diff options
| author | Josef Bacik <josef@toxicpanda.com> | 2022-09-30 16:45:13 -0400 |
|---|---|---|
| committer | David Sterba <dsterba@suse.com> | 2022-12-05 18:00:36 +0100 |
| commit | e5e886bad9e9e87b767ade3884faec1cfdec9b43 (patch) | |
| tree | e9aff5b62a9b96b17cd526b9d71b5c00c1fba181 /fs | |
| parent | 123a7f008c9e2b25b451c116620f1f6c77bd6b2b (diff) | |
btrfs: add cached_state to read_extent_buffer_subpage
We don't use a cached state here at all, which generally makes sense as
async reads are going to unlock at endio time. However for blocking
reads we will call wait_extent_bit() for our range. Since the
lock_extent() stuff will return the cached_state for the start of the
range this is a helpful optimization to have for this case, we'll have
the exact state we want to wait on. Add a cached state here and simply
throw it away if we're a non-blocking read, otherwise we'll get a small
improvement by eliminating some tree searches.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/btrfs/extent_io.c | 15 |
1 files changed, 10 insertions, 5 deletions
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 836851233618..7891d375eb43 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -4949,6 +4949,7 @@ static int read_extent_buffer_subpage(struct extent_buffer *eb, int wait, struct btrfs_fs_info *fs_info = eb->fs_info; struct extent_io_tree *io_tree; struct page *page = eb->pages[0]; + struct extent_state *cached_state = NULL; struct btrfs_bio_ctrl bio_ctrl = { .mirror_num = mirror_num, }; @@ -4960,10 +4961,11 @@ static int read_extent_buffer_subpage(struct extent_buffer *eb, int wait, if (wait == WAIT_NONE) { if (!try_lock_extent(io_tree, eb->start, eb->start + eb->len - 1, - NULL)) + &cached_state)) return -EAGAIN; } else { - ret = lock_extent(io_tree, eb->start, eb->start + eb->len - 1, NULL); + ret = lock_extent(io_tree, eb->start, eb->start + eb->len - 1, + &cached_state); if (ret < 0) return ret; } @@ -4973,7 +4975,8 @@ static int read_extent_buffer_subpage(struct extent_buffer *eb, int wait, PageUptodate(page) || btrfs_subpage_test_uptodate(fs_info, page, eb->start, eb->len)) { set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags); - unlock_extent(io_tree, eb->start, eb->start + eb->len - 1, NULL); + unlock_extent(io_tree, eb->start, eb->start + eb->len - 1, + &cached_state); return ret; } @@ -4998,11 +5001,13 @@ static int read_extent_buffer_subpage(struct extent_buffer *eb, int wait, atomic_dec(&eb->io_pages); } submit_one_bio(&bio_ctrl); - if (ret || wait != WAIT_COMPLETE) + if (ret || wait != WAIT_COMPLETE) { + free_extent_state(cached_state); return ret; + } wait_extent_bit(io_tree, eb->start, eb->start + eb->len - 1, - EXTENT_LOCKED, NULL); + EXTENT_LOCKED, &cached_state); if (!test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags)) ret = -EIO; return ret; |