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authorNadia Derbey <Nadia.Derbey@bull.net>2007-10-18 23:40:48 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-10-19 11:53:44 -0700
commit7ca7e564e049d8b350ec9d958ff25eaa24226352 (patch)
treee3c1397dc898dbd7c685c6a052425e7346eb79d1 /ipc/sem.c
parentd2b20b11547cefc89d6c81937e81afaf3c62808b (diff)
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ipc: store ipcs into IDRs
This patch introduces ipcs storage into IDRs. The main changes are: . This ipc_ids structure is changed: the entries array is changed into a root idr structure. . The grow_ary() routine is removed: it is not needed anymore when adding an ipc structure, since we are now using the IDR facility. . The ipc_rmid() routine interface is changed: . there is no need for this routine to return the pointer passed in as argument: it is now declared as a void . since the id is now part of the kern_ipc_perm structure, no need to have it as an argument to the routine Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'ipc/sem.c')
-rw-r--r--ipc/sem.c111
1 files changed, 65 insertions, 46 deletions
diff --git a/ipc/sem.c b/ipc/sem.c
index 64ff4261f4e..f92a2565d12 100644
--- a/ipc/sem.c
+++ b/ipc/sem.c
@@ -90,7 +90,6 @@
#define sem_lock(ns, id) ((struct sem_array*)ipc_lock(&sem_ids(ns), id))
#define sem_unlock(sma) ipc_unlock(&(sma)->sem_perm)
-#define sem_rmid(ns, id) ((struct sem_array*)ipc_rmid(&sem_ids(ns), id))
#define sem_checkid(ns, sma, semid) \
ipc_checkid(&sem_ids(ns),&sma->sem_perm,semid)
#define sem_buildid(ns, id, seq) \
@@ -99,7 +98,7 @@
static struct ipc_ids init_sem_ids;
static int newary(struct ipc_namespace *, key_t, int, int);
-static void freeary(struct ipc_namespace *ns, struct sem_array *sma, int id);
+static void freeary(struct ipc_namespace *, struct sem_array *);
#ifdef CONFIG_PROC_FS
static int sysvipc_sem_proc_show(struct seq_file *s, void *it);
#endif
@@ -129,7 +128,7 @@ static void __sem_init_ns(struct ipc_namespace *ns, struct ipc_ids *ids)
ns->sc_semopm = SEMOPM;
ns->sc_semmni = SEMMNI;
ns->used_sems = 0;
- ipc_init_ids(ids, ns->sc_semmni);
+ ipc_init_ids(ids);
}
int sem_init_ns(struct ipc_namespace *ns)
@@ -146,20 +145,24 @@ int sem_init_ns(struct ipc_namespace *ns)
void sem_exit_ns(struct ipc_namespace *ns)
{
- int i;
struct sem_array *sma;
+ int next_id;
+ int total, in_use;
mutex_lock(&sem_ids(ns).mutex);
- for (i = 0; i <= sem_ids(ns).max_id; i++) {
- sma = sem_lock(ns, i);
+
+ in_use = sem_ids(ns).in_use;
+
+ for (total = 0, next_id = 0; total < in_use; next_id++) {
+ sma = idr_find(&sem_ids(ns).ipcs_idr, next_id);
if (sma == NULL)
continue;
-
- freeary(ns, sma, i);
+ ipc_lock_by_ptr(&sma->sem_perm);
+ freeary(ns, sma);
+ total++;
}
mutex_unlock(&sem_ids(ns).mutex);
- ipc_fini_ids(ns->ids[IPC_SEM_IDS]);
kfree(ns->ids[IPC_SEM_IDS]);
ns->ids[IPC_SEM_IDS] = NULL;
}
@@ -172,6 +175,11 @@ void __init sem_init (void)
IPC_SEM_IDS, sysvipc_sem_proc_show);
}
+static inline void sem_rmid(struct ipc_namespace *ns, struct sem_array *s)
+{
+ ipc_rmid(&sem_ids(ns), &s->sem_perm);
+}
+
/*
* Lockless wakeup algorithm:
* Without the check/retry algorithm a lockless wakeup is possible:
@@ -243,7 +251,7 @@ static int newary (struct ipc_namespace *ns, key_t key, int nsems, int semflg)
}
ns->used_sems += nsems;
- sma->sem_id = sem_buildid(ns, id, sma->sem_perm.seq);
+ sma->sem_perm.id = sem_buildid(ns, id, sma->sem_perm.seq);
sma->sem_base = (struct sem *) &sma[1];
/* sma->sem_pending = NULL; */
sma->sem_pending_last = &sma->sem_pending;
@@ -252,12 +260,12 @@ static int newary (struct ipc_namespace *ns, key_t key, int nsems, int semflg)
sma->sem_ctime = get_seconds();
sem_unlock(sma);
- return sma->sem_id;
+ return sma->sem_perm.id;
}
asmlinkage long sys_semget (key_t key, int nsems, int semflg)
{
- int id, err = -EINVAL;
+ int err;
struct sem_array *sma;
struct ipc_namespace *ns;
