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>
39 #define MQUEUE_MAGIC 0x19800202
40 #define DIRENT_SIZE 20
41 #define FILENT_SIZE 80
47 #define STATE_PENDING 1
50 struct ext_wait_queue { /* queue of sleeping tasks */
51 struct task_struct *task;
52 struct list_head list;
53 struct msg_msg *msg; /* ptr of loaded message */
54 int state; /* one of STATE_* values */
57 struct mqueue_inode_info {
59 struct inode vfs_inode;
60 wait_queue_head_t wait_q;
62 struct msg_msg **messages;
65 struct sigevent notify;
66 struct pid* notify_owner;
67 struct user_struct *user; /* user who created, for accounting */
68 struct sock *notify_sock;
69 struct sk_buff *notify_cookie;
71 /* for tasks waiting for free space and messages, respectively */
72 struct ext_wait_queue e_wait_q[2];
74 unsigned long qsize; /* size of queue in memory (sum of all msgs) */
77 static const struct inode_operations mqueue_dir_inode_operations;
78 static const struct file_operations mqueue_file_operations;
79 static const struct super_operations mqueue_super_ops;
80 static void remove_notification(struct mqueue_inode_info *info);
82 static struct kmem_cache *mqueue_inode_cachep;
84 static struct ctl_table_header * mq_sysctl_table;
86 static inline struct mqueue_inode_info *MQUEUE_I(struct inode *inode)
88 return container_of(inode, struct mqueue_inode_info, vfs_inode);
92 * This routine should be called with the mq_lock held.
94 static inline struct ipc_namespace *__get_ns_from_inode(struct inode *inode)
96 return get_ipc_ns(inode->i_sb->s_fs_info);
99 static struct ipc_namespace *get_ns_from_inode(struct inode *inode)
101 struct ipc_namespace *ns;
104 ns = __get_ns_from_inode(inode);
105 spin_unlock(&mq_lock);
109 static struct inode *mqueue_get_inode(struct super_block *sb,
110 struct ipc_namespace *ipc_ns, int mode,
111 struct mq_attr *attr)
113 struct user_struct *u = current_user();
116 inode = new_inode(sb);
118 inode->i_mode = mode;
119 inode->i_uid = current_fsuid();
120 inode->i_gid = current_fsgid();
121 inode->i_mtime = inode->i_ctime = inode->i_atime =
125 struct mqueue_inode_info *info;
126 struct task_struct *p = current;
127 unsigned long mq_bytes, mq_msg_tblsz;
129 inode->i_fop = &mqueue_file_operations;
130 inode->i_size = FILENT_SIZE;
131 /* mqueue specific info */
132 info = MQUEUE_I(inode);
133 spin_lock_init(&info->lock);
134 init_waitqueue_head(&info->wait_q);
135 INIT_LIST_HEAD(&info->e_wait_q[0].list);
136 INIT_LIST_HEAD(&info->e_wait_q[1].list);
137 info->notify_owner = NULL;
139 info->user = NULL; /* set when all is ok */
140 memset(&info->attr, 0, sizeof(info->attr));
141 info->attr.mq_maxmsg = ipc_ns->mq_msg_max;
142 info->attr.mq_msgsize = ipc_ns->mq_msgsize_max;
144 info->attr.mq_maxmsg = attr->mq_maxmsg;
145 info->attr.mq_msgsize = attr->mq_msgsize;
147 mq_msg_tblsz = info->attr.mq_maxmsg * sizeof(struct msg_msg *);
148 info->messages = kmalloc(mq_msg_tblsz, GFP_KERNEL);
152 mq_bytes = (mq_msg_tblsz +
153 (info->attr.mq_maxmsg * info->attr.mq_msgsize));
156 if (u->mq_bytes + mq_bytes < u->mq_bytes ||
157 u->mq_bytes + mq_bytes >
158 p->signal->rlim[RLIMIT_MSGQUEUE].rlim_cur) {
159 spin_unlock(&mq_lock);
160 kfree(info->messages);
163 u->mq_bytes += mq_bytes;
