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 #include "androidcompat.h"
  21
  22 #include <unistd.h>
  23 #include <stdint.h>
  24 #include <dirent.h>
  25 #include <fcntl.h>
  26 #include <pthread.h>
  27 #include <math.h>
  28 #include <ftw.h>
  29 #include <sys/wait.h>
  30 #include <assert.h>
  31 #include <getopt.h>
  32 #include <limits.h>
  33
  34 #include <sys/stat.h>
  35 #include <sys/types.h>
  36 #include <sys/ioctl.h>
  37 #include <sys/time.h>
  38 #include <sys/types.h>
  39 #include <sys/xattr.h>
  40 #include <uuid/uuid.h>
  41
  42 #include "ctree.h"
  43 #include "ioctl.h"
  44 #include "commands.h"
  45 #include "utils.h"
  46 #include "list.h"
  47 #include "btrfs-list.h"
  48
  49 #include "send.h"
  50 #include "send-stream.h"
  51 #include "send-utils.h"
  52
  53 static int g_verbose = 0;
  54
  55 struct btrfs_receive
  56 {
  57         int mnt_fd;
  58         int dest_dir_fd;
  59
  60         int write_fd;
  61         char write_path[PATH_MAX];
  62
  63         char *root_path;
  64         char *dest_dir_path; /* relative to root_path */
  65         char full_subvol_path[PATH_MAX];
  66         char *full_root_path;
  67         int dest_dir_chroot;
  68
  69         struct subvol_info cur_subvol;
  70         /*
  71          * Substitute for cur_subvol::path which is a pointer and we cannot
  72          * change it to an array as it's a public API.
  73          */
  74         char cur_subvol_path[PATH_MAX];
  75
  76         struct subvol_uuid_search sus;
  77
  78         int honor_end_cmd;
  79
  80         /*
  81          * Buffer to store capabilities from security.capabilities xattr,
  82          * usually 20 bytes, but make same room for potentially larger
  83          * encodings. Must be set only once per file, denoted by length > 0.
  84          */
  85         char cached_capabilities[64];
  86         int cached_capabilities_len;
  87 };
  88
  89 static int finish_subvol(struct btrfs_receive *r)
  90 {
  91         int ret;
  92         int subvol_fd = -1;
  93         struct btrfs_ioctl_received_subvol_args rs_args;
  94         char uuid_str[BTRFS_UUID_UNPARSED_SIZE];
  95         u64 flags;
  96
  97         if (r->cur_subvol_path[0] == 0)
  98                 return 0;
  99
 100         subvol_fd = openat(r->mnt_fd, r->cur_subvol_path,
 101                         O_RDONLY | O_NOATIME);
 102         if (subvol_fd < 0) {
 103                 ret = -errno;
 104                 error("cannot open %s: %s\n",
 105                                 r->cur_subvol_path, strerror(-ret));
 106                 goto out;
 107         }
 108
 109         memset(&rs_args, 0, sizeof(rs_args));
 110         memcpy(rs_args.uuid, r->cur_subvol.received_uuid, BTRFS_UUID_SIZE);
 111         rs_args.stransid = r->cur_subvol.stransid;
 112
 113         if (g_verbose >= 1) {
 114                 uuid_unparse((u8*)rs_args.uuid, uuid_str);
 115                 fprintf(stderr, "BTRFS_IOC_SET_RECEIVED_SUBVOL uuid=%s, "
 116                                 "stransid=%llu\n", uuid_str, rs_args.stransid);
 117         }
 118
 119         ret = ioctl(subvol_fd, BTRFS_IOC_SET_RECEIVED_SUBVOL, &rs_args);
 120         if (ret < 0) {
 121                 ret = -errno;
 122                 error("ioctl BTRFS_IOC_SET_RECEIVED_SUBVOL failed: %s",
 123                                 strerror(-ret));
 124                 goto out;
 125         }
 126         r->cur_subvol.rtransid = rs_args.rtransid;
 127
 128         ret = ioctl(subvol_fd, BTRFS_IOC_SUBVOL_GETFLAGS, &flags);
 129         if (ret < 0) {
 130                 ret = -errno;
 131                 error("ioctl BTRFS_IOC_SUBVOL_GETFLAGS failed: %s",
 132                                 strerror(-ret));
 133                 goto out;
 134         }
 135
 136         flags |= BTRFS_SUBVOL_RDONLY;
 137
 138         ret = ioctl(subvol_fd, BTRFS_IOC_SUBVOL_SETFLAGS, &flags);
 139         if (ret < 0) {
 140                 ret = -errno;
 141                 error("failed to make subvolume read only: %s",
 142                                 strerror(-ret));
 143                 goto out;
 144         }
 145
 146         ret = 0;
 147
 148 out:
 149         if (r->cur_subvol_path[0]) {
 150                 r->cur_subvol_path[0] = 0;
 151         }
 152         if (subvol_fd != -1)
 153                 close(subvol_fd);
 154         return ret;
 155 }
 156
 157 static int process_subvol(const char *path, const u8 *uuid, u64 ctransid,
 158                           void *user)
 159 {
 160         int ret;
 161         struct btrfs_receive *r = user;
 162         struct btrfs_ioctl_vol_args args_v1;
 163         char uuid_str[BTRFS_UUID_UNPARSED_SIZE];
 164
 165         ret = finish_subvol(r);
 166         if (ret < 0)
 167                 goto out;
 168
 169         BUG_ON(r->cur_subvol.path);
 170         BUG_ON(r->cur_subvol_path[0]);
 171
 172         if (*r->dest_dir_path == 0) {
 173                 strncpy_null(r->cur_subvol_path, path);
 174         } else {
 175                 ret = path_cat_out(r->cur_subvol_path, r->dest_dir_path, path);
 176                 if (ret < 0) {
 177                         error("subvol: path invalid: %s\n", path);
 178                         goto out;
 179                 }
 180         }
 181         ret = path_cat3_out(r->full_subvol_path, r->root_path,
