The Design and Implementation of the FreeBSD Operating System, Second Edition
Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)


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FreeBSD/Linux Kernel Cross Reference
sys/kern/uipc_mqueue.c

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    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: releng/9.0/sys/kern/uipc_mqueue.c 225617 2011-09-16 13:58:51Z kmacy $");
   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/capability.h>
   56 #include <sys/dirent.h>
   57 #include <sys/event.h>
   58 #include <sys/eventhandler.h>
   59 #include <sys/fcntl.h>
   60 #include <sys/file.h>
   61 #include <sys/filedesc.h>
   62 #include <sys/lock.h>
   63 #include <sys/malloc.h>
   64 #include <sys/module.h>
   65 #include <sys/mount.h>
   66 #include <sys/mqueue.h>
   67 #include <sys/mutex.h>
   68 #include <sys/namei.h>
   69 #include <sys/posix4.h>
   70 #include <sys/poll.h>
   71 #include <sys/priv.h>
   72 #include <sys/proc.h>
   73 #include <sys/queue.h>
   74 #include <sys/sysproto.h>
   75 #include <sys/stat.h>
   76 #include <sys/syscall.h>
   77 #include <sys/syscallsubr.h>
   78 #include <sys/sysent.h>
   79 #include <sys/sx.h>
   80 #include <sys/sysctl.h>
   81 #include <sys/taskqueue.h>
   82 #include <sys/unistd.h>
   83 #include <sys/vnode.h>
   84 #include <machine/atomic.h>
   85 
   86 FEATURE(p1003_1b_mqueue, "POSIX P1003.1B message queues support");
   87 
   88 /*
   89  * Limits and constants
   90  */
   91 #define MQFS_NAMELEN            NAME_MAX
   92 #define MQFS_DELEN              (8 + MQFS_NAMELEN)
   93 
   94 /* node types */
   95 typedef enum {
   96         mqfstype_none = 0,
   97         mqfstype_root,
   98         mqfstype_dir,
   99         mqfstype_this,
  100         mqfstype_parent,
  101         mqfstype_file,
  102         mqfstype_symlink,
  103 } mqfs_type_t;
  104 
  105 struct mqfs_node;
  106 
  107 /*
  108  * mqfs_info: describes a mqfs instance
  109  */
  110 struct mqfs_info {
  111         struct sx               mi_lock;
  112         struct mqfs_node        *mi_root;
  113         struct unrhdr           *mi_unrhdr;
  114 };
  115 
  116 struct mqfs_vdata {
  117         LIST_ENTRY(mqfs_vdata)  mv_link;
  118         struct mqfs_node        *mv_node;
  119         struct vnode            *mv_vnode;
  120         struct task             mv_task;
  121 };
  122 
  123 /*
  124  * mqfs_node: describes a node (file or directory) within a mqfs
  125  */
  126 struct mqfs_node {
  127         char                    mn_name[MQFS_NAMELEN+1];
  128         struct mqfs_info        *mn_info;
  129         struct mqfs_node        *mn_parent;
  130         LIST_HEAD(,mqfs_node)   mn_children;
  131         LIST_ENTRY(mqfs_node)   mn_sibling;
  132         LIST_HEAD(,mqfs_vdata)  mn_vnodes;
  133         int                     mn_refcount;
  134         mqfs_type_t             mn_type;
  135         int                     mn_deleted;
  136         uint32_t                mn_fileno;
  137         void                    *mn_data;
  138         struct timespec         mn_birth;
  139         struct timespec         mn_ctime;
  140         struct timespec         mn_atime;
  141         struct timespec         mn_mtime;
  142         uid_t                   mn_uid;
  143         gid_t                   mn_gid;
  144         int                     mn_mode;
  145 };
  146 
  147 #define VTON(vp)        (((struct mqfs_vdata *)((vp)->v_data))->mv_node)
  148 #define VTOMQ(vp)       ((struct mqueue *)(VTON(vp)->mn_data))
  149 #define VFSTOMQFS(m)    ((struct mqfs_info *)((m)->mnt_data))
  150 #define FPTOMQ(fp)      ((struct mqueue *)(((struct mqfs_node *) \
  151                                 (fp)->f_data)->mn_data))
  152 
  153 TAILQ_HEAD(msgq, mqueue_msg);
  154 
  155 struct mqueue;
  156 
  157 struct mqueue_notifier {
  158         LIST_ENTRY(mqueue_notifier)     nt_link;
  159         struct sigevent                 nt_sigev;
  160         ksiginfo_t                      nt_ksi;
  161         struct proc                     *nt_proc;
  162 };
  163 
  164 struct mqueue {
  165         struct mtx      mq_mutex;
  166         int             mq_flags;
  167         long            mq_maxmsg;
  168         long            mq_msgsize;
  169         long            mq_curmsgs;
  170         long            mq_totalbytes;
  171         struct msgq     mq_msgq;
  172         int             mq_receivers;
  173         int             mq_senders;
  174         struct selinfo  mq_rsel;
  175         struct selinfo  mq_wsel;
  176         struct mqueue_notifier  *mq_notifier;
  177 };
  178 
  179 #define MQ_RSEL         0x01
  180 #define MQ_WSEL         0x02
  181 
  182 struct mqueue_msg {
  183         TAILQ_ENTRY(mqueue_msg) msg_link;
  184         unsigned int    msg_prio;
  185         unsigned int    msg_size;
  186         /* following real data... */
  187 };
  188 
  189 SYSCTL_NODE(_kern, OID_AUTO, mqueue, CTLFLAG_RW, 0,
  190         "POSIX real time message queue");
  191 
  192 static int      default_maxmsg  = 10;
  193 static int      default_msgsize = 1024;
  194 
  195 static int      maxmsg = 100;
  196 SYSCTL_INT(_kern_mqueue, OID_AUTO, maxmsg, CTLFLAG_RW,
  197     &maxmsg, 0, "Default maximum messages in queue");
  198 static int      maxmsgsize = 16384;
  199 SYSCTL_INT(_kern_mqueue, OID_AUTO, maxmsgsize, CTLFLAG_RW,
  200     &maxmsgsize, 0, "Default maximum message size");
  201 static int      maxmq = 100;
  202 SYSCTL_INT(_kern_mqueue, OID_AUTO, maxmq, CTLFLAG_RW,
  203     &maxmq, 0, "maximum message queues");
  204 static int      curmq = 0;
  205 SYSCTL_INT(_kern_mqueue, OID_AUTO, curmq, CTLFLAG_RW,
  206     &curmq, 0, "current message queue number");
  207 static int      unloadable = 0;
  208 static MALLOC_DEFINE(M_MQUEUEDATA, "mqdata", "mqueue data");
  209 
  210 static eventhandler_tag exit_tag;
  211 
  212 /* Only one instance per-system */
  213 static struct mqfs_info         mqfs_data;
  214 static uma_zone_t               mqnode_zone;
  215 static uma_zone_t               mqueue_zone;
  216 static uma_zone_t               mvdata_zone;
  217 static uma_zone_t               mqnoti_zone;
  218 static struct vop_vector        mqfs_vnodeops;
  219 static struct fileops           mqueueops;
  220 
  221 /*
  222  * Directory structure construction and manipulation
  223  */
  224 #ifdef notyet
  225 static struct mqfs_node *mqfs_create_dir(struct mqfs_node *parent,
  226         const char *name, int namelen, struct ucred *cred, int mode);
  227 static struct mqfs_node *mqfs_create_link(struct mqfs_node *parent,
  228         const char *name, int namelen, struct ucred *cred, int mode);
  229 #endif
  230 
  231 static struct mqfs_node *mqfs_create_file(struct mqfs_node *parent,
  232         const char *name, int namelen, struct ucred *cred, int mode);
  233 static int      mqfs_destroy(struct mqfs_node *mn);
  234 static void     mqfs_fileno_alloc(struct mqfs_info *mi, struct mqfs_node *mn);
  235 static void     mqfs_fileno_free(struct mqfs_info *mi, struct mqfs_node *mn);
  236 static int      mqfs_allocv(struct mount *mp, struct vnode **vpp, struct mqfs_node *pn);
  237 
  238 /*
  239  * Message queue construction and maniplation
  240  */
  241 static struct mqueue    *mqueue_alloc(const struct mq_attr *attr);
  242 static void     mqueue_free(struct mqueue *mq);
  243 static int      mqueue_send(struct mqueue *mq, const char *msg_ptr,
  244                         size_t msg_len, unsigned msg_prio, int waitok,
  245                         const struct timespec *abs_timeout);
  246 static int      mqueue_receive(struct mqueue *mq, char *msg_ptr,
  247                         size_t msg_len, unsigned *msg_prio, int waitok,
  248                         const struct timespec *abs_timeout);
  249 static int      _mqueue_send(struct mqueue *mq, struct mqueue_msg *msg,
  250                         int timo);
  251 static int      _mqueue_recv(struct mqueue *mq, struct mqueue_msg **msg,
  252                         int timo);
  253 static void     mqueue_send_notification(struct mqueue *mq);
  254 static void     mqueue_fdclose(struct thread *td, int fd, struct file *fp);
  255 static void     mq_proc_exit(void *arg, struct proc *p);
  256 
  257 /*
  258  * kqueue filters
  259  */
  260 static void     filt_mqdetach(struct knote *kn);
  261 static int      filt_mqread(struct knote *kn, long hint);
  262 static int      filt_mqwrite(struct knote *kn, long hint);
  263 
  264 struct filterops mq_rfiltops = {
  265         .f_isfd = 1,
  266         .f_detach = filt_mqdetach,
  267         .f_event = filt_mqread,
  268 };
  269 struct filterops mq_wfiltops = {
  270         .f_isfd = 1,
  271         .f_detach = filt_mqdetach,
  272         .f_event = filt_mqwrite,
  273 };
  274 
  275 /*
  276  * Initialize fileno bitmap
  277  */
  278 static void
  279 mqfs_fileno_init(struct mqfs_info *mi)
  280 {
  281         struct unrhdr *up;
  282 
  283         up = new_unrhdr(1, INT_MAX, NULL);
  284         mi->mi_unrhdr = up;
  285 }
  286 
  287 /*
  288  * Tear down fileno bitmap
  289  */
  290 static void
  291 mqfs_fileno_uninit(struct mqfs_info *mi)
  292 {
  293         struct unrhdr *up;
  294 
  295         up = mi->mi_unrhdr;
  296         mi->mi_unrhdr = NULL;
  297         delete_unrhdr(up);
  298 }
  299 
  300 /*
  301  * Allocate a file number
  302  */
  303 static void
  304 mqfs_fileno_alloc(struct mqfs_info *mi, struct mqfs_node *mn)
  305 {
  306         /* make sure our parent has a file number */
  307         if (mn->mn_parent && !mn->mn_parent->mn_fileno)
  308                 mqfs_fileno_alloc(mi, mn->mn_parent);
  309 
  310         switch (mn->mn_type) {
  311         case mqfstype_root:
  312         case mqfstype_dir:
  313         case mqfstype_file:
  314         case mqfstype_symlink:
  315                 mn->mn_fileno = alloc_unr(mi->mi_unrhdr);
  316                 break;
  317         case mqfstype_this:
  318                 KASSERT(mn->mn_parent != NULL,
  319                     ("mqfstype_this node has no parent"));
  320                 mn->mn_fileno = mn->mn_parent->mn_fileno;
  321                 break;
  322         case mqfstype_parent:
  323                 KASSERT(mn->mn_parent != NULL,
  324                     ("mqfstype_parent node has no parent"));
  325                 if (mn->mn_parent == mi->mi_root) {
  326                         mn->mn_fileno = mn->mn_parent->mn_fileno;
  327                         break;
  328                 }
  329                 KASSERT(mn->mn_parent->mn_parent != NULL,
  330                     ("mqfstype_parent node has no grandparent"));
  331                 mn->mn_fileno = mn->mn_parent->mn_parent->mn_fileno;
  332                 break;
  333         default:
  334                 KASSERT(0,
  335                     ("mqfs_fileno_alloc() called for unknown type node: %d",
  336                         mn->mn_type));
  337                 break;
  338         }
  339 }
  340 
  341 /*
  342  * Release a file number
  343  */
  344 static void
  345 mqfs_fileno_free(struct mqfs_info *mi, struct mqfs_node *mn)
  346 {
  347         switch (mn->mn_type) {
  348         case mqfstype_root:
  349         case mqfstype_dir:
  350         case mqfstype_file:
  351         case mqfstype_symlink:
  352                 free_unr(mi->mi_unrhdr, mn->mn_fileno);
  353                 break;
  354         case mqfstype_this:
  355         case mqfstype_parent:
  356                 /* ignore these, as they don't "own" their file number */
  357                 break;
  358         default:
  359                 KASSERT(0,
  360                     ("mqfs_fileno_free() called for unknown type node: %d", 
  361                         mn->mn_type));
  362                 break;
  363         }
  364 }
  365 
  366 static __inline struct mqfs_node *
  367 mqnode_alloc(void)
  368 {
  369         return uma_zalloc(mqnode_zone, M_WAITOK | M_ZERO);
  370 }
  371 
  372 static __inline void
  373 mqnode_free(struct mqfs_node *node)