164 spin_unlock(&mq_lock);
167 info->user = get_uid(u);
168 } else if (S_ISDIR(mode)) {
170 /* Some things misbehave if size == 0 on a directory */
171 inode->i_size = 2 * DIRENT_SIZE;
172 inode->i_op = &mqueue_dir_inode_operations;
173 inode->i_fop = &simple_dir_operations;
178 make_bad_inode(inode);
183 static int mqueue_fill_super(struct super_block *sb, void *data, int silent)
186 struct ipc_namespace *ns = data;
189 sb->s_blocksize = PAGE_CACHE_SIZE;
190 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
191 sb->s_magic = MQUEUE_MAGIC;
192 sb->s_op = &mqueue_super_ops;
194 inode = mqueue_get_inode(sb, ns, S_IFDIR | S_ISVTX | S_IRWXUGO,
201 sb->s_root = d_alloc_root(inode);
211 static int mqueue_get_sb(struct file_system_type *fs_type,
212 int flags, const char *dev_name,
213 void *data, struct vfsmount *mnt)
215 if (!(flags & MS_KERNMOUNT))
216 data = current->nsproxy->ipc_ns;
217 return get_sb_ns(fs_type, flags, data, mqueue_fill_super, mnt);
220 static void init_once(void *foo)
222 struct mqueue_inode_info *p = (struct mqueue_inode_info *) foo;
224 inode_init_once(&p->vfs_inode);
227 static struct inode *mqueue_alloc_inode(struct super_block *sb)
229 struct mqueue_inode_info *ei;
231 ei = kmem_cache_alloc(mqueue_inode_cachep, GFP_KERNEL);
234 return &ei->vfs_inode;
237 static void mqueue_destroy_inode(struct inode *inode)
239 kmem_cache_free(mqueue_inode_cachep, MQUEUE_I(inode));
242 static void mqueue_delete_inode(struct inode *inode)
244 struct mqueue_inode_info *info;
245 struct user_struct *user;
246 unsigned long mq_bytes;
248 struct ipc_namespace *ipc_ns;
250 if (S_ISDIR(inode->i_mode)) {
254 ipc_ns = get_ns_from_inode(inode);
255 info = MQUEUE_I(inode);
256 spin_lock(&info->lock);
257 for (i = 0; i < info->attr.mq_curmsgs; i++)
258 free_msg(info->messages[i]);
259 kfree(info->messages);
260 spin_unlock(&info->lock);
264 /* Total amount of bytes accounted for the mqueue */
265 mq_bytes = info->attr.mq_maxmsg * (sizeof(struct msg_msg *)
266 + info->attr.mq_msgsize);
270 user->mq_bytes -= mq_bytes;
272 * get_ns_from_inode() ensures that the
273 * (ipc_ns = sb->s_fs_info) is either a valid ipc_ns
274 * to which we now hold a reference, or it is NULL.
275 * We can't put it here under mq_lock, though.
278 ipc_ns->mq_queues_count--;
279 spin_unlock(&mq_lock);
286 static int mqueue_create(struct inode *dir, struct dentry *dentry,
287 int mode, struct nameidata *nd)
290 struct mq_attr *attr = dentry->d_fsdata;
292 struct ipc_namespace *ipc_ns;
295 ipc_ns = __get_ns_from_inode(dir);
300 if (ipc_ns->mq_queues_count >= ipc_ns->mq_queues_max &&
301 !capable(CAP_SYS_RESOURCE)) {
305 ipc_ns->mq_queues_count++;
306 spin_unlock(&mq_lock);
308 inode = mqueue_get_inode(dir->i_sb, ipc_ns, mode, attr);
312 ipc_ns->mq_queues_count--;
317 dir->i_size += DIRENT_SIZE;
318 dir->i_ctime = dir->i_mtime = dir->i_atime = CURRENT_TIME;
320 d_instantiate(dentry, inode);
324 spin_unlock(&mq_lock);
330 static int mqueue_unlink(struct inode *dir, struct dentry *dentry)
332 struct inode *inode = dentry->d_inode;
334 dir->i_ctime = dir->i_mtime = dir->i_atime = CURRENT_TIME;
335 dir->i_size -= DIRENT_SIZE;
342 * This is routine for system read from queue file.
