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         args.name[BTRFS_PATH_NAME_MAX-1] = 0;
 115         res = ioctl(fddst, BTRFS_IOC_SUBVOL_CREATE, &args);
 116         e = errno;
 117
 118         close(fddst);
 119
 120         if(res < 0 ){
 121                 fprintf( stderr, "ERROR: cannot create subvolume - %s\n",
 122                         strerror(e));
 123                 return 11;
 124         }
 125
 126         return 0;
 127 }
 128
 129 /*
 130  * test if path is a subvolume:
 131  * this function return
 132  * 0-> path exists but it is not a subvolume
 133  * 1-> path exists and it is  a subvolume
 134  * -1 -> path is unaccessible
 135  */
 136 static int test_issubvolume(char *path)
 137 {
 138         struct stat     st;
 139         int             res;
 140
 141         res = stat(path, &st);
 142         if(res < 0 )
 143                 return -1;
 144
 145         return (st.st_ino == 256) && S_ISDIR(st.st_mode);
 146 }
 147
 148 static const char * const cmd_subvol_delete_usage[] = {
 149         "btrfs subvolume delete <name>",
 150         "Delete a subvolume",
 151         NULL
 152 };
 153
 154 static int cmd_subvol_delete(int argc, char **argv)
 155 {
 156         int     res, fd, len, e;
 157         struct btrfs_ioctl_vol_args     args;
 158         char    *dname, *vname, *cpath;
 159         char    *path;
 160
 161         if (check_argc_exact(argc, 2))
 162                 usage(cmd_subvol_delete_usage);
 163
 164         path = argv[1];
 165
 166         res = test_issubvolume(path);
 167         if(res<0){
 168                 fprintf(stderr, "ERROR: error accessing '%s'\n", path);
 169                 return 12;
 170         }
 171         if(!res){
 172                 fprintf(stderr, "ERROR: '%s' is not a subvolume\n", path);
 173                 return 13;
 174         }
 175
 176         cpath = realpath(path, 0);
 177         dname = strdup(cpath);
 178         dname = dirname(dname);
 179         vname = strdup(cpath);
 180         vname = basename(vname);
 181         free(cpath);
 182
 183         if( !strcmp(vname,".") || !strcmp(vname,"..") ||
 184              strchr(vname, '/') ){
 185                 fprintf(stderr, "ERROR: incorrect subvolume name ('%s')\n",
 186                         vname);
 187                 return 14;
 188         }
 189
 190         len = strlen(vname);
 191         if (len == 0 || len >= BTRFS_VOL_NAME_MAX) {
 192                 fprintf(stderr, "ERROR: snapshot name too long ('%s)\n",
 193                         vname);
 194                 return 14;
 195         }
 196
 197         fd = open_file_or_dir(dname);
 198         if (fd < 0) {
 199                 close(fd);
 200                 fprintf(stderr, "ERROR: can't access to '%s'\n", dname);
 201                 return 12;
 202         }
 203
 204         printf("Delete subvolume '%s/%s'\n", dname, vname);
 205         strncpy(args.name, vname, BTRFS_PATH_NAME_MAX);
 206         args.name[BTRFS_PATH_NAME_MAX-1] = 0;
 207         res = ioctl(fd, BTRFS_IOC_SNAP_DESTROY, &args);
 208         e = errno;
 209
 210         close(fd);
 211
 212         if(res < 0 ){
 213                 fprintf( stderr, "ERROR: cannot delete '%s/%s' - %s\n",
 214                         dname, vname, strerror(e));
 215                 return 11;
 216         }
 217
 218         return 0;
 219 }
 220
 221 static const char * const cmd_subvol_list_usage[] = {
 222         "btrfs subvolume list [-p] <path>",
 223         "List subvolumes (and snapshots)",
 224         "",
 225         "-p     print parent ID",
 226         NULL
 227 };
 228
 229 static int cmd_subvol_list(int argc, char **argv)
 230 {
 231         int fd;
 232         int ret;
 233         int print_parent = 0;
 234         char *subvol;
 235
 236         optind = 1;
 237         while(1) {
 238                 int c = getopt(argc, argv, "p");
 239                 if (c < 0)
 240                         break;
 241
 242                 switch(c) {
 243                 case 'p':
 244                         print_parent = 1;
 245                         break;
 246                 default:
 247                         usage(cmd_subvol_list_usage);
 248                 }
 249         }
 250
 251         if (check_argc_exact(argc - optind, 1))
 252                 usage(cmd_subvol_list_usage);
 253
 254         subvol = argv[optind];
 255
 256         ret = test_issubvolume(subvol);
 257         if (ret < 0) {
 258                 fprintf(stderr, "ERROR: error accessing '%s'\n", subvol);
 259                 return 12;
 260         }
 261         if (!ret) {
 262                 fprintf(stderr, "ERROR: '%s' is not a subvolume\n", subvol);
