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 https://opensource.org/licenses/CDDL-1.0. 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 /* 23 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. 24 * Copyright (c) 2011 Lawrence Livermore National Security, LLC. 25 */ 26 27 #include <libintl.h> 28 #include <unistd.h> 29 #include <sys/file.h> 30 #include <sys/mount.h> 31 #include <sys/mntent.h> 32 #include <sys/stat.h> 33 #include <libzfs.h> 34 #include <libzutil.h> 35 #include <locale.h> 36 #include <getopt.h> 37 #include <fcntl.h> 38 #include <errno.h> 39 40 #define ZS_COMMENT 0x00000000 /* comment */ 41 #define ZS_ZFSUTIL 0x00000001 /* caller is zfs(8) */ 42 43 libzfs_handle_t *g_zfs; 44 45 /* 46 * Opportunistically convert a target string into a pool name. If the 47 * string does not represent a block device with a valid zfs label 48 * then it is passed through without modification. 49 */ 50 static void 51 parse_dataset(const char *target, char **dataset) 52 { 53 /* 54 * Prior to util-linux 2.36.2, if a file or directory in the 55 * current working directory was named 'dataset' then mount(8) 56 * would prepend the current working directory to the dataset. 57 * Check for it and strip the prepended path when it is added. 58 */ 59 char cwd[PATH_MAX]; 60 if (getcwd(cwd, PATH_MAX) == NULL) { 61 perror("getcwd"); 62 return; 63 } 64 int len = strlen(cwd); 65 if (strncmp(cwd, target, len) == 0) 66 target += len; 67 68 /* Assume pool/dataset is more likely */ 69 strlcpy(*dataset, target, PATH_MAX); 70 71 int fd = open(target, O_RDONLY | O_CLOEXEC); 72 if (fd < 0) 73 return; 74 75 nvlist_t *cfg = NULL; 76 if (zpool_read_label(fd, &cfg, NULL) == 0) { 77 char *nm = NULL; 78 if (!nvlist_lookup_string(cfg, ZPOOL_CONFIG_POOL_NAME, &nm)) 79 strlcpy(*dataset, nm, PATH_MAX); 80 nvlist_free(cfg); 81 } 82 83 if (close(fd)) 84 perror("close"); 85 } 86 87 /* 88 * Update the mtab_* code to use the libmount library when it is commonly 89 * available otherwise fallback to legacy mode. The mount(8) utility will 90 * manage the lock file for us to prevent racing updates to /etc/mtab. 91 */ 92 static int 93 mtab_is_writeable(void) 94 { 95 struct stat st; 96 int error, fd; 97 98 error = lstat("/etc/mtab", &st); 99 if (error || S_ISLNK(st.st_mode)) 100 return (0); 101 102 fd = open("/etc/mtab", O_RDWR | O_CREAT, 0644); 103 if (fd < 0) 104 return (0); 105 106 close(fd); 107 return (1); 108 } 109 110 static int 111 mtab_update(const char *dataset, const char *mntpoint, const char *type, 112 const char *mntopts) 113 { 114 struct mntent mnt; 115 FILE *fp; 116 int error; 117 118 mnt.mnt_fsname = (char *)dataset; 119 mnt.mnt_dir = (char *)mntpoint; 120 mnt.mnt_type = (char *)type; 121 mnt.mnt_opts = (char *)(mntopts ?: ""); 122 mnt.mnt_freq = 0; 123 mnt.mnt_passno = 0; 124 125 fp = setmntent("/etc/mtab", "a+e"); 126 if (!fp) { 127 (void) fprintf(stderr, gettext( 128 "filesystem '%s' was mounted, but /etc/mtab " 129 "could not be opened due to error: %s\n"), 130 dataset, strerror(errno)); 131 return (MOUNT_FILEIO); 132 } 133 134 error = addmntent(fp, &mnt); 135 if (error) { 136 (void) fprintf(stderr, gettext( 137 "filesystem '%s' was mounted, but /etc/mtab " 138 "could not be updated due to error: %s\n"), 139 dataset, strerror(errno)); 140 return (MOUNT_FILEIO); 141 } 142 143 (void) endmntent(fp); 144 145 return (MOUNT_SUCCESS); 146 } 147 148 int 149 main(int argc, char **argv) 150 { 151 zfs_handle_t *zhp; 152 char prop[ZFS_MAXPROPLEN]; 153 uint64_t zfs_version = 0; 154 char mntopts[MNT_LINE_MAX] = { '\0' }; 155 char badopt[MNT_LINE_MAX] = { '\0' }; 156 char mtabopt[MNT_LINE_MAX] = { '\0' }; 157 char mntpoint[PATH_MAX]; 158 char dataset[PATH_MAX], *pdataset = dataset; 159 unsigned long mntflags = 0, zfsflags = 0, remount = 0; 160 