sys/vfs/autofs/autofs.c

   1 /*-
   2  * Copyright (c) 2016 The DragonFly Project
   3  * Copyright (c) 2014 The FreeBSD Foundation
   4  * All rights reserved.
   5  *
   6  * This software was developed by Edward Tomasz Napierala under sponsorship
   7  * from the FreeBSD Foundation.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  28  * SUCH DAMAGE.
  29  *
  30  */
  31 /*-
  32  * Copyright (c) 1989, 1991, 1993, 1995
  33  *      The Regents of the University of California.  All rights reserved.
  34  *
  35  * This code is derived from software contributed to Berkeley by
  36  * Rick Macklem at The University of Guelph.
  37  *
  38  * Redistribution and use in source and binary forms, with or without
  39  * modification, are permitted provided that the following conditions
  40  * are met:
  41  * 1. Redistributions of source code must retain the above copyright
  42  *    notice, this list of conditions and the following disclaimer.
  43  * 2. Redistributions in binary form must reproduce the above copyright
  44  *    notice, this list of conditions and the following disclaimer in the
  45  *    documentation and/or other materials provided with the distribution.
  46  * 4. Neither the name of the University nor the names of its contributors
  47  *    may be used to endorse or promote products derived from this software
  48  *    without specific prior written permission.
  49  *
  50  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  51  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  52  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  53  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  54  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  55  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  56  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  57  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  58  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  59  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  60  * SUCH DAMAGE.
  61  *
  62  */
  63
  64 #include <sys/kernel.h>
  65 #include <sys/module.h>
  66 #include <sys/sysctl.h>
  67 #include <sys/queue.h>
  68 #include <sys/signalvar.h>
  69 #include <sys/refcount.h>
  70 #include <sys/kern_syscall.h>
  71
  72 #include "autofs.h"
  73 #include "autofs_ioctl.h"
  74
  75 MALLOC_DEFINE(M_AUTOFS, "autofs", "Automounter filesystem");
  76
  77 struct objcache *autofs_request_objcache = NULL;
  78 static struct objcache_malloc_args autofs_request_args = {
  79         sizeof(struct autofs_request), M_AUTOFS,
  80 };
  81
  82 struct objcache *autofs_node_objcache = NULL;
  83 static struct objcache_malloc_args autofs_node_args = {
  84         sizeof(struct autofs_node), M_AUTOFS,
  85 };
  86
  87 static int      autofs_open(struct dev_open_args *ap);
  88 static int      autofs_close(struct dev_close_args *ap);
  89 static int      autofs_ioctl(struct dev_ioctl_args *ap);
  90
  91 struct dev_ops autofs_ops = {
  92         { "autofs", 0, 0 },
  93         .d_open         = autofs_open,
  94         .d_close        = autofs_close,
  95         .d_ioctl        = autofs_ioctl,
  96 };
  97
  98 /*
  99  * List of signals that can interrupt an autofs trigger.
