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 /* 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(char *dataset, char *mntpoint, char *type, char *mntopts) 112 { 113 struct mntent mnt; 114 FILE *fp; 115 int error; 116 117 mnt.mnt_fsname = dataset; 118 mnt.mnt_dir = mntpoint; 119 mnt.mnt_type = type; 120 mnt.mnt_opts = mntopts ? mntopts : ""; 121 mnt.mnt_freq = 0; 122 mnt.mnt_passno = 0; 123 124 fp = setmntent("/etc/mtab", "a+"); 125 if (!fp) { 126 (void) fprintf(stderr, gettext( 127 "filesystem '%s' was mounted, but /etc/mtab " 128 "could not be opened due to error: %s\n"), 129 dataset, strerror(errno)); 130 return (MOUNT_FILEIO); 131 } 132 133 error = addmntent(fp, &mnt); 134 if (error) { 135 (void) fprintf(stderr, gettext( 136 "filesystem '%s' was mounted, but /etc/mtab " 137 "could not be updated due to error: %s\n"), 138 dataset, strerror(errno)); 139 return (MOUNT_FILEIO); 140 } 141 142 (void) endmntent(fp); 143 144 return (MOUNT_SUCCESS); 145 } 146 147 int 148 main(int argc, char **argv) 149 { 150 zfs_handle_t *zhp; 151 char prop[ZFS_MAXPROPLEN]; 152 uint64_t zfs_version = 0; 153 char mntopts[MNT_LINE_MAX] = { '\0' }; 154 char badopt[MNT_LINE_MAX] = { '\0' }; 155 char mtabopt[MNT_LINE_MAX] = { '\0' }; 156 char mntpoint[PATH_MAX]; 157 char dataset[PATH_MAX], *pdataset = dataset; 158 unsigned long mntflags = 0, zfsflags = 0, remount = 0; 159 int sloppy = 0, fake = 0, verbose = 0, nomtab = 0, zfsutil = 0; 160 int error, c; 161 162 (void) setlocale(LC_ALL, ""); 163 (void) setlocale(LC_NUMERIC, "C"); 164 (void) textdomain(TEXT_DOMAIN); 165 166 opterr = 0; 167 168 /* check options */ 169 while ((c = getopt_long(argc, argv, "sfnvo:h?", 0, 0)) != -1) { 170 switch (c) { 171 case 's': 172 sloppy = 1; 173 break; 174 case 'f': 175 fake = 1; 176 break; 177 case 'n': 178 nomtab = 1; 179 break; 180 case 'v': 181 verbose++; 182 break; 183 case 'o': 184 (void) strlcpy(mntopts, optarg, sizeof (mntopts)); 185 break; 186 case 'h': 187 case '?': 188 if (optopt) 189 (void) fprintf(stderr, 190 gettext("Invalid option '%c'\n"), optopt); 191 (void) fprintf(stderr, gettext("Usage: mount.zfs " 192 "[-sfnvh] [-o options] <dataset> <mountpoint>\n")); 193 return (MOUNT_USAGE); 194 } 195 } 196 197 argc -= optind; 198 argv += optind; 199 200 /* check that we only have two arguments */ 201 if (argc != 2) { 202 if (argc == 0) 203 (void) fprintf(stderr, gettext("missing dataset " 204 "argument\n")); 205 else if (argc == 1) 206 (void) fprintf(stderr, 207 gettext("missing mountpoint argument\n")); 208 else 209 (void) fprintf(stderr, gettext("too many arguments\n")); 210 (void) fprintf(stderr, "usage: mount <dataset> <mountpoint>\n"); 211 return (MOUNT_USAGE); 212 } 213 214 parse_dataset(argv[0], &pdataset); 215 216 /* canonicalize the mount point */ 217 if (realpath(argv[1], mntpoint) == NULL) { 218 (void) fprintf(stderr, gettext("filesystem '%s' cannot be " 219 "mounted at '%s' due to canonicalization error: %s\n"), 220 dataset, argv[1], strerror(errno)); 221 return (MOUNT_SYSERR); 222 } 223 224 /* validate mount options and set mntflags */ 225 error = zfs_parse_mount_options(mntopts, &mntflags, &zfsflags, sloppy, 226 badopt, mtabopt); 227 if (error) { 228 switch (error) { 229 case ENOMEM: 230 (void) fprintf(stderr, gettext("filesystem '%s' " 231 "cannot be mounted due to a memory allocation " 232 "failure.