2 * POSIX message queues filesystem for Linux.
4 * Copyright (C) 2003,2004 Krzysztof Benedyczak (golbi@mat.uni.torun.pl)
5 * Michal Wronski (michal.wronski@gmail.com)
7 * Spinlocks: Mohamed Abbas (abbas.mohamed@intel.com)
8 * Lockless receive & send, fd based notify:
9 * Manfred Spraul (manfred@colorfullife.com)
11 * Audit: George Wilson (ltcgcw@us.ibm.com)
13 * This file is released under the GPL.
16 #include <linux/capability.h>
17 #include <linux/init.h>
18 #include <linux/pagemap.h>
19 #include <linux/file.h>
20 #include <linux/mount.h>
21 #include <linux/namei.h>
22 #include <linux/sysctl.h>
23 #include <linux/poll.h>
24 #include <linux/mqueue.h>
25 #include <linux/msg.h>
26 #include <linux/skbuff.h>
27 #include <linux/netlink.h>
28 #include <linux/syscalls.h>
29 #include <linux/audit.h>
30 #include <linux/signal.h>
31 #include <linux/mutex.h>
32 #include <linux/nsproxy.h>
33 #include <linux/pid.h>
34 #include <linux/ipc_namespace.h>
35 #include <linux/slab.h>
40 #define MQUEUE_MAGIC 0x19800202
41 #define DIRENT_SIZE 20
42 #define FILENT_SIZE 80
48 #define STATE_PENDING 1
51 struct ext_wait_queue { /* queue of sleeping tasks */
52 struct task_struct *task;
53 struct list_head list;
54 struct msg_msg *msg; /* ptr of loaded message */
55 int state; /* one of STATE_* values */
58 struct mqueue_inode_info {
60 struct inode vfs_inode;
61 wait_queue_head_t wait_q;
63 struct msg_msg **messages;
66 struct sigevent notify;
67 struct pid* notify_owner;
68 struct user_struct *user; /* user who created, for accounting */
69 struct sock *notify_sock;
70 struct sk_buff *notify_cookie;
72 /* for tasks waiting for free space and messages, respectively */
73 struct ext_wait_queue e_wait_q[2];
75 unsigned long qsize; /* size of queue in memory (sum of all msgs) */
78 static const struct inode_operations mqueue_dir_inode_operations;
79 static const struct file_operations mqueue_file_operations;
80 static const struct super_operations mqueue_super_ops;
81 static void remove_notification(struct mqueue_inode_info *info);
83 static struct kmem_cache *mqueue_inode_cachep;
85 static struct ctl_table_header * mq_sysctl_table;
87 static inline struct mqueue_inode_info *MQUEUE_I(struct inode *inode)
89 return container_of(inode, struct mqueue_inode_info, vfs_inode);
93 * This routine should be called with the mq_lock held.
95 static inline struct ipc_namespace *__get_ns_from_inode(struct inode *inode)
97 return get_ipc_ns(inode->i_sb->s_fs_info);
100 static struct ipc_namespace *get_ns_from_inode(struct inode *inode)
102 struct ipc_namespace *ns;
105 ns = __get_ns_from_inode(inode);
106 spin_unlock(&mq_lock);
110 static struct inode *mqueue_get_inode(struct super_block *sb,
111 struct ipc_namespace *ipc_ns, int mode,
112 struct mq_attr *attr)
114 struct user_struct *u = current_user();
117 inode = new_inode(sb);
119 inode->i_mode = mode;
120 inode->i_uid = current_fsuid();
121 inode->i_gid = current_fsgid();
122 inode->i_mtime = inode->i_ctime = inode->i_atime =
126 struct mqueue_inode_info *info;
127 struct task_struct *p = current;
128 unsigned long mq_bytes, mq_msg_tblsz;
130 inode->i_fop = &mqueue_file_operations;
131 inode->i_size = FILENT_SIZE;
