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
);
121 inode
->i_ino
= get_next_ino();
122 inode
->i_mode
= mode
;
123 inode
->i_uid
= current_fsuid();
124 inode
->i_gid
= current_fsgid();
125 inode
->i_mtime
= inode
->i_ctime
= inode
->i_atime
= CURRENT_TIME
;
128 struct mqueue_inode_info
*info
;
129 struct task_struct
*p
= current
;
130 unsigned long mq_bytes
, mq_msg_tblsz
;
132 inode
->i_fop
= &mqueue_file_operations
;
133 inode
->i_size
= FILENT_SIZE
;
134 /* mqueue specific info */
135 info
= MQUEUE_I(inode
);
136 spin_lock_init(&info
->lock
);
137 init_waitqueue_head(&info
->wait_q
);
138 INIT_LIST_HEAD(&info
->e_wait_q
[0].list
);
139 INIT_LIST_HEAD(&info
->e_wait_q
[1].list
);
140 info
->notify_owner
= NULL
;
142 info
->user
= NULL
; /* set when all is ok */
143 memset(&info
->attr
, 0, sizeof(info
->attr
));
144 info
->attr
.mq_maxmsg
= ipc_ns
->mq_msg_max
;
145 info
->attr
.mq_msgsize
= ipc_ns
->mq_msgsize_max
;
147 info
->attr
.mq_maxmsg
= attr
->mq_maxmsg
;
148 info
->attr
.mq_msgsize
= attr
->mq_msgsize
;
150 mq_msg_tblsz
= info
->attr
.mq_maxmsg
* sizeof(struct msg_msg
*);
151 info
->messages
= kmalloc(mq_msg_tblsz
, GFP_KERNEL
);
155 mq_bytes
= (mq_msg_tblsz
+
156 (info
->attr
.mq_maxmsg
* info
->attr
.mq_msgsize
));
159 if (u
->mq_bytes
+ mq_bytes
< u
->mq_bytes
||
160 u
->mq_bytes
+ mq_bytes
> task_rlimit(p
, RLIMIT_MSGQUEUE
)) {
161 spin_unlock(&mq_lock
);
162 /* mqueue_evict_inode() releases info->messages */
165 u
->mq_bytes
+= mq_bytes
;
166 spin_unlock(&mq_lock
);
169 info
->user
= get_uid(u
);
170 } else if (S_ISDIR(mode
)) {
172 /* Some things misbehave if size == 0 on a directory */
173 inode
->i_size
= 2 * DIRENT_SIZE
;
174 inode
->i_op
= &mqueue_dir_inode_operations
;
175 inode
->i_fop
= &simple_dir_operations
;
185 static int mqueue_fill_super(struct super_block
*sb
, void *data
, int silent
)
188 struct ipc_namespace
*ns
= data
;
191 sb
->s_blocksize
= PAGE_CACHE_SIZE
;
192 sb
->s_blocksize_bits
= PAGE_CACHE_SHIFT
;
193 sb
->s_magic
= MQUEUE_MAGIC
;
194 sb
->s_op
= &mqueue_super_ops
;
196 inode
= mqueue_get_inode(sb
, ns
, S_IFDIR
| S_ISVTX
| S_IRWXUGO
,
203 sb
->s_root
= d_alloc_root(inode
);
215 static struct dentry
*mqueue_mount(struct file_system_type
*fs_type
,
216 int flags
, const char *dev_name
,
219 if (!(flags
& MS_KERNMOUNT
))
220 data
= current
->nsproxy
->ipc_ns
;
221 return mount_ns(fs_type
, flags
, data
, mqueue_fill_super
);
224 static void init_once(void *foo
)
226 struct mqueue_inode_info
*p
= (struct mqueue_inode_info
*) foo
;
228 inode_init_once(&p
->vfs_inode
);
231 static struct inode
*mqueue_alloc_inode(struct super_block
*sb
)
233 struct mqueue_inode_info
*ei
;
235 ei
= kmem_cache_alloc(mqueue_inode_cachep
, GFP_KERNEL
);
238 return &ei
->vfs_inode
;
241 static void mqueue_i_callback(struct rcu_head
*head
)
243 struct inode
*inode
= container_of(head
