1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 /* 22 * Copyright 2009 Sun Microsystems, Inc. All rights reserved. 23 * Use is subject to license terms. 24 * Copyright 2015 Joyent, Inc. All rights reserved. 25 * Copyright (c) 2017 by Delphix. All rights reserved. 26 */ 27 28 /* 29 * This is the /dev (hence, the sdev_ prefix) filesystem. 30 */ 31 32 #include <sys/types.h> 33 #include <sys/param.h> 34 #include <sys/sysmacros.h> 35 #include <sys/systm.h> 36 #include <sys/kmem.h> 37 #include <sys/time.h> 38 #include <sys/pathname.h> 39 #include <sys/vfs.h> 40 #include <sys/vfs_opreg.h> 41 #include <sys/vnode.h> 42 #include <sys/file.h> 43 #include <sys/stat.h> 44 #include <sys/uio.h> 45 #include <sys/stat.h> 46 #include <sys/errno.h> 47 #include <sys/cmn_err.h> 48 #include <sys/cred.h> 49 #include <sys/statvfs.h> 50 #include <sys/policy.h> 51 #include <sys/mount.h> 52 #include <sys/debug.h> 53 #include <sys/modctl.h> 54 #include <sys/mkdev.h> 55 #include <fs/fs_subr.h> 56 #include <sys/fs/sdev_impl.h> 57 #include <sys/fs/snode.h> 58 #include <sys/fs/dv_node.h> 59 #include <sys/sunndi.h> 60 #include <sys/mntent.h> 61 #include <sys/disp.h> 62 63 /* 64 * /dev vfs operations. 65 */ 66 67 /* 68 * globals 69 */ 70 struct sdev_data *sdev_origins; /* mount info for origins under /dev */ 71 kmutex_t sdev_lock; /* used for mount/unmount/rename synchronization */ 72 taskq_t *sdev_taskq = NULL; 73 74 /* 75 * static 76 */ 77 static major_t devmajor; /* the fictitious major we live on */ 78 static major_t devminor; /* the fictitious minor of this instance */ 79 static struct sdev_data *sdev_mntinfo = NULL; /* linked list of instances */ 80 81 /* LINTED E_STATIC_UNUSED */ /* useful for debugging */ 82 static struct vnode *sdev_stale_attrvp; /* stale root attrvp after remount */ 83 84 static int sdev_mount(struct vfs *, struct vnode *, struct mounta *, 85 struct cred *); 86 static int sdev_unmount(struct vfs *, int, struct cred *); 87 static int sdev_root(struct vfs *, struct vnode **); 88 static int sdev_statvfs(struct vfs *, struct statvfs64 *); 89 static void sdev_insert_mntinfo(struct sdev_data *); 90 static int devinit(int, char *); 91 92 static vfsdef_t sdev_vfssw = { 93 VFSDEF_VERSION, 94 "dev", /* type name string */ 95 devinit, /* init routine */ 96 VSW_CANREMOUNT, /* flags */ 97 NULL /* mount options table prototype */ 98 }; 99 100 101 /* 102 * Module linkage information 103 */ 104 static struct modlfs modlfs = { 105 &mod_fsops, "/dev filesystem", &sdev_vfssw 106 }; 107 108 static struct modlinkage modlinkage = { 109 MODREV_1, (void *)&modlfs, NULL 110 }; 111 112 int 113 _init(void) 114 { 115 int e; 116 117 mutex_init(&sdev_lock, NULL, MUTEX_DEFAULT, NULL); 118 sdev_node_cache_init(); 119 sdev_devfsadm_lockinit(); 120 if ((e = mod_install(&modlinkage)) != 0) { 121 sdev_devfsadm_lockdestroy(); 122 sdev_node_cache_fini(); 123 mutex_destroy(&sdev_lock); 124 return (e); 125 } 126 return (0); 127 } 128 129 /* 130 * dev module remained loaded for the global /dev instance 131 */ 132 int 133 _fini(void) 134 { 135 return (EBUSY); 136 } 137 138 int 139 _info(struct modinfo *modinfop) 140 { 141 return (mod_info(&modlinkage, modinfop)); 142 } 