--- /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/slab.h>
+#include <linux/blkdev.h>
+#include <linux/writeback.h>
+#include <linux/pagevec.h>
+#include "ctree.h"
+#include "transaction.h"
+#include "btrfs_inode.h"
+#include "extent_io.h"
+#include "disk-io.h"
+
+static struct kmem_cache *btrfs_ordered_extent_cache;
+
+static u64 entry_end(struct btrfs_ordered_extent *entry)
+{
+ if (entry->file_offset + entry->len < entry->file_offset)
+ return (u64)-1;
+ return entry->file_offset + entry->len;
+}
+
+/* returns NULL if the insertion worked, or it returns the node it did find
+ * in the tree
+ */
+static struct rb_node *tree_insert(struct rb_root *root, u64 file_offset,
+ struct rb_node *node)
+{
+ struct rb_node **p = &root->rb_node;
+ struct rb_node *parent = NULL;
+ struct btrfs_ordered_extent *entry;
+
+ while (*p) {
+ parent = *p;
+ entry = rb_entry(parent, struct btrfs_ordered_extent, rb_node);
+
+ if (file_offset < entry->file_offset)
+ p = &(*p)->rb_left;
+ else if (file_offset >= entry_end(entry))
+ p = &(*p)->rb_right;
+ else
+ return parent;
+ }
+
+ rb_link_node(node, parent, p);
+ rb_insert_color(node, root);
+ return NULL;
+}
+
+static void ordered_data_tree_panic(struct inode *inode, int errno,
+ u64 offset)
+{
+ struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
+ btrfs_panic(fs_info, errno, "Inconsistency in ordered tree at offset "
+ "%llu", offset);
+}
+
+/*
+ * look for a given offset in the tree, and if it can't be found return the
+ * first lesser offset
+ */
+static struct rb_node *__tree_search(struct rb_root *root, u64 file_offset,
+ struct rb_node **prev_ret)
+{
+ struct rb_node *n = root->rb_node;
+ struct rb_node *prev = NULL;
+ struct rb_node *test;
+ struct btrfs_ordered_extent *entry;
+ struct btrfs_ordered_extent *prev_entry = NULL;
+
+ while (n) {
+ entry = rb_entry(n, struct btrfs_ordered_extent, rb_node);
+ prev = n;
+ prev_entry = entry;
+
+ if (file_offset < entry->file_offset)
+ n = n->rb_left;
+ else if (file_offset >= entry_end(entry))
+ n = n->rb_right;
+ else
+ return n;
+ }
+ if (!prev_ret)
+ return NULL;
+
+ while (prev && file_offset >= entry_end(prev_entry)) {
+ test = rb_next(prev);
+ if (!test)
+ break;
+ prev_entry = rb_entry(test, struct btrfs_ordered_extent,
+ rb_node);
+ if (file_offset < entry_end(prev_entry))
+ break;
+
+ prev = test;
+ }
+ if (prev)
+ prev_entry = rb_entry(prev, struct btrfs_ordered_extent,
+ rb_node);
+ while (prev && file_offset < entry_end(prev_entry)) {
+ test = rb_prev(prev);
+ if (!test)
+ break;
+ prev_entry = rb_entry(test, struct btrfs_ordered_extent,
+ rb_node);
+ prev = test;
+ }
+ *prev_ret = prev;
+ return NULL;
+}
+
+/*
+ * helper to check if a given offset is inside a given entry
+ */
+static int offset_in_entry(struct btrfs_ordered_extent *entry, u64 file_offset)
+{
+ if (file_offset < entry->file_offset ||
+ entry->file_offset + entry->len <= file_offset)
+ return 0;
+ return 1;
+}
+
+static int range_overlaps(struct btrfs_ordered_extent *entry, u64 file_offset,
+ u64 len)
+{
+ if (file_offset + len <= entry->file_offset ||
+ entry->file_offset + entry->len <= file_offset)
+ return 0;
+ return 1;
+}
+
+/*
+ * look find the first ordered struct that has this offset, otherwise
+ * the first one less than this offset
+ */
+static inline struct rb_node *tree_search(struct btrfs_ordered_inode_tree *tree,
+ u64 file_offset)
+{
+ struct rb_root *root = &tree->tree;
+ struct rb_node *prev = NULL;
+ struct rb_node *ret;
+ struct btrfs_ordered_extent *entry;
+
+ if (tree->last) {
+ entry = rb_entry(tree->last, struct btrfs_ordered_extent,
+ rb_node);
+ if (offset_in_entry(entry, file_offset))
+ return tree->last;
+ }
+ ret = __tree_search(root, file_offset, &prev);
+ if (!ret)
+ ret = prev;
+ if (ret)
+ tree->last = ret;
+ return ret;
+}
+
+/* allocate and add a new ordered_extent into the per-inode tree.
