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         if (r->cur_subvol.path) {
 170                 error("subvol: another one already started, path ptr: %s",
 171                                 r->cur_subvol.path);
 172                 ret = -EINVAL;
 173                 goto out;
 174         }
 175         if (r->cur_subvol_path[0]) {
 176                 error("subvol: another one already started, path buf: %s",
 177                                 r->cur_subvol.path);
 178                 ret = -EINVAL;
 179                 goto out;
 180         }
 181
 182         if (*r->dest_dir_path == 0) {
 183                 strncpy_null(r->cur_subvol_path, path);
 184         } else {
 185                 ret = path_cat_out(r->cur_subvol_path, r->dest_dir_path, path);
 186                 if (ret < 0) {
 187                         error("subvol: path invalid: %s\n", path);
 188                         goto out;
 189                 }
 190         }
 191         ret = path_cat3_out(r->full_subvol_path, r->root_path,
 192                         r->dest_dir_path, path);
 193         if (ret < 0) {
 194                 error("subvol: path invalid: %s", path);
 195                 goto out;
 196         }
 197
 198         fprintf(stderr, "At subvol %s\n", path);
 199
 200         memcpy(r->cur_subvol.received_uuid, uuid, BTRFS_UUID_SIZE);
 201         r->cur_subvol.stransid = ctransid;
 202
 203         if (g_verbose) {
 204                 uuid_unparse((u8*)r->cur_subvol.received_uuid, uuid_str);
 205                 fprintf(stderr, "receiving subvol %s uuid=%s, stransid=%llu\n",
 206                                 path, uuid_str,
 207                                 r->cur_subvol.stransid);
 208         }
 209
 210         memset(&args_v1, 0, sizeof(args_v1));
 211         strncpy_null(args_v1.name, path);
 212         ret = ioctl(r->dest_dir_fd, BTRFS_IOC_SUBVOL_CREATE, &args_v1);
 213         if (ret < 0) {
 214                 ret = -errno;
 215                 error("creating subvolume %s failed: %s", path, strerror(-ret));
 216                 goto out;
 217         }
 218
 219 out:
 220         return ret;
 221 }
 222
 223 static int process_snapshot(const char *path, const u8 *uuid, u64 ctransid,
 224                             const u8 *parent_uuid, u64 parent_ctransid,
 225                             void *user)
 226 {
 227         int ret;
 228         struct btrfs_receive *r = user;
 229         char uuid_str[BTRFS_UUID_UNPARSED_SIZE];
 230         struct btrfs_ioctl_vol_args_v2 args_v2;
 231         struct subvol_info *parent_subvol = NULL;
 232
 233         ret = finish_subvol(r);
 234         if (ret < 0)
 235                 goto out;
 236
 237         if (r->cur_subvol.path) {
 238                 error("snapshot: another one already started, path ptr: %s",
 239                                 r->cur_subvol.path);
 240                 ret = -EINVAL;
 241                 goto out;
 242         }
 243         if (r->cur_subvol_path[0]) {
 244                 error("snapshot: another one already started, path buf: %s",
 245                                 r->cur_subvol.path);
 246                 ret = -EINVAL;
 247                 goto out;
 248         }
 249
 250         if (*r->dest_dir_path == 0) {
 251                 strncpy_null(r->cur_subvol_path, path);
 252         } else {
 253                 ret = path_cat_out(r->cur_subvol_path, r->dest_dir_path, path);
 254                 if (ret < 0) {
 255                         error("snapshot: path invalid: %s", path);
 256                         goto out;
 257                 }
 258         }
 259         ret = path_cat3_out(r->full_subvol_path, r->root_path,
 260                         r->dest_dir_path, path);
 261         if (ret < 0) {
 262                 error("snapshot: path invalid: %s", path);
 263                 goto out;
 264         }
 265
 266         fprintf(stdout, "At snapshot %s\n", path);
 267
 268         memcpy(r->cur_subvol.received_uuid, uuid, BTRFS_UUID_SIZE);
 269         r->cur_subvol.stransid = ctransid;
 270
 271         if (g_verbose) {
 272                 uuid_unparse((u8*)r->cur_subvol.received_uuid, uuid_str);
 273                 fprintf(stderr, "receiving snapshot %s uuid=%s, "
 274                                 "ctransid=%llu ", path, uuid_str,
 275                                 r->cur_subvol.stransid);
 276                 uuid_unparse(parent_uuid, uuid_str);
 277                 fprintf(stderr, "parent_uuid=%s, parent_ctransid=%llu\n",
 278                                 uuid_str, parent_ctransid);
 279         }
 280
 281         memset(&args_v2, 0, sizeof(args_v2));
 282         strncpy_null(args_v2.name, path);
 283
 284         parent_subvol = subvol_uuid_search(&r->sus, 0, parent_uuid,
 285                         parent_ctransid, NULL, subvol_search_by_received_uuid);
 286         if (!parent_subvol) {
 287                 parent_subvol = subvol_uuid_search(&r->sus, 0, parent_uuid,
 288                                 parent_ctransid, NULL, subvol_search_by_uuid);
 289         }
 290         if (!parent_subvol) {
 291                 ret = -ENOENT;
 292                 error("cannot find parent subvolume");
 293                 goto out;
 294         }
 295
 296         /*
 297          * The path is resolved from the root subvol, but we could be in some
 298          * subvolume under the root subvolume, so try and adjust the path to be
 299          * relative to our root path.