 100  */
 101 int autofs_sig_set[] = {
 102         SIGINT,
 103         SIGTERM,
 104         SIGHUP,
 105         SIGKILL,
 106         SIGQUIT
 107 };
 108
 109 struct autofs_softc     *autofs_softc = NULL;
 110
 111 SYSCTL_NODE(_vfs, OID_AUTO, autofs, CTLFLAG_RD, 0, "Automounter filesystem");
 112 int autofs_debug = 1;
 113 TUNABLE_INT("vfs.autofs.debug", &autofs_debug);
 114 SYSCTL_INT(_vfs_autofs, OID_AUTO, debug, CTLFLAG_RW,
 115     &autofs_debug, 1, "Enable debug messages");
 116 int autofs_mount_on_stat = 0;   /* XXX: Not supported on DragonFly */
 117 TUNABLE_INT("vfs.autofs.mount_on_stat", &autofs_mount_on_stat);
 118 SYSCTL_INT(_vfs_autofs, OID_AUTO, mount_on_stat, CTLFLAG_RW,
 119     &autofs_mount_on_stat, 0, "Trigger mount on stat(2) on mountpoint "
 120     "(not supported on DragonFly)");
 121 static int autofs_timeout = 30;
 122 TUNABLE_INT("vfs.autofs.timeout", &autofs_timeout);
 123 SYSCTL_INT(_vfs_autofs, OID_AUTO, timeout, CTLFLAG_RW,
 124     &autofs_timeout, 30, "Number of seconds to wait for automountd(8)");
 125 static int autofs_cache = 600;
 126 TUNABLE_INT("vfs.autofs.cache", &autofs_cache);
 127 SYSCTL_INT(_vfs_autofs, OID_AUTO, cache, CTLFLAG_RW,
 128     &autofs_cache, 600, "Number of seconds to wait before reinvoking "
 129     "automountd(8) for any given file or directory");
 130 static int autofs_retry_attempts = 3;
 131 TUNABLE_INT("vfs.autofs.retry_attempts", &autofs_retry_attempts);
 132 SYSCTL_INT(_vfs_autofs, OID_AUTO, retry_attempts, CTLFLAG_RW,
 133     &autofs_retry_attempts, 3, "Number of attempts before failing mount");
 134 static int autofs_retry_delay = 1;
 135 TUNABLE_INT("vfs.autofs.retry_delay", &autofs_retry_delay);
 136 SYSCTL_INT(_vfs_autofs, OID_AUTO, retry_delay, CTLFLAG_RW,
 137     &autofs_retry_delay, 1, "Number of seconds before retrying");
 138 static int autofs_interruptible = 1;
 139 TUNABLE_INT("vfs.autofs.interruptible", &autofs_interruptible);
 140 SYSCTL_INT(_vfs_autofs, OID_AUTO, interruptible, CTLFLAG_RW,
 141     &autofs_interruptible, 1, "Allow requests to be interrupted by signal");
 142
 143 static __inline pid_t
 144 proc_pgid(const struct proc *p)
 145 {
 146         return (p->p_pgrp->pg_id);
 147 }
 148
 149 static int
 150 autofs_node_cmp(const struct autofs_node *a, const struct autofs_node *b)
 151 {
 152         return (strcmp(a->an_name, b->an_name));
 153 }
 154
 155 RB_GENERATE(autofs_node_tree, autofs_node, an_link, autofs_node_cmp);
 156
 157 static boolean_t
 158 autofs_request_objcache_ctor(void *obj, void *privdata, int ocflags)
 159 {
 160         struct autofs_request *ar = obj;
 161
 162         memset(ar, 0, sizeof(*ar));
 163         return (TRUE);
 164 }
 165
 166 static boolean_t
 167 autofs_node_objcache_ctor(void *obj, void *privdata, int ocflags)
 168 {
 169         struct autofs_node *an = obj;
 170
 171         memset(an, 0, sizeof(*an));
 172         return (TRUE);
 173 }
 174
 175 int
 176 autofs_init(struct vfsconf *vfsp)
 177 {
 178         KASSERT(autofs_softc == NULL,
 179             ("softc %p, should be NULL", autofs_softc));
 180
 181         autofs_softc = kmalloc(sizeof(*autofs_softc), M_AUTOFS,
 182             M_WAITOK | M_ZERO);
 183
 184         autofs_request_objcache = objcache_create("autofs_request", 0, 0,
 185                 autofs_request_objcache_ctor, NULL, NULL,
 186                 objcache_malloc_alloc,
 187                 objcache_malloc_free,
 188                 &autofs_request_args);
 189
 190         autofs_node_objcache = objcache_create("autofs_node", 0, 0,
 191                 autofs_node_objcache_ctor, NULL, NULL,
 192                 objcache_malloc_alloc,
 193                 objcache_malloc_free,
 194                 &autofs_node_args);
 195
 196         TAILQ_INIT(&autofs_softc->sc_requests);
 197         cv_init(&autofs_softc->sc_cv, "autofscv");
 198         lockinit(&autofs_softc->sc_lock, "autofssclk", 0, 0);