  374 {
  375         uma_zfree(mqnode_zone, node);
  376 }
  377 
  378 static __inline void
  379 mqnode_addref(struct mqfs_node *node)
  380 {
  381         atomic_fetchadd_int(&node->mn_refcount, 1);
  382 }
  383 
  384 static __inline void
  385 mqnode_release(struct mqfs_node *node)
  386 {
  387         struct mqfs_info *mqfs;
  388         int old, exp;
  389 
  390         mqfs = node->mn_info;
  391         old = atomic_fetchadd_int(&node->mn_refcount, -1);
  392         if (node->mn_type == mqfstype_dir ||
  393             node->mn_type == mqfstype_root)
  394                 exp = 3; /* include . and .. */
  395         else
  396                 exp = 1;
  397         if (old == exp) {
  398                 int locked = sx_xlocked(&mqfs->mi_lock);
  399                 if (!locked)
  400                         sx_xlock(&mqfs->mi_lock);
  401                 mqfs_destroy(node);
  402                 if (!locked)
  403                         sx_xunlock(&mqfs->mi_lock);
  404         }
  405 }
  406 
  407 /*
  408  * Add a node to a directory
  409  */
  410 static int
  411 mqfs_add_node(struct mqfs_node *parent, struct mqfs_node *node)
  412 {
  413         KASSERT(parent != NULL, ("%s(): parent is NULL", __func__));
  414         KASSERT(parent->mn_info != NULL,
  415             ("%s(): parent has no mn_info", __func__));
  416         KASSERT(parent->mn_type == mqfstype_dir ||
  417             parent->mn_type == mqfstype_root,
  418             ("%s(): parent is not a directory", __func__));
  419 
  420         node->mn_info = parent->mn_info;
  421         node->mn_parent = parent;
  422         LIST_INIT(&node->mn_children);
  423         LIST_INIT(&node->mn_vnodes);
  424         LIST_INSERT_HEAD(&parent->mn_children, node, mn_sibling);
  425         mqnode_addref(parent);
  426         return (0);
  427 }
  428 
  429 static struct mqfs_node *
  430 mqfs_create_node(const char *name, int namelen, struct ucred *cred, int mode,
  431         int nodetype)
  432 {
  433         struct mqfs_node *node;
  434 
  435         node = mqnode_alloc();
  436         strncpy(node->mn_name, name, namelen);
  437         node->mn_type = nodetype;
  438         node->mn_refcount = 1;
  439         vfs_timestamp(&node->mn_birth);
  440         node->mn_ctime = node->mn_atime = node->mn_mtime
  441                 = node->mn_birth;
  442         node->mn_uid = cred->cr_uid;
  443         node->mn_gid = cred->cr_gid;
  444         node->mn_mode = mode;
  445         return (node);
  446 }
  447 
  448 /*
  449  * Create a file
  450  */
  451 static struct mqfs_node *
  452 mqfs_create_file(struct mqfs_node *parent, const char *name, int namelen,
  453         struct ucred *cred, int mode)
  454 {
  455         struct mqfs_node *node;
  456 
  457         node = mqfs_create_node(name, namelen, cred, mode, mqfstype_file);
  458         if (mqfs_add_node(parent, node) != 0) {
  459                 mqnode_free(node);
  460                 return (NULL);
  461         }
  462         return (node);
  463 }
  464 
  465 /*
  466  * Add . and .. to a directory
  467  */
  468 static int
  469 mqfs_fixup_dir(struct mqfs_node *parent)
  470 {
  471         struct mqfs_node *dir;
  472 
  473         dir = mqnode_alloc();
  474         dir->mn_name[0] = '.';
  475         dir->mn_type = mqfstype_this;
  476         dir->mn_refcount = 1;
  477         if (mqfs_add_node(parent, dir) != 0) {
  478                 mqnode_free(dir);
  479                 return (-1);
  480         }
  481 
  482         dir = mqnode_alloc();
  483         dir->mn_name[0] = dir->mn_name[1] = '.';
  484         dir->mn_type = mqfstype_parent;
  485         dir->mn_refcount = 1;
  486 
  487         if (mqfs_add_node(parent, dir) != 0) {
  488                 mqnode_free(dir);
  489                 return (-1);
  490         }
  491 
  492         return (0);
  493 }
  494 
  495 #ifdef notyet
  496 
  497 /*
  498  * Create a directory
  499  */
  500 static struct mqfs_node *
  501 mqfs_create_dir(struct mqfs_node *parent, const char *name, int namelen,
  502         struct ucred *cred, int mode)
  503 {
  504         struct mqfs_node *node;
  505 
  506         node = mqfs_create_node(name, namelen, cred, mode, mqfstype_dir);
  507         if (mqfs_add_node(parent, node) != 0) {
  508                 mqnode_free(node);
  509                 return (NULL);
  510         }
  511 
  512         if (mqfs_fixup_dir(node) != 0) {
  513                 mqfs_destroy(node);
  514                 return (NULL);
  515         }
  516         return (node);
  517 }
  518 
  519 /*
  520  * Create a symlink
  521  */
  522 static struct mqfs_node *
  523 mqfs_create_link(struct mqfs_node *parent, const char *name, int namelen,
  524         struct ucred *cred, int mode)
  525 {
  526         struct mqfs_node *node;
  527 
  528         node = mqfs_create_node(name, namelen, cred, mode, mqfstype_symlink);
  529         if (mqfs_add_node(parent, node) != 0) {
  530                 mqnode_free(node);
  531                 return (NULL);
  532         }
  533         return (node);
  534 }
  535 
  536 #endif
  537 
  538 /*
  539  * Destroy a node or a tree of nodes
  540  */
  541 static int
  542 mqfs_destroy(struct mqfs_node *node)
  543 {
  544         struct mqfs_node *parent;
  545 
  546         KASSERT(node != NULL,
  547             ("%s(): node is NULL", __func__));
  548         KASSERT(node->mn_info != NULL,
  549             ("%s(): node has no mn_info", __func__));
  550 
  551         /* destroy children */
  552         if (node->mn_type == mqfstype_dir || node->mn_type == mqfstype_root)
  553                 while (! LIST_EMPTY(&node->mn_children))
  554                         mqfs_destroy(LIST_FIRST(&node->mn_children));
  555 
  556         /* unlink from parent */
  557         if ((parent = node->mn_parent) != NULL) {
  558                 KASSERT(parent->mn_info == node->mn_info,
  559                     ("%s(): parent has different mn_info", __func__));
  560                 LIST_REMOVE(node, mn_sibling);
  561         }
  562 
  563         if (node->mn_fileno != 0)
  564                 mqfs_fileno_free(node->mn_info, node);
  565         if (node->mn_data != NULL)
  566                 mqueue_free(node->mn_data);
  567         mqnode_free(node);
  568         return (0);
  569 }
  570 
  571 /*
  572  * Mount a mqfs instance
  573  */
  574 static int
  575 mqfs_mount(struct mount *mp)
  576 {
  577         struct statfs *sbp;
  578 
  579         if (mp->mnt_flag & MNT_UPDATE)
  580                 return (EOPNOTSUPP);
  581 
  582         mp->mnt_data = &mqfs_data;
  583         MNT_ILOCK(mp);
  584         mp->mnt_flag |= MNT_LOCAL;
  585         mp->mnt_kern_flag |= MNTK_MPSAFE;
  586         MNT_IUNLOCK(mp);
  587         vfs_getnewfsid(mp);
  588 
  589         sbp = &mp->mnt_stat;
  590         vfs_mountedfrom(mp, "mqueue");
  591         sbp->f_bsize = PAGE_SIZE;
  592         sbp->f_iosize = PAGE_SIZE;
  593         sbp->f_blocks = 1;
  594         sbp->f_bfree = 0;
  595         sbp->f_bavail = 0;
  596         sbp->f_files = 1;
  597         sbp->f_ffree = 0;
  598         return (0);
  599 }
  600 
  601 /*
  602  * Unmount a mqfs instance
  603  */
  604 static int
  605 mqfs_unmount(struct mount *mp, int mntflags)
  606 {
  607         int error;
  608 
  609         error = vflush(mp, 0, (mntflags & MNT_FORCE) ?  FORCECLOSE : 0,
  610             curthread);
  611         return (error);
  612 }
  613 
  614 /*
  615  * Return a root vnode
  616  */
  617 static int
  618 mqfs_root(struct mount *mp, int flags, struct vnode **vpp)
  619 {
  620         struct mqfs_info *mqfs;
  621         int ret;
  622 
  623         mqfs = VFSTOMQFS(mp);
  624         ret = mqfs_allocv(mp, vpp, mqfs->mi_root);
  625         return (ret);
  626 }
  627 
  628 /*
  629  * Return filesystem stats
  630  */
  631 static int
  632 mqfs_statfs(struct mount *mp, struct statfs *sbp)
  633 {
  634         /* XXX update statistics */
  635         return (0);
  636 }
  637 
  638 /*
  639  * Initialize a mqfs instance
  640  */
  641 static int
  642 mqfs_init(struct vfsconf *vfc)
  643 {
  644         struct mqfs_node *root;
  645         struct mqfs_info *mi;
  646 
  647         mqnode_zone = uma_zcreate("mqnode", sizeof(struct mqfs_node),
  648                 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
  649         mqueue_zone = uma_zcreate("mqueue", sizeof(struct mqueue),
  650                 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
  651         mvdata_zone = uma_zcreate("mvdata",
  652                 sizeof(struct mqfs_vdata), NULL, NULL, NULL,
  653                 NULL, UMA_ALIGN_PTR, 0);
  654         mqnoti_zone = uma_zcreate("mqnotifier", sizeof(struct mqueue_notifier),
  655                 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
  656         mi = &mqfs_data;
  657         sx_init(&mi->mi_lock, "mqfs lock");
  658         /* set up the root diretory */
  659         root = mqfs_create_node("/", 1, curthread->td_ucred, 01777,
  660                 mqfstype_root);
  661         root->mn_info = mi;
  662         LIST_INIT(&root->mn_children);
  663         LIST_INIT(&root->mn_vnodes);
  664         mi->mi_root = root;
  665         mqfs_fileno_init(mi);
  666         mqfs_fileno_alloc(mi, root);
  667         mqfs_fixup_dir(root);
  668         exit_tag = EVENTHANDLER_REGISTER(process_exit, mq_proc_exit, NULL,
  669             EVENTHANDLER_PRI_ANY);
  670         mq_fdclose = mqueue_fdclose;
  671         p31b_setcfg(CTL_P1003_1B_MESSAGE_PASSING, _POSIX_MESSAGE_PASSING);
  672         return (0);
  673 }
  674 
  675 /*
  676  * Destroy a mqfs instance
  677  */
  678 static int
  679 mqfs_uninit(struct vfsconf *vfc)
  680 {
  681         struct mqfs_info *mi;
  682 
  683         if (!unloadable)
  684                 return (EOPNOTSUPP);
  685         EVENTHANDLER_DEREGISTER(process_exit, exit_tag);
  686         mi = &mqfs_data;
  687         mqfs_destroy(mi->mi_root);
  688         mi->mi_root = NULL;
  689         mqfs_fileno_uninit(mi);
  690         sx_destroy(&mi->mi_lock);
  691         uma_zdestroy(mqnode_zone);
  692         uma_zdestroy(mqueue_zone);
  693         uma_zdestroy(mvdata_zone);
  694         uma_zdestroy(mqnoti_zone);
  695         return (0);
  696 }
  697 
  698 /*
  699  * task routine
  700  */
  701 static void
  702 do_recycle(void *context, int pending __unused)
  703 {
  704         struct vnode *vp = (struct vnode *)context;
  705 
  706         vrecycle(vp, curthread);
  707         vdrop(vp);
  708 }
  709 
  710 /*
  711  * Allocate a vnode
  712  */
  713 static int
  714 mqfs_allocv(struct mount *mp, struct vnode **vpp, struct mqfs_node *pn)
  715 {
  716         struct mqfs_vdata *vd;
  717         struct mqfs_info  *mqfs;
  718         struct vnode *newvpp;
  719         int error;
  720 
  721         mqfs = pn->mn_info;
  722         *vpp = NULL;
  723         sx_xlock(&mqfs->mi_lock);
  724         LIST_FOREACH(vd, &pn->mn_vnodes, mv_link) {
  725                 if (vd->mv_vnode->v_mount == mp) {
  726                         vhold(vd->mv_vnode);
  727                         break;
  728                 }
  729         }
  730 
  731         if (vd != NULL) {
  732 found:
  733                 *vpp = vd->mv_vnode;
  734                 sx_xunlock(&mqfs->mi_lock);
  735                 error = vget(*vpp, LK_RETRY | LK_EXCLUSIVE, curthread);
  736                 vdrop(*vpp);
  737                 return (error);
  738         }
  739         sx_xunlock(&mqfs->mi_lock);
  740 
  741         error = getnewvnode("mqueue", mp, &mqfs_vnodeops, &newvpp);
  742         if (error)
  743                 return (error);
  744         vn_lock(newvpp, LK_EXCLUSIVE | LK_RETRY);
  745         error = insmntque(newvpp, mp);
  746         if (error != 0)
  747                 return (error);
  748 
  749         sx_xlock(&mqfs->mi_lock);
  750         /*
  751          * Check if it has already been allocated
  752          * while we were blocked.
