Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
Merge tag 'io_uring-5.8-2020-07-05' of git://git.kernel.dk/linux-block
Pull io_uring fix from Jens Axboe:
"Andres reported a regression with the fix that was merged earlier this
week, where his setup of using signals to interrupt io_uring CQ waits
no longer worked correctly.
Fix this, and also limit our use of TWA_SIGNAL to the case where we
need it, and continue using TWA_RESUME for task_work as before.
Since the original is marked for 5.7 stable, let's flush this one out
early"
* tag 'io_uring-5.8-2020-07-05' of git://git.kernel.dk/linux-block:
io_uring: fix regression with always ignoring signals in io_cqring_wait()
+22
-7
+22
-7
fs/io_uring.c
+22
-7
fs/io_uring.c
···
4072
4072
int error;
4073
4073
};
4074
4074
4075
-
static int io_req_task_work_add(struct io_kiocb *req, struct callback_head *cb,
4076
-
int notify)
4075
+
static int io_req_task_work_add(struct io_kiocb *req, struct callback_head *cb)
4077
4076
{
4078
4077
struct task_struct *tsk = req->task;
4079
-
int ret;
4078
+
struct io_ring_ctx *ctx = req->ctx;
4079
+
int ret, notify = TWA_RESUME;
4080
4080
4081
-
if (req->ctx->flags & IORING_SETUP_SQPOLL)
4081
+
/*
4082
+
* SQPOLL kernel thread doesn't need notification, just a wakeup.
4083
+
* If we're not using an eventfd, then TWA_RESUME is always fine,
4084
+
* as we won't have dependencies between request completions for
4085
+
* other kernel wait conditions.
4086
+
*/
4087
+
if (ctx->flags & IORING_SETUP_SQPOLL)
4082
4088
notify = 0;
4089
+
else if (ctx->cq_ev_fd)
4090
+
notify = TWA_SIGNAL;
4083
4091
4084
4092
ret = task_work_add(tsk, cb, notify);
4085
4093
if (!ret)
···
4118
4110
* of executing it. We can't safely execute it anyway, as we may not
4119
4111
* have the needed state needed for it anyway.
4120
4112
*/
4121
-
ret = io_req_task_work_add(req, &req->task_work, TWA_SIGNAL);
4113
+
ret = io_req_task_work_add(req, &req->task_work);
4122
4114
if (unlikely(ret)) {
4123
4115
WRITE_ONCE(poll->canceled, true);
4124
4116
tsk = io_wq_get_task(req->ctx->io_wq);
···
6209
6201
if (current->task_works)
6210
6202
task_work_run();
6211
6203
if (signal_pending(current)) {
6212
-
ret = -ERESTARTSYS;
6204
+
if (current->jobctl & JOBCTL_TASK_WORK) {
6205
+
spin_lock_irq(¤t->sighand->siglock);
6206
+
current->jobctl &= ~JOBCTL_TASK_WORK;
6207
+
recalc_sigpending();
6208
+
spin_unlock_irq(¤t->sighand->siglock);
6209
+
continue;
6210
+
}
6211
+
ret = -EINTR;
6213
6212
break;
6214
6213
}
6215
6214
if (io_should_wake(&iowq, false))
···
6225
6210
} while (1);
6226
6211
finish_wait(&ctx->wait, &iowq.wq);
6227
6212
6228
-
restore_saved_sigmask_unless(ret == -ERESTARTSYS);
6213
+
restore_saved_sigmask_unless(ret == -EINTR);
6229
6214
6230
6215
return READ_ONCE(rings->cq.head) == READ_ONCE(rings->cq.tail) ? ret : 0;
6231
6216
}