 199         autofs_softc->sc_dev_opened = false;
 200
 201         autofs_softc->sc_cdev = make_dev(&autofs_ops, 0, UID_ROOT,
 202             GID_OPERATOR, 0640, "autofs");
 203         if (autofs_softc->sc_cdev == NULL) {
 204                 AUTOFS_WARN("failed to create device node");
 205                 objcache_destroy(autofs_request_objcache);
 206                 objcache_destroy(autofs_node_objcache);
 207                 kfree(autofs_softc, M_AUTOFS);
 208
 209                 return (ENODEV);
 210         }
 211         autofs_softc->sc_cdev->si_drv1 = autofs_softc;
 212
 213         return (0);
 214 }
 215
 216 int
 217 autofs_uninit(struct vfsconf *vfsp)
 218 {
 219         lockmgr(&autofs_softc->sc_lock, LK_EXCLUSIVE);
 220         if (autofs_softc->sc_dev_opened) {
 221                 lockmgr(&autofs_softc->sc_lock, LK_RELEASE);
 222                 return (EBUSY);
 223         }
 224
 225         if (autofs_softc->sc_cdev != NULL)
 226                 destroy_dev(autofs_softc->sc_cdev);
 227
 228         objcache_destroy(autofs_request_objcache);
 229         objcache_destroy(autofs_node_objcache);
 230
 231         lockmgr(&autofs_softc->sc_lock, LK_RELEASE);
 232
 233         kfree(autofs_softc, M_AUTOFS);  /* race with open */
 234         autofs_softc = NULL;
 235
 236         return (0);
 237 }
 238
 239 bool
 240 autofs_ignore_thread(void)
 241 {
 242         struct proc *curp = curproc;
 243
 244         if (autofs_softc->sc_dev_opened == false)
 245                 return (false);
 246
 247         lwkt_gettoken(&curp->p_token);
 248         if (autofs_softc->sc_dev_sid == proc_pgid(curp)) {
 249                 lwkt_reltoken(&curp->p_token);
 250                 return (true);
 251         }
 252         lwkt_reltoken(&curp->p_token);
 253
 254         return (false);
 255 }
 256
 257 char *
 258 autofs_path(struct autofs_node *anp)
 259 {
 260         struct autofs_mount *amp = anp->an_mount;
 261         char *path, *tmp;
 262
 263         path = kstrdup("", M_AUTOFS);
 264         for (; anp->an_parent != NULL; anp = anp->an_parent) {
 265                 tmp = kmalloc(strlen(anp->an_name) + strlen(path) + 2,
 266                     M_AUTOFS, M_WAITOK);
 267                 strcpy(tmp, anp->an_name);
 268                 strcat(tmp, "/");
 269                 strcat(tmp, path);
 270                 kfree(path, M_AUTOFS);
 271                 path = tmp;
 272         }
 273
 274         tmp = kmalloc(strlen(amp->am_on) + strlen(path) + 2,
 275             M_AUTOFS, M_WAITOK);
 276         strcpy(tmp, amp->am_on);
 277         strcat(tmp, "/");
 278         strcat(tmp, path);
 279         kfree(path, M_AUTOFS);
 280         path = tmp;
 281
 282         return (path);
 283 }
 284
 285 static void
 286 autofs_task(void *context, int pending)
 287 {
 288         struct autofs_request *ar = context;
 289
 290         lockmgr(&autofs_softc->sc_lock, LK_EXCLUSIVE);
 291         AUTOFS_WARN("request %d for %s timed out after %d seconds",
 292             ar->ar_id, ar->ar_path, autofs_timeout);
 293
 294         ar->ar_error = ETIMEDOUT;
 295         ar->ar_wildcards = true;
 296         ar->ar_done = true;
 297         ar->ar_in_progress = false;
 298         cv_broadcast(&autofs_softc->sc_cv);
 299         lockmgr(&autofs_softc->sc_lock, LK_RELEASE);
 300 }
 301
 302 bool
 303 autofs_cached(struct autofs_node *anp, const char *component, int componentlen)
 304 {
 305         struct autofs_mount *amp = anp->an_mount;
 306         int error;
 307
 308         AUTOFS_ASSERT_UNLOCKED(amp);
 309
 310         /*
 311          * For root node we need to request automountd(8) assistance even
 312          * if the node is marked as cached, but the requested top-level
 313          * directory does not exist.  This is necessary for wildcard indirect
 314          * map keys to work.  We don't do this if we know that there are
 315          * no wildcards.
