btrfs-convert.c

   1 /*
   2  * Copyright (C) 2007 Oracle.  All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public
   6  * License v2 as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public
  14  * License along with this program; if not, write to the
  15  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  16  * Boston, MA 021110-1307, USA.
  17  */
  18
  19 #include "kerncompat.h"
  20
  21 #include <sys/ioctl.h>
  22 #include <sys/mount.h>
  23 #include <stdio.h>
  24 #include <stdlib.h>
  25 #include <sys/types.h>
  26 #include <sys/stat.h>
  27 #include <fcntl.h>
  28 #include <unistd.h>
  29 #include <uuid/uuid.h>
  30 #include <linux/limits.h>
  31 #include <getopt.h>
  32
  33 #include "ctree.h"
  34 #include "disk-io.h"
  35 #include "volumes.h"
  36 #include "transaction.h"
  37 #include "crc32c.h"
  38 #include "utils.h"
  39 #include "task-utils.h"
  40 #include <ext2fs/ext2_fs.h>
  41 #include <ext2fs/ext2fs.h>
  42 #include <ext2fs/ext2_ext_attr.h>
  43
  44 #define INO_OFFSET (BTRFS_FIRST_FREE_OBJECTID - EXT2_ROOT_INO)
  45 #define CONV_IMAGE_SUBVOL_OBJECTID BTRFS_FIRST_FREE_OBJECTID
  46
  47 /*
  48  * Compatibility code for e2fsprogs 1.41 which doesn't support RO compat flag
  49  * BIGALLOC.
  50  * Unlike normal RO compat flag, BIGALLOC affects how e2fsprogs check used
  51  * space, and btrfs-convert heavily relies on it.
  52  */
  53 #ifdef HAVE_OLD_E2FSPROGS
  54 #define EXT2FS_CLUSTER_RATIO(fs)        (1)
  55 #define EXT2_CLUSTERS_PER_GROUP(s)      (EXT2_BLOCKS_PER_GROUP(s))
  56 #define EXT2FS_B2C(fs, blk)             (blk)
  57 #endif
  58
  59 struct task_ctx {
  60         uint32_t max_copy_inodes;
  61         uint32_t cur_copy_inodes;
  62         struct task_info *info;
  63 };
  64
  65 static void *print_copied_inodes(void *p)
  66 {
  67         struct task_ctx *priv = p;
  68         const char work_indicator[] = { '.', 'o', 'O', 'o' };
  69         uint32_t count = 0;
  70
  71         task_period_start(priv->info, 1000 /* 1s */);
  72         while (1) {
  73                 count++;
  74                 printf("copy inodes [%c] [%10d/%10d]\r",
  75                        work_indicator[count % 4], priv->cur_copy_inodes,
  76                        priv->max_copy_inodes);
  77                 fflush(stdout);
  78                 task_period_wait(priv->info);
  79         }
  80
  81         return NULL;
  82 }
  83
  84 static int after_copied_inodes(void *p)
  85 {
  86         printf("\n");
  87         fflush(stdout);
  88
  89         return 0;
  90 }
  91
  92 struct btrfs_convert_context;
  93 struct btrfs_convert_operations {
  94         const char *name;
  95         int (*open_fs)(struct btrfs_convert_context *cctx, const char *devname);
  96         int (*read_used_space)(struct btrfs_convert_context *cctx);
  97         int (*copy_inodes)(struct btrfs_convert_context *cctx,
  98                          struct btrfs_root *root, int datacsum,
  99                          int packing, int noxattr, struct task_ctx *p);
 100         void (*close_fs)(struct btrfs_convert_context *cctx);
 101 };
 102
 103 static void init_convert_context(struct btrfs_convert_context *cctx)
 104 {
 105         cache_tree_init(&cctx->used);
 106         cache_tree_init(&cctx->data_chunks);
 107         cache_tree_init(&cctx->free);
 108 }
 109
 110 static void clean_convert_context(struct btrfs_convert_context *cctx)
 111 {
 112         free_extent_cache_tree(&cctx->used);
 113         free_extent_cache_tree(&cctx->data_chunks);
 114         free_extent_cache_tree(&cctx->free);
 115 }
 116
 117 static inline int copy_inodes(struct btrfs_convert_context *cctx,
 118                               struct btrfs_root *root, int datacsum,
 119                               int packing, int noxattr, struct task_ctx *p)
 120 {
 121         return cctx->convert_ops->copy_inodes(cctx, root, datacsum, packing,
 122                                              noxattr, p);
 123 }
 124
 125 static inline void convert_close_fs(struct btrfs_convert_context *cctx)
 126 {
 127         cctx->convert_ops->close_fs(cctx);
 128 }
 129
 130 /*
 131  * Open Ext2fs in readonly mode, read block allocation bitmap and
 132  * inode bitmap into memory.
