io_uring-5.8-2020-06-26

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Merge tag 'io_uring-5.8-2020-06-26' of git://git.kernel.dk/linux-block

Pull io_uring fixes from Jens Axboe:
 "Three small fixes:

   - Close a corner case for polled IO resubmission (Pavel)

   - Toss commands when exiting (Pavel)

   - Fix SQPOLL conditional reschedule on perpetually busy submit
     (Xuan)"

* tag 'io_uring-5.8-2020-06-26' of git://git.kernel.dk/linux-block:
  io_uring: fix current->mm NULL dereference on exit
  io_uring: fix hanging iopoll in case of -EAGAIN
  io_uring: fix io_sq_thread no schedule when busy
This commit is contained in:
Linus Torvalds 2020-06-27 09:02:49 -07:00
commit ab0f2473d3

View File

@ -890,6 +890,7 @@ static int __io_sqe_files_update(struct io_ring_ctx *ctx,
struct io_uring_files_update *ip,
unsigned nr_args);
static int io_grab_files(struct io_kiocb *req);
static void io_complete_rw_common(struct kiocb *kiocb, long res);
static void io_cleanup_req(struct io_kiocb *req);
static int io_file_get(struct io_submit_state *state, struct io_kiocb *req,
int fd, struct file **out_file, bool fixed);
@ -1749,6 +1750,14 @@ static void io_iopoll_queue(struct list_head *again)
do {
req = list_first_entry(again, struct io_kiocb, list);
list_del(&req->list);
/* shouldn't happen unless io_uring is dying, cancel reqs */
if (unlikely(!current->mm)) {
io_complete_rw_common(&req->rw.kiocb, -EAGAIN);
io_put_req(req);
continue;
}
refcount_inc(&req->refs);
io_queue_async_work(req);
} while (!list_empty(again));
@ -1994,10 +2003,8 @@ static void io_complete_rw_iopoll(struct kiocb *kiocb, long res, long res2)
WRITE_ONCE(req->result, res);
/* order with io_poll_complete() checking ->result */
if (res != -EAGAIN) {
smp_wmb();
WRITE_ONCE(req->iopoll_completed, 1);
}
smp_wmb();
WRITE_ONCE(req->iopoll_completed, 1);
}
/*
@ -5353,9 +5360,6 @@ static int io_issue_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe,
if ((ctx->flags & IORING_SETUP_IOPOLL) && req->file) {
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);
@ -6011,7 +6015,7 @@ static int io_sq_thread(void *data)
* If submit got -EBUSY, flag us as needing the application
* to enter the kernel to reap and flush events.
*/
if (!to_submit || ret == -EBUSY) {
if (!to_submit || ret == -EBUSY || need_resched()) {
/*
* Drop cur_mm before scheduling, we can't hold it for
* long periods (or over schedule()). Do this before
@ -6027,7 +6031,7 @@ static int io_sq_thread(void *data)
* more IO, we should wait for the application to
* reap events and wake us up.
*/
if (!list_empty(&ctx->poll_list) ||
if (!list_empty(&ctx->poll_list) || need_resched() ||
(!time_after(jiffies, timeout) && ret != -EBUSY &&
!percpu_ref_is_dying(&ctx->refs))) {
if (current->task_works)