io_uring: further limit non-owner defer-tw cq waiting
In case of DEFER_TASK_WORK we try to restrict waiters to only one task,
which is also the only submitter; however, we don't do it reliably,
which might be very confusing and backfire in the future. E.g. we
currently allow multiple tasks in io_iopoll_check().
Fixes: c0e0d6ba25
("io_uring: add IORING_SETUP_DEFER_TASKRUN")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Reviewed-by: Dylan Yudaken <dylany@fb.com>
Link: https://lore.kernel.org/r/94c83c0a7fe468260ee2ec31bdb0095d6e874ba2.1662652536.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Родитель
ac9e5784bb
Коммит
76de6749d1
|
@ -1398,6 +1398,9 @@ static int io_iopoll_check(struct io_ring_ctx *ctx, long min)
|
|||
int ret = 0;
|
||||
unsigned long check_cq;
|
||||
|
||||
if (!io_allowed_run_tw(ctx))
|
||||
return -EEXIST;
|
||||
|
||||
check_cq = READ_ONCE(ctx->check_cq);
|
||||
if (unlikely(check_cq)) {
|
||||
if (check_cq & BIT(IO_CHECK_CQ_OVERFLOW_BIT))
|
||||
|
@ -2382,6 +2385,9 @@ static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events,
|
|||
ktime_t timeout = KTIME_MAX;
|
||||
int ret;
|
||||
|
||||
if (!io_allowed_run_tw(ctx))
|
||||
return -EEXIST;
|
||||
|
||||
do {
|
||||
/* always run at least 1 task work to process local work */
|
||||
ret = io_run_task_work_ctx(ctx);
|
||||
|
|
|
@ -329,4 +329,15 @@ static inline struct io_kiocb *io_alloc_req(struct io_ring_ctx *ctx)
|
|||
return container_of(node, struct io_kiocb, comp_list);
|
||||
}
|
||||
|
||||
static inline bool io_allowed_run_tw(struct io_ring_ctx *ctx)
|
||||
{
|
||||
if (!(ctx->flags & IORING_SETUP_DEFER_TASKRUN))
|
||||
return true;
|
||||
if (unlikely(ctx->submitter_task != current)) {
|
||||
/* maybe this is before any submissions */
|
||||
return !ctx->submitter_task;
|
||||
}
|
||||
return true;
|
||||
}
|
||||
|
||||
#endif
|
||||
|
|
Загрузка…
Ссылка в новой задаче