--- /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/kernel.h>
+#include <linux/bio.h>
+#include <linux/buffer_head.h>
+#include <linux/file.h>
+#include <linux/fs.h>
+#include <linux/pagemap.h>
+#include <linux/highmem.h>
+#include <linux/time.h>
+#include <linux/init.h>
+#include <linux/string.h>
+#include <linux/backing-dev.h>
+#include <linux/mpage.h>
+#include <linux/swap.h>
+#include <linux/writeback.h>
+#include <linux/statfs.h>
+#include <linux/compat.h>
+#include <linux/bit_spinlock.h>
+#include <linux/xattr.h>
+#include <linux/posix_acl.h>
+#include <linux/falloc.h>
+#include <linux/slab.h>
+#include <linux/ratelimit.h>
+#include <linux/mount.h>
+#include <linux/btrfs.h>
+#include <linux/blkdev.h>
+#include <linux/posix_acl_xattr.h>
+#include <linux/uio.h>
+#include "ctree.h"
+#include "disk-io.h"
+#include "transaction.h"
+#include "btrfs_inode.h"
+#include "print-tree.h"
+#include "ordered-data.h"
+#include "xattr.h"
+#include "tree-log.h"
+#include "volumes.h"
+#include "compression.h"
+#include "locking.h"
+#include "free-space-cache.h"
+#include "inode-map.h"
+#include "backref.h"
+#include "hash.h"
+#include "props.h"
+#include "qgroup.h"
+
+struct btrfs_iget_args {
+ struct btrfs_key *location;
+ struct btrfs_root *root;
+};
+
+static const struct inode_operations btrfs_dir_inode_operations;
+static const struct inode_operations btrfs_symlink_inode_operations;
+static const struct inode_operations btrfs_dir_ro_inode_operations;
+static const struct inode_operations btrfs_special_inode_operations;
+static const struct inode_operations btrfs_file_inode_operations;
+static const struct address_space_operations btrfs_aops;
+static const struct address_space_operations btrfs_symlink_aops;
+static const struct file_operations btrfs_dir_file_operations;
+static struct extent_io_ops btrfs_extent_io_ops;
+
+static struct kmem_cache *btrfs_inode_cachep;
+static struct kmem_cache *btrfs_delalloc_work_cachep;
+struct kmem_cache *btrfs_trans_handle_cachep;
+struct kmem_cache *btrfs_transaction_cachep;
+struct kmem_cache *btrfs_path_cachep;
+struct kmem_cache *btrfs_free_space_cachep;
+
+#define S_SHIFT 12
+static unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
+ [S_IFREG >> S_SHIFT] = BTRFS_FT_REG_FILE,
+ [S_IFDIR >> S_SHIFT] = BTRFS_FT_DIR,
+ [S_IFCHR >> S_SHIFT] = BTRFS_FT_CHRDEV,
+ [S_IFBLK >> S_SHIFT] = BTRFS_FT_BLKDEV,
+ [S_IFIFO >> S_SHIFT] = BTRFS_FT_FIFO,
+ [S_IFSOCK >> S_SHIFT] = BTRFS_FT_SOCK,
+ [S_IFLNK >> S_SHIFT] = BTRFS_FT_SYMLINK,
+};
+
+static int btrfs_setsize(struct inode *inode, struct iattr *attr);
+static int btrfs_truncate(struct inode *inode);
+static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent);
+static noinline int cow_file_range(struct inode *inode,
+ struct page *locked_page,
+ u64 start, u64 end, int *page_started,
+ unsigned long *nr_written, int unlock);
+static struct extent_map *create_pinned_em(struct inode *inode, u64 start,
+ u64 len, u64 orig_start,
+ u64 block_start, u64 block_len,
+ u64 orig_block_len, u64 ram_bytes,
+ int type);
+
+static int btrfs_dirty_inode(struct inode *inode);
+
+#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
+void btrfs_test_inode_set_ops(struct inode *inode)
+{
+ BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
+}
+#endif
+
+static int btrfs_init_inode_security(struct btrfs_trans_handle *trans,
+ struct inode *inode, struct inode *dir,
+ const struct qstr *qstr)
+{
+ int err;
+
+ err = btrfs_init_acl(trans, inode, dir);
+ if (!err)
+ err = btrfs_xattr_security_init(trans, inode, dir, qstr);
+ return err;
+}
+
+/*
+ * this does all the hard work for inserting an inline extent into
+ * the btree. The caller should have done a btrfs_drop_extents so that
+ * no overlapping inline items exist in the btree
+ */
+static int insert_inline_extent(struct btrfs_trans_handle *trans,
+ struct btrfs_path *path, int extent_inserted,
+ struct btrfs_root *root, struct inode *inode,
+ u64 start, size_t size, size_t compressed_size,
+ int compress_type,
+ struct page **compressed_pages)
+{
+ struct extent_buffer *leaf;
+ struct page *page = NULL;
+ char *kaddr;
+ unsigned long ptr;
+ struct btrfs_file_extent_item *ei;
+ int err = 0;
+ int ret;
+ size_t cur_size = size;
+ unsigned long offset;
+
+ if (compressed_size && compressed_pages)
+ cur_size = compressed_size;
+
+ inode_add_bytes(inode, size);
+
+ if (!extent_inserted) {
+ struct btrfs_key key;
+ size_t datasize;
+
+ key.objectid = btrfs_ino(inode);
+ key.offset = start;
+ key.type = BTRFS_EXTENT_DATA_KEY;
+
+ datasize = btrfs_file_extent_calc_inline_size(cur_size);
+ path->leave_spinning = 1;
+ ret = btrfs_insert_empty_item(trans, root, path, &key,
+ datasize);
+ if (ret) {
+ err = ret;
+ goto fail;
+ }
+ }
+ leaf = path->nodes[0];
+ ei = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_file_extent_item);
+ btrfs_set_file_extent_generation(leaf, ei, trans->transid);
+ btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE);
+ btrfs_set_file_extent_encryption(leaf, ei, 0);
+ btrfs_set_file_extent_other_encoding(leaf, ei, 0);
+ btrfs_set_file_extent_ram_bytes(leaf, ei, size);
+ ptr = btrfs_file_extent_inline_start(ei);
+
+ if (compress_type != BTRFS_COMPRESS_NONE) {
+ struct page *cpage;
+ int i = 0;
+ while (compressed_size > 0) {
+ cpage = compressed_pages[i];
+ cur_size = min_t(unsigned long, compressed_size,
+ PAGE_CACHE_SIZE);
+
+ kaddr = kmap_atomic(cpage);
+ write_extent_buffer(leaf, kaddr, ptr, cur_size);
+ kunmap_atomic(kaddr);
+
+ i++;
+ ptr += cur_size;
+ compressed_size -= cur_size;
+ }
+ btrfs_set_file_extent_compression(leaf, ei,
+ compress_type);
+ } else {
+ page = find_get_page(inode->i_mapping,
+ start >> PAGE_CACHE_SHIFT);
+ btrfs_set_file_extent_compression(leaf, ei, 0);
+ kaddr = kmap_atomic(page);
+ offset = start & (PAGE_CACHE_SIZE - 1);
+ write_extent_buffer(leaf, kaddr + offset, ptr, size);
+ kunmap_atomic(kaddr);
+ page_cache_release(page);
+ }
+ btrfs_mark_buffer_dirty(leaf);
+ btrfs_release_path(path);
+
+ /*
+ * we're an inline extent, so nobody can
+ * extend the file past i_size without locking
+ * a page we already have locked.
+ *
+ * We must do any isize and inode updates
+ * before we unlock the pages. Otherwise we
+ * could end up racing with unlink.
+ */
+ BTRFS_I(inode)->disk_i_size = inode->i_size;
+ ret = btrfs_update_inode(trans, root, inode);
+
+ return ret;
+fail:
+ return err;
+}
+
+
+/*
+ * conditionally insert an inline extent into the file. This
+ * does the checks required to make sure the data is small enough
+ * to fit as an inline extent.
+ */
+static noinline int cow_file_range_inline(struct btrfs_root *root,
+ struct inode *inode, u64 start,
+ u64 end, size_t compressed_size,
+ int compress_type,
+ struct page **compressed_pages)
+{
+ struct btrfs_trans_handle *trans;
+ u64 isize = i_size_read(inode);
+ u64 actual_end = min(end + 1, isize);
+ u64 inline_len = actual_end - start;
+ u64 aligned_end = ALIGN(end, root->sectorsize);
+ u64 data_len = inline_len;
+ int ret;
+ struct btrfs_path *path;
+ int extent_inserted = 0;
+ u32 extent_item_size;
+
+ if (compressed_size)
+ data_len = compressed_size;
+
+ if (start > 0 ||
+ actual_end > PAGE_CACHE_SIZE ||
+ data_len > BTRFS_MAX_INLINE_DATA_SIZE(root) ||
+ (!compressed_size &&
+ (actual_end & (root->sectorsize - 1)) == 0) ||
+ end + 1 < isize ||
+ data_len > root->fs_info->max_inline) {
+ return 1;
+ }
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ trans = btrfs_join_transaction(root);
+ if (IS_ERR(trans)) {
+ btrfs_free_path(path);
+ return PTR_ERR(trans);
+ }
+ trans->block_rsv = &root->fs_info->delalloc_block_rsv;
+
+ if (compressed_size && compressed_pages)
+ extent_item_size = btrfs_file_extent_calc_inline_size(
+ compressed_size);
+ else
+ extent_item_size = btrfs_file_extent_calc_inline_size(
+ inline_len);
+
+ ret = __btrfs_drop_extents(trans, root, inode, path,
+ start, aligned_end, NULL,
+ 1, 1, extent_item_size, &extent_inserted);
+ if (ret) {
+ btrfs_abort_transaction(trans, root, ret);
+ goto out;
+ }
+
+ if (isize > actual_end)
+ inline_len = min_t(u64, isize, actual_end);
+ ret = insert_inline_extent(trans, path, extent_inserted,
+ root, inode, start,
+ inline_len, compressed_size,
+ compress_type, compressed_pages);
+ if (ret && ret != -ENOSPC) {
+ btrfs_abort_transaction(trans, root, ret);
+ goto out;
+ } else if (ret == -ENOSPC) {
+ ret = 1;
+ goto out;
+ }
+
+ set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
+ btrfs_delalloc_release_metadata(inode, end + 1 - start);
+ btrfs_drop_extent_cache(inode, start, aligned_end - 1, 0);
+out:
+ btrfs_free_path(path);
+ btrfs_end_transaction(trans, root);
+ return ret;
+}
+
+struct async_extent {
+ u64 start;
+ u64 ram_size;
+ u64 compressed_size;
+ struct page **pages;
+ unsigned long nr_pages;
+ int compress_type;
+ struct list_head list;
+};
+
+struct async_cow {
+ struct inode *inode;
+ struct btrfs_root *root;
+ struct page *locked_page;
+ u64 start;
+ u64 end;
+ struct list_head extents;
+ struct btrfs_work work;
+};
+
+static noinline int add_async_extent(struct async_cow *cow,
+ u64 start, u64 ram_size,
+ u64 compressed_size,
+ struct page **pages,
+ unsigned long nr_pages,
+ int compress_type)
+{
+ struct async_extent *async_extent;
+
+ async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS);
+ BUG_ON(!async_extent); /* -ENOMEM */
+ async_extent->start = start;
+ async_extent->ram_size = ram_size;
+ async_extent->compressed_size = compressed_size;
+ async_extent->pages = pages;
+ async_extent->nr_pages = nr_pages;
+ async_extent->compress_type = compress_type;
+ list_add_tail(&async_extent->list, &cow->extents);
+ return 0;
+}
+
+static inline int inode_need_compress(struct inode *inode)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+
+ /* force compress */
+ if (btrfs_test_opt(root, FORCE_COMPRESS))
+ return 1;
+ /* bad compression ratios */
+ if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS)
+ return 0;
+ if (btrfs_test_opt(root, COMPRESS) ||
+ BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS ||
+ BTRFS_I(inode)->force_compress)
+ return 1;
+ return 0;
+}
+
+/*
+ * we create compressed extents in two phases. The first
+ * phase compresses a range of pages that have already been
+ * locked (both pages and state bits are locked).
+ *
+ * This is done inside an ordered work queue, and the compression
+ * is spread across many cpus. The actual IO submission is step
+ * two, and the ordered work queue takes care of making sure that
+ * happens in the same order things were put onto the queue by
+ * writepages and friends.
+ *
+ * If this code finds it can't get good compression, it puts an
+ * entry onto the work queue to write the uncompressed bytes. This
+ * makes sure that both compressed inodes and uncompressed inodes
+ * are written in the same order that the flusher thread sent them
+ * down.
+ */
+static noinline void compress_file_range(struct inode *inode,
+ struct page *locked_page,
+ u64 start, u64 end,
+ struct async_cow *async_cow,
+ int *num_added)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ u64 num_bytes;
+ u64 blocksize = root->sectorsize;
+ u64 actual_end;
+ u64 isize = i_size_read(inode);
+ int ret = 0;
+ struct page **pages = NULL;
+ unsigned long nr_pages;
+ unsigned long nr_pages_ret = 0;
+ unsigned long total_compressed = 0;
+ unsigned long total_in = 0;
+ unsigned long max_compressed = 128 * 1024;
+ unsigned long max_uncompressed = 128 * 1024;
+ int i;
+ int will_compress;
+ int compress_type = root->fs_info->compress_type;
+ int redirty = 0;
+
+ /* if this is a small write inside eof, kick off a defrag */
+ if ((end - start + 1) < 16 * 1024 &&
+ (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
+ btrfs_add_inode_defrag(NULL, inode);
+
+ actual_end = min_t(u64, isize, end + 1);
+again:
+ will_compress = 0;
+ nr_pages = (end >> PAGE_CACHE_SHIFT) - (start >> PAGE_CACHE_SHIFT) + 1;
+ nr_pages = min(nr_pages, (128 * 1024UL) / PAGE_CACHE_SIZE);
+
+ /*
+ * we don't want to send crud past the end of i_size through
+ * compression, that's just a waste of CPU time. So, if the
+ * end of the file is before the start of our current
+ * requested range of bytes, we bail out to the uncompressed
+ * cleanup code that can deal with all of this.
+ *
+ * It isn't really the fastest way to fix things, but this is a
+ * very uncommon corner.
+ */
+ if (actual_end <= start)
+ goto cleanup_and_bail_uncompressed;
+
+ total_compressed = actual_end - start;
+
+ /*
+ * skip compression for a small file range(<=blocksize) that
+ * isn't an inline extent, since it dosen't save disk space at all.
+ */
+ if (total_compressed <= blocksize &&
+ (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
+ goto cleanup_and_bail_uncompressed;
+
+ /* we want to make sure that amount of ram required to uncompress
+ * an extent is reasonable, so we limit the total size in ram
+ * of a compressed extent to 128k. This is a crucial number
+ * because it also controls how easily we can spread reads across
+ * cpus for decompression.
+ *
+ * We also want to make sure the amount of IO required to do
+ * a random read is reasonably small, so we limit the size of
+ * a compressed extent to 128k.
+ */
+ total_compressed = min(total_compressed, max_uncompressed);
+ num_bytes = ALIGN(end - start + 1, blocksize);
+ num_bytes = max(blocksize, num_bytes);
+ total_in = 0;
+ ret = 0;
+
+ /*
+ * we do compression for mount -o compress and when the
+ * inode has not been flagged as nocompress. This flag can
+ * change at any time if we discover bad compression ratios.
+ */
+ if (inode_need_compress(inode)) {
+ WARN_ON(pages);
+ pages = kcalloc(nr_pages, sizeof(struct page *), GFP_NOFS);
+ if (!pages) {
+ /* just bail out to the uncompressed code */
+ goto cont;
+ }
+
+ if (BTRFS_I(inode)->force_compress)
+ compress_type = BTRFS_I(inode)->force_compress;
+
+ /*
+ * we need to call clear_page_dirty_for_io on each
+ * page in the range. Otherwise applications with the file
+ * mmap'd can wander in and change the page contents while
+ * we are compressing them.
+ *
+ * If the compression fails for any reason, we set the pages
+ * dirty again later on.
+ */
+ extent_range_clear_dirty_for_io(inode, start, end);
+ redirty = 1;
+ ret = btrfs_compress_pages(compress_type,
+ inode->i_mapping, start,
+ total_compressed, pages,
+ nr_pages, &nr_pages_ret,
+ &total_in,
+ &total_compressed,
+ max_compressed);
+
+ if (!ret) {
+ unsigned long offset = total_compressed &
+ (PAGE_CACHE_SIZE - 1);
+ struct page *page = pages[nr_pages_ret - 1];
+ char *kaddr;
+
+ /* zero the tail end of the last page, we might be
+ * sending it down to disk
+ */
+ if (offset) {
+ kaddr = kmap_atomic(page);
+ memset(kaddr + offset, 0,
+ PAGE_CACHE_SIZE - offset);
+ kunmap_atomic(kaddr);
+ }
+ will_compress = 1;
+ }
+ }
+cont:
+ if (start == 0) {
+ /* lets try to make an inline extent */
+ if (ret || total_in < (actual_end - start)) {
+ /* we didn't compress the entire range, try
+ * to make an uncompressed inline extent.
+ */
+ ret = cow_file_range_inline(root, inode, start, end,
+ 0, 0, NULL);
+ } else {
+ /* try making a compressed inline extent */
+ ret = cow_file_range_inline(root, inode, start, end,
+ total_compressed,
+ compress_type, pages);
+ }
+ if (ret <= 0) {
+ unsigned long clear_flags = EXTENT_DELALLOC |
+ EXTENT_DEFRAG;
+ unsigned long page_error_op;
+
+ clear_flags |= (ret < 0) ? EXTENT_DO_ACCOUNTING : 0;
+ page_error_op = ret < 0 ? PAGE_SET_ERROR : 0;
+
+ /*
+ * inline extent creation worked or returned error,
+ * we don't need to create any more async work items.
+ * Unlock and free up our temp pages.
+ */
+ extent_clear_unlock_delalloc(inode, start, end, NULL,
+ clear_flags, PAGE_UNLOCK |
+ PAGE_CLEAR_DIRTY |
+ PAGE_SET_WRITEBACK |
+ page_error_op |
+ PAGE_END_WRITEBACK);
+ goto free_pages_out;
+ }
+ }
+
+ if (will_compress) {
+ /*
+ * we aren't doing an inline extent round the compressed size
+ * up to a block size boundary so the allocator does sane
+ * things
+ */
+ total_compressed = ALIGN(total_compressed, blocksize);
+
+ /*
+ * one last check to make sure the compression is really a
+ * win, compare the page count read with the blocks on disk
+ */
+ total_in = ALIGN(total_in, PAGE_CACHE_SIZE);
+ if (total_compressed >= total_in) {
+ will_compress = 0;
+ } else {
+ num_bytes = total_in;
+ }
+ }
+ if (!will_compress && pages) {
+ /*
+ * the compression code ran but failed to make things smaller,
+ * free any pages it allocated and our page pointer array
+ */
+ for (i = 0; i < nr_pages_ret; i++) {
+ WARN_ON(pages[i]->mapping);
+ page_cache_release(pages[i]);
+ }
+ kfree(pages);
+ pages = NULL;
+ total_compressed = 0;
+ nr_pages_ret = 0;
+
+ /* flag the file so we don't compress in the future */
+ if (!btrfs_test_opt(root, FORCE_COMPRESS) &&
+ !(BTRFS_I(inode)->force_compress)) {
+ BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
+ }
+ }
+ if (will_compress) {
+ *num_added += 1;
+
+ /* the async work queues will take care of doing actual
+ * allocation on disk for these compressed pages,
+ * and will submit them to the elevator.
+ */
+ add_async_extent(async_cow, start, num_bytes,
+ total_compressed, pages, nr_pages_ret,
+ compress_type);
+
+ if (start + num_bytes < end) {
+ start += num_bytes;
+ pages = NULL;
+ cond_resched();
+ goto again;
+ }
+ } else {
+cleanup_and_bail_uncompressed:
+ /*
+ * No compression, but we still need to write the pages in
+ * the file we've been given so far. redirty the locked
+ * page if it corresponds to our extent and set things up
+ * for the async work queue to run cow_file_range to do
+ * the normal delalloc dance
+ */
+ if (page_offset(locked_page) >= start &&
+ page_offset(locked_page) <= end) {
+ __set_page_dirty_nobuffers(locked_page);
+ /* unlocked later on in the async handlers */
+ }
+ if (redirty)
+ extent_range_redirty_for_io(inode, start, end);
+ add_async_extent(async_cow, start, end - start + 1,
+ 0, NULL, 0, BTRFS_COMPRESS_NONE);
+ *num_added += 1;
+ }
+
+ return;
+
+free_pages_out:
+ for (i = 0; i < nr_pages_ret; i++) {
+ WARN_ON(pages[i]->mapping);
+ page_cache_release(pages[i]);
+ }
+ kfree(pages);
+}
+
+static void free_async_extent_pages(struct async_extent *async_extent)
+{
+ int i;
+
+ if (!async_extent->pages)
+ return;
+
+ for (i = 0; i < async_extent->nr_pages; i++) {
+ WARN_ON(async_extent->pages[i]->mapping);
+ page_cache_release(async_extent->pages[i]);
+ }
+ kfree(async_extent->pages);
+ async_extent->nr_pages = 0;
+ async_extent->pages = NULL;
+}
+
+/*
+ * phase two of compressed writeback. This is the ordered portion
+ * of the code, which only gets called in the order the work was
+ * queued. We walk all the async extents created by compress_file_range
+ * and send them down to the disk.
+ */
+static noinline void submit_compressed_extents(struct inode *inode,
+ struct async_cow *async_cow)
+{
+ struct async_extent *async_extent;
+ u64 alloc_hint = 0;
+ struct btrfs_key ins;
+ struct extent_map *em;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
+ struct extent_io_tree *io_tree;
+ int ret = 0;
+
+again:
+ while (!list_empty(&async_cow->extents)) {
+ async_extent = list_entry(async_cow->extents.next,
+ struct async_extent, list);
+ list_del(&async_extent->list);
+
+ io_tree = &BTRFS_I(inode)->io_tree;
+
+retry:
+ /* did the compression code fall back to uncompressed IO? */
+ if (!async_extent->pages) {
+ int page_started = 0;
+ unsigned long nr_written = 0;
+
+ lock_extent(io_tree, async_extent->start,
+ async_extent->start +
+ async_extent->ram_size - 1);
+
+ /* allocate blocks */
+ ret = cow_file_range(inode, async_cow->locked_page,
+ async_extent->start,
+ async_extent->start +
+ async_extent->ram_size - 1,
+ &page_started, &nr_written, 0);
+
+ /* JDM XXX */
+
+ /*
+ * if page_started, cow_file_range inserted an
+ * inline extent and took care of all the unlocking
+ * and IO for us. Otherwise, we need to submit
+ * all those pages down to the drive.
+ */
+ if (!page_started && !ret)
+ extent_write_locked_range(io_tree,
+ inode, async_extent->start,
+ async_extent->start +
+ async_extent->ram_size - 1,
+ btrfs_get_extent,
+ WB_SYNC_ALL);
+ else if (ret)
+ unlock_page(async_cow->locked_page);
+ kfree(async_extent);
+ cond_resched();
+ continue;
+ }
+
+ lock_extent(io_tree, async_extent->start,
+ async_extent->start + async_extent->ram_size - 1);
+
+ ret = btrfs_reserve_extent(root,
+ async_extent->compressed_size,
+ async_extent->compressed_size,
+ 0, alloc_hint, &ins, 1, 1);
+ if (ret) {
+ free_async_extent_pages(async_extent);
+
+ if (ret == -ENOSPC) {
+ unlock_extent(io_tree, async_extent->start,
+ async_extent->start +
+ async_extent->ram_size - 1);
+
+ /*
+ * we need to redirty the pages if we decide to
+ * fallback to uncompressed IO, otherwise we
+ * will not submit these pages down to lower
+ * layers.
+ */
+ extent_range_redirty_for_io(inode,
+ async_extent->start,
+ async_extent->start +
+ async_extent->ram_size - 1);
+
+ goto retry;
+ }
+ goto out_free;
+ }
+ /*
+ * here we're doing allocation and writeback of the
+ * compressed pages
+ */
+ btrfs_drop_extent_cache(inode, async_extent->start,
+ async_extent->start +
+ async_extent->ram_size - 1, 0);
+
+ em = alloc_extent_map();
+ if (!em) {
+ ret = -ENOMEM;
+ goto out_free_reserve;
+ }
+ em->start = async_extent->start;
+ em->len = async_extent->ram_size;
+ em->orig_start = em->start;
+ em->mod_start = em->start;
+ em->mod_len = em->len;
+
+ em->block_start = ins.objectid;
+ em->block_len = ins.offset;
+ em->orig_block_len = ins.offset;
+ em->ram_bytes = async_extent->ram_size;
+ em->bdev = root->fs_info->fs_devices->latest_bdev;
+ em->compress_type = async_extent->compress_type;
+ set_bit(EXTENT_FLAG_PINNED, &em->flags);
+ set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
+ em->generation = -1;
+
+ while (1) {
+ write_lock(&em_tree->lock);
+ ret = add_extent_mapping(em_tree, em, 1);
+ write_unlock(&em_tree->lock);
+ if (ret != -EEXIST) {
+ free_extent_map(em);
+ break;
+ }
+ btrfs_drop_extent_cache(inode, async_extent->start,
+ async_extent->start +
+ async_extent->ram_size - 1, 0);
+ }
+
+ if (ret)
+ goto out_free_reserve;
+
+ ret = btrfs_add_ordered_extent_compress(inode,
+ async_extent->start,
+ ins.objectid,
+ async_extent->ram_size,
+ ins.offset,
+ BTRFS_ORDERED_COMPRESSED,
+ async_extent->compress_type);
+ if (ret) {
+ btrfs_drop_extent_cache(inode, async_extent->start,
+ async_extent->start +
+ async_extent->ram_size - 1, 0);
+ goto out_free_reserve;
+ }
+
+ /*
+ * clear dirty, set writeback and unlock the pages.
+ */
+ extent_clear_unlock_delalloc(inode, async_extent->start,
+ async_extent->start +
+ async_extent->ram_size - 1,
+ NULL, EXTENT_LOCKED | EXTENT_DELALLOC,
+ PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
+ PAGE_SET_WRITEBACK);
+ ret = btrfs_submit_compressed_write(inode,
+ async_extent->start,
+ async_extent->ram_size,
+ ins.objectid,
+ ins.offset, async_extent->pages,
+ async_extent->nr_pages);
+ if (ret) {
+ struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
+ struct page *p = async_extent->pages[0];
+ const u64 start = async_extent->start;
+ const u64 end = start + async_extent->ram_size - 1;
+
+ p->mapping = inode->i_mapping;
+ tree->ops->writepage_end_io_hook(p, start, end,
+ NULL, 0);
+ p->mapping = NULL;
+ extent_clear_unlock_delalloc(inode, start, end, NULL, 0,
+ PAGE_END_WRITEBACK |
+ PAGE_SET_ERROR);
+ free_async_extent_pages(async_extent);
+ }
+ alloc_hint = ins.objectid + ins.offset;
+ kfree(async_extent);
+ cond_resched();
+ }
+ return;
+out_free_reserve:
+ btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1);
+out_free:
+ extent_clear_unlock_delalloc(inode, async_extent->start,
+ async_extent->start +
+ async_extent->ram_size - 1,
+ NULL, EXTENT_LOCKED | EXTENT_DELALLOC |
+ EXTENT_DEFRAG | EXTENT_DO_ACCOUNTING,
+ PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
+ PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK |
+ PAGE_SET_ERROR);
+ free_async_extent_pages(async_extent);
+ kfree(async_extent);
+ goto again;
+}
+
+static u64 get_extent_allocation_hint(struct inode *inode, u64 start,
+ u64 num_bytes)
+{
+ struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
+ struct extent_map *em;
+ u64 alloc_hint = 0;
+
+ read_lock(&em_tree->lock);
+ em = search_extent_mapping(em_tree, start, num_bytes);
+ if (em) {
+ /*
+ * if block start isn't an actual block number then find the
+ * first block in this inode and use that as a hint. If that
+ * block is also bogus then just don't worry about it.
+ */
+ if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
+ free_extent_map(em);
+ em = search_extent_mapping(em_tree, 0, 0);
+ if (em && em->block_start < EXTENT_MAP_LAST_BYTE)
+ alloc_hint = em->block_start;
+ if (em)
+ free_extent_map(em);
+ } else {
+ alloc_hint = em->block_start;
+ free_extent_map(em);
+ }
+ }
+ read_unlock(&em_tree->lock);
+
+ return alloc_hint;
+}
+
+/*
+ * when extent_io.c finds a delayed allocation range in the file,
+ * the call backs end up in this code. The basic idea is to
+ * allocate extents on disk for the range, and create ordered data structs
+ * in ram to track those extents.
+ *
+ * locked_page is the page that writepage had locked already. We use
+ * it to make sure we don't do extra locks or unlocks.
+ *
+ * *page_started is set to one if we unlock locked_page and do everything
+ * required to start IO on it. It may be clean and already done with
+ * IO when we return.
+ */
+static noinline int cow_file_range(struct inode *inode,
+ struct page *locked_page,
+ u64 start, u64 end, int *page_started,
+ unsigned long *nr_written,
+ int unlock)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ u64 alloc_hint = 0;
+ u64 num_bytes;
+ unsigned long ram_size;
+ u64 disk_num_bytes;
+ u64 cur_alloc_size;
+ u64 blocksize = root->sectorsize;
+ struct btrfs_key ins;
+ struct extent_map *em;
+ struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
+ int ret = 0;
+
+ if (btrfs_is_free_space_inode(inode)) {
+ WARN_ON_ONCE(1);
+ ret = -EINVAL;
+ goto out_unlock;
+ }
+
+ num_bytes = ALIGN(end - start + 1, blocksize);
+ num_bytes = max(blocksize, num_bytes);
+ disk_num_bytes = num_bytes;
+
+ /* if this is a small write inside eof, kick off defrag */
+ if (num_bytes < 64 * 1024 &&
+ (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
+ btrfs_add_inode_defrag(NULL, inode);
+
+ if (start == 0) {
+ /* lets try to make an inline extent */
+ ret = cow_file_range_inline(root, inode, start, end, 0, 0,
+ NULL);
+ if (ret == 0) {
+ extent_clear_unlock_delalloc(inode, start, end, NULL,
+ EXTENT_LOCKED | EXTENT_DELALLOC |
+ EXTENT_DEFRAG, PAGE_UNLOCK |
+ PAGE_CLEAR_DIRTY | PAGE_SET_WRITEBACK |
+ PAGE_END_WRITEBACK);
+
+ *nr_written = *nr_written +
+ (end - start + PAGE_CACHE_SIZE) / PAGE_CACHE_SIZE;
+ *page_started = 1;
+ goto out;
+ } else if (ret < 0) {
+ goto out_unlock;
+ }
+ }
+
+ BUG_ON(disk_num_bytes >
+ btrfs_super_total_bytes(root->fs_info->super_copy));
+
+ alloc_hint = get_extent_allocation_hint(inode, start, num_bytes);
+ btrfs_drop_extent_cache(inode, start, start + num_bytes - 1, 0);
+
+ while (disk_num_bytes > 0) {
+ unsigned long op;
+
+ cur_alloc_size = disk_num_bytes;
+ ret = btrfs_reserve_extent(root, cur_alloc_size,
+ root->sectorsize, 0, alloc_hint,
+ &ins, 1, 1);
+ if (ret < 0)
+ goto out_unlock;
+
+ em = alloc_extent_map();
+ if (!em) {
+ ret = -ENOMEM;
+ goto out_reserve;
+ }
+ em->start = start;
+ em->orig_start = em->start;
+ ram_size = ins.offset;
+ em->len = ins.offset;
+ em->mod_start = em->start;
+ em->mod_len = em->len;
+
+ em->block_start = ins.objectid;
+ em->block_len = ins.offset;
+ em->orig_block_len = ins.offset;
+ em->ram_bytes = ram_size;
+ em->bdev = root->fs_info->fs_devices->latest_bdev;
+ set_bit(EXTENT_FLAG_PINNED, &em->flags);
+ em->generation = -1;
+
+ while (1) {
+ write_lock(&em_tree->lock);
+ ret = add_extent_mapping(em_tree, em, 1);
+ write_unlock(&em_tree->lock);
+ if (ret != -EEXIST) {
+ free_extent_map(em);
+ break;
+ }
+ btrfs_drop_extent_cache(inode, start,
+ start + ram_size - 1, 0);
+ }
+ if (ret)
+ goto out_reserve;
+
+ cur_alloc_size = ins.offset;
+ ret = btrfs_add_ordered_extent(inode, start, ins.objectid,
+ ram_size, cur_alloc_size, 0);
+ if (ret)
+ goto out_drop_extent_cache;
+
+ if (root->root_key.objectid ==
+ BTRFS_DATA_RELOC_TREE_OBJECTID) {
+ ret = btrfs_reloc_clone_csums(inode, start,
+ cur_alloc_size);
+ if (ret)
+ goto out_drop_extent_cache;
+ }
+
+ if (disk_num_bytes < cur_alloc_size)
+ break;
+
+ /* we're not doing compressed IO, don't unlock the first
+ * page (which the caller expects to stay locked), don't
+ * clear any dirty bits and don't set any writeback bits
+ *
+ * Do set the Private2 bit so we know this page was properly
+ * setup for writepage
+ */
+ op = unlock ? PAGE_UNLOCK : 0;
+ op |= PAGE_SET_PRIVATE2;
+
+ extent_clear_unlock_delalloc(inode, start,
+ start + ram_size - 1, locked_page,
+ EXTENT_LOCKED | EXTENT_DELALLOC,
+ op);
+ disk_num_bytes -= cur_alloc_size;
+ num_bytes -= cur_alloc_size;
+ alloc_hint = ins.objectid + ins.offset;
+ start += cur_alloc_size;
+ }
+out:
+ return ret;
+
+out_drop_extent_cache:
+ btrfs_drop_extent_cache(inode, start, start + ram_size - 1, 0);
+out_reserve:
+ btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1);
+out_unlock:
+ extent_clear_unlock_delalloc(inode, start, end, locked_page,
+ EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
+ EXTENT_DELALLOC | EXTENT_DEFRAG,
+ PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
+ PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK);
+ goto out;
+}
+
+/*
+ * work queue call back to started compression on a file and pages
+ */
+static noinline void async_cow_start(struct btrfs_work *work)
+{
+ struct async_cow *async_cow;
+ int num_added = 0;
+ async_cow = container_of(work, struct async_cow, work);
+
+ compress_file_range(async_cow->inode, async_cow->locked_page,
+ async_cow->start, async_cow->end, async_cow,
+ &num_added);
+ if (num_added == 0) {
+ btrfs_add_delayed_iput(async_cow->inode);
+ async_cow->inode = NULL;
+ }
+}
+
+/*
+ * work queue call back to submit previously compressed pages
+ */
+static noinline void async_cow_submit(struct btrfs_work *work)
+{
+ struct async_cow *async_cow;
+ struct btrfs_root *root;
+ unsigned long nr_pages;
+
+ async_cow = container_of(work, struct async_cow, work);
+
+ root = async_cow->root;
+ nr_pages = (async_cow->end - async_cow->start + PAGE_CACHE_SIZE) >>
+ PAGE_CACHE_SHIFT;
+
+ if (atomic_sub_return(nr_pages, &root->fs_info->async_delalloc_pages) <
+ 5 * 1024 * 1024 &&
+ waitqueue_active(&root->fs_info->async_submit_wait))
+ wake_up(&root->fs_info->async_submit_wait);
+
+ if (async_cow->inode)
+ submit_compressed_extents(async_cow->inode, async_cow);
+}
+
+static noinline void async_cow_free(struct btrfs_work *work)
+{
+ struct async_cow *async_cow;
+ async_cow = container_of(work, struct async_cow, work);
+ if (async_cow->inode)
+ btrfs_add_delayed_iput(async_cow->inode);
+ kfree(async_cow);
+}
+
+static int cow_file_range_async(struct inode *inode, struct page *locked_page,
+ u64 start, u64 end, int *page_started,
+ unsigned long *nr_written)
+{
+ struct async_cow *async_cow;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ unsigned long nr_pages;
+ u64 cur_end;
+ int limit = 10 * 1024 * 1024;
+
+ clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED,
+ 1, 0, NULL, GFP_NOFS);
+ while (start < end) {
+ async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS);
+ BUG_ON(!async_cow); /* -ENOMEM */
+ async_cow->inode = igrab(inode);
+ async_cow->root = root;
+ async_cow->locked_page = locked_page;
+ async_cow->start = start;
+
+ if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS &&
+ !btrfs_test_opt(root, FORCE_COMPRESS))
+ cur_end = end;
+ else
+ cur_end = min(end, start + 512 * 1024 - 1);
+
+ async_cow->end = cur_end;
+ INIT_LIST_HEAD(&async_cow->extents);
+
+ btrfs_init_work(&async_cow->work,
+ btrfs_delalloc_helper,
+ async_cow_start, async_cow_submit,
+ async_cow_free);
+
+ nr_pages = (cur_end - start + PAGE_CACHE_SIZE) >>
+ PAGE_CACHE_SHIFT;
+ atomic_add(nr_pages, &root->fs_info->async_delalloc_pages);
+
+ btrfs_queue_work(root->fs_info->delalloc_workers,
+ &async_cow->work);
+
+ if (atomic_read(&root->fs_info->async_delalloc_pages) > limit) {
+ wait_event(root->fs_info->async_submit_wait,
+ (atomic_read(&root->fs_info->async_delalloc_pages) <
+ limit));
+ }
+
+ while (atomic_read(&root->fs_info->async_submit_draining) &&
+ atomic_read(&root->fs_info->async_delalloc_pages)) {
+ wait_event(root->fs_info->async_submit_wait,
+ (atomic_read(&root->fs_info->async_delalloc_pages) ==
+ 0));
+ }
+
+ *nr_written += nr_pages;
+ start = cur_end + 1;
+ }
+ *page_started = 1;
+ return 0;
+}
+
+static noinline int csum_exist_in_range(struct btrfs_root *root,
+ u64 bytenr, u64 num_bytes)
+{
+ int ret;
+ struct btrfs_ordered_sum *sums;
+ LIST_HEAD(list);
+
+ ret = btrfs_lookup_csums_range(root->fs_info->csum_root, bytenr,
+ bytenr + num_bytes - 1, &list, 0);
+ if (ret == 0 && list_empty(&list))
+ return 0;
+
+ while (!list_empty(&list)) {
+ sums = list_entry(list.next, struct btrfs_ordered_sum, list);
+ list_del(&sums->list);
+ kfree(sums);
+ }
+ return 1;
+}
+
+/*
+ * when nowcow writeback call back. This checks for snapshots or COW copies
+ * of the extents that exist in the file, and COWs the file as required.
