Btrfs: use cached state when dirtying pages during buffered write

From: Filipe Manana <[email protected]>

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.

---
 fs/btrfs/file.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

index e0d15c0d1641..aaab1838cece 100644
@@ -1755,7 +1755,7 @@ static noinline ssize_t __btrfs_buffered_write(struct file *file,
 
 		if (copied > 0)
 			ret = btrfs_dirty_pages(inode, pages, dirty_pages,
-						pos, copied, NULL);
+						pos, copied, &cached_state);
 		if (need_unlock)
 			unlock_extent_cached(&BTRFS_I(inode)->io_tree,
 					     lockstart, lockend, &cached_state,

2.11.0