 316          */
 317         if (anp->an_parent == NULL && componentlen != 0 && anp->an_wildcards) {
 318                 KKASSERT(amp->am_root == anp);
 319                 lockmgr(&amp->am_lock, LK_SHARED);
 320                 error = autofs_node_find(anp, component, componentlen, NULL);
 321                 lockmgr(&amp->am_lock, LK_RELEASE);
 322                 if (error)
 323                         return (false);
 324         }
 325
 326         return (anp->an_cached);
 327 }
 328
 329 static void
 330 autofs_cache_callout(void *context)
 331 {
 332         struct autofs_node *anp = context;
 333
 334         autofs_node_uncache(anp);
 335 }
 336
 337 void
 338 autofs_flush(struct autofs_mount *amp)
 339 {
 340         struct autofs_node *anp = amp->am_root;
 341         struct autofs_node *child;
 342
 343         lockmgr(&amp->am_lock, LK_EXCLUSIVE);
 344         RB_FOREACH(child, autofs_node_tree, &anp->an_children) {
 345                 autofs_node_uncache(child);
 346         }
 347         autofs_node_uncache(amp->am_root);
 348         lockmgr(&amp->am_lock, LK_RELEASE);
 349
 350         AUTOFS_DEBUG("%s flushed", amp->am_on);
 351 }
 352
 353 /*
 354  * The set/restore sigmask functions are used to (temporarily) overwrite
 355  * the thread sigmask during triggering.
 356  */
 357 static void
 358 autofs_set_sigmask(sigset_t *oldset)
 359 {
 360         struct lwp *lp = curthread->td_lwp;
 361         sigset_t newset;
 362         int i;
 363
 364         SIGFILLSET(newset);
 365         /* Remove the autofs set of signals from newset */
 366         lwkt_gettoken(&lp->lwp_token);
 367         for (i = 0; i < sizeof(autofs_sig_set)/sizeof(int); i++) {
 368                 /*
 369                  * But make sure we leave the ones already masked
 370                  * by the process, i.e. remove the signal from the
 371                  * temporary signalmask only if it wasn't already
 372                  * in sigmask.
 373                  */
 374                 if (!SIGISMEMBER(lp->lwp_sigmask, autofs_sig_set[i]) &&
 375                     !SIGISMEMBER(lp->lwp_proc->p_sigacts->ps_sigignore,
 376                     autofs_sig_set[i])) {
 377                         SIGDELSET(newset, autofs_sig_set[i]);
 378                 }
 379         }
 380         kern_sigprocmask(SIG_SETMASK, &newset, oldset);
 381         lwkt_reltoken(&lp->lwp_token);
 382 }
 383
 384 static void
 385 autofs_restore_sigmask(sigset_t *set)
 386 {
 387         kern_sigprocmask(SIG_SETMASK, set, NULL);
 388 }
 389
 390 static int
 391 autofs_trigger_one(struct autofs_node *anp,
 392     const char *component, int componentlen)
 393 {
 394 #define _taskqueue_thread (taskqueue_thread[mycpuid])
 395         struct autofs_mount *amp = anp->an_mount;
 396         struct autofs_node *firstanp;
 397         struct autofs_request *ar;
 398         sigset_t oldset;
 399         char *key, *path;
 400         int error = 0, request_error, last;
 401         bool wildcards;
 402
 403         KKASSERT(AUTOFS_LOCK_STATUS(&autofs_softc->sc_lock) == LK_EXCLUSIVE);
 404
 405         if (anp->an_parent == NULL) {
 406                 key = kstrndup(component, componentlen, M_AUTOFS);
 407         } else {
 408                 for (firstanp = anp; firstanp->an_parent->an_parent != NULL;
 409                     firstanp = firstanp->an_parent)
 410                         continue;
 411                 key = kstrdup(firstanp->an_name, M_AUTOFS);
 412         }
 413
 414         path = autofs_path(anp);
 415
 416         TAILQ_FOREACH(ar, &autofs_softc->sc_requests, ar_next) {
 417                 if (strcmp(ar->ar_path, path))
 418                         continue;
 419                 if (strcmp(ar->ar_key, key))
