io_uring: ensure workqueue offload grabs ring mutex for poll list

A previous commit moved the locking for the async sqthread, but didn't
take into account that the io-wq workers still need it. We can't use
req->in_async for this anymore as both the sqthread and io-wq workers
set it, gate the need for locking on io_wq_current_is_worker() instead.

Fixes: 8a4955ff1c ("io_uring: sqthread should grab ctx->uring_lock for submissions")
Reported-by: Bijan Mottahedeh <bijan.mottahedeh@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Jens Axboe 2020-01-15 21:51:17 -07:00
parent 797f3f535d
commit 11ba820bf1

View file

@ -3286,10 +3286,19 @@ static int io_issue_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe,
return ret;
if (ctx->flags & IORING_SETUP_IOPOLL) {
const bool in_async = io_wq_current_is_worker();
if (req->result == -EAGAIN)
return -EAGAIN;
/* workqueue context doesn't hold uring_lock, grab it now */
if (in_async)
mutex_lock(&ctx->uring_lock);
io_iopoll_req_issued(req);
if (in_async)
mutex_unlock(&ctx->uring_lock);
}
return 0;