 263                 return 13;
 264         }
 265
 266         fd = open_file_or_dir(subvol);
 267         if (fd < 0) {
 268                 fprintf(stderr, "ERROR: can't access '%s'\n", subvol);
 269                 return 12;
 270         }
 271         ret = list_subvols(fd, print_parent, 0);
 272         if (ret)
 273                 return 19;
 274         return 0;
 275 }
 276
 277 static const char * const cmd_snapshot_usage[] = {
 278         "btrfs subvolume snapshot [-r] <source> [<dest>/]<name>",
 279         "Create a snapshot of the subvolume",
 280         "Create a writable/readonly snapshot of the subvolume <source> with",
 281         "the name <name> in the <dest> directory",
 282         "",
 283         "-r     create a readonly snapshot",
 284         NULL
 285 };
 286
 287 static int cmd_snapshot(int argc, char **argv)
 288 {
 289         char    *subvol, *dst;
 290         int     res, fd, fddst, len, e, readonly = 0;
 291         char    *newname;
 292         char    *dstdir;
 293         struct btrfs_ioctl_vol_args_v2  args;
 294
 295         memset(&args, 0, sizeof(args));
 296
 297         optind = 1;
 298         while (1) {
 299                 int c = getopt(argc, argv, "r");
 300                 if (c < 0)
 301                         break;
 302
 303                 switch (c) {
 304                 case 'r':
 305                         readonly = 1;
 306                         break;
 307                 default:
 308                         usage(cmd_snapshot_usage);
 309                 }
 310         }
 311
 312         if (check_argc_exact(argc - optind, 2))
 313                 usage(cmd_snapshot_usage);
 314
 315         subvol = argv[optind];
 316         dst = argv[optind + 1];
 317
 318         res = test_issubvolume(subvol);
 319         if(res<0){
 320                 fprintf(stderr, "ERROR: error accessing '%s'\n", subvol);
 321                 return 12;
 322         }
 323         if(!res){
 324                 fprintf(stderr, "ERROR: '%s' is not a subvolume\n", subvol);
 325                 return 13;
 326         }
 327
 328         res = test_isdir(dst);
 329         if(res == 0 ){
 330                 fprintf(stderr, "ERROR: '%s' exists and it is not a directory\n", dst);
 331                 return 12;
 332         }
 333
 334         if(res>0){
 335                 newname = strdup(subvol);
 336                 newname = basename(newname);
 337                 dstdir = dst;
 338         }else{
 339                 newname = strdup(dst);
 340                 newname = basename(newname);
 341                 dstdir = strdup(dst);
 342                 dstdir = dirname(dstdir);
 343         }
 344
 345         if( !strcmp(newname,".") || !strcmp(newname,"..") ||
 346              strchr(newname, '/') ){
 347                 fprintf(stderr, "ERROR: incorrect snapshot name ('%s')\n",
 348                         newname);
 349                 return 14;
 350         }
 351
 352         len = strlen(newname);
 353         if (len == 0 || len >= BTRFS_VOL_NAME_MAX) {
 354                 fprintf(stderr, "ERROR: snapshot name too long ('%s)\n",
 355                         newname);
 356                 return 14;
 357         }
 358
 359         fddst = open_file_or_dir(dstdir);
 360         if (fddst < 0) {
 361                 fprintf(stderr, "ERROR: can't access to '%s'\n", dstdir);
 362                 return 12;
 363         }
 364
 365         fd = open_file_or_dir(subvol);
 366         if (fd < 0) {
 367                 close(fddst);
 368                 fprintf(stderr, "ERROR: can't access to '%s'\n", dstdir);
 369                 return 12;
 370         }
 371
 372         if (readonly) {
 373                 args.flags |= BTRFS_SUBVOL_RDONLY;
 374                 printf("Create a readonly snapshot of '%s' in '%s/%s'\n",
 375                        subvol, dstdir, newname);
 376         } else {
 377                 printf("Create a snapshot of '%s' in '%s/%s'\n",
 378                        subvol, dstdir, newname);
 379         }
 380
 381         args.fd = fd;
 382         strncpy(args.name, newname, BTRFS_SUBVOL_NAME_MAX);
 383         args.name[BTRFS_SUBVOL_NAME_MAX-1] = 0;
 384         res = ioctl(fddst, BTRFS_IOC_SNAP_CREATE_V2, &args);
 385         e = errno;
 386
 387         close(fd);
 388         close(fddst);
 389
 390         if(res < 0 ){
 391                 fprintf( stderr, "ERROR: cannot snapshot '%s' - %s\n",
 392                         subvol, strerror(e));
 393                 return 11;
 394         }
 395
 396         return 0;
 397 }
 398
 399 static const char * const cmd_subvol_get_default_usage[] = {