+ * file_offset is the logical offset in the file
+ *
+ * start is the disk block number of an extent already reserved in the
+ * extent allocation tree
+ *
+ * len is the length of the extent
+ *
+ * The tree is given a single reference on the ordered extent that was
+ * inserted.
+ */
+static int __btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
+ u64 start, u64 len, u64 disk_len,
+ int type, int dio, int compress_type)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_ordered_inode_tree *tree;
+ struct rb_node *node;
+ struct btrfs_ordered_extent *entry;
+
+ tree = &BTRFS_I(inode)->ordered_tree;
+ entry = kmem_cache_zalloc(btrfs_ordered_extent_cache, GFP_NOFS);
+ if (!entry)
+ return -ENOMEM;
+
+ entry->file_offset = file_offset;
+ entry->start = start;
+ entry->len = len;
+ if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM) &&
+ !(type == BTRFS_ORDERED_NOCOW))
+ entry->csum_bytes_left = disk_len;
+ entry->disk_len = disk_len;
+ entry->bytes_left = len;
+ entry->inode = igrab(inode);
+ entry->compress_type = compress_type;
+ entry->truncated_len = (u64)-1;
+ if (type != BTRFS_ORDERED_IO_DONE && type != BTRFS_ORDERED_COMPLETE)
+ set_bit(type, &entry->flags);
+
+ if (dio)
+ set_bit(BTRFS_ORDERED_DIRECT, &entry->flags);
+
+ /* one ref for the tree */
+ atomic_set(&entry->refs, 1);
+ init_waitqueue_head(&entry->wait);
+ INIT_LIST_HEAD(&entry->list);
+ INIT_LIST_HEAD(&entry->root_extent_list);
+ INIT_LIST_HEAD(&entry->work_list);
+ init_completion(&entry->completion);
+ INIT_LIST_HEAD(&entry->log_list);
+ INIT_LIST_HEAD(&entry->trans_list);
+
+ trace_btrfs_ordered_extent_add(inode, entry);
+
+ spin_lock_irq(&tree->lock);
+ node = tree_insert(&tree->tree, file_offset,
+ &entry->rb_node);
+ if (node)
+ ordered_data_tree_panic(inode, -EEXIST, file_offset);
+ spin_unlock_irq(&tree->lock);
+
+ spin_lock(&root->ordered_extent_lock);
+ list_add_tail(&entry->root_extent_list,
+ &root->ordered_extents);
+ root->nr_ordered_extents++;
+ if (root->nr_ordered_extents == 1) {
+ spin_lock(&root->fs_info->ordered_root_lock);
+ BUG_ON(!list_empty(&root->ordered_root));
+ list_add_tail(&root->ordered_root,
+ &root->fs_info->ordered_roots);
+ spin_unlock(&root->fs_info->ordered_root_lock);
+ }
+ spin_unlock(&root->ordered_extent_lock);
+
+ return 0;
+}
+
+int btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
+ u64 start, u64 len, u64 disk_len, int type)
+{
+ return __btrfs_add_ordered_extent(inode, file_offset, start, len,
+ disk_len, type, 0,
+ BTRFS_COMPRESS_NONE);
+}
+
+int btrfs_add_ordered_extent_dio(struct inode *inode, u64 file_offset,
+ u64 start, u64 len, u64 disk_len, int type)
+{
+ return __btrfs_add_ordered_extent(inode, file_offset, start, len,
+ disk_len, type, 1,
+ BTRFS_COMPRESS_NONE);
+}
+
+int btrfs_add_ordered_extent_compress(struct inode *inode, u64 file_offset,
+ u64 start, u64 len, u64 disk_len,
+ int type, int compress_type)
+{
+ return __btrfs_add_ordered_extent(inode, file_offset, start, len,
+ disk_len, type, 0,
+ compress_type);
+}
+
+/*
+ * Add a struct btrfs_ordered_sum into the list of checksums to be inserted
+ * when an ordered extent is finished. If the list covers more than one
+ * ordered extent, it is split across multiples.