343 * To avoid mess with doing here some sort of mq_receive we allow
344 * to read only queue size & notification info (the only values
345 * that are interesting from user point of view and aren't accessible
346 * through std routines)
348 static ssize_t mqueue_read_file(struct file *filp, char __user *u_data,
349 size_t count, loff_t *off)
351 struct mqueue_inode_info *info = MQUEUE_I(filp->f_path.dentry->d_inode);
352 char buffer[FILENT_SIZE];
355 spin_lock(&info->lock);
356 snprintf(buffer, sizeof(buffer),
357 "QSIZE:%-10lu NOTIFY:%-5d SIGNO:%-5d NOTIFY_PID:%-6d\n",
359 info->notify_owner ? info->notify.sigev_notify : 0,
360 (info->notify_owner &&
361 info->notify.sigev_notify == SIGEV_SIGNAL) ?
362 info->notify.sigev_signo : 0,
363 pid_vnr(info->notify_owner));
364 spin_unlock(&info->lock);
365 buffer[sizeof(buffer)-1] = '\0';
367 ret = simple_read_from_buffer(u_data, count, off, buffer,
372 filp->f_path.dentry->d_inode->i_atime = filp->f_path.dentry->d_inode->i_ctime = CURRENT_TIME;
376 static int mqueue_flush_file(struct file *filp, fl_owner_t id)
378 struct mqueue_inode_info *info = MQUEUE_I(filp->f_path.dentry->d_inode);
380 spin_lock(&info->lock);
381 if (task_tgid(current) == info->notify_owner)
382 remove_notification(info);
384 spin_unlock(&info->lock);
388 static unsigned int mqueue_poll_file(struct file *filp, struct poll_table_struct *poll_tab)
390 struct mqueue_inode_info *info = MQUEUE_I(filp->f_path.dentry->d_inode);
393 poll_wait(filp, &info->wait_q, poll_tab);
395 spin_lock(&info->lock);
396 if (info->attr.mq_curmsgs)
397 retval = POLLIN | POLLRDNORM;
399 if (info->attr.mq_curmsgs < info->attr.mq_maxmsg)
400 retval |= POLLOUT | POLLWRNORM;
401 spin_unlock(&info->lock);
406 /* Adds current to info->e_wait_q[sr] before element with smaller prio */
407 static void wq_add(struct mqueue_inode_info *info, int sr,
408 struct ext_wait_queue *ewp)
410 struct ext_wait_queue *walk;
414 list_for_each_entry(walk, &info->e_wait_q[sr].list, list) {
415 if (walk->task->static_prio <= current->static_prio) {
416 list_add_tail(&ewp->list, &walk->list);
420 list_add_tail(&ewp->list, &info->e_wait_q[sr].list);
424 * Puts current task to sleep. Caller must hold queue lock. After return
428 static int wq_sleep(struct mqueue_inode_info *info, int sr,
429 long timeout, struct ext_wait_queue *ewp)
434 wq_add(info, sr, ewp);
437 set_current_state(TASK_INTERRUPTIBLE);
439 spin_unlock(&info->lock);
440 time = schedule_timeout(timeout);
442 while (ewp->state == STATE_PENDING)
445 if (ewp->state == STATE_READY) {
449 spin_lock(&info->lock);
450 if (ewp->state == STATE_READY) {
454 if (signal_pending(current)) {
455 retval = -ERESTARTSYS;
463 list_del(&ewp->list);
465 spin_unlock(&info->lock);
471 * Returns waiting task that should be serviced first or NULL if none exists
473 static struct ext_wait_queue *wq_get_first_waiter(
474 struct mqueue_inode_info *info, int sr)
476 struct list_head *ptr;
478 ptr = info->e_wait_q[sr].list.prev;
479 if (ptr == &info->e_wait_q[sr].list)
481 return list_entry(ptr, struct ext_wait_queue, list);
484 /* Auxiliary functions to manipulate messages' list */
485 static void msg_insert(struct msg_msg *ptr, struct mqueue_inode_info *info)
489 k = info->attr.mq_curmsgs - 1;
490 while (k >= 0 && info->messages[k]->m_type >= ptr->m_type) {
491 info->messages[k + 1] = info->messages[k];
494 info->attr.mq_curmsgs++;
