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 #include "qgroup.h"
  30
  31 #include "commands.h"
  32
  33 /* btrfs-list.c */
  34 int list_subvols(int fd, int print_parent, int get_default);
  35 int find_updated_files(int fd, u64 root_id, u64 oldest_gen);
  36
  37 static const char * const subvolume_cmd_group_usage[] = {
  38         "btrfs subvolume <command> <args>",
  39         NULL
  40 };
  41
  42 /*
  43  * test if path is a directory
  44  * this function return
  45  * 0-> path exists but it is not a directory
  46  * 1-> path exists and it is  a directory
  47  * -1 -> path is unaccessible
  48  */
  49 static int test_isdir(char *path)
  50 {
  51         struct stat     st;
  52         int             res;
  53
  54         res = stat(path, &st);
  55         if(res < 0 )
  56                 return -1;
  57
  58         return S_ISDIR(st.st_mode);
  59 }
  60
  61 static const char * const cmd_subvol_create_usage[] = {
  62         "btrfs subvolume create [<dest>/]<name>",
  63         "Create a subvolume",
  64         "Create a subvolume <name> in <dest>.  If <dest> is not given",
  65         "subvolume <name> will be created in the current directory.",
  66         NULL
  67 };
  68
  69 static int cmd_subvol_create(int argc, char **argv)
  70 {
  71         int     res, fddst, len, e;
  72         char    *newname;
  73         char    *dstdir;
  74         char    *dst;
  75         struct btrfs_qgroup_inherit *inherit = NULL;
  76
  77         optind = 1;
  78         while (1) {
  79                 int c = getopt(argc, argv, "c:i:r");
  80                 if (c < 0)
  81                         break;
  82
  83                 switch (c) {
  84                 case 'c':
  85                         res = qgroup_inherit_add_copy(&inherit, optarg, 0);
  86                         if (res)
  87                                 return res;
  88                         break;
  89                 case 'i':
  90                         res = qgroup_inherit_add_group(&inherit, optarg);
  91                         if (res)
  92                                 return res;
  93                         break;
  94                 default:
  95                         usage(cmd_subvol_create_usage);
  96                 }
  97         }
  98
  99         if (check_argc_exact(argc - optind, 1))
 100                 usage(cmd_subvol_create_usage);
 101
 102         dst = argv[optind];
 103
 104         res = test_isdir(dst);
 105         if(res >= 0 ){
 106                 fprintf(stderr, "ERROR: '%s' exists\n", dst);
 107                 return 12;
 108         }
 109
 110         newname = strdup(dst);
 111         newname = basename(newname);
 112         dstdir = strdup(dst);
 113         dstdir = dirname(dstdir);
 114
 115         if( !strcmp(newname,".") || !strcmp(newname,"..") ||
 116              strchr(newname, '/') ){
 117                 fprintf(stderr, "ERROR: uncorrect subvolume name ('%s')\n",
 118                         newname);
 119                 return 14;
 120         }
 121
 122         len = strlen(newname);
 123         if (len == 0 || len >= BTRFS_VOL_NAME_MAX) {
 124                 fprintf(stderr, "ERROR: subvolume name too long ('%s)\n",
 125                         newname);
 126                 return 14;
 127         }
 128
 129         fddst = open_file_or_dir(dstdir);
 130         if (fddst < 0) {
 131                 fprintf(stderr, "ERROR: can't access to '%s'\n", dstdir);
 132                 return 12;
 133         }
 134
 135         printf("Create subvolume '%s/%s'\n", dstdir, newname);
 136         if (inherit) {
 137                 struct btrfs_ioctl_vol_args_v2  args;
 138
 139                 memset(&args, 0, sizeof(args));
 140                 strncpy(args.name, newname, BTRFS_SUBVOL_NAME_MAX);
 141                 args.name[BTRFS_SUBVOL_NAME_MAX-1] = 0;
