uipc_mqueue.c revision 152948
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: head/sys/kern/uipc_mqueue.c 152948 2005-11-30 05:12:03Z davidxu $");
47
48#include <sys/param.h>
49#include <sys/kernel.h>
50#include <sys/systm.h>
51#include <sys/limits.h>
52#include <sys/buf.h>
53#include <sys/dirent.h>
54#include <sys/event.h>
55#include <sys/eventhandler.h>
56#include <sys/fcntl.h>
57#include <sys/filedesc.h>
58#include <sys/file.h>
59#include <sys/limits.h>
60#include <sys/lock.h>
61#include <sys/malloc.h>
62#include <sys/module.h>
63#include <sys/mount.h>
64#include <sys/mqueue.h>
65#include <sys/mutex.h>
66#include <sys/namei.h>
67#include <sys/poll.h>
68#include <sys/proc.h>
69#include <sys/queue.h>
70#include <sys/sysproto.h>
71#include <sys/stat.h>
72#include <sys/sysent.h>
73#include <sys/syscall.h>
74#include <sys/syscallsubr.h>
75#include <sys/sx.h>
76#include <sys/sysctl.h>
77#include <sys/sysctl.h>
78#include <sys/vnode.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 */
92typedef 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
102struct mqfs_node;
103
104/*
105 * mqfs_info: describes a mqfs instance
106 */
107struct mqfs_info {
108	struct sx		mi_lock;
109	struct mqfs_node	*mi_root;
110	struct unrhdr		*mi_unrhdr;
111};
112
113struct 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 */
123struct 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	u_int32_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
150TAILQ_HEAD(msgq, mqueue_msg);
151
152struct mqueue;
153
154struct 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	int				nt_fd;
160};
161
162struct mqueue {
163	struct mtx	mq_mutex;
164	int		mq_flags;
165	long		mq_maxmsg;
166	long		mq_msgsize;
167	long		mq_curmsgs;
168	long		mq_totalbytes;
169	struct msgq	mq_msgq;
170	int		mq_receivers;
171	int		mq_senders;
172	struct selinfo	mq_rsel;
173	struct selinfo	mq_wsel;
174	struct mqueue_notifier	*mq_notifier;
175};
176
177#define	MQ_RSEL		0x01
178#define	MQ_WSEL		0x02
179
180struct mqueue_msg {
181	TAILQ_ENTRY(mqueue_msg)	msg_link;
182	unsigned int	msg_prio;
183	unsigned int	msg_size;
184	/* following real data... */
185};
186
187SYSCTL_NODE(_kern, OID_AUTO, mqueue, CTLFLAG_RW, 0,
188	"POSIX real time message queue");
189
190static int	default_maxmsg  = 10;
191static int	default_msgsize = 1024;
192
193static int	maxmsg = 20;
194SYSCTL_INT(_kern_mqueue, OID_AUTO, maxmsg, CTLFLAG_RW,
195    &maxmsg, 0, "Default maximum messages in queue");
196static int	maxmsgsize = 16384;
197SYSCTL_INT(_kern_mqueue, OID_AUTO, maxmsgsize, CTLFLAG_RW,
198    &maxmsgsize, 0, "Default maximum message size");
199static int	maxmq = 100;
200SYSCTL_INT(_kern_mqueue, OID_AUTO, maxmq, CTLFLAG_RW,
201    &maxmq, 0, "maximum message queues");
202static int	curmq = 0;
203SYSCTL_INT(_kern_mqueue, OID_AUTO, curmq, CTLFLAG_RW,
204    &curmq, 0, "current message queue number");
205static int	unloadable = 0;
206static MALLOC_DEFINE(M_MQUEUEDATA, "mqdata", "mqueue data");
207
208static eventhandler_tag exit_tag;
209
210/* Only one instance per-system */
211static struct mqfs_info		mqfs_data;
212static uma_zone_t		mqnode_zone;
213static uma_zone_t		mqueue_zone;
214static uma_zone_t		mvdata_zone;
215static uma_zone_t		mqnoti_zone;
216static struct vop_vector	mqfs_vnodeops;
217static struct fileops		mqueueops;
218
219/*
220 * Directory structure construction and manipulation
221 */
222#ifdef notyet
223static struct mqfs_node	*mqfs_create_dir(struct mqfs_node *parent,
224	const char *name, int namelen);
225#endif
226
227static struct mqfs_node	*mqfs_create_file(struct mqfs_node *parent,
228	const char *name, int namelen);
229struct mqfs_node	*mqfs_create_link(struct mqfs_node *parent,
230	const char *name, int namelen);
231static int	mqfs_destroy(struct mqfs_node *mn);
232static void	mqfs_fileno_alloc(struct mqfs_info *mi, struct mqfs_node *mn);
233static void	mqfs_fileno_free(struct mqfs_info *mi, struct mqfs_node *mn);
234static int	mqfs_allocv(struct mount *mp, struct vnode **vpp, struct mqfs_node *pn);
235
236/*
237 * Message queue construction and maniplation
238 */
239static struct mqueue	*mqueue_alloc(const struct mq_attr *attr);
240static void	mqueue_free(struct mqueue *mq);
241static int	mqueue_send(struct mqueue *mq, const char *msg_ptr,
242			size_t msg_len, unsigned msg_prio, int waitok,
243			const struct timespec *abs_timeout);
244static int	mqueue_receive(struct mqueue *mq, char *msg_ptr,
245			size_t msg_len, unsigned *msg_prio, int waitok,
246			const struct timespec *abs_timeout);
247static int	_mqueue_send(struct mqueue *mq, struct mqueue_msg *msg,
248			int timo);
249static int	_mqueue_recv(struct mqueue *mq, struct mqueue_msg **msg,
250			int timo);
251static void	mqueue_send_notification(struct mqueue *mq);
252static void	mqueue_fdclose(struct thread *td, int fd, struct file *fp);
253static void	mq_proc_exit(void *arg, struct proc *p);
254
255/*
256 * kqueue filters
257 */
258static void	filt_mqdetach(struct knote *kn);
259static int	filt_mqread(struct knote *kn, long hint);
260static int	filt_mqwrite(struct knote *kn, long hint);
261
262struct filterops mq_rfiltops =
263	{ 1, NULL, filt_mqdetach, filt_mqread };
264struct filterops mq_wfiltops =
265	{ 1, NULL, filt_mqdetach, filt_mqwrite };
266
267/*
268 * Initialize fileno bitmap
269 */
270static void
271mqfs_fileno_init(struct mqfs_info *mi)
272{
273	struct unrhdr *up;
274
275	up = new_unrhdr(1, INT_MAX, NULL);
276	mi->mi_unrhdr = up;
277}
278
279/*
280 * Tear down fileno bitmap
281 */
282static void
283mqfs_fileno_uninit(struct mqfs_info *mi)
284{
285	struct unrhdr *up;
286
287	up = mi->mi_unrhdr;
288	mi->mi_unrhdr = NULL;
289	delete_unrhdr(up);
290}
291
292/*
293 * Allocate a file number
294 */
295static void
296mqfs_fileno_alloc(struct mqfs_info *mi, struct mqfs_node *mn)
297{
298	/* make sure our parent has a file number */
299	if (mn->mn_parent && !mn->mn_parent->mn_fileno)
300		mqfs_fileno_alloc(mi, mn->mn_parent);
301
302	switch (mn->mn_type) {
303	case mqfstype_root:
304	case mqfstype_dir:
305	case mqfstype_file:
306	case mqfstype_symlink:
307		mn->mn_fileno = alloc_unr(mi->mi_unrhdr);
308		break;
309	case mqfstype_this:
310		KASSERT(mn->mn_parent != NULL,
311		    ("mqfstype_this node has no parent"));
312		mn->mn_fileno = mn->mn_parent->mn_fileno;
313		break;
314	case mqfstype_parent:
315		KASSERT(mn->mn_parent != NULL,
316		    ("mqfstype_parent node has no parent"));
317		if (mn->mn_parent == mi->mi_root) {
318			mn->mn_fileno = mn->mn_parent->mn_fileno;
319			break;
320		}
321		KASSERT(mn->mn_parent->mn_parent != NULL,
322		    ("mqfstype_parent node has no grandparent"));
323		mn->mn_fileno = mn->mn_parent->mn_parent->mn_fileno;
324		break;
325	default:
326		KASSERT(0,
327		    ("mqfs_fileno_alloc() called for unknown type node: %d",
328			mn->mn_type));
329		break;
330	}
331}
332
333/*
334 * Release a file number
335 */
336static void
337mqfs_fileno_free(struct mqfs_info *mi, struct mqfs_node *mn)
338{
339	switch (mn->mn_type) {
340	case mqfstype_root:
341	case mqfstype_dir:
342	case mqfstype_file:
343	case mqfstype_symlink:
344		free_unr(mi->mi_unrhdr, mn->mn_fileno);
345		break;
346	case mqfstype_this:
347	case mqfstype_parent:
348		/* ignore these, as they don't "own" their file number */
349		break;
350	default:
351		KASSERT(0,
352		    ("mqfs_fileno_free() called for unknown type node: %d",
353			mn->mn_type));
354		break;
355	}
356}
357
358static __inline struct mqfs_node *
359mqnode_alloc(void)
360{
361	return uma_zalloc(mqnode_zone, M_WAITOK | M_ZERO);
362}
363
364static __inline void
365mqnode_free(struct mqfs_node *node)
366{
367	uma_zfree(mqnode_zone, node);
368}
369
370static __inline void
371mqnode_addref(struct mqfs_node *node)
372{
373	atomic_fetchadd_int(&node->mn_refcount, 1);
374}
375
376static __inline void
377mqnode_release(struct mqfs_node *node)
378{
379	int old, exp;
380
381	old = atomic_fetchadd_int(&node->mn_refcount, -1);
