1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1989, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed 8 * to Berkeley by John Heidemann of the UCLA Ficus project. 9 * 10 * Source: * @(#)i405_init.c 2.10 92/04/27 UCLA Ficus project 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)vfs_init.c 8.3 (Berkeley) 1/4/94 37 */ 38 39 #include <sys/cdefs.h> 40 __FBSDID("$FreeBSD$"); 41 42 #include <sys/param.h> 43 #include <sys/systm.h> 44 #include <sys/fnv_hash.h> 45 #include <sys/jail.h> 46 #include <sys/kernel.h> 47 #include <sys/linker.h> 48 #include <sys/mount.h> 49 #include <sys/proc.h> 50 #include <sys/sx.h> 51 #include <sys/syscallsubr.h> 52 #include <sys/sysctl.h> 53 #include <sys/vnode.h> 54 #include <sys/malloc.h> 55 56 static int vfs_register(struct vfsconf *); 57 static int vfs_unregister(struct vfsconf *); 58 59 MALLOC_DEFINE(M_VNODE, "vnodes", "Dynamically allocated vnodes"); 60 61 /* 62 * The highest defined VFS number. 63 */ 64 int maxvfsconf = VFS_GENERIC + 1; 65 66 /* 67 * Single-linked list of configured VFSes. 68 * New entries are added/deleted by vfs_register()/vfs_unregister() 69 */ 70 struct vfsconfhead vfsconf = TAILQ_HEAD_INITIALIZER(vfsconf); 71 struct sx vfsconf_sx; 72 SX_SYSINIT(vfsconf, &vfsconf_sx, "vfsconf"); 73 74 /* 75 * Loader.conf variable vfs.typenumhash enables setting vfc_typenum using a hash 76 * calculation on vfc_name, so that it doesn't change when file systems are 77 * loaded in a different order. This will avoid the NFS server file handles from 78 * changing for file systems that use vfc_typenum in their fsid. 79 */ 80 static int vfs_typenumhash = 1; 81 SYSCTL_INT(_vfs, OID_AUTO, typenumhash, CTLFLAG_RDTUN, &vfs_typenumhash, 0, 82 "Set vfc_typenum using a hash calculation on vfc_name, so that it does not" 83 "change when file systems are loaded in a different order."); 84 85 /* 86 * A Zen vnode attribute structure. 87 * 88 * Initialized when the first filesystem registers by vfs_register(). 89 */ 90 struct vattr va_null; 91 92 /* 93 * vfs_init.c 94 * 95 * Allocate and fill in operations vectors. 96 * 97 * An undocumented feature of this approach to defining operations is that 98 * there can be multiple entries in vfs_opv_descs for the same operations 99 * vector. This allows third parties to extend the set of operations 100 * supported by another layer in a binary compatibile way. For example, 101 * assume that NFS needed to be modified to support Ficus. NFS has an entry 102 * (probably nfs_vnopdeop_decls) declaring all the operations NFS supports by 103 * default. Ficus could add another entry (ficus_nfs_vnodeop_decl_entensions) 104 * listing those new operations Ficus adds to NFS, all without modifying the 105 * NFS code. (Of couse, the OTW NFS protocol still needs to be munged, but 106 * that is a(whole)nother story.) This is a feature. 107 */ 108 109 /* 110 * Routines having to do with the management of the vnode table. 