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                 fprintf(stderr, "ERROR: open %s failed. %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                 fprintf(stderr, "ERROR: BTRFS_IOC_SET_RECEIVED_SUBVOL failed. %s\n",
 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                 fprintf(stderr, "ERROR: BTRFS_IOC_SUBVOL_GETFLAGS failed. %s\n",
 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                 fprintf(stderr, "ERROR: failed to make subvolume read only. "
 142                                 "%s\n", 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                         fprintf(stderr, "ERROR: subvol: path invalid: %s\n",
 178                                         path);
 179                         goto out;
 180                 }
 181         }
 182         ret = path_cat3_out(r->full_subvol_path, r->root_path,
 183                         r->dest_dir_path, path);
 184         if (ret < 0) {
 185                 fprintf(stderr, "ERROR: subvol: path invalid: %s\n", path);
 186                 goto out;
 187         }
 188
 189         fprintf(stderr, "At subvol %s\n", path);
 190
 191         memcpy(r->cur_subvol.received_uuid, uuid, BTRFS_UUID_SIZE);
 192         r->cur_subvol.stransid = ctransid;
 193
 194         if (g_verbose) {
 195                 uuid_unparse((u8*)r->cur_subvol.received_uuid, uuid_str);
 196                 fprintf(stderr, "receiving subvol %s uuid=%s, stransid=%llu\n",
 197                                 path, uuid_str,
 198                                 r->cur_subvol.stransid);
 199         }
 200
 201         memset(&args_v1, 0, sizeof(args_v1));
 202         strncpy_null(args_v1.name, path);
 203         ret = ioctl(r->dest_dir_fd, BTRFS_IOC_SUBVOL_CREATE, &args_v1);
 204         if (ret < 0) {
 205                 ret = -errno;
 206                 fprintf(stderr, "ERROR: creating subvolume %s failed. "
 207                                 "%s\n", path, strerror(-ret));
 208                 goto out;
 209         }
 210
 211 out:
 212         return ret;
 213 }
 214
 215 static int process_snapshot(const char *path, const u8 *uuid, u64 ctransid,
 216                             const u8 *parent_uuid, u64 parent_ctransid,
 217                             void *user)
 218 {
 219         int ret;
 220         struct btrfs_receive *r = user;
 221         char uuid_str[BTRFS_UUID_UNPARSED_SIZE];
 222         struct btrfs_ioctl_vol_args_v2 args_v2;
 223         struct subvol_info *parent_subvol = NULL;
 224
 225         ret = finish_subvol(r);
 226         if (ret < 0)
 227                 goto out;
 228
 229         BUG_ON(r->cur_subvol.path);
 230         BUG_ON(r->cur_subvol_path[0]);
 231
 232         if (*r->dest_dir_path == 0) {
 233                 strncpy_null(r->cur_subvol_path, path);
 234         } else {
 235                 ret = path_cat_out(r->cur_subvol_path, r->dest_dir_path, path);
 236                 if (ret < 0) {
 237                         fprintf(stderr, "ERROR: snapshot: path invalid: %s\n",
 238                                         path);
 239                         goto out;
 240                 }
 241         }
 242         ret = path_cat3_out(r->full_subvol_path, r->root_path,
 243                         r->dest_dir_path, path);
 244         if (ret < 0) {
 245                 fprintf(stderr, "ERROR: snapshot: path invalid: %s\n", path);
 246                 goto out;
 247         }
 248
 249         fprintf(stdout, "At snapshot %s\n", path);
 250
 251         memcpy(r->cur_subvol.received_uuid, uuid, BTRFS_UUID_SIZE);
 252         r->cur_subvol.stransid = ctransid;
 253
 254         if (g_verbose) {
 255                 uuid_unparse((u8*)r->cur_subvol.received_uuid, uuid_str);
 256                 fprintf(stderr, "receiving snapshot %s uuid=%s, "
 257                                 "ctransid=%llu ", path, uuid_str,
 258                                 r->cur_subvol.stransid);
 259                 uuid_unparse(parent_uuid, uuid_str);
 260                 fprintf(stderr, "parent_uuid=%s, parent_ctransid=%llu\n",
 261                                 uuid_str, parent_ctransid);
 262         }
 263
 264         memset(&args_v2, 0, sizeof(args_v2));
 265         strncpy_null(args_v2.name, path);
 266
 267         parent_subvol = subvol_uuid_search(&r->sus, 0, parent_uuid,
 268                         parent_ctransid, NULL, subvol_search_by_received_uuid);
 269         if (!parent_subvol) {
 270                 parent_subvol = subvol_uuid_search(&r->sus, 0, parent_uuid,
 271                                 parent_ctransid, NULL, subvol_search_by_uuid);
 272         }
 273         if (!parent_subvol) {
 274                 ret = -ENOENT;
 275                 fprintf(stderr, "ERROR: could not find parent subvolume\n");
 276                 goto out;
 277         }
 278
 279         /*
 280          * The path is resolved from the root subvol, but we could be in some
 281          * subvolume under the root subvolume, so try and adjust the path to be
 282          * relative to our root path.