382	if (node->mn_type == mqfstype_dir ||
383	    node->mn_type == mqfstype_root)
384		exp = 3; /* include . and .. */
385	else
386		exp = 1;
387	if (old == exp)
388		mqfs_destroy(node);
389}
390
391/*
392 * Add a node to a directory
393 */
394static int
395mqfs_add_node(struct mqfs_node *parent, struct mqfs_node *node)
396{
397	KASSERT(parent != NULL, ("%s(): parent is NULL", __func__));
398	KASSERT(parent->mn_info != NULL,
399	    ("%s(): parent has no mn_info", __func__));
400	KASSERT(parent->mn_type == mqfstype_dir ||
401	    parent->mn_type == mqfstype_root,
402	    ("%s(): parent is not a directory", __func__));
403
404	node->mn_info = parent->mn_info;
405	node->mn_parent = parent;
406	LIST_INIT(&node->mn_children);
407	LIST_INIT(&node->mn_vnodes);
408	LIST_INSERT_HEAD(&parent->mn_children, node, mn_sibling);
409	mqnode_addref(parent);
410	return (0);
411}
412
413/*
414 * Add . and .. to a directory
415 */
416static int
417mqfs_fixup_dir(struct mqfs_node *parent)
418{
419	struct mqfs_node *dir;
420
421	dir = mqnode_alloc();
422	dir->mn_name[0] = '.';
423	dir->mn_type = mqfstype_this;
424	dir->mn_refcount = 1;
425	if (mqfs_add_node(parent, dir) != 0) {
426		mqnode_free(dir);
427		return (-1);
428	}
429
430	dir = mqnode_alloc();
431	dir->mn_name[0] = dir->mn_name[1] = '.';
432	dir->mn_type = mqfstype_parent;
433	dir->mn_refcount = 1;
434
435	if (mqfs_add_node(parent, dir) != 0) {
436		mqnode_free(dir);
437		return (-1);
438	}
439
440	return (0);
441}
442
443#ifdef notyet
444
445/*
446 * Create a directory
447 */
448static struct mqfs_node *
449mqfs_create_dir(struct mqfs_node *parent, const char *name, int namelen)
450{
451	struct mqfs_node *dir;
452
453	dir = mqnode_alloc();
454	strncpy(dir->mn_name, name, namelen);
455	dir->mn_type = mqfstype_dir;
456	dir->mn_refcount = 1;
457	if (mqfs_add_node(parent, dir) != 0) {
458		mqnode_free(dir);
459		return (NULL);
460	}
461
462	if (mqfs_fixup_dir(dir) != 0) {
463		mqfs_destroy(dir);
464		return (NULL);
465	}
466
467	return (dir);
468}
469
470/*
471 * Create a symlink
472 */
473static struct mqfs_node *
474mqfs_create_link(struct mqfs_node *parent, const char *name, int namelen)
475{
476	struct mqfs_node *node;
477
478	node = mqfs_create_file(parent, name, namelen);
479	if (node == NULL)
480		return (NULL);
481	node->mn_type = mqfstype_symlink;
482	return (node);
483}
484
485#endif
486
487/*
488 * Create a file
489 */
490static struct mqfs_node *
491mqfs_create_file(struct mqfs_node *parent, const char *name, int namelen)
492{
493	struct mqfs_node *node;
494
495	node = mqnode_alloc();
496	strncpy(node->mn_name, name, namelen);
497	node->mn_type = mqfstype_file;
498	node->mn_refcount = 1;
499
500	if (mqfs_add_node(parent, node) != 0) {
501		mqnode_free(node);
502		return (NULL);
503	}
504	return (node);
505}
506
507/*
508 * Destroy a node or a tree of nodes
509 */
510static int
511mqfs_destroy(struct mqfs_node *node)
512{
513	struct mqfs_node *parent;
514
515	KASSERT(node != NULL,
516	    ("%s(): node is NULL", __func__));
517	KASSERT(node->mn_info != NULL,
518	    ("%s(): node has no mn_info", __func__));
519
520	/* destroy children */
521	if (node->mn_type == mqfstype_dir || node->mn_type == mqfstype_root)
522		while (! LIST_EMPTY(&node->mn_children))
523			mqfs_destroy(LIST_FIRST(&node->mn_children));
524
525	/* unlink from parent */
526	if ((parent = node->mn_parent) != NULL) {
527		KASSERT(parent->mn_info == node->mn_info,
528		    ("%s(): parent has different mn_info", __func__));
529		LIST_REMOVE(node, mn_sibling);
530	}
531
532	if (node->mn_fileno != 0)
533		mqfs_fileno_free(node->mn_info, node);
534	if (node->mn_data != NULL)
535		mqueue_free(node->mn_data);
536	mqnode_free(node);
537	return (0);
538}
539
540/*
541 * Mount a mqfs instance
542 */
543static int
544mqfs_mount(struct mount *mp, struct thread *td)
545{
546	struct statfs *sbp;
547
548	if (mp->mnt_flag & MNT_UPDATE)
549		return (EOPNOTSUPP);
550
551	mp->mnt_data = &mqfs_data;
552	mp->mnt_flag |= MNT_LOCAL;
553	/* mp->mnt_kern_flag |= MNTK_MPSAFE; */
554	vfs_getnewfsid(mp);
555
556	sbp = &mp->mnt_stat;
557	vfs_mountedfrom(mp, "mqueue");
558	sbp->f_bsize = PAGE_SIZE;
559	sbp->f_iosize = PAGE_SIZE;
560	sbp->f_blocks = 1;
561	sbp->f_bfree = 0;
562	sbp->f_bavail = 0;
563	sbp->f_files = 1;
564	sbp->f_ffree = 0;
565	return (0);
566}
567
568/*
569 * Unmount a mqfs instance
570 */
571static int
572mqfs_unmount(struct mount *mp, int mntflags, struct thread *td)
573{
574	int error;
575
576	error = vflush(mp, 0, (mntflags & MNT_FORCE) ?  FORCECLOSE : 0, td);
577	return (error);
578}
579
580/*
581 * Return a root vnode
582 */
583static int
584mqfs_root(struct mount *mp, int flags, struct vnode **vpp, struct thread *td)
585{
586	struct mqfs_info *mqfs;
587	int ret;
588
589	mqfs = VFSTOMQFS(mp);
590	sx_xlock(&mqfs->mi_lock);
591	ret = mqfs_allocv(mp, vpp, mqfs->mi_root);
592	sx_xunlock(&mqfs->mi_lock);
593	return (ret);
594}
595
596/*
597 * Return filesystem stats
598 */
599static int
600mqfs_statfs(struct mount *mp, struct statfs *sbp, struct thread *td)
601{
602	/* XXX update statistics */
603	return (0);
604}
605
606/*
607 * Initialize a mqfs instance
608 */
609static int
610mqfs_init(struct vfsconf *vfc)
611{
612	struct mqfs_node *root;
613	struct mqfs_info *mi;
614
615	mqnode_zone = uma_zcreate("mqnode", sizeof(struct mqfs_node),
616		NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
617	mqueue_zone = uma_zcreate("mqueue", sizeof(struct mqueue),
618		NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
619	mvdata_zone = uma_zcreate("mvdata",
620		sizeof(struct mqfs_vdata), NULL, NULL, NULL,
621		NULL, UMA_ALIGN_PTR, 0);
622	mqnoti_zone = uma_zcreate("mqnotifier", sizeof(struct mqueue_notifier),
623		NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
624	mi = &mqfs_data;
625	sx_init(&mi->mi_lock, "mqfs lock");
626	/* set up the root diretory */
627	root = mqnode_alloc();
628	root->mn_type = mqfstype_root;
629	root->mn_refcount = 1;
630	root->mn_name[0] = '/';
631	root->mn_info = mi;
632	LIST_INIT(&root->mn_children);
633	LIST_INIT(&root->mn_vnodes);
634	root->mn_mode = 01777;
635	mi->mi_root = root;
636	mqfs_fileno_init(mi);
637	mqfs_fileno_alloc(mi, root);
638	mqfs_fixup_dir(root);
639	exit_tag = EVENTHANDLER_REGISTER(process_exit, mq_proc_exit, NULL,
640	    EVENTHANDLER_PRI_ANY);
641	mq_fdclose = mqueue_fdclose;
642	return (0);
643}
644
645/*
646 * Destroy a mqfs instance
647 */
648static int
649mqfs_uninit(struct vfsconf *vfc)
650{
651	struct mqfs_info *mi;
652
653	if (!unloadable)
654		return (EOPNOTSUPP);
655	EVENTHANDLER_DEREGISTER(process_exit, exit_tag);
656	mi = &mqfs_data;
657	mqfs_destroy(mi->mi_root);
658	mi->mi_root = NULL;
659	mqfs_fileno_uninit(mi);
660	sx_destroy(&mi->mi_lock);
661	uma_zdestroy(mqnode_zone);
662	uma_zdestroy(mqueue_zone);
663	uma_zdestroy(mvdata_zone);
664	uma_zdestroy(mqnoti_zone);
665	return (0);
666}
667
668/*
669 * task routine
670 */
671static void
672do_recycle(void *context, int pending __unused)
673{
674	struct vnode *vp = (struct vnode *)context;
675
676	vrecycle(vp, curthread);
677	vdrop(vp);
678}
679
680/*
681 * Allocate a vnode
682 */
683static int
684mqfs_allocv(struct mount *mp, struct vnode **vpp, struct mqfs_node *pn)
685{
686	struct mqfs_vdata *vd;
687	int error;
688
689	LIST_FOREACH(vd, &pn->mn_vnodes, mv_link) {
690		if (vd->mv_vnode->v_mount == mp)
691			break;
692	}
693
694	if (vd != NULL) {
695		if (vget(vd->mv_vnode, 0, curthread) == 0) {
696			*vpp = vd->mv_vnode;
697			vn_lock(*vpp, LK_RETRY | LK_EXCLUSIVE,
698			    curthread);
699			return (0);
700		}
701		/* XXX if this can happen, we're in trouble */
702	}
703
704	error = getnewvnode("mqueue", mp, &mqfs_vnodeops, vpp);
705	if (error)
706		return (error);
707	vd = uma_zalloc(mvdata_zone, M_WAITOK);
708	(*vpp)->v_data = vd;
709	vd->mv_vnode = *vpp;
710	vd->mv_node = pn;
711	TASK_INIT(&vd->mv_task, 0, do_recycle, *vpp);
712	LIST_INSERT_HEAD(&pn->mn_vnodes, vd, mv_link);
713	mqnode_addref(pn);