 300          */
 301         if (r->full_root_path) {
 302                 size_t root_len;
 303                 size_t sub_len;
 304
 305                 root_len = strlen(r->full_root_path);
 306                 sub_len = strlen(parent_subvol->path);
 307
 308                 /* First make sure the parent subvol is actually in our path */
 309                 if (sub_len < root_len ||
 310                     strstr(parent_subvol->path, r->full_root_path) == NULL) {
 311                         error(
 312                 "parent subvol is not reachable from inside the root subvol");
 313                         ret = -ENOENT;
 314                         goto out;
 315                 }
 316
 317                 if (sub_len == root_len) {
 318                         parent_subvol->path[0] = '/';
 319                         parent_subvol->path[1] = '\0';
 320                 } else {
 321                         /*
 322                          * root path is foo/bar
 323                          * subvol path is foo/bar/baz
 324                          *
 325                          * we need to have baz be the path, so we need to move
 326                          * the bit after foo/bar/, so path + root_len + 1, and
 327                          * move the part we care about, so sub_len - root_len -
 328                          * 1.
 329                          */
 330                         memmove(parent_subvol->path,
 331                                 parent_subvol->path + root_len + 1,
 332                                 sub_len - root_len - 1);
 333                         parent_subvol->path[sub_len - root_len - 1] = '\0';
 334                 }
 335         }
 336         /*if (rs_args.ctransid > rs_args.rtransid) {
 337                 if (!r->force) {
 338                         ret = -EINVAL;
 339                         fprintf(stderr, "ERROR: subvolume %s was modified after it was received.\n", r->subvol_parent_name);
 340                         goto out;
 341                 } else {
 342                         fprintf(stderr, "WARNING: subvolume %s was modified after it was received.\n", r->subvol_parent_name);
 343                 }
 344         }*/
 345
 346         if (*parent_subvol->path == 0)
 347                 args_v2.fd = dup(r->mnt_fd);
 348         else
 349                 args_v2.fd = openat(r->mnt_fd, parent_subvol->path,
 350                                 O_RDONLY | O_NOATIME);
 351         if (args_v2.fd < 0) {
 352                 ret = -errno;
 353                 if (errno != ENOENT)
 354                         error("cannot open %s: %s",
 355                                         parent_subvol->path, strerror(-ret));
 356                 else
 357                         fprintf(stderr,
 358                                 "It seems that you have changed your default "
 359                                 "subvolume or you specify other subvolume to\n"
 360                                 "mount btrfs, try to remount this btrfs filesystem "
 361                                 "with fs tree, and run btrfs receive again!\n");
 362                 goto out;
 363         }
 364
 365         ret = ioctl(r->dest_dir_fd, BTRFS_IOC_SNAP_CREATE_V2, &args_v2);
 366         close(args_v2.fd);
 367         if (ret < 0) {
 368                 ret = -errno;
 369                 error("creating snapshot %s -> %s failed: %s",
 370                                 parent_subvol->path, path, strerror(-ret));
 371                 goto out;
 372         }
 373
 374 out:
 375         if (parent_subvol) {
 376                 free(parent_subvol->path);
 377                 free(parent_subvol);
 378         }
 379         return ret;
 380 }
 381
 382 static int process_mkfile(const char *path, void *user)
 383 {
 384         int ret;
 385         struct btrfs_receive *r = user;
 386         char full_path[PATH_MAX];
 387
 388         ret = path_cat_out(full_path, r->full_subvol_path, path);
 389         if (ret < 0) {
 390                 error("mkfile: path invalid: %s", path);
 391                 goto out;
 392         }
 393
 394         if (g_verbose >= 2)
 395                 fprintf(stderr, "mkfile %s\n", path);
 396
 397         ret = creat(full_path, 0600);
 398         if (ret < 0) {
 399                 ret = -errno;
 400                 error("mkfile %s failed: %s", path, strerror(-ret));
 401                 goto out;
 402         }
 403         close(ret);
 404         ret = 0;
 405
 406 out:
 407         return ret;
 408 }
 409
 410 static int process_mkdir(const char *path, void *user)
 411 {
 412         int ret;
 413         struct btrfs_receive *r = user;
 414         char full_path[PATH_MAX];
 415
 416         ret = path_cat_out(full_path, r->full_subvol_path, path);
 417         if (ret < 0) {
