On 10/16/19 10:13 AM, Greg KH wrote:
> On Wed, Oct 16, 2019 at 09:04:43AM -0700, gregkh@xxxxxxxxxxxxxxxxxxx wrote:
>>
>> The patch below does not apply to the 5.3-stable tree.
>> If someone wants it applied there, or to any other stable or longterm
>> tree, then please email the backport, including the original git commit
>> id to <stable@xxxxxxxxxxxxxxx>.
>>
>> thanks,
>>
>> greg k-h
>>
>> ------------------ original commit in Linus's tree ------------------
>>
>> >From 8a99734081775c012a4a6c442fdef0379fe52bdf Mon Sep 17 00:00:00 2001
>> From: Jens Axboe <axboe@xxxxxxxxx>
>> Date: Wed, 9 Oct 2019 14:40:13 -0600
>> Subject: [PATCH] io_uring: only flush workqueues on fileset removal
>>
>> We should not remove the workqueue, we just need to ensure that the
>> workqueues are synced. The workqueues are torn down on ctx removal.
>>
>> Cc: stable@xxxxxxxxxxxxxxx
>> Fixes: 6b06314c47e1 ("io_uring: add file set registration")
>> Reported-by: Stefan Hajnoczi <stefanha@xxxxxxxxxx>
>> Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
>>
>> diff --git a/fs/io_uring.c b/fs/io_uring.c
>> index ceb3497bdd2a..2c44648217bd 100644
>> --- a/fs/io_uring.c
>> +++ b/fs/io_uring.c
>> @@ -2866,8 +2866,12 @@ static void io_finish_async(struct io_ring_ctx *ctx)
>> static void io_destruct_skb(struct sk_buff *skb)
>> {
>> struct io_ring_ctx *ctx = skb->sk->sk_user_data;
>> + int i;
>> +
>> + for (i = 0; i < ARRAY_SIZE(ctx->sqo_wq); i++)
>> + if (ctx->sqo_wq[i])
>> + flush_workqueue(ctx->sqo_wq[i]);
>>
>> - io_finish_async(ctx);
>> unix_destruct_scm(skb);
>> }
>>
>>
>
> This fails to build as sqo_wq is a pointer in 5.3, not an arrary.
> Backporting that array change feels "big" for 5.3, is that needed here,
> or can this be fixed differently?
Yeah, we don't need to do that. It's just a pointer in 5.3, not an
array of pointers, so the below should be all we need for 5.3 (and
5.2/5.1).
diff --git a/fs/io_uring.c b/fs/io_uring.c
index cfb48bd088e1..e05f302cfb41 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -2564,7 +2564,8 @@ static void io_destruct_skb(struct sk_buff *skb)
{
struct io_ring_ctx *ctx = skb->sk->sk_user_data;
- io_finish_async(ctx);
+ if (ctx->sqo_wq)
+ flush_workqueue(ctx->sqo_wq);
unix_destruct_scm(skb);
}
--
Jens Axboe