 182                         r->dest_dir_path, path);
 183         if (ret < 0) {
 184                 error("subvol: path invalid: %s", path);
 185                 goto out;
 186         }
 187
 188         fprintf(stderr, "At subvol %s\n", path);
 189
 190         memcpy(r->cur_subvol.received_uuid, uuid, BTRFS_UUID_SIZE);
 191         r->cur_subvol.stransid = ctransid;
 192
 193         if (g_verbose) {
 194                 uuid_unparse((u8*)r->cur_subvol.received_uuid, uuid_str);
 195                 fprintf(stderr, "receiving subvol %s uuid=%s, stransid=%llu\n",
 196                                 path, uuid_str,
 197                                 r->cur_subvol.stransid);
 198         }
 199
 200         memset(&args_v1, 0, sizeof(args_v1));
 201         strncpy_null(args_v1.name, path);
 202         ret = ioctl(r->dest_dir_fd, BTRFS_IOC_SUBVOL_CREATE, &args_v1);
 203         if (ret < 0) {
 204                 ret = -errno;
 205                 error("creating subvolume %s failed: %s", path, strerror(-ret));
 206                 goto out;
 207         }
 208
 209 out:
 210         return ret;
 211 }
 212
 213 static int process_snapshot(const char *path, const u8 *uuid, u64 ctransid,
 214                             const u8 *parent_uuid, u64 parent_ctransid,
 215                             void *user)
 216 {
 217         int ret;
 218         struct btrfs_receive *r = user;
 219         char uuid_str[BTRFS_UUID_UNPARSED_SIZE];
 220         struct btrfs_ioctl_vol_args_v2 args_v2;
 221         struct subvol_info *parent_subvol = NULL;
 222
 223         ret = finish_subvol(r);
 224         if (ret < 0)
 225                 goto out;
 226
 227         BUG_ON(r->cur_subvol.path);
 228         BUG_ON(r->cur_subvol_path[0]);
 229
 230         if (*r->dest_dir_path == 0) {
 231                 strncpy_null(r->cur_subvol_path, path);
 232         } else {
 233                 ret = path_cat_out(r->cur_subvol_path, r->dest_dir_path, path);
 234                 if (ret < 0) {
 235                         error("snapshot: path invalid: %s", path);
 236                         goto out;
 237                 }
 238         }
 239         ret = path_cat3_out(r->full_subvol_path, r->root_path,
 240                         r->dest_dir_path, path);
 241         if (ret < 0) {
 242                 error("snapshot: path invalid: %s", path);
 243                 goto out;
 244         }
 245
 246         fprintf(stdout, "At snapshot %s\n", path);
 247
 248         memcpy(r->cur_subvol.received_uuid, uuid, BTRFS_UUID_SIZE);
 249         r->cur_subvol.stransid = ctransid;
 250
 251         if (g_verbose) {
 252                 uuid_unparse((u8*)r->cur_subvol.received_uuid, uuid_str);
 253                 fprintf(stderr, "receiving snapshot %s uuid=%s, "
 254                                 "ctransid=%llu ", path, uuid_str,
 255                                 r->cur_subvol.stransid);
 256                 uuid_unparse(parent_uuid, uuid_str);
 257                 fprintf(stderr, "parent_uuid=%s, parent_ctransid=%llu\n",
 258                                 uuid_str, parent_ctransid);
 259         }
 260
 261         memset(&args_v2, 0, sizeof(args_v2));
 262         strncpy_null(args_v2.name, path);
 263
 264         parent_subvol = subvol_uuid_search(&r->sus, 0, parent_uuid,
 265                         parent_ctransid, NULL, subvol_search_by_received_uuid);
 266         if (!parent_subvol) {
 267                 parent_subvol = subvol_uuid_search(&r->sus, 0, parent_uuid,
 268                                 parent_ctransid, NULL, subvol_search_by_uuid);
 269         }
 270         if (!parent_subvol) {
 271                 ret = -ENOENT;
 272                 error("cannot find parent subvolume");
 273                 goto out;
 274         }
 275
 276         /*
 277          * The path is resolved from the root subvol, but we could be in some
 278          * subvolume under the root subvolume, so try and adjust the path to be
 279          * relative to our root path.
 280          */
 281         if (r->full_root_path) {
 282                 size_t root_len;
 283                 size_t sub_len;
 284
 285                 root_len = strlen(r->full_root_path);
 286                 sub_len = strlen(parent_subvol->path);
 287
 288                 /* First make sure the parent subvol is actually in our path */
 289                 if (sub_len < root_len ||
 290                     strstr(parent_subvol->path, r->full_root_path) == NULL) {
 291                         error(
 292                 "parent subvol is not reachable from inside the root subvol");
 293                         ret = -ENOENT;
 294                         goto out;
 295                 }
 296
 297                 if (sub_len == root_len) {
 298                         parent_subvol->path[0] = '/';
 299                         parent_subvol->path[1] = '\0';
 300                 } else {
 301                         /*
 302                          * root path is foo/bar
 303                          * subvol path is foo/bar/baz
 304                          *
 305                          * we need to have baz be the path, so we need to move
 306                          * the bit after foo/bar/, so path + root_len + 1, and
 307                          * move the part we care about, so sub_len - root_len -
 308                          * 1.