, struct inode
, i_rcu
);
244 INIT_LIST_HEAD(&inode
->i_dentry
);
245 kmem_cache_free(mqueue_inode_cachep
, MQUEUE_I(inode
));
248 static void mqueue_destroy_inode(struct inode
*inode
)
250 call_rcu(&inode
->i_rcu
, mqueue_i_callback
);
253 static void mqueue_evict_inode(struct inode
*inode
)
255 struct mqueue_inode_info
*info
;
256 struct user_struct
*user
;
257 unsigned long mq_bytes
;
259 struct ipc_namespace
*ipc_ns
;
261 end_writeback(inode
);
263 if (S_ISDIR(inode
->i_mode
))
266 ipc_ns
= get_ns_from_inode(inode
);
267 info
= MQUEUE_I(inode
);
268 spin_lock(&info
->lock
);
269 for (i
= 0; i
< info
->attr
.mq_curmsgs
; i
++)
270 free_msg(info
->messages
[i
]);
271 kfree(info
->messages
);
272 spin_unlock(&info
->lock
);
274 /* Total amount of bytes accounted for the mqueue */
275 mq_bytes
= info
->attr
.mq_maxmsg
* (sizeof(struct msg_msg
*)
276 + info
->attr
.mq_msgsize
);
280 user
->mq_bytes
-= mq_bytes
;
282 * get_ns_from_inode() ensures that the
283 * (ipc_ns = sb->s_fs_info) is either a valid ipc_ns
284 * to which we now hold a reference, or it is NULL.
285 * We can't put it here under mq_lock, though.
288 ipc_ns
->mq_queues_count
--;
289 spin_unlock(&mq_lock
);
296 static int mqueue_create(struct inode
*dir
, struct dentry
*dentry
,
297 int mode
, struct nameidata
*nd
)
300 struct mq_attr
*attr
= dentry
->d_fsdata
;
302 struct ipc_namespace
*ipc_ns
;
305 ipc_ns
= __get_ns_from_inode(dir
);
310 if (ipc_ns
->mq_queues_count
>= ipc_ns
->mq_queues_max
&&
311 !capable(CAP_SYS_RESOURCE
)) {
315 ipc_ns
->mq_queues_count
++;
316 spin_unlock(&mq_lock
);
318 inode
= mqueue_get_inode(dir
->i_sb
, ipc_ns
, mode
, attr
);
322 ipc_ns
->mq_queues_count
--;
327 dir
->i_size
+= DIRENT_SIZE
;
328 dir
->i_ctime
= dir
->i_mtime
= dir
->i_atime
= CURRENT_TIME
;
330 d_instantiate(dentry
, inode
);
334 spin_unlock(&mq_lock
);
340 static int mqueue_unlink(struct inode
*dir
, struct dentry
*dentry
)
342 struct inode
*inode
= dentry
->d_inode
;
344 dir
->i_ctime
= dir
->i_mtime
= dir
->i_atime
= CURRENT_TIME
;
345 dir
->i_size
-= DIRENT_SIZE
;
352 * This is routine for system read from queue file.
353 * To avoid mess with doing here some sort of mq_receive we allow
354 * to read only queue size & notification info (the only values
355 * that are interesting from user point of view and aren't accessible
356 * through std routines)
358 static ssize_t
mqueue_read_file(struct file
*filp
, char __user
*u_data
,
359 size_t count
, loff_t
*off
)
361 struct mqueue_inode_info
*info
= MQUEUE_I(filp
->f_path
.dentry
->d_inode
);
362 char buffer
[FILENT_SIZE
];
365 spin_lock(&info
->lock
);
366 snprintf(buffer
, sizeof(buffer
),
367 "QSIZE:%-10lu NOTIFY:%-5d SIGNO:%-5d NOTIFY_PID:%-6d\n",
369 info
->notify_owner
? info
->notify
.sigev_notify
: 0,
370 (info
->notify_owner
&&
371 info
->notify
.sigev_notify
== SIGEV_SIGNAL
) ?
