cmds-receive.c

   1 /*
   2  * Copyright (C) 2012 Alexander Block.  All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public
   6  * License v2 as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public
  14  * License along with this program; if not, write to the
  15  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  16  * Boston, MA 021110-1307, USA.
  17  */
  18
  19 #include "kerncompat.h"
  20
  21 #include <unistd.h>
  22 #include <stdint.h>
  23 #include <dirent.h>
  24 #include <fcntl.h>
  25 #include <pthread.h>
  26 #include <math.h>
  27 #include <ftw.h>
  28 #include <wait.h>
  29 #include <assert.h>
  30 #include <getopt.h>
  31
  32 #include <sys/stat.h>
  33 #include <sys/types.h>
  34 #include <sys/ioctl.h>
  35 #include <sys/time.h>
  36 #include <sys/types.h>
  37 #include <sys/xattr.h>
  38 #include <uuid/uuid.h>
  39
  40 #include "ctree.h"
  41 #include "ioctl.h"
  42 #include "commands.h"
  43 #include "utils.h"
  44 #include "list.h"
  45 #include "btrfs-list.h"
  46
  47 #include "send.h"
  48 #include "send-stream.h"
  49 #include "send-utils.h"
  50
  51 static int g_verbose = 0;
  52
  53 struct btrfs_receive
  54 {
  55         int mnt_fd;
  56         int dest_dir_fd;
  57
  58         int write_fd;
  59         char *write_path;
  60
  61         char *root_path;
  62         char *dest_dir_path; /* relative to root_path */
  63         char *full_subvol_path;
  64         char *full_root_path;
  65         int dest_dir_chroot;
  66
  67         struct subvol_info cur_subvol;
  68
  69         struct subvol_uuid_search sus;
  70
  71         int honor_end_cmd;
  72
  73         /*
  74          * Buffer to store capabilities from security.capabilities xattr,
  75          * usually 20 bytes, but make same room for potentially larger
  76          * encodings. Must be set only once per file, denoted by length > 0.
  77          */
  78         char cached_capabilities[64];
  79         int cached_capabilities_len;
  80 };
  81
  82 static int finish_subvol(struct btrfs_receive *r)
  83 {
  84         int ret;
  85         int subvol_fd = -1;
  86         struct btrfs_ioctl_received_subvol_args rs_args;
  87         char uuid_str[BTRFS_UUID_UNPARSED_SIZE];
  88         u64 flags;
  89
  90         if (r->cur_subvol.path == NULL)
  91                 return 0;
  92
  93         subvol_fd = openat(r->mnt_fd, r->cur_subvol.path,
  94                         O_RDONLY | O_NOATIME);
  95         if (subvol_fd < 0) {
  96                 ret = -errno;
  97                 fprintf(stderr, "ERROR: open %s failed. %s\n",
  98                                 r->cur_subvol.path, strerror(-ret));
  99                 goto out;
 100         }
 101
 102         memset(&rs_args, 0, sizeof(rs_args));
 103         memcpy(rs_args.uuid, r->cur_subvol.received_uuid, BTRFS_UUID_SIZE);
 104         rs_args.stransid = r->cur_subvol.stransid;
 105
 106         if (g_verbose >= 1) {
 107                 uuid_unparse((u8*)rs_args.uuid, uuid_str);
 108                 fprintf(stderr, "BTRFS_IOC_SET_RECEIVED_SUBVOL uuid=%s, "
 109                                 "stransid=%llu\n", uuid_str, rs_args.stransid);
 110         }
 111
 112         ret = ioctl(subvol_fd, BTRFS_IOC_SET_RECEIVED_SUBVOL, &rs_args);
 113         if (ret < 0) {
 114                 ret = -errno;
 115                 fprintf(stderr, "ERROR: BTRFS_IOC_SET_RECEIVED_SUBVOL failed. %s\n",
 116                                 strerror(-ret));
 117                 goto out;
 118         }
 119         r->cur_subvol.rtransid = rs_args.rtransid;
 120
 121         ret = ioctl(subvol_fd, BTRFS_IOC_SUBVOL_GETFLAGS, &flags);
 122         if (ret < 0) {
 123                 ret = -errno;
 124                 fprintf(stderr, "ERROR: BTRFS_IOC_SUBVOL_GETFLAGS failed. %s\n",
 125                                 strerror(-ret));
 126                 goto out;
 127         }
 128
 129         flags |= BTRFS_SUBVOL_RDONLY;
 130
 131         ret = ioctl(subvol_fd, BTRFS_IOC_SUBVOL_SETFLAGS, &flags);
 132         if (ret < 0) {
 133                 ret = -errno;
 134                 fprintf(stderr, "ERROR: failed to make subvolume read only. "
 135                                 "%s\n", strerror(-ret));
 136                 goto out;
 137         }
 138
 139         ret = 0;
 140
 141 out:
 142         if (r->cur_subvol.path) {
 143                 free(r->cur_subvol.path);
 144                 r->cur_subvol.path = NULL;
 145         }
 146         if (subvol_fd != -1)
 147                 close(subvol_fd);
 148         return ret;
 149 }
 150
 151 static int process_subvol(const char *path, const u8 *uuid, u64 ctransid,
 152                           void *user)
 153 {
 154         int ret;
 155         struct btrfs_receive *r = user;
 156         struct btrfs_ioctl_vol_args args_v1;
 157         char uuid_str[BTRFS_UUID_UNPARSED_SIZE];
 158
 159         ret = finish_subvol(r);
 160         if (ret < 0)
 161                 goto out;
 162
 163         BUG_ON(r->cur_subvol.path);
 164
 165         if (strlen(r->dest_dir_path) == 0)
 166                 r->cur_subvol.path = strdup(path);