 309                          */
 310                         memmove(parent_subvol->path,
 311                                 parent_subvol->path + root_len + 1,
 312                                 sub_len - root_len - 1);
 313                         parent_subvol->path[sub_len - root_len - 1] = '\0';
 314                 }
 315         }
 316         /*if (rs_args.ctransid > rs_args.rtransid) {
 317                 if (!r->force) {
 318                         ret = -EINVAL;
 319                         fprintf(stderr, "ERROR: subvolume %s was modified after it was received.\n", r->subvol_parent_name);
 320                         goto out;
 321                 } else {
 322                         fprintf(stderr, "WARNING: subvolume %s was modified after it was received.\n", r->subvol_parent_name);
 323                 }
 324         }*/
 325
 326         if (*parent_subvol->path == 0)
 327                 args_v2.fd = dup(r->mnt_fd);
 328         else
 329                 args_v2.fd = openat(r->mnt_fd, parent_subvol->path,
 330                                 O_RDONLY | O_NOATIME);
 331         if (args_v2.fd < 0) {
 332                 ret = -errno;
 333                 if (errno != ENOENT)
 334                         error("cannot open %s: %s",
 335                                         parent_subvol->path, strerror(-ret));
 336                 else
 337                         fprintf(stderr,
 338                                 "It seems that you have changed your default "
 339                                 "subvolume or you specify other subvolume to\n"
 340                                 "mount btrfs, try to remount this btrfs filesystem "
 341                                 "with fs tree, and run btrfs receive again!\n");
 342                 goto out;
 343         }
 344
 345         ret = ioctl(r->dest_dir_fd, BTRFS_IOC_SNAP_CREATE_V2, &args_v2);
 346         close(args_v2.fd);
 347         if (ret < 0) {
 348                 ret = -errno;
 349                 error("creating snapshot %s -> %s failed: %s",
 350                                 parent_subvol->path, path, strerror(-ret));
 351                 goto out;
 352         }
 353
 354 out:
 355         if (parent_subvol) {
 356                 free(parent_subvol->path);
 357                 free(parent_subvol);
 358         }
 359         return ret;
 360 }
 361
 362 static int process_mkfile(const char *path, void *user)
 363 {
 364         int ret;
 365         struct btrfs_receive *r = user;
 366         char full_path[PATH_MAX];
 367
 368         ret = path_cat_out(full_path, r->full_subvol_path, path);
 369         if (ret < 0) {
 370                 error("mkfile: path invalid: %s", path);
 371                 goto out;
 372         }
 373
 374         if (g_verbose >= 2)
 375                 fprintf(stderr, "mkfile %s\n", path);
 376
 377         ret = creat(full_path, 0600);
 378         if (ret < 0) {
 379                 ret = -errno;
 380                 error("mkfile %s failed: %s", path, strerror(-ret));
 381                 goto out;
 382         }
 383         close(ret);
 384         ret = 0;
 385
 386 out:
 387         return ret;
 388 }
 389
 390 static int process_mkdir(const char *path, void *user)
 391 {
 392         int ret;
 393         struct btrfs_receive *r = user;
 394         char full_path[PATH_MAX];
 395
 396         ret = path_cat_out(full_path, r->full_subvol_path, path);
 397         if (ret < 0) {
 398                 error("mkdir: path invalid: %s", path);
 399                 goto out;
 400         }
 401
 402         if (g_verbose >= 2)
 403                 fprintf(stderr, "mkdir %s\n", path);
 404
 405         ret = mkdir(full_path, 0700);
 406         if (ret < 0) {
 407                 ret = -errno;
 408                 error("mkdir %s failed: %s", path, strerror(-ret));
 409         }
 410
 411 out:
 412         return ret;
 413 }
 414
 415 static int process_mknod(const char *path, u64 mode, u64 dev, void *user)
 416 {
 417         int ret;
 418         struct btrfs_receive *r = user;
 419         char full_path[PATH_MAX];
 420
 421         ret = path_cat_out(full_path, r->full_subvol_path, path);
 422         if (ret < 0) {
 423                 error("mknod: path invalid: %s", path);
 424                 goto out;
 425         }
 426
 427         if (g_verbose >= 2)
 428                 fprintf(stderr, "mknod %s mode=%llu, dev=%llu\n",
 429                                 path, mode, dev);
 430
 431         ret = mknod(full_path, mode & S_IFMT, dev);
 432         if (ret < 0) {
 433                 ret = -errno;
 434                 error("mknod %s failed: %s", path, strerror(-ret));
 435         }
 436
 437 out:
 438         return ret;
 439 }
 440
 441 static int process_mkfifo(const char *path, void *user)
 442 {
 443         int ret;
 444         struct btrfs_receive *r = user;
 445         char full_path[PATH_MAX];
 446
 447         ret = path_cat_out(full_path, r->full_subvol_path, path);
 448         if (ret < 0) {
 449                 error("mkfifo: path invalid: %s", path);
 450                 goto out;
 451         }
 452
 453         if (g_verbose >= 2)
 454                 fprintf(stderr, "mkfifo %s\n", path);
 455
 456         ret = mkfifo(full_path, 0600);
 457         if (ret < 0) {
 458                 ret = -errno;
 459                 error("mkfifo %s failed: %s", path, strerror(-ret));
 460         }
 461
 462 out:
 463         return ret;
 464 }
 465
 466 static int process_mksock(const char *path, void *user)
 467 {
 468         int ret;
 469         struct btrfs_receive *r = user;
 470         char full_path[PATH_MAX];
 471
 472         ret = path_cat_out(full_path, r->full_subvol_path, path);
 473         if (ret < 0) {
 474                 error("mksock: path invalid: %s", path);
 475                 goto out;
 476         }
 477
 478         if (g_verbose >= 2)
 479                 fprintf(stderr, "mksock %s\n", path);
 480
 481         ret = mknod(full_path, 0600 | S_IFSOCK, 0);
 482         if (ret < 0) {
