[PATCH 1/5] dm-writecache: report I/O error if flush failed

[Mikulas Patocka <mpatocka@redhat.com>]

There was a bug that if writecache_flush fails due to I/O error, the
error is not reported in the FUA bio. This commit fixes it.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Assisted-by: opencode:big-pickle
Cc: stable@vger.kernel.org
Fixes: 48debafe4f2f ("dm: add writecache target")

---
 drivers/md/dm-writecache.c |    7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

Index: linux-2.6/drivers/md/dm-writecache.c
===================================================================
--- linux-2.6.orig/drivers/md/dm-writecache.c
+++ linux-2.6/drivers/md/dm-writecache.c
@@ -1493,10 +1493,13 @@ bio_copy:
 		}
 	} while (bio->bi_iter.bi_size);
 
-	if (unlikely(bio->bi_opf & REQ_FUA || wc->uncommitted_blocks >= wc->autocommit_blocks))
+	if (unlikely(bio->bi_opf & REQ_FUA || wc->uncommitted_blocks >= wc->autocommit_blocks)) {
 		writecache_flush(wc);
-	else
+		if (writecache_has_error(wc))
+			bio->bi_status = BLK_STS_IOERR;
+	} else {
 		writecache_schedule_autocommit(wc);
+	}
 
 	return WC_MAP_SUBMIT;
 }