 142                 args.flags |= BTRFS_SUBVOL_QGROUP_INHERIT;
 143                 args.size = qgroup_inherit_size(inherit);
 144                 args.qgroup_inherit = inherit;
 145
 146                 res = ioctl(fddst, BTRFS_IOC_SUBVOL_CREATE_V2, &args);
 147         } else {
 148                 struct btrfs_ioctl_vol_args     args;
 149
 150                 memset(&args, 0, sizeof(args));
 151                 strncpy(args.name, newname, BTRFS_SUBVOL_NAME_MAX);
 152                 args.name[BTRFS_SUBVOL_NAME_MAX-1] = 0;
 153
 154                 res = ioctl(fddst, BTRFS_IOC_SUBVOL_CREATE, &args);
 155         }
 156
 157         e = errno;
 158
 159         close(fddst);
 160
 161         if(res < 0 ){
 162                 fprintf( stderr, "ERROR: cannot create subvolume - %s\n",
 163                         strerror(e));
 164                 return 11;
 165         }
 166         free(inherit);
 167
 168         return 0;
 169 }
 170
 171 /*
 172  * test if path is a subvolume:
 173  * this function return
 174  * 0-> path exists but it is not a subvolume
 175  * 1-> path exists and it is  a subvolume
 176  * -1 -> path is unaccessible
 177  */
 178 int test_issubvolume(char *path)
 179 {
 180         struct stat     st;
 181         int             res;
 182
 183         res = stat(path, &st);
 184         if(res < 0 )
 185                 return -1;
 186
 187         return (st.st_ino == 256) && S_ISDIR(st.st_mode);
 188 }
 189
 190 static const char * const cmd_subvol_delete_usage[] = {
 191         "btrfs subvolume delete <name>",
 192         "Delete a subvolume",
 193         NULL
 194 };
 195
 196 static int cmd_subvol_delete(int argc, char **argv)
 197 {
 198         int     res, fd, len, e;
 199         struct btrfs_ioctl_vol_args     args;
 200         char    *dname, *vname, *cpath;
 201         char    *path;
 202
 203         if (check_argc_exact(argc, 2))
 204                 usage(cmd_subvol_delete_usage);
 205
 206         path = argv[1];
 207
 208         res = test_issubvolume(path);
 209         if(res<0){
 210                 fprintf(stderr, "ERROR: error accessing '%s'\n", path);
 211                 return 12;
 212         }
 213         if(!res){
 214                 fprintf(stderr, "ERROR: '%s' is not a subvolume\n", path);
 215                 return 13;
 216         }
 217
 218         cpath = realpath(path, 0);
 219         dname = strdup(cpath);
 220         dname = dirname(dname);
 221         vname = strdup(cpath);
 222         vname = basename(vname);
 223         free(cpath);
 224
 225         if( !strcmp(vname,".") || !strcmp(vname,"..") ||
 226              strchr(vname, '/') ){
 227                 fprintf(stderr, "ERROR: incorrect subvolume name ('%s')\n",
 228                         vname);
 229                 return 14;
 230         }
 231
 232         len = strlen(vname);
 233         if (len == 0 || len >= BTRFS_VOL_NAME_MAX) {
 234                 fprintf(stderr, "ERROR: snapshot name too long ('%s)\n",
 235                         vname);
 236                 return 14;
 237         }
 238
 239         fd = open_file_or_dir(dname);
 240         if (fd < 0) {
 241                 close(fd);
 242                 fprintf(stderr, "ERROR: can't access to '%s'\n", dname);
 243                 return 12;
 244         }
 245
 246         printf("Delete subvolume '%s/%s'\n", dname, vname);
 247         strncpy(args.name, vname, BTRFS_PATH_NAME_MAX);
 248         args.name[BTRFS_PATH_NAME_MAX-1] = 0;
 249         res = ioctl(fd, BTRFS_IOC_SNAP_DESTROY, &args);
 250         e = errno;
 251
 252         close(fd);
 253
 254         if(res < 0 ){
 255                 fprintf( stderr, "ERROR: cannot delete '%s/%s' - %s\n",
 256                         dname, vname, strerror(e));
 257                 return 11;
 258         }
 259
 260         return 0;
 261 }
 262
 263 static const char * const cmd_subvol_list_usage[] = {
