From: David Lechner Date: Tue, 1 Oct 2024 22:30:18 +0000 (-0500) Subject: cleanup: Add conditional guard helper X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=36c2cf88808d47e926d11b98734f154fe4a9f50f;p=users%2Fjedix%2Flinux-maple.git cleanup: Add conditional guard helper Add a new if_not_guard() macro to cleanup.h for handling conditional guards such as mutext_trylock(). This is more ergonomic than scoped_guard() for most use cases. Instead of hiding the error handling statement in the macro args, it works like a normal if statement and allow the error path to be indented while the normal code flow path is not indented. And it avoid unwanted side-effect from hidden for loop in scoped_guard(). Signed-off-by: David Lechner Co-developed-by: Fabio M. De Francesco Signed-off-by: Fabio M. De Francesco Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Dan Williams Link: https://lkml.kernel.org/r/20241001-cleanup-if_not_cond_guard-v1-1-7753810b0f7a@baylibre.com --- diff --git a/include/linux/cleanup.h b/include/linux/cleanup.h index 0cc66f8d28e7b..e859f79b9d2d9 100644 --- a/include/linux/cleanup.h +++ b/include/linux/cleanup.h @@ -273,6 +273,12 @@ static inline class_##_name##_t class_##_name##ext##_constructor(_init_args) \ * an anonymous instance of the (guard) class, not recommended for * conditional locks. * + * if_not_guard(name, args...) { }: + * convenience macro for conditional guards that calls the statement that + * follows only if the lock was not acquired (typically an error return). + * + * Only for conditional locks. + * * 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 @@ -343,6 +349,15 @@ _label: \ #define scoped_cond_guard(_name, _fail, args...) \ __scoped_cond_guard(_name, _fail, __UNIQUE_ID(label), args) + +#define __if_not_guard(_name, _id, args...) \ + BUILD_BUG_ON(!__is_cond_ptr(_name)); \ + CLASS(_name, _id)(args); \ + if (!__guard_ptr(_name)(&_id)) + +#define if_not_guard(_name, args...) \ + __if_not_guard(_name, __UNIQUE_ID(guard), args) + /* * Additional helper macros for generating lock guards with types, either for * locks that don't have a native type (eg. RCU, preempt) or those that need a