ipc: rename ids->rw_mutex

commit d9a605e40b1376eb02b067d7690580255a0df68f upstream.

Since in some situations the lock can be shared for readers, we shouldn't
be calling it a mutex, rename it to rwsem.

Signed-off-by: Davidlohr Bueso <davidlohr.bueso@hp.com>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 12 insertions, 12 deletions

diff --git a/ipc/sem.c b/ipc/sem.c
index 41088899783d..69b6a21f3844 100644
--- a/ipc/sem.c
+++ b/ipc/sem.c
@@ -322,7 +322,7 @@ static inline void sem_unlock(struct sem_array *sma, int locknum)
 }
 
 /*
- * sem_lock_(check_) routines are called in the paths where the rw_mutex
+ * sem_lock_(check_) routines are called in the paths where the rwsem
  * is not held.
  *
  * The caller holds the RCU read lock.
@@ -426,7 +426,7 @@ static inline void sem_rmid(struct ipc_namespace *ns, struct sem_array *s)
  * @ns: namespace
  * @params: ptr to the structure that contains key, semflg and nsems
  *
- * Called with sem_ids.rw_mutex held (as a writer)
+ * Called with sem_ids.rwsem held (as a writer)
  */
 
 static int newary(struct ipc_namespace *ns, struct ipc_params *params)
@@ -492,7 +492,7 @@ static int newary(struct ipc_namespace *ns, struct ipc_params *params)
 
 
 /*
- * Called with sem_ids.rw_mutex and ipcp locked.
+ * Called with sem_ids.rwsem and ipcp locked.
  */
 static inline int sem_security(struct kern_ipc_perm *ipcp, int semflg)
 {
@@ -503,7 +503,7 @@ static inline int sem_security(struct kern_ipc_perm *ipcp, int semflg)
 }
 
 /*
- * Called with sem_ids.rw_mutex and ipcp locked.
+ * Called with sem_ids.rwsem and ipcp locked.
  */
 static inline int sem_more_checks(struct kern_ipc_perm *ipcp,
                                 struct ipc_params *params)
@@ -994,8 +994,8 @@ static int count_semzcnt (struct sem_array * sma, ushort semnum)
         return semzcnt;
 }
 
-/* Free a semaphore set. freeary() is called with sem_ids.rw_mutex locked
- * as a writer and the spinlock for this semaphore set hold. sem_ids.rw_mutex
+/* Free a semaphore set. freeary() is called with sem_ids.rwsem locked
+ * as a writer and the spinlock for this semaphore set hold. sem_ids.rwsem
  * remains locked on exit.
  */
 static void freeary(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp)
@@ -1116,7 +1116,7 @@ static int semctl_nolock(struct ipc_namespace *ns, int semid,
                 seminfo.semmnu = SEMMNU;
                 seminfo.semmap = SEMMAP;
                 seminfo.semume = SEMUME;
-                down_read(&sem_ids(ns).rw_mutex);
+                down_read(&sem_ids(ns).rwsem);
                 if (cmd == SEM_INFO) {
                         seminfo.semusz = sem_ids(ns).in_use;
                         seminfo.semaem = ns->used_sems;
@@ -1125,7 +1125,7 @@ static int semctl_nolock(struct ipc_namespace *ns, int semid,
                         seminfo.semaem = SEMAEM;
                 }
                 max_id = ipc_get_maxid(&sem_ids(ns));
-                up_read(&sem_ids(ns).rw_mutex);
+                up_read(&sem_ids(ns).rwsem);
                 if (copy_to_user(p, &seminfo, sizeof(struct seminfo))) 
                         return -EFAULT;
                 return (max_id < 0) ? 0: max_id;
@@ -1431,9 +1431,9 @@ copy_semid_from_user(struct semid64_ds *out, void __user *buf, int version)
 }
 
 /*
- * This function handles some semctl commands which require the rw_mutex
+ * This function handles some semctl commands which require the rwsem
  * to be held in write mode.
- * NOTE: no locks must be held, the rw_mutex is taken inside this function.
+ * NOTE: no locks must be held, the rwsem is taken inside this function.
  */
 static int semctl_down(struct ipc_namespace *ns, int semid,
                        int cmd, int version, void __user *p)
@@ -1448,7 +1448,7 @@ static int semctl_down(struct ipc_namespace *ns, int semid,
                         return -EFAULT;
         }
 
-        down_write(&sem_ids(ns).rw_mutex);
+        down_write(&sem_ids(ns).rwsem);
         rcu_read_lock();
 
         ipcp = ipcctl_pre_down_nolock(ns, &sem_ids(ns), semid, cmd,
@@ -1487,7 +1487,7 @@ out_unlock0:
 out_unlock1:
         rcu_read_unlock();
 out_up:
-        up_write(&sem_ids(ns).rw_mutex);
+        up_write(&sem_ids(ns).rwsem);
         return err;
 }