6.13-stable review patch. If anyone has any objections, please let me know.
------------------
From: Pavel Begunkov <asml.silence@xxxxxxxxx>
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@xxxxxxxxxxxxxxx
Reported-by: chase xd <sl1589472800@xxxxxxxxx>
Fixes: fc68fcda04910 ("io_uring/rw: add support for IORING_OP_READ_MULTISHOT")
Signed-off-by: Pavel Begunkov <asml.silence@xxxxxxxxx>
Link: https://lore.kernel.org/r/7d51732c125159d17db4fe16f51ec41b936973f8.1739919038.git.asml.silence@xxxxxxxxx
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
io_uring/rw.c | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)
--- a/io_uring/rw.c
+++ b/io_uring/rw.c
@@ -866,7 +866,15 @@ 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
@@ -891,7 +899,8 @@ 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;
}