 167         else
 168                 r->cur_subvol.path = path_cat(r->dest_dir_path, path);
 169         free(r->full_subvol_path);
 170         r->full_subvol_path = path_cat3(r->root_path, r->dest_dir_path, path);
 171
 172         fprintf(stderr, "At subvol %s\n", path);
 173
 174         memcpy(r->cur_subvol.received_uuid, uuid, BTRFS_UUID_SIZE);
 175         r->cur_subvol.stransid = ctransid;
 176
 177         if (g_verbose) {
 178                 uuid_unparse((u8*)r->cur_subvol.received_uuid, uuid_str);
 179                 fprintf(stderr, "receiving subvol %s uuid=%s, stransid=%llu\n",
 180                                 path, uuid_str,
 181                                 r->cur_subvol.stransid);
 182         }
 183
 184         memset(&args_v1, 0, sizeof(args_v1));
 185         strncpy_null(args_v1.name, path);
 186         ret = ioctl(r->dest_dir_fd, BTRFS_IOC_SUBVOL_CREATE, &args_v1);
 187         if (ret < 0) {
 188                 ret = -errno;
 189                 fprintf(stderr, "ERROR: creating subvolume %s failed. "
 190                                 "%s\n", path, strerror(-ret));
 191                 goto out;
 192         }
 193
 194 out:
 195         return ret;
 196 }
 197
 198 static int process_snapshot(const char *path, const u8 *uuid, u64 ctransid,
 199                             const u8 *parent_uuid, u64 parent_ctransid,
 200                             void *user)
 201 {
 202         int ret;
 203         struct btrfs_receive *r = user;
 204         char uuid_str[BTRFS_UUID_UNPARSED_SIZE];
 205         struct btrfs_ioctl_vol_args_v2 args_v2;
 206         struct subvol_info *parent_subvol = NULL;
 207
 208         ret = finish_subvol(r);
 209         if (ret < 0)
 210                 goto out;
 211
 212         BUG_ON(r->cur_subvol.path);
 213
 214         if (strlen(r->dest_dir_path) == 0)
 215                 r->cur_subvol.path = strdup(path);
 216         else
 217                 r->cur_subvol.path = path_cat(r->dest_dir_path, path);
 218         free(r->full_subvol_path);
 219         r->full_subvol_path = path_cat3(r->root_path, r->dest_dir_path, path);
 220
 221         fprintf(stdout, "At snapshot %s\n", path);
 222
 223         memcpy(r->cur_subvol.received_uuid, uuid, BTRFS_UUID_SIZE);
 224         r->cur_subvol.stransid = ctransid;
 225
 226         if (g_verbose) {
 227                 uuid_unparse((u8*)r->cur_subvol.received_uuid, uuid_str);
 228                 fprintf(stderr, "receiving snapshot %s uuid=%s, "
 229                                 "ctransid=%llu ", path, uuid_str,
 230                                 r->cur_subvol.stransid);
 231                 uuid_unparse(parent_uuid, uuid_str);
 232                 fprintf(stderr, "parent_uuid=%s, parent_ctransid=%llu\n",
 233                                 uuid_str, parent_ctransid);
 234         }
 235
 236         memset(&args_v2, 0, sizeof(args_v2));
 237         strncpy_null(args_v2.name, path);
 238
 239         parent_subvol = subvol_uuid_search(&r->sus, 0, parent_uuid,
 240                         parent_ctransid, NULL, subvol_search_by_received_uuid);
 241         if (!parent_subvol) {
 242                 parent_subvol = subvol_uuid_search(&r->sus, 0, parent_uuid,
 243                                 parent_ctransid, NULL, subvol_search_by_uuid);
 244         }
 245         if (!parent_subvol) {
 246                 ret = -ENOENT;
 247                 fprintf(stderr, "ERROR: could not find parent subvolume\n");
 248                 goto out;
 249         }
 250
 251         /*
 252          * The path is resolved from the root subvol, but we could be in some
 253          * subvolume under the root subvolume, so try and adjust the path to be
 254          * relative to our root path.
 255          */
 256         if (r->full_root_path) {
 257                 size_t root_len;
 258                 size_t sub_len;
 259
 260                 root_len = strlen(r->full_root_path);
 261                 sub_len = strlen(parent_subvol->path);
 262
 263                 /* First make sure the parent subvol is actually in our path */
 264                 if (sub_len < root_len ||
 265                     strstr(parent_subvol->path, r->full_root_path) == NULL) {
 266                         fprintf(stderr, "ERROR: parent subvol is not reachable"
 267                                 " from inside the root subvol.\n");
 268                         ret = -ENOENT;
 269                         goto out;
 270                 }
 271
 272                 if (sub_len == root_len) {
 273                         parent_subvol->path[0] = '/';
 274                         parent_subvol->path[1] = '\0';
 275                 } else {
 276                         /*
 277                          * root path is foo/bar
 278                          * subvol path is foo/bar/baz
 279                          *
 280                          * we need to have baz be the path, so we need to move
 281                          * the bit after foo/bar/, so path + root_len + 1, and
 282                          * move the part we care about, so sub_len - root_len -
 283                          * 1.