+ *
+ * If no cow copies or snapshots exist, we write directly to the existing
+ * blocks on disk
+ */
+static noinline int run_delalloc_nocow(struct inode *inode,
+ struct page *locked_page,
+ u64 start, u64 end, int *page_started, int force,
+ unsigned long *nr_written)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_trans_handle *trans;
+ struct extent_buffer *leaf;
+ struct btrfs_path *path;
+ struct btrfs_file_extent_item *fi;
+ struct btrfs_key found_key;
+ u64 cow_start;
+ u64 cur_offset;
+ u64 extent_end;
+ u64 extent_offset;
+ u64 disk_bytenr;
+ u64 num_bytes;
+ u64 disk_num_bytes;
+ u64 ram_bytes;
+ int extent_type;
+ int ret, err;
+ int type;
+ int nocow;
+ int check_prev = 1;
+ bool nolock;
+ u64 ino = btrfs_ino(inode);
+
+ path = btrfs_alloc_path();
+ if (!path) {
+ extent_clear_unlock_delalloc(inode, start, end, locked_page,
+ EXTENT_LOCKED | EXTENT_DELALLOC |
+ EXTENT_DO_ACCOUNTING |
+ EXTENT_DEFRAG, PAGE_UNLOCK |
+ PAGE_CLEAR_DIRTY |
+ PAGE_SET_WRITEBACK |
+ PAGE_END_WRITEBACK);
+ return -ENOMEM;
+ }
+
+ nolock = btrfs_is_free_space_inode(inode);
+
+ if (nolock)
+ trans = btrfs_join_transaction_nolock(root);
+ else
+ trans = btrfs_join_transaction(root);
+
+ if (IS_ERR(trans)) {
+ extent_clear_unlock_delalloc(inode, start, end, locked_page,
+ EXTENT_LOCKED | EXTENT_DELALLOC |
+ EXTENT_DO_ACCOUNTING |
+ EXTENT_DEFRAG, PAGE_UNLOCK |
+ PAGE_CLEAR_DIRTY |
+ PAGE_SET_WRITEBACK |
+ PAGE_END_WRITEBACK);
+ btrfs_free_path(path);
+ return PTR_ERR(trans);
+ }
+
+ trans->block_rsv = &root->fs_info->delalloc_block_rsv;
+
+ cow_start = (u64)-1;
+ cur_offset = start;
+ while (1) {
+ ret = btrfs_lookup_file_extent(trans, root, path, ino,
+ cur_offset, 0);
+ if (ret < 0)
+ goto error;
+ if (ret > 0 && path->slots[0] > 0 && check_prev) {
+ leaf = path->nodes[0];
+ btrfs_item_key_to_cpu(leaf, &found_key,
+ path->slots[0] - 1);
+ if (found_key.objectid == ino &&
+ found_key.type == BTRFS_EXTENT_DATA_KEY)
+ path->slots[0]--;
+ }
+ check_prev = 0;
+next_slot:
+ leaf = path->nodes[0];
+ if (path->slots[0] >= btrfs_header_nritems(leaf)) {
+ ret = btrfs_next_leaf(root, path);
+ if (ret < 0)
+ goto error;
+ if (ret > 0)
+ break;
+ leaf = path->nodes[0];
+ }
+
+ nocow = 0;
+ disk_bytenr = 0;
+ num_bytes = 0;
+ btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
+
+ if (found_key.objectid > ino ||
+ found_key.type > BTRFS_EXTENT_DATA_KEY ||
+ found_key.offset > end)
+ break;
+
+ if (found_key.offset > cur_offset) {
+ extent_end = found_key.offset;
+ extent_type = 0;
+ goto out_check;
+ }
+
+ fi = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_file_extent_item);
+ extent_type = btrfs_file_extent_type(leaf, fi);
+
+ ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
+ if (extent_type == BTRFS_FILE_EXTENT_REG ||
+ extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
+ disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
+ extent_offset = btrfs_file_extent_offset(leaf, fi);
+ extent_end = found_key.offset +
+ btrfs_file_extent_num_bytes(leaf, fi);
+ disk_num_bytes =
+ btrfs_file_extent_disk_num_bytes(leaf, fi);
+ if (extent_end <= start) {
+ path->slots[0]++;
+ goto next_slot;
+ }
+ if (disk_bytenr == 0)
+ goto out_check;
+ if (btrfs_file_extent_compression(leaf, fi) ||
+ btrfs_file_extent_encryption(leaf, fi) ||
+ btrfs_file_extent_other_encoding(leaf, fi))
+ goto out_check;
+ if (extent_type == BTRFS_FILE_EXTENT_REG && !force)
+ goto out_check;
+ if (btrfs_extent_readonly(root, disk_bytenr))
+ goto out_check;
+ if (btrfs_cross_ref_exist(trans, root, ino,
+ found_key.offset -
+ extent_offset, disk_bytenr))
+ goto out_check;
+ disk_bytenr += extent_offset;
+ disk_bytenr += cur_offset - found_key.offset;
+ num_bytes = min(end + 1, extent_end) - cur_offset;
+ /*
+ * if there are pending snapshots for this root,
+ * we fall into common COW way.
+ */
+ if (!nolock) {
+ err = btrfs_start_write_no_snapshoting(root);
+ if (!err)
+ goto out_check;
+ }
+ /*
+ * force cow if csum exists in the range.
+ * this ensure that csum for a given extent are
+ * either valid or do not exist.
+ */
+ if (csum_exist_in_range(root, disk_bytenr, num_bytes))
+ goto out_check;
+ nocow = 1;
+ } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
+ extent_end = found_key.offset +
+ btrfs_file_extent_inline_len(leaf,
+ path->slots[0], fi);
+ extent_end = ALIGN(extent_end, root->sectorsize);
+ } else {
+ BUG_ON(1);
+ }
+out_check:
+ if (extent_end <= start) {
+ path->slots[0]++;
+ if (!nolock && nocow)
+ btrfs_end_write_no_snapshoting(root);
+ goto next_slot;
+ }
+ if (!nocow) {
+ if (cow_start == (u64)-1)
+ cow_start = cur_offset;
+ cur_offset = extent_end;
+ if (cur_offset > end)
+ break;
+ path->slots[0]++;
+ goto next_slot;
+ }
+
+ btrfs_release_path(path);
+ if (cow_start != (u64)-1) {
+ ret = cow_file_range(inode, locked_page,
+ cow_start, found_key.offset - 1,
+ page_started, nr_written, 1);
+ if (ret) {
+ if (!nolock && nocow)
+ btrfs_end_write_no_snapshoting(root);
+ goto error;
+ }
+ cow_start = (u64)-1;
+ }
+
+ if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
+ struct extent_map *em;
+ struct extent_map_tree *em_tree;
+ em_tree = &BTRFS_I(inode)->extent_tree;
+ em = alloc_extent_map();
+ BUG_ON(!em); /* -ENOMEM */
+ em->start = cur_offset;
+ em->orig_start = found_key.offset - extent_offset;
+ em->len = num_bytes;
+ em->block_len = num_bytes;
+ em->block_start = disk_bytenr;
+ em->orig_block_len = disk_num_bytes;
+ em->ram_bytes = ram_bytes;
+ em->bdev = root->fs_info->fs_devices->latest_bdev;
+ em->mod_start = em->start;
+ em->mod_len = em->len;
+ set_bit(EXTENT_FLAG_PINNED, &em->flags);
+ set_bit(EXTENT_FLAG_FILLING, &em->flags);
+ em->generation = -1;
+ while (1) {
+ write_lock(&em_tree->lock);
+ ret = add_extent_mapping(em_tree, em, 1);
+ write_unlock(&em_tree->lock);
+ if (ret != -EEXIST) {
+ free_extent_map(em);
+ break;
+ }
+ btrfs_drop_extent_cache(inode, em->start,
+ em->start + em->len - 1, 0);
+ }
+ type = BTRFS_ORDERED_PREALLOC;
+ } else {
+ type = BTRFS_ORDERED_NOCOW;
+ }
+
+ ret = btrfs_add_ordered_extent(inode, cur_offset, disk_bytenr,
+ num_bytes, num_bytes, type);
+ BUG_ON(ret); /* -ENOMEM */
+
+ if (root->root_key.objectid ==
+ BTRFS_DATA_RELOC_TREE_OBJECTID) {
+ ret = btrfs_reloc_clone_csums(inode, cur_offset,
+ num_bytes);
+ if (ret) {
+ if (!nolock && nocow)
+ btrfs_end_write_no_snapshoting(root);
+ goto error;
+ }
+ }
+
+ extent_clear_unlock_delalloc(inode, cur_offset,
+ cur_offset + num_bytes - 1,
+ locked_page, EXTENT_LOCKED |
+ EXTENT_DELALLOC, PAGE_UNLOCK |
+ PAGE_SET_PRIVATE2);
+ if (!nolock && nocow)
+ btrfs_end_write_no_snapshoting(root);
+ cur_offset = extent_end;
+ if (cur_offset > end)
+ break;
+ }
+ btrfs_release_path(path);
+
+ if (cur_offset <= end && cow_start == (u64)-1) {
+ cow_start = cur_offset;
+ cur_offset = end;
+ }
+
+ if (cow_start != (u64)-1) {
+ ret = cow_file_range(inode, locked_page, cow_start, end,
+ page_started, nr_written, 1);
+ if (ret)
+ goto error;
+ }
+
+error:
+ err = btrfs_end_transaction(trans, root);
+ if (!ret)
+ ret = err;
+
+ if (ret && cur_offset < end)
+ extent_clear_unlock_delalloc(inode, cur_offset, end,
+ locked_page, EXTENT_LOCKED |
+ EXTENT_DELALLOC | EXTENT_DEFRAG |
+ EXTENT_DO_ACCOUNTING, PAGE_UNLOCK |
+ PAGE_CLEAR_DIRTY |
+ PAGE_SET_WRITEBACK |
+ PAGE_END_WRITEBACK);
+ btrfs_free_path(path);
+ return ret;
+}
+
+static inline int need_force_cow(struct inode *inode, u64 start, u64 end)
+{
+
+ if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
+ !(BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC))
+ return 0;
+
+ /*
+ * @defrag_bytes is a hint value, no spinlock held here,
+ * if is not zero, it means the file is defragging.
+ * Force cow if given extent needs to be defragged.
+ */
+ if (BTRFS_I(inode)->defrag_bytes &&
+ test_range_bit(&BTRFS_I(inode)->io_tree, start, end,
+ EXTENT_DEFRAG, 0, NULL))
+ return 1;
+
+ return 0;
+}
+
+/*
+ * extent_io.c call back to do delayed allocation processing
+ */
+static int run_delalloc_range(struct inode *inode, struct page *locked_page,
+ u64 start, u64 end, int *page_started,
+ unsigned long *nr_written)
+{
+ int ret;
+ int force_cow = need_force_cow(inode, start, end);
+
+ if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW && !force_cow) {
+ ret = run_delalloc_nocow(inode, locked_page, start, end,
+ page_started, 1, nr_written);
+ } else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC && !force_cow) {
+ ret = run_delalloc_nocow(inode, locked_page, start, end,
+ page_started, 0, nr_written);
+ } else if (!inode_need_compress(inode)) {
+ ret = cow_file_range(inode, locked_page, start, end,
+ page_started, nr_written, 1);
+ } else {
+ set_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
+ &BTRFS_I(inode)->runtime_flags);
+ ret = cow_file_range_async(inode, locked_page, start, end,
+ page_started, nr_written);
+ }
+ return ret;
+}
+
+static void btrfs_split_extent_hook(struct inode *inode,
+ struct extent_state *orig, u64 split)
+{
+ u64 size;
+
+ /* not delalloc, ignore it */
+ if (!(orig->state & EXTENT_DELALLOC))
+ return;
+
+ size = orig->end - orig->start + 1;
+ if (size > BTRFS_MAX_EXTENT_SIZE) {
+ u64 num_extents;
+ u64 new_size;
+
+ /*
+ * See the explanation in btrfs_merge_extent_hook, the same
+ * applies here, just in reverse.
+ */
+ new_size = orig->end - split + 1;
+ num_extents = div64_u64(new_size + BTRFS_MAX_EXTENT_SIZE - 1,
+ BTRFS_MAX_EXTENT_SIZE);
+ new_size = split - orig->start;
+ num_extents += div64_u64(new_size + BTRFS_MAX_EXTENT_SIZE - 1,
+ BTRFS_MAX_EXTENT_SIZE);
+ if (div64_u64(size + BTRFS_MAX_EXTENT_SIZE - 1,
+ BTRFS_MAX_EXTENT_SIZE) >= num_extents)
+ return;
+ }
+
+ spin_lock(&BTRFS_I(inode)->lock);
+ BTRFS_I(inode)->outstanding_extents++;
+ spin_unlock(&BTRFS_I(inode)->lock);
+}
+
+/*
+ * extent_io.c merge_extent_hook, used to track merged delayed allocation
+ * extents so we can keep track of new extents that are just merged onto old
+ * extents, such as when we are doing sequential writes, so we can properly
+ * account for the metadata space we'll need.
+ */
+static void btrfs_merge_extent_hook(struct inode *inode,
+ struct extent_state *new,
+ struct extent_state *other)
+{
+ u64 new_size, old_size;
+ u64 num_extents;
+
+ /* not delalloc, ignore it */
+ if (!(other->state & EXTENT_DELALLOC))
+ return;
+
+ if (new->start > other->start)
+ new_size = new->end - other->start + 1;
+ else
+ new_size = other->end - new->start + 1;
+
+ /* we're not bigger than the max, unreserve the space and go */
+ if (new_size <= BTRFS_MAX_EXTENT_SIZE) {
+ spin_lock(&BTRFS_I(inode)->lock);
+ BTRFS_I(inode)->outstanding_extents--;
+ spin_unlock(&BTRFS_I(inode)->lock);
+ return;
+ }
+
+ /*
+ * We have to add up either side to figure out how many extents were
+ * accounted for before we merged into one big extent. If the number of
+ * extents we accounted for is <= the amount we need for the new range
+ * then we can return, otherwise drop. Think of it like this
+ *
+ * [ 4k][MAX_SIZE]
+ *
+ * So we've grown the extent by a MAX_SIZE extent, this would mean we
+ * need 2 outstanding extents, on one side we have 1 and the other side
+ * we have 1 so they are == and we can return. But in this case
+ *
+ * [MAX_SIZE+4k][MAX_SIZE+4k]
+ *
+ * Each range on their own accounts for 2 extents, but merged together
+ * they are only 3 extents worth of accounting, so we need to drop in
+ * this case.
+ */
+ old_size = other->end - other->start + 1;
+ num_extents = div64_u64(old_size + BTRFS_MAX_EXTENT_SIZE - 1,
+ BTRFS_MAX_EXTENT_SIZE);
+ old_size = new->end - new->start + 1;
+ num_extents += div64_u64(old_size + BTRFS_MAX_EXTENT_SIZE - 1,
+ BTRFS_MAX_EXTENT_SIZE);
+
+ if (div64_u64(new_size + BTRFS_MAX_EXTENT_SIZE - 1,
+ BTRFS_MAX_EXTENT_SIZE) >= num_extents)
+ return;
+
+ spin_lock(&BTRFS_I(inode)->lock);
+ BTRFS_I(inode)->outstanding_extents--;
+ spin_unlock(&BTRFS_I(inode)->lock);
+}
+
+static void btrfs_add_delalloc_inodes(struct btrfs_root *root,
+ struct inode *inode)
+{
+ spin_lock(&root->delalloc_lock);
+ if (list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
+ list_add_tail(&BTRFS_I(inode)->delalloc_inodes,
+ &root->delalloc_inodes);
+ set_bit(BTRFS_INODE_IN_DELALLOC_LIST,
+ &BTRFS_I(inode)->runtime_flags);
+ root->nr_delalloc_inodes++;
+ if (root->nr_delalloc_inodes == 1) {
+ spin_lock(&root->fs_info->delalloc_root_lock);
+ BUG_ON(!list_empty(&root->delalloc_root));
+ list_add_tail(&root->delalloc_root,
+ &root->fs_info->delalloc_roots);
+ spin_unlock(&root->fs_info->delalloc_root_lock);
+ }
+ }
+ spin_unlock(&root->delalloc_lock);
+}
+
+static void btrfs_del_delalloc_inode(struct btrfs_root *root,
+ struct inode *inode)
+{
+ spin_lock(&root->delalloc_lock);
+ if (!list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
+ list_del_init(&BTRFS_I(inode)->delalloc_inodes);
+ clear_bit(BTRFS_INODE_IN_DELALLOC_LIST,
+ &BTRFS_I(inode)->runtime_flags);
+ root->nr_delalloc_inodes--;
+ if (!root->nr_delalloc_inodes) {
+ spin_lock(&root->fs_info->delalloc_root_lock);
+ BUG_ON(list_empty(&root->delalloc_root));
+ list_del_init(&root->delalloc_root);
+ spin_unlock(&root->fs_info->delalloc_root_lock);
+ }
+ }
+ spin_unlock(&root->delalloc_lock);
+}
+
+/*
+ * extent_io.c set_bit_hook, used to track delayed allocation
+ * bytes in this file, and to maintain the list of inodes that
+ * have pending delalloc work to be done.
+ */
+static void btrfs_set_bit_hook(struct inode *inode,
+ struct extent_state *state, unsigned *bits)
+{
+
+ if ((*bits & EXTENT_DEFRAG) && !(*bits & EXTENT_DELALLOC))
+ WARN_ON(1);
+ /*
+ * set_bit and clear bit hooks normally require _irqsave/restore
+ * but in this case, we are only testing for the DELALLOC
+ * bit, which is only set or cleared with irqs on
+ */
+ if (!(state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ u64 len = state->end + 1 - state->start;
+ bool do_list = !btrfs_is_free_space_inode(inode);
+
+ if (*bits & EXTENT_FIRST_DELALLOC) {
+ *bits &= ~EXTENT_FIRST_DELALLOC;
+ } else {
+ spin_lock(&BTRFS_I(inode)->lock);
+ BTRFS_I(inode)->outstanding_extents++;
+ spin_unlock(&BTRFS_I(inode)->lock);
+ }
+
+ /* For sanity tests */
+ if (btrfs_test_is_dummy_root(root))
+ return;
+
+ __percpu_counter_add(&root->fs_info->delalloc_bytes, len,
+ root->fs_info->delalloc_batch);
+ spin_lock(&BTRFS_I(inode)->lock);
+ BTRFS_I(inode)->delalloc_bytes += len;
+ if (*bits & EXTENT_DEFRAG)
+ BTRFS_I(inode)->defrag_bytes += len;
+ if (do_list && !test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
+ &BTRFS_I(inode)->runtime_flags))
+ btrfs_add_delalloc_inodes(root, inode);
+ spin_unlock(&BTRFS_I(inode)->lock);
+ }
+}
+
+/*
+ * extent_io.c clear_bit_hook, see set_bit_hook for why
+ */
+static void btrfs_clear_bit_hook(struct inode *inode,
+ struct extent_state *state,
+ unsigned *bits)
+{
+ u64 len = state->end + 1 - state->start;
+ u64 num_extents = div64_u64(len + BTRFS_MAX_EXTENT_SIZE -1,
+ BTRFS_MAX_EXTENT_SIZE);
+
+ spin_lock(&BTRFS_I(inode)->lock);
+ if ((state->state & EXTENT_DEFRAG) && (*bits & EXTENT_DEFRAG))
+ BTRFS_I(inode)->defrag_bytes -= len;
+ spin_unlock(&BTRFS_I(inode)->lock);
+
+ /*
+ * set_bit and clear bit hooks normally require _irqsave/restore
+ * but in this case, we are only testing for the DELALLOC
+ * bit, which is only set or cleared with irqs on
+ */
+ if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ bool do_list = !btrfs_is_free_space_inode(inode);
+
+ if (*bits & EXTENT_FIRST_DELALLOC) {
+ *bits &= ~EXTENT_FIRST_DELALLOC;
+ } else if (!(*bits & EXTENT_DO_ACCOUNTING)) {
+ spin_lock(&BTRFS_I(inode)->lock);
+ BTRFS_I(inode)->outstanding_extents -= num_extents;
+ spin_unlock(&BTRFS_I(inode)->lock);
+ }
+
+ /*
+ * We don't reserve metadata space for space cache inodes so we
+ * don't need to call dellalloc_release_metadata if there is an
+ * error.
+ */
+ if (*bits & EXTENT_DO_ACCOUNTING &&
+ root != root->fs_info->tree_root)
+ btrfs_delalloc_release_metadata(inode, len);
+
+ /* For sanity tests. */
+ if (btrfs_test_is_dummy_root(root))
+ return;
+
+ if (root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
+ && do_list && !(state->state & EXTENT_NORESERVE))
+ btrfs_free_reserved_data_space(inode, len);
+
+ __percpu_counter_add(&root->fs_info->delalloc_bytes, -len,
+ root->fs_info->delalloc_batch);
+ spin_lock(&BTRFS_I(inode)->lock);
+ BTRFS_I(inode)->delalloc_bytes -= len;
+ if (do_list && BTRFS_I(inode)->delalloc_bytes == 0 &&
+ test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
+ &BTRFS_I(inode)->runtime_flags))
+ btrfs_del_delalloc_inode(root, inode);
+ spin_unlock(&BTRFS_I(inode)->lock);
+ }
+}
+
+/*
+ * extent_io.c merge_bio_hook, this must check the chunk tree to make sure
+ * we don't create bios that span stripes or chunks
+ */
+int btrfs_merge_bio_hook(int rw, struct page *page, unsigned long offset,
+ size_t size, struct bio *bio,
+ unsigned long bio_flags)
+{
+ struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
+ u64 logical = (u64)bio->bi_iter.bi_sector << 9;
+ u64 length = 0;
+ u64 map_length;
+ int ret;
+
+ if (bio_flags & EXTENT_BIO_COMPRESSED)
+ return 0;
+
+ length = bio->bi_iter.bi_size;
+ map_length = length;
+ ret = btrfs_map_block(root->fs_info, rw, logical,
+ &map_length, NULL, 0);
+ /* Will always return 0 with map_multi == NULL */
+ BUG_ON(ret < 0);
+ if (map_length < length + size)
+ return 1;
+ return 0;
+}
+
+/*
+ * in order to insert checksums into the metadata in large chunks,
+ * we wait until bio submission time. All the pages in the bio are
+ * checksummed and sums are attached onto the ordered extent record.
+ *
+ * At IO completion time the cums attached on the ordered extent record
+ * are inserted into the btree
+ */
+static int __btrfs_submit_bio_start(struct inode *inode, int rw,
+ struct bio *bio, int mirror_num,
+ unsigned long bio_flags,
+ u64 bio_offset)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ int ret = 0;
+
+ ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
+ BUG_ON(ret); /* -ENOMEM */
+ return 0;
+}
+
+/*
+ * in order to insert checksums into the metadata in large chunks,
+ * we wait until bio submission time. All the pages in the bio are
+ * checksummed and sums are attached onto the ordered extent record.
+ *
+ * At IO completion time the cums attached on the ordered extent record
+ * are inserted into the btree
+ */
+static int __btrfs_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
+ int mirror_num, unsigned long bio_flags,
+ u64 bio_offset)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ int ret;
+
+ ret = btrfs_map_bio(root, rw, bio, mirror_num, 1);
+ if (ret)
+ bio_endio(bio, ret);
+ return ret;
+}
+
+/*
+ * extent_io.c submission hook. This does the right thing for csum calculation
+ * on write, or reading the csums from the tree before a read
+ */
+static int btrfs_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
+ int mirror_num, unsigned long bio_flags,
+ u64 bio_offset)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ int ret = 0;
+ int skip_sum;
+ int metadata = 0;
+ int async = !atomic_read(&BTRFS_I(inode)->sync_writers);
+
+ skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
+
+ if (btrfs_is_free_space_inode(inode))
+ metadata = 2;
+
+ if (!(rw & REQ_WRITE)) {
+ ret = btrfs_bio_wq_end_io(root->fs_info, bio, metadata);
+ if (ret)
+ goto out;
+
+ if (bio_flags & EXTENT_BIO_COMPRESSED) {
+ ret = btrfs_submit_compressed_read(inode, bio,
+ mirror_num,
+ bio_flags);
+ goto out;
+ } else if (!skip_sum) {
+ ret = btrfs_lookup_bio_sums(root, inode, bio, NULL);
+ if (ret)
+ goto out;
+ }
+ goto mapit;
+ } else if (async && !skip_sum) {
+ /* csum items have already been cloned */
+ if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
+ goto mapit;
+ /* we're doing a write, do the async checksumming */
+ ret = btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
+ inode, rw, bio, mirror_num,
+ bio_flags, bio_offset,
+ __btrfs_submit_bio_start,
+ __btrfs_submit_bio_done);
+ goto out;
+ } else if (!skip_sum) {
+ ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
+ if (ret)
+ goto out;
+ }
+
+mapit:
+ ret = btrfs_map_bio(root, rw, bio, mirror_num, 0);
+
+out:
+ if (ret < 0)
+ bio_endio(bio, ret);
+ return ret;
+}
+
+/*
+ * given a list of ordered sums record them in the inode. This happens
+ * at IO completion time based on sums calculated at bio submission time.
+ */
+static noinline int add_pending_csums(struct btrfs_trans_handle *trans,
+ struct inode *inode, u64 file_offset,
+ struct list_head *list)
+{
+ struct btrfs_ordered_sum *sum;
+
+ list_for_each_entry(sum, list, list) {
+ trans->adding_csums = 1;
+ btrfs_csum_file_blocks(trans,
+ BTRFS_I(inode)->root->fs_info->csum_root, sum);
+ trans->adding_csums = 0;
+ }
+ return 0;
+}
+
+int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end,
+ struct extent_state **cached_state)
+{
+ WARN_ON((end & (PAGE_CACHE_SIZE - 1)) == 0);
+ return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end,
+ cached_state, GFP_NOFS);
+}
+
+/* see btrfs_writepage_start_hook for details on why this is required */
+struct btrfs_writepage_fixup {
+ struct page *page;
+ struct btrfs_work work;
+};
+
+static void btrfs_writepage_fixup_worker(struct btrfs_work *work)
+{
+ struct btrfs_writepage_fixup *fixup;
+ struct btrfs_ordered_extent *ordered;
+ struct extent_state *cached_state = NULL;
+ struct page *page;
+ struct inode *inode;
+ u64 page_start;
+ u64 page_end;
+ int ret;
+
+ fixup = container_of(work, struct btrfs_writepage_fixup, work);
+ page = fixup->page;
+again:
+ lock_page(page);
+ if (!page->mapping || !PageDirty(page) || !PageChecked(page)) {
+ ClearPageChecked(page);
+ goto out_page;
+ }
+
+ inode = page->mapping->host;
+ page_start = page_offset(page);
+ page_end = page_offset(page) + PAGE_CACHE_SIZE - 1;
+
+ lock_extent_bits(&BTRFS_I(inode)->io_tree, page_start, page_end, 0,
+ &cached_state);
+
+ /* already ordered? We're done */
+ if (PagePrivate2(page))
+ goto out;
+
+ ordered = btrfs_lookup_ordered_extent(inode, page_start);
+ if (ordered) {
+ unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start,
+ page_end, &cached_state, GFP_NOFS);
+ unlock_page(page);
+ btrfs_start_ordered_extent(inode, ordered, 1);
+ btrfs_put_ordered_extent(ordered);
+ goto again;
+ }
+
+ ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
+ if (ret) {
+ mapping_set_error(page->mapping, ret);
+ end_extent_writepage(page, ret, page_start, page_end);
+ ClearPageChecked(page);
+ goto out;
+ }
+
+ btrfs_set_extent_delalloc(inode, page_start, page_end, &cached_state);
+ ClearPageChecked(page);
+ set_page_dirty(page);
+out:
+ unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end,
+ &cached_state, GFP_NOFS);
+out_page:
+ unlock_page(page);
+ page_cache_release(page);
+ kfree(fixup);
+}
+
+/*
+ * There are a few paths in the higher layers of the kernel that directly
+ * set the page dirty bit without asking the filesystem if it is a
+ * good idea. This causes problems because we want to make sure COW
+ * properly happens and the data=ordered rules are followed.
+ *
+ * In our case any range that doesn't have the ORDERED bit set
+ * hasn't been properly setup for IO. We kick off an async process
+ * to fix it up. The async helper will wait for ordered extents, set
+ * the delalloc bit and make it safe to write the page.
+ */
+static int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end)
+{
+ struct inode *inode = page->mapping->host;
+ struct btrfs_writepage_fixup *fixup;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+
+ /* this page is properly in the ordered list */
+ if (TestClearPagePrivate2(page))
+ return 0;
+
+ if (PageChecked(page))
+ return -EAGAIN;
+
+ fixup = kzalloc(sizeof(*fixup), GFP_NOFS);
+ if (!fixup)
+ return -EAGAIN;
+
+ SetPageChecked(page);
+ page_cache_get(page);
+ btrfs_init_work(&fixup->work, btrfs_fixup_helper,
+ btrfs_writepage_fixup_worker, NULL, NULL);
+ fixup->page = page;
+ btrfs_queue_work(root->fs_info->fixup_workers, &fixup->work);
+ return -EBUSY;
+}
+
+static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
+ struct inode *inode, u64 file_pos,
+ u64 disk_bytenr, u64 disk_num_bytes,
+ u64 num_bytes, u64 ram_bytes,
+ u8 compression, u8 encryption,
+ u16 other_encoding, int extent_type)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_file_extent_item *fi;
+ struct btrfs_path *path;
+ struct extent_buffer *leaf;
+ struct btrfs_key ins;
+ int extent_inserted = 0;
+ int ret;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ /*
+ * we may be replacing one extent in the tree with another.
+ * The new extent is pinned in the extent map, and we don't want
+ * to drop it from the cache until it is completely in the btree.
+ *
+ * So, tell btrfs_drop_extents to leave this extent in the cache.
+ * the caller is expected to unpin it and allow it to be merged
+ * with the others.
+ */
+ ret = __btrfs_drop_extents(trans, root, inode, path, file_pos,
+ file_pos + num_bytes, NULL, 0,
+ 1, sizeof(*fi), &extent_inserted);
+ if (ret)
+ goto out;
+
+ if (!extent_inserted) {
+ ins.objectid = btrfs_ino(inode);
+ ins.offset = file_pos;
+ ins.type = BTRFS_EXTENT_DATA_KEY;
+
+ path->leave_spinning = 1;
+ ret = btrfs_insert_empty_item(trans, root, path, &ins,
+ sizeof(*fi));
+ if (ret)
+ goto out;
+ }
+ leaf = path->nodes[0];
+ fi = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_file_extent_item);
+ btrfs_set_file_extent_generation(leaf, fi, trans->transid);
+ btrfs_set_file_extent_type(leaf, fi, extent_type);
+ btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr);
+ btrfs_set_file_extent_disk_num_bytes(leaf, fi, disk_num_bytes);
+ btrfs_set_file_extent_offset(leaf, fi, 0);
+ btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
+ btrfs_set_file_extent_ram_bytes(leaf, fi, ram_bytes);
+ btrfs_set_file_extent_compression(leaf, fi, compression);
+ btrfs_set_file_extent_encryption(leaf, fi, encryption);
+ btrfs_set_file_extent_other_encoding(leaf, fi, other_encoding);
+
+ btrfs_mark_buffer_dirty(leaf);
+ btrfs_release_path(path);
+
+ inode_add_bytes(inode, num_bytes);
+
+ ins.objectid = disk_bytenr;
+ ins.offset = disk_num_bytes;
+ ins.type = BTRFS_EXTENT_ITEM_KEY;
+ ret = btrfs_alloc_reserved_file_extent(trans, root,
+ root->root_key.objectid,
+ btrfs_ino(inode), file_pos, &ins);
+out:
+ btrfs_free_path(path);
+
+ return ret;
+}
+
+/* snapshot-aware defrag */
+struct sa_defrag_extent_backref {
+ struct rb_node node;
+ struct old_sa_defrag_extent *old;
+ u64 root_id;
+ u64 inum;
+ u64 file_pos;
+ u64 extent_offset;
+ u64 num_bytes;
+ u64 generation;
+};
+
+struct old_sa_defrag_extent {
+ struct list_head list;
+ struct new_sa_defrag_extent *new;
+
+ u64 extent_offset;
+ u64 bytenr;
+ u64 offset;
+ u64 len;
+ int count;
+};
+
+struct new_sa_defrag_extent {
+ struct rb_root root;
+ struct list_head head;
+ struct btrfs_path *path;
+ struct inode *inode;
+ u64 file_pos;
+ u64 len;
+ u64 bytenr;
+ u64 disk_len;
+ u8 compress_type;
+};
+
+static int backref_comp(struct sa_defrag_extent_backref *b1,
+ struct sa_defrag_extent_backref *b2)
+{
+ if (b1->root_id < b2->root_id)
+ return -1;
+ else if (b1->root_id > b2->root_id)
+ return 1;
+
+ if (b1->inum < b2->inum)
+ return -1;
+ else if (b1->inum > b2->inum)
+ return 1;
+
+ if (b1->file_pos < b2->file_pos)
+ return -1;
+ else if (b1->file_pos > b2->file_pos)
+ return 1;
+
+ /*
+ * [------------------------------] ===> (a range of space)
+ * |<--->| |<---->| =============> (fs/file tree A)
+ * |<---------------------------->| ===> (fs/file tree B)
+ *
+ * A range of space can refer to two file extents in one tree while
+ * refer to only one file extent in another tree.
+ *
+ * So we may process a disk offset more than one time(two extents in A)
+ * and locate at the same extent(one extent in B), then insert two same
+ * backrefs(both refer to the extent in B).
+ */
+ return 0;
+}
+
+static void backref_insert(struct rb_root *root,
+ struct sa_defrag_extent_backref *backref)
+{
+ struct rb_node **p = &root->rb_node;
+ struct rb_node *parent = NULL;
+ struct sa_defrag_extent_backref *entry;
+ int ret;
+
+ while (*p) {
+ parent = *p;
+ entry = rb_entry(parent, struct sa_defrag_extent_backref, node);
+
+ ret = backref_comp(backref, entry);
+ if (ret < 0)
+ p = &(*p)->rb_left;
+ else
+ p = &(*p)->rb_right;
+ }
+
+ rb_link_node(&backref->node, parent, p);
+ rb_insert_color(&backref->node, root);
+}
+
+/*
+ * Note the backref might has changed, and in this case we just return 0.
+ */
+static noinline int record_one_backref(u64 inum, u64 offset, u64 root_id,
+ void *ctx)
+{
+ struct btrfs_file_extent_item *extent;
+ struct btrfs_fs_info *fs_info;
+ struct old_sa_defrag_extent *old = ctx;
+ struct new_sa_defrag_extent *new = old->new;
+ struct btrfs_path *path = new->path;
+ struct btrfs_key key;
+ struct btrfs_root *root;
+ struct sa_defrag_extent_backref *backref;
+ struct extent_buffer *leaf;
+ struct inode *inode = new->inode;
+ int slot;
+ int ret;
+ u64 extent_offset;
+ u64 num_bytes;
+
+ if (BTRFS_I(inode)->root->root_key.objectid == root_id &&
+ inum == btrfs_ino(inode))
+ return 0;
+
+ key.objectid = root_id;
+ key.type = BTRFS_ROOT_ITEM_KEY;
+ key.offset = (u64)-1;
+
+ fs_info = BTRFS_I(inode)->root->fs_info;
+ root = btrfs_read_fs_root_no_name(fs_info, &key);
+ if (IS_ERR(root)) {
+ if (PTR_ERR(root) == -ENOENT)
+ return 0;
+ WARN_ON(1);
+ pr_debug("inum=%llu, offset=%llu, root_id=%llu\n",
+ inum, offset, root_id);
+ return PTR_ERR(root);
+ }
+
+ key.objectid = inum;
+ key.type = BTRFS_EXTENT_DATA_KEY;
+ if (offset > (u64)-1 << 32)
+ key.offset = 0;
+ else
+ key.offset = offset;
+
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (WARN_ON(ret < 0))
+ return ret;
+ ret = 0;
+
+ while (1) {
+ cond_resched();
+
+ leaf = path->nodes[0];
+ slot = path->slots[0];
+
+ if (slot >= btrfs_header_nritems(leaf)) {
+ ret = btrfs_next_leaf(root, path);
+ if (ret < 0) {
+ goto out;
+ } else if (ret > 0) {
+ ret = 0;
+ goto out;
+ }
+ continue;
+ }
+
+ path->slots[0]++;
+
+ btrfs_item_key_to_cpu(leaf, &key, slot);
+
+ if (key.objectid > inum)
+ goto out;
+
+ if (key.objectid < inum || key.type != BTRFS_EXTENT_DATA_KEY)
+ continue;
+
+ extent = btrfs_item_ptr(leaf, slot,
+ struct btrfs_file_extent_item);
+
+ if (btrfs_file_extent_disk_bytenr(leaf, extent) != old->bytenr)
+ continue;
+
+ /*
+ * 'offset' refers to the exact key.offset,
+ * NOT the 'offset' field in btrfs_extent_data_ref, ie.
+ * (key.offset - extent_offset).
+ */
+ if (key.offset != offset)
+ continue;
+
+ extent_offset = btrfs_file_extent_offset(leaf, extent);
+ num_bytes = btrfs_file_extent_num_bytes(leaf, extent);
+
+ if (extent_offset >= old->extent_offset + old->offset +
+ old->len || extent_offset + num_bytes <=
+ old->extent_offset + old->offset)
+ continue;
+ break;
+ }
+
+ backref = kmalloc(sizeof(*backref), GFP_NOFS);
+ if (!backref) {
+ ret = -ENOENT;
+ goto out;
+ }
+
+ backref->root_id = root_id;
+ backref->inum = inum;
+ backref->file_pos = offset;
+ backref->num_bytes = num_bytes;
+ backref->extent_offset = extent_offset;
+ backref->generation = btrfs_file_extent_generation(leaf, extent);
+ backref->old = old;
+ backref_insert(&new->root, backref);
+ old->count++;
+out:
+ btrfs_release_path(path);
+ WARN_ON(ret);
+ return ret;
+}
+
+static noinline bool record_extent_backrefs(struct btrfs_path *path,
+ struct new_sa_defrag_extent *new)
+{
+ struct btrfs_fs_info *fs_info = BTRFS_I(new->inode)->root->fs_info;
+ struct old_sa_defrag_extent *old, *tmp;
+ int ret;
+
+ new->path = path;
+
+ list_for_each_entry_safe(old, tmp, &new->head, list) {
+ ret = iterate_inodes_from_logical(old->bytenr +
+ old->extent_offset, fs_info,
+ path, record_one_backref,
+ old);
+ if (ret < 0 && ret != -ENOENT)
+ return false;
+
+ /* no backref to be processed for this extent */
+ if (!old->count) {
+ list_del(&old->list);
+ kfree(old);
+ }
+ }
+
+ if (list_empty(&new->head))
+ return false;
+
+ return true;
+}
+
+static int relink_is_mergable(struct extent_buffer *leaf,
+ struct btrfs_file_extent_item *fi,
+ struct new_sa_defrag_extent *new)
+{
+ if (btrfs_file_extent_disk_bytenr(leaf, fi) != new->bytenr)
+ return 0;
+
+ if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG)
+ return 0;
+
+ if (btrfs_file_extent_compression(leaf, fi) != new->compress_type)
+ return 0;
+
+ if (btrfs_file_extent_encryption(leaf, fi) ||
+ btrfs_file_extent_other_encoding(leaf, fi))
+ return 0;
+
+ return 1;
+}
+
+/*
+ * Note the backref might has changed, and in this case we just return 0.
