6.12-stable review patch. If anyone has any objections, please let me know.
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From: Pavel Begunkov asml.silence@gmail.com
commit 67b0025d19f99fb9fbb8b62e6975553c183f3a16 upstream.
At the moment we can't sanely handle queuing an async request from a multishot context, so disable them. It shouldn't matter as pollable files / socekts don't normally do async.
Patching it in __io_read() is not the cleanest way, but it's simpler than other options, so let's fix it there and clean up on top.
Cc: stable@vger.kernel.org Reported-by: chase xd sl1589472800@gmail.com Fixes: fc68fcda04910 ("io_uring/rw: add support for IORING_OP_READ_MULTISHOT") Signed-off-by: Pavel Begunkov asml.silence@gmail.com Link: https://lore.kernel.org/r/7d51732c125159d17db4fe16f51ec41b936973f8.173991903... Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- io_uring/rw.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-)
--- a/io_uring/rw.c +++ b/io_uring/rw.c @@ -862,7 +862,15 @@ static int __io_read(struct io_kiocb *re if (unlikely(ret)) return ret;
- ret = io_iter_do_read(rw, &io->iter); + if (unlikely(req->opcode == IORING_OP_READ_MULTISHOT)) { + void *cb_copy = rw->kiocb.ki_complete; + + rw->kiocb.ki_complete = NULL; + ret = io_iter_do_read(rw, &io->iter); + rw->kiocb.ki_complete = cb_copy; + } else { + ret = io_iter_do_read(rw, &io->iter); + }
/* * Some file systems like to return -EOPNOTSUPP for an IOCB_NOWAIT @@ -887,7 +895,8 @@ static int __io_read(struct io_kiocb *re } else if (ret == -EIOCBQUEUED) { return IOU_ISSUE_SKIP_COMPLETE; } else if (ret == req->cqe.res || ret <= 0 || !force_nonblock || - (req->flags & REQ_F_NOWAIT) || !need_complete_io(req)) { + (req->flags & REQ_F_NOWAIT) || !need_complete_io(req) || + (issue_flags & IO_URING_F_MULTISHOT)) { /* read all, failed, already did sync or don't want to retry */ goto done; }