }
+
+ wret = walk_up_tree(trans, root, path, wc, parent_level);
+ if (wret < 0)
+ ret = wret;
+ if (wret != 0)
+ break;
+ }
+
+ kfree(wc);
+ btrfs_free_path(path);
+ return ret;
+}
+
+static u64 update_block_group_flags(struct btrfs_root *root, u64 flags)
+{
+ u64 num_devices;
+ u64 stripped;
+
+ /*
+ * if restripe for this chunk_type is on pick target profile and
+ * return, otherwise do the usual balance
+ */
+ stripped = get_restripe_target(root->fs_info, flags);
+ if (stripped)
+ return extended_to_chunk(stripped);
+
+ num_devices = root->fs_info->fs_devices->rw_devices;
+
+ stripped = BTRFS_BLOCK_GROUP_RAID0 |
+ BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6 |
+ BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10;
+
+ if (num_devices == 1) {
+ stripped |= BTRFS_BLOCK_GROUP_DUP;
+ stripped = flags & ~stripped;
+
+ /* turn raid0 into single device chunks */
+ if (flags & BTRFS_BLOCK_GROUP_RAID0)
+ return stripped;
+
+ /* turn mirroring into duplication */
+ if (flags & (BTRFS_BLOCK_GROUP_RAID1 |
+ BTRFS_BLOCK_GROUP_RAID10))
+ return stripped | BTRFS_BLOCK_GROUP_DUP;
+ } else {
+ /* they already had raid on here, just return */
+ if (flags & stripped)
+ return flags;
+
+ stripped |= BTRFS_BLOCK_GROUP_DUP;
+ stripped = flags & ~stripped;
+
+ /* switch duplicated blocks with raid1 */
+ if (flags & BTRFS_BLOCK_GROUP_DUP)
+ return stripped | BTRFS_BLOCK_GROUP_RAID1;
+
+ /* this is drive concat, leave it alone */
+ }
+
+ return flags;
+}
+
+static int set_block_group_ro(struct btrfs_block_group_cache *cache, int force)
+{
+ struct btrfs_space_info *sinfo = cache->space_info;
+ u64 num_bytes;
+ u64 min_allocable_bytes;
+ int ret = -ENOSPC;
+
+
+ /*
+ * We need some metadata space and system metadata space for
+ * allocating chunks in some corner cases until we force to set
+ * it to be readonly.
+ */
+ if ((sinfo->flags &
+ (BTRFS_BLOCK_GROUP_SYSTEM | BTRFS_BLOCK_GROUP_METADATA)) &&
+ !force)
+ min_allocable_bytes = 1 * 1024 * 1024;
+ else
+ min_allocable_bytes = 0;
+
+ spin_lock(&sinfo->lock);
+ spin_lock(&cache->lock);
+
+ if (cache->ro) {
+ ret = 0;
+ goto out;
+ }
+
+ num_bytes = cache->key.offset - cache->reserved - cache->pinned -
+ cache->bytes_super - btrfs_block_group_used(&cache->item);
+
+ if (sinfo->bytes_used + sinfo->bytes_reserved + sinfo->bytes_pinned +
+ sinfo->bytes_may_use + sinfo->bytes_readonly + num_bytes +
+ min_allocable_bytes <= sinfo->total_bytes) {
+ sinfo->bytes_readonly += num_bytes;
+ cache->ro = 1;
+ list_add_tail(&cache->ro_list, &sinfo->ro_bgs);
+ ret = 0;
+ }
+out:
+ spin_unlock(&cache->lock);
+ spin_unlock(&sinfo->lock);
+ return ret;
+}
+
+int btrfs_set_block_group_ro(struct btrfs_root *root,
+ struct btrfs_block_group_cache *cache)
+
+{
+ struct btrfs_trans_handle *trans;
+ u64 alloc_flags;
+ int ret;
+
+ BUG_ON(cache->ro);
+
+again:
+ trans = btrfs_join_transaction(root);
+ if (IS_ERR(trans))
+ return PTR_ERR(trans);
+
+ /*
+ * we're not allowed to set block groups readonly after the dirty
+ * block groups cache has started writing. If it already started,
+ * back off and let this transaction commit
+ */
+ mutex_lock(&root->fs_info->ro_block_group_mutex);
+ if (trans->transaction->dirty_bg_run) {
+ u64 transid = trans->transid;
+
+ mutex_unlock(&root->fs_info->ro_block_group_mutex);
+ btrfs_end_transaction(trans, root);
+
+ ret = btrfs_wait_for_commit(root, transid);
+ if (ret)
+ return ret;
+ goto again;
+ }
+
+ /*
+ * if we are changing raid levels, try to allocate a corresponding
+ * block group with the new raid level.
+ */
+ alloc_flags = update_block_group_flags(root, cache->flags);
+ if (alloc_flags != cache->flags) {
+ ret = do_chunk_alloc(trans, root, alloc_flags,
+ CHUNK_ALLOC_FORCE);
+ /*
+ * ENOSPC is allowed here, we may have enough space
+ * already allocated at the new raid level to
+ * carry on
+ */
+ if (ret == -ENOSPC)
+ ret = 0;
+ if (ret < 0)
+ goto out;
+ }
+
+ ret = set_block_group_ro(cache, 0);
+ if (!ret)
+ goto out;
+ alloc_flags = get_alloc_profile(root, cache->space_info->flags);
+ ret = do_chunk_alloc(trans, root, alloc_flags,
+ CHUNK_ALLOC_FORCE);
+ if (ret < 0)
+ goto out;
+ ret = set_block_group_ro(cache, 0);
+out:
+ if (cache->flags & BTRFS_BLOCK_GROUP_SYSTEM) {
+ alloc_flags = update_block_group_flags(root, cache->flags);
+ lock_chunks(root->fs_info->chunk_root);
+ check_system_chunk(trans, root, alloc_flags);
+ unlock_chunks(root->fs_info->chunk_root);
+ }
+ mutex_unlock(&root->fs_info->ro_block_group_mutex);
+
+ btrfs_end_transaction(trans, root);
+ return ret;
+}
+
+int btrfs_force_chunk_alloc(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, u64 type)
+{
+ u64 alloc_flags = get_alloc_profile(root, type);
+ return do_chunk_alloc(trans, root, alloc_flags,
+ CHUNK_ALLOC_FORCE);
+}
+
+/*
+ * helper to account the unused space of all the readonly block group in the
+ * space_info. takes mirrors into account.