372 info
->notify
.sigev_signo
: 0,
373 pid_vnr(info
->notify_owner
));
374 spin_unlock(&info
->lock
);
375 buffer
[sizeof(buffer
)-1] = '\0';
377 ret
= simple_read_from_buffer(u_data
, count
, off
, buffer
,
382 filp
->f_path
.dentry
->d_inode
->i_atime
= filp
->f_path
.dentry
->d_inode
->i_ctime
= CURRENT_TIME
;
386 static int mqueue_flush_file(struct file
*filp
, fl_owner_t id
)
388 struct mqueue_inode_info
*info
= MQUEUE_I(filp
->f_path
.dentry
->d_inode
);
390 spin_lock(&info
->lock
);
391 if (task_tgid(current
) == info
->notify_owner
)
392 remove_notification(info
);
394 spin_unlock(&info
->lock
);
398 static unsigned int mqueue_poll_file(struct file
*filp
, struct poll_table_struct
*poll_tab
)
400 struct mqueue_inode_info
*info
= MQUEUE_I(filp
->f_path
.dentry
->d_inode
);
403 poll_wait(filp
, &info
->wait_q
, poll_tab
);
405 spin_lock(&info
->lock
);
406 if (info
->attr
.mq_curmsgs
)
407 retval
= POLLIN
| POLLRDNORM
;
409 if (info
->attr
.mq_curmsgs
< info
->attr
.mq_maxmsg
)
410 retval
|= POLLOUT
| POLLWRNORM
;
411 spin_unlock(&info
->lock
);
416 /* Adds current to info->e_wait_q[sr] before element with smaller prio */
417 static void wq_add(struct mqueue_inode_info
*info
, int sr
,
418 struct ext_wait_queue
*ewp
)
420 struct ext_wait_queue
*walk
;
424 list_for_each_entry(walk
, &info
->e_wait_q
[sr
].list
, list
) {
425 if (walk
->task
->static_prio
<= current
->static_prio
) {
426 list_add_tail(&ewp
->list
, &walk
->list
);
430 list_add_tail(&ewp
->list
, &info
->e_wait_q
[sr
].list
);
434 * Puts current task to sleep. Caller must hold queue lock. After return
438 static int wq_sleep(struct mqueue_inode_info
*info
, int sr
,
439 ktime_t
*timeout
, struct ext_wait_queue
*ewp
)
444 wq_add(info
, sr
, ewp
);
447 set_current_state(TASK_INTERRUPTIBLE
);
449 spin_unlock(&info
->lock
);
450 time
= schedule_hrtimeout_range_clock(timeout
,
451 HRTIMER_MODE_ABS
, 0, CLOCK_REALTIME
);
453 while (ewp
->state
== STATE_PENDING
)
456 if (ewp
->state
== STATE_READY
) {
460 spin_lock(&info
->lock
);
461 if (ewp
->state
== STATE_READY
) {
465 if (signal_pending(current
)) {
466 retval
= -ERESTARTSYS
;
474 list_del(&ewp
->list
);
476 spin_unlock(&info
->lock
);
482 * Returns waiting task that should be serviced first or NULL if none exists
484 static struct ext_wait_queue
*wq_get_first_waiter(
485 struct mqueue_inode_info
*info
, int sr
)
487 struct list_head
*ptr
;
489 ptr
= info
->e_wait_q
[sr
].list
.prev
;
490 if (ptr
== &info
->e_wait_q
[sr
].list
)
492 return list_entry(ptr
, struct ext_wait_queue
, list
);
495 /* Auxiliary functions to manipulate messages' list */
496 static void msg_insert(struct msg_msg
*ptr
, struct mqueue_inode_info
*info
)
500 k
= info
->attr
.mq_curmsgs
- 1;
501 while (k
>= 0 && info
->messages
[k
]->m_type
>= ptr
->m_type
) {
502 info
->messages
[k
+ 1] = info
->messages
[k
];
505 info
->attr
.mq_curmsgs
++;
506 info
->qsize
+= ptr
->m_ts
;
507 info
->messages
[k
+ 1] = ptr
;
510 static inline struct msg_msg
*msg_get(struct mqueue_inode_info
*info
)
512 info
->qsize
-= info
->messages
[--info
->attr
.mq_curmsgs
]->m_ts
;
513 return info