714	switch (pn->mn_type) {
715	case mqfstype_root:
716		(*vpp)->v_vflag = VV_ROOT;
717		/* fall through */
718	case mqfstype_dir:
719	case mqfstype_this:
720	case mqfstype_parent:
721		(*vpp)->v_type = VDIR;
722		break;
723	case mqfstype_file:
724		(*vpp)->v_type = VREG;
725		break;
726	case mqfstype_symlink:
727		(*vpp)->v_type = VLNK;
728		break;
729	case mqfstype_none:
730		KASSERT(0, ("mqfs_allocf called for null node\n"));
731	default:
732		panic("%s has unexpected type: %d", pn->mn_name, pn->mn_type);
733	}
734	vn_lock(*vpp, LK_RETRY | LK_EXCLUSIVE, curthread);
735	return (0);
736}
737
738/*
739 * Search a directory entry
740 */
741static struct mqfs_node *
742mqfs_search(struct mqfs_node *pd, const char *name, int len)
743{
744	struct mqfs_node *pn;
745
746	LIST_FOREACH(pn, &pd->mn_children, mn_sibling) {
747		if (strncmp(pn->mn_name, name, len) == 0)
748			return (pn);
749	}
750	return (NULL);
751}
752
753/*
754 * Look up a file or directory
755 */
756static int
757mqfs_lookupx(struct vop_cachedlookup_args *ap)
758{
759	struct componentname *cnp;
760	struct vnode *dvp, **vpp;
761	struct mqfs_node *pd;
762	struct mqfs_node *pn;
763	int nameiop, flags, error, namelen;
764	char *pname;
765	struct thread *td;
766
767	cnp = ap->a_cnp;
768	vpp = ap->a_vpp;
769	dvp = ap->a_dvp;
770	pname = cnp->cn_nameptr;
771	namelen = cnp->cn_namelen;
772	td = cnp->cn_thread;
773	flags = cnp->cn_flags;
774	nameiop = cnp->cn_nameiop;
775	pd = VTON(dvp);
776	pn = NULL;
777	*vpp = NULLVP;
778
779	if (dvp->v_type != VDIR)
780		return (ENOTDIR);
781
782	error = VOP_ACCESS(dvp, VEXEC, cnp->cn_cred, cnp->cn_thread);
783	if (error)
784		return (error);
785
786	/* shortcut: check if the name is too long */
787	if (cnp->cn_namelen >= MQFS_NAMELEN)
788		return (ENOENT);
789
790	/* self */
791	if (namelen == 1 && pname[0] == '.') {
792		if ((flags & ISLASTCN) && nameiop != LOOKUP)
793			return (EINVAL);
794		pn = pd;
795		*vpp = dvp;
796		VREF(dvp);
797		return (0);
798	}
799
800	/* parent */
801	if (cnp->cn_flags & ISDOTDOT) {
802		if (dvp->v_vflag & VV_ROOT)
803			return (EIO);
804		if ((flags & ISLASTCN) && nameiop != LOOKUP)
805			return (EINVAL);
806		VOP_UNLOCK(dvp, 0, cnp->cn_thread);
807		KASSERT(pd->mn_parent, ("non-root directory has no parent"));
808		pn = pd->mn_parent;
809		error = mqfs_allocv(dvp->v_mount, vpp, pn);
810		vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY, td);
811		return (error);
812	}
813
814	/* named node */
815	pn = mqfs_search(pd, pname, namelen);
816
817	/* found */
818	if (pn != NULL) {
819		/* DELETE */
820		if (nameiop == DELETE && (flags & ISLASTCN)) {
821			error = VOP_ACCESS(dvp, VWRITE, cnp->cn_cred, td);
822			if (error)
823				return (error);
824			if (*vpp == dvp) {
825				VREF(dvp);
826				*vpp = dvp;
827				return (0);
828			}
829		}
830
831		/* allocate vnode */
832		error = mqfs_allocv(dvp->v_mount, vpp, pn);
833		if (error == 0 && cnp->cn_flags & MAKEENTRY)
834			cache_enter(dvp, *vpp, cnp);
835		return (error);
836	}
837
838	/* not found */
839
840	/* will create a new entry in the directory ? */
841	if ((nameiop == CREATE || nameiop == RENAME) && (flags & LOCKPARENT)
842	    && (flags & ISLASTCN)) {
843		error = VOP_ACCESS(dvp, VWRITE, cnp->cn_cred, td);
844		if (error)
845			return (error);
846		cnp->cn_flags |= SAVENAME;
847		return (EJUSTRETURN);
848	}
849	return (ENOENT);
850}
851
852#if 0
853struct vop_lookup_args {
854	struct vop_generic_args a_gen;
855	struct vnode *a_dvp;
856	struct vnode **a_vpp;
857	struct componentname *a_cnp;
858};
859#endif
860
861/*
862 * vnode lookup operation
863 */
864static int
865mqfs_lookup(struct vop_cachedlookup_args *ap)
866{
867	struct mqfs_info *mqfs = VFSTOMQFS(ap->a_dvp->v_mount);
868	int rc;
869
870	sx_xlock(&mqfs->mi_lock);
871	rc = mqfs_lookupx(ap);
872	sx_xunlock(&mqfs->mi_lock);
873	return (rc);
874}
875
876#if 0
877struct vop_create_args {
878	struct vnode *a_dvp;
879	struct vnode **a_vpp;
880	struct componentname *a_cnp;
881	struct vattr *a_vap;
882};
883#endif
884
885/*
886 * vnode creation operation
887 */
888static int
889mqfs_create(struct vop_create_args *ap)
890{
891	struct mqfs_info *mqfs = VFSTOMQFS(ap->a_dvp->v_mount);
892	struct componentname *cnp = ap->a_cnp;
893	struct mqfs_node *pd;
894	struct mqfs_node *pn;
895	struct mqueue *mq;
896	int error;
897
898	pd = VTON(ap->a_dvp);
899	if (pd->mn_type != mqfstype_root && pd->mn_type != mqfstype_dir)
900		return (ENOTDIR);
901	mq = mqueue_alloc(NULL);
902	if (mq == NULL)
903		return (EAGAIN);
904	sx_xlock(&mqfs->mi_lock);
905#if 0
906	/* named node */
907	pn = mqfs_search(pd, cnp->cn_nameptr, cnp->cn_namelen);
908	if (pn != NULL) {
909		mqueue_free(mq);
910		sx_xunlock(&mqfs->mi_lock);
911		return (EEXIST);
912	}
913#else
914	if ((cnp->cn_flags & HASBUF) == 0)
915		panic("%s: no name", __func__);
916#endif
917	pn = mqfs_create_file(pd, cnp->cn_nameptr, cnp->cn_namelen);
918	pn->mn_mode = ap->a_vap->va_mode;
919	pn->mn_uid = cnp->cn_cred->cr_uid;
920	pn->mn_gid = cnp->cn_cred->cr_gid;
921	pn->mn_data = mq;
922	getnanotime(&pn->mn_birth);
923	pn->mn_ctime = pn->mn_atime = pn->mn_mtime = pn->mn_birth;
924	/* node attribute */
925	error = mqfs_allocv(ap->a_dvp->v_mount, ap->a_vpp, pn);
926	sx_xunlock(&mqfs->mi_lock);
927	return (error);
928}
929
930/*
931 * Remove an entry
932 */
933static
934int do_unlink(struct mqfs_node *pn, struct ucred *ucred)
935{
936	struct mqfs_node *parent;
937	struct mqfs_vdata *vd;
938	int error = 0;
939
940	sx_assert(&pn->mn_info->mi_lock, SX_LOCKED);
941
942	if (ucred->cr_uid != pn->mn_uid &&
943	    (error = suser_cred(ucred, 0)) != 0)
944		error = EACCES;
945	else if (!pn->mn_deleted) {
946		parent = pn->mn_parent;
947		pn->mn_parent = NULL;
948		pn->mn_deleted = 1;
949		LIST_REMOVE(pn, mn_sibling);
950		LIST_FOREACH(vd, &pn->mn_vnodes, mv_link) {
951			cache_purge(vd->mv_vnode);
952			vhold(vd->mv_vnode);
953			taskqueue_enqueue(taskqueue_thread, &vd->mv_task);
954		}
955		mqnode_release(pn);
956		mqnode_release(parent);
957	} else
958		error = ENOENT;
959	return (error);
960}
961
962#if 0
963struct vop_remove_args {
964	struct vnode *a_dvp;
965	struct vnode *a_vp;
966	struct componentname *a_cnp;
967};
968#endif
969
970/*
971 * vnode removal operation
972 */
973static int
974mqfs_remove(struct vop_remove_args *ap)
975{
976	struct mqfs_info *mqfs = VFSTOMQFS(ap->a_dvp->v_mount);
977	struct mqfs_node *pn;
978	int error;
979
980	if (ap->a_vp->v_type == VDIR)
981                return (EPERM);
982	pn = VTON(ap->a_vp);
983	sx_xlock(&mqfs->mi_lock);
984	error = do_unlink(pn, ap->a_cnp->cn_cred);
985	sx_xunlock(&mqfs->mi_lock);
986	return (error);
987}
988
989#if 0
990struct vop_inactive_args {
991	struct vnode *a_vp;
992	struct thread *a_td;
993};
994#endif
995
996static int
997mqfs_inactive(struct vop_inactive_args *ap)
998{
999	struct mqfs_node *pn = VTON(ap->a_vp);
1000
1001	if (pn->mn_deleted)
1002		vrecycle(ap->a_vp, ap->a_td);
1003	return (0);
1004}
1005
1006#if 0
1007struct vop_reclaim_args {
1008	struct vop_generic_args a_gen;
1009	struct vnode *a_vp;
1010	struct thread *a_td;
1011};
1012#endif
1013
1014static int
1015mqfs_reclaim(struct vop_reclaim_args *ap)
1016{
1017	struct mqfs_info *mqfs = VFSTOMQFS(ap->a_vp->v_mount);
1018	struct vnode *vp = ap->a_vp;
1019	struct mqfs_node *pn;
1020	struct mqfs_vdata *vd;
1021
1022	vd = vp->v_data;
1023	pn = vd->mv_node;
1024	sx_xlock(&mqfs->mi_lock);
1025	vp->v_data = NULL;
1026	LIST_REMOVE(vd, mv_link);
1027	uma_zfree(mvdata_zone, vd);
1028	mqnode_release(pn);
1029	sx_xunlock(&mqfs->mi_lock);
1030	return (0);
1031}
1032
1033#if 0
1034struct vop_open_args {
1035	struct vop_generic_args a_gen;
1036	struct vnode *a_vp;
1037	int a_mode;
1038	struct ucred *a_cred;
1039	struct thread *a_td;
1040	int a_fdidx;
1041};
1042#endif
1043
1044static int
1045mqfs_open(struct vop_open_args *ap)
1046{
1047	return (0);
1048}
1049
1050#if 0
1051struct vop_close_args {
1052	struct vop_generic_args a_gen;
