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
diff --git a/fs/io_uring.c b/fs/io_uring.c
index a78201b..e507737 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -890,6 +890,7 @@
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 @@
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 @@
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 @@
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 @@
* 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 @@
* 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)