->messages
[info
->attr
.mq_curmsgs
];
516 static inline void set_cookie(struct sk_buff
*skb
, char code
)
518 ((char*)skb
->data
)[NOTIFY_COOKIE_LEN
-1] = code
;
522 * The next function is only to split too long sys_mq_timedsend
524 static void __do_notify(struct mqueue_inode_info
*info
)
527 * invoked when there is registered process and there isn't process
528 * waiting synchronously for message AND state of queue changed from
529 * empty to not empty. Here we are sure that no one is waiting
531 if (info
->notify_owner
&&
532 info
->attr
.mq_curmsgs
== 1) {
533 struct siginfo sig_i
;
534 switch (info
->notify
.sigev_notify
) {
540 sig_i
.si_signo
= info
->notify
.sigev_signo
;
542 sig_i
.si_code
= SI_MESGQ
;
543 sig_i
.si_value
= info
->notify
.sigev_value
;
544 sig_i
.si_pid
= task_tgid_nr_ns(current
,
545 ns_of_pid(info
->notify_owner
));
546 sig_i
.si_uid
= current_uid();
548 kill_pid_info(info
->notify
.sigev_signo
,
549 &sig_i
, info
->notify_owner
);
552 set_cookie(info
->notify_cookie
, NOTIFY_WOKENUP
);
553 netlink_sendskb(info
->notify_sock
, info
->notify_cookie
);
556 /* after notification unregisters process */
557 put_pid(info
->notify_owner
);
558 info
->notify_owner
= NULL
;
560 wake_up(&info
->wait_q
);
563 static int prepare_timeout(const struct timespec __user
*u_abs_timeout
,
564 ktime_t
*expires
, struct timespec
*ts
)
566 if (copy_from_user(ts
, u_abs_timeout
, sizeof(struct timespec
)))
568 if (!timespec_valid(ts
))
571 *expires
= timespec_to_ktime(*ts
);
575 static void remove_notification(struct mqueue_inode_info
*info
)
577 if (info
->notify_owner
!= NULL
&&
578 info
->notify
.sigev_notify
== SIGEV_THREAD
) {
579 set_cookie(info
->notify_cookie
, NOTIFY_REMOVED
);
580 netlink_sendskb(info
->notify_sock
, info
->notify_cookie
);
582 put_pid(info
->notify_owner
);
583 info
->notify_owner
= NULL
;
586 static int mq_attr_ok(struct ipc_namespace
*ipc_ns
, struct mq_attr
*attr
)
588 if (attr
->mq_maxmsg
<= 0 || attr
->mq_msgsize
<= 0)
590 if (capable(CAP_SYS_RESOURCE
)) {
591 if (attr
->mq_maxmsg
> HARD_MSGMAX
)
594 if (attr
->mq_maxmsg
> ipc_ns
->mq_msg_max
||
595 attr
->mq_msgsize
> ipc_ns
->mq_msgsize_max
)
598 /* check for overflow */
599 if (attr
->mq_msgsize
> ULONG_MAX
/attr
->mq_maxmsg
)
601 if ((unsigned long)(attr
->mq_maxmsg
* (attr
->mq_msgsize
602 + sizeof (struct msg_msg
*))) <
603 (unsigned long)(attr
->mq_maxmsg
* attr
->mq_msgsize
))
609 * Invoked when creating a new queue via sys_mq_open
611 static struct file
*do_create(struct ipc_namespace
*ipc_ns
, struct dentry
*dir
,
612 struct dentry
*dentry
, int oflag
, mode_t mode
,
613 struct mq_attr
*attr
)
615 const struct cred
*cred
= current_cred();
620 if (!mq_attr_ok(ipc_ns
, attr
)) {
624 /* store for use during create */
625 dentry
->d_fsdata
= attr
;
628 mode
&= ~current_umask();
629 ret
= mnt_want_write(ipc_ns
->mq_mnt
);
632 ret
= vfs_create(dir
->d_inode
, dentry
, mode
, NULL
);
633 dentry
->d_fsdata
= NULL
;
637 result
= dentry_open(dentry
, ipc_ns
->mq_mnt
, oflag
, cred
);
639 * dentry_open() took a persistent mnt_want_write(),
640 * so we can now drop this one.
