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ipc: store ipcs into IDRs
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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 <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Nadia Derbey authored and Linus Torvalds committed Oct 19, 2007
1 parent d2b20b1 commit 7ca7e56
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Showing 9 changed files with 331 additions and 313 deletions.
1 change: 1 addition & 0 deletions include/linux/ipc.h
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Original file line number Diff line number Diff line change
Expand Up @@ -89,6 +89,7 @@ struct kern_ipc_perm
{
spinlock_t lock;
int deleted;
int id;
key_t key;
uid_t uid;
gid_t gid;
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1 change: 0 additions & 1 deletion include/linux/msg.h
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Original file line number Diff line number Diff line change
Expand Up @@ -77,7 +77,6 @@ struct msg_msg {
/* one msq_queue structure for each present queue on the system */
struct msg_queue {
struct kern_ipc_perm q_perm;
int q_id;
time_t q_stime; /* last msgsnd time */
time_t q_rtime; /* last msgrcv time */
time_t q_ctime; /* last change time */
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1 change: 0 additions & 1 deletion include/linux/sem.h
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Original file line number Diff line number Diff line change
Expand Up @@ -90,7 +90,6 @@ struct sem {
/* One sem_array data structure for each set of semaphores in the system. */
struct sem_array {
struct kern_ipc_perm sem_perm; /* permissions .. see ipc.h */
int sem_id;
time_t sem_otime; /* last semop time */
time_t sem_ctime; /* last change time */
struct sem *sem_base; /* ptr to first semaphore in array */
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1 change: 0 additions & 1 deletion include/linux/shm.h
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Original file line number Diff line number Diff line change
Expand Up @@ -79,7 +79,6 @@ struct shmid_kernel /* private to the kernel */
{
struct kern_ipc_perm shm_perm;
struct file * shm_file;
int id;
unsigned long shm_nattch;
unsigned long shm_segsz;
time_t shm_atim;
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115 changes: 70 additions & 45 deletions ipc/msg.c
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Original file line number Diff line number Diff line change
Expand Up @@ -75,13 +75,12 @@ static struct ipc_ids init_msg_ids;

#define msg_lock(ns, id) ((struct msg_queue*)ipc_lock(&msg_ids(ns), id))
#define msg_unlock(msq) ipc_unlock(&(msq)->q_perm)
#define msg_rmid(ns, id) ((struct msg_queue*)ipc_rmid(&msg_ids(ns), id))
#define msg_checkid(ns, msq, msgid) \
ipc_checkid(&msg_ids(ns), &msq->q_perm, msgid)
#define msg_buildid(ns, id, seq) \
ipc_buildid(&msg_ids(ns), id, seq)

static void freeque (struct ipc_namespace *ns, struct msg_queue *msq, int id);
static void freeque(struct ipc_namespace *, struct msg_queue *);
static int newque (struct ipc_namespace *ns, key_t key, int msgflg);
#ifdef CONFIG_PROC_FS
static int sysvipc_msg_proc_show(struct seq_file *s, void *it);
Expand All @@ -93,7 +92,7 @@ static void __msg_init_ns(struct ipc_namespace *ns, struct ipc_ids *ids)
ns->msg_ctlmax = MSGMAX;
ns->msg_ctlmnb = MSGMNB;
ns->msg_ctlmni = MSGMNI;
ipc_init_ids(ids, ns->msg_ctlmni);
ipc_init_ids(ids);
}

int msg_init_ns(struct ipc_namespace *ns)
Expand All @@ -110,20 +109,24 @@ int msg_init_ns(struct ipc_namespace *ns)

void msg_exit_ns(struct ipc_namespace *ns)
{
int i;
struct msg_queue *msq;
int next_id;
int total, in_use;

mutex_lock(&msg_ids(ns).mutex);
for (i = 0; i <= msg_ids(ns).max_id; i++) {
msq = msg_lock(ns, i);

in_use = msg_ids(ns).in_use;

