Commit 8ecf596e authored by Filipe Manana's avatar Filipe Manana Committed by David Sterba
Browse files

btrfs: update comment for delalloc flush and oe wait in btrfs_clone_files() 



Make the comment more detailed about why we need to flush delalloc and
wait for ordered extent completion before attempting to invalidate the
page cache.

Reviewed-by: default avatarQu Wenruo <wqu@suse.com>
Reviewed-by: default avatarBoris Burkov <boris@bur.io>
Signed-off-by: default avatarFilipe Manana <fdmanana@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent ae23fee4

fs/btrfs/reflink.c

+7 −2
Original line number Diff line number Diff line
@@ -754,8 +754,13 @@ static noinline int btrfs_clone_files(struct file *file, struct file *file_src, 


	/*

	 * We may have copied an inline extent into a page of the destination

	 * range, so wait for writeback to complete before invalidating pages

	 * from the page cache. This is a rare case.

	 * range. So flush delalloc and wait for ordered extent completion.

	 * This is to ensure the invalidation below does not fail, as if for

	 * example it finds a dirty folio, our folio release callback

	 * (btrfs_release_folio()) returns false, which makes the invalidation

	 * return an -EBUSY error. We can't ignore such failures since they

	 * could come from some range other than the copied inline extent's

	 * destination range and we have no way to know that.

	 */

	ret = btrfs_wait_ordered_range(BTRFS_I(inode), destoff, len);

	if (ret < 0)