Messages in this thread Patch in this message | | | From | "Fabio M. De Francesco" <> | Subject | [PATCH 1/2 v3] cleanup: Add cond_guard() to conditional guards | Date | Tue, 6 Feb 2024 13:13:00 +0100 |
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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: Dave Jiang <dave.jiang@intel.com> Cc: 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> 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..d70454e9f8dc 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) -- 2.43.0
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