+ */
+u64 btrfs_account_ro_block_groups_free_space(struct btrfs_space_info *sinfo)
+{
+ struct btrfs_block_group_cache *block_group;
+ u64 free_bytes = 0;
+ int factor;
+
+ /* It's df, we don't care if it's racey */
+ if (list_empty(&sinfo->ro_bgs))
+ return 0;
+
+ spin_lock(&sinfo->lock);
+ list_for_each_entry(block_group, &sinfo->ro_bgs, ro_list) {
+ spin_lock(&block_group->lock);
+
+ if (!block_group->ro) {
+ spin_unlock(&block_group->lock);
+ continue;
+ }
+
+ if (block_group->flags & (BTRFS_BLOCK_GROUP_RAID1 |
+ BTRFS_BLOCK_GROUP_RAID10 |
+ BTRFS_BLOCK_GROUP_DUP))
+ factor = 2;
+ else
+ factor = 1;
+
+ free_bytes += (block_group->key.offset -
+ btrfs_block_group_used(&block_group->item)) *
+ factor;
+
+ spin_unlock(&block_group->lock);
+ }
+ spin_unlock(&sinfo->lock);
+
+ return free_bytes;
+}
+
+void btrfs_set_block_group_rw(struct btrfs_root *root,
+ struct btrfs_block_group_cache *cache)
+{
+ struct btrfs_space_info *sinfo = cache->space_info;
+ u64 num_bytes;
+
+ BUG_ON(!cache->ro);
+
+ spin_lock(&sinfo->lock);
+ spin_lock(&cache->lock);
+ num_bytes = cache->key.offset - cache->reserved - cache->pinned -
+ cache->bytes_super - btrfs_block_group_used(&cache->item);
+ sinfo->bytes_readonly -= num_bytes;
+ cache->ro = 0;
+ list_del_init(&cache->ro_list);
+ spin_unlock(&cache->lock);
+ spin_unlock(&sinfo->lock);
+}
+
+/*
+ * checks to see if its even possible to relocate this block group.
+ *
+ * @return - -1 if it's not a good idea to relocate this block group, 0 if its
+ * ok to go ahead and try.
+ */
+int btrfs_can_relocate(struct btrfs_root *root, u64 bytenr)
+{
+ struct btrfs_block_group_cache *block_group;
+ struct btrfs_space_info *space_info;
+ struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
+ struct btrfs_device *device;
+ struct btrfs_trans_handle *trans;
+ u64 min_free;
+ u64 dev_min = 1;
+ u64 dev_nr = 0;
+ u64 target;
+ int index;
+ int full = 0;
+ int ret = 0;
+
+ block_group = btrfs_lookup_block_group(root->fs_info, bytenr);
+
+ /* odd, couldn't find the block group, leave it alone */
+ if (!block_group)
+ return -1;
+
+ min_free = btrfs_block_group_used(&block_group->item);
+
+ /* no bytes used, we're good */
+ if (!min_free)
+ goto out;
+
+ space_info = block_group->space_info;
+ spin_lock(&space_info->lock);
+
+ full = space_info->full;
+
+ /*
+ * if this is the last block group we have in this space, we can't
+ * relocate it unless we're able to allocate a new chunk below.
+ *
+ * Otherwise, we need to make sure we have room in the space to handle
+ * all of the extents from this block group. If we can, we're good
+ */
+ if ((space_info->total_bytes != block_group->key.offset) &&
+ (space_info->bytes_used + space_info->bytes_reserved +
+ space_info->bytes_pinned + space_info->bytes_readonly +
+ min_free < space_info->total_bytes)) {
+ spin_unlock(&space_info->lock);
+ goto out;
+ }
+ spin_unlock(&space_info->lock);
+
+ /*
+ * ok we don't have enough space, but maybe we have free space on our
+ * devices to allocate new chunks for relocation, so loop through our
+ * alloc devices and guess if we have enough space. if this block
+ * group is going to be restriped, run checks against the target
+ * profile instead of the current one.
+ */
+ ret = -1;
+
+ /*
+ * index:
+ * 0: raid10
+ * 1: raid1
+ * 2: dup
+ * 3: raid0
+ * 4: single
+ */
+ target = get_restripe_target(root->fs_info, block_group->flags);
+ if (target) {
+ index = __get_raid_index(extended_to_chunk(target));
+ } else {
+ /*
+ * this is just a balance, so if we were marked as full
+ * we know there is no space for a new chunk
+ */
+ if (full)
+ goto out;
+
+ index = get_block_group_index(block_group);
+ }
+
+ if (index == BTRFS_RAID_RAID10) {
+ dev_min = 4;
+ /* Divide by 2 */
+ min_free >>= 1;
+ } else if (index == BTRFS_RAID_RAID1) {
+ dev_min = 2;
+ } else if (index == BTRFS_RAID_DUP) {
+ /* Multiply by 2 */
+ min_free <<= 1;
+ } else if (index == BTRFS_RAID_RAID0) {
+ dev_min = fs_devices->rw_devices;
+ min_free = div64_u64(min_free, dev_min);
+ }
+
+ /* We need to do this so that we can look at pending chunks */
+ trans = btrfs_join_transaction(root);
+ if (IS_ERR(trans)) {
+ ret = PTR_ERR(trans);
+ goto out;
+ }
+
+ mutex_lock(&root->fs_info->chunk_mutex);
+ list_for_each_entry(device, &fs_devices->alloc_list, dev_alloc_list) {
+ u64 dev_offset;
+
+ /*
+ * check to make sure we can actually find a chunk with enough
+ * space to fit our block group in.