 283          */
 284         if (r->full_root_path) {
 285                 size_t root_len;
 286                 size_t sub_len;
 287
 288                 root_len = strlen(r->full_root_path);
 289                 sub_len = strlen(parent_subvol->path);
 290
 291                 /* First make sure the parent subvol is actually in our path */
 292                 if (sub_len < root_len ||
 293                     strstr(parent_subvol->path, r->full_root_path) == NULL) {
 294                         fprintf(stderr, "ERROR: parent subvol is not reachable"
 295                                 " from inside the root subvol.\n");
 296                         ret = -ENOENT;
 297                         goto out;
 298                 }
 299
 300                 if (sub_len == root_len) {
 301                         parent_subvol->path[0] = '/';
 302                         parent_subvol->path[1] = '\0';
 303                 } else {
 304                         /*
 305                          * root path is foo/bar
 306                          * subvol path is foo/bar/baz
 307                          *
 308                          * we need to have baz be the path, so we need to move
 309                          * the bit after foo/bar/, so path + root_len + 1, and
 310                          * move the part we care about, so sub_len - root_len -
 311                          * 1.
 312                          */
 313                         memmove(parent_subvol->path,
 314                                 parent_subvol->path + root_len + 1,
 315                                 sub_len - root_len - 1);
 316                         parent_subvol->path[sub_len - root_len - 1] = '\0';
 317                 }
 318         }
 319         /*if (rs_args.ctransid > rs_args.rtransid) {
 320                 if (!r->force) {
 321                         ret = -EINVAL;
 322                         fprintf(stderr, "ERROR: subvolume %s was modified after it was received.\n", r->subvol_parent_name);
 323                         goto out;
 324                 } else {
 325                         fprintf(stderr, "WARNING: subvolume %s was modified after it was received.\n", r->subvol_parent_name);
 326                 }
 327         }*/
 328
 329         if (*parent_subvol->path == 0)
 330                 args_v2.fd = dup(r->mnt_fd);
 331         else
 332                 args_v2.fd = openat(r->mnt_fd, parent_subvol->path,
 333                                 O_RDONLY | O_NOATIME);
 334         if (args_v2.fd < 0) {
 335                 ret = -errno;
 336                 if (errno != ENOENT)
 337                         fprintf(stderr, "ERROR: open %s failed. %s\n",
 338                                         parent_subvol->path, strerror(-ret));
 339                 else
 340                         fprintf(stderr,
 341                                 "It seems that you have changed your default "
 342                                 "subvolume or you specify other subvolume to\n"
 343                                 "mount btrfs, try to remount this btrfs filesystem "
 344                                 "with fs tree, and run btrfs receive again!\n");
 345                 goto out;
 346         }
 347
 348         ret = ioctl(r->dest_dir_fd, BTRFS_IOC_SNAP_CREATE_V2, &args_v2);
 349         close(args_v2.fd);
 350         if (ret < 0) {
 351                 ret = -errno;
 352                 fprintf(stderr, "ERROR: creating snapshot %s -> %s "
 353                                 "failed. %s\n", parent_subvol->path,
 354                                 path, strerror(-ret));
 355                 goto out;
 356         }
 357
 358 out:
 359         if (parent_subvol) {
 360                 free(parent_subvol->path);
 361                 free(parent_subvol);
 362         }
 363         return ret;
 364 }
 365
 366 static int process_mkfile(const char *path, void *user)
 367 {
 368         int ret;
 369         struct btrfs_receive *r = user;
 370         char full_path[PATH_MAX];
 371
 372         ret = path_cat_out(full_path, r->full_subvol_path, path);
 373         if (ret < 0) {
 374                 fprintf(stderr, "ERROR: mkfile: path invalid: %s\n", path);
 375                 goto out;
 376         }
 377
 378         if (g_verbose >= 2)
 379                 fprintf(stderr, "mkfile %s\n", path);
 380
 381         ret = creat(full_path, 0600);
 382         if (ret < 0) {
 383                 ret = -errno;
 384                 fprintf(stderr, "ERROR: mkfile %s failed. %s\n", path,
 385                                 strerror(-ret));
 386                 goto out;
 387         }
 388         close(ret);
 389         ret = 0;
 390
 391 out:
 392         return ret;
 393 }
 394
 395 static int process_mkdir(const char *path, void *user)
 396 {
 397         int ret;
 398         struct btrfs_receive *r = user;
 399         char full_path[PATH_MAX];
 400
 401         ret = path_cat_out(full_path, r->full_subvol_path, path);
 402         if (ret < 0) {
 403                 fprintf(stderr, "ERROR: mkdir: path invalid: %s\n", path);
 404                 goto out;
 405         }
 406
 407         if (g_verbose >= 2)
 408                 fprintf(stderr, "mkdir %s\n", path);
 409
 410         ret = mkdir(full_path, 0700);
 411         if (ret < 0) {
 412                 ret = -errno;
 413                 fprintf(stderr, "ERROR: mkdir %s failed. %s\n", path,
 414                                 strerror(-ret));