+ */
+void btrfs_add_ordered_sum(struct inode *inode,
+ struct btrfs_ordered_extent *entry,
+ struct btrfs_ordered_sum *sum)
+{
+ struct btrfs_ordered_inode_tree *tree;
+
+ tree = &BTRFS_I(inode)->ordered_tree;
+ spin_lock_irq(&tree->lock);
+ list_add_tail(&sum->list, &entry->list);
+ WARN_ON(entry->csum_bytes_left < sum->len);
+ entry->csum_bytes_left -= sum->len;
+ if (entry->csum_bytes_left == 0)
+ wake_up(&entry->wait);
+ spin_unlock_irq(&tree->lock);
+}
+
+/*
+ * this is used to account for finished IO across a given range
+ * of the file. The IO may span ordered extents. If
+ * a given ordered_extent is completely done, 1 is returned, otherwise
+ * 0.
+ *
+ * test_and_set_bit on a flag in the struct btrfs_ordered_extent is used
+ * to make sure this function only returns 1 once for a given ordered extent.
+ *
+ * file_offset is updated to one byte past the range that is recorded as
+ * complete. This allows you to walk forward in the file.
+ */
+int btrfs_dec_test_first_ordered_pending(struct inode *inode,
+ struct btrfs_ordered_extent **cached,
+ u64 *file_offset, u64 io_size, int uptodate)
+{
+ struct btrfs_ordered_inode_tree *tree;
+ struct rb_node *node;
+ struct btrfs_ordered_extent *entry = NULL;
+ int ret;
+ unsigned long flags;
+ u64 dec_end;
+ u64 dec_start;
+ u64 to_dec;
+
+ tree = &BTRFS_I(inode)->ordered_tree;
+ spin_lock_irqsave(&tree->lock, flags);
+ node = tree_search(tree, *file_offset);
+ if (!node) {
+ ret = 1;
+ goto out;
+ }
+
+ entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
+ if (!offset_in_entry(entry, *file_offset)) {
+ ret = 1;
+ goto out;
+ }
+
+ dec_start = max(*file_offset, entry->file_offset);
+ dec_end = min(*file_offset + io_size, entry->file_offset +
+ entry->len);
+ *file_offset = dec_end;
+ if (dec_start > dec_end) {
+ btrfs_crit(BTRFS_I(inode)->root->fs_info,
+ "bad ordering dec_start %llu end %llu", dec_start, dec_end);
+ }
+ to_dec = dec_end - dec_start;
+ if (to_dec > entry->bytes_left) {
+ btrfs_crit(BTRFS_I(inode)->root->fs_info,
+ "bad ordered accounting left %llu size %llu",
+ entry->bytes_left, to_dec);
+ }
+ entry->bytes_left -= to_dec;
+ if (!uptodate)
+ set_bit(BTRFS_ORDERED_IOERR, &entry->flags);
+
+ if (entry->bytes_left == 0) {
+ ret = test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
+ if (waitqueue_active(&entry->wait))
+ wake_up(&entry->wait);
+ } else {
+ ret = 1;
+ }
+out:
+ if (!ret && cached && entry) {
+ *cached = entry;
+ atomic_inc(&entry->refs);
+ }
+ spin_unlock_irqrestore(&tree->lock, flags);
+ return ret == 0;
+}
+
+/*
+ * this is used to account for finished IO across a given range
+ * of the file. The IO should not span ordered extents. If
+ * a given ordered_extent is completely done, 1 is returned, otherwise
+ * 0.
+ *
+ * test_and_set_bit on a flag in the struct btrfs_ordered_extent is used
+ * to make sure this function only returns 1 once for a given ordered extent.