  753          */
  754         LIST_FOREACH(vd, &pn->mn_vnodes, mv_link) {
  755                 if (vd->mv_vnode->v_mount == mp) {
  756                         vhold(vd->mv_vnode);
  757                         sx_xunlock(&mqfs->mi_lock);
  758 
  759                         vgone(newvpp);
  760                         vput(newvpp);
  761                         goto found;
  762                 }
  763         }
  764 
  765         *vpp = newvpp;
  766 
  767         vd = uma_zalloc(mvdata_zone, M_WAITOK);
  768         (*vpp)->v_data = vd;
  769         vd->mv_vnode = *vpp;
  770         vd->mv_node = pn;
  771         TASK_INIT(&vd->mv_task, 0, do_recycle, *vpp);
  772         LIST_INSERT_HEAD(&pn->mn_vnodes, vd, mv_link);
  773         mqnode_addref(pn);
  774         switch (pn->mn_type) {
  775         case mqfstype_root:
  776                 (*vpp)->v_vflag = VV_ROOT;
  777                 /* fall through */
  778         case mqfstype_dir:
  779         case mqfstype_this:
  780         case mqfstype_parent:
  781                 (*vpp)->v_type = VDIR;
  782                 break;
  783         case mqfstype_file:
  784                 (*vpp)->v_type = VREG;
  785                 break;
  786         case mqfstype_symlink:
  787                 (*vpp)->v_type = VLNK;
  788                 break;
  789         case mqfstype_none:
  790                 KASSERT(0, ("mqfs_allocf called for null node\n"));
  791         default:
  792                 panic("%s has unexpected type: %d", pn->mn_name, pn->mn_type);
  793         }
  794         sx_xunlock(&mqfs->mi_lock);
  795         return (0);
  796 }
  797 
  798 /* 
  799  * Search a directory entry
  800  */
  801 static struct mqfs_node *
  802 mqfs_search(struct mqfs_node *pd, const char *name, int len)
  803 {
  804         struct mqfs_node *pn;
  805 
  806         sx_assert(&pd->mn_info->mi_lock, SX_LOCKED);
  807         LIST_FOREACH(pn, &pd->mn_children, mn_sibling) {
  808                 if (strncmp(pn->mn_name, name, len) == 0 &&
  809                     pn->mn_name[len] == '\0')
  810                         return (pn);
  811         }
  812         return (NULL);
  813 }
  814 
  815 /*
  816  * Look up a file or directory.
  817  */
  818 static int
  819 mqfs_lookupx(struct vop_cachedlookup_args *ap)
  820 {
  821         struct componentname *cnp;
  822         struct vnode *dvp, **vpp;
  823         struct mqfs_node *pd;
  824         struct mqfs_node *pn;
  825         struct mqfs_info *mqfs;
  826         int nameiop, flags, error, namelen;
  827         char *pname;
  828         struct thread *td;
  829 
  830         cnp = ap->a_cnp;
  831         vpp = ap->a_vpp;
  832         dvp = ap->a_dvp;
  833         pname = cnp->cn_nameptr;
  834         namelen = cnp->cn_namelen;
  835         td = cnp->cn_thread;
  836         flags = cnp->cn_flags;
  837         nameiop = cnp->cn_nameiop;
  838         pd = VTON(dvp);
  839         pn = NULL;
  840         mqfs = pd->mn_info;
  841         *vpp = NULLVP;
  842 
  843         if (dvp->v_type != VDIR)
  844                 return (ENOTDIR);
  845 
  846         error = VOP_ACCESS(dvp, VEXEC, cnp->cn_cred, cnp->cn_thread);
  847         if (error)
  848                 return (error);
  849 
  850         /* shortcut: check if the name is too long */
  851         if (cnp->cn_namelen >= MQFS_NAMELEN)
  852                 return (ENOENT);
  853 
  854         /* self */
  855         if (namelen == 1 && pname[0] == '.') {
  856                 if ((flags & ISLASTCN) && nameiop != LOOKUP)
  857                         return (EINVAL);
  858                 pn = pd;
  859                 *vpp = dvp;
  860                 VREF(dvp);
  861                 return (0);
  862         }
  863 
  864         /* parent */
  865         if (cnp->cn_flags & ISDOTDOT) {
  866                 if (dvp->v_vflag & VV_ROOT)
  867                         return (EIO);
  868                 if ((flags & ISLASTCN) && nameiop != LOOKUP)
  869                         return (EINVAL);
  870                 VOP_UNLOCK(dvp, 0);
  871                 KASSERT(pd->mn_parent, ("non-root directory has no parent"));
  872                 pn = pd->mn_parent;
  873                 error = mqfs_allocv(dvp->v_mount, vpp, pn);
  874                 vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY);
  875                 return (error);
  876         }
  877 
  878         /* named node */
  879         sx_xlock(&mqfs->mi_lock);
  880         pn = mqfs_search(pd, pname, namelen);
  881         if (pn != NULL)
  882                 mqnode_addref(pn);
  883         sx_xunlock(&mqfs->mi_lock);
  884         
  885         /* found */
  886         if (pn != NULL) {
  887                 /* DELETE */
  888                 if (nameiop == DELETE && (flags & ISLASTCN)) {
  889                         error = VOP_ACCESS(dvp, VWRITE, cnp->cn_cred, td);
  890                         if (error) {
  891                                 mqnode_release(pn);
  892                                 return (error);
  893                         }
  894                         if (*vpp == dvp) {
  895                                 VREF(dvp);
  896                                 *vpp = dvp;
  897                                 mqnode_release(pn);
  898                                 return (0);
  899                         }
  900                 }
  901 
  902                 /* allocate vnode */
  903                 error = mqfs_allocv(dvp->v_mount, vpp, pn);
  904                 mqnode_release(pn);
  905                 if (error == 0 && cnp->cn_flags & MAKEENTRY)
  906                         cache_enter(dvp, *vpp, cnp);
  907                 return (error);
  908         }
  909         
  910         /* not found */
  911 
  912         /* will create a new entry in the directory ? */
  913         if ((nameiop == CREATE || nameiop == RENAME) && (flags & LOCKPARENT)
  914             && (flags & ISLASTCN)) {
  915                 error = VOP_ACCESS(dvp, VWRITE, cnp->cn_cred, td);
  916                 if (error)
  917                         return (error);
  918                 cnp->cn_flags |= SAVENAME;
  919                 return (EJUSTRETURN);
  920         }
  921         return (ENOENT);
  922 }
  923 
  924 #if 0
  925 struct vop_lookup_args {
  926         struct vop_generic_args a_gen;
  927         struct vnode *a_dvp;
  928         struct vnode **a_vpp;
  929         struct componentname *a_cnp;
  930 };
  931 #endif
  932 
  933 /*
  934  * vnode lookup operation
  935  */
  936 static int
  937 mqfs_lookup(struct vop_cachedlookup_args *ap)
  938 {
  939         int rc;
  940 
  941         rc = mqfs_lookupx(ap);
  942         return (rc);
  943 }
  944 
  945 #if 0
  946 struct vop_create_args {
  947         struct vnode *a_dvp;
  948         struct vnode **a_vpp;
  949         struct componentname *a_cnp;
  950         struct vattr *a_vap;
  951 };
  952 #endif
  953 
  954 /*
  955  * vnode creation operation
  956  */
  957 static int
  958 mqfs_create(struct vop_create_args *ap)
  959 {
  960         struct mqfs_info *mqfs = VFSTOMQFS(ap->a_dvp->v_mount);
  961         struct componentname *cnp = ap->a_cnp;
  962         struct mqfs_node *pd;
  963         struct mqfs_node *pn;
  964         struct mqueue *mq;
  965         int error;
  966 
  967         pd = VTON(ap->a_dvp);
  968         if (pd->mn_type != mqfstype_root && pd->mn_type != mqfstype_dir)
  969                 return (ENOTDIR);
  970         mq = mqueue_alloc(NULL);
  971         if (mq == NULL)
  972                 return (EAGAIN);
  973         sx_xlock(&mqfs->mi_lock);
  974         if ((cnp->cn_flags & HASBUF) == 0)
  975                 panic("%s: no name", __func__);
  976         pn = mqfs_create_file(pd, cnp->cn_nameptr, cnp->cn_namelen,
  977                 cnp->cn_cred, ap->a_vap->va_mode);
  978         if (pn == NULL) {
  979                 sx_xunlock(&mqfs->mi_lock);
  980                 error = ENOSPC;
  981         } else {
  982                 mqnode_addref(pn);
  983                 sx_xunlock(&mqfs->mi_lock);
  984                 error = mqfs_allocv(ap->a_dvp->v_mount, ap->a_vpp, pn);
  985                 mqnode_release(pn);
  986                 if (error)
  987                         mqfs_destroy(pn);
  988                 else
  989                         pn->mn_data = mq;
  990         }
  991         if (error)
  992                 mqueue_free(mq);
  993         return (error);
  994 }
  995 
  996 /*
  997  * Remove an entry
  998  */
  999 static
 1000 int do_unlink(struct mqfs_node *pn, struct ucred *ucred)
 1001 {
 1002         struct mqfs_node *parent;
 1003         struct mqfs_vdata *vd;
 1004         int error = 0;
 1005 
 1006         sx_assert(&pn->mn_info->mi_lock, SX_LOCKED);
 1007 
 1008         if (ucred->cr_uid != pn->mn_uid &&
 1009             (error = priv_check_cred(ucred, PRIV_MQ_ADMIN, 0)) != 0)
 1010                 error = EACCES;
 1011         else if (!pn->mn_deleted) {
 1012                 parent = pn->mn_parent;
 1013                 pn->mn_parent = NULL;
 1014                 pn->mn_deleted = 1;
 1015                 LIST_REMOVE(pn, mn_sibling);
 1016                 LIST_FOREACH(vd, &pn->mn_vnodes, mv_link) {
 1017                         cache_purge(vd->mv_vnode);
 1018                         vhold(vd->mv_vnode);
 1019                         taskqueue_enqueue(taskqueue_thread, &vd->mv_task);
 1020                 }
 1021                 mqnode_release(pn);
 1022                 mqnode_release(parent);
 1023         } else
 1024                 error = ENOENT;
 1025         return (error);
 1026 }
 1027 
 1028 #if 0
 1029 struct vop_remove_args {
 1030         struct vnode *a_dvp;
 1031         struct vnode *a_vp;
 1032         struct componentname *a_cnp;
 1033 };
 1034 #endif
 1035 
 1036 /*
 1037  * vnode removal operation
 1038  */
 1039 static int
 1040 mqfs_remove(struct vop_remove_args *ap)
 1041 {
 1042         struct mqfs_info *mqfs = VFSTOMQFS(ap->a_dvp->v_mount);
 1043         struct mqfs_node *pn;
 1044         int error;
 1045 
 1046         if (ap->a_vp->v_type == VDIR)
 1047                 return (EPERM);
 1048         pn = VTON(ap->a_vp);
 1049         sx_xlock(&mqfs->mi_lock);
 1050         error = do_unlink(pn, ap->a_cnp->cn_cred);
 1051         sx_xunlock(&mqfs->mi_lock);
 1052         return (error);
 1053 }
 1054 
 1055 #if 0
 1056 struct vop_inactive_args {
 1057         struct vnode *a_vp;
 1058         struct thread *a_td;
 1059 };
 1060 #endif
 1061 
 1062 static int
 1063 mqfs_inactive(struct vop_inactive_args *ap)
 1064 {
 1065         struct mqfs_node *pn = VTON(ap->a_vp);
 1066 
 1067         if (pn->mn_deleted)
 1068                 vrecycle(ap->a_vp, ap->a_td);
 1069         return (0);
 1070 }
 1071 
 1072 #if 0
 1073 struct vop_reclaim_args {
 1074         struct vop_generic_args a_gen;
 1075         struct vnode *a_vp;
 1076         struct thread *a_td;
 1077 };
 1078 #endif
 1079 
 1080 static int
 1081 mqfs_reclaim(struct vop_reclaim_args *ap)
 1082 {
 1083         struct mqfs_info *mqfs = VFSTOMQFS(ap->a_vp->v_mount);
 1084         struct vnode *vp = ap->a_vp;
 1085         struct mqfs_node *pn;
 1086         struct mqfs_vdata *vd;
 1087 
 1088         vd = vp->v_data;
 1089         pn = vd->mv_node;
 1090         sx_xlock(&mqfs->mi_lock);
 1091         vp->v_data = NULL;
 1092         LIST_REMOVE(vd, mv_link);
 1093         uma_zfree(mvdata_zone, vd);
 1094         mqnode_release(pn);
 1095         sx_xunlock(&mqfs->mi_lock);
 1096         return (0);
 1097 }
 1098 
 1099 #if 0
 1100 struct vop_open_args {
 1101         struct vop_generic_args a_gen;
 1102         struct vnode *a_vp;
 1103         int a_mode;
 1104         struct ucred *a_cred;
 1105         struct thread *a_td;
 1106         struct file *a_fp;
 1107 };
 1108 #endif
 1109 
 1110 static int
 1111 mqfs_open(struct vop_open_args *ap)
 1112 {
 1113         return (0);
 1114 }
 1115 
 1116 #if 0
 1117 struct vop_close_args {
 1118         struct vop_generic_args a_gen;
 1119         struct vnode *a_vp;
 1120         int a_fflag;
 1121         struct ucred *a_cred;
 1122         struct thread *a_td;
 1123 };
 1124 #endif
 1125 
 1126 static int
 1127 mqfs_close(struct vop_close_args *ap)
 1128 {
 1129         return (0);
 1130 }
 1131 
 1132 #if 0
 1133 struct vop_access_args {
 1134         struct vop_generic_args a_gen;
 1135         struct vnode *a_vp;
 1136         accmode_t a_accmode;
 1137         struct ucred *a_cred;
 1138         struct thread *a_td;
 1139 };
 1140 #endif
 1141 
 1142 /*
 1143  * Verify permissions
 1144  */
 1145 static int
 1146 mqfs_access(struct vop_access_args *ap)
 1147 {
 1148         struct vnode *vp = ap->a_vp;
 1149         struct vattr vattr;
 1150         int error;
 1151 
 1152         error = VOP_GETATTR(vp, &vattr, ap->a_cred);
 1153         if (error)
 1154                 return (error);
 1155         error = vaccess(vp->v_type, vattr.va_mode, vattr.va_uid,
 1156             vattr.va_gid, ap->a_accmode, ap->a_cred, NULL);
 1157         return (error);
 1158 }
 1159 
 1160 #if 0
 1161 struct vop_getattr_args {
 1162         struct vop_generic_args a_gen;
 1163         struct vnode *a_vp;
 1164         struct vattr *a_vap;
 1165         struct ucred *a_cred;
 1166 };
 1167 #endif
 1168 
 1169 /*
 1170  * Get file attributes
 1171  */
 1172 static int
 1173 mqfs_getattr(struct vop_getattr_args *ap)
 1174 {
 1175         struct vnode *vp = ap->a_vp;
 1176         struct mqfs_node *pn = VTON(vp);
 1177         struct vattr *vap = ap->a_vap;
 1178         int error = 0;
 1179 
 1180         vap->va_type = vp->v_type;
 1181         vap->va_mode = pn->mn_mode;
 1182         vap->va_nlink = 1;
 1183         vap->va_uid = pn->mn_uid;
 1184         vap->va_gid = pn->mn_gid;
 1185         vap->va_fsid = vp->v_mount->mnt_stat.f_fsid.val[0];
 1186         vap->va_fileid = pn->mn_fileno;
 1187         vap->va_size = 0;
 1188         vap->va_blocksize = PAGE_SIZE;
 1189         vap->va_bytes = vap->va_size = 0;
 1190         vap->va_atime = pn->mn_atime;
 1191         vap->va_mtime = pn->mn_mtime;
 1192         vap->va_ctime = pn->mn_ctime;
 1193         vap->va_birthtime = pn->mn_birth;
 1194         vap->va_gen = 0;
 1195         vap->va_flags = 0;
 1196         vap->va_rdev = NODEV;
 1197         vap->va_bytes = 0;
 1198         vap->va_filerev = 0;
 1199         return (error);
 1200 }
 1201 
 1202 #if 0
 1203 struct vop_setattr_args {
 1204         struct vop_generic_args a_gen;
 1205         struct vnode *a_vp;
 1206         struct vattr *a_vap;
 1207         struct ucred *a_cred;
 1208 };
 1209 #endif
 1210 /*
 1211  * Set attributes
 1212  */
 1213 static int
 1214 mqfs_setattr(struct vop_setattr_args *ap)
 1215 {
 1216         struct mqfs_node *pn;
 1217         struct vattr *vap;
 1218         struct vnode *vp;
 1219         struct thread *td;
 1220         int c, error;
 1221         uid_t uid;
 1222         gid_t gid;
 1223 
 1224         td = curthread;
 1225         vap = ap->a_vap;
 1226         vp = ap->a_vp;
 1227         if ((vap->va_type != VNON) ||
 1228             (vap->va_nlink != VNOVAL) ||
 1229             (vap->va_fsid != VNOVAL) ||
 1230             (vap->va_fileid != VNOVAL) ||
 1231             (vap->va_blocksize != VNOVAL) ||
 1232             (vap->va_flags != VNOVAL && vap->va_flags != 0) ||
 1233             (vap->va_rdev != VNOVAL) ||
 1234             ((int)vap->va_bytes != VNOVAL) ||
 1235             (vap->va_gen != VNOVAL)) {
 1236                 return (EINVAL);
 1237         }
 1238 
 1239         pn = VTON(vp);
 1240 
 1241         error = c = 0;
 1242         if (vap->va_uid == (uid_t)VNOVAL)
 1243                 uid = pn->mn_uid;
 1244         else
 1245                 uid = vap->va_uid;
 1246         if (vap->va_gid == (gid_t)VNOVAL)
 1247                 gid = pn->mn_gid;
 1248         else
 1249                 gid = vap->va_gid;
 1250 
 1251         if (uid != pn->mn_uid || gid != pn->mn_gid) {
 1252                 /*
 1253                  * To modify the ownership of a file, must possess VADMIN
 1254                  * for that file.