+ */
+static noinline int relink_extent_backref(struct btrfs_path *path,
+ struct sa_defrag_extent_backref *prev,
+ struct sa_defrag_extent_backref *backref)
+{
+ struct btrfs_file_extent_item *extent;
+ struct btrfs_file_extent_item *item;
+ struct btrfs_ordered_extent *ordered;
+ struct btrfs_trans_handle *trans;
+ struct btrfs_fs_info *fs_info;
+ struct btrfs_root *root;
+ struct btrfs_key key;
+ struct extent_buffer *leaf;
+ struct old_sa_defrag_extent *old = backref->old;
+ struct new_sa_defrag_extent *new = old->new;
+ struct inode *src_inode = new->inode;
+ struct inode *inode;
+ struct extent_state *cached = NULL;
+ int ret = 0;
+ u64 start;
+ u64 len;
+ u64 lock_start;
+ u64 lock_end;
+ bool merge = false;
+ int index;
+
+ if (prev && prev->root_id == backref->root_id &&
+ prev->inum == backref->inum &&
+ prev->file_pos + prev->num_bytes == backref->file_pos)
+ merge = true;
+
+ /* step 1: get root */
+ key.objectid = backref->root_id;
+ key.type = BTRFS_ROOT_ITEM_KEY;
+ key.offset = (u64)-1;
+
+ fs_info = BTRFS_I(src_inode)->root->fs_info;
+ index = srcu_read_lock(&fs_info->subvol_srcu);
+
+ root = btrfs_read_fs_root_no_name(fs_info, &key);
+ if (IS_ERR(root)) {
+ srcu_read_unlock(&fs_info->subvol_srcu, index);
+ if (PTR_ERR(root) == -ENOENT)
+ return 0;
+ return PTR_ERR(root);
+ }
+
+ if (btrfs_root_readonly(root)) {
+ srcu_read_unlock(&fs_info->subvol_srcu, index);
+ return 0;
+ }
+
+ /* step 2: get inode */
+ key.objectid = backref->inum;
+ key.type = BTRFS_INODE_ITEM_KEY;
+ key.offset = 0;
+
+ inode = btrfs_iget(fs_info->sb, &key, root, NULL);
+ if (IS_ERR(inode)) {
+ srcu_read_unlock(&fs_info->subvol_srcu, index);
+ return 0;
+ }
+
+ srcu_read_unlock(&fs_info->subvol_srcu, index);
+
+ /* step 3: relink backref */
+ lock_start = backref->file_pos;
+ lock_end = backref->file_pos + backref->num_bytes - 1;
+ lock_extent_bits(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
+ 0, &cached);
+
+ ordered = btrfs_lookup_first_ordered_extent(inode, lock_end);
+ if (ordered) {
+ btrfs_put_ordered_extent(ordered);
+ goto out_unlock;
+ }
+
+ trans = btrfs_join_transaction(root);
+ if (IS_ERR(trans)) {
+ ret = PTR_ERR(trans);
+ goto out_unlock;
+ }
+
+ key.objectid = backref->inum;
+ key.type = BTRFS_EXTENT_DATA_KEY;
+ key.offset = backref->file_pos;
+
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret < 0) {
+ goto out_free_path;
+ } else if (ret > 0) {
+ ret = 0;
+ goto out_free_path;
+ }
+
+ extent = btrfs_item_ptr(path->nodes[0], path->slots[0],
+ struct btrfs_file_extent_item);
+
+ if (btrfs_file_extent_generation(path->nodes[0], extent) !=
+ backref->generation)
+ goto out_free_path;
+
+ btrfs_release_path(path);
+
+ start = backref->file_pos;
+ if (backref->extent_offset < old->extent_offset + old->offset)
+ start += old->extent_offset + old->offset -
+ backref->extent_offset;
+
+ len = min(backref->extent_offset + backref->num_bytes,
+ old->extent_offset + old->offset + old->len);
+ len -= max(backref->extent_offset, old->extent_offset + old->offset);
+
+ ret = btrfs_drop_extents(trans, root, inode, start,
+ start + len, 1);
+ if (ret)
+ goto out_free_path;
+again:
+ key.objectid = btrfs_ino(inode);
+ key.type = BTRFS_EXTENT_DATA_KEY;
+ key.offset = start;
+
+ path->leave_spinning = 1;
+ if (merge) {
+ struct btrfs_file_extent_item *fi;
+ u64 extent_len;
+ struct btrfs_key found_key;
+
+ ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
+ if (ret < 0)
+ goto out_free_path;
+
+ path->slots[0]--;
+ leaf = path->nodes[0];
+ btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
+
+ fi = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_file_extent_item);
+ extent_len = btrfs_file_extent_num_bytes(leaf, fi);
+
+ if (extent_len + found_key.offset == start &&
+ relink_is_mergable(leaf, fi, new)) {
+ btrfs_set_file_extent_num_bytes(leaf, fi,
+ extent_len + len);
+ btrfs_mark_buffer_dirty(leaf);
+ inode_add_bytes(inode, len);
+
+ ret = 1;
+ goto out_free_path;
+ } else {
+ merge = false;
+ btrfs_release_path(path);
+ goto again;
+ }
+ }
+
+ ret = btrfs_insert_empty_item(trans, root, path, &key,
+ sizeof(*extent));
+ if (ret) {
+ btrfs_abort_transaction(trans, root, ret);
+ goto out_free_path;
+ }
+
+ leaf = path->nodes[0];
+ item = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_file_extent_item);
+ btrfs_set_file_extent_disk_bytenr(leaf, item, new->bytenr);
+ btrfs_set_file_extent_disk_num_bytes(leaf, item, new->disk_len);
+ btrfs_set_file_extent_offset(leaf, item, start - new->file_pos);
+ btrfs_set_file_extent_num_bytes(leaf, item, len);
+ btrfs_set_file_extent_ram_bytes(leaf, item, new->len);
+ btrfs_set_file_extent_generation(leaf, item, trans->transid);
+ btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
+ btrfs_set_file_extent_compression(leaf, item, new->compress_type);
+ btrfs_set_file_extent_encryption(leaf, item, 0);
+ btrfs_set_file_extent_other_encoding(leaf, item, 0);
+
+ btrfs_mark_buffer_dirty(leaf);
+ inode_add_bytes(inode, len);
+ btrfs_release_path(path);
+
+ ret = btrfs_inc_extent_ref(trans, root, new->bytenr,
+ new->disk_len, 0,
+ backref->root_id, backref->inum,
+ new->file_pos, 0); /* start - extent_offset */
+ if (ret) {
+ btrfs_abort_transaction(trans, root, ret);
+ goto out_free_path;
+ }
+
+ ret = 1;
+out_free_path:
+ btrfs_release_path(path);
+ path->leave_spinning = 0;
+ btrfs_end_transaction(trans, root);
+out_unlock:
+ unlock_extent_cached(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
+ &cached, GFP_NOFS);
+ iput(inode);
+ return ret;
+}
+
+static void free_sa_defrag_extent(struct new_sa_defrag_extent *new)
+{
+ struct old_sa_defrag_extent *old, *tmp;
+
+ if (!new)
+ return;
+
+ list_for_each_entry_safe(old, tmp, &new->head, list) {
+ list_del(&old->list);
+ kfree(old);
+ }
+ kfree(new);
+}
+
+static void relink_file_extents(struct new_sa_defrag_extent *new)
+{
+ struct btrfs_path *path;
+ struct sa_defrag_extent_backref *backref;
+ struct sa_defrag_extent_backref *prev = NULL;
+ struct inode *inode;
+ struct btrfs_root *root;
+ struct rb_node *node;
+ int ret;
+
+ inode = new->inode;
+ root = BTRFS_I(inode)->root;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return;
+
+ if (!record_extent_backrefs(path, new)) {
+ btrfs_free_path(path);
+ goto out;
+ }
+ btrfs_release_path(path);
+
+ while (1) {
+ node = rb_first(&new->root);
+ if (!node)
+ break;
+ rb_erase(node, &new->root);
+
+ backref = rb_entry(node, struct sa_defrag_extent_backref, node);
+
+ ret = relink_extent_backref(path, prev, backref);
+ WARN_ON(ret < 0);
+
+ kfree(prev);
+
+ if (ret == 1)
+ prev = backref;
+ else
+ prev = NULL;
+ cond_resched();
+ }
+ kfree(prev);
+
+ btrfs_free_path(path);
+out:
+ free_sa_defrag_extent(new);
+
+ atomic_dec(&root->fs_info->defrag_running);
+ wake_up(&root->fs_info->transaction_wait);
+}
+
+static struct new_sa_defrag_extent *
+record_old_file_extents(struct inode *inode,
+ struct btrfs_ordered_extent *ordered)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_path *path;
+ struct btrfs_key key;
+ struct old_sa_defrag_extent *old;
+ struct new_sa_defrag_extent *new;
+ int ret;
+
+ new = kmalloc(sizeof(*new), GFP_NOFS);
+ if (!new)
+ return NULL;
+
+ new->inode = inode;
+ new->file_pos = ordered->file_offset;
+ new->len = ordered->len;
+ new->bytenr = ordered->start;
+ new->disk_len = ordered->disk_len;
+ new->compress_type = ordered->compress_type;
+ new->root = RB_ROOT;
+ INIT_LIST_HEAD(&new->head);
+
+ path = btrfs_alloc_path();
+ if (!path)
+ goto out_kfree;
+
+ key.objectid = btrfs_ino(inode);
+ key.type = BTRFS_EXTENT_DATA_KEY;
+ key.offset = new->file_pos;
+
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret < 0)
+ goto out_free_path;
+ if (ret > 0 && path->slots[0] > 0)
+ path->slots[0]--;
+
+ /* find out all the old extents for the file range */
+ while (1) {
+ struct btrfs_file_extent_item *extent;
+ struct extent_buffer *l;
+ int slot;
+ u64 num_bytes;
+ u64 offset;
+ u64 end;
+ u64 disk_bytenr;
+ u64 extent_offset;
+
+ l = path->nodes[0];
+ slot = path->slots[0];
+
+ if (slot >= btrfs_header_nritems(l)) {
+ ret = btrfs_next_leaf(root, path);
+ if (ret < 0)
+ goto out_free_path;
+ else if (ret > 0)
+ break;
+ continue;
+ }
+
+ btrfs_item_key_to_cpu(l, &key, slot);
+
+ if (key.objectid != btrfs_ino(inode))
+ break;
+ if (key.type != BTRFS_EXTENT_DATA_KEY)
+ break;
+ if (key.offset >= new->file_pos + new->len)
+ break;
+
+ extent = btrfs_item_ptr(l, slot, struct btrfs_file_extent_item);
+
+ num_bytes = btrfs_file_extent_num_bytes(l, extent);
+ if (key.offset + num_bytes < new->file_pos)
+ goto next;
+
+ disk_bytenr = btrfs_file_extent_disk_bytenr(l, extent);
+ if (!disk_bytenr)
+ goto next;
+
+ extent_offset = btrfs_file_extent_offset(l, extent);
+
+ old = kmalloc(sizeof(*old), GFP_NOFS);
+ if (!old)
+ goto out_free_path;
+
+ offset = max(new->file_pos, key.offset);
+ end = min(new->file_pos + new->len, key.offset + num_bytes);
+
+ old->bytenr = disk_bytenr;
+ old->extent_offset = extent_offset;
+ old->offset = offset - key.offset;
+ old->len = end - offset;
+ old->new = new;
+ old->count = 0;
+ list_add_tail(&old->list, &new->head);
+next:
+ path->slots[0]++;
+ cond_resched();
+ }
+
+ btrfs_free_path(path);
+ atomic_inc(&root->fs_info->defrag_running);
+
+ return new;
+
+out_free_path:
+ btrfs_free_path(path);
+out_kfree:
+ free_sa_defrag_extent(new);
+ return NULL;
+}
+
+static void btrfs_release_delalloc_bytes(struct btrfs_root *root,
+ u64 start, u64 len)
+{
+ struct btrfs_block_group_cache *cache;
+
+ cache = btrfs_lookup_block_group(root->fs_info, start);
+ ASSERT(cache);
+
+ spin_lock(&cache->lock);
+ cache->delalloc_bytes -= len;
+ spin_unlock(&cache->lock);
+
+ btrfs_put_block_group(cache);
+}
+
+/* as ordered data IO finishes, this gets called so we can finish
+ * an ordered extent if the range of bytes in the file it covers are
+ * fully written.
+ */
+static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent)
+{
+ struct inode *inode = ordered_extent->inode;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_trans_handle *trans = NULL;
+ struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
+ struct extent_state *cached_state = NULL;
+ struct new_sa_defrag_extent *new = NULL;
+ int compress_type = 0;
+ int ret = 0;
+ u64 logical_len = ordered_extent->len;
+ bool nolock;
+ bool truncated = false;
+
+ nolock = btrfs_is_free_space_inode(inode);
+
+ if (test_bit(BTRFS_ORDERED_IOERR, &ordered_extent->flags)) {
+ ret = -EIO;
+ goto out;
+ }
+
+ btrfs_free_io_failure_record(inode, ordered_extent->file_offset,
+ ordered_extent->file_offset +
+ ordered_extent->len - 1);
+
+ if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered_extent->flags)) {
+ truncated = true;
+ logical_len = ordered_extent->truncated_len;
+ /* Truncated the entire extent, don't bother adding */
+ if (!logical_len)
+ goto out;
+ }
+
+ if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) {
+ BUG_ON(!list_empty(&ordered_extent->list)); /* Logic error */
+ btrfs_ordered_update_i_size(inode, 0, ordered_extent);
+ if (nolock)
+ trans = btrfs_join_transaction_nolock(root);
+ else
+ trans = btrfs_join_transaction(root);
+ if (IS_ERR(trans)) {
+ ret = PTR_ERR(trans);
+ trans = NULL;
+ goto out;
+ }
+ trans->block_rsv = &root->fs_info->delalloc_block_rsv;
+ ret = btrfs_update_inode_fallback(trans, root, inode);
+ if (ret) /* -ENOMEM or corruption */
+ btrfs_abort_transaction(trans, root, ret);
+ goto out;
+ }
+
+ lock_extent_bits(io_tree, ordered_extent->file_offset,
+ ordered_extent->file_offset + ordered_extent->len - 1,
+ 0, &cached_state);
+
+ ret = test_range_bit(io_tree, ordered_extent->file_offset,
+ ordered_extent->file_offset + ordered_extent->len - 1,
+ EXTENT_DEFRAG, 1, cached_state);
+ if (ret) {
+ u64 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
+ if (0 && last_snapshot >= BTRFS_I(inode)->generation)
+ /* the inode is shared */
+ new = record_old_file_extents(inode, ordered_extent);
+
+ clear_extent_bit(io_tree, ordered_extent->file_offset,
+ ordered_extent->file_offset + ordered_extent->len - 1,
+ EXTENT_DEFRAG, 0, 0, &cached_state, GFP_NOFS);
+ }
+
+ if (nolock)
+ trans = btrfs_join_transaction_nolock(root);
+ else
+ trans = btrfs_join_transaction(root);
+ if (IS_ERR(trans)) {
+ ret = PTR_ERR(trans);
+ trans = NULL;
+ goto out_unlock;
+ }
+
+ trans->block_rsv = &root->fs_info->delalloc_block_rsv;
+
+ if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags))
+ compress_type = ordered_extent->compress_type;
+ if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
+ BUG_ON(compress_type);
+ ret = btrfs_mark_extent_written(trans, inode,
+ ordered_extent->file_offset,
+ ordered_extent->file_offset +
+ logical_len);
+ } else {
+ BUG_ON(root == root->fs_info->tree_root);
+ ret = insert_reserved_file_extent(trans, inode,
+ ordered_extent->file_offset,
+ ordered_extent->start,
+ ordered_extent->disk_len,
+ logical_len, logical_len,
+ compress_type, 0, 0,
+ BTRFS_FILE_EXTENT_REG);
+ if (!ret)
+ btrfs_release_delalloc_bytes(root,
+ ordered_extent->start,
+ ordered_extent->disk_len);
+ }
+ unpin_extent_cache(&BTRFS_I(inode)->extent_tree,
+ ordered_extent->file_offset, ordered_extent->len,
+ trans->transid);
+ if (ret < 0) {
+ btrfs_abort_transaction(trans, root, ret);
+ goto out_unlock;
+ }
+
+ add_pending_csums(trans, inode, ordered_extent->file_offset,
+ &ordered_extent->list);
+
+ btrfs_ordered_update_i_size(inode, 0, ordered_extent);
+ ret = btrfs_update_inode_fallback(trans, root, inode);
+ if (ret) { /* -ENOMEM or corruption */
+ btrfs_abort_transaction(trans, root, ret);
+ goto out_unlock;
+ }
+ ret = 0;
+out_unlock:
+ unlock_extent_cached(io_tree, ordered_extent->file_offset,
+ ordered_extent->file_offset +
+ ordered_extent->len - 1, &cached_state, GFP_NOFS);
+out:
+ if (root != root->fs_info->tree_root)
+ btrfs_delalloc_release_metadata(inode, ordered_extent->len);
+ if (trans)
+ btrfs_end_transaction(trans, root);
+
+ if (ret || truncated) {
+ u64 start, end;
+
+ if (truncated)
+ start = ordered_extent->file_offset + logical_len;
+ else
+ start = ordered_extent->file_offset;
+ end = ordered_extent->file_offset + ordered_extent->len - 1;
+ clear_extent_uptodate(io_tree, start, end, NULL, GFP_NOFS);
+
+ /* Drop the cache for the part of the extent we didn't write. */
+ btrfs_drop_extent_cache(inode, start, end, 0);
+
+ /*
+ * If the ordered extent had an IOERR or something else went
+ * wrong we need to return the space for this ordered extent
+ * back to the allocator. We only free the extent in the
+ * truncated case if we didn't write out the extent at all.
+ */
+ if ((ret || !logical_len) &&
+ !test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) &&
+ !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags))
+ btrfs_free_reserved_extent(root, ordered_extent->start,
+ ordered_extent->disk_len, 1);
+ }
+
+
+ /*
+ * This needs to be done to make sure anybody waiting knows we are done
+ * updating everything for this ordered extent.
+ */
+ btrfs_remove_ordered_extent(inode, ordered_extent);
+
+ /* for snapshot-aware defrag */
+ if (new) {
+ if (ret) {
+ free_sa_defrag_extent(new);
+ atomic_dec(&root->fs_info->defrag_running);
+ } else {
+ relink_file_extents(new);
+ }
+ }
+
+ /* once for us */
+ btrfs_put_ordered_extent(ordered_extent);
+ /* once for the tree */
+ btrfs_put_ordered_extent(ordered_extent);
+
+ return ret;
+}
+
+static void finish_ordered_fn(struct btrfs_work *work)
+{
+ struct btrfs_ordered_extent *ordered_extent;
+ ordered_extent = container_of(work, struct btrfs_ordered_extent, work);
+ btrfs_finish_ordered_io(ordered_extent);
+}
+
+static int btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end,
+ struct extent_state *state, int uptodate)
+{
+ struct inode *inode = page->mapping->host;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_ordered_extent *ordered_extent = NULL;
+ struct btrfs_workqueue *wq;
+ btrfs_work_func_t func;
+
+ trace_btrfs_writepage_end_io_hook(page, start, end, uptodate);
+
+ ClearPagePrivate2(page);
+ if (!btrfs_dec_test_ordered_pending(inode, &ordered_extent, start,
+ end - start + 1, uptodate))
+ return 0;
+
+ if (btrfs_is_free_space_inode(inode)) {
+ wq = root->fs_info->endio_freespace_worker;
+ func = btrfs_freespace_write_helper;
+ } else {
+ wq = root->fs_info->endio_write_workers;
+ func = btrfs_endio_write_helper;
+ }
+
+ btrfs_init_work(&ordered_extent->work, func, finish_ordered_fn, NULL,
+ NULL);
+ btrfs_queue_work(wq, &ordered_extent->work);
+
+ return 0;
+}
+
+static int __readpage_endio_check(struct inode *inode,
+ struct btrfs_io_bio *io_bio,
+ int icsum, struct page *page,
+ int pgoff, u64 start, size_t len)
+{
+ char *kaddr;
+ u32 csum_expected;
+ u32 csum = ~(u32)0;
+ static DEFINE_RATELIMIT_STATE(_rs, DEFAULT_RATELIMIT_INTERVAL,
+ DEFAULT_RATELIMIT_BURST);
+
+ csum_expected = *(((u32 *)io_bio->csum) + icsum);
+
+ kaddr = kmap_atomic(page);
+ csum = btrfs_csum_data(kaddr + pgoff, csum, len);
+ btrfs_csum_final(csum, (char *)&csum);
+ if (csum != csum_expected)
+ goto zeroit;
+
+ kunmap_atomic(kaddr);
+ return 0;
+zeroit:
+ if (__ratelimit(&_rs))
+ btrfs_warn(BTRFS_I(inode)->root->fs_info,
+ "csum failed ino %llu off %llu csum %u expected csum %u",
+ btrfs_ino(inode), start, csum, csum_expected);
+ memset(kaddr + pgoff, 1, len);
+ flush_dcache_page(page);
+ kunmap_atomic(kaddr);
+ if (csum_expected == 0)
+ return 0;
+ return -EIO;
+}
+
+/*
+ * when reads are done, we need to check csums to verify the data is correct
+ * if there's a match, we allow the bio to finish. If not, the code in
+ * extent_io.c will try to find good copies for us.
+ */
+static int btrfs_readpage_end_io_hook(struct btrfs_io_bio *io_bio,
+ u64 phy_offset, struct page *page,
+ u64 start, u64 end, int mirror)
+{
+ size_t offset = start - page_offset(page);
+ struct inode *inode = page->mapping->host;
+ struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+
+ if (PageChecked(page)) {
+ ClearPageChecked(page);
+ return 0;
+ }
+
+ if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
+ return 0;
+
+ if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID &&
+ test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1, NULL)) {
+ clear_extent_bits(io_tree, start, end, EXTENT_NODATASUM,
+ GFP_NOFS);
+ return 0;
+ }
+
+ phy_offset >>= inode->i_sb->s_blocksize_bits;
+ return __readpage_endio_check(inode, io_bio, phy_offset, page, offset,
+ start, (size_t)(end - start + 1));
+}
+
+struct delayed_iput {
+ struct list_head list;
+ struct inode *inode;
+};
+
+/* JDM: If this is fs-wide, why can't we add a pointer to
+ * btrfs_inode instead and avoid the allocation? */
+void btrfs_add_delayed_iput(struct inode *inode)
+{
+ struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
+ struct delayed_iput *delayed;
+
+ if (atomic_add_unless(&inode->i_count, -1, 1))
+ return;
+
+ delayed = kmalloc(sizeof(*delayed), GFP_NOFS | __GFP_NOFAIL);
+ delayed->inode = inode;
+
+ spin_lock(&fs_info->delayed_iput_lock);
+ list_add_tail(&delayed->list, &fs_info->delayed_iputs);
+ spin_unlock(&fs_info->delayed_iput_lock);
+}
+
+void btrfs_run_delayed_iputs(struct btrfs_root *root)
+{
+ LIST_HEAD(list);
+ struct btrfs_fs_info *fs_info = root->fs_info;
+ struct delayed_iput *delayed;
+ int empty;
+
+ spin_lock(&fs_info->delayed_iput_lock);
+ empty = list_empty(&fs_info->delayed_iputs);
+ spin_unlock(&fs_info->delayed_iput_lock);
+ if (empty)
+ return;
+
+ down_read(&fs_info->delayed_iput_sem);
+
+ spin_lock(&fs_info->delayed_iput_lock);
+ list_splice_init(&fs_info->delayed_iputs, &list);
+ spin_unlock(&fs_info->delayed_iput_lock);
+
+ while (!list_empty(&list)) {
+ delayed = list_entry(list.next, struct delayed_iput, list);
+ list_del(&delayed->list);
+ iput(delayed->inode);
+ kfree(delayed);
+ }
+
+ up_read(&root->fs_info->delayed_iput_sem);
+}
+
+/*
+ * This is called in transaction commit time. If there are no orphan
+ * files in the subvolume, it removes orphan item and frees block_rsv
+ * structure.
+ */
+void btrfs_orphan_commit_root(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root)
+{
+ struct btrfs_block_rsv *block_rsv;
+ int ret;
+
+ if (atomic_read(&root->orphan_inodes) ||
+ root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE)
+ return;
+
+ spin_lock(&root->orphan_lock);
+ if (atomic_read(&root->orphan_inodes)) {
+ spin_unlock(&root->orphan_lock);
+ return;
+ }
+
+ if (root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE) {
+ spin_unlock(&root->orphan_lock);
+ return;
+ }
+
+ block_rsv = root->orphan_block_rsv;
+ root->orphan_block_rsv = NULL;
+ spin_unlock(&root->orphan_lock);
+
+ if (test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state) &&
+ btrfs_root_refs(&root->root_item) > 0) {
+ ret = btrfs_del_orphan_item(trans, root->fs_info->tree_root,
+ root->root_key.objectid);
+ if (ret)
+ btrfs_abort_transaction(trans, root, ret);
+ else
+ clear_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED,
+ &root->state);
+ }
+
+ if (block_rsv) {
+ WARN_ON(block_rsv->size > 0);
+ btrfs_free_block_rsv(root, block_rsv);
+ }
+}
+
+/*
+ * This creates an orphan entry for the given inode in case something goes
+ * wrong in the middle of an unlink/truncate.
+ *
+ * NOTE: caller of this function should reserve 5 units of metadata for
+ * this function.
+ */
+int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct inode *inode)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_block_rsv *block_rsv = NULL;
+ int reserve = 0;
+ int insert = 0;
+ int ret;
+
+ if (!root->orphan_block_rsv) {
+ block_rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
+ if (!block_rsv)
+ return -ENOMEM;
+ }
+
+ spin_lock(&root->orphan_lock);
+ if (!root->orphan_block_rsv) {
+ root->orphan_block_rsv = block_rsv;
+ } else if (block_rsv) {
+ btrfs_free_block_rsv(root, block_rsv);
+ block_rsv = NULL;
+ }
+
+ if (!test_and_set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
+ &BTRFS_I(inode)->runtime_flags)) {
+#if 0
+ /*
+ * For proper ENOSPC handling, we should do orphan
+ * cleanup when mounting. But this introduces backward
+ * compatibility issue.
+ */
+ if (!xchg(&root->orphan_item_inserted, 1))
+ insert = 2;
+ else
+ insert = 1;
+#endif
+ insert = 1;
+ atomic_inc(&root->orphan_inodes);
+ }
+
+ if (!test_and_set_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
+ &BTRFS_I(inode)->runtime_flags))
+ reserve = 1;
+ spin_unlock(&root->orphan_lock);
+
+ /* grab metadata reservation from transaction handle */
+ if (reserve) {
+ ret = btrfs_orphan_reserve_metadata(trans, inode);
+ BUG_ON(ret); /* -ENOSPC in reservation; Logic error? JDM */
+ }
+
+ /* insert an orphan item to track this unlinked/truncated file */
+ if (insert >= 1) {
+ ret = btrfs_insert_orphan_item(trans, root, btrfs_ino(inode));
+ if (ret) {
+ atomic_dec(&root->orphan_inodes);
+ if (reserve) {
+ clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
+ &BTRFS_I(inode)->runtime_flags);
+ btrfs_orphan_release_metadata(inode);
+ }
+ if (ret != -EEXIST) {
+ clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
+ &BTRFS_I(inode)->runtime_flags);
+ btrfs_abort_transaction(trans, root, ret);
+ return ret;
+ }
+ }
+ ret = 0;
+ }
+
+ /* insert an orphan item to track subvolume contains orphan files */
+ if (insert >= 2) {
+ ret = btrfs_insert_orphan_item(trans, root->fs_info->tree_root,
+ root->root_key.objectid);
+ if (ret && ret != -EEXIST) {
+ btrfs_abort_transaction(trans, root, ret);
+ return ret;
+ }
+ }
+ return 0;
+}
+
+/*
+ * We have done the truncate/delete so we can go ahead and remove the orphan
+ * item for this particular inode.
+ */
+static int btrfs_orphan_del(struct btrfs_trans_handle *trans,
+ struct inode *inode)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ int delete_item = 0;
+ int release_rsv = 0;
+ int ret = 0;
+
+ spin_lock(&root->orphan_lock);
+ if (test_and_clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
+ &BTRFS_I(inode)->runtime_flags))
+ delete_item = 1;
+
+ if (test_and_clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
+ &BTRFS_I(inode)->runtime_flags))
+ release_rsv = 1;
+ spin_unlock(&root->orphan_lock);
+
+ if (delete_item) {
+ atomic_dec(&root->orphan_inodes);
+ if (trans)
+ ret = btrfs_del_orphan_item(trans, root,
+ btrfs_ino(inode));
+ }
+
+ if (release_rsv)
+ btrfs_orphan_release_metadata(inode);
+
+ return ret;
+}
+
+/*
+ * this cleans up any orphans that may be left on the list from the last use
+ * of this root.
+ */
+int btrfs_orphan_cleanup(struct btrfs_root *root)
+{
+ struct btrfs_path *path;
+ struct extent_buffer *leaf;
+ struct btrfs_key key, found_key;
+ struct btrfs_trans_handle *trans;
+ struct inode *inode;
+ u64 last_objectid = 0;
+ int ret = 0, nr_unlink = 0, nr_truncate = 0;
+
+ if (cmpxchg(&root->orphan_cleanup_state, 0, ORPHAN_CLEANUP_STARTED))
+ return 0;
+
+ path = btrfs_alloc_path();
+ if (!path) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ path->reada = -1;
+
+ key.objectid = BTRFS_ORPHAN_OBJECTID;
+ key.type = BTRFS_ORPHAN_ITEM_KEY;
+ key.offset = (u64)-1;
+
+ while (1) {
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret < 0)
+ goto out;
+
+ /*
+ * if ret == 0 means we found what we were searching for, which
+ * is weird, but possible, so only screw with path if we didn't
+ * find the key and see if we have stuff that matches
+ */
+ if (ret > 0) {
+ ret = 0;
+ if (path->slots[0] == 0)
+ break;
+ path->slots[0]--;
+ }
+
+ /* pull out the item */
+ leaf = path->nodes[0];
+ btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
+
+ /* make sure the item matches what we want */
+ if (found_key.objectid != BTRFS_ORPHAN_OBJECTID)
+ break;
+ if (found_key.type != BTRFS_ORPHAN_ITEM_KEY)
+ break;
+
+ /* release the path since we're done with it */
+ btrfs_release_path(path);
+
+ /*
+ * this is where we are basically btrfs_lookup, without the
+ * crossing root thing. we store the inode number in the
+ * offset of the orphan item.
+ */
+
+ if (found_key.offset == last_objectid) {
+ btrfs_err(root->fs_info,
+ "Error removing orphan entry, stopping orphan cleanup");
+ ret = -EINVAL;
+ goto out;
+ }
+
+ last_objectid = found_key.offset;
+
+ found_key.objectid = found_key.offset;
+ found_key.type = BTRFS_INODE_ITEM_KEY;
+ found_key.offset = 0;
+ inode = btrfs_iget(root->fs_info->sb, &found_key, root, NULL);
+ ret = PTR_ERR_OR_ZERO(inode);
+ if (ret && ret != -ESTALE)
+ goto out;
+
+ if (ret == -ESTALE && root == root->fs_info->tree_root) {
+ struct btrfs_root *dead_root;
+ struct btrfs_fs_info *fs_info = root->fs_info;
+ int is_dead_root = 0;
+
+ /*
+ * this is an orphan in the tree root. Currently these
+ * could come from 2 sources:
+ * a) a snapshot deletion in progress
+ * b) a free space cache inode
+ * We need to distinguish those two, as the snapshot
+ * orphan must not get deleted.
+ * find_dead_roots already ran before us, so if this
+ * is a snapshot deletion, we should find the root
+ * in the dead_roots list
+ */
+ spin_lock(&fs_info->trans_lock);
+ list_for_each_entry(dead_root, &fs_info->dead_roots,
+ root_list) {
+ if (dead_root->root_key.objectid ==
+ found_key.objectid) {
+ is_dead_root = 1;
+ break;
+ }
+ }
+ spin_unlock(&fs_info->trans_lock);
+ if (is_dead_root) {
+ /* prevent this orphan from being found again */
+ key.offset = found_key.objectid - 1;
+ continue;
+ }
+ }
+ /*
+ * Inode is already gone but the orphan item is still there,
+ * kill the orphan item.
+ */
+ if (ret == -ESTALE) {
+ trans = btrfs_start_transaction(root, 1);
+ if (IS_ERR(trans)) {
+ ret = PTR_ERR(trans);
+ goto out;
+ }
+ btrfs_debug(root->fs_info, "auto deleting %Lu",
+ found_key.objectid);
+ ret = btrfs_del_orphan_item(trans, root,
+ found_key.objectid);
+ btrfs_end_transaction(trans, root);
+ if (ret)
+ goto out;
+ continue;
+ }
+
+ /*
+ * add this inode to the orphan list so btrfs_orphan_del does
+ * the proper thing when we hit it
+ */
+ set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
+ &BTRFS_I(inode)->runtime_flags);
+ atomic_inc(&root->orphan_inodes);
+
+ /* if we have links, this was a truncate, lets do that */
+ if (inode->i_nlink) {
+ if (WARN_ON(!S_ISREG(inode->i_mode))) {
+ iput(inode);
+ continue;
+ }
+ nr_truncate++;
+
+ /* 1 for the orphan item deletion. */
+ trans = btrfs_start_transaction(root, 1);
+ if (IS_ERR(trans)) {
+ iput(inode);
+ ret = PTR_ERR(trans);
+ goto out;
+ }
+ ret = btrfs_orphan_add(trans, inode);
+ btrfs_end_transaction(trans, root);
+ if (ret) {
+ iput(inode);
+ goto out;
+ }
+
+ ret = btrfs_truncate(inode);
+ if (ret)
+ btrfs_orphan_del(NULL, inode);
+ } else {
+ nr_unlink++;
+ }
+
+ /* this will do delete_inode and everything for us */
+ iput(inode);
+ if (ret)
+ goto out;
+ }
+ /* release the path since we're done with it */
+ btrfs_release_path(path);
+
+ root->orphan_cleanup_state = ORPHAN_CLEANUP_DONE;
+
+ if (root->orphan_block_rsv)
+ btrfs_block_rsv_release(root, root->orphan_block_rsv,
+ (u64)-1);
+
+ if (root->orphan_block_rsv ||
+ test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state)) {
+ trans = btrfs_join_transaction(root);
+ if (!IS_ERR(trans))
+ btrfs_end_transaction(trans, root);
+ }
+
+ if (nr_unlink)
+ btrfs_debug(root->fs_info, "unlinked %d orphans", nr_unlink);
+ if (nr_truncate)
+ btrfs_debug(root->fs_info, "truncated %d orphans", nr_truncate);
+
+out:
+ if (ret)
+ btrfs_err(root->fs_info,
+ "could not do orphan cleanup %d", ret);
+ btrfs_free_path(path);
+ return ret;
+}
+
+/*
+ * very simple check to peek ahead in the leaf looking for xattrs. If we
+ * don't find any xattrs, we know there can't be any acls.
+ *
+ * slot is the slot the inode is in, objectid is the objectid of the inode
+ */
+static noinline int acls_after_inode_item(struct extent_buffer *leaf,
+ int slot, u64 objectid,
+ int *first_xattr_slot)
+{
+ u32 nritems = btrfs_header_nritems(leaf);
+ struct btrfs_key found_key;
+ static u64 xattr_access = 0;
+ static u64 xattr_default = 0;
+ int scanned = 0;
+
+ if (!xattr_access) {
+ xattr_access = btrfs_name_hash(POSIX_ACL_XATTR_ACCESS,
+ strlen(POSIX_ACL_XATTR_ACCESS));
+ xattr_default = btrfs_name_hash(POSIX_ACL_XATTR_DEFAULT,
+ strlen(POSIX_ACL_XATTR_DEFAULT));
+ }
+
+ slot++;
+ *first_xattr_slot = -1;
+ while (slot < nritems) {
+ btrfs_item_key_to_cpu(leaf, &found_key, slot);
+
+ /* we found a different objectid, there must not be acls */
+ if (found_key.objectid != objectid)
+ return 0;
+
+ /* we found an xattr, assume we've got an acl */
+ if (found_key.type == BTRFS_XATTR_ITEM_KEY) {
+ if (*first_xattr_slot == -1)
+ *first_xattr_slot = slot;
+ if (found_key.offset == xattr_access ||
+ found_key.offset == xattr_default)
+ return 1;
+ }
+
+ /*
+ * we found a key greater than an xattr key, there can't
+ * be any acls later on
+ */
+ if (found_key.type > BTRFS_XATTR_ITEM_KEY)
+ return 0;
+
+ slot++;
+ scanned++;
+
+ /*
+ * it goes inode, inode backrefs, xattrs, extents,
+ * so if there are a ton of hard links to an inode there can
+ * be a lot of backrefs. Don't waste time searching too hard,
+ * this is just an optimization
+ */
+ if (scanned >= 8)
+ break;
+ }
+ /* we hit the end of the leaf before we found an xattr or
+ * something larger than an xattr. We have to assume the inode
+ * has acls
+ */
+ if (*first_xattr_slot == -1)
+ *first_xattr_slot = slot;
+ return 1;
+}
+
+/*
+ * read an inode from the btree into the in-memory inode
+ */
+static void btrfs_read_locked_inode(struct inode *inode)
+{
+ struct btrfs_path *path;
+ struct extent_buffer *leaf;
+ struct btrfs_inode_item *inode_item;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_key location;
+ unsigned long ptr;
+ int maybe_acls;
+ u32 rdev;
+ int ret;
+ bool filled = false;
+ int first_xattr_slot;
+
+ ret = btrfs_fill_inode(inode, &rdev);
+ if (!ret)
+ filled = true;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ goto make_bad;
+
+ memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
+
+ ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
+ if (ret)
+ goto make_bad;
+
+ leaf = path->nodes[0];
+
+ if (filled)
+ goto cache_index;
+
+ inode_item = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_inode_item);
+ inode->i_mode = btrfs_inode_mode(leaf, inode_item);
+ set_nlink(inode, btrfs_inode_nlink(leaf, inode_item));
+ i_uid_write(inode, btrfs_inode_uid(leaf, inode_item));
+ i_gid_write(inode, btrfs_inode_gid(leaf, inode_item));
+ btrfs_i_size_write(inode, btrfs_inode_size(leaf, inode_item));
+
+ inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->atime);
+ inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->atime);
+
+ inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->mtime);
+ inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->mtime);
+
+ inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->ctime);
+ inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->ctime);
+
+ BTRFS_I(inode)->i_otime.tv_sec =
+ btrfs_timespec_sec(leaf, &inode_item->otime);
+ BTRFS_I(inode)->i_otime.tv_nsec =
+ btrfs_timespec_nsec(leaf, &inode_item->otime);
+
+ inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item));
+ BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item);
+ BTRFS_I(inode)->last_trans = btrfs_inode_transid(leaf, inode_item);
+
+ inode->i_version = btrfs_inode_sequence(leaf, inode_item);
+ inode->i_generation = BTRFS_I(inode)->generation;
+ inode->i_rdev = 0;
+ rdev = btrfs_inode_rdev(leaf, inode_item);
+
+ BTRFS_I(inode)->index_cnt = (u64)-1;
+ BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item);
+
+cache_index:
+ /*
+ * If we were modified in the current generation and evicted from memory
+ * and then re-read we need to do a full sync since we don't have any
+ * idea about which extents were modified before we were evicted from
+ * cache.
+ *
+ * This is required for both inode re-read from disk and delayed inode
+ * in delayed_nodes_tree.