 284                          */
 285                         memmove(parent_subvol->path,
 286                                 parent_subvol->path + root_len + 1,
 287                                 sub_len - root_len - 1);
 288                         parent_subvol->path[sub_len - root_len - 1] = '\0';
 289                 }
 290         }
 291         /*if (rs_args.ctransid > rs_args.rtransid) {
 292                 if (!r->force) {
 293                         ret = -EINVAL;
 294                         fprintf(stderr, "ERROR: subvolume %s was modified after it was received.\n", r->subvol_parent_name);
 295                         goto out;
 296                 } else {
 297                         fprintf(stderr, "WARNING: subvolume %s was modified after it was received.\n", r->subvol_parent_name);
 298                 }
 299         }*/
 300
 301         if (strlen(parent_subvol->path) == 0)
 302                 args_v2.fd = dup(r->mnt_fd);
 303         else
 304                 args_v2.fd = openat(r->mnt_fd, parent_subvol->path,
 305                                 O_RDONLY | O_NOATIME);
 306         if (args_v2.fd < 0) {
 307                 ret = -errno;
 308                 if (errno != ENOENT)
 309                         fprintf(stderr, "ERROR: open %s failed. %s\n",
 310                                         parent_subvol->path, strerror(-ret));
 311                 else
 312                         fprintf(stderr,
 313                                 "It seems that you have changed your default "
 314                                 "subvolume or you specify other subvolume to\n"
 315                                 "mount btrfs, try to remount this btrfs filesystem "
 316                                 "with fs tree, and run btrfs receive again!\n");
 317                 goto out;
 318         }
 319
 320         ret = ioctl(r->dest_dir_fd, BTRFS_IOC_SNAP_CREATE_V2, &args_v2);
 321         close(args_v2.fd);
 322         if (ret < 0) {
 323                 ret = -errno;
 324                 fprintf(stderr, "ERROR: creating snapshot %s -> %s "
 325                                 "failed. %s\n", parent_subvol->path,
 326                                 path, strerror(-ret));
 327                 goto out;
 328         }
 329
 330 out:
 331         if (parent_subvol) {
 332                 free(parent_subvol->path);
 333                 free(parent_subvol);
 334         }
 335         return ret;
 336 }
 337
 338 static int process_mkfile(const char *path, void *user)
 339 {
 340         int ret;
 341         struct btrfs_receive *r = user;
 342         char *full_path = path_cat(r->full_subvol_path, path);
 343
 344         if (g_verbose >= 2)
 345                 fprintf(stderr, "mkfile %s\n", path);
 346
 347         ret = creat(full_path, 0600);
 348         if (ret < 0) {
 349                 ret = -errno;
 350                 fprintf(stderr, "ERROR: mkfile %s failed. %s\n", path,
 351                                 strerror(-ret));
 352                 goto out;
 353         }
 354         close(ret);
 355         ret = 0;
 356
 357 out:
 358         free(full_path);
 359         return ret;
 360 }
 361
 362 static int process_mkdir(const char *path, void *user)
 363 {
 364         int ret;
 365         struct btrfs_receive *r = user;
 366         char *full_path = path_cat(r->full_subvol_path, path);
 367
 368         if (g_verbose >= 2)
 369                 fprintf(stderr, "mkdir %s\n", path);
 370
 371         ret = mkdir(full_path, 0700);
 372         if (ret < 0) {
 373                 ret = -errno;
 374                 fprintf(stderr, "ERROR: mkdir %s failed. %s\n", path,
 375                                 strerror(-ret));
 376         }
 377
 378         free(full_path);
 379         return ret;
 380 }
 381
 382 static int process_mknod(const char *path, u64 mode, u64 dev, void *user)
 383 {
 384         int ret;
 385         struct btrfs_receive *r = user;
 386         char *full_path = path_cat(r->full_subvol_path, path);
 387
 388         if (g_verbose >= 2)
 389                 fprintf(stderr, "mknod %s mode=%llu, dev=%llu\n",
 390                                 path, mode, dev);
 391
 392         ret = mknod(full_path, mode & S_IFMT, dev);
 393         if (ret < 0) {
 394                 ret = -errno;
 395                 fprintf(stderr, "ERROR: mknod %s failed. %s\n", path,
 396                                 strerror(-ret));
 397         }
 398
 399         free(full_path);
 400         return ret;
 401 }
 402
 403 static int process_mkfifo(const char *path, void *user)
 404 {
 405         int ret;
 406         struct btrfs_receive *r = user;
 407         char *full_path = path_cat(r->full_subvol_path, path);
 408
 409         if (g_verbose >= 2)
 410                 fprintf(stderr, "mkfifo %s\n", path);
 411
 412         ret = mkfifo(full_path, 0600);
 413         if (ret < 0) {
 414                 ret = -errno;
 415                 fprintf(stderr, "ERROR: mkfifo %s failed. %s\n", path,
 416                                 strerror(-ret));
 417         }
 418
 419         free(full_path);
 420         return ret;
 421 }
 422
 423 static int process_mksock(const char *path, void *user)
 424 {
 425         int ret;
 426         struct btrfs_receive *r = user;
 427         char *full_path = path_cat(r->full_subvol_path, path);
 428
 429         if (g_verbose >= 2)
 430                 fprintf(stderr, "mksock %s\n", path);
 431
 432         ret = mknod(full_path, 0600 | S_IFSOCK, 0);
