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