From 06efa5f30c28eaf237247ca8c4cb46eb62cb6bd9 Mon Sep 17 00:00:00 2001 From: Kent Overstreet Date: Sat, 22 Jun 2024 21:38:58 -0400 Subject: closures: closure_get_not_zero(), closure_return_sync() Provide new primitives for solving a lifetime issue with bcachefs btree_trans objects. closure_sync_return(): like closure_sync(), wait synchronously for any outstanding gets. like closure_return, the closure is considered "finished" and the ref left at 0. closure_get_not_zero(): get a ref on a closure if it's alive, i.e. the ref is not zero. Signed-off-by: Kent Overstreet --- include/linux/closure.h | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) (limited to 'include') diff --git a/include/linux/closure.h b/include/linux/closure.h index 99155df162d0..59b8c06b11ff 100644 --- a/include/linux/closure.h +++ b/include/linux/closure.h @@ -284,6 +284,21 @@ static inline void closure_get(struct closure *cl) #endif } +/** + * closure_get_not_zero + */ +static inline bool closure_get_not_zero(struct closure *cl) +{ + unsigned old = atomic_read(&cl->remaining); + do { + if (!(old & CLOSURE_REMAINING_MASK)) + return false; + + } while (!atomic_try_cmpxchg_acquire(&cl->remaining, &old, old + 1)); + + return true; +} + /** * closure_init - Initialize a closure, setting the refcount to 1 * @cl: closure to initialize @@ -310,6 +325,12 @@ static inline void closure_init_stack(struct closure *cl) atomic_set(&cl->remaining, CLOSURE_REMAINING_INITIALIZER); } +static inline void closure_init_stack_release(struct closure *cl) +{ + memset(cl, 0, sizeof(struct closure)); + atomic_set_release(&cl->remaining, CLOSURE_REMAINING_INITIALIZER); +} + /** * closure_wake_up - wake up all closures on a wait list, * with memory barrier @@ -355,6 +376,8 @@ do { \ */ #define closure_return(_cl) continue_at((_cl), NULL, NULL) +void closure_return_sync(struct closure *cl); + /** * continue_at_nobarrier - jump to another function without barrier * -- cgit v1.2.3