[PATCH] knfsd: make nlmclnt_next_cookie SMP safe
The way we incremented the NLM cookie in nlmclnt_next_cookie was not thread
safe. This patch changes the counter to an atomic_t
Signed-off-by: Olaf Kirch <okir@suse.de>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/fs/lockd/clntproc.c b/fs/lockd/clntproc.c
index 7e6f22e..3d84f60 100644
--- a/fs/lockd/clntproc.c
+++ b/fs/lockd/clntproc.c
@@ -36,14 +36,14 @@
/*
* Cookie counter for NLM requests
*/
-static u32 nlm_cookie = 0x1234;
+static atomic_t nlm_cookie = ATOMIC_INIT(0x1234);
-static inline void nlmclnt_next_cookie(struct nlm_cookie *c)
+void nlmclnt_next_cookie(struct nlm_cookie *c)
{
- memcpy(c->data, &nlm_cookie, 4);
- memset(c->data+4, 0, 4);
+ u32 cookie = atomic_inc_return(&nlm_cookie);
+
+ memcpy(c->data, &cookie, 4);
c->len=4;
- nlm_cookie++;
}
static struct nlm_lockowner *nlm_get_lockowner(struct nlm_lockowner *lockowner)
diff --git a/include/linux/lockd/lockd.h b/include/linux/lockd/lockd.h
index 7be7aea..a345650 100644
--- a/include/linux/lockd/lockd.h
+++ b/include/linux/lockd/lockd.h
@@ -157,6 +157,7 @@
u32 nlmclnt_grant(const struct sockaddr_in *addr, const struct nlm_lock *);
void nlmclnt_recovery(struct nlm_host *);
int nlmclnt_reclaim(struct nlm_host *, struct file_lock *);
+void nlmclnt_next_cookie(struct nlm_cookie *);
/*
* Host cache