 418                 error("mkdir: path invalid: %s", path);
 419                 goto out;
 420         }
 421
 422         if (g_verbose >= 2)
 423                 fprintf(stderr, "mkdir %s\n", path);
 424
 425         ret = mkdir(full_path, 0700);
 426         if (ret < 0) {
 427                 ret = -errno;
 428                 error("mkdir %s failed: %s", path, strerror(-ret));
 429         }
 430
 431 out:
 432         return ret;
 433 }
 434
 435 static int process_mknod(const char *path, u64 mode, u64 dev, void *user)
 436 {
 437         int ret;
 438         struct btrfs_receive *r = user;
 439         char full_path[PATH_MAX];
 440
 441         ret = path_cat_out(full_path, r->full_subvol_path, path);
 442         if (ret < 0) {
 443                 error("mknod: path invalid: %s", path);
 444                 goto out;
 445         }
 446
 447         if (g_verbose >= 2)
 448                 fprintf(stderr, "mknod %s mode=%llu, dev=%llu\n",
 449                                 path, mode, dev);
 450
 451         ret = mknod(full_path, mode & S_IFMT, dev);
 452         if (ret < 0) {
 453                 ret = -errno;
 454                 error("mknod %s failed: %s", path, strerror(-ret));
 455         }
 456
 457 out:
 458         return ret;
 459 }
 460
 461 static int process_mkfifo(const char *path, void *user)
 462 {
 463         int ret;
 464         struct btrfs_receive *r = user;
 465         char full_path[PATH_MAX];
 466
 467         ret = path_cat_out(full_path, r->full_subvol_path, path);
 468         if (ret < 0) {
 469                 error("mkfifo: path invalid: %s", path);
 470                 goto out;
 471         }
 472
 473         if (g_verbose >= 2)
 474                 fprintf(stderr, "mkfifo %s\n", path);
 475
 476         ret = mkfifo(full_path, 0600);
 477         if (ret < 0) {
 478                 ret = -errno;
 479                 error("mkfifo %s failed: %s", path, strerror(-ret));
 480         }
 481
 482 out:
 483         return ret;
 484 }
 485
 486 static int process_mksock(const char *path, void *user)
 487 {
 488         int ret;
 489         struct btrfs_receive *r = user;
 490         char full_path[PATH_MAX];
 491
 492         ret = path_cat_out(full_path, r->full_subvol_path, path);
 493         if (ret < 0) {
 494                 error("mksock: path invalid: %s", path);
 495                 goto out;
 496         }
 497
 498         if (g_verbose >= 2)
 499                 fprintf(stderr, "mksock %s\n", path);
 500
 501         ret = mknod(full_path, 0600 | S_IFSOCK, 0);
 502         if (ret < 0) {
 503                 ret = -errno;
 504                 error("mknod %s failed: %s", path, strerror(-ret));
 505         }
 506
 507 out:
 508         return ret;
 509 }
 510
 511 static int process_symlink(const char *path, const char *lnk, void *user)
 512 {
 513         int ret;
 514         struct btrfs_receive *r = user;
 515         char full_path[PATH_MAX];
 516
 517         ret = path_cat_out(full_path, r->full_subvol_path, path);
 518         if (ret < 0) {
 519                 error("symlink: path invalid: %s", path);
 520                 goto out;
 521         }
 522
 523         if (g_verbose >= 2)
 524                 fprintf(stderr, "symlink %s -> %s\n", path, lnk);
 525
 526         ret = symlink(lnk, full_path);
 527         if (ret < 0) {
 528                 ret = -errno;
 529                 error("symlink %s -> %s failed: %s", path,
 530                                 lnk, strerror(-ret));
 531         }
 532
 533 out:
 534         return ret;
 535 }
 536
 537 static int process_rename(const char *from, const char *to, void *user)
 538 {
 539         int ret;
 540         struct btrfs_receive *r = user;
 541         char full_from[PATH_MAX];
 542         char full_to[PATH_MAX];
 543
 544         ret = path_cat_out(full_from, r->full_subvol_path, from);
 545         if (ret < 0) {
 546                 error("rename: source path invalid: %s", from);
 547                 goto out;
 548         }
 549
 550         ret = path_cat_out(full_to, r->full_subvol_path, to);
 551         if (ret < 0) {
 552                 error("rename: target path invalid: %s", to);
 553                 goto out;
 554         }
 555
 556         if (g_verbose >= 2)
 557                 fprintf(stderr, "rename %s -> %s\n", from, to);
 558
 559         ret = rename(full_from, full_to);
 560         if (ret < 0) {
 561                 ret = -errno;
 562                 error("rename %s -> %s failed: %s", from,
 563                                 to, strerror(-ret));
 564         }
 565
 566 out:
 567         return ret;
 568 }
 569
 570 static int process_link(const char *path, const char *lnk, void *user)
 571 {
 572         int ret;
 573         struct btrfs_receive *r = user;
 574         char full_path[PATH_MAX];
 575         char full_link_path[PATH_MAX];
 576