+ */
+int btrfs_dec_test_ordered_pending(struct inode *inode,
+ struct btrfs_ordered_extent **cached,
+ u64 file_offset, u64 io_size, int uptodate)
+{
+ struct btrfs_ordered_inode_tree *tree;
+ struct rb_node *node;
+ struct btrfs_ordered_extent *entry = NULL;
+ unsigned long flags;
+ int ret;
+
+ tree = &BTRFS_I(inode)->ordered_tree;
+ spin_lock_irqsave(&tree->lock, flags);
+ if (cached && *cached) {
+ entry = *cached;
+ goto have_entry;
+ }
+
+ node = tree_search(tree, file_offset);
+ if (!node) {
+ ret = 1;
+ goto out;
+ }
+
+ entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
+have_entry:
+ if (!offset_in_entry(entry, file_offset)) {
+ ret = 1;
+ goto out;
+ }
+
+ if (io_size > entry->bytes_left) {
+ btrfs_crit(BTRFS_I(inode)->root->fs_info,
+ "bad ordered accounting left %llu size %llu",
+ entry->bytes_left, io_size);
+ }
+ entry->bytes_left -= io_size;
+ if (!uptodate)
+ set_bit(BTRFS_ORDERED_IOERR, &entry->flags);
+
+ if (entry->bytes_left == 0) {
+ ret = test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
+ if (waitqueue_active(&entry->wait))
+ wake_up(&entry->wait);
+ } else {
+ ret = 1;
+ }
+out:
+ if (!ret && cached && entry) {
+ *cached = entry;
+ atomic_inc(&entry->refs);
+ }
+ spin_unlock_irqrestore(&tree->lock, flags);
+ return ret == 0;
+}
+
+/* Needs to either be called under a log transaction or the log_mutex */
+void btrfs_get_logged_extents(struct inode *inode,
+ struct list_head *logged_list,
+ const loff_t start,
+ const loff_t end)
+{
+ struct btrfs_ordered_inode_tree *tree;
+ struct btrfs_ordered_extent *ordered;
+ struct rb_node *n;
+ struct rb_node *prev;
+
+ tree = &BTRFS_I(inode)->ordered_tree;
+ spin_lock_irq(&tree->lock);
+ n = __tree_search(&tree->tree, end, &prev);
+ if (!n)
+ n = prev;
+ for (; n; n = rb_prev(n)) {
+ ordered = rb_entry(n, struct btrfs_ordered_extent, rb_node);
+ if (ordered->file_offset > end)
+ continue;
+ if (entry_end(ordered) <= start)
+ break;
+ if (test_and_set_bit(BTRFS_ORDERED_LOGGED, &ordered->flags))
+ continue;
+ list_add(&ordered->log_list, logged_list);
+ atomic_inc(&ordered->refs);
+ }
+ spin_unlock_irq(&tree->lock);
+}
+
+void btrfs_put_logged_extents(struct list_head *logged_list)
+{
+ struct btrfs_ordered_extent *ordered;
+
+ while (!list_empty(logged_list)) {
+ ordered = list_first_entry(logged_list,
+ struct btrfs_ordered_extent,
+ log_list);
+ list_del_init(&ordered->log_list);
+ btrfs_put_ordered_extent(ordered);
+ }
+}
+
+void btrfs_submit_logged_extents(struct list_head *logged_list,
+ struct btrfs_root *log)
+{
+ int index = log->log_transid % 2;
+
+ spin_lock_irq(&log->log_extents_lock[index]);
+ list_splice_tail(logged_list, &log->logged_list[index]);
+ spin_unlock_irq(&log->log_extents_lock[index]);
+}
+
+void btrfs_wait_logged_extents(struct btrfs_trans_handle *trans,
+ struct btrfs_root *log, u64 transid)
+{
+ struct btrfs_ordered_extent *ordered;
+ int index = transid % 2;
+
+ spin_lock_irq(&log->log_extents_lock[index]);
+ while (!list_empty(&log->logged_list[index])) {
+ ordered = list_first_entry(&log->logged_list[index],
+ struct btrfs_ordered_extent,
+ log_list);
+ list_del_init(&ordered->log_list);
+ spin_unlock_irq(&log->log_extents_lock[index]);
+
+ if (!test_bit(BTRFS_ORDERED_IO_DONE, &ordered->flags) &&
+ !test_bit(BTRFS_ORDERED_DIRECT, &ordered->flags)) {
+ struct inode *inode = ordered->inode;
+ u64 start = ordered->file_offset;
+ u64 end = ordered->file_offset + ordered->len - 1;
+
+ WARN_ON(!inode);
+ filemap_fdatawrite_range(inode->i_mapping, start, end);
+ }
+ wait_event(ordered->wait, test_bit(BTRFS_ORDERED_IO_DONE,
+ &ordered->flags));
+
+ list_add_tail(&ordered->trans_list, &trans->ordered);
+ spin_lock_irq(&log->log_extents_lock[index]);
+ }
+ spin_unlock_irq(&log->log_extents_lock[index]);
+}
+
+void btrfs_free_logged_extents(struct btrfs_root *log, u64 transid)
+{
+ struct btrfs_ordered_extent *ordered;
+ int index = transid % 2;
+
+ spin_lock_irq(&log->log_extents_lock[index]);
+ while (!list_empty(&log->logged_list[index])) {
+ ordered = list_first_entry(&log->logged_list[index],
+ struct btrfs_ordered_extent,
+ log_list);
+ list_del_init(&ordered->log_list);
+ spin_unlock_irq(&log->log_extents_lock[index]);
+ btrfs_put_ordered_extent(ordered);
+ spin_lock_irq(&log->log_extents_lock[index]);
+ }
+ spin_unlock_irq(&log->log_extents_lock[index]);
+}
+
+/*
+ * used to drop a reference on an ordered extent. This will free
+ * the extent if the last reference is dropped
+ */
+void btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry)
+{
+ struct list_head *cur;
+ struct btrfs_ordered_sum *sum;
+
+ trace_btrfs_ordered_extent_put(entry->inode, entry);
+
+ if (atomic_dec_and_test(&entry->refs)) {
+ if (entry->inode)
+ btrfs_add_delayed_iput(entry->inode);
+ while (!list_empty(&entry->list)) {
+ cur = entry->list.next;
+ sum = list_entry(cur, struct btrfs_ordered_sum, list);
+ list_del(&sum->list);
+ kfree(sum);
+ }
+ kmem_cache_free(btrfs_ordered_extent_cache, entry);
+ }
+}
+
+/*
+ * remove an ordered extent from the tree. No references are dropped
+ * and waiters are woken up.