+ */
+ if (device->total_bytes > device->bytes_used + min_free &&
+ !device->is_tgtdev_for_dev_replace) {
+ ret = find_free_dev_extent(trans, device, min_free,
+ &dev_offset, NULL);
+ if (!ret)
+ dev_nr++;
+
+ if (dev_nr >= dev_min)
+ break;
+
+ ret = -1;
+ }
+ }
+ mutex_unlock(&root->fs_info->chunk_mutex);
+ btrfs_end_transaction(trans, root);
+out:
+ btrfs_put_block_group(block_group);
+ return ret;
+}
+
+static int find_first_block_group(struct btrfs_root *root,
+ struct btrfs_path *path, struct btrfs_key *key)
+{
+ int ret = 0;
+ struct btrfs_key found_key;
+ struct extent_buffer *leaf;
+ int slot;
+
+ ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
+ if (ret < 0)
+ goto out;
+
+ while (1) {
+ slot = path->slots[0];
+ leaf = path->nodes[0];
+ if (slot >= btrfs_header_nritems(leaf)) {
+ ret = btrfs_next_leaf(root, path);
+ if (ret == 0)
+ continue;
+ if (ret < 0)
+ goto out;
+ break;
+ }
+ btrfs_item_key_to_cpu(leaf, &found_key, slot);
+
+ if (found_key.objectid >= key->objectid &&
+ found_key.type == BTRFS_BLOCK_GROUP_ITEM_KEY) {
+ ret = 0;
+ goto out;
+ }
+ path->slots[0]++;
+ }
+out:
+ return ret;
+}
+
+void btrfs_put_block_group_cache(struct btrfs_fs_info *info)
+{
+ struct btrfs_block_group_cache *block_group;
+ u64 last = 0;
+
+ while (1) {
+ struct inode *inode;
+
+ block_group = btrfs_lookup_first_block_group(info, last);
+ while (block_group) {
+ spin_lock(&block_group->lock);
+ if (block_group->iref)
+ break;
+ spin_unlock(&block_group->lock);
+ block_group = next_block_group(info->tree_root,
+ block_group);
+ }
+ if (!block_group) {
+ if (last == 0)
+ break;
+ last = 0;
+ continue;
+ }
+
+ inode = block_group->inode;
+ block_group->iref = 0;
+ block_group->inode = NULL;
+ spin_unlock(&block_group->lock);
+ iput(inode);
+ last = block_group->key.objectid + block_group->key.offset;
+ btrfs_put_block_group(block_group);
+ }
+}
+
+int btrfs_free_block_groups(struct btrfs_fs_info *info)
+{
+ struct btrfs_block_group_cache *block_group;
+ struct btrfs_space_info *space_info;
+ struct btrfs_caching_control *caching_ctl;
+ struct rb_node *n;
+
+ down_write(&info->commit_root_sem);
+ while (!list_empty(&info->caching_block_groups)) {
+ caching_ctl = list_entry(info->caching_block_groups.next,
+ struct btrfs_caching_control, list);
+ list_del(&caching_ctl->list);
+ put_caching_control(caching_ctl);
+ }
+ up_write(&info->commit_root_sem);
+
+ spin_lock(&info->unused_bgs_lock);
+ while (!list_empty(&info->unused_bgs)) {
+ block_group = list_first_entry(&info->unused_bgs,
+ struct btrfs_block_group_cache,
+ bg_list);
+ list_del_init(&block_group->bg_list);
+ btrfs_put_block_group(block_group);
+ }
+ spin_unlock(&info->unused_bgs_lock);
+
+ spin_lock(&info->block_group_cache_lock);
+ while ((n = rb_last(&info->block_group_cache_tree)) != NULL) {
+ block_group = rb_entry(n, struct btrfs_block_group_cache,
+ cache_node);
+ rb_erase(&block_group->cache_node,
+ &info->block_group_cache_tree);
+ RB_CLEAR_NODE(&block_group->cache_node);
+ spin_unlock(&info->block_group_cache_lock);
+
+ down_write(&block_group->space_info->groups_sem);
+ list_del(&block_group->list);
+ up_write(&block_group->space_info->groups_sem);
+
+ if (block_group->cached == BTRFS_CACHE_STARTED)
+ wait_block_group_cache_done(block_group);
+
+ /*
+ * We haven't cached this block group, which means we could
+ * possibly have excluded extents on this block group.
+ */
+ if (block_group->cached == BTRFS_CACHE_NO ||
+ block_group->cached == BTRFS_CACHE_ERROR)
+ free_excluded_extents(info->extent_root, block_group);
+
+ btrfs_remove_free_space_cache(block_group);
+ btrfs_put_block_group(block_group);
+
+ spin_lock(&info->block_group_cache_lock);
+ }
+ spin_unlock(&info->block_group_cache_lock);
+
+ /* now that all the block groups are freed, go through and
+ * free all the space_info structs. This is only called during
+ * the final stages of unmount, and so we know nobody is
+ * using them. We call synchronize_rcu() once before we start,
+ * just to be on the safe side.
+ */
+ synchronize_rcu();
+
+ release_global_block_rsv(info);
+
+ while (!list_empty(&info->space_info)) {
+ int i;
+
+ space_info = list_entry(info->space_info.next,
+ struct btrfs_space_info,
+ list);
+ if (btrfs_test_opt(info->tree_root, ENOSPC_DEBUG)) {
+ if (WARN_ON(space_info->bytes_pinned > 0 ||
+ space_info->bytes_reserved > 0 ||
+ space_info->bytes_may_use > 0)) {
+ dump_space_info(space_info, 0, 0);
+ }
+ }
+ list_del(&space_info->list);
+ for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) {
+ struct kobject *kobj;
+ kobj = space_info->block_group_kobjs[i];
+ space_info->block_group_kobjs[i] = NULL;
+ if (kobj) {
+ kobject_del(kobj);
+ kobject_put(kobj);
+ }
+ }
+ kobject_del(&space_info->kobj);
+ kobject_put(&space_info->kobj);
+ }
+ return 0;
+}
+
+static void __link_block_group(struct btrfs_space_info *space_info,
+ struct btrfs_block_group_cache *cache)
+{
+ int index = get_block_group_index(cache);
+ bool first = false;
+
+ down_write(&space_info->groups_sem);
+ if (list_empty(&space_info->block_groups[index]))
+ first = true;
+ list_add_tail(&cache->list, &space_info->block_groups[index]);
+ up_write(&space_info->groups_sem);
+
+ if (first) {
+ struct raid_kobject *rkobj;
+ int ret;
+
+ rkobj = kzalloc(sizeof(*rkobj), GFP_NOFS);
+ if (!rkobj)
+ goto out_err;
+ rkobj->raid_type = index;
+ kobject_init(&rkobj->kobj, &btrfs_raid_ktype);
+ ret = kobject_add(&rkobj->kobj, &space_info->kobj,
+ "%s", get_raid_name(index));
+ if (ret) {
+ kobject_put(&rkobj->kobj);
+ goto out_err;
+ }
+ space_info->block_group_kobjs[index] = &rkobj->kobj;
+ }
+
+ return;
+out_err:
+ pr_warn("BTRFS: failed to add kobject for block cache. ignoring.\n");
