atomic_(dec|sub)_return_release() are a thing now - use them.
Also, delete the useless barrier in set_closure_fn(): it's redundant
with the memory barrier in closure_put(0.
Since closure_put() would now otherwise just have a release barrier, we
also need a new barrier when the ref hits 0 -
smp_acquire__after_ctrl_dep().
Signed-off-by: Kent Overstreet <kent.overstreet@xxxxxxxxx>
---
include/linux/closure.h | 2 --
lib/closure.c | 6 ++++--
2 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/include/linux/closure.h b/include/linux/closure.h
index 722a586bb224..bdab17050bc8 100644
--- a/include/linux/closure.h
+++ b/include/linux/closure.h
@@ -233,8 +233,6 @@ static inline void set_closure_fn(struct closure *cl, closure_fn *fn,
closure_set_ip(cl);
cl->fn = fn;
cl->wq = wq;
- /* between atomic_dec() in closure_put() */
- smp_mb__before_atomic();
}
static inline void closure_queue(struct closure *cl)
diff --git a/lib/closure.c b/lib/closure.c
index 0855e698ced1..501dfa277b59 100644
--- a/lib/closure.c
+++ b/lib/closure.c
@@ -21,6 +21,8 @@ static inline void closure_put_after_sub(struct closure *cl, int flags)
BUG_ON(!r && (flags & ~CLOSURE_DESTRUCTOR));
if (!r) {
+ smp_acquire__after_ctrl_dep();
+
if (cl->fn && !(flags & CLOSURE_DESTRUCTOR)) {
atomic_set(&cl->remaining,
CLOSURE_REMAINING_INITIALIZER);
@@ -43,7 +45,7 @@ static inline void closure_put_after_sub(struct closure *cl, int flags)
/* For clearing flags with the same atomic op as a put */
void closure_sub(struct closure *cl, int v)
{
- closure_put_after_sub(cl, atomic_sub_return(v, &cl->remaining));
+ closure_put_after_sub(cl, atomic_sub_return_release(v, &cl->remaining));
}
EXPORT_SYMBOL(closure_sub);
@@ -52,7 +54,7 @@ EXPORT_SYMBOL(closure_sub);
*/
void closure_put(struct closure *cl)
{
- closure_put_after_sub(cl, atomic_dec_return(&cl->remaining));
+ closure_put_after_sub(cl, atomic_dec_return_release(&cl->remaining));
}
EXPORT_SYMBOL(closure_put);
--
2.42.0