111 */ 112 113 static struct vfsconf * 114 vfs_byname_locked(const char *name) 115 { 116 struct vfsconf *vfsp; 117 118 sx_assert(&vfsconf_sx, SA_LOCKED); 119 if (!strcmp(name, "ffs")) 120 name = "ufs"; 121 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 122 if (!strcmp(name, vfsp->vfc_name)) 123 return (vfsp); 124 } 125 return (NULL); 126 } 127 128 struct vfsconf * 129 vfs_byname(const char *name) 130 { 131 struct vfsconf *vfsp; 132 133 vfsconf_slock(); 134 vfsp = vfs_byname_locked(name); 135 vfsconf_sunlock(); 136 return (vfsp); 137 } 138 139 struct vfsconf * 140 vfs_byname_kld(const char *fstype, struct thread *td, int *error) 141 { 142 struct vfsconf *vfsp; 143 int fileid, loaded; 144 145 vfsp = vfs_byname(fstype); 146 if (vfsp != NULL) 147 return (vfsp); 148 149 /* Try to load the respective module. */ 150 *error = kern_kldload(td, fstype, &fileid); 151 loaded = (*error == 0); 152 if (*error == EEXIST) 153 *error = 0; 154 if (*error) 155 return (NULL); 156 157 /* Look up again to see if the VFS was loaded. */ 158 vfsp = vfs_byname(fstype); 159 if (vfsp == NULL) { 160 if (loaded) 161 (void)kern_kldunload(td, fileid, LINKER_UNLOAD_FORCE); 162 *error = ENODEV; 163 return (NULL); 164 } 165 return (vfsp); 166 } 167 168 static int 169 vfs_mount_sigdefer(struct mount *mp) 170 { 171 int prev_stops, rc; 172 173 TSRAW(curthread, TS_ENTER, "VFS_MOUNT", mp->mnt_vfc->vfc_name); 174 prev_stops = sigdeferstop(SIGDEFERSTOP_SILENT); 175 rc = (*mp->mnt_vfc->vfc_vfsops_sd->vfs_mount)(mp); 176 sigallowstop(prev_stops); 177 TSRAW(curthread, TS_EXIT, "VFS_MOUNT", mp->mnt_vfc->vfc_name); 178 return (rc); 179 } 180 181 static int 182 vfs_unmount_sigdefer(struct mount *mp, int mntflags) 183 { 184 int prev_stops, rc; 185 186 prev_stops = sigdeferstop(SIGDEFERSTOP_SILENT); 187 rc = (*mp->mnt_vfc->vfc_vfsops_sd->vfs_unmount)(mp, mntflags); 188 sigallowstop(prev_stops); 189 return (rc); 190 } 191 192 static int 193 vfs_root_sigdefer(struct mount *mp, int flags, struct vnode **vpp) 194 { 195 int prev_stops, rc; 196 197 prev_stops = sigdeferstop(SIGDEFERSTOP_SILENT); 198 rc = (*mp->mnt_vfc->vfc_vfsops_sd->vfs_root)(mp, flags, vpp); 199 sigallowstop(prev_stops); 200 return (rc); 201 } 202 203 static int 204 vfs_quotactl_sigdefer(struct mount *mp, int cmd, uid_t uid, void *arg) 205 { 206 int prev_stops, rc; 207 208 prev_stops = sigdeferstop(SIGDEFERSTOP_SILENT); 209 rc = (*mp->mnt_vfc->vfc_vfsops_sd->vfs_quotactl)(mp, cmd, uid, arg); 210 sigallowstop(prev_stops); 211 return (rc); 212 } 213 214 static int 215 vfs_statfs_sigdefer(struct mount *mp, struct statfs *sbp) 216 { 217 int prev_stops, rc; 218 219 prev_stops = sigdeferstop(SIGDEFERSTOP_SILENT); 220 rc = (*mp->mnt_vfc->vfc_vfsops_sd->vfs_statfs)(mp, sbp); 221 sigallowstop(prev_stops); 222 return (rc); 223 } 224 225 static int 226 vfs_sync_sigdefer(struct mount *mp, int waitfor) 227 { 228 int prev_stops, rc; 229 230 prev_stops = sigdeferstop(SIGDEFERSTOP_SILENT); 231 rc = (*mp->mnt_vfc->vfc_vfsops_sd->vfs_sync)(mp, waitfor); 232 sigallowstop(prev_stops); 233 return (rc); 234 } 235 236 static int 237 vfs_vget_sigdefer(struct mount *mp, ino_t ino, int flags, struct vnode **vpp) 238 { 239 int prev_stops, rc; 240 241 prev_stops = sigdeferstop(SIGDEFERSTOP_SILENT); 242 rc = (*mp->mnt_vfc->vfc_vfsops_sd->vfs_vget)(mp, ino, flags, vpp); 243 sigallowstop(prev_stops); 244 return (rc); 245 } 246 247 static int 248 vfs_fhtovp_sigdefer(struct mount *mp, struct fid *fidp, int flags, 249 struct vnode **vpp) 250 { 251 int prev_stops, rc; 252 253 prev_stops = sigdeferstop(SIGDEFERSTOP_SILENT); 254 rc = (*mp->mnt_vfc->vfc_vfsops_sd->vfs_fhtovp)(mp, fidp, flags, vpp); 255 sigallowstop(prev_stops); 256 return (rc); 257 } 258 259 static int 260 vfs_checkexp_sigdefer(struct mount *mp, struct sockaddr *nam, int *exflg, 261 struct ucred **credp, int *numsecflavors, int **secflavors) 262 { 263 int prev_stops, rc; 264 265 prev_stops = sigdeferstop(SIGDEFERSTOP_SILENT); 266 rc = (*mp->mnt_vfc->vfc_vfsops_sd->vfs_checkexp)(mp, nam, exflg, credp, 267 numsecflavors, secflavors); 268 sigallowstop(prev_stops); 269 return (rc); 270 } 271 272 static int 273 vfs_extattrctl_sigdefer(struct mount *mp, int cmd, struct vnode *filename_vp, 274 int attrnamespace, const char *attrname) 275 { 276 int prev_stops, rc; 277 278 prev_stops = sigdeferstop(SIGDEFERSTOP_SILENT); 279 rc = (*mp->mnt_vfc->vfc_vfsops_sd->vfs_extattrctl)(mp, cmd, 280 filename_vp, attrnamespace, attrname); 281 sigallowstop(prev_stops); 282 return (rc); 283 } 284 285 static int 286 vfs_sysctl_sigdefer(struct mount *mp, fsctlop_t op, struct sysctl_req *req) 287 { 288 int prev_stops, rc; 289 290 prev_stops = sigdeferstop(SIGDEFERSTOP_SILENT); 291 rc = (*mp->mnt_vfc->vfc_vfsops_sd->vfs_sysctl)(mp, op, req); 292 sigallowstop(prev_stops); 293 return (rc); 294 } 295 296 static void 297 vfs_susp_clean_sigdefer(struct mount *mp) 298 { 299 int prev_stops; 300 301 if (*mp->mnt_vfc->vfc_vfsops_sd->vfs_susp_clean == NULL) 302 return; 303 prev_stops = sigdeferstop(SIGDEFERSTOP_SILENT); 304 (*mp->mnt_vfc->vfc_vfsops_sd->vfs_susp_clean)(mp); 305 sigallowstop(prev_stops); 306 } 307 308 static void 309 vfs_reclaim_lowervp_sigdefer(struct mount *mp, struct vnode *vp) 310 { 311 int prev_stops; 312 313 if (*mp->mnt_vfc->vfc_vfsops_sd->vfs_reclaim_lowervp == NULL) 314 return; 315 prev_stops = sigdeferstop(SIGDEFERSTOP_SILENT); 316 (*mp->mnt_vfc->vfc_vfsops_sd->vfs_reclaim_lowervp)(mp, vp); 317 sigallowstop(prev_stops); 318 } 319 320 static void 321 vfs_unlink_lowervp_sigdefer(struct mount *mp, struct vnode *vp) 322 { 323 int prev_stops; 324 325 if (*mp->mnt_vfc->vfc_vfsops_sd->vfs_unlink_lowervp == NULL) 326 return; 327 prev_stops = sigdeferstop(SIGDEFERSTOP_SILENT); 328 (*(mp)->mnt_vfc->vfc_vfsops_sd->vfs_unlink_lowervp)(mp, vp); 329 sigallowstop(prev_stops); 330 } 331 332 static void 333 vfs_purge_sigdefer(struct mount *mp) 334 { 335 int prev_stops; 336 337 prev_stops = sigdeferstop(SIGDEFERSTOP_SILENT); 338 (*mp->mnt_vfc->vfc_vfsops_sd->vfs_purge)(mp); 339 sigallowstop(prev_stops); 340 } 341 342 static struct vfsops vfsops_sigdefer = { 343 .vfs_mount = vfs_mount_sigdefer, 344 .vfs_unmount = vfs_unmount_sigdefer, 345 .vfs_root = vfs_root_sigdefer, 346 .vfs_quotactl = vfs_quotactl_sigdefer, 347 .vfs_statfs = vfs_statfs_sigdefer, 348 .vfs_sync = vfs_sync_sigdefer, 349 .vfs_vget = vfs_vget_sigdefer, 350 .vfs_fhtovp = vfs_fhtovp_sigdefer, 351 .vfs_checkexp = vfs_checkexp_sigdefer, 352 .vfs_extattrctl = vfs_extattrctl_sigdefer, 353 .vfs_sysctl = vfs_sysctl_sigdefer, 354 .vfs_susp_clean = vfs_susp_clean_sigdefer, 355 .vfs_reclaim_lowervp = vfs_reclaim_lowervp_sigdefer, 