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Commit 01b8b07a authored by Pierre Peiffer's avatar Pierre Peiffer Committed by Linus Torvalds
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IPC: consolidate sem_exit_ns(), msg_exit_ns() and shm_exit_ns() 



sem_exit_ns(), msg_exit_ns() and shm_exit_ns() are all called when an
ipc_namespace is released to free all ipcs of each type.  But in fact, they
do the same thing: they loop around all ipcs to free them individually by
calling a specific routine.

This patch proposes to consolidate this by introducing a common function,
free_ipcs(), that do the job.  The specific routine to call on each
individual ipcs is passed as parameter.  For this, these ipc-specific
'free' routines are reworked to take a generic 'struct ipc_perm' as
parameter.

Signed-off-by: default avatarPierre Peiffer <pierre.peiffer@bull.net>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Nadia Derbey <Nadia.Derbey@bull.net>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent ed2ddbf8

include/linux/ipc_namespace.h

+4 −1
Original line number Diff line number Diff line
@@ -44,6 +44,9 @@ extern struct ipc_namespace init_ipc_ns; 
extern void free_ipc_ns(struct kref *kref);

extern struct ipc_namespace *copy_ipcs(unsigned long flags,

				       struct ipc_namespace *ns);

extern void free_ipcs(struct ipc_namespace *ns, struct ipc_ids *ids,

		      void (*free)(struct ipc_namespace *,

				   struct kern_ipc_perm *));



static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)

{

ipc/msg.c

+5 −23
Original line number Diff line number Diff line
@@ -72,7 +72,7 @@ struct msg_sender { 
#define msg_unlock(msq)		ipc_unlock(&(msq)->q_perm)

#define msg_buildid(id, seq)	ipc_buildid(id, seq)



static void freeque(struct ipc_namespace *, struct msg_queue *);

static void freeque(struct ipc_namespace *, struct kern_ipc_perm *);

static int newque(struct ipc_namespace *, struct ipc_params *);

#ifdef CONFIG_PROC_FS

static int sysvipc_msg_proc_show(struct seq_file *s, void *it);
@@ -91,26 +91,7 @@ void msg_init_ns(struct ipc_namespace *ns) 
#ifdef CONFIG_IPC_NS

void msg_exit_ns(struct ipc_namespace *ns)

{

	struct msg_queue *msq;

	struct kern_ipc_perm *perm;

	int next_id;

	int total, in_use;



	down_write(&msg_ids(ns).rw_mutex);



	in_use = msg_ids(ns).in_use;



	for (total = 0, next_id = 0; total < in_use; next_id++) {

		perm = idr_find(&msg_ids(ns).ipcs_idr, next_id);

		if (perm == NULL)

			continue;

		ipc_lock_by_ptr(perm);

		msq = container_of(perm, struct msg_queue, q_perm);

		freeque(ns, msq);

		total++;

	}



	up_write(&msg_ids(ns).rw_mutex);

	free_ipcs(ns, &msg_ids(ns), freeque);

}

#endif
@@ -274,9 +255,10 @@ static void expunge_all(struct msg_queue *msq, int res) 
 * msg_ids.rw_mutex (writer) and the spinlock for this message queue are held

 * before freeque() is called. msg_ids.rw_mutex remains locked on exit.

 */

static void freeque(struct ipc_namespace *ns, struct msg_queue *msq)

static void freeque(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp)

{

	struct list_head *tmp;

	struct msg_queue *msq = container_of(ipcp, struct msg_queue, q_perm);



	expunge_all(msq, -EIDRM);

	ss_wakeup(&msq->q_senders, 1);
@@ -582,7 +564,7 @@ asmlinkage long sys_msgctl(int msqid, int cmd, struct msqid_ds __user *buf) 
		break;

	}

	case IPC_RMID:

		freeque(ns, msq);

		freeque(ns, &msq->q_perm);

		break;

	}

	err = 0;

ipc/namespace.c

+30 −0
Original line number Diff line number Diff line
@@ -44,6 +44,36 @@ struct ipc_namespace *copy_ipcs(unsigned long flags, struct ipc_namespace *ns) 
	return new_ns;

}



/*

 * free_ipcs - free all ipcs of one type

 * @ns:   the namespace to remove the ipcs from

 * @ids:  the table of ipcs to free

 * @free: the function called to free each individual ipc

 *

 * Called for each kind of ipc when an ipc_namespace exits.