 577         ret = path_cat_out(full_path, r->full_subvol_path, path);
 578         if (ret < 0) {
 579                 error("link: source path invalid: %s", full_path);
 580                 goto out;
 581         }
 582
 583         ret = path_cat_out(full_link_path, r->full_subvol_path, lnk);
 584         if (ret < 0) {
 585                 error("link: target path invalid: %s", full_link_path);
 586                 goto out;
 587         }
 588
 589         if (g_verbose >= 2)
 590                 fprintf(stderr, "link %s -> %s\n", path, lnk);
 591
 592         ret = link(full_link_path, full_path);
 593         if (ret < 0) {
 594                 ret = -errno;
 595                 error("link %s -> %s failed: %s", path, lnk, strerror(-ret));
 596         }
 597
 598 out:
 599         return ret;
 600 }
 601
 602
 603 static int process_unlink(const char *path, void *user)
 604 {
 605         int ret;
 606         struct btrfs_receive *r = user;
 607         char full_path[PATH_MAX];
 608
 609         ret = path_cat_out(full_path, r->full_subvol_path, path);
 610         if (ret < 0) {
 611                 error("unlink: path invalid: %s", path);
 612                 goto out;
 613         }
 614
 615         if (g_verbose >= 2)
 616                 fprintf(stderr, "unlink %s\n", path);
 617
 618         ret = unlink(full_path);
 619         if (ret < 0) {
 620                 ret = -errno;
 621                 error("unlink %s failed. %s", path, strerror(-ret));
 622         }
 623
 624 out:
 625         return ret;
 626 }
 627
 628 static int process_rmdir(const char *path, void *user)
 629 {
 630         int ret;
 631         struct btrfs_receive *r = user;
 632         char full_path[PATH_MAX];
 633
 634         ret = path_cat_out(full_path, r->full_subvol_path, path);
 635         if (ret < 0) {
 636                 error("rmdir: path invalid: %s", path);
 637                 goto out;
 638         }
 639
 640         if (g_verbose >= 2)
 641                 fprintf(stderr, "rmdir %s\n", path);
 642
 643         ret = rmdir(full_path);
 644         if (ret < 0) {
 645                 ret = -errno;
 646                 error("rmdir %s failed: %s", path, strerror(-ret));
 647         }
 648
 649 out:
 650         return ret;
 651 }
 652
 653 static int open_inode_for_write(struct btrfs_receive *r, const char *path)
 654 {
 655         int ret = 0;
 656
 657         if (r->write_fd != -1) {
 658                 if (strcmp(r->write_path, path) == 0)
 659                         goto out;
 660                 close(r->write_fd);
 661                 r->write_fd = -1;
 662         }
 663
 664         r->write_fd = open(path, O_RDWR);
 665         if (r->write_fd < 0) {
 666                 ret = -errno;
 667                 error("cannot open %s: %s", path, strerror(-ret));
 668                 goto out;
 669         }
 670         strncpy_null(r->write_path, path);
 671
 672 out:
 673         return ret;
 674 }
 675
 676 static void close_inode_for_write(struct btrfs_receive *r)
 677 {
 678         if(r->write_fd == -1)
 679                 return;
 680
 681         close(r->write_fd);
 682         r->write_fd = -1;
 683         r->write_path[0] = 0;
 684 }
 685
 686 static int process_write(const char *path, const void *data, u64 offset,
 687                          u64 len, void *user)
 688 {
 689         int ret = 0;
 690         struct btrfs_receive *r = user;
 691         char full_path[PATH_MAX];
 692         u64 pos = 0;
 693         int w;
 694
 695         ret = path_cat_out(full_path, r->full_subvol_path, path);
 696         if (ret < 0) {
 697                 error("write: path invalid: %s", path);
 698                 goto out;
 699         }
 700
 701         ret = open_inode_for_write(r, full_path);
 702         if (ret < 0)
 703                 goto out;
 704
 705         while (pos < len) {
 706                 w = pwrite(r->write_fd, (char*)data + pos, len - pos,
 707                                 offset + pos);
 708                 if (w < 0) {
 709                         ret = -errno;
 710                         error("writing to %s failed: %s\n",
 711                                         path, strerror(-ret));
 712                         goto out;
 713                 }
 714                 pos += w;
 715         }
 716
 717 out:
 718         return ret;
 719 }
 720
 721 static int process_clone(const char *path, u64 offset, u64 len,
 722                          const u8 *clone_uuid, u64 clone_ctransid,
 723                          const char *clone_path, u64 clone_offset,
 724                          void *user)
 725 {
 726         int ret;
 727         struct btrfs_receive *r = user;
 728         struct btrfs_ioctl_clone_range_args clone_args;
 729         struct subvol_info *si = NULL;
 730         char full_path[PATH_MAX];
 731         char *subvol_path = NULL;
