We go through various hoops to disallow signals for the IO threads, but
there's really no reason why we cannot just allow them. The IO threads
never return to userspace like a normal thread, and hence don't go through
normal signal processing. Instead, just check for a pending signal as part
of the work loop, and call get_signal() to handle it for us if anything
is pending.
With that, we can support receiving signals, including special ones like
SIGSTOP.
Signed-off-by: Jens Axboe <ax...@kernel.dk>
---
fs/io-wq.c | 21 +++++++++++++++++----
fs/io_uring.c | 10 ++++++++--
2 files changed, 25 insertions(+), 6 deletions(-)
diff --git a/fs/io-wq.c b/fs/io-wq.c
index b7c1fa932cb3..2dbdc552f3ba 100644
--- a/fs/io-wq.c
+++ b/fs/io-wq.c
@@ -505,8 +505,14 @@ static int io_wqe_worker(void *data)
ret = schedule_timeout(WORKER_IDLE_TIMEOUT);
if (try_to_freeze() || ret)
continue;
- if (fatal_signal_pending(current))
- break;
+ if (signal_pending(current)) {
+ struct ksignal ksig;
+
+ if (fatal_signal_pending(current))
+ break;
+ get_signal(&ksig);
+ continue;
+ }
/* timed out, exit unless we're the fixed worker */
if (test_bit(IO_WQ_BIT_EXIT, &wq->state) ||
!(worker->flags & IO_WORKER_F_FIXED))
@@ -715,8 +721,15 @@ static int io_wq_manager(void *data)
io_wq_check_workers(wq);
schedule_timeout(HZ);
try_to_freeze();
- if (fatal_signal_pending(current))
- set_bit(IO_WQ_BIT_EXIT, &wq->state);
+ if (signal_pending(current)) {
+ struct ksignal ksig;
+
+ if (fatal_signal_pending(current))
+ set_bit(IO_WQ_BIT_EXIT, &wq->state);
+ else
+ get_signal(&ksig);
+ continue;
+ }
} while (!test_bit(IO_WQ_BIT_EXIT, &wq->state));
io_wq_check_workers(wq);
diff --git a/fs/io_uring.c b/fs/io_uring.c
index 54ea561db4a5..3a9d021db328 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -6765,8 +6765,14 @@ static int io_sq_thread(void *data)
timeout = jiffies + sqd->sq_thread_idle;
continue;
}
- if (fatal_signal_pending(current))
- break;
+ if (signal_pending(current)) {
+ struct ksignal ksig;
+
+ if (fatal_signal_pending(current))
+ break;
+ get_signal(&ksig);
+ continue;
+ }
sqt_spin = false;
cap_entries = !list_is_singular(&sqd->ctx_list);
list_for_each_entry(ctx, &sqd->ctx_list, sqd_list) {
--
2.31.0
