From: Jens Axboe axboe@kernel.dk
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@vger.kernel.org # 5.5 Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- 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 {