cmds-subvolume.c

   1 /*
   2  * This program is free software; you can redistribute it and/or
   3  * modify it under the terms of the GNU General Public
   4  * License v2 as published by the Free Software Foundation.
   5  *
   6  * This program is distributed in the hope that it will be useful,
   7  * but WITHOUT ANY WARRANTY; without even the implied warranty of
   8  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   9  * General Public License for more details.
  10  *
  11  * You should have received a copy of the GNU General Public
  12  * License along with this program; if not, write to the
  13  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  14  * Boston, MA 021110-1307, USA.
  15  */
  16
  17 #include <stdio.h>
  18 #include <stdlib.h>
  19 #include <string.h>
  20 #include <unistd.h>
  21 #include <sys/ioctl.h>
  22 #include <errno.h>
  23 #include <sys/stat.h>
  24 #include <libgen.h>
  25 #include <limits.h>
  26
  27 #include "kerncompat.h"
  28 #include "ioctl.h"
  29
  30 #include "commands.h"
  31
  32 /* btrfs-list.c */
  33 int list_subvols(int fd, int print_parent, int get_default);
  34 int find_updated_files(int fd, u64 root_id, u64 oldest_gen);
  35
  36 static const char * const subvolume_cmd_group_usage[] = {
  37         "btrfs subvolume <command> <args>",
  38         NULL
  39 };
  40
  41 /*
  42  * test if path is a directory
  43  * this function return
  44  * 0-> path exists but it is not a directory
  45  * 1-> path exists and it is  a directory
  46  * -1 -> path is unaccessible
  47  */
  48 static int test_isdir(char *path)
  49 {
  50         struct stat     st;
  51         int             res;
  52
  53         res = stat(path, &st);
  54         if(res < 0 )
  55                 return -1;
  56
  57         return S_ISDIR(st.st_mode);
  58 }
  59
  60 static const char * const cmd_subvol_create_usage[] = {
  61         "btrfs subvolume create [<dest>/]<name>",
  62         "Create a subvolume",
  63         "Create a subvolume <name> in <dest>.  If <dest> is not given",
  64         "subvolume <name> will be created in the current directory.",
  65         NULL
  66 };
  67
  68 static int cmd_subvol_create(int argc, char **argv)
  69 {
  70         int     res, fddst, len, e;
  71         char    *newname;
  72         char    *dstdir;
  73         struct btrfs_ioctl_vol_args     args;
  74         char    *dst;
  75
  76         if (check_argc_exact(argc, 2))
  77                 usage(cmd_subvol_create_usage);
  78
  79         dst = argv[1];
  80
  81         res = test_isdir(dst);
  82         if(res >= 0 ){
  83                 fprintf(stderr, "ERROR: '%s' exists\n", dst);
  84                 return 12;
  85         }
  86
  87         newname = strdup(dst);
  88         newname = basename(newname);
  89         dstdir = strdup(dst);
  90         dstdir = dirname(dstdir);
  91
  92         if( !strcmp(newname,".") || !strcmp(newname,"..") ||
  93              strchr(newname, '/') ){
  94                 fprintf(stderr, "ERROR: uncorrect subvolume name ('%s')\n",
  95                         newname);
  96                 return 14;
  97         }
  98
  99         len = strlen(newname);
 100         if (len == 0 || len >= BTRFS_VOL_NAME_MAX) {
 101                 fprintf(stderr, "ERROR: subvolume name too long ('%s)\n",
 102                         newname);
 103                 return 14;
 104         }
 105
 106         fddst = open_file_or_dir(dstdir);
 107         if (fddst < 0) {
 108                 fprintf(stderr, "ERROR: can't access to '%s'\n", dstdir);
 109                 return 12;
 110         }
 111
 112         printf("Create subvolume '%s/%s'\n", dstdir, newname);
 113         strncpy(args.name, newname, BTRFS_PATH_NAME_MAX);
 114         res = ioctl(fddst, BTRFS_IOC_SUBVOL_CREATE, &args);
 115         e = errno;
 116
 117         close(fddst);
 118
 119         if(res < 0 ){
 120                 fprintf( stderr, "ERROR: cannot create subvolume - %s\n",
 121                         strerror(e));
 122                 return 11;
 123         }
 124
 125         return 0;
 126 }
 127
 128 /*
 129  * test if path is a subvolume:
 130  * this function return
 131  * 0-> path exists but it is not a subvolume
 132  * 1-> path exists and it is  a subvolume
 133  * -1 -> path is unaccessible
 134  */
 135 static int test_issubvolume(char *path)
 136 {
