xref: /freebsd/sys/kern/uipc_mqueue.c (revision 050570efa79efcc9cf5adeb545f1a679c8dc377b)
1 /*-
2  * Copyright (c) 2005 David Xu <davidxu@freebsd.org>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  *
26  */
27 
28 /*
29  * POSIX message queue implementation.
30  *
31  * 1) A mqueue filesystem can be mounted, each message queue appears
32  *    in mounted directory, user can change queue's permission and
33  *    ownership, or remove a queue. Manually creating a file in the
34  *    directory causes a message queue to be created in the kernel with
35  *    default message queue attributes applied and same name used, this
36  *    method is not advocated since mq_open syscall allows user to specify
37  *    different attributes. Also the file system can be mounted multiple
38  *    times at different mount points but shows same contents.
39  *
40  * 2) Standard POSIX message queue API. The syscalls do not use vfs layer,
41  *    but directly operate on internal data structure, this allows user to
42  *    use the IPC facility without having to mount mqueue file system.
43  */
44 
45 #include <sys/cdefs.h>
46 __FBSDID("$FreeBSD$");
47 
48 #include "opt_compat.h"
49 
50 #include <sys/param.h>
51 #include <sys/kernel.h>
52 #include <sys/systm.h>
53 #include <sys/limits.h>
54 #include <sys/buf.h>
55 #include <sys/dirent.h>
56 #include <sys/event.h>
57 #include <sys/eventhandler.h>
58 #include <sys/fcntl.h>
59 #include <sys/file.h>
60 #include <sys/filedesc.h>
61 #include <sys/lock.h>
62 #include <sys/malloc.h>
63 #include <sys/module.h>
64 #include <sys/mount.h>
65 #include <sys/mqueue.h>
66 #include <sys/mutex.h>
67 #include <sys/namei.h>
68 #include <sys/posix4.h>
69 #include <sys/poll.h>
70 #include <sys/priv.h>
71 #include <sys/proc.h>
72 #include <sys/queue.h>
73 #include <sys/sysproto.h>
74 #include <sys/stat.h>
75 #include <sys/syscall.h>
76 #include <sys/syscallsubr.h>
77 #include <sys/sysent.h>
78 #include <sys/sx.h>
79 #include <sys/sysctl.h>
80 #include <sys/taskqueue.h>
81 #include <sys/unistd.h>
82 #include <sys/vnode.h>
83 #include <machine/atomic.h>
84 
85 /*
86  * Limits and constants
87  */
88 #define	MQFS_NAMELEN		NAME_MAX
89 #define MQFS_DELEN		(8 + MQFS_NAMELEN)
90 
91 /* node types */
92 typedef enum {
93 	mqfstype_none = 0,
94 	mqfstype_root,
95 	mqfstype_dir,
96 	mqfstype_this,
97 	mqfstype_parent,
98 	mqfstype_file,
99 	mqfstype_symlink,
100 } mqfs_type_t;
101 
102 struct mqfs_node;
103 
104 /*
105  * mqfs_info: describes a mqfs instance
106  */
107 struct mqfs_info {
108 	struct sx		mi_lock;
109 	struct mqfs_node	*mi_root;
110 	struct unrhdr		*mi_unrhdr;
111 };
112 
113 struct mqfs_vdata {
114 	LIST_ENTRY(mqfs_vdata)	mv_link;
115 	struct mqfs_node	*mv_node;
116 	struct vnode		*mv_vnode;
117 	struct task		mv_task;
118 };
119 
120 /*
121  * mqfs_node: describes a node (file or directory) within a mqfs
122  */
123 struct mqfs_node {
124 	char			mn_name[MQFS_NAMELEN+1];
125 	struct mqfs_info	*mn_info;
126 	struct mqfs_node	*mn_parent;
127 	LIST_HEAD(,mqfs_node)	mn_children;
128 	LIST_ENTRY(mqfs_node)	mn_sibling;
129 	LIST_HEAD(,mqfs_vdata)	mn_vnodes;
130 	int			mn_refcount;
131 	mqfs_type_t		mn_type;
132 	int			mn_deleted;
133 	uint32_t		mn_fileno;
134 	void			*mn_data;
135 	struct timespec		mn_birth;
136 	struct timespec		mn_ctime;
137 	struct timespec		mn_atime;
138 	struct timespec		mn_mtime;
139 	uid_t			mn_uid;
140 	gid_t			mn_gid;
141 	int			mn_mode;
142 };
143 
144 #define	VTON(vp)	(((struct mqfs_vdata *)((vp)->v_data))->mv_node)
145 #define VTOMQ(vp) 	((struct mqueue *)(VTON(vp)->mn_data))
146 #define	VFSTOMQFS(m)	((struct mqfs_info *)((m)->mnt_data))
147 #define	FPTOMQ(fp)	((struct mqueue *)(((struct mqfs_node *) \
148 				(fp)->f_data)->mn_data))
149 
150 TAILQ_HEAD(msgq, mqueue_msg);
151 
152 struct mqueue;
153 
154 struct mqueue_notifier {
155 	LIST_ENTRY(mqueue_notifier)	nt_link;
156 	struct sigevent			nt_sigev;
157 	ksiginfo_t			nt_ksi;
158 	struct proc			*nt_proc;
159 };
160 
161 struct mqueue {
162 	struct mtx	mq_mutex;
163 	int		mq_flags;
164 	long		mq_maxmsg;
165 	long		mq_msgsize;
166 	long		mq_curmsgs;
167 	long		mq_totalbytes;
168 	struct msgq	mq_msgq;
169 	int		mq_receivers;
170 	int		mq_senders;
171 	struct selinfo	mq_rsel;
172 	struct selinfo	mq_wsel;
173 	struct mqueue_notifier	*mq_notifier;
174 };
175 
176 #define	MQ_RSEL		0x01
177 #define	MQ_WSEL		0x02
178 
179 struct mqueue_msg {
180 	TAILQ_ENTRY(mqueue_msg)	msg_link;
181 	unsigned int	msg_prio;
182 	unsigned int	msg_size;
183 	/* following real data... */
184 };
185 
186 SYSCTL_NODE(_kern, OID_AUTO, mqueue, CTLFLAG_RW, 0,
187 	"POSIX real time message queue");
188 
189 static int	default_maxmsg  = 10;
190 static int	default_msgsize = 1024;
191 
192 static int	maxmsg = 100;
193 SYSCTL_INT(_kern_mqueue, OID_AUTO, maxmsg, CTLFLAG_RW,
194     &maxmsg, 0, "Default maximum messages in queue");
195 static int	maxmsgsize = 16384;
196 SYSCTL_INT(_kern_mqueue, OID_AUTO, maxmsgsize, CTLFLAG_RW,
197     &maxmsgsize, 0, "Default maximum message size");
198 static int	maxmq = 100;
199 SYSCTL_INT(_kern_mqueue, OID_AUTO, maxmq, CTLFLAG_RW,
200     &maxmq, 0, "maximum message queues");
201 static int	curmq = 0;
202 SYSCTL_INT(_kern_mqueue, OID_AUTO, curmq, CTLFLAG_RW,
203     &curmq, 0, "current message queue number");
204 static int	unloadable = 0;
205 static MALLOC_DEFINE(M_MQUEUEDATA, "mqdata", "mqueue data");
206 
207 static eventhandler_tag exit_tag;
208 
209 /* Only one instance per-system */
210 static struct mqfs_info		mqfs_data;
211 static uma_zone_t		mqnode_zone;
212 static uma_zone_t		mqueue_zone;
213 static uma_zone_t		mvdata_zone;
214 static uma_zone_t		mqnoti_zone;
215 static struct vop_vector	mqfs_vnodeops;
216 static struct fileops		mqueueops;
217 
218 /*
219  * Directory structure construction and manipulation
220  */
221 #ifdef notyet
222 static struct mqfs_node	*mqfs_create_dir(struct mqfs_node *parent,
223 	const char *name, int namelen, struct ucred *cred, int mode);
224 static struct mqfs_node	*mqfs_create_link(struct mqfs_node *parent,
225 	const char *name, int namelen, struct ucred *cred, int mode);
226 #endif
227 
228 static struct mqfs_node	*mqfs_create_file(struct mqfs_node *parent,
229 	const char *name, int namelen, struct ucred *cred, int mode);
230 static int	mqfs_destroy(struct mqfs_node *mn);
231 static void	mqfs_fileno_alloc(struct mqfs_info *mi, struct mqfs_node *mn);
232 static void	mqfs_fileno_free(struct mqfs_info *mi, struct mqfs_node *mn);
233 static int	mqfs_allocv(struct mount *mp, struct vnode **vpp, struct mqfs_node *pn);
234 
235 /*
236  * Message queue construction and maniplation
237  */
238 static struct mqueue	*mqueue_alloc(const struct mq_attr *attr);
239 static void	mqueue_free(struct mqueue *mq);
240 static int	mqueue_send(struct mqueue *mq, const char *msg_ptr,
241 			size_t msg_len, unsigned msg_prio, int waitok,
242 			const struct timespec *abs_timeout);
243 static int	mqueue_receive(struct mqueue *mq, char *msg_ptr,
244 			size_t msg_len, unsigned *msg_prio, int waitok,
245 			const struct timespec *abs_timeout);
246 static int	_mqueue_send(struct mqueue *mq, struct mqueue_msg *msg,
247 			int timo);
248 static int	_mqueue_recv(struct mqueue *mq, struct mqueue_msg **msg,
249 			int timo);
250 static void	mqueue_send_notification(struct mqueue *mq);
251 static void	mqueue_fdclose(struct thread *td, int fd, struct file *fp);
252 static void	mq_proc_exit(void *arg, struct proc *p);
253 
254 /*
255  * kqueue filters
256  */
257 static void	filt_mqdetach(struct knote *kn);
258 static int	filt_mqread(struct knote *kn, long hint);
259 static int	filt_mqwrite(struct knote *kn, long hint);
260 
261 struct filterops mq_rfiltops = {
262 	.f_isfd = 1,
263 	.f_detach = filt_mqdetach,
264 	.f_event = filt_mqread,
265 };
266 struct filterops mq_wfiltops = {
267 	.f_isfd = 1,
268 	.f_detach = filt_mqdetach,
269 	.f_event = filt_mqwrite,
270 };
271 
272 /*
273  * Initialize fileno bitmap
274  */
275 static void
276 mqfs_fileno_init(struct mqfs_info *mi)
277 {
278 	struct unrhdr *up;
279 
280 	up = new_unrhdr(1, INT_MAX, NULL);
281 	mi->mi_unrhdr = up;
282 }
283 
284 /*
285  * Tear down fileno bitmap
286  */
287 static void
288 mqfs_fileno_uninit(struct mqfs_info *mi)
289 {
290 	struct unrhdr *up;
291 
292 	up = mi->mi_unrhdr;
293 	mi->mi_unrhdr = NULL;
294 	delete_unrhdr(up);
295 }
296 
297 /*
298  * Allocate a file number
299  */
300 static void
301 mqfs_fileno_alloc(struct mqfs_info *mi, struct mqfs_node *mn)
302 {
303 	/* make sure our parent has a file number */
304 	if (mn->mn_parent && !mn->mn_parent->mn_fileno)
305 		mqfs_fileno_alloc(mi, mn->mn_parent);
306 
307 	switch (mn->mn_type) {
308 	case mqfstype_root:
309 	case mqfstype_dir:
310 	case mqfstype_file:
311 	case mqfstype_symlink:
312 		mn->mn_fileno = alloc_unr(mi->mi_unrhdr);
313 		break;
314 	case mqfstype_this:
315 		KASSERT(mn->mn_parent != NULL,
316 		    ("mqfstype_this node has no parent"));
317 		mn->mn_fileno = mn->mn_parent->mn_fileno;
318 		break;
319 	case mqfstype_parent:
320 		KASSERT(mn->mn_parent != NULL,
321 		    ("mqfstype_parent node has no parent"));
322 		if (mn->mn_parent == mi->mi_root) {
323 			mn->mn_fileno = mn->mn_parent->mn_fileno;
324 			break;
325 		}
326 		KASSERT(mn->mn_parent->mn_parent != NULL,
327 		    ("mqfstype_parent node has no grandparent"));
328 		mn->mn_fileno = mn->mn_parent->mn_parent->mn_fileno;
329 		break;
330 	default:
331 		KASSERT(0,
332 		    ("mqfs_fileno_alloc() called for unknown type node: %d",
333 			mn->mn_type));
334 		break;
335 	}
336 }
337 
338 /*
339  * Release a file number
340  */
341 static void
342 mqfs_fileno_free(struct mqfs_info *mi, struct mqfs_node *mn)
343 {
344 	switch (mn->mn_type) {
345 	case mqfstype_root:
346 	case mqfstype_dir:
347 	case mqfstype_file:
348 	case mqfstype_symlink:
349 		free_unr(mi->mi_unrhdr, mn->mn_fileno);
350 		break;
351 	case mqfstype_this:
352 	case mqfstype_parent:
353 		/* ignore these, as they don't "own" their file number */
354 		break;
355 	default:
356 		KASSERT(0,
357 		    ("mqfs_fileno_free() called for unknown type node: %d",
358 			mn->mn_type));
359 		break;
360 	}
361 }
362 
363 static __inline struct mqfs_node *
364 mqnode_alloc(void)
365 {
366 	return uma_zalloc(mqnode_zone, M_WAITOK | M_ZERO);
367 }
368 
369 static __inline void
370 mqnode_free(struct mqfs_node *node)
371 {
372 	uma_zfree(mqnode_zone, node);
373 }
374 
375 static __inline void
376 mqnode_addref(struct mqfs_node *node)
377 {
378 	atomic_fetchadd_int(&node->mn_refcount, 1);
379 }
380 
381 static __inline void
382 mqnode_release(struct mqfs_node *node)
383 {
384 	struct mqfs_info *mqfs;
385 	int old, exp;
386 
387 	mqfs = node->mn_info;
388 	old = atomic_fetchadd_int(&node->mn_refcount, -1);
389 	if (node->mn_type == mqfstype_dir ||
390 	    node->mn_type == mqfstype_root)
391 		exp = 3; /* include . and .. */
392 	else
393 		exp = 1;
394 	if (old == exp) {
395 		int locked = sx_xlocked(&mqfs->mi_lock);
396 		if (!locked)
397 			sx_xlock(&mqfs->mi_lock);
398 		mqfs_destroy(node);
399 		if (!locked)
400 			sx_xunlock(&mqfs->mi_lock);
401 	}
402 }
403 
404 /*
405  * Add a node to a directory
406  */
407 static int
408 mqfs_add_node(struct mqfs_node *parent, struct mqfs_node *node)
409 {
410 	KASSERT(parent != NULL, ("%s(): parent is NULL", __func__));
411 	KASSERT(parent->mn_info != NULL,
412 	    ("%s(): parent has no mn_info", __func__));
413 	KASSERT(parent->mn_type == mqfstype_dir ||
414 	    parent->mn_type == mqfstype_root,
415 	    ("%s(): parent is not a directory", __func__));
416 
417 	node->mn_info = parent->mn_info;
418 	node->mn_parent = parent;
419 	LIST_INIT(&node->mn_children);
420 	LIST_INIT(&node->mn_vnodes);
421 	LIST_INSERT_HEAD(&parent->mn_children, node, mn_sibling);
422 	mqnode_addref(parent);
423 	return (0);
424 }
425 
426 static struct mqfs_node *
427 mqfs_create_node(const char *name, int namelen, struct ucred *cred, int mode,
428 	int nodetype)
429 {
430 	struct mqfs_node *node;
431 
432 	node = mqnode_alloc();
433 	strncpy(node->mn_name, name, namelen);
434 	node->mn_type = nodetype;
435 	node->mn_refcount = 1;
436 	vfs_timestamp(&node->mn_birth);
437 	node->mn_ctime = node->mn_atime = node->mn_mtime
438 		= node->mn_birth;
439 	node->mn_uid = cred->cr_uid;
440 	node->mn_gid = cred->cr_gid;
441 	node->mn_mode = mode;
442 	return (node);
443 }
444 
445 /*
446  * Create a file
447  */
448 static struct mqfs_node *
449 mqfs_create_file(struct mqfs_node *parent, const char *name, int namelen,
450 	struct ucred *cred, int mode)
451 {
452 	struct mqfs_node *node;
453 
454 	node = mqfs_create_node(name, namelen, cred, mode, mqfstype_file);
455 	if (mqfs_add_node(parent, node) != 0) {
456 		mqnode_free(node);
457 		return (NULL);
458 	}
459 	return (node);
460 }
461 
462 /*
463  * Add . and .. to a directory
464  */
465 static int
466 mqfs_fixup_dir(struct mqfs_node *parent)
467 {
468 	struct mqfs_node *dir;
469 
470 	dir = mqnode_alloc();
471 	dir->mn_name[0] = '.';
472 	dir->mn_type = mqfstype_this;
473 	dir->mn_refcount = 1;
474 	if (mqfs_add_node(parent, dir) != 0) {
475 		mqnode_free(dir);
476 		return (-1);
477 	}
478 
479 	dir = mqnode_alloc();
480 	dir->mn_name[0] = dir->mn_name[1] = '.';
481 	dir->mn_type = mqfstype_parent;
482 	dir->mn_refcount = 1;
483 
484 	if (mqfs_add_node(parent, dir) != 0) {
485 		mqnode_free(dir);
486 		return (-1);
487 	}
488 
489 	return (0);
490 }
491 
492 #ifdef notyet
493 
494 /*
495  * Create a directory
496  */
497 static struct mqfs_node *
498 mqfs_create_dir(struct mqfs_node *parent, const char *name, int namelen,
499 	struct ucred *cred, int mode)
500 {
501 	struct mqfs_node *node;
502 
503 	node = mqfs_create_node(name, namelen, cred, mode, mqfstype_dir);
504 	if (mqfs_add_node(parent, node) != 0) {
505 		mqnode_free(node);
506 		return (NULL);
507 	}
508 
509 	if (mqfs_fixup_dir(node) != 0) {
510 		mqfs_destroy(node);
511 		return (NULL);
512 	}
513 	return (node);
514 }
515 
516 /*
517  * Create a symlink
518  */
519 static struct mqfs_node *
520 mqfs_create_link(struct mqfs_node *parent, const char *name, int namelen,
521 	struct ucred *cred, int mode)
522 {
523 	struct mqfs_node *node;
524 
525 	node = mqfs_create_node(name, namelen, cred, mode, mqfstype_symlink);
526 	if (mqfs_add_node(parent, node) != 0) {
527 		mqnode_free(node);
528 		return (NULL);
529 	}
530 	return (node);
531 }
532 
533 #endif
534 
535 /*
536  * Destroy a node or a tree of nodes
537  */
538 static int
539 mqfs_destroy(struct mqfs_node *node)
540 {
541 	struct mqfs_node *parent;
542 
543 	KASSERT(node != NULL,
544 	    ("%s(): node is NULL", __func__));
545 	KASSERT(node->mn_info != NULL,
546 	    ("%s(): node has no mn_info", __func__));
547 
548 	/* destroy children */
549 	if (node->mn_type == mqfstype_dir || node->mn_type == mqfstype_root)
550 		while (! LIST_EMPTY(&node->mn_children))
551 			mqfs_destroy(LIST_FIRST(&node->mn_children));
552 
553 	/* unlink from parent */
554 	if ((parent = node->mn_parent) != NULL) {
555 		KASSERT(parent->mn_info == node->mn_info,
556 		    ("%s(): parent has different mn_info", __func__));
557 		LIST_REMOVE(node, mn_sibling);
558 	}
559 
560 	if (node->mn_fileno != 0)
561 		mqfs_fileno_free(node->mn_info, node);
562 	if (node->mn_data != NULL)
563 		mqueue_free(node->mn_data);
564 	mqnode_free(node);
565 	return (0);
566 }
567 
568 /*
569  * Mount a mqfs instance
570  */
571 static int
572 mqfs_mount(struct mount *mp)
573 {
574 	struct statfs *sbp;
575 
576 	if (mp->mnt_flag & MNT_UPDATE)
577 		return (EOPNOTSUPP);
578 
579 	mp->mnt_data = &mqfs_data;
580 	MNT_ILOCK(mp);
581 	mp->mnt_flag |= MNT_LOCAL;
582 	mp->mnt_kern_flag |= MNTK_MPSAFE;
583 	MNT_IUNLOCK(mp);
584 	vfs_getnewfsid(mp);
585 
586 	sbp = &mp->mnt_stat;
587 	vfs_mountedfrom(mp, "mqueue");
588 	sbp->f_bsize = PAGE_SIZE;
589 	sbp->f_iosize = PAGE_SIZE;
590 	sbp->f_blocks = 1;
591 	sbp->f_bfree = 0;
592 	sbp->f_bavail = 0;
593 	sbp->f_files = 1;
594 	sbp->f_ffree = 0;
595 	return (0);
596 }
597 
598 /*
599  * Unmount a mqfs instance
600  */
601 static int
602 mqfs_unmount(struct mount *mp, int mntflags)
603 {
604 	int error;
605 
606 	error = vflush(mp, 0, (mntflags & MNT_FORCE) ?  FORCECLOSE : 0,
607 	    curthread);
608 	return (error);
609 }
610 
611 /*
612  * Return a root vnode
613  */
614 static int
615 mqfs_root(struct mount *mp, int flags, struct vnode **vpp)
616 {
617 	struct mqfs_info *mqfs;
618 	int ret;
619 
620 	mqfs = VFSTOMQFS(mp);
621 	ret = mqfs_allocv(mp, vpp, mqfs->mi_root);
622 	return (ret);
623 }
624 
625 /*
626  * Return filesystem stats
627  */
628 static int
629 mqfs_statfs(struct mount *mp, struct statfs *sbp)
630 {
631 	/* XXX update statistics */
632 	return (0);
633 }
634 
635 /*
636  * Initialize a mqfs instance
637  */
638 static int
639 mqfs_init(struct vfsconf *vfc)
640 {
641 	struct mqfs_node *root;
642 	struct mqfs_info *mi;
643 
644 	mqnode_zone = uma_zcreate("mqnode", sizeof(struct mqfs_node),
645 		NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
646 	mqueue_zone = uma_zcreate("mqueue", sizeof(struct mqueue),
647 		NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
648 	mvdata_zone = uma_zcreate("mvdata",
649 		sizeof(struct mqfs_vdata), NULL, NULL, NULL,
650 		NULL, UMA_ALIGN_PTR, 0);
651 	mqnoti_zone = uma_zcreate("mqnotifier", sizeof(struct mqueue_notifier),
652 		NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
653 	mi = &mqfs_data;
654 	sx_init(&mi->mi_lock, "mqfs lock");
655 	/* set up the root diretory */
656 	root = mqfs_create_node("/", 1, curthread->td_ucred, 01777,
657 		mqfstype_root);
658 	root->mn_info = mi;
659 	LIST_INIT(&root->mn_children);
660 	LIST_INIT(&root->mn_vnodes);
661 	mi->mi_root = root;
662 	mqfs_fileno_init(mi);
663 	mqfs_fileno_alloc(mi, root);
664 	mqfs_fixup_dir(root);
665 	exit_tag = EVENTHANDLER_REGISTER(process_exit, mq_proc_exit, NULL,
666 	    EVENTHANDLER_PRI_ANY);
667 	mq_fdclose = mqueue_fdclose;
668 	p31b_setcfg(CTL_P1003_1B_MESSAGE_PASSING, _POSIX_MESSAGE_PASSING);
669 	return (0);
670 }
671 
672 /*
673  * Destroy a mqfs instance
674  */
675 static int
676 mqfs_uninit(struct vfsconf *vfc)
677 {
678 	struct mqfs_info *mi;
679 
680 	if (!unloadable)
681 		return (EOPNOTSUPP);
682 	EVENTHANDLER_DEREGISTER(process_exit, exit_tag);
683 	mi = &mqfs_data;
684 	mqfs_destroy(mi->mi_root);
685 	mi->mi_root = NULL;
686 	mqfs_fileno_uninit(mi);
687 	sx_destroy(&mi->mi_lock);
688 	uma_zdestroy(mqnode_zone);
689 	uma_zdestroy(mqueue_zone);
690 	uma_zdestroy(mvdata_zone);
691 	uma_zdestroy(mqnoti_zone);
692 	return (0);
693 }
694 
695 /*
696  * task routine
697  */
698 static void
699 do_recycle(void *context, int pending __unused)
700 {
701 	struct vnode *vp = (struct vnode *)context;
702 
703 	vrecycle(vp, curthread);
704 	vdrop(vp);
705 }
706 
707 /*
708  * Allocate a vnode
709  */
710 static int
711 mqfs_allocv(struct mount *mp, struct vnode **vpp, struct mqfs_node *pn)
712 {
713 	struct mqfs_vdata *vd;
714 	struct mqfs_info  *mqfs;
715 	struct vnode *newvpp;
716 	int error;
717 
718 	mqfs = pn->mn_info;
719 	*vpp = NULL;
720 	sx_xlock(&mqfs->mi_lock);
721 	LIST_FOREACH(vd, &pn->mn_vnodes, mv_link) {
722 		if (vd->mv_vnode->v_mount == mp) {
723 			vhold(vd->mv_vnode);
724 			break;
725 		}
726 	}
727 
728 	if (vd != NULL) {
729 found:
730 		*vpp = vd->mv_vnode;
731 		sx_xunlock(&mqfs->mi_lock);
732 		error = vget(*vpp, LK_RETRY | LK_EXCLUSIVE, curthread);
733 		vdrop(*vpp);
734 		return (error);
735 	}
736 	sx_xunlock(&mqfs->mi_lock);
737 
738 	error = getnewvnode("mqueue", mp, &mqfs_vnodeops, &newvpp);
739 	if (error)
740 		return (error);
741 	vn_lock(newvpp, LK_EXCLUSIVE | LK_RETRY);
742 	error = insmntque(newvpp, mp);
743 	if (error != 0)
744 		return (error);
745 
746 	sx_xlock(&mqfs->mi_lock);
747 	/*
748 	 * Check if it has already been allocated
749 	 * while we were blocked.
