1 /*- 2 * Copyright (c) 2000,2004 3 * Poul-Henning Kamp. 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. Neither the name of the University nor the names of its contributors 11 * may be used to endorse or promote products derived from this software 12 * without specific prior written permission. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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 * From: FreeBSD: src/sys/miscfs/kernfs/kernfs_vfsops.c 1.36 27 * 28 * $FreeBSD$ 29 */ 30 31 #include <sys/param.h> 32 #include <sys/systm.h> 33 #include <sys/conf.h> 34 #include <sys/dirent.h> 35 #include <sys/kernel.h> 36 #include <sys/limits.h> 37 #include <sys/lock.h> 38 #include <sys/malloc.h> 39 #include <sys/proc.h> 40 #include <sys/sx.h> 41 #include <sys/sysctl.h> 42 #include <sys/vnode.h> 43 44 #include <sys/kdb.h> 45 46 #include <fs/devfs/devfs.h> 47 #include <fs/devfs/devfs_int.h> 48 49 #include <security/mac/mac_framework.h> 50 51 /* 52 * The one true (but secret) list of active devices in the system. 53 * Locked by dev_lock()/devmtx 54 */ 55 struct cdev_priv_list cdevp_list = TAILQ_HEAD_INITIALIZER(cdevp_list); 56 57 struct unrhdr *devfs_inos; 58 59 60 static MALLOC_DEFINE(M_DEVFS2, "DEVFS2", "DEVFS data 2"); 61 static MALLOC_DEFINE(M_DEVFS3, "DEVFS3", "DEVFS data 3"); 62 static MALLOC_DEFINE(M_CDEVP, "DEVFS1", "DEVFS cdev_priv storage"); 63 64 static SYSCTL_NODE(_vfs, OID_AUTO, devfs, CTLFLAG_RW, 0, "DEVFS filesystem"); 65 66 static unsigned devfs_generation; 67 SYSCTL_UINT(_vfs_devfs, OID_AUTO, generation, CTLFLAG_RD, 68 &devfs_generation, 0, "DEVFS generation number"); 69 70 unsigned devfs_rule_depth = 1; 71 SYSCTL_UINT(_vfs_devfs, OID_AUTO, rule_depth, CTLFLAG_RW, 72 &devfs_rule_depth, 0, "Max depth of ruleset include"); 73 74 /* 75 * Helper sysctl for devname(3). We're given a dev_t and return the 76 * name, if any, registered by the device driver. 77 */ 78 static int 79 sysctl_devname(SYSCTL_HANDLER_ARGS) 80 { 81 int error; 82 dev_t ud; 83 struct cdev_priv *cdp; 84 struct cdev *dev; 85 86 error = SYSCTL_IN(req, &ud, sizeof (ud)); 87 if (error) 88 return (error); 89 if (ud == NODEV) 90 return (EINVAL); 91 dev = NULL; 92 dev_lock(); 93 TAILQ_FOREACH(cdp, &cdevp_list, cdp_list) 94 if (cdp->cdp_inode == ud) { 95 dev = &cdp->cdp_c; 96 dev_refl(dev); 97 break; 98 } 99 dev_unlock(); 100 if (dev == NULL) 101 return (ENOENT); 102 error = SYSCTL_OUT(req, dev->si_name, strlen(dev->si_name) + 1); 103 dev_rel(dev); 104 return (error); 105 } 106 107 SYSCTL_PROC(_kern, OID_AUTO, devname, 108 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_ANYBODY|CTLFLAG_MPSAFE, 109 NULL, 0, sysctl_devname, "", "devname(3) handler"); 110 111 SYSCTL_INT(_debug_sizeof, OID_AUTO, cdev, CTLFLAG_RD, 112 0, sizeof(struct cdev), "sizeof(struct cdev)"); 113 114 SYSCTL_INT(_debug_sizeof, OID_AUTO, cdev_priv, CTLFLAG_RD, 115 0, sizeof(struct cdev_priv), "sizeof(struct cdev_priv)"); 116 117 struct cdev * 118 devfs_alloc(int flags) 119 { 120 struct cdev_priv *cdp; 121 struct cdev *cdev; 122 struct timespec