+ */
+void btrfs_remove_ordered_extent(struct inode *inode,
+ struct btrfs_ordered_extent *entry)
+{
+ struct btrfs_ordered_inode_tree *tree;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct rb_node *node;
+
+ tree = &BTRFS_I(inode)->ordered_tree;
+ spin_lock_irq(&tree->lock);
+ node = &entry->rb_node;
+ rb_erase(node, &tree->tree);
+ if (tree->last == node)
+ tree->last = NULL;
+ set_bit(BTRFS_ORDERED_COMPLETE, &entry->flags);
+ spin_unlock_irq(&tree->lock);
+
+ spin_lock(&root->ordered_extent_lock);
+ list_del_init(&entry->root_extent_list);
+ root->nr_ordered_extents--;
+
+ trace_btrfs_ordered_extent_remove(inode, entry);
+
+ if (!root->nr_ordered_extents) {
+ spin_lock(&root->fs_info->ordered_root_lock);
+ BUG_ON(list_empty(&root->ordered_root));
+ list_del_init(&root->ordered_root);
+ spin_unlock(&root->fs_info->ordered_root_lock);
+ }
+ spin_unlock(&root->ordered_extent_lock);
+ wake_up(&entry->wait);
+}
+
+static void btrfs_run_ordered_extent_work(struct btrfs_work *work)
+{
+ struct btrfs_ordered_extent *ordered;
+
+ ordered = container_of(work, struct btrfs_ordered_extent, flush_work);
+ btrfs_start_ordered_extent(ordered->inode, ordered, 1);
+ complete(&ordered->completion);
+}
+
+/*
+ * wait for all the ordered extents in a root. This is done when balancing
+ * space between drives.
+ */
+int btrfs_wait_ordered_extents(struct btrfs_root *root, int nr)
+{
+ struct list_head splice, works;
+ struct btrfs_ordered_extent *ordered, *next;
+ int count = 0;
+
+ INIT_LIST_HEAD(&splice);
+ INIT_LIST_HEAD(&works);
+
+ mutex_lock(&root->ordered_extent_mutex);
+ spin_lock(&root->ordered_extent_lock);
+ list_splice_init(&root->ordered_extents, &splice);
+ while (!list_empty(&splice) && nr) {
+ ordered = list_first_entry(&splice, struct btrfs_ordered_extent,
+ root_extent_list);
+ list_move_tail(&ordered->root_extent_list,
+ &root->ordered_extents);
+ atomic_inc(&ordered->refs);
+ spin_unlock(&root->ordered_extent_lock);
+
+ btrfs_init_work(&ordered->flush_work,
+ btrfs_flush_delalloc_helper,
+ btrfs_run_ordered_extent_work, NULL, NULL);
+ list_add_tail(&ordered->work_list, &works);
+ btrfs_queue_work(root->fs_info->flush_workers,
+ &ordered->flush_work);
+
+ cond_resched();
+ spin_lock(&root->ordered_extent_lock);
+ if (nr != -1)
+ nr--;
+ count++;
+ }
+ list_splice_tail(&splice, &root->ordered_extents);
+ spin_unlock(&root->ordered_extent_lock);
+
+ list_for_each_entry_safe(ordered, next, &works, work_list) {
+ list_del_init(&ordered->work_list);
+ wait_for_completion(&ordered->completion);
+ btrfs_put_ordered_extent(ordered);
+ cond_resched();
+ }
+ mutex_unlock(&root->ordered_extent_mutex);
+
+ return count;
+}
+
+void btrfs_wait_ordered_roots(struct btrfs_fs_info *fs_info, int nr)
+{
+ struct btrfs_root *root;
+ struct list_head splice;
+ int done;
+
+ INIT_LIST_HEAD(&splice);
+
+ mutex_lock(&fs_info->ordered_operations_mutex);
+ spin_lock(&fs_info->ordered_root_lock);
+ list_splice_init(&fs_info->ordered_roots, &splice);
+ while (!list_empty(&splice) && nr) {
+ root = list_first_entry(&splice, struct btrfs_root,
+ ordered_root);
+ root = btrfs_grab_fs_root(root);
+ BUG_ON(!root);
+ list_move_tail(&root->ordered_root,
+ &fs_info->ordered_roots);
+ spin_unlock(&fs_info->ordered_root_lock);
+
+ done = btrfs_wait_ordered_extents(root, nr);
+ btrfs_put_fs_root(root);
+
+ spin_lock(&fs_info->ordered_root_lock);
+ if (nr != -1) {
+ nr -= done;
+ WARN_ON(nr < 0);
+ }
+ }
+ list_splice_tail(&splice, &fs_info->ordered_roots);