132 /* mqueue specific info */
133 info = MQUEUE_I(inode);
134 spin_lock_init(&info->lock);
135 init_waitqueue_head(&info->wait_q);
136 INIT_LIST_HEAD(&info->e_wait_q[0].list);
137 INIT_LIST_HEAD(&info->e_wait_q[1].list);
138 info->notify_owner = NULL;
140 info->user = NULL; /* set when all is ok */
141 memset(&info->attr, 0, sizeof(info->attr));
142 info->attr.mq_maxmsg = ipc_ns->mq_msg_max;
143 info->attr.mq_msgsize = ipc_ns->mq_msgsize_max;
145 info->attr.mq_maxmsg = attr->mq_maxmsg;
146 info->attr.mq_msgsize = attr->mq_msgsize;
148 mq_msg_tblsz = info->attr.mq_maxmsg * sizeof(struct msg_msg *);
149 info->messages = kmalloc(mq_msg_tblsz, GFP_KERNEL);
153 mq_bytes = (mq_msg_tblsz +
154 (info->attr.mq_maxmsg * info->attr.mq_msgsize));
157 if (u->mq_bytes + mq_bytes < u->mq_bytes ||
158 u->mq_bytes + mq_bytes >
159 task_rlimit(p, RLIMIT_MSGQUEUE)) {
160 spin_unlock(&mq_lock);
161 kfree(info->messages);
164 u->mq_bytes += mq_bytes;
165 spin_unlock(&mq_lock);
168 info->user = get_uid(u);
169 } else if (S_ISDIR(mode)) {
171 /* Some things misbehave if size == 0 on a directory */
172 inode->i_size = 2 * DIRENT_SIZE;
173 inode->i_op = &mqueue_dir_inode_operations;
174 inode->i_fop = &simple_dir_operations;
179 make_bad_inode(inode);
184 static int mqueue_fill_super(struct super_block *sb, void *data, int silent)
187 struct ipc_namespace *ns = data;
190 sb->s_blocksize = PAGE_CACHE_SIZE;
191 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
192 sb->s_magic = MQUEUE_MAGIC;
193 sb->s_op = &mqueue_super_ops;
195 inode = mqueue_get_inode(sb, ns, S_IFDIR | S_ISVTX | S_IRWXUGO,
202 sb->s_root = d_alloc_root(inode);
214 static int mqueue_get_sb(struct file_system_type *fs_type,
215 int flags, const char *dev_name,
216 void *data, struct vfsmount *mnt)
218 if (!(flags & MS_KERNMOUNT))
219 data = current->nsproxy->ipc_ns;
220 return get_sb_ns(fs_type, flags, data, mqueue_fill_super, mnt);
223 static void init_once(void *foo)
225 struct mqueue_inode_info *p = (struct mqueue_inode_info *) foo;
227 inode_init_once(&p->vfs_inode);
230 static struct inode *mqueue_alloc_inode(struct super_block *sb)
232 struct mqueue_inode_info *ei;
234 ei = kmem_cache_alloc(mqueue_inode_cachep, GFP_KERNEL);
237 return &ei->vfs_inode;
240 static void mqueue_destroy_inode(struct inode *inode)
242 kmem_cache_free(mqueue_inode_cachep, MQUEUE_I(inode));
245 static void mqueue_delete_inode(struct inode *inode)
247 struct mqueue_inode_info *info;
248 struct user_struct *user;
249 unsigned long mq_bytes;
251 struct ipc_namespace *ipc_ns;
253 if (S_ISDIR(inode->i_mode)) {
257 ipc_ns = get_ns_from_inode(inode);
258 info = MQUEUE_I(inode);
259 spin_lock(&info->lock);
260 for (i = 0; i < info->attr.mq_curmsgs; i++)
261 free_msg(info->messages[i]);
262 kfree(info->messages);
263 spin_unlock(&info->lock);
267 /* Total amount of bytes accounted for the mqueue */
268 mq_bytes = info->attr.mq_maxmsg * (sizeof(struct msg_msg *)
269 + info->attr.mq_msgsize);
273 user->mq_bytes -= mq_bytes;
275 * get_ns_from_inode() ensures that the
276 * (ipc_ns = sb->s_fs_info) is either a valid ipc_ns
277 * to which we now hold a reference, or it is NULL.
278 * We can't put it here under mq_lock, though.