int sloppy = 0, fake = 0, verbose = 0, nomtab = 0, zfsutil = 0; 161 int error, c; 162 163 (void) setlocale(LC_ALL, ""); 164 (void) setlocale(LC_NUMERIC, "C"); 165 (void) textdomain(TEXT_DOMAIN); 166 167 opterr = 0; 168 169 /* check options */ 170 while ((c = getopt_long(argc, argv, "sfnvo:h?", 0, 0)) != -1) { 171 switch (c) { 172 case 's': 173 sloppy = 1; 174 break; 175 case 'f': 176 fake = 1; 177 break; 178 case 'n': 179 nomtab = 1; 180 break; 181 case 'v': 182 verbose++; 183 break; 184 case 'o': 185 (void) strlcpy(mntopts, optarg, sizeof (mntopts)); 186 break; 187 case 'h': 188 case '?': 189 if (optopt) 190 (void) fprintf(stderr, 191 gettext("Invalid option '%c'\n"), optopt); 192 (void) fprintf(stderr, gettext("Usage: mount.zfs " 193 "[-sfnvh] [-o options] <dataset> <mountpoint>\n")); 194 return (MOUNT_USAGE); 195 } 196 } 197 198 argc -= optind; 199 argv += optind; 200 201 /* check that we only have two arguments */ 202 if (argc != 2) { 203 if (argc == 0) 204 (void) fprintf(stderr, gettext("missing dataset " 205 "argument\n")); 206 else if (argc == 1) 207 (void) fprintf(stderr, 208 gettext("missing mountpoint argument\n")); 209 else 210 (void) fprintf(stderr, gettext("too many arguments\n")); 211 (void) fprintf(stderr, "usage: mount <dataset> <mountpoint>\n"); 212 return (MOUNT_USAGE); 213 } 214 215 parse_dataset(argv[0], &pdataset); 216 217 /* canonicalize the mount point */ 218 if (realpath(argv[1], mntpoint) == NULL) { 219 (void) fprintf(stderr, gettext("filesystem '%s' cannot be " 220 "mounted at '%s' due to canonicalization error: %s\n"), 221 dataset, argv[1], strerror(errno)); 222 return (MOUNT_SYSERR); 223 } 224 225 /* validate mount options and set mntflags */ 226 error = zfs_parse_mount_options(mntopts, &mntflags, &zfsflags, sloppy, 227 badopt, mtabopt); 228 if (error) { 229 switch (error) { 230 case ENOMEM: 231 (void) fprintf(stderr, gettext("filesystem '%s' " 232 "cannot be mounted due to a memory allocation " 233 "failure.\n"), dataset); 234 return (MOUNT_SYSERR); 235 case ENOENT: 236 (void) fprintf(stderr, gettext("filesystem '%s' " 237 "cannot be mounted due to invalid option " 238 "'%s'.\n"), dataset, badopt); 239 (void) fprintf(stderr, gettext("Use the '-s' option " 240 "to ignore the bad mount option.\n")); 241 return (MOUNT_USAGE); 242 default: 243 (void) fprintf(stderr, gettext("filesystem '%s' " 244 "cannot be mounted due to internal error %d.\n"), 245 dataset, error); 246 return (MOUNT_SOFTWARE); 247 } 248 } 249 250 if (mntflags & MS_REMOUNT) { 251 nomtab = 1; 252 remount = 1; 253 } 254 255 if (zfsflags & ZS_ZFSUTIL) 256 zfsutil = 1; 257 258 if ((g_zfs = libzfs_init()) == NULL) { 259 (void) fprintf(stderr, "%s\n", libzfs_error_init(errno)); 260 return (MOUNT_SYSERR); 261 } 262 263 /* try to open the dataset to access the mount point */ 264 if ((zhp = zfs_open(g_zfs, dataset, 265 ZFS_TYPE_FILESYSTEM | ZFS_TYPE_SNAPSHOT)) == NULL) { 266 (void) fprintf(stderr, gettext("filesystem '%s' cannot be " 267 "mounted, unable to open the dataset\n"), dataset); 268 libzfs_fini(g_zfs); 269 return (MOUNT_USAGE); 270 } 271 272 if (!zfsutil || sloppy || 273 libzfs_envvar_is_set("ZFS_MOUNT_HELPER")) { 274 zfs_adjust_mount_options(zhp, mntpoint, mntopts, mtabopt); 275 } 276 277 /* treat all snapshots as legacy mount points */ 278 if (zfs_get_type(zhp) == ZFS_TYPE_SNAPSHOT) 279 (void) strlcpy(prop, ZFS_MOUNTPOINT_LEGACY, ZFS_MAXPROPLEN); 280 else 281 (void) zfs_prop_get(zhp, ZFS_PROP_MOUNTPOINT, prop, 282 sizeof (prop), NULL, NULL, 0, B_FALSE); 283 284 /* 285 * Fetch the max supported zfs version in case we get ENOTSUP 286 * back from the mount command, since we need the zfs handle 287 * to do so. 288 */ 289 zfs_version = zfs_prop_get_int(zhp, ZFS_PROP_VERSION); 290 if (zfs_version == 0) { 291 fprintf(stderr, gettext("unable to fetch " 292 "ZFS version for filesystem '%s'\n"), dataset); 293 zfs_close(zhp); 294 libzfs_fini(g_zfs); 295 return (MOUNT_SYSERR); 296 } 297 298 /* 299 * Legacy mount points may only be mounted using 'mount', never using 300 * 'zfs mount'. However, since 'zfs mount' actually invokes 'mount' 301 * we differentiate the two cases using the 'zfsutil' mount option. 