 1255                  */
 1256                 if ((error = VOP_ACCESS(vp, VADMIN, ap->a_cred, td)))
 1257                         return (error);
 1258 
 1259                 /*
 1260                  * XXXRW: Why is there a privilege check here: shouldn't the
 1261                  * check in VOP_ACCESS() be enough?  Also, are the group bits
 1262                  * below definitely right?
 1263                  */
 1264                 if (((ap->a_cred->cr_uid != pn->mn_uid) || uid != pn->mn_uid ||
 1265                     (gid != pn->mn_gid && !groupmember(gid, ap->a_cred))) &&
 1266                     (error = priv_check(td, PRIV_MQ_ADMIN)) != 0)
 1267                         return (error);
 1268                 pn->mn_uid = uid;
 1269                 pn->mn_gid = gid;
 1270                 c = 1;
 1271         }
 1272 
 1273         if (vap->va_mode != (mode_t)VNOVAL) {
 1274                 if ((ap->a_cred->cr_uid != pn->mn_uid) &&
 1275                     (error = priv_check(td, PRIV_MQ_ADMIN)))
 1276                         return (error);
 1277                 pn->mn_mode = vap->va_mode;
 1278                 c = 1;
 1279         }
 1280 
 1281         if (vap->va_atime.tv_sec != VNOVAL || vap->va_mtime.tv_sec != VNOVAL) {
 1282                 /* See the comment in ufs_vnops::ufs_setattr(). */
 1283                 if ((error = VOP_ACCESS(vp, VADMIN, ap->a_cred, td)) &&
 1284                     ((vap->va_vaflags & VA_UTIMES_NULL) == 0 ||
 1285                     (error = VOP_ACCESS(vp, VWRITE, ap->a_cred, td))))
 1286                         return (error);
 1287                 if (vap->va_atime.tv_sec != VNOVAL) {
 1288                         pn->mn_atime = vap->va_atime;
 1289                 }
 1290                 if (vap->va_mtime.tv_sec != VNOVAL) {
 1291                         pn->mn_mtime = vap->va_mtime;
 1292                 }
 1293                 c = 1;
 1294         }
 1295         if (c) {
 1296                 vfs_timestamp(&pn->mn_ctime);
 1297         }
 1298         return (0);
 1299 }
 1300 
 1301 #if 0
 1302 struct vop_read_args {
 1303         struct vop_generic_args a_gen;
 1304         struct vnode *a_vp;
 1305         struct uio *a_uio;
 1306         int a_ioflag;
 1307         struct ucred *a_cred;
 1308 };
 1309 #endif
 1310 
 1311 /*
 1312  * Read from a file
 1313  */
 1314 static int
 1315 mqfs_read(struct vop_read_args *ap)
 1316 {
 1317         char buf[80];
 1318         struct vnode *vp = ap->a_vp;
 1319         struct uio *uio = ap->a_uio;
 1320         struct mqfs_node *pn;
 1321         struct mqueue *mq;
 1322         int len, error;
 1323 
 1324         if (vp->v_type != VREG)
 1325                 return (EINVAL);
 1326 
 1327         pn = VTON(vp);
 1328         mq = VTOMQ(vp);
 1329         snprintf(buf, sizeof(buf),
 1330                 "QSIZE:%-10ld MAXMSG:%-10ld CURMSG:%-10ld MSGSIZE:%-10ld\n",
 1331                 mq->mq_totalbytes,
 1332                 mq->mq_maxmsg,
 1333                 mq->mq_curmsgs,
 1334                 mq->mq_msgsize);
 1335         buf[sizeof(buf)-1] = '\0';
 1336         len = strlen(buf);
 1337         error = uiomove_frombuf(buf, len, uio);
 1338         return (error);
 1339 }
 1340 
 1341 #if 0
 1342 struct vop_readdir_args {
 1343         struct vop_generic_args a_gen;
 1344         struct vnode *a_vp;
 1345         struct uio *a_uio;
 1346         struct ucred *a_cred;
 1347         int *a_eofflag;
 1348         int *a_ncookies;
 1349         u_long **a_cookies;
 1350 };
 1351 #endif
 1352 
 1353 /*
 1354  * Return directory entries.
 1355  */
 1356 static int
 1357 mqfs_readdir(struct vop_readdir_args *ap)
 1358 {
 1359         struct vnode *vp;
 1360         struct mqfs_info *mi;
 1361         struct mqfs_node *pd;
 1362         struct mqfs_node *pn;
 1363         struct dirent entry;
 1364         struct uio *uio;
 1365         int *tmp_ncookies = NULL;
 1366         off_t offset;
 1367         int error, i;
 1368 
 1369         vp = ap->a_vp;
 1370         mi = VFSTOMQFS(vp->v_mount);
 1371         pd = VTON(vp);
 1372         uio = ap->a_uio;
 1373 
 1374         if (vp->v_type != VDIR)
 1375                 return (ENOTDIR);
 1376 
 1377         if (uio->uio_offset < 0)
 1378                 return (EINVAL);
 1379 
 1380         if (ap->a_ncookies != NULL) {
 1381                 tmp_ncookies = ap->a_ncookies;
 1382                 *ap->a_ncookies = 0;
 1383                 ap->a_ncookies = NULL;
 1384         }
 1385 
 1386         error = 0;
 1387         offset = 0;
 1388 
 1389         sx_xlock(&mi->mi_lock);
 1390 
 1391         LIST_FOREACH(pn, &pd->mn_children, mn_sibling) {
 1392                 entry.d_reclen = sizeof(entry);
 1393                 if (!pn->mn_fileno)
 1394                         mqfs_fileno_alloc(mi, pn);
 1395                 entry.d_fileno = pn->mn_fileno;
 1396                 for (i = 0; i < MQFS_NAMELEN - 1 && pn->mn_name[i] != '\0'; ++i)
 1397                         entry.d_name[i] = pn->mn_name[i];
 1398                 entry.d_name[i] = 0;
 1399                 entry.d_namlen = i;
 1400                 switch (pn->mn_type) {
 1401                 case mqfstype_root:
 1402                 case mqfstype_dir:
 1403                 case mqfstype_this:
 1404                 case mqfstype_parent:
 1405                         entry.d_type = DT_DIR;
 1406                         break;
 1407                 case mqfstype_file:
 1408                         entry.d_type = DT_REG;
 1409                         break;
 1410                 case mqfstype_symlink:
 1411                         entry.d_type = DT_LNK;
 1412                         break;
 1413                 default:
 1414                         panic("%s has unexpected node type: %d", pn->mn_name,
 1415                                 pn->mn_type);
 1416                 }
 1417                 if (entry.d_reclen > uio->uio_resid)
 1418                         break;
 1419                 if (offset >= uio->uio_offset) {
 1420                         error = vfs_read_dirent(ap, &entry, offset);
 1421                         if (error)
 1422                                 break;
 1423                 }
 1424                 offset += entry.d_reclen;
 1425         }
 1426         sx_xunlock(&mi->mi_lock);
 1427 
 1428         uio->uio_offset = offset;
 1429 
 1430         if (tmp_ncookies != NULL)
 1431                 ap->a_ncookies = tmp_ncookies;
 1432 
 1433         return (error);
 1434 }
 1435 
 1436 #ifdef notyet
 1437 
 1438 #if 0
 1439 struct vop_mkdir_args {
 1440         struct vnode *a_dvp;
 1441         struvt vnode **a_vpp;
 1442         struvt componentname *a_cnp;
 1443         struct vattr *a_vap;
 1444 };
 1445 #endif
 1446 
 1447 /*
 1448  * Create a directory.
 1449  */
 1450 static int
 1451 mqfs_mkdir(struct vop_mkdir_args *ap)
 1452 {
 1453         struct mqfs_info *mqfs = VFSTOMQFS(ap->a_dvp->v_mount);
 1454         struct componentname *cnp = ap->a_cnp;
 1455         struct mqfs_node *pd = VTON(ap->a_dvp);
 1456         struct mqfs_node *pn;
 1457         int error;
 1458 
 1459         if (pd->mn_type != mqfstype_root && pd->mn_type != mqfstype_dir)
 1460                 return (ENOTDIR);
 1461         sx_xlock(&mqfs->mi_lock);
 1462         if ((cnp->cn_flags & HASBUF) == 0)
 1463                 panic("%s: no name", __func__);
 1464         pn = mqfs_create_dir(pd, cnp->cn_nameptr, cnp->cn_namelen,
 1465                 ap->a_vap->cn_cred, ap->a_vap->va_mode);
 1466         if (pn != NULL)
 1467                 mqnode_addref(pn);
 1468         sx_xunlock(&mqfs->mi_lock);
 1469         if (pn == NULL) {
 1470                 error = ENOSPC;
 1471         } else {
 1472                 error = mqfs_allocv(ap->a_dvp->v_mount, ap->a_vpp, pn);
 1473                 mqnode_release(pn);
 1474         }
 1475         return (error);
 1476 }
 1477 
 1478 #if 0
 1479 struct vop_rmdir_args {
 1480         struct vnode *a_dvp;
 1481         struct vnode *a_vp;
 1482         struct componentname *a_cnp;
 1483 };
 1484 #endif
 1485 
 1486 /*
 1487  * Remove a directory.