 420                         continue;
 421
 422                 KASSERT(strcmp(ar->ar_from, amp->am_from) == 0,
 423                     ("from changed; %s != %s", ar->ar_from, amp->am_from));
 424                 KASSERT(strcmp(ar->ar_prefix, amp->am_prefix) == 0,
 425                     ("prefix changed; %s != %s",
 426                      ar->ar_prefix, amp->am_prefix));
 427                 KASSERT(strcmp(ar->ar_options, amp->am_options) == 0,
 428                     ("options changed; %s != %s",
 429                      ar->ar_options, amp->am_options));
 430                 break;
 431         }
 432
 433         if (ar != NULL) {
 434                 refcount_acquire(&ar->ar_refcount);
 435         } else {
 436                 ar = objcache_get(autofs_request_objcache, M_WAITOK);
 437                 ar->ar_mount = amp;
 438                 ar->ar_id = autofs_softc->sc_last_request_id++;
 439                 ar->ar_done = false;
 440                 ar->ar_error = 0;
 441                 ar->ar_wildcards = false;
 442                 ar->ar_in_progress = false;
 443                 strlcpy(ar->ar_from, amp->am_from, sizeof(ar->ar_from));
 444                 strlcpy(ar->ar_path, path, sizeof(ar->ar_path));
 445                 strlcpy(ar->ar_prefix, amp->am_prefix, sizeof(ar->ar_prefix));
 446                 strlcpy(ar->ar_key, key, sizeof(ar->ar_key));
 447                 strlcpy(ar->ar_options,
 448                     amp->am_options, sizeof(ar->ar_options));
 449                 TIMEOUT_TASK_INIT(_taskqueue_thread, &ar->ar_task, 0,
 450                     autofs_task, ar);
 451                 taskqueue_enqueue_timeout(_taskqueue_thread, &ar->ar_task,
 452                     autofs_timeout * hz);
 453                 refcount_init(&ar->ar_refcount, 1);
 454                 TAILQ_INSERT_TAIL(&autofs_softc->sc_requests, ar, ar_next);
 455         }
 456
 457         cv_broadcast(&autofs_softc->sc_cv);
 458         while (ar->ar_done == false) {
 459                 if (autofs_interruptible) {
 460                         autofs_set_sigmask(&oldset);
 461                         error = cv_wait_sig(&autofs_softc->sc_cv,
 462                             &autofs_softc->sc_lock);
 463                         autofs_restore_sigmask(&oldset);
 464                         if (error) {
 465                                 AUTOFS_WARN("cv_wait_sig for %s failed "
 466                                     "with error %d", ar->ar_path, error);
 467                                 break;
 468                         }
 469                 } else {
 470                         cv_wait(&autofs_softc->sc_cv, &autofs_softc->sc_lock);
 471                 }
 472         }
 473
 474         request_error = ar->ar_error;
 475         if (request_error)
 476                 AUTOFS_WARN("request for %s completed with error %d",
 477                     ar->ar_path, request_error);
 478
 479         wildcards = ar->ar_wildcards;
 480
 481         last = refcount_release(&ar->ar_refcount);
 482         if (last) {
 483                 TAILQ_REMOVE(&autofs_softc->sc_requests, ar, ar_next);
 484                 lockmgr(&autofs_softc->sc_lock, LK_RELEASE);
 485                 taskqueue_cancel_timeout(_taskqueue_thread, &ar->ar_task, NULL);
 486                 taskqueue_drain_timeout(_taskqueue_thread, &ar->ar_task);
 487                 objcache_put(autofs_request_objcache, ar);
 488                 lockmgr(&autofs_softc->sc_lock, LK_EXCLUSIVE);
 489         }
 490
 491         /*
 492          * Note that we do not do negative caching on purpose.  This
 493          * way the user can retry access at any time, e.g. after fixing
 494          * the failure reason, without waiting for cache timer to expire.