+ spin_unlock(&fs_info->ordered_root_lock);
+ mutex_unlock(&fs_info->ordered_operations_mutex);
+}
+
+/*
+ * Used to start IO or wait for a given ordered extent to finish.
+ *
+ * If wait is one, this effectively waits on page writeback for all the pages
+ * in the extent, and it waits on the io completion code to insert
+ * metadata into the btree corresponding to the extent
+ */
+void btrfs_start_ordered_extent(struct inode *inode,
+ struct btrfs_ordered_extent *entry,
+ int wait)
+{
+ u64 start = entry->file_offset;
+ u64 end = start + entry->len - 1;
+
+ trace_btrfs_ordered_extent_start(inode, entry);
+
+ /*
+ * pages in the range can be dirty, clean or writeback. We
+ * start IO on any dirty ones so the wait doesn't stall waiting
+ * for the flusher thread to find them
+ */
+ if (!test_bit(BTRFS_ORDERED_DIRECT, &entry->flags))
+ filemap_fdatawrite_range(inode->i_mapping, start, end);
+ if (wait) {
+ wait_event(entry->wait, test_bit(BTRFS_ORDERED_COMPLETE,
+ &entry->flags));
+ }
+}
+
+/*
+ * Used to wait on ordered extents across a large range of bytes.
+ */
+int btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len)
+{
+ int ret = 0;
+ int ret_wb = 0;
+ u64 end;
+ u64 orig_end;
+ struct btrfs_ordered_extent *ordered;
+
+ if (start + len < start) {
+ orig_end = INT_LIMIT(loff_t);
+ } else {
+ orig_end = start + len - 1;
+ if (orig_end > INT_LIMIT(loff_t))
+ orig_end = INT_LIMIT(loff_t);
+ }
+
+ /* start IO across the range first to instantiate any delalloc
+ * extents
+ */
+ ret = btrfs_fdatawrite_range(inode, start, orig_end);
+ if (ret)
+ return ret;
+
+ /*
+ * If we have a writeback error don't return immediately. Wait first
+ * for any ordered extents that haven't completed yet. This is to make
+ * sure no one can dirty the same page ranges and call writepages()
+ * before the ordered extents complete - to avoid failures (-EEXIST)
+ * when adding the new ordered extents to the ordered tree.
+ */
+ ret_wb = filemap_fdatawait_range(inode->i_mapping, start, orig_end);
+
+ end = orig_end;
+ while (1) {
+ ordered = btrfs_lookup_first_ordered_extent(inode, end);
+ if (!ordered)
+ break;
+ if (ordered->file_offset > orig_end) {
+ btrfs_put_ordered_extent(ordered);
+ break;
+ }
+ if (ordered->file_offset + ordered->len <= start) {
+ btrfs_put_ordered_extent(ordered);
+ break;
+ }
+ btrfs_start_ordered_extent(inode, ordered, 1);
+ end = ordered->file_offset;
+ if (test_bit(BTRFS_ORDERED_IOERR, &ordered->flags))
+ ret = -EIO;
+ btrfs_put_ordered_extent(ordered);
+ if (ret || end == 0 || end == start)
+ break;
+ end--;
+ }
+ return ret_wb ? ret_wb : ret;
+}
+
+/*
+ * find an ordered extent corresponding to file_offset. return NULL if
+ * nothing is found, otherwise take a reference on the extent and return it
+ */
+struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct inode *inode,
+ u64 file_offset)
+{
+ struct btrfs_ordered_inode_tree *tree;
+ struct rb_node *node;
+ struct btrfs_ordered_extent *entry = NULL;
+
+ tree = &BTRFS_I(inode)->ordered_tree;
+ spin_lock_irq(&tree->lock);
+ node = tree_search(tree, file_offset);
+ if (!node)
+ goto out;
+
+ entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
+ if (!offset_in_entry(entry, file_offset))
+ entry = NULL;
+ if (entry)
+ atomic_inc(&entry->refs);
+out:
+ spin_unlock_irq(&tree->lock);
+ return entry;
+}
+
+/* Since the DIO code tries to lock a wide area we need to look for any ordered
+ * extents that exist in the range, rather than just the start of the range.