for (total = 0, next_id = 0; total < in_use; next_id++) {
msq = idr_find(&msg_ids(ns).ipcs_idr, next_id);
if (msq == NULL)
continue;

freeque(ns, msq, i);
ipc_lock_by_ptr(&msq->q_perm);
freeque(ns, msq);
total++;
}
mutex_unlock(&msg_ids(ns).mutex);

ipc_fini_ids(ns->ids[IPC_MSG_IDS]);
kfree(ns->ids[IPC_MSG_IDS]);
ns->ids[IPC_MSG_IDS] = NULL;
}
Expand All @@ -136,6 +139,11 @@ void __init msg_init(void)
IPC_MSG_IDS, sysvipc_msg_proc_show);
}

static inline void msg_rmid(struct ipc_namespace *ns, struct msg_queue *s)
{
ipc_rmid(&msg_ids(ns), &s->q_perm);
}

static int newque (struct ipc_namespace *ns, key_t key, int msgflg)
{
struct msg_queue *msq;
Expand All @@ -155,14 +163,17 @@ static int newque (struct ipc_namespace *ns, key_t key, int msgflg)
return retval;
}

/*
* ipc_addid() locks msq
*/
id = ipc_addid(&msg_ids(ns), &msq->q_perm, ns->msg_ctlmni);
if (id == -1) {
security_msg_queue_free(msq);
ipc_rcu_putref(msq);
return -ENOSPC;
}

msq->q_id = msg_buildid(ns, id, msq->q_perm.seq);
msq->q_perm.id = msg_buildid(ns, id, msq->q_perm.seq);
msq->q_stime = msq->q_rtime = 0;
msq->q_ctime = get_seconds();
msq->q_cbytes = msq->q_qnum = 0;
Expand All @@ -171,9 +182,10 @@ static int newque (struct ipc_namespace *ns, key_t key, int msgflg)
INIT_LIST_HEAD(&msq->q_messages);
INIT_LIST_HEAD(&msq->q_receivers);
INIT_LIST_HEAD(&msq->q_senders);

msg_unlock(msq);

return msq->q_id;
return msq->q_perm.id;
}

static inline void ss_add(struct msg_queue *msq, struct msg_sender *mss)
Expand Down Expand Up @@ -225,18 +237,18 @@ static void expunge_all(struct msg_queue *msq, int res)
/*
* freeque() wakes up waiters on the sender and receiver waiting queue,
* removes the message queue from message queue ID
* array, and cleans up all the messages associated with this queue.
* IDR, and cleans up all the messages associated with this queue.
*
* msg_ids.mutex and the spinlock for this message queue is hold
* msg_ids.mutex and the spinlock for this message queue are held
* before freeque() is called. msg_ids.mutex remains locked on exit.
*/
static void freeque(struct ipc_namespace *ns, struct msg_queue *msq, int id)
static void freeque(struct ipc_namespace *ns, struct msg_queue *msq)
{
struct list_head *tmp;

expunge_all(msq, -EIDRM);
ss_wakeup(&msq->q_senders, 1);
msq = msg_rmid(ns, id);
msg_rmid(ns, msq);
msg_unlock(msq);

tmp = msq->q_messages.next;
Expand All @@ -255,36 +267,51 @@ static void freeque(struct ipc_namespace *ns, struct msg_queue *msq, int id)
asmlinkage long sys_msgget(key_t key, int msgflg)
{
struct msg_queue *msq;
int id, ret = -EPERM;
int ret;
struct ipc_namespace *ns;

ns = current->nsproxy->ipc_ns;
mutex_lock(&msg_ids(ns).mutex);
if (key == IPC_PRIVATE)
ret = newque(ns, key, msgflg);
else if ((id = ipc_findkey(&msg_ids(ns), key)) == -1) { /* key not used */
if (!(msgflg & IPC_CREAT))
ret = -ENOENT;
else