281 ipc_ns->mq_queues_count--;
282 spin_unlock(&mq_lock);
289 static int mqueue_create(struct inode *dir, struct dentry *dentry,
290 int mode, struct nameidata *nd)
293 struct mq_attr *attr = dentry->d_fsdata;
295 struct ipc_namespace *ipc_ns;
298 ipc_ns = __get_ns_from_inode(dir);
303 if (ipc_ns->mq_queues_count >= ipc_ns->mq_queues_max &&
304 !capable(CAP_SYS_RESOURCE)) {
308 ipc_ns->mq_queues_count++;
309 spin_unlock(&mq_lock);
311 inode = mqueue_get_inode(dir->i_sb, ipc_ns, mode, attr);
315 ipc_ns->mq_queues_count--;
320 dir->i_size += DIRENT_SIZE;
321 dir->i_ctime = dir->i_mtime = dir->i_atime = CURRENT_TIME;
323 d_instantiate(dentry, inode);
327 spin_unlock(&mq_lock);
333 static int mqueue_unlink(struct inode *dir, struct dentry *dentry)
335 struct inode *inode = dentry->d_inode;
337 dir->i_ctime = dir->i_mtime = dir->i_atime = CURRENT_TIME;
338 dir->i_size -= DIRENT_SIZE;
345 * This is routine for system read from queue file.
346 * To avoid mess with doing here some sort of mq_receive we allow
347 * to read only queue size & notification info (the only values
348 * that are interesting from user point of view and aren't accessible
349 * through std routines)
351 static ssize_t mqueue_read_file(struct file *filp, char __user *u_data,
352 size_t count, loff_t *off)
354 struct mqueue_inode_info *info = MQUEUE_I(filp->f_path.dentry->d_inode);
355 char buffer[FILENT_SIZE];
358 spin_lock(&info->lock);
359 snprintf(buffer, sizeof(buffer),
360 "QSIZE:%-10lu NOTIFY:%-5d SIGNO:%-5d NOTIFY_PID:%-6d\n",
362 info->notify_owner ? info->notify.sigev_notify : 0,
363 (info->notify_owner &&
364 info->notify.sigev_notify == SIGEV_SIGNAL) ?
365 info->notify.sigev_signo : 0,
366 pid_vnr(info->notify_owner));
367 spin_unlock(&info->lock);
368 buffer[sizeof(buffer)-1] = '\0';
370 ret = simple_read_from_buffer(u_data, count, off, buffer,
375 filp->f_path.dentry->d_inode->i_atime = filp->f_path.dentry->d_inode->i_ctime = CURRENT_TIME;
379 static int mqueue_flush_file(struct file *filp, fl_owner_t id)
381 struct mqueue_inode_info *info = MQUEUE_I(filp->f_path.dentry->d_inode);
383 spin_lock(&info->lock);
384 if (task_tgid(current) == info->notify_owner)
385 remove_notification(info);
387 spin_unlock(&info->lock);
391 static unsigned int mqueue_poll_file(struct file *filp, struct poll_table_struct *poll_tab)
393 struct mqueue_inode_info *info = MQUEUE_I(filp->f_path.dentry->d_inode);
396 poll_wait(filp, &info->wait_q, poll_tab);
398 spin_lock(&info->lock);
399 if (info->attr.mq_curmsgs)
400 retval = POLLIN | POLLRDNORM;
402 if (info->attr.mq_curmsgs < info->attr.mq_maxmsg)
403 retval |= POLLOUT | POLLWRNORM;
404 spin_unlock(&info->lock);
409 /* Adds current to info->e_wait_q[sr] before element with smaller prio */
410 static void wq_add(struct mqueue_inode_info *info, int sr,
411 struct ext_wait_queue *ewp)
413 struct ext_wait_queue *walk;
417 list_for_each_entry(walk, &info->e_wait_q[sr].list, list) {
418 if (walk->task->static_prio <= current->static_prio) {
419 list_add_tail(&ewp->list, &walk->list);
423 list_add_tail(&ewp->list, &info->e_wait_q[sr].list);
427 * Puts current task to sleep. Caller must hold queue lock. After return
431 static int wq_sleep(struct mqueue_inode_info *info, int sr,
432 long timeout, struct ext_wait_queue *ewp)
437 wq_add(info, sr, ewp);
440 set_current_state(TASK_INTERRUPTIBLE);
442 spin_unlock(&info->lock);
443 time = schedule_timeout(timeout);
445 while (ewp->state == STATE_PENDING)
448 if (ewp->state == STATE_READY) {
452 spin_lock(&info->lock);
453 if (ewp->state == STATE_READY) {
457 if (signal_pending(current)) {
458 retval = -ERESTARTSYS;
466 list_del(&ewp->list);
468 spin_unlock(&info->lock);
474 * Returns waiting task that should be serviced first or NULL if none exists
476 static struct ext_wait_queue *wq_get_first_waiter(
477 struct mqueue_inode_info *info, int sr)
479 struct list_head *ptr;