ts; 123 124 cdp = malloc(sizeof *cdp, M_CDEVP, M_USE_RESERVE | M_ZERO | 125 ((flags & MAKEDEV_NOWAIT) ? M_NOWAIT : M_WAITOK)); 126 if (cdp == NULL) 127 return (NULL); 128 129 cdp->cdp_dirents = &cdp->cdp_dirent0; 130 cdp->cdp_dirent0 = NULL; 131 cdp->cdp_maxdirent = 0; 132 cdp->cdp_inode = 0; 133 134 cdev = &cdp->cdp_c; 135 136 cdev->si_name = cdev->__si_namebuf; 137 LIST_INIT(&cdev->si_children); 138 vfs_timestamp(&ts); 139 cdev->si_atime = cdev->si_mtime = cdev->si_ctime = ts; 140 cdev->si_cred = NULL; 141 142 return (cdev); 143 } 144 145 int 146 devfs_dev_exists(const char *name) 147 { 148 struct cdev_priv *cdp; 149 150 mtx_assert(&devmtx, MA_OWNED); 151 152 TAILQ_FOREACH(cdp, &cdevp_list, cdp_list) { 153 if ((cdp->cdp_flags & CDP_ACTIVE) == 0) 154 continue; 155 if (devfs_pathpath(cdp->cdp_c.si_name, name) != 0) 156 return (1); 157 if (devfs_pathpath(name, cdp->cdp_c.si_name) != 0) 158 return (1); 159 } 160 if (devfs_dir_find(name) != 0) 161 return (1); 162 163 return (0); 164 } 165 166 void 167 devfs_free(struct cdev *cdev) 168 { 169 struct cdev_priv *cdp; 170 171 cdp = cdev2priv(cdev); 172 if (cdev->si_cred != NULL) 173 crfree(cdev->si_cred); 174 devfs_free_cdp_inode(cdp->cdp_inode); 175 if (cdp->cdp_maxdirent > 0) 176 free(cdp->cdp_dirents, M_DEVFS2); 177 free(cdp, M_CDEVP); 178 } 179 180 struct devfs_dirent * 181 devfs_find(struct devfs_dirent *dd, const char *name, int namelen, int type) 182 { 183 struct devfs_dirent *de; 184 185 TAILQ_FOREACH(de, &dd->de_dlist, de_list) { 186 if (namelen != de->de_dirent->d_namlen) 187 continue; 188 if (type != 0 && type != de->de_dirent->d_type) 189 continue; 190 if (bcmp(name, de->de_dirent->d_name, namelen) != 0) 191 continue; 192 break; 193 } 194 KASSERT(de == NULL || (de->de_flags & DE_DOOMED) == 0, 195 ("devfs_find: returning a doomed entry")); 196 return (de); 197 } 198 199 struct devfs_dirent * 200 devfs_newdirent(char *name, int namelen) 201 { 202 int i; 203 struct devfs_dirent *de; 204 struct dirent d; 205 206 d.d_namlen = namelen; 207 i = sizeof (*de) + GENERIC_DIRSIZ(&d); 208 de = malloc(i, M_DEVFS3, M_WAITOK | M_ZERO); 209 de->de_dirent = (struct dirent *)(de + 1); 210 de->de_dirent->d_namlen = namelen; 211 de->de_dirent->d_reclen = GENERIC_DIRSIZ(&d); 212 bcopy(name, de->de_dirent->d_name, namelen); 213 de->de_dirent->d_name[namelen] = '\0'; 214 vfs_timestamp(&de->de_ctime); 215 de->de_mtime = de->de_atime = de->de_ctime; 216 de->de_links = 1; 217 de->de_holdcnt = 1; 218 #ifdef MAC 219 mac_devfs_init(de); 220 #endif 221 return (de); 222 } 223 224 struct devfs_dirent * 225 devfs_parent_dirent(struct devfs_dirent *de) 226 { 227 228 if (de->de_dirent->d_type != DT_DIR) 229 return (de->de_dir); 230 231 if (de->de_flags & (DE_DOT | DE_DOTDOT)) 232 return (NULL); 233 234 de = TAILQ_FIRST(&de->de_dlist); /* "." */ 235 if (de == NULL) 236 return (NULL); 237 de = TAILQ_NEXT(de, de_list); /* ".." */ 238 if (de == NULL) 239 return (NULL); 240 241 return (de->de_dir); 242 } 243 244 struct devfs_dirent * 245 devfs_vmkdir(struct devfs_mount *dmp, char *name, int namelen, struct devfs_dirent *dotdot, u_int inode) 246 { 247 struct devfs_dirent *dd; 248 struct devfs_dirent *de; 249 250 /* Create the new directory */ 251 dd = devfs_newdirent(name, namelen); 252 TAILQ_INIT(&dd->de_dlist); 253 dd->de_dirent->d_type = DT_DIR; 254 dd->de_mode = 0555; 255 dd->de_links = 2; 256 dd->de_dir = dd; 257 if (inode != 0) 258 dd->de_inode = inode; 259 else 260 dd->de_inode = alloc_unr(devfs_inos); 261 262 /* 263 * "." and ".." are always the two first entries in the 264 * de_dlist list. 265 * 266 * Create the "." entry in the new directory. 267 */ 268 de = devfs_newdirent(".", 1); 269 de->de_dirent->d_type = DT_DIR; 270 de->de_flags |= DE_DOT; 271 TAILQ_INSERT_TAIL(&dd->de_dlist, de, de_list); 272 de->de_dir = dd; 273 274 /* Create the ".." entry in the new directory. */ 275 de = devfs_newdirent("..", 2); 276 de->de_dirent->d_type = DT_DIR; 277 de->de_flags |= DE_DOTDOT; 278 TAILQ_INSERT_TAIL(&dd->de_dlist, de, de_list); 279 if (dotdot == NULL) { 280 de->de_dir = dd; 281 } else { 282 de->de_dir = dotdot; 283 sx_assert(&dmp->dm_lock, SX_XLOCKED); 284 TAILQ_INSERT_TAIL(&dotdot->de_dlist, dd, de_list); 285 dotdot->de_links++; 286 devfs_rules_apply(dmp, dd); 287 } 288 289 #ifdef MAC 290 mac_devfs_create_directory(dmp->dm_mount, name, namelen, dd); 291 #endif 292 return (dd); 293 } 294 295 void 296 devfs_dirent_free(struct devfs_dirent *de) 297 { 298 free(de, M_DEVFS3); 299 } 300 301 /* 302 * Removes a directory if it is empty. Also empty parent directories are 303 * removed recursively. 304 */ 305 static void 306 devfs_rmdir_empty(struct devfs_mount *dm, struct devfs_dirent *de) 307 { 308 struct devfs_dirent *dd, *de_dot, *de_dotdot; 309 310 sx_assert(&dm->dm_lock, SX_XLOCKED); 311 312 for (;;) { 313 KASSERT(de->de_dirent->d_type == DT_DIR, 314 ("devfs_rmdir_empty: de is not a directory")); 315 316 if ((de->de_flags & DE_DOOMED) != 0 || de == dm->dm_rootdir) 317 return; 318 319 de_dot = TAILQ_FIRST(&de->de_dlist); 320 KASSERT(de_dot != NULL, ("devfs_rmdir_empty: . missing")); 321 de_dotdot = TAILQ_NEXT(de_dot, de_list); 322 KASSERT(de_dotdot != NULL, ("devfs_rmdir_empty: .. missing")); 323 /* Return if the directory is not empty. */ 324 if (TAILQ_NEXT(de_dotdot, de_list) != NULL) 325 return; 326 327 dd = devfs_parent_dirent(de); 328 KASSERT(dd != NULL, ("devfs_rmdir_empty: NULL dd")); 329 TAILQ_REMOVE(&de->de_dlist, de_dot, de_list); 330 TAILQ_REMOVE(&de->de_dlist, de_dotdot, de_list); 331 TAILQ_REMOVE(&dd->de_dlist, de, de_list); 332 DEVFS_DE_HOLD(dd); 333 devfs_delete(dm, de, DEVFS_DEL_NORECURSE); 334 devfs_delete(dm, de_dot, DEVFS_DEL_NORECURSE); 335 devfs_delete(dm, de_dotdot, DEVFS_DEL_NORECURSE); 336 if (DEVFS_DE_DROP(dd)) { 337 devfs_dirent_free(dd); 338 return; 339 } 340 341 de = dd; 342 } 343 } 344 345 /* 346 * The caller needs to hold the dm for the duration of the call since 347 * dm->dm_lock may be temporary dropped. 