 400         "btrfs subvolume get-default <path>",
 401         "Get the default subvolume of a filesystem",
 402         NULL
 403 };
 404
 405 static int cmd_subvol_get_default(int argc, char **argv)
 406 {
 407         int fd;
 408         int ret;
 409         char *subvol;
 410
 411         if (check_argc_exact(argc, 2))
 412                 usage(cmd_subvol_get_default_usage);
 413
 414         subvol = argv[1];
 415
 416         ret = test_issubvolume(subvol);
 417         if (ret < 0) {
 418                 fprintf(stderr, "ERROR: error accessing '%s'\n", subvol);
 419                 return 12;
 420         }
 421         if (!ret) {
 422                 fprintf(stderr, "ERROR: '%s' is not a subvolume\n", subvol);
 423                 return 13;
 424         }
 425
 426         fd = open_file_or_dir(subvol);
 427         if (fd < 0) {
 428                 fprintf(stderr, "ERROR: can't access '%s'\n", subvol);
 429                 return 12;
 430         }
 431         ret = list_subvols(fd, 0, 1);
 432         if (ret)
 433                 return 19;
 434         return 0;
 435 }
 436
 437 static const char * const cmd_subvol_set_default_usage[] = {
 438         "btrfs subvolume set-default <subvolid> <path>",
 439         "Set the default subvolume of a filesystem",
 440         NULL
 441 };
 442
 443 static int cmd_subvol_set_default(int argc, char **argv)
 444 {
 445         int     ret=0, fd, e;
 446         u64     objectid;
 447         char    *path;
 448         char    *subvolid;
 449
 450         if (check_argc_exact(argc, 3))
 451                 usage(cmd_subvol_set_default_usage);
 452
 453         subvolid = argv[1];
 454         path = argv[2];
 455
 456         fd = open_file_or_dir(path);
 457         if (fd < 0) {
 458                 fprintf(stderr, "ERROR: can't access to '%s'\n", path);
 459                 return 12;
 460         }
 461
 462         objectid = (unsigned long long)strtoll(subvolid, NULL, 0);
 463         if (errno == ERANGE) {
 464                 fprintf(stderr, "ERROR: invalid tree id (%s)\n",subvolid);
 465                 return 30;
 466         }
 467         ret = ioctl(fd, BTRFS_IOC_DEFAULT_SUBVOL, &objectid);
 468         e = errno;
 469         close(fd);
 470         if( ret < 0 ){
 471                 fprintf(stderr, "ERROR: unable to set a new default subvolume - %s\n",
 472                         strerror(e));
 473                 return 30;
 474         }
 475         return 0;
 476 }
 477
 478 static const char * const cmd_find_new_usage[] = {
 479         "btrfs subvolume find-new <path> <lastgen>",
 480         "List the recently modified files in a filesystem",
 481         NULL
 482 };
 483
 484 static int cmd_find_new(int argc, char **argv)
 485 {
 486         int fd;
 487         int ret;
 488         char *subvol;
 489         u64 last_gen;
 490
 491         if (check_argc_exact(argc, 3))
 492                 usage(cmd_find_new_usage);
 493
 494         subvol = argv[1];
 495         last_gen = atoll(argv[2]);
 496
 497         ret = test_issubvolume(subvol);
 498         if (ret < 0) {
 499                 fprintf(stderr, "ERROR: error accessing '%s'\n", subvol);
 500                 return 12;
 501         }
 502         if (!ret) {
 503                 fprintf(stderr, "ERROR: '%s' is not a subvolume\n", subvol);
 504                 return 13;
 505         }
 506
 507         fd = open_file_or_dir(subvol);
 508         if (fd < 0) {
 509                 fprintf(stderr, "ERROR: can't access '%s'\n", subvol);
 510                 return 12;
 511         }
 512         ret = find_updated_files(fd, 0, last_gen);
 513         if (ret)
 514                 return 19;
 515         return 0;
 516 }
 517
 518 const struct cmd_group subvolume_cmd_group = {
 519         subvolume_cmd_group_usage, NULL, {
 520                 { "create", cmd_subvol_create, cmd_subvol_create_usage, NULL, 0 },
 521                 { "delete", cmd_subvol_delete, cmd_subvol_delete_usage, NULL, 0 },
 522                 { "list", cmd_subvol_list, cmd_subvol_list_usage, NULL, 0 },
 523                 { "snapshot", cmd_snapshot, cmd_snapshot_usage, NULL, 0 },
 524                 { "get-default", cmd_subvol_get_default,
 525                         cmd_subvol_get_default_usage, NULL, 0 },
 526                 { "set-default", cmd_subvol_set_default,
 527                         cmd_subvol_set_default_usage, NULL, 0 },
 528                 { "find-new", cmd_find_new, cmd_find_new_usage, NULL, 0 },
 529                 { 0, 0, 0, 0, 0 }
 530         }
 531 };
 532
 533 int cmd_subvolume(int argc, char **argv)
 534 {
 535         return handle_command_group(&subvolume_cmd_group, argc, argv);
 536 }