 133  */
 134 static int ext2_open_fs(struct btrfs_convert_context *cctx, const char *name)
 135 {
 136         errcode_t ret;
 137         ext2_filsys ext2_fs;
 138         ext2_ino_t ino;
 139         u32 ro_feature;
 140
 141         ret = ext2fs_open(name, 0, 0, 0, unix_io_manager, &ext2_fs);
 142         if (ret) {
 143                 fprintf(stderr, "ext2fs_open: %s\n", error_message(ret));
 144                 return -1;
 145         }
 146         /*
 147          * We need to know exactly the used space, some RO compat flags like
 148          * BIGALLOC will affect how used space is present.
 149          * So we need manuall check any unsupported RO compat flags
 150          */
 151         ro_feature = ext2_fs->super->s_feature_ro_compat;
 152         if (ro_feature & ~EXT2_LIB_FEATURE_RO_COMPAT_SUPP) {
 153                 error(
 154 "unsupported RO features detected: %x, abort convert to avoid possible corruption",
 155                       ro_feature & ~EXT2_LIB_FEATURE_COMPAT_SUPP);
 156                 goto fail;
 157         }
 158         ret = ext2fs_read_inode_bitmap(ext2_fs);
 159         if (ret) {
 160                 fprintf(stderr, "ext2fs_read_inode_bitmap: %s\n",
 161                         error_message(ret));
 162                 goto fail;
 163         }
 164         ret = ext2fs_read_block_bitmap(ext2_fs);
 165         if (ret) {
 166                 fprintf(stderr, "ext2fs_read_block_bitmap: %s\n",
 167                         error_message(ret));
 168                 goto fail;
 169         }
 170         /*
 171          * search each block group for a free inode. this set up
 172          * uninit block/inode bitmaps appropriately.
 173          */
 174         ino = 1;
 175         while (ino <= ext2_fs->super->s_inodes_count) {
 176                 ext2_ino_t foo;
 177                 ext2fs_new_inode(ext2_fs, ino, 0, NULL, &foo);
 178                 ino += EXT2_INODES_PER_GROUP(ext2_fs->super);
 179         }
 180
 181         if (!(ext2_fs->super->s_feature_incompat &
 182               EXT2_FEATURE_INCOMPAT_FILETYPE)) {
 183                 fprintf(stderr, "filetype feature is missing\n");
 184                 goto fail;
 185         }
 186
 187         cctx->fs_data = ext2_fs;
 188         cctx->blocksize = ext2_fs->blocksize;
 189         cctx->block_count = ext2_fs->super->s_blocks_count;
 190         cctx->total_bytes = ext2_fs->blocksize * ext2_fs->super->s_blocks_count;
 191         cctx->volume_name = strndup(ext2_fs->super->s_volume_name, 16);
 192         cctx->first_data_block = ext2_fs->super->s_first_data_block;
 193         cctx->inodes_count = ext2_fs->super->s_inodes_count;
 194         cctx->free_inodes_count = ext2_fs->super->s_free_inodes_count;
 195         return 0;
 196 fail:
 197         ext2fs_close(ext2_fs);
 198         return -1;
 199 }
 200
 201 static int __ext2_add_one_block(ext2_filsys fs, char *bitmap,
 202                                 unsigned long group_nr, struct cache_tree *used)
 203 {
 204         unsigned long offset;
 205         unsigned i;
 206         int ret = 0;
 207
 208         offset = fs->super->s_first_data_block;
 209         offset /= EXT2FS_CLUSTER_RATIO(fs);
 210         offset += group_nr * EXT2_CLUSTERS_PER_GROUP(fs->super);
 211         for (i = 0; i < EXT2_CLUSTERS_PER_GROUP(fs->super); i++) {
 212                 if (ext2fs_test_bit(i, bitmap)) {
 213                         u64 start;
 214
 215                         start = (i + offset) * EXT2FS_CLUSTER_RATIO(fs);
 216                         start *= fs->blocksize;
 217                         ret = add_merge_cache_extent(used, start,
 218                                                      fs->blocksize);