ret = idr_pre_get(&msg_ids(ns).ipcs_idr, GFP_KERNEL);

if (key == IPC_PRIVATE) {
if (!ret)
ret = -ENOMEM;
else {
mutex_lock(&msg_ids(ns).mutex);
ret = newque(ns, key, msgflg);
} else if (msgflg & IPC_CREAT && msgflg & IPC_EXCL) {
ret = -EEXIST;
mutex_unlock(&msg_ids(ns).mutex);
}
} else {
msq = msg_lock(ns, id);
BUG_ON(msq == NULL);
if (ipcperms(&msq->q_perm, msgflg))
ret = -EACCES;
else {
int qid = msg_buildid(ns, id, msq->q_perm.seq);

ret = security_msg_queue_associate(msq, msgflg);
if (!ret)
ret = qid;
mutex_lock(&msg_ids(ns).mutex);
msq = (struct msg_queue *) ipc_findkey(&msg_ids(ns), key);
if (msq == NULL) {
/* key not used */
if (!(msgflg & IPC_CREAT))
ret = -ENOENT;
else if (!ret)
ret = -ENOMEM;
else
ret = newque(ns, key, msgflg);
} else {
/* msq has been locked by ipc_findkey() */

if (msgflg & IPC_CREAT && msgflg & IPC_EXCL)
ret = -EEXIST;
else {
if (ipcperms(&msq->q_perm, msgflg))
ret = -EACCES;
else {
ret = security_msg_queue_associate(
msq, msgflg);
if (!ret)
ret = msq->q_perm.id;
}
}
msg_unlock(msq);
}
msg_unlock(msq);
mutex_unlock(&msg_ids(ns).mutex);
}
mutex_unlock(&msg_ids(ns).mutex);

return ret;
}
Expand Down Expand Up @@ -430,22 +457,20 @@ asmlinkage long sys_msgctl(int msqid, int cmd, struct msqid_ds __user *buf)
msginfo.msgpool = MSGPOOL;
msginfo.msgtql = MSGTQL;
}
max_id = msg_ids(ns).max_id;
max_id = ipc_get_maxid(&msg_ids(ns));
mutex_unlock(&msg_ids(ns).mutex);
if (copy_to_user(buf, &msginfo, sizeof(struct msginfo)))
return -EFAULT;
return (max_id < 0) ? 0 : max_id;
}
case MSG_STAT:
case MSG_STAT: /* msqid is an index rather than a msg queue id */
case IPC_STAT:
{
struct msqid64_ds tbuf;
int success_return;

if (!buf)
return -EFAULT;
if (cmd == MSG_STAT && msqid >= msg_ids(ns).entries->size)
return -EINVAL;

memset(&tbuf, 0, sizeof(tbuf));

Expand All @@ -454,7 +479,7 @@ asmlinkage long sys_msgctl(int msqid, int cmd, struct msqid_ds __user *buf)
return -EINVAL;

if (cmd == MSG_STAT) {
success_return = msg_buildid(ns, msqid, msq->q_perm.seq);
success_return = msq->q_perm.id;
} else {
err = -EIDRM;
if (msg_checkid(ns, msq, msqid))
Expand Down Expand Up @@ -552,7 +577,7 @@ asmlinkage long sys_msgctl(int msqid, int cmd, struct msqid_ds __user *buf)
break;
}
case IPC_RMID:
freeque(ns, msq, msqid);
freeque(ns, msq);
break;
}
err = 0;
Expand Down Expand Up @@ -926,7 +951,7 @@ static int sysvipc_msg_proc_show(struct seq_file *s, void *it)
return seq_printf(s,
"%10d %10d %4o %10lu %10lu %5u %5u %5u %5u %5u %5u %10lu %10lu %10lu\n",
msq->q_perm.key,
msq->q_id,
msq->q_perm.id,
msq->q_perm.mode,
msq->q_cbytes,
msq->q_qnum,
Expand Down
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