481 ptr = info->e_wait_q[sr].list.prev;
482 if (ptr == &info->e_wait_q[sr].list)
484 return list_entry(ptr, struct ext_wait_queue, list);
487 /* Auxiliary functions to manipulate messages' list */
488 static void msg_insert(struct msg_msg *ptr, struct mqueue_inode_info *info)
492 k = info->attr.mq_curmsgs - 1;
493 while (k >= 0 && info->messages[k]->m_type >= ptr->m_type) {
494 info->messages[k + 1] = info->messages[k];
497 info->attr.mq_curmsgs++;
498 info->qsize += ptr->m_ts;
499 info->messages[k + 1] = ptr;
502 static inline struct msg_msg *msg_get(struct mqueue_inode_info *info)
504 info->qsize -= info->messages[--info->attr.mq_curmsgs]->m_ts;
505 return info->messages[info->attr.mq_curmsgs];
508 static inline void set_cookie(struct sk_buff *skb, char code)
510 ((char*)skb->data)[NOTIFY_COOKIE_LEN-1] = code;
514 * The next function is only to split too long sys_mq_timedsend
516 static void __do_notify(struct mqueue_inode_info *info)
519 * invoked when there is registered process and there isn't process
520 * waiting synchronously for message AND state of queue changed from
521 * empty to not empty. Here we are sure that no one is waiting
523 if (info->notify_owner &&
524 info->attr.mq_curmsgs == 1) {
525 struct siginfo sig_i;
526 switch (info->notify.sigev_notify) {
532 sig_i.si_signo = info->notify.sigev_signo;
534 sig_i.si_code = SI_MESGQ;
535 sig_i.si_value = info->notify.sigev_value;
536 sig_i.si_pid = task_tgid_nr_ns(current,
537 ns_of_pid(info->notify_owner));
538 sig_i.si_uid = current_uid();
540 kill_pid_info(info->notify.sigev_signo,
541 &sig_i, info->notify_owner);
544 set_cookie(info->notify_cookie, NOTIFY_WOKENUP);
545 netlink_sendskb(info->notify_sock, info->notify_cookie);
548 /* after notification unregisters process */
549 put_pid(info->notify_owner);
550 info->notify_owner = NULL;
552 wake_up(&info->wait_q);
555 static long prepare_timeout(struct timespec *p)
557 struct timespec nowts;
561 if (unlikely(p->tv_nsec < 0 || p->tv_sec < 0
562 || p->tv_nsec >= NSEC_PER_SEC))
564 nowts = CURRENT_TIME;
565 /* first subtract as jiffies can't be too big */
566 p->tv_sec -= nowts.tv_sec;
567 if (p->tv_nsec < nowts.tv_nsec) {
568 p->tv_nsec += NSEC_PER_SEC;
571 p->tv_nsec -= nowts.tv_nsec;
575 timeout = timespec_to_jiffies(p) + 1;
577 return MAX_SCHEDULE_TIMEOUT;
582 static void remove_notification(struct mqueue_inode_info *info)
584 if (info->notify_owner != NULL &&
585 info->notify.sigev_notify == SIGEV_THREAD) {
586 set_cookie(info->notify_cookie, NOTIFY_REMOVED);
587 netlink_sendskb(info->notify_sock, info->notify_cookie);
589 put_pid(info->notify_owner);
590 info->notify_owner = NULL;
593 static int mq_attr_ok(struct ipc_namespace *ipc_ns, struct mq_attr *attr)
595 if (attr->mq_maxmsg <= 0 || attr->mq_msgsize <= 0)
597 if (capable(CAP_SYS_RESOURCE)) {
598 if (attr->mq_maxmsg > HARD_MSGMAX)
601 if (attr->mq_maxmsg > ipc_ns->mq_msg_max ||
602 attr->mq_msgsize > ipc_ns->mq_msgsize_max)
605 /* check for overflow */
606 if (attr->mq_msgsize > ULONG_MAX/attr->mq_maxmsg)
608 if ((unsigned long)(attr->mq_maxmsg * (attr->mq_msgsize
609 + sizeof (struct msg_msg *))) <
610 (unsigned long)(attr->mq_maxmsg * attr->mq_msgsize))
616 * Invoked when creating a new queue via sys_mq_open
618 static struct file *do_create(struct ipc_namespace *ipc_ns, struct dentry *dir,
619 struct dentry *dentry, int oflag, mode_t mode,
620 struct mq_attr *attr)
622 const struct cred *cred = current_cred();
627 if (!mq_attr_ok(ipc_ns, attr)) {
631 /* store for use during create */
632 dentry->d_fsdata = attr;
635 mode &= ~current_umask();
636 ret = mnt_want_write(ipc_ns->mq_mnt);
639 ret = vfs_create(dir->d_inode, dentry, mode, NULL);
640 dentry->d_fsdata = NULL;
644 result = dentry_open(dentry, ipc_ns->mq_mnt, oflag, cred);
646 * dentry_open() took a persistent mnt_want_write(),
647 * so we can now drop this one.