 483                 ret = -errno;
 484                 error("mknod %s failed: %s", path, strerror(-ret));
 485         }
 486
 487 out:
 488         return ret;
 489 }
 490
 491 static int process_symlink(const char *path, const char *lnk, void *user)
 492 {
 493         int ret;
 494         struct btrfs_receive *r = user;
 495         char full_path[PATH_MAX];
 496
 497         ret = path_cat_out(full_path, r->full_subvol_path, path);
 498         if (ret < 0) {
 499                 error("symlink: path invalid: %s", path);
 500                 goto out;
 501         }
 502
 503         if (g_verbose >= 2)
 504                 fprintf(stderr, "symlink %s -> %s\n", path, lnk);
 505
 506         ret = symlink(lnk, full_path);
 507         if (ret < 0) {
 508                 ret = -errno;
 509                 error("symlink %s -> %s failed: %s", path,
 510                                 lnk, strerror(-ret));
 511         }
 512
 513 out:
 514         return ret;
 515 }
 516
 517 static int process_rename(const char *from, const char *to, void *user)
 518 {
 519         int ret;
 520         struct btrfs_receive *r = user;
 521         char full_from[PATH_MAX];
 522         char full_to[PATH_MAX];
 523
 524         ret = path_cat_out(full_from, r->full_subvol_path, from);
 525         if (ret < 0) {
 526                 error("rename: source path invalid: %s", from);
 527                 goto out;
 528         }
 529
 530         ret = path_cat_out(full_to, r->full_subvol_path, to);
 531         if (ret < 0) {
 532                 error("rename: target path invalid: %s", to);
 533                 goto out;
 534         }
 535
 536         if (g_verbose >= 2)
 537                 fprintf(stderr, "rename %s -> %s\n", from, to);
 538
 539         ret = rename(full_from, full_to);
 540         if (ret < 0) {
 541                 ret = -errno;
 542                 error("rename %s -> %s failed: %s", from,
 543                                 to, strerror(-ret));
 544         }
 545
 546 out:
 547         return ret;
 548 }
 549
 550 static int process_link(const char *path, const char *lnk, void *user)
 551 {
 552         int ret;
 553         struct btrfs_receive *r = user;
 554         char full_path[PATH_MAX];
 555         char full_link_path[PATH_MAX];
 556
 557         ret = path_cat_out(full_path, r->full_subvol_path, path);
 558         if (ret < 0) {
 559                 error("link: source path invalid: %s", full_path);
 560                 goto out;
 561         }
 562
 563         ret = path_cat_out(full_link_path, r->full_subvol_path, lnk);
 564         if (ret < 0) {
 565                 error("link: target path invalid: %s", full_link_path);
 566                 goto out;
 567         }
 568
 569         if (g_verbose >= 2)
 570                 fprintf(stderr, "link %s -> %s\n", path, lnk);
 571
 572         ret = link(full_link_path, full_path);
 573         if (ret < 0) {
 574                 ret = -errno;
 575                 error("link %s -> %s failed: %s", path, lnk, strerror(-ret));
 576         }
 577
 578 out:
 579         return ret;
 580 }
 581
 582
 583 static int process_unlink(const char *path, void *user)
 584 {
 585         int ret;
 586         struct btrfs_receive *r = user;
 587         char full_path[PATH_MAX];
 588
 589         ret = path_cat_out(full_path, r->full_subvol_path, path);
 590         if (ret < 0) {
 591                 error("unlink: path invalid: %s", path);
 592                 goto out;
 593         }
 594
 595         if (g_verbose >= 2)
 596                 fprintf(stderr, "unlink %s\n", path);
 597
 598         ret = unlink(full_path);
 599         if (ret < 0) {
 600                 ret = -errno;
 601                 error("unlink %s failed. %s", path, strerror(-ret));
 602         }
 603
 604 out:
 605         return ret;
 606 }
 607
 608 static int process_rmdir(const char *path, void *user)
 609 {
 610         int ret;
 611         struct btrfs_receive *r = user;
 612         char full_path[PATH_MAX];
 613
 614         ret = path_cat_out(full_path, r->full_subvol_path, path);
 615         if (ret < 0) {
 616                 error("rmdir: path invalid: %s", path);
 617                 goto out;
 618         }
 619
 620         if (g_verbose >= 2)
 621                 fprintf(stderr, "rmdir %s\n", path);
 622
 623         ret = rmdir(full_path);
 624         if (ret < 0) {
 625                 ret = -errno;
 626                 error("rmdir %s failed: %s", path, strerror(-ret));
 627         }
 628
 629 out:
 630         return ret;
 631 }
 632
 633 static int open_inode_for_write(struct btrfs_receive *r, const char *path)
 634 {
 635         int ret = 0;
 636
 637         if (r->write_fd != -1) {
 638                 if (strcmp(r->write_path, path) == 0)
 639                         goto out;
 640                 close(r->write_fd);
 641                 r->write_fd = -1;
 642         }
 643
 644         r->write_fd = open(path, O_RDWR);
 645         if (r->write_fd < 0) {
 646                 ret = -errno;
 647                 error("cannont open %s: %s", path, strerror(-ret));
 648                 goto out;
 649         }
 650         strncpy_null(r->write_path, path);
 651
 652 out:
 653         return ret;
 654 }
 655
 656 static void close_inode_for_write(struct btrfs_receive *r)
 657 {
 658         if(r->write_fd == -1)
 659                 return;
 660
 661         close(r->write_fd);
 662         r->write_fd = -1;
 663         r->write_path[0] = 0;
 664 }
 665
 666 static int process_write(const char *path, const void *data, u64 offset,
 667                          u64 len, void *user)
 668 {
 669         int ret = 0;
 670         struct btrfs_receive *r = user;
 671         char full_path[PATH_MAX];
 672         u64 pos = 0;
 673         int w;
 674
 675         ret = path_cat_out(full_path, r->full_subvol_path, path);
 676         if (ret < 0) {
 677                 error("write: path invalid: %s", path);
 678                 goto out;
 679         }
 680
 681         ret = open_inode_for_write(r, full_path);