750 	 */
751 	LIST_FOREACH(vd, &pn->mn_vnodes, mv_link) {
752 		if (vd->mv_vnode->v_mount == mp) {
753 			vhold(vd->mv_vnode);
754 			sx_xunlock(&mqfs->mi_lock);
755 
756 			vgone(newvpp);
757 			vput(newvpp);
758 			goto found;
759 		}
760 	}
761 
762 	*vpp = newvpp;
763 
764 	vd = uma_zalloc(mvdata_zone, M_WAITOK);
765 	(*vpp)->v_data = vd;
766 	vd->mv_vnode = *vpp;
767 	vd->mv_node = pn;
768 	TASK_INIT(&vd->mv_task, 0, do_recycle, *vpp);
769 	LIST_INSERT_HEAD(&pn->mn_vnodes, vd, mv_link);
770 	mqnode_addref(pn);
771 	switch (pn->mn_type) {
772 	case mqfstype_root:
773 		(*vpp)->v_vflag = VV_ROOT;
774 		/* fall through */
775 	case mqfstype_dir:
776 	case mqfstype_this:
777 	case mqfstype_parent:
778 		(*vpp)->v_type = VDIR;
779 		break;
780 	case mqfstype_file:
781 		(*vpp)->v_type = VREG;
782 		break;
783 	case mqfstype_symlink:
784 		(*vpp)->v_type = VLNK;
785 		break;
786 	case mqfstype_none:
787 		KASSERT(0, ("mqfs_allocf called for null node\n"));
788 	default:
789 		panic("%s has unexpected type: %d", pn->mn_name, pn->mn_type);
790 	}
791 	sx_xunlock(&mqfs->mi_lock);
792 	return (0);
793 }
794 
795 /*
796  * Search a directory entry
797  */
798 static struct mqfs_node *
799 mqfs_search(struct mqfs_node *pd, const char *name, int len)
800 {
801 	struct mqfs_node *pn;
802 
803 	sx_assert(&pd->mn_info->mi_lock, SX_LOCKED);
804 	LIST_FOREACH(pn, &pd->mn_children, mn_sibling) {
805 		if (strncmp(pn->mn_name, name, len) == 0 &&
806 		    pn->mn_name[len] == '\0')
807 			return (pn);
808 	}
809 	return (NULL);
810 }
811 
812 /*
813  * Look up a file or directory.
814  */
815 static int
816 mqfs_lookupx(struct vop_cachedlookup_args *ap)
817 {
818 	struct componentname *cnp;
819 	struct vnode *dvp, **vpp;
820 	struct mqfs_node *pd;
821 	struct mqfs_node *pn;
822 	struct mqfs_info *mqfs;
823 	int nameiop, flags, error, namelen;
824 	char *pname;
825 	struct thread *td;
826 
827 	cnp = ap->a_cnp;
828 	vpp = ap->a_vpp;
829 	dvp = ap->a_dvp;
830 	pname = cnp->cn_nameptr;
831 	namelen = cnp->cn_namelen;
832 	td = cnp->cn_thread;
833 	flags = cnp->cn_flags;
834 	nameiop = cnp->cn_nameiop;
835 	pd = VTON(dvp);
836 	pn = NULL;
837 	mqfs = pd->mn_info;
838 	*vpp = NULLVP;
839 
840 	if (dvp->v_type != VDIR)
841 		return (ENOTDIR);
842 
843 	error = VOP_ACCESS(dvp, VEXEC, cnp->cn_cred, cnp->cn_thread);
844 	if (error)
845 		return (error);
846 
847 	/* shortcut: check if the name is too long */
848 	if (cnp->cn_namelen >= MQFS_NAMELEN)
849 		return (ENOENT);
850 
851 	/* self */
852 	if (namelen == 1 && pname[0] == '.') {
853 		if ((flags & ISLASTCN) && nameiop != LOOKUP)
854 			return (EINVAL);
855 		pn = pd;
856 		*vpp = dvp;
857 		VREF(dvp);
858 		return (0);
859 	}
860 
861 	/* parent */
862 	if (cnp->cn_flags & ISDOTDOT) {
863 		if (dvp->v_vflag & VV_ROOT)
864 			return (EIO);
865 		if ((flags & ISLASTCN) && nameiop != LOOKUP)
866 			return (EINVAL);
867 		VOP_UNLOCK(dvp, 0);
868 		KASSERT(pd->mn_parent, ("non-root directory has no parent"));
869 		pn = pd->mn_parent;
870 		error = mqfs_allocv(dvp->v_mount, vpp, pn);
871 		vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY);
872 		return (error);
873 	}
874 
875 	/* named node */
876 	sx_xlock(&mqfs->mi_lock);
877 	pn = mqfs_search(pd, pname, namelen);
878 	if (pn != NULL)
879 		mqnode_addref(pn);
880 	sx_xunlock(&mqfs->mi_lock);
881 
882 	/* found */
883 	if (pn != NULL) {
884 		/* DELETE */
885 		if (nameiop == DELETE && (flags & ISLASTCN)) {
886 			error = VOP_ACCESS(dvp, VWRITE, cnp->cn_cred, td);
887 			if (error) {
888 				mqnode_release(pn);
889 				return (error);
890 			}
891 			if (*vpp == dvp) {
892 				VREF(dvp);
893 				*vpp = dvp;
894 				mqnode_release(pn);
895 				return (0);
896 			}
897 		}
898 
899 		/* allocate vnode */
900 		error = mqfs_allocv(dvp->v_mount, vpp, pn);
901 		mqnode_release(pn);
902 		if (error == 0 && cnp->cn_flags & MAKEENTRY)
903 			cache_enter(dvp, *vpp, cnp);
904 		return (error);
905 	}
906 
907 	/* not found */
908 
909 	/* will create a new entry in the directory ? */
910 	if ((nameiop == CREATE || nameiop == RENAME) && (flags & LOCKPARENT)
911 	    && (flags & ISLASTCN)) {
912 		error = VOP_ACCESS(dvp, VWRITE, cnp->cn_cred, td);
913 		if (error)
914 			return (error);
915 		cnp->cn_flags |= SAVENAME;
916 		return (EJUSTRETURN);
917 	}
918 	return (ENOENT);
919 }
920 
921 #if 0
922 struct vop_lookup_args {
923 	struct vop_generic_args a_gen;
924 	struct vnode *a_dvp;
925 	struct vnode **a_vpp;
926 	struct componentname *a_cnp;
927 };
928 #endif
929 
930 /*
931  * vnode lookup operation
932  */
933 static int
934 mqfs_lookup(struct vop_cachedlookup_args *ap)
935 {
936 	int rc;
937 
938 	rc = mqfs_lookupx(ap);
939 	return (rc);
940 }
941 
942 #if 0
943 struct vop_create_args {
944 	struct vnode *a_dvp;
945 	struct vnode **a_vpp;
946 	struct componentname *a_cnp;
947 	struct vattr *a_vap;
948 };
949 #endif
950 
951 /*
952  * vnode creation operation
953  */
954 static int
955 mqfs_create(struct vop_create_args *ap)
956 {
957 	struct mqfs_info *mqfs = VFSTOMQFS(ap->a_dvp->v_mount);
958 	struct componentname *cnp = ap->a_cnp;
959 	struct mqfs_node *pd;
960 	struct mqfs_node *pn;
961 	struct mqueue *mq;
962 	int error;
963 
964 	pd = VTON(ap->a_dvp);
965 	if (pd->mn_type != mqfstype_root && pd->mn_type != mqfstype_dir)
966 		return (ENOTDIR);
967 	mq = mqueue_alloc(NULL);
968 	if (mq == NULL)
969 		return (EAGAIN);
970 	sx_xlock(&mqfs->mi_lock);
971 	if ((cnp->cn_flags & HASBUF) == 0)
972 		panic("%s: no name", __func__);
973 	pn = mqfs_create_file(pd, cnp->cn_nameptr, cnp->cn_namelen,
974 		cnp->cn_cred, ap->a_vap->va_mode);
975 	if (pn == NULL) {
976 		sx_xunlock(&mqfs->mi_lock);
977 		error = ENOSPC;
978 	} else {
979 		mqnode_addref(pn);
980 		sx_xunlock(&mqfs->mi_lock);
981 		error = mqfs_allocv(ap->a_dvp->v_mount, ap->a_vpp, pn);
982 		mqnode_release(pn);
983 		if (error)
984 			mqfs_destroy(pn);
985 		else
986 			pn->mn_data = mq;
987 	}
988 	if (error)
989 		mqueue_free(mq);
990 	return (error);
991 }
992 
993 /*
994  * Remove an entry
995  */
996 static
997 int do_unlink(struct mqfs_node *pn, struct ucred *ucred)
998 {
999 	struct mqfs_node *parent;
1000 	struct mqfs_vdata *vd;
1001 	int error = 0;
1002 
1003 	sx_assert(&pn->mn_info->mi_lock, SX_LOCKED);
1004 
1005 	if (ucred->cr_uid != pn->mn_uid &&
1006 	    (error = priv_check_cred(ucred, PRIV_MQ_ADMIN, 0)) != 0)
1007 		error = EACCES;
1008 	else if (!pn->mn_deleted) {
1009 		parent = pn->mn_parent;
1010 		pn->mn_parent = NULL;
1011 		pn->mn_deleted = 1;
1012 		LIST_REMOVE(pn, mn_sibling);
1013 		LIST_FOREACH(vd, &pn->mn_vnodes, mv_link) {
1014 			cache_purge(vd->mv_vnode);
1015 			vhold(vd->mv_vnode);
1016 			taskqueue_enqueue(taskqueue_thread, &vd->mv_task);
1017 		}
1018 		mqnode_release(pn);
1019 		mqnode_release(parent);
1020 	} else
1021 		error = ENOENT;
1022 	return (error);
1023 }
1024 
1025 #if 0
1026 struct vop_remove_args {
1027 	struct vnode *a_dvp;
1028 	struct vnode *a_vp;
1029 	struct componentname *a_cnp;
1030 };
1031 #endif
1032 
1033 /*
1034  * vnode removal operation
1035  */
1036 static int
1037 mqfs_remove(struct vop_remove_args *ap)
1038 {
1039 	struct mqfs_info *mqfs = VFSTOMQFS(ap->a_dvp->v_mount);
1040 	struct mqfs_node *pn;
1041 	int error;
1042 
1043 	if (ap->a_vp->v_type == VDIR)
1044                 return (EPERM);
1045 	pn = VTON(ap->a_vp);
1046 	sx_xlock(&mqfs->mi_lock);
1047 	error = do_unlink(pn, ap->a_cnp->cn_cred);
1048 	sx_xunlock(&mqfs->mi_lock);
1049 	return (error);
1050 }
1051 
1052 #if 0
1053 struct vop_inactive_args {
1054 	struct vnode *a_vp;
1055 	struct thread *a_td;
1056 };
1057 #endif
1058 
1059 static int
1060 mqfs_inactive(struct vop_inactive_args *ap)
1061 {
1062 	struct mqfs_node *pn = VTON(ap->a_vp);
1063 
1064 	if (pn->mn_deleted)
1065 		vrecycle(ap->a_vp, ap->a_td);
1066 	return (0);
1067 }
1068 
1069 #if 0
1070 struct vop_reclaim_args {
1071 	struct vop_generic_args a_gen;
1072 	struct vnode *a_vp;
1073 	struct thread *a_td;
1074 };
1075 #endif
1076 
1077 static int
1078 mqfs_reclaim(struct vop_reclaim_args *ap)
1079 {
1080 	struct mqfs_info *mqfs = VFSTOMQFS(ap->a_vp->v_mount);
1081 	struct vnode *vp = ap->a_vp;
1082 	struct mqfs_node *pn;
1083 	struct mqfs_vdata *vd;
1084 
1085 	vd = vp->v_data;
1086 	pn = vd->mv_node;
1087 	sx_xlock(&mqfs->mi_lock);
1088 	vp->v_data = NULL;
1089 	LIST_REMOVE(vd, mv_link);
1090 	uma_zfree(mvdata_zone, vd);
1091 	mqnode_release(pn);
1092 	sx_xunlock(&mqfs->mi_lock);
1093 	return (0);
1094 }
1095 
1096 #if 0
1097 struct vop_open_args {
1098 	struct vop_generic_args a_gen;
1099 	struct vnode *a_vp;
1100 	int a_mode;