143 144 /*ARGSUSED*/ 145 static int 146 devinit(int fstype, char *name) 147 { 148 static const fs_operation_def_t dev_vfsops_tbl[] = { 149 VFSNAME_MOUNT, { .vfs_mount = sdev_mount }, 150 VFSNAME_UNMOUNT, { .vfs_unmount = sdev_unmount }, 151 VFSNAME_ROOT, { .vfs_root = sdev_root }, 152 VFSNAME_STATVFS, { .vfs_statvfs = sdev_statvfs }, 153 NULL, NULL 154 }; 155 156 int error; 157 extern major_t getudev(void); 158 159 devtype = fstype; 160 161 error = vfs_setfsops(fstype, dev_vfsops_tbl, NULL); 162 if (error != 0) { 163 cmn_err(CE_WARN, "devinit: bad vfs ops tbl"); 164 return (error); 165 } 166 167 error = vn_make_ops("dev", sdev_vnodeops_tbl, &sdev_vnodeops); 168 if (error != 0) { 169 (void) vfs_freevfsops_by_type(fstype); 170 cmn_err(CE_WARN, "devinit: bad vnode ops tbl"); 171 return (error); 172 } 173 174 if ((devmajor = getudev()) == (major_t)-1) { 175 cmn_err(CE_WARN, "%s: can't get unique dev", sdev_vfssw.name); 176 return (1); 177 } 178 179 /* initialize negative cache */ 180 sdev_ncache_init(); 181 182 return (0); 183 } 184 185 /* 186 * Both mount point and backing store directory name are 187 * passed in from userland 188 */ 189 static int 190 sdev_mount(struct vfs *vfsp, struct vnode *mvp, struct mounta *uap, 191 struct cred *cr) 192 { 193 struct sdev_data *sdev_data; 194 struct vnode *avp; 195 struct sdev_node *dv; 196 struct sdev_mountargs *args = NULL; 197 int error = 0; 198 dev_t devdev; 199 200 /* 201 * security check 202 */ 203 if ((secpolicy_fs_mount(cr, mvp, vfsp) != 0) || 204 (secpolicy_sys_devices(cr) != 0)) 205 return (EPERM); 206 207 /* 208 * Sanity check the mount point 209 */ 210 if (mvp->v_type != VDIR) 211 return (ENOTDIR); 212 213 /* 214 * Sanity Check for overlay mount. 215 */ 216 mutex_enter(&mvp->v_lock); 217 if ((uap->flags & MS_OVERLAY) == 0 && 218 (uap->flags & MS_REMOUNT) == 0 && 219 (mvp->v_count > 1 || (mvp->v_flag & VROOT))) { 220 mutex_exit(&mvp->v_lock); 221 return (EBUSY); 222 } 223 mutex_exit(&mvp->v_lock); 224 225 args = kmem_zalloc(sizeof (*args), KM_SLEEP); 226 227 if ((uap->flags & MS_DATA) && 228 (uap->datalen != 0 && uap->dataptr != NULL)) { 229 /* copy in the arguments */ 230 if (error = sdev_copyin_mountargs(uap, args)) 231 goto cleanup; 232 } 233 234 /* 235 * Sanity check the backing store 236 */ 237 if (args->sdev_attrdir) { 238 /* user supplied an attribute store */ 239 if (error = lookupname((char *)(uintptr_t)args->sdev_attrdir, 240 UIO_USERSPACE, FOLLOW, NULLVPP, &avp)) { 241 cmn_err(CE_NOTE, "/dev fs: lookup on attribute " 242 "directory %s failed", 243 (char *)(uintptr_t)args->sdev_attrdir); 244 goto cleanup; 245 } 246 247 if (avp->v_type != VDIR) { 248 VN_RELE(avp); 249 error = ENOTDIR; 250 goto cleanup; 251 } 252 } else { 253 /* use mountp as the attribute store */ 254 avp = mvp; 255 VN_HOLD(avp); 256 } 257 258 mutex_enter(&sdev_lock); 259 260 /* 261 * Check that the taskq has been created. We can't do this in our 262 * _init or devinit because they run too early for ddi_taskq_create. 