 1488  */
 1489 static int
 1490 mqfs_rmdir(struct vop_rmdir_args *ap)
 1491 {
 1492         struct mqfs_info *mqfs = VFSTOMQFS(ap->a_dvp->v_mount);
 1493         struct mqfs_node *pn = VTON(ap->a_vp);
 1494         struct mqfs_node *pt;
 1495 
 1496         if (pn->mn_type != mqfstype_dir)
 1497                 return (ENOTDIR);
 1498 
 1499         sx_xlock(&mqfs->mi_lock);
 1500         if (pn->mn_deleted) {
 1501                 sx_xunlock(&mqfs->mi_lock);
 1502                 return (ENOENT);
 1503         }
 1504 
 1505         pt = LIST_FIRST(&pn->mn_children);
 1506         pt = LIST_NEXT(pt, mn_sibling);
 1507         pt = LIST_NEXT(pt, mn_sibling);
 1508         if (pt != NULL) {
 1509                 sx_xunlock(&mqfs->mi_lock);
 1510                 return (ENOTEMPTY);
 1511         }
 1512         pt = pn->mn_parent;
 1513         pn->mn_parent = NULL;
 1514         pn->mn_deleted = 1;
 1515         LIST_REMOVE(pn, mn_sibling);
 1516         mqnode_release(pn);
 1517         mqnode_release(pt);
 1518         sx_xunlock(&mqfs->mi_lock);
 1519         cache_purge(ap->a_vp);
 1520         return (0);
 1521 }
 1522 
 1523 #endif /* notyet */
 1524 
 1525 /*
 1526  * Allocate a message queue
 1527  */
 1528 static struct mqueue *
 1529 mqueue_alloc(const struct mq_attr *attr)
 1530 {
 1531         struct mqueue *mq;
 1532 
 1533         if (curmq >= maxmq)
 1534                 return (NULL);
 1535         mq = uma_zalloc(mqueue_zone, M_WAITOK | M_ZERO);
 1536         TAILQ_INIT(&mq->mq_msgq);
 1537         if (attr != NULL) {
 1538                 mq->mq_maxmsg = attr->mq_maxmsg;
 1539                 mq->mq_msgsize = attr->mq_msgsize;
 1540         } else {
 1541                 mq->mq_maxmsg = default_maxmsg;
 1542                 mq->mq_msgsize = default_msgsize;
 1543         }
 1544         mtx_init(&mq->mq_mutex, "mqueue lock", NULL, MTX_DEF);
 1545         knlist_init_mtx(&mq->mq_rsel.si_note, &mq->mq_mutex);
 1546         knlist_init_mtx(&mq->mq_wsel.si_note, &mq->mq_mutex);
 1547         atomic_add_int(&curmq, 1);
 1548         return (mq);
 1549 }
 1550 
 1551 /*
 1552  * Destroy a message queue
 1553  */
 1554 static void
 1555 mqueue_free(struct mqueue *mq)
 1556 {
 1557         struct mqueue_msg *msg;
 1558 
 1559         while ((msg = TAILQ_FIRST(&mq->mq_msgq)) != NULL) {
 1560                 TAILQ_REMOVE(&mq->mq_msgq, msg, msg_link);
 1561                 free(msg, M_MQUEUEDATA);
 1562         }
 1563 
 1564         mtx_destroy(&mq->mq_mutex);
 1565         seldrain(&mq->mq_rsel);
 1566         seldrain(&mq->mq_wsel);
 1567         knlist_destroy(&mq->mq_rsel.si_note);
 1568         knlist_destroy(&mq->mq_wsel.si_note);
 1569         uma_zfree(mqueue_zone, mq);
 1570         atomic_add_int(&curmq, -1);
 1571 }
 1572 
 1573 /*
 1574  * Load a message from user space
 1575  */
 1576 static struct mqueue_msg *
 1577 mqueue_loadmsg(const char *msg_ptr, size_t msg_size, int msg_prio)
 1578 {
 1579         struct mqueue_msg *msg;
 1580         size_t len;
 1581         int error;
 1582 
 1583         len = sizeof(struct mqueue_msg) + msg_size;
 1584         msg = malloc(len, M_MQUEUEDATA, M_WAITOK);
 1585         error = copyin(msg_ptr, ((char *)msg) + sizeof(struct mqueue_msg),
 1586             msg_size);
 1587         if (error) {
 1588                 free(msg, M_MQUEUEDATA);
 1589                 msg = NULL;
 1590         } else {
 1591                 msg->msg_size = msg_size;
 1592                 msg->msg_prio = msg_prio;
 1593         }
 1594         return (msg);
 1595 }
 1596 
 1597 /*
 1598  * Save a message to user space
 1599  */
 1600 static int
 1601 mqueue_savemsg(struct mqueue_msg *msg, char *msg_ptr, int *msg_prio)
 1602 {
 1603         int error;
 1604 
 1605         error = copyout(((char *)msg) + sizeof(*msg), msg_ptr,
 1606                 msg->msg_size);
 1607         if (error == 0 && msg_prio != NULL)
 1608                 error = copyout(&msg->msg_prio, msg_prio, sizeof(int));
 1609         return (error);
 1610 }
 1611 
 1612 /*
 1613  * Free a message's memory
 1614  */
 1615 static __inline void
 1616 mqueue_freemsg(struct mqueue_msg *msg)
 1617 {
 1618         free(msg, M_MQUEUEDATA);
 1619 }
 1620 
 1621 /*
 1622  * Send a message. if waitok is false, thread will not be
 1623  * blocked if there is no data in queue, otherwise, absolute
 1624  * time will be checked.
 1625  */
 1626 int
 1627 mqueue_send(struct mqueue *mq, const char *msg_ptr,
 1628         size_t msg_len, unsigned msg_prio, int waitok,
 1629         const struct timespec *abs_timeout)
 1630 {
 1631         struct mqueue_msg *msg;
 1632         struct timespec ts, ts2;
 1633         struct timeval tv;
 1634         int error;
 1635 
 1636         if (msg_prio >= MQ_PRIO_MAX)
 1637                 return (EINVAL);
 1638         if (msg_len > mq->mq_msgsize)
 1639                 return (EMSGSIZE);
 1640         msg = mqueue_loadmsg(msg_ptr, msg_len, msg_prio);
 1641         if (msg == NULL)
 1642                 return (EFAULT);
 1643 
 1644         /* O_NONBLOCK case */
 1645         if (!waitok) {
 1646                 error = _mqueue_send(mq, msg, -1);
 1647                 if (error)
 1648                         goto bad;
 1649                 return (0);
 1650         }
 1651 
 1652         /* we allow a null timeout (wait forever) */
 1653         if (abs_timeout == NULL) {
 1654                 error = _mqueue_send(mq, msg, 0);
 1655                 if (error)
 1656                         goto bad;
 1657                 return (0);
 1658         }
 1659 
 1660         /* send it before checking time */
 1661         error = _mqueue_send(mq, msg, -1);
 1662         if (error == 0)
 1663                 return (0);
 1664 
 1665         if (error != EAGAIN)
 1666                 goto bad;
 1667 
 1668         if (abs_timeout->tv_nsec >= 1000000000 || abs_timeout->tv_nsec < 0) {
 1669                 error = EINVAL;
 1670                 goto bad;
 1671         }
 1672         for (;;) {
 1673                 ts2 = *abs_timeout;
 1674                 getnanotime(&ts);
 1675                 timespecsub(&ts2, &ts);
 1676                 if (ts2.tv_sec < 0 || (ts2.tv_sec == 0 && ts2.tv_nsec <= 0)) {
 1677                         error = ETIMEDOUT;
 1678                         break;
 1679                 }
 1680                 TIMESPEC_TO_TIMEVAL(&tv, &ts2);
 1681                 error = _mqueue_send(mq, msg, tvtohz(&tv));
 1682                 if (error != ETIMEDOUT)
 1683                         break;
 1684         }
 1685         if (error == 0)
 1686                 return (0);
 1687 bad:
 1688         mqueue_freemsg(msg);
 1689         return (error);
 1690 }
 1691 
 1692 /*
 1693  * Common routine to send a message
 1694  */
 1695 static int
 1696 _mqueue_send(struct mqueue *mq, struct mqueue_msg *msg, int timo)
 1697 {       
 1698         struct mqueue_msg *msg2;
 1699         int error = 0;
 1700 
 1701         mtx_lock(&mq->mq_mutex);
 1702         while (mq->mq_curmsgs >= mq->mq_maxmsg && error == 0) {
 1703                 if (timo < 0) {
 1704                         mtx_unlock(&mq->mq_mutex);
 1705                         return (EAGAIN);
 1706                 }
 1707                 mq->mq_senders++;
 1708                 error = msleep(&mq->mq_senders, &mq->mq_mutex,
 1709                             PCATCH, "mqsend", timo);
 1710                 mq->mq_senders--;
 1711                 if (error == EAGAIN)
 1712                         error = ETIMEDOUT;
 1713         }
 1714         if (mq->mq_curmsgs >= mq->mq_maxmsg) {
 1715                 mtx_unlock(&mq->mq_mutex);
 1716                 return (error);
 1717         }
 1718         error = 0;
 1719         if (TAILQ_EMPTY(&mq->mq_msgq)) {
 1720                 TAILQ_INSERT_HEAD(&mq->mq_msgq, msg, msg_link);
 1721         } else {
 1722                 if (msg->msg_prio <= TAILQ_LAST(&mq->mq_msgq, msgq)->msg_prio) {
 1723                         TAILQ_INSERT_TAIL(&mq->mq_msgq, msg, msg_link);
 1724                 } else {
 1725                         TAILQ_FOREACH(msg2, &mq->mq_msgq, msg_link) {
 1726                                 if (msg2->msg_prio < msg->msg_prio)
 1727                                         break;
 1728                         }
 1729                         TAILQ_INSERT_BEFORE(msg2, msg, msg_link);
 1730                 }
 1731         }
 1732         mq->mq_curmsgs++;
 1733         mq->mq_totalbytes += msg->msg_size;
 1734         if (mq->mq_receivers)
 1735                 wakeup_one(&mq->mq_receivers);
 1736         else if (mq->mq_notifier != NULL)
 1737                 mqueue_send_notification(mq);
 1738         if (mq->mq_flags & MQ_RSEL) {
 1739                 mq->mq_flags &= ~MQ_RSEL;
 1740                 selwakeup(&mq->mq_rsel);
 1741         }
 1742         KNOTE_LOCKED(&mq->mq_rsel.si_note, 0);
 1743         mtx_unlock(&mq->mq_mutex);
 1744         return (0);
 1745 }
 1746 
 1747 /*
 1748  * Send realtime a signal to process which registered itself
 1749  * successfully by mq_notify.
 1750  */
 1751 static void
 1752 mqueue_send_notification(struct mqueue *mq)
 1753 {
 1754         struct mqueue_notifier *nt;
 1755         struct thread *td;
 1756         struct proc *p;
 1757         int error;
 1758 
 1759         mtx_assert(&mq->mq_mutex, MA_OWNED);
 1760         nt = mq->mq_notifier;
 1761         if (nt->nt_sigev.sigev_notify != SIGEV_NONE) {
 1762                 p = nt->nt_proc;
 1763                 error = sigev_findtd(p, &nt->nt_sigev, &td);
 1764                 if (error) {
 1765                         mq->mq_notifier = NULL;
 1766                         return;
 1767                 }
 1768                 if (!KSI_ONQ(&nt->nt_ksi)) {
 1769                         ksiginfo_set_sigev(&nt->nt_ksi, &nt->nt_sigev);
 1770                         tdsendsignal(p, td, nt->nt_ksi.ksi_signo, &nt->nt_ksi);
 1771                 }
 1772                 PROC_UNLOCK(p);
 1773         }
 1774         mq->mq_notifier = NULL;
 1775 }
 1776 
 1777 /*
 1778  * Get a message. if waitok is false, thread will not be
 1779  * blocked if there is no data in queue, otherwise, absolute
 1780  * time will be checked.