\n"), dataset); 233 return (MOUNT_SYSERR); 234 case ENOENT: 235 (void) fprintf(stderr, gettext("filesystem '%s' " 236 "cannot be mounted due to invalid option " 237 "'%s'.\n"), dataset, badopt); 238 (void) fprintf(stderr, gettext("Use the '-s' option " 239 "to ignore the bad mount option.\n")); 240 return (MOUNT_USAGE); 241 default: 242 (void) fprintf(stderr, gettext("filesystem '%s' " 243 "cannot be mounted due to internal error %d.\n"), 244 dataset, error); 245 return (MOUNT_SOFTWARE); 246 } 247 } 248 249 if (mntflags & MS_REMOUNT) { 250 nomtab = 1; 251 remount = 1; 252 } 253 254 if (zfsflags & ZS_ZFSUTIL) 255 zfsutil = 1; 256 257 if ((g_zfs = libzfs_init()) == NULL) { 258 (void) fprintf(stderr, "%s\n", libzfs_error_init(errno)); 259 return (MOUNT_SYSERR); 260 } 261 262 /* try to open the dataset to access the mount point */ 263 if ((zhp = zfs_open(g_zfs, dataset, 264 ZFS_TYPE_FILESYSTEM | ZFS_TYPE_SNAPSHOT)) == NULL) { 265 (void) fprintf(stderr, gettext("filesystem '%s' cannot be " 266 "mounted, unable to open the dataset\n"), dataset); 267 libzfs_fini(g_zfs); 268 return (MOUNT_USAGE); 269 } 270 271 if (!zfsutil || sloppy || 272 libzfs_envvar_is_set("ZFS_MOUNT_HELPER")) { 273 zfs_adjust_mount_options(zhp, mntpoint, mntopts, mtabopt); 274 } 275 276 /* treat all snapshots as legacy mount points */ 277 if (zfs_get_type(zhp) == ZFS_TYPE_SNAPSHOT) 278 (void) strlcpy(prop, ZFS_MOUNTPOINT_LEGACY, ZFS_MAXPROPLEN); 279 else 280 (void) zfs_prop_get(zhp, ZFS_PROP_MOUNTPOINT, prop, 281 sizeof (prop), NULL, NULL, 0, B_FALSE); 282 283 /* 284 * Fetch the max supported zfs version in case we get ENOTSUP 285 * back from the mount command, since we need the zfs handle 286 * to do so. 287 */ 288 zfs_version = zfs_prop_get_int(zhp, ZFS_PROP_VERSION); 289 if (zfs_version == 0) { 290 fprintf(stderr, gettext("unable to fetch " 291 "ZFS version for filesystem '%s'\n"), dataset); 292 zfs_close(zhp); 293 libzfs_fini(g_zfs); 294 return (MOUNT_SYSERR); 295 } 296 297 /* 298 * Legacy mount points may only be mounted using 'mount', never using 299 * 'zfs mount'. However, since 'zfs mount' actually invokes 'mount' 300 * we differentiate the two cases using the 'zfsutil' mount option. 301 * This mount option should only be supplied by the 'zfs mount' util. 302 * 303 * The only exception to the above rule is '-o remount' which is 304 * always allowed for non-legacy datasets. This is done because when 305 * using zfs as your root file system both rc.sysinit/umountroot and 306 * systemd depend on 'mount -o remount <mountpoint>' to work. 307 */ 308 if (zfsutil && (strcmp(prop, ZFS_MOUNTPOINT_LEGACY) == 0)) { 309 (void) fprintf(stderr, gettext( 310 "filesystem '%s' cannot be mounted using 'zfs mount'.