1101 	struct ucred *a_cred;
1102 	struct thread *a_td;
1103 	struct file *a_fp;
1104 };
1105 #endif
1106 
1107 static int
1108 mqfs_open(struct vop_open_args *ap)
1109 {
1110 	return (0);
1111 }
1112 
1113 #if 0
1114 struct vop_close_args {
1115 	struct vop_generic_args a_gen;
1116 	struct vnode *a_vp;
1117 	int a_fflag;
1118 	struct ucred *a_cred;
1119 	struct thread *a_td;
1120 };
1121 #endif
1122 
1123 static int
1124 mqfs_close(struct vop_close_args *ap)
1125 {
1126 	return (0);
1127 }
1128 
1129 #if 0
1130 struct vop_access_args {
1131 	struct vop_generic_args a_gen;
1132 	struct vnode *a_vp;
1133 	accmode_t a_accmode;
1134 	struct ucred *a_cred;
1135 	struct thread *a_td;
1136 };
1137 #endif
1138 
1139 /*
1140  * Verify permissions
1141  */
1142 static int
1143 mqfs_access(struct vop_access_args *ap)
1144 {
1145 	struct vnode *vp = ap->a_vp;
1146 	struct vattr vattr;
1147 	int error;
1148 
1149 	error = VOP_GETATTR(vp, &vattr, ap->a_cred);
1150 	if (error)
1151 		return (error);
1152 	error = vaccess(vp->v_type, vattr.va_mode, vattr.va_uid,
1153 	    vattr.va_gid, ap->a_accmode, ap->a_cred, NULL);
1154 	return (error);
1155 }
1156 
1157 #if 0
1158 struct vop_getattr_args {
1159 	struct vop_generic_args a_gen;
1160 	struct vnode *a_vp;
1161 	struct vattr *a_vap;
1162 	struct ucred *a_cred;
1163 };
1164 #endif
1165 
1166 /*
1167  * Get file attributes
1168  */
1169 static int
1170 mqfs_getattr(struct vop_getattr_args *ap)
1171 {
1172 	struct vnode *vp = ap->a_vp;
1173 	struct mqfs_node *pn = VTON(vp);
1174 	struct vattr *vap = ap->a_vap;
1175 	int error = 0;
1176 
1177 	vap->va_type = vp->v_type;
1178 	vap->va_mode = pn->mn_mode;
1179 	vap->va_nlink = 1;
1180 	vap->va_uid = pn->mn_uid;
1181 	vap->va_gid = pn->mn_gid;
1182 	vap->va_fsid = vp->v_mount->mnt_stat.f_fsid.val[0];
1183 	vap->va_fileid = pn->mn_fileno;
1184 	vap->va_size = 0;
1185 	vap->va_blocksize = PAGE_SIZE;
1186 	vap->va_bytes = vap->va_size = 0;
1187 	vap->va_atime = pn->mn_atime;
1188 	vap->va_mtime = pn->mn_mtime;
1189 	vap->va_ctime = pn->mn_ctime;
1190 	vap->va_birthtime = pn->mn_birth;
1191 	vap->va_gen = 0;
1192 	vap->va_flags = 0;
1193 	vap->va_rdev = NODEV;
1194 	vap->va_bytes = 0;
1195 	vap->va_filerev = 0;
1196 	return (error);
1197 }
1198 
1199 #if 0
1200 struct vop_setattr_args {
1201 	struct vop_generic_args a_gen;
1202 	struct vnode *a_vp;
1203 	struct vattr *a_vap;
1204 	struct ucred *a_cred;
1205 };
1206 #endif
1207 /*
1208  * Set attributes
1209  */
1210 static int
1211 mqfs_setattr(struct vop_setattr_args *ap)
1212 {
1213 	struct mqfs_node *pn;
1214 	struct vattr *vap;
1215 	struct vnode *vp;
1216 	struct thread *td;
1217 	int c, error;
1218 	uid_t uid;
1219 	gid_t gid;
1220 
1221 	td = curthread;
1222 	vap = ap->a_vap;
1223 	vp = ap->a_vp;
1224 	if ((vap->va_type != VNON) ||
1225 	    (vap->va_nlink != VNOVAL) ||
1226 	    (vap->va_fsid != VNOVAL) ||
1227 	    (vap->va_fileid != VNOVAL) ||
1228 	    (vap->va_blocksize != VNOVAL) ||
1229 	    (vap->va_flags != VNOVAL && vap->va_flags != 0) ||
1230 	    (vap->va_rdev != VNOVAL) ||
1231 	    ((int)vap->va_bytes != VNOVAL) ||
1232 	    (vap->va_gen != VNOVAL)) {
1233 		return (EINVAL);
1234 	}
1235 
1236 	pn = VTON(vp);
1237 
1238 	error = c = 0;
1239 	if (vap->va_uid == (uid_t)VNOVAL)
1240 		uid = pn->mn_uid;
1241 	else
1242 		uid = vap->va_uid;
1243 	if (vap->va_gid == (gid_t)VNOVAL)
1244 		gid = pn->mn_gid;
1245 	else
1246 		gid = vap->va_gid;
1247 
1248 	if (uid != pn->mn_uid || gid != pn->mn_gid) {
1249 		/*
1250 		 * To modify the ownership of a file, must possess VADMIN
1251 		 * for that file.
1252 		 */
1253 		if ((error = VOP_ACCESS(vp, VADMIN, ap->a_cred, td)))
1254 			return (error);
1255 
1256 		/*
1257 		 * XXXRW: Why is there a privilege check here: shouldn't the
1258 		 * check in VOP_ACCESS() be enough?  Also, are the group bits
1259 		 * below definitely right?
1260 		 */
1261 		if (((ap->a_cred->cr_uid != pn->mn_uid) || uid != pn->mn_uid ||
1262 		    (gid != pn->mn_gid && !groupmember(gid, ap->a_cred))) &&
1263 		    (error = priv_check(td, PRIV_MQ_ADMIN)) != 0)
1264 			return (error);
1265 		pn->mn_uid = uid;
1266 		pn->mn_gid = gid;
1267 		c = 1;
1268 	}
1269 
1270 	if (vap->va_mode != (mode_t)VNOVAL) {
1271 		if ((ap->a_cred->cr_uid != pn->mn_uid) &&
1272 		    (error = priv_check(td, PRIV_MQ_ADMIN)))
1273 			return (error);
1274 		pn->mn_mode = vap->va_mode;
1275 		c = 1;
1276 	}
1277 
1278 	if (vap->va_atime.tv_sec != VNOVAL || vap->va_mtime.tv_sec != VNOVAL) {
1279 		/* See the comment in ufs_vnops::ufs_setattr(). */
1280 		if ((error = VOP_ACCESS(vp, VADMIN, ap->a_cred, td)) &&
1281 		    ((vap->va_vaflags & VA_UTIMES_NULL) == 0 ||
1282 		    (error = VOP_ACCESS(vp, VWRITE, ap->a_cred, td))))
1283 			return (error);
1284 		if (vap->va_atime.tv_sec != VNOVAL) {
1285 			pn->mn_atime = vap->va_atime;
1286 		}
1287 		if (vap->va_mtime.tv_sec != VNOVAL) {
1288 			pn->mn_mtime = vap->va_mtime;
1289 		}
1290 		c = 1;
1291 	}
1292 	if (c) {
1293 		vfs_timestamp(&pn->mn_ctime);
1294 	}
1295 	return (0);
1296 }
1297 
1298 #if 0
1299 struct vop_read_args {
1300 	struct vop_generic_args a_gen;
1301 	struct vnode *a_vp;
1302 	struct uio *a_uio;
1303 	int a_ioflag;
1304 	struct ucred *a_cred;
1305 };
1306 #endif
1307 
1308 /*
1309  * Read from a file
1310  */
1311 static int
1312 mqfs_read(struct vop_read_args *ap)
1313 {
1314 	char buf[80];
1315 	struct vnode *vp = ap->a_vp;
1316 	struct uio *uio = ap->a_uio;
1317 	struct mqfs_node *pn;
1318 	struct mqueue *mq;
1319 	int len, error;
1320 
1321 	if (vp->v_type != VREG)
1322 		return (EINVAL);
1323 
1324 	pn = VTON(vp);
1325 	mq = VTOMQ(vp);
1326 	snprintf(buf, sizeof(buf),
1327 		"QSIZE:%-10ld MAXMSG:%-10ld CURMSG:%-10ld MSGSIZE:%-10ld\n",
1328 		mq->mq_totalbytes,
1329 		mq->mq_maxmsg,
1330 		mq->mq_curmsgs,
1331 		mq->mq_msgsize);
1332 	buf[sizeof(buf)-1] = '\0';
1333 	len = strlen(buf);
1334 	error = uiomove_frombuf(buf, len, uio);
1335 	return (error);
1336 }
1337 
1338 #if 0
1339 struct vop_readdir_args {
1340 	struct vop_generic_args a_gen;
1341 	struct vnode *a_vp;
1342 	struct uio *a_uio;
1343 	struct ucred *a_cred;
1344 	int *a_eofflag;
1345 	int *a_ncookies;
1346 	u_long **a_cookies;
1347 };
1348 #endif
1349 
1350 /*
1351  * Return directory entries.
1352  */
1353 static int
1354 mqfs_readdir(struct vop_readdir_args *ap)
1355 {
1356 	struct vnode *vp;
1357 	struct mqfs_info *mi;
1358 	struct mqfs_node *pd;
1359 	struct mqfs_node *pn;
1360 	struct dirent entry;
1361 	struct uio *uio;
1362 	int *tmp_ncookies = NULL;
1363 	off_t offset;
1364 	int error, i;
1365 
1366 	vp = ap->a_vp;
1367 	mi = VFSTOMQFS(vp->v_mount);
1368 	pd = VTON(vp);
1369 	uio = ap->a_uio;
1370 
1371 	if (vp->v_type != VDIR)
1372 		return (ENOTDIR);
1373 
1374 	if (uio->uio_offset < 0)
1375 		return (EINVAL);
1376 
1377 	if (ap->a_ncookies != NULL) {
1378 		tmp_ncookies = ap->a_ncookies;
1379 		*ap->a_ncookies = 0;
1380 		ap->a_ncookies = NULL;
1381         }
1382 
1383 	error = 0;
1384 	offset = 0;
1385 
1386 	sx_xlock(&mi->mi_lock);
1387 
1388 	LIST_FOREACH(pn, &pd->mn_children, mn_sibling) {
1389 		entry.d_reclen = sizeof(entry);
1390 		if (!pn->mn_fileno)
1391 			mqfs_fileno_alloc(mi, pn);
1392 		entry.d_fileno = pn->mn_fileno;
1393 		for (i = 0; i < MQFS_NAMELEN - 1 && pn->mn_name[i] != '\0'; ++i)
1394 			entry.d_name[i] = pn->mn_name[i];
1395 		entry.d_name[i] = 0;
1396 		entry.d_namlen = i;
1397 		switch (pn->mn_type) {
1398 		case mqfstype_root:
1399 		case mqfstype_dir:
1400 		case mqfstype_this:
1401 		case mqfstype_parent:
1402 			entry.d_type = DT_DIR;
1403 			break;
1404 		case mqfstype_file:
1405 			entry.d_type = DT_REG;
1406 			break;
1407 		case mqfstype_symlink:
1408 			entry.d_type = DT_LNK;
1409 			break;
1410 		default:
1411 			panic("%s has unexpected node type: %d", pn->mn_name,
1412 				pn->mn_type);
1413 		}
1414 		if (entry.d_reclen > uio->uio_resid)
1415                         break;
1416 		if (offset >= uio->uio_offset) {
1417 			error = vfs_read_dirent(ap, &entry, offset);
1418                         if (error)
1419                                 break;
1420                 }
1421                 offset += entry.d_reclen;
1422 	}
1423 	sx_xunlock(&mi->mi_lock);
1424 
1425 	uio->uio_offset = offset;
1426 
1427 	if (tmp_ncookies != NULL)
1428 		ap->a_ncookies = tmp_ncookies;
1429 
1430 	return (error);
1431 }
1432 
1433 #ifdef notyet
1434 
1435 #if 0
1436 struct vop_mkdir_args {
1437 	struct vnode *a_dvp;
1438 	struvt vnode **a_vpp;
1439 	struvt componentname *a_cnp;
1440 	struct vattr *a_vap;
1441 };
1442 #endif
1443 
1444 /*
1445  * Create a directory.