+ */
+ if (BTRFS_I(inode)->last_trans == root->fs_info->generation)
+ set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
+ &BTRFS_I(inode)->runtime_flags);
+
+ path->slots[0]++;
+ if (inode->i_nlink != 1 ||
+ path->slots[0] >= btrfs_header_nritems(leaf))
+ goto cache_acl;
+
+ btrfs_item_key_to_cpu(leaf, &location, path->slots[0]);
+ if (location.objectid != btrfs_ino(inode))
+ goto cache_acl;
+
+ ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
+ if (location.type == BTRFS_INODE_REF_KEY) {
+ struct btrfs_inode_ref *ref;
+
+ ref = (struct btrfs_inode_ref *)ptr;
+ BTRFS_I(inode)->dir_index = btrfs_inode_ref_index(leaf, ref);
+ } else if (location.type == BTRFS_INODE_EXTREF_KEY) {
+ struct btrfs_inode_extref *extref;
+
+ extref = (struct btrfs_inode_extref *)ptr;
+ BTRFS_I(inode)->dir_index = btrfs_inode_extref_index(leaf,
+ extref);
+ }
+cache_acl:
+ /*
+ * try to precache a NULL acl entry for files that don't have
+ * any xattrs or acls
+ */
+ maybe_acls = acls_after_inode_item(leaf, path->slots[0],
+ btrfs_ino(inode), &first_xattr_slot);
+ if (first_xattr_slot != -1) {
+ path->slots[0] = first_xattr_slot;
+ ret = btrfs_load_inode_props(inode, path);
+ if (ret)
+ btrfs_err(root->fs_info,
+ "error loading props for ino %llu (root %llu): %d",
+ btrfs_ino(inode),
+ root->root_key.objectid, ret);
+ }
+ btrfs_free_path(path);
+
+ if (!maybe_acls)
+ cache_no_acl(inode);
+
+ switch (inode->i_mode & S_IFMT) {
+ case S_IFREG:
+ inode->i_mapping->a_ops = &btrfs_aops;
+ BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
+ inode->i_fop = &btrfs_file_operations;
+ inode->i_op = &btrfs_file_inode_operations;
+ break;
+ case S_IFDIR:
+ inode->i_fop = &btrfs_dir_file_operations;
+ if (root == root->fs_info->tree_root)
+ inode->i_op = &btrfs_dir_ro_inode_operations;
+ else
+ inode->i_op = &btrfs_dir_inode_operations;
+ break;
+ case S_IFLNK:
+ inode->i_op = &btrfs_symlink_inode_operations;
+ inode->i_mapping->a_ops = &btrfs_symlink_aops;
+ break;
+ default:
+ inode->i_op = &btrfs_special_inode_operations;
+ init_special_inode(inode, inode->i_mode, rdev);
+ break;
+ }
+
+ btrfs_update_iflags(inode);
+ return;
+
+make_bad:
+ btrfs_free_path(path);
+ make_bad_inode(inode);
+}
+
+/*
+ * given a leaf and an inode, copy the inode fields into the leaf
+ */
+static void fill_inode_item(struct btrfs_trans_handle *trans,
+ struct extent_buffer *leaf,
+ struct btrfs_inode_item *item,
+ struct inode *inode)
+{
+ struct btrfs_map_token token;
+
+ btrfs_init_map_token(&token);
+
+ btrfs_set_token_inode_uid(leaf, item, i_uid_read(inode), &token);
+ btrfs_set_token_inode_gid(leaf, item, i_gid_read(inode), &token);
+ btrfs_set_token_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size,
+ &token);
+ btrfs_set_token_inode_mode(leaf, item, inode->i_mode, &token);
+ btrfs_set_token_inode_nlink(leaf, item, inode->i_nlink, &token);
+
+ btrfs_set_token_timespec_sec(leaf, &item->atime,
+ inode->i_atime.tv_sec, &token);
+ btrfs_set_token_timespec_nsec(leaf, &item->atime,
+ inode->i_atime.tv_nsec, &token);
+
+ btrfs_set_token_timespec_sec(leaf, &item->mtime,
+ inode->i_mtime.tv_sec, &token);
+ btrfs_set_token_timespec_nsec(leaf, &item->mtime,
+ inode->i_mtime.tv_nsec, &token);
+
+ btrfs_set_token_timespec_sec(leaf, &item->ctime,
+ inode->i_ctime.tv_sec, &token);
+ btrfs_set_token_timespec_nsec(leaf, &item->ctime,
+ inode->i_ctime.tv_nsec, &token);
+
+ btrfs_set_token_timespec_sec(leaf, &item->otime,
+ BTRFS_I(inode)->i_otime.tv_sec, &token);
+ btrfs_set_token_timespec_nsec(leaf, &item->otime,
+ BTRFS_I(inode)->i_otime.tv_nsec, &token);
+
+ btrfs_set_token_inode_nbytes(leaf, item, inode_get_bytes(inode),
+ &token);
+ btrfs_set_token_inode_generation(leaf, item, BTRFS_I(inode)->generation,
+ &token);
+ btrfs_set_token_inode_sequence(leaf, item, inode->i_version, &token);
+ btrfs_set_token_inode_transid(leaf, item, trans->transid, &token);
+ btrfs_set_token_inode_rdev(leaf, item, inode->i_rdev, &token);
+ btrfs_set_token_inode_flags(leaf, item, BTRFS_I(inode)->flags, &token);
+ btrfs_set_token_inode_block_group(leaf, item, 0, &token);
+}
+
+/*
+ * copy everything in the in-memory inode into the btree.
+ */
+static noinline int btrfs_update_inode_item(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, struct inode *inode)
+{
+ struct btrfs_inode_item *inode_item;
+ struct btrfs_path *path;
+ struct extent_buffer *leaf;
+ int ret;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ path->leave_spinning = 1;
+ ret = btrfs_lookup_inode(trans, root, path, &BTRFS_I(inode)->location,
+ 1);
+ if (ret) {
+ if (ret > 0)
+ ret = -ENOENT;
+ goto failed;
+ }
+
+ leaf = path->nodes[0];
+ inode_item = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_inode_item);
+
+ fill_inode_item(trans, leaf, inode_item, inode);
+ btrfs_mark_buffer_dirty(leaf);
+ btrfs_set_inode_last_trans(trans, inode);
+ ret = 0;
+failed:
+ btrfs_free_path(path);
+ return ret;
+}
+
+/*
+ * copy everything in the in-memory inode into the btree.
+ */
+noinline int btrfs_update_inode(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, struct inode *inode)
+{
+ int ret;
+
+ /*
+ * If the inode is a free space inode, we can deadlock during commit
+ * if we put it into the delayed code.
+ *
+ * The data relocation inode should also be directly updated
+ * without delay
+ */
+ if (!btrfs_is_free_space_inode(inode)
+ && root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
+ && !root->fs_info->log_root_recovering) {
+ btrfs_update_root_times(trans, root);
+
+ ret = btrfs_delayed_update_inode(trans, root, inode);
+ if (!ret)
+ btrfs_set_inode_last_trans(trans, inode);
+ return ret;
+ }
+
+ return btrfs_update_inode_item(trans, root, inode);
+}
+
+noinline int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct inode *inode)
+{
+ int ret;
+
+ ret = btrfs_update_inode(trans, root, inode);
+ if (ret == -ENOSPC)
+ return btrfs_update_inode_item(trans, root, inode);
+ return ret;
+}
+
+/*
+ * unlink helper that gets used here in inode.c and in the tree logging
+ * recovery code. It remove a link in a directory with a given name, and
+ * also drops the back refs in the inode to the directory
+ */
+static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct inode *dir, struct inode *inode,
+ const char *name, int name_len)
+{
+ struct btrfs_path *path;
+ int ret = 0;
+ struct extent_buffer *leaf;
+ struct btrfs_dir_item *di;
+ struct btrfs_key key;
+ u64 index;
+ u64 ino = btrfs_ino(inode);
+ u64 dir_ino = btrfs_ino(dir);
+
+ path = btrfs_alloc_path();
+ if (!path) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ path->leave_spinning = 1;
+ di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
+ name, name_len, -1);
+ if (IS_ERR(di)) {
+ ret = PTR_ERR(di);
+ goto err;
+ }
+ if (!di) {
+ ret = -ENOENT;
+ goto err;
+ }
+ leaf = path->nodes[0];
+ btrfs_dir_item_key_to_cpu(leaf, di, &key);
+ ret = btrfs_delete_one_dir_name(trans, root, path, di);
+ if (ret)
+ goto err;
+ btrfs_release_path(path);
+
+ /*
+ * If we don't have dir index, we have to get it by looking up
+ * the inode ref, since we get the inode ref, remove it directly,
+ * it is unnecessary to do delayed deletion.
+ *
+ * But if we have dir index, needn't search inode ref to get it.
+ * Since the inode ref is close to the inode item, it is better
+ * that we delay to delete it, and just do this deletion when
+ * we update the inode item.
+ */
+ if (BTRFS_I(inode)->dir_index) {
+ ret = btrfs_delayed_delete_inode_ref(inode);
+ if (!ret) {
+ index = BTRFS_I(inode)->dir_index;
+ goto skip_backref;
+ }
+ }
+
+ ret = btrfs_del_inode_ref(trans, root, name, name_len, ino,
+ dir_ino, &index);
+ if (ret) {
+ btrfs_info(root->fs_info,
+ "failed to delete reference to %.*s, inode %llu parent %llu",
+ name_len, name, ino, dir_ino);
+ btrfs_abort_transaction(trans, root, ret);
+ goto err;
+ }
+skip_backref:
+ ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
+ if (ret) {
+ btrfs_abort_transaction(trans, root, ret);
+ goto err;
+ }
+
+ ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len,
+ inode, dir_ino);
+ if (ret != 0 && ret != -ENOENT) {
+ btrfs_abort_transaction(trans, root, ret);
+ goto err;
+ }
+
+ ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len,
+ dir, index);
+ if (ret == -ENOENT)
+ ret = 0;
+ else if (ret)
+ btrfs_abort_transaction(trans, root, ret);
+err:
+ btrfs_free_path(path);
+ if (ret)
+ goto out;
+
+ btrfs_i_size_write(dir, dir->i_size - name_len * 2);
+ inode_inc_iversion(inode);
+ inode_inc_iversion(dir);
+ inode->i_ctime = dir->i_mtime = dir->i_ctime = CURRENT_TIME;
+ ret = btrfs_update_inode(trans, root, dir);
+out:
+ return ret;
+}
+
+int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct inode *dir, struct inode *inode,
+ const char *name, int name_len)
+{
+ int ret;
+ ret = __btrfs_unlink_inode(trans, root, dir, inode, name, name_len);
+ if (!ret) {
+ drop_nlink(inode);
+ ret = btrfs_update_inode(trans, root, inode);
+ }
+ return ret;
+}
+
+/*
+ * helper to start transaction for unlink and rmdir.
+ *
+ * unlink and rmdir are special in btrfs, they do not always free space, so
+ * if we cannot make our reservations the normal way try and see if there is
+ * plenty of slack room in the global reserve to migrate, otherwise we cannot
+ * allow the unlink to occur.
+ */
+static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir)
+{
+ struct btrfs_trans_handle *trans;
+ struct btrfs_root *root = BTRFS_I(dir)->root;
+ int ret;
+
+ /*
+ * 1 for the possible orphan item
+ * 1 for the dir item
+ * 1 for the dir index
+ * 1 for the inode ref
+ * 1 for the inode
+ */
+ trans = btrfs_start_transaction(root, 5);
+ if (!IS_ERR(trans) || PTR_ERR(trans) != -ENOSPC)
+ return trans;
+
+ if (PTR_ERR(trans) == -ENOSPC) {
+ u64 num_bytes = btrfs_calc_trans_metadata_size(root, 5);
+
+ trans = btrfs_start_transaction(root, 0);
+ if (IS_ERR(trans))
+ return trans;
+ ret = btrfs_cond_migrate_bytes(root->fs_info,
+ &root->fs_info->trans_block_rsv,
+ num_bytes, 5);
+ if (ret) {
+ btrfs_end_transaction(trans, root);
+ return ERR_PTR(ret);
+ }
+ trans->block_rsv = &root->fs_info->trans_block_rsv;
+ trans->bytes_reserved = num_bytes;
+ }
+ return trans;
+}
+
+static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
+{
+ struct btrfs_root *root = BTRFS_I(dir)->root;
+ struct btrfs_trans_handle *trans;
+ struct inode *inode = d_inode(dentry);
+ int ret;
+
+ trans = __unlink_start_trans(dir);
+ if (IS_ERR(trans))
+ return PTR_ERR(trans);
+
+ btrfs_record_unlink_dir(trans, dir, d_inode(dentry), 0);
+
+ ret = btrfs_unlink_inode(trans, root, dir, d_inode(dentry),
+ dentry->d_name.name, dentry->d_name.len);
+ if (ret)
+ goto out;
+
+ if (inode->i_nlink == 0) {
+ ret = btrfs_orphan_add(trans, inode);
+ if (ret)
+ goto out;
+ }
+
+out:
+ btrfs_end_transaction(trans, root);
+ btrfs_btree_balance_dirty(root);
+ return ret;
+}
+
+int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct inode *dir, u64 objectid,
+ const char *name, int name_len)
+{
+ struct btrfs_path *path;
+ struct extent_buffer *leaf;
+ struct btrfs_dir_item *di;
+ struct btrfs_key key;
+ u64 index;
+ int ret;
+ u64 dir_ino = btrfs_ino(dir);
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
+ name, name_len, -1);
+ if (IS_ERR_OR_NULL(di)) {
+ if (!di)
+ ret = -ENOENT;
+ else
+ ret = PTR_ERR(di);
+ goto out;
+ }
+
+ leaf = path->nodes[0];
+ btrfs_dir_item_key_to_cpu(leaf, di, &key);
+ WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid);
+ ret = btrfs_delete_one_dir_name(trans, root, path, di);
+ if (ret) {
+ btrfs_abort_transaction(trans, root, ret);
+ goto out;
+ }
+ btrfs_release_path(path);
+
+ ret = btrfs_del_root_ref(trans, root->fs_info->tree_root,
+ objectid, root->root_key.objectid,
+ dir_ino, &index, name, name_len);
+ if (ret < 0) {
+ if (ret != -ENOENT) {
+ btrfs_abort_transaction(trans, root, ret);
+ goto out;
+ }
+ di = btrfs_search_dir_index_item(root, path, dir_ino,
+ name, name_len);
+ if (IS_ERR_OR_NULL(di)) {
+ if (!di)
+ ret = -ENOENT;
+ else
+ ret = PTR_ERR(di);
+ btrfs_abort_transaction(trans, root, ret);
+ goto out;
+ }
+
+ leaf = path->nodes[0];
+ btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
+ btrfs_release_path(path);
+ index = key.offset;
+ }
+ btrfs_release_path(path);
+
+ ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
+ if (ret) {
+ btrfs_abort_transaction(trans, root, ret);
+ goto out;
+ }
+
+ btrfs_i_size_write(dir, dir->i_size - name_len * 2);
+ inode_inc_iversion(dir);
+ dir->i_mtime = dir->i_ctime = CURRENT_TIME;
+ ret = btrfs_update_inode_fallback(trans, root, dir);
+ if (ret)
+ btrfs_abort_transaction(trans, root, ret);
+out:
+ btrfs_free_path(path);
+ return ret;
+}
+
+static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
+{
+ struct inode *inode = d_inode(dentry);
+ int err = 0;
+ struct btrfs_root *root = BTRFS_I(dir)->root;
+ struct btrfs_trans_handle *trans;
+
+ if (inode->i_size > BTRFS_EMPTY_DIR_SIZE)
+ return -ENOTEMPTY;
+ if (btrfs_ino(inode) == BTRFS_FIRST_FREE_OBJECTID)
+ return -EPERM;
+
+ trans = __unlink_start_trans(dir);
+ if (IS_ERR(trans))
+ return PTR_ERR(trans);
+
+ if (unlikely(btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
+ err = btrfs_unlink_subvol(trans, root, dir,
+ BTRFS_I(inode)->location.objectid,
+ dentry->d_name.name,
+ dentry->d_name.len);
+ goto out;
+ }
+
+ err = btrfs_orphan_add(trans, inode);
+ if (err)
+ goto out;
+
+ /* now the directory is empty */
+ err = btrfs_unlink_inode(trans, root, dir, d_inode(dentry),
+ dentry->d_name.name, dentry->d_name.len);
+ if (!err)
+ btrfs_i_size_write(inode, 0);
+out:
+ btrfs_end_transaction(trans, root);
+ btrfs_btree_balance_dirty(root);
+
+ return err;
+}
+
+static int truncate_space_check(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ u64 bytes_deleted)
+{
+ int ret;
+
+ bytes_deleted = btrfs_csum_bytes_to_leaves(root, bytes_deleted);
+ ret = btrfs_block_rsv_add(root, &root->fs_info->trans_block_rsv,
+ bytes_deleted, BTRFS_RESERVE_NO_FLUSH);
+ if (!ret)
+ trans->bytes_reserved += bytes_deleted;
+ return ret;
+
+}
+
+/*
+ * this can truncate away extent items, csum items and directory items.
+ * It starts at a high offset and removes keys until it can't find
+ * any higher than new_size
+ *
+ * csum items that cross the new i_size are truncated to the new size
+ * as well.
+ *
+ * min_type is the minimum key type to truncate down to. If set to 0, this
+ * will kill all the items on this inode, including the INODE_ITEM_KEY.
+ */
+int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct inode *inode,
+ u64 new_size, u32 min_type)
+{
+ struct btrfs_path *path;
+ struct extent_buffer *leaf;
+ struct btrfs_file_extent_item *fi;
+ struct btrfs_key key;
+ struct btrfs_key found_key;
+ u64 extent_start = 0;
+ u64 extent_num_bytes = 0;
+ u64 extent_offset = 0;
+ u64 item_end = 0;
+ u64 last_size = (u64)-1;
+ u32 found_type = (u8)-1;
+ int found_extent;
+ int del_item;
+ int pending_del_nr = 0;
+ int pending_del_slot = 0;
+ int extent_type = -1;
+ int ret;
+ int err = 0;
+ u64 ino = btrfs_ino(inode);
+ u64 bytes_deleted = 0;
+ bool be_nice = 0;
+ bool should_throttle = 0;
+ bool should_end = 0;
+
+ BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY);
+
+ /*
+ * for non-free space inodes and ref cows, we want to back off from
+ * time to time
+ */
+ if (!btrfs_is_free_space_inode(inode) &&
+ test_bit(BTRFS_ROOT_REF_COWS, &root->state))
+ be_nice = 1;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+ path->reada = -1;
+
+ /*
+ * We want to drop from the next block forward in case this new size is
+ * not block aligned since we will be keeping the last block of the
+ * extent just the way it is.
+ */
+ if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
+ root == root->fs_info->tree_root)
+ btrfs_drop_extent_cache(inode, ALIGN(new_size,
+ root->sectorsize), (u64)-1, 0);
+
+ /*
+ * This function is also used to drop the items in the log tree before
+ * we relog the inode, so if root != BTRFS_I(inode)->root, it means
+ * it is used to drop the loged items. So we shouldn't kill the delayed
+ * items.
+ */
+ if (min_type == 0 && root == BTRFS_I(inode)->root)
+ btrfs_kill_delayed_inode_items(inode);
+
+ key.objectid = ino;
+ key.offset = (u64)-1;
+ key.type = (u8)-1;
+
+search_again:
+ /*
+ * with a 16K leaf size and 128MB extents, you can actually queue
+ * up a huge file in a single leaf. Most of the time that
+ * bytes_deleted is > 0, it will be huge by the time we get here
+ */
+ if (be_nice && bytes_deleted > 32 * 1024 * 1024) {
+ if (btrfs_should_end_transaction(trans, root)) {
+ err = -EAGAIN;
+ goto error;
+ }
+ }
+
+
+ path->leave_spinning = 1;
+ ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
+ if (ret < 0) {
+ err = ret;
+ goto out;
+ }
+
+ if (ret > 0) {
+ /* there are no items in the tree for us to truncate, we're
+ * done
+ */
+ if (path->slots[0] == 0)
+ goto out;
+ path->slots[0]--;
+ }
+
+ while (1) {
+ fi = NULL;
+ leaf = path->nodes[0];
+ btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
+ found_type = found_key.type;
+
+ if (found_key.objectid != ino)
+ break;
+
+ if (found_type < min_type)
+ break;
+
+ item_end = found_key.offset;
+ if (found_type == BTRFS_EXTENT_DATA_KEY) {
+ fi = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_file_extent_item);
+ extent_type = btrfs_file_extent_type(leaf, fi);
+ if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
+ item_end +=
+ btrfs_file_extent_num_bytes(leaf, fi);
+ } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
+ item_end += btrfs_file_extent_inline_len(leaf,
+ path->slots[0], fi);
+ }
+ item_end--;
+ }
+ if (found_type > min_type) {
+ del_item = 1;
+ } else {
+ if (item_end < new_size)
+ break;
+ if (found_key.offset >= new_size)
+ del_item = 1;
+ else
+ del_item = 0;
+ }
+ found_extent = 0;
+ /* FIXME, shrink the extent if the ref count is only 1 */
+ if (found_type != BTRFS_EXTENT_DATA_KEY)
+ goto delete;
+
+ if (del_item)
+ last_size = found_key.offset;
+ else
+ last_size = new_size;
+
+ if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
+ u64 num_dec;
+ extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
+ if (!del_item) {
+ u64 orig_num_bytes =
+ btrfs_file_extent_num_bytes(leaf, fi);
+ extent_num_bytes = ALIGN(new_size -
+ found_key.offset,
+ root->sectorsize);
+ btrfs_set_file_extent_num_bytes(leaf, fi,
+ extent_num_bytes);
+ num_dec = (orig_num_bytes -
+ extent_num_bytes);
+ if (test_bit(BTRFS_ROOT_REF_COWS,
+ &root->state) &&
+ extent_start != 0)
+ inode_sub_bytes(inode, num_dec);
+ btrfs_mark_buffer_dirty(leaf);
+ } else {
+ extent_num_bytes =
+ btrfs_file_extent_disk_num_bytes(leaf,
+ fi);
+ extent_offset = found_key.offset -
+ btrfs_file_extent_offset(leaf, fi);
+
+ /* FIXME blocksize != 4096 */
+ num_dec = btrfs_file_extent_num_bytes(leaf, fi);
+ if (extent_start != 0) {
+ found_extent = 1;
+ if (test_bit(BTRFS_ROOT_REF_COWS,
+ &root->state))
+ inode_sub_bytes(inode, num_dec);
+ }
+ }
+ } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
+ /*
+ * we can't truncate inline items that have had
+ * special encodings
+ */
+ if (!del_item &&
+ btrfs_file_extent_compression(leaf, fi) == 0 &&
+ btrfs_file_extent_encryption(leaf, fi) == 0 &&
+ btrfs_file_extent_other_encoding(leaf, fi) == 0) {
+ u32 size = new_size - found_key.offset;
+
+ if (test_bit(BTRFS_ROOT_REF_COWS, &root->state))
+ inode_sub_bytes(inode, item_end + 1 -
+ new_size);
+
+ /*
+ * update the ram bytes to properly reflect
+ * the new size of our item
+ */
+ btrfs_set_file_extent_ram_bytes(leaf, fi, size);
+ size =
+ btrfs_file_extent_calc_inline_size(size);
+ btrfs_truncate_item(root, path, size, 1);
+ } else if (test_bit(BTRFS_ROOT_REF_COWS,
+ &root->state)) {
+ inode_sub_bytes(inode, item_end + 1 -
+ found_key.offset);
+ }
+ }
+delete:
+ if (del_item) {
+ if (!pending_del_nr) {
+ /* no pending yet, add ourselves */
+ pending_del_slot = path->slots[0];
+ pending_del_nr = 1;
+ } else if (pending_del_nr &&
+ path->slots[0] + 1 == pending_del_slot) {
+ /* hop on the pending chunk */
+ pending_del_nr++;
+ pending_del_slot = path->slots[0];
+ } else {
+ BUG();
+ }
+ } else {
+ break;
+ }
+ should_throttle = 0;
+
+ if (found_extent &&
+ (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
+ root == root->fs_info->tree_root)) {
+ btrfs_set_path_blocking(path);
+ bytes_deleted += extent_num_bytes;
+ ret = btrfs_free_extent(trans, root, extent_start,
+ extent_num_bytes, 0,
+ btrfs_header_owner(leaf),
+ ino, extent_offset, 0);
+ BUG_ON(ret);
+ if (btrfs_should_throttle_delayed_refs(trans, root))
+ btrfs_async_run_delayed_refs(root,
+ trans->delayed_ref_updates * 2, 0);
+ if (be_nice) {
+ if (truncate_space_check(trans, root,
+ extent_num_bytes)) {
+ should_end = 1;
+ }
+ if (btrfs_should_throttle_delayed_refs(trans,
+ root)) {
+ should_throttle = 1;
+ }
+ }
+ }
+
+ if (found_type == BTRFS_INODE_ITEM_KEY)
+ break;
+
+ if (path->slots[0] == 0 ||
+ path->slots[0] != pending_del_slot ||
+ should_throttle || should_end) {
+ if (pending_del_nr) {
+ ret = btrfs_del_items(trans, root, path,
+ pending_del_slot,
+ pending_del_nr);
+ if (ret) {
+ btrfs_abort_transaction(trans,
+ root, ret);
+ goto error;
+ }
+ pending_del_nr = 0;
+ }
+ btrfs_release_path(path);
+ if (should_throttle) {
+ unsigned long updates = trans->delayed_ref_updates;
+ if (updates) {
+ trans->delayed_ref_updates = 0;
+ ret = btrfs_run_delayed_refs(trans, root, updates * 2);
+ if (ret && !err)
+ err = ret;
+ }
+ }
+ /*
+ * if we failed to refill our space rsv, bail out
+ * and let the transaction restart
+ */
+ if (should_end) {
+ err = -EAGAIN;
+ goto error;
+ }
+ goto search_again;
+ } else {
+ path->slots[0]--;
+ }
+ }
+out:
+ if (pending_del_nr) {
+ ret = btrfs_del_items(trans, root, path, pending_del_slot,
+ pending_del_nr);
+ if (ret)
+ btrfs_abort_transaction(trans, root, ret);
+ }
+error:
+ if (last_size != (u64)-1 &&
+ root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID)
+ btrfs_ordered_update_i_size(inode, last_size, NULL);
+
+ btrfs_free_path(path);
+
+ if (be_nice && bytes_deleted > 32 * 1024 * 1024) {
+ unsigned long updates = trans->delayed_ref_updates;
+ if (updates) {
+ trans->delayed_ref_updates = 0;
+ ret = btrfs_run_delayed_refs(trans, root, updates * 2);
+ if (ret && !err)
+ err = ret;
+ }
+ }
+ return err;
+}
+
+/*
+ * btrfs_truncate_page - read, zero a chunk and write a page
+ * @inode - inode that we're zeroing
+ * @from - the offset to start zeroing
+ * @len - the length to zero, 0 to zero the entire range respective to the
+ * offset
+ * @front - zero up to the offset instead of from the offset on
+ *
+ * This will find the page for the "from" offset and cow the page and zero the
+ * part we want to zero. This is used with truncate and hole punching.
+ */
+int btrfs_truncate_page(struct inode *inode, loff_t from, loff_t len,
+ int front)
+{
+ struct address_space *mapping = inode->i_mapping;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
+ struct btrfs_ordered_extent *ordered;
+ struct extent_state *cached_state = NULL;
+ char *kaddr;
+ u32 blocksize = root->sectorsize;
+ pgoff_t index = from >> PAGE_CACHE_SHIFT;
+ unsigned offset = from & (PAGE_CACHE_SIZE-1);
+ struct page *page;
+ gfp_t mask = btrfs_alloc_write_mask(mapping);
+ int ret = 0;
+ u64 page_start;
+ u64 page_end;
+
+ if ((offset & (blocksize - 1)) == 0 &&
+ (!len || ((len & (blocksize - 1)) == 0)))
+ goto out;
+ ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
+ if (ret)
+ goto out;
+
+again:
+ page = find_or_create_page(mapping, index, mask);
+ if (!page) {
+ btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ page_start = page_offset(page);
+ page_end = page_start + PAGE_CACHE_SIZE - 1;
+
+ if (!PageUptodate(page)) {
+ ret = btrfs_readpage(NULL, page);
+ lock_page(page);
+ if (page->mapping != mapping) {
+ unlock_page(page);
+ page_cache_release(page);
+ goto again;
+ }
+ if (!PageUptodate(page)) {
+ ret = -EIO;
+ goto out_unlock;
+ }
+ }
+ wait_on_page_writeback(page);
+
+ lock_extent_bits(io_tree, page_start, page_end, 0, &cached_state);
+ set_page_extent_mapped(page);
+
+ ordered = btrfs_lookup_ordered_extent(inode, page_start);
+ if (ordered) {
+ unlock_extent_cached(io_tree, page_start, page_end,
+ &cached_state, GFP_NOFS);
+ unlock_page(page);
+ page_cache_release(page);
+ btrfs_start_ordered_extent(inode, ordered, 1);
+ btrfs_put_ordered_extent(ordered);
+ goto again;
+ }
+
+ clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
+ EXTENT_DIRTY | EXTENT_DELALLOC |
+ EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
+ 0, 0, &cached_state, GFP_NOFS);
+
+ ret = btrfs_set_extent_delalloc(inode, page_start, page_end,
+ &cached_state);
+ if (ret) {
+ unlock_extent_cached(io_tree, page_start, page_end,
+ &cached_state, GFP_NOFS);
+ goto out_unlock;
+ }
+
+ if (offset != PAGE_CACHE_SIZE) {
+ if (!len)
+ len = PAGE_CACHE_SIZE - offset;
+ kaddr = kmap(page);
+ if (front)
+ memset(kaddr, 0, offset);
+ else
+ memset(kaddr + offset, 0, len);
+ flush_dcache_page(page);
+ kunmap(page);
+ }
+ ClearPageChecked(page);
+ set_page_dirty(page);
+ unlock_extent_cached(io_tree, page_start, page_end, &cached_state,
+ GFP_NOFS);
+
+out_unlock:
+ if (ret)
+ btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
+ unlock_page(page);
+ page_cache_release(page);
+out:
+ return ret;
+}
+
+static int maybe_insert_hole(struct btrfs_root *root, struct inode *inode,
+ u64 offset, u64 len)
+{
+ struct btrfs_trans_handle *trans;
+ int ret;
+
+ /*
+ * Still need to make sure the inode looks like it's been updated so
+ * that any holes get logged if we fsync.
+ */
+ if (btrfs_fs_incompat(root->fs_info, NO_HOLES)) {
+ BTRFS_I(inode)->last_trans = root->fs_info->generation;
+ BTRFS_I(inode)->last_sub_trans = root->log_transid;
+ BTRFS_I(inode)->last_log_commit = root->last_log_commit;
+ return 0;
+ }
+
+ /*
+ * 1 - for the one we're dropping
+ * 1 - for the one we're adding
+ * 1 - for updating the inode.
+ */
+ trans = btrfs_start_transaction(root, 3);
+ if (IS_ERR(trans))
+ return PTR_ERR(trans);
+
+ ret = btrfs_drop_extents(trans, root, inode, offset, offset + len, 1);
+ if (ret) {
+ btrfs_abort_transaction(trans, root, ret);
+ btrfs_end_transaction(trans, root);
+ return ret;
+ }
+
+ ret = btrfs_insert_file_extent(trans, root, btrfs_ino(inode), offset,
+ 0, 0, len, 0, len, 0, 0, 0);
+ if (ret)
+ btrfs_abort_transaction(trans, root, ret);
+ else
+ btrfs_update_inode(trans, root, inode);
+ btrfs_end_transaction(trans, root);
+ return ret;
+}
+
+/*
+ * This function puts in dummy file extents for the area we're creating a hole
+ * for. So if we are truncating this file to a larger size we need to insert
+ * these file extents so that btrfs_get_extent will return a EXTENT_MAP_HOLE for
+ * the range between oldsize and size
+ */
+int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
+ struct extent_map *em = NULL;
+ struct extent_state *cached_state = NULL;
+ struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
+ u64 hole_start = ALIGN(oldsize, root->sectorsize);
+ u64 block_end = ALIGN(size, root->sectorsize);
+ u64 last_byte;
+ u64 cur_offset;
+ u64 hole_size;
+ int err = 0;
+
+ /*
+ * If our size started in the middle of a page we need to zero out the
+ * rest of the page before we expand the i_size, otherwise we could
+ * expose stale data.
+ */
+ err = btrfs_truncate_page(inode, oldsize, 0, 0);
+ if (err)
+ return err;
+
+ if (size <= hole_start)
+ return 0;
+
+ while (1) {
+ struct btrfs_ordered_extent *ordered;
+
+ lock_extent_bits(io_tree, hole_start, block_end - 1, 0,
+ &cached_state);
+ ordered = btrfs_lookup_ordered_range(inode, hole_start,
+ block_end - hole_start);
+ if (!ordered)
+ break;
+ unlock_extent_cached(io_tree, hole_start, block_end - 1,
+ &cached_state, GFP_NOFS);
+ btrfs_start_ordered_extent(inode, ordered, 1);
+ btrfs_put_ordered_extent(ordered);
+ }
+
+ cur_offset = hole_start;
+ while (1) {
+ em = btrfs_get_extent(inode, NULL, 0, cur_offset,
+ block_end - cur_offset, 0);
+ if (IS_ERR(em)) {
+ err = PTR_ERR(em);
+ em = NULL;
+ break;
+ }
+ last_byte = min(extent_map_end(em), block_end);
+ last_byte = ALIGN(last_byte , root->sectorsize);
+ if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
+ struct extent_map *hole_em;
+ hole_size = last_byte - cur_offset;
+
+ err = maybe_insert_hole(root, inode, cur_offset,
+ hole_size);
+ if (err)
+ break;
+ btrfs_drop_extent_cache(inode, cur_offset,
+ cur_offset + hole_size - 1, 0);
+ hole_em = alloc_extent_map();
+ if (!hole_em) {
+ set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
+ &BTRFS_I(inode)->runtime_flags);
+ goto next;
+ }
+ hole_em->start = cur_offset;
+ hole_em->len = hole_size;
+ hole_em->orig_start = cur_offset;
+
+ hole_em->block_start = EXTENT_MAP_HOLE;
+ hole_em->block_len = 0;
+ hole_em->orig_block_len = 0;
+ hole_em->ram_bytes = hole_size;
+ hole_em->bdev = root->fs_info->fs_devices->latest_bdev;
+ hole_em->compress_type = BTRFS_COMPRESS_NONE;
+ hole_em->generation = root->fs_info->generation;
+
+ while (1) {
+ write_lock(&em_tree->lock);
+ err = add_extent_mapping(em_tree, hole_em, 1);
+ write_unlock(&em_tree->lock);
+ if (err != -EEXIST)
+ break;
+ btrfs_drop_extent_cache(inode, cur_offset,
+ cur_offset +
+ hole_size - 1, 0);
+ }
+ free_extent_map(hole_em);
+ }
+next:
+ free_extent_map(em);
+ em = NULL;
+ cur_offset = last_byte;
+ if (cur_offset >= block_end)
+ break;
+ }
+ free_extent_map(em);
+ unlock_extent_cached(io_tree, hole_start, block_end - 1, &cached_state,
+ GFP_NOFS);
+ return err;
+}
+
+static int wait_snapshoting_atomic_t(atomic_t *a)
+{
+ schedule();
+ return 0;
+}
+
+static void wait_for_snapshot_creation(struct btrfs_root *root)
+{
+ while (true) {
+ int ret;
+
+ ret = btrfs_start_write_no_snapshoting(root);
+ if (ret)
+ break;
+ wait_on_atomic_t(&root->will_be_snapshoted,
+ wait_snapshoting_atomic_t,
+ TASK_UNINTERRUPTIBLE);
+ }
+}
+
+static int btrfs_setsize(struct inode *inode, struct iattr *attr)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_trans_handle *trans;
+ loff_t oldsize = i_size_read(inode);
+ loff_t newsize = attr->ia_size;
+ int mask = attr->ia_valid;
+ int ret;
+
+ /*
+ * The regular truncate() case without ATTR_CTIME and ATTR_MTIME is a
+ * special case where we need to update the times despite not having
+ * these flags set. For all other operations the VFS set these flags
+ * explicitly if it wants a timestamp update.
+ */
+ if (newsize != oldsize) {
+ inode_inc_iversion(inode);
+ if (!(mask & (ATTR_CTIME | ATTR_MTIME)))
+ inode->i_ctime = inode->i_mtime =
+ current_fs_time(inode->i_sb);
+ }
+
+ if (newsize > oldsize) {
+ truncate_pagecache(inode, newsize);
+ /*
+ * Don't do an expanding truncate while snapshoting is ongoing.
+ * This is to ensure the snapshot captures a fully consistent
+ * state of this file - if the snapshot captures this expanding
+ * truncation, it must capture all writes that happened before
+ * this truncation.
+ */
+ wait_for_snapshot_creation(root);
+ ret = btrfs_cont_expand(inode, oldsize, newsize);
+ if (ret) {
+ btrfs_end_write_no_snapshoting(root);
+ return ret;
+ }
+
+ trans = btrfs_start_transaction(root, 1);
+ if (IS_ERR(trans)) {
+ btrfs_end_write_no_snapshoting(root);
+ return PTR_ERR(trans);
+ }
+
+ i_size_write(inode, newsize);
+ btrfs_ordered_update_i_size(inode, i_size_read(inode), NULL);
+ ret = btrfs_update_inode(trans, root, inode);
+ btrfs_end_write_no_snapshoting(root);
+ btrfs_end_transaction(trans, root);
+ } else {
+
+ /*
+ * We're truncating a file that used to have good data down to
+ * zero. Make sure it gets into the ordered flush list so that
+ * any new writes get down to disk quickly.
+ */
+ if (newsize == 0)
+ set_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
+ &BTRFS_I(inode)->runtime_flags);
+
+ /*
+ * 1 for the orphan item we're going to add
+ * 1 for the orphan item deletion.
+ */
+ trans = btrfs_start_transaction(root, 2);
+ if (IS_ERR(trans))
+ return PTR_ERR(trans);
+
+ /*
+ * We need to do this in case we fail at _any_ point during the
+ * actual truncate. Once we do the truncate_setsize we could
+ * invalidate pages which forces any outstanding ordered io to
+ * be instantly completed which will give us extents that need
+ * to be truncated. If we fail to get an orphan inode down we
+ * could have left over extents that were never meant to live,
+ * so we need to garuntee from this point on that everything
+ * will be consistent.
+ */
+ ret = btrfs_orphan_add(trans, inode);
+ btrfs_end_transaction(trans, root);
+ if (ret)
+ return ret;
+
+ /* we don't support swapfiles, so vmtruncate shouldn't fail */
+ truncate_setsize(inode, newsize);
+
+ /* Disable nonlocked read DIO to avoid the end less truncate */
+ btrfs_inode_block_unlocked_dio(inode);
+ inode_dio_wait(inode);
+ btrfs_inode_resume_unlocked_dio(inode);
+
+ ret = btrfs_truncate(inode);
+ if (ret && inode->i_nlink) {
+ int err;
+
+ /*
+ * failed to truncate, disk_i_size is only adjusted down
+ * as we remove extents, so it should represent the true
+ * size of the inode, so reset the in memory size and
+ * delete our orphan entry.