642 mnt_drop_write(ipc_ns
->mq_mnt
);
646 mnt_drop_write(ipc_ns
->mq_mnt
);
649 mntput(ipc_ns
->mq_mnt
);
653 /* Opens existing queue */
654 static struct file
*do_open(struct ipc_namespace
*ipc_ns
,
655 struct dentry
*dentry
, int oflag
)
658 const struct cred
*cred
= current_cred();
660 static const int oflag2acc
[O_ACCMODE
] = { MAY_READ
, MAY_WRITE
,
661 MAY_READ
| MAY_WRITE
};
663 if ((oflag
& O_ACCMODE
) == (O_RDWR
| O_WRONLY
)) {
668 if (inode_permission(dentry
->d_inode
, oflag2acc
[oflag
& O_ACCMODE
])) {
673 return dentry_open(dentry
, ipc_ns
->mq_mnt
, oflag
, cred
);
677 mntput(ipc_ns
->mq_mnt
);
681 SYSCALL_DEFINE4(mq_open
, const char __user
*, u_name
, int, oflag
, mode_t
, mode
,
682 struct mq_attr __user
*, u_attr
)
684 struct dentry
*dentry
;
689 struct ipc_namespace
*ipc_ns
= current
->nsproxy
->ipc_ns
;
691 if (u_attr
&& copy_from_user(&attr
, u_attr
, sizeof(struct mq_attr
)))
694 audit_mq_open(oflag
, mode
, u_attr
? &attr
: NULL
);
696 if (IS_ERR(name
= getname(u_name
)))
697 return PTR_ERR(name
);
699 fd
= get_unused_fd_flags(O_CLOEXEC
);
703 mutex_lock(&ipc_ns
->mq_mnt
->mnt_root
->d_inode
->i_mutex
);
704 dentry
= lookup_one_len(name
, ipc_ns
->mq_mnt
->mnt_root
, strlen(name
));
705 if (IS_ERR(dentry
)) {
706 error
= PTR_ERR(dentry
);
709 mntget(ipc_ns
->mq_mnt
);
711 if (oflag
& O_CREAT
) {
712 if (dentry
->d_inode
) { /* entry already exists */
713 audit_inode(name
, dentry
);
714 if (oflag
& O_EXCL
) {
718 filp
= do_open(ipc_ns
, dentry
, oflag
);
720 filp
= do_create(ipc_ns
, ipc_ns
->mq_mnt
->mnt_root
,
722 u_attr
? &attr
: NULL
);
725 if (!dentry
->d_inode
) {
729 audit_inode(name
, dentry
);
730 filp
= do_open(ipc_ns
, dentry
, oflag
);
734 error
= PTR_ERR(filp
);
738 fd_install(fd
, filp
);
743 mntput(ipc_ns
->mq_mnt
);
748 mutex_unlock(&ipc_ns
->mq_mnt
->mnt_root
->d_inode
->i_mutex
);
754 SYSCALL_DEFINE1(mq_unlink
, const char __user
*, u_name
)
758 struct dentry
*dentry
;
759 struct inode
*inode
= NULL
;
760 struct ipc_namespace
*ipc_ns
= current
->nsproxy
->ipc_ns
;
762 name
= getname(u_name
);
764 return PTR_ERR(name
);
766 mutex_lock_nested(&ipc_ns
->mq_mnt
->mnt_root
->d_inode
->i_mutex
,
768 dentry
= lookup_one_len(name
, ipc_ns
->mq_mnt
->mnt_root
, strlen(name
));
769 if (IS_ERR(dentry
)) {
770 err
= PTR_ERR(dentry
);
774 if (!dentry
->d_inode
) {
779 inode
= dentry
->d_inode
;
782 err
= mnt_want_write(ipc_ns
->mq_mnt
);
785 err
= vfs_unlink(dentry
->d_parent
->d_inode
, dentry
);
786 mnt_drop_write(ipc_ns
->mq_mnt
);
791 mutex_unlock(&ipc_ns
->mq_mnt
->mnt_root
->d_inode
->i_mutex
);
799 /* Pipelined send and receive functions.
801 * If a receiver finds no waiting message, then it registers itself in the
802 * list of waiting receivers. A sender checks that list before adding the new
803 * message into the message array. If there is a waiting receiver, then it
804 * bypasses the message array and directly hands the message over to the
806 * The receiver accepts the message and returns without grabbing the queue
807 * spinlock. Therefore an intermediate STATE_PENDING state and memory barriers
808 * are necessary. The same algorithm is used for sysv semaphores, see
809 * ipc/sem.c for more details.