1446  */
1447 static int
1448 mqfs_mkdir(struct vop_mkdir_args *ap)
1449 {
1450 	struct mqfs_info *mqfs = VFSTOMQFS(ap->a_dvp->v_mount);
1451 	struct componentname *cnp = ap->a_cnp;
1452 	struct mqfs_node *pd = VTON(ap->a_dvp);
1453 	struct mqfs_node *pn;
1454 	int error;
1455 
1456 	if (pd->mn_type != mqfstype_root && pd->mn_type != mqfstype_dir)
1457 		return (ENOTDIR);
1458 	sx_xlock(&mqfs->mi_lock);
1459 	if ((cnp->cn_flags & HASBUF) == 0)
1460 		panic("%s: no name", __func__);
1461 	pn = mqfs_create_dir(pd, cnp->cn_nameptr, cnp->cn_namelen,
1462 		ap->a_vap->cn_cred, ap->a_vap->va_mode);
1463 	if (pn != NULL)
1464 		mqnode_addref(pn);
1465 	sx_xunlock(&mqfs->mi_lock);
1466 	if (pn == NULL) {
1467 		error = ENOSPC;
1468 	} else {
1469 		error = mqfs_allocv(ap->a_dvp->v_mount, ap->a_vpp, pn);
1470 		mqnode_release(pn);
1471 	}
1472 	return (error);
1473 }
1474 
1475 #if 0
1476 struct vop_rmdir_args {
1477 	struct vnode *a_dvp;
1478 	struct vnode *a_vp;
1479 	struct componentname *a_cnp;
1480 };
1481 #endif
1482 
1483 /*
1484  * Remove a directory.
1485  */
1486 static int
1487 mqfs_rmdir(struct vop_rmdir_args *ap)
1488 {
1489 	struct mqfs_info *mqfs = VFSTOMQFS(ap->a_dvp->v_mount);
1490 	struct mqfs_node *pn = VTON(ap->a_vp);
1491 	struct mqfs_node *pt;
1492 
1493 	if (pn->mn_type != mqfstype_dir)
1494 		return (ENOTDIR);
1495 
1496 	sx_xlock(&mqfs->mi_lock);
1497 	if (pn->mn_deleted) {
1498 		sx_xunlock(&mqfs->mi_lock);
1499 		return (ENOENT);
1500 	}
1501 
1502 	pt = LIST_FIRST(&pn->mn_children);
1503 	pt = LIST_NEXT(pt, mn_sibling);
1504 	pt = LIST_NEXT(pt, mn_sibling);
1505 	if (pt != NULL) {
1506 		sx_xunlock(&mqfs->mi_lock);
1507 		return (ENOTEMPTY);
1508 	}
1509 	pt = pn->mn_parent;
1510 	pn->mn_parent = NULL;
1511 	pn->mn_deleted = 1;
1512 	LIST_REMOVE(pn, mn_sibling);
1513 	mqnode_release(pn);
1514 	mqnode_release(pt);
1515 	sx_xunlock(&mqfs->mi_lock);
1516 	cache_purge(ap->a_vp);
1517 	return (0);
1518 }
1519 
1520 #endif /* notyet */
1521 
1522 /*
1523  * Allocate a message queue
1524  */
1525 static struct mqueue *
1526 mqueue_alloc(const struct mq_attr *attr)
1527 {
1528 	struct mqueue *mq;
1529 
1530 	if (curmq >= maxmq)
1531 		return (NULL);
1532 	mq = uma_zalloc(mqueue_zone, M_WAITOK | M_ZERO);
1533 	TAILQ_INIT(&mq->mq_msgq);
1534 	if (attr != NULL) {
1535 		mq->mq_maxmsg = attr->mq_maxmsg;
1536 		mq->mq_msgsize = attr->mq_msgsize;
1537 	} else {
1538 		mq->mq_maxmsg = default_maxmsg;
1539 		mq->mq_msgsize = default_msgsize;
1540 	}
1541 	mtx_init(&mq->mq_mutex, "mqueue lock", NULL, MTX_DEF);
1542 	knlist_init_mtx(&mq->mq_rsel.si_note, &mq->mq_mutex);
1543 	knlist_init_mtx(&mq->mq_wsel.si_note, &mq->mq_mutex);
1544 	atomic_add_int(&curmq, 1);
1545 	return (mq);
1546 }
1547 
1548 /*
1549  * Destroy a message queue
1550  */
1551 static void
1552 mqueue_free(struct mqueue *mq)
1553 {
1554 	struct mqueue_msg *msg;
1555 
1556 	while ((msg = TAILQ_FIRST(&mq->mq_msgq)) != NULL) {
1557 		TAILQ_REMOVE(&mq->mq_msgq, msg, msg_link);
1558 		free(msg, M_MQUEUEDATA);
1559 	}
1560 
1561 	mtx_destroy(&mq->mq_mutex);
1562 	knlist_destroy(&mq->mq_rsel.si_note);
1563 	knlist_destroy(&mq->mq_wsel.si_note);
1564 	uma_zfree(mqueue_zone, mq);
1565 	atomic_add_int(&curmq, -1);
1566 }
1567 
1568 /*
1569  * Load a message from user space
1570  */
1571 static struct mqueue_msg *
1572 mqueue_loadmsg(const char *msg_ptr, size_t msg_size, int msg_prio)
1573 {
1574 	struct mqueue_msg *msg;
1575 	size_t len;
1576 	int error;
1577 
1578 	len = sizeof(struct mqueue_msg) + msg_size;
1579 	msg = malloc(len, M_MQUEUEDATA, M_WAITOK);
1580 	error = copyin(msg_ptr, ((char *)msg) + sizeof(struct mqueue_msg),
1581 	    msg_size);
1582 	if (error) {
1583 		free(msg, M_MQUEUEDATA);
1584 		msg = NULL;
1585 	} else {
1586 		msg->msg_size = msg_size;
1587 		msg->msg_prio = msg_prio;
1588 	}
1589 	return (msg);
1590 }
1591 
1592 /*
1593  * Save a message to user space
1594  */
1595 static int
1596 mqueue_savemsg(struct mqueue_msg *msg, char *msg_ptr, int *msg_prio)
1597 {
1598 	int error;
1599 
1600 	error = copyout(((char *)msg) + sizeof(*msg), msg_ptr,
1601 		msg->msg_size);
1602 	if (error == 0 && msg_prio != NULL)
1603 		error = copyout(&msg->msg_prio, msg_prio, sizeof(int));
1604 	return (error);
1605 }
1606 
1607 /*
1608  * Free a message's memory
1609  */
1610 static __inline void
1611 mqueue_freemsg(struct mqueue_msg *msg)
1612 {
1613 	free(msg, M_MQUEUEDATA);
1614 }
1615 
1616 /*
1617  * Send a message. if waitok is false, thread will not be
1618  * blocked if there is no data in queue, otherwise, absolute
1619  * time will be checked.
1620  */
1621 int
1622 mqueue_send(struct mqueue *mq, const char *msg_ptr,
1623 	size_t msg_len, unsigned msg_prio, int waitok,
1624 	const struct timespec *abs_timeout)
1625 {
1626 	struct mqueue_msg *msg;
1627 	struct timespec ts, ts2;
1628 	struct timeval tv;
1629 	int error;
1630 
1631 	if (msg_prio >= MQ_PRIO_MAX)
1632 		return (EINVAL);
1633 	if (msg_len > mq->mq_msgsize)
1634 		return (EMSGSIZE);
1635 	msg = mqueue_loadmsg(msg_ptr, msg_len, msg_prio);
1636 	if (msg == NULL)
1637 		return (EFAULT);
1638 
1639 	/* O_NONBLOCK case */
1640 	if (!waitok) {
1641 		error = _mqueue_send(mq, msg, -1);
1642 		if (error)
1643 			goto bad;
1644 		return (0);
1645 	}
1646 
1647 	/* we allow a null timeout (wait forever) */
1648 	if (abs_timeout == NULL) {
1649 		error = _mqueue_send(mq, msg, 0);
1650 		if (error)
1651 			goto bad;
1652 		return (0);
1653 	}
1654 
1655 	/* send it before checking time */
1656 	error = _mqueue_send(mq, msg, -1);
1657 	if (error == 0)
1658 		return (0);
1659 
1660 	if (error != EAGAIN)
1661 		goto bad;
1662 
1663 	if (abs_timeout->tv_nsec >= 1000000000 || abs_timeout->tv_nsec < 0) {
1664 		error = EINVAL;
1665 		goto bad;
1666 	}
1667 	for (;;) {
1668 		ts2 = *abs_timeout;
1669 		getnanotime(&ts);
1670 		timespecsub(&ts2, &ts);
1671 		if (ts2.tv_sec < 0 || (ts2.tv_sec == 0 && ts2.tv_nsec <= 0)) {
1672 			error = ETIMEDOUT;
1673 			break;
1674 		}
1675 		TIMESPEC_TO_TIMEVAL(&tv, &ts2);
1676 		error = _mqueue_send(mq, msg, tvtohz(&tv));
1677 		if (error != ETIMEDOUT)
1678 			break;
1679 	}
1680 	if (error == 0)
1681 		return (0);
1682 bad:
1683 	mqueue_freemsg(msg);
1684 	return (error);
1685 }
1686 
1687 /*
1688  * Common routine to send a message
1689  */
1690 static int
1691 _mqueue_send(struct mqueue *mq, struct mqueue_msg *msg, int timo)
1692 {
1693 	struct mqueue_msg *msg2;
1694 	int error = 0;
1695 
1696 	mtx_lock(&mq->mq_mutex);
1697 	while (mq->mq_curmsgs >= mq->mq_maxmsg && error == 0) {
1698 		if (timo < 0) {
1699 			mtx_unlock(&mq->mq_mutex);
1700 			return (EAGAIN);
1701 		}
1702 		mq->mq_senders++;
1703 		error = msleep(&mq->mq_senders, &mq->mq_mutex,
1704 			    PCATCH, "mqsend", timo);
1705 		mq->mq_senders--;
1706 		if (error == EAGAIN)
1707 			error = ETIMEDOUT;
1708 	}
1709 	if (mq->mq_curmsgs >= mq->mq_maxmsg) {
1710 		mtx_unlock(&mq->mq_mutex);
1711 		return (error);
1712 	}
1713 	error = 0;
1714 	if (TAILQ_EMPTY(&mq->mq_msgq)) {
1715 		TAILQ_INSERT_HEAD(&mq->mq_msgq, msg, msg_link);
1716 	} else {
1717 		if (msg->msg_prio <= TAILQ_LAST(&mq->mq_msgq, msgq)->msg_prio) {
1718 			TAILQ_INSERT_TAIL(&mq->mq_msgq, msg, msg_link);
1719 		} else {
1720 			TAILQ_FOREACH(msg2, &mq->mq_msgq, msg_link) {
1721 				if (msg2->msg_prio < msg->msg_prio)
1722 					break;
1723 			}
1724 			TAILQ_INSERT_BEFORE(msg2, msg, msg_link);
1725 		}
1726 	}
1727 	mq->mq_curmsgs++;
1728 	mq->mq_totalbytes += msg->msg_size;
1729 	if (mq->mq_receivers)
1730 		wakeup_one(&mq->mq_receivers);
1731 	else if (mq->mq_notifier != NULL)
1732 		mqueue_send_notification(mq);
1733 	if (mq->mq_flags & MQ_RSEL) {
1734 		mq->mq_flags &= ~MQ_RSEL;
1735 		selwakeup(&mq->mq_rsel);
1736 	}
1737 	KNOTE_LOCKED(&mq->mq_rsel.si_note, 0);
1738 	mtx_unlock(&mq->mq_mutex);
1739 	return (0);
1740 }
1741 
1742 /*
1743  * Send realtime a signal to process which registered itself
1744  * successfully by mq_notify.
1745  */
1746 static void
1747 mqueue_send_notification(struct mqueue *mq)
1748 {
1749 	struct mqueue_notifier *nt;
1750 	struct thread *td;
1751 	struct proc *p;
1752 	int error;
1753 
1754 	mtx_assert(&mq->mq_mutex, MA_OWNED);
1755 	nt = mq->mq_notifier;
1756 	if (nt->nt_sigev.sigev_notify != SIGEV_NONE) {
1757 		p = nt->nt_proc;
1758 		error = sigev_findtd(p, &nt->nt_sigev, &td);
1759 		if (error) {
1760 			mq->mq_notifier = NULL;
1761 			return;
1762 		}
1763 		if (!KSI_ONQ(&nt->nt_ksi)) {
1764 			ksiginfo_set_sigev(&nt->nt_ksi, &nt->nt_sigev);
1765 			tdsendsignal(p, td, nt->nt_ksi.ksi_signo, &nt->nt_ksi);
1766 		}
1767 		PROC_UNLOCK(p);
1768 	}
1769 	mq->mq_notifier = NULL;
1770 }
1771 
1772 /*
1773  * Get a message. if waitok is false, thread will not be
1774  * blocked if there is no data in queue, otherwise, absolute
1775  * time will be checked.