 219                         if (ret < 0)
 220                                 break;
 221                 }
 222         }
 223         return ret;
 224 }
 225
 226 /*
 227  * Read all used ext2 space into cctx->used cache tree
 228  */
 229 static int ext2_read_used_space(struct btrfs_convert_context *cctx)
 230 {
 231         ext2_filsys fs = (ext2_filsys)cctx->fs_data;
 232         blk64_t blk_itr = EXT2FS_B2C(fs, fs->super->s_first_data_block);
 233         struct cache_tree *used_tree = &cctx->used;
 234         char *block_bitmap = NULL;
 235         unsigned long i;
 236         int block_nbytes;
 237         int ret = 0;
 238
 239         block_nbytes = EXT2_CLUSTERS_PER_GROUP(fs->super) / 8;
 240         /* Shouldn't happen */
 241         BUG_ON(!fs->block_map);
 242
 243         block_bitmap = malloc(block_nbytes);
 244         if (!block_bitmap)
 245                 return -ENOMEM;
 246
 247         for (i = 0; i < fs->group_desc_count; i++) {
 248                 ret = ext2fs_get_block_bitmap_range(fs->block_map, blk_itr,
 249                                                 block_nbytes * 8, block_bitmap);
 250                 if (ret) {
 251                         error("fail to get bitmap from ext2, %s",
 252                               strerror(-ret));
 253                         break;
 254                 }
 255                 ret = __ext2_add_one_block(fs, block_bitmap, i, used_tree);
 256                 if (ret < 0) {
 257                         error("fail to build used space tree, %s",
 258                               strerror(-ret));
 259                         break;
 260                 }
 261                 blk_itr += EXT2_CLUSTERS_PER_GROUP(fs->super);
 262         }
 263
 264         free(block_bitmap);
 265         return ret;
 266 }
 267
 268 static void ext2_close_fs(struct btrfs_convert_context *cctx)
 269 {
 270         if (cctx->volume_name) {
 271                 free(cctx->volume_name);
 272                 cctx->volume_name = NULL;
 273         }
 274         ext2fs_close(cctx->fs_data);
 275 }
 276
 277 static int intersect_with_sb(u64 bytenr, u64 num_bytes)
 278 {
 279         int i;
 280         u64 offset;
 281
 282         for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
 283                 offset = btrfs_sb_offset(i);
 284                 offset &= ~((u64)BTRFS_STRIPE_LEN - 1);
 285
 286                 if (bytenr < offset + BTRFS_STRIPE_LEN &&
 287                     bytenr + num_bytes > offset)
 288                         return 1;
 289         }
 290         return 0;
 291 }
 292
 293 static int convert_insert_dirent(struct btrfs_trans_handle *trans,
 294                                  struct btrfs_root *root,
 295                                  const char *name, size_t name_len,
 296                                  u64 dir, u64 objectid,
 297                                  u8 file_type, u64 index_cnt,
 298                                  struct btrfs_inode_item *inode)
 299 {
 300         int ret;
 301         u64 inode_size;
 302         struct btrfs_key location = {
 303                 .objectid = objectid,
 304                 .offset = 0,
 305                 .type = BTRFS_INODE_ITEM_KEY,
 306         };
 307
 308         ret = btrfs_insert_dir_item(trans, root, name, name_len,
 309                                     dir, &location, file_type, index_cnt);
 310         if (ret)
 311                 return ret;
 312         ret = btrfs_insert_inode_ref(trans, root, name, name_len,
 313                                      objectid, dir, index_cnt);
 314         if (ret)
 315                 return ret;
 316         inode_size = btrfs_stack_inode_size(inode) + name_len * 2;