649 mnt_drop_write(ipc_ns->mq_mnt);
653 mnt_drop_write(ipc_ns->mq_mnt);
656 mntput(ipc_ns->mq_mnt);
660 /* Opens existing queue */
661 static struct file *do_open(struct ipc_namespace *ipc_ns,
662 struct dentry *dentry, int oflag)
665 const struct cred *cred = current_cred();
667 static const int oflag2acc[O_ACCMODE] = { MAY_READ, MAY_WRITE,
668 MAY_READ | MAY_WRITE };
670 if ((oflag & O_ACCMODE) == (O_RDWR | O_WRONLY)) {
675 if (inode_permission(dentry->d_inode, oflag2acc[oflag & O_ACCMODE])) {
680 return dentry_open(dentry, ipc_ns->mq_mnt, oflag, cred);
684 mntput(ipc_ns->mq_mnt);
688 SYSCALL_DEFINE4(mq_open, const char __user *, u_name, int, oflag, mode_t, mode,
689 struct mq_attr __user *, u_attr)
691 struct dentry *dentry;
696 struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns;
698 if (u_attr && copy_from_user(&attr, u_attr, sizeof(struct mq_attr)))
701 audit_mq_open(oflag, mode, u_attr ? &attr : NULL);
703 if (IS_ERR(name = getname(u_name)))
704 return PTR_ERR(name);
706 fd = get_unused_fd_flags(O_CLOEXEC);
710 mutex_lock(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex);
711 dentry = lookup_one_len(name, ipc_ns->mq_mnt->mnt_root, strlen(name));
712 if (IS_ERR(dentry)) {
713 error = PTR_ERR(dentry);
716 mntget(ipc_ns->mq_mnt);
718 if (oflag & O_CREAT) {
719 if (dentry->d_inode) { /* entry already exists */
720 audit_inode(name, dentry);
721 if (oflag & O_EXCL) {
725 filp = do_open(ipc_ns, dentry, oflag);
727 filp = do_create(ipc_ns, ipc_ns->mq_mnt->mnt_root,
729 u_attr ? &attr : NULL);
732 if (!dentry->d_inode) {
736 audit_inode(name, dentry);
737 filp = do_open(ipc_ns, dentry, oflag);
741 error = PTR_ERR(filp);
745 fd_install(fd, filp);
750 mntput(ipc_ns->mq_mnt);
755 mutex_unlock(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex);
761 SYSCALL_DEFINE1(mq_unlink, const char __user *, u_name)
765 struct dentry *dentry;
766 struct inode *inode = NULL;
767 struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns;
769 name = getname(u_name);
771 return PTR_ERR(name);
773 mutex_lock_nested(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex,
775 dentry = lookup_one_len(name, ipc_ns->mq_mnt->mnt_root, strlen(name));
776 if (IS_ERR(dentry)) {
777 err = PTR_ERR(dentry);
781 if (!dentry->d_inode) {
786 inode = dentry->d_inode;
788 atomic_inc(&inode->i_count);
789 err = mnt_want_write(ipc_ns->mq_mnt);
792 err = vfs_unlink(dentry->d_parent->d_inode, dentry);
793 mnt_drop_write(ipc_ns->mq_mnt);
798 mutex_unlock(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex);
806 /* Pipelined send and receive functions.