495 info->qsize += ptr->m_ts;
496 info->messages[k + 1] = ptr;
499 static inline struct msg_msg *msg_get(struct mqueue_inode_info *info)
501 info->qsize -= info->messages[--info->attr.mq_curmsgs]->m_ts;
502 return info->messages[info->attr.mq_curmsgs];
505 static inline void set_cookie(struct sk_buff *skb, char code)
507 ((char*)skb->data)[NOTIFY_COOKIE_LEN-1] = code;
511 * The next function is only to split too long sys_mq_timedsend
513 static void __do_notify(struct mqueue_inode_info *info)
516 * invoked when there is registered process and there isn't process
517 * waiting synchronously for message AND state of queue changed from
518 * empty to not empty. Here we are sure that no one is waiting
520 if (info->notify_owner &&
521 info->attr.mq_curmsgs == 1) {
522 struct siginfo sig_i;
523 switch (info->notify.sigev_notify) {
529 sig_i.si_signo = info->notify.sigev_signo;
531 sig_i.si_code = SI_MESGQ;
532 sig_i.si_value = info->notify.sigev_value;
533 sig_i.si_pid = task_tgid_nr_ns(current,
534 ns_of_pid(info->notify_owner));
535 sig_i.si_uid = current_uid();
537 kill_pid_info(info->notify.sigev_signo,
538 &sig_i, info->notify_owner);
541 set_cookie(info->notify_cookie, NOTIFY_WOKENUP);
542 netlink_sendskb(info->notify_sock, info->notify_cookie);
545 /* after notification unregisters process */
546 put_pid(info->notify_owner);
547 info->notify_owner = NULL;
549 wake_up(&info->wait_q);
552 static long prepare_timeout(struct timespec *p)
554 struct timespec nowts;
558 if (unlikely(p->tv_nsec < 0 || p->tv_sec < 0
559 || p->tv_nsec >= NSEC_PER_SEC))
561 nowts = CURRENT_TIME;
562 /* first subtract as jiffies can't be too big */
563 p->tv_sec -= nowts.tv_sec;
564 if (p->tv_nsec < nowts.tv_nsec) {
565 p->tv_nsec += NSEC_PER_SEC;
568 p->tv_nsec -= nowts.tv_nsec;
572 timeout = timespec_to_jiffies(p) + 1;
574 return MAX_SCHEDULE_TIMEOUT;
579 static void remove_notification(struct mqueue_inode_info *info)
581 if (info->notify_owner != NULL &&
582 info->notify.sigev_notify == SIGEV_THREAD) {
583 set_cookie(info->notify_cookie, NOTIFY_REMOVED);
584 netlink_sendskb(info->notify_sock, info->notify_cookie);
586 put_pid(info->notify_owner);
587 info->notify_owner = NULL;
590 static int mq_attr_ok(struct ipc_namespace *ipc_ns, struct mq_attr *attr)
592 if (attr->mq_maxmsg <= 0 || attr->mq_msgsize <= 0)
594 if (capable(CAP_SYS_RESOURCE)) {
595 if (attr->mq_maxmsg > HARD_MSGMAX)
598 if (attr->mq_maxmsg > ipc_ns->mq_msg_max ||
599 attr->mq_msgsize > ipc_ns->mq_msgsize_max)
602 /* check for overflow */
603 if (attr->mq_msgsize > ULONG_MAX/attr->mq_maxmsg)
605 if ((unsigned long)(attr->mq_maxmsg * (attr->mq_msgsize
606 + sizeof (struct msg_msg *))) <
607 (unsigned long)(attr->mq_maxmsg * attr->mq_msgsize))
613 * Invoked when creating a new queue via sys_mq_open
615 static struct file *do_create(struct ipc_namespace *ipc_ns, struct dentry *dir,
616 struct dentry *dentry, int oflag, mode_t mode,
617 struct mq_attr *attr)
619 const struct cred *cred = current_cred();
625 if (!mq_attr_ok(ipc_ns, attr))
627 /* store for use during create */
628 dentry->d_fsdata = attr;
631 mode &= ~current_umask();
632 ret = mnt_want_write(ipc_ns->mq_mnt);
635 ret = vfs_create(dir->d_inode, dentry, mode, NULL);
636 dentry->d_fsdata = NULL;
640 result = dentry_open(dentry, ipc_ns->mq_mnt, oflag, cred);
642 * dentry_open() took a persistent mnt_want_write(),
643 * so we can now drop this one.