348 */ 349 void 350 devfs_delete(struct devfs_mount *dm, struct devfs_dirent *de, int flags) 351 { 352 struct devfs_dirent *dd; 353 struct vnode *vp; 354 355 KASSERT((de->de_flags & DE_DOOMED) == 0, 356 ("devfs_delete doomed dirent")); 357 de->de_flags |= DE_DOOMED; 358 359 if ((flags & DEVFS_DEL_NORECURSE) == 0) { 360 dd = devfs_parent_dirent(de); 361 if (dd != NULL) 362 DEVFS_DE_HOLD(dd); 363 if (de->de_flags & DE_USER) { 364 KASSERT(dd != NULL, ("devfs_delete: NULL dd")); 365 devfs_dir_unref_de(dm, dd); 366 } 367 } else 368 dd = NULL; 369 370 mtx_lock(&devfs_de_interlock); 371 vp = de->de_vnode; 372 if (vp != NULL) { 373 VI_LOCK(vp); 374 mtx_unlock(&devfs_de_interlock); 375 vholdl(vp); 376 sx_unlock(&dm->dm_lock); 377 if ((flags & DEVFS_DEL_VNLOCKED) == 0) 378 vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK | LK_RETRY); 379 else 380 VI_UNLOCK(vp); 381 vgone(vp); 382 if ((flags & DEVFS_DEL_VNLOCKED) == 0) 383 VOP_UNLOCK(vp, 0); 384 vdrop(vp); 385 sx_xlock(&dm->dm_lock); 386 } else 387 mtx_unlock(&devfs_de_interlock); 388 if (de->de_symlink) { 389 free(de->de_symlink, M_DEVFS); 390 de->de_symlink = NULL; 391 } 392 #ifdef MAC 393 mac_devfs_destroy(de); 394 #endif 395 if (de->de_inode > DEVFS_ROOTINO) { 396 devfs_free_cdp_inode(de->de_inode); 397 de->de_inode = 0; 398 } 399 if (DEVFS_DE_DROP(de)) 400 devfs_dirent_free(de); 401 402 if (dd != NULL) { 403 if (DEVFS_DE_DROP(dd)) 404 devfs_dirent_free(dd); 405 else 406 devfs_rmdir_empty(dm, dd); 407 } 408 } 409 410 /* 411 * Called on unmount. 412 * Recursively removes the entire tree. 413 * The caller needs to hold the dm for the duration of the call. 414 */ 415 416 static void 417 devfs_purge(struct devfs_mount *dm, struct devfs_dirent *dd) 418 { 419 struct devfs_dirent *de; 420 421 sx_assert(&dm->dm_lock, SX_XLOCKED); 422 423 DEVFS_DE_HOLD(dd); 424 for (;;) { 425 /* 426 * Use TAILQ_LAST() to remove "." and ".." last. 427 * We might need ".." to resolve a path in 428 * devfs_dir_unref_de(). 429 */ 430 de = TAILQ_LAST(&dd->de_dlist, devfs_dlist_head); 431 if (de == NULL) 432 break; 433 TAILQ_REMOVE(&dd->de_dlist, de, de_list); 434 if (de->de_flags & DE_USER) 435 devfs_dir_unref_de(dm, dd); 436 if (de->de_flags & (DE_DOT | DE_DOTDOT)) 437 devfs_delete(dm, de, DEVFS_DEL_NORECURSE); 438 else if (de->de_dirent->d_type == DT_DIR) 439 devfs_purge(dm, de); 440 else 441 devfs_delete(dm, de, DEVFS_DEL_NORECURSE); 442 } 443 if (DEVFS_DE_DROP(dd)) 444 devfs_dirent_free(dd); 445 else if ((dd->de_flags & DE_DOOMED) == 0) 446 devfs_delete(dm, dd, DEVFS_DEL_NORECURSE); 447 } 448 449 /* 450 * Each cdev_priv has an array of pointers to devfs_dirent which is indexed 451 * by the mount points dm_idx. 452 * This function extends the array when necessary, taking into account that 453 * the default array is 1 element and not malloc'ed. 454 */ 455 static void 456 devfs_metoo(struct cdev_priv *cdp, struct devfs_mount *dm) 457 { 458 struct devfs_dirent **dep; 459 int siz; 460 461 siz = (dm->dm_idx + 1) * sizeof *dep; 462 dep = malloc(siz, M_DEVFS2, M_WAITOK | M_ZERO); 463 dev_lock(); 464 if (dm->dm_idx <= cdp->cdp_maxdirent) { 465 /* We got raced */ 466 dev_unlock(); 467 free(dep, M_DEVFS2); 468 return; 469 } 470 memcpy(dep, cdp->cdp_dirents, (cdp->cdp_maxdirent + 1) * sizeof *dep); 471 if (cdp->cdp_maxdirent > 0) 472 free(cdp->cdp_dirents, M_DEVFS2); 473 cdp->cdp_dirents = dep; 474 /* 475 * XXX: if malloc told us how much we actually got this could 476 * XXX: be optimized. 