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Message-ID: <e9a1cfed-42e9-4174-bbb3-1a3680cf6a5c@kernel.dk>
Date:   Sun, 3 Dec 2023 19:13:56 -0700
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Subject: Re: [PATCH 1/2] Allow a kthread to declare that it calls
 task_work_run()
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To:     NeilBrown <neilb@suse.de>, Al Viro <viro@zeniv.linux.org.uk>,
        Christian Brauner <brauner@kernel.org>,
        Oleg Nesterov <oleg@redhat.com>,
        Chuck Lever <chuck.lever@oracle.com>,
        Jeff Layton <jlayton@kernel.org>,
        Ingo Molnar <mingo@redhat.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Juri Lelli <juri.lelli@redhat.com>,
        Vincent Guittot <vincent.guittot@linaro.org>
Cc:     linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-nfs@vger.kernel.org
References: <20231204014042.6754-1-neilb@suse.de>
 <20231204014042.6754-2-neilb@suse.de>
From:   Jens Axboe <axboe@kernel.dk>
In-Reply-To: <20231204014042.6754-2-neilb@suse.de>
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On 12/3/23 6:36 PM, NeilBrown wrote:
> diff --git a/fs/namespace.c b/fs/namespace.c
> index e157efc54023..46d640b70ca9 100644
> --- a/fs/namespace.c
> +++ b/fs/namespace.c
> @@ -1328,7 +1328,7 @@ static void mntput_no_expire(struct mount *mnt)
>  
>  	if (likely(!(mnt->mnt.mnt_flags & MNT_INTERNAL))) {
>  		struct task_struct *task = current;
> -		if (likely(!(task->flags & PF_KTHREAD))) {
> +		if (likely((task->flags & PF_RUNS_TASK_WORK))) {

Extraneous parens here.

> diff --git a/kernel/task_work.c b/kernel/task_work.c
> index 95a7e1b7f1da..aec19876e121 100644
> --- a/kernel/task_work.c
> +++ b/kernel/task_work.c
> @@ -183,3 +183,4 @@ void task_work_run(void)
>  		} while (work);
>  	}
>  }
> +EXPORT_SYMBOL(task_work_run);

If we're exporting this, then I think that function needs a big
disclaimer on exactly when it is safe to call it. And it most certainly
needs to be a _GPL export.

-- 
Jens Axboe