 264         "btrfs subvolume list [-p] <path>",
 265         "List subvolumes (and snapshots)",
 266         "",
 267         "-p     print parent ID",
 268         NULL
 269 };
 270
 271 static int cmd_subvol_list(int argc, char **argv)
 272 {
 273         int fd;
 274         int ret;
 275         int print_parent = 0;
 276         char *subvol;
 277
 278         optind = 1;
 279         while(1) {
 280                 int c = getopt(argc, argv, "p");
 281                 if (c < 0)
 282                         break;
 283
 284                 switch(c) {
 285                 case 'p':
 286                         print_parent = 1;
 287                         break;
 288                 default:
 289                         usage(cmd_subvol_list_usage);
 290                 }
 291         }
 292
 293         if (check_argc_exact(argc - optind, 1))
 294                 usage(cmd_subvol_list_usage);
 295
 296         subvol = argv[optind];
 297
 298         ret = test_issubvolume(subvol);
 299         if (ret < 0) {
 300                 fprintf(stderr, "ERROR: error accessing '%s'\n", subvol);
 301                 return 12;
 302         }
 303         if (!ret) {
 304                 fprintf(stderr, "ERROR: '%s' is not a subvolume\n", subvol);
 305                 return 13;
 306         }
 307
 308         fd = open_file_or_dir(subvol);
 309         if (fd < 0) {
 310                 fprintf(stderr, "ERROR: can't access '%s'\n", subvol);
 311                 return 12;
 312         }
 313         ret = list_subvols(fd, print_parent, 0);
 314         if (ret)
 315                 return 19;
 316         return 0;
 317 }
 318
 319 static const char * const cmd_snapshot_usage[] = {
 320         "btrfs subvolume snapshot [-r] <source> [<dest>/]<name>",
 321         "Create a snapshot of the subvolume",
 322         "Create a writable/readonly snapshot of the subvolume <source> with",
 323         "the name <name> in the <dest> directory",
 324         "",
 325         "-r     create a readonly snapshot",
 326         NULL
 327 };
 328
 329 static int cmd_snapshot(int argc, char **argv)
 330 {
 331         char    *subvol, *dst;
 332         int     res, fd, fddst, len, e, readonly = 0;
 333         char    *newname;
 334         char    *dstdir;
 335         struct btrfs_ioctl_vol_args_v2  args;
 336         struct btrfs_qgroup_inherit *inherit = NULL;
 337
 338         optind = 1;
 339         memset(&args, 0, sizeof(args));
 340         while (1) {
 341                 int c = getopt(argc, argv, "c:i:r");
 342                 if (c < 0)
 343                         break;
 344
 345                 switch (c) {
 346                 case 'c':
 347                         res = qgroup_inherit_add_copy(&inherit, optarg, 0);
 348                         if (res)
 349                                 return res;
 350                         break;
 351                 case 'i':
 352                         res = qgroup_inherit_add_group(&inherit, optarg);
 353                         if (res)
 354                                 return res;
 355                         break;
 356                 case 'r':
 357                         readonly = 1;
 358                         break;
 359                 case 'x':
 360                         res = qgroup_inherit_add_copy(&inherit, optarg, 1);
 361                         if (res)
 362                                 return res;
 363                         break;
 364                 default:
 365                         usage(cmd_snapshot_usage);
 366                 }
 367         }
 368
 369         if (check_argc_exact(argc - optind, 2))
 370                 usage(cmd_snapshot_usage);
 371
 372         subvol = argv[optind];
 373         dst = argv[optind + 1];
 374
 375         res = test_issubvolume(subvol);
 376         if(res<0){
