From e33e17ee1098d8d751552ac11c111e1c1a3db014 Mon Sep 17 00:00:00 2001 From: Jeff Mahoney Date: Mon, 15 Jun 2015 09:41:19 -0400 Subject: btrfs: add missing discards when unpinning extents with -o discard When we clear the dirty bits in btrfs_delete_unused_bgs for extents in the empty block group, it results in btrfs_finish_extent_commit being unable to discard the freed extents. The block group removal patch added an alternate path to forget extents other than btrfs_finish_extent_commit. As a result, any extents that would be freed when the block group is removed aren't discarded. In my test run, with a large copy of mixed sized files followed by removal, it left nearly 2/3 of extents undiscarded. To clean up the block groups, we add the removed block group onto a list that will be discarded after transaction commit. Signed-off-by: Jeff Mahoney Reviewed-by: Filipe Manana Tested-by: Filipe Manana Signed-off-by: Chris Mason --- fs/btrfs/free-space-cache.c | 57 ++++++++++++++++++++++++++------------------- 1 file changed, 33 insertions(+), 24 deletions(-) (limited to 'fs/btrfs/free-space-cache.c') diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c index fb5a6b1..abe3a66 100644 --- a/fs/btrfs/free-space-cache.c +++ b/fs/btrfs/free-space-cache.c @@ -3272,35 +3272,23 @@ next: return ret; } -int btrfs_trim_block_group(struct btrfs_block_group_cache *block_group, - u64 *trimmed, u64 start, u64 end, u64 minlen) +void btrfs_get_block_group_trimming(struct btrfs_block_group_cache *cache) { - int ret; + atomic_inc(&cache->trimming); +} - *trimmed = 0; +void btrfs_put_block_group_trimming(struct btrfs_block_group_cache *block_group) +{ + struct extent_map_tree *em_tree; + struct extent_map *em; + bool cleanup; spin_lock(&block_group->lock); - if (block_group->removed) { - spin_unlock(&block_group->lock); - return 0; - } - atomic_inc(&block_group->trimming); + cleanup = (atomic_dec_and_test(&block_group->trimming) && + block_group->removed); spin_unlock(&block_group->lock); - ret = trim_no_bitmap(block_group, trimmed, start, end, minlen); - if (ret) - goto out; - - ret = trim_bitmaps(block_group, trimmed, start, end, minlen); -out: - spin_lock(&block_group->lock); - if (atomic_dec_and_test(&block_group->trimming) && - block_group->removed) { - struct extent_map_tree *em_tree; - struct extent_map *em; - - spin_unlock(&block_group->lock); - + if (cleanup) { lock_chunks(block_group->fs_info->chunk_root); em_tree = &block_group->fs_info->mapping_tree.map_tree; write_lock(&em_tree->lock); @@ -3324,10 +3312,31 @@ out: * this block group have left 1 entry each one. Free them. */ __btrfs_remove_free_space_cache(block_group->free_space_ctl); - } else { + } +} + +int btrfs_trim_block_group(struct btrfs_block_group_cache *block_group, + u64 *trimmed, u64 start, u64 end, u64 minlen) +{ + int ret; + + *trimmed = 0; + + spin_lock(&block_group->lock); + if (block_group->removed) { spin_unlock(&block_group->lock); + return 0; } + btrfs_get_block_group_trimming(block_group); + spin_unlock(&block_group->lock); + + ret = trim_no_bitmap(block_group, trimmed, start, end, minlen); + if (ret) + goto out; + ret = trim_bitmaps(block_group, trimmed, start, end, minlen); +out: + btrfs_put_block_group_trimming(block_group); return ret; } -- cgit v1.1