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io_uring: process task work in io_uring_register()

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We do this for CQ ring wait, in case task_work completions come in. We
should do the same in io_uring_register(), to avoid spurious -EINTR
if the ring quiescing ends up having to process task_work to complete
the operation

Reported-by: Dan Melnic <dmm@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Jens Axboe 2020-09-24 13:32:18 -06:00
parent 91d8f5191e
commit af9c1a44f8
1 changed files with 28 additions and 12 deletions
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40
fs/io_uring.c
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@ -6950,6 +6950,22 @@ static int io_wake_function(struct wait_queue_entry *curr, unsigned int mode,
return autoremove_wake_function(curr, mode, wake_flags, key);
}
static int io_run_task_work_sig(void)
{
if (io_run_task_work())
return 1;
if (!signal_pending(current))
return 0;
if (current->jobctl & JOBCTL_TASK_WORK) {
spin_lock_irq(&current->sighand->siglock);
current->jobctl &= ~JOBCTL_TASK_WORK;
recalc_sigpending();
spin_unlock_irq(&current->sighand->siglock);
return 1;
}
return -EINTR;
}
/*
* Wait until events become available, if we don't already have some. The
* application must reap them itself, as they reside on the shared cq ring.
@ -6995,19 +7011,11 @@ static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events,
prepare_to_wait_exclusive(&ctx->wait, &iowq.wq,
TASK_INTERRUPTIBLE);
/* make sure we run task_work before checking for signals */
if (io_run_task_work())
ret = io_run_task_work_sig();
if (ret > 0)
continue;
if (signal_pending(current)) {
if (current->jobctl & JOBCTL_TASK_WORK) {
spin_lock_irq(&current->sighand->siglock);
current->jobctl &= ~JOBCTL_TASK_WORK;
recalc_sigpending();
spin_unlock_irq(&current->sighand->siglock);
continue;
}
ret = -EINTR;
else if (ret < 0)
break;
}
if (io_should_wake(&iowq, false))
break;
schedule();
@ -9666,8 +9674,16 @@ static int __io_uring_register(struct io_ring_ctx *ctx, unsigned opcode,
* after we've killed the percpu ref.
*/
mutex_unlock(&ctx->uring_lock);
ret = wait_for_completion_interruptible(&ctx->ref_comp);
do {
ret = wait_for_completion_interruptible(&ctx->ref_comp);
if (!ret)
break;
if (io_run_task_work_sig() > 0)
continue;
} while (1);
mutex_lock(&ctx->uring_lock);
if (ret) {
percpu_ref_resurrect(&ctx->refs);
ret = -EINTR;