We're taking a free space extent out of the free space cache, trimming it and then putting it back into the cache.
However for an extent that is smaller than the specified minimum length, it's taken out but won't be put back, which causes space leak. Signed-off-by: Li Zefan <[email protected]> --- Unfortunately I have no trim-able device to test the patch. --- fs/btrfs/free-space-cache.c | 34 +++++++++++++++++----------------- 1 files changed, 17 insertions(+), 17 deletions(-) diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c index 9f985a4..292c0d9 100644 --- a/fs/btrfs/free-space-cache.c +++ b/fs/btrfs/free-space-cache.c @@ -2460,6 +2460,7 @@ int btrfs_trim_block_group(struct btrfs_block_group_cache *block_group, u64 bytes = 0; u64 actually_trimmed; int ret = 0; + int update_ret; *trimmed = 0; @@ -2483,6 +2484,7 @@ int btrfs_trim_block_group(struct btrfs_block_group_cache *block_group, } if (entry->bitmap) { + bytes = 0; ret = search_bitmap(ctl, entry, &start, &bytes); if (!ret) { if (start >= end) { @@ -2490,6 +2492,8 @@ int btrfs_trim_block_group(struct btrfs_block_group_cache *block_group, break; } bytes = min(bytes, end - start); + if (bytes < minlen) + goto next; bitmap_clear_bits(ctl, entry, start, bytes); if (entry->bytes == 0) free_bitmap(ctl, entry); @@ -2503,33 +2507,29 @@ int btrfs_trim_block_group(struct btrfs_block_group_cache *block_group, } else { start = entry->offset; bytes = min(entry->bytes, end - start); + if (bytes < minlen) + goto next; unlink_free_space(ctl, entry); kmem_cache_free(btrfs_free_space_cachep, entry); } spin_unlock(&ctl->tree_lock); - if (bytes >= minlen) { - int update_ret; - update_ret = btrfs_update_reserved_bytes(block_group, - bytes, 1, 1); + update_ret = btrfs_update_reserved_bytes(block_group, + bytes, 1, 1); - ret = btrfs_error_discard_extent(fs_info->extent_root, - start, - bytes, - &actually_trimmed); + ret = btrfs_error_discard_extent(fs_info->extent_root, start, + bytes, &actually_trimmed); - btrfs_add_free_space(block_group, start, bytes); - if (!update_ret) - btrfs_update_reserved_bytes(block_group, - bytes, 0, 1); + btrfs_add_free_space(block_group, start, bytes); + if (!update_ret) + btrfs_update_reserved_bytes(block_group, bytes, 0, 1); - if (ret) - break; - *trimmed += actually_trimmed; - } + if (ret) + break; + *trimmed += actually_trimmed; +next: start += bytes; - bytes = 0; if (fatal_signal_pending(current)) { ret = -ERESTARTSYS; -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