 415         }
 416
 417 out:
 418         return ret;
 419 }
 420
 421 static int process_mknod(const char *path, u64 mode, u64 dev, void *user)
 422 {
 423         int ret;
 424         struct btrfs_receive *r = user;
 425         char full_path[PATH_MAX];
 426
 427         ret = path_cat_out(full_path, r->full_subvol_path, path);
 428         if (ret < 0) {
 429                 fprintf(stderr, "ERROR: mknod: path invalid: %s\n", path);
 430                 goto out;
 431         }
 432
 433         if (g_verbose >= 2)
 434                 fprintf(stderr, "mknod %s mode=%llu, dev=%llu\n",
 435                                 path, mode, dev);
 436
 437         ret = mknod(full_path, mode & S_IFMT, dev);
 438         if (ret < 0) {
 439                 ret = -errno;
 440                 fprintf(stderr, "ERROR: mknod %s failed. %s\n", path,
 441                                 strerror(-ret));
 442         }
 443
 444 out:
 445         return ret;
 446 }
 447
 448 static int process_mkfifo(const char *path, void *user)
 449 {
 450         int ret;
 451         struct btrfs_receive *r = user;
 452         char full_path[PATH_MAX];
 453
 454         ret = path_cat_out(full_path, r->full_subvol_path, path);
 455         if (ret < 0) {
 456                 fprintf(stderr, "ERROR: mkfifo: path invalid: %s\n", path);
 457                 goto out;
 458         }
 459
 460         if (g_verbose >= 2)
 461                 fprintf(stderr, "mkfifo %s\n", path);
 462
 463         ret = mkfifo(full_path, 0600);
 464         if (ret < 0) {
 465                 ret = -errno;
 466                 fprintf(stderr, "ERROR: mkfifo %s failed. %s\n", path,
 467                                 strerror(-ret));
 468         }
 469
 470 out:
 471         return ret;
 472 }
 473
 474 static int process_mksock(const char *path, void *user)
 475 {
 476         int ret;
 477         struct btrfs_receive *r = user;
 478         char full_path[PATH_MAX];
 479
 480         ret = path_cat_out(full_path, r->full_subvol_path, path);
 481         if (ret < 0) {
 482                 fprintf(stderr, "ERROR: mksock: path invalid: %s\n", path);
 483                 goto out;
 484         }
 485
 486         if (g_verbose >= 2)
 487                 fprintf(stderr, "mksock %s\n", path);
 488
 489         ret = mknod(full_path, 0600 | S_IFSOCK, 0);
 490         if (ret < 0) {
 491                 ret = -errno;
 492                 fprintf(stderr, "ERROR: mknod %s failed. %s\n", path,
 493                                 strerror(-ret));
 494         }
 495
 496 out:
 497         return ret;
 498 }
 499
 500 static int process_symlink(const char *path, const char *lnk, void *user)
 501 {
 502         int ret;
 503         struct btrfs_receive *r = user;
 504         char full_path[PATH_MAX];
 505
 506         ret = path_cat_out(full_path, r->full_subvol_path, path);
 507         if (ret < 0) {
 508                 fprintf(stderr, "ERROR: symlink: path invalid: %s\n", path);
 509                 goto out;
 510         }
 511
 512         if (g_verbose >= 2)
 513                 fprintf(stderr, "symlink %s -> %s\n", path, lnk);
 514
 515         ret = symlink(lnk, full_path);
 516         if (ret < 0) {
 517                 ret = -errno;
 518                 fprintf(stderr, "ERROR: symlink %s -> %s failed. %s\n", path,
 519                                 lnk, strerror(-ret));
 520         }
 521
 522 out:
 523         return ret;
 524 }
 525
 526 static int process_rename(const char *from, const char *to, void *user)
 527 {
 528         int ret;
 529         struct btrfs_receive *r = user;
 530         char full_from[PATH_MAX];
 531         char full_to[PATH_MAX];
 532
 533         ret = path_cat_out(full_from, r->full_subvol_path, from);
 534         if (ret < 0) {
 535                 fprintf(stderr, "ERROR: rename: source path invalid: %s\n",
 536                                 from);
 537                 goto out;
 538         }
 539
 540         ret = path_cat_out(full_to, r->full_subvol_path, to);
 541         if (ret < 0) {
 542                 fprintf(stderr, "ERROR: rename: target path invalid: %s\n",
 543                                 to);
 544                 goto out;
 545         }
 546
 547         if (g_verbose >= 2)
 548                 fprintf(stderr, "rename %s -> %s\n", from, to);
 549
 550         ret = rename(full_from, full_to);
 551         if (ret < 0) {
 552                 ret = -errno;
 553                 fprintf(stderr, "ERROR: rename %s -> %s failed. %s\n", from,
 554                                 to, strerror(-ret));
 555         }
 556
 557 out:
 558         return ret;
 559 }
 560
 561 static int process_link(const char *path, const char *lnk, void *user)
 562 {
 563         int ret;
 564         struct btrfs_receive *r = user;
 565         char full_path[PATH_MAX];
 566         char full_link_path[PATH_MAX];
 567
 568         ret = path_cat_out(full_path, r->full_subvol_path, path);
 569         if (ret < 0) {
 570                 fprintf(stderr, "ERROR: link: source path invalid: %s\n",
 571                                 full_path);
 572                 goto out;
 573         }
 574
 575         ret = path_cat_out(full_link_path, r->full_subvol_path, lnk);
 576         if (ret < 0) {
 577                 fprintf(stderr, "ERROR: link: target path invalid: %s\n",
 578                                 full_link_path);
 579                 goto out;
 580         }
 581