356 .vfs_unlink_lowervp = vfs_unlink_lowervp_sigdefer, 357 .vfs_purge = vfs_purge_sigdefer, 358 359 }; 360 361 /* Register a new filesystem type in the global table */ 362 static int 363 vfs_register(struct vfsconf *vfc) 364 { 365 struct sysctl_oid *oidp; 366 struct vfsops *vfsops; 367 static int once; 368 struct vfsconf *tvfc; 369 uint32_t hashval; 370 int secondpass; 371 372 if (!once) { 373 vattr_null(&va_null); 374 once = 1; 375 } 376 377 if (vfc->vfc_version != VFS_VERSION) { 378 printf("ERROR: filesystem %s, unsupported ABI version %x\n", 379 vfc->vfc_name, vfc->vfc_version); 380 return (EINVAL); 381 } 382 vfsconf_lock(); 383 if (vfs_byname_locked(vfc->vfc_name) != NULL) { 384 vfsconf_unlock(); 385 return (EEXIST); 386 } 387 388 if (vfs_typenumhash != 0) { 389 /* 390 * Calculate a hash on vfc_name to use for vfc_typenum. Unless 391 * all of 1<->255 are assigned, it is limited to 8bits since 392 * that is what ZFS uses from vfc_typenum and is also the 393 * preferred range for vfs_getnewfsid(). 394 */ 395 hashval = fnv_32_str(vfc->vfc_name, FNV1_32_INIT); 396 hashval &= 0xff; 397 secondpass = 0; 398 do { 399 /* Look for and fix any collision. */ 400 TAILQ_FOREACH(tvfc, &vfsconf, vfc_list) { 401 if (hashval == tvfc->vfc_typenum) { 402 if (hashval == 255 && secondpass == 0) { 403 hashval = 1; 404 secondpass = 1; 405 } else 406 hashval++; 407 break; 408 } 409 } 410 } while (tvfc != NULL); 411 vfc->vfc_typenum = hashval; 412 if (vfc->vfc_typenum >= maxvfsconf) 413 maxvfsconf = vfc->vfc_typenum + 1; 414 } else 415 vfc->vfc_typenum = maxvfsconf++; 416 TAILQ_INSERT_TAIL(&vfsconf, vfc, vfc_list); 417 418 /* 419 * Initialise unused ``struct vfsops'' fields, to use 420 * the vfs_std*() functions. Note, we need the mount 421 * and unmount operations, at the least. The check 422 * for vfsops available is just a debugging aid. 423 */ 424 KASSERT(vfc->vfc_vfsops != NULL, 425 ("Filesystem %s has no vfsops", vfc->vfc_name)); 426 /* 427 * Check the mount and unmount operations. 428 */ 429 vfsops = vfc->vfc_vfsops; 430 KASSERT(vfsops->vfs_mount != NULL, 431 ("Filesystem %s has no mount op", vfc->vfc_name)); 432 KASSERT(vfsops->vfs_unmount != NULL, 433 ("Filesystem %s has no unmount op", vfc->vfc_name)); 434 435 if (vfsops->vfs_root == NULL) 436 /* return file system's root vnode */ 437 vfsops->vfs_root = vfs_stdroot; 438 if (vfsops->vfs_quotactl == NULL) 439 /* quota control */ 440 vfsops->vfs_quotactl = vfs_stdquotactl; 441 if (vfsops->vfs_statfs == NULL) 442 /* return file system's status */ 443 vfsops->vfs_statfs = vfs_stdstatfs; 444 if (vfsops->vfs_sync == NULL) 445 /* 446 * flush unwritten data (nosync) 447 * file systems can use vfs_stdsync 448 * explicitly by setting it in the 449 * vfsop vector. 