811 * The same algorithm is used for senders.
814 /* pipelined_send() - send a message directly to the task waiting in
815 * sys_mq_timedreceive() (without inserting message into a queue).
817 static inline void pipelined_send(struct mqueue_inode_info
*info
,
818 struct msg_msg
*message
,
819 struct ext_wait_queue
*receiver
)
821 receiver
->msg
= message
;
822 list_del(&receiver
->list
);
823 receiver
->state
= STATE_PENDING
;
824 wake_up_process(receiver
->task
);
826 receiver
->state
= STATE_READY
;
829 /* pipelined_receive() - if there is task waiting in sys_mq_timedsend()
830 * gets its message and put to the queue (we have one free place for sure). */
831 static inline void pipelined_receive(struct mqueue_inode_info
*info
)
833 struct ext_wait_queue
*sender
= wq_get_first_waiter(info
, SEND
);
837 wake_up_interruptible(&info
->wait_q
);
840 msg_insert(sender
->msg
, info
);
841 list_del(&sender
->list
);
842 sender
->state
= STATE_PENDING
;
843 wake_up_process(sender
->task
);
845 sender
->state
= STATE_READY
;
848 SYSCALL_DEFINE5(mq_timedsend
, mqd_t
, mqdes
, const char __user
*, u_msg_ptr
,
849 size_t, msg_len
, unsigned int, msg_prio
,
850 const struct timespec __user
*, u_abs_timeout
)
854 struct ext_wait_queue wait
;
855 struct ext_wait_queue
*receiver
;
856 struct msg_msg
*msg_ptr
;
857 struct mqueue_inode_info
*info
;
858 ktime_t expires
, *timeout
= NULL
;
863 int res
= prepare_timeout(u_abs_timeout
, &expires
, &ts
);
869 if (unlikely(msg_prio
>= (unsigned long) MQ_PRIO_MAX
))
872 audit_mq_sendrecv(mqdes
, msg_len
, msg_prio
, timeout
? &ts
: NULL
);
875 if (unlikely(!filp
)) {
880 inode
= filp
->f_path
.dentry
->d_inode
;
881 if (unlikely(filp
->f_op
!= &mqueue_file_operations
)) {
885 info
= MQUEUE_I(inode
);
886 audit_inode(NULL
, filp
->f_path
.dentry
);
888 if (unlikely(!(filp
->f_mode
& FMODE_WRITE
))) {
893 if (unlikely(msg_len
> info
->attr
.mq_msgsize
)) {
898 /* First try to allocate memory, before doing anything with
899 * existing queues. */
900 msg_ptr
= load_msg(u_msg_ptr
, msg_len
);
901 if (IS_ERR(msg_ptr
)) {
902 ret
= PTR_ERR(msg_ptr
);
905 msg_ptr
->m_ts
= msg_len
;
906 msg_ptr
->m_type
= msg_prio
;
908 spin_lock(&info
->lock
);
910 if (info
->attr
.mq_curmsgs
== info
->attr
.mq_maxmsg
) {
911 if (filp
->f_flags
& O_NONBLOCK
) {
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
)
947 struct msg_msg
*msg_ptr
;
950 struct mqueue_inode_info
*info
;
951 struct ext_wait_queue wait
;
952 ktime_t expires
, *timeout
= NULL
;
956 int res
= prepare_timeout(u_abs_timeout
, &expires
, &ts
);
962 audit_mq_sendrecv(mqdes
, msg_len
, 0, timeout
? &ts
: NULL
);
965 if (unlikely(!filp
)) {
970 inode
= filp
->f_path
.dentry
->d_inode
;
971 if (unlikely(filp
->f_op
!= &mqueue_file_operations
)) {
975 info
= MQUEUE_I(inode
);
976 audit_inode(NULL
, filp
->f_path
.dentry
);
978 if (unlikely(!(filp
->f_mode
& FMODE_READ
))) {
983 /* checks if buffer is big enough */
984 if (unlikely(msg_len
< info
->attr
.mq_msgsize
)) {
989 spin_lock(&info
->lock
);
990 if (info
->attr
.mq_curmsgs
== 0) {
991 if (filp
->f_flags
& O_NONBLOCK
) {
992 spin_unlock(&info
->lock
);
996 wait
.state
= STATE_NONE
;
997 ret
= wq_sleep(info
, RECV
, timeout
, &wait
);
1001 msg_ptr
= msg_get(info
);
1003 inode
->i_atime
= inode
->i_mtime
= inode
->i_ctime
=
1006 /* There is now free space in queue. */
1007 pipelined_receive(info
);
1008 spin_unlock(&info
->lock
);
1012 ret
= msg_ptr
->m_ts
;
1014 if ((u_msg_prio
&& put_user(msg_ptr
->m_type
, u_msg_prio
)) ||
1015 store_msg(u_msg_ptr
, msg_ptr
, msg_ptr
->m_ts
)) {
1027 * Notes: the case when user wants us to deregister (with NULL as pointer)
1028 * and he isn't currently owner of notification, will be silently discarded.