 732         char full_clone_path[PATH_MAX];
 733         int clone_fd = -1;
 734
 735         ret = path_cat_out(full_path, r->full_subvol_path, path);
 736         if (ret < 0) {
 737                 error("clone: source path invalid: %s", path);
 738                 goto out;
 739         }
 740
 741         ret = open_inode_for_write(r, full_path);
 742         if (ret < 0)
 743                 goto out;
 744
 745         si = subvol_uuid_search(&r->sus, 0, clone_uuid, clone_ctransid, NULL,
 746                         subvol_search_by_received_uuid);
 747         if (!si) {
 748                 if (memcmp(clone_uuid, r->cur_subvol.received_uuid,
 749                                 BTRFS_UUID_SIZE) == 0) {
 750                         /* TODO check generation of extent */
 751                         subvol_path = strdup(r->cur_subvol_path);
 752                 } else {
 753                         ret = -ENOENT;
 754                         error("clone: did not find source subvol");
 755                         goto out;
 756                 }
 757         } else {
 758                 /*if (rs_args.ctransid > rs_args.rtransid) {
 759                         if (!r->force) {
 760                                 ret = -EINVAL;
 761                                 fprintf(stderr, "ERROR: subvolume %s was "
 762                                                 "modified after it was "
 763                                                 "received.\n",
 764                                                 r->subvol_parent_name);
 765                                 goto out;
 766                         } else {
 767                                 fprintf(stderr, "WARNING: subvolume %s was "
 768                                                 "modified after it was "
 769                                                 "received.\n",
 770                                                 r->subvol_parent_name);
 771                         }
 772                 }*/
 773                 subvol_path = strdup(si->path);
 774         }
 775
 776         ret = path_cat_out(full_clone_path, subvol_path, clone_path);
 777         if (ret < 0) {
 778                 error("clone: target path invalid: %s", clone_path);
 779                 goto out;
 780         }
 781
 782         clone_fd = openat(r->mnt_fd, full_clone_path, O_RDONLY | O_NOATIME);
 783         if (clone_fd < 0) {
 784                 ret = -errno;
 785                 error("cannot open %s: %s", 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 < 0) {
 795                 ret = -errno;
 796                 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                 error("set_xattr: path invalid: %s", 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                         warning("capabilities set multiple times per file: %s",
 831                                 full_path);
 832                 if (len > sizeof(r->cached_capabilities)) {
 833                         error("capabilities encoded to %d bytes, buffer too small",
 834                                 len);
 835                         ret = -E2BIG;
 836                         goto out;
 837                 }
 838                 r->cached_capabilities_len = len;
 839                 memcpy(r->cached_capabilities, data, len);
 840         }
 841
 842         if (g_verbose >= 2) {
 843                 fprintf(stderr, "set_xattr %s - name=%s data_len=%d "
 844                                 "data=%.*s\n", path, name, len,
 845                                 len, (char*)data);
 846         }
 847
 848         ret = lsetxattr(full_path, name, data, len, 0);
 849         if (ret < 0) {
 850                 ret = -errno;
 851                 error("lsetxattr %s %s=%.*s failed: %s",
 852                                 path, name, len, (char*)data, strerror(-ret));
 853                 goto out;
 854         }
 855
 856 out:
 857         return ret;
 858 }
 859
 860 static int process_remove_xattr(const char *path, const char *name, void *user)
 861 {
 862         int ret = 0;
 863         struct btrfs_receive *r = user;
 864         char full_path[PATH_MAX];
 865
 866         ret = path_cat_out(full_path, r->full_subvol_path, path);
 867         if (ret < 0) {
 868                 error("remove_xattr: path invalid: %s", path);
 869                 goto out;
 870         }
 871
 872         if (g_verbose >= 2) {
 873                 fprintf(stderr, "remove_xattr %s - name=%s\n",
 874                                 path, name);
 875         }
 876
 877         ret = lremovexattr(full_path, name);
 878         if (ret < 0) {
 879                 ret = -errno;
 880                 error("lremovexattr %s %s failed: %s",
 881                                 path, name, strerror(-ret));
 882                 goto out;
 883         }
