From: Qu Wenruo <wqu@suse.com>
Date: Tue, 6 Apr 2021 00:36:02 +0000 (+0800)
Subject: btrfs: make lock_extent_buffer_for_io() to be subpage compatible
X-Git-Tag: accepted/tizen/unified/20230118.172025~7052^2~41
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=f3156df944754d9984b1595994caa1c93b8cae3b;p=platform%2Fkernel%2Flinux-rpi.git

btrfs: make lock_extent_buffer_for_io() to be subpage compatible

For subpage metadata, we don't use page locking at all.  So just skip
the page locking part for subpage.  The rest of the function can be
reused.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
---

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index e0713b0..396ba23 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -3967,7 +3967,13 @@ static noinline_for_stack int lock_extent_buffer_for_io(struct extent_buffer *eb
 
 	btrfs_tree_unlock(eb);
 
-	if (!ret)
+	/*
+	 * Either we don't need to submit any tree block, or we're submitting
+	 * subpage eb.
+	 * Subpage metadata doesn't use page locking at all, so we can skip
+	 * the page locking.
+	 */
+	if (!ret || fs_info->sectorsize < PAGE_SIZE)
 		return ret;
 
 	num_pages = num_extent_pages(eb);