1029 * It isn't explicitly defined in the POSIX.
1031 SYSCALL_DEFINE2(mq_notify
, mqd_t
, mqdes
,
1032 const struct sigevent __user
*, u_notification
)
1037 struct inode
*inode
;
1038 struct sigevent notification
;
1039 struct mqueue_inode_info
*info
;
1042 if (u_notification
) {
1043 if (copy_from_user(¬ification
, u_notification
,
1044 sizeof(struct sigevent
)))
1048 audit_mq_notify(mqdes
, u_notification
? ¬ification
: NULL
);
1052 if (u_notification
!= NULL
) {
1053 if (unlikely(notification
.sigev_notify
!= SIGEV_NONE
&&
1054 notification
.sigev_notify
!= SIGEV_SIGNAL
&&
1055 notification
.sigev_notify
!= SIGEV_THREAD
))
1057 if (notification
.sigev_notify
== SIGEV_SIGNAL
&&
1058 !valid_signal(notification
.sigev_signo
)) {
1061 if (notification
.sigev_notify
== SIGEV_THREAD
) {
1064 /* create the notify skb */
1065 nc
= alloc_skb(NOTIFY_COOKIE_LEN
, GFP_KERNEL
);
1070 if (copy_from_user(nc
->data
,
1071 notification
.sigev_value
.sival_ptr
,
1072 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
);
1086 sock
= netlink_getsockbyfilp(filp
);
1089 ret
= PTR_ERR(sock
);
1094 timeo
= MAX_SCHEDULE_TIMEOUT
;
1095 ret
= netlink_attachskb(sock
, nc
, &timeo
, NULL
);
1112 inode
= filp
->f_path
.dentry
->d_inode
;
1113 if (unlikely(filp
->f_op
!= &mqueue_file_operations
)) {
1117 info
= MQUEUE_I(inode
);
1120 spin_lock(&info
->lock
);
1121 if (u_notification
== NULL
) {
1122 if (info
->notify_owner
== task_tgid(current
)) {
1123 remove_notification(info
);
1124 inode
->i_atime
= inode
->i_ctime
= CURRENT_TIME
;
1126 } else if (info
->notify_owner
!= NULL
) {
1129 switch (notification
.sigev_notify
) {
1131 info
->notify
.sigev_notify
= SIGEV_NONE
;
1134 info
->notify_sock
= sock
;
1135 info
->notify_cookie
= nc
;
1138 info
->notify
.sigev_notify
= SIGEV_THREAD
;
1141 info
->notify
.sigev_signo
= notification
.sigev_signo
;
1142 info
->notify
.sigev_value
= notification
.sigev_value
;
1143 info
->notify
.sigev_notify
= SIGEV_SIGNAL
;
1147 info
->notify_owner
= get_pid(task_tgid(current
));
1148 inode
->i_atime
= inode
->i_ctime
= CURRENT_TIME
;
1150 spin_unlock(&info
->lock
);
1155 netlink_detachskb(sock
, nc
);
1162 SYSCALL_DEFINE3(mq_getsetattr
, mqd_t
, mqdes
,
1163 const struct mq_attr __user
*, u_mqstat
,
1164 struct mq_attr __user
*, u_omqstat
)
1167 struct mq_attr mqstat
, omqstat
;
1169 struct inode
*inode
;
1170 struct mqueue_inode_info
*info
;
1172 if (u_mqstat
!= NULL
) {
1173 if (copy_from_user(&mqstat
, u_mqstat
, sizeof(struct mq_attr
)))
1175 if (mqstat
.mq_flags
& (~O_NONBLOCK
))
1185 inode
= filp
->f_path
.dentry
->d_inode
;
1186 if (unlikely(filp
