6.10-stable review patch. If anyone has any objections, please let me know.
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From: Jens Axboe axboe@kernel.dk
commit c0a9d496e0fece67db777bd48550376cf2960c47 upstream.
Some file systems, ocfs2 in this case, will return -EOPNOTSUPP for an IOCB_NOWAIT read/write attempt. While this can be argued to be correct, the usual return value for something that requires blocking issue is -EAGAIN.
A refactoring io_uring commit dropped calling kiocb_done() for negative return values, which is otherwise where we already do that transformation. To ensure we catch it in both spots, check it in __io_read() itself as well.
Reported-by: Robert Sander r.sander@heinlein-support.de Link: https://fosstodon.org/@gurubert@mastodon.gurubert.de/113112431889638440 Cc: stable@vger.kernel.org Fixes: a08d195b586a ("io_uring/rw: split io_read() into a helper") Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- io_uring/rw.c | 8 ++++++++ 1 file changed, 8 insertions(+)
--- a/io_uring/rw.c +++ b/io_uring/rw.c @@ -856,6 +856,14 @@ static int __io_read(struct io_kiocb *re
ret = io_iter_do_read(rw, &io->iter);
+ /* + * Some file systems like to return -EOPNOTSUPP for an IOCB_NOWAIT + * issue, even though they should be returning -EAGAIN. To be safe, + * retry from blocking context for either. + */ + if (ret == -EOPNOTSUPP && force_nonblock) + ret = -EAGAIN; + if (ret == -EAGAIN || (req->flags & REQ_F_REISSUE)) { req->flags &= ~REQ_F_REISSUE; /* If we can poll, just do that. */