 317         btrfs_set_stack_inode_size(inode, inode_size);
 318
 319         return 0;
 320 }
 321
 322 struct dir_iterate_data {
 323         struct btrfs_trans_handle *trans;
 324         struct btrfs_root *root;
 325         struct btrfs_inode_item *inode;
 326         u64 objectid;
 327         u64 index_cnt;
 328         u64 parent;
 329         int errcode;
 330 };
 331
 332 static u8 filetype_conversion_table[EXT2_FT_MAX] = {
 333         [EXT2_FT_UNKNOWN]       = BTRFS_FT_UNKNOWN,
 334         [EXT2_FT_REG_FILE]      = BTRFS_FT_REG_FILE,
 335         [EXT2_FT_DIR]           = BTRFS_FT_DIR,
 336         [EXT2_FT_CHRDEV]        = BTRFS_FT_CHRDEV,
 337         [EXT2_FT_BLKDEV]        = BTRFS_FT_BLKDEV,
 338         [EXT2_FT_FIFO]          = BTRFS_FT_FIFO,
 339         [EXT2_FT_SOCK]          = BTRFS_FT_SOCK,
 340         [EXT2_FT_SYMLINK]       = BTRFS_FT_SYMLINK,
 341 };
 342
 343 static int dir_iterate_proc(ext2_ino_t dir, int entry,
 344                             struct ext2_dir_entry *dirent,
 345                             int offset, int blocksize,
 346                             char *buf,void *priv_data)
 347 {
 348         int ret;
 349         int file_type;
 350         u64 objectid;
 351         char dotdot[] = "..";
 352         struct dir_iterate_data *idata = (struct dir_iterate_data *)priv_data;
 353         int name_len;
 354
 355         name_len = dirent->name_len & 0xFF;
 356
 357         objectid = dirent->inode + INO_OFFSET;
 358         if (!strncmp(dirent->name, dotdot, name_len)) {
 359                 if (name_len == 2) {
 360                         BUG_ON(idata->parent != 0);
 361                         idata->parent = objectid;
 362                 }
 363                 return 0;
 364         }
 365         if (dirent->inode < EXT2_GOOD_OLD_FIRST_INO)
 366                 return 0;
 367
 368         file_type = dirent->name_len >> 8;
 369         BUG_ON(file_type > EXT2_FT_SYMLINK);
 370
 371         ret = convert_insert_dirent(idata->trans, idata->root, dirent->name,
 372                                     name_len, idata->objectid, objectid,
 373                                     filetype_conversion_table[file_type],
 374                                     idata->index_cnt, idata->inode);
 375         if (ret < 0) {
 376                 idata->errcode = ret;
 377                 return BLOCK_ABORT;
 378         }
 379
 380         idata->index_cnt++;
 381         return 0;
 382 }
 383
 384 static int create_dir_entries(struct btrfs_trans_handle *trans,
 385                               struct btrfs_root *root, u64 objectid,
 386                               struct btrfs_inode_item *btrfs_inode,
 387                               ext2_filsys ext2_fs, ext2_ino_t ext2_ino)
 388 {
 389         int ret;
 390         errcode_t err;
 391         struct dir_iterate_data data = {
 392                 .trans          = trans,
 393                 .root           = root,
 394                 .inode          = btrfs_inode,
 395                 .objectid       = objectid,
 396                 .index_cnt      = 2,
 397                 .parent         = 0,
 398                 .errcode        = 0,
 399         };
 400
 401         err = ext2fs_dir_iterate2(ext2_fs, ext2_ino, 0, NULL,
 402                                   dir_iterate_proc, &data);
 403         if (err)
 404                 goto error;
 405         ret = data.errcode;
 406         if (ret == 0 && data.parent == objectid) {
 407                 ret = btrfs_insert_inode_ref(trans, root, "..", 2,
 408                                              objectid, objectid, 0);
 409         }
 410         return ret;
 411 error:
 412         fprintf(stderr, "ext2fs_dir_iterate2: %s\n", error_message(err));