1776  */
1777 int
1778 mqueue_receive(struct mqueue *mq, char *msg_ptr,
1779 	size_t msg_len, unsigned *msg_prio, int waitok,
1780 	const struct timespec *abs_timeout)
1781 {
1782 	struct mqueue_msg *msg;
1783 	struct timespec ts, ts2;
1784 	struct timeval tv;
1785 	int error;
1786 
1787 	if (msg_len < mq->mq_msgsize)
1788 		return (EMSGSIZE);
1789 
1790 	/* O_NONBLOCK case */
1791 	if (!waitok) {
1792 		error = _mqueue_recv(mq, &msg, -1);
1793 		if (error)
1794 			return (error);
1795 		goto received;
1796 	}
1797 
1798 	/* we allow a null timeout (wait forever). */
1799 	if (abs_timeout == NULL) {
1800 		error = _mqueue_recv(mq, &msg, 0);
1801 		if (error)
1802 			return (error);
1803 		goto received;
1804 	}
1805 
1806 	/* try to get a message before checking time */
1807 	error = _mqueue_recv(mq, &msg, -1);
1808 	if (error == 0)
1809 		goto received;
1810 
1811 	if (error != EAGAIN)
1812 		return (error);
1813 
1814 	if (abs_timeout->tv_nsec >= 1000000000 || abs_timeout->tv_nsec < 0) {
1815 		error = EINVAL;
1816 		return (error);
1817 	}
1818 
1819 	for (;;) {
1820 		ts2 = *abs_timeout;
1821 		getnanotime(&ts);
1822 		timespecsub(&ts2, &ts);
1823 		if (ts2.tv_sec < 0 || (ts2.tv_sec == 0 && ts2.tv_nsec <= 0)) {
1824 			error = ETIMEDOUT;
1825 			return (error);
1826 		}
1827 		TIMESPEC_TO_TIMEVAL(&tv, &ts2);
1828 		error = _mqueue_recv(mq, &msg, tvtohz(&tv));
1829 		if (error == 0)
1830 			break;
1831 		if (error != ETIMEDOUT)
1832 			return (error);
1833 	}
1834 
1835 received:
1836 	error = mqueue_savemsg(msg, msg_ptr, msg_prio);
1837 	if (error == 0) {
1838 		curthread->td_retval[0] = msg->msg_size;
1839 		curthread->td_retval[1] = 0;
1840 	}
1841 	mqueue_freemsg(msg);
1842 	return (error);
1843 }
1844 
1845 /*
1846  * Common routine to receive a message
1847  */
1848 static int
1849 _mqueue_recv(struct mqueue *mq, struct mqueue_msg **msg, int timo)
1850 {
1851 	int error = 0;
1852 
1853 	mtx_lock(&mq->mq_mutex);
1854 	while ((*msg = TAILQ_FIRST(&mq->mq_msgq)) == NULL && error == 0) {
1855 		if (timo < 0) {
1856 			mtx_unlock(&mq->mq_mutex);
1857 			return (EAGAIN);
1858 		}
1859 		mq->mq_receivers++;
1860 		error = msleep(&mq->mq_receivers, &mq->mq_mutex,
1861 			    PCATCH, "mqrecv", timo);
1862 		mq->mq_receivers--;
1863 		if (error == EAGAIN)
1864 			error = ETIMEDOUT;
1865 	}
1866 	if (*msg != NULL) {
1867 		error = 0;
1868 		TAILQ_REMOVE(&mq->mq_msgq, *msg, msg_link);
1869 		mq->mq_curmsgs--;
1870 		mq->mq_totalbytes -= (*msg)->msg_size;
1871 		if (mq->mq_senders)
1872 			wakeup_one(&mq->mq_senders);
1873 		if (mq->mq_flags & MQ_WSEL) {
1874 			mq->mq_flags &= ~MQ_WSEL;
1875 			selwakeup(&mq->mq_wsel);
1876 		}
1877 		KNOTE_LOCKED(&mq->mq_wsel.si_note, 0);
1878 	}
1879 	if (mq->mq_notifier != NULL && mq->mq_receivers == 0 &&
1880 	    !TAILQ_EMPTY(&mq->mq_msgq)) {
1881 		mqueue_send_notification(mq);
1882 	}
1883 	mtx_unlock(&mq->mq_mutex);
1884 	return (error);
1885 }
1886 
1887 static __inline struct mqueue_notifier *
1888 notifier_alloc(void)
1889 {
1890 	return (uma_zalloc(mqnoti_zone, M_WAITOK | M_ZERO));
1891 }
1892 
1893 static __inline void
1894 notifier_free(struct mqueue_notifier *p)
1895 {
1896 	uma_zfree(mqnoti_zone, p);
1897 }
1898 
1899 static struct mqueue_notifier *
1900 notifier_search(struct proc *p, int fd)
1901 {
1902 	struct mqueue_notifier *nt;
1903 
1904 	LIST_FOREACH(nt, &p->p_mqnotifier, nt_link) {
1905 		if (nt->nt_ksi.ksi_mqd == fd)
1906 			break;
1907 	}
1908 	return (nt);
1909 }
1910 
1911 static __inline void
1912 notifier_insert(struct proc *p, struct mqueue_notifier *nt)
1913 {
1914 	LIST_INSERT_HEAD(&p->p_mqnotifier, nt, nt_link);
1915 }
1916 
1917 static __inline void
1918 notifier_delete(struct proc *p, struct mqueue_notifier *nt)
1919 {
1920 	LIST_REMOVE(nt, nt_link);
1921 	notifier_free(nt);
1922 }
1923 
1924 static void
1925 notifier_remove(struct proc *p, struct mqueue *mq, int fd)
1926 {
1927 	struct mqueue_notifier *nt;
1928 
1929 	mtx_assert(&mq->mq_mutex, MA_OWNED);
1930 	PROC_LOCK(p);
1931 	nt = notifier_search(p, fd);
1932 	if (nt != NULL) {
1933 		if (mq->mq_notifier == nt)
1934 			mq->mq_notifier = NULL;
1935 		sigqueue_take(&nt->nt_ksi);
1936 		notifier_delete(p, nt);
1937 	}
1938 	PROC_UNLOCK(p);
1939 }
1940 
1941 static int
1942 kern_kmq_open(struct thread *td, const char *upath, int flags, mode_t mode,
1943     const struct mq_attr *attr)
1944 {
1945 	char path[MQFS_NAMELEN + 1];
1946 	struct mqfs_node *pn;
1947 	struct filedesc *fdp;
1948 	struct file *fp;
1949 	struct mqueue *mq;
1950 	int fd, error, len, cmode;
1951 
1952 	fdp = td->td_proc->p_fd;
1953 	cmode = (((mode & ~fdp->fd_cmask) & ALLPERMS) & ~S_ISTXT);
1954 	mq = NULL;
1955 	if ((flags & O_CREAT) != 0 && attr != NULL) {
1956 		if (attr->mq_maxmsg <= 0 || attr->mq_maxmsg > maxmsg)
1957 			return (EINVAL);
1958 		if (attr->mq_msgsize <= 0 || attr->mq_msgsize > maxmsgsize)
1959 			return (EINVAL);
1960 	}
1961 
1962 	error = copyinstr(upath, path, MQFS_NAMELEN + 1, NULL);
1963         if (error)
1964 		return (error);
1965 
1966 	/*
1967 	 * The first character of name must be a slash  (/) character
1968 	 * and the remaining characters of name cannot include any slash
1969 	 * characters.
1970 	 */
1971 	len = strlen(path);
1972 	if (len < 2  || path[0] != '/' || index(path + 1, '/') != NULL)
1973 		return (EINVAL);
1974 
1975 	error = falloc(td, &fp, &fd);
1976 	if (error)
1977 		return (error);
1978 
1979 	sx_xlock(&mqfs_data.mi_lock);
1980 	pn = mqfs_search(mqfs_data.mi_root, path + 1, len - 1);
1981 	if (pn == NULL) {
1982 		if (!(flags & O_CREAT)) {
1983 			error = ENOENT;
1984 		} else {
1985 			mq = mqueue_alloc(attr);
1986 			if (mq == NULL) {
1987 				error = ENFILE;
1988 			} else {
1989 				pn = mqfs_create_file(mqfs_data.mi_root,
1990 				         path + 1, len - 1, td->td_ucred,
1991 					 cmode);
1992 				if (pn == NULL) {
1993 					error = ENOSPC;
1994 					mqueue_free(mq);
1995 				}
1996 			}
1997 		}
1998 
1999 		if (error == 0) {
2000 			pn->mn_data = mq;
2001 		}
2002 	} else {
2003 		if ((flags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL)) {
2004 			error = EEXIST;
2005 		} else {
2006 			accmode_t accmode = 0;
2007 
2008 			if (flags & FREAD)
2009 				accmode |= VREAD;
2010 			if (flags & FWRITE)
2011 				accmode |= VWRITE;
2012 			error = vaccess(VREG, pn->mn_mode, pn->mn_uid,
2013 				    pn->mn_gid, accmode, td->td_ucred, NULL);
2014 		}
2015 	}
2016 
2017 	if (error) {
2018 		sx_xunlock(&mqfs_data.mi_lock);
2019 		fdclose(fdp, fp, fd, td);
2020 		fdrop(fp, td);
2021 		return (error);
2022 	}
2023 
2024 	mqnode_addref(pn);
2025 	sx_xunlock(&mqfs_data.mi_lock);
2026 
2027 	finit(fp, flags & (FREAD | FWRITE | O_NONBLOCK), DTYPE_MQUEUE, pn,
2028 	    &mqueueops);
2029 
2030 	FILEDESC_XLOCK(fdp);
2031 	if (fdp->fd_ofiles[fd] == fp)
2032 		fdp->fd_ofileflags[fd] |= UF_EXCLOSE;
2033 	FILEDESC_XUNLOCK(fdp);
2034 	td->td_retval[0] = fd;
2035 	fdrop(fp, td);
2036 	return (0);
2037 }
2038 
2039 /*
2040  * Syscall to open a message queue.
2041  */
2042 int
2043 kmq_open(struct thread *td, struct kmq_open_args *uap)
2044 {
2045 	struct mq_attr attr;
2046 	int flags, error;
2047 
2048 	if ((uap->flags & O_ACCMODE) == O_ACCMODE)
2049 		return (EINVAL);
2050 	flags = FFLAGS(uap->flags);
2051 	if ((flags & O_CREAT) != 0 && uap->attr != NULL) {
2052 		error = copyin(uap->attr, &attr, sizeof(attr));
2053 		if (error)
2054 			return (error);
2055 	}
2056 	return (kern_kmq_open(td, uap->path, flags, uap->mode,
2057 	    uap->attr != NULL ? &attr : NULL));
2058 }
2059 
2060 /*
2061  * Syscall to unlink a message queue.