 433         if (ret < 0) {
 434                 ret = -errno;
 435                 fprintf(stderr, "ERROR: mknod %s failed. %s\n", path,
 436                                 strerror(-ret));
 437         }
 438
 439         free(full_path);
 440         return ret;
 441 }
 442
 443 static int process_symlink(const char *path, const char *lnk, void *user)
 444 {
 445         int ret;
 446         struct btrfs_receive *r = user;
 447         char *full_path = path_cat(r->full_subvol_path, path);
 448
 449         if (g_verbose >= 2)
 450                 fprintf(stderr, "symlink %s -> %s\n", path, lnk);
 451
 452         ret = symlink(lnk, full_path);
 453         if (ret < 0) {
 454                 ret = -errno;
 455                 fprintf(stderr, "ERROR: symlink %s -> %s failed. %s\n", path,
 456                                 lnk, strerror(-ret));
 457         }
 458
 459         free(full_path);
 460         return ret;
 461 }
 462
 463 static int process_rename(const char *from, const char *to, void *user)
 464 {
 465         int ret;
 466         struct btrfs_receive *r = user;
 467         char *full_from = path_cat(r->full_subvol_path, from);
 468         char *full_to = path_cat(r->full_subvol_path, to);
 469
 470         if (g_verbose >= 2)
 471                 fprintf(stderr, "rename %s -> %s\n", from, to);
 472
 473         ret = rename(full_from, full_to);
 474         if (ret < 0) {
 475                 ret = -errno;
 476                 fprintf(stderr, "ERROR: rename %s -> %s failed. %s\n", from,
 477                                 to, strerror(-ret));
 478         }
 479
 480         free(full_from);
 481         free(full_to);
 482         return ret;
 483 }
 484
 485 static int process_link(const char *path, const char *lnk, void *user)
 486 {
 487         int ret;
 488         struct btrfs_receive *r = user;
 489         char *full_path = path_cat(r->full_subvol_path, path);
 490         char *full_link_path = path_cat(r->full_subvol_path, lnk);
 491
 492         if (g_verbose >= 2)
 493                 fprintf(stderr, "link %s -> %s\n", path, lnk);
 494
 495         ret = link(full_link_path, full_path);
 496         if (ret < 0) {
 497                 ret = -errno;
 498                 fprintf(stderr, "ERROR: link %s -> %s failed. %s\n", path,
 499                                 lnk, strerror(-ret));
 500         }
 501
 502         free(full_path);
 503         free(full_link_path);
 504         return ret;
 505 }
 506
 507
 508 static int process_unlink(const char *path, void *user)
 509 {
 510         int ret;
 511         struct btrfs_receive *r = user;
 512         char *full_path = path_cat(r->full_subvol_path, path);
 513
 514         if (g_verbose >= 2)
 515                 fprintf(stderr, "unlink %s\n", path);
 516
 517         ret = unlink(full_path);
 518         if (ret < 0) {
 519                 ret = -errno;
 520                 fprintf(stderr, "ERROR: unlink %s failed. %s\n", path,
 521                                 strerror(-ret));
 522         }
 523
 524         free(full_path);
 525         return ret;
 526 }
 527
 528 static int process_rmdir(const char *path, void *user)
 529 {
 530         int ret;
 531         struct btrfs_receive *r = user;
 532         char *full_path = path_cat(r->full_subvol_path, path);
 533
 534         if (g_verbose >= 2)
 535                 fprintf(stderr, "rmdir %s\n", path);
 536
 537         ret = rmdir(full_path);
 538         if (ret < 0) {
 539                 ret = -errno;
 540                 fprintf(stderr, "ERROR: rmdir %s failed. %s\n", path,
 541                                 strerror(-ret));
 542         }
 543
 544         free(full_path);
 545         return ret;
 546 }
 547
 548
 549 static int open_inode_for_write(struct btrfs_receive *r, const char *path)
 550 {
 551         int ret = 0;
 552
 553         if (r->write_fd != -1) {
 554                 if (strcmp(r->write_path, path) == 0)
 555                         goto out;
 556                 close(r->write_fd);
 557                 r->write_fd = -1;
 558         }
 559
 560         r->write_fd = open(path, O_RDWR);
 561         if (r->write_fd < 0) {
 562                 ret = -errno;
 563                 fprintf(stderr, "ERROR: open %s failed. %s\n", path,
 564                                 strerror(-ret));
 565                 goto out;
 566         }
 567         free(r->write_path);
 568         r->write_path = strdup(path);
 569
 570 out:
 571         return ret;
 572 }
 573
 574 static void close_inode_for_write(struct btrfs_receive *r)
 575 {
 576         if(r->write_fd == -1)
 577                 return;
 578
 579         close(r->write_fd);
 580         r->write_fd = -1;
 581         r->write_path[0] = 0;
 582 }
 583
 584 static int process_write(const char *path, const void *data, u64 offset,
 585                          u64 len, void *user)
 586 {
 587         int ret = 0;
 588         struct btrfs_receive *r = user;
 589         char *full_path = path_cat(r->full_subvol_path, path);
 590         u64 pos = 0;
 591         int w;
 592
 593         ret = open_inode_for_write(r, full_path);
 594         if (ret < 0)
 595                 goto out;
 596
 597         while (pos < len) {
 598                 w = pwrite(r->write_fd, (char*)data + pos, len - pos,
 599                                 offset + pos);
 600                 if (w < 0) {
 601                         ret = -errno;
 602                         fprintf(stderr, "ERROR: writing to %s failed. %s\n",