645 mnt_drop_write(ipc_ns->mq_mnt);
649 mnt_drop_write(ipc_ns->mq_mnt);
652 mntput(ipc_ns->mq_mnt);
656 /* Opens existing queue */
657 static struct file *do_open(struct ipc_namespace *ipc_ns,
658 struct dentry *dentry, int oflag)
661 const struct cred *cred = current_cred();
663 static const int oflag2acc[O_ACCMODE] = { MAY_READ, MAY_WRITE,
664 MAY_READ | MAY_WRITE };
666 if ((oflag & O_ACCMODE) == (O_RDWR | O_WRONLY)) {
671 if (inode_permission(dentry->d_inode, oflag2acc[oflag & O_ACCMODE])) {
676 return dentry_open(dentry, ipc_ns->mq_mnt, oflag, cred);
680 mntput(ipc_ns->mq_mnt);
684 SYSCALL_DEFINE4(mq_open, const char __user *, u_name, int, oflag, mode_t, mode,
685 struct mq_attr __user *, u_attr)
687 struct dentry *dentry;
692 struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns;
694 if (u_attr && copy_from_user(&attr, u_attr, sizeof(struct mq_attr)))
697 audit_mq_open(oflag, mode, u_attr ? &attr : NULL);
699 if (IS_ERR(name = getname(u_name)))
700 return PTR_ERR(name);
702 fd = get_unused_fd_flags(O_CLOEXEC);
706 mutex_lock(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex);
707 dentry = lookup_one_len(name, ipc_ns->mq_mnt->mnt_root, strlen(name));
708 if (IS_ERR(dentry)) {
709 error = PTR_ERR(dentry);
712 mntget(ipc_ns->mq_mnt);
714 if (oflag & O_CREAT) {
715 if (dentry->d_inode) { /* entry already exists */
716 audit_inode(name, dentry);
720 filp = do_open(ipc_ns, dentry, oflag);
722 filp = do_create(ipc_ns, ipc_ns->mq_mnt->mnt_root,
724 u_attr ? &attr : NULL);
728 if (!dentry->d_inode)
730 audit_inode(name, dentry);
731 filp = do_open(ipc_ns, dentry, oflag);
735 error = PTR_ERR(filp);
739 fd_install(fd, filp);
744 mntput(ipc_ns->mq_mnt);
749 mutex_unlock(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex);
755 SYSCALL_DEFINE1(mq_unlink, const char __user *, u_name)
759 struct dentry *dentry;
760 struct inode *inode = NULL;
761 struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns;
763 name = getname(u_name);
765 return PTR_ERR(name);
767 mutex_lock_nested(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex,
769 dentry = lookup_one_len(name, ipc_ns->mq_mnt->mnt_root, strlen(name));
770 if (IS_ERR(dentry)) {
771 err = PTR_ERR(dentry);
775 if (!dentry->d_inode) {
780 inode = dentry->d_inode;
782 atomic_inc(&inode->i_count);
783 err = mnt_want_write(ipc_ns->mq_mnt);
786 err = vfs_unlink(dentry->d_parent->d_inode, dentry);
787 mnt_drop_write(ipc_ns->mq_mnt);
792 mutex_unlock(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex);
800 /* Pipelined send and receive functions.
802 * If a receiver finds no waiting message, then it registers itself in the
803 * list of waiting receivers. A sender checks that list before adding the new
804 * message into the message array. If there is a waiting receiver, then it
805 * bypasses the message array and directly hands the message over to the
807 * The receiver accepts the message and returns without grabbing the queue
808 * spinlock. Therefore an intermediate STATE_PENDING state and memory barriers
809 * are necessary. The same algorithm is used for sysv semaphores, see
810 * ipc/sem.c for more details.
812 * The same algorithm is used for senders.
815 /* pipelined_send() - send a message directly to the task waiting in
816 * sys_mq_timedreceive() (without inserting message into a queue).
