Revert "block: end bio with BLK_STS_AGAIN in case of non-mq devs and REQ_NOWAIT"

This reverts commit c58c1f83436b501d45d4050fd1296d71a9760bcb.

io_uring does do the right thing for this case, and we're still returning
-EAGAIN to userspace for the cases we don't support. Revert this change
to avoid doing endless spins of resubmits.

Cc: stable@vger.kernel.org # v5.6
Reported-by: Bijan Mottahedeh <bijan.mottahedeh@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/block/blk-core.c b/block/blk-core.c
index 7e4a1da..9bfaee0 100644 (file)
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -891,14 +891,11 @@ generic_make_request_checks(struct bio *bio)
        }
 
        /*
-        * Non-mq queues do not honor REQ_NOWAIT, so complete a bio
-        * with BLK_STS_AGAIN status in order to catch -EAGAIN and
-        * to give a chance to the caller to repeat request gracefully.
+        * For a REQ_NOWAIT based request, return -EOPNOTSUPP
+        * if queue is not a request based queue.
         */
-       if ((bio->bi_opf & REQ_NOWAIT) && !queue_is_mq(q)) {
-               status = BLK_STS_AGAIN;
-               goto end_io;
-       }
+       if ((bio->bi_opf & REQ_NOWAIT) && !queue_is_mq(q))
+               goto not_supported;
 
        if (should_fail_bio(bio))
                goto end_io;