Messages in this thread | | | Date | Thu, 8 Feb 2024 08:21:24 -0800 | From | Ira Weiny <> | Subject | Re: [PATCH 1/2 v4] cleanup: Add cond_guard() to conditional guards |
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Jonathan Cameron wrote: > On Thu, 8 Feb 2024 14:04:23 +0100 > "Fabio M. De Francesco" <fabio.maria.de.francesco@linux.intel.com> wrote: > > > Add cond_guard() macro to conditional guards. > > > > cond_guard() is a guard to be used with the conditional variants of locks, > > like down_read_trylock() or mutex_lock_interruptible(). > > > > It takes a statement (or statement-expression) that is passed as its > > second argument. That statement (or statement-expression) is executed if > > waiting for a lock is interrupted or if a _trylock() fails in case of > > contention. > > > > Usage example: > > > > cond_guard(mutex_intr, return -EINTR, &mutex); > > > > Consistent with other usage of _guard(), locks are unlocked at the exit of the > > scope where cond_guard() is called. > > > > Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> > I like the defensive else {}
Agreed.
Re-
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
> > Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> > > > > Cc: Peter Zijlstra <peterz@infradead.org> > > Suggested-by: Dan Williams <dan.j.williams@intel.com> > > Suggested-by: Ira Weiny <ira.weiny@intel.com> > > Reviewed-by: Dave Jiang <dave.jiang@intel.com> > > Reviewed-by: Ira Weiny <ira.weiny@intel.com> > > Signed-off-by: Fabio M. De Francesco <fabio.maria.de.francesco@linux.intel.com> > > --- > > include/linux/cleanup.h | 15 +++++++++++++++ > > 1 file changed, 15 insertions(+) > > > > diff --git a/include/linux/cleanup.h b/include/linux/cleanup.h > > index c2d09bc4f976..7b54ee996414 100644 > > --- a/include/linux/cleanup.h > > +++ b/include/linux/cleanup.h > > @@ -134,6 +134,16 @@ static inline class_##_name##_t class_##_name##ext##_constructor(_init_args) \ > > * an anonymous instance of the (guard) class, not recommended for > > * conditional locks. > > * > > + * cond_guard(name, fail, args...): > > + * a guard to be used with the conditional variants of locks, like > > + * down_read_trylock() or mutex_lock_interruptible. 'fail' is a > > + * statement or statement-expression that is executed if waiting for a > > + * lock is interrupted or if a _trylock() fails in case of contention. > > + * > > + * Example: > > + * > > + * cond_guard(mutex_intr, return -EINTR, &mutex); > > + * > > * scoped_guard (name, args...) { }: > > * similar to CLASS(name, scope)(args), except the variable (with the > > * explicit name 'scope') is declard in a for-loop such that its scope is > > @@ -165,6 +175,11 @@ static inline class_##_name##_t class_##_name##ext##_constructor(_init_args) \ > > > > #define __guard_ptr(_name) class_##_name##_lock_ptr > > > > +#define cond_guard(_name, _fail, args...) \ > > + CLASS(_name, scope)(args); \ > > + if (!__guard_ptr(_name)(&scope)) _fail; \ > > + else { } > > + > > #define scoped_guard(_name, args...) \ > > for (CLASS(_name, scope)(args), \ > > *done = NULL; __guard_ptr(_name)(&scope) && !done; done = (void *)1) > >
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