@@ -265,34 +273,50 @@ asmlinkage long sys_semget (key_t key, int nsems, int semflg)
if (nsems < 0 || nsems > ns->sc_semmsl)
return -EINVAL;
- mutex_lock(&sem_ids(ns).mutex);
-
+
+ err = idr_pre_get(&sem_ids(ns).ipcs_idr, GFP_KERNEL);
+
if (key == IPC_PRIVATE) {
- err = newary(ns, key, nsems, semflg);
- } else if ((id = ipc_findkey(&sem_ids(ns), key)) == -1) { /* key not used */
- if (!(semflg & IPC_CREAT))
- err = -ENOENT;
- else
+ if (!err)
+ err = -ENOMEM;
+ else {
+ mutex_lock(&sem_ids(ns).mutex);
err = newary(ns, key, nsems, semflg);
- } else if (semflg & IPC_CREAT && semflg & IPC_EXCL) {
- err = -EEXIST;
+ mutex_unlock(&sem_ids(ns).mutex);
+ }
} else {
- sma = sem_lock(ns, id);
- BUG_ON(sma==NULL);
- if (nsems > sma->sem_nsems)
- err = -EINVAL;
- else if (ipcperms(&sma->sem_perm, semflg))
- err = -EACCES;
- else {
- int semid = sem_buildid(ns, id, sma->sem_perm.seq);
- err = security_sem_associate(sma, semflg);
- if (!err)
- err = semid;
+ mutex_lock(&sem_ids(ns).mutex);
+ sma = (struct sem_array *) ipc_findkey(&sem_ids(ns), key);
+ if (sma == NULL) {
+ /* key not used */
+ if (!(semflg & IPC_CREAT))
+ err = -ENOENT;
+ else if (!err)
+ err = -ENOMEM;
+ else
+ err = newary(ns, key, nsems, semflg);
+ } else {
+ /* sma has been locked by ipc_findkey() */
+
+ if (semflg & IPC_CREAT && semflg & IPC_EXCL)
+ err = -EEXIST;
+ else {
+ if (nsems > sma->sem_nsems)
+ err = -EINVAL;
+ else if (ipcperms(&sma->sem_perm, semflg))
+ err = -EACCES;
+ else {
+ err = security_sem_associate(sma,
+ semflg);
+ if (!err)
+ err = sma->sem_perm.id;
+ }
+ }
+ sem_unlock(sma);
}
- sem_unlock(sma);
+ mutex_unlock(&sem_ids(ns).mutex);
}
- mutex_unlock(&sem_ids(ns).mutex);
return err;
}
@@ -491,11 +515,10 @@ static int count_semzcnt (struct sem_array * sma, ushort semnum)
* the spinlock for this semaphore set hold. sem_ids.mutex remains locked
* on exit.
*/
-static void freeary (struct ipc_namespace *ns, struct sem_array *sma, int id)
+static void freeary(struct ipc_namespace *ns, struct sem_array *sma)
{
struct sem_undo *un;
struct sem_queue *q;
- int size;
/* Invalidate the existing undo structures for this semaphore set.
* (They will be freed without any further action in exit_sem()
@@ -518,12 +541,11 @@ static void freeary (struct ipc_namespace *ns, struct sem_array *sma, int id)
q = n;
}
- /* Remove the semaphore set from the ID array*/
- sma = sem_rmid(ns, id);
+ /* Remove the semaphore set from the IDR */
+ sem_rmid(ns, sma);
sem_unlock(sma);
ns->used_sems -= sma->sem_nsems;
- size = sizeof (*sma) + sma->sem_nsems * sizeof (struct sem);
security_sem_free(sma);
ipc_rcu_putref(sma);
}
@@ -584,7 +606,7 @@ static int semctl_nolock(struct ipc_namespace *ns, int semid, int semnum,
seminfo.semusz = SEMUSZ;
seminfo.semaem = SEMAEM;
}
- max_id = sem_ids(ns).max_id;
+ max_id = ipc_get_maxid(&sem_ids(ns));
mutex_unlock(&sem_ids(ns).mutex);
if (copy_to_user (arg.__buf, &seminfo, sizeof(struct seminfo)))
return -EFAULT;
@@ -595,9 +617,6 @@ static int semctl_nolock(struct ipc_namespace *ns, int semid, int semnum,
struct semid64_ds tbuf;
int id;
- if(semid >= sem_ids(ns).entries->size)
- return -EINVAL;
-
memset(&tbuf,0,sizeof(tbuf));
sma = sem_lock(ns, semid);
@@ -612,7 +631,7 @@ static int semctl_nolock(struct ipc_namespace *ns, int semid, int semnum,
if (err)
goto out_unlock;
- id = sem_buildid(ns, semid, sma->sem_perm.seq);
+ id = sma->sem_perm.id;
kernel_to_ipc64_perm(&sma->sem_perm, &tbuf.sem_perm);
tbuf.sem_otime = sma->sem_otime;
@@ -894,7 +913,7 @@ static int semctl_down(struct ipc_namespace *ns, int semid, int semnum,
switch(cmd){
case IPC_RMID:
- freeary(ns, sma, semid);
+ freeary(ns, sma);
err = 0;
break;
case IPC_SET:
@@ -1402,7 +1421,7 @@ static int sysvipc_sem_proc_show(struct seq_file *s, void *it)
return seq_printf(s,
"%10d %10d %4o %10lu %5u %5u %5u %5u %10lu %10lu\n",
sma->sem_perm.key,
- sma->sem_id,
+ sma->sem_perm.id,
sma->sem_perm.mode,
sma->sem_nsems,
sma->sem_perm.uid,