808 * If a receiver finds no waiting message, then it registers itself in the
809 * list of waiting receivers. A sender checks that list before adding the new
810 * message into the message array. If there is a waiting receiver, then it
811 * bypasses the message array and directly hands the message over to the
813 * The receiver accepts the message and returns without grabbing the queue
814 * spinlock. Therefore an intermediate STATE_PENDING state and memory barriers
815 * are necessary. The same algorithm is used for sysv semaphores, see
816 * ipc/sem.c for more details.
818 * The same algorithm is used for senders.
821 /* pipelined_send() - send a message directly to the task waiting in
822 * sys_mq_timedreceive() (without inserting message into a queue).
824 static inline void pipelined_send(struct mqueue_inode_info *info,
825 struct msg_msg *message,
826 struct ext_wait_queue *receiver)
828 receiver->msg = message;
829 list_del(&receiver->list);
830 receiver->state = STATE_PENDING;
831 wake_up_process(receiver->task);
833 receiver->state = STATE_READY;
836 /* pipelined_receive() - if there is task waiting in sys_mq_timedsend()
837 * gets its message and put to the queue (we have one free place for sure). */
838 static inline void pipelined_receive(struct mqueue_inode_info *info)
840 struct ext_wait_queue *sender = wq_get_first_waiter(info, SEND);
844 wake_up_interruptible(&info->wait_q);
847 msg_insert(sender->msg, info);
848 list_del(&sender->list);
849 sender->state = STATE_PENDING;
850 wake_up_process(sender->task);
852 sender->state = STATE_READY;
855 SYSCALL_DEFINE5(mq_timedsend, mqd_t, mqdes, const char __user *, u_msg_ptr,
856 size_t, msg_len, unsigned int, msg_prio,
857 const struct timespec __user *, u_abs_timeout)
861 struct ext_wait_queue wait;
862 struct ext_wait_queue *receiver;
863 struct msg_msg *msg_ptr;
864 struct mqueue_inode_info *info;
865 struct timespec ts, *p = NULL;
870 if (copy_from_user(&ts, u_abs_timeout,
871 sizeof(struct timespec)))
876 if (unlikely(msg_prio >= (unsigned long) MQ_PRIO_MAX))
879 audit_mq_sendrecv(mqdes, msg_len, msg_prio, p);
880 timeout = prepare_timeout(p);
883 if (unlikely(!filp)) {
888 inode = filp->f_path.dentry->d_inode;
889 if (unlikely(filp->f_op != &mqueue_file_operations)) {
893 info = MQUEUE_I(inode);
894 audit_inode(NULL, filp->f_path.dentry);
896 if (unlikely(!(filp->f_mode & FMODE_WRITE))) {
901 if (unlikely(msg_len > info->attr.mq_msgsize)) {
906 /* First try to allocate memory, before doing anything with
907 * existing queues. */
908 msg_ptr = load_msg(u_msg_ptr, msg_len);
909 if (IS_ERR(msg_ptr)) {
910 ret = PTR_ERR(msg_ptr);
913 msg_ptr->m_ts = msg_len;
914 msg_ptr->m_type = msg_prio;
916 spin_lock(&info->lock);
918 if (info->attr.mq_curmsgs == info->attr.mq_maxmsg) {
919 if (filp->f_flags & O_NONBLOCK) {
920 spin_unlock(&info->lock);
922 } else if (unlikely(timeout < 0)) {
923 spin_unlock(&info->lock);
927 wait.msg = (void *) msg_ptr;
928 wait.state = STATE_NONE;
929 ret = wq_sleep(info, SEND, timeout, &wait);
934 receiver = wq_get_first_waiter(info, RECV);
936 pipelined_send(info, msg_ptr, receiver);
938 /* adds message to the queue */
939 msg_insert(msg_ptr, info);
942 inode->i_atime = inode->i_mtime = inode->i_ctime =
944 spin_unlock(&info->lock);
953 SYSCALL_DEFINE5(mq_timedreceive, mqd_t, mqdes, char __user *, u_msg_ptr,