1053	struct vnode *a_vp;
1054	int a_fflag;
1055	struct ucred *a_cred;
1056	struct thread *a_td;
1057};
1058#endif
1059
1060static int
1061mqfs_close(struct vop_close_args *ap)
1062{
1063	return (0);
1064}
1065
1066#if 0
1067struct vop_access_args {
1068	struct vop_generic_args a_gen;
1069	struct vnode *a_vp;
1070	int a_mode;
1071	struct ucred *a_cred;
1072	struct thread *a_td;
1073};
1074#endif
1075
1076/*
1077 * Verify permissions
1078 */
1079static int
1080mqfs_access(struct vop_access_args *ap)
1081{
1082	struct vnode *vp = ap->a_vp;
1083	struct vattr vattr;
1084	int error;
1085
1086	error = VOP_GETATTR(vp, &vattr, ap->a_cred, ap->a_td);
1087	if (error)
1088		return (error);
1089	error = vaccess(vp->v_type, vattr.va_mode, vattr.va_uid,
1090	    vattr.va_gid, ap->a_mode, ap->a_cred, NULL);
1091	return (error);
1092}
1093
1094#if 0
1095struct vop_getattr_args {
1096	struct vop_generic_args a_gen;
1097	struct vnode *a_vp;
1098	struct vattr *a_vap;
1099	struct ucred *a_cred;
1100	struct thread *a_td;
1101};
1102#endif
1103
1104/*
1105 * Get file attributes
1106 */
1107static int
1108mqfs_getattr(struct vop_getattr_args *ap)
1109{
1110	struct vnode *vp = ap->a_vp;
1111	struct mqfs_node *pn = VTON(vp);
1112	struct vattr *vap = ap->a_vap;
1113	int error = 0;
1114
1115	VATTR_NULL(vap);
1116	vap->va_type = vp->v_type;
1117	vap->va_mode = pn->mn_mode;
1118	vap->va_nlink = 1;
1119	vap->va_uid = pn->mn_uid;
1120	vap->va_gid = pn->mn_gid;
1121	vap->va_fsid = vp->v_mount->mnt_stat.f_fsid.val[0];
1122	vap->va_fileid = pn->mn_fileno;
1123	vap->va_size = 0;
1124	vap->va_blocksize = PAGE_SIZE;
1125	vap->va_bytes = vap->va_size = 0;
1126	vap->va_atime = pn->mn_atime;
1127	vap->va_mtime = pn->mn_mtime;
1128	vap->va_ctime = pn->mn_ctime;
1129	vap->va_birthtime = pn->mn_birth;
1130	vap->va_gen = 0;
1131	vap->va_flags = 0;
1132	vap->va_rdev = 0;
1133	vap->va_bytes = 0;
1134	vap->va_filerev = 0;
1135	vap->va_vaflags = 0;
1136	return (error);
1137}
1138
1139#if 0
1140struct vop_setattr_args {
1141	struct vop_generic_args a_gen;
1142	struct vnode *a_vp;
1143	struct vattr *a_vap;
1144	struct ucred *a_cred;
1145	struct thread *a_td;
1146};
1147#endif
1148/*
1149 * Set attributes
1150 */
1151static int
1152mqfs_setattr(struct vop_setattr_args *ap)
1153{
1154	struct mqfs_node *pn;
1155	struct vattr *vap;
1156	struct vnode *vp;
1157	int c, error;
1158	uid_t uid;
1159	gid_t gid;
1160
1161	vap = ap->a_vap;
1162	vp = ap->a_vp;
1163	if ((vap->va_type != VNON) ||
1164	    (vap->va_nlink != VNOVAL) ||
1165	    (vap->va_fsid != VNOVAL) ||
1166	    (vap->va_fileid != VNOVAL) ||
1167	    (vap->va_blocksize != VNOVAL) ||
1168	    (vap->va_flags != VNOVAL && vap->va_flags != 0) ||
1169	    (vap->va_rdev != VNOVAL) ||
1170	    ((int)vap->va_bytes != VNOVAL) ||
1171	    (vap->va_gen != VNOVAL)) {
1172		return (EINVAL);
1173	}
1174
1175	pn = VTON(vp);
1176
1177	error = c = 0;
1178	if (vap->va_uid == (uid_t)VNOVAL)
1179		uid = pn->mn_uid;
1180	else
1181		uid = vap->va_uid;
1182	if (vap->va_gid == (gid_t)VNOVAL)
1183		gid = pn->mn_gid;
1184	else
1185		gid = vap->va_gid;
1186
1187	if (uid != pn->mn_uid || gid != pn->mn_gid) {
1188		/*
1189		 * To modify the ownership of a file, must possess VADMIN
1190		 * for that file.
1191		 */
1192		if ((error = VOP_ACCESS(vp, VADMIN, ap->a_cred, ap->a_td)))
1193			return (error);
1194		if (((ap->a_cred->cr_uid != pn->mn_uid) || uid != pn->mn_uid ||
1195		    (gid != pn->mn_gid && !groupmember(gid, ap->a_cred))) &&
1196		    (error = suser_cred(ap->a_td->td_ucred, SUSER_ALLOWJAIL))
1197                       != 0)
1198			return (error);
1199		pn->mn_uid = uid;
1200		pn->mn_gid = gid;
1201		c = 1;
1202	}
1203
1204	if (vap->va_mode != (mode_t)VNOVAL) {
1205		if ((ap->a_cred->cr_uid != pn->mn_uid) &&
1206		    (error = suser_cred(ap->a_td->td_ucred, SUSER_ALLOWJAIL)))
1207			return (error);
1208		pn->mn_mode = vap->va_mode;
1209		c = 1;
1210	}
1211
1212	if (vap->va_atime.tv_sec != VNOVAL || vap->va_mtime.tv_sec != VNOVAL) {
1213		/* See the comment in ufs_vnops::ufs_setattr(). */
1214		if ((error = VOP_ACCESS(vp, VADMIN, ap->a_cred, ap->a_td)) &&
1215		    ((vap->va_vaflags & VA_UTIMES_NULL) == 0 ||
1216		    (error = VOP_ACCESS(vp, VWRITE, ap->a_cred, ap->a_td))))
1217			return (error);
1218		if (vap->va_atime.tv_sec != VNOVAL) {
1219			pn->mn_atime = vap->va_atime;
1220		}
1221		if (vap->va_mtime.tv_sec != VNOVAL) {
1222			pn->mn_mtime = vap->va_mtime;
1223		}
1224		c = 1;
1225	}
1226	if (c) {
1227		vfs_timestamp(&pn->mn_ctime);
1228	}
1229	return (0);
1230}
1231
1232#if 0
1233struct vop_read_args {
1234	struct vop_generic_args a_gen;
1235	struct vnode *a_vp;
1236	struct uio *a_uio;
1237	int a_ioflag;
1238	struct ucred *a_cred;
1239};
1240#endif
1241
1242/*
1243 * Read from a file
1244 */
1245static int
1246mqfs_read(struct vop_read_args *ap)
1247{
1248	char buf[80];
1249	struct vnode *vp = ap->a_vp;
1250	struct uio *uio = ap->a_uio;
1251	struct mqfs_node *pn;
1252	struct mqueue *mq;
1253	int len, error;
1254
1255	if (vp->v_type != VREG)
1256		return (EINVAL);
1257
1258	pn = VTON(vp);
1259	mq = VTOMQ(vp);
1260	snprintf(buf, sizeof(buf),
1261		"QSIZE:%-10ld MAXMSG:%-10ld CURMSG:%-10ld MSGSIZE:%-10ld\n",
1262		mq->mq_totalbytes,
1263		mq->mq_maxmsg,
1264		mq->mq_curmsgs,
1265		mq->mq_msgsize);
1266	buf[sizeof(buf)-1] = '\0';
1267	len = strlen(buf);
1268	error = uiomove_frombuf(buf, len, uio);
1269	return (error);
1270}
1271
1272#if 0
1273struct vop_readdir_args {
1274	struct vop_generic_args a_gen;
1275	struct vnode *a_vp;
1276	struct uio *a_uio;
1277	struct ucred *a_cred;
1278	int *a_eofflag;
1279	int *a_ncookies;
1280	u_long **a_cookies;
1281};
1282#endif
1283
1284/*
1285 * Return directory entries.
1286 */
1287static int
1288mqfs_readdir(struct vop_readdir_args *ap)
1289{
1290	struct vnode *vp;
1291	struct mqfs_info *mi;
1292	struct mqfs_node *pd;
1293	struct mqfs_node *pn;
1294	struct dirent entry;
1295	struct uio *uio;
1296	int *tmp_ncookies = NULL;
1297	off_t offset;
1298	int error, i;
1299
1300	vp = ap->a_vp;
1301	mi = VFSTOMQFS(vp->v_mount);
1302	pd = VTON(vp);
1303	uio = ap->a_uio;
1304
1305	if (vp->v_type != VDIR)
1306		return (ENOTDIR);
1307
1308	if (uio->uio_offset < 0)
1309		return (EINVAL);
1310
1311	if (ap->a_ncookies != NULL) {
1312		tmp_ncookies = ap->a_ncookies;
1313		*ap->a_ncookies = 0;
1314		ap->a_ncookies = NULL;
1315        }
1316
1317	error = 0;
1318	offset = 0;
1319
1320	sx_xlock(&mi->mi_lock);
1321
1322	LIST_FOREACH(pn, &pd->mn_children, mn_sibling) {
1323		entry.d_reclen = sizeof(entry);
1324		if (!pn->mn_fileno)
1325			mqfs_fileno_alloc(mi, pn);
1326		entry.d_fileno = pn->mn_fileno;
1327		for (i = 0; i < MQFS_NAMELEN - 1 && pn->mn_name[i] != '\0'; ++i)
1328			entry.d_name[i] = pn->mn_name[i];
1329		entry.d_name[i] = 0;
1330		entry.d_namlen = i;
1331		switch (pn->mn_type) {
1332		case mqfstype_root:
1333		case mqfstype_dir:
1334		case mqfstype_this:
1335		case mqfstype_parent:
1336			entry.d_type = DT_DIR;
1337			break;
1338		case mqfstype_file:
1339			entry.d_type = DT_REG;
1340			break;
1341		case mqfstype_symlink:
1342			entry.d_type = DT_LNK;
1343			break;
1344		default:
1345			panic("%s has unexpected node type: %d", pn->mn_name,
1346				pn->mn_type);
1347		}
1348		if (entry.d_reclen > uio->uio_resid)
1349                        break;
1350		if (offset >= uio->uio_offset) {
1351			error = vfs_read_dirent(ap, &entry, offset);
1352                        if (error)
1353                                break;
1354                }
1355                offset += entry.d_reclen;
1356	}
1357	sx_xunlock(&mi->mi_lock);
1358
1359	uio->uio_offset = offset;
1360
1361	if (tmp_ncookies != NULL)
1362		ap->a_ncookies = tmp_ncookies;
1363
1364	return (error);
1365}
1366
1367#ifdef notyet
1368
1369#if 0
1370struct vop_mkdir_args {
1371	struct vnode *a_dvp;
1372	struvt vnode **a_vpp;
1373	struvt componentname *a_cnp;
1374	struct vattr *a_vap;
1375};
1376#endif
1377
1378/*
1379 * Create a directory.