 582         if (g_verbose >= 2)
 583                 fprintf(stderr, "link %s -> %s\n", path, lnk);
 584
 585         ret = link(full_link_path, full_path);
 586         if (ret < 0) {
 587                 ret = -errno;
 588                 fprintf(stderr, "ERROR: link %s -> %s failed. %s\n", path,
 589                                 lnk, strerror(-ret));
 590         }
 591
 592 out:
 593         return ret;
 594 }
 595
 596
 597 static int process_unlink(const char *path, void *user)
 598 {
 599         int ret;
 600         struct btrfs_receive *r = user;
 601         char full_path[PATH_MAX];
 602
 603         ret = path_cat_out(full_path, r->full_subvol_path, path);
 604         if (ret < 0) {
 605                 fprintf(stderr, "ERROR: unlink: path invalid: %s\n", path);
 606                 goto out;
 607         }
 608
 609         if (g_verbose >= 2)
 610                 fprintf(stderr, "unlink %s\n", path);
 611
 612         ret = unlink(full_path);
 613         if (ret < 0) {
 614                 ret = -errno;
 615                 fprintf(stderr, "ERROR: unlink %s failed. %s\n", path,
 616                                 strerror(-ret));
 617         }
 618
 619 out:
 620         return ret;
 621 }
 622
 623 static int process_rmdir(const char *path, void *user)
 624 {
 625         int ret;
 626         struct btrfs_receive *r = user;
 627         char full_path[PATH_MAX];
 628
 629         ret = path_cat_out(full_path, r->full_subvol_path, path);
 630         if (ret < 0) {
 631                 fprintf(stderr, "ERROR: rmdir: path invalid: %s\n", path);
 632                 goto out;
 633         }
 634
 635         if (g_verbose >= 2)
 636                 fprintf(stderr, "rmdir %s\n", path);
 637
 638         ret = rmdir(full_path);
 639         if (ret < 0) {
 640                 ret = -errno;
 641                 fprintf(stderr, "ERROR: rmdir %s failed. %s\n", path,
 642                                 strerror(-ret));
 643         }
 644
 645 out:
 646         return ret;
 647 }
 648
 649 static int open_inode_for_write(struct btrfs_receive *r, const char *path)
 650 {
 651         int ret = 0;
 652
 653         if (r->write_fd != -1) {
 654                 if (strcmp(r->write_path, path) == 0)
 655                         goto out;
 656                 close(r->write_fd);
 657                 r->write_fd = -1;
 658         }
 659
 660         r->write_fd = open(path, O_RDWR);
 661         if (r->write_fd < 0) {
 662                 ret = -errno;
 663                 fprintf(stderr, "ERROR: open %s failed. %s\n", path,
 664                                 strerror(-ret));
 665                 goto out;
 666         }
 667         strncpy_null(r->write_path, path);
 668
 669 out:
 670         return ret;
 671 }
 672
 673 static void close_inode_for_write(struct btrfs_receive *r)
 674 {
 675         if(r->write_fd == -1)
 676                 return;
 677
 678         close(r->write_fd);
 679         r->write_fd = -1;
 680         r->write_path[0] = 0;
 681 }
 682
 683 static int process_write(const char *path, const void *data, u64 offset,
 684                          u64 len, void *user)
 685 {
 686         int ret = 0;
 687         struct btrfs_receive *r = user;
 688         char full_path[PATH_MAX];
 689         u64 pos = 0;
 690         int w;
 691
 692         ret = path_cat_out(full_path, r->full_subvol_path, path);
 693         if (ret < 0) {
 694                 fprintf(stderr, "ERROR: write: path invalid: %s\n", path);
 695                 goto out;
 696         }
 697
 698         ret = open_inode_for_write(r, full_path);
 699         if (ret < 0)
 700                 goto out;
 701
 702         while (pos < len) {
 703                 w = pwrite(r->write_fd, (char*)data + pos, len - pos,
 704                                 offset + pos);
 705                 if (w < 0) {
 706                         ret = -errno;
 707                         fprintf(stderr, "ERROR: writing to %s failed. %s\n",
 708                                         path, strerror(-ret));
 709                         goto out;
 710                 }
 711                 pos += w;
 712         }
 713
 714 out:
 715         return ret;
 716 }
 717
 718 static int process_clone(const char *path, u64 offset, u64 len,
 719                          const u8 *clone_uuid, u64 clone_ctransid,
 720                          const char *clone_path, u64 clone_offset,
 721                          void *user)
 722 {
 723         int ret;
 724         struct btrfs_receive *r = user;
 725         struct btrfs_ioctl_clone_range_args clone_args;
 726         struct subvol_info *si = NULL;
 727         char full_path[PATH_MAX];
 728         char *subvol_path = NULL;
 729         char full_clone_path[PATH_MAX];
 730         int clone_fd = -1;
 731
 732         ret = path_cat_out(full_path, r->full_subvol_path, path);
 733         if (ret < 0) {
 734                 fprintf(stderr, "ERROR: clone: source path invalid: %s\n",
 735                                 path);
 736                 goto out;
 737         }
 738
 739         ret = open_inode_for_write(r, full_path);
 740         if (ret < 0)
 741                 goto out;
 742
 743         si = subvol_uuid_search(&r->sus, 0, clone_uuid, clone_ctransid, NULL,
 744                         subvol_search_by_received_uuid);
 745         if (!si) {
 746                 if (memcmp(clone_uuid, r->cur_subvol.received_uuid,