954 size_t, msg_len, unsigned int __user *, u_msg_prio,
955 const struct timespec __user *, u_abs_timeout)
959 struct msg_msg *msg_ptr;
962 struct mqueue_inode_info *info;
963 struct ext_wait_queue wait;
964 struct timespec ts, *p = NULL;
967 if (copy_from_user(&ts, u_abs_timeout,
968 sizeof(struct timespec)))
973 audit_mq_sendrecv(mqdes, msg_len, 0, p);
974 timeout = prepare_timeout(p);
977 if (unlikely(!filp)) {
982 inode = filp->f_path.dentry->d_inode;
983 if (unlikely(filp->f_op != &mqueue_file_operations)) {
987 info = MQUEUE_I(inode);
988 audit_inode(NULL, filp->f_path.dentry);
990 if (unlikely(!(filp->f_mode & FMODE_READ))) {
995 /* checks if buffer is big enough */
996 if (unlikely(msg_len < info->attr.mq_msgsize)) {
1001 spin_lock(&info->lock);
1002 if (info->attr.mq_curmsgs == 0) {
1003 if (filp->f_flags & O_NONBLOCK) {
1004 spin_unlock(&info->lock);
1007 } else if (unlikely(timeout < 0)) {
1008 spin_unlock(&info->lock);
1012 wait.task = current;
1013 wait.state = STATE_NONE;
1014 ret = wq_sleep(info, RECV, timeout, &wait);
1018 msg_ptr = msg_get(info);
1020 inode->i_atime = inode->i_mtime = inode->i_ctime =
1023 /* There is now free space in queue. */
1024 pipelined_receive(info);
1025 spin_unlock(&info->lock);
1029 ret = msg_ptr->m_ts;
1031 if ((u_msg_prio && put_user(msg_ptr->m_type, u_msg_prio)) ||
1032 store_msg(u_msg_ptr, msg_ptr, msg_ptr->m_ts)) {
1044 * Notes: the case when user wants us to deregister (with NULL as pointer)
1045 * and he isn't currently owner of notification, will be silently discarded.
1046 * It isn't explicitly defined in the POSIX.
1048 SYSCALL_DEFINE2(mq_notify, mqd_t, mqdes,
1049 const struct sigevent __user *, u_notification)
1054 struct inode *inode;
1055 struct sigevent notification;
1056 struct mqueue_inode_info *info;
1059 if (u_notification) {
1060 if (copy_from_user(¬ification, u_notification,
1061 sizeof(struct sigevent)))
1065 audit_mq_notify(mqdes, u_notification ? ¬ification : NULL);
1069 if (u_notification != NULL) {
1070 if (unlikely(notification.sigev_notify != SIGEV_NONE &&
1071 notification.sigev_notify != SIGEV_SIGNAL &&
1072 notification.sigev_notify != SIGEV_THREAD))
1074 if (notification.sigev_notify == SIGEV_SIGNAL &&
1075 !valid_signal(notification.sigev_signo)) {
1078 if (notification.sigev_notify == SIGEV_THREAD) {
1081 /* create the notify skb */
1082 nc = alloc_skb(NOTIFY_COOKIE_LEN, GFP_KERNEL);
1087 if (copy_from_user(nc->data,
1088 notification.sigev_value.sival_ptr,
1089 NOTIFY_COOKIE_LEN)) {
1094 /* TODO: add a header? */
1095 skb_put(nc, NOTIFY_COOKIE_LEN);
1096 /* and attach it to the socket */
1098 filp = fget(notification.sigev_signo);
1103 sock = netlink_getsockbyfilp(filp);
1106 ret = PTR_ERR(sock);
1111 timeo = MAX_SCHEDULE_TIMEOUT;
1112 ret = netlink_attachskb(sock, nc, &timeo, NULL);
1129 inode = filp->f_path.dentry->d_inode;
1130 if (unlikely(filp->f_op != &mqueue_file_operations)) {
1134 info = MQUEUE_I(inode);
1137 spin_lock(&info->lock);
1138 if (u_notification == NULL) {
1139 if (info->notify_owner == task_tgid(current)) {
1140 remove_notification(info);
1141 inode->i_atime = inode->i_ctime = CURRENT_TIME;
1143 } else if (info->notify_owner != NULL) {
1146 switch (notification.sigev_notify) {
1148 info->notify.sigev_notify = SIGEV_NONE;
1151 info->notify_sock = sock;
1152 info->notify_cookie = nc;