 1781  */
 1782 int
 1783 mqueue_receive(struct mqueue *mq, char *msg_ptr,
 1784         size_t msg_len, unsigned *msg_prio, int waitok,
 1785         const struct timespec *abs_timeout)
 1786 {
 1787         struct mqueue_msg *msg;
 1788         struct timespec ts, ts2;
 1789         struct timeval tv;
 1790         int error;
 1791 
 1792         if (msg_len < mq->mq_msgsize)
 1793                 return (EMSGSIZE);
 1794 
 1795         /* O_NONBLOCK case */
 1796         if (!waitok) {
 1797                 error = _mqueue_recv(mq, &msg, -1);
 1798                 if (error)
 1799                         return (error);
 1800                 goto received;
 1801         }
 1802 
 1803         /* we allow a null timeout (wait forever). */
 1804         if (abs_timeout == NULL) {
 1805                 error = _mqueue_recv(mq, &msg, 0);
 1806                 if (error)
 1807                         return (error);
 1808                 goto received;
 1809         }
 1810 
 1811         /* try to get a message before checking time */
 1812         error = _mqueue_recv(mq, &msg, -1);
 1813         if (error == 0)
 1814                 goto received;
 1815 
 1816         if (error != EAGAIN)
 1817                 return (error);
 1818 
 1819         if (abs_timeout->tv_nsec >= 1000000000 || abs_timeout->tv_nsec < 0) {
 1820                 error = EINVAL;
 1821                 return (error);
 1822         }
 1823 
 1824         for (;;) {
 1825                 ts2 = *abs_timeout;
 1826                 getnanotime(&ts);
 1827                 timespecsub(&ts2, &ts);
 1828                 if (ts2.tv_sec < 0 || (ts2.tv_sec == 0 && ts2.tv_nsec <= 0)) {
 1829                         error = ETIMEDOUT;
 1830                         return (error);
 1831                 }
 1832                 TIMESPEC_TO_TIMEVAL(&tv, &ts2);
 1833                 error = _mqueue_recv(mq, &msg, tvtohz(&tv));
 1834                 if (error == 0)
 1835                         break;
 1836                 if (error != ETIMEDOUT)
 1837                         return (error);
 1838         }
 1839 
 1840 received:
 1841         error = mqueue_savemsg(msg, msg_ptr, msg_prio);
 1842         if (error == 0) {
 1843                 curthread->td_retval[0] = msg->msg_size;
 1844                 curthread->td_retval[1] = 0;
 1845         }
 1846         mqueue_freemsg(msg);
 1847         return (error);
 1848 }
 1849 
 1850 /*
 1851  * Common routine to receive a message
 1852  */
 1853 static int
 1854 _mqueue_recv(struct mqueue *mq, struct mqueue_msg **msg, int timo)
 1855 {       
 1856         int error = 0;
 1857         
 1858         mtx_lock(&mq->mq_mutex);
 1859         while ((*msg = TAILQ_FIRST(&mq->mq_msgq)) == NULL && error == 0) {
 1860                 if (timo < 0) {
 1861                         mtx_unlock(&mq->mq_mutex);
 1862                         return (EAGAIN);
 1863                 }
 1864                 mq->mq_receivers++;
 1865                 error = msleep(&mq->mq_receivers, &mq->mq_mutex,
 1866                             PCATCH, "mqrecv", timo);
 1867                 mq->mq_receivers--;
 1868                 if (error == EAGAIN)
 1869                         error = ETIMEDOUT;
 1870         }
 1871         if (*msg != NULL) {
 1872                 error = 0;
 1873                 TAILQ_REMOVE(&mq->mq_msgq, *msg, msg_link);
 1874                 mq->mq_curmsgs--;
 1875                 mq->mq_totalbytes -= (*msg)->msg_size;
 1876                 if (mq->mq_senders)
 1877                         wakeup_one(&mq->mq_senders);
 1878                 if (mq->mq_flags & MQ_WSEL) {
 1879                         mq->mq_flags &= ~MQ_WSEL;
 1880                         selwakeup(&mq->mq_wsel);
 1881                 }
 1882                 KNOTE_LOCKED(&mq->mq_wsel.si_note, 0);
 1883         }
 1884         if (mq->mq_notifier != NULL && mq->mq_receivers == 0 &&
 1885             !TAILQ_EMPTY(&mq->mq_msgq)) {
 1886                 mqueue_send_notification(mq);
 1887         }
 1888         mtx_unlock(&mq->mq_mutex);
 1889         return (error);
 1890 }
 1891 
 1892 static __inline struct mqueue_notifier *
 1893 notifier_alloc(void)
 1894 {
 1895         return (uma_zalloc(mqnoti_zone, M_WAITOK | M_ZERO));
 1896 }
 1897 
 1898 static __inline void
 1899 notifier_free(struct mqueue_notifier *p)
 1900 {
 1901         uma_zfree(mqnoti_zone, p);
 1902 }
 1903 
 1904 static struct mqueue_notifier *
 1905 notifier_search(struct proc *p, int fd)
 1906 {
 1907         struct mqueue_notifier *nt;
 1908 
 1909         LIST_FOREACH(nt, &p->p_mqnotifier, nt_link) {
 1910                 if (nt->nt_ksi.ksi_mqd == fd)
 1911                         break;
 1912         }
 1913         return (nt);
 1914 }
 1915 
 1916 static __inline void
 1917 notifier_insert(struct proc *p, struct mqueue_notifier *nt)
 1918 {
 1919         LIST_INSERT_HEAD(&p->p_mqnotifier, nt, nt_link);
 1920 }
 1921 
 1922 static __inline void
 1923 notifier_delete(struct proc *p, struct mqueue_notifier *nt)
 1924 {
 1925         LIST_REMOVE(nt, nt_link);
 1926         notifier_free(nt);
 1927 }
 1928 
 1929 static void
 1930 notifier_remove(struct proc *p, struct mqueue *mq, int fd)
 1931 {
 1932         struct mqueue_notifier *nt;
 1933 
 1934         mtx_assert(&mq->mq_mutex, MA_OWNED);
 1935         PROC_LOCK(p);
 1936         nt = notifier_search(p, fd);
 1937         if (nt != NULL) {
 1938                 if (mq->mq_notifier == nt)
 1939                         mq->mq_notifier = NULL;
 1940                 sigqueue_take(&nt->nt_ksi);
 1941                 notifier_delete(p, nt);
 1942         }
 1943         PROC_UNLOCK(p);
 1944 }
 1945 
 1946 static int
 1947 kern_kmq_open(struct thread *td, const char *upath, int flags, mode_t mode,
 1948     const struct mq_attr *attr)
 1949 {
 1950         char path[MQFS_NAMELEN + 1];
 1951         struct mqfs_node *pn;
 1952         struct filedesc *fdp;
 1953         struct file *fp;
 1954         struct mqueue *mq;
 1955         int fd, error, len, cmode;
 1956 
 1957         fdp = td->td_proc->p_fd;
 1958         cmode = (((mode & ~fdp->fd_cmask) & ALLPERMS) & ~S_ISTXT);
 1959         mq = NULL;
 1960         if ((flags & O_CREAT) != 0 && attr != NULL) {
 1961                 if (attr->mq_maxmsg <= 0 || attr->mq_maxmsg > maxmsg)
 1962                         return (EINVAL);
 1963                 if (attr->mq_msgsize <= 0 || attr->mq_msgsize > maxmsgsize)
 1964                         return (EINVAL);
 1965         }
 1966 
 1967         error = copyinstr(upath, path, MQFS_NAMELEN + 1, NULL);
 1968         if (error)
 1969                 return (error);
 1970 
 1971         /*
 1972          * The first character of name must be a slash  (/) character
 1973          * and the remaining characters of name cannot include any slash
 1974          * characters. 
 1975          */
 1976         len = strlen(path);
 1977         if (len < 2  || path[0] != '/' || index(path + 1, '/') != NULL)
 1978                 return (EINVAL);
 1979 
 1980         error = falloc(td, &fp, &fd, 0);
 1981         if (error)
 1982                 return (error);
 1983 
 1984         sx_xlock(&mqfs_data.mi_lock);
 1985         pn = mqfs_search(mqfs_data.mi_root, path + 1, len - 1);
 1986         if (pn == NULL) {
 1987                 if (!(flags & O_CREAT)) {
 1988                         error = ENOENT;
 1989                 } else {
 1990                         mq = mqueue_alloc(attr);
 1991                         if (mq == NULL) {
 1992                                 error = ENFILE;
 1993                         } else {
 1994                                 pn = mqfs_create_file(mqfs_data.mi_root,
 1995                                          path + 1, len - 1, td->td_ucred,
 1996                                          cmode);
 1997                                 if (pn == NULL) {
 1998                                         error = ENOSPC;
 1999                                         mqueue_free(mq);
 2000                                 }
 2001                         }
 2002                 }
 2003 
 2004                 if (error == 0) {
 2005                         pn->mn_data = mq;
 2006                 }
 2007         } else {
 2008                 if ((flags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL)) {
 2009                         error = EEXIST;
 2010                 } else {
 2011                         accmode_t accmode = 0;
 2012 
 2013                         if (flags & FREAD)
 2014                                 accmode |= VREAD;
 2015                         if (flags & FWRITE)
 2016                                 accmode |= VWRITE;
 2017                         error = vaccess(VREG, pn->mn_mode, pn->mn_uid,
 2018                                     pn->mn_gid, accmode, td->td_ucred, NULL);
 2019                 }
 2020         }
 2021 
 2022         if (error) {
 2023                 sx_xunlock(&mqfs_data.mi_lock);
 2024                 fdclose(fdp, fp, fd, td);
 2025                 fdrop(fp, td);
 2026                 return (error);
 2027         }
 2028 
 2029         mqnode_addref(pn);
 2030         sx_xunlock(&mqfs_data.mi_lock);
 2031 
 2032         finit(fp, flags & (FREAD | FWRITE | O_NONBLOCK), DTYPE_MQUEUE, pn,
 2033             &mqueueops);
 2034 
 2035         FILEDESC_XLOCK(fdp);
 2036         if (fdp->fd_ofiles[fd] == fp)
 2037                 fdp->fd_ofileflags[fd] |= UF_EXCLOSE;
 2038         FILEDESC_XUNLOCK(fdp);
 2039         td->td_retval[0] = fd;
 2040         fdrop(fp, td);
 2041         return (0);
 2042 }
 2043 
 2044 /*
 2045  * Syscall to open a message queue.
 2046  */
 2047 int
 2048 sys_kmq_open(struct thread *td, struct kmq_open_args *uap)
 2049 {
 2050         struct mq_attr attr;
 2051         int flags, error;
 2052 
 2053         if ((uap->flags & O_ACCMODE) == O_ACCMODE)
 2054                 return (EINVAL);
 2055         flags = FFLAGS(uap->flags);
 2056         if ((flags & O_CREAT) != 0 && uap->attr != NULL) {
 2057                 error = copyin(uap->attr, &attr, sizeof(attr));
 2058                 if (error)
 2059                         return (error);
 2060         }
 2061         return (kern_kmq_open(td, uap->path, flags, uap->mode,
 2062             uap->attr != NULL ? &attr : NULL));
 2063 }
 2064 
 2065 /*
 2066  * Syscall to unlink a message queue.
 2067  */
 2068 int
 2069 sys_kmq_unlink(struct thread *td, struct kmq_unlink_args *uap)
 2070 {
 2071         char path[MQFS_NAMELEN+1];
 2072         struct mqfs_node *pn;
 2073         int error, len;
 2074 
 2075         error = copyinstr(uap->path, path, MQFS_NAMELEN + 1, NULL);
 2076         if (error)
 2077                 return (error);
 2078 
 2079         len = strlen(path);
 2080         if (len < 2  || path[0] != '/' || index(path + 1, '/') != NULL)
 2081                 return (EINVAL);
 2082 
 2083         sx_xlock(&mqfs_data.mi_lock);
 2084         pn = mqfs_search(mqfs_data.mi_root, path + 1, len - 1);
 2085         if (pn != NULL)
 2086                 error = do_unlink(pn, td->td_ucred);
 2087         else
 2088                 error = ENOENT;
 2089         sx_xunlock(&mqfs_data.mi_lock);
 2090         return (error);
 2091 }
 2092 
 2093 typedef int (*_fgetf)(struct thread *, int, cap_rights_t, struct file **);
 2094 
 2095 /*
 2096  * Get message queue by giving file slot
 2097  */
 2098 static int
 2099 _getmq(struct thread *td, int fd, cap_rights_t rights, _fgetf func,
 2100        struct file **fpp, struct mqfs_node **ppn, struct mqueue **pmq)
 2101 {
 2102         struct mqfs_node *pn;
 2103         int error;
 2104 
 2105         error = func(td, fd, rights, fpp);
 2106         if (error)
 2107                 return (error);
 2108         if (&mqueueops != (*fpp)->f_ops) {
 2109                 fdrop(*fpp, td);
 2110                 return (EBADF);
 2111         }
 2112         pn = (*fpp)->f_data;
 2113         if (ppn)
 2114                 *ppn = pn;
 2115         if (pmq)
 2116                 *pmq = pn->mn_data;
 2117         return (0);
 2118 }
 2119 
 2120 static __inline int
 2121 getmq(struct thread *td, int fd, struct file **fpp, struct mqfs_node **ppn,
 2122         struct mqueue **pmq)
 2123 {
 2124         return _getmq(td, fd, CAP_POLL_EVENT, fget, fpp, ppn, pmq);
 2125 }
 2126 
 2127 static __inline int
 2128 getmq_read(struct thread *td, int fd, struct file **fpp,
 2129          struct mqfs_node **ppn, struct mqueue **pmq)
 2130 {
 2131         return _getmq(td, fd, CAP_READ, fget_read, fpp, ppn, pmq);
 2132 }
 2133 
 2134 static __inline int
 2135 getmq_write(struct thread *td, int fd, struct file **fpp,
 2136         struct mqfs_node **ppn, struct mqueue **pmq)