 495          */
 496         if (error == 0 && request_error == 0 && autofs_cache > 0) {
 497                 autofs_node_cache(anp);
 498                 anp->an_wildcards = wildcards;
 499                 callout_reset(&anp->an_callout, autofs_cache * hz,
 500                     autofs_cache_callout, anp);
 501         }
 502
 503         kfree(key, M_AUTOFS);
 504         kfree(path, M_AUTOFS);
 505
 506         if (error)
 507                 return (error);
 508         return (request_error);
 509 }
 510
 511 int
 512 autofs_trigger(struct autofs_node *anp,
 513     const char *component, int componentlen)
 514 {
 515         int error, dummy;
 516
 517         for (;;) {
 518                 error = autofs_trigger_one(anp, component, componentlen);
 519                 if (error == 0) {
 520                         anp->an_retries = 0;
 521                         return (0);
 522                 }
 523                 if (error == EINTR || error == ERESTART) {
 524                         AUTOFS_DEBUG("trigger interrupted by signal, "
 525                             "not retrying");
 526                         anp->an_retries = 0;
 527                         return (error);
 528                 }
 529                 anp->an_retries++;
 530                 if (anp->an_retries >= autofs_retry_attempts) {
 531                         AUTOFS_DEBUG("trigger failed %d times; returning "
 532                             "error %d", anp->an_retries, error);
 533                         anp->an_retries = 0;
 534                         return (error);
 535
 536                 }
 537                 AUTOFS_DEBUG("trigger failed with error %d; will retry in "
 538                     "%d seconds, %d attempts left", error, autofs_retry_delay,
 539                     autofs_retry_attempts - anp->an_retries);
 540                 lockmgr(&autofs_softc->sc_lock, LK_RELEASE);
 541                 tsleep(&dummy, 0, "autofs_retry", autofs_retry_delay * hz);
 542                 lockmgr(&autofs_softc->sc_lock, LK_EXCLUSIVE);
 543         }
 544 }
 545
 546 static int
 547 autofs_ioctl_request(struct autofs_daemon_request *adr)
 548 {
 549         struct proc *curp = curproc;
 550         struct autofs_request *ar;
 551         int error;
 552
 553         lockmgr(&autofs_softc->sc_lock, LK_EXCLUSIVE);
 554         for (;;) {
 555                 TAILQ_FOREACH(ar, &autofs_softc->sc_requests, ar_next) {
 556                         if (ar->ar_done)
 557                                 continue;
 558                         if (ar->ar_in_progress)
 559                                 continue;
 560                         break;
 561                 }
 562
 563                 if (ar != NULL)
 564                         break;
 565
 566                 error = cv_wait_sig(&autofs_softc->sc_cv,
 567                     &autofs_softc->sc_lock);
 568                 if (error) {
 569                         lockmgr(&autofs_softc->sc_lock, LK_RELEASE);
 570                         return (error);
 571                 }
 572         }
 573
 574         ar->ar_in_progress = true;
 575
 576         adr->adr_id = ar->ar_id;
 577         strlcpy(adr->adr_from, ar->ar_from, sizeof(adr->adr_from));
 578         strlcpy(adr->adr_path, ar->ar_path, sizeof(adr->adr_path));
 579         strlcpy(adr->adr_prefix, ar->ar_prefix, sizeof(adr->adr_prefix));
 580         strlcpy(adr->adr_key, ar->ar_key, sizeof(adr->adr_key));
 581         strlcpy(adr->adr_options, ar->ar_options, sizeof(adr->adr_options));
 582
 583         lockmgr(&autofs_softc->sc_lock, LK_RELEASE);
 584
 585         lwkt_gettoken(&curp->p_token);
 586         autofs_softc->sc_dev_sid = proc_pgid(curp);
 587         lwkt_reltoken(&curp->p_token);
 588
 589         return (0);
 590 }
 591
 592 static int