1155 info->notify.sigev_notify = SIGEV_THREAD;
1158 info->notify.sigev_signo = notification.sigev_signo;
1159 info->notify.sigev_value = notification.sigev_value;
1160 info->notify.sigev_notify = SIGEV_SIGNAL;
1164 info->notify_owner = get_pid(task_tgid(current));
1165 inode->i_atime = inode->i_ctime = CURRENT_TIME;
1167 spin_unlock(&info->lock);
1172 netlink_detachskb(sock, nc);
1179 SYSCALL_DEFINE3(mq_getsetattr, mqd_t, mqdes,
1180 const struct mq_attr __user *, u_mqstat,
1181 struct mq_attr __user *, u_omqstat)
1184 struct mq_attr mqstat, omqstat;
1186 struct inode *inode;
1187 struct mqueue_inode_info *info;
1189 if (u_mqstat != NULL) {
1190 if (copy_from_user(&mqstat, u_mqstat, sizeof(struct mq_attr)))
1192 if (mqstat.mq_flags & (~O_NONBLOCK))
1202 inode = filp->f_path.dentry->d_inode;
1203 if (unlikely(filp->f_op != &mqueue_file_operations)) {
1207 info = MQUEUE_I(inode);
1209 spin_lock(&info->lock);
1211 omqstat = info->attr;
1212 omqstat.mq_flags = filp->f_flags & O_NONBLOCK;
1214 audit_mq_getsetattr(mqdes, &mqstat);
1215 spin_lock(&filp->f_lock);
1216 if (mqstat.mq_flags & O_NONBLOCK)
1217 filp->f_flags |= O_NONBLOCK;
1219 filp->f_flags &= ~O_NONBLOCK;
1220 spin_unlock(&filp->f_lock);
1222 inode->i_atime = inode->i_ctime = CURRENT_TIME;
1225 spin_unlock(&info->lock);
1228 if (u_omqstat != NULL && copy_to_user(u_omqstat, &omqstat,
1229 sizeof(struct mq_attr)))
1238 static const struct inode_operations mqueue_dir_inode_operations = {
1239 .lookup = simple_lookup,
1240 .create = mqueue_create,
1241 .unlink = mqueue_unlink,
1244 static const struct file_operations mqueue_file_operations = {
1245 .flush = mqueue_flush_file,
1246 .poll = mqueue_poll_file,
1247 .read = mqueue_read_file,
1250 static const struct super_operations mqueue_super_ops = {
1251 .alloc_inode = mqueue_alloc_inode,
1252 .destroy_inode = mqueue_destroy_inode,
1253 .statfs = simple_statfs,
1254 .delete_inode = mqueue_delete_inode,
1255 .drop_inode = generic_delete_inode,
1258 static struct file_system_type mqueue_fs_type = {
1260 .get_sb = mqueue_get_sb,
1261 .kill_sb = kill_litter_super,
1264 int mq_init_ns(struct ipc_namespace *ns)
1266 ns->mq_queues_count = 0;
1267 ns->mq_queues_max = DFLT_QUEUESMAX;
1268 ns->mq_msg_max = DFLT_MSGMAX;
1269 ns->mq_msgsize_max = DFLT_MSGSIZEMAX;
1271 ns->mq_mnt = kern_mount_data(&mqueue_fs_type, ns);
1272 if (IS_ERR(ns->mq_mnt)) {
1273 int err = PTR_ERR(ns->mq_mnt);
1280 void mq_clear_sbinfo(struct ipc_namespace *ns)
1282 ns->mq_mnt->mnt_sb->s_fs_info = NULL;
1285 void mq_put_mnt(struct ipc_namespace *ns)
1290 static int __init init_mqueue_fs(void)
1294 mqueue_inode_cachep = kmem_cache_create("mqueue_inode_cache",
1295 sizeof(struct mqueue_inode_info), 0,
1296 SLAB_HWCACHE_ALIGN, init_once);
1297 if (mqueue_inode_cachep == NULL)
1300 /* ignore failures - they are not fatal */
1301 mq_sysctl_table = mq_register_sysctl_table();
1303 error = register_filesystem(&mqueue_fs_type);
1307 spin_lock_init(&mq_lock);
1309 init_ipc_ns.mq_mnt = kern_mount_data(&mqueue_fs_type, &init_ipc_ns);
1310 if (IS_ERR(init_ipc_ns.mq_mnt)) {
1311 error = PTR_ERR(init_ipc_ns.mq_mnt);
1312 goto out_filesystem;
1318 unregister_filesystem(&mqueue_fs_type);
1320 if (mq_sysctl_table)
1321 unregister_sysctl_table(mq_sysctl_table);
1322 kmem_cache_destroy(mqueue_inode_cachep);
1326 __initcall(init_mqueue_fs);