263 */ 264 if (sdev_taskq == NULL) { 265 sdev_taskq = taskq_create("sdev", 1, minclsyspri, 1, 1, 0); 266 if (sdev_taskq == NULL) { 267 error = ENOMEM; 268 mutex_exit(&sdev_lock); 269 VN_RELE(avp); 270 goto cleanup; 271 } 272 } 273 274 /* 275 * handling installation 276 */ 277 if (uap->flags & MS_REMOUNT) { 278 sdev_data = (struct sdev_data *)vfsp->vfs_data; 279 ASSERT(sdev_data); 280 281 dv = sdev_data->sdev_root; 282 ASSERT(dv == dv->sdev_dotdot); 283 284 /* 285 * mark all existing sdev_nodes (except root node) stale 286 */ 287 sdev_stale(dv); 288 289 /* Reset previous mountargs */ 290 if (sdev_data->sdev_mountargs) { 291 kmem_free(sdev_data->sdev_mountargs, 292 sizeof (struct sdev_mountargs)); 293 } 294 sdev_data->sdev_mountargs = args; 295 args = NULL; /* so it won't be freed below */ 296 297 sdev_stale_attrvp = dv->sdev_attrvp; 298 dv->sdev_attrvp = avp; 299 vfsp->vfs_mtime = ddi_get_time(); 300 301 mutex_exit(&sdev_lock); 302 goto cleanup; /* we're done */ 303 } 304 305 /* 306 * Create and initialize the vfs-private data. 307 */ 308 devdev = makedevice(devmajor, devminor); 309 while (vfs_devismounted(devdev)) { 310 devminor = (devminor + 1) & MAXMIN32; 311 312 /* 313 * All the minor numbers are used up. 314 */ 315 if (devminor == 0) { 316 mutex_exit(&sdev_lock); 317 VN_RELE(avp); 318 error = ENODEV; 319 goto cleanup; 320 } 321 322 devdev = makedevice(devmajor, devminor); 323 } 324 325 dv = sdev_mkroot(vfsp, devdev, mvp, avp, cr); 326 sdev_data = kmem_zalloc(sizeof (struct sdev_data), KM_SLEEP); 327 vfsp->vfs_dev = devdev; 328 vfsp->vfs_data = (caddr_t)sdev_data; 329 vfsp->vfs_fstype = devtype; 330 vfsp->vfs_bsize = DEV_BSIZE; 331 vfsp->vfs_mtime = ddi_get_time(); 332 vfs_make_fsid(&vfsp->vfs_fsid, vfsp->vfs_dev, devtype); 333 334 ASSERT(dv == dv->sdev_dotdot); 335 336 sdev_data->sdev_vfsp = vfsp; 337 sdev_data->sdev_root = dv; 338 sdev_data->sdev_mountargs = args; 339 340 /* get acl flavor from attribute dir */ 341 if (VOP_PATHCONF(avp, _PC_ACL_ENABLED, &sdev_data->sdev_acl_flavor, 342 kcred, NULL) != 0 || sdev_data->sdev_acl_flavor == 0) 343 sdev_data->sdev_acl_flavor = _ACL_ACLENT_ENABLED; 344 345 args = NULL; /* so it won't be freed below */ 346 sdev_insert_mntinfo(sdev_data); 347 mutex_exit(&sdev_lock); 348 349 if (!SDEV_IS_GLOBAL(dv)) { 350 ASSERT(sdev_origins); 351 dv->sdev_flags &= ~SDEV_GLOBAL; 352 dv->sdev_origin = sdev_origins->sdev_root; 353 } else { 354 sdev_ncache_setup(); 355 rw_enter(&dv->sdev_contents, RW_WRITER); 356 sdev_filldir_dynamic(dv); 357 rw_exit(&dv->sdev_contents); 358 } 359 360 sdev_update_timestamps(dv->sdev_attrvp, 361 cr, AT_CTIME|AT_MTIME|AT_ATIME); 362 363 cleanup: 364 if (args) 365 kmem_free(args, sizeof (*args)); 366 return (error); 367 } 368 369 /* 370 * unmounting the non-global /dev instances, e.g. when deleting a Kevlar zone. 371 */ 372 static int 373 sdev_unmount(struct vfs *vfsp, int flag, struct cred *cr) 374 { 375 struct sdev_node *dv; 376 int error; 377 struct sdev_data *sdev_data, *prev, *next; 378 379 /* 380 * enforce the security policies 381 */ 382 if ((secpolicy_fs_unmount(cr, vfsp) != 0) || 383 (secpolicy_sys_devices(cr) != 0)) 384 return (EPERM); 385 386 if (flag & MS_FORCE) 387 return (ENOTSUP); 388 389 mutex_enter(&sdev_lock); 390 dv = VFSTOSDEVFS(vfsp)->sdev_root; 391 ASSERT(dv == dv->sdev_dotdot); 392 if (SDEVTOV(dv)->v_count > 1) { 393 mutex_exit(&sdev_lock); 