+}
+
+static struct btrfs_block_group_cache *
+btrfs_create_block_group_cache(struct btrfs_root *root, u64 start, u64 size)
+{
+ struct btrfs_block_group_cache *cache;
+
+ cache = kzalloc(sizeof(*cache), GFP_NOFS);
+ if (!cache)
+ return NULL;
+
+ cache->free_space_ctl = kzalloc(sizeof(*cache->free_space_ctl),
+ GFP_NOFS);
+ if (!cache->free_space_ctl) {
+ kfree(cache);
+ return NULL;
+ }
+
+ cache->key.objectid = start;
+ cache->key.offset = size;
+ cache->key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
+
+ cache->sectorsize = root->sectorsize;
+ cache->fs_info = root->fs_info;
+ cache->full_stripe_len = btrfs_full_stripe_len(root,
+ &root->fs_info->mapping_tree,
+ start);
+ atomic_set(&cache->count, 1);
+ spin_lock_init(&cache->lock);
+ init_rwsem(&cache->data_rwsem);
+ INIT_LIST_HEAD(&cache->list);
+ INIT_LIST_HEAD(&cache->cluster_list);
+ INIT_LIST_HEAD(&cache->bg_list);
+ INIT_LIST_HEAD(&cache->ro_list);
+ INIT_LIST_HEAD(&cache->dirty_list);
+ INIT_LIST_HEAD(&cache->io_list);
+ btrfs_init_free_space_ctl(cache);
+ atomic_set(&cache->trimming, 0);
+
+ return cache;
+}
+
+int btrfs_read_block_groups(struct btrfs_root *root)
+{
+ struct btrfs_path *path;
+ int ret;
+ struct btrfs_block_group_cache *cache;
+ struct btrfs_fs_info *info = root->fs_info;
+ struct btrfs_space_info *space_info;
+ struct btrfs_key key;
+ struct btrfs_key found_key;
+ struct extent_buffer *leaf;
+ int need_clear = 0;
+ u64 cache_gen;
+
+ root = info->extent_root;
+ key.objectid = 0;
+ key.offset = 0;
+ key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+ path->reada = 1;
+
+ cache_gen = btrfs_super_cache_generation(root->fs_info->super_copy);
+ if (btrfs_test_opt(root, SPACE_CACHE) &&
+ btrfs_super_generation(root->fs_info->super_copy) != cache_gen)
+ need_clear = 1;
+ if (btrfs_test_opt(root, CLEAR_CACHE))
+ need_clear = 1;
+
+ while (1) {
+ ret = find_first_block_group(root, path, &key);
+ if (ret > 0)
+ break;
+ if (ret != 0)
+ goto error;
+
+ leaf = path->nodes[0];
+ btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
+
+ cache = btrfs_create_block_group_cache(root, found_key.objectid,
+ found_key.offset);
+ if (!cache) {
+ ret = -ENOMEM;
+ goto error;
+ }
+
+ if (need_clear) {
+ /*
+ * When we mount with old space cache, we need to
+ * set BTRFS_DC_CLEAR and set dirty flag.
+ *
+ * a) Setting 'BTRFS_DC_CLEAR' makes sure that we
+ * truncate the old free space cache inode and
+ * setup a new one.
+ * b) Setting 'dirty flag' makes sure that we flush
+ * the new space cache info onto disk.
+ */
+ if (btrfs_test_opt(root, SPACE_CACHE))
+ cache->disk_cache_state = BTRFS_DC_CLEAR;
+ }
+
+ read_extent_buffer(leaf, &cache->item,
+ btrfs_item_ptr_offset(leaf, path->slots[0]),
+ sizeof(cache->item));
+ cache->flags = btrfs_block_group_flags(&cache->item);
+
+ key.objectid = found_key.objectid + found_key.offset;
+ btrfs_release_path(path);
+
+ /*
+ * We need to exclude the super stripes now so that the space
+ * info has super bytes accounted for, otherwise we'll think
+ * we have more space than we actually do.
+ */
+ ret = exclude_super_stripes(root, cache);
+ if (ret) {
+ /*
+ * We may have excluded something, so call this just in
+ * case.
+ */
+ free_excluded_extents(root, cache);
+ btrfs_put_block_group(cache);
+ goto error;
+ }
+
+ /*
+ * check for two cases, either we are full, and therefore
+ * don't need to bother with the caching work since we won't
+ * find any space, or we are empty, and we can just add all
+ * the space in and be done with it. This saves us _alot_ of
+ * time, particularly in the full case.
+ */
+ if (found_key.offset == btrfs_block_group_used(&cache->item)) {
+ cache->last_byte_to_unpin = (u64)-1;
+ cache->cached = BTRFS_CACHE_FINISHED;
+ free_excluded_extents(root, cache);
+ } else if (btrfs_block_group_used(&cache->item) == 0) {
+ cache->last_byte_to_unpin = (u64)-1;
+ cache->cached = BTRFS_CACHE_FINISHED;
+ add_new_free_space(cache, root->fs_info,
+ found_key.objectid,
+ found_key.objectid +
+ found_key.offset);
+ free_excluded_extents(root, cache);
+ }
+
+ ret = btrfs_add_block_group_cache(root->fs_info, cache);
+ if (ret) {
+ btrfs_remove_free_space_cache(cache);
+ btrfs_put_block_group(cache);
+ goto error;
+ }
+
+ ret = update_space_info(info, cache->flags, found_key.offset,
+ btrfs_block_group_used(&cache->item),
+ &space_info);
+ if (ret) {
+ btrfs_remove_free_space_cache(cache);
+ spin_lock(&info->block_group_cache_lock);
+ rb_erase(&cache->cache_node,
+ &info->block_group_cache_tree);
+ RB_CLEAR_NODE(&cache->cache_node);
+ spin_unlock(&info->block_group_cache_lock);
+ btrfs_put_block_group(cache);
+ goto error;
+ }
+
+ cache->space_info = space_info;
+ spin_lock(&cache->space_info->lock);
+ cache->space_info->bytes_readonly += cache->bytes_super;
+ spin_unlock(&cache->space_info->lock);
+
+ __link_block_group(space_info, cache);
+
+ set_avail_alloc_bits(root->fs_info, cache->flags);
+ if (btrfs_chunk_readonly(root, cache->key.objectid)) {
+ set_block_group_ro(cache, 1);
+ } else if (btrfs_block_group_used(&cache->item) == 0) {
+ spin_lock(&info->unused_bgs_lock);
+ /* Should always be true but just in case. */
+ if (list_empty(&cache->bg_list)) {
+ btrfs_get_block_group(cache);
+ list_add_tail(&cache->bg_list,
+ &info->unused_bgs);
+ }
+ spin_unlock(&info->unused_bgs_lock);
+ }
+ }
+
+ list_for_each_entry_rcu(space_info, &root->fs_info->space_info, list) {
+ if (!(get_alloc_profile(root, space_info->flags) &
+ (BTRFS_BLOCK_GROUP_RAID10 |
+ BTRFS_BLOCK_GROUP_RAID1 |
+ BTRFS_BLOCK_GROUP_RAID5 |
+ BTRFS_BLOCK_GROUP_RAID6 |
+ BTRFS_BLOCK_GROUP_DUP)))
+ continue;
+ /*
+ * avoid allocating from un-mirrored block group if there are
+ * mirrored block groups.