1380 */
1381static int
1382mqfs_mkdir(struct vop_mkdir_args *ap)
1383{
1384	struct mqfs_info *mqfs = VFSTOMQFS(ap->a_dvp->v_mount);
1385	struct componentname *cnp = ap->a_cnp;
1386	struct mqfs_node *pd = VTON(ap->a_dvp);
1387	struct mqfs_node *pn;
1388	int error;
1389
1390	if (pd->mn_type != mqfstype_root && pd->mn_type != mqfstype_dir)
1391		return (ENOTDIR);
1392	sx_xlock(&mqfs->mi_lock);
1393#if 0
1394	/* named node */
1395	pn = mqfs_search(pd, cnp->cn_nameptr, cnp->cn_namelen);
1396	if (pn != NULL) {
1397		sx_xunlock(&mqfs->mi_lock);
1398		return (EEXIST);
1399	}
1400#else
1401	if ((cnp->cn_flags & HASBUF) == 0)
1402		panic("%s: no name", __func__);
1403#endif
1404	pn = mqfs_create_dir(pd, cnp->cn_nameptr, cnp->cn_namelen);
1405	pn->mn_mode = ap->a_vap->va_mode;
1406	pn->mn_uid = cnp->cn_cred->cr_uid;
1407	pn->mn_gid = cnp->cn_cred->cr_gid;
1408	getnanotime(&pn->mn_birth);
1409	pn->mn_ctime = pn->mn_atime = pn->mn_mtime = pn->mn_birth;
1410	/* node attribute */
1411	error = mqfs_allocv(ap->a_dvp->v_mount, ap->a_vpp, pn);
1412	sx_xunlock(&mqfs->mi_lock);
1413	return (error);
1414}
1415
1416#if 0
1417struct vop_rmdir_args {
1418	struct vnode *a_dvp;
1419	struct vnode *a_vp;
1420	struct componentname *a_cnp;
1421};
1422#endif
1423
1424/*
1425 * Remove a directory.
1426 */
1427static int
1428mqfs_rmdir(struct vop_rmdir_args *ap)
1429{
1430	struct mqfs_info *mqfs = VFSTOMQFS(ap->a_dvp->v_mount);
1431	struct mqfs_node *pn = VTON(ap->a_vp);
1432	struct mqfs_node *pt;
1433
1434	if (pn->mn_type != mqfstype_dir)
1435		return (ENOTDIR);
1436
1437	sx_xlock(&mqfs->mi_lock);
1438	if (pn->mn_deleted) {
1439		sx_xunlock(&mqfs->mi_lock);
1440		return (ENOENT);
1441	}
1442
1443	pt = LIST_FIRST(&pn->mn_children);
1444	pt = LIST_NEXT(pt, mn_sibling);
1445	pt = LIST_NEXT(pt, mn_sibling);
1446	if (pt != NULL) {
1447		sx_xunlock(&mqfs->mi_lock);
1448		return (ENOTEMPTY);
1449	}
1450	pt = pn->mn_parent;
1451	pn->mn_parent = NULL;
1452	pn->mn_deleted = 1;
1453	LIST_REMOVE(pn, mn_sibling);
1454	mqnode_release(pn);
1455	mqnode_release(pt);
1456	sx_xunlock(&mqfs->mi_lock);
1457	cache_purge(ap->a_vp);
1458	return (0);
1459}
1460
1461#endif /* notyet */
1462
1463/*
1464 * Allocate a message queue
1465 */
1466static struct mqueue *
1467mqueue_alloc(const struct mq_attr *attr)
1468{
1469	struct mqueue *mq;
1470
1471	if (curmq >= maxmq)
1472		return (NULL);
1473	mq = uma_zalloc(mqueue_zone, M_WAITOK | M_ZERO);
1474	TAILQ_INIT(&mq->mq_msgq);
1475	if (attr != NULL) {
1476		mq->mq_maxmsg = attr->mq_maxmsg;
1477		mq->mq_msgsize = attr->mq_msgsize;
1478	} else {
1479		mq->mq_maxmsg = default_maxmsg;
1480		mq->mq_msgsize = default_msgsize;
1481	}
1482	mtx_init(&mq->mq_mutex, "mqueue", NULL, MTX_DEF);
1483	knlist_init(&mq->mq_rsel.si_note, &mq->mq_mutex, NULL, NULL, NULL);
1484	knlist_init(&mq->mq_wsel.si_note, &mq->mq_mutex, NULL, NULL, NULL);
1485	atomic_add_int(&curmq, 1);
1486	return (mq);
1487}
1488
1489/*
1490 * Destroy a message queue
1491 */
1492static void
1493mqueue_free(struct mqueue *mq)
1494{
1495	struct mqueue_msg *msg;
1496
1497	while ((msg = TAILQ_FIRST(&mq->mq_msgq)) != NULL) {
1498		TAILQ_REMOVE(&mq->mq_msgq, msg, msg_link);
1499		FREE(msg, M_MQUEUEDATA);
1500	}
1501
1502	mtx_destroy(&mq->mq_mutex);
1503	knlist_destroy(&mq->mq_rsel.si_note);
1504	knlist_destroy(&mq->mq_wsel.si_note);
1505	uma_zfree(mqueue_zone, mq);
1506	atomic_add_int(&curmq, -1);
1507}
1508
1509/*
1510 * Load a message from user space
1511 */
1512static struct mqueue_msg *
1513mqueue_loadmsg(const char *msg_ptr, size_t msg_size, int msg_prio)
1514{
1515	struct mqueue_msg *msg;
1516	size_t len;
1517	int error;
1518
1519	len = sizeof(struct mqueue_msg) + msg_size;
1520	MALLOC(msg, struct mqueue_msg *, len, M_MQUEUEDATA, M_WAITOK);
1521	error = copyin(msg_ptr, ((char *)msg) + sizeof(struct mqueue_msg),
1522	    msg_size);
1523	if (error) {
1524		FREE(msg, M_MQUEUEDATA);
1525		msg = NULL;
1526	} else {
1527		msg->msg_size = msg_size;
1528		msg->msg_prio = msg_prio;
1529	}
1530	return (msg);
1531}
1532
1533/*
1534 * Save a message to user space
1535 */
1536static int
1537mqueue_savemsg(struct mqueue_msg *msg, char *msg_ptr, int *msg_prio)
1538{
1539	int error;
1540
1541	error = copyout(((char *)msg) + sizeof(*msg), msg_ptr,
1542		msg->msg_size);
1543	if (error == 0 && msg_prio != NULL)
1544		error = copyout(&msg->msg_prio, msg_prio, sizeof(int));
1545	return (error);
1546}
1547
1548/*
1549 * Free a message's memory
1550 */
1551static __inline void
1552mqueue_freemsg(struct mqueue_msg *msg)
1553{
1554	FREE(msg, M_MQUEUEDATA);
1555}
1556
1557/*
1558 * Send a message. if waitok is false, thread will not be
1559 * blocked if there is no data in queue, otherwise, absolute
1560 * time will be checked.
1561 */
1562int
1563mqueue_send(struct mqueue *mq, const char *msg_ptr,
1564	size_t msg_len, unsigned msg_prio, int waitok,
1565	const struct timespec *abs_timeout)
1566{
1567	struct mqueue_msg *msg;
1568	struct timespec ets, ts, ts2;
1569	struct timeval tv;
1570	int error;
1571
1572	if (msg_len > mq->mq_msgsize)
1573		return (EMSGSIZE);
1574	msg = mqueue_loadmsg(msg_ptr, msg_len, msg_prio);
1575	if (msg == NULL)
1576		return (EFAULT);
1577
1578	/* O_NONBLOCK case */
1579	if (!waitok) {
1580		error = _mqueue_send(mq, msg, -1);
1581		if (error)
1582			goto bad;
1583		return (0);
1584	}
1585
1586	/* we allow a null timeout (wait forever) */
1587	if (abs_timeout == NULL) {
1588		error = _mqueue_send(mq, msg, 0);
1589		if (error)
1590			goto bad;
1591		return (0);
1592	}
1593
1594	/* send it before checking time */
1595	error = _mqueue_send(mq, msg, -1);
1596	if (error == 0)
1597		return (0);
1598
1599	if (error != EAGAIN)
1600		goto bad;
1601
1602	error = copyin(abs_timeout, &ets, sizeof(ets));
1603	if (error != 0)
1604		goto bad;
1605	if (ets.tv_nsec >= 1000000000 || ets.tv_nsec < 0) {
1606		error = EINVAL;
1607		goto bad;
1608	}
1609	for (;;) {
1610		ts2 = ets;
1611		getnanouptime(&ts);
1612		timespecsub(&ts2, &ts);
1613		if (ts2.tv_sec < 0 || (ts2.tv_sec == 0 && ts2.tv_nsec <= 0)) {
1614			error = ETIMEDOUT;
1615			break;
1616		}
1617		TIMESPEC_TO_TIMEVAL(&tv, &ts2);
1618		error = _mqueue_send(mq, msg, tvtohz(&tv));
1619		if (error != ETIMEDOUT)
1620			break;
1621	}
1622	if (error == 0)
1623		return (0);
1624bad:
1625	mqueue_freemsg(msg);
1626	return (error);
1627}
1628
1629/*
1630 * Common routine to send a message
1631 */
1632static int
1633_mqueue_send(struct mqueue *mq, struct mqueue_msg *msg, int timo)
1634{
1635	struct mqueue_msg *msg2;
1636	int error = 0;
1637
1638	mtx_lock(&mq->mq_mutex);
1639	while (mq->mq_curmsgs >= mq->mq_maxmsg && error == 0) {
1640		if (timo < 0) {
1641			mtx_unlock(&mq->mq_mutex);
1642			mqueue_freemsg(msg);
1643			return (EAGAIN);
1644		}
1645		mq->mq_senders++;
1646		error = msleep(&mq->mq_senders, &mq->mq_mutex,
1647			    PSOCK | PCATCH, "mqsend", timo);
1648		mq->mq_senders--;
1649		if (error == EAGAIN)
1650			error = ETIMEDOUT;
1651	}
1652	if (mq->mq_curmsgs >= mq->mq_maxmsg) {
1653		mtx_unlock(&mq->mq_mutex);
1654		return (error);
1655	}
1656	error = 0;
1657	if (TAILQ_EMPTY(&mq->mq_msgq)) {
1658		TAILQ_INSERT_HEAD(&mq->mq_msgq, msg, msg_link);
1659	} else {
1660		if (msg->msg_prio <= TAILQ_LAST(&mq->mq_msgq, msgq)->msg_prio) {
1661			TAILQ_INSERT_TAIL(&mq->mq_msgq, msg, msg_link);
1662		} else {
1663			TAILQ_FOREACH(msg2, &mq->mq_msgq, msg_link) {
1664				if (msg2->msg_prio < msg->msg_prio)
1665					break;
1666			}
1667			TAILQ_INSERT_BEFORE(msg2, msg, msg_link);
1668		}
1669	}
1670	mq->mq_curmsgs++;
1671	mq->mq_totalbytes += msg->msg_size;
1672	if (mq->mq_receivers)
1673		wakeup_one(&mq->mq_receivers);
1674	else if (mq->mq_notifier != NULL)
1675		mqueue_send_notification(mq);
1676	if (mq->mq_flags & MQ_RSEL) {
1677		mq->mq_flags &= ~MQ_RSEL;
1678		selwakeuppri(&mq->mq_rsel, PSOCK);
1679	}
1680	KNOTE_LOCKED(&mq->mq_rsel.si_note, 0);
1681	mtx_unlock(&mq->mq_mutex);
1682	return (0);
1683}
1684
1685/*
1686 * Send realtime a signal to process which registered itself
1687 * successfully by mq_notify.
