Btrfs: use cached state when dirtying pages during buffered write

During a buffered IO write, we can have an extent state that we got when
we locked the range (if the range starts at an offset lower than eof), so
always pass it to btrfs_dirty_pages() so that setting the delalloc bit
in the range does not need to do a full search in the inode's io tree,
saving time and reducing the amount of time we hold the io tree's lock.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 16c8031..cba2ac3 100644 (file)
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -1755,7 +1755,7 @@ again:
 
                if (copied > 0)
                        ret = btrfs_dirty_pages(inode, pages, dirty_pages,
-                                               pos, copied, NULL);
+                                               pos, copied, &cached_state);
                if (extents_locked)
                        unlock_extent_cached(&BTRFS_I(inode)->io_tree,
                                             lockstart, lockend, &cached_state);