diff options
| -rw-r--r-- | fs/btrfs/extent_io.c | 32 |
1 files changed, 24 insertions, 8 deletions
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index fbb05b0f7ebc..7441245b1ceb 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -2752,7 +2752,7 @@ static int emit_last_fiemap_cache(struct fiemap_extent_info *fieinfo, static int fiemap_next_leaf_item(struct btrfs_inode *inode, struct btrfs_path *path) { - struct extent_buffer *clone; + struct extent_buffer *clone = path->nodes[0]; struct btrfs_key key; int slot; int ret; @@ -2761,29 +2761,45 @@ static int fiemap_next_leaf_item(struct btrfs_inode *inode, struct btrfs_path *p if (path->slots[0] < btrfs_header_nritems(path->nodes[0])) return 0; + /* + * Add a temporary extra ref to an already cloned extent buffer to + * prevent btrfs_next_leaf() freeing it, we want to reuse it to avoid + * the cost of allocating a new one. + */ + ASSERT(test_bit(EXTENT_BUFFER_UNMAPPED, &clone->bflags)); + atomic_inc(&clone->refs); + ret = btrfs_next_leaf(inode->root, path); if (ret != 0) - return ret; + goto out; /* * Don't bother with cloning if there are no more file extent items for * our inode. */ btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); - if (key.objectid != btrfs_ino(inode) || key.type != BTRFS_EXTENT_DATA_KEY) - return 1; + if (key.objectid != btrfs_ino(inode) || key.type != BTRFS_EXTENT_DATA_KEY) { + ret = 1; + goto out; + } /* See the comment at fiemap_search_slot() about why we clone. */ - clone = btrfs_clone_extent_buffer(path->nodes[0]); - if (!clone) - return -ENOMEM; + copy_extent_buffer_full(clone, path->nodes[0]); + /* + * Important to preserve the start field, for the optimizations when + * checking if extents are shared (see extent_fiemap()). + */ + clone->start = path->nodes[0]->start; slot = path->slots[0]; btrfs_release_path(path); path->nodes[0] = clone; path->slots[0] = slot; +out: + if (ret) + free_extent_buffer(clone); - return 0; + return ret; } /* |