302 * This mount option should only be supplied by the 'zfs mount' util. 303 * 304 * The only exception to the above rule is '-o remount' which is 305 * always allowed for non-legacy datasets. This is done because when 306 * using zfs as your root file system both rc.sysinit/umountroot and 307 * systemd depend on 'mount -o remount <mountpoint>' to work. 308 */ 309 if (zfsutil && (strcmp(prop, ZFS_MOUNTPOINT_LEGACY) == 0)) { 310 (void) fprintf(stderr, gettext( 311 "filesystem '%s' cannot be mounted using 'zfs mount'.\n" 312 "Use 'zfs set mountpoint=%s' or 'mount -t zfs %s %s'.\n" 313 "See zfs(8) for more information.\n"), 314 dataset, mntpoint, dataset, mntpoint); 315 zfs_close(zhp); 316 libzfs_fini(g_zfs); 317 return (MOUNT_USAGE); 318 } 319 320 if (!zfsutil && !(remount || fake) && 321 strcmp(prop, ZFS_MOUNTPOINT_LEGACY)) { 322 (void) fprintf(stderr, gettext( 323 "filesystem '%s' cannot be mounted using 'mount'.\n" 324 "Use 'zfs set mountpoint=%s' or 'zfs mount %s'.\n" 325 "See zfs(8) for more information.\n"), 326 dataset, "legacy", dataset); 327 zfs_close(zhp); 328 libzfs_fini(g_zfs); 329 return (MOUNT_USAGE); 330 } 331 332 if (verbose) 333 (void) fprintf(stdout, gettext("mount.zfs:\n" 334 " dataset: \"%s\"\n mountpoint: \"%s\"\n" 335 " mountflags: 0x%lx\n zfsflags: 0x%lx\n" 336 " mountopts: \"%s\"\n mtabopts: \"%s\"\n"), 337 dataset, mntpoint, mntflags, zfsflags, mntopts, mtabopt); 338 339 if (!fake) { 340 if (zfsutil && !sloppy && 341 !libzfs_envvar_is_set("ZFS_MOUNT_HELPER")) { 342 error = zfs_mount_at(zhp, mntopts, mntflags, mntpoint); 343 if (error) { 344 (void) fprintf(stderr, "zfs_mount_at() failed: " 345 "%s", libzfs_error_description(g_zfs)); 346 zfs_close(zhp); 347 libzfs_fini(g_zfs); 348 return (MOUNT_SYSERR); 349 } 350 } else { 351 error = mount(dataset, mntpoint, MNTTYPE_ZFS, 352 mntflags, mntopts); 353 } 354 } 355 356 zfs_close(zhp); 357 libzfs_fini(g_zfs); 358 359 if (error) { 360 switch (errno) { 361 case ENOENT: 362 (void) fprintf(stderr, gettext("mount point " 363 "'%s' does not exist\n"), mntpoint); 364 return (MOUNT_SYSERR); 365 case EBUSY: 366 (void) fprintf(stderr, gettext("filesystem " 367 "'%s' is already mounted\n"), dataset); 368 return (MOUNT_BUSY); 369 case ENOTSUP: 370 if (zfs_version > ZPL_VERSION) { 371 (void) fprintf(stderr, 372 gettext("filesystem '%s' (v%d) is not " 373 "supported by this implementation of " 374 "ZFS (max v%d).\n"), dataset, 375 (int)zfs_version, (int)ZPL_VERSION); 376 } else { 377 (void) fprintf(stderr, 378 gettext("filesystem '%s' mount " 379 "failed for unknown reason.\n"), dataset); 380 } 381 return (MOUNT_SYSERR); 382 #ifdef MS_MANDLOCK 383 case EPERM: 384 if (mntflags & MS_MANDLOCK) { 385 (void) fprintf(stderr, gettext("filesystem " 386 "'%s' has the 'nbmand=on' property set, " 387 "this mount\noption may be disabled in " 388 "your kernel. Use 'zfs set nbmand=off'\n" 389 "to disable this option and try to " 390 "mount the filesystem again.\n"), dataset); 391 return (MOUNT_SYSERR); 392 } 393 #endif 394 zfs_fallthrough; 395 default: 396 (void) fprintf(stderr, gettext("filesystem " 397 "'%s' can not be mounted: %s\n"), dataset, 398 strerror(errno)); 399 return (MOUNT_USAGE); 400 } 401 } 402 403 if (!nomtab && mtab_is_writeable()) { 404 error = mtab_update(dataset, mntpoint, MNTTYPE_ZFS, mtabopt); 405 if (error) 406 return (error); 407 } 408 409 return (MOUNT_SUCCESS); 410 } 411