+ */
+struct btrfs_ordered_extent *btrfs_lookup_ordered_range(struct inode *inode,
+ u64 file_offset,
+ u64 len)
+{
+ struct btrfs_ordered_inode_tree *tree;
+ struct rb_node *node;
+ struct btrfs_ordered_extent *entry = NULL;
+
+ tree = &BTRFS_I(inode)->ordered_tree;
+ spin_lock_irq(&tree->lock);
+ node = tree_search(tree, file_offset);
+ if (!node) {
+ node = tree_search(tree, file_offset + len);
+ if (!node)
+ goto out;
+ }
+
+ while (1) {
+ entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
+ if (range_overlaps(entry, file_offset, len))
+ break;
+
+ if (entry->file_offset >= file_offset + len) {
+ entry = NULL;
+ break;
+ }
+ entry = NULL;
+ node = rb_next(node);
+ if (!node)
+ break;
+ }
+out:
+ if (entry)
+ atomic_inc(&entry->refs);
+ spin_unlock_irq(&tree->lock);
+ return entry;
+}
+
+/*
+ * lookup and return any extent before 'file_offset'. NULL is returned
+ * if none is found
+ */
+struct btrfs_ordered_extent *
+btrfs_lookup_first_ordered_extent(struct inode *inode, u64 file_offset)
+{
+ struct btrfs_ordered_inode_tree *tree;
+ struct rb_node *node;
+ struct btrfs_ordered_extent *entry = NULL;
+
+ tree = &BTRFS_I(inode)->ordered_tree;
+ spin_lock_irq(&tree->lock);
+ node = tree_search(tree, file_offset);
+ if (!node)
+ goto out;
+
+ entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
+ atomic_inc(&entry->refs);
+out:
+ spin_unlock_irq(&tree->lock);
+ return entry;
+}
+
+/*
+ * After an extent is done, call this to conditionally update the on disk
+ * i_size. i_size is updated to cover any fully written part of the file.
+ */
+int btrfs_ordered_update_i_size(struct inode *inode, u64 offset,
+ struct btrfs_ordered_extent *ordered)
+{
+ struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree;
+ u64 disk_i_size;
+ u64 new_i_size;
+ u64 i_size = i_size_read(inode);
+ struct rb_node *node;
+ struct rb_node *prev = NULL;
+ struct btrfs_ordered_extent *test;
+ int ret = 1;
+
+ spin_lock_irq(&tree->lock);
+ if (ordered) {
+ offset = entry_end(ordered);
+ if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags))
+ offset = min(offset,
+ ordered->file_offset +
+ ordered->truncated_len);
+ } else {
+ offset = ALIGN(offset, BTRFS_I(inode)->root->sectorsize);
+ }
+ disk_i_size = BTRFS_I(inode)->disk_i_size;
+
+ /* truncate file */
+ if (disk_i_size > i_size) {
+ BTRFS_I(inode)->disk_i_size = i_size;
+ ret = 0;
+ goto out;
+ }
+
+ /*
+ * if the disk i_size is already at the inode->i_size, or
+ * this ordered extent is inside the disk i_size, we're done
+ */
+ if (disk_i_size == i_size)
+ goto out;
+
+ /*
+ * We still need to update disk_i_size if outstanding_isize is greater
+ * than disk_i_size.
+ */
+ if (offset <= disk_i_size &&
+ (!ordered || ordered->outstanding_isize <= disk_i_size))
+ goto out;
+
+ /*
+ * walk backward from this ordered extent to disk_i_size.