 413         return -1;
 414 }
 415
 416 static int read_disk_extent(struct btrfs_root *root, u64 bytenr,
 417                             u32 num_bytes, char *buffer)
 418 {
 419         int ret;
 420         struct btrfs_fs_devices *fs_devs = root->fs_info->fs_devices;
 421
 422         ret = pread(fs_devs->latest_bdev, buffer, num_bytes, bytenr);
 423         if (ret != num_bytes)
 424                 goto fail;
 425         ret = 0;
 426 fail:
 427         if (ret > 0)
 428                 ret = -1;
 429         return ret;
 430 }
 431
 432 static int csum_disk_extent(struct btrfs_trans_handle *trans,
 433                             struct btrfs_root *root,
 434                             u64 disk_bytenr, u64 num_bytes)
 435 {
 436         u32 blocksize = root->sectorsize;
 437         u64 offset;
 438         char *buffer;
 439         int ret = 0;
 440
 441         buffer = malloc(blocksize);
 442         if (!buffer)
 443                 return -ENOMEM;
 444         for (offset = 0; offset < num_bytes; offset += blocksize) {
 445                 ret = read_disk_extent(root, disk_bytenr + offset,
 446                                         blocksize, buffer);
 447                 if (ret)
 448                         break;
 449                 ret = btrfs_csum_file_block(trans,
 450                                             root->fs_info->csum_root,
 451                                             disk_bytenr + num_bytes,
 452                                             disk_bytenr + offset,
 453                                             buffer, blocksize);
 454                 if (ret)
 455                         break;
 456         }
 457         free(buffer);
 458         return ret;
 459 }
 460
 461 struct blk_iterate_data {
 462         struct btrfs_trans_handle *trans;
 463         struct btrfs_root *root;
 464         struct btrfs_root *convert_root;
 465         struct btrfs_inode_item *inode;
 466         u64 convert_ino;
 467         u64 objectid;
 468         u64 first_block;
 469         u64 disk_block;
 470         u64 num_blocks;
 471         u64 boundary;
 472         int checksum;
 473         int errcode;
 474 };
 475
 476 static void init_blk_iterate_data(struct blk_iterate_data *data,
 477                                   struct btrfs_trans_handle *trans,
 478                                   struct btrfs_root *root,
 479                                   struct btrfs_inode_item *inode,
 480                                   u64 objectid, int checksum)
 481 {
 482         struct btrfs_key key;
 483
 484         data->trans             = trans;
 485         data->root              = root;
 486         data->inode             = inode;
 487         data->objectid          = objectid;
 488         data->first_block       = 0;
 489         data->disk_block        = 0;
 490         data->num_blocks        = 0;
 491         data->boundary          = (u64)-1;
 492         data->checksum          = checksum;
 493         data->errcode           = 0;
 494
 495         key.objectid = CONV_IMAGE_SUBVOL_OBJECTID;
 496         key.type = BTRFS_ROOT_ITEM_KEY;
 497         key.offset = (u64)-1;
 498         data->convert_root = btrfs_read_fs_root(root->fs_info, &key);
 499         /* Impossible as we just opened it before */
 500         BUG_ON(!data->convert_root || IS_ERR(data->convert_root));
 501         data->convert_ino = BTRFS_FIRST_FREE_OBJECTID + 1;
 502 }
 503
 504 /*
 505  * Record a file extent in original filesystem into btrfs one.
 506  * The special point is, old disk_block can point to a reserved range.
 507  * So here, we don't use disk_block directly but search convert_root
 508  * to get the real disk_bytenr.