+ */
+ trans = btrfs_join_transaction(root);
+ if (IS_ERR(trans)) {
+ btrfs_orphan_del(NULL, inode);
+ return ret;
+ }
+ i_size_write(inode, BTRFS_I(inode)->disk_i_size);
+ err = btrfs_orphan_del(trans, inode);
+ if (err)
+ btrfs_abort_transaction(trans, root, err);
+ btrfs_end_transaction(trans, root);
+ }
+ }
+
+ return ret;
+}
+
+static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
+{
+ struct inode *inode = d_inode(dentry);
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ int err;
+
+ if (btrfs_root_readonly(root))
+ return -EROFS;
+
+ err = inode_change_ok(inode, attr);
+ if (err)
+ return err;
+
+ if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) {
+ err = btrfs_setsize(inode, attr);
+ if (err)
+ return err;
+ }
+
+ if (attr->ia_valid) {
+ setattr_copy(inode, attr);
+ inode_inc_iversion(inode);
+ err = btrfs_dirty_inode(inode);
+
+ if (!err && attr->ia_valid & ATTR_MODE)
+ err = posix_acl_chmod(inode, inode->i_mode);
+ }
+
+ return err;
+}
+
+/*
+ * While truncating the inode pages during eviction, we get the VFS calling
+ * btrfs_invalidatepage() against each page of the inode. This is slow because
+ * the calls to btrfs_invalidatepage() result in a huge amount of calls to
+ * lock_extent_bits() and clear_extent_bit(), which keep merging and splitting
+ * extent_state structures over and over, wasting lots of time.
+ *
+ * Therefore if the inode is being evicted, let btrfs_invalidatepage() skip all
+ * those expensive operations on a per page basis and do only the ordered io
+ * finishing, while we release here the extent_map and extent_state structures,
+ * without the excessive merging and splitting.
+ */
+static void evict_inode_truncate_pages(struct inode *inode)
+{
+ struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
+ struct extent_map_tree *map_tree = &BTRFS_I(inode)->extent_tree;
+ struct rb_node *node;
+
+ ASSERT(inode->i_state & I_FREEING);
+ truncate_inode_pages_final(&inode->i_data);
+
+ write_lock(&map_tree->lock);
+ while (!RB_EMPTY_ROOT(&map_tree->map)) {
+ struct extent_map *em;
+
+ node = rb_first(&map_tree->map);
+ em = rb_entry(node, struct extent_map, rb_node);
+ clear_bit(EXTENT_FLAG_PINNED, &em->flags);
+ clear_bit(EXTENT_FLAG_LOGGING, &em->flags);
+ remove_extent_mapping(map_tree, em);
+ free_extent_map(em);
+ if (need_resched()) {
+ write_unlock(&map_tree->lock);
+ cond_resched();
+ write_lock(&map_tree->lock);
+ }
+ }
+ write_unlock(&map_tree->lock);
+
+ spin_lock(&io_tree->lock);
+ while (!RB_EMPTY_ROOT(&io_tree->state)) {
+ struct extent_state *state;
+ struct extent_state *cached_state = NULL;
+
+ node = rb_first(&io_tree->state);
+ state = rb_entry(node, struct extent_state, rb_node);
+ atomic_inc(&state->refs);
+ spin_unlock(&io_tree->lock);
+
+ lock_extent_bits(io_tree, state->start, state->end,
+ 0, &cached_state);
+ clear_extent_bit(io_tree, state->start, state->end,
+ EXTENT_LOCKED | EXTENT_DIRTY |
+ EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
+ EXTENT_DEFRAG, 1, 1,
+ &cached_state, GFP_NOFS);
+ free_extent_state(state);
+
+ cond_resched();
+ spin_lock(&io_tree->lock);
+ }
+ spin_unlock(&io_tree->lock);
+}
+
+void btrfs_evict_inode(struct inode *inode)
+{
+ struct btrfs_trans_handle *trans;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_block_rsv *rsv, *global_rsv;
+ int steal_from_global = 0;
+ u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
+ int ret;
+
+ trace_btrfs_inode_evict(inode);
+
+ evict_inode_truncate_pages(inode);
+
+ if (inode->i_nlink &&
+ ((btrfs_root_refs(&root->root_item) != 0 &&
+ root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID) ||
+ btrfs_is_free_space_inode(inode)))
+ goto no_delete;
+
+ if (is_bad_inode(inode)) {
+ btrfs_orphan_del(NULL, inode);
+ goto no_delete;
+ }
+ /* do we really want it for ->i_nlink > 0 and zero btrfs_root_refs? */
+ btrfs_wait_ordered_range(inode, 0, (u64)-1);
+
+ btrfs_free_io_failure_record(inode, 0, (u64)-1);
+
+ if (root->fs_info->log_root_recovering) {
+ BUG_ON(test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
+ &BTRFS_I(inode)->runtime_flags));
+ goto no_delete;
+ }
+
+ if (inode->i_nlink > 0) {
+ BUG_ON(btrfs_root_refs(&root->root_item) != 0 &&
+ root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID);
+ goto no_delete;
+ }
+
+ ret = btrfs_commit_inode_delayed_inode(inode);
+ if (ret) {
+ btrfs_orphan_del(NULL, inode);
+ goto no_delete;
+ }
+
+ rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
+ if (!rsv) {
+ btrfs_orphan_del(NULL, inode);
+ goto no_delete;
+ }
+ rsv->size = min_size;
+ rsv->failfast = 1;
+ global_rsv = &root->fs_info->global_block_rsv;
+
+ btrfs_i_size_write(inode, 0);
+
+ /*
+ * This is a bit simpler than btrfs_truncate since we've already
+ * reserved our space for our orphan item in the unlink, so we just
+ * need to reserve some slack space in case we add bytes and update
+ * inode item when doing the truncate.
+ */
+ while (1) {
+ ret = btrfs_block_rsv_refill(root, rsv, min_size,
+ BTRFS_RESERVE_FLUSH_LIMIT);
+
+ /*
+ * Try and steal from the global reserve since we will
+ * likely not use this space anyway, we want to try as
+ * hard as possible to get this to work.
+ */
+ if (ret)
+ steal_from_global++;
+ else
+ steal_from_global = 0;
+ ret = 0;
+
+ /*
+ * steal_from_global == 0: we reserved stuff, hooray!
+ * steal_from_global == 1: we didn't reserve stuff, boo!
+ * steal_from_global == 2: we've committed, still not a lot of
+ * room but maybe we'll have room in the global reserve this
+ * time.
+ * steal_from_global == 3: abandon all hope!
+ */
+ if (steal_from_global > 2) {
+ btrfs_warn(root->fs_info,
+ "Could not get space for a delete, will truncate on mount %d",
+ ret);
+ btrfs_orphan_del(NULL, inode);
+ btrfs_free_block_rsv(root, rsv);
+ goto no_delete;
+ }
+
+ trans = btrfs_join_transaction(root);
+ if (IS_ERR(trans)) {
+ btrfs_orphan_del(NULL, inode);
+ btrfs_free_block_rsv(root, rsv);
+ goto no_delete;
+ }
+
+ /*
+ * We can't just steal from the global reserve, we need tomake
+ * sure there is room to do it, if not we need to commit and try
+ * again.
+ */
+ if (steal_from_global) {
+ if (!btrfs_check_space_for_delayed_refs(trans, root))
+ ret = btrfs_block_rsv_migrate(global_rsv, rsv,
+ min_size);
+ else
+ ret = -ENOSPC;
+ }
+
+ /*
+ * Couldn't steal from the global reserve, we have too much
+ * pending stuff built up, commit the transaction and try it
+ * again.
+ */
+ if (ret) {
+ ret = btrfs_commit_transaction(trans, root);
+ if (ret) {
+ btrfs_orphan_del(NULL, inode);
+ btrfs_free_block_rsv(root, rsv);
+ goto no_delete;
+ }
+ continue;
+ } else {
+ steal_from_global = 0;
+ }
+
+ trans->block_rsv = rsv;
+
+ ret = btrfs_truncate_inode_items(trans, root, inode, 0, 0);
+ if (ret != -ENOSPC && ret != -EAGAIN)
+ break;
+
+ trans->block_rsv = &root->fs_info->trans_block_rsv;
+ btrfs_end_transaction(trans, root);
+ trans = NULL;
+ btrfs_btree_balance_dirty(root);
+ }
+
+ btrfs_free_block_rsv(root, rsv);
+
+ /*
+ * Errors here aren't a big deal, it just means we leave orphan items
+ * in the tree. They will be cleaned up on the next mount.
+ */
+ if (ret == 0) {
+ trans->block_rsv = root->orphan_block_rsv;
+ btrfs_orphan_del(trans, inode);
+ } else {
+ btrfs_orphan_del(NULL, inode);
+ }
+
+ trans->block_rsv = &root->fs_info->trans_block_rsv;
+ if (!(root == root->fs_info->tree_root ||
+ root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID))
+ btrfs_return_ino(root, btrfs_ino(inode));
+
+ btrfs_end_transaction(trans, root);
+ btrfs_btree_balance_dirty(root);
+no_delete:
+ btrfs_remove_delayed_node(inode);
+ clear_inode(inode);
+ return;
+}
+
+/*
+ * this returns the key found in the dir entry in the location pointer.
+ * If no dir entries were found, location->objectid is 0.
+ */
+static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
+ struct btrfs_key *location)
+{
+ const char *name = dentry->d_name.name;
+ int namelen = dentry->d_name.len;
+ struct btrfs_dir_item *di;
+ struct btrfs_path *path;
+ struct btrfs_root *root = BTRFS_I(dir)->root;
+ int ret = 0;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ di = btrfs_lookup_dir_item(NULL, root, path, btrfs_ino(dir), name,
+ namelen, 0);
+ if (IS_ERR(di))
+ ret = PTR_ERR(di);
+
+ if (IS_ERR_OR_NULL(di))
+ goto out_err;
+
+ btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
+out:
+ btrfs_free_path(path);
+ return ret;
+out_err:
+ location->objectid = 0;
+ goto out;
+}
+
+/*
+ * when we hit a tree root in a directory, the btrfs part of the inode
+ * needs to be changed to reflect the root directory of the tree root. This
+ * is kind of like crossing a mount point.
+ */
+static int fixup_tree_root_location(struct btrfs_root *root,
+ struct inode *dir,
+ struct dentry *dentry,
+ struct btrfs_key *location,
+ struct btrfs_root **sub_root)
+{
+ struct btrfs_path *path;
+ struct btrfs_root *new_root;
+ struct btrfs_root_ref *ref;
+ struct extent_buffer *leaf;
+ struct btrfs_key key;
+ int ret;
+ int err = 0;
+
+ path = btrfs_alloc_path();
+ if (!path) {
+ err = -ENOMEM;
+ goto out;
+ }
+
+ err = -ENOENT;
+ key.objectid = BTRFS_I(dir)->root->root_key.objectid;
+ key.type = BTRFS_ROOT_REF_KEY;
+ key.offset = location->objectid;
+
+ ret = btrfs_search_slot(NULL, root->fs_info->tree_root, &key, path,
+ 0, 0);
+ if (ret) {
+ if (ret < 0)
+ err = ret;
+ goto out;
+ }
+
+ leaf = path->nodes[0];
+ ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
+ if (btrfs_root_ref_dirid(leaf, ref) != btrfs_ino(dir) ||
+ btrfs_root_ref_name_len(leaf, ref) != dentry->d_name.len)
+ goto out;
+
+ ret = memcmp_extent_buffer(leaf, dentry->d_name.name,
+ (unsigned long)(ref + 1),
+ dentry->d_name.len);
+ if (ret)
+ goto out;
+
+ btrfs_release_path(path);
+
+ new_root = btrfs_read_fs_root_no_name(root->fs_info, location);
+ if (IS_ERR(new_root)) {
+ err = PTR_ERR(new_root);
+ goto out;
+ }
+
+ *sub_root = new_root;
+ location->objectid = btrfs_root_dirid(&new_root->root_item);
+ location->type = BTRFS_INODE_ITEM_KEY;
+ location->offset = 0;
+ err = 0;
+out:
+ btrfs_free_path(path);
+ return err;
+}
+
+static void inode_tree_add(struct inode *inode)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_inode *entry;
+ struct rb_node **p;
+ struct rb_node *parent;
+ struct rb_node *new = &BTRFS_I(inode)->rb_node;
+ u64 ino = btrfs_ino(inode);
+
+ if (inode_unhashed(inode))
+ return;
+ parent = NULL;
+ spin_lock(&root->inode_lock);
+ p = &root->inode_tree.rb_node;
+ while (*p) {
+ parent = *p;
+ entry = rb_entry(parent, struct btrfs_inode, rb_node);
+
+ if (ino < btrfs_ino(&entry->vfs_inode))
+ p = &parent->rb_left;
+ else if (ino > btrfs_ino(&entry->vfs_inode))
+ p = &parent->rb_right;
+ else {
+ WARN_ON(!(entry->vfs_inode.i_state &
+ (I_WILL_FREE | I_FREEING)));
+ rb_replace_node(parent, new, &root->inode_tree);
+ RB_CLEAR_NODE(parent);
+ spin_unlock(&root->inode_lock);
+ return;
+ }
+ }
+ rb_link_node(new, parent, p);
+ rb_insert_color(new, &root->inode_tree);
+ spin_unlock(&root->inode_lock);
+}
+
+static void inode_tree_del(struct inode *inode)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ int empty = 0;
+
+ spin_lock(&root->inode_lock);
+ if (!RB_EMPTY_NODE(&BTRFS_I(inode)->rb_node)) {
+ rb_erase(&BTRFS_I(inode)->rb_node, &root->inode_tree);
+ RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node);
+ empty = RB_EMPTY_ROOT(&root->inode_tree);
+ }
+ spin_unlock(&root->inode_lock);
+
+ if (empty && btrfs_root_refs(&root->root_item) == 0) {
+ synchronize_srcu(&root->fs_info->subvol_srcu);
+ spin_lock(&root->inode_lock);
+ empty = RB_EMPTY_ROOT(&root->inode_tree);
+ spin_unlock(&root->inode_lock);
+ if (empty)
+ btrfs_add_dead_root(root);
+ }
+}
+
+void btrfs_invalidate_inodes(struct btrfs_root *root)
+{
+ struct rb_node *node;
+ struct rb_node *prev;
+ struct btrfs_inode *entry;
+ struct inode *inode;
+ u64 objectid = 0;
+
+ if (!test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state))
+ WARN_ON(btrfs_root_refs(&root->root_item) != 0);
+
+ spin_lock(&root->inode_lock);
+again:
+ node = root->inode_tree.rb_node;
+ prev = NULL;
+ while (node) {
+ prev = node;
+ entry = rb_entry(node, struct btrfs_inode, rb_node);
+
+ if (objectid < btrfs_ino(&entry->vfs_inode))
+ node = node->rb_left;
+ else if (objectid > btrfs_ino(&entry->vfs_inode))
+ node = node->rb_right;
+ else
+ break;
+ }
+ if (!node) {
+ while (prev) {
+ entry = rb_entry(prev, struct btrfs_inode, rb_node);
+ if (objectid <= btrfs_ino(&entry->vfs_inode)) {
+ node = prev;
+ break;
+ }
+ prev = rb_next(prev);
+ }
+ }
+ while (node) {
+ entry = rb_entry(node, struct btrfs_inode, rb_node);
+ objectid = btrfs_ino(&entry->vfs_inode) + 1;
+ inode = igrab(&entry->vfs_inode);
+ if (inode) {
+ spin_unlock(&root->inode_lock);
+ if (atomic_read(&inode->i_count) > 1)
+ d_prune_aliases(inode);
+ /*
+ * btrfs_drop_inode will have it removed from
+ * the inode cache when its usage count
+ * hits zero.
+ */
+ iput(inode);
+ cond_resched();
+ spin_lock(&root->inode_lock);
+ goto again;
+ }
+
+ if (cond_resched_lock(&root->inode_lock))
+ goto again;
+
+ node = rb_next(node);
+ }
+ spin_unlock(&root->inode_lock);
+}
+
+static int btrfs_init_locked_inode(struct inode *inode, void *p)
+{
+ struct btrfs_iget_args *args = p;
+ inode->i_ino = args->location->objectid;
+ memcpy(&BTRFS_I(inode)->location, args->location,
+ sizeof(*args->location));
+ BTRFS_I(inode)->root = args->root;
+ return 0;
+}
+
+static int btrfs_find_actor(struct inode *inode, void *opaque)
+{
+ struct btrfs_iget_args *args = opaque;
+ return args->location->objectid == BTRFS_I(inode)->location.objectid &&
+ args->root == BTRFS_I(inode)->root;
+}
+
+static struct inode *btrfs_iget_locked(struct super_block *s,
+ struct btrfs_key *location,
+ struct btrfs_root *root)
+{
+ struct inode *inode;
+ struct btrfs_iget_args args;
+ unsigned long hashval = btrfs_inode_hash(location->objectid, root);
+
+ args.location = location;
+ args.root = root;
+
+ inode = iget5_locked(s, hashval, btrfs_find_actor,
+ btrfs_init_locked_inode,
+ (void *)&args);
+ return inode;
+}
+
+/* Get an inode object given its location and corresponding root.
+ * Returns in *is_new if the inode was read from disk
+ */
+struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location,
+ struct btrfs_root *root, int *new)
+{
+ struct inode *inode;
+
+ inode = btrfs_iget_locked(s, location, root);
+ if (!inode)
+ return ERR_PTR(-ENOMEM);
+
+ if (inode->i_state & I_NEW) {
+ btrfs_read_locked_inode(inode);
+ if (!is_bad_inode(inode)) {
+ inode_tree_add(inode);
+ unlock_new_inode(inode);
+ if (new)
+ *new = 1;
+ } else {
+ unlock_new_inode(inode);
+ iput(inode);
+ inode = ERR_PTR(-ESTALE);
+ }
+ }
+
+ return inode;
+}
+
+static struct inode *new_simple_dir(struct super_block *s,
+ struct btrfs_key *key,
+ struct btrfs_root *root)
+{
+ struct inode *inode = new_inode(s);
+
+ if (!inode)
+ return ERR_PTR(-ENOMEM);
+
+ BTRFS_I(inode)->root = root;
+ memcpy(&BTRFS_I(inode)->location, key, sizeof(*key));
+ set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags);
+
+ inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID;
+ inode->i_op = &btrfs_dir_ro_inode_operations;
+ inode->i_fop = &simple_dir_operations;
+ inode->i_mode = S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO;
+ inode->i_mtime = CURRENT_TIME;
+ inode->i_atime = inode->i_mtime;
+ inode->i_ctime = inode->i_mtime;
+ BTRFS_I(inode)->i_otime = inode->i_mtime;
+
+ return inode;
+}
+
+struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
+{
+ struct inode *inode;
+ struct btrfs_root *root = BTRFS_I(dir)->root;
+ struct btrfs_root *sub_root = root;
+ struct btrfs_key location;
+ int index;
+ int ret = 0;
+
+ if (dentry->d_name.len > BTRFS_NAME_LEN)
+ return ERR_PTR(-ENAMETOOLONG);
+
+ ret = btrfs_inode_by_name(dir, dentry, &location);
+ if (ret < 0)
+ return ERR_PTR(ret);
+
+ if (location.objectid == 0)
+ return ERR_PTR(-ENOENT);
+
+ if (location.type == BTRFS_INODE_ITEM_KEY) {
+ inode = btrfs_iget(dir->i_sb, &location, root, NULL);
+ return inode;
+ }
+
+ BUG_ON(location.type != BTRFS_ROOT_ITEM_KEY);
+
+ index = srcu_read_lock(&root->fs_info->subvol_srcu);
+ ret = fixup_tree_root_location(root, dir, dentry,
+ &location, &sub_root);
+ if (ret < 0) {
+ if (ret != -ENOENT)
+ inode = ERR_PTR(ret);
+ else
+ inode = new_simple_dir(dir->i_sb, &location, sub_root);
+ } else {
+ inode = btrfs_iget(dir->i_sb, &location, sub_root, NULL);
+ }
+ srcu_read_unlock(&root->fs_info->subvol_srcu, index);
+
+ if (!IS_ERR(inode) && root != sub_root) {
+ down_read(&root->fs_info->cleanup_work_sem);
+ if (!(inode->i_sb->s_flags & MS_RDONLY))
+ ret = btrfs_orphan_cleanup(sub_root);
+ up_read(&root->fs_info->cleanup_work_sem);
+ if (ret) {
+ iput(inode);
+ inode = ERR_PTR(ret);
+ }
+ }
+
+ return inode;
+}
+
+static int btrfs_dentry_delete(const struct dentry *dentry)
+{
+ struct btrfs_root *root;
+ struct inode *inode = d_inode(dentry);
+
+ if (!inode && !IS_ROOT(dentry))
+ inode = d_inode(dentry->d_parent);
+
+ if (inode) {
+ root = BTRFS_I(inode)->root;
+ if (btrfs_root_refs(&root->root_item) == 0)
+ return 1;
+
+ if (btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
+ return 1;
+ }
+ return 0;
+}
+
+static void btrfs_dentry_release(struct dentry *dentry)
+{
+ kfree(dentry->d_fsdata);
+}
+
+static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
+ unsigned int flags)
+{
+ struct inode *inode;
+
+ inode = btrfs_lookup_dentry(dir, dentry);
+ if (IS_ERR(inode)) {
+ if (PTR_ERR(inode) == -ENOENT)
+ inode = NULL;
+ else
+ return ERR_CAST(inode);
+ }
+
+ return d_splice_alias(inode, dentry);
+}
+
+unsigned char btrfs_filetype_table[] = {
+ DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
+};
+
+static int btrfs_real_readdir(struct file *file, struct dir_context *ctx)
+{
+ struct inode *inode = file_inode(file);
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_item *item;
+ struct btrfs_dir_item *di;
+ struct btrfs_key key;
+ struct btrfs_key found_key;
+ struct btrfs_path *path;
+ struct list_head ins_list;
+ struct list_head del_list;
+ int ret;
+ struct extent_buffer *leaf;
+ int slot;
+ unsigned char d_type;
+ int over = 0;
+ u32 di_cur;
+ u32 di_total;
+ u32 di_len;
+ int key_type = BTRFS_DIR_INDEX_KEY;
+ char tmp_name[32];
+ char *name_ptr;
+ int name_len;
+ int is_curr = 0; /* ctx->pos points to the current index? */
+
+ /* FIXME, use a real flag for deciding about the key type */
+ if (root->fs_info->tree_root == root)
+ key_type = BTRFS_DIR_ITEM_KEY;
+
+ if (!dir_emit_dots(file, ctx))
+ return 0;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ path->reada = 1;
+
+ if (key_type == BTRFS_DIR_INDEX_KEY) {
+ INIT_LIST_HEAD(&ins_list);
+ INIT_LIST_HEAD(&del_list);
+ btrfs_get_delayed_items(inode, &ins_list, &del_list);
+ }
+
+ key.type = key_type;
+ key.offset = ctx->pos;
+ key.objectid = btrfs_ino(inode);
+
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret < 0)
+ goto err;
+
+ while (1) {
+ leaf = path->nodes[0];
+ slot = path->slots[0];
+ if (slot >= btrfs_header_nritems(leaf)) {
+ ret = btrfs_next_leaf(root, path);
+ if (ret < 0)
+ goto err;
+ else if (ret > 0)
+ break;
+ continue;
+ }
+
+ item = btrfs_item_nr(slot);
+ btrfs_item_key_to_cpu(leaf, &found_key, slot);
+
+ if (found_key.objectid != key.objectid)
+ break;
+ if (found_key.type != key_type)
+ break;
+ if (found_key.offset < ctx->pos)
+ goto next;
+ if (key_type == BTRFS_DIR_INDEX_KEY &&
+ btrfs_should_delete_dir_index(&del_list,
+ found_key.offset))
+ goto next;
+
+ ctx->pos = found_key.offset;
+ is_curr = 1;
+
+ di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
+ di_cur = 0;
+ di_total = btrfs_item_size(leaf, item);
+
+ while (di_cur < di_total) {
+ struct btrfs_key location;
+
+ if (verify_dir_item(root, leaf, di))
+ break;
+
+ name_len = btrfs_dir_name_len(leaf, di);
+ if (name_len <= sizeof(tmp_name)) {
+ name_ptr = tmp_name;
+ } else {
+ name_ptr = kmalloc(name_len, GFP_NOFS);
+ if (!name_ptr) {
+ ret = -ENOMEM;
+ goto err;
+ }
+ }
+ read_extent_buffer(leaf, name_ptr,
+ (unsigned long)(di + 1), name_len);
+
+ d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
+ btrfs_dir_item_key_to_cpu(leaf, di, &location);
+
+
+ /* is this a reference to our own snapshot? If so
+ * skip it.
+ *
+ * In contrast to old kernels, we insert the snapshot's
+ * dir item and dir index after it has been created, so
+ * we won't find a reference to our own snapshot. We
+ * still keep the following code for backward
+ * compatibility.
+ */
+ if (location.type == BTRFS_ROOT_ITEM_KEY &&
+ location.objectid == root->root_key.objectid) {
+ over = 0;
+ goto skip;
+ }
+ over = !dir_emit(ctx, name_ptr, name_len,
+ location.objectid, d_type);
+
+skip:
+ if (name_ptr != tmp_name)
+ kfree(name_ptr);
+
+ if (over)
+ goto nopos;
+ di_len = btrfs_dir_name_len(leaf, di) +
+ btrfs_dir_data_len(leaf, di) + sizeof(*di);
+ di_cur += di_len;
+ di = (struct btrfs_dir_item *)((char *)di + di_len);
+ }
+next:
+ path->slots[0]++;
+ }
+
+ if (key_type == BTRFS_DIR_INDEX_KEY) {
+ if (is_curr)
+ ctx->pos++;
+ ret = btrfs_readdir_delayed_dir_index(ctx, &ins_list);
+ if (ret)
+ goto nopos;
+ }
+
+ /* Reached end of directory/root. Bump pos past the last item. */
+ ctx->pos++;
+
+ /*
+ * Stop new entries from being returned after we return the last
+ * entry.
+ *
+ * New directory entries are assigned a strictly increasing
+ * offset. This means that new entries created during readdir
+ * are *guaranteed* to be seen in the future by that readdir.
+ * This has broken buggy programs which operate on names as
+ * they're returned by readdir. Until we re-use freed offsets
+ * we have this hack to stop new entries from being returned
+ * under the assumption that they'll never reach this huge
+ * offset.
+ *
+ * This is being careful not to overflow 32bit loff_t unless the
+ * last entry requires it because doing so has broken 32bit apps
+ * in the past.
+ */
+ if (key_type == BTRFS_DIR_INDEX_KEY) {
+ if (ctx->pos >= INT_MAX)
+ ctx->pos = LLONG_MAX;
+ else
+ ctx->pos = INT_MAX;
+ }
+nopos:
+ ret = 0;
+err:
+ if (key_type == BTRFS_DIR_INDEX_KEY)
+ btrfs_put_delayed_items(&ins_list, &del_list);
+ btrfs_free_path(path);
+ return ret;
+}
+
+int btrfs_write_inode(struct inode *inode, struct writeback_control *wbc)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_trans_handle *trans;
+ int ret = 0;
+ bool nolock = false;
+
+ if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
+ return 0;
+
+ if (btrfs_fs_closing(root->fs_info) && btrfs_is_free_space_inode(inode))
+ nolock = true;
+
+ if (wbc->sync_mode == WB_SYNC_ALL) {
+ if (nolock)
+ trans = btrfs_join_transaction_nolock(root);
+ else
+ trans = btrfs_join_transaction(root);
+ if (IS_ERR(trans))
+ return PTR_ERR(trans);
+ ret = btrfs_commit_transaction(trans, root);
+ }
+ return ret;
+}
+
+/*
+ * This is somewhat expensive, updating the tree every time the
+ * inode changes. But, it is most likely to find the inode in cache.
+ * FIXME, needs more benchmarking...there are no reasons other than performance
+ * to keep or drop this code.
+ */
+static int btrfs_dirty_inode(struct inode *inode)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_trans_handle *trans;
+ int ret;
+
+ if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
+ return 0;
+
+ trans = btrfs_join_transaction(root);
+ if (IS_ERR(trans))
+ return PTR_ERR(trans);
+
+ ret = btrfs_update_inode(trans, root, inode);
+ if (ret && ret == -ENOSPC) {
+ /* whoops, lets try again with the full transaction */
+ btrfs_end_transaction(trans, root);
+ trans = btrfs_start_transaction(root, 1);
+ if (IS_ERR(trans))
+ return PTR_ERR(trans);
+
+ ret = btrfs_update_inode(trans, root, inode);
+ }
+ btrfs_end_transaction(trans, root);
+ if (BTRFS_I(inode)->delayed_node)
+ btrfs_balance_delayed_items(root);
+
+ return ret;
+}
+
+/*
+ * This is a copy of file_update_time. We need this so we can return error on
+ * ENOSPC for updating the inode in the case of file write and mmap writes.
+ */
+static int btrfs_update_time(struct inode *inode, struct timespec *now,
+ int flags)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+
+ if (btrfs_root_readonly(root))
+ return -EROFS;
+
+ if (flags & S_VERSION)
+ inode_inc_iversion(inode);
+ if (flags & S_CTIME)
+ inode->i_ctime = *now;
+ if (flags & S_MTIME)
+ inode->i_mtime = *now;
+ if (flags & S_ATIME)
+ inode->i_atime = *now;
+ return btrfs_dirty_inode(inode);
+}
+
+/*
+ * find the highest existing sequence number in a directory
+ * and then set the in-memory index_cnt variable to reflect
+ * free sequence numbers
+ */
+static int btrfs_set_inode_index_count(struct inode *inode)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_key key, found_key;
+ struct btrfs_path *path;
+ struct extent_buffer *leaf;
+ int ret;
+
+ key.objectid = btrfs_ino(inode);
+ key.type = BTRFS_DIR_INDEX_KEY;
+ key.offset = (u64)-1;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret < 0)
+ goto out;
+ /* FIXME: we should be able to handle this */
+ if (ret == 0)
+ goto out;
+ ret = 0;
+
+ /*
+ * MAGIC NUMBER EXPLANATION:
+ * since we search a directory based on f_pos we have to start at 2
+ * since '.' and '..' have f_pos of 0 and 1 respectively, so everybody
+ * else has to start at 2
+ */
+ if (path->slots[0] == 0) {
+ BTRFS_I(inode)->index_cnt = 2;
+ goto out;
+ }
+
+ path->slots[0]--;
+
+ leaf = path->nodes[0];
+ btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
+
+ if (found_key.objectid != btrfs_ino(inode) ||
+ found_key.type != BTRFS_DIR_INDEX_KEY) {
+ BTRFS_I(inode)->index_cnt = 2;
+ goto out;
+ }
+
+ BTRFS_I(inode)->index_cnt = found_key.offset + 1;
+out:
+ btrfs_free_path(path);
+ return ret;
+}
+
+/*
+ * helper to find a free sequence number in a given directory. This current
+ * code is very simple, later versions will do smarter things in the btree
+ */
+int btrfs_set_inode_index(struct inode *dir, u64 *index)
+{
+ int ret = 0;
+
+ if (BTRFS_I(dir)->index_cnt == (u64)-1) {
+ ret = btrfs_inode_delayed_dir_index_count(dir);
+ if (ret) {
+ ret = btrfs_set_inode_index_count(dir);
+ if (ret)
+ return ret;
+ }
+ }
+
+ *index = BTRFS_I(dir)->index_cnt;
+ BTRFS_I(dir)->index_cnt++;
+
+ return ret;
+}
+
+static int btrfs_insert_inode_locked(struct inode *inode)
+{
+ struct btrfs_iget_args args;
+ args.location = &BTRFS_I(inode)->location;
+ args.root = BTRFS_I(inode)->root;
+
+ return insert_inode_locked4(inode,
+ btrfs_inode_hash(inode->i_ino, BTRFS_I(inode)->root),
+ btrfs_find_actor, &args);
+}
+
+static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct inode *dir,
+ const char *name, int name_len,
+ u64 ref_objectid, u64 objectid,
+ umode_t mode, u64 *index)
+{
+ struct inode *inode;
+ struct btrfs_inode_item *inode_item;
+ struct btrfs_key *location;
+ struct btrfs_path *path;
+ struct btrfs_inode_ref *ref;
+ struct btrfs_key key[2];
+ u32 sizes[2];
+ int nitems = name ? 2 : 1;
+ unsigned long ptr;
+ int ret;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return ERR_PTR(-ENOMEM);
+
+ inode = new_inode(root->fs_info->sb);
+ if (!inode) {
+ btrfs_free_path(path);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ /*
+ * O_TMPFILE, set link count to 0, so that after this point,
+ * we fill in an inode item with the correct link count.
+ */
+ if (!name)
+ set_nlink(inode, 0);
+
+ /*
+ * we have to initialize this early, so we can reclaim the inode
+ * number if we fail afterwards in this function.
+ */
+ inode->i_ino = objectid;
+
+ if (dir && name) {
+ trace_btrfs_inode_request(dir);
+
+ ret = btrfs_set_inode_index(dir, index);
+ if (ret) {
+ btrfs_free_path(path);
+ iput(inode);
+ return ERR_PTR(ret);
+ }
+ } else if (dir) {
+ *index = 0;
+ }
+ /*
+ * index_cnt is ignored for everything but a dir,
+ * btrfs_get_inode_index_count has an explanation for the magic
+ * number
+ */
+ BTRFS_I(inode)->index_cnt = 2;
+ BTRFS_I(inode)->dir_index = *index;
+ BTRFS_I(inode)->root = root;
+ BTRFS_I(inode)->generation = trans->transid;
+ inode->i_generation = BTRFS_I(inode)->generation;
+
+ /*
+ * We could have gotten an inode number from somebody who was fsynced
+ * and then removed in this same transaction, so let's just set full
+ * sync since it will be a full sync anyway and this will blow away the
+ * old info in the log.
+ */
+ set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
+
+ key[0].objectid = objectid;
+ key[0].type = BTRFS_INODE_ITEM_KEY;
+ key[0].offset = 0;
+
+ sizes[0] = sizeof(struct btrfs_inode_item);
+
+ if (name) {
+ /*
+ * Start new inodes with an inode_ref. This is slightly more
+ * efficient for small numbers of hard links since they will
+ * be packed into one item. Extended refs will kick in if we
+ * add more hard links than can fit in the ref item.
+ */
+ key[1].objectid = objectid;
+ key[1].type = BTRFS_INODE_REF_KEY;
+ key[1].offset = ref_objectid;
+
+ sizes[1] = name_len + sizeof(*ref);
+ }
+
+ location = &BTRFS_I(inode)->location;
+ location->objectid = objectid;
+ location->offset = 0;
+ location->type = BTRFS_INODE_ITEM_KEY;
+
+ ret = btrfs_insert_inode_locked(inode);
+ if (ret < 0)
+ goto fail;
+
+ path->leave_spinning = 1;
+ ret = btrfs_insert_empty_items(trans, root, path, key, sizes, nitems);
+ if (ret != 0)
+ goto fail_unlock;
+
+ inode_init_owner(inode, dir, mode);
+ inode_set_bytes(inode, 0);
+
+ inode->i_mtime = CURRENT_TIME;
+ inode->i_atime = inode->i_mtime;
+ inode->i_ctime = inode->i_mtime;
+ BTRFS_I(inode)->i_otime = inode->i_mtime;
+
+ inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
+ struct btrfs_inode_item);
+ memset_extent_buffer(path->nodes[0], 0, (unsigned long)inode_item,
+ sizeof(*inode_item));
+ fill_inode_item(trans, path->nodes[0], inode_item, inode);
+
+ if (name) {
+ ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
+ struct btrfs_inode_ref);
+ btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
+ btrfs_set_inode_ref_index(path->nodes[0], ref, *index);
+ ptr = (unsigned long)(ref + 1);
+ write_extent_buffer(path->nodes[0], name, ptr, name_len);
+ }
+
+ btrfs_mark_buffer_dirty(path->nodes[0]);
+ btrfs_free_path(path);
+
+ btrfs_inherit_iflags(inode, dir);
+
+ if (S_ISREG(mode)) {
+ if (btrfs_test_opt(root, NODATASUM))
+ BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
+ if (btrfs_test_opt(root, NODATACOW))
+ BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW |
+ BTRFS_INODE_NODATASUM;
+ }
+
+ inode_tree_add(inode);
+
+ trace_btrfs_inode_new(inode);
+ btrfs_set_inode_last_trans(trans, inode);
+
+ btrfs_update_root_times(trans, root);
+
+ ret = btrfs_inode_inherit_props(trans, inode, dir);
+ if (ret)
+ btrfs_err(root->fs_info,
+ "error inheriting props for ino %llu (root %llu): %d",
+ btrfs_ino(inode), root->root_key.objectid, ret);
+
+ return inode;
+
+fail_unlock:
+ unlock_new_inode(inode);
+fail:
+ if (dir && name)
+ BTRFS_I(dir)->index_cnt--;
+ btrfs_free_path(path);
+ iput(inode);
+ return ERR_PTR(ret);
+}
+
+static inline u8 btrfs_inode_type(struct inode *inode)
+{
+ return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
+}
+
+/*
+ * utility function to add 'inode' into 'parent_inode' with
+ * a give name and a given sequence number.
+ * if 'add_backref' is true, also insert a backref from the
+ * inode to the parent directory.
+ */
+int btrfs_add_link(struct btrfs_trans_handle *trans,
+ struct inode *parent_inode, struct inode *inode,
+ const char *name, int name_len, int add_backref, u64 index)
+{
+ int ret = 0;
+ struct btrfs_key key;
+ struct btrfs_root *root = BTRFS_I(parent_inode)->root;
+ u64 ino = btrfs_ino(inode);
+ u64 parent_ino = btrfs_ino(parent_inode);
+
+ if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
+ memcpy(&key, &BTRFS_I(inode)->root->root_key, sizeof(key));
+ } else {
+ key.objectid = ino;
+ key.type = BTRFS_INODE_ITEM_KEY;
+ key.offset = 0;
+ }
+
+ if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
+ ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
+ key.objectid, root->root_key.objectid,
+ parent_ino, index, name, name_len);
+ } else if (add_backref) {
+ ret = btrfs_insert_inode_ref(trans, root, name, name_len, ino,
+ parent_ino, index);
+ }
+
+ /* Nothing to clean up yet */
+ if (ret)
+ return ret;
+
+ ret = btrfs_insert_dir_item(trans, root, name, name_len,
+ parent_inode, &key,
+ btrfs_inode_type(inode), index);
+ if (ret == -EEXIST || ret == -EOVERFLOW)
+ goto fail_dir_item;
+ else if (ret) {
+ btrfs_abort_transaction(trans, root, ret);
+ return ret;
+ }
+
+ btrfs_i_size_write(parent_inode, parent_inode->i_size +
+ name_len * 2);
+ inode_inc_iversion(parent_inode);
+ parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME;
+ ret = btrfs_update_inode(trans, root, parent_inode);
+ if (ret)
+ btrfs_abort_transaction(trans, root, ret);
+ return ret;
+
+fail_dir_item:
+ if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
+ u64 local_index;
+ int err;
+ err = btrfs_del_root_ref(trans, root->fs_info->tree_root,
+ key.objectid, root->root_key.objectid,
+ parent_ino, &local_index, name, name_len);
+
+ } else if (add_backref) {
+ u64 local_index;
+ int err;
+
+ err = btrfs_del_inode_ref(trans, root, name, name_len,
+ ino, parent_ino, &local_index);
+ }
+ return ret;
+}
+
+static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
+ struct inode *dir, struct dentry *dentry,
+ struct inode *inode, int backref, u64 index)
+{
+ int err = btrfs_add_link(trans, dir, inode,
+ dentry->d_name.name, dentry->d_name.len,
+ backref, index);
+ if (err > 0)
+ err = -EEXIST;
+ return err;
+}
+
+static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
+ umode_t mode, dev_t rdev)
+{
+ struct btrfs_trans_handle *trans;
+ struct btrfs_root *root = BTRFS_I(dir)->root;
+ struct inode *inode = NULL;
+ int err;
+ int drop_inode = 0;
+ u64 objectid;
+ u64 index = 0;
+
+ if (!new_valid_dev(rdev))
+ return -EINVAL;
+
+ /*
+ * 2 for inode item and ref
+ * 2 for dir items
+ * 1 for xattr if selinux is on
+ */
+ trans = btrfs_start_transaction(root, 5);
+ if (IS_ERR(trans))
+ return PTR_ERR(trans);
+
+ err = btrfs_find_free_ino(root, &objectid);
+ if (err)
+ goto out_unlock;
+
+ inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
+ dentry->d_name.len, btrfs_ino(dir), objectid,
+ mode, &index);
+ if (IS_ERR(inode)) {
+ err = PTR_ERR(inode);
+ goto out_unlock;
+ }
+
+ /*
+ * If the active LSM wants to access the inode during
+ * d_instantiate it needs these. Smack checks to see
+ * if the filesystem supports xattrs by looking at the
+ * ops vector.