 377                 fprintf(stderr, "ERROR: error accessing '%s'\n", subvol);
 378                 return 12;
 379         }
 380         if(!res){
 381                 fprintf(stderr, "ERROR: '%s' is not a subvolume\n", subvol);
 382                 return 13;
 383         }
 384
 385         res = test_isdir(dst);
 386         if(res == 0 ){
 387                 fprintf(stderr, "ERROR: '%s' exists and it is not a directory\n", dst);
 388                 return 12;
 389         }
 390
 391         if(res>0){
 392                 newname = strdup(subvol);
 393                 newname = basename(newname);
 394                 dstdir = dst;
 395         }else{
 396                 newname = strdup(dst);
 397                 newname = basename(newname);
 398                 dstdir = strdup(dst);
 399                 dstdir = dirname(dstdir);
 400         }
 401
 402         if( !strcmp(newname,".") || !strcmp(newname,"..") ||
 403              strchr(newname, '/') ){
 404                 fprintf(stderr, "ERROR: incorrect snapshot name ('%s')\n",
 405                         newname);
 406                 return 14;
 407         }
 408
 409         len = strlen(newname);
 410         if (len == 0 || len >= BTRFS_VOL_NAME_MAX) {
 411                 fprintf(stderr, "ERROR: snapshot name too long ('%s)\n",
 412                         newname);
 413                 return 14;
 414         }
 415
 416         fddst = open_file_or_dir(dstdir);
 417         if (fddst < 0) {
 418                 fprintf(stderr, "ERROR: can't access to '%s'\n", dstdir);
 419                 return 12;
 420         }
 421
 422         fd = open_file_or_dir(subvol);
 423         if (fd < 0) {
 424                 close(fddst);
 425                 fprintf(stderr, "ERROR: can't access to '%s'\n", dstdir);
 426                 return 12;
 427         }
 428
 429         if (readonly) {
 430                 args.flags |= BTRFS_SUBVOL_RDONLY;
 431                 printf("Create a readonly snapshot of '%s' in '%s/%s'\n",
 432                        subvol, dstdir, newname);
 433         } else {
 434                 printf("Create a snapshot of '%s' in '%s/%s'\n",
 435                        subvol, dstdir, newname);
 436         }
 437
 438         args.fd = fd;
 439         if (inherit) {
 440                 args.flags |= BTRFS_SUBVOL_QGROUP_INHERIT;
 441                 args.size = qgroup_inherit_size(inherit);
 442                 args.qgroup_inherit = inherit;
 443         }
 444         strncpy(args.name, newname, BTRFS_SUBVOL_NAME_MAX);
 445         args.name[BTRFS_SUBVOL_NAME_MAX-1] = 0;
 446         res = ioctl(fddst, BTRFS_IOC_SNAP_CREATE_V2, &args);
 447         e = errno;
 448
 449         close(fd);
 450         close(fddst);
 451
 452         if(res < 0 ){
 453                 fprintf( stderr, "ERROR: cannot snapshot '%s' - %s\n",
 454                         subvol, strerror(e));
 455                 return 11;
 456         }
 457         free(inherit);
 458
 459         return 0;
 460 }
 461
 462 static const char * const cmd_subvol_get_default_usage[] = {
 463         "btrfs subvolume get-default <path>",
 464         "Get the default subvolume of a filesystem",
 465         NULL
 466 };
 467
 468 static int cmd_subvol_get_default(int argc, char **argv)
 469 {
 470         int fd;
 471         int ret;
 472         char *subvol;
 473
 474         if (check_argc_exact(argc, 2))
 475                 usage(cmd_subvol_get_default_usage);
 476
 477         subvol = argv[1];
 478
 479         ret = test_issubvolume(subvol);
 480         if (ret < 0) {
 481                 fprintf(stderr, "ERROR: error accessing '%s'\n", subvol);
 482                 return 12;
 483         }
 484         if (!ret) {
 485                 fprintf(stderr, "ERROR: '%s' is not a subvolume\n", subvol);
 486                 return 13;
 487         }
 488
 489         fd = open_file_or_dir(subvol);