 747                                 BTRFS_UUID_SIZE) == 0) {
 748                         /* TODO check generation of extent */
 749                         subvol_path = strdup(r->cur_subvol_path);
 750                 } else {
 751                         ret = -ENOENT;
 752                         fprintf(stderr, "ERROR: did not find source subvol.\n");
 753                         goto out;
 754                 }
 755         } else {
 756                 /*if (rs_args.ctransid > rs_args.rtransid) {
 757                         if (!r->force) {
 758                                 ret = -EINVAL;
 759                                 fprintf(stderr, "ERROR: subvolume %s was "
 760                                                 "modified after it was "
 761                                                 "received.\n",
 762                                                 r->subvol_parent_name);
 763                                 goto out;
 764                         } else {
 765                                 fprintf(stderr, "WARNING: subvolume %s was "
 766                                                 "modified after it was "
 767                                                 "received.\n",
 768                                                 r->subvol_parent_name);
 769                         }
 770                 }*/
 771                 subvol_path = strdup(si->path);
 772         }
 773
 774         ret = path_cat_out(full_clone_path, subvol_path, clone_path);
 775         if (ret < 0) {
 776                 fprintf(stderr, "ERROR: clone: target path invalid: %s\n",
 777                                 clone_path);
 778                 goto out;
 779         }
 780
 781         clone_fd = openat(r->mnt_fd, full_clone_path, O_RDONLY | O_NOATIME);
 782         if (clone_fd < 0) {
 783                 ret = -errno;
 784                 fprintf(stderr, "ERROR: failed to open %s. %s\n",
 785                                 full_clone_path, strerror(-ret));
 786                 goto out;
 787         }
 788
 789         clone_args.src_fd = clone_fd;
 790         clone_args.src_offset = clone_offset;
 791         clone_args.src_length = len;
 792         clone_args.dest_offset = offset;
 793         ret = ioctl(r->write_fd, BTRFS_IOC_CLONE_RANGE, &clone_args);
 794         if (ret) {
 795                 ret = -errno;
 796                 fprintf(stderr, "ERROR: failed to clone extents to %s\n%s\n",
 797                                 path, strerror(-ret));
 798                 goto out;
 799         }
 800
 801 out:
 802         if (si) {
 803                 free(si->path);
 804                 free(si);
 805         }
 806         free(subvol_path);
 807         if (clone_fd != -1)
 808                 close(clone_fd);
 809         return ret;
 810 }
 811
 812
 813 static int process_set_xattr(const char *path, const char *name,
 814                              const void *data, int len, void *user)
 815 {
 816         int ret = 0;
 817         struct btrfs_receive *r = user;
 818         char full_path[PATH_MAX];
 819
 820         ret = path_cat_out(full_path, r->full_subvol_path, path);
 821         if (ret < 0) {
 822                 fprintf(stderr, "ERROR: set_xattr: path invalid: %s\n", path);
 823                 goto out;
 824         }
 825
 826         if (strcmp("security.capability", name) == 0) {
 827                 if (g_verbose >= 3)
 828                         fprintf(stderr, "set_xattr: cache capabilities\n");
 829                 if (r->cached_capabilities_len)
 830                         fprintf(stderr,
 831                           "WARNING: capabilities set multiple times per file: %s\n",
 832                                 full_path);
 833                 if (len > sizeof(r->cached_capabilities)) {
 834                         fprintf(stderr,
 835                           "ERROR: capabilities encoded to %d bytes, buffer too small\n",
 836                                 len);
 837                         ret = -E2BIG;
 838                         goto out;
 839                 }
 840                 r->cached_capabilities_len = len;
 841                 memcpy(r->cached_capabilities, data, len);
 842         }
 843
 844         if (g_verbose >= 2) {
 845                 fprintf(stderr, "set_xattr %s - name=%s data_len=%d "
 846                                 "data=%.*s\n", path, name, len,
 847                                 len, (char*)data);
 848         }
 849
 850         ret = lsetxattr(full_path, name, data, len, 0);
 851         if (ret < 0) {
 852                 ret = -errno;
 853                 fprintf(stderr, "ERROR: lsetxattr %s %s=%.*s failed. %s\n",
 854                                 path, name, len, (char*)data, strerror(-ret));
 855                 goto out;
 856         }
 857
 858 out:
 859         return ret;
 860 }
 861
 862 static int process_remove_xattr(const char *path, const char *name, void *user)
 863 {
 864         int ret = 0;
 865         struct btrfs_receive *r = user;
 866         char full_path[PATH_MAX];
 867
 868         ret = path_cat_out(full_path, r->full_subvol_path, path);
 869         if (ret < 0) {
 870                 fprintf(stderr, "ERROR: remove_xattr: path invalid: %s\n",
 871                                 path);
 872                 goto out;
 873         }
 874
 875         if (g_verbose >= 2) {
 876                 fprintf(stderr, "remove_xattr %s - name=%s\n",
 877                                 path, name);