818 static inline void pipelined_send(struct mqueue_inode_info *info,
819 struct msg_msg *message,
820 struct ext_wait_queue *receiver)
822 receiver->msg = message;
823 list_del(&receiver->list);
824 receiver->state = STATE_PENDING;
825 wake_up_process(receiver->task);
827 receiver->state = STATE_READY;
830 /* pipelined_receive() - if there is task waiting in sys_mq_timedsend()
831 * gets its message and put to the queue (we have one free place for sure). */
832 static inline void pipelined_receive(struct mqueue_inode_info *info)
834 struct ext_wait_queue *sender = wq_get_first_waiter(info, SEND);
838 wake_up_interruptible(&info->wait_q);
841 msg_insert(sender->msg, info);
842 list_del(&sender->list);
843 sender->state = STATE_PENDING;
844 wake_up_process(sender->task);
846 sender->state = STATE_READY;
849 SYSCALL_DEFINE5(mq_timedsend, mqd_t, mqdes, const char __user *, u_msg_ptr,
850 size_t, msg_len, unsigned int, msg_prio,
851 const struct timespec __user *, u_abs_timeout)
855 struct ext_wait_queue wait;
856 struct ext_wait_queue *receiver;
857 struct msg_msg *msg_ptr;
858 struct mqueue_inode_info *info;
859 struct timespec ts, *p = NULL;
864 if (copy_from_user(&ts, u_abs_timeout,
865 sizeof(struct timespec)))
870 if (unlikely(msg_prio >= (unsigned long) MQ_PRIO_MAX))
873 audit_mq_sendrecv(mqdes, msg_len, msg_prio, p);
874 timeout = prepare_timeout(p);
881 inode = filp->f_path.dentry->d_inode;
882 if (unlikely(filp->f_op != &mqueue_file_operations))
884 info = MQUEUE_I(inode);
885 audit_inode(NULL, filp->f_path.dentry);
887 if (unlikely(!(filp->f_mode & FMODE_WRITE)))
890 if (unlikely(msg_len > info->attr.mq_msgsize)) {
895 /* First try to allocate memory, before doing anything with
896 * existing queues. */
897 msg_ptr = load_msg(u_msg_ptr, msg_len);
898 if (IS_ERR(msg_ptr)) {
899 ret = PTR_ERR(msg_ptr);
902 msg_ptr->m_ts = msg_len;
903 msg_ptr->m_type = msg_prio;
905 spin_lock(&info->lock);
907 if (info->attr.mq_curmsgs == info->attr.mq_maxmsg) {
908 if (filp->f_flags & O_NONBLOCK) {
909 spin_unlock(&info->lock);
911 } else if (unlikely(timeout < 0)) {
912 spin_unlock(&info->lock);
916 wait.msg = (void *) msg_ptr;
917 wait.state = STATE_NONE;
918 ret = wq_sleep(info, SEND, timeout, &wait);
923 receiver = wq_get_first_waiter(info, RECV);
925 pipelined_send(info, msg_ptr, receiver);
927 /* adds message to the queue */
928 msg_insert(msg_ptr, info);
931 inode->i_atime = inode->i_mtime = inode->i_ctime =
933 spin_unlock(&info->lock);
942 SYSCALL_DEFINE5(mq_timedreceive, mqd_t, mqdes, char __user *, u_msg_ptr,
943 size_t, msg_len, unsigned int __user *, u_msg_prio,
944 const struct timespec __user *, u_abs_timeout)
948 struct msg_msg *msg_ptr;
951 struct mqueue_inode_info *info;
952 struct ext_wait_queue wait;
953 struct timespec ts, *p = NULL;
956 if (copy_from_user(&ts, u_abs_timeout,
957 sizeof(struct timespec)))
962 audit_mq_sendrecv(mqdes, msg_len, 0, p);
963 timeout = prepare_timeout(p);
970 inode = filp->f_path.dentry->d_inode;
971 if (unlikely(filp->f_op != &mqueue_file_operations))
973 info = MQUEUE_I(inode);
974 audit_inode(NULL, filp->f_path.dentry);
976 if (unlikely(!(filp->f_mode & FMODE_READ)))
979 /* checks if buffer is big enough */
980 if (unlikely(msg_len < info->attr.mq_msgsize)) {
985 spin_lock(&info->lock);
986 if (info->attr.mq_curmsgs == 0) {
987 if (filp->f_flags & O_NONBLOCK) {
988 spin_unlock(&info->lock);
991 } else if (unlikely(timeout < 0)) {
992 spin_unlock(&info->lock);
997 wait.state = STATE_NONE;
998 ret = wq_sleep(info, RECV, timeout, &wait);
1002 msg_ptr = msg_get(info);
1004 inode->i_atime = inode->i_mtime = inode->i_ctime =
1007 /* There is now free space in queue. */
1008 pipelined_receive(info);
1009 spin_unlock(&info->lock);
1013 ret = msg_ptr->m_ts;
1015 if ((u_msg_prio && put_user(msg_ptr->m_type, u_msg_prio)) ||
1016 store_msg(u_msg_ptr, msg_ptr, msg_ptr->m_ts)) {
1028 * Notes: the case when user wants us to deregister (with NULL as pointer)
1029 * and he isn't currently owner of notification, will be silently discarded.
