From 7ca7e564e049d8b350ec9d958ff25eaa24226352 Mon Sep 17 00:00:00 2001 From: Nadia Derbey Date: Thu, 18 Oct 2007 23:40:48 -0700 Subject: 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 Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- ipc/sem.c | 111 ++++++++++++++++++++++++++++++++++++-------------------------- 1 file changed, 65 insertions(+), 46 deletions(-) (limited to 'ipc/sem.c') 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, -- cgit v1.2.3