 137         struct stat     st;
 138         int             res;
 139
 140         res = stat(path, &st);
 141         if(res < 0 )
 142                 return -1;
 143
 144         return (st.st_ino == 256) && S_ISDIR(st.st_mode);
 145 }
 146
 147 static const char * const cmd_subvol_delete_usage[] = {
 148         "btrfs subvolume delete <name>",
 149         "Delete a subvolume",
 150         NULL
 151 };
 152
 153 static int cmd_subvol_delete(int argc, char **argv)
 154 {
 155         int     res, fd, len, e;
 156         struct btrfs_ioctl_vol_args     args;
 157         char    *dname, *vname, *cpath;
 158         char    *path;
 159
 160         if (check_argc_exact(argc, 2))
 161                 usage(cmd_subvol_delete_usage);
 162
 163         path = argv[1];
 164
 165         res = test_issubvolume(path);
 166         if(res<0){
 167                 fprintf(stderr, "ERROR: error accessing '%s'\n", path);
 168                 return 12;
 169         }
 170         if(!res){
 171                 fprintf(stderr, "ERROR: '%s' is not a subvolume\n", path);
 172                 return 13;
 173         }
 174
 175         cpath = realpath(path, 0);
 176         dname = strdup(cpath);
 177         dname = dirname(dname);
 178         vname = strdup(cpath);
 179         vname = basename(vname);
 180         free(cpath);
 181
 182         if( !strcmp(vname,".") || !strcmp(vname,"..") ||
 183              strchr(vname, '/') ){
 184                 fprintf(stderr, "ERROR: incorrect subvolume name ('%s')\n",
 185                         vname);
 186                 return 14;
 187         }
 188
 189         len = strlen(vname);
 190         if (len == 0 || len >= BTRFS_VOL_NAME_MAX) {
 191                 fprintf(stderr, "ERROR: snapshot name too long ('%s)\n",
 192                         vname);
 193                 return 14;
 194         }
 195
 196         fd = open_file_or_dir(dname);
 197         if (fd < 0) {
 198                 close(fd);
 199                 fprintf(stderr, "ERROR: can't access to '%s'\n", dname);
 200                 return 12;
 201         }
 202
 203         printf("Delete subvolume '%s/%s'\n", dname, vname);
 204         strncpy(args.name, vname, BTRFS_PATH_NAME_MAX);
 205         res = ioctl(fd, BTRFS_IOC_SNAP_DESTROY, &args);
 206         e = errno;
 207
 208         close(fd);
 209
 210         if(res < 0 ){
 211                 fprintf( stderr, "ERROR: cannot delete '%s/%s' - %s\n",
 212                         dname, vname, strerror(e));
 213                 return 11;
 214         }
 215
 216         return 0;
 217 }
 218
 219 static const char * const cmd_subvol_list_usage[] = {
 220         "btrfs subvolume list [-p] <path>",
 221         "List subvolumes (and snapshots)",
 222         "",
 223         "-p     print parent ID",
 224         NULL
 225 };
 226
 227 static int cmd_subvol_list(int argc, char **argv)
 228 {
 229         int fd;
 230         int ret;
 231         int print_parent = 0;
 232         char *subvol;
 233
 234         optind = 1;
 235         while(1) {
 236                 int c = getopt(argc, argv, "p");
 237                 if (c < 0)
 238                         break;
 239
 240                 switch(c) {
 241                 case 'p':
 242                         print_parent = 1;
 243                         break;
 244                 default:
 245                         usage(cmd_subvol_list_usage);
 246                 }
 247         }
 248
 249         if (check_argc_exact(argc - optind, 1))
 250                 usage(cmd_subvol_list_usage);
 251
 252         subvol = argv[optind];
 253
 254         ret = test_issubvolume(subvol);
 255         if (ret < 0) {
 256                 fprintf(stderr, "ERROR: error accessing '%s'\n", subvol);
 257                 return 12;
 258         }
 259         if (!ret) {
 260                 fprintf(stderr, "ERROR: '%s' is not a subvolume\n", subvol);
 261                 return 13;
 262         }
 263
 264         fd = open_file_or_dir(subvol);
 265         if (fd < 0) {
 266                 fprintf(stderr, "ERROR: can't access '%s'\n", subvol);
 267                 return 12;
 268         }
 269         ret = list_subvols(fd, print_parent, 0);
 270         if (ret)
 271                 return 19;
 272         return 0;
 273 }
 274
 275 static const char * const cmd_snapshot_usage[] = {
 276         "btrfs subvolume snapshot [-r] <source> [<dest>/]<name>",