 682         if (ret < 0)
 683                 goto out;
 684
 685         while (pos < len) {
 686                 w = pwrite(r->write_fd, (char*)data + pos, len - pos,
 687                                 offset + pos);
 688                 if (w < 0) {
 689                         ret = -errno;
 690                         error("writing to %s failed: %s\n",
 691                                         path, strerror(-ret));
 692                         goto out;
 693                 }
 694                 pos += w;
 695         }
 696
 697 out:
 698         return ret;
 699 }
 700
 701 static int process_clone(const char *path, u64 offset, u64 len,
 702                          const u8 *clone_uuid, u64 clone_ctransid,
 703                          const char *clone_path, u64 clone_offset,
 704                          void *user)
 705 {
 706         int ret;
 707         struct btrfs_receive *r = user;
 708         struct btrfs_ioctl_clone_range_args clone_args;
 709         struct subvol_info *si = NULL;
 710         char full_path[PATH_MAX];
 711         char *subvol_path = NULL;
 712         char full_clone_path[PATH_MAX];
 713         int clone_fd = -1;
 714
 715         ret = path_cat_out(full_path, r->full_subvol_path, path);
 716         if (ret < 0) {
 717                 error("clone: source path invalid: %s", path);
 718                 goto out;
 719         }
 720
 721         ret = open_inode_for_write(r, full_path);
 722         if (ret < 0)
 723                 goto out;
 724
 725         si = subvol_uuid_search(&r->sus, 0, clone_uuid, clone_ctransid, NULL,
 726                         subvol_search_by_received_uuid);
 727         if (!si) {
 728                 if (memcmp(clone_uuid, r->cur_subvol.received_uuid,
 729                                 BTRFS_UUID_SIZE) == 0) {
 730                         /* TODO check generation of extent */
 731                         subvol_path = strdup(r->cur_subvol_path);
 732                 } else {
 733                         ret = -ENOENT;
 734                         error("clone: did not find source subvol");
 735                         goto out;
 736                 }
 737         } else {
 738                 /*if (rs_args.ctransid > rs_args.rtransid) {
 739                         if (!r->force) {
 740                                 ret = -EINVAL;
 741                                 fprintf(stderr, "ERROR: subvolume %s was "
 742                                                 "modified after it was "
 743                                                 "received.\n",
 744                                                 r->subvol_parent_name);
 745                                 goto out;
 746                         } else {
 747                                 fprintf(stderr, "WARNING: subvolume %s was "
 748                                                 "modified after it was "
 749                                                 "received.\n",
 750                                                 r->subvol_parent_name);
 751                         }
 752                 }*/
 753                 subvol_path = strdup(si->path);
 754         }
 755
 756         ret = path_cat_out(full_clone_path, subvol_path, clone_path);
 757         if (ret < 0) {
 758                 error("clone: target path invalid: %s", clone_path);
 759                 goto out;
 760         }
 761
 762         clone_fd = openat(r->mnt_fd, full_clone_path, O_RDONLY | O_NOATIME);
 763         if (clone_fd < 0) {
 764                 ret = -errno;
 765                 error("cannot open %s: %s", full_clone_path, strerror(-ret));
 766                 goto out;
 767         }
 768
 769         clone_args.src_fd = clone_fd;
 770         clone_args.src_offset = clone_offset;
 771         clone_args.src_length = len;
 772         clone_args.dest_offset = offset;
 773         ret = ioctl(r->write_fd, BTRFS_IOC_CLONE_RANGE, &clone_args);
 774         if (ret < 0) {
 775                 ret = -errno;
 776                 error("failed to clone extents to %s\n%s\n",
 777                                 path, strerror(-ret));
 778                 goto out;
 779         }
 780
 781 out:
 782         if (si) {
 783                 free(si->path);
 784                 free(si);
 785         }
 786         free(subvol_path);
 787         if (clone_fd != -1)
 788                 close(clone_fd);
 789         return ret;
 790 }
 791
 792
 793 static int process_set_xattr(const char *path, const char *name,
 794                              const void *data, int len, void *user)
 795 {
 796         int ret = 0;
 797         struct btrfs_receive *r = user;
 798         char full_path[PATH_MAX];
 799
 800         ret = path_cat_out(full_path, r->full_subvol_path, path);
 801         if (ret < 0) {
 802                 error("set_xattr: path invalid: %s", path);
 803                 goto out;
 804         }
 805
 806         if (strcmp("security.capability", name) == 0) {
 807                 if (g_verbose >= 3)
 808                         fprintf(stderr, "set_xattr: cache capabilities\n");
 809                 if (r->cached_capabilities_len)
 810                         warning("capabilities set multiple times per file: %s",
 811                                 full_path);
 812                 if (len > sizeof(r->cached_capabilities)) {
 813                         error("capabilities encoded to %d bytes, buffer too small",
 814                                 len);
 815                         ret = -E2BIG;
 816                         goto out;
 817                 }
 818                 r->cached_capabilities_len = len;
 819                 memcpy(r->cached_capabilities, data, len);
 820         }
 821
 822         if (g_verbose >= 2) {
 823                 fprintf(stderr, "set_xattr %s - name=%s data_len=%d "
 824                                 "data=%.*s\n", path, name, len,
 825                                 len, (char*)data);
 826         }
 827
 828         ret = lsetxattr(full_path, name, data, len, 0);
