Re: [PATCH V5 9/9] null_blk: serialize configfs attribute shows with the file-scope lock

[Zizhi Wo]

在 2026/7/25 5:16, Bart Van Assche 写道:
> On 7/13/26 9:18 PM, Zizhi Wo wrote:
> > diff --git a/drivers/block/null_blk/main.c b/drivers/block/null_blk/ 
> > main.c
> > index 67cd32d28887..c8487a630e1a 100644
> > --- a/drivers/block/null_blk/main.c
> > +++ b/drivers/block/null_blk/main.c
> > @@ -345,8 +345,14 @@ static ssize_t nullb_device_bool_attr_store(bool 
> > *val, const char *page,
> >   static ssize_t                                \
> >   nullb_device_##NAME##_show(struct config_item *item, char *page)    \
> >   {                                    \
> > -    return nullb_device_##TYPE##_attr_show(                \
> > +    ssize_t ret;                            \
> > +                                    \
> > +    mutex_lock(&lock);                        \
> > +    ret = nullb_device_##TYPE##_attr_show(                \
> >                   to_nullb_device(item)->NAME, page);    \
> > +    mutex_unlock(&lock);                        \
> > +                                    \
> > +    return ret;                            \
> >   }                                    \
> >   static ssize_t                                \
> >   nullb_device_##NAME##_store(struct config_item *item, const char 
> > *page,    \
> > @@ -479,7 +485,13 @@ NULLB_DEVICE_ATTR(badblocks_partial_io, bool, NULL);
> >   static ssize_t nullb_device_power_show(struct config_item *item, 
> > char *page)
> >   {
> > -    return nullb_device_bool_attr_show(to_nullb_device(item)->power, 
> > page);
> > +    ssize_t ret;
> > +
> > +    mutex_lock(&lock);
> > +    ret = nullb_device_bool_attr_show(to_nullb_device(item)->power, 
> > page);
> > +    mutex_unlock(&lock);
> > +
> > +    return ret;
> >   }
>
> The above changes would be much more elegant if guard()() would be used 
> instead of explicit mutex_lock() and mutex_unlock() calls.
>
> Thanks,
>
> Bart.

Thanks Bart. Will switch to using guard() in the next version :)

Thanks,
Zizhi Wo