+ * if we find an ordered extent then we can't update disk i_size
+ * yet
+ */
+ if (ordered) {
+ node = rb_prev(&ordered->rb_node);
+ } else {
+ prev = tree_search(tree, offset);
+ /*
+ * we insert file extents without involving ordered struct,
+ * so there should be no ordered struct cover this offset
+ */
+ if (prev) {
+ test = rb_entry(prev, struct btrfs_ordered_extent,
+ rb_node);
+ BUG_ON(offset_in_entry(test, offset));
+ }
+ node = prev;
+ }
+ for (; node; node = rb_prev(node)) {
+ test = rb_entry(node, struct btrfs_ordered_extent, rb_node);
+
+ /* We treat this entry as if it doesnt exist */
+ if (test_bit(BTRFS_ORDERED_UPDATED_ISIZE, &test->flags))
+ continue;
+ if (test->file_offset + test->len <= disk_i_size)
+ break;
+ if (test->file_offset >= i_size)
+ break;
+ if (entry_end(test) > disk_i_size) {
+ /*
+ * we don't update disk_i_size now, so record this
+ * undealt i_size. Or we will not know the real
+ * i_size.
+ */
+ if (test->outstanding_isize < offset)
+ test->outstanding_isize = offset;
+ if (ordered &&
+ ordered->outstanding_isize >
+ test->outstanding_isize)
+ test->outstanding_isize =
+ ordered->outstanding_isize;
+ goto out;
+ }
+ }
+ new_i_size = min_t(u64, offset, i_size);
+
+ /*
+ * Some ordered extents may completed before the current one, and
+ * we hold the real i_size in ->outstanding_isize.
+ */
+ if (ordered && ordered->outstanding_isize > new_i_size)
+ new_i_size = min_t(u64, ordered->outstanding_isize, i_size);
+ BTRFS_I(inode)->disk_i_size = new_i_size;
+ ret = 0;
+out:
+ /*
+ * We need to do this because we can't remove ordered extents until
+ * after the i_disk_size has been updated and then the inode has been
+ * updated to reflect the change, so we need to tell anybody who finds
+ * this ordered extent that we've already done all the real work, we
+ * just haven't completed all the other work.
+ */
+ if (ordered)
+ set_bit(BTRFS_ORDERED_UPDATED_ISIZE, &ordered->flags);
+ spin_unlock_irq(&tree->lock);
+ return ret;
+}
+
+/*
+ * search the ordered extents for one corresponding to 'offset' and
+ * try to find a checksum. This is used because we allow pages to
+ * be reclaimed before their checksum is actually put into the btree
+ */
+int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u64 disk_bytenr,
+ u32 *sum, int len)
+{
+ struct btrfs_ordered_sum *ordered_sum;
+ struct btrfs_ordered_extent *ordered;
+ struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree;
+ unsigned long num_sectors;
+ unsigned long i;
+ u32 sectorsize = BTRFS_I(inode)->root->sectorsize;
+ int index = 0;
+
+ ordered = btrfs_lookup_ordered_extent(inode, offset);
+ if (!ordered)
+ return 0;
+
+ spin_lock_irq(&tree->lock);
+ list_for_each_entry_reverse(ordered_sum, &ordered->list, list) {
+ if (disk_bytenr >= ordered_sum->bytenr &&
+ disk_bytenr < ordered_sum->bytenr + ordered_sum->len) {
+ i = (disk_bytenr - ordered_sum->bytenr) >>
+ inode->i_sb->s_blocksize_bits;
+ num_sectors = ordered_sum->len >>
+ inode->i_sb->s_blocksize_bits;
+ num_sectors = min_t(int, len - index, num_sectors - i);
+ memcpy(sum + index, ordered_sum->sums + i,
+ num_sectors);
+
+ index += (int)num_sectors;
+ if (index == len)
+ goto out;
+ disk_bytenr += num_sectors * sectorsize;
+ }
+ }
+out:
+ spin_unlock_irq(&tree->lock);
+ btrfs_put_ordered_extent(ordered);
+ return index;
+}
+
+int __init ordered_data_init(void)
+{
+ btrfs_ordered_extent_cache = kmem_cache_create("btrfs_ordered_extent",
+ sizeof(struct btrfs_ordered_extent), 0,
+ SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD,
+ NULL);
+ if (!btrfs_ordered_extent_cache)
+ return -ENOMEM;
+
+ return 0;
+}
+
+void ordered_data_exit(void)
+{
+ if (btrfs_ordered_extent_cache)
+ kmem_cache_destroy(btrfs_ordered_extent_cache);
+}
Code Review / kvmfornfv.git / blobdiff