477 */ 478 cdp->cdp_maxdirent = dm->dm_idx; 479 dev_unlock(); 480 } 481 482 /* 483 * The caller needs to hold the dm for the duration of the call. 484 */ 485 static int 486 devfs_populate_loop(struct devfs_mount *dm, int cleanup) 487 { 488 struct cdev_priv *cdp; 489 struct devfs_dirent *de; 490 struct devfs_dirent *dd; 491 struct cdev *pdev; 492 int de_flags, j; 493 char *q, *s; 494 495 sx_assert(&dm->dm_lock, SX_XLOCKED); 496 dev_lock(); 497 TAILQ_FOREACH(cdp, &cdevp_list, cdp_list) { 498 499 KASSERT(cdp->cdp_dirents != NULL, ("NULL cdp_dirents")); 500 501 /* 502 * If we are unmounting, or the device has been destroyed, 503 * clean up our dirent. 504 */ 505 if ((cleanup || !(cdp->cdp_flags & CDP_ACTIVE)) && 506 dm->dm_idx <= cdp->cdp_maxdirent && 507 cdp->cdp_dirents[dm->dm_idx] != NULL) { 508 de = cdp->cdp_dirents[dm->dm_idx]; 509 cdp->cdp_dirents[dm->dm_idx] = NULL; 510 KASSERT(cdp == de->de_cdp, 511 ("%s %d %s %p %p", __func__, __LINE__, 512 cdp->cdp_c.si_name, cdp, de->de_cdp)); 513 KASSERT(de->de_dir != NULL, ("Null de->de_dir")); 514 dev_unlock(); 515 516 TAILQ_REMOVE(&de->de_dir->de_dlist, de, de_list); 517 de->de_cdp = NULL; 518 de->de_inode = 0; 519 devfs_delete(dm, de, 0); 520 dev_lock(); 521 cdp->cdp_inuse--; 522 dev_unlock(); 523 return (1); 524 } 525 /* 526 * GC any lingering devices 527 */ 528 if (!(cdp->cdp_flags & CDP_ACTIVE)) { 529 if (cdp->cdp_inuse > 0) 530 continue; 531 TAILQ_REMOVE(&cdevp_list, cdp, cdp_list); 532 dev_unlock(); 533 dev_rel(&cdp->cdp_c); 534 return (1); 535 } 536 /* 537 * Don't create any new dirents if we are unmounting 538 */ 539 if (cleanup) 540 continue; 541 KASSERT((cdp->cdp_flags & CDP_ACTIVE), ("Bogons, I tell ya'!")); 542 543 if (dm->dm_idx <= cdp->cdp_maxdirent && 544 cdp->cdp_dirents[dm->dm_idx] != NULL) { 545 de = cdp->cdp_dirents[dm->dm_idx]; 546 KASSERT(cdp == de->de_cdp, ("inconsistent cdp")); 547 continue; 548 } 549 550 551 cdp->cdp_inuse++; 552 dev_unlock(); 553 554 if (dm->dm_idx > cdp->cdp_maxdirent) 555 devfs_metoo(cdp, dm); 556 557 dd = dm->dm_rootdir; 558 s = cdp->cdp_c.si_name; 559 for (;;) { 560 for (q = s; *q != '/' && *q != '\0'; q++) 561 continue; 562 if (*q != '/') 563 break; 564 de = devfs_find(dd, s, q - s, 0); 565 if (de == NULL) 566 de = devfs_vmkdir(dm, s, q - s, dd, 0); 567 else if (de->de_dirent->d_type == DT_LNK) { 568 de = devfs_find(dd, s, q - s, DT_DIR); 569 if (de == NULL) 570 de = devfs_vmkdir(dm, s, q - s, dd, 0); 571 de->de_flags |= DE_COVERED; 572 } 573 s = q + 1; 574 dd = de; 575 KASSERT(dd->de_dirent->d_type == DT_DIR && 576 (dd->de_flags & (DE_DOT | DE_DOTDOT)) == 0, 577 ("%s: invalid directory (si_name=%s)", 578 __func__, cdp->cdp_c.si_name)); 579 580 } 581 de_flags = 0; 582 de = devfs_find(dd, s, q - s, DT_LNK); 583 if (de != NULL) 584 de_flags |= DE_COVERED; 585 586 de = devfs_newdirent(s, q - s); 587 if (cdp->cdp_c.si_flags & SI_ALIAS) { 588 de->de_uid = 0; 589 de->de_gid = 0; 590 de->de_mode = 0755; 591 de->de_dirent->d_type = DT_LNK; 592 pdev = cdp->cdp_c.si_parent; 593 j = strlen(pdev->si_name) + 1; 594 de->de_symlink = malloc(j, M_DEVFS, M_WAITOK); 595 bcopy(pdev->si_name, de->de_symlink, j); 596 } else { 597 de->de_uid = cdp->cdp_c.si_uid; 598 de->de_gid = cdp->cdp_c.si_gid; 599 de->de_mode = cdp->cdp_c.si_mode; 600 de->de_dirent->d_type = DT_CHR; 601 } 602 de->de_flags |= de_flags; 603 de->de_inode = cdp->cdp_inode; 604 de->de_cdp = cdp; 605 #ifdef MAC 606 mac_devfs_create_device(cdp->cdp_c.si_cred, dm->dm_mount, 607 &cdp->cdp_c, de); 608 #endif 609 de->de_dir = dd; 610 TAILQ_INSERT_TAIL(&dd->de_dlist, de, de_list); 611 devfs_rules_apply(dm, de); 612 dev_lock(); 613 /* XXX: could check that cdp is still active here */ 614 KASSERT(cdp->cdp_dirents[dm->dm_idx] == NULL, 615 ("%s %d\n", __func__, __LINE__)); 616 cdp->cdp_dirents[dm->dm_idx] = de; 617 KASSERT(de->de_cdp != (void *)0xdeadc0de, 618 ("%s %d\n", __func__, __LINE__)); 619 dev_unlock(); 620 return (1); 621 } 622 dev_unlock(); 623 return (0); 624 } 625 626 /* 627 * The caller needs to hold the dm for the duration of the call. 628 */ 629 void 630 devfs_populate(struct devfs_mount *dm) 631 { 632 unsigned gen; 633 634 sx_assert(&dm->dm_lock, SX_XLOCKED); 635 gen = devfs_generation; 636 if (dm->dm_generation == gen) 637 return; 638 while (devfs_populate_loop(dm, 0)) 639 continue; 640 dm->dm_generation = gen; 641 } 642 643 /* 644 * The caller needs to hold the dm for the duration of the call. 645 */ 646 void 647 devfs_cleanup(struct devfs_mount *dm) 648 { 649 650 sx_assert(&dm->dm_lock, SX_XLOCKED); 651 while (devfs_populate_loop(dm, 1)) 652 continue; 653 devfs_purge(dm, dm->dm_rootdir); 654 } 655 656 /* 657 * devfs_create() and devfs_destroy() are called from kern_conf.c and 658 * in both cases the devlock() mutex is held, so no further locking 659 * is necesary and no sleeping allowed. 660 */ 661 662 void 663 devfs_create(struct cdev *dev) 664 { 665 struct cdev_priv *cdp; 666 667 mtx_assert(&devmtx, MA_OWNED); 668 cdp = cdev2priv(dev); 669 cdp->cdp_flags |= CDP_ACTIVE; 670 cdp->cdp_inode = alloc_unrl(devfs_inos); 671 dev_refl(dev); 672 TAILQ_INSERT_TAIL(&cdevp_list, cdp, cdp_list); 673 devfs_generation++; 674 } 675 676 void 677 devfs_destroy(struct cdev *dev) 678 { 679 struct cdev_priv *cdp; 680 681 mtx_assert(&devmtx, MA_OWNED); 682 cdp = cdev2priv(dev); 683 cdp->cdp_flags &= ~CDP_ACTIVE; 684 devfs_generation++; 685 } 686 687 ino_t 688 devfs_alloc_cdp_inode(void) 689 { 690 691 return (alloc_unr(devfs_inos)); 692 } 693 694 void 695 devfs_free_cdp_inode(ino_t ino) 696 { 697 698 if (ino > 0) 699 free_unr(devfs_inos, ino); 700 } 701 702 static void 703 devfs_devs_init(void *junk __unused) 704 { 705 706 devfs_inos = new_unrhdr(DEVFS_ROOTINO + 1, INT_MAX, &devmtx); 707 } 708 709 SYSINIT(devfs_devs, SI_SUB_DEVFS, SI_ORDER_FIRST, devfs_devs_init, NULL); 710