 2137 {
 2138         return _getmq(td, fd, CAP_WRITE, fget_write, fpp, ppn, pmq);
 2139 }
 2140 
 2141 static int
 2142 kern_kmq_setattr(struct thread *td, int mqd, const struct mq_attr *attr,
 2143     struct mq_attr *oattr)
 2144 {
 2145         struct mqueue *mq;
 2146         struct file *fp;
 2147         u_int oflag, flag;
 2148         int error;
 2149 
 2150         if (attr != NULL && (attr->mq_flags & ~O_NONBLOCK) != 0)
 2151                 return (EINVAL);
 2152         error = getmq(td, mqd, &fp, NULL, &mq);
 2153         if (error)
 2154                 return (error);
 2155         oattr->mq_maxmsg  = mq->mq_maxmsg;
 2156         oattr->mq_msgsize = mq->mq_msgsize;
 2157         oattr->mq_curmsgs = mq->mq_curmsgs;
 2158         if (attr != NULL) {
 2159                 do {
 2160                         oflag = flag = fp->f_flag;
 2161                         flag &= ~O_NONBLOCK;
 2162                         flag |= (attr->mq_flags & O_NONBLOCK);
 2163                 } while (atomic_cmpset_int(&fp->f_flag, oflag, flag) == 0);
 2164         } else
 2165                 oflag = fp->f_flag;
 2166         oattr->mq_flags = (O_NONBLOCK & oflag);
 2167         fdrop(fp, td);
 2168         return (error);
 2169 }
 2170 
 2171 int
 2172 sys_kmq_setattr(struct thread *td, struct kmq_setattr_args *uap)
 2173 {
 2174         struct mq_attr attr, oattr;
 2175         int error;
 2176 
 2177         if (uap->attr != NULL) {
 2178                 error = copyin(uap->attr, &attr, sizeof(attr));
 2179                 if (error != 0)
 2180                         return (error);
 2181         }
 2182         error = kern_kmq_setattr(td, uap->mqd, uap->attr != NULL ? &attr : NULL,
 2183             &oattr);
 2184         if (error != 0)
 2185                 return (error);
 2186         if (uap->oattr != NULL)
 2187                 error = copyout(&oattr, uap->oattr, sizeof(oattr));
 2188         return (error);
 2189 }
 2190 
 2191 int
 2192 sys_kmq_timedreceive(struct thread *td, struct kmq_timedreceive_args *uap)
 2193 {
 2194         struct mqueue *mq;
 2195         struct file *fp;
 2196         struct timespec *abs_timeout, ets;
 2197         int error;
 2198         int waitok;
 2199 
 2200         error = getmq_read(td, uap->mqd, &fp, NULL, &mq);
 2201         if (error)
 2202                 return (error);
 2203         if (uap->abs_timeout != NULL) {
 2204                 error = copyin(uap->abs_timeout, &ets, sizeof(ets));
 2205                 if (error != 0)
 2206                         return (error);
 2207                 abs_timeout = &ets;
 2208         } else
 2209                 abs_timeout = NULL;
 2210         waitok = !(fp->f_flag & O_NONBLOCK);
 2211         error = mqueue_receive(mq, uap->msg_ptr, uap->msg_len,
 2212                 uap->msg_prio, waitok, abs_timeout);
 2213         fdrop(fp, td);
 2214         return (error);
 2215 }
 2216 
 2217 int
 2218 sys_kmq_timedsend(struct thread *td, struct kmq_timedsend_args *uap)
 2219 {
 2220         struct mqueue *mq;
 2221         struct file *fp;
 2222         struct timespec *abs_timeout, ets;
 2223         int error, waitok;
 2224 
 2225         error = getmq_write(td, uap->mqd, &fp, NULL, &mq);
 2226         if (error)
 2227                 return (error);
 2228         if (uap->abs_timeout != NULL) {
 2229                 error = copyin(uap->abs_timeout, &ets, sizeof(ets));
 2230                 if (error != 0)
 2231                         return (error);
 2232                 abs_timeout = &ets;
 2233         } else
 2234                 abs_timeout = NULL;
 2235         waitok = !(fp->f_flag & O_NONBLOCK);
 2236         error = mqueue_send(mq, uap->msg_ptr, uap->msg_len,
 2237                 uap->msg_prio, waitok, abs_timeout);
 2238         fdrop(fp, td);
 2239         return (error);
 2240 }
 2241 
 2242 int
 2243 sys_kmq_notify(struct thread *td, struct kmq_notify_args *uap)
 2244 {
 2245         struct sigevent ev;
 2246         struct filedesc *fdp;
 2247         struct proc *p;
 2248         struct mqueue *mq;
 2249         struct file *fp, *fp2;
 2250         struct mqueue_notifier *nt, *newnt = NULL;
 2251         int error;
 2252 
 2253         p = td->td_proc;
 2254         fdp = td->td_proc->p_fd;
 2255         if (uap->sigev) {
 2256                 error = copyin(uap->sigev, &ev, sizeof(ev));
 2257                 if (error)
 2258                         return (error);
 2259                 if (ev.sigev_notify != SIGEV_SIGNAL &&
 2260                     ev.sigev_notify != SIGEV_THREAD_ID &&
 2261                     ev.sigev_notify != SIGEV_NONE)
 2262                         return (EINVAL);
 2263                 if ((ev.sigev_notify == SIGEV_SIGNAL ||
 2264                      ev.sigev_notify == SIGEV_THREAD_ID) &&
 2265                         !_SIG_VALID(ev.sigev_signo))
 2266                         return (EINVAL);
 2267         }
 2268         error = getmq(td, uap->mqd, &fp, NULL, &mq);
 2269         if (error)
 2270                 return (error);
 2271 again:
 2272         FILEDESC_SLOCK(fdp);
 2273         fp2 = fget_locked(fdp, uap->mqd);
 2274         if (fp2 == NULL) {
 2275                 FILEDESC_SUNLOCK(fdp);
 2276                 error = EBADF;
 2277                 goto out;
 2278         }
 2279         error = cap_funwrap(fp2, CAP_POLL_EVENT, &fp2);
 2280         if (error) {
 2281                 FILEDESC_SUNLOCK(fdp);
 2282                 goto out;
 2283         }
 2284         if (fp2 != fp) {
 2285                 FILEDESC_SUNLOCK(fdp);
 2286                 error = EBADF;
 2287                 goto out;
 2288         }
 2289         mtx_lock(&mq->mq_mutex);
 2290         FILEDESC_SUNLOCK(fdp);
 2291         if (uap->sigev != NULL) {
 2292                 if (mq->mq_notifier != NULL) {
 2293                         error = EBUSY;
 2294                 } else {
 2295                         PROC_LOCK(p);
 2296                         nt = notifier_search(p, uap->mqd);
 2297                         if (nt == NULL) {
 2298                                 if (newnt == NULL) {
 2299                                         PROC_UNLOCK(p);
 2300                                         mtx_unlock(&mq->mq_mutex);
 2301                                         newnt = notifier_alloc();
 2302                                         goto again;
 2303                                 }
 2304                         }
 2305 
 2306                         if (nt != NULL) {
 2307                                 sigqueue_take(&nt->nt_ksi);
 2308                                 if (newnt != NULL) {
 2309                                         notifier_free(newnt);
 2310                                         newnt = NULL;
 2311                                 }
 2312                         } else {
 2313                                 nt = newnt;
 2314                                 newnt = NULL;
 2315                                 ksiginfo_init(&nt->nt_ksi);
 2316                                 nt->nt_ksi.ksi_flags |= KSI_INS | KSI_EXT;
 2317                                 nt->nt_ksi.ksi_code = SI_MESGQ;
 2318                                 nt->nt_proc = p;
 2319                                 nt->nt_ksi.ksi_mqd = uap->mqd;
 2320                                 notifier_insert(p, nt);
 2321                         }
 2322                         nt->nt_sigev = ev;
 2323                         mq->mq_notifier = nt;
 2324                         PROC_UNLOCK(p);
 2325                         /*
 2326                          * if there is no receivers and message queue
 2327                          * is not empty, we should send notification
 2328                          * as soon as possible.
 2329                          */
 2330                         if (mq->mq_receivers == 0 &&
 2331                             !TAILQ_EMPTY(&mq->mq_msgq))
 2332                                 mqueue_send_notification(mq);
 2333                 }
 2334         } else {
 2335                 notifier_remove(p, mq, uap->mqd);
 2336         }
 2337         mtx_unlock(&mq->mq_mutex);
 2338 
 2339 out:
 2340         fdrop(fp, td);
 2341         if (newnt != NULL)
 2342                 notifier_free(newnt);
 2343         return (error);
 2344 }
 2345 
 2346 static void
 2347 mqueue_fdclose(struct thread *td, int fd, struct file *fp)
 2348 {
 2349         struct filedesc *fdp;
 2350         struct mqueue *mq;
 2351  
 2352         fdp = td->td_proc->p_fd;
 2353         FILEDESC_LOCK_ASSERT(fdp);
 2354 
 2355         if (fp->f_ops == &mqueueops) {
 2356                 mq = FPTOMQ(fp);
 2357                 mtx_lock(&mq->mq_mutex);
 2358                 notifier_remove(td->td_proc, mq, fd);
 2359 
 2360                 /* have to wakeup thread in same process */
 2361                 if (mq->mq_flags & MQ_RSEL) {
 2362                         mq->mq_flags &= ~MQ_RSEL;
 2363                         selwakeup(&mq->mq_rsel);
 2364                 }
 2365                 if (mq->mq_flags & MQ_WSEL) {
 2366                         mq->mq_flags &= ~MQ_WSEL;
 2367                         selwakeup(&mq->mq_wsel);
 2368                 }
 2369                 mtx_unlock(&mq->mq_mutex);
 2370         }
 2371 }
 2372 
 2373 static void
 2374 mq_proc_exit(void *arg __unused, struct proc *p)
 2375 {
 2376         struct filedesc *fdp;
 2377         struct file *fp;
 2378         struct mqueue *mq;
 2379         int i;
 2380 
 2381         fdp = p->p_fd;
 2382         FILEDESC_SLOCK(fdp);
 2383         for (i = 0; i < fdp->fd_nfiles; ++i) {
 2384                 fp = fget_locked(fdp, i);
 2385                 if (fp != NULL && fp->f_ops == &mqueueops) {
 2386                         mq = FPTOMQ(fp);
 2387                         mtx_lock(&mq->mq_mutex);
 2388                         notifier_remove(p, FPTOMQ(fp), i);
 2389                         mtx_unlock(&mq->mq_mutex);
 2390                 }
 2391         }
 2392         FILEDESC_SUNLOCK(fdp);
 2393         KASSERT(LIST_EMPTY(&p->p_mqnotifier), ("mq notifiers left"));
 2394 }
 2395 
 2396 static int
 2397 mqf_read(struct file *fp, struct uio *uio, struct ucred *active_cred,
 2398         int flags, struct thread *td)
 2399 {
 2400         return (EOPNOTSUPP);
 2401 }
 2402 
 2403 static int
 2404 mqf_write(struct file *fp, struct uio *uio, struct ucred *active_cred,
 2405         int flags, struct thread *td)
 2406 {
 2407         return (EOPNOTSUPP);
 2408 }
 2409 
 2410 static int
 2411 mqf_truncate(struct file *fp, off_t length, struct ucred *active_cred,
 2412     struct thread *td)
 2413 {
 2414 
 2415         return (EINVAL);
 2416 }
 2417 
 2418 static int
 2419 mqf_ioctl(struct file *fp, u_long cmd, void *data,
 2420         struct ucred *active_cred, struct thread *td)
 2421 {
 2422         return (ENOTTY);
 2423 }
 2424 
 2425 static int
 2426 mqf_poll(struct file *fp, int events, struct ucred *active_cred,
 2427         struct thread *td)
 2428 {
 2429         struct mqueue *mq = FPTOMQ(fp);
 2430         int revents = 0;
 2431 
 2432         mtx_lock(&mq->mq_mutex);
 2433         if (events & (POLLIN | POLLRDNORM)) {
 2434                 if (mq->mq_curmsgs) {
 2435                         revents |= events & (POLLIN | POLLRDNORM);
 2436                 } else {
 2437                         mq->mq_flags |= MQ_RSEL;
 2438                         selrecord(td, &mq->mq_rsel);
 2439                 }
 2440         }
 2441         if (events & POLLOUT) {
 2442                 if (mq->mq_curmsgs < mq->mq_maxmsg)
 2443                         revents |= POLLOUT;
 2444                 else {
 2445                         mq->mq_flags |= MQ_WSEL;
 2446                         selrecord(td, &mq->mq_wsel);
 2447                 }
 2448         }
 2449         mtx_unlock(&mq->mq_mutex);
 2450         return (revents);
 2451 }
 2452 
 2453 static int
 2454 mqf_close(struct file *fp, struct thread *td)
 2455 {
 2456         struct mqfs_node *pn;
 2457 
 2458         fp->f_ops = &badfileops;
 2459         pn = fp->f_data;
 2460         fp->f_data = NULL;
 2461         sx_xlock(&mqfs_data.mi_lock);
 2462         mqnode_release(pn);
 2463         sx_xunlock(&mqfs_data.mi_lock);
 2464         return (0);
 2465 }
 2466 
 2467 static int
 2468 mqf_stat(struct file *fp, struct stat *st, struct ucred *active_cred,
 2469         struct thread *td)
 2470 {
 2471         struct mqfs_node *pn = fp->f_data;
 2472 
 2473         bzero(st, sizeof *st);
 2474         sx_xlock(&mqfs_data.mi_lock);
 2475         st->st_atim = pn->mn_atime;
 2476         st->st_mtim = pn->mn_mtime;
 2477         st->st_ctim = pn->mn_ctime;
