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io_uring/rw: treat -EOPNOTSUPP for IOCB_NOWAIT like -EAGAIN

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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: a08d195b58 ("io_uring/rw: split io_read() into a helper")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Jens Axboe 2024-09-10 08:30:57 -06:00
parent f011c9cf04
commit c0a9d496e0
1 changed files with 8 additions and 0 deletions
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8
io_uring/rw.c
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@ -855,6 +855,14 @@ static int __io_read(struct io_kiocb *req, unsigned int issue_flags)
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. */