1688 */
1689static void
1690mqueue_send_notification(struct mqueue *mq)
1691{
1692	struct mqueue_notifier *nt;
1693	struct proc *p;
1694
1695	mtx_assert(&mq->mq_mutex, MA_OWNED);
1696	nt = mq->mq_notifier;
1697	p = nt->nt_proc;
1698	PROC_LOCK(p);
1699	if (!KSI_ONQ(&nt->nt_ksi))
1700		psignal_event(p, &nt->nt_sigev, &nt->nt_ksi);
1701	PROC_UNLOCK(p);
1702	mq->mq_notifier = NULL;
1703}
1704
1705/*
1706 * Get a message. if waitok is false, thread will not be
1707 * blocked if there is no data in queue, otherwise, absolute
1708 * time will be checked.
1709 */
1710int
1711mqueue_receive(struct mqueue *mq, char *msg_ptr,
1712	size_t msg_len, unsigned *msg_prio, int waitok,
1713	const struct timespec *abs_timeout)
1714{
1715	struct mqueue_msg *msg;
1716	struct timespec ets, ts, ts2;
1717	struct timeval tv;
1718	int error;
1719
1720	if (msg_len < mq->mq_msgsize)
1721		return (EMSGSIZE);
1722
1723	/* O_NONBLOCK case */
1724	if (!waitok) {
1725		error = _mqueue_recv(mq, &msg, -1);
1726		if (error)
1727			return (error);
1728		goto received;
1729	}
1730
1731	/* we allow a null timeout (wait forever). */
1732	if (abs_timeout == NULL) {
1733		error = _mqueue_recv(mq, &msg, 0);
1734		if (error)
1735			return (error);
1736		goto received;
1737	}
1738
1739	/* try to get a message before checking time */
1740	error = _mqueue_recv(mq, &msg, -1);
1741	if (error == 0)
1742		goto received;
1743
1744	if (error != EAGAIN)
1745		return (error);
1746
1747	error = copyin(abs_timeout, &ets, sizeof(ets));
1748	if (error != 0)
1749		return (error);
1750	if (ets.tv_nsec >= 1000000000 || ets.tv_nsec < 0) {
1751		error = EINVAL;
1752		return (error);
1753	}
1754
1755	for (;;) {
1756		ts2 = ets;
1757		getnanouptime(&ts);
1758		timespecsub(&ts2, &ts);
1759		if (ts2.tv_sec < 0 || (ts2.tv_sec == 0 && ts2.tv_nsec <= 0)) {
1760			error = ETIMEDOUT;
1761			return (error);
1762		}
1763		TIMESPEC_TO_TIMEVAL(&tv, &ts2);
1764		error = _mqueue_recv(mq, &msg, tvtohz(&tv));
1765		if (error == 0)
1766			break;
1767		if (error != ETIMEDOUT)
1768			return (error);
1769	}
1770
1771received:
1772	error = mqueue_savemsg(msg, msg_ptr, msg_prio);
1773	if (error == 0) {
1774		curthread->td_retval[0] = msg->msg_size;
1775		curthread->td_retval[1] = 0;
1776	}
1777	mqueue_freemsg(msg);
1778	return (error);
1779}
1780
1781/*
1782 * Common routine to receive a message
1783 */
1784static int
1785_mqueue_recv(struct mqueue *mq, struct mqueue_msg **msg, int timo)
1786{
1787	int error = 0;
1788
1789	mtx_lock(&mq->mq_mutex);
1790	while ((*msg = TAILQ_FIRST(&mq->mq_msgq)) == NULL && error == 0) {
1791		if (timo < 0) {
1792			mtx_unlock(&mq->mq_mutex);
1793			return (EAGAIN);
1794		}
1795		mq->mq_receivers++;
1796		error = msleep(&mq->mq_receivers, &mq->mq_mutex,
1797			    PSOCK | PCATCH, "mqrecv", timo);
1798		mq->mq_receivers--;
1799		if (error == EAGAIN)
1800			error = ETIMEDOUT;
1801	}
1802	if (*msg != NULL) {
1803		error = 0;
1804		TAILQ_REMOVE(&mq->mq_msgq, *msg, msg_link);
1805		mq->mq_curmsgs--;
1806		mq->mq_totalbytes -= (*msg)->msg_size;
1807		if (mq->mq_senders)
1808			wakeup_one(&mq->mq_senders);
1809		if (mq->mq_flags & MQ_WSEL) {
1810			mq->mq_flags &= ~MQ_WSEL;
1811			selwakeuppri(&mq->mq_wsel, PSOCK);
1812		}
1813		KNOTE_LOCKED(&mq->mq_wsel.si_note, 0);
1814	}
1815	if (mq->mq_notifier != NULL && mq->mq_receivers == 0 &&
1816	    !TAILQ_EMPTY(&mq->mq_msgq)) {
1817		mqueue_send_notification(mq);
1818	}
1819	mtx_unlock(&mq->mq_mutex);
1820	return (error);
1821}
1822
1823static __inline struct mqueue_notifier *
1824notifier_alloc(void)
1825{
1826	return (uma_zalloc(mqnoti_zone, M_WAITOK | M_ZERO));
1827}
1828
1829static __inline void
1830notifier_free(struct mqueue_notifier *p)
1831{
1832	uma_zfree(mqnoti_zone, p);
1833}
1834
1835static struct mqueue_notifier *
1836notifier_search(struct proc *p, int fd)
1837{
1838	struct mqueue_notifier *nt;
1839
1840	LIST_FOREACH(nt, &p->p_mqnotifier, nt_link) {
1841		if (nt->nt_fd == fd)
1842			break;
1843	}
1844	return (nt);
1845}
1846
1847static void
1848notifier_insert(struct proc *p, struct mqueue_notifier *nt)
1849{
1850	LIST_INSERT_HEAD(&p->p_mqnotifier, nt, nt_link);
1851}
1852
1853static void
1854notifier_delete(struct proc *p, struct mqueue_notifier *nt)
1855{
1856	LIST_REMOVE(nt, nt_link);
1857	notifier_free(nt);
1858}
1859
1860static void
1861notifier_remove(struct proc *p, struct mqueue *mq, int fd)
1862{
1863	struct mqueue_notifier *nt;
1864
1865	mtx_assert(&mq->mq_mutex, MA_OWNED);
1866	PROC_LOCK(p);
1867	nt = notifier_search(p, fd);
1868	if (nt != NULL) {
1869		if (mq->mq_notifier == nt)
1870			mq->mq_notifier = NULL;
1871		sigqueue_take(&nt->nt_ksi);
1872		notifier_delete(p, nt);
1873	}
1874	PROC_UNLOCK(p);
1875}
1876
1877/*
1878 * Syscall to open a message queue
1879 */
1880int
1881mq_open(struct thread *td, struct mq_open_args *uap)
1882{
1883	char path[MQFS_NAMELEN + 1];
1884	struct mq_attr attr, *pattr;
1885	struct mqfs_node *pn;
1886	struct filedesc *fdp;
1887	struct file *fp;
1888	struct mqueue *mq;
1889	int fd, error, len, flags, cmode;
1890
1891	if ((uap->flags & O_ACCMODE) == O_ACCMODE)
1892		return (EINVAL);
1893
1894	fdp = td->td_proc->p_fd;
1895	flags = FFLAGS(uap->flags);
1896	cmode = (((uap->mode & ~fdp->fd_cmask) & ALLPERMS) & ~S_ISTXT);
1897	mq = NULL;
1898	if ((flags & O_CREAT) && (uap->attr != NULL)) {
1899		error = copyin(uap->attr, &attr, sizeof(attr));
1900		if (error)
1901			return (error);
1902		if (attr.mq_maxmsg <= 0 || attr.mq_maxmsg > maxmsg)
1903			return (EINVAL);
1904		if (attr.mq_msgsize <= 0 || attr.mq_msgsize > maxmsgsize)
1905			return (EINVAL);
1906		pattr = &attr;
1907	} else
1908		pattr = NULL;
1909
1910	error = copyinstr(uap->path, path, MQFS_NAMELEN + 1, NULL);
1911        if (error)
1912		return (error);
1913
1914	/*
1915	 * The first character of name must be a slash  (/) character
1916	 * and the remaining characters of name cannot include any slash
1917	 * characters.
