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>
This commit is contained in:
Родитель
6546bc4279
Коммит
6ff3797218
61
ipc/sem.c
61
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);
|
||||
|
|
Загрузка…
Ссылка в новой задаче