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| author |   David Lechner <dlechner@baylibre.com> | 2024-10-01 17:30:18 -0500 |
|---|---|---|
| committer |   Peter Zijlstra <peterz@infradead.org> | 2024-10-25 10:01:51 +0200 |
| commit | 36c2cf88808d47e926d11b98734f154fe4a9f50f (patch) | |
| tree | 0d2ecf68e8d6c112bebcb5a9ae7fc9e445312a5b | |
| parent | cleanup: Adjust scoped_guard() macros to avoid potential warning (diff) | |
| download | wireguard-linux-36c2cf88808d47e926d11b98734f154fe4a9f50f.tar.xz wireguard-linux-36c2cf88808d47e926d11b98734f154fe4a9f50f.zip | |
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 <dlechner@baylibre.com>
Co-developed-by: Fabio M. De Francesco <fabio.m.de.francesco@linux.intel.com>
Signed-off-by: Fabio M. De Francesco <fabio.m.de.francesco@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Link: https://lkml.kernel.org/r/20241001-cleanup-if_not_cond_guard-v1-1-7753810b0f7a@baylibre.com
| -rw-r--r-- | include/linux/cleanup.h | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/include/linux/cleanup.h b/include/linux/cleanup.h index 0cc66f8d28e7..e859f79b9d2d 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...) { <error handling> }: + * 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 |