IPC/semaphores: code factorisation

Trivial patch which adds some small locking functions and makes use of them to
factorize some part of the code and to make it cleaner.

Signed-off-by: Pierre Peiffer <pierre.peiffer@bull.net>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Cc: Nadia Derbey <Nadia.Derbey@bull.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 31 insertions, 30 deletions

diff --git a/ipc/sem.c b/ipc/sem.c
index 08da8648925d..1b5ae352cde4 100644
--- a/ipc/sem.c
+++ b/ipc/sem.c
@@ -180,6 +180,25 @@ static inline struct sem_array *sem_lock_check(struct ipc_namespace *ns,
         return container_of(ipcp, struct sem_array, sem_perm);
 }
 
+static inline void sem_lock_and_putref(struct sem_array *sma)
+{
+        ipc_lock_by_ptr(&sma->sem_perm);
+        ipc_rcu_putref(sma);
+}
+
+static inline void sem_getref_and_unlock(struct sem_array *sma)
+{
+        ipc_rcu_getref(sma);
+        ipc_unlock(&(sma)->sem_perm);
+}
+
+static inline void sem_putref(struct sem_array *sma)
+{
+        ipc_lock_by_ptr(&sma->sem_perm);
+        ipc_rcu_putref(sma);
+        ipc_unlock(&(sma)->sem_perm);
+}
+
 static inline void sem_rmid(struct ipc_namespace *ns, struct sem_array *s)
 {
         ipc_rmid(&sem_ids(ns), &s->sem_perm);
@@ -698,19 +717,15 @@ static int semctl_main(struct ipc_namespace *ns, int semid, int semnum,
                 int i;
 
                 if(nsems > SEMMSL_FAST) {
-                        ipc_rcu_getref(sma);
-                        sem_unlock(sma);                        
+                        sem_getref_and_unlock(sma);
 
                         sem_io = ipc_alloc(sizeof(ushort)*nsems);
                         if(sem_io == NULL) {
-                                ipc_lock_by_ptr(&sma->sem_perm);
-                                ipc_rcu_putref(sma);
-                                sem_unlock(sma);
+                                sem_putref(sma);
                                 return -ENOMEM;
                         }
 
-                        ipc_lock_by_ptr(&sma->sem_perm);
-                        ipc_rcu_putref(sma);
+                        sem_lock_and_putref(sma);
                         if (sma->sem_perm.deleted) {
                                 sem_unlock(sma);
                                 err = -EIDRM;
@@ -731,38 +746,30 @@ static int semctl_main(struct ipc_namespace *ns, int semid, int semnum,
                 int i;
                 struct sem_undo *un;
 
-                ipc_rcu_getref(sma);
-                sem_unlock(sma);
+                sem_getref_and_unlock(sma);
 
                 if(nsems > SEMMSL_FAST) {
                         sem_io = ipc_alloc(sizeof(ushort)*nsems);
                         if(sem_io == NULL) {
-                                ipc_lock_by_ptr(&sma->sem_perm);
-                                ipc_rcu_putref(sma);
-                                sem_unlock(sma);
+                                sem_putref(sma);
                                 return -ENOMEM;
                         }
                 }
 
                 if (copy_from_user (sem_io, arg.array, nsems*sizeof(ushort))) {
-                        ipc_lock_by_ptr(&sma->sem_perm);
-                        ipc_rcu_putref(sma);
-                        sem_unlock(sma);
+                        sem_putref(sma);
                         err = -EFAULT;
                         goto out_free;
                 }
 
                 for (i = 0; i < nsems; i++) {
                         if (sem_io[i] > SEMVMX) {
-                                ipc_lock_by_ptr(&sma->sem_perm);
-                                ipc_rcu_putref(sma);
-                                sem_unlock(sma);
+                                sem_putref(sma);
                                 err = -ERANGE;
                                 goto out_free;
                         }
                 }
-                ipc_lock_by_ptr(&sma->sem_perm);
-                ipc_rcu_putref(sma);
+                sem_lock_and_putref(sma);
                 if (sma->sem_perm.deleted) {
                         sem_unlock(sma);
                         err = -EIDRM;
@@ -1042,14 +1049,11 @@ static struct sem_undo *find_undo(struct ipc_namespace *ns, int semid)
                 return ERR_PTR(PTR_ERR(sma));
 
         nsems = sma->sem_nsems;
-        ipc_rcu_getref(sma);
-        sem_unlock(sma);
+        sem_getref_and_unlock(sma);
 
         new = kzalloc(sizeof(struct sem_undo) + sizeof(short)*nsems, GFP_KERNEL);
         if (!new) {
-                ipc_lock_by_ptr(&sma->sem_perm);
-                ipc_rcu_putref(sma);
-                sem_unlock(sma);
+                sem_putref(sma);
                 return ERR_PTR(-ENOMEM);
         }
         new->semadj = (short *) &new[1];
@@ -1060,13 +1064,10 @@ static struct sem_undo *find_undo(struct ipc_namespace *ns, int semid)
         if (un) {
                 spin_unlock(&ulp->lock);
                 kfree(new);
-                ipc_lock_by_ptr(&sma->sem_perm);
-                ipc_rcu_putref(sma);
-                sem_unlock(sma);
+                sem_putref(sma);
                 goto out;
         }
-        ipc_lock_by_ptr(&sma->sem_perm);
-        ipc_rcu_putref(sma);
+        sem_lock_and_putref(sma);
         if (sma->sem_perm.deleted) {
                 sem_unlock(sma);
                 spin_unlock(&ulp->lock);