On Fri, 2023-01-13 at 19:52 +0800, Hou Tao wrote: > From: Hou Tao <houtao1@xxxxxxxxxx> > > 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@xxxxxxxxxxxxxxxxx> > Signed-off-by: Hou Tao <houtao1@xxxxxxxxxx> > --- > 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@xxxxxxxxxx>