 2478         st->st_birthtim = pn->mn_birth;
 2479         st->st_uid = pn->mn_uid;
 2480         st->st_gid = pn->mn_gid;
 2481         st->st_mode = S_IFIFO | pn->mn_mode;
 2482         sx_xunlock(&mqfs_data.mi_lock);
 2483         return (0);
 2484 }
 2485 
 2486 static int
 2487 mqf_chmod(struct file *fp, mode_t mode, struct ucred *active_cred,
 2488     struct thread *td)
 2489 {
 2490         struct mqfs_node *pn;
 2491         int error;
 2492 
 2493         error = 0;
 2494         pn = fp->f_data;
 2495         sx_xlock(&mqfs_data.mi_lock);
 2496         error = vaccess(VREG, pn->mn_mode, pn->mn_uid, pn->mn_gid, VADMIN,
 2497             active_cred, NULL);
 2498         if (error != 0)
 2499                 goto out;
 2500         pn->mn_mode = mode & ACCESSPERMS;
 2501 out:
 2502         sx_xunlock(&mqfs_data.mi_lock);
 2503         return (error);
 2504 }
 2505 
 2506 static int
 2507 mqf_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred,
 2508     struct thread *td)
 2509 {
 2510         struct mqfs_node *pn;
 2511         int error;
 2512 
 2513         error = 0;
 2514         pn = fp->f_data;
 2515         sx_xlock(&mqfs_data.mi_lock);
 2516         if (uid == (uid_t)-1)
 2517                 uid = pn->mn_uid;
 2518         if (gid == (gid_t)-1)
 2519                 gid = pn->mn_gid;
 2520         if (((uid != pn->mn_uid && uid != active_cred->cr_uid) ||
 2521             (gid != pn->mn_gid && !groupmember(gid, active_cred))) &&
 2522             (error = priv_check_cred(active_cred, PRIV_VFS_CHOWN, 0)))
 2523                 goto out;
 2524         pn->mn_uid = uid;
 2525         pn->mn_gid = gid;
 2526 out:
 2527         sx_xunlock(&mqfs_data.mi_lock);
 2528         return (error);
 2529 }
 2530 
 2531 static int
 2532 mqf_kqfilter(struct file *fp, struct knote *kn)
 2533 {
 2534         struct mqueue *mq = FPTOMQ(fp);
 2535         int error = 0;
 2536 
 2537         if (kn->kn_filter == EVFILT_READ) {
 2538                 kn->kn_fop = &mq_rfiltops;
 2539                 knlist_add(&mq->mq_rsel.si_note, kn, 0);
 2540         } else if (kn->kn_filter == EVFILT_WRITE) {
 2541                 kn->kn_fop = &mq_wfiltops;
 2542                 knlist_add(&mq->mq_wsel.si_note, kn, 0);
 2543         } else
 2544                 error = EINVAL;
 2545         return (error);
 2546 }
 2547 
 2548 static void
 2549 filt_mqdetach(struct knote *kn)
 2550 {
 2551         struct mqueue *mq = FPTOMQ(kn->kn_fp);
 2552 
 2553         if (kn->kn_filter == EVFILT_READ)
 2554                 knlist_remove(&mq->mq_rsel.si_note, kn, 0);
 2555         else if (kn->kn_filter == EVFILT_WRITE)
 2556                 knlist_remove(&mq->mq_wsel.si_note, kn, 0);
 2557         else
 2558                 panic("filt_mqdetach");
 2559 }
 2560 
 2561 static int
 2562 filt_mqread(struct knote *kn, long hint)
 2563 {
 2564         struct mqueue *mq = FPTOMQ(kn->kn_fp);
 2565 
 2566         mtx_assert(&mq->mq_mutex, MA_OWNED);
 2567         return (mq->mq_curmsgs != 0);
 2568 }
 2569 
 2570 static int
 2571 filt_mqwrite(struct knote *kn, long hint)
 2572 {
 2573         struct mqueue *mq = FPTOMQ(kn->kn_fp);
 2574 
 2575         mtx_assert(&mq->mq_mutex, MA_OWNED);
 2576         return (mq->mq_curmsgs < mq->mq_maxmsg);
 2577 }
 2578 
 2579 static struct fileops mqueueops = {
 2580         .fo_read                = mqf_read,
 2581         .fo_write               = mqf_write,
 2582         .fo_truncate            = mqf_truncate,
 2583         .fo_ioctl               = mqf_ioctl,
 2584         .fo_poll                = mqf_poll,
 2585         .fo_kqfilter            = mqf_kqfilter,
 2586         .fo_stat                = mqf_stat,
 2587         .fo_chmod               = mqf_chmod,
 2588         .fo_chown               = mqf_chown,
 2589         .fo_close               = mqf_close
 2590 };
 2591 
 2592 static struct vop_vector mqfs_vnodeops = {
 2593         .vop_default            = &default_vnodeops,
 2594         .vop_access             = mqfs_access,
 2595         .vop_cachedlookup       = mqfs_lookup,
 2596         .vop_lookup             = vfs_cache_lookup,
 2597         .vop_reclaim            = mqfs_reclaim,
 2598         .vop_create             = mqfs_create,
 2599         .vop_remove             = mqfs_remove,
 2600         .vop_inactive           = mqfs_inactive,
 2601         .vop_open               = mqfs_open,
 2602         .vop_close              = mqfs_close,
 2603         .vop_getattr            = mqfs_getattr,
 2604         .vop_setattr            = mqfs_setattr,
 2605         .vop_read               = mqfs_read,
 2606         .vop_write              = VOP_EOPNOTSUPP,
 2607         .vop_readdir            = mqfs_readdir,
 2608         .vop_mkdir              = VOP_EOPNOTSUPP,
 2609         .vop_rmdir              = VOP_EOPNOTSUPP
 2610 };
 2611 
 2612 static struct vfsops mqfs_vfsops = {
 2613         .vfs_init               = mqfs_init,
 2614         .vfs_uninit             = mqfs_uninit,
 2615         .vfs_mount              = mqfs_mount,
 2616         .vfs_unmount            = mqfs_unmount,
 2617         .vfs_root               = mqfs_root,
 2618         .vfs_statfs             = mqfs_statfs,
 2619 };
 2620 
 2621 static struct vfsconf mqueuefs_vfsconf = {
 2622         .vfc_version = VFS_VERSION,
 2623         .vfc_name = "mqueuefs",
 2624         .vfc_vfsops = &mqfs_vfsops,
 2625         .vfc_typenum = -1,
 2626         .vfc_flags = VFCF_SYNTHETIC
 2627 };
 2628 
 2629 static struct syscall_helper_data mq_syscalls[] = {
 2630         SYSCALL_INIT_HELPER(kmq_open),
 2631         SYSCALL_INIT_HELPER(kmq_setattr),
 2632         SYSCALL_INIT_HELPER(kmq_timedsend),
 2633         SYSCALL_INIT_HELPER(kmq_timedreceive),
 2634         SYSCALL_INIT_HELPER(kmq_notify),
 2635         SYSCALL_INIT_HELPER(kmq_unlink),
 2636         SYSCALL_INIT_LAST
 2637 };
 2638 
 2639 #ifdef COMPAT_FREEBSD32
 2640 #include <compat/freebsd32/freebsd32.h>
 2641 #include <compat/freebsd32/freebsd32_proto.h>
 2642 #include <compat/freebsd32/freebsd32_syscall.h>
 2643 #include <compat/freebsd32/freebsd32_util.h>
 2644 
 2645 static void
 2646 mq_attr_from32(const struct mq_attr32 *from, struct mq_attr *to)
 2647 {
 2648 
 2649         to->mq_flags = from->mq_flags;
 2650         to->mq_maxmsg = from->mq_maxmsg;
 2651         to->mq_msgsize = from->mq_msgsize;
 2652         to->mq_curmsgs = from->mq_curmsgs;
 2653 }
 2654 
 2655 static void
 2656 mq_attr_to32(const struct mq_attr *from, struct mq_attr32 *to)
 2657 {
 2658 
 2659         to->mq_flags = from->mq_flags;
 2660         to->mq_maxmsg = from->mq_maxmsg;
 2661         to->mq_msgsize = from->mq_msgsize;
 2662         to->mq_curmsgs = from->mq_curmsgs;
 2663 }
 2664 
 2665 int
 2666 freebsd32_kmq_open(struct thread *td, struct freebsd32_kmq_open_args *uap)
 2667 {
 2668         struct mq_attr attr;
 2669         struct mq_attr32 attr32;
 2670         int flags, error;
 2671 
 2672         if ((uap->flags & O_ACCMODE) == O_ACCMODE)
 2673                 return (EINVAL);
 2674         flags = FFLAGS(uap->flags);
 2675         if ((flags & O_CREAT) != 0 && uap->attr != NULL) {
 2676                 error = copyin(uap->attr, &attr32, sizeof(attr32));
 2677                 if (error)
 2678                         return (error);
 2679                 mq_attr_from32(&attr32, &attr);
 2680         }
 2681         return (kern_kmq_open(td, uap->path, flags, uap->mode,
 2682             uap->attr != NULL ? &attr : NULL));
 2683 }
 2684 
 2685 int
 2686 freebsd32_kmq_setattr(struct thread *td, struct freebsd32_kmq_setattr_args *uap)
 2687 {
 2688         struct mq_attr attr, oattr;
 2689         struct mq_attr32 attr32, oattr32;
 2690         int error;
 2691 
 2692         if (uap->attr != NULL) {
 2693                 error = copyin(uap->attr, &attr32, sizeof(attr32));
 2694                 if (error != 0)
 2695                         return (error);
 2696                 mq_attr_from32(&attr32, &attr);
 2697         }
 2698         error = kern_kmq_setattr(td, uap->mqd, uap->attr != NULL ? &attr : NULL,
 2699             &oattr);
 2700         if (error != 0)
 2701                 return (error);
 2702         if (uap->oattr != NULL) {
 2703                 mq_attr_to32(&oattr, &oattr32);
 2704                 error = copyout(&oattr32, uap->oattr, sizeof(oattr32));
 2705         }
 2706         return (error);
 2707 }
 2708 
 2709 int
 2710 freebsd32_kmq_timedsend(struct thread *td,
 2711     struct freebsd32_kmq_timedsend_args *uap)
 2712 {
 2713         struct mqueue *mq;
 2714         struct file *fp;
 2715         struct timespec32 ets32;
 2716         struct timespec *abs_timeout, ets;
 2717         int error;
 2718         int waitok;
 2719 
 2720         error = getmq_read(td, uap->mqd, &fp, NULL, &mq);
 2721         if (error)
 2722                 return (error);
 2723         if (uap->abs_timeout != NULL) {
 2724                 error = copyin(uap->abs_timeout, &ets32, sizeof(ets32));
 2725                 if (error != 0)
 2726                         return (error);
 2727                 CP(ets32, ets, tv_sec);
 2728                 CP(ets32, ets, tv_nsec);
 2729                 abs_timeout = &ets;
 2730         } else
 2731                 abs_timeout = NULL;
 2732         waitok = !(fp->f_flag & O_NONBLOCK);
 2733         error = mqueue_send(mq, uap->msg_ptr, uap->msg_len,
 2734                 uap->msg_prio, waitok, abs_timeout);
 2735         fdrop(fp, td);
 2736         return (error);
 2737 }
 2738 
 2739 int
 2740 freebsd32_kmq_timedreceive(struct thread *td,
 2741     struct freebsd32_kmq_timedreceive_args *uap)
 2742 {
 2743         struct mqueue *mq;
 2744         struct file *fp;
 2745         struct timespec32 ets32;
 2746         struct timespec *abs_timeout, ets;
 2747         int error, waitok;
 2748 
 2749         error = getmq_write(td, uap->mqd, &fp, NULL, &mq);
 2750         if (error)
 2751                 return (error);
 2752         if (uap->abs_timeout != NULL) {
 2753                 error = copyin(uap->abs_timeout, &ets32, sizeof(ets32));
 2754                 if (error != 0)
 2755                         return (error);
 2756                 CP(ets32, ets, tv_sec);
 2757                 CP(ets32, ets, tv_nsec);
 2758                 abs_timeout = &ets;
 2759         } else
 2760                 abs_timeout = NULL;
 2761         waitok = !(fp->f_flag & O_NONBLOCK);
 2762         error = mqueue_receive(mq, uap->msg_ptr, uap->msg_len,
 2763                 uap->msg_prio, waitok, abs_timeout);
 2764         fdrop(fp, td);
 2765         return (error);
 2766 }
 2767 
 2768 static struct syscall_helper_data mq32_syscalls[] = {
 2769         SYSCALL32_INIT_HELPER(freebsd32_kmq_open),
 2770         SYSCALL32_INIT_HELPER(freebsd32_kmq_setattr),
 2771         SYSCALL32_INIT_HELPER(freebsd32_kmq_timedsend),
 2772         SYSCALL32_INIT_HELPER(freebsd32_kmq_timedreceive),
 2773         SYSCALL32_INIT_HELPER_COMPAT(kmq_notify),
 2774         SYSCALL32_INIT_HELPER_COMPAT(kmq_unlink),
 2775         SYSCALL_INIT_LAST
 2776 };
 2777 #endif
 2778 
 2779 static int
 2780 mqinit(void)
 2781 {
 2782         int error;
 2783 
 2784         error = syscall_helper_register(mq_syscalls);
 2785         if (error != 0)
 2786                 return (error);
 2787 #ifdef COMPAT_FREEBSD32
 2788         error = syscall32_helper_register(mq32_syscalls);
 2789         if (error != 0)
 2790                 return (error);
 2791 #endif
 2792         return (0);
 2793 }
 2794 
 2795 static int
 2796 mqunload(void)
 2797 {
 2798 
 2799 #ifdef COMPAT_FREEBSD32
 2800         syscall32_helper_unregister(mq32_syscalls);
 2801 #endif
 2802         syscall_helper_unregister(mq_syscalls);
 2803         return (0);
 2804 }
 2805 
 2806 static int
 2807 mq_modload(struct module *module, int cmd, void *arg)
 2808 {
 2809         int error = 0;
 2810 
 2811         error = vfs_modevent(module, cmd, arg);
 2812         if (error != 0)
 2813                 return (error);
 2814 
 2815         switch (cmd) {
 2816         case MOD_LOAD:
 2817                 error = mqinit();
 2818                 if (error != 0)
 2819                         mqunload();
 2820                 break;
 2821         case MOD_UNLOAD:
 2822                 error = mqunload();
 2823                 break;
 2824         default:
 2825                 break;
 2826         }
 2827         return (error);
 2828 }
 2829 
 2830 static moduledata_t mqueuefs_mod = {
 2831         "mqueuefs",
 2832         mq_modload,
 2833         &mqueuefs_vfsconf
 2834 };
 2835 DECLARE_MODULE(mqueuefs, mqueuefs_mod, SI_SUB_VFS, SI_ORDER_MIDDLE);
 2836 MODULE_VERSION(mqueuefs, 1);

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