 884
 885 out:
 886         return ret;
 887 }
 888
 889 static int process_truncate(const char *path, u64 size, void *user)
 890 {
 891         int ret = 0;
 892         struct btrfs_receive *r = user;
 893         char full_path[PATH_MAX];
 894
 895         ret = path_cat_out(full_path, r->full_subvol_path, path);
 896         if (ret < 0) {
 897                 error("truncate: path invalid: %s", path);
 898                 goto out;
 899         }
 900
 901         if (g_verbose >= 2)
 902                 fprintf(stderr, "truncate %s size=%llu\n", path, size);
 903
 904         ret = truncate(full_path, size);
 905         if (ret < 0) {
 906                 ret = -errno;
 907                 error("truncate %s failed: %s", path, strerror(-ret));
 908                 goto out;
 909         }
 910
 911 out:
 912         return ret;
 913 }
 914
 915 static int process_chmod(const char *path, u64 mode, void *user)
 916 {
 917         int ret = 0;
 918         struct btrfs_receive *r = user;
 919         char full_path[PATH_MAX];
 920
 921         ret = path_cat_out(full_path, r->full_subvol_path, path);
 922         if (ret < 0) {
 923                 error("chmod: path invalid: %s", path);
 924                 goto out;
 925         }
 926
 927         if (g_verbose >= 2)
 928                 fprintf(stderr, "chmod %s - mode=0%o\n", path, (int)mode);
 929
 930         ret = chmod(full_path, mode);
 931         if (ret < 0) {
 932                 ret = -errno;
 933                 error("chmod %s failed: %s", path, strerror(-ret));
 934                 goto out;
 935         }
 936
 937 out:
 938         return ret;
 939 }
 940
 941 static int process_chown(const char *path, u64 uid, u64 gid, void *user)
 942 {
 943         int ret = 0;
 944         struct btrfs_receive *r = user;
 945         char full_path[PATH_MAX];
 946
 947         ret = path_cat_out(full_path, r->full_subvol_path, path);
 948         if (ret < 0) {
 949                 error("chown: path invalid: %s", path);
 950                 goto out;
 951         }
 952
 953         if (g_verbose >= 2)
 954                 fprintf(stderr, "chown %s - uid=%llu, gid=%llu\n", path,
 955                                 uid, gid);
 956
 957         ret = lchown(full_path, uid, gid);
 958         if (ret < 0) {
 959                 ret = -errno;
 960                 error("chown %s failed: %s", path, strerror(-ret));
 961                 goto out;
 962         }
 963
 964         if (r->cached_capabilities_len) {
 965                 if (g_verbose >= 2)
 966                         fprintf(stderr, "chown: restore capabilities\n");
 967                 ret = lsetxattr(full_path, "security.capability",
 968                                 r->cached_capabilities,
 969                                 r->cached_capabilities_len, 0);
 970                 memset(r->cached_capabilities, 0,
 971                                 sizeof(r->cached_capabilities));
 972                 r->cached_capabilities_len = 0;
 973                 if (ret < 0) {
 974                         ret = -errno;
 975                         error("restoring capabilities %s: %s",
 976                                         path, strerror(-ret));
 977                         goto out;
 978                 }
 979         }
 980
 981 out:
 982         return ret;
 983 }
 984
 985 static int process_utimes(const char *path, struct timespec *at,
 986                           struct timespec *mt, struct timespec *ct,
 987                           void *user)
 988 {
 989         int ret = 0;
 990         struct btrfs_receive *r = user;
 991         char full_path[PATH_MAX];
 992         struct timespec tv[2];
 993
 994         ret = path_cat_out(full_path, r->full_subvol_path, path);
 995         if (ret < 0) {
 996                 error("utimes: path invalid: %s", path);
 997                 goto out;
 998         }
 999
1000         if (g_verbose >= 2)
1001                 fprintf(stderr, "utimes %s\n", path);
1002
1003         tv[0] = *at;
1004         tv[1] = *mt;
1005         ret = utimensat(AT_FDCWD, full_path, tv, AT_SYMLINK_NOFOLLOW);
1006         if (ret < 0) {
1007                 ret = -errno;
1008                 error("utimes %s failed: %s",
1009                                 path, strerror(-ret));
1010                 goto out;
1011         }
1012
1013 out:
1014         return ret;
1015 }
1016
1017 static int process_update_extent(const char *path, u64 offset, u64 len,
1018                 void *user)
1019 {
1020         if (g_verbose >= 2)
1021                 fprintf(stderr, "update_extent %s: offset=%llu, len=%llu\n",
1022                                 path, (unsigned long long)offset,
1023                                 (unsigned long long)len);
1024
1025         /*
1026          * Sent with BTRFS_SEND_FLAG_NO_FILE_DATA, nothing to do.
