Messages in this thread Patch in this message | | | Subject | [PATCH 1/3] cleanup: Add cond_guard() to conditional guards | From | Dan Williams <> | Date | Tue, 27 Feb 2024 08:48:53 -0800 |
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From: Fabio M. De Francesco <fabio.maria.de.francesco@linux.intel.com>
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. This macro can be called multiple times in the same scope.
Cc: Dave Jiang <dave.jiang@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Suggested-by: Dan Williams <dan.j.williams@intel.com> Suggested-by: Ira Weiny <ira.weiny@intel.com> Suggested-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Fabio M. De Francesco <fabio.maria.de.francesco@linux.intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> --- include/linux/cleanup.h | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+)
diff --git a/include/linux/cleanup.h b/include/linux/cleanup.h index c2d09bc4f976..602afb85da34 100644 --- a/include/linux/cleanup.h +++ b/include/linux/cleanup.h @@ -134,6 +134,19 @@ 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); + * + * This macro can be called multiple times in the same scope, for it + * declares unique instances of type 'name'. + * * 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 +178,13 @@ static inline class_##_name##_t class_##_name##ext##_constructor(_init_args) \ #define __guard_ptr(_name) class_##_name##_lock_ptr +#define __cond_guard(__unique, _name, _fail, args...) \ + CLASS(_name, __unique)(args); \ + if (!__guard_ptr(_name)(&__unique)) _fail; \ + else { } +#define cond_guard(_name, _fail, args...) \ + __cond_guard(__UNIQUE_ID(scope), _name, _fail, args) + #define scoped_guard(_name, args...) \ for (CLASS(_name, scope)(args), \ *done = NULL; __guard_ptr(_name)(&scope) && !done; done = (void *)1)
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