\n" 311 "Use 'zfs set mountpoint=%s' or 'mount -t zfs %s %s'.\n" 312 "See zfs(8) for more information.\n"), 313 dataset, mntpoint, dataset, mntpoint); 314 zfs_close(zhp); 315 libzfs_fini(g_zfs); 316 return (MOUNT_USAGE); 317 } 318 319 if (!zfsutil && !(remount || fake) && 320 strcmp(prop, ZFS_MOUNTPOINT_LEGACY)) { 321 (void) fprintf(stderr, gettext( 322 "filesystem '%s' cannot be mounted using 'mount'.\n" 323 "Use 'zfs set mountpoint=%s' or 'zfs mount %s'.\n" 324 "See zfs(8) for more information.\n"), 325 dataset, "legacy", dataset); 326 zfs_close(zhp); 327 libzfs_fini(g_zfs); 328 return (MOUNT_USAGE); 329 } 330 331 if (verbose) 332 (void) fprintf(stdout, gettext("mount.zfs:\n" 333 " dataset: \"%s\"\n mountpoint: \"%s\"\n" 334 " mountflags: 0x%lx\n zfsflags: 0x%lx\n" 335 " mountopts: \"%s\"\n mtabopts: \"%s\"\n"), 336 dataset, mntpoint, mntflags, zfsflags, mntopts, mtabopt); 337 338 if (!fake) { 339 if (zfsutil && !sloppy && 340 !libzfs_envvar_is_set("ZFS_MOUNT_HELPER")) { 341 error = zfs_mount_at(zhp, mntopts, mntflags, mntpoint); 342 if (error) { 343 (void) fprintf(stderr, "zfs_mount_at() failed: " 344 "%s", libzfs_error_description(g_zfs)); 345 zfs_close(zhp); 346 libzfs_fini(g_zfs); 347 return (MOUNT_SYSERR); 348 } 349 } else { 350 error = mount(dataset, mntpoint, MNTTYPE_ZFS, 351 mntflags, mntopts); 352 } 353 } 354 355 zfs_close(zhp); 356 libzfs_fini(g_zfs); 357 358 if (error) { 359 switch (errno) { 360 case ENOENT: 361 (void) fprintf(stderr, gettext("mount point " 362 "'%s' does not exist\n"), mntpoint); 363 return (MOUNT_SYSERR); 364 case EBUSY: 365 (void) fprintf(stderr, gettext("filesystem " 366 "'%s' is already mounted\n"), dataset); 367 return (MOUNT_BUSY); 368 case ENOTSUP: 369 if (zfs_version > ZPL_VERSION) { 370 (void) fprintf(stderr, 371 gettext("filesystem '%s' (v%d) is not " 372 "supported by this implementation of " 373 "ZFS (max v%d).\n"), dataset, 374 (int)zfs_version, (int)ZPL_VERSION); 375 } else { 376 (void) fprintf(stderr, 377 gettext("filesystem '%s' mount " 378 "failed for unknown reason.\n"), dataset); 379 } 380 return (MOUNT_SYSERR); 381 #ifdef MS_MANDLOCK 382 case EPERM: 383 if (mntflags & MS_MANDLOCK) { 384 (void) fprintf(stderr, gettext("filesystem " 385 "'%s' has the 'nbmand=on' property set, " 386 "this mount\noption may be disabled in " 387 "your kernel. Use 'zfs set nbmand=off'\n" 388 "to disable this option and try to " 389 "mount the filesystem again.\n"), dataset); 390 return (MOUNT_SYSERR); 391 } 392 #endif 393 zfs_fallthrough; 394 default: 395 (void) fprintf(stderr, gettext("filesystem " 396 "'%s' can not be mounted: %s\n"), dataset, 397 strerror(errno)); 398 return (MOUNT_USAGE); 399 } 400 } 401 402 if (!nomtab && mtab_is_writeable()) { 403 error = mtab_update(dataset, mntpoint, MNTTYPE_ZFS, mtabopt); 404 if (error) 405 return (error); 406 } 407 408 return (MOUNT_SUCCESS); 409 } 410