1027          */
1028
1029         return 0;
1030 }
1031
1032 static struct btrfs_send_ops send_ops = {
1033         .subvol = process_subvol,
1034         .snapshot = process_snapshot,
1035         .mkfile = process_mkfile,
1036         .mkdir = process_mkdir,
1037         .mknod = process_mknod,
1038         .mkfifo = process_mkfifo,
1039         .mksock = process_mksock,
1040         .symlink = process_symlink,
1041         .rename = process_rename,
1042         .link = process_link,
1043         .unlink = process_unlink,
1044         .rmdir = process_rmdir,
1045         .write = process_write,
1046         .clone = process_clone,
1047         .set_xattr = process_set_xattr,
1048         .remove_xattr = process_remove_xattr,
1049         .truncate = process_truncate,
1050         .chmod = process_chmod,
1051         .chown = process_chown,
1052         .utimes = process_utimes,
1053         .update_extent = process_update_extent,
1054 };
1055
1056 static int do_receive(struct btrfs_receive *r, const char *tomnt,
1057                       char *realmnt, int r_fd, u64 max_errors)
1058 {
1059         u64 subvol_id;
1060         int ret;
1061         char *dest_dir_full_path;
1062         char root_subvol_path[PATH_MAX];
1063         int end = 0;
1064         int count;
1065
1066         dest_dir_full_path = realpath(tomnt, NULL);
1067         if (!dest_dir_full_path) {
1068                 ret = -errno;
1069                 error("realpath(%s) failed: %s", tomnt, strerror(-ret));
1070                 goto out;
1071         }
1072         r->dest_dir_fd = open(dest_dir_full_path, O_RDONLY | O_NOATIME);
1073         if (r->dest_dir_fd < 0) {
1074                 ret = -errno;
1075                 error("cannot open destination directory %s: %s",
1076                         dest_dir_full_path, strerror(-ret));
1077                 goto out;
1078         }
1079
1080         if (realmnt[0]) {
1081                 r->root_path = realmnt;
1082         } else {
1083                 ret = find_mount_root(dest_dir_full_path, &r->root_path);
1084                 if (ret < 0) {
1085                         error("failed to determine mount point for %s: %s",
1086                                 dest_dir_full_path, strerror(-ret));
1087                         ret = -EINVAL;
1088                         goto out;
1089                 }
1090                 if (ret > 0) {
1091                         error("%s doesn't belong to btrfs mount point",
1092                                 dest_dir_full_path);
1093                         ret = -EINVAL;
1094                         goto out;
1095                 }
1096         }
1097         r->mnt_fd = open(r->root_path, O_RDONLY | O_NOATIME);
1098         if (r->mnt_fd < 0) {
1099                 ret = -errno;
1100                 error("cannot open %s: %s", r->root_path, strerror(-ret));
1101                 goto out;
1102         }
1103
1104         /*
1105          * If we use -m or a default subvol we want to resolve the path to the
1106          * subvolume we're sitting in so that we can adjust the paths of any
1107          * subvols we want to receive in.
1108          */
1109         ret = btrfs_list_get_path_rootid(r->mnt_fd, &subvol_id);
1110         if (ret)
1111                 goto out;
1112
1113         root_subvol_path[0] = 0;
1114         ret = btrfs_subvolid_resolve(r->mnt_fd, root_subvol_path,
1115                                      PATH_MAX, subvol_id);
1116         if (ret) {
1117                 error("cannot resolve our subvol path");
1118                 goto out;
1119         }
1120
1121         /*
1122          * Ok we're inside of a subvol off of the root subvol, we need to
1123          * actually set full_root_path.
1124          */
1125         if (*root_subvol_path)
1126                 r->full_root_path = root_subvol_path;
1127
1128         if (r->dest_dir_chroot) {
1129                 if (chroot(dest_dir_full_path)) {
1130                         ret = -errno;
1131                         error("failed to chroot to %s: %s",
1132                                 dest_dir_full_path, strerror(-ret));
1133                         goto out;
1134                 }
1135                 if (chdir("/")) {
1136                         ret = -errno;
1137                         error("failed to chdir to / after chroot: %s",
1138                                 strerror(-ret));
1139                         goto out;
1140                 }
1141                 fprintf(stderr, "Chroot to %s\n", dest_dir_full_path);
1142                 r->root_path = strdup("/");
1143                 r->dest_dir_path = r->root_path;
1144         } else {
1145                 /*
1146                  * find_mount_root returns a root_path that is a subpath of
1147                  * dest_dir_full_path. Now get the other part of root_path,
1148                  * which is the destination dir relative to root_path.
1149                  */
1150                 r->dest_dir_path = dest_dir_full_path + strlen(r->root_path);
1151                 while (r->dest_dir_path[0] == '/')
1152                         r->dest_dir_path++;
1153         }
1154
1155         ret = subvol_uuid_search_init(r->mnt_fd, &r->sus);
1156         if (ret < 0)
1157                 goto out;
1158
1159         count = 0;
1160         while (!end) {
1161                 if (r->cached_capabilities_len) {
1162                         if (g_verbose >= 3)
1163                                 fprintf(stderr, "clear cached capabilities\n");
1164                         memset(r->cached_capabilities, 0,
1165                                         sizeof(r->cached_capabilities));
1166                         r->cached_capabilities_len = 0;
1167                 }
1168
1169                 ret = btrfs_read_and_process_send_stream(r_fd, &send_ops, r,
1170                                                          r->honor_end_cmd,
1171                                                          max_errors);
1172                 if (ret < 0)
1173                         goto out;
1174                 /* Empty stream is invalid */
1175                 if (ret && count == 0) {
1176                         error("empty stream is not considered valid");