+ */
+ inode->i_op = &btrfs_special_inode_operations;
+ init_special_inode(inode, inode->i_mode, rdev);
+
+ err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
+ if (err)
+ goto out_unlock_inode;
+
+ err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
+ if (err) {
+ goto out_unlock_inode;
+ } else {
+ btrfs_update_inode(trans, root, inode);
+ unlock_new_inode(inode);
+ d_instantiate(dentry, inode);
+ }
+
+out_unlock:
+ btrfs_end_transaction(trans, root);
+ btrfs_balance_delayed_items(root);
+ btrfs_btree_balance_dirty(root);
+ if (drop_inode) {
+ inode_dec_link_count(inode);
+ iput(inode);
+ }
+ return err;
+
+out_unlock_inode:
+ drop_inode = 1;
+ unlock_new_inode(inode);
+ goto out_unlock;
+
+}
+
+static int btrfs_create(struct inode *dir, struct dentry *dentry,
+ umode_t mode, bool excl)
+{
+ struct btrfs_trans_handle *trans;
+ struct btrfs_root *root = BTRFS_I(dir)->root;
+ struct inode *inode = NULL;
+ int drop_inode_on_err = 0;
+ int err;
+ u64 objectid;
+ u64 index = 0;
+
+ /*
+ * 2 for inode item and ref
+ * 2 for dir items
+ * 1 for xattr if selinux is on
+ */
+ trans = btrfs_start_transaction(root, 5);
+ if (IS_ERR(trans))
+ return PTR_ERR(trans);
+
+ err = btrfs_find_free_ino(root, &objectid);
+ if (err)
+ goto out_unlock;
+
+ inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
+ dentry->d_name.len, btrfs_ino(dir), objectid,
+ mode, &index);
+ if (IS_ERR(inode)) {
+ err = PTR_ERR(inode);
+ goto out_unlock;
+ }
+ drop_inode_on_err = 1;
+ /*
+ * If the active LSM wants to access the inode during
+ * d_instantiate it needs these. Smack checks to see
+ * if the filesystem supports xattrs by looking at the
+ * ops vector.
+ */
+ inode->i_fop = &btrfs_file_operations;
+ inode->i_op = &btrfs_file_inode_operations;
+ inode->i_mapping->a_ops = &btrfs_aops;
+
+ err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
+ if (err)
+ goto out_unlock_inode;
+
+ err = btrfs_update_inode(trans, root, inode);
+ if (err)
+ goto out_unlock_inode;
+
+ err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
+ if (err)
+ goto out_unlock_inode;
+
+ BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
+ unlock_new_inode(inode);
+ d_instantiate(dentry, inode);
+
+out_unlock:
+ btrfs_end_transaction(trans, root);
+ if (err && drop_inode_on_err) {
+ inode_dec_link_count(inode);
+ iput(inode);
+ }
+ btrfs_balance_delayed_items(root);
+ btrfs_btree_balance_dirty(root);
+ return err;
+
+out_unlock_inode:
+ unlock_new_inode(inode);
+ goto out_unlock;
+
+}
+
+static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
+ struct dentry *dentry)
+{
+ struct btrfs_trans_handle *trans;
+ struct btrfs_root *root = BTRFS_I(dir)->root;
+ struct inode *inode = d_inode(old_dentry);
+ u64 index;
+ int err;
+ int drop_inode = 0;
+
+ /* do not allow sys_link's with other subvols of the same device */
+ if (root->objectid != BTRFS_I(inode)->root->objectid)
+ return -EXDEV;
+
+ if (inode->i_nlink >= BTRFS_LINK_MAX)
+ return -EMLINK;
+
+ err = btrfs_set_inode_index(dir, &index);
+ if (err)
+ goto fail;
+
+ /*
+ * 2 items for inode and inode ref
+ * 2 items for dir items
+ * 1 item for parent inode
+ */
+ trans = btrfs_start_transaction(root, 5);
+ if (IS_ERR(trans)) {
+ err = PTR_ERR(trans);
+ goto fail;
+ }
+
+ /* There are several dir indexes for this inode, clear the cache. */
+ BTRFS_I(inode)->dir_index = 0ULL;
+ inc_nlink(inode);
+ inode_inc_iversion(inode);
+ inode->i_ctime = CURRENT_TIME;
+ ihold(inode);
+ set_bit(BTRFS_INODE_COPY_EVERYTHING, &BTRFS_I(inode)->runtime_flags);
+
+ err = btrfs_add_nondir(trans, dir, dentry, inode, 1, index);
+
+ if (err) {
+ drop_inode = 1;
+ } else {
+ struct dentry *parent = dentry->d_parent;
+ err = btrfs_update_inode(trans, root, inode);
+ if (err)
+ goto fail;
+ if (inode->i_nlink == 1) {
+ /*
+ * If new hard link count is 1, it's a file created
+ * with open(2) O_TMPFILE flag.
+ */
+ err = btrfs_orphan_del(trans, inode);
+ if (err)
+ goto fail;
+ }
+ d_instantiate(dentry, inode);
+ btrfs_log_new_name(trans, inode, NULL, parent);
+ }
+
+ btrfs_end_transaction(trans, root);
+ btrfs_balance_delayed_items(root);
+fail:
+ if (drop_inode) {
+ inode_dec_link_count(inode);
+ iput(inode);
+ }
+ btrfs_btree_balance_dirty(root);
+ return err;
+}
+
+static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
+{
+ struct inode *inode = NULL;
+ struct btrfs_trans_handle *trans;
+ struct btrfs_root *root = BTRFS_I(dir)->root;
+ int err = 0;
+ int drop_on_err = 0;
+ u64 objectid = 0;
+ u64 index = 0;
+
+ /*
+ * 2 items for inode and ref
+ * 2 items for dir items
+ * 1 for xattr if selinux is on
+ */
+ trans = btrfs_start_transaction(root, 5);
+ if (IS_ERR(trans))
+ return PTR_ERR(trans);
+
+ err = btrfs_find_free_ino(root, &objectid);
+ if (err)
+ goto out_fail;
+
+ inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
+ dentry->d_name.len, btrfs_ino(dir), objectid,
+ S_IFDIR | mode, &index);
+ if (IS_ERR(inode)) {
+ err = PTR_ERR(inode);
+ goto out_fail;
+ }
+
+ drop_on_err = 1;
+ /* these must be set before we unlock the inode */
+ inode->i_op = &btrfs_dir_inode_operations;
+ inode->i_fop = &btrfs_dir_file_operations;
+
+ err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
+ if (err)
+ goto out_fail_inode;
+
+ btrfs_i_size_write(inode, 0);
+ err = btrfs_update_inode(trans, root, inode);
+ if (err)
+ goto out_fail_inode;
+
+ err = btrfs_add_link(trans, dir, inode, dentry->d_name.name,
+ dentry->d_name.len, 0, index);
+ if (err)
+ goto out_fail_inode;
+
+ d_instantiate(dentry, inode);
+ /*
+ * mkdir is special. We're unlocking after we call d_instantiate
+ * to avoid a race with nfsd calling d_instantiate.
+ */
+ unlock_new_inode(inode);
+ drop_on_err = 0;
+
+out_fail:
+ btrfs_end_transaction(trans, root);
+ if (drop_on_err) {
+ inode_dec_link_count(inode);
+ iput(inode);
+ }
+ btrfs_balance_delayed_items(root);
+ btrfs_btree_balance_dirty(root);
+ return err;
+
+out_fail_inode:
+ unlock_new_inode(inode);
+ goto out_fail;
+}
+
+/* Find next extent map of a given extent map, caller needs to ensure locks */
+static struct extent_map *next_extent_map(struct extent_map *em)
+{
+ struct rb_node *next;
+
+ next = rb_next(&em->rb_node);
+ if (!next)
+ return NULL;
+ return container_of(next, struct extent_map, rb_node);
+}
+
+static struct extent_map *prev_extent_map(struct extent_map *em)
+{
+ struct rb_node *prev;
+
+ prev = rb_prev(&em->rb_node);
+ if (!prev)
+ return NULL;
+ return container_of(prev, struct extent_map, rb_node);
+}
+
+/* helper for btfs_get_extent. Given an existing extent in the tree,
+ * the existing extent is the nearest extent to map_start,
+ * and an extent that you want to insert, deal with overlap and insert
+ * the best fitted new extent into the tree.
+ */
+static int merge_extent_mapping(struct extent_map_tree *em_tree,
+ struct extent_map *existing,
+ struct extent_map *em,
+ u64 map_start)
+{
+ struct extent_map *prev;
+ struct extent_map *next;
+ u64 start;
+ u64 end;
+ u64 start_diff;
+
+ BUG_ON(map_start < em->start || map_start >= extent_map_end(em));
+
+ if (existing->start > map_start) {
+ next = existing;
+ prev = prev_extent_map(next);
+ } else {
+ prev = existing;
+ next = next_extent_map(prev);
+ }
+
+ start = prev ? extent_map_end(prev) : em->start;
+ start = max_t(u64, start, em->start);
+ end = next ? next->start : extent_map_end(em);
+ end = min_t(u64, end, extent_map_end(em));
+ start_diff = start - em->start;
+ em->start = start;
+ em->len = end - start;
+ if (em->block_start < EXTENT_MAP_LAST_BYTE &&
+ !test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
+ em->block_start += start_diff;
+ em->block_len -= start_diff;
+ }
+ return add_extent_mapping(em_tree, em, 0);
+}
+
+static noinline int uncompress_inline(struct btrfs_path *path,
+ struct inode *inode, struct page *page,
+ size_t pg_offset, u64 extent_offset,
+ struct btrfs_file_extent_item *item)
+{
+ int ret;
+ struct extent_buffer *leaf = path->nodes[0];
+ char *tmp;
+ size_t max_size;
+ unsigned long inline_size;
+ unsigned long ptr;
+ int compress_type;
+
+ WARN_ON(pg_offset != 0);
+ compress_type = btrfs_file_extent_compression(leaf, item);
+ max_size = btrfs_file_extent_ram_bytes(leaf, item);
+ inline_size = btrfs_file_extent_inline_item_len(leaf,
+ btrfs_item_nr(path->slots[0]));
+ tmp = kmalloc(inline_size, GFP_NOFS);
+ if (!tmp)
+ return -ENOMEM;
+ ptr = btrfs_file_extent_inline_start(item);
+
+ read_extent_buffer(leaf, tmp, ptr, inline_size);
+
+ max_size = min_t(unsigned long, PAGE_CACHE_SIZE, max_size);
+ ret = btrfs_decompress(compress_type, tmp, page,
+ extent_offset, inline_size, max_size);
+ kfree(tmp);
+ return ret;
+}
+
+/*
+ * a bit scary, this does extent mapping from logical file offset to the disk.
+ * the ugly parts come from merging extents from the disk with the in-ram
+ * representation. This gets more complex because of the data=ordered code,
+ * where the in-ram extents might be locked pending data=ordered completion.
+ *
+ * This also copies inline extents directly into the page.
+ */
+
+struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
+ size_t pg_offset, u64 start, u64 len,
+ int create)
+{
+ int ret;
+ int err = 0;
+ u64 extent_start = 0;
+ u64 extent_end = 0;
+ u64 objectid = btrfs_ino(inode);
+ u32 found_type;
+ struct btrfs_path *path = NULL;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_file_extent_item *item;
+ struct extent_buffer *leaf;
+ struct btrfs_key found_key;
+ struct extent_map *em = NULL;
+ struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
+ struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
+ struct btrfs_trans_handle *trans = NULL;
+ const bool new_inline = !page || create;
+
+again:
+ read_lock(&em_tree->lock);
+ em = lookup_extent_mapping(em_tree, start, len);
+ if (em)
+ em->bdev = root->fs_info->fs_devices->latest_bdev;
+ read_unlock(&em_tree->lock);
+
+ if (em) {
+ if (em->start > start || em->start + em->len <= start)
+ free_extent_map(em);
+ else if (em->block_start == EXTENT_MAP_INLINE && page)
+ free_extent_map(em);
+ else
+ goto out;
+ }
+ em = alloc_extent_map();
+ if (!em) {
+ err = -ENOMEM;
+ goto out;
+ }
+ em->bdev = root->fs_info->fs_devices->latest_bdev;
+ em->start = EXTENT_MAP_HOLE;
+ em->orig_start = EXTENT_MAP_HOLE;
+ em->len = (u64)-1;
+ em->block_len = (u64)-1;
+
+ if (!path) {
+ path = btrfs_alloc_path();
+ if (!path) {
+ err = -ENOMEM;
+ goto out;
+ }
+ /*
+ * Chances are we'll be called again, so go ahead and do
+ * readahead
+ */
+ path->reada = 1;
+ }
+
+ ret = btrfs_lookup_file_extent(trans, root, path,
+ objectid, start, trans != NULL);
+ if (ret < 0) {
+ err = ret;
+ goto out;
+ }
+
+ if (ret != 0) {
+ if (path->slots[0] == 0)
+ goto not_found;
+ path->slots[0]--;
+ }
+
+ leaf = path->nodes[0];
+ item = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_file_extent_item);
+ /* are we inside the extent that was found? */
+ btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
+ found_type = found_key.type;
+ if (found_key.objectid != objectid ||
+ found_type != BTRFS_EXTENT_DATA_KEY) {
+ /*
+ * If we backup past the first extent we want to move forward
+ * and see if there is an extent in front of us, otherwise we'll
+ * say there is a hole for our whole search range which can
+ * cause problems.
+ */
+ extent_end = start;
+ goto next;
+ }
+
+ found_type = btrfs_file_extent_type(leaf, item);
+ extent_start = found_key.offset;
+ if (found_type == BTRFS_FILE_EXTENT_REG ||
+ found_type == BTRFS_FILE_EXTENT_PREALLOC) {
+ extent_end = extent_start +
+ btrfs_file_extent_num_bytes(leaf, item);
+ } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
+ size_t size;
+ size = btrfs_file_extent_inline_len(leaf, path->slots[0], item);
+ extent_end = ALIGN(extent_start + size, root->sectorsize);
+ }
+next:
+ if (start >= extent_end) {
+ path->slots[0]++;
+ if (path->slots[0] >= btrfs_header_nritems(leaf)) {
+ ret = btrfs_next_leaf(root, path);
+ if (ret < 0) {
+ err = ret;
+ goto out;
+ }
+ if (ret > 0)
+ goto not_found;
+ leaf = path->nodes[0];
+ }
+ btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
+ if (found_key.objectid != objectid ||
+ found_key.type != BTRFS_EXTENT_DATA_KEY)
+ goto not_found;
+ if (start + len <= found_key.offset)
+ goto not_found;
+ if (start > found_key.offset)
+ goto next;
+ em->start = start;
+ em->orig_start = start;
+ em->len = found_key.offset - start;
+ goto not_found_em;
+ }
+
+ btrfs_extent_item_to_extent_map(inode, path, item, new_inline, em);
+
+ if (found_type == BTRFS_FILE_EXTENT_REG ||
+ found_type == BTRFS_FILE_EXTENT_PREALLOC) {
+ goto insert;
+ } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
+ unsigned long ptr;
+ char *map;
+ size_t size;
+ size_t extent_offset;
+ size_t copy_size;
+
+ if (new_inline)
+ goto out;
+
+ size = btrfs_file_extent_inline_len(leaf, path->slots[0], item);
+ extent_offset = page_offset(page) + pg_offset - extent_start;
+ copy_size = min_t(u64, PAGE_CACHE_SIZE - pg_offset,
+ size - extent_offset);
+ em->start = extent_start + extent_offset;
+ em->len = ALIGN(copy_size, root->sectorsize);
+ em->orig_block_len = em->len;
+ em->orig_start = em->start;
+ ptr = btrfs_file_extent_inline_start(item) + extent_offset;
+ if (create == 0 && !PageUptodate(page)) {
+ if (btrfs_file_extent_compression(leaf, item) !=
+ BTRFS_COMPRESS_NONE) {
+ ret = uncompress_inline(path, inode, page,
+ pg_offset,
+ extent_offset, item);
+ if (ret) {
+ err = ret;
+ goto out;
+ }
+ } else {
+ map = kmap(page);
+ read_extent_buffer(leaf, map + pg_offset, ptr,
+ copy_size);
+ if (pg_offset + copy_size < PAGE_CACHE_SIZE) {
+ memset(map + pg_offset + copy_size, 0,
+ PAGE_CACHE_SIZE - pg_offset -
+ copy_size);
+ }
+ kunmap(page);
+ }
+ flush_dcache_page(page);
+ } else if (create && PageUptodate(page)) {
+ BUG();
+ if (!trans) {
+ kunmap(page);
+ free_extent_map(em);
+ em = NULL;
+
+ btrfs_release_path(path);
+ trans = btrfs_join_transaction(root);
+
+ if (IS_ERR(trans))
+ return ERR_CAST(trans);
+ goto again;
+ }
+ map = kmap(page);
+ write_extent_buffer(leaf, map + pg_offset, ptr,
+ copy_size);
+ kunmap(page);
+ btrfs_mark_buffer_dirty(leaf);
+ }
+ set_extent_uptodate(io_tree, em->start,
+ extent_map_end(em) - 1, NULL, GFP_NOFS);
+ goto insert;
+ }
+not_found:
+ em->start = start;
+ em->orig_start = start;
+ em->len = len;
+not_found_em:
+ em->block_start = EXTENT_MAP_HOLE;
+ set_bit(EXTENT_FLAG_VACANCY, &em->flags);
+insert:
+ btrfs_release_path(path);
+ if (em->start > start || extent_map_end(em) <= start) {
+ btrfs_err(root->fs_info, "bad extent! em: [%llu %llu] passed [%llu %llu]",
+ em->start, em->len, start, len);
+ err = -EIO;
+ goto out;
+ }
+
+ err = 0;
+ write_lock(&em_tree->lock);
+ ret = add_extent_mapping(em_tree, em, 0);
+ /* it is possible that someone inserted the extent into the tree
+ * while we had the lock dropped. It is also possible that
+ * an overlapping map exists in the tree
+ */
+ if (ret == -EEXIST) {
+ struct extent_map *existing;
+
+ ret = 0;
+
+ existing = search_extent_mapping(em_tree, start, len);
+ /*
+ * existing will always be non-NULL, since there must be
+ * extent causing the -EEXIST.
+ */
+ if (start >= extent_map_end(existing) ||
+ start <= existing->start) {
+ /*
+ * The existing extent map is the one nearest to
+ * the [start, start + len) range which overlaps
+ */
+ err = merge_extent_mapping(em_tree, existing,
+ em, start);
+ free_extent_map(existing);
+ if (err) {
+ free_extent_map(em);
+ em = NULL;
+ }
+ } else {
+ free_extent_map(em);
+ em = existing;
+ err = 0;
+ }
+ }
+ write_unlock(&em_tree->lock);
+out:
+
+ trace_btrfs_get_extent(root, em);
+
+ if (path)
+ btrfs_free_path(path);
+ if (trans) {
+ ret = btrfs_end_transaction(trans, root);
+ if (!err)
+ err = ret;
+ }
+ if (err) {
+ free_extent_map(em);
+ return ERR_PTR(err);
+ }
+ BUG_ON(!em); /* Error is always set */
+ return em;
+}
+
+struct extent_map *btrfs_get_extent_fiemap(struct inode *inode, struct page *page,
+ size_t pg_offset, u64 start, u64 len,
+ int create)
+{
+ struct extent_map *em;
+ struct extent_map *hole_em = NULL;
+ u64 range_start = start;
+ u64 end;
+ u64 found;
+ u64 found_end;
+ int err = 0;
+
+ em = btrfs_get_extent(inode, page, pg_offset, start, len, create);
+ if (IS_ERR(em))
+ return em;
+ if (em) {
+ /*
+ * if our em maps to
+ * - a hole or
+ * - a pre-alloc extent,
+ * there might actually be delalloc bytes behind it.
+ */
+ if (em->block_start != EXTENT_MAP_HOLE &&
+ !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
+ return em;
+ else
+ hole_em = em;
+ }
+
+ /* check to see if we've wrapped (len == -1 or similar) */
+ end = start + len;
+ if (end < start)
+ end = (u64)-1;
+ else
+ end -= 1;
+
+ em = NULL;
+
+ /* ok, we didn't find anything, lets look for delalloc */
+ found = count_range_bits(&BTRFS_I(inode)->io_tree, &range_start,
+ end, len, EXTENT_DELALLOC, 1);
+ found_end = range_start + found;
+ if (found_end < range_start)
+ found_end = (u64)-1;
+
+ /*
+ * we didn't find anything useful, return
+ * the original results from get_extent()
+ */
+ if (range_start > end || found_end <= start) {
+ em = hole_em;
+ hole_em = NULL;
+ goto out;
+ }
+
+ /* adjust the range_start to make sure it doesn't
+ * go backwards from the start they passed in
+ */
+ range_start = max(start, range_start);
+ found = found_end - range_start;
+
+ if (found > 0) {
+ u64 hole_start = start;
+ u64 hole_len = len;
+
+ em = alloc_extent_map();
+ if (!em) {
+ err = -ENOMEM;
+ goto out;
+ }
+ /*
+ * when btrfs_get_extent can't find anything it
+ * returns one huge hole
+ *
+ * make sure what it found really fits our range, and
+ * adjust to make sure it is based on the start from
+ * the caller
+ */
+ if (hole_em) {
+ u64 calc_end = extent_map_end(hole_em);
+
+ if (calc_end <= start || (hole_em->start > end)) {
+ free_extent_map(hole_em);
+ hole_em = NULL;
+ } else {
+ hole_start = max(hole_em->start, start);
+ hole_len = calc_end - hole_start;
+ }
+ }
+ em->bdev = NULL;
+ if (hole_em && range_start > hole_start) {
+ /* our hole starts before our delalloc, so we
+ * have to return just the parts of the hole
+ * that go until the delalloc starts
+ */
+ em->len = min(hole_len,
+ range_start - hole_start);
+ em->start = hole_start;
+ em->orig_start = hole_start;
+ /*
+ * don't adjust block start at all,
+ * it is fixed at EXTENT_MAP_HOLE
+ */
+ em->block_start = hole_em->block_start;
+ em->block_len = hole_len;
+ if (test_bit(EXTENT_FLAG_PREALLOC, &hole_em->flags))
+ set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
+ } else {
+ em->start = range_start;
+ em->len = found;
+ em->orig_start = range_start;
+ em->block_start = EXTENT_MAP_DELALLOC;
+ em->block_len = found;
+ }
+ } else if (hole_em) {
+ return hole_em;
+ }
+out:
+
+ free_extent_map(hole_em);
+ if (err) {
+ free_extent_map(em);
+ return ERR_PTR(err);
+ }
+ return em;
+}
+
+static struct extent_map *btrfs_new_extent_direct(struct inode *inode,
+ u64 start, u64 len)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct extent_map *em;
+ struct btrfs_key ins;
+ u64 alloc_hint;
+ int ret;
+
+ alloc_hint = get_extent_allocation_hint(inode, start, len);
+ ret = btrfs_reserve_extent(root, len, root->sectorsize, 0,
+ alloc_hint, &ins, 1, 1);
+ if (ret)
+ return ERR_PTR(ret);
+
+ em = create_pinned_em(inode, start, ins.offset, start, ins.objectid,
+ ins.offset, ins.offset, ins.offset, 0);
+ if (IS_ERR(em)) {
+ btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1);
+ return em;
+ }
+
+ ret = btrfs_add_ordered_extent_dio(inode, start, ins.objectid,
+ ins.offset, ins.offset, 0);
+ if (ret) {
+ btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1);
+ free_extent_map(em);
+ return ERR_PTR(ret);
+ }
+
+ return em;
+}
+
+/*
+ * returns 1 when the nocow is safe, < 1 on error, 0 if the
+ * block must be cow'd
+ */
+noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len,
+ u64 *orig_start, u64 *orig_block_len,
+ u64 *ram_bytes)
+{
+ struct btrfs_trans_handle *trans;
+ struct btrfs_path *path;
+ int ret;
+ struct extent_buffer *leaf;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
+ struct btrfs_file_extent_item *fi;
+ struct btrfs_key key;
+ u64 disk_bytenr;
+ u64 backref_offset;
+ u64 extent_end;
+ u64 num_bytes;
+ int slot;
+ int found_type;
+ bool nocow = (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW);
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ ret = btrfs_lookup_file_extent(NULL, root, path, btrfs_ino(inode),
+ offset, 0);
+ if (ret < 0)
+ goto out;
+
+ slot = path->slots[0];
+ if (ret == 1) {
+ if (slot == 0) {
+ /* can't find the item, must cow */
+ ret = 0;
+ goto out;
+ }
+ slot--;
+ }
+ ret = 0;
+ leaf = path->nodes[0];
+ btrfs_item_key_to_cpu(leaf, &key, slot);
+ if (key.objectid != btrfs_ino(inode) ||
+ key.type != BTRFS_EXTENT_DATA_KEY) {
+ /* not our file or wrong item type, must cow */
+ goto out;
+ }
+
+ if (key.offset > offset) {
+ /* Wrong offset, must cow */
+ goto out;
+ }
+
+ fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
+ found_type = btrfs_file_extent_type(leaf, fi);
+ if (found_type != BTRFS_FILE_EXTENT_REG &&
+ found_type != BTRFS_FILE_EXTENT_PREALLOC) {
+ /* not a regular extent, must cow */
+ goto out;
+ }
+
+ if (!nocow && found_type == BTRFS_FILE_EXTENT_REG)
+ goto out;
+
+ extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
+ if (extent_end <= offset)
+ goto out;
+
+ disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
+ if (disk_bytenr == 0)
+ goto out;
+
+ if (btrfs_file_extent_compression(leaf, fi) ||
+ btrfs_file_extent_encryption(leaf, fi) ||
+ btrfs_file_extent_other_encoding(leaf, fi))
+ goto out;
+
+ backref_offset = btrfs_file_extent_offset(leaf, fi);
+
+ if (orig_start) {
+ *orig_start = key.offset - backref_offset;
+ *orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi);
+ *ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
+ }
+
+ if (btrfs_extent_readonly(root, disk_bytenr))
+ goto out;
+
+ num_bytes = min(offset + *len, extent_end) - offset;
+ if (!nocow && found_type == BTRFS_FILE_EXTENT_PREALLOC) {
+ u64 range_end;
+
+ range_end = round_up(offset + num_bytes, root->sectorsize) - 1;
+ ret = test_range_bit(io_tree, offset, range_end,
+ EXTENT_DELALLOC, 0, NULL);
+ if (ret) {
+ ret = -EAGAIN;
+ goto out;
+ }
+ }
+
+ btrfs_release_path(path);
+
+ /*
+ * look for other files referencing this extent, if we
+ * find any we must cow
+ */
+ trans = btrfs_join_transaction(root);
+ if (IS_ERR(trans)) {
+ ret = 0;
+ goto out;
+ }
+
+ ret = btrfs_cross_ref_exist(trans, root, btrfs_ino(inode),
+ key.offset - backref_offset, disk_bytenr);
+ btrfs_end_transaction(trans, root);
+ if (ret) {
+ ret = 0;
+ goto out;
+ }
+
+ /*
+ * adjust disk_bytenr and num_bytes to cover just the bytes
+ * in this extent we are about to write. If there
+ * are any csums in that range we have to cow in order
+ * to keep the csums correct
+ */
+ disk_bytenr += backref_offset;
+ disk_bytenr += offset - key.offset;
+ if (csum_exist_in_range(root, disk_bytenr, num_bytes))
+ goto out;
+ /*
+ * all of the above have passed, it is safe to overwrite this extent
+ * without cow
+ */
+ *len = num_bytes;
+ ret = 1;
+out:
+ btrfs_free_path(path);
+ return ret;
+}
+
+bool btrfs_page_exists_in_range(struct inode *inode, loff_t start, loff_t end)
+{
+ struct radix_tree_root *root = &inode->i_mapping->page_tree;
+ int found = false;
+ void **pagep = NULL;
+ struct page *page = NULL;
+ int start_idx;
+ int end_idx;
+
+ start_idx = start >> PAGE_CACHE_SHIFT;
+
+ /*
+ * end is the last byte in the last page. end == start is legal
+ */
+ end_idx = end >> PAGE_CACHE_SHIFT;
+
+ rcu_read_lock();
+
+ /* Most of the code in this while loop is lifted from
+ * find_get_page. It's been modified to begin searching from a
+ * page and return just the first page found in that range. If the
+ * found idx is less than or equal to the end idx then we know that
+ * a page exists. If no pages are found or if those pages are
+ * outside of the range then we're fine (yay!) */
+ while (page == NULL &&
+ radix_tree_gang_lookup_slot(root, &pagep, NULL, start_idx, 1)) {
+ page = radix_tree_deref_slot(pagep);
+ if (unlikely(!page))
+ break;
+
+ if (radix_tree_exception(page)) {
+ if (radix_tree_deref_retry(page)) {
+ page = NULL;
+ continue;
+ }
+ /*
+ * Otherwise, shmem/tmpfs must be storing a swap entry
+ * here as an exceptional entry: so return it without
+ * attempting to raise page count.
+ */
+ page = NULL;
+ break; /* TODO: Is this relevant for this use case? */
+ }
+
+ if (!page_cache_get_speculative(page)) {
+ page = NULL;
+ continue;
+ }
+
+ /*
+ * Has the page moved?
+ * This is part of the lockless pagecache protocol. See
+ * include/linux/pagemap.h for details.
+ */
+ if (unlikely(page != *pagep)) {
+ page_cache_release(page);
+ page = NULL;
+ }
+ }
+
+ if (page) {
+ if (page->index <= end_idx)
+ found = true;
+ page_cache_release(page);
+ }
+
+ rcu_read_unlock();
+ return found;
+}
+
+static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend,
+ struct extent_state **cached_state, int writing)
+{
+ struct btrfs_ordered_extent *ordered;
+ int ret = 0;
+
+ while (1) {
+ lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
+ 0, cached_state);
+ /*
+ * We're concerned with the entire range that we're going to be
+ * doing DIO to, so we need to make sure theres no ordered
+ * extents in this range.
+ */
+ ordered = btrfs_lookup_ordered_range(inode, lockstart,
+ lockend - lockstart + 1);
+
+ /*
+ * We need to make sure there are no buffered pages in this
+ * range either, we could have raced between the invalidate in
+ * generic_file_direct_write and locking the extent. The
+ * invalidate needs to happen so that reads after a write do not
+ * get stale data.
+ */
+ if (!ordered &&
+ (!writing ||
+ !btrfs_page_exists_in_range(inode, lockstart, lockend)))
+ break;
+
+ unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
+ cached_state, GFP_NOFS);
+
+ if (ordered) {
+ btrfs_start_ordered_extent(inode, ordered, 1);
+ btrfs_put_ordered_extent(ordered);
+ } else {
+ /* Screw you mmap */
+ ret = btrfs_fdatawrite_range(inode, lockstart, lockend);
+ if (ret)
+ break;
+ ret = filemap_fdatawait_range(inode->i_mapping,
+ lockstart,
+ lockend);
+ if (ret)
+ break;
+
+ /*
+ * If we found a page that couldn't be invalidated just
+ * fall back to buffered.
+ */
+ ret = invalidate_inode_pages2_range(inode->i_mapping,
+ lockstart >> PAGE_CACHE_SHIFT,
+ lockend >> PAGE_CACHE_SHIFT);
+ if (ret)
+ break;
+ }
+
+ cond_resched();
+ }
+
+ return ret;
+}
+
+static struct extent_map *create_pinned_em(struct inode *inode, u64 start,
+ u64 len, u64 orig_start,
+ u64 block_start, u64 block_len,
+ u64 orig_block_len, u64 ram_bytes,
+ int type)
+{
+ struct extent_map_tree *em_tree;
+ struct extent_map *em;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ int ret;
+
+ em_tree = &BTRFS_I(inode)->extent_tree;
+ em = alloc_extent_map();
+ if (!em)
+ return ERR_PTR(-ENOMEM);
+
+ em->start = start;
+ em->orig_start = orig_start;
+ em->mod_start = start;
+ em->mod_len = len;
+ em->len = len;
+ em->block_len = block_len;
+ em->block_start = block_start;
+ em->bdev = root->fs_info->fs_devices->latest_bdev;
+ em->orig_block_len = orig_block_len;
+ em->ram_bytes = ram_bytes;
+ em->generation = -1;
+ set_bit(EXTENT_FLAG_PINNED, &em->flags);
+ if (type == BTRFS_ORDERED_PREALLOC)
+ set_bit(EXTENT_FLAG_FILLING, &em->flags);
+
+ do {
+ btrfs_drop_extent_cache(inode, em->start,
+ em->start + em->len - 1, 0);
+ write_lock(&em_tree->lock);
+ ret = add_extent_mapping(em_tree, em, 1);
+ write_unlock(&em_tree->lock);
+ } while (ret == -EEXIST);
+
+ if (ret) {
+ free_extent_map(em);
+ return ERR_PTR(ret);
+ }
+
+ return em;
+}
+
+
+static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
+ struct buffer_head *bh_result, int create)
+{
+ struct extent_map *em;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct extent_state *cached_state = NULL;
+ u64 start = iblock << inode->i_blkbits;
+ u64 lockstart, lockend;
+ u64 len = bh_result->b_size;
+ u64 *outstanding_extents = NULL;
+ int unlock_bits = EXTENT_LOCKED;
+ int ret = 0;
+
+ if (create)
+ unlock_bits |= EXTENT_DIRTY;
+ else
+ len = min_t(u64, len, root->sectorsize);
+
+ lockstart = start;
+ lockend = start + len - 1;
+
+ if (current->journal_info) {
+ /*
+ * Need to pull our outstanding extents and set journal_info to NULL so
+ * that anything that needs to check if there's a transction doesn't get
+ * confused.
+ */
+ outstanding_extents = current->journal_info;
+ current->journal_info = NULL;
+ }
+
+ /*
+ * If this errors out it's because we couldn't invalidate pagecache for
+ * this range and we need to fallback to buffered.
+ */
+ if (lock_extent_direct(inode, lockstart, lockend, &cached_state, create))
+ return -ENOTBLK;
+
+ em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
+ if (IS_ERR(em)) {
+ ret = PTR_ERR(em);
+ goto unlock_err;
+ }
+
+ /*
+ * Ok for INLINE and COMPRESSED extents we need to fallback on buffered
+ * io. INLINE is special, and we could probably kludge it in here, but
+ * it's still buffered so for safety lets just fall back to the generic
+ * buffered path.
+ *
+ * For COMPRESSED we _have_ to read the entire extent in so we can
+ * decompress it, so there will be buffering required no matter what we
+ * do, so go ahead and fallback to buffered.
+ *
+ * We return -ENOTBLK because thats what makes DIO go ahead and go back
+ * to buffered IO. Don't blame me, this is the price we pay for using
+ * the generic code.
+ */
+ if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) ||
+ em->block_start == EXTENT_MAP_INLINE) {
+ free_extent_map(em);
+ ret = -ENOTBLK;
+ goto unlock_err;
+ }
+
+ /* Just a good old fashioned hole, return */
+ if (!create && (em->block_start == EXTENT_MAP_HOLE ||
+ test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
+ free_extent_map(em);
+ goto unlock_err;
+ }
+
+ /*
+ * We don't allocate a new extent in the following cases
+ *
+ * 1) The inode is marked as NODATACOW. In this case we'll just use the
+ * existing extent.
+ * 2) The extent is marked as PREALLOC. We're good to go here and can
+ * just use the extent.
+ *
+ */
+ if (!create) {
+ len = min(len, em->len - (start - em->start));
+ lockstart = start + len;
+ goto unlock;
+ }
+
+ if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) ||
+ ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
+ em->block_start != EXTENT_MAP_HOLE)) {
+ int type;
+ u64 block_start, orig_start, orig_block_len, ram_bytes;
+
+ if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
+ type = BTRFS_ORDERED_PREALLOC;
+ else
+ type = BTRFS_ORDERED_NOCOW;
+ len = min(len, em->len - (start - em->start));
+ block_start = em->block_start + (start - em->start);
+
+ if (can_nocow_extent(inode, start, &len, &orig_start,
+ &orig_block_len, &ram_bytes) == 1) {
+ if (type == BTRFS_ORDERED_PREALLOC) {
+ free_extent_map(em);
+ em = create_pinned_em(inode, start, len,
+ orig_start,
+ block_start, len,
+ orig_block_len,
+ ram_bytes, type);
+ if (IS_ERR(em)) {
+ ret = PTR_ERR(em);
+ goto unlock_err;
+ }
+ }
+
+ ret = btrfs_add_ordered_extent_dio(inode, start,
+ block_start, len, len, type);
+ if (ret) {
+ free_extent_map(em);
+ goto unlock_err;
+ }
+ goto unlock;
+ }
+ }
+
+ /*
+ * this will cow the extent, reset the len in case we changed
+ * it above
+ */
+ len = bh_result->b_size;
+ free_extent_map(em);
+ em = btrfs_new_extent_direct(inode, start, len);
+ if (IS_ERR(em)) {
+ ret = PTR_ERR(em);
+ goto unlock_err;
+ }
+ len = min(len, em->len - (start - em->start));
+unlock:
+ bh_result->b_blocknr = (em->block_start + (start - em->start)) >>
+ inode->i_blkbits;
+ bh_result->b_size = len;
+ bh_result->b_bdev = em->bdev;
+ set_buffer_mapped(bh_result);
+ if (create) {
+ if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
+ set_buffer_new(bh_result);
+
+ /*
+ * Need to update the i_size under the extent lock so buffered
+ * readers will get the updated i_size when we unlock.
+ */
+ if (start + len > i_size_read(inode))
+ i_size_write(inode, start + len);
+
+ /*
+ * If we have an outstanding_extents count still set then we're
+ * within our reservation, otherwise we need to adjust our inode
+ * counter appropriately.