 878         }
 879
 880         ret = lremovexattr(full_path, name);
 881         if (ret < 0) {
 882                 ret = -errno;
 883                 fprintf(stderr, "ERROR: lremovexattr %s %s failed. %s\n",
 884                                 path, name, strerror(-ret));
 885                 goto out;
 886         }
 887
 888 out:
 889         return ret;
 890 }
 891
 892 static int process_truncate(const char *path, u64 size, void *user)
 893 {
 894         int ret = 0;
 895         struct btrfs_receive *r = user;
 896         char full_path[PATH_MAX];
 897
 898         ret = path_cat_out(full_path, r->full_subvol_path, path);
 899         if (ret < 0) {
 900                 fprintf(stderr, "ERROR: truncate: path invalid: %s\n", path);
 901                 goto out;
 902         }
 903
 904         if (g_verbose >= 2)
 905                 fprintf(stderr, "truncate %s size=%llu\n", path, size);
 906
 907         ret = truncate(full_path, size);
 908         if (ret < 0) {
 909                 ret = -errno;
 910                 fprintf(stderr, "ERROR: truncate %s failed. %s\n",
 911                                 path, strerror(-ret));
 912                 goto out;
 913         }
 914
 915 out:
 916         return ret;
 917 }
 918
 919 static int process_chmod(const char *path, u64 mode, void *user)
 920 {
 921         int ret = 0;
 922         struct btrfs_receive *r = user;
 923         char full_path[PATH_MAX];
 924
 925         ret = path_cat_out(full_path, r->full_subvol_path, path);
 926         if (ret < 0) {
 927                 fprintf(stderr, "ERROR: chmod: path invalid: %s\n", path);
 928                 goto out;
 929         }
 930
 931         if (g_verbose >= 2)
 932                 fprintf(stderr, "chmod %s - mode=0%o\n", path, (int)mode);
 933
 934         ret = chmod(full_path, mode);
 935         if (ret < 0) {
 936                 ret = -errno;
 937                 fprintf(stderr, "ERROR: chmod %s failed. %s\n",
 938                                 path, strerror(-ret));
 939                 goto out;
 940         }
 941
 942 out:
 943         return ret;
 944 }
 945
 946 static int process_chown(const char *path, u64 uid, u64 gid, void *user)
 947 {
 948         int ret = 0;
 949         struct btrfs_receive *r = user;
 950         char full_path[PATH_MAX];
 951
 952         ret = path_cat_out(full_path, r->full_subvol_path, path);
 953         if (ret < 0) {
 954                 fprintf(stderr, "ERROR: chown: path invalid: %s\n", path);
 955                 goto out;
 956         }
 957
 958         if (g_verbose >= 2)
 959                 fprintf(stderr, "chown %s - uid=%llu, gid=%llu\n", path,
 960                                 uid, gid);
 961
 962         ret = lchown(full_path, uid, gid);
 963         if (ret < 0) {
 964                 ret = -errno;
 965                 fprintf(stderr, "ERROR: chown %s failed. %s\n",
 966                                 path, strerror(-ret));
 967                 goto out;
 968         }
 969
 970         if (r->cached_capabilities_len) {
 971                 if (g_verbose >= 2)
 972                         fprintf(stderr, "chown: restore capabilities\n");
 973                 ret = lsetxattr(full_path, "security.capability",
 974                                 r->cached_capabilities,
 975                                 r->cached_capabilities_len, 0);
 976                 memset(r->cached_capabilities, 0,
 977                                 sizeof(r->cached_capabilities));
 978                 r->cached_capabilities_len = 0;
 979                 if (ret < 0) {
 980                         ret = -errno;
 981                         fprintf(stderr, "ERROR: restoring capabilities %s: %s\n",
 982                                         path, strerror(-ret));
 983                         goto out;
 984                 }
 985         }
 986
 987 out:
 988         return ret;
 989 }
 990
 991 static int process_utimes(const char *path, struct timespec *at,
 992                           struct timespec *mt, struct timespec *ct,
 993                           void *user)
 994 {
 995         int ret = 0;
 996         struct btrfs_receive *r = user;
 997         char full_path[PATH_MAX];
 998         struct timespec tv[2];
 999
1000         ret = path_cat_out(full_path, r->full_subvol_path, path);
1001         if (ret < 0) {
1002                 fprintf(stderr, "ERROR: utimes: path invalid: %s\n", path);
1003                 goto out;
1004         }
1005
1006         if (g_verbose >= 2)
1007                 fprintf(stderr, "utimes %s\n", path);
1008
1009         tv[0] = *at;
1010         tv[1] = *mt;
1011         ret = utimensat(AT_FDCWD, full_path, tv, AT_SYMLINK_NOFOLLOW);
1012         if (ret < 0) {
1013                 ret = -errno;
1014                 fprintf(stderr, "ERROR: utimes %s failed. %s\n",
1015                                 path, strerror(-ret));
1016                 goto out;
1017         }
1018
1019 out:
1020         return ret;
1021 }
1022
1023 static int process_update_extent(const char *path, u64 offset, u64 len,
1024                 void *user)
1025 {
1026         if (g_verbose >= 2)
1027                 fprintf(stderr, "update_extent %s: offset=%llu, len=%llu\n",
1028                                 path, (unsigned long long)offset,
1029                                 (unsigned long long)len);
1030
1031         /*
1032          * Sent with BTRFS_SEND_FLAG_NO_FILE_DATA, nothing to do.