 829         if (ret < 0) {
 830                 ret = -errno;
 831                 error("lsetxattr %s %s=%.*s failed: %s",
 832                                 path, name, len, (char*)data, strerror(-ret));
 833                 goto out;
 834         }
 835
 836 out:
 837         return ret;
 838 }
 839
 840 static int process_remove_xattr(const char *path, const char *name, void *user)
 841 {
 842         int ret = 0;
 843         struct btrfs_receive *r = user;
 844         char full_path[PATH_MAX];
 845
 846         ret = path_cat_out(full_path, r->full_subvol_path, path);
 847         if (ret < 0) {
 848                 error("remove_xattr: path invalid: %s", path);
 849                 goto out;
 850         }
 851
 852         if (g_verbose >= 2) {
 853                 fprintf(stderr, "remove_xattr %s - name=%s\n",
 854                                 path, name);
 855         }
 856
 857         ret = lremovexattr(full_path, name);
 858         if (ret < 0) {
 859                 ret = -errno;
 860                 error("lremovexattr %s %s failed: %s",
 861                                 path, name, strerror(-ret));
 862                 goto out;
 863         }
 864
 865 out:
 866         return ret;
 867 }
 868
 869 static int process_truncate(const char *path, u64 size, void *user)
 870 {
 871         int ret = 0;
 872         struct btrfs_receive *r = user;
 873         char full_path[PATH_MAX];
 874
 875         ret = path_cat_out(full_path, r->full_subvol_path, path);
 876         if (ret < 0) {
 877                 error("truncate: path invalid: %s", path);
 878                 goto out;
 879         }
 880
 881         if (g_verbose >= 2)
 882                 fprintf(stderr, "truncate %s size=%llu\n", path, size);
 883
 884         ret = truncate(full_path, size);
 885         if (ret < 0) {
 886                 ret = -errno;
 887                 error("truncate %s failed: %s", path, strerror(-ret));
 888                 goto out;
 889         }
 890
 891 out:
 892         return ret;
 893 }
 894
 895 static int process_chmod(const char *path, u64 mode, void *user)
 896 {
 897         int ret = 0;
 898         struct btrfs_receive *r = user;
 899         char full_path[PATH_MAX];
 900
 901         ret = path_cat_out(full_path, r->full_subvol_path, path);
 902         if (ret < 0) {
 903                 error("chmod: path invalid: %s", path);
 904                 goto out;
 905         }
 906
 907         if (g_verbose >= 2)
 908                 fprintf(stderr, "chmod %s - mode=0%o\n", path, (int)mode);
 909
 910         ret = chmod(full_path, mode);
 911         if (ret < 0) {
 912                 ret = -errno;
 913                 error("chmod %s failed: %s", path, strerror(-ret));
 914                 goto out;
 915         }
 916
 917 out:
 918         return ret;
 919 }
 920
 921 static int process_chown(const char *path, u64 uid, u64 gid, void *user)
 922 {
 923         int ret = 0;
 924         struct btrfs_receive *r = user;
 925         char full_path[PATH_MAX];
 926
 927         ret = path_cat_out(full_path, r->full_subvol_path, path);
 928         if (ret < 0) {
 929                 error("chown: path invalid: %s", path);
 930                 goto out;
 931         }
 932
 933         if (g_verbose >= 2)
 934                 fprintf(stderr, "chown %s - uid=%llu, gid=%llu\n", path,
 935                                 uid, gid);
 936
 937         ret = lchown(full_path, uid, gid);
 938         if (ret < 0) {
 939                 ret = -errno;
 940                 error("chown %s failed: %s", path, strerror(-ret));
 941                 goto out;
 942         }
 943
 944         if (r->cached_capabilities_len) {
 945                 if (g_verbose >= 2)
 946                         fprintf(stderr, "chown: restore capabilities\n");
 947                 ret = lsetxattr(full_path, "security.capability",
 948                                 r->cached_capabilities,
 949                                 r->cached_capabilities_len, 0);
 950                 memset(r->cached_capabilities, 0,
 951                                 sizeof(r->cached_capabilities));
 952                 r->cached_capabilities_len = 0;
 953                 if (ret < 0) {
 954                         ret = -errno;
 955                         error("restoring capabilities %s: %s",
 956                                         path, strerror(-ret));
 957                         goto out;
 958                 }
 959         }
 960
 961 out:
 962         return ret;
 963 }
 964
 965 static int process_utimes(const char *path, struct timespec *at,
 966                           struct timespec *mt, struct timespec *ct,
 967                           void *user)
 968 {
 969         int ret = 0;
 970         struct btrfs_receive *r = user;
 971         char full_path[PATH_MAX];
 972         struct timespec tv[2];
 973
 974         ret = path_cat_out(full_path, r->full_subvol_path, path);
 975         if (ret < 0) {
 976                 error("utimes: path invalid: %s", path);
 977                 goto out;
 978         }
 979
 980         if (g_verbose >= 2)
 981                 fprintf(stderr, "utimes %s\n", path);
 982
 983         tv[0] = *at;
 984         tv[1] = *mt;
 985         ret = utimensat(AT_FDCWD, full_path, tv, AT_SYMLINK_NOFOLLOW);
 986         if (ret < 0) {
 987                 ret = -errno;
 988                 error("utimes %s failed: %s",
 989                                 path, strerror(-ret));
 990                 goto out;
 991         }
 992
 993 out:
 994         return ret;
 995 }
 996
 997 static int process_update_extent(const char *path, u64 offset, u64 len,
 998                 void *user)
 999 {
1000         if (g_verbose >= 2)
1001                 fprintf(stderr, "update_extent %s: offset=%llu, len=%llu\n",
1002                                 path, (unsigned long long)offset,
1003                                 (unsigned long long)len);
1004
1005         /*
1006          * Sent with BTRFS_SEND_FLAG_NO_FILE_DATA, nothing to do.