394 return (EBUSY); 395 } 396 397 /* 398 * global instance remains mounted 399 */ 400 if (SDEV_IS_GLOBAL(dv)) { 401 mutex_exit(&sdev_lock); 402 return (EBUSY); 403 } 404 mutex_exit(&sdev_lock); 405 406 /* verify the v_count */ 407 if ((error = sdev_cleandir(dv, NULL, 0)) != 0) { 408 return (error); 409 } 410 ASSERT(SDEVTOV(dv)->v_count == 1); 411 412 /* release hold on root node and destroy it */ 413 SDEV_RELE(dv); 414 dv->sdev_nlink -= 2; 415 sdev_nodedestroy(dv, 0); 416 417 sdev_data = (struct sdev_data *)vfsp->vfs_data; 418 vfsp->vfs_data = (caddr_t)0; 419 420 /* 421 * XXX separate it into sdev_delete_mntinfo() if useful 422 */ 423 mutex_enter(&sdev_lock); 424 prev = sdev_data->sdev_prev; 425 next = sdev_data->sdev_next; 426 if (prev) 427 prev->sdev_next = next; 428 else 429 sdev_mntinfo = next; 430 if (next) 431 next->sdev_prev = prev; 432 mutex_exit(&sdev_lock); 433 434 if (sdev_data->sdev_mountargs) { 435 kmem_free(sdev_data->sdev_mountargs, 436 sizeof (struct sdev_mountargs)); 437 } 438 kmem_free(sdev_data, sizeof (struct sdev_data)); 439 return (0); 440 } 441 442 /* 443 * return root vnode for given vfs 444 */ 445 static int 446 sdev_root(struct vfs *vfsp, struct vnode **vpp) 447 { 448 *vpp = SDEVTOV(VFSTOSDEVFS(vfsp)->sdev_root); 449 VN_HOLD(*vpp); 450 return (0); 451 } 452 453 /* 454 * return 'generic superblock' information to userland. 455 * 456 * not much that we can usefully admit to here 457 */ 458 static int 459 sdev_statvfs(struct vfs *vfsp, struct statvfs64 *sbp) 460 { 461 dev32_t d32; 462 463 bzero(sbp, sizeof (*sbp)); 464 sbp->f_frsize = sbp->f_bsize = vfsp->vfs_bsize; 465 sbp->f_files = kmem_cache_stat(sdev_node_cache, "alloc"); 466 467 /* no illusions that free/avail files is relevant to dev */ 468 sbp->f_ffree = 0; 469 sbp->f_favail = 0; 470 471 /* no illusions that blocks are relevant to devfs */ 472 sbp->f_bfree = 0; 473 sbp->f_bavail = 0; 474 sbp->f_blocks = 0; 475 476 (void) cmpldev(&d32, vfsp->vfs_dev); 477 sbp->f_fsid = d32; 478 (void) strcpy(sbp->f_basetype, vfssw[devtype].vsw_name); 479 sbp->f_flag = vf_to_stf(vfsp->vfs_flag); 480 sbp->f_namemax = MAXNAMELEN - 1; 481 (void) strcpy(sbp->f_fstr, "dev"); 482 483 return (0); 484 } 485 486 static void 487 sdev_insert_mntinfo(struct sdev_data *data) 488 { 489 ASSERT(mutex_owned(&sdev_lock)); 490 data->sdev_next = sdev_mntinfo; 491 data->sdev_prev = NULL; 492 if (sdev_mntinfo) { 493 sdev_mntinfo->sdev_prev = data; 494 } else { 495 sdev_origins = data; 496 } 497 sdev_mntinfo = data; 498 } 499 500 struct sdev_data * 501 sdev_find_mntinfo(char *mntpt) 502 { 503 struct sdev_data *mntinfo; 504 505 mutex_enter(&sdev_lock); 506 mntinfo = sdev_mntinfo; 507 while (mntinfo) { 508 if (strcmp(mntpt, mntinfo->sdev_root->sdev_name) == 0) { 509 VN_HOLD(SDEVTOV(mntinfo->sdev_root)); 510 break; 511 } 512 mntinfo = mntinfo->sdev_next; 513 } 514 mutex_exit(&sdev_lock); 515 return (mntinfo); 516 } 517 518 void 519 sdev_mntinfo_rele(struct sdev_data *mntinfo) 520 { 521 vnode_t *vp; 522 523 mutex_enter(&sdev_lock); 524 vp = SDEVTOV(mntinfo->sdev_root); 525 mutex_enter(&vp->v_lock); 526 VN_RELE_LOCKED(vp); 527 mutex_exit(&vp->v_lock); 528 mutex_exit(&sdev_lock); 529 } 530