diff options
| author | Liu Bo <bo.liu@linux.alibaba.com> | 2018-08-23 03:51:52 +0800 |
|---|---|---|
| committer | David Sterba <dsterba@suse.com> | 2018-10-15 17:23:33 +0200 |
| commit | 07e1ce096db3605f3e0c98695df66a51e2be9f05 (patch) | |
| tree | 3e4a910cd136c1b6666d3be7e33b826dbd016db6 /fs/btrfs/volumes.c | |
| parent | 03a1d4c891634dd5b98da865fb783e8b22d4d027 (diff) | |
Btrfs: extent_map: use rb_first_cached
rb_first_cached() trades an extra pointer "leftmost" for doing the
same job as rb_first() but in O(1).
As evict_inode_truncate_pages() removes all extent mapping by always
looking for the first rb entry, it's helpful to use rb_first_cached
instead.
For more details about the optimization see patch "Btrfs: delayed-refs:
use rb_first_cached for href_root".
Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com>
Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs/btrfs/volumes.c')
| -rw-r--r-- | fs/btrfs/volumes.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 86c2330ac83f..909c578506ee 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -1613,7 +1613,7 @@ static u64 find_next_chunk(struct btrfs_fs_info *fs_info) em_tree = &fs_info->mapping_tree.map_tree; read_lock(&em_tree->lock); - n = rb_last(&em_tree->map); + n = rb_last(&em_tree->map.rb_root); if (n) { em = rb_entry(n, struct extent_map, rb_node); ret = em->start + em->len; @@ -7445,7 +7445,7 @@ static int verify_chunk_dev_extent_mapping(struct btrfs_fs_info *fs_info) int ret = 0; read_lock(&em_tree->lock); - for (node = rb_first(&em_tree->map); node; node = rb_next(node)) { + for (node = rb_first_cached(&em_tree->map); node; node = rb_next(node)) { em = rb_entry(node, struct extent_map, rb_node); if (em->map_lookup->num_stripes != em->map_lookup->verified_stripes) { |