From: Jens Axboe <axboe@xxxxxxxxx>
commit faac996ccd5da95bc56b91aa80f2643c2d0a1c56 upstream.
For non-blocking issue, we set IOCB_NOWAIT in the kiocb. However, on a
raw block device, this yields an -EOPNOTSUPP return, as non-blocking
writes aren't supported. Turn this -EOPNOTSUPP into -EAGAIN, so we retry
from blocking context with IOCB_NOWAIT cleared.
Cc: stable@xxxxxxxxxxxxxxx # 5.5
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/io_uring.c | 6 ++++++
1 file changed, 6 insertions(+)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -1978,6 +1978,12 @@ static int io_write(struct io_kiocb *req
ret2 = call_write_iter(req->file, kiocb, &iter);
else
ret2 = loop_rw_iter(WRITE, req->file, kiocb, &iter);
+ /*
+ * Raw bdev writes will -EOPNOTSUPP for IOCB_NOWAIT. Just
+ * retry them without IOCB_NOWAIT.
+ */
+ if (ret2 == -EOPNOTSUPP && (kiocb->ki_flags & IOCB_NOWAIT))
+ ret2 = -EAGAIN;
if (!force_nonblock || ret2 != -EAGAIN) {
kiocb_done(kiocb, ret2, nxt, req->in_async);
} else {
