[PATCH] btrfs: Record error in btree_csum_one_bio()

[Qu Wenruo <wqu@suse.com>]

Since commit 6dc4f100c175 ("block: allow bio_for_each_segment_all() to
iterate over multi-page bvec"), break will only break the inner loop of
bio_for_each_segment_all(), unable to break the outer loop.

So here we add a new variable @err to record the first error we hit, and
return the error, so that write time checker can work as designed.

Signed-off-by: Qu Wenruo <wqu@suse.com>
---
 fs/btrfs/disk-io.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 6fe9197f6ee4..9e4d129bb649 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -832,18 +832,18 @@ static blk_status_t btree_csum_one_bio(struct bio *bio)
 {
 	struct bio_vec *bvec;
 	struct btrfs_root *root;
-	int i, ret = 0;
+	int i, ret = 0, err = 0;
 	struct bvec_iter_all iter_all;
 
 	ASSERT(!bio_flagged(bio, BIO_CLONED));
 	bio_for_each_segment_all(bvec, bio, i, iter_all) {
 		root = BTRFS_I(bvec->bv_page->mapping->host)->root;
 		ret = csum_dirty_buffer(root->fs_info, bvec->bv_page);
-		if (ret)
-			break;
+		if (ret && !err)
+			err = ret;
 	}
 
-	return errno_to_blk_status(ret);
+	return errno_to_blk_status(err);
 }
 
 static blk_status_t btree_submit_bio_start(void *private_data, struct bio *bio,
-- 
2.21.0