1918	 */
1919	len = strlen(path);
1920	if (len < 2  || path[0] != '/' || index(path + 1, '/') != NULL)
1921		return (EINVAL);
1922
1923	error = falloc(td, &fp, &fd);
1924	if (error)
1925		return (error);
1926
1927	sx_xlock(&mqfs_data.mi_lock);
1928	pn = mqfs_search(mqfs_data.mi_root, path + 1, len - 1);
1929	if (pn == NULL) {
1930		if (!(flags & O_CREAT)) {
1931			error = ENOENT;
1932		} else {
1933			mq = mqueue_alloc(pattr);
1934			if (mq == NULL) {
1935				error = ENFILE;
1936			} else {
1937				pn = mqfs_create_file(mqfs_data.mi_root,
1938				         path + 1, len - 1);
1939				if (pn == NULL) {
1940					error = ENOSPC;
1941					mqueue_free(mq);
1942				}
1943			}
1944		}
1945
1946		if (error == 0) {
1947			pn->mn_data = mq;
1948			getnanotime(&pn->mn_birth);
1949			pn->mn_ctime = pn->mn_atime = pn->mn_mtime
1950			  = pn->mn_birth;
1951			pn->mn_uid = td->td_ucred->cr_uid;
1952			pn->mn_gid = td->td_ucred->cr_gid;
1953			pn->mn_mode = cmode;
1954		}
1955	} else {
1956		if ((flags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL)) {
1957			error = EEXIST;
1958		} else {
1959			int acc_mode = 0;
1960
1961			if (flags & FREAD)
1962				acc_mode |= VREAD;
1963			if (flags & FWRITE)
1964				acc_mode |= VWRITE;
1965			error = vaccess(VREG, pn->mn_mode, pn->mn_uid,
1966				    pn->mn_gid, acc_mode, td->td_ucred, NULL);
1967		}
1968	}
1969
1970	if (error) {
1971		sx_xunlock(&mqfs_data.mi_lock);
1972		fdclose(fdp, fp, fd, td);
1973		fdrop(fp, td);
1974		return (error);
1975	}
1976
1977	mqnode_addref(pn);
1978	sx_xunlock(&mqfs_data.mi_lock);
1979
1980	FILE_LOCK(fp);
1981	fp->f_flag = (flags & (FREAD | FWRITE | O_NONBLOCK));
1982	fp->f_type = DTYPE_MQUEUE;
1983	fp->f_ops = &mqueueops;
1984	fp->f_data = pn;
1985	FILE_UNLOCK(fp);
1986
1987	FILEDESC_LOCK_FAST(fdp);
1988	if (fdp->fd_ofiles[fd] == fp)
1989		fdp->fd_ofileflags[fd] |= UF_EXCLOSE;
1990	FILEDESC_UNLOCK_FAST(fdp);
1991	td->td_retval[0] = fd;
1992	fdrop(fp, td);
1993	return (0);
1994}
1995
1996/*
1997 * Syscall to unlink a message queue
1998 */
1999int
2000mq_unlink(struct thread *td, struct mq_unlink_args *uap)
2001{
2002	char path[MQFS_NAMELEN+1];
2003	struct mqfs_node *pn;
2004	int error, len;
2005
2006	error = copyinstr(uap->path, path, MQFS_NAMELEN + 1, NULL);
2007        if (error)
2008		return (error);
2009
2010	len = strlen(path);
2011	if (len < 2  || path[0] != '/' || index(path + 1, '/') != NULL)
2012		return (EINVAL);
2013
2014	sx_xlock(&mqfs_data.mi_lock);
2015	pn = mqfs_search(mqfs_data.mi_root, path + 1, len - 1);
2016	if (pn != NULL)
2017		error = do_unlink(pn, td->td_ucred);
2018	else
2019		error = ENOENT;
2020	sx_xunlock(&mqfs_data.mi_lock);
2021	return (error);
2022}
2023
2024typedef int (*_fgetf)(struct thread *, int, struct file **);
2025
2026/*
2027 * Get message queue by giving file slot
2028 */
2029static int
2030_getmq(struct thread *td, int fd, _fgetf func,
2031       struct file **fpp, struct mqfs_node **ppn, struct mqueue **pmq)
2032{
2033	struct mqfs_node *pn;
2034	int error;
2035
2036	error = func(td, fd, fpp);
2037	if (error)
2038		return (error);
2039	if (&mqueueops != (*fpp)->f_ops) {
2040		fdrop(*fpp, td);
2041		return (EBADF);
2042	}
2043	pn = (*fpp)->f_data;
2044	if (ppn)
2045		*ppn = pn;
2046	if (pmq)
2047		*pmq = pn->mn_data;
2048	return (0);
2049}
2050
2051static __inline int
2052getmq(struct thread *td, int fd, struct file **fpp, struct mqfs_node **ppn,
2053	struct mqueue **pmq)
2054{
2055	return _getmq(td, fd, fget, fpp, ppn, pmq);
2056}
2057
2058static __inline int
2059getmq_read(struct thread *td, int fd, struct file **fpp,
2060	 struct mqfs_node **ppn, struct mqueue **pmq)
2061{
2062	return _getmq(td, fd, fget_read, fpp, ppn, pmq);
2063}
2064
2065static __inline int
2066getmq_write(struct thread *td, int fd, struct file **fpp,
2067	struct mqfs_node **ppn, struct mqueue **pmq)
2068{
2069	return _getmq(td, fd, fget_write, fpp, ppn, pmq);
2070}
2071
2072/*
2073 * Syscall
2074 */
2075int
2076mq_setattr(struct thread *td, struct mq_setattr_args *uap)
2077{
2078	struct mqueue *mq;
2079	struct file *fp;
2080	struct mq_attr attr, oattr;
2081	int error;
2082
2083	if (uap->attr) {
2084		error = copyin(uap->attr, &attr, sizeof(attr));
2085		if (error)
2086			return (error);
2087		if (attr.mq_flags & ~O_NONBLOCK)
2088			return (EINVAL);
2089	}
2090	error = getmq(td, uap->mqd, &fp, NULL, &mq);
2091	if (error)
2092		return (error);
2093	oattr.mq_maxmsg  = mq->mq_maxmsg;
2094	oattr.mq_msgsize = mq->mq_msgsize;
2095	oattr.mq_curmsgs = mq->mq_curmsgs;
2096	FILE_LOCK(fp);
2097	oattr.mq_flags = (O_NONBLOCK & fp->f_flag);
2098	if (uap->attr) {
2099		fp->f_flag &= ~O_NONBLOCK;
2100		fp->f_flag |= (attr.mq_flags & O_NONBLOCK);
2101	}
2102	FILE_UNLOCK(fp);
2103	fdrop(fp, td);
2104	if (uap->oattr)
2105		error = copyout(&oattr, uap->oattr, sizeof(oattr));
2106	return (error);
2107}
2108
2109/*
2110 * Syscall
2111 */
2112int
2113mq_timedreceive(struct thread *td, struct mq_timedreceive_args *uap)
2114{
2115	struct mqueue *mq;
2116	struct file *fp;
2117	int error;
2118	int waitok;
2119
2120	error = getmq_read(td, uap->mqd, &fp, NULL, &mq);
2121	if (error)
2122		return (error);
2123	waitok = !(fp->f_flag & O_NONBLOCK);
2124	error = mqueue_receive(mq, uap->msg_ptr, uap->msg_len,
2125		uap->msg_prio, waitok, uap->abs_timeout);
2126	fdrop(fp, td);
2127	return (error);
2128}
2129
2130/*
2131 * Syscall
2132 */
2133int
2134mq_timedsend(struct thread *td, struct mq_timedsend_args *uap)
2135{
2136	struct mqueue *mq;
2137	struct file *fp;
2138	int error, waitok;
2139
2140	error = getmq_write(td, uap->mqd, &fp, NULL, &mq);
2141	if (error)
2142		return (error);
2143	waitok = !(fp->f_flag & O_NONBLOCK);
2144	error = mqueue_send(mq, uap->msg_ptr, uap->msg_len,
2145		uap->msg_prio, waitok, uap->abs_timeout);
2146	fdrop(fp, td);
2147	return (error);
2148}
2149
2150/*
2151 * Syscall
2152 */
2153int
2154mq_notify(struct thread *td, struct mq_notify_args *uap)
2155{
2156	struct sigevent ev;
2157	struct filedesc *fdp;
2158	struct proc *p;
2159	struct mqueue *mq;
2160	struct file *fp;
2161	struct mqueue_notifier *nt, *newnt = NULL;
2162	int error;
2163
2164	p = td->td_proc;
2165	fdp = td->td_proc->p_fd;
2166	if (uap->sigev) {
2167		error = copyin(uap->sigev, &ev, sizeof(ev));
2168		if (error)
2169			return (error);
2170		if (ev.sigev_notify != SIGEV_SIGNAL &&
2171		    ev.sigev_notify != SIGEV_THREAD_ID)
2172			return (EINVAL);
2173		if ((ev.sigev_notify == SIGEV_SIGNAL ||
2174		     ev.sigev_notify == SIGEV_THREAD_ID) &&
2175			!_SIG_VALID(ev.sigev_signo))
2176			return (EINVAL);
2177	}
2178	error = getmq(td, uap->mqd, &fp, NULL, &mq);
2179	if (error)
2180		return (error);
2181again:
2182	FILEDESC_LOCK_FAST(fdp);
2183	if (fget_locked(fdp, uap->mqd) != fp) {
2184		FILEDESC_UNLOCK_FAST(fdp);
2185		error = EBADF;
2186		goto out;
2187	}
2188	mtx_lock(&mq->mq_mutex);
2189	FILEDESC_UNLOCK_FAST(fdp);
2190	if (uap->sigev != NULL) {
2191		if (mq->mq_notifier != NULL) {
2192			error = EBUSY;
2193		} else {
2194			PROC_LOCK(p);
2195			nt = notifier_search(p, uap->mqd);
2196			if (nt == NULL) {
2197				if (newnt == NULL) {
2198					PROC_UNLOCK(p);
2199					mtx_unlock(&mq->mq_mutex);
2200					newnt = notifier_alloc();
2201					goto again;
2202				}
2203			}
2204
2205			if (nt != NULL) {
2206				sigqueue_take(&nt->nt_ksi);
2207				if (newnt != NULL) {
2208					notifier_free(newnt);
2209					newnt = NULL;
2210				}
2211			} else {
2212				nt = newnt;
2213				newnt = NULL;
2214				ksiginfo_init(&nt->nt_ksi);
2215				nt->nt_ksi.ksi_flags |= KSI_INS | KSI_EXT;
2216				nt->nt_ksi.ksi_code = SI_MESGQ;
2217				nt->nt_proc = p;
2218				nt->nt_fd = uap->mqd;
2219				notifier_insert(p, nt);
2220			}
2221			nt->nt_sigev = ev;
2222			mq->mq_notifier = nt;
2223			PROC_UNLOCK(p);
2224			/*
2225			 * if there is no receivers and message queue
2226			 * is not empty, we should send notification
2227			 * as soon as possible.