1030 * It isn't explicitly defined in the POSIX.
1032 SYSCALL_DEFINE2(mq_notify, mqd_t, mqdes,
1033 const struct sigevent __user *, u_notification)
1038 struct inode *inode;
1039 struct sigevent notification;
1040 struct mqueue_inode_info *info;
1043 if (u_notification) {
1044 if (copy_from_user(¬ification, u_notification,
1045 sizeof(struct sigevent)))
1049 audit_mq_notify(mqdes, u_notification ? ¬ification : NULL);
1053 if (u_notification != NULL) {
1054 if (unlikely(notification.sigev_notify != SIGEV_NONE &&
1055 notification.sigev_notify != SIGEV_SIGNAL &&
1056 notification.sigev_notify != SIGEV_THREAD))
1058 if (notification.sigev_notify == SIGEV_SIGNAL &&
1059 !valid_signal(notification.sigev_signo)) {
1062 if (notification.sigev_notify == SIGEV_THREAD) {
1065 /* create the notify skb */
1066 nc = alloc_skb(NOTIFY_COOKIE_LEN, GFP_KERNEL);
1071 if (copy_from_user(nc->data,
1072 notification.sigev_value.sival_ptr,
1073 NOTIFY_COOKIE_LEN)) {
1077 /* TODO: add a header? */
1078 skb_put(nc, NOTIFY_COOKIE_LEN);
1079 /* and attach it to the socket */
1081 filp = fget(notification.sigev_signo);
1085 sock = netlink_getsockbyfilp(filp);
1088 ret = PTR_ERR(sock);
1093 timeo = MAX_SCHEDULE_TIMEOUT;
1094 ret = netlink_attachskb(sock, nc, &timeo, NULL);
1110 inode = filp->f_path.dentry->d_inode;
1111 if (unlikely(filp->f_op != &mqueue_file_operations))
1113 info = MQUEUE_I(inode);
1116 spin_lock(&info->lock);
1117 if (u_notification == NULL) {
1118 if (info->notify_owner == task_tgid(current)) {
1119 remove_notification(info);
1120 inode->i_atime = inode->i_ctime = CURRENT_TIME;
1122 } else if (info->notify_owner != NULL) {
1125 switch (notification.sigev_notify) {
1127 info->notify.sigev_notify = SIGEV_NONE;
1130 info->notify_sock = sock;
1131 info->notify_cookie = nc;
1134 info->notify.sigev_notify = SIGEV_THREAD;
1137 info->notify.sigev_signo = notification.sigev_signo;
1138 info->notify.sigev_value = notification.sigev_value;
1139 info->notify.sigev_notify = SIGEV_SIGNAL;
1143 info->notify_owner = get_pid(task_tgid(current));
1144 inode->i_atime = inode->i_ctime = CURRENT_TIME;
1146 spin_unlock(&info->lock);
1151 netlink_detachskb(sock, nc);
1158 SYSCALL_DEFINE3(mq_getsetattr, mqd_t, mqdes,
1159 const struct mq_attr __user *, u_mqstat,
1160 struct mq_attr __user *, u_omqstat)
1163 struct mq_attr mqstat, omqstat;
1165 struct inode *inode;
1166 struct mqueue_inode_info *info;
1168 if (u_mqstat != NULL) {
1169 if (copy_from_user(&mqstat, u_mqstat, sizeof(struct mq_attr)))
1171 if (mqstat.mq_flags & (~O_NONBLOCK))