2062  */
2063 int
2064 kmq_unlink(struct thread *td, struct kmq_unlink_args *uap)
2065 {
2066 	char path[MQFS_NAMELEN+1];
2067 	struct mqfs_node *pn;
2068 	int error, len;
2069 
2070 	error = copyinstr(uap->path, path, MQFS_NAMELEN + 1, NULL);
2071         if (error)
2072 		return (error);
2073 
2074 	len = strlen(path);
2075 	if (len < 2  || path[0] != '/' || index(path + 1, '/') != NULL)
2076 		return (EINVAL);
2077 
2078 	sx_xlock(&mqfs_data.mi_lock);
2079 	pn = mqfs_search(mqfs_data.mi_root, path + 1, len - 1);
2080 	if (pn != NULL)
2081 		error = do_unlink(pn, td->td_ucred);
2082 	else
2083 		error = ENOENT;
2084 	sx_xunlock(&mqfs_data.mi_lock);
2085 	return (error);
2086 }
2087 
2088 typedef int (*_fgetf)(struct thread *, int, struct file **);
2089 
2090 /*
2091  * Get message queue by giving file slot
2092  */
2093 static int
2094 _getmq(struct thread *td, int fd, _fgetf func,
2095        struct file **fpp, struct mqfs_node **ppn, struct mqueue **pmq)
2096 {
2097 	struct mqfs_node *pn;
2098 	int error;
2099 
2100 	error = func(td, fd, fpp);
2101 	if (error)
2102 		return (error);
2103 	if (&mqueueops != (*fpp)->f_ops) {
2104 		fdrop(*fpp, td);
2105 		return (EBADF);
2106 	}
2107 	pn = (*fpp)->f_data;
2108 	if (ppn)
2109 		*ppn = pn;
2110 	if (pmq)
2111 		*pmq = pn->mn_data;
2112 	return (0);
2113 }
2114 
2115 static __inline int
2116 getmq(struct thread *td, int fd, struct file **fpp, struct mqfs_node **ppn,
2117 	struct mqueue **pmq)
2118 {
2119 	return _getmq(td, fd, fget, fpp, ppn, pmq);
2120 }
2121 
2122 static __inline int
2123 getmq_read(struct thread *td, int fd, struct file **fpp,
2124 	 struct mqfs_node **ppn, struct mqueue **pmq)
2125 {
2126 	return _getmq(td, fd, fget_read, fpp, ppn, pmq);
2127 }
2128 
2129 static __inline int
2130 getmq_write(struct thread *td, int fd, struct file **fpp,
2131 	struct mqfs_node **ppn, struct mqueue **pmq)
2132 {
2133 	return _getmq(td, fd, fget_write, fpp, ppn, pmq);
2134 }
2135 
2136 static int
2137 kern_kmq_setattr(struct thread *td, int mqd, const struct mq_attr *attr,
2138     struct mq_attr *oattr)
2139 {
2140 	struct mqueue *mq;
2141 	struct file *fp;
2142 	u_int oflag, flag;
2143 	int error;
2144 
2145 	if (attr != NULL && (attr->mq_flags & ~O_NONBLOCK) != 0)
2146 		return (EINVAL);
2147 	error = getmq(td, mqd, &fp, NULL, &mq);
2148 	if (error)
2149 		return (error);
2150 	oattr->mq_maxmsg  = mq->mq_maxmsg;
2151 	oattr->mq_msgsize = mq->mq_msgsize;
2152 	oattr->mq_curmsgs = mq->mq_curmsgs;
2153 	if (attr != NULL) {
2154 		do {
2155 			oflag = flag = fp->f_flag;
2156 			flag &= ~O_NONBLOCK;
2157 			flag |= (attr->mq_flags & O_NONBLOCK);
2158 		} while (atomic_cmpset_int(&fp->f_flag, oflag, flag) == 0);
2159 	} else
2160 		oflag = fp->f_flag;
2161 	oattr->mq_flags = (O_NONBLOCK & oflag);
2162 	fdrop(fp, td);
2163 	return (error);
2164 }
2165 
2166 int
2167 kmq_setattr(struct thread *td, struct kmq_setattr_args *uap)
2168 {
2169 	struct mq_attr attr, oattr;
2170 	int error;
2171 
2172 	if (uap->attr != NULL) {
2173 		error = copyin(uap->attr, &attr, sizeof(attr));
2174 		if (error != 0)
2175 			return (error);
2176 	}
2177 	error = kern_kmq_setattr(td, uap->mqd, uap->attr != NULL ? &attr : NULL,
2178 	    &oattr);
2179 	if (error != 0)
2180 		return (error);
2181 	if (uap->oattr != NULL)
2182 		error = copyout(&oattr, uap->oattr, sizeof(oattr));
2183 	return (error);
2184 }
2185 
2186 int
2187 kmq_timedreceive(struct thread *td, struct kmq_timedreceive_args *uap)
2188 {
2189 	struct mqueue *mq;
2190 	struct file *fp;
2191 	struct timespec *abs_timeout, ets;
2192 	int error;
2193 	int waitok;
2194 
2195 	error = getmq_read(td, uap->mqd, &fp, NULL, &mq);
2196 	if (error)
2197 		return (error);
2198 	if (uap->abs_timeout != NULL) {
2199 		error = copyin(uap->abs_timeout, &ets, sizeof(ets));
2200 		if (error != 0)
2201 			return (error);
2202 		abs_timeout = &ets;
2203 	} else
2204 		abs_timeout = NULL;
2205 	waitok = !(fp->f_flag & O_NONBLOCK);
2206 	error = mqueue_receive(mq, uap->msg_ptr, uap->msg_len,
2207 		uap->msg_prio, waitok, abs_timeout);
2208 	fdrop(fp, td);
2209 	return (error);
2210 }
2211 
2212 int
2213 kmq_timedsend(struct thread *td, struct kmq_timedsend_args *uap)
2214 {
2215 	struct mqueue *mq;
2216 	struct file *fp;
2217 	struct timespec *abs_timeout, ets;
2218 	int error, waitok;
2219 
2220 	error = getmq_write(td, uap->mqd, &fp, NULL, &mq);
2221 	if (error)
2222 		return (error);
2223 	if (uap->abs_timeout != NULL) {
2224 		error = copyin(uap->abs_timeout, &ets, sizeof(ets));
2225 		if (error != 0)
2226 			return (error);
2227 		abs_timeout = &ets;
2228 	} else
2229 		abs_timeout = NULL;
2230 	waitok = !(fp->f_flag & O_NONBLOCK);
2231 	error = mqueue_send(mq, uap->msg_ptr, uap->msg_len,
2232 		uap->msg_prio, waitok, abs_timeout);
2233 	fdrop(fp, td);
2234 	return (error);
2235 }
2236 
2237 int
2238 kmq_notify(struct thread *td, struct kmq_notify_args *uap)
2239 {
2240 	struct sigevent ev;
2241 	struct filedesc *fdp;
2242 	struct proc *p;
2243 	struct mqueue *mq;
2244 	struct file *fp;
2245 	struct mqueue_notifier *nt, *newnt = NULL;
2246 	int error;
2247 
2248 	p = td->td_proc;
2249 	fdp = td->td_proc->p_fd;
2250 	if (uap->sigev) {
2251 		error = copyin(uap->sigev, &ev, sizeof(ev));
2252 		if (error)
2253 			return (error);
2254 		if (ev.sigev_notify != SIGEV_SIGNAL &&
2255 		    ev.sigev_notify != SIGEV_THREAD_ID &&
2256 		    ev.sigev_notify != SIGEV_NONE)
2257 			return (EINVAL);
2258 		if ((ev.sigev_notify == SIGEV_SIGNAL ||
2259 		     ev.sigev_notify == SIGEV_THREAD_ID) &&
2260 			!_SIG_VALID(ev.sigev_signo))
2261 			return (EINVAL);
2262 	}
2263 	error = getmq(td, uap->mqd, &fp, NULL, &mq);
2264 	if (error)
2265 		return (error);
2266 again:
2267 	FILEDESC_SLOCK(fdp);
2268 	if (fget_locked(fdp, uap->mqd) != fp) {
2269 		FILEDESC_SUNLOCK(fdp);
2270 		error = EBADF;
2271 		goto out;
2272 	}
2273 	mtx_lock(&mq->mq_mutex);
2274 	FILEDESC_SUNLOCK(fdp);
2275 	if (uap->sigev != NULL) {
2276 		if (mq->mq_notifier != NULL) {
2277 			error = EBUSY;
2278 		} else {
2279 			PROC_LOCK(p);
2280 			nt = notifier_search(p, uap->mqd);
2281 			if (nt == NULL) {
2282 				if (newnt == NULL) {
2283 					PROC_UNLOCK(p);
2284 					mtx_unlock(&mq->mq_mutex);
2285 					newnt = notifier_alloc();
2286 					goto again;
2287 				}
2288 			}
2289 
2290 			if (nt != NULL) {
2291 				sigqueue_take(&nt->nt_ksi);
2292 				if (newnt != NULL) {
2293 					notifier_free(newnt);
2294 					newnt = NULL;
2295 				}
2296 			} else {
2297 				nt = newnt;
2298 				newnt = NULL;
2299 				ksiginfo_init(&nt->nt_ksi);
2300 				nt->nt_ksi.ksi_flags |= KSI_INS | KSI_EXT;
2301 				nt->nt_ksi.ksi_code = SI_MESGQ;
2302 				nt->nt_proc = p;
2303 				nt->nt_ksi.ksi_mqd = uap->mqd;
2304 				notifier_insert(p, nt);
2305 			}
2306 			nt->nt_sigev = ev;
2307 			mq->mq_notifier = nt;
2308 			PROC_UNLOCK(p);
2309 			/*
2310 			 * if there is no receivers and message queue
2311 			 * is not empty, we should send notification
2312 			 * as soon as possible.
2313 			 */
2314 			if (mq->mq_receivers == 0 &&
2315 			    !TAILQ_EMPTY(&mq->mq_msgq))
2316 				mqueue_send_notification(mq);
2317 		}
2318 	} else {
2319 		notifier_remove(p, mq, uap->mqd);
2320 	}
2321 	mtx_unlock(&mq->mq_mutex);
2322 
2323 out:
2324 	fdrop(fp, td);
2325 	if (newnt != NULL)
2326 		notifier_free(newnt);
2327 	return (error);
2328 }
2329 
2330 static void
2331 mqueue_fdclose(struct thread *td, int fd, struct file *fp)
2332 {
2333 	struct filedesc *fdp;
2334 	struct mqueue *mq;
2335 
2336 	fdp = td->td_proc->p_fd;
2337 	FILEDESC_LOCK_ASSERT(fdp);
2338 
2339 	if (fp->f_ops == &mqueueops) {
2340 		mq = FPTOMQ(fp);
2341 		mtx_lock(&mq->mq_mutex);
2342 		notifier_remove(td->td_proc, mq, fd);
2343 
2344 		/* have to wakeup thread in same process */
2345 		if (mq->mq_flags & MQ_RSEL) {
2346 			mq->mq_flags &= ~MQ_RSEL;
2347 			selwakeup(&mq->mq_rsel);
2348 		}
2349 		if (mq->mq_flags & MQ_WSEL) {
2350 			mq->mq_flags &= ~MQ_WSEL;
2351 			selwakeup(&mq->mq_wsel);
2352 		}
2353 		mtx_unlock(&mq->mq_mutex);
2354 	}
2355 }
2356 
2357 static void
2358 mq_proc_exit(void *arg __unused, struct proc *p)
2359 {
2360 	struct filedesc *fdp;
2361 	struct file *fp;
2362 	struct mqueue *mq;
2363 	int i;
2364 
2365 	fdp = p->p_fd;
2366 	FILEDESC_SLOCK(fdp);
2367 	for (i = 0; i < fdp->fd_nfiles; ++i) {
2368 		fp = fget_locked(fdp, i);
2369 		if (fp != NULL && fp->f_ops == &mqueueops) {
2370 			mq = FPTOMQ(fp);
2371 			mtx_lock(&mq->mq_mutex);
2372 			notifier_remove(p, FPTOMQ(fp), i);
2373 			mtx_unlock(&mq->mq_mutex);
2374 		}
2375 	}
2376 	FILEDESC_SUNLOCK(fdp);
2377 	KASSERT(LIST_EMPTY(&p->p_mqnotifier), ("mq notifiers left"));
2378 }
2379 
2380 static int
2381 mqf_read(struct file *fp, struct uio *uio, struct ucred *active_cred,
2382 	int flags, struct thread *td)
2383 {
2384 	return (EOPNOTSUPP);
2385 }
2386 
2387 static int
2388 mqf_write(struct file *fp, struct uio *uio, struct ucred *active_cred,
2389 	int flags, struct thread *td)
2390 {
2391 	return (EOPNOTSUPP);
2392 }
2393 
2394 static int
2395 mqf_truncate(struct file *fp, off_t length, struct ucred *active_cred,
2396     struct thread *td)
2397 {
2398 
2399 	return (EINVAL);
2400 }
2401 
2402 static int
2403 mqf_ioctl(struct file *fp, u_long cmd, void *data,
2404 	struct ucred *active_cred, struct thread *td)
2405 {
2406 	return (ENOTTY);
2407 }
2408 
2409 static int
2410 mqf_poll(struct file *fp, int events, struct ucred *active_cred,
2411 	struct thread *td)
2412 {
2413 	struct mqueue *mq = FPTOMQ(fp);
2414 	int revents = 0;
2415 
2416 	mtx_lock(&mq->mq_mutex);
2417 	if (events & (POLLIN | POLLRDNORM)) {
2418 		if (mq->mq_curmsgs) {