 277         "Create a snapshot of the subvolume",
 278         "Create a writable/readonly snapshot of the subvolume <source> with",
 279         "the name <name> in the <dest> directory",
 280         "",
 281         "-r     create a readonly snapshot",
 282         NULL
 283 };
 284
 285 static int cmd_snapshot(int argc, char **argv)
 286 {
 287         char    *subvol, *dst;
 288         int     res, fd, fddst, len, e, readonly = 0;
 289         char    *newname;
 290         char    *dstdir;
 291         struct btrfs_ioctl_vol_args_v2  args;
 292
 293         memset(&args, 0, sizeof(args));
 294
 295         optind = 1;
 296         while (1) {
 297                 int c = getopt(argc, argv, "r");
 298                 if (c < 0)
 299                         break;
 300
 301                 switch (c) {
 302                 case 'r':
 303                         readonly = 1;
 304                         break;
 305                 default:
 306                         usage(cmd_snapshot_usage);
 307                 }
 308         }
 309
 310         if (check_argc_exact(argc - optind, 2))
 311                 usage(cmd_snapshot_usage);
 312
 313         subvol = argv[optind];
 314         dst = argv[optind + 1];
 315
 316         res = test_issubvolume(subvol);
 317         if(res<0){
 318                 fprintf(stderr, "ERROR: error accessing '%s'\n", subvol);
 319                 return 12;
 320         }
 321         if(!res){
 322                 fprintf(stderr, "ERROR: '%s' is not a subvolume\n", subvol);
 323                 return 13;
 324         }
 325
 326         res = test_isdir(dst);
 327         if(res == 0 ){
 328                 fprintf(stderr, "ERROR: '%s' exists and it is not a directory\n", dst);
 329                 return 12;
 330         }
 331
 332         if(res>0){
 333                 newname = strdup(subvol);
 334                 newname = basename(newname);
 335                 dstdir = dst;
 336         }else{
 337                 newname = strdup(dst);
 338                 newname = basename(newname);
 339                 dstdir = strdup(dst);
 340                 dstdir = dirname(dstdir);
 341         }
 342
 343         if( !strcmp(newname,".") || !strcmp(newname,"..") ||
 344              strchr(newname, '/') ){
 345                 fprintf(stderr, "ERROR: incorrect snapshot name ('%s')\n",
 346                         newname);
 347                 return 14;
 348         }
 349
 350         len = strlen(newname);
 351         if (len == 0 || len >= BTRFS_VOL_NAME_MAX) {
 352                 fprintf(stderr, "ERROR: snapshot name too long ('%s)\n",
 353                         newname);
 354                 return 14;
 355         }
 356
 357         fddst = open_file_or_dir(dstdir);
 358         if (fddst < 0) {
 359                 fprintf(stderr, "ERROR: can't access to '%s'\n", dstdir);
 360                 return 12;
 361         }
 362
 363         fd = open_file_or_dir(subvol);
 364         if (fd < 0) {
 365                 close(fddst);
 366                 fprintf(stderr, "ERROR: can't access to '%s'\n", dstdir);
 367                 return 12;
 368         }
 369
 370         if (readonly) {
 371                 args.flags |= BTRFS_SUBVOL_RDONLY;
 372                 printf("Create a readonly snapshot of '%s' in '%s/%s'\n",
 373                        subvol, dstdir, newname);
 374         } else {
 375                 printf("Create a snapshot of '%s' in '%s/%s'\n",
 376                        subvol, dstdir, newname);
 377         }
 378
 379         args.fd = fd;
 380         strncpy(args.name, newname, BTRFS_SUBVOL_NAME_MAX);
 381         res = ioctl(fddst, BTRFS_IOC_SNAP_CREATE_V2, &args);
 382         e = errno;
 383
 384         close(fd);
 385         close(fddst);
 386
 387         if(res < 0 ){
 388                 fprintf( stderr, "ERROR: cannot snapshot '%s' - %s\n",
 389                         subvol, strerror(e));
 390                 return 11;
 391         }
 392
 393         return 0;
 394 }
 395
 396 static const char * const cmd_subvol_get_default_usage[] = {
 397         "btrfs subvolume get-dafault <path>",
 398         "Get the default subvolume of a filesystem",
 399         NULL
 400 };
 401
 402 static int cmd_subvol_get_default(int argc, char **argv)
 403 {
 404         int fd;
 405         int ret;
 406         char *subvol;
 407