 */

void free_ipcs(struct ipc_namespace *ns, struct ipc_ids *ids,

	       void (*free)(struct ipc_namespace *, struct kern_ipc_perm *))

{

	struct kern_ipc_perm *perm;

	int next_id;

	int total, in_use;



	down_write(&ids->rw_mutex);



	in_use = ids->in_use;



	for (total = 0, next_id = 0; total < in_use; next_id++) {

		perm = idr_find(&ids->ipcs_idr, next_id);

		if (perm == NULL)

			continue;

		ipc_lock_by_ptr(perm);

		free(ns, perm);

		total++;

	}

	up_write(&ids->rw_mutex);

}



void free_ipc_ns(struct kref *kref)

{

	struct ipc_namespace *ns;

ipc/sem.c

+5 −22
Original line number Diff line number Diff line
@@ -94,7 +94,7 @@ 
#define sem_buildid(id, seq)	ipc_buildid(id, seq)



static int newary(struct ipc_namespace *, struct ipc_params *);

static void freeary(struct ipc_namespace *, struct sem_array *);

static void freeary(struct ipc_namespace *, struct kern_ipc_perm *);

#ifdef CONFIG_PROC_FS

static int sysvipc_sem_proc_show(struct seq_file *s, void *it);

#endif
@@ -129,25 +129,7 @@ void sem_init_ns(struct ipc_namespace *ns) 
#ifdef CONFIG_IPC_NS

void sem_exit_ns(struct ipc_namespace *ns)

{

	struct sem_array *sma;

	struct kern_ipc_perm *perm;

	int next_id;

	int total, in_use;



	down_write(&sem_ids(ns).rw_mutex);



	in_use = sem_ids(ns).in_use;



	for (total = 0, next_id = 0; total < in_use; next_id++) {

		perm = idr_find(&sem_ids(ns).ipcs_idr, next_id);

		if (perm == NULL)

			continue;

		ipc_lock_by_ptr(perm);

		sma = container_of(perm, struct sem_array, sem_perm);

		freeary(ns, sma);

		total++;

	}

	up_write(&sem_ids(ns).rw_mutex);

	free_ipcs(ns, &sem_ids(ns), freeary);

}

#endif
@@ -542,10 +524,11 @@ static int count_semzcnt (struct sem_array * sma, ushort semnum) 
 * as a writer and the spinlock for this semaphore set hold. sem_ids.rw_mutex

 * remains locked on exit.

 */

static void freeary(struct ipc_namespace *ns, struct sem_array *sma)

static void freeary(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp)

{

	struct sem_undo *un;

	struct sem_queue *q;

	struct sem_array *sma = container_of(ipcp, struct sem_array, sem_perm);



	/* Invalidate the existing undo structures for this semaphore set.

	 * (They will be freed without any further action in exit_sem()
@@ -926,7 +909,7 @@ static int semctl_down(struct ipc_namespace *ns, int semid, int semnum, 


	switch(cmd){

	case IPC_RMID:

		freeary(ns, sma);

		freeary(ns, ipcp);

		err = 0;

		break;

	case IPC_SET:

ipc/shm.c

+6 −21
Original line number Diff line number Diff line
@@ -83,8 +83,11 @@ void shm_init_ns(struct ipc_namespace *ns) 
 * Called with shm_ids.rw_mutex (writer) and the shp structure locked.

 * Only shm_ids.rw_mutex remains locked on exit.

 */

static void do_shm_rmid(struct ipc_namespace *ns, struct shmid_kernel *shp)

static void do_shm_rmid(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp)

{

	struct shmid_kernel *shp;

	shp = container_of(ipcp, struct shmid_kernel, shm_perm);



	if (shp->shm_nattch){

		shp->shm_perm.mode |= SHM_DEST;

		/* Do not find it any more */
@@ -97,25 +100,7 @@ static void do_shm_rmid(struct ipc_namespace *ns, struct shmid_kernel *shp) 
#ifdef CONFIG_IPC_NS

void shm_exit_ns(struct ipc_namespace *ns)

{

	struct shmid_kernel *shp;

	struct kern_ipc_perm *perm;

	int next_id;

	int total, in_use;



	down_write(&shm_ids(ns).rw_mutex);



	in_use = shm_ids(ns).in_use;



	for (total = 0, next_id = 0; total < in_use; next_id++) {

		perm = idr_find(&shm_ids(ns).ipcs_idr, next_id);

		if (perm == NULL)

			continue;

		ipc_lock_by_ptr(perm);

		shp = container_of(perm, struct shmid_kernel, shm_perm);

		do_shm_rmid(ns, shp);

		total++;

	}

	up_write(&shm_ids(ns).rw_mutex);

	free_ipcs(ns, &shm_ids(ns), do_shm_rmid);

}

#endif
@@ -832,7 +817,7 @@ asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf) 
		if (err)

			goto out_unlock_up;



		do_shm_rmid(ns, shp);

		do_shm_rmid(ns, &shp->shm_perm);

		up_write(&shm_ids(ns).rw_mutex);

		goto out;

	}