1033          */
1034
1035         return 0;
1036 }
1037
1038 static struct btrfs_send_ops send_ops = {
1039         .subvol = process_subvol,
1040         .snapshot = process_snapshot,
1041         .mkfile = process_mkfile,
1042         .mkdir = process_mkdir,
1043         .mknod = process_mknod,
1044         .mkfifo = process_mkfifo,
1045         .mksock = process_mksock,
1046         .symlink = process_symlink,
1047         .rename = process_rename,
1048         .link = process_link,
1049         .unlink = process_unlink,
1050         .rmdir = process_rmdir,
1051         .write = process_write,
1052         .clone = process_clone,
1053         .set_xattr = process_set_xattr,
1054         .remove_xattr = process_remove_xattr,
1055         .truncate = process_truncate,
1056         .chmod = process_chmod,
1057         .chown = process_chown,
1058         .utimes = process_utimes,
1059         .update_extent = process_update_extent,
1060 };
1061
1062 static int do_receive(struct btrfs_receive *r, const char *tomnt,
1063                       char *realmnt, int r_fd, u64 max_errors)
1064 {
1065         u64 subvol_id;
1066         int ret;
1067         char *dest_dir_full_path;
1068         char root_subvol_path[PATH_MAX];
1069         int end = 0;
1070
1071         dest_dir_full_path = realpath(tomnt, NULL);
1072         if (!dest_dir_full_path) {
1073                 ret = -errno;
1074                 fprintf(stderr, "ERROR: realpath(%s) failed. %s\n", tomnt,
1075                         strerror(-ret));
1076                 goto out;
1077         }
1078         r->dest_dir_fd = open(dest_dir_full_path, O_RDONLY | O_NOATIME);
1079         if (r->dest_dir_fd < 0) {
1080                 ret = -errno;
1081                 fprintf(stderr,
1082                         "ERROR: failed to open destination directory %s. %s\n",
1083                         dest_dir_full_path, strerror(-ret));
1084                 goto out;
1085         }
1086
1087         if (realmnt[0]) {
1088                 r->root_path = realmnt;
1089         } else {
1090                 ret = find_mount_root(dest_dir_full_path, &r->root_path);
1091                 if (ret < 0) {
1092                         fprintf(stderr,
1093                                 "ERROR: failed to determine mount point for %s: %s\n",
1094                                 dest_dir_full_path, strerror(-ret));
1095                         ret = -EINVAL;
1096                         goto out;
1097                 }
1098                 if (ret > 0) {
1099                         fprintf(stderr,
1100                         "ERROR: %s doesn't belong to btrfs mount point\n",
1101                         dest_dir_full_path);
1102                         ret = -EINVAL;
1103                         goto out;
1104                 }
1105         }
1106         r->mnt_fd = open(r->root_path, O_RDONLY | O_NOATIME);
1107         if (r->mnt_fd < 0) {
1108                 ret = -errno;
1109                 fprintf(stderr, "ERROR: failed to open %s. %s\n", r->root_path,
1110                         strerror(-ret));
1111                 goto out;
1112         }
1113
1114         /*
1115          * If we use -m or a default subvol we want to resolve the path to the
1116          * subvolume we're sitting in so that we can adjust the paths of any
1117          * subvols we want to receive in.
1118          */
1119         ret = btrfs_list_get_path_rootid(r->mnt_fd, &subvol_id);
1120         if (ret) {
1121                 fprintf(stderr, "ERROR: couldn't resolve our subvolid %d\n",
1122                         ret);
1123                 goto out;
1124         }
1125
1126         root_subvol_path[0] = 0;
1127         ret = btrfs_subvolid_resolve(r->mnt_fd, root_subvol_path,
1128                                      PATH_MAX, subvol_id);
1129         if (ret) {
1130                 fprintf(stderr, "ERROR: couldn't resolve our subvol path\n");
1131                 goto out;
1132         }
1133
1134         /*
1135          * Ok we're inside of a subvol off of the root subvol, we need to
1136          * actually set full_root_path.
1137          */
1138         if (*root_subvol_path)
1139                 r->full_root_path = root_subvol_path;
1140
1141         if (r->dest_dir_chroot) {
1142                 if (chroot(dest_dir_full_path)) {
1143                         ret = -errno;
1144                         fprintf(stderr,
1145                                 "ERROR: failed to chroot to %s, %s\n",
1146                                 dest_dir_full_path,
1147                                 strerror(-ret));
1148                         goto out;
1149                 }
1150                 if (chdir("/")) {
1151                         ret = -errno;
1152                         fprintf(stderr,
1153                                 "ERROR: failed to chdir to /, %s\n",
1154                                 strerror(-ret));
1155                         goto out;
1156                 }
1157                 fprintf(stderr, "Chroot to %s\n", dest_dir_full_path);
1158                 r->root_path = strdup("/");
1159                 r->dest_dir_path = r->root_path;
1160         } else {
1161                 /*
1162                  * find_mount_root returns a root_path that is a subpath of
1163                  * dest_dir_full_path. Now get the other part of root_path,
1164                  * which is the destination dir relative to root_path.