1007          */
1008
1009         return 0;
1010 }
1011
1012 static struct btrfs_send_ops send_ops = {
1013         .subvol = process_subvol,
1014         .snapshot = process_snapshot,
1015         .mkfile = process_mkfile,
1016         .mkdir = process_mkdir,
1017         .mknod = process_mknod,
1018         .mkfifo = process_mkfifo,
1019         .mksock = process_mksock,
1020         .symlink = process_symlink,
1021         .rename = process_rename,
1022         .link = process_link,
1023         .unlink = process_unlink,
1024         .rmdir = process_rmdir,
1025         .write = process_write,
1026         .clone = process_clone,
1027         .set_xattr = process_set_xattr,
1028         .remove_xattr = process_remove_xattr,
1029         .truncate = process_truncate,
1030         .chmod = process_chmod,
1031         .chown = process_chown,
1032         .utimes = process_utimes,
1033         .update_extent = process_update_extent,
1034 };
1035
1036 static int do_receive(struct btrfs_receive *r, const char *tomnt,
1037                       char *realmnt, int r_fd, u64 max_errors)
1038 {
1039         u64 subvol_id;
1040         int ret;
1041         char *dest_dir_full_path;
1042         char root_subvol_path[PATH_MAX];
1043         int end = 0;
1044
1045         dest_dir_full_path = realpath(tomnt, NULL);
1046         if (!dest_dir_full_path) {
1047                 ret = -errno;
1048                 error("realpath(%s) failed: %s", tomnt, strerror(-ret));
1049                 goto out;
1050         }
1051         r->dest_dir_fd = open(dest_dir_full_path, O_RDONLY | O_NOATIME);
1052         if (r->dest_dir_fd < 0) {
1053                 ret = -errno;
1054                 error("cannot open destination directory %s: %s",
1055                         dest_dir_full_path, strerror(-ret));
1056                 goto out;
1057         }
1058
1059         if (realmnt[0]) {
1060                 r->root_path = realmnt;
1061         } else {
1062                 ret = find_mount_root(dest_dir_full_path, &r->root_path);
1063                 if (ret < 0) {
1064                         error("failed to determine mount point for %s: %s",
1065                                 dest_dir_full_path, strerror(-ret));
1066                         ret = -EINVAL;
1067                         goto out;
1068                 }
1069                 if (ret > 0) {
1070                         error("%s doesn't belong to btrfs mount point",
1071                                 dest_dir_full_path);
1072                         ret = -EINVAL;
1073                         goto out;
1074                 }
1075         }
1076         r->mnt_fd = open(r->root_path, O_RDONLY | O_NOATIME);
1077         if (r->mnt_fd < 0) {
1078                 ret = -errno;
1079                 error("cannot open %s: %s", r->root_path, strerror(-ret));
1080                 goto out;
1081         }
1082
1083         /*
1084          * If we use -m or a default subvol we want to resolve the path to the
1085          * subvolume we're sitting in so that we can adjust the paths of any
1086          * subvols we want to receive in.
1087          */
1088         ret = btrfs_list_get_path_rootid(r->mnt_fd, &subvol_id);
1089         if (ret) {
1090                 error("cannot resolve our subvolid: %d",
1091                         ret);
1092                 goto out;
1093         }
1094
1095         root_subvol_path[0] = 0;
1096         ret = btrfs_subvolid_resolve(r->mnt_fd, root_subvol_path,
1097                                      PATH_MAX, subvol_id);
1098         if (ret) {
1099                 error("cannot resolve our subvol path");
1100                 goto out;
1101         }
1102
1103         /*
1104          * Ok we're inside of a subvol off of the root subvol, we need to
1105          * actually set full_root_path.
1106          */
1107         if (*root_subvol_path)
1108                 r->full_root_path = root_subvol_path;
1109
1110         if (r->dest_dir_chroot) {
1111                 if (chroot(dest_dir_full_path)) {
1112                         ret = -errno;
1113                         error("failed to chroot to %s: %s",
1114                                 dest_dir_full_path, strerror(-ret));
1115                         goto out;
1116                 }
1117                 if (chdir("/")) {
1118                         ret = -errno;
1119                         error("failed to chdir to / after chroot: %s",
1120                                 strerror(-ret));
1121                         goto out;
1122                 }
1123                 fprintf(stderr, "Chroot to %s\n", dest_dir_full_path);
1124                 r->root_path = strdup("/");
1125                 r->dest_dir_path = r->root_path;
1126         } else {
1127                 /*
1128                  * find_mount_root returns a root_path that is a subpath of
1129                  * dest_dir_full_path. Now get the other part of root_path,
1130                  * which is the destination dir relative to root_path.