2419 			revents |= events & (POLLIN | POLLRDNORM);
2420 		} else {
2421 			mq->mq_flags |= MQ_RSEL;
2422 			selrecord(td, &mq->mq_rsel);
2423  		}
2424 	}
2425 	if (events & POLLOUT) {
2426 		if (mq->mq_curmsgs < mq->mq_maxmsg)
2427 			revents |= POLLOUT;
2428 		else {
2429 			mq->mq_flags |= MQ_WSEL;
2430 			selrecord(td, &mq->mq_wsel);
2431 		}
2432 	}
2433 	mtx_unlock(&mq->mq_mutex);
2434 	return (revents);
2435 }
2436 
2437 static int
2438 mqf_close(struct file *fp, struct thread *td)
2439 {
2440 	struct mqfs_node *pn;
2441 
2442 	fp->f_ops = &badfileops;
2443 	pn = fp->f_data;
2444 	fp->f_data = NULL;
2445 	sx_xlock(&mqfs_data.mi_lock);
2446 	mqnode_release(pn);
2447 	sx_xunlock(&mqfs_data.mi_lock);
2448 	return (0);
2449 }
2450 
2451 static int
2452 mqf_stat(struct file *fp, struct stat *st, struct ucred *active_cred,
2453 	struct thread *td)
2454 {
2455 	struct mqfs_node *pn = fp->f_data;
2456 
2457 	bzero(st, sizeof *st);
2458 	st->st_atim = pn->mn_atime;
2459 	st->st_mtim = pn->mn_mtime;
2460 	st->st_ctim = pn->mn_ctime;
2461 	st->st_birthtim = pn->mn_birth;
2462 	st->st_uid = pn->mn_uid;
2463 	st->st_gid = pn->mn_gid;
2464 	st->st_mode = S_IFIFO | pn->mn_mode;
2465 	return (0);
2466 }
2467 
2468 static int
2469 mqf_kqfilter(struct file *fp, struct knote *kn)
2470 {
2471 	struct mqueue *mq = FPTOMQ(fp);
2472 	int error = 0;
2473 
2474 	if (kn->kn_filter == EVFILT_READ) {
2475 		kn->kn_fop = &mq_rfiltops;
2476 		knlist_add(&mq->mq_rsel.si_note, kn, 0);
2477 	} else if (kn->kn_filter == EVFILT_WRITE) {
2478 		kn->kn_fop = &mq_wfiltops;
2479 		knlist_add(&mq->mq_wsel.si_note, kn, 0);
2480 	} else
2481 		error = EINVAL;
2482 	return (error);
2483 }
2484 
2485 static void
2486 filt_mqdetach(struct knote *kn)
2487 {
2488 	struct mqueue *mq = FPTOMQ(kn->kn_fp);
2489 
2490 	if (kn->kn_filter == EVFILT_READ)
2491 		knlist_remove(&mq->mq_rsel.si_note, kn, 0);
2492 	else if (kn->kn_filter == EVFILT_WRITE)
2493 		knlist_remove(&mq->mq_wsel.si_note, kn, 0);
2494 	else
2495 		panic("filt_mqdetach");
2496 }
2497 
2498 static int
2499 filt_mqread(struct knote *kn, long hint)
2500 {
2501 	struct mqueue *mq = FPTOMQ(kn->kn_fp);
2502 
2503 	mtx_assert(&mq->mq_mutex, MA_OWNED);
2504 	return (mq->mq_curmsgs != 0);
2505 }
2506 
2507 static int
2508 filt_mqwrite(struct knote *kn, long hint)
2509 {
2510 	struct mqueue *mq = FPTOMQ(kn->kn_fp);
2511 
2512 	mtx_assert(&mq->mq_mutex, MA_OWNED);
2513 	return (mq->mq_curmsgs < mq->mq_maxmsg);
2514 }
2515 
2516 static struct fileops mqueueops = {
2517 	.fo_read		= mqf_read,
2518 	.fo_write		= mqf_write,
2519 	.fo_truncate		= mqf_truncate,
2520 	.fo_ioctl		= mqf_ioctl,
2521 	.fo_poll		= mqf_poll,
2522 	.fo_kqfilter		= mqf_kqfilter,
2523 	.fo_stat		= mqf_stat,
2524 	.fo_close		= mqf_close
2525 };
2526 
2527 static struct vop_vector mqfs_vnodeops = {
2528 	.vop_default 		= &default_vnodeops,
2529 	.vop_access		= mqfs_access,
2530 	.vop_cachedlookup	= mqfs_lookup,
2531 	.vop_lookup		= vfs_cache_lookup,
2532 	.vop_reclaim		= mqfs_reclaim,
2533 	.vop_create		= mqfs_create,
2534 	.vop_remove		= mqfs_remove,
2535 	.vop_inactive		= mqfs_inactive,
2536 	.vop_open		= mqfs_open,
2537 	.vop_close		= mqfs_close,
2538 	.vop_getattr		= mqfs_getattr,
2539 	.vop_setattr		= mqfs_setattr,
2540 	.vop_read		= mqfs_read,
2541 	.vop_write		= VOP_EOPNOTSUPP,
2542 	.vop_readdir		= mqfs_readdir,
2543 	.vop_mkdir		= VOP_EOPNOTSUPP,
2544 	.vop_rmdir		= VOP_EOPNOTSUPP
2545 };
2546 
2547 static struct vfsops mqfs_vfsops = {
2548 	.vfs_init 		= mqfs_init,
2549 	.vfs_uninit		= mqfs_uninit,
2550 	.vfs_mount		= mqfs_mount,
2551 	.vfs_unmount		= mqfs_unmount,
2552 	.vfs_root		= mqfs_root,
2553 	.vfs_statfs		= mqfs_statfs,
2554 };
2555 
2556 static struct vfsconf mqueuefs_vfsconf = {
2557 	.vfc_version = VFS_VERSION,
2558 	.vfc_name = "mqueuefs",
2559 	.vfc_vfsops = &mqfs_vfsops,
2560 	.vfc_typenum = -1,
2561 	.vfc_flags = VFCF_SYNTHETIC
2562 };
2563 
2564 static struct syscall_helper_data mq_syscalls[] = {
2565 	SYSCALL_INIT_HELPER(kmq_open),
2566 	SYSCALL_INIT_HELPER(kmq_setattr),
2567 	SYSCALL_INIT_HELPER(kmq_timedsend),
2568 	SYSCALL_INIT_HELPER(kmq_timedreceive),
2569 	SYSCALL_INIT_HELPER(kmq_notify),
2570 	SYSCALL_INIT_HELPER(kmq_unlink),
2571 	SYSCALL_INIT_LAST
2572 };
2573 
2574 #ifdef COMPAT_FREEBSD32
2575 #include <compat/freebsd32/freebsd32.h>
2576 #include <compat/freebsd32/freebsd32_proto.h>
2577 #include <compat/freebsd32/freebsd32_syscall.h>
2578 #include <compat/freebsd32/freebsd32_util.h>
2579 
2580 static void
2581 mq_attr_from32(const struct mq_attr32 *from, struct mq_attr *to)
2582 {
2583 
2584 	to->mq_flags = from->mq_flags;
2585 	to->mq_maxmsg = from->mq_maxmsg;
2586 	to->mq_msgsize = from->mq_msgsize;
2587 	to->mq_curmsgs = from->mq_curmsgs;
2588 }
2589 
2590 static void
2591 mq_attr_to32(const struct mq_attr *from, struct mq_attr32 *to)
2592 {
2593 
2594 	to->mq_flags = from->mq_flags;
2595 	to->mq_maxmsg = from->mq_maxmsg;
2596 	to->mq_msgsize = from->mq_msgsize;
2597 	to->mq_curmsgs = from->mq_curmsgs;
2598 }
2599 
2600 int
2601 freebsd32_kmq_open(struct thread *td, struct freebsd32_kmq_open_args *uap)
2602 {
2603 	struct mq_attr attr;
2604 	struct mq_attr32 attr32;
2605 	int flags, error;
2606 
2607 	if ((uap->flags & O_ACCMODE) == O_ACCMODE)
2608 		return (EINVAL);
2609 	flags = FFLAGS(uap->flags);
2610 	if ((flags & O_CREAT) != 0 && uap->attr != NULL) {
2611 		error = copyin(uap->attr, &attr32, sizeof(attr32));
2612 		if (error)
2613 			return (error);
2614 		mq_attr_from32(&attr32, &attr);
2615 	}
2616 	return (kern_kmq_open(td, uap->path, flags, uap->mode,
2617 	    uap->attr != NULL ? &attr : NULL));
2618 }
2619 
2620 int
2621 freebsd32_kmq_setattr(struct thread *td, struct freebsd32_kmq_setattr_args *uap)
2622 {
2623 	struct mq_attr attr, oattr;
2624 	struct mq_attr32 attr32, oattr32;
2625 	int error;
2626 
2627 	if (uap->attr != NULL) {
2628 		error = copyin(uap->attr, &attr32, sizeof(attr32));
2629 		if (error != 0)
2630 			return (error);
2631 		mq_attr_from32(&attr32, &attr);
2632 	}
2633 	error = kern_kmq_setattr(td, uap->mqd, uap->attr != NULL ? &attr : NULL,
2634 	    &oattr);
2635 	if (error != 0)
2636 		return (error);
2637 	if (uap->oattr != NULL) {
2638 		mq_attr_to32(&oattr, &oattr32);
2639 		error = copyout(&oattr32, uap->oattr, sizeof(oattr32));
2640 	}
2641 	return (error);
2642 }
2643 
2644 int
2645 freebsd32_kmq_timedsend(struct thread *td,
2646     struct freebsd32_kmq_timedsend_args *uap)
2647 {
2648 	struct mqueue *mq;
2649 	struct file *fp;
2650 	struct timespec32 ets32;
2651 	struct timespec *abs_timeout, ets;
2652 	int error;
2653 	int waitok;
2654 
2655 	error = getmq_read(td, uap->mqd, &fp, NULL, &mq);
2656 	if (error)
2657 		return (error);
2658 	if (uap->abs_timeout != NULL) {
2659 		error = copyin(uap->abs_timeout, &ets32, sizeof(ets32));
2660 		if (error != 0)
2661 			return (error);
2662 		CP(ets32, ets, tv_sec);
2663 		CP(ets32, ets, tv_nsec);
2664 		abs_timeout = &ets;
2665 	} else
2666 		abs_timeout = NULL;
2667 	waitok = !(fp->f_flag & O_NONBLOCK);
2668 	error = mqueue_send(mq, uap->msg_ptr, uap->msg_len,
2669 		uap->msg_prio, waitok, abs_timeout);
2670 	fdrop(fp, td);
2671 	return (error);
2672 }
2673 
2674 int
2675 freebsd32_kmq_timedreceive(struct thread *td,
2676     struct freebsd32_kmq_timedreceive_args *uap)
2677 {
2678 	struct mqueue *mq;
2679 	struct file *fp;
2680 	struct timespec32 ets32;
2681 	struct timespec *abs_timeout, ets;
2682 	int error, waitok;
2683 
2684 	error = getmq_write(td, uap->mqd, &fp, NULL, &mq);
2685 	if (error)
2686 		return (error);
2687 	if (uap->abs_timeout != NULL) {
2688 		error = copyin(uap->abs_timeout, &ets32, sizeof(ets32));
2689 		if (error != 0)
2690 			return (error);
2691 		CP(ets32, ets, tv_sec);
2692 		CP(ets32, ets, tv_nsec);
2693 		abs_timeout = &ets;
2694 	} else
2695 		abs_timeout = NULL;
2696 	waitok = !(fp->f_flag & O_NONBLOCK);
2697 	error = mqueue_receive(mq, uap->msg_ptr, uap->msg_len,
2698 		uap->msg_prio, waitok, abs_timeout);
2699 	fdrop(fp, td);
2700 	return (error);
2701 }
2702 
2703 static struct syscall_helper_data mq32_syscalls[] = {
2704 	SYSCALL32_INIT_HELPER(freebsd32_kmq_open),
2705 	SYSCALL32_INIT_HELPER(freebsd32_kmq_setattr),
2706 	SYSCALL32_INIT_HELPER(freebsd32_kmq_timedsend),
2707 	SYSCALL32_INIT_HELPER(freebsd32_kmq_timedreceive),
2708 	SYSCALL32_INIT_HELPER(kmq_notify),
2709 	SYSCALL32_INIT_HELPER(kmq_unlink),
2710 	SYSCALL_INIT_LAST
2711 };
2712 #endif
2713 
2714 static int
2715 mqinit(void)
2716 {
2717 	int error;
2718 
2719 	error = syscall_helper_register(mq_syscalls);
2720 	if (error != 0)
2721 		return (error);
2722 #ifdef COMPAT_FREEBSD32
2723 	error = syscall32_helper_register(mq32_syscalls);
2724 	if (error != 0)
2725 		return (error);
2726 #endif
2727 	return (0);
2728 }
2729 
2730 static int
2731 mqunload(void)
2732 {
2733 
2734 #ifdef COMPAT_FREEBSD32
2735 	syscall32_helper_unregister(mq32_syscalls);
2736 #endif
2737 	syscall_helper_unregister(mq_syscalls);
2738 	return (0);
2739 }
2740 
2741 static int
2742 mq_modload(struct module *module, int cmd, void *arg)
2743 {
2744 	int error = 0;
2745 
2746 	error = vfs_modevent(module, cmd, arg);
2747 	if (error != 0)
2748 		return (error);
2749 
2750 	switch (cmd) {
2751 	case MOD_LOAD:
2752 		error = mqinit();
2753 		if (error != 0)
2754 			mqunload();
2755 		break;
2756 	case MOD_UNLOAD:
2757 		error = mqunload();
2758 		break;
2759 	default:
2760 		break;
2761 	}
2762 	return (error);
2763 }
2764 
2765 static moduledata_t mqueuefs_mod = {
2766 	"mqueuefs",
2767 	mq_modload,
2768 	&mqueuefs_vfsconf
2769 };
2770 DECLARE_MODULE(mqueuefs, mqueuefs_mod, SI_SUB_VFS, SI_ORDER_MIDDLE);
2771 MODULE_VERSION(mqueuefs, 1);
2772