On 9/21/21 7:25 AM, Jens Axboe wrote:
> On 9/21/21 12:40 AM, Dave Chinner wrote:
>> Hi Jens,
>>
>> I updated all my trees from 5.14 to 5.15-rc2 this morning and
>> immediately had problems running the recoveryloop fstest group on
>> them. These tests have a typical pattern of "run load in the
>> background, shutdown the filesystem, kill load, unmount and test
>> recovery".
>>
>> Whent eh load includes fsstress, and it gets killed after shutdown,
>> it hangs on exit like so:
>>
>> # echo w > /proc/sysrq-trigger
>> [ 370.669482] sysrq: Show Blocked State
>> [ 370.671732] task:fsstress state:D stack:11088 pid: 9619 ppid: 9615 flags:0x00000000
>> [ 370.675870] Call Trace:
>> [ 370.677067] __schedule+0x310/0x9f0
>> [ 370.678564] schedule+0x67/0xe0
>> [ 370.679545] schedule_timeout+0x114/0x160
>> [ 370.682002] __wait_for_common+0xc0/0x160
>> [ 370.684274] wait_for_completion+0x24/0x30
>> [ 370.685471] do_coredump+0x202/0x1150
>> [ 370.690270] get_signal+0x4c2/0x900
>> [ 370.691305] arch_do_signal_or_restart+0x106/0x7a0
>> [ 370.693888] exit_to_user_mode_prepare+0xfb/0x1d0
>> [ 370.695241] syscall_exit_to_user_mode+0x17/0x40
>> [ 370.696572] do_syscall_64+0x42/0x80
>> [ 370.697620] entry_SYSCALL_64_after_hwframe+0x44/0xae
>>
>> It's 100% reproducable on one of my test machines, but only one of
>> them. That one machine is running fstests on pmem, so it has
>> synchronous storage. Every other test machine using normal async
>> storage (nvme, iscsi, etc) and none of them are hanging.
>>
>> A quick troll of the commit history between 5.14 and 5.15-rc2
>> indicates a couple of potential candidates. The 5th kernel build
>> (instead of ~16 for a bisect) told me that commit 15e20db2e0ce
>> ("io-wq: only exit on fatal signals") is the cause of the
>> regression. I've confirmed that this is the first commit where the
>> problem shows up.
>
> Thanks for the report Dave, I'll take a look. Can you elaborate on
> exactly what is being run? And when killed, it's a non-fatal signal?
Can you try with this patch?
diff --git a/fs/io-wq.c b/fs/io-wq.c
index b5fd015268d7..1e55a0a2a217 100644
--- a/fs/io-wq.c
+++ b/fs/io-wq.c
@@ -586,7 +586,8 @@ static int io_wqe_worker(void *data)
if (!get_signal(&ksig))
continue;
- if (fatal_signal_pending(current))
+ if (fatal_signal_pending(current) ||
+ signal_group_exit(current->signal)) {
break;
continue;
}
--
Jens Axboe