 603                                         path, strerror(-ret));
 604                         goto out;
 605                 }
 606                 pos += w;
 607         }
 608
 609 out:
 610         free(full_path);
 611         return ret;
 612 }
 613
 614 static int process_clone(const char *path, u64 offset, u64 len,
 615                          const u8 *clone_uuid, u64 clone_ctransid,
 616                          const char *clone_path, u64 clone_offset,
 617                          void *user)
 618 {
 619         int ret;
 620         struct btrfs_receive *r = user;
 621         struct btrfs_ioctl_clone_range_args clone_args;
 622         struct subvol_info *si = NULL;
 623         char *full_path = path_cat(r->full_subvol_path, path);
 624         char *subvol_path = NULL;
 625         char *full_clone_path = NULL;
 626         int clone_fd = -1;
 627
 628         ret = open_inode_for_write(r, full_path);
 629         if (ret < 0)
 630                 goto out;
 631
 632         si = subvol_uuid_search(&r->sus, 0, clone_uuid, clone_ctransid, NULL,
 633                         subvol_search_by_received_uuid);
 634         if (!si) {
 635                 if (memcmp(clone_uuid, r->cur_subvol.received_uuid,
 636                                 BTRFS_UUID_SIZE) == 0) {
 637                         /* TODO check generation of extent */
 638                         subvol_path = strdup(r->cur_subvol.path);
 639                 } else {
 640                         ret = -ENOENT;
 641                         fprintf(stderr, "ERROR: did not find source subvol.\n");
 642                         goto out;
 643                 }
 644         } else {
 645                 /*if (rs_args.ctransid > rs_args.rtransid) {
 646                         if (!r->force) {
 647                                 ret = -EINVAL;
 648                                 fprintf(stderr, "ERROR: subvolume %s was "
 649                                                 "modified after it was "
 650                                                 "received.\n",
 651                                                 r->subvol_parent_name);
 652                                 goto out;
 653                         } else {
 654                                 fprintf(stderr, "WARNING: subvolume %s was "
 655                                                 "modified after it was "
 656                                                 "received.\n",
 657                                                 r->subvol_parent_name);
 658                         }
 659                 }*/
 660                 subvol_path = strdup(si->path);
 661         }
 662
 663         full_clone_path = path_cat(subvol_path, clone_path);
 664
 665         clone_fd = openat(r->mnt_fd, full_clone_path, O_RDONLY | O_NOATIME);
 666         if (clone_fd < 0) {
 667                 ret = -errno;
 668                 fprintf(stderr, "ERROR: failed to open %s. %s\n",
 669                                 full_clone_path, strerror(-ret));
 670                 goto out;
 671         }
 672
 673         clone_args.src_fd = clone_fd;
 674         clone_args.src_offset = clone_offset;
 675         clone_args.src_length = len;
 676         clone_args.dest_offset = offset;
 677         ret = ioctl(r->write_fd, BTRFS_IOC_CLONE_RANGE, &clone_args);
 678         if (ret) {
 679                 ret = -errno;
 680                 fprintf(stderr, "ERROR: failed to clone extents to %s\n%s\n",
 681                                 path, strerror(-ret));
 682                 goto out;
 683         }
 684
 685 out:
 686         if (si) {
 687                 free(si->path);
 688                 free(si);
 689         }
 690         free(full_path);
 691         free(full_clone_path);
 692         free(subvol_path);
 693         if (clone_fd != -1)
 694                 close(clone_fd);
 695         return ret;
 696 }
 697
 698
 699 static int process_set_xattr(const char *path, const char *name,
 700                              const void *data, int len, void *user)
 701 {
 702         int ret = 0;
 703         struct btrfs_receive *r = user;
 704         char *full_path = path_cat(r->full_subvol_path, path);
 705
 706         if (strcmp("security.capability", name) == 0) {
 707                 if (g_verbose >= 3)
 708                         fprintf(stderr, "set_xattr: cache capabilities\n");
 709                 if (r->cached_capabilities_len)
 710                         fprintf(stderr,
 711                           "WARNING: capabilities set multiple times per file: %s\n",
 712                                 full_path);
 713                 if (len > sizeof(r->cached_capabilities)) {
 714                         fprintf(stderr,
 715                           "ERROR: capabilities encoded to %d bytes, buffer too small\n",
 716                                 len);
 717                         ret = -E2BIG;
 718                         goto out;
 719                 }
 720                 r->cached_capabilities_len = len;
 721                 memcpy(r->cached_capabilities, data, len);
 722         }
 723
 724         if (g_verbose >= 2) {
 725                 fprintf(stderr, "set_xattr %s - name=%s data_len=%d "
 726                                 "data=%.*s\n", path, name, len,
 727                                 len, (char*)data);
 728         }
 729
 730         ret = lsetxattr(full_path, name, data, len, 0);
 731         if (ret < 0) {
 732                 ret = -errno;