 593 autofs_ioctl_done_101(struct autofs_daemon_done_101 *add)
 594 {
 595         struct autofs_request *ar;
 596
 597         lockmgr(&autofs_softc->sc_lock, LK_EXCLUSIVE);
 598         TAILQ_FOREACH(ar, &autofs_softc->sc_requests, ar_next) {
 599                 if (ar->ar_id == add->add_id)
 600                         break;
 601         }
 602
 603         if (ar == NULL) {
 604                 lockmgr(&autofs_softc->sc_lock, LK_RELEASE);
 605                 AUTOFS_DEBUG("id %d not found", add->add_id);
 606                 return (ESRCH);
 607         }
 608
 609         ar->ar_error = add->add_error;
 610         ar->ar_wildcards = true;
 611         ar->ar_done = true;
 612         ar->ar_in_progress = false;
 613         cv_broadcast(&autofs_softc->sc_cv);
 614
 615         lockmgr(&autofs_softc->sc_lock, LK_RELEASE);
 616
 617         return (0);
 618 }
 619
 620 static int
 621 autofs_ioctl_done(struct autofs_daemon_done *add)
 622 {
 623         struct autofs_request *ar;
 624
 625         lockmgr(&autofs_softc->sc_lock, LK_EXCLUSIVE);
 626         TAILQ_FOREACH(ar, &autofs_softc->sc_requests, ar_next) {
 627                 if (ar->ar_id == add->add_id)
 628                         break;
 629         }
 630
 631         if (ar == NULL) {
 632                 lockmgr(&autofs_softc->sc_lock, LK_RELEASE);
 633                 AUTOFS_DEBUG("id %d not found", add->add_id);
 634                 return (ESRCH);
 635         }
 636
 637         ar->ar_error = add->add_error;
 638         ar->ar_wildcards = add->add_wildcards;
 639         ar->ar_done = true;
 640         ar->ar_in_progress = false;
 641         cv_broadcast(&autofs_softc->sc_cv);
 642
 643         lockmgr(&autofs_softc->sc_lock, LK_RELEASE);
 644
 645         return (0);
 646 }
 647
 648 static int
 649 autofs_open(struct dev_open_args *ap)
 650 {
 651         lockmgr(&autofs_softc->sc_lock, LK_EXCLUSIVE);
 652         /*
 653          * We must never block automountd(8) and its descendants, and we use
 654          * session ID to determine that: we store session id of the process
 655          * that opened the device, and then compare it with session ids
 656          * of triggering processes.  This means running a second automountd(8)
 657          * instance would break the previous one.  The check below prevents
 658          * it from happening.
 659          */
 660         if (autofs_softc->sc_dev_opened) {
 661                 lockmgr(&autofs_softc->sc_lock, LK_RELEASE);
 662                 return (EBUSY);
 663         }
 664
 665         autofs_softc->sc_dev_opened = true;
 666         lockmgr(&autofs_softc->sc_lock, LK_RELEASE);
 667
 668         return (0);
 669 }
 670
 671 static int
 672 autofs_close(struct dev_close_args *ap)
 673 {
 674         lockmgr(&autofs_softc->sc_lock, LK_EXCLUSIVE);
 675         KASSERT(autofs_softc->sc_dev_opened, ("not opened?"));
 676         autofs_softc->sc_dev_opened = false;
 677         lockmgr(&autofs_softc->sc_lock, LK_RELEASE);
 678
 679         return (0);
 680 }
 681
 682 static int
 683 autofs_ioctl(struct dev_ioctl_args *ap)
 684 {
 685         u_long cmd = ap->a_cmd;
 686         void *arg = ap->a_data;
 687
 688         KASSERT(autofs_softc->sc_dev_opened, ("not opened?"));
 689
 690         switch (cmd) {
 691         case AUTOFSREQUEST:
 692                 return (autofs_ioctl_request(
 693                     (struct autofs_daemon_request *)arg));
 694         case AUTOFSDONE101:
 695                 return (autofs_ioctl_done_101(
 696                     (struct autofs_daemon_done_101 *)arg));
 697         case AUTOFSDONE:
 698                 return (autofs_ioctl_done(
 699                     (struct autofs_daemon_done *)arg));
 700         default:
 701                 AUTOFS_DEBUG("invalid cmd %lx", cmd);
 702                 return (EINVAL);
 703         }
 704 }