450 */ 451 vfsops->vfs_sync = vfs_stdnosync; 452 if (vfsops->vfs_vget == NULL) 453 /* convert an inode number to a vnode */ 454 vfsops->vfs_vget = vfs_stdvget; 455 if (vfsops->vfs_fhtovp == NULL) 456 /* turn an NFS file handle into a vnode */ 457 vfsops->vfs_fhtovp = vfs_stdfhtovp; 458 if (vfsops->vfs_checkexp == NULL) 459 /* check if file system is exported */ 460 vfsops->vfs_checkexp = vfs_stdcheckexp; 461 if (vfsops->vfs_init == NULL) 462 /* file system specific initialisation */ 463 vfsops->vfs_init = vfs_stdinit; 464 if (vfsops->vfs_uninit == NULL) 465 /* file system specific uninitialisation */ 466 vfsops->vfs_uninit = vfs_stduninit; 467 if (vfsops->vfs_extattrctl == NULL) 468 /* extended attribute control */ 469 vfsops->vfs_extattrctl = vfs_stdextattrctl; 470 if (vfsops->vfs_sysctl == NULL) 471 vfsops->vfs_sysctl = vfs_stdsysctl; 472 473 if ((vfc->vfc_flags & VFCF_SBDRY) != 0) { 474 vfc->vfc_vfsops_sd = vfc->vfc_vfsops; 475 vfc->vfc_vfsops = &vfsops_sigdefer; 476 } 477 478 if (vfc->vfc_flags & VFCF_JAIL) 479 prison_add_vfs(vfc); 480 481 /* 482 * Call init function for this VFS... 483 */ 484 if ((vfc->vfc_flags & VFCF_SBDRY) != 0) 485 vfc->vfc_vfsops_sd->vfs_init(vfc); 486 else 487 vfc->vfc_vfsops->vfs_init(vfc); 488 vfsconf_unlock(); 489 490 /* 491 * If this filesystem has a sysctl node under vfs 492 * (i.e. vfs.xxfs), then change the oid number of that node to 493 * match the filesystem's type number. This allows user code 494 * which uses the type number to read sysctl variables defined 495 * by the filesystem to continue working. Since the oids are 496 * in a sorted list, we need to make sure the order is 497 * preserved by re-registering the oid after modifying its 498 * number. 499 */ 500 sysctl_wlock(); 501 SLIST_FOREACH(oidp, SYSCTL_CHILDREN(&sysctl___vfs), oid_link) { 502 if (strcmp(oidp->oid_name, vfc->vfc_name) == 0) { 503 sysctl_unregister_oid(oidp); 504 oidp->oid_number = vfc->vfc_typenum; 505 sysctl_register_oid(oidp); 506 break; 507 } 508 } 509 sysctl_wunlock(); 510 511 return (0); 512 } 513 514 515 /* Remove registration of a filesystem type */ 516 static int 517 vfs_unregister(struct vfsconf *vfc) 518 { 519 struct vfsconf *vfsp; 520 int error, maxtypenum; 521 522 vfsconf_lock(); 523 vfsp = vfs_byname_locked(vfc->vfc_name); 524 if (vfsp == NULL) { 525 vfsconf_unlock(); 526 return (EINVAL); 527 } 528 if (vfsp->vfc_refcount != 0) { 529 vfsconf_unlock(); 530 return (EBUSY); 531 } 532 error = 0; 533 if ((vfc->vfc_flags & VFCF_SBDRY) != 0) { 534 if (vfc->vfc_vfsops_sd->vfs_uninit != NULL) 535 error = vfc->vfc_vfsops_sd->vfs_uninit(vfsp); 536 } else { 537 if (vfc->vfc_vfsops->vfs_uninit != NULL) { 538 error = vfc->vfc_vfsops->vfs_uninit(vfsp); 539 } 540 if (error != 0) { 541 vfsconf_unlock(); 542 return (error); 543 } 544 } 545 TAILQ_REMOVE(&vfsconf, vfsp, vfc_list); 546 maxtypenum = VFS_GENERIC; 547 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) 548 if (maxtypenum < vfsp->vfc_typenum) 549 maxtypenum = vfsp->vfc_typenum; 550 maxvfsconf = maxtypenum + 1; 551 vfsconf_unlock(); 552 return (0); 553 } 554 555 /* 556 * Standard kernel module handling code for filesystem modules. 557 * Referenced from VFS_SET(). 558 */ 559 int 560 vfs_modevent(module_t mod, int type, void *data) 561 { 562 struct vfsconf *vfc; 563 int error = 0; 564 565 vfc = (struct vfsconf *)data; 566 567 switch (type) { 568 case MOD_LOAD: 569 if (vfc) 570 error = vfs_register(vfc); 571 break; 572 573 case MOD_UNLOAD: 574 if (vfc) 575 error = vfs_unregister(vfc); 576 break; 577 default: 578 error = EOPNOTSUPP; 579 break; 580 } 581 return (error); 582 } 583