diff options
| -rw-r--r-- | fs/btrfs/ioctl.c | 97 |
1 files changed, 49 insertions, 48 deletions
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index c5254dde1f0..a98f7d25282 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -786,39 +786,57 @@ none: return -ENOENT; } -/* - * Validaty check of prev em and next em: - * 1) no prev/next em - * 2) prev/next em is an hole/inline extent - */ -static int check_adjacent_extents(struct inode *inode, struct extent_map *em) +static struct extent_map *defrag_lookup_extent(struct inode *inode, u64 start) { struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; - struct extent_map *prev = NULL, *next = NULL; - int ret = 0; + struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; + struct extent_map *em; + u64 len = PAGE_CACHE_SIZE; + /* + * hopefully we have this extent in the tree already, try without + * the full extent lock + */ read_lock(&em_tree->lock); - prev = lookup_extent_mapping(em_tree, em->start - 1, (u64)-1); - next = lookup_extent_mapping(em_tree, em->start + em->len, (u64)-1); + em = lookup_extent_mapping(em_tree, start, len); read_unlock(&em_tree->lock); - if ((!prev || prev->block_start >= EXTENT_MAP_LAST_BYTE) && - (!next || next->block_start >= EXTENT_MAP_LAST_BYTE)) - ret = 1; - free_extent_map(prev); - free_extent_map(next); + if (!em) { + /* get the big lock and read metadata off disk */ + lock_extent(io_tree, start, start + len - 1); + em = btrfs_get_extent(inode, NULL, 0, start, len, 0); + unlock_extent(io_tree, start, start + len - 1); + if (IS_ERR(em)) + return NULL; + } + + return em; +} + +static bool defrag_check_next_extent(struct inode *inode, struct extent_map *em) +{ + struct extent_map *next; + bool ret = true; + + /* this is the last extent */ + if (em->start + em->len >= i_size_read(inode)) + return false; + + next = defrag_lookup_extent(inode, em->start + em->len); + if (!next || next->block_start >= EXTENT_MAP_LAST_BYTE) + ret = false; + + free_extent_map(next); return ret; } -static int should_defrag_range(struct inode *inode, u64 start, u64 len, - int thresh, u64 *last_len, u64 *skip, - u64 *defrag_end) +static int should_defrag_range(struct inode *inode, u64 start, int thresh, + u64 *last_len, u64 *skip, u64 *defrag_end) { - struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; - struct extent_map *em = NULL; - struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; + struct extent_map *em; int ret = 1; + bool next_mergeable = true; /* * make sure that once we start defragging an extent, we keep on @@ -829,23 +847,9 @@ static int should_defrag_range(struct inode *inode, u64 start, u64 len, *skip = 0; - /* - * hopefully we have this extent in the tree already, try without - * the full extent lock - */ - read_lock(&em_tree->lock); - em = lookup_extent_mapping(em_tree, start, len); - read_unlock(&em_tree->lock); - - if (!em) { - /* get the big lock and read metadata off disk */ - lock_extent(io_tree, start, start + len - 1); - em = btrfs_get_extent(inode, NULL, 0, start, len, 0); - unlock_extent(io_tree, start, start + len - 1); - - if (IS_ERR(em)) - return 0; - } + em = defrag_lookup_extent(inode, start); + if (!em) + return 0; /* this will cover holes, and inline extents */ if (em->block_start >= EXTENT_MAP_LAST_BYTE) { @@ -853,18 +857,15 @@ static int should_defrag_range(struct inode *inode, u64 start, u64 len, goto out; } - /* If we have nothing to merge with us, just skip. */ - if (check_adjacent_extents(inode, em)) { - ret = 0; - goto out; - } + next_mergeable = defrag_check_next_extent(inode, em); /* - * we hit a real extent, if it is big don't bother defragging it again + * we hit a real extent, if it is big or the next extent is not a + * real extent, don't bother defragging it */ - if ((*last_len == 0 || *last_len >= thresh) && em->len >= thresh) + if ((*last_len == 0 || *last_len >= thresh) && + (em->len >= thresh || !next_mergeable)) ret = 0; - out: /* * last_len ends up being a counter of how many bytes we've defragged. @@ -1143,8 +1144,8 @@ int btrfs_defrag_file(struct inode *inode, struct file *file, break; if (!should_defrag_range(inode, (u64)i << PAGE_CACHE_SHIFT, - PAGE_CACHE_SIZE, extent_thresh, - &last_len, &skip, &defrag_end)) { + extent_thresh, &last_len, &skip, + &defrag_end)) { unsigned long next; /* * the should_defrag function tells us how much to skip |