ieee1394: csr1212: proper refcounting
At least since nodemgr got rid of coarse global locking, accesses to
struct csr1212_keyval's reference counter should be atomic and coupled
with proper barriers. Also, calls to csr1212_keep_keyval(kv) should
occur before kv is being used.
(We probably should convert refcnt to struct kref, but how to keep
csr1212_destroy_keyval's implementation non-recursively then?)
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
diff --git a/drivers/ieee1394/csr1212.h b/drivers/ieee1394/csr1212.h
index df909ce..043039f 100644
--- a/drivers/ieee1394/csr1212.h
+++ b/drivers/ieee1394/csr1212.h
@@ -32,6 +32,7 @@
#include <linux/types.h>
#include <linux/slab.h>
+#include <asm/atomic.h>
#define CSR1212_MALLOC(size) kmalloc((size), GFP_KERNEL)
#define CSR1212_FREE(ptr) kfree(ptr)
@@ -149,7 +150,7 @@
struct csr1212_directory directory;
} value;
struct csr1212_keyval *associate;
- int refcnt;
+ atomic_t refcnt;
/* used in generating and/or parsing CSR image */
struct csr1212_keyval *next, *prev; /* flat list of CSR elements */
@@ -350,7 +351,8 @@
* need for code to retain a keyval that has been parsed. */
static inline void csr1212_keep_keyval(struct csr1212_keyval *kv)
{
- kv->refcnt++;
+ atomic_inc(&kv->refcnt);
+ smp_mb__after_atomic_inc();
}