 733                 fprintf(stderr, "ERROR: lsetxattr %s %s=%.*s failed. %s\n",
 734                                 path, name, len, (char*)data, strerror(-ret));
 735                 goto out;
 736         }
 737
 738 out:
 739         free(full_path);
 740         return ret;
 741 }
 742
 743 static int process_remove_xattr(const char *path, const char *name, void *user)
 744 {
 745         int ret = 0;
 746         struct btrfs_receive *r = user;
 747         char *full_path = path_cat(r->full_subvol_path, path);
 748
 749         if (g_verbose >= 2) {
 750                 fprintf(stderr, "remove_xattr %s - name=%s\n",
 751                                 path, name);
 752         }
 753
 754         ret = lremovexattr(full_path, name);
 755         if (ret < 0) {
 756                 ret = -errno;
 757                 fprintf(stderr, "ERROR: lremovexattr %s %s failed. %s\n",
 758                                 path, name, strerror(-ret));
 759                 goto out;
 760         }
 761
 762 out:
 763         free(full_path);
 764         return ret;
 765 }
 766
 767 static int process_truncate(const char *path, u64 size, void *user)
 768 {
 769         int ret = 0;
 770         struct btrfs_receive *r = user;
 771         char *full_path = path_cat(r->full_subvol_path, path);
 772
 773         if (g_verbose >= 2)
 774                 fprintf(stderr, "truncate %s size=%llu\n", path, size);
 775
 776         ret = truncate(full_path, size);
 777         if (ret < 0) {
 778                 ret = -errno;
 779                 fprintf(stderr, "ERROR: truncate %s failed. %s\n",
 780                                 path, strerror(-ret));
 781                 goto out;
 782         }
 783
 784 out:
 785         free(full_path);
 786         return ret;
 787 }
 788
 789 static int process_chmod(const char *path, u64 mode, void *user)
 790 {
 791         int ret = 0;
 792         struct btrfs_receive *r = user;
 793         char *full_path = path_cat(r->full_subvol_path, path);
 794
 795         if (g_verbose >= 2)
 796                 fprintf(stderr, "chmod %s - mode=0%o\n", path, (int)mode);
 797
 798         ret = chmod(full_path, mode);
 799         if (ret < 0) {
 800                 ret = -errno;
 801                 fprintf(stderr, "ERROR: chmod %s failed. %s\n",
 802                                 path, strerror(-ret));
 803                 goto out;
 804         }
 805
 806 out:
 807         free(full_path);
 808         return ret;
 809 }
 810
 811 static int process_chown(const char *path, u64 uid, u64 gid, void *user)
 812 {
 813         int ret = 0;
 814         struct btrfs_receive *r = user;
 815         char *full_path = path_cat(r->full_subvol_path, path);
 816
 817         if (g_verbose >= 2)
 818                 fprintf(stderr, "chown %s - uid=%llu, gid=%llu\n", path,
 819                                 uid, gid);
 820
 821         ret = lchown(full_path, uid, gid);
 822         if (ret < 0) {
 823                 ret = -errno;
 824                 fprintf(stderr, "ERROR: chown %s failed. %s\n",
 825                                 path, strerror(-ret));
 826                 goto out;
 827         }
 828
 829         if (r->cached_capabilities_len) {
 830                 if (g_verbose >= 2)
 831                         fprintf(stderr, "chown: restore capabilities\n");
 832                 ret = lsetxattr(full_path, "security.capability",
 833                                 r->cached_capabilities,
 834                                 r->cached_capabilities_len, 0);
 835                 memset(r->cached_capabilities, 0,
 836                                 sizeof(r->cached_capabilities));
 837                 r->cached_capabilities_len = 0;
 838                 if (ret < 0) {
 839                         ret = -errno;
 840                         fprintf(stderr, "ERROR: restoring capabilities %s: %s\n",
 841                                         path, strerror(-ret));
 842                         goto out;
 843                 }
 844         }
 845
 846 out:
 847         free(full_path);
 848         return ret;
 849 }
 850
 851 static int process_utimes(const char *path, struct timespec *at,
 852                           struct timespec *mt, struct timespec *ct,
 853                           void *user)
 854 {
 855         int ret = 0;
 856         struct btrfs_receive *r = user;
 857         char *full_path = path_cat(r->full_subvol_path, path);
 858         struct timespec tv[2];
 859
 860         if (g_verbose >= 2)
 861                 fprintf(stderr, "utimes %s\n", path);
 862
 863         tv[0] = *at;
 864         tv[1] = *mt;
 865         ret = utimensat(AT_FDCWD, full_path, tv, AT_SYMLINK_NOFOLLOW);
 866         if (ret < 0) {
 867                 ret = -errno;
 868                 fprintf(stderr, "ERROR: utimes %s failed. %s\n",
 869                                 path, strerror(-ret));
 870                 goto out;
 871         }
 872
 873 out:
 874         free(full_path);
 875         return ret;
 876 }
 877
 878 static int process_update_extent(const char *path, u64 offset, u64 len,
 879                 void *user)
 880 {
 881         if (g_verbose >= 2)
 882                 fprintf(stderr, "update_extent %s: offset=%llu, len=%llu\n",
 883                                 path, (unsigned long long)offset,
 884                                 (unsigned long long)len);
 885
 886         /*
 887          * Sent with BTRFS_SEND_FLAG_NO_FILE_DATA, nothing to do.