+ */
+ list_for_each_entry(cache,
+ &space_info->block_groups[BTRFS_RAID_RAID0],
+ list)
+ set_block_group_ro(cache, 1);
+ list_for_each_entry(cache,
+ &space_info->block_groups[BTRFS_RAID_SINGLE],
+ list)
+ set_block_group_ro(cache, 1);
+ }
+
+ init_global_block_rsv(info);
+ ret = 0;
+error:
+ btrfs_free_path(path);
+ return ret;
+}
+
+void btrfs_create_pending_block_groups(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root)
+{
+ struct btrfs_block_group_cache *block_group, *tmp;
+ struct btrfs_root *extent_root = root->fs_info->extent_root;
+ struct btrfs_block_group_item item;
+ struct btrfs_key key;
+ int ret = 0;
+
+ list_for_each_entry_safe(block_group, tmp, &trans->new_bgs, bg_list) {
+ if (ret)
+ goto next;
+
+ spin_lock(&block_group->lock);
+ memcpy(&item, &block_group->item, sizeof(item));
+ memcpy(&key, &block_group->key, sizeof(key));
+ spin_unlock(&block_group->lock);
+
+ ret = btrfs_insert_item(trans, extent_root, &key, &item,
+ sizeof(item));
+ if (ret)
+ btrfs_abort_transaction(trans, extent_root, ret);
+ ret = btrfs_finish_chunk_alloc(trans, extent_root,
+ key.objectid, key.offset);
+ if (ret)
+ btrfs_abort_transaction(trans, extent_root, ret);
+next:
+ list_del_init(&block_group->bg_list);
+ }
+}
+
+int btrfs_make_block_group(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, u64 bytes_used,
+ u64 type, u64 chunk_objectid, u64 chunk_offset,
+ u64 size)
+{
+ int ret;
+ struct btrfs_root *extent_root;
+ struct btrfs_block_group_cache *cache;
+
+ extent_root = root->fs_info->extent_root;
+
+ btrfs_set_log_full_commit(root->fs_info, trans);
+
+ cache = btrfs_create_block_group_cache(root, chunk_offset, size);
+ if (!cache)
+ return -ENOMEM;
+
+ btrfs_set_block_group_used(&cache->item, bytes_used);
+ btrfs_set_block_group_chunk_objectid(&cache->item, chunk_objectid);
+ btrfs_set_block_group_flags(&cache->item, type);
+
+ cache->flags = type;
+ cache->last_byte_to_unpin = (u64)-1;
+ cache->cached = BTRFS_CACHE_FINISHED;
+ ret = exclude_super_stripes(root, cache);
+ if (ret) {
+ /*
+ * We may have excluded something, so call this just in
+ * case.
+ */
+ free_excluded_extents(root, cache);
+ btrfs_put_block_group(cache);
+ return ret;
+ }
+
+ add_new_free_space(cache, root->fs_info, chunk_offset,
+ chunk_offset + size);
+
+ free_excluded_extents(root, cache);
+
+ ret = btrfs_add_block_group_cache(root->fs_info, cache);
+ if (ret) {
+ btrfs_remove_free_space_cache(cache);
+ btrfs_put_block_group(cache);
+ return ret;
+ }
+
+ ret = update_space_info(root->fs_info, cache->flags, size, bytes_used,
+ &cache->space_info);
+ if (ret) {
+ btrfs_remove_free_space_cache(cache);
+ spin_lock(&root->fs_info->block_group_cache_lock);
+ rb_erase(&cache->cache_node,
+ &root->fs_info->block_group_cache_tree);
+ RB_CLEAR_NODE(&cache->cache_node);
+ spin_unlock(&root->fs_info->block_group_cache_lock);
+ btrfs_put_block_group(cache);
+ return ret;
+ }
+ update_global_block_rsv(root->fs_info);
+
+ spin_lock(&cache->space_info->lock);
+ cache->space_info->bytes_readonly += cache->bytes_super;
+ spin_unlock(&cache->space_info->lock);
+
+ __link_block_group(cache->space_info, cache);
+
+ list_add_tail(&cache->bg_list, &trans->new_bgs);
+
+ set_avail_alloc_bits(extent_root->fs_info, type);
+
+ return 0;
+}
+
+static void clear_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
+{
+ u64 extra_flags = chunk_to_extended(flags) &
+ BTRFS_EXTENDED_PROFILE_MASK;
+
+ write_seqlock(&fs_info->profiles_lock);
+ if (flags & BTRFS_BLOCK_GROUP_DATA)
+ fs_info->avail_data_alloc_bits &= ~extra_flags;
+ if (flags & BTRFS_BLOCK_GROUP_METADATA)
+ fs_info->avail_metadata_alloc_bits &= ~extra_flags;
+ if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
+ fs_info->avail_system_alloc_bits &= ~extra_flags;
+ write_sequnlock(&fs_info->profiles_lock);
+}
+
+int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, u64 group_start,
+ struct extent_map *em)
+{
+ struct btrfs_path *path;
+ struct btrfs_block_group_cache *block_group;
+ struct btrfs_free_cluster *cluster;
+ struct btrfs_root *tree_root = root->fs_info->tree_root;
+ struct btrfs_key key;
+ struct inode *inode;
+ struct kobject *kobj = NULL;
+ int ret;
+ int index;
+ int factor;
+ struct btrfs_caching_control *caching_ctl = NULL;
+ bool remove_em;
+
+ root = root->fs_info->extent_root;
+
+ block_group = btrfs_lookup_block_group(root->fs_info, group_start);
+ BUG_ON(!block_group);
+ BUG_ON(!block_group->ro);
+
+ /*
+ * Free the reserved super bytes from this block group before
+ * remove it.