 490         if (fd < 0) {
 491                 fprintf(stderr, "ERROR: can't access '%s'\n", subvol);
 492                 return 12;
 493         }
 494         ret = list_subvols(fd, 0, 1);
 495         if (ret)
 496                 return 19;
 497         return 0;
 498 }
 499
 500 static const char * const cmd_subvol_set_default_usage[] = {
 501         "btrfs subvolume set-default <subvolid> <path>",
 502         "Set the default subvolume of a filesystem",
 503         NULL
 504 };
 505
 506 static int cmd_subvol_set_default(int argc, char **argv)
 507 {
 508         int     ret=0, fd, e;
 509         u64     objectid;
 510         char    *path;
 511         char    *subvolid;
 512
 513         if (check_argc_exact(argc, 3))
 514                 usage(cmd_subvol_set_default_usage);
 515
 516         subvolid = argv[1];
 517         path = argv[2];
 518
 519         fd = open_file_or_dir(path);
 520         if (fd < 0) {
 521                 fprintf(stderr, "ERROR: can't access to '%s'\n", path);
 522                 return 12;
 523         }
 524
 525         objectid = (unsigned long long)strtoll(subvolid, NULL, 0);
 526         if (errno == ERANGE) {
 527                 fprintf(stderr, "ERROR: invalid tree id (%s)\n",subvolid);
 528                 return 30;
 529         }
 530         ret = ioctl(fd, BTRFS_IOC_DEFAULT_SUBVOL, &objectid);
 531         e = errno;
 532         close(fd);
 533         if( ret < 0 ){
 534                 fprintf(stderr, "ERROR: unable to set a new default subvolume - %s\n",
 535                         strerror(e));
 536                 return 30;
 537         }
 538         return 0;
 539 }
 540
 541 static const char * const cmd_find_new_usage[] = {
 542         "btrfs subvolume find-new <path> <lastgen>",
 543         "List the recently modified files in a filesystem",
 544         NULL
 545 };
 546
 547 static int cmd_find_new(int argc, char **argv)
 548 {
 549         int fd;
 550         int ret;
 551         char *subvol;
 552         u64 last_gen;
 553
 554         if (check_argc_exact(argc, 3))
 555                 usage(cmd_find_new_usage);
 556
 557         subvol = argv[1];
 558         last_gen = atoll(argv[2]);
 559
 560         ret = test_issubvolume(subvol);
 561         if (ret < 0) {
 562                 fprintf(stderr, "ERROR: error accessing '%s'\n", subvol);
 563                 return 12;
 564         }
 565         if (!ret) {
 566                 fprintf(stderr, "ERROR: '%s' is not a subvolume\n", subvol);
 567                 return 13;
 568         }
 569
 570         fd = open_file_or_dir(subvol);
 571         if (fd < 0) {
 572                 fprintf(stderr, "ERROR: can't access '%s'\n", subvol);
 573                 return 12;
 574         }
 575         ret = find_updated_files(fd, 0, last_gen);
 576         if (ret)
 577                 return 19;
 578         return 0;
 579 }
 580
 581 const struct cmd_group subvolume_cmd_group = {
 582         subvolume_cmd_group_usage, NULL, {
 583                 { "create", cmd_subvol_create, cmd_subvol_create_usage, NULL, 0 },
 584                 { "delete", cmd_subvol_delete, cmd_subvol_delete_usage, NULL, 0 },
 585                 { "list", cmd_subvol_list, cmd_subvol_list_usage, NULL, 0 },
 586                 { "snapshot", cmd_snapshot, cmd_snapshot_usage, NULL, 0 },
 587                 { "get-default", cmd_subvol_get_default,
 588                         cmd_subvol_get_default_usage, NULL, 0 },
 589                 { "set-default", cmd_subvol_set_default,
 590                         cmd_subvol_set_default_usage, NULL, 0 },
 591                 { "find-new", cmd_find_new, cmd_find_new_usage, NULL, 0 },
 592                 { 0, 0, 0, 0, 0 }
 593         }
 594 };
 595
 596 int cmd_subvolume(int argc, char **argv)
 597 {
 598         return handle_command_group(&subvolume_cmd_group, argc, argv);
 599 }