1165                  */
1166                 r->dest_dir_path = dest_dir_full_path + strlen(r->root_path);
1167                 while (r->dest_dir_path[0] == '/')
1168                         r->dest_dir_path++;
1169         }
1170
1171         ret = subvol_uuid_search_init(r->mnt_fd, &r->sus);
1172         if (ret < 0)
1173                 goto out;
1174
1175         while (!end) {
1176                 if (r->cached_capabilities_len) {
1177                         if (g_verbose >= 3)
1178                                 fprintf(stderr, "clear cached capabilities\n");
1179                         memset(r->cached_capabilities, 0,
1180                                         sizeof(r->cached_capabilities));
1181                         r->cached_capabilities_len = 0;
1182                 }
1183
1184                 ret = btrfs_read_and_process_send_stream(r_fd, &send_ops, r,
1185                                                          r->honor_end_cmd,
1186                                                          max_errors);
1187                 if (ret < 0)
1188                         goto out;
1189                 if (ret)
1190                         end = 1;
1191
1192                 close_inode_for_write(r);
1193                 ret = finish_subvol(r);
1194                 if (ret < 0)
1195                         goto out;
1196         }
1197         ret = 0;
1198
1199 out:
1200         if (r->write_fd != -1) {
1201                 close(r->write_fd);
1202                 r->write_fd = -1;
1203         }
1204
1205         if (r->root_path != realmnt)
1206                 free(r->root_path);
1207         r->root_path = NULL;
1208         r->dest_dir_path = NULL;
1209         free(dest_dir_full_path);
1210         subvol_uuid_search_finit(&r->sus);
1211         if (r->mnt_fd != -1) {
1212                 close(r->mnt_fd);
1213                 r->mnt_fd = -1;
1214         }
1215         if (r->dest_dir_fd != -1) {
1216                 close(r->dest_dir_fd);
1217                 r->dest_dir_fd = -1;
1218         }
1219
1220         return ret;
1221 }
1222
1223 int cmd_receive(int argc, char **argv)
1224 {
1225         char *tomnt = NULL;
1226         char fromfile[PATH_MAX];
1227         char realmnt[PATH_MAX];
1228         struct btrfs_receive r;
1229         int receive_fd = fileno(stdin);
1230         u64 max_errors = 1;
1231         int ret = 0;
1232
1233         memset(&r, 0, sizeof(r));
1234         r.mnt_fd = -1;
1235         r.write_fd = -1;
1236         r.dest_dir_fd = -1;
1237         r.dest_dir_chroot = 0;
1238         realmnt[0] = 0;
1239         fromfile[0] = 0;
1240
1241         while (1) {
1242                 int c;
1243                 static const struct option long_opts[] = {
1244                         { "max-errors", required_argument, NULL, 'E' },
1245                         { "chroot", no_argument, NULL, 'C' },
1246                         { NULL, 0, NULL, 0 }
1247                 };
1248
1249                 c = getopt_long(argc, argv, "Cevf:m:", long_opts, NULL);
1250                 if (c < 0)
1251                         break;
1252
1253                 switch (c) {
1254                 case 'v':
1255                         g_verbose++;
1256                         break;
1257                 case 'f':
1258                         if (arg_copy_path(fromfile, optarg, sizeof(fromfile))) {
1259                                 fprintf(stderr,
1260                                     "ERROR: input file path too long (%zu)\n",
1261                                     strlen(optarg));
1262                                 ret = 1;
1263                                 goto out;
1264                         }
1265                         break;
1266                 case 'e':
1267                         r.honor_end_cmd = 1;
1268                         break;
1269                 case 'C':
1270                         r.dest_dir_chroot = 1;
1271                         break;
1272                 case 'E':
1273                         max_errors = arg_strtou64(optarg);
1274                         break;
1275                 case 'm':
1276                         if (arg_copy_path(realmnt, optarg, sizeof(realmnt))) {
1277                                 fprintf(stderr,
1278                                     "ERROR: mount point path too long (%zu)\n",
1279                                     strlen(optarg));
1280                                 ret = 1;
1281                                 goto out;
1282                         }
1283                         break;
1284                 case '?':
1285                 default:
1286                         fprintf(stderr, "ERROR: receive args invalid.\n");
1287                         return 1;
1288                 }
1289         }
1290
1291         if (check_argc_exact(argc - optind, 1))
1292                 usage(cmd_receive_usage);
1293
1294         tomnt = argv[optind];
1295
1296         if (fromfile[0]) {
1297                 receive_fd = open(fromfile, O_RDONLY | O_NOATIME);
1298                 if (receive_fd < 0) {
1299                         fprintf(stderr, "ERROR: failed to open %s\n", fromfile);
1300                         goto out;
1301                 }
1302         }
1303
1304         ret = do_receive(&r, tomnt, realmnt, receive_fd, max_errors);
1305
1306 out:
1307
1308         return !!ret;
1309 }
1310
1311 const char * const cmd_receive_usage[] = {
1312         "btrfs receive [-ve] [-f <infile>] [--max-errors <N>] <mount>",
1313         "Receive subvolumes from stdin.",
1314         "Receives one or more subvolumes that were previously",
1315         "sent with btrfs send. The received subvolumes are stored",
1316         "into <mount>.",
1317         "btrfs receive will fail in case a receiving subvolume",
1318         "already exists. It will also fail in case a previously",
1319         "received subvolume was changed after it was received.",
1320         "After receiving a subvolume, it is immediately set to",
1321         "read only.\n",
1322         "-v               Enable verbose debug output. Each",
1323         "                 occurrence of this option increases the",
1324         "                 verbose level more.",
1325         "-f <infile>      By default, btrfs receive uses stdin",
1326         "                 to receive the subvolumes. Use this",
1327         "                 option to specify a file to use instead.",
1328         "-e               Terminate after receiving an <end cmd>",
1329         "                 in the data stream. Without this option,",
1330         "                 the receiver terminates only if an error",
1331         "                 is recognized or on EOF.",
1332         "-C|--chroot      confine the process to <mount> using chroot",
1333         "--max-errors <N> Terminate as soon as N errors happened while",
1334         "                 processing commands from the send stream.",
1335         "                 Default value is 1. A value of 0 means no limit.",
1336         "-m <mountpoint>  The root mount point of the destination fs.",
1337         "                 If you do not have /proc use this to tell us where ",
1338         "                 this file system is mounted.",
1339         NULL
1340 };