+ */
+ free_excluded_extents(root, block_group);
+
+ memcpy(&key, &block_group->key, sizeof(key));
+ index = get_block_group_index(block_group);
+ if (block_group->flags & (BTRFS_BLOCK_GROUP_DUP |
+ BTRFS_BLOCK_GROUP_RAID1 |
+ BTRFS_BLOCK_GROUP_RAID10))
+ factor = 2;
+ else
+ factor = 1;
+
+ /* make sure this block group isn't part of an allocation cluster */
+ cluster = &root->fs_info->data_alloc_cluster;
+ spin_lock(&cluster->refill_lock);
+ btrfs_return_cluster_to_free_space(block_group, cluster);
+ spin_unlock(&cluster->refill_lock);
+
+ /*
+ * make sure this block group isn't part of a metadata
+ * allocation cluster
+ */
+ cluster = &root->fs_info->meta_alloc_cluster;
+ spin_lock(&cluster->refill_lock);
+ btrfs_return_cluster_to_free_space(block_group, cluster);
+ spin_unlock(&cluster->refill_lock);
+
+ path = btrfs_alloc_path();
+ if (!path) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ /*
+ * get the inode first so any iput calls done for the io_list
+ * aren't the final iput (no unlinks allowed now)
+ */
+ inode = lookup_free_space_inode(tree_root, block_group, path);
+
+ mutex_lock(&trans->transaction->cache_write_mutex);
+ /*
+ * make sure our free spache cache IO is done before remove the
+ * free space inode
+ */
+ spin_lock(&trans->transaction->dirty_bgs_lock);
+ if (!list_empty(&block_group->io_list)) {
+ list_del_init(&block_group->io_list);
+
+ WARN_ON(!IS_ERR(inode) && inode != block_group->io_ctl.inode);
+
+ spin_unlock(&trans->transaction->dirty_bgs_lock);
+ btrfs_wait_cache_io(root, trans, block_group,
+ &block_group->io_ctl, path,
+ block_group->key.objectid);
+ btrfs_put_block_group(block_group);
+ spin_lock(&trans->transaction->dirty_bgs_lock);
+ }
+
+ if (!list_empty(&block_group->dirty_list)) {
+ list_del_init(&block_group->dirty_list);
+ btrfs_put_block_group(block_group);
+ }
+ spin_unlock(&trans->transaction->dirty_bgs_lock);
+ mutex_unlock(&trans->transaction->cache_write_mutex);
+
+ if (!IS_ERR(inode)) {
+ ret = btrfs_orphan_add(trans, inode);
+ if (ret) {
+ btrfs_add_delayed_iput(inode);
+ goto out;
+ }
+ clear_nlink(inode);
+ /* One for the block groups ref */
+ spin_lock(&block_group->lock);
+ if (block_group->iref) {
+ block_group->iref = 0;
+ block_group->inode = NULL;
+ spin_unlock(&block_group->lock);
+ iput(inode);
+ } else {
+ spin_unlock(&block_group->lock);
+ }
+ /* One for our lookup ref */
+ btrfs_add_delayed_iput(inode);
+ }
+
+ key.objectid = BTRFS_FREE_SPACE_OBJECTID;
+ key.offset = block_group->key.objectid;
+ key.type = 0;
+
+ ret = btrfs_search_slot(trans, tree_root, &key, path, -1, 1);
+ if (ret < 0)
+ goto out;
+ if (ret > 0)
+ btrfs_release_path(path);
+ if (ret == 0) {
+ ret = btrfs_del_item(trans, tree_root, path);
+ if (ret)
+ goto out;
+ btrfs_release_path(path);
+ }
+
+ spin_lock(&root->fs_info->block_group_cache_lock);
+ rb_erase(&block_group->cache_node,
+ &root->fs_info->block_group_cache_tree);
+ RB_CLEAR_NODE(&block_group->cache_node);
+
+ if (root->fs_info->first_logical_byte == block_group->key.objectid)
+ root->fs_info->first_logical_byte = (u64)-1;
+ spin_unlock(&root->fs_info->block_group_cache_lock);
+
+ down_write(&block_group->space_info->groups_sem);
+ /*
+ * we must use list_del_init so people can check to see if they
+ * are still on the list after taking the semaphore
+ */
+ list_del_init(&block_group->list);
+ if (list_empty(&block_group->space_info->block_groups[index])) {
+ kobj = block_group->space_info->block_group_kobjs[index];
+ block_group->space_info->block_group_kobjs[index] = NULL;
+ clear_avail_alloc_bits(root->fs_info, block_group->flags);
+ }
+ up_write(&block_group->space_info->groups_sem);
+ if (kobj) {
+ kobject_del(kobj);
+ kobject_put(kobj);
+ }
+
+ if (block_group->has_caching_ctl)
+ caching_ctl = get_caching_control(block_group);
+ if (block_group->cached == BTRFS_CACHE_STARTED)
+ wait_block_group_cache_done(block_group);
+ if (block_group->has_caching_ctl) {
+ down_write(&root->fs_info->commit_root_sem);
+ if (!caching_ctl) {
+ struct btrfs_caching_control *ctl;
+
+ list_for_each_entry(ctl,
+ &root->fs_info->caching_block_groups, list)
+ if (ctl->block_group == block_group) {
+ caching_ctl = ctl;
+ atomic_inc(&caching_ctl->count);
+ break;
+ }
+ }
+ if (caching_ctl)
+ list_del_init(&caching_ctl->list);
+ up_write(&root->fs_info->commit_root_sem);
+ if (caching_ctl) {
+ /* Once for the caching bgs list and once for us. */
+ put_caching_control(caching_ctl);
+ put_caching_control(caching_ctl);
+ }
+ }
+
+ spin_lock(&trans->transaction->dirty_bgs_lock);
+ if (!list_empty(&block_group->dirty_list)) {
+ WARN_ON(1);
+ }
+ if (!list_empty(&block_group->io_list)) {
+ WARN_ON(1);
+ }
+ spin_unlock(&trans->transaction->dirty_bgs_lock);
+ btrfs_remove_free_space_cache(block_group);
+
+ spin_lock(&block_group->space_info->lock);
+ list_del_init(&block_group->ro_list);
+
+ if (btrfs_test_opt(root, ENOSPC_DEBUG)) {
+ WARN_ON(block_group->space_info->total_bytes
+ < block_group->key.offset);
+ WARN_ON(block_group->space_info->bytes_readonly
+ < block_group->key.offset);
+ WARN_ON(block_group->space_info->disk_total
+ < block_group->key.offset * factor);
+ }
+ block_group->space_info->total_bytes -= block_group->key.offset;
+ block_group->space_info->bytes_readonly -= block_group->key.offset;
+ block_group->space_info->disk_total -= block_group->key.offset * factor;
+
+ spin_unlock(&block_group->space_info->lock);
+
+ memcpy(&key, &block_group->key, sizeof(key));
+
+ lock_chunks(root);
+ if (!list_empty(&em->list)) {
+ /* We're in the transaction->pending_chunks list. */
+ free_extent_map(em);
+ }
+ spin_lock(&block_group->lock);
+ block_group->removed = 1;
+ /*
+ * At this point trimming can't start on this block group, because we
+ * removed the block group from the tree fs_info->block_group_cache_tree
+ * so no one can't find it anymore and even if someone already got this
+ * block group before we removed it from the rbtree, they have already
+ * incremented block_group->trimming - if they didn't, they won't find
+ * any free space entries because we already removed them all when we
+ * called btrfs_remove_free_space_cache().