1131                  */
1132                 r->dest_dir_path = dest_dir_full_path + strlen(r->root_path);
1133                 while (r->dest_dir_path[0] == '/')
1134                         r->dest_dir_path++;
1135         }
1136
1137         ret = subvol_uuid_search_init(r->mnt_fd, &r->sus);
1138         if (ret < 0)
1139                 goto out;
1140
1141         while (!end) {
1142                 if (r->cached_capabilities_len) {
1143                         if (g_verbose >= 3)
1144                                 fprintf(stderr, "clear cached capabilities\n");
1145                         memset(r->cached_capabilities, 0,
1146                                         sizeof(r->cached_capabilities));
1147                         r->cached_capabilities_len = 0;
1148                 }
1149
1150                 ret = btrfs_read_and_process_send_stream(r_fd, &send_ops, r,
1151                                                          r->honor_end_cmd,
1152                                                          max_errors);
1153                 if (ret < 0)
1154                         goto out;
1155                 if (ret)
1156                         end = 1;
1157
1158                 close_inode_for_write(r);
1159                 ret = finish_subvol(r);
1160                 if (ret < 0)
1161                         goto out;
1162         }
1163         ret = 0;
1164
1165 out:
1166         if (r->write_fd != -1) {
1167                 close(r->write_fd);
1168                 r->write_fd = -1;
1169         }
1170
1171         if (r->root_path != realmnt)
1172                 free(r->root_path);
1173         r->root_path = NULL;
1174         r->dest_dir_path = NULL;
1175         free(dest_dir_full_path);
1176         subvol_uuid_search_finit(&r->sus);
1177         if (r->mnt_fd != -1) {
1178                 close(r->mnt_fd);
1179                 r->mnt_fd = -1;
1180         }
1181         if (r->dest_dir_fd != -1) {
1182                 close(r->dest_dir_fd);
1183                 r->dest_dir_fd = -1;
1184         }
1185
1186         return ret;
1187 }
1188
1189 int cmd_receive(int argc, char **argv)
1190 {
1191         char *tomnt = NULL;
1192         char fromfile[PATH_MAX];
1193         char realmnt[PATH_MAX];
1194         struct btrfs_receive r;
1195         int receive_fd = fileno(stdin);
1196         u64 max_errors = 1;
1197         int ret = 0;
1198
1199         memset(&r, 0, sizeof(r));
1200         r.mnt_fd = -1;
1201         r.write_fd = -1;
1202         r.dest_dir_fd = -1;
1203         r.dest_dir_chroot = 0;
1204         realmnt[0] = 0;
1205         fromfile[0] = 0;
1206
1207         while (1) {
1208                 int c;
1209                 static const struct option long_opts[] = {
1210                         { "max-errors", required_argument, NULL, 'E' },
1211                         { "chroot", no_argument, NULL, 'C' },
1212                         { NULL, 0, NULL, 0 }
1213                 };
1214
1215                 c = getopt_long(argc, argv, "Cevf:m:", long_opts, NULL);
1216                 if (c < 0)
1217                         break;
1218
1219                 switch (c) {
1220                 case 'v':
1221                         g_verbose++;
1222                         break;
1223                 case 'f':
1224                         if (arg_copy_path(fromfile, optarg, sizeof(fromfile))) {
1225                                 error("input file path too long (%zu)",
1226                                         strlen(optarg));
1227                                 ret = 1;
1228                                 goto out;
1229                         }
1230                         break;
1231                 case 'e':
1232                         r.honor_end_cmd = 1;
1233                         break;
1234                 case 'C':
1235                         r.dest_dir_chroot = 1;
1236                         break;
1237                 case 'E':
1238                         max_errors = arg_strtou64(optarg);
1239                         break;
1240                 case 'm':
1241                         if (arg_copy_path(realmnt, optarg, sizeof(realmnt))) {
1242                                 error("mount point path too long (%zu)",
1243                                         strlen(optarg));
1244                                 ret = 1;
1245                                 goto out;
1246                         }
1247                         break;
1248                 case '?':
1249                 default:
1250                         error("receive args invalid");
1251                         return 1;
1252                 }
1253         }
1254
1255         if (check_argc_exact(argc - optind, 1))
1256                 usage(cmd_receive_usage);
1257
1258         tomnt = argv[optind];
1259
1260         if (fromfile[0]) {
1261                 receive_fd = open(fromfile, O_RDONLY | O_NOATIME);
1262                 if (receive_fd < 0) {
1263                         error("cannot open %s: %s", fromfile, strerror(errno));
1264                         goto out;
1265                 }
1266         }
1267
1268         ret = do_receive(&r, tomnt, realmnt, receive_fd, max_errors);
1269         if (receive_fd != fileno(stdin))
1270                 close(receive_fd);
1271
1272 out:
1273
1274         return !!ret;
1275 }
1276
1277 const char * const cmd_receive_usage[] = {
1278         "btrfs receive [-ve] [-f <infile>] [--max-errors <N>] <mount>",
1279         "Receive subvolumes from stdin.",
1280         "Receives one or more subvolumes that were previously",
1281         "sent with btrfs send. The received subvolumes are stored",
1282         "into <mount>.",
1283         "btrfs receive will fail in case a receiving subvolume",
1284         "already exists. It will also fail in case a previously",
1285         "received subvolume was changed after it was received.",
1286         "After receiving a subvolume, it is immediately set to",
1287         "read only.\n",
1288         "-v               Enable verbose debug output. Each",
1289         "                 occurrence of this option increases the",
1290         "                 verbose level more.",
1291         "-f <infile>      By default, btrfs receive uses stdin",
1292         "                 to receive the subvolumes. Use this",
1293         "                 option to specify a file to use instead.",
1294         "-e               Terminate after receiving an <end cmd>",
1295         "                 in the data stream. Without this option,",
1296         "                 the receiver terminates only if an error",
1297         "                 is recognized or on EOF.",
1298         "-C|--chroot      confine the process to <mount> using chroot",
1299         "--max-errors <N> Terminate as soon as N errors happened while",
1300         "                 processing commands from the send stream.",
1301         "                 Default value is 1. A value of 0 means no limit.",
1302         "-m <mountpoint>  The root mount point of the destination fs.",
1303         "                 If you do not have /proc use this to tell us where ",
1304         "                 this file system is mounted.",
1305         NULL
1306 };