1177                         ret = -EINVAL;
1178                         goto out;
1179                 }
1180                 count++;
1181                 if (ret)
1182                         end = 1;
1183
1184                 close_inode_for_write(r);
1185                 ret = finish_subvol(r);
1186                 if (ret < 0)
1187                         goto out;
1188         }
1189         ret = 0;
1190
1191 out:
1192         if (r->write_fd != -1) {
1193                 close(r->write_fd);
1194                 r->write_fd = -1;
1195         }
1196
1197         if (r->root_path != realmnt)
1198                 free(r->root_path);
1199         r->root_path = NULL;
1200         r->dest_dir_path = NULL;
1201         free(dest_dir_full_path);
1202         subvol_uuid_search_finit(&r->sus);
1203         if (r->mnt_fd != -1) {
1204                 close(r->mnt_fd);
1205                 r->mnt_fd = -1;
1206         }
1207         if (r->dest_dir_fd != -1) {
1208                 close(r->dest_dir_fd);
1209                 r->dest_dir_fd = -1;
1210         }
1211
1212         return ret;
1213 }
1214
1215 int cmd_receive(int argc, char **argv)
1216 {
1217         char *tomnt = NULL;
1218         char fromfile[PATH_MAX];
1219         char realmnt[PATH_MAX];
1220         struct btrfs_receive r;
1221         int receive_fd = fileno(stdin);
1222         u64 max_errors = 1;
1223         int ret = 0;
1224
1225         memset(&r, 0, sizeof(r));
1226         r.mnt_fd = -1;
1227         r.write_fd = -1;
1228         r.dest_dir_fd = -1;
1229         r.dest_dir_chroot = 0;
1230         realmnt[0] = 0;
1231         fromfile[0] = 0;
1232
1233         while (1) {
1234                 int c;
1235                 static const struct option long_opts[] = {
1236                         { "max-errors", required_argument, NULL, 'E' },
1237                         { "chroot", no_argument, NULL, 'C' },
1238                         { NULL, 0, NULL, 0 }
1239                 };
1240
1241                 c = getopt_long(argc, argv, "Cevf:m:", long_opts, NULL);
1242                 if (c < 0)
1243                         break;
1244
1245                 switch (c) {
1246                 case 'v':
1247                         g_verbose++;
1248                         break;
1249                 case 'f':
1250                         if (arg_copy_path(fromfile, optarg, sizeof(fromfile))) {
1251                                 error("input file path too long (%zu)",
1252                                         strlen(optarg));
1253                                 ret = 1;
1254                                 goto out;
1255                         }
1256                         break;
1257                 case 'e':
1258                         r.honor_end_cmd = 1;
1259                         break;
1260                 case 'C':
1261                         r.dest_dir_chroot = 1;
1262                         break;
1263                 case 'E':
1264                         max_errors = arg_strtou64(optarg);
1265                         break;
1266                 case 'm':
1267                         if (arg_copy_path(realmnt, optarg, sizeof(realmnt))) {
1268                                 error("mount point path too long (%zu)",
1269                                         strlen(optarg));
1270                                 ret = 1;
1271                                 goto out;
1272                         }
1273                         break;
1274                 case '?':
1275                 default:
1276                         error("receive args invalid");
1277                         return 1;
1278                 }
1279         }
1280
1281         if (check_argc_exact(argc - optind, 1))
1282                 usage(cmd_receive_usage);
1283
1284         tomnt = argv[optind];
1285
1286         if (fromfile[0]) {
1287                 receive_fd = open(fromfile, O_RDONLY | O_NOATIME);
1288                 if (receive_fd < 0) {
1289                         error("cannot open %s: %s", fromfile, strerror(errno));
1290                         goto out;
1291                 }
1292         }
1293
1294         ret = do_receive(&r, tomnt, realmnt, receive_fd, max_errors);
1295         if (receive_fd != fileno(stdin))
1296                 close(receive_fd);
1297
1298 out:
1299
1300         return !!ret;
1301 }
1302
1303 const char * const cmd_receive_usage[] = {
1304         "btrfs receive [-ve] [-f <infile>] [--max-errors <N>] <mount>",
1305         "Receive subvolumes from stdin.",
1306         "Receives one or more subvolumes that were previously",
1307         "sent with btrfs send. The received subvolumes are stored",
1308         "into <mount>.",
1309         "btrfs receive will fail in case a receiving subvolume",
1310         "already exists. It will also fail in case a previously",
1311         "received subvolume was changed after it was received.",
1312         "After receiving a subvolume, it is immediately set to",
1313         "read only.\n",
1314         "-v               Enable verbose debug output. Each",
1315         "                 occurrence of this option increases the",
1316         "                 verbose level more.",
1317         "-f <infile>      By default, btrfs receive uses stdin",
1318         "                 to receive the subvolumes. Use this",
1319         "                 option to specify a file to use instead.",
1320         "-e               Terminate after receiving an <end cmd>",
1321         "                 in the data stream. Without this option,",
1322         "                 the receiver terminates only if an error",
1323         "                 is recognized or on EOF.",
1324         "-C|--chroot      confine the process to <mount> using chroot",
1325         "--max-errors <N> Terminate as soon as N errors happened while",
1326         "                 processing commands from the send stream.",
1327         "                 Default value is 1. A value of 0 means no limit.",
1328         "-m <mountpoint>  The root mount point of the destination fs.",
1329         "                 If you do not have /proc use this to tell us where ",
1330         "                 this file system is mounted.",
1331         NULL
1332 };