 408         if (check_argc_exact(argc, 2))
 409                 usage(cmd_subvol_get_default_usage);
 410
 411         subvol = argv[1];
 412
 413         ret = test_issubvolume(subvol);
 414         if (ret < 0) {
 415                 fprintf(stderr, "ERROR: error accessing '%s'\n", subvol);
 416                 return 12;
 417         }
 418         if (!ret) {
 419                 fprintf(stderr, "ERROR: '%s' is not a subvolume\n", subvol);
 420                 return 13;
 421         }
 422
 423         fd = open_file_or_dir(subvol);
 424         if (fd < 0) {
 425                 fprintf(stderr, "ERROR: can't access '%s'\n", subvol);
 426                 return 12;
 427         }
 428         ret = list_subvols(fd, 0, 1);
 429         if (ret)
 430                 return 19;
 431         return 0;
 432 }
 433
 434 static const char * const cmd_subvol_set_default_usage[] = {
 435         "btrfs subvolume set-dafault <subvolid> <path>",
 436         "Set the default subvolume of a filesystem",
 437         NULL
 438 };
 439
 440 static int cmd_subvol_set_default(int argc, char **argv)
 441 {
 442         int     ret=0, fd, e;
 443         u64     objectid;
 444         char    *path;
 445         char    *subvolid;
 446
 447         if (check_argc_exact(argc, 3))
 448                 usage(cmd_subvol_set_default_usage);
 449
 450         subvolid = argv[1];
 451         path = argv[2];
 452
 453         fd = open_file_or_dir(path);
 454         if (fd < 0) {
 455                 fprintf(stderr, "ERROR: can't access to '%s'\n", path);
 456                 return 12;
 457         }
 458
 459         objectid = (unsigned long long)strtoll(subvolid, NULL, 0);
 460         if (errno == ERANGE) {
 461                 fprintf(stderr, "ERROR: invalid tree id (%s)\n",subvolid);
 462                 return 30;
 463         }
 464         ret = ioctl(fd, BTRFS_IOC_DEFAULT_SUBVOL, &objectid);
 465         e = errno;
 466         close(fd);
 467         if( ret < 0 ){
 468                 fprintf(stderr, "ERROR: unable to set a new default subvolume - %s\n",
 469                         strerror(e));
 470                 return 30;
 471         }
 472         return 0;
 473 }
 474
 475 static const char * const cmd_find_new_usage[] = {
 476         "btrfs subvolume find-new <path> <lastgen>",
 477         "List the recently modified files in a filesystem",
 478         NULL
 479 };
 480
 481 static int cmd_find_new(int argc, char **argv)
 482 {
 483         int fd;
 484         int ret;
 485         char *subvol;
 486         u64 last_gen;
 487
 488         if (check_argc_exact(argc, 3))
 489                 usage(cmd_find_new_usage);
 490
 491         subvol = argv[1];
 492         last_gen = atoll(argv[2]);
 493
 494         ret = test_issubvolume(subvol);
 495         if (ret < 0) {
 496                 fprintf(stderr, "ERROR: error accessing '%s'\n", subvol);
 497                 return 12;
 498         }
 499         if (!ret) {
 500                 fprintf(stderr, "ERROR: '%s' is not a subvolume\n", subvol);
 501                 return 13;
 502         }
 503
 504         fd = open_file_or_dir(subvol);
 505         if (fd < 0) {
 506                 fprintf(stderr, "ERROR: can't access '%s'\n", subvol);
 507                 return 12;
 508         }
 509         ret = find_updated_files(fd, 0, last_gen);
 510         if (ret)
 511                 return 19;
 512         return 0;
 513 }
 514
 515 const struct cmd_group subvolume_cmd_group = {
 516         subvolume_cmd_group_usage, NULL, {
 517                 { "create", cmd_subvol_create, cmd_subvol_create_usage, NULL, 0 },
 518                 { "delete", cmd_subvol_delete, cmd_subvol_delete_usage, NULL, 0 },
 519                 { "list", cmd_subvol_list, cmd_subvol_list_usage, NULL, 0 },
 520                 { "snapshot", cmd_snapshot, cmd_snapshot_usage, NULL, 0 },
 521                 { "get-default", cmd_subvol_get_default,
 522                         cmd_subvol_get_default_usage, NULL, 0 },
 523                 { "set-default", cmd_subvol_set_default,
 524                         cmd_subvol_set_default_usage, NULL, 0 },
 525                 { "find-new", cmd_find_new, cmd_find_new_usage, NULL, 0 },
 526                 { 0, 0, 0, 0, 0 }
 527         }
 528 };
 529
 530 int cmd_subvolume(int argc, char **argv)
 531 {
 532         return handle_command_group(&subvolume_cmd_group, argc, argv);
 533 }