lkml.org 
[lkml]   [2023]   [Jan]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH v3 2/2] fscache: Use clear_and_wake_up_bit() in fscache_create_volume_work()
From
Date
On Fri, 2023-01-13 at 19:52 +0800, Hou Tao wrote:
> From: Hou Tao <houtao1@huawei.com>
>
> fscache_create_volume_work() uses wake_up_bit() to wake up the processes
> which are waiting for the completion of volume creation. According to
> comments in wake_up_bit() and waitqueue_active(), an extra smp_mb() is
> needed to guarantee the memory order between FSCACHE_VOLUME_CREATING
> flag and waitqueue_active() before invoking wake_up_bit().
>
> Fixing it by using clear_and_wake_up_bit() to add the missing memory
> barrier.
>
> Reviewed-by: Jingbo Xu <jefflexu@linux.alibaba.com>
> Signed-off-by: Hou Tao <houtao1@huawei.com>
> ---
> fs/fscache/volume.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/fs/fscache/volume.c b/fs/fscache/volume.c
> index 903af9d85f8b..cdf991bdd9de 100644
> --- a/fs/fscache/volume.c
> +++ b/fs/fscache/volume.c
> @@ -280,8 +280,7 @@ static void fscache_create_volume_work(struct work_struct *work)
> fscache_end_cache_access(volume->cache,
> fscache_access_acquire_volume_end);
>
> - clear_bit_unlock(FSCACHE_VOLUME_CREATING, &volume->flags);
> - wake_up_bit(&volume->flags, FSCACHE_VOLUME_CREATING);
> + clear_and_wake_up_bit(FSCACHE_VOLUME_CREATING, &volume->flags);
> fscache_put_volume(volume, fscache_volume_put_create_work);
> }
>

Reviewed-by: Jeff Layton <jlayton@kernel.org>

\
 
 \ /
  Last update: 2023-03-26 23:39    [W:0.083 / U:0.160 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site