+ *
+ * And we must not remove the extent map from the fs_info->mapping_tree
+ * to prevent the same logical address range and physical device space
+ * ranges from being reused for a new block group. This is because our
+ * fs trim operation (btrfs_trim_fs() / btrfs_ioctl_fitrim()) is
+ * completely transactionless, so while it is trimming a range the
+ * currently running transaction might finish and a new one start,
+ * allowing for new block groups to be created that can reuse the same
+ * physical device locations unless we take this special care.
+ */
+ remove_em = (atomic_read(&block_group->trimming) == 0);
+ /*
+ * Make sure a trimmer task always sees the em in the pinned_chunks list
+ * if it sees block_group->removed == 1 (needs to lock block_group->lock
+ * before checking block_group->removed).
+ */
+ if (!remove_em) {
+ /*
+ * Our em might be in trans->transaction->pending_chunks which
+ * is protected by fs_info->chunk_mutex ([lock|unlock]_chunks),
+ * and so is the fs_info->pinned_chunks list.
+ *
+ * So at this point we must be holding the chunk_mutex to avoid
+ * any races with chunk allocation (more specifically at
+ * volumes.c:contains_pending_extent()), to ensure it always
+ * sees the em, either in the pending_chunks list or in the
+ * pinned_chunks list.
+ */
+ list_move_tail(&em->list, &root->fs_info->pinned_chunks);
+ }
+ spin_unlock(&block_group->lock);
+
+ if (remove_em) {
+ struct extent_map_tree *em_tree;
+
+ em_tree = &root->fs_info->mapping_tree.map_tree;
+ write_lock(&em_tree->lock);
+ /*
+ * The em might be in the pending_chunks list, so make sure the
+ * chunk mutex is locked, since remove_extent_mapping() will
+ * delete us from that list.
+ */
+ remove_extent_mapping(em_tree, em);
+ write_unlock(&em_tree->lock);
+ /* once for the tree */
+ free_extent_map(em);
+ }
+
+ unlock_chunks(root);
+
+ btrfs_put_block_group(block_group);
+ btrfs_put_block_group(block_group);
+
+ ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
+ if (ret > 0)
+ ret = -EIO;
+ if (ret < 0)
+ goto out;
+
+ ret = btrfs_del_item(trans, root, path);
+out:
+ btrfs_free_path(path);
+ return ret;
+}
+
+/*
+ * Process the unused_bgs list and remove any that don't have any allocated
+ * space inside of them.
+ */
+void btrfs_delete_unused_bgs(struct btrfs_fs_info *fs_info)
+{
+ struct btrfs_block_group_cache *block_group;
+ struct btrfs_space_info *space_info;
+ struct btrfs_root *root = fs_info->extent_root;
+ struct btrfs_trans_handle *trans;
+ int ret = 0;
+
+ if (!fs_info->open)
+ return;
+
+ spin_lock(&fs_info->unused_bgs_lock);
+ while (!list_empty(&fs_info->unused_bgs)) {
+ u64 start, end;
+
+ block_group = list_first_entry(&fs_info->unused_bgs,
+ struct btrfs_block_group_cache,
+ bg_list);
+ space_info = block_group->space_info;
+ list_del_init(&block_group->bg_list);
+ if (ret || btrfs_mixed_space_info(space_info)) {
+ btrfs_put_block_group(block_group);
+ continue;
+ }
+ spin_unlock(&fs_info->unused_bgs_lock);
+
+ /* Don't want to race with allocators so take the groups_sem */
+ down_write(&space_info->groups_sem);
+ spin_lock(&block_group->lock);
+ if (block_group->reserved ||
+ btrfs_block_group_used(&block_group->item) ||
+ block_group->ro) {
+ /*
+ * We want to bail if we made new allocations or have
+ * outstanding allocations in this block group. We do
+ * the ro check in case balance is currently acting on
+ * this block group.
+ */
+ spin_unlock(&block_group->lock);
+ up_write(&space_info->groups_sem);
+ goto next;
+ }
+ spin_unlock(&block_group->lock);
+
+ /* We don't want to force the issue, only flip if it's ok. */
+ ret = set_block_group_ro(block_group, 0);
+ up_write(&space_info->groups_sem);
+ if (ret < 0) {
+ ret = 0;
+ goto next;
+ }
+
+ /*
+ * Want to do this before we do anything else so we can recover
+ * properly if we fail to join the transaction.
+ */
+ /* 1 for btrfs_orphan_reserve_metadata() */
+ trans = btrfs_start_transaction(root, 1);
+ if (IS_ERR(trans)) {
+ btrfs_set_block_group_rw(root, block_group);
+ ret = PTR_ERR(trans);
+ goto next;
+ }
+
+ /*
+ * We could have pending pinned extents for this block group,
+ * just delete them, we don't care about them anymore.
+ */
+ start = block_group->key.objectid;
+ end = start + block_group->key.offset - 1;
+ /*
+ * Hold the unused_bg_unpin_mutex lock to avoid racing with
+ * btrfs_finish_extent_commit(). If we are at transaction N,
+ * another task might be running finish_extent_commit() for the
+ * previous transaction N - 1, and have seen a range belonging
+ * to the block group in freed_extents[] before we were able to
+ * clear the whole block group range from freed_extents[]. This
+ * means that task can lookup for the block group after we
+ * unpinned it from freed_extents[] and removed it, leading to
+ * a BUG_ON() at btrfs_unpin_extent_range().