2228			 */
2229			if (mq->mq_receivers == 0 &&
2230			    !TAILQ_EMPTY(&mq->mq_msgq))
2231				mqueue_send_notification(mq);
2232		}
2233	} else {
2234		notifier_remove(p, mq, uap->mqd);
2235	}
2236	mtx_unlock(&mq->mq_mutex);
2237
2238out:
2239	fdrop(fp, td);
2240	if (newnt != NULL)
2241		notifier_free(newnt);
2242	return (error);
2243}
2244
2245static void
2246mqueue_fdclose(struct thread *td, int fd, struct file *fp)
2247{
2248	struct filedesc *fdp;
2249	struct mqueue *mq;
2250
2251	fdp = td->td_proc->p_fd;
2252	FILEDESC_LOCK_ASSERT(fdp, MA_OWNED);
2253	if (fp->f_ops == &mqueueops) {
2254		mq = FPTOMQ(fp);
2255		mtx_lock(&mq->mq_mutex);
2256		notifier_remove(td->td_proc, mq, fd);
2257
2258		/* have to wakeup thread in same process */
2259		if (mq->mq_flags & MQ_RSEL) {
2260			mq->mq_flags &= ~MQ_RSEL;
2261			selwakeuppri(&mq->mq_rsel, PSOCK);
2262		}
2263		if (mq->mq_flags & MQ_WSEL) {
2264			mq->mq_flags &= ~MQ_WSEL;
2265			selwakeuppri(&mq->mq_wsel, PSOCK);
2266		}
2267		mtx_unlock(&mq->mq_mutex);
2268	}
2269}
2270
2271static void
2272mq_proc_exit(void *arg __unused, struct proc *p)
2273{
2274	struct filedesc *fdp;
2275	struct file *fp;
2276	struct mqueue *mq;
2277	int i;
2278
2279	fdp = p->p_fd;
2280	FILEDESC_LOCK_FAST(fdp);
2281	for (i = 0; i < fdp->fd_nfiles; ++i) {
2282		fp = fget_locked(fdp, i);
2283		if (fp != NULL && fp->f_ops == &mqueueops) {
2284			mq = FPTOMQ(fp);
2285			mtx_lock(&mq->mq_mutex);
2286			notifier_remove(p, FPTOMQ(fp), i);
2287			mtx_unlock(&mq->mq_mutex);
2288		}
2289	}
2290	FILEDESC_UNLOCK_FAST(fdp);
2291	KASSERT(LIST_EMPTY(&p->p_mqnotifier), ("mq notifiers left"));
2292}
2293
2294static int
2295mqf_read(struct file *fp, struct uio *uio, struct ucred *active_cred,
2296	int flags, struct thread *td)
2297{
2298	return (EOPNOTSUPP);
2299}
2300
2301static int
2302mqf_write(struct file *fp, struct uio *uio, struct ucred *active_cred,
2303	int flags, struct thread *td)
2304{
2305	return (EOPNOTSUPP);
2306}
2307
2308static int
2309mqf_ioctl(struct file *fp, u_long cmd, void *data,
2310	struct ucred *active_cred, struct thread *td)
2311{
2312	return (ENOTTY);
2313}
2314
2315static int
2316mqf_poll(struct file *fp, int events, struct ucred *active_cred,
2317	struct thread *td)
2318{
2319	struct mqueue *mq = FPTOMQ(fp);
2320	int revents = 0;
2321
2322	mtx_lock(&mq->mq_mutex);
2323	if (events & (POLLIN | POLLRDNORM)) {
2324		if (mq->mq_curmsgs) {
2325			revents |= events & (POLLIN | POLLRDNORM);
2326		} else {
2327			mq->mq_flags |= MQ_RSEL;
2328			selrecord(td, &mq->mq_rsel);
2329 		}
2330	}
2331	if (events & POLLOUT) {
2332		if (mq->mq_curmsgs < mq->mq_maxmsg)
2333			revents |= POLLOUT;
2334		else {
2335			mq->mq_flags |= MQ_WSEL;
2336			selrecord(td, &mq->mq_wsel);
2337		}
2338	}
2339	mtx_unlock(&mq->mq_mutex);
2340	return (revents);
2341}
2342
2343static int
2344mqf_close(struct file *fp, struct thread *td)
2345{
2346	struct mqfs_node *pn;
2347
2348	FILE_LOCK(fp);
2349	fp->f_ops = &badfileops;
2350	FILE_UNLOCK(fp);
2351	pn = fp->f_data;
2352	fp->f_data = NULL;
2353	sx_xlock(&mqfs_data.mi_lock);
2354	mqnode_release(pn);
2355	sx_xunlock(&mqfs_data.mi_lock);
2356	return (0);
2357}
2358
2359static int
2360mqf_stat(struct file *fp, struct stat *st, struct ucred *active_cred,
2361	struct thread *td)
2362{
2363	struct mqfs_node *pn = fp->f_data;
2364
2365	bzero(st, sizeof *st);
2366	st->st_atimespec = pn->mn_atime;
2367	st->st_mtimespec = pn->mn_mtime;
2368	st->st_ctimespec = pn->mn_ctime;
2369	st->st_birthtimespec = pn->mn_birth;
2370	st->st_uid = pn->mn_uid;
2371	st->st_gid = pn->mn_gid;
2372	st->st_mode = S_IFIFO | pn->mn_mode;
2373	return (0);
2374}
2375
2376static int
2377mqf_kqfilter(struct file *fp, struct knote *kn)
2378{
2379	struct mqueue *mq = FPTOMQ(fp);
2380	int error = 0;
2381
2382	if (kn->kn_filter == EVFILT_READ) {
2383		kn->kn_fop = &mq_rfiltops;
2384		knlist_add(&mq->mq_rsel.si_note, kn, 0);
2385	} else if (kn->kn_filter == EVFILT_WRITE) {
2386		kn->kn_fop = &mq_wfiltops;
2387		knlist_add(&mq->mq_wsel.si_note, kn, 0);
2388	} else
2389		error = EINVAL;
2390	return (error);
2391}
2392
2393static void
2394filt_mqdetach(struct knote *kn)
2395{
2396	struct mqueue *mq = FPTOMQ(kn->kn_fp);
2397
2398	if (kn->kn_filter == EVFILT_READ)
2399		knlist_remove(&mq->mq_rsel.si_note, kn, 0);
2400	else if (kn->kn_filter == EVFILT_WRITE)
2401		knlist_remove(&mq->mq_wsel.si_note, kn, 0);
2402	else
2403		panic("filt_mqdetach");
2404}
2405
2406static int
2407filt_mqread(struct knote *kn, long hint)
2408{
2409	struct mqueue *mq = FPTOMQ(kn->kn_fp);
2410
2411	mtx_assert(&mq->mq_mutex, MA_OWNED);
2412	return (mq->mq_curmsgs != 0);
2413}
2414
2415static int
2416filt_mqwrite(struct knote *kn, long hint)
2417{
2418	struct mqueue *mq = FPTOMQ(kn->kn_fp);
2419
2420	mtx_assert(&mq->mq_mutex, MA_OWNED);
2421	return (mq->mq_curmsgs < mq->mq_maxmsg);
2422}
2423
2424static struct fileops mqueueops = {
2425	.fo_read		= mqf_read,
2426	.fo_write		= mqf_write,
2427	.fo_ioctl		= mqf_ioctl,
2428	.fo_poll		= mqf_poll,
2429	.fo_kqfilter		= mqf_kqfilter,
2430	.fo_stat		= mqf_stat,
2431	.fo_close		= mqf_close
2432};
2433
2434static struct vop_vector mqfs_vnodeops = {
2435	.vop_default 		= &default_vnodeops,
2436	.vop_access		= mqfs_access,
2437	.vop_cachedlookup	= mqfs_lookup,
2438	.vop_lookup		= vfs_cache_lookup,
2439	.vop_reclaim		= mqfs_reclaim,
2440	.vop_create		= mqfs_create,
2441	.vop_remove		= mqfs_remove,
2442	.vop_inactive		= mqfs_inactive,
2443	.vop_open		= mqfs_open,
2444	.vop_close		= mqfs_close,
2445	.vop_getattr		= mqfs_getattr,
2446	.vop_setattr		= mqfs_setattr,
2447	.vop_read		= mqfs_read,
2448	.vop_write		= VOP_EOPNOTSUPP,
2449	.vop_readdir		= mqfs_readdir,
2450	.vop_mkdir		= VOP_EOPNOTSUPP,
2451	.vop_rmdir		= VOP_EOPNOTSUPP
2452};
2453
2454static struct vfsops mqfs_vfsops = {
2455	.vfs_init 		= mqfs_init,
2456	.vfs_uninit		= mqfs_uninit,
2457	.vfs_mount		= mqfs_mount,
2458	.vfs_unmount		= mqfs_unmount,
2459	.vfs_root		= mqfs_root,
2460	.vfs_statfs		= mqfs_statfs,
2461};
2462
2463SYSCALL_MODULE_HELPER(mq_open);
2464SYSCALL_MODULE_HELPER(mq_setattr);
2465SYSCALL_MODULE_HELPER(mq_timedsend);
2466SYSCALL_MODULE_HELPER(mq_timedreceive);
2467SYSCALL_MODULE_HELPER(mq_notify);
2468SYSCALL_MODULE_HELPER(mq_unlink);
2469
2470VFS_SET(mqfs_vfsops, mqueuefs, VFCF_SYNTHETIC);
2471MODULE_VERSION(mqueuefs, 1);
2472