bcache: kill closure locking code
Also flesh out the documentation a bit
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
diff --git a/drivers/md/bcache/closure.c b/drivers/md/bcache/closure.c
index dfff241..7a228de 100644
--- a/drivers/md/bcache/closure.c
+++ b/drivers/md/bcache/closure.c
@@ -11,19 +11,6 @@
#include "closure.h"
-#define CL_FIELD(type, field) \
- case TYPE_ ## type: \
- return &container_of(cl, struct type, cl)->field
-
-static struct closure_waitlist *closure_waitlist(struct closure *cl)
-{
- switch (cl->type) {
- CL_FIELD(closure_with_waitlist, wait);
- default:
- return NULL;
- }
-}
-
static inline void closure_put_after_sub(struct closure *cl, int flags)
{
int r = flags & CLOSURE_REMAINING_MASK;
@@ -42,17 +29,10 @@
closure_queue(cl);
} else {
struct closure *parent = cl->parent;
- struct closure_waitlist *wait = closure_waitlist(cl);
closure_fn *destructor = cl->fn;
closure_debug_destroy(cl);
- smp_mb();
- atomic_set(&cl->remaining, -1);
-
- if (wait)
- closure_wake_up(wait);
-
if (destructor)
destructor(cl);
@@ -69,19 +49,18 @@
}
EXPORT_SYMBOL(closure_sub);
+/**
+ * closure_put - decrement a closure's refcount
+ */
void closure_put(struct closure *cl)
{
closure_put_after_sub(cl, atomic_dec_return(&cl->remaining));
}
EXPORT_SYMBOL(closure_put);
-static void set_waiting(struct closure *cl, unsigned long f)
-{
-#ifdef CONFIG_BCACHE_CLOSURES_DEBUG
- cl->waiting_on = f;
-#endif
-}
-
+/**
+ * closure_wake_up - wake up all closures on a wait list, without memory barrier
+ */
void __closure_wake_up(struct closure_waitlist *wait_list)
{
struct llist_node *list;
@@ -106,27 +85,34 @@
cl = container_of(reverse, struct closure, list);
reverse = llist_next(reverse);
- set_waiting(cl, 0);
+ closure_set_waiting(cl, 0);
closure_sub(cl, CLOSURE_WAITING + 1);
}
}
EXPORT_SYMBOL(__closure_wake_up);
-bool closure_wait(struct closure_waitlist *list, struct closure *cl)
+/**
+ * closure_wait - add a closure to a waitlist
+ *
+ * @waitlist will own a ref on @cl, which will be released when
+ * closure_wake_up() is called on @waitlist.
+ *
+ */
+bool closure_wait(struct closure_waitlist *waitlist, struct closure *cl)
{
if (atomic_read(&cl->remaining) & CLOSURE_WAITING)
return false;
- set_waiting(cl, _RET_IP_);
+ closure_set_waiting(cl, _RET_IP_);
atomic_add(CLOSURE_WAITING + 1, &cl->remaining);
- llist_add(&cl->list, &list->list);
+ llist_add(&cl->list, &waitlist->list);
return true;
}
EXPORT_SYMBOL(closure_wait);
/**
- * closure_sync() - sleep until a closure a closure has nothing left to wait on
+ * closure_sync - sleep until a closure a closure has nothing left to wait on
*
* Sleeps until the refcount hits 1 - the thread that's running the closure owns
* the last refcount.
@@ -148,46 +134,6 @@
}
EXPORT_SYMBOL(closure_sync);
-/**
- * closure_trylock() - try to acquire the closure, without waiting
- * @cl: closure to lock
- *
- * Returns true if the closure was succesfully locked.
- */
-bool closure_trylock(struct closure *cl, struct closure *parent)
-{
- if (atomic_cmpxchg(&cl->remaining, -1,
- CLOSURE_REMAINING_INITIALIZER) != -1)
- return false;
-
- smp_mb();
-
- cl->parent = parent;
- if (parent)
- closure_get(parent);
-
- closure_set_ret_ip(cl);
- closure_debug_create(cl);
- return true;
-}
-EXPORT_SYMBOL(closure_trylock);
-
-void __closure_lock(struct closure *cl, struct closure *parent,
- struct closure_waitlist *wait_list)
-{
- struct closure wait;
- closure_init_stack(&wait);
-
- while (1) {
- if (closure_trylock(cl, parent))
- return;
-
- closure_wait_event(wait_list, &wait,
- atomic_read(&cl->remaining) == -1);
- }
-}
-EXPORT_SYMBOL(__closure_lock);
-
#ifdef CONFIG_BCACHE_CLOSURES_DEBUG
static LIST_HEAD(closure_list);