 888          */
 889
 890         return 0;
 891 }
 892
 893 static struct btrfs_send_ops send_ops = {
 894         .subvol = process_subvol,
 895         .snapshot = process_snapshot,
 896         .mkfile = process_mkfile,
 897         .mkdir = process_mkdir,
 898         .mknod = process_mknod,
 899         .mkfifo = process_mkfifo,
 900         .mksock = process_mksock,
 901         .symlink = process_symlink,
 902         .rename = process_rename,
 903         .link = process_link,
 904         .unlink = process_unlink,
 905         .rmdir = process_rmdir,
 906         .write = process_write,
 907         .clone = process_clone,
 908         .set_xattr = process_set_xattr,
 909         .remove_xattr = process_remove_xattr,
 910         .truncate = process_truncate,
 911         .chmod = process_chmod,
 912         .chown = process_chown,
 913         .utimes = process_utimes,
 914         .update_extent = process_update_extent,
 915 };
 916
 917 static int do_receive(struct btrfs_receive *r, const char *tomnt,
 918                       char *realmnt, int r_fd, u64 max_errors)
 919 {
 920         u64 subvol_id;
 921         int ret;
 922         char *dest_dir_full_path;
 923         char *root_subvol_path;
 924         int end = 0;
 925
 926         dest_dir_full_path = realpath(tomnt, NULL);
 927         if (!dest_dir_full_path) {
 928                 ret = -errno;
 929                 fprintf(stderr, "ERROR: realpath(%s) failed. %s\n", tomnt,
 930                         strerror(-ret));
 931                 goto out;
 932         }
 933         r->dest_dir_fd = open(dest_dir_full_path, O_RDONLY | O_NOATIME);
 934         if (r->dest_dir_fd < 0) {
 935                 ret = -errno;
 936                 fprintf(stderr,
 937                         "ERROR: failed to open destination directory %s. %s\n",
 938                         dest_dir_full_path, strerror(-ret));
 939                 goto out;
 940         }
 941
 942         if (realmnt) {
 943                 r->root_path = realmnt;
 944         } else {
 945                 ret = find_mount_root(dest_dir_full_path, &r->root_path);
 946                 if (ret < 0) {
 947                         fprintf(stderr,
 948                                 "ERROR: failed to determine mount point for %s: %s\n",
 949                                 dest_dir_full_path, strerror(-ret));
 950                         ret = -EINVAL;
 951                         goto out;
 952                 }
 953                 if (ret > 0) {
 954                         fprintf(stderr,
 955                         "ERROR: %s doesn't belong to btrfs mount point\n",
 956                         dest_dir_full_path);
 957                         ret = -EINVAL;
 958                         goto out;
 959                 }
 960         }
 961         r->mnt_fd = open(r->root_path, O_RDONLY | O_NOATIME);
 962         if (r->mnt_fd < 0) {
 963                 ret = -errno;
 964                 fprintf(stderr, "ERROR: failed to open %s. %s\n", r->root_path,
 965                         strerror(-ret));
 966                 goto out;
 967         }
 968
 969         /*
 970          * If we use -m or a default subvol we want to resolve the path to the
 971          * subvolume we're sitting in so that we can adjust the paths of any
 972          * subvols we want to receive in.
 973          */
 974         ret = btrfs_list_get_path_rootid(r->mnt_fd, &subvol_id);
 975         if (ret) {
 976                 fprintf(stderr, "ERROR: couldn't resolve our subvolid %d\n",
 977                         ret);
 978                 goto out;
 979         }
 980
 981         root_subvol_path = malloc(PATH_MAX);
 982         if (!root_subvol_path) {
 983                 ret = -ENOMEM;
 984                 fprintf(stderr, "ERROR: couldn't allocate buffer for the root "
 985                         "subvol path\n");
 986                 goto out;
 987         }
 988
 989         ret = btrfs_subvolid_resolve(r->mnt_fd, root_subvol_path,
 990                                      PATH_MAX, subvol_id);
 991         if (ret) {
 992                 fprintf(stderr, "ERROR: couldn't resolve our subvol path\n");
 993                 goto out;
 994         }
 995
 996         /*
 997          * Ok we're inside of a subvol off of the root subvol, we need to
 998          * actually set full_root_path.
 999          */
1000         if (strlen(root_subvol_path))
1001                 r->full_root_path = root_subvol_path;
1002         else
1003                 free(root_subvol_path);
1004
1005         if (r->dest_dir_chroot) {
1006                 if (chroot(dest_dir_full_path)) {
1007                         ret = -errno;
1008                         fprintf(stderr,
1009                                 "ERROR: failed to chroot to %s, %s\n",
1010                                 dest_dir_full_path,
1011                                 strerror(-ret));
1012                         goto out;
1013                 }
1014                 if (chdir("/")) {
1015                         ret = -errno;
1016                         fprintf(stderr,
1017                                 "ERROR: failed to chdir to /, %s\n",
1018                                 strerror(-ret));
1019                         goto out;
1020                 }
1021                 fprintf(stderr, "Chroot to %s\n", dest_dir_full_path);
1022                 r->root_path = strdup("/");
1023                 r->dest_dir_path = r->root_path;
1024         } else {
1025                 /*
1026                  * find_mount_root returns a root_path that is a subpath of
1027                  * dest_dir_full_path. Now get the other part of root_path,
1028                  * which is the destination dir relative to root_path.