+ */
+ mutex_lock(&fs_info->unused_bg_unpin_mutex);
+ ret = clear_extent_bits(&fs_info->freed_extents[0], start, end,
+ EXTENT_DIRTY, GFP_NOFS);
+ if (ret) {
+ mutex_unlock(&fs_info->unused_bg_unpin_mutex);
+ btrfs_set_block_group_rw(root, block_group);
+ goto end_trans;
+ }
+ ret = clear_extent_bits(&fs_info->freed_extents[1], start, end,
+ EXTENT_DIRTY, GFP_NOFS);
+ if (ret) {
+ mutex_unlock(&fs_info->unused_bg_unpin_mutex);
+ btrfs_set_block_group_rw(root, block_group);
+ goto end_trans;
+ }
+ mutex_unlock(&fs_info->unused_bg_unpin_mutex);
+
+ /* Reset pinned so btrfs_put_block_group doesn't complain */
+ spin_lock(&space_info->lock);
+ spin_lock(&block_group->lock);
+
+ space_info->bytes_pinned -= block_group->pinned;
+ space_info->bytes_readonly += block_group->pinned;
+ percpu_counter_add(&space_info->total_bytes_pinned,
+ -block_group->pinned);
+ block_group->pinned = 0;
+
+ spin_unlock(&block_group->lock);
+ spin_unlock(&space_info->lock);
+
+ /*
+ * Btrfs_remove_chunk will abort the transaction if things go
+ * horribly wrong.
+ */
+ ret = btrfs_remove_chunk(trans, root,
+ block_group->key.objectid);
+end_trans:
+ btrfs_end_transaction(trans, root);
+next:
+ btrfs_put_block_group(block_group);
+ spin_lock(&fs_info->unused_bgs_lock);
+ }
+ spin_unlock(&fs_info->unused_bgs_lock);
+}
+
+int btrfs_init_space_info(struct btrfs_fs_info *fs_info)
+{
+ struct btrfs_space_info *space_info;
+ struct btrfs_super_block *disk_super;
+ u64 features;
+ u64 flags;
+ int mixed = 0;
+ int ret;
+
+ disk_super = fs_info->super_copy;
+ if (!btrfs_super_root(disk_super))
+ return 1;
+
+ features = btrfs_super_incompat_flags(disk_super);
+ if (features & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS)
+ mixed = 1;
+
+ flags = BTRFS_BLOCK_GROUP_SYSTEM;
+ ret = update_space_info(fs_info, flags, 0, 0, &space_info);
+ if (ret)
+ goto out;
+
+ if (mixed) {
+ flags = BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA;
+ ret = update_space_info(fs_info, flags, 0, 0, &space_info);
+ } else {
+ flags = BTRFS_BLOCK_GROUP_METADATA;
+ ret = update_space_info(fs_info, flags, 0, 0, &space_info);
+ if (ret)
+ goto out;
+
+ flags = BTRFS_BLOCK_GROUP_DATA;
+ ret = update_space_info(fs_info, flags, 0, 0, &space_info);
+ }
+out:
+ return ret;
+}
+
+int btrfs_error_unpin_extent_range(struct btrfs_root *root, u64 start, u64 end)
+{
+ return unpin_extent_range(root, start, end, false);
+}
+
+int btrfs_trim_fs(struct btrfs_root *root, struct fstrim_range *range)
+{
+ struct btrfs_fs_info *fs_info = root->fs_info;
+ struct btrfs_block_group_cache *cache = NULL;
+ u64 group_trimmed;
+ u64 start;
+ u64 end;
+ u64 trimmed = 0;
+ u64 total_bytes = btrfs_super_total_bytes(fs_info->super_copy);
+ int ret = 0;
+
+ /*
+ * try to trim all FS space, our block group may start from non-zero.
+ */
+ if (range->len == total_bytes)
+ cache = btrfs_lookup_first_block_group(fs_info, range->start);
+ else
+ cache = btrfs_lookup_block_group(fs_info, range->start);
+
+ while (cache) {
+ if (cache->key.objectid >= (range->start + range->len)) {
+ btrfs_put_block_group(cache);
+ break;
+ }
+
+ start = max(range->start, cache->key.objectid);
+ end = min(range->start + range->len,
+ cache->key.objectid + cache->key.offset);
+
+ if (end - start >= range->minlen) {
+ if (!block_group_cache_done(cache)) {
+ ret = cache_block_group(cache, 0);
+ if (ret) {
+ btrfs_put_block_group(cache);
+ break;
+ }
+ ret = wait_block_group_cache_done(cache);
+ if (ret) {
+ btrfs_put_block_group(cache);
+ break;
+ }
+ }
+ ret = btrfs_trim_block_group(cache,
+ &group_trimmed,
+ start,
+ end,
+ range->minlen);
+
+ trimmed += group_trimmed;
+ if (ret) {
+ btrfs_put_block_group(cache);
+ break;
+ }
+ }
+
+ cache = next_block_group(fs_info->tree_root, cache);
+ }
+
+ range->len = trimmed;
+ return ret;
+}
+
+/*
+ * btrfs_{start,end}_write_no_snapshoting() are similar to
+ * mnt_{want,drop}_write(), they are used to prevent some tasks from writing
+ * data into the page cache through nocow before the subvolume is snapshoted,
+ * but flush the data into disk after the snapshot creation, or to prevent
+ * operations while snapshoting is ongoing and that cause the snapshot to be
+ * inconsistent (writes followed by expanding truncates for example).
+ */
+void btrfs_end_write_no_snapshoting(struct btrfs_root *root)
+{
+ percpu_counter_dec(&root->subv_writers->counter);
+ /*
+ * Make sure counter is updated before we wake up
+ * waiters.
+ */
+ smp_mb();
+ if (waitqueue_active(&root->subv_writers->wait))
+ wake_up(&root->subv_writers->wait);
+}
+
+int btrfs_start_write_no_snapshoting(struct btrfs_root *root)
+{
+ if (atomic_read(&root->will_be_snapshoted))
+ return 0;
+
+ percpu_counter_inc(&root->subv_writers->counter);
+ /*
+ * Make sure counter is updated before we check for snapshot creation.
+ */
+ smp_mb();
+ if (atomic_read(&root->will_be_snapshoted)) {
+ btrfs_end_write_no_snapshoting(root);
+ return 0;
+ }
+ return 1;
+}
Code Review / kvmfornfv.git / blobdiff