+ */
+ if (*outstanding_extents) {
+ (*outstanding_extents)--;
+ } else {
+ spin_lock(&BTRFS_I(inode)->lock);
+ BTRFS_I(inode)->outstanding_extents++;
+ spin_unlock(&BTRFS_I(inode)->lock);
+ }
+
+ current->journal_info = outstanding_extents;
+ btrfs_free_reserved_data_space(inode, len);
+ }
+
+ /*
+ * In the case of write we need to clear and unlock the entire range,
+ * in the case of read we need to unlock only the end area that we
+ * aren't using if there is any left over space.
+ */
+ if (lockstart < lockend) {
+ clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
+ lockend, unlock_bits, 1, 0,
+ &cached_state, GFP_NOFS);
+ } else {
+ free_extent_state(cached_state);
+ }
+
+ free_extent_map(em);
+
+ return 0;
+
+unlock_err:
+ clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend,
+ unlock_bits, 1, 0, &cached_state, GFP_NOFS);
+ if (outstanding_extents)
+ current->journal_info = outstanding_extents;
+ return ret;
+}
+
+static inline int submit_dio_repair_bio(struct inode *inode, struct bio *bio,
+ int rw, int mirror_num)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ int ret;
+
+ BUG_ON(rw & REQ_WRITE);
+
+ bio_get(bio);
+
+ ret = btrfs_bio_wq_end_io(root->fs_info, bio,
+ BTRFS_WQ_ENDIO_DIO_REPAIR);
+ if (ret)
+ goto err;
+
+ ret = btrfs_map_bio(root, rw, bio, mirror_num, 0);
+err:
+ bio_put(bio);
+ return ret;
+}
+
+static int btrfs_check_dio_repairable(struct inode *inode,
+ struct bio *failed_bio,
+ struct io_failure_record *failrec,
+ int failed_mirror)
+{
+ int num_copies;
+
+ num_copies = btrfs_num_copies(BTRFS_I(inode)->root->fs_info,
+ failrec->logical, failrec->len);
+ if (num_copies == 1) {
+ /*
+ * we only have a single copy of the data, so don't bother with
+ * all the retry and error correction code that follows. no
+ * matter what the error is, it is very likely to persist.
+ */
+ pr_debug("Check DIO Repairable: cannot repair, num_copies=%d, next_mirror %d, failed_mirror %d\n",
+ num_copies, failrec->this_mirror, failed_mirror);
+ return 0;
+ }
+
+ failrec->failed_mirror = failed_mirror;
+ failrec->this_mirror++;
+ if (failrec->this_mirror == failed_mirror)
+ failrec->this_mirror++;
+
+ if (failrec->this_mirror > num_copies) {
+ pr_debug("Check DIO Repairable: (fail) num_copies=%d, next_mirror %d, failed_mirror %d\n",
+ num_copies, failrec->this_mirror, failed_mirror);
+ return 0;
+ }
+
+ return 1;
+}
+
+static int dio_read_error(struct inode *inode, struct bio *failed_bio,
+ struct page *page, u64 start, u64 end,
+ int failed_mirror, bio_end_io_t *repair_endio,
+ void *repair_arg)
+{
+ struct io_failure_record *failrec;
+ struct bio *bio;
+ int isector;
+ int read_mode;
+ int ret;
+
+ BUG_ON(failed_bio->bi_rw & REQ_WRITE);
+
+ ret = btrfs_get_io_failure_record(inode, start, end, &failrec);
+ if (ret)
+ return ret;
+
+ ret = btrfs_check_dio_repairable(inode, failed_bio, failrec,
+ failed_mirror);
+ if (!ret) {
+ free_io_failure(inode, failrec);
+ return -EIO;
+ }
+
+ if (failed_bio->bi_vcnt > 1)
+ read_mode = READ_SYNC | REQ_FAILFAST_DEV;
+ else
+ read_mode = READ_SYNC;
+
+ isector = start - btrfs_io_bio(failed_bio)->logical;
+ isector >>= inode->i_sb->s_blocksize_bits;
+ bio = btrfs_create_repair_bio(inode, failed_bio, failrec, page,
+ 0, isector, repair_endio, repair_arg);
+ if (!bio) {
+ free_io_failure(inode, failrec);
+ return -EIO;
+ }
+
+ btrfs_debug(BTRFS_I(inode)->root->fs_info,
+ "Repair DIO Read Error: submitting new dio read[%#x] to this_mirror=%d, in_validation=%d\n",
+ read_mode, failrec->this_mirror, failrec->in_validation);
+
+ ret = submit_dio_repair_bio(inode, bio, read_mode,
+ failrec->this_mirror);
+ if (ret) {
+ free_io_failure(inode, failrec);
+ bio_put(bio);
+ }
+
+ return ret;
+}
+
+struct btrfs_retry_complete {
+ struct completion done;
+ struct inode *inode;
+ u64 start;
+ int uptodate;
+};
+
+static void btrfs_retry_endio_nocsum(struct bio *bio, int err)
+{
+ struct btrfs_retry_complete *done = bio->bi_private;
+ struct bio_vec *bvec;
+ int i;
+
+ if (err)
+ goto end;
+
+ done->uptodate = 1;
+ bio_for_each_segment_all(bvec, bio, i)
+ clean_io_failure(done->inode, done->start, bvec->bv_page, 0);
+end:
+ complete(&done->done);
+ bio_put(bio);
+}
+
+static int __btrfs_correct_data_nocsum(struct inode *inode,
+ struct btrfs_io_bio *io_bio)
+{
+ struct bio_vec *bvec;
+ struct btrfs_retry_complete done;
+ u64 start;
+ int i;
+ int ret;
+
+ start = io_bio->logical;
+ done.inode = inode;
+
+ bio_for_each_segment_all(bvec, &io_bio->bio, i) {
+try_again:
+ done.uptodate = 0;
+ done.start = start;
+ init_completion(&done.done);
+
+ ret = dio_read_error(inode, &io_bio->bio, bvec->bv_page, start,
+ start + bvec->bv_len - 1,
+ io_bio->mirror_num,
+ btrfs_retry_endio_nocsum, &done);
+ if (ret)
+ return ret;
+
+ wait_for_completion(&done.done);
+
+ if (!done.uptodate) {
+ /* We might have another mirror, so try again */
+ goto try_again;
+ }
+
+ start += bvec->bv_len;
+ }
+
+ return 0;
+}
+
+static void btrfs_retry_endio(struct bio *bio, int err)
+{
+ struct btrfs_retry_complete *done = bio->bi_private;
+ struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
+ struct bio_vec *bvec;
+ int uptodate;
+ int ret;
+ int i;
+
+ if (err)
+ goto end;
+
+ uptodate = 1;
+ bio_for_each_segment_all(bvec, bio, i) {
+ ret = __readpage_endio_check(done->inode, io_bio, i,
+ bvec->bv_page, 0,
+ done->start, bvec->bv_len);
+ if (!ret)
+ clean_io_failure(done->inode, done->start,
+ bvec->bv_page, 0);
+ else
+ uptodate = 0;
+ }
+
+ done->uptodate = uptodate;
+end:
+ complete(&done->done);
+ bio_put(bio);
+}
+
+static int __btrfs_subio_endio_read(struct inode *inode,
+ struct btrfs_io_bio *io_bio, int err)
+{
+ struct bio_vec *bvec;
+ struct btrfs_retry_complete done;
+ u64 start;
+ u64 offset = 0;
+ int i;
+ int ret;
+
+ err = 0;
+ start = io_bio->logical;
+ done.inode = inode;
+
+ bio_for_each_segment_all(bvec, &io_bio->bio, i) {
+ ret = __readpage_endio_check(inode, io_bio, i, bvec->bv_page,
+ 0, start, bvec->bv_len);
+ if (likely(!ret))
+ goto next;
+try_again:
+ done.uptodate = 0;
+ done.start = start;
+ init_completion(&done.done);
+
+ ret = dio_read_error(inode, &io_bio->bio, bvec->bv_page, start,
+ start + bvec->bv_len - 1,
+ io_bio->mirror_num,
+ btrfs_retry_endio, &done);
+ if (ret) {
+ err = ret;
+ goto next;
+ }
+
+ wait_for_completion(&done.done);
+
+ if (!done.uptodate) {
+ /* We might have another mirror, so try again */
+ goto try_again;
+ }
+next:
+ offset += bvec->bv_len;
+ start += bvec->bv_len;
+ }
+
+ return err;
+}
+
+static int btrfs_subio_endio_read(struct inode *inode,
+ struct btrfs_io_bio *io_bio, int err)
+{
+ bool skip_csum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
+
+ if (skip_csum) {
+ if (unlikely(err))
+ return __btrfs_correct_data_nocsum(inode, io_bio);
+ else
+ return 0;
+ } else {
+ return __btrfs_subio_endio_read(inode, io_bio, err);
+ }
+}
+
+static void btrfs_endio_direct_read(struct bio *bio, int err)
+{
+ struct btrfs_dio_private *dip = bio->bi_private;
+ struct inode *inode = dip->inode;
+ struct bio *dio_bio;
+ struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
+
+ if (dip->flags & BTRFS_DIO_ORIG_BIO_SUBMITTED)
+ err = btrfs_subio_endio_read(inode, io_bio, err);
+
+ unlock_extent(&BTRFS_I(inode)->io_tree, dip->logical_offset,
+ dip->logical_offset + dip->bytes - 1);
+ dio_bio = dip->dio_bio;
+
+ kfree(dip);
+
+ /* If we had a csum failure make sure to clear the uptodate flag */
+ if (err)
+ clear_bit(BIO_UPTODATE, &dio_bio->bi_flags);
+ dio_end_io(dio_bio, err);
+
+ if (io_bio->end_io)
+ io_bio->end_io(io_bio, err);
+ bio_put(bio);
+}
+
+static void btrfs_endio_direct_write(struct bio *bio, int err)
+{
+ struct btrfs_dio_private *dip = bio->bi_private;
+ struct inode *inode = dip->inode;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_ordered_extent *ordered = NULL;
+ u64 ordered_offset = dip->logical_offset;
+ u64 ordered_bytes = dip->bytes;
+ struct bio *dio_bio;
+ int ret;
+
+ if (err)
+ goto out_done;
+again:
+ ret = btrfs_dec_test_first_ordered_pending(inode, &ordered,
+ &ordered_offset,
+ ordered_bytes, !err);
+ if (!ret)
+ goto out_test;
+
+ btrfs_init_work(&ordered->work, btrfs_endio_write_helper,
+ finish_ordered_fn, NULL, NULL);
+ btrfs_queue_work(root->fs_info->endio_write_workers,
+ &ordered->work);
+out_test:
+ /*
+ * our bio might span multiple ordered extents. If we haven't
+ * completed the accounting for the whole dio, go back and try again
+ */
+ if (ordered_offset < dip->logical_offset + dip->bytes) {
+ ordered_bytes = dip->logical_offset + dip->bytes -
+ ordered_offset;
+ ordered = NULL;
+ goto again;
+ }
+out_done:
+ dio_bio = dip->dio_bio;
+
+ kfree(dip);
+
+ /* If we had an error make sure to clear the uptodate flag */
+ if (err)
+ clear_bit(BIO_UPTODATE, &dio_bio->bi_flags);
+ dio_end_io(dio_bio, err);
+ bio_put(bio);
+}
+
+static int __btrfs_submit_bio_start_direct_io(struct inode *inode, int rw,
+ struct bio *bio, int mirror_num,
+ unsigned long bio_flags, u64 offset)
+{
+ int ret;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ ret = btrfs_csum_one_bio(root, inode, bio, offset, 1);
+ BUG_ON(ret); /* -ENOMEM */
+ return 0;
+}
+
+static void btrfs_end_dio_bio(struct bio *bio, int err)
+{
+ struct btrfs_dio_private *dip = bio->bi_private;
+
+ if (err)
+ btrfs_warn(BTRFS_I(dip->inode)->root->fs_info,
+ "direct IO failed ino %llu rw %lu sector %#Lx len %u err no %d",
+ btrfs_ino(dip->inode), bio->bi_rw,
+ (unsigned long long)bio->bi_iter.bi_sector,
+ bio->bi_iter.bi_size, err);
+
+ if (dip->subio_endio)
+ err = dip->subio_endio(dip->inode, btrfs_io_bio(bio), err);
+
+ if (err) {
+ dip->errors = 1;
+
+ /*
+ * before atomic variable goto zero, we must make sure
+ * dip->errors is perceived to be set.
+ */
+ smp_mb__before_atomic();
+ }
+
+ /* if there are more bios still pending for this dio, just exit */
+ if (!atomic_dec_and_test(&dip->pending_bios))
+ goto out;
+
+ if (dip->errors) {
+ bio_io_error(dip->orig_bio);
+ } else {
+ set_bit(BIO_UPTODATE, &dip->dio_bio->bi_flags);
+ bio_endio(dip->orig_bio, 0);
+ }
+out:
+ bio_put(bio);
+}
+
+static struct bio *btrfs_dio_bio_alloc(struct block_device *bdev,
+ u64 first_sector, gfp_t gfp_flags)
+{
+ int nr_vecs = bio_get_nr_vecs(bdev);
+ return btrfs_bio_alloc(bdev, first_sector, nr_vecs, gfp_flags);
+}
+
+static inline int btrfs_lookup_and_bind_dio_csum(struct btrfs_root *root,
+ struct inode *inode,
+ struct btrfs_dio_private *dip,
+ struct bio *bio,
+ u64 file_offset)
+{
+ struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
+ struct btrfs_io_bio *orig_io_bio = btrfs_io_bio(dip->orig_bio);
+ int ret;
+
+ /*
+ * We load all the csum data we need when we submit
+ * the first bio to reduce the csum tree search and
+ * contention.
+ */
+ if (dip->logical_offset == file_offset) {
+ ret = btrfs_lookup_bio_sums_dio(root, inode, dip->orig_bio,
+ file_offset);
+ if (ret)
+ return ret;
+ }
+
+ if (bio == dip->orig_bio)
+ return 0;
+
+ file_offset -= dip->logical_offset;
+ file_offset >>= inode->i_sb->s_blocksize_bits;
+ io_bio->csum = (u8 *)(((u32 *)orig_io_bio->csum) + file_offset);
+
+ return 0;
+}
+
+static inline int __btrfs_submit_dio_bio(struct bio *bio, struct inode *inode,
+ int rw, u64 file_offset, int skip_sum,
+ int async_submit)
+{
+ struct btrfs_dio_private *dip = bio->bi_private;
+ int write = rw & REQ_WRITE;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ int ret;
+
+ if (async_submit)
+ async_submit = !atomic_read(&BTRFS_I(inode)->sync_writers);
+
+ bio_get(bio);
+
+ if (!write) {
+ ret = btrfs_bio_wq_end_io(root->fs_info, bio,
+ BTRFS_WQ_ENDIO_DATA);
+ if (ret)
+ goto err;
+ }
+
+ if (skip_sum)
+ goto map;
+
+ if (write && async_submit) {
+ ret = btrfs_wq_submit_bio(root->fs_info,
+ inode, rw, bio, 0, 0,
+ file_offset,
+ __btrfs_submit_bio_start_direct_io,
+ __btrfs_submit_bio_done);
+ goto err;
+ } else if (write) {
+ /*
+ * If we aren't doing async submit, calculate the csum of the
+ * bio now.
+ */
+ ret = btrfs_csum_one_bio(root, inode, bio, file_offset, 1);
+ if (ret)
+ goto err;
+ } else {
+ ret = btrfs_lookup_and_bind_dio_csum(root, inode, dip, bio,
+ file_offset);
+ if (ret)
+ goto err;
+ }
+map:
+ ret = btrfs_map_bio(root, rw, bio, 0, async_submit);
+err:
+ bio_put(bio);
+ return ret;
+}
+
+static int btrfs_submit_direct_hook(int rw, struct btrfs_dio_private *dip,
+ int skip_sum)
+{
+ struct inode *inode = dip->inode;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct bio *bio;
+ struct bio *orig_bio = dip->orig_bio;
+ struct bio_vec *bvec = orig_bio->bi_io_vec;
+ u64 start_sector = orig_bio->bi_iter.bi_sector;
+ u64 file_offset = dip->logical_offset;
+ u64 submit_len = 0;
+ u64 map_length;
+ int nr_pages = 0;
+ int ret;
+ int async_submit = 0;
+
+ map_length = orig_bio->bi_iter.bi_size;
+ ret = btrfs_map_block(root->fs_info, rw, start_sector << 9,
+ &map_length, NULL, 0);
+ if (ret)
+ return -EIO;
+
+ if (map_length >= orig_bio->bi_iter.bi_size) {
+ bio = orig_bio;
+ dip->flags |= BTRFS_DIO_ORIG_BIO_SUBMITTED;
+ goto submit;
+ }
+
+ /* async crcs make it difficult to collect full stripe writes. */
+ if (btrfs_get_alloc_profile(root, 1) & BTRFS_BLOCK_GROUP_RAID56_MASK)
+ async_submit = 0;
+ else
+ async_submit = 1;
+
+ bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev, start_sector, GFP_NOFS);
+ if (!bio)
+ return -ENOMEM;
+
+ bio->bi_private = dip;
+ bio->bi_end_io = btrfs_end_dio_bio;
+ btrfs_io_bio(bio)->logical = file_offset;
+ atomic_inc(&dip->pending_bios);
+
+ while (bvec <= (orig_bio->bi_io_vec + orig_bio->bi_vcnt - 1)) {
+ if (map_length < submit_len + bvec->bv_len ||
+ bio_add_page(bio, bvec->bv_page, bvec->bv_len,
+ bvec->bv_offset) < bvec->bv_len) {
+ /*
+ * inc the count before we submit the bio so
+ * we know the end IO handler won't happen before
+ * we inc the count. Otherwise, the dip might get freed
+ * before we're done setting it up
+ */
+ atomic_inc(&dip->pending_bios);
+ ret = __btrfs_submit_dio_bio(bio, inode, rw,
+ file_offset, skip_sum,
+ async_submit);
+ if (ret) {
+ bio_put(bio);
+ atomic_dec(&dip->pending_bios);
+ goto out_err;
+ }
+
+ start_sector += submit_len >> 9;
+ file_offset += submit_len;
+
+ submit_len = 0;
+ nr_pages = 0;
+
+ bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev,
+ start_sector, GFP_NOFS);
+ if (!bio)
+ goto out_err;
+ bio->bi_private = dip;
+ bio->bi_end_io = btrfs_end_dio_bio;
+ btrfs_io_bio(bio)->logical = file_offset;
+
+ map_length = orig_bio->bi_iter.bi_size;
+ ret = btrfs_map_block(root->fs_info, rw,
+ start_sector << 9,
+ &map_length, NULL, 0);
+ if (ret) {
+ bio_put(bio);
+ goto out_err;
+ }
+ } else {
+ submit_len += bvec->bv_len;
+ nr_pages++;
+ bvec++;
+ }
+ }
+
+submit:
+ ret = __btrfs_submit_dio_bio(bio, inode, rw, file_offset, skip_sum,
+ async_submit);
+ if (!ret)
+ return 0;
+
+ bio_put(bio);
+out_err:
+ dip->errors = 1;
+ /*
+ * before atomic variable goto zero, we must
+ * make sure dip->errors is perceived to be set.
+ */
+ smp_mb__before_atomic();
+ if (atomic_dec_and_test(&dip->pending_bios))
+ bio_io_error(dip->orig_bio);
+
+ /* bio_end_io() will handle error, so we needn't return it */
+ return 0;
+}
+
+static void btrfs_submit_direct(int rw, struct bio *dio_bio,
+ struct inode *inode, loff_t file_offset)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_dio_private *dip;
+ struct bio *io_bio;
+ struct btrfs_io_bio *btrfs_bio;
+ int skip_sum;
+ int write = rw & REQ_WRITE;
+ int ret = 0;
+
+ skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
+
+ io_bio = btrfs_bio_clone(dio_bio, GFP_NOFS);
+ if (!io_bio) {
+ ret = -ENOMEM;
+ goto free_ordered;
+ }
+
+ dip = kzalloc(sizeof(*dip), GFP_NOFS);
+ if (!dip) {
+ ret = -ENOMEM;
+ goto free_io_bio;
+ }
+
+ dip->private = dio_bio->bi_private;
+ dip->inode = inode;
+ dip->logical_offset = file_offset;
+ dip->bytes = dio_bio->bi_iter.bi_size;
+ dip->disk_bytenr = (u64)dio_bio->bi_iter.bi_sector << 9;
+ io_bio->bi_private = dip;
+ dip->orig_bio = io_bio;
+ dip->dio_bio = dio_bio;
+ atomic_set(&dip->pending_bios, 0);
+ btrfs_bio = btrfs_io_bio(io_bio);
+ btrfs_bio->logical = file_offset;
+
+ if (write) {
+ io_bio->bi_end_io = btrfs_endio_direct_write;
+ } else {
+ io_bio->bi_end_io = btrfs_endio_direct_read;
+ dip->subio_endio = btrfs_subio_endio_read;
+ }
+
+ ret = btrfs_submit_direct_hook(rw, dip, skip_sum);
+ if (!ret)
+ return;
+
+ if (btrfs_bio->end_io)
+ btrfs_bio->end_io(btrfs_bio, ret);
+free_io_bio:
+ bio_put(io_bio);
+
+free_ordered:
+ /*
+ * If this is a write, we need to clean up the reserved space and kill
+ * the ordered extent.
+ */
+ if (write) {
+ struct btrfs_ordered_extent *ordered;
+ ordered = btrfs_lookup_ordered_extent(inode, file_offset);
+ if (!test_bit(BTRFS_ORDERED_PREALLOC, &ordered->flags) &&
+ !test_bit(BTRFS_ORDERED_NOCOW, &ordered->flags))
+ btrfs_free_reserved_extent(root, ordered->start,
+ ordered->disk_len, 1);
+ btrfs_put_ordered_extent(ordered);
+ btrfs_put_ordered_extent(ordered);
+ }
+ bio_endio(dio_bio, ret);
+}
+
+static ssize_t check_direct_IO(struct btrfs_root *root, struct kiocb *iocb,
+ const struct iov_iter *iter, loff_t offset)
+{
+ int seg;
+ int i;
+ unsigned blocksize_mask = root->sectorsize - 1;
+ ssize_t retval = -EINVAL;
+
+ if (offset & blocksize_mask)
+ goto out;
+
+ if (iov_iter_alignment(iter) & blocksize_mask)
+ goto out;
+
+ /* If this is a write we don't need to check anymore */
+ if (iov_iter_rw(iter) == WRITE)
+ return 0;
+ /*
+ * Check to make sure we don't have duplicate iov_base's in this
+ * iovec, if so return EINVAL, otherwise we'll get csum errors
+ * when reading back.
+ */
+ for (seg = 0; seg < iter->nr_segs; seg++) {
+ for (i = seg + 1; i < iter->nr_segs; i++) {
+ if (iter->iov[seg].iov_base == iter->iov[i].iov_base)
+ goto out;
+ }
+ }
+ retval = 0;
+out:
+ return retval;
+}
+
+static ssize_t btrfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
+ loff_t offset)
+{
+ struct file *file = iocb->ki_filp;
+ struct inode *inode = file->f_mapping->host;
+ u64 outstanding_extents = 0;
+ size_t count = 0;
+ int flags = 0;
+ bool wakeup = true;
+ bool relock = false;
+ ssize_t ret;
+
+ if (check_direct_IO(BTRFS_I(inode)->root, iocb, iter, offset))
+ return 0;
+
+ inode_dio_begin(inode);
+ smp_mb__after_atomic();
+
+ /*
+ * The generic stuff only does filemap_write_and_wait_range, which
+ * isn't enough if we've written compressed pages to this area, so
+ * we need to flush the dirty pages again to make absolutely sure
+ * that any outstanding dirty pages are on disk.
+ */
+ count = iov_iter_count(iter);
+ if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
+ &BTRFS_I(inode)->runtime_flags))
+ filemap_fdatawrite_range(inode->i_mapping, offset,
+ offset + count - 1);
+
+ if (iov_iter_rw(iter) == WRITE) {
+ /*
+ * If the write DIO is beyond the EOF, we need update
+ * the isize, but it is protected by i_mutex. So we can
+ * not unlock the i_mutex at this case.
+ */
+ if (offset + count <= inode->i_size) {
+ mutex_unlock(&inode->i_mutex);
+ relock = true;
+ }
+ ret = btrfs_delalloc_reserve_space(inode, count);
+ if (ret)
+ goto out;
+ outstanding_extents = div64_u64(count +
+ BTRFS_MAX_EXTENT_SIZE - 1,
+ BTRFS_MAX_EXTENT_SIZE);
+
+ /*
+ * We need to know how many extents we reserved so that we can
+ * do the accounting properly if we go over the number we
+ * originally calculated. Abuse current->journal_info for this.
+ */
+ current->journal_info = &outstanding_extents;
+ } else if (test_bit(BTRFS_INODE_READDIO_NEED_LOCK,
+ &BTRFS_I(inode)->runtime_flags)) {
+ inode_dio_end(inode);
+ flags = DIO_LOCKING | DIO_SKIP_HOLES;
+ wakeup = false;
+ }
+
+ ret = __blockdev_direct_IO(iocb, inode,
+ BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev,
+ iter, offset, btrfs_get_blocks_direct, NULL,
+ btrfs_submit_direct, flags);
+ if (iov_iter_rw(iter) == WRITE) {
+ current->journal_info = NULL;
+ if (ret < 0 && ret != -EIOCBQUEUED)
+ btrfs_delalloc_release_space(inode, count);
+ else if (ret >= 0 && (size_t)ret < count)
+ btrfs_delalloc_release_space(inode,
+ count - (size_t)ret);
+ }
+out:
+ if (wakeup)
+ inode_dio_end(inode);
+ if (relock)
+ mutex_lock(&inode->i_mutex);
+
+ return ret;
+}
+
+#define BTRFS_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC)
+
+static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
+ __u64 start, __u64 len)
+{
+ int ret;
+
+ ret = fiemap_check_flags(fieinfo, BTRFS_FIEMAP_FLAGS);
+ if (ret)
+ return ret;
+
+ return extent_fiemap(inode, fieinfo, start, len, btrfs_get_extent_fiemap);
+}
+
+int btrfs_readpage(struct file *file, struct page *page)
+{
+ struct extent_io_tree *tree;
+ tree = &BTRFS_I(page->mapping->host)->io_tree;
+ return extent_read_full_page(tree, page, btrfs_get_extent, 0);
+}
+
+static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
+{
+ struct extent_io_tree *tree;
+
+
+ if (current->flags & PF_MEMALLOC) {
+ redirty_page_for_writepage(wbc, page);
+ unlock_page(page);
+ return 0;
+ }
+ tree = &BTRFS_I(page->mapping->host)->io_tree;
+ return extent_write_full_page(tree, page, btrfs_get_extent, wbc);
+}
+
+static int btrfs_writepages(struct address_space *mapping,
+ struct writeback_control *wbc)
+{
+ struct extent_io_tree *tree;
+
+ tree = &BTRFS_I(mapping->host)->io_tree;
+ return extent_writepages(tree, mapping, btrfs_get_extent, wbc);
+}
+
+static int
+btrfs_readpages(struct file *file, struct address_space *mapping,
+ struct list_head *pages, unsigned nr_pages)
+{
+ struct extent_io_tree *tree;
+ tree = &BTRFS_I(mapping->host)->io_tree;
+ return extent_readpages(tree, mapping, pages, nr_pages,
+ btrfs_get_extent);
+}
+static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags)
+{
+ struct extent_io_tree *tree;
+ struct extent_map_tree *map;
+ int ret;
+
+ tree = &BTRFS_I(page->mapping->host)->io_tree;
+ map = &BTRFS_I(page->mapping->host)->extent_tree;
+ ret = try_release_extent_mapping(map, tree, page, gfp_flags);
+ if (ret == 1) {
+ ClearPagePrivate(page);
+ set_page_private(page, 0);
+ page_cache_release(page);
+ }
+ return ret;
+}
+
+static int btrfs_releasepage(struct page *page, gfp_t gfp_flags)
+{
+ if (PageWriteback(page) || PageDirty(page))
+ return 0;
+ return __btrfs_releasepage(page, gfp_flags & GFP_NOFS);
+}
+
+static void btrfs_invalidatepage(struct page *page, unsigned int offset,
+ unsigned int length)
+{
+ struct inode *inode = page->mapping->host;
+ struct extent_io_tree *tree;
+ struct btrfs_ordered_extent *ordered;
+ struct extent_state *cached_state = NULL;
+ u64 page_start = page_offset(page);
+ u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
+ int inode_evicting = inode->i_state & I_FREEING;
+
+ /*
+ * we have the page locked, so new writeback can't start,
+ * and the dirty bit won't be cleared while we are here.
+ *
+ * Wait for IO on this page so that we can safely clear
+ * the PagePrivate2 bit and do ordered accounting
+ */
+ wait_on_page_writeback(page);
+
+ tree = &BTRFS_I(inode)->io_tree;
+ if (offset) {
+ btrfs_releasepage(page, GFP_NOFS);
+ return;
+ }
+
+ if (!inode_evicting)
+ lock_extent_bits(tree, page_start, page_end, 0, &cached_state);
+ ordered = btrfs_lookup_ordered_extent(inode, page_start);
+ if (ordered) {
+ /*
+ * IO on this page will never be started, so we need
+ * to account for any ordered extents now
+ */
+ if (!inode_evicting)
+ clear_extent_bit(tree, page_start, page_end,
+ EXTENT_DIRTY | EXTENT_DELALLOC |
+ EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
+ EXTENT_DEFRAG, 1, 0, &cached_state,
+ GFP_NOFS);
+ /*
+ * whoever cleared the private bit is responsible
+ * for the finish_ordered_io
+ */
+ if (TestClearPagePrivate2(page)) {
+ struct btrfs_ordered_inode_tree *tree;
+ u64 new_len;
+
+ tree = &BTRFS_I(inode)->ordered_tree;
+
+ spin_lock_irq(&tree->lock);
+ set_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags);
+ new_len = page_start - ordered->file_offset;
+ if (new_len < ordered->truncated_len)
+ ordered->truncated_len = new_len;
+ spin_unlock_irq(&tree->lock);
+
+ if (btrfs_dec_test_ordered_pending(inode, &ordered,
+ page_start,
+ PAGE_CACHE_SIZE, 1))
+ btrfs_finish_ordered_io(ordered);
+ }
+ btrfs_put_ordered_extent(ordered);
+ if (!inode_evicting) {
+ cached_state = NULL;
+ lock_extent_bits(tree, page_start, page_end, 0,
+ &cached_state);
+ }
+ }
+
+ if (!inode_evicting) {
+ clear_extent_bit(tree, page_start, page_end,
+ EXTENT_LOCKED | EXTENT_DIRTY |
+ EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
+ EXTENT_DEFRAG, 1, 1,
+ &cached_state, GFP_NOFS);
+
+ __btrfs_releasepage(page, GFP_NOFS);
+ }
+
+ ClearPageChecked(page);
+ if (PagePrivate(page)) {
+ ClearPagePrivate(page);
+ set_page_private(page, 0);
+ page_cache_release(page);
+ }
+}
+
+/*
+ * btrfs_page_mkwrite() is not allowed to change the file size as it gets
+ * called from a page fault handler when a page is first dirtied. Hence we must
+ * be careful to check for EOF conditions here. We set the page up correctly
+ * for a written page which means we get ENOSPC checking when writing into
+ * holes and correct delalloc and unwritten extent mapping on filesystems that
+ * support these features.
+ *
+ * We are not allowed to take the i_mutex here so we have to play games to
+ * protect against truncate races as the page could now be beyond EOF. Because
+ * vmtruncate() writes the inode size before removing pages, once we have the
+ * page lock we can determine safely if the page is beyond EOF. If it is not
+ * beyond EOF, then the page is guaranteed safe against truncation until we
+ * unlock the page.
+ */
+int btrfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
+{
+ struct page *page = vmf->page;
+ struct inode *inode = file_inode(vma->vm_file);
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
+ struct btrfs_ordered_extent *ordered;
+ struct extent_state *cached_state = NULL;
+ char *kaddr;
+ unsigned long zero_start;
+ loff_t size;
+ int ret;
+ int reserved = 0;
+ u64 page_start;
+ u64 page_end;
+
+ sb_start_pagefault(inode->i_sb);
+ ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
+ if (!ret) {
+ ret = file_update_time(vma->vm_file);
+ reserved = 1;
+ }
+ if (ret) {
+ if (ret == -ENOMEM)
+ ret = VM_FAULT_OOM;
+ else /* -ENOSPC, -EIO, etc */
+ ret = VM_FAULT_SIGBUS;
+ if (reserved)
+ goto out;
+ goto out_noreserve;
+ }
+
+ ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */
+again:
+ lock_page(page);
+ size = i_size_read(inode);
+ page_start = page_offset(page);
+ page_end = page_start + PAGE_CACHE_SIZE - 1;
+
+ if ((page->mapping != inode->i_mapping) ||
+ (page_start >= size)) {
+ /* page got truncated out from underneath us */
+ goto out_unlock;
+ }
+ wait_on_page_writeback(page);
+
+ lock_extent_bits(io_tree, page_start, page_end, 0, &cached_state);
+ set_page_extent_mapped(page);
+
+ /*
+ * we can't set the delalloc bits if there are pending ordered
+ * extents. Drop our locks and wait for them to finish
+ */
+ ordered = btrfs_lookup_ordered_extent(inode, page_start);
+ if (ordered) {
+ unlock_extent_cached(io_tree, page_start, page_end,
+ &cached_state, GFP_NOFS);
+ unlock_page(page);
+ btrfs_start_ordered_extent(inode, ordered, 1);
+ btrfs_put_ordered_extent(ordered);
+ goto again;
+ }
+
+ /*
+ * XXX - page_mkwrite gets called every time the page is dirtied, even
+ * if it was already dirty, so for space accounting reasons we need to
+ * clear any delalloc bits for the range we are fixing to save. There
+ * is probably a better way to do this, but for now keep consistent with
+ * prepare_pages in the normal write path.
+ */
+ clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
+ EXTENT_DIRTY | EXTENT_DELALLOC |
+ EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
+ 0, 0, &cached_state, GFP_NOFS);
+
+ ret = btrfs_set_extent_delalloc(inode, page_start, page_end,
+ &cached_state);
+ if (ret) {
+ unlock_extent_cached(io_tree, page_start, page_end,
+ &cached_state, GFP_NOFS);
+ ret = VM_FAULT_SIGBUS;
+ goto out_unlock;
+ }
+ ret = 0;
+
+ /* page is wholly or partially inside EOF */
+ if (page_start + PAGE_CACHE_SIZE > size)
+ zero_start = size & ~PAGE_CACHE_MASK;
+ else
+ zero_start = PAGE_CACHE_SIZE;
+
+ if (zero_start != PAGE_CACHE_SIZE) {
+ kaddr = kmap(page);
+ memset(kaddr + zero_start, 0, PAGE_CACHE_SIZE - zero_start);
+ flush_dcache_page(page);
+ kunmap(page);
+ }
+ ClearPageChecked(page);
+ set_page_dirty(page);
+ SetPageUptodate(page);
+
+ BTRFS_I(inode)->last_trans = root->fs_info->generation;
+ BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid;
+ BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit;
+
+ unlock_extent_cached(io_tree, page_start, page_end, &cached_state, GFP_NOFS);
+
+out_unlock:
+ if (!ret) {
+ sb_end_pagefault(inode->i_sb);
+ return VM_FAULT_LOCKED;
+ }
+ unlock_page(page);
+out:
+ btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
+out_noreserve:
+ sb_end_pagefault(inode->i_sb);
+ return ret;
+}
+
+static int btrfs_truncate(struct inode *inode)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_block_rsv *rsv;
+ int ret = 0;
+ int err = 0;
+ struct btrfs_trans_handle *trans;
+ u64 mask = root->sectorsize - 1;
+ u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
+
+ ret = btrfs_wait_ordered_range(inode, inode->i_size & (~mask),
+ (u64)-1);
+ if (ret)
+ return ret;
+
+ /*
+ * Yes ladies and gentelment, this is indeed ugly. The fact is we have
+ * 3 things going on here
+ *
+ * 1) We need to reserve space for our orphan item and the space to
+ * delete our orphan item. Lord knows we don't want to have a dangling
+ * orphan item because we didn't reserve space to remove it.
+ *
+ * 2) We need to reserve space to update our inode.
+ *
+ * 3) We need to have something to cache all the space that is going to
+ * be free'd up by the truncate operation, but also have some slack
+ * space reserved in case it uses space during the truncate (thank you
+ * very much snapshotting).
+ *
+ * And we need these to all be seperate. The fact is we can use alot of
+ * space doing the truncate, and we have no earthly idea how much space
+ * we will use, so we need the truncate reservation to be seperate so it
+ * doesn't end up using space reserved for updating the inode or
+ * removing the orphan item. We also need to be able to stop the
+ * transaction and start a new one, which means we need to be able to
+ * update the inode several times, and we have no idea of knowing how
+ * many times that will be, so we can't just reserve 1 item for the
+ * entirety of the opration, so that has to be done seperately as well.
+ * Then there is the orphan item, which does indeed need to be held on
+ * to for the whole operation, and we need nobody to touch this reserved
+ * space except the orphan code.
+ *
+ * So that leaves us with
+ *
+ * 1) root->orphan_block_rsv - for the orphan deletion.
+ * 2) rsv - for the truncate reservation, which we will steal from the
+ * transaction reservation.
+ * 3) fs_info->trans_block_rsv - this will have 1 items worth left for
+ * updating the inode.
+ */
+ rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
+ if (!rsv)
+ return -ENOMEM;
+ rsv->size = min_size;
+ rsv->failfast = 1;
+
+ /*
+ * 1 for the truncate slack space
+ * 1 for updating the inode.
+ */
+ trans = btrfs_start_transaction(root, 2);
+ if (IS_ERR(trans)) {
+ err = PTR_ERR(trans);
+ goto out;
+ }
+
+ /* Migrate the slack space for the truncate to our reserve */
+ ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv, rsv,
+ min_size);
+ BUG_ON(ret);
+
+ /*
+ * So if we truncate and then write and fsync we normally would just
+ * write the extents that changed, which is a problem if we need to
+ * first truncate that entire inode. So set this flag so we write out
+ * all of the extents in the inode to the sync log so we're completely
+ * safe.
+ */
+ set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
+ trans->block_rsv = rsv;
+
+ while (1) {
+ ret = btrfs_truncate_inode_items(trans, root, inode,
+ inode->i_size,
+ BTRFS_EXTENT_DATA_KEY);
+ if (ret != -ENOSPC && ret != -EAGAIN) {
+ err = ret;
+ break;
+ }
+
+ trans->block_rsv = &root->fs_info->trans_block_rsv;
+ ret = btrfs_update_inode(trans, root, inode);
+ if (ret) {
+ err = ret;
+ break;
+ }
+
+ btrfs_end_transaction(trans, root);
+ btrfs_btree_balance_dirty(root);
+
+ trans = btrfs_start_transaction(root, 2);
+ if (IS_ERR(trans)) {
+ ret = err = PTR_ERR(trans);
+ trans = NULL;
+ break;
+ }
+
+ ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv,
+ rsv, min_size);
+ BUG_ON(ret); /* shouldn't happen */
+ trans->block_rsv = rsv;
+ }
+
+ if (ret == 0 && inode->i_nlink > 0) {
+ trans->block_rsv = root->orphan_block_rsv;
+ ret = btrfs_orphan_del(trans, inode);
+ if (ret)
+ err = ret;
+ }
+
+ if (trans) {
+ trans->block_rsv = &root->fs_info->trans_block_rsv;
+ ret = btrfs_update_inode(trans, root, inode);
+ if (ret && !err)
+ err = ret;
+
+ ret = btrfs_end_transaction(trans, root);
+ btrfs_btree_balance_dirty(root);
+ }
+
+out:
+ btrfs_free_block_rsv(root, rsv);
+
+ if (ret && !err)
+ err = ret;
+
+ return err;
+}
+
+/*
+ * create a new subvolume directory/inode (helper for the ioctl).