1029                  */
1030                 r->dest_dir_path = dest_dir_full_path + strlen(r->root_path);
1031                 while (r->dest_dir_path[0] == '/')
1032                         r->dest_dir_path++;
1033         }
1034
1035         ret = subvol_uuid_search_init(r->mnt_fd, &r->sus);
1036         if (ret < 0)
1037                 goto out;
1038
1039         while (!end) {
1040                 if (r->cached_capabilities_len) {
1041                         if (g_verbose >= 3)
1042                                 fprintf(stderr, "clear cached capabilities\n");
1043                         memset(r->cached_capabilities, 0,
1044                                         sizeof(r->cached_capabilities));
1045                         r->cached_capabilities_len = 0;
1046                 }
1047
1048                 ret = btrfs_read_and_process_send_stream(r_fd, &send_ops, r,
1049                                                          r->honor_end_cmd,
1050                                                          max_errors);
1051                 if (ret < 0)
1052                         goto out;
1053                 if (ret)
1054                         end = 1;
1055
1056                 close_inode_for_write(r);
1057                 ret = finish_subvol(r);
1058                 if (ret < 0)
1059                         goto out;
1060         }
1061         ret = 0;
1062
1063 out:
1064         if (r->write_fd != -1) {
1065                 close(r->write_fd);
1066                 r->write_fd = -1;
1067         }
1068         free(r->root_path);
1069         r->root_path = NULL;
1070         free(r->write_path);
1071         r->write_path = NULL;
1072         free(r->full_subvol_path);
1073         r->full_subvol_path = NULL;
1074         r->dest_dir_path = NULL;
1075         free(dest_dir_full_path);
1076         if (r->cur_subvol.path) {
1077                 free(r->cur_subvol.path);
1078                 r->cur_subvol.path = NULL;
1079         }
1080         subvol_uuid_search_finit(&r->sus);
1081         if (r->mnt_fd != -1) {
1082                 close(r->mnt_fd);
1083                 r->mnt_fd = -1;
1084         }
1085         if (r->dest_dir_fd != -1) {
1086                 close(r->dest_dir_fd);
1087                 r->dest_dir_fd = -1;
1088         }
1089         if (r->full_root_path) {
1090                 free(r->full_root_path);
1091                 r->full_root_path = NULL;
1092         }
1093         return ret;
1094 }
1095
1096 int cmd_receive(int argc, char **argv)
1097 {
1098         char *tomnt = NULL;
1099         char *fromfile = NULL;
1100         char *realmnt = NULL;
1101         struct btrfs_receive r;
1102         int receive_fd = fileno(stdin);
1103         u64 max_errors = 1;
1104         int ret = 0;
1105
1106         memset(&r, 0, sizeof(r));
1107         r.mnt_fd = -1;
1108         r.write_fd = -1;
1109         r.dest_dir_fd = -1;
1110         r.dest_dir_chroot = 0;
1111
1112         while (1) {
1113                 int c;
1114                 static const struct option long_opts[] = {
1115                         { "max-errors", required_argument, NULL, 'E' },
1116                         { "chroot", no_argument, NULL, 'C' },
1117                         { NULL, 0, NULL, 0 }
1118                 };
1119
1120                 c = getopt_long(argc, argv, "Cevf:m:", long_opts, NULL);
1121                 if (c < 0)
1122                         break;
1123
1124                 switch (c) {
1125                 case 'v':
1126                         g_verbose++;
1127                         break;
1128                 case 'f':
1129                         fromfile = optarg;
1130                         break;
1131                 case 'e':
1132                         r.honor_end_cmd = 1;
1133                         break;
1134                 case 'C':
1135                         r.dest_dir_chroot = 1;
1136                         break;
1137                 case 'E':
1138                         max_errors = arg_strtou64(optarg);
1139                         break;
1140                 case 'm':
1141                         free(realmnt);
1142                         realmnt = strdup(optarg);
1143                         if (!realmnt) {
1144                                 fprintf(stderr, "ERROR: couldn't allocate realmnt.\n");
1145                                 goto out;
1146                         }
1147                         break;
1148                 case '?':
1149                 default:
1150                         fprintf(stderr, "ERROR: receive args invalid.\n");
1151                         return 1;
1152                 }
1153         }
1154
1155         if (check_argc_exact(argc - optind, 1))
1156                 usage(cmd_receive_usage);
1157
1158         tomnt = argv[optind];
1159
1160         if (fromfile) {
1161                 receive_fd = open(fromfile, O_RDONLY | O_NOATIME);
1162                 if (receive_fd < 0) {
1163                         fprintf(stderr, "ERROR: failed to open %s\n", fromfile);
1164                         goto out;
1165                 }
1166         }
1167
1168         ret = do_receive(&r, tomnt, realmnt, receive_fd, max_errors);
1169
1170 out:
1171         free(realmnt);
1172
1173         return !!ret;
1174 }
1175
1176 const char * const cmd_receive_usage[] = {
1177         "btrfs receive [-ve] [-f <infile>] [--max-errors <N>] <mount>",
1178         "Receive subvolumes from stdin.",
1179         "Receives one or more subvolumes that were previously",
1180         "sent with btrfs send. The received subvolumes are stored",
1181         "into <mount>.",
1182         "btrfs receive will fail in case a receiving subvolume",
1183         "already exists. It will also fail in case a previously",
1184         "received subvolume was changed after it was received.",
1185         "After receiving a subvolume, it is immediately set to",
1186         "read only.\n",
1187         "-v               Enable verbose debug output. Each",
1188         "                 occurrence of this option increases the",
1189         "                 verbose level more.",
1190         "-f <infile>      By default, btrfs receive uses stdin",
1191         "                 to receive the subvolumes. Use this",
1192         "                 option to specify a file to use instead.",
1193         "-e               Terminate after receiving an <end cmd>",
1194         "                 in the data stream. Without this option,",
1195         "                 the receiver terminates only if an error",
1196         "                 is recognized or on EOF.",
1197         "-C|--chroot      confine the process to <mount> using chroot",
1198         "--max-errors <N> Terminate as soon as N errors happened while",
1199         "                 processing commands from the send stream.",
1200         "                 Default value is 1. A value of 0 means no limit.",
1201         "-m <mountpoint>  The root mount point of the destination fs.",
1202         "                 If you do not have /proc use this to tell us where ",
1203         "                 this file system is mounted.",
1204         NULL
1205 };