->f_op
!= &mqueue_file_operations
)) {
1190 info
= MQUEUE_I(inode
);
1192 spin_lock(&info
->lock
);
1194 omqstat
= info
->attr
;
1195 omqstat
.mq_flags
= filp
->f_flags
& O_NONBLOCK
;
1197 audit_mq_getsetattr(mqdes
, &mqstat
);
1198 spin_lock(&filp
->f_lock
);
1199 if (mqstat
.mq_flags
& O_NONBLOCK
)
1200 filp
->f_flags
|= O_NONBLOCK
;
1202 filp
->f_flags
&= ~O_NONBLOCK
;
1203 spin_unlock(&filp
->f_lock
);
1205 inode
->i_atime
= inode
->i_ctime
= CURRENT_TIME
;
1208 spin_unlock(&info
->lock
);
1211 if (u_omqstat
!= NULL
&& copy_to_user(u_omqstat
, &omqstat
,
1212 sizeof(struct mq_attr
)))
1221 static const struct inode_operations mqueue_dir_inode_operations
= {
1222 .lookup
= simple_lookup
,
1223 .create
= mqueue_create
,
1224 .unlink
= mqueue_unlink
,
1227 static const struct file_operations mqueue_file_operations
= {
1228 .flush
= mqueue_flush_file
,
1229 .poll
= mqueue_poll_file
,
1230 .read
= mqueue_read_file
,
1231 .llseek
= default_llseek
,
1234 static const struct super_operations mqueue_super_ops
= {
1235 .alloc_inode
= mqueue_alloc_inode
,
1236 .destroy_inode
= mqueue_destroy_inode
,
1237 .evict_inode
= mqueue_evict_inode
,
1238 .statfs
= simple_statfs
,
1241 static struct file_system_type mqueue_fs_type
= {
1243 .mount
= mqueue_mount
,
1244 .kill_sb
= kill_litter_super
,
1247 int mq_init_ns(struct ipc_namespace
*ns
)
1249 ns
->mq_queues_count
= 0;
1250 ns
->mq_queues_max
= DFLT_QUEUESMAX
;
1251 ns
->mq_msg_max
= DFLT_MSGMAX
;
1252 ns
->mq_msgsize_max
= DFLT_MSGSIZEMAX
;
1254 ns
->mq_mnt
= kern_mount_data(&mqueue_fs_type
, ns
);
1255 if (IS_ERR(ns
->mq_mnt
)) {
1256 int err
= PTR_ERR(ns
->mq_mnt
);
1263 void mq_clear_sbinfo(struct ipc_namespace
*ns
)
1265 ns
->mq_mnt
->mnt_sb
->s_fs_info
= NULL
;
1268 void mq_put_mnt(struct ipc_namespace
*ns
)
1273 static int __init
init_mqueue_fs(void)
1277 mqueue_inode_cachep
= kmem_cache_create("mqueue_inode_cache",
1278 sizeof(struct mqueue_inode_info
), 0,
1279 SLAB_HWCACHE_ALIGN
, init_once
);
1280 if (mqueue_inode_cachep
== NULL
)
1283 /* ignore failures - they are not fatal */
1284 mq_sysctl_table
= mq_register_sysctl_table();
1286 error
= register_filesystem(&mqueue_fs_type
);
1290 spin_lock_init(&mq_lock
);
1292 init_ipc_ns
.mq_mnt
= kern_mount_data(&mqueue_fs_type
, &init_ipc_ns
);
1293 if (IS_ERR(init_ipc_ns
.mq_mnt
)) {
1294 error
= PTR_ERR(init_ipc_ns
.mq_mnt
);
1295 goto out_filesystem
;
1301 unregister_filesystem(&mqueue_fs_type
);
1303 if (mq_sysctl_table
)
1304 unregister_sysctl_table(mq_sysctl_table
);
1305 kmem_cache_destroy(mqueue_inode_cachep
);
1309 __initcall(init_mqueue_fs
);