+ */
+int btrfs_create_subvol_root(struct btrfs_trans_handle *trans,
+ struct btrfs_root *new_root,
+ struct btrfs_root *parent_root,
+ u64 new_dirid)
+{
+ struct inode *inode;
+ int err;
+ u64 index = 0;
+
+ inode = btrfs_new_inode(trans, new_root, NULL, "..", 2,
+ new_dirid, new_dirid,
+ S_IFDIR | (~current_umask() & S_IRWXUGO),
+ &index);
+ if (IS_ERR(inode))
+ return PTR_ERR(inode);
+ inode->i_op = &btrfs_dir_inode_operations;
+ inode->i_fop = &btrfs_dir_file_operations;
+
+ set_nlink(inode, 1);
+ btrfs_i_size_write(inode, 0);
+ unlock_new_inode(inode);
+
+ err = btrfs_subvol_inherit_props(trans, new_root, parent_root);
+ if (err)
+ btrfs_err(new_root->fs_info,
+ "error inheriting subvolume %llu properties: %d",
+ new_root->root_key.objectid, err);
+
+ err = btrfs_update_inode(trans, new_root, inode);
+
+ iput(inode);
+ return err;
+}
+
+struct inode *btrfs_alloc_inode(struct super_block *sb)
+{
+ struct btrfs_inode *ei;
+ struct inode *inode;
+
+ ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
+ if (!ei)
+ return NULL;
+
+ ei->root = NULL;
+ ei->generation = 0;
+ ei->last_trans = 0;
+ ei->last_sub_trans = 0;
+ ei->logged_trans = 0;
+ ei->delalloc_bytes = 0;
+ ei->defrag_bytes = 0;
+ ei->disk_i_size = 0;
+ ei->flags = 0;
+ ei->csum_bytes = 0;
+ ei->index_cnt = (u64)-1;
+ ei->dir_index = 0;
+ ei->last_unlink_trans = 0;
+ ei->last_log_commit = 0;
+
+ spin_lock_init(&ei->lock);
+ ei->outstanding_extents = 0;
+ ei->reserved_extents = 0;
+
+ ei->runtime_flags = 0;
+ ei->force_compress = BTRFS_COMPRESS_NONE;
+
+ ei->delayed_node = NULL;
+
+ ei->i_otime.tv_sec = 0;
+ ei->i_otime.tv_nsec = 0;
+
+ inode = &ei->vfs_inode;
+ extent_map_tree_init(&ei->extent_tree);
+ extent_io_tree_init(&ei->io_tree, &inode->i_data);
+ extent_io_tree_init(&ei->io_failure_tree, &inode->i_data);
+ ei->io_tree.track_uptodate = 1;
+ ei->io_failure_tree.track_uptodate = 1;
+ atomic_set(&ei->sync_writers, 0);
+ mutex_init(&ei->log_mutex);
+ mutex_init(&ei->delalloc_mutex);
+ btrfs_ordered_inode_tree_init(&ei->ordered_tree);
+ INIT_LIST_HEAD(&ei->delalloc_inodes);
+ RB_CLEAR_NODE(&ei->rb_node);
+
+ return inode;
+}
+
+#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
+void btrfs_test_destroy_inode(struct inode *inode)
+{
+ btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
+ kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
+}
+#endif
+
+static void btrfs_i_callback(struct rcu_head *head)
+{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
+}
+
+void btrfs_destroy_inode(struct inode *inode)
+{
+ struct btrfs_ordered_extent *ordered;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+
+ WARN_ON(!hlist_empty(&inode->i_dentry));
+ WARN_ON(inode->i_data.nrpages);
+ WARN_ON(BTRFS_I(inode)->outstanding_extents);
+ WARN_ON(BTRFS_I(inode)->reserved_extents);
+ WARN_ON(BTRFS_I(inode)->delalloc_bytes);
+ WARN_ON(BTRFS_I(inode)->csum_bytes);
+ WARN_ON(BTRFS_I(inode)->defrag_bytes);
+
+ /*
+ * This can happen where we create an inode, but somebody else also
+ * created the same inode and we need to destroy the one we already
+ * created.
+ */
+ if (!root)
+ goto free;
+
+ if (test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
+ &BTRFS_I(inode)->runtime_flags)) {
+ btrfs_info(root->fs_info, "inode %llu still on the orphan list",
+ btrfs_ino(inode));
+ atomic_dec(&root->orphan_inodes);
+ }
+
+ while (1) {
+ ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1);
+ if (!ordered)
+ break;
+ else {
+ btrfs_err(root->fs_info, "found ordered extent %llu %llu on inode cleanup",
+ ordered->file_offset, ordered->len);
+ btrfs_remove_ordered_extent(inode, ordered);
+ btrfs_put_ordered_extent(ordered);
+ btrfs_put_ordered_extent(ordered);
+ }
+ }
+ inode_tree_del(inode);
+ btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
+free:
+ call_rcu(&inode->i_rcu, btrfs_i_callback);
+}
+
+int btrfs_drop_inode(struct inode *inode)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+
+ if (root == NULL)
+ return 1;
+
+ /* the snap/subvol tree is on deleting */
+ if (btrfs_root_refs(&root->root_item) == 0)
+ return 1;
+ else
+ return generic_drop_inode(inode);
+}
+
+static void init_once(void *foo)
+{
+ struct btrfs_inode *ei = (struct btrfs_inode *) foo;
+
+ inode_init_once(&ei->vfs_inode);
+}
+
+void btrfs_destroy_cachep(void)
+{
+ /*
+ * Make sure all delayed rcu free inodes are flushed before we
+ * destroy cache.
+ */
+ rcu_barrier();
+ if (btrfs_inode_cachep)
+ kmem_cache_destroy(btrfs_inode_cachep);
+ if (btrfs_trans_handle_cachep)
+ kmem_cache_destroy(btrfs_trans_handle_cachep);
+ if (btrfs_transaction_cachep)
+ kmem_cache_destroy(btrfs_transaction_cachep);
+ if (btrfs_path_cachep)
+ kmem_cache_destroy(btrfs_path_cachep);
+ if (btrfs_free_space_cachep)
+ kmem_cache_destroy(btrfs_free_space_cachep);
+ if (btrfs_delalloc_work_cachep)
+ kmem_cache_destroy(btrfs_delalloc_work_cachep);
+}
+
+int btrfs_init_cachep(void)
+{
+ btrfs_inode_cachep = kmem_cache_create("btrfs_inode",
+ sizeof(struct btrfs_inode), 0,
+ SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, init_once);
+ if (!btrfs_inode_cachep)
+ goto fail;
+
+ btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle",
+ sizeof(struct btrfs_trans_handle), 0,
+ SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
+ if (!btrfs_trans_handle_cachep)
+ goto fail;
+
+ btrfs_transaction_cachep = kmem_cache_create("btrfs_transaction",
+ sizeof(struct btrfs_transaction), 0,
+ SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
+ if (!btrfs_transaction_cachep)
+ goto fail;
+
+ btrfs_path_cachep = kmem_cache_create("btrfs_path",
+ sizeof(struct btrfs_path), 0,
+ SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
+ if (!btrfs_path_cachep)
+ goto fail;
+
+ btrfs_free_space_cachep = kmem_cache_create("btrfs_free_space",
+ sizeof(struct btrfs_free_space), 0,
+ SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
+ if (!btrfs_free_space_cachep)
+ goto fail;
+
+ btrfs_delalloc_work_cachep = kmem_cache_create("btrfs_delalloc_work",
+ sizeof(struct btrfs_delalloc_work), 0,
+ SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD,
+ NULL);
+ if (!btrfs_delalloc_work_cachep)
+ goto fail;
+
+ return 0;
+fail:
+ btrfs_destroy_cachep();
+ return -ENOMEM;
+}
+
+static int btrfs_getattr(struct vfsmount *mnt,
+ struct dentry *dentry, struct kstat *stat)
+{
+ u64 delalloc_bytes;
+ struct inode *inode = d_inode(dentry);
+ u32 blocksize = inode->i_sb->s_blocksize;
+
+ generic_fillattr(inode, stat);
+ stat->dev = BTRFS_I(inode)->root->anon_dev;
+ stat->blksize = PAGE_CACHE_SIZE;
+
+ spin_lock(&BTRFS_I(inode)->lock);
+ delalloc_bytes = BTRFS_I(inode)->delalloc_bytes;
+ spin_unlock(&BTRFS_I(inode)->lock);
+ stat->blocks = (ALIGN(inode_get_bytes(inode), blocksize) +
+ ALIGN(delalloc_bytes, blocksize)) >> 9;
+ return 0;
+}
+
+static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
+ struct inode *new_dir, struct dentry *new_dentry)
+{
+ struct btrfs_trans_handle *trans;
+ struct btrfs_root *root = BTRFS_I(old_dir)->root;
+ struct btrfs_root *dest = BTRFS_I(new_dir)->root;
+ struct inode *new_inode = d_inode(new_dentry);
+ struct inode *old_inode = d_inode(old_dentry);
+ struct timespec ctime = CURRENT_TIME;
+ u64 index = 0;
+ u64 root_objectid;
+ int ret;
+ u64 old_ino = btrfs_ino(old_inode);
+
+ if (btrfs_ino(new_dir) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
+ return -EPERM;
+
+ /* we only allow rename subvolume link between subvolumes */
+ if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
+ return -EXDEV;
+
+ if (old_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID ||
+ (new_inode && btrfs_ino(new_inode) == BTRFS_FIRST_FREE_OBJECTID))
+ return -ENOTEMPTY;
+
+ if (S_ISDIR(old_inode->i_mode) && new_inode &&
+ new_inode->i_size > BTRFS_EMPTY_DIR_SIZE)
+ return -ENOTEMPTY;
+
+
+ /* check for collisions, even if the name isn't there */
+ ret = btrfs_check_dir_item_collision(dest, new_dir->i_ino,
+ new_dentry->d_name.name,
+ new_dentry->d_name.len);
+
+ if (ret) {
+ if (ret == -EEXIST) {
+ /* we shouldn't get
+ * eexist without a new_inode */
+ if (WARN_ON(!new_inode)) {
+ return ret;
+ }
+ } else {
+ /* maybe -EOVERFLOW */
+ return ret;
+ }
+ }
+ ret = 0;
+
+ /*
+ * we're using rename to replace one file with another. Start IO on it
+ * now so we don't add too much work to the end of the transaction
+ */
+ if (new_inode && S_ISREG(old_inode->i_mode) && new_inode->i_size)
+ filemap_flush(old_inode->i_mapping);
+
+ /* close the racy window with snapshot create/destroy ioctl */
+ if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
+ down_read(&root->fs_info->subvol_sem);
+ /*
+ * We want to reserve the absolute worst case amount of items. So if
+ * both inodes are subvols and we need to unlink them then that would
+ * require 4 item modifications, but if they are both normal inodes it
+ * would require 5 item modifications, so we'll assume their normal
+ * inodes. So 5 * 2 is 10, plus 1 for the new link, so 11 total items
+ * should cover the worst case number of items we'll modify.
+ */
+ trans = btrfs_start_transaction(root, 11);
+ if (IS_ERR(trans)) {
+ ret = PTR_ERR(trans);
+ goto out_notrans;
+ }
+
+ if (dest != root)
+ btrfs_record_root_in_trans(trans, dest);
+
+ ret = btrfs_set_inode_index(new_dir, &index);
+ if (ret)
+ goto out_fail;
+
+ BTRFS_I(old_inode)->dir_index = 0ULL;
+ if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
+ /* force full log commit if subvolume involved. */
+ btrfs_set_log_full_commit(root->fs_info, trans);
+ } else {
+ ret = btrfs_insert_inode_ref(trans, dest,
+ new_dentry->d_name.name,
+ new_dentry->d_name.len,
+ old_ino,
+ btrfs_ino(new_dir), index);
+ if (ret)
+ goto out_fail;
+ /*
+ * this is an ugly little race, but the rename is required
+ * to make sure that if we crash, the inode is either at the
+ * old name or the new one. pinning the log transaction lets
+ * us make sure we don't allow a log commit to come in after
+ * we unlink the name but before we add the new name back in.
+ */
+ btrfs_pin_log_trans(root);
+ }
+
+ inode_inc_iversion(old_dir);
+ inode_inc_iversion(new_dir);
+ inode_inc_iversion(old_inode);
+ old_dir->i_ctime = old_dir->i_mtime = ctime;
+ new_dir->i_ctime = new_dir->i_mtime = ctime;
+ old_inode->i_ctime = ctime;
+
+ if (old_dentry->d_parent != new_dentry->d_parent)
+ btrfs_record_unlink_dir(trans, old_dir, old_inode, 1);
+
+ if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
+ root_objectid = BTRFS_I(old_inode)->root->root_key.objectid;
+ ret = btrfs_unlink_subvol(trans, root, old_dir, root_objectid,
+ old_dentry->d_name.name,
+ old_dentry->d_name.len);
+ } else {
+ ret = __btrfs_unlink_inode(trans, root, old_dir,
+ d_inode(old_dentry),
+ old_dentry->d_name.name,
+ old_dentry->d_name.len);
+ if (!ret)
+ ret = btrfs_update_inode(trans, root, old_inode);
+ }
+ if (ret) {
+ btrfs_abort_transaction(trans, root, ret);
+ goto out_fail;
+ }
+
+ if (new_inode) {
+ inode_inc_iversion(new_inode);
+ new_inode->i_ctime = CURRENT_TIME;
+ if (unlikely(btrfs_ino(new_inode) ==
+ BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
+ root_objectid = BTRFS_I(new_inode)->location.objectid;
+ ret = btrfs_unlink_subvol(trans, dest, new_dir,
+ root_objectid,
+ new_dentry->d_name.name,
+ new_dentry->d_name.len);
+ BUG_ON(new_inode->i_nlink == 0);
+ } else {
+ ret = btrfs_unlink_inode(trans, dest, new_dir,
+ d_inode(new_dentry),
+ new_dentry->d_name.name,
+ new_dentry->d_name.len);
+ }
+ if (!ret && new_inode->i_nlink == 0)
+ ret = btrfs_orphan_add(trans, d_inode(new_dentry));
+ if (ret) {
+ btrfs_abort_transaction(trans, root, ret);
+ goto out_fail;
+ }
+ }
+
+ ret = btrfs_add_link(trans, new_dir, old_inode,
+ new_dentry->d_name.name,
+ new_dentry->d_name.len, 0, index);
+ if (ret) {
+ btrfs_abort_transaction(trans, root, ret);
+ goto out_fail;
+ }
+
+ if (old_inode->i_nlink == 1)
+ BTRFS_I(old_inode)->dir_index = index;
+
+ if (old_ino != BTRFS_FIRST_FREE_OBJECTID) {
+ struct dentry *parent = new_dentry->d_parent;
+ btrfs_log_new_name(trans, old_inode, old_dir, parent);
+ btrfs_end_log_trans(root);
+ }
+out_fail:
+ btrfs_end_transaction(trans, root);
+out_notrans:
+ if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
+ up_read(&root->fs_info->subvol_sem);
+
+ return ret;
+}
+
+static int btrfs_rename2(struct inode *old_dir, struct dentry *old_dentry,
+ struct inode *new_dir, struct dentry *new_dentry,
+ unsigned int flags)
+{
+ if (flags & ~RENAME_NOREPLACE)
+ return -EINVAL;
+
+ return btrfs_rename(old_dir, old_dentry, new_dir, new_dentry);
+}
+
+static void btrfs_run_delalloc_work(struct btrfs_work *work)
+{
+ struct btrfs_delalloc_work *delalloc_work;
+ struct inode *inode;
+
+ delalloc_work = container_of(work, struct btrfs_delalloc_work,
+ work);
+ inode = delalloc_work->inode;
+ if (delalloc_work->wait) {
+ btrfs_wait_ordered_range(inode, 0, (u64)-1);
+ } else {
+ filemap_flush(inode->i_mapping);
+ if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
+ &BTRFS_I(inode)->runtime_flags))
+ filemap_flush(inode->i_mapping);
+ }
+
+ if (delalloc_work->delay_iput)
+ btrfs_add_delayed_iput(inode);
+ else
+ iput(inode);
+ complete(&delalloc_work->completion);
+}
+
+struct btrfs_delalloc_work *btrfs_alloc_delalloc_work(struct inode *inode,
+ int wait, int delay_iput)
+{
+ struct btrfs_delalloc_work *work;
+
+ work = kmem_cache_zalloc(btrfs_delalloc_work_cachep, GFP_NOFS);
+ if (!work)
+ return NULL;
+
+ init_completion(&work->completion);
+ INIT_LIST_HEAD(&work->list);
+ work->inode = inode;
+ work->wait = wait;
+ work->delay_iput = delay_iput;
+ WARN_ON_ONCE(!inode);
+ btrfs_init_work(&work->work, btrfs_flush_delalloc_helper,
+ btrfs_run_delalloc_work, NULL, NULL);
+
+ return work;
+}
+
+void btrfs_wait_and_free_delalloc_work(struct btrfs_delalloc_work *work)
+{
+ wait_for_completion(&work->completion);
+ kmem_cache_free(btrfs_delalloc_work_cachep, work);
+}
+
+/*
+ * some fairly slow code that needs optimization. This walks the list
+ * of all the inodes with pending delalloc and forces them to disk.
+ */
+static int __start_delalloc_inodes(struct btrfs_root *root, int delay_iput,
+ int nr)
+{
+ struct btrfs_inode *binode;
+ struct inode *inode;
+ struct btrfs_delalloc_work *work, *next;
+ struct list_head works;
+ struct list_head splice;
+ int ret = 0;
+
+ INIT_LIST_HEAD(&works);
+ INIT_LIST_HEAD(&splice);
+
+ mutex_lock(&root->delalloc_mutex);
+ spin_lock(&root->delalloc_lock);
+ list_splice_init(&root->delalloc_inodes, &splice);
+ while (!list_empty(&splice)) {
+ binode = list_entry(splice.next, struct btrfs_inode,
+ delalloc_inodes);
+
+ list_move_tail(&binode->delalloc_inodes,
+ &root->delalloc_inodes);
+ inode = igrab(&binode->vfs_inode);
+ if (!inode) {
+ cond_resched_lock(&root->delalloc_lock);
+ continue;
+ }
+ spin_unlock(&root->delalloc_lock);
+
+ work = btrfs_alloc_delalloc_work(inode, 0, delay_iput);
+ if (!work) {
+ if (delay_iput)
+ btrfs_add_delayed_iput(inode);
+ else
+ iput(inode);
+ ret = -ENOMEM;
+ goto out;
+ }
+ list_add_tail(&work->list, &works);
+ btrfs_queue_work(root->fs_info->flush_workers,
+ &work->work);
+ ret++;
+ if (nr != -1 && ret >= nr)
+ goto out;
+ cond_resched();
+ spin_lock(&root->delalloc_lock);
+ }
+ spin_unlock(&root->delalloc_lock);
+
+out:
+ list_for_each_entry_safe(work, next, &works, list) {
+ list_del_init(&work->list);
+ btrfs_wait_and_free_delalloc_work(work);
+ }
+
+ if (!list_empty_careful(&splice)) {
+ spin_lock(&root->delalloc_lock);
+ list_splice_tail(&splice, &root->delalloc_inodes);
+ spin_unlock(&root->delalloc_lock);
+ }
+ mutex_unlock(&root->delalloc_mutex);
+ return ret;
+}
+
+int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput)
+{
+ int ret;
+
+ if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state))
+ return -EROFS;
+
+ ret = __start_delalloc_inodes(root, delay_iput, -1);
+ if (ret > 0)
+ ret = 0;
+ /*
+ * the filemap_flush will queue IO into the worker threads, but
+ * we have to make sure the IO is actually started and that
+ * ordered extents get created before we return
+ */
+ atomic_inc(&root->fs_info->async_submit_draining);
+ while (atomic_read(&root->fs_info->nr_async_submits) ||
+ atomic_read(&root->fs_info->async_delalloc_pages)) {
+ wait_event(root->fs_info->async_submit_wait,
+ (atomic_read(&root->fs_info->nr_async_submits) == 0 &&
+ atomic_read(&root->fs_info->async_delalloc_pages) == 0));
+ }
+ atomic_dec(&root->fs_info->async_submit_draining);
+ return ret;
+}
+
+int btrfs_start_delalloc_roots(struct btrfs_fs_info *fs_info, int delay_iput,
+ int nr)
+{
+ struct btrfs_root *root;
+ struct list_head splice;
+ int ret;
+
+ if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
+ return -EROFS;
+
+ INIT_LIST_HEAD(&splice);
+
+ mutex_lock(&fs_info->delalloc_root_mutex);
+ spin_lock(&fs_info->delalloc_root_lock);
+ list_splice_init(&fs_info->delalloc_roots, &splice);
+ while (!list_empty(&splice) && nr) {
+ root = list_first_entry(&splice, struct btrfs_root,
+ delalloc_root);
+ root = btrfs_grab_fs_root(root);
+ BUG_ON(!root);
+ list_move_tail(&root->delalloc_root,
+ &fs_info->delalloc_roots);
+ spin_unlock(&fs_info->delalloc_root_lock);
+
+ ret = __start_delalloc_inodes(root, delay_iput, nr);
+ btrfs_put_fs_root(root);
+ if (ret < 0)
+ goto out;
+
+ if (nr != -1) {
+ nr -= ret;
+ WARN_ON(nr < 0);
+ }
+ spin_lock(&fs_info->delalloc_root_lock);
+ }
+ spin_unlock(&fs_info->delalloc_root_lock);
+
+ ret = 0;
+ atomic_inc(&fs_info->async_submit_draining);
+ while (atomic_read(&fs_info->nr_async_submits) ||
+ atomic_read(&fs_info->async_delalloc_pages)) {
+ wait_event(fs_info->async_submit_wait,
+ (atomic_read(&fs_info->nr_async_submits) == 0 &&
+ atomic_read(&fs_info->async_delalloc_pages) == 0));
+ }
+ atomic_dec(&fs_info->async_submit_draining);
+out:
+ if (!list_empty_careful(&splice)) {
+ spin_lock(&fs_info->delalloc_root_lock);
+ list_splice_tail(&splice, &fs_info->delalloc_roots);
+ spin_unlock(&fs_info->delalloc_root_lock);
+ }
+ mutex_unlock(&fs_info->delalloc_root_mutex);
+ return ret;
+}
+
+static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
+ const char *symname)
+{
+ struct btrfs_trans_handle *trans;
+ struct btrfs_root *root = BTRFS_I(dir)->root;
+ struct btrfs_path *path;
+ struct btrfs_key key;
+ struct inode *inode = NULL;
+ int err;
+ int drop_inode = 0;
+ u64 objectid;
+ u64 index = 0;
+ int name_len;
+ int datasize;
+ unsigned long ptr;
+ struct btrfs_file_extent_item *ei;
+ struct extent_buffer *leaf;
+
+ name_len = strlen(symname);
+ if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
+ return -ENAMETOOLONG;
+
+ /*
+ * 2 items for inode item and ref
+ * 2 items for dir items
+ * 1 item for xattr if selinux is on
+ */
+ trans = btrfs_start_transaction(root, 5);
+ if (IS_ERR(trans))
+ return PTR_ERR(trans);
+
+ err = btrfs_find_free_ino(root, &objectid);
+ if (err)
+ goto out_unlock;
+
+ inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
+ dentry->d_name.len, btrfs_ino(dir), objectid,
+ S_IFLNK|S_IRWXUGO, &index);
+ if (IS_ERR(inode)) {
+ err = PTR_ERR(inode);
+ goto out_unlock;
+ }
+
+ /*
+ * If the active LSM wants to access the inode during
+ * d_instantiate it needs these. Smack checks to see
+ * if the filesystem supports xattrs by looking at the
+ * ops vector.
+ */
+ inode->i_fop = &btrfs_file_operations;
+ inode->i_op = &btrfs_file_inode_operations;
+ inode->i_mapping->a_ops = &btrfs_aops;
+ BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
+
+ err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
+ if (err)
+ goto out_unlock_inode;
+
+ err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
+ if (err)
+ goto out_unlock_inode;
+
+ path = btrfs_alloc_path();
+ if (!path) {
+ err = -ENOMEM;
+ goto out_unlock_inode;
+ }
+ key.objectid = btrfs_ino(inode);
+ key.offset = 0;
+ key.type = BTRFS_EXTENT_DATA_KEY;
+ datasize = btrfs_file_extent_calc_inline_size(name_len);
+ err = btrfs_insert_empty_item(trans, root, path, &key,
+ datasize);
+ if (err) {
+ btrfs_free_path(path);
+ goto out_unlock_inode;
+ }
+ leaf = path->nodes[0];
+ ei = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_file_extent_item);
+ btrfs_set_file_extent_generation(leaf, ei, trans->transid);
+ btrfs_set_file_extent_type(leaf, ei,
+ BTRFS_FILE_EXTENT_INLINE);
+ btrfs_set_file_extent_encryption(leaf, ei, 0);
+ btrfs_set_file_extent_compression(leaf, ei, 0);
+ btrfs_set_file_extent_other_encoding(leaf, ei, 0);
+ btrfs_set_file_extent_ram_bytes(leaf, ei, name_len);
+
+ ptr = btrfs_file_extent_inline_start(ei);
+ write_extent_buffer(leaf, symname, ptr, name_len);
+ btrfs_mark_buffer_dirty(leaf);
+ btrfs_free_path(path);
+
+ inode->i_op = &btrfs_symlink_inode_operations;
+ inode->i_mapping->a_ops = &btrfs_symlink_aops;
+ inode_set_bytes(inode, name_len);
+ btrfs_i_size_write(inode, name_len);
+ err = btrfs_update_inode(trans, root, inode);
+ if (err) {
+ drop_inode = 1;
+ goto out_unlock_inode;
+ }
+
+ unlock_new_inode(inode);
+ d_instantiate(dentry, inode);
+
+out_unlock:
+ btrfs_end_transaction(trans, root);
+ if (drop_inode) {
+ inode_dec_link_count(inode);
+ iput(inode);
+ }
+ btrfs_btree_balance_dirty(root);
+ return err;
+
+out_unlock_inode:
+ drop_inode = 1;
+ unlock_new_inode(inode);
+ goto out_unlock;
+}
+
+static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
+ u64 start, u64 num_bytes, u64 min_size,
+ loff_t actual_len, u64 *alloc_hint,
+ struct btrfs_trans_handle *trans)
+{
+ struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
+ struct extent_map *em;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_key ins;
+ u64 cur_offset = start;
+ u64 i_size;
+ u64 cur_bytes;
+ int ret = 0;
+ bool own_trans = true;
+
+ if (trans)
+ own_trans = false;
+ while (num_bytes > 0) {
+ if (own_trans) {
+ trans = btrfs_start_transaction(root, 3);
+ if (IS_ERR(trans)) {
+ ret = PTR_ERR(trans);
+ break;
+ }
+ }
+
+ cur_bytes = min(num_bytes, 256ULL * 1024 * 1024);
+ cur_bytes = max(cur_bytes, min_size);
+ ret = btrfs_reserve_extent(root, cur_bytes, min_size, 0,
+ *alloc_hint, &ins, 1, 0);
+ if (ret) {
+ if (own_trans)
+ btrfs_end_transaction(trans, root);
+ break;
+ }
+
+ ret = insert_reserved_file_extent(trans, inode,
+ cur_offset, ins.objectid,
+ ins.offset, ins.offset,
+ ins.offset, 0, 0, 0,
+ BTRFS_FILE_EXTENT_PREALLOC);
+ if (ret) {
+ btrfs_free_reserved_extent(root, ins.objectid,
+ ins.offset, 0);
+ btrfs_abort_transaction(trans, root, ret);
+ if (own_trans)
+ btrfs_end_transaction(trans, root);
+ break;
+ }
+
+ btrfs_drop_extent_cache(inode, cur_offset,
+ cur_offset + ins.offset -1, 0);
+
+ em = alloc_extent_map();
+ if (!em) {
+ set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
+ &BTRFS_I(inode)->runtime_flags);
+ goto next;
+ }
+
+ em->start = cur_offset;
+ em->orig_start = cur_offset;
+ em->len = ins.offset;
+ em->block_start = ins.objectid;
+ em->block_len = ins.offset;
+ em->orig_block_len = ins.offset;
+ em->ram_bytes = ins.offset;
+ em->bdev = root->fs_info->fs_devices->latest_bdev;
+ set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
+ em->generation = trans->transid;
+
+ while (1) {
+ write_lock(&em_tree->lock);
+ ret = add_extent_mapping(em_tree, em, 1);
+ write_unlock(&em_tree->lock);
+ if (ret != -EEXIST)
+ break;
+ btrfs_drop_extent_cache(inode, cur_offset,
+ cur_offset + ins.offset - 1,
+ 0);
+ }
+ free_extent_map(em);
+next:
+ num_bytes -= ins.offset;
+ cur_offset += ins.offset;
+ *alloc_hint = ins.objectid + ins.offset;
+
+ inode_inc_iversion(inode);
+ inode->i_ctime = CURRENT_TIME;
+ BTRFS_I(inode)->flags |= BTRFS_INODE_PREALLOC;
+ if (!(mode & FALLOC_FL_KEEP_SIZE) &&
+ (actual_len > inode->i_size) &&
+ (cur_offset > inode->i_size)) {
+ if (cur_offset > actual_len)
+ i_size = actual_len;
+ else
+ i_size = cur_offset;
+ i_size_write(inode, i_size);
+ btrfs_ordered_update_i_size(inode, i_size, NULL);
+ }
+
+ ret = btrfs_update_inode(trans, root, inode);
+
+ if (ret) {
+ btrfs_abort_transaction(trans, root, ret);
+ if (own_trans)
+ btrfs_end_transaction(trans, root);
+ break;
+ }
+
+ if (own_trans)
+ btrfs_end_transaction(trans, root);
+ }
+ return ret;
+}
+
+int btrfs_prealloc_file_range(struct inode *inode, int mode,
+ u64 start, u64 num_bytes, u64 min_size,
+ loff_t actual_len, u64 *alloc_hint)
+{
+ return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
+ min_size, actual_len, alloc_hint,
+ NULL);
+}
+
+int btrfs_prealloc_file_range_trans(struct inode *inode,
+ struct btrfs_trans_handle *trans, int mode,
+ u64 start, u64 num_bytes, u64 min_size,
+ loff_t actual_len, u64 *alloc_hint)
+{
+ return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
+ min_size, actual_len, alloc_hint, trans);
+}
+
+static int btrfs_set_page_dirty(struct page *page)
+{
+ return __set_page_dirty_nobuffers(page);
+}
+
+static int btrfs_permission(struct inode *inode, int mask)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ umode_t mode = inode->i_mode;
+
+ if (mask & MAY_WRITE &&
+ (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) {
+ if (btrfs_root_readonly(root))
+ return -EROFS;
+ if (BTRFS_I(inode)->flags & BTRFS_INODE_READONLY)
+ return -EACCES;
+ }
+ return generic_permission(inode, mask);
+}
+
+static int btrfs_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
+{
+ struct btrfs_trans_handle *trans;
+ struct btrfs_root *root = BTRFS_I(dir)->root;
+ struct inode *inode = NULL;
+ u64 objectid;
+ u64 index;
+ int ret = 0;
+
+ /*
+ * 5 units required for adding orphan entry
+ */
+ trans = btrfs_start_transaction(root, 5);
+ if (IS_ERR(trans))
+ return PTR_ERR(trans);
+
+ ret = btrfs_find_free_ino(root, &objectid);
+ if (ret)
+ goto out;
+
+ inode = btrfs_new_inode(trans, root, dir, NULL, 0,
+ btrfs_ino(dir), objectid, mode, &index);
+ if (IS_ERR(inode)) {
+ ret = PTR_ERR(inode);
+ inode = NULL;
+ goto out;
+ }
+
+ inode->i_fop = &btrfs_file_operations;
+ inode->i_op = &btrfs_file_inode_operations;
+
+ inode->i_mapping->a_ops = &btrfs_aops;
+ BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
+
+ ret = btrfs_init_inode_security(trans, inode, dir, NULL);
+ if (ret)
+ goto out_inode;
+
+ ret = btrfs_update_inode(trans, root, inode);
+ if (ret)
+ goto out_inode;
+ ret = btrfs_orphan_add(trans, inode);
+ if (ret)
+ goto out_inode;
+
+ /*
+ * We set number of links to 0 in btrfs_new_inode(), and here we set
+ * it to 1 because d_tmpfile() will issue a warning if the count is 0,
+ * through:
+ *
+ * d_tmpfile() -> inode_dec_link_count() -> drop_nlink()
+ */
+ set_nlink(inode, 1);
+ unlock_new_inode(inode);
+ d_tmpfile(dentry, inode);
+ mark_inode_dirty(inode);
+
+out:
+ btrfs_end_transaction(trans, root);
+ if (ret)
+ iput(inode);
+ btrfs_balance_delayed_items(root);
+ btrfs_btree_balance_dirty(root);
+ return ret;
+
+out_inode:
+ unlock_new_inode(inode);
+ goto out;
+
+}
+
+/* Inspired by filemap_check_errors() */
+int btrfs_inode_check_errors(struct inode *inode)
+{
+ int ret = 0;
+
+ if (test_bit(AS_ENOSPC, &inode->i_mapping->flags) &&
+ test_and_clear_bit(AS_ENOSPC, &inode->i_mapping->flags))
+ ret = -ENOSPC;
+ if (test_bit(AS_EIO, &inode->i_mapping->flags) &&
+ test_and_clear_bit(AS_EIO, &inode->i_mapping->flags))
+ ret = -EIO;
+
+ return ret;
+}
+
+static const struct inode_operations btrfs_dir_inode_operations = {
+ .getattr = btrfs_getattr,
+ .lookup = btrfs_lookup,
+ .create = btrfs_create,
+ .unlink = btrfs_unlink,
+ .link = btrfs_link,
+ .mkdir = btrfs_mkdir,
+ .rmdir = btrfs_rmdir,
+ .rename2 = btrfs_rename2,
+ .symlink = btrfs_symlink,
+ .setattr = btrfs_setattr,
+ .mknod = btrfs_mknod,
+ .setxattr = btrfs_setxattr,
+ .getxattr = btrfs_getxattr,
+ .listxattr = btrfs_listxattr,
+ .removexattr = btrfs_removexattr,
+ .permission = btrfs_permission,
+ .get_acl = btrfs_get_acl,
+ .set_acl = btrfs_set_acl,
+ .update_time = btrfs_update_time,
+ .tmpfile = btrfs_tmpfile,
+};
+static const struct inode_operations btrfs_dir_ro_inode_operations = {
+ .lookup = btrfs_lookup,
+ .permission = btrfs_permission,
+ .get_acl = btrfs_get_acl,
+ .set_acl = btrfs_set_acl,
+ .update_time = btrfs_update_time,
+};
+
+static const struct file_operations btrfs_dir_file_operations = {
+ .llseek = generic_file_llseek,
+ .read = generic_read_dir,
+ .iterate = btrfs_real_readdir,
+ .unlocked_ioctl = btrfs_ioctl,
+#ifdef CONFIG_COMPAT
+ .compat_ioctl = btrfs_ioctl,
+#endif
+ .release = btrfs_release_file,
+ .fsync = btrfs_sync_file,
+};
+
+static struct extent_io_ops btrfs_extent_io_ops = {
+ .fill_delalloc = run_delalloc_range,
+ .submit_bio_hook = btrfs_submit_bio_hook,
+ .merge_bio_hook = btrfs_merge_bio_hook,
+ .readpage_end_io_hook = btrfs_readpage_end_io_hook,
+ .writepage_end_io_hook = btrfs_writepage_end_io_hook,
+ .writepage_start_hook = btrfs_writepage_start_hook,
+ .set_bit_hook = btrfs_set_bit_hook,
+ .clear_bit_hook = btrfs_clear_bit_hook,
+ .merge_extent_hook = btrfs_merge_extent_hook,
+ .split_extent_hook = btrfs_split_extent_hook,
+};
+
+/*
+ * btrfs doesn't support the bmap operation because swapfiles
+ * use bmap to make a mapping of extents in the file. They assume
+ * these extents won't change over the life of the file and they
+ * use the bmap result to do IO directly to the drive.
+ *
+ * the btrfs bmap call would return logical addresses that aren't
+ * suitable for IO and they also will change frequently as COW
+ * operations happen. So, swapfile + btrfs == corruption.
+ *
+ * For now we're avoiding this by dropping bmap.
+ */
+static const struct address_space_operations btrfs_aops = {
+ .readpage = btrfs_readpage,
+ .writepage = btrfs_writepage,
+ .writepages = btrfs_writepages,
+ .readpages = btrfs_readpages,
+ .direct_IO = btrfs_direct_IO,
+ .invalidatepage = btrfs_invalidatepage,
+ .releasepage = btrfs_releasepage,
+ .set_page_dirty = btrfs_set_page_dirty,
+ .error_remove_page = generic_error_remove_page,
+};
+
+static const struct address_space_operations btrfs_symlink_aops = {
+ .readpage = btrfs_readpage,
+ .writepage = btrfs_writepage,
+ .invalidatepage = btrfs_invalidatepage,
+ .releasepage = btrfs_releasepage,
+};
+
+static const struct inode_operations btrfs_file_inode_operations = {
+ .getattr = btrfs_getattr,
+ .setattr = btrfs_setattr,
+ .setxattr = btrfs_setxattr,
+ .getxattr = btrfs_getxattr,
+ .listxattr = btrfs_listxattr,
+ .removexattr = btrfs_removexattr,
+ .permission = btrfs_permission,
+ .fiemap = btrfs_fiemap,
+ .get_acl = btrfs_get_acl,
+ .set_acl = btrfs_set_acl,
+ .update_time = btrfs_update_time,
+};
+static const struct inode_operations btrfs_special_inode_operations = {
+ .getattr = btrfs_getattr,
+ .setattr = btrfs_setattr,
+ .permission = btrfs_permission,
+ .setxattr = btrfs_setxattr,
+ .getxattr = btrfs_getxattr,
+ .listxattr = btrfs_listxattr,
+ .removexattr = btrfs_removexattr,
+ .get_acl = btrfs_get_acl,
+ .set_acl = btrfs_set_acl,
+ .update_time = btrfs_update_time,
+};
+static const struct inode_operations btrfs_symlink_inode_operations = {
+ .readlink = generic_readlink,
+ .follow_link = page_follow_link_light,
+ .put_link = page_put_link,
+ .getattr = btrfs_getattr,
+ .setattr = btrfs_setattr,
+ .permission = btrfs_permission,
+ .setxattr = btrfs_setxattr,
+ .getxattr = btrfs_getxattr,
+ .listxattr = btrfs_listxattr,
+ .removexattr = btrfs_removexattr,
+ .update_time = btrfs_update_time,
+};
+
+const struct dentry_operations btrfs_dentry_operations = {
+ .d_delete = btrfs_dentry_delete,
+ .d_release = btrfs_dentry_release,
+};
Code Review / kvmfornfv.git / blobdiff