1180 inode = filp->f_path.dentry->d_inode;
1181 if (unlikely(filp->f_op != &mqueue_file_operations))
1183 info = MQUEUE_I(inode);
1185 spin_lock(&info->lock);
1187 omqstat = info->attr;
1188 omqstat.mq_flags = filp->f_flags & O_NONBLOCK;
1190 audit_mq_getsetattr(mqdes, &mqstat);
1191 spin_lock(&filp->f_lock);
1192 if (mqstat.mq_flags & O_NONBLOCK)
1193 filp->f_flags |= O_NONBLOCK;
1195 filp->f_flags &= ~O_NONBLOCK;
1196 spin_unlock(&filp->f_lock);
1198 inode->i_atime = inode->i_ctime = CURRENT_TIME;
1201 spin_unlock(&info->lock);
1204 if (u_omqstat != NULL && copy_to_user(u_omqstat, &omqstat,
1205 sizeof(struct mq_attr)))
1214 static const struct inode_operations mqueue_dir_inode_operations = {
1215 .lookup = simple_lookup,
1216 .create = mqueue_create,
1217 .unlink = mqueue_unlink,
1220 static const struct file_operations mqueue_file_operations = {
1221 .flush = mqueue_flush_file,
1222 .poll = mqueue_poll_file,
1223 .read = mqueue_read_file,
1226 static const struct super_operations mqueue_super_ops = {
1227 .alloc_inode = mqueue_alloc_inode,
1228 .destroy_inode = mqueue_destroy_inode,
1229 .statfs = simple_statfs,
1230 .delete_inode = mqueue_delete_inode,
1231 .drop_inode = generic_delete_inode,
1234 static struct file_system_type mqueue_fs_type = {
1236 .get_sb = mqueue_get_sb,
1237 .kill_sb = kill_litter_super,
1240 int mq_init_ns(struct ipc_namespace *ns)
1242 ns->mq_queues_count = 0;
1243 ns->mq_queues_max = DFLT_QUEUESMAX;
1244 ns->mq_msg_max = DFLT_MSGMAX;
1245 ns->mq_msgsize_max = DFLT_MSGSIZEMAX;
1247 ns->mq_mnt = kern_mount_data(&mqueue_fs_type, ns);
1248 if (IS_ERR(ns->mq_mnt)) {
1249 int err = PTR_ERR(ns->mq_mnt);
1256 void mq_clear_sbinfo(struct ipc_namespace *ns)
1258 ns->mq_mnt->mnt_sb->s_fs_info = NULL;
1261 void mq_put_mnt(struct ipc_namespace *ns)
1266 static int __init init_mqueue_fs(void)
1270 mqueue_inode_cachep = kmem_cache_create("mqueue_inode_cache",
1271 sizeof(struct mqueue_inode_info), 0,
1272 SLAB_HWCACHE_ALIGN, init_once);
1273 if (mqueue_inode_cachep == NULL)
1276 /* ignore failues - they are not fatal */
1277 mq_sysctl_table = mq_register_sysctl_table();
1279 error = register_filesystem(&mqueue_fs_type);
1283 spin_lock_init(&mq_lock);
1285 init_ipc_ns.mq_mnt = kern_mount_data(&mqueue_fs_type, &init_ipc_ns);
1286 if (IS_ERR(init_ipc_ns.mq_mnt)) {
1287 error = PTR_ERR(init_ipc_ns.mq_mnt);
1288 goto out_filesystem;
1294 unregister_filesystem(&mqueue_fs_type);
1296 if (mq_sysctl_table)
1297 unregister_sysctl_table(mq_sysctl_table);
1298 kmem_cache_destroy(mqueue_inode_cachep);
1302 __initcall(init_mqueue_fs);