 509  */
 510 static int record_file_blocks(struct blk_iterate_data *data,
 511                               u64 file_block, u64 disk_block, u64 num_blocks)
 512 {
 513         int ret = 0;
 514         struct btrfs_root *root = data->root;
 515         struct btrfs_root *convert_root = data->convert_root;
 516         struct btrfs_path *path;
 517         u64 file_pos = file_block * root->sectorsize;
 518         u64 old_disk_bytenr = disk_block * root->sectorsize;
 519         u64 num_bytes = num_blocks * root->sectorsize;
 520         u64 cur_off = old_disk_bytenr;
 521
 522         /* Hole, pass it to record_file_extent directly */
 523         if (old_disk_bytenr == 0)
 524                 return btrfs_record_file_extent(data->trans, root,
 525                                 data->objectid, data->inode, file_pos, 0,
 526                                 num_bytes);
 527
 528         path = btrfs_alloc_path();
 529         if (!path)
 530                 return -ENOMEM;
 531
 532         /*
 533          * Search real disk bytenr from convert root
 534          */
 535         while (cur_off < old_disk_bytenr + num_bytes) {
 536                 struct btrfs_key key;
 537                 struct btrfs_file_extent_item *fi;
 538                 struct extent_buffer *node;
 539                 int slot;
 540                 u64 extent_disk_bytenr;
 541                 u64 extent_num_bytes;
 542                 u64 real_disk_bytenr;
 543                 u64 cur_len;
 544
 545                 key.objectid = data->convert_ino;
 546                 key.type = BTRFS_EXTENT_DATA_KEY;
 547                 key.offset = cur_off;
 548
 549                 ret = btrfs_search_slot(NULL, convert_root, &key, path, 0, 0);
 550                 if (ret < 0)
 551                         break;
 552                 if (ret > 0) {
 553                         ret = btrfs_previous_item(convert_root, path,
 554                                                   data->convert_ino,
 555                                                   BTRFS_EXTENT_DATA_KEY);
 556                         if (ret < 0)
 557                                 break;
 558                         if (ret > 0) {
 559                                 ret = -ENOENT;
 560                                 break;
 561                         }
 562                 }
 563                 node = path->nodes[0];
 564                 slot = path->slots[0];
 565                 btrfs_item_key_to_cpu(node, &key, slot);
 566                 BUG_ON(key.type != BTRFS_EXTENT_DATA_KEY ||
 567                        key.objectid != data->convert_ino ||
 568                        key.offset > cur_off);
 569                 fi = btrfs_item_ptr(node, slot, struct btrfs_file_extent_item);
 570                 extent_disk_bytenr = btrfs_file_extent_disk_bytenr(node, fi);
 571                 extent_num_bytes = btrfs_file_extent_disk_num_bytes(node, fi);
 572                 BUG_ON(cur_off - key.offset >= extent_num_bytes);
 573                 btrfs_release_path(path);
 574
 575                 real_disk_bytenr = cur_off - key.offset + extent_disk_bytenr;
 576                 cur_len = min(key.offset + extent_num_bytes,
 577                               old_disk_bytenr + num_bytes) - cur_off;
 578                 ret = btrfs_record_file_extent(data->trans, data->root,
 579                                         data->objectid, data->inode, file_pos,
 580                                         real_disk_bytenr, cur_len);
 581                 if (ret < 0)
 582                         break;
 583                 cur_off += cur_len;
 584                 file_pos += cur_len;
 585
 586                 /*
 587                  * No need to care about csum
 588                  * As every byte of old fs image is calculated for csum, no
 589                  * need to waste CPU cycles now.
 590                  */
 591         }
 592         btrfs_free_path(path);
 593         return ret;
 594 }
 595
 596 static int block_iterate_proc(u64 disk_block, u64 file_block,
 597                               struct blk_iterate_data *idata)
 598 {
 599         int ret = 0;
 600         int sb_region;
 601         int do_barrier;
 602         struct btrfs_root *root = idata->root;
 603         struct btrfs_block_group_cache *cache;
 604         u64 bytenr = disk_block * root->sectorsize;
 605
 606         sb_region = intersect_with_sb(bytenr, root->sectorsize);
 607         do_barrier = sb_region || disk_block >= idata->boundary;
 608         if ((idata->num_blocks > 0 && do_barrier) ||
 609             (file_block > idata->first_block + idata->num_blocks) ||
 610             (disk_block != idata->disk_block + idata->num_blocks)) {
 611                 if (idata->num_blocks > 0) {
 612                         ret = record_file_blocks(idata, idata->first_block,
 613                                                  idata->disk_block,
 614                                                  idata->num_blocks);
 615                         if (ret)
 616                                 goto fail;
 617                         idata->first_block += idata->num_blocks;
 618                         idata->num_blocks = 0;
 619                 }
 620                 if (file_block > idata->first_block) {
 621                         ret = record_file_blocks(idata, idata->first_block,
 622                                         0, file_block - idata->first_block);
 623                         if (ret)
 624                                 goto fail;
 625                 }
 626
 627                 if (sb_region) {
 628                         bytenr += BTRFS_STRIPE_LEN - 1;
 629                         bytenr &= ~((u64)BTRFS_STRIPE_LEN - 1);
 630                 } else {
 631                         cache = btrfs_lookup_block_group(root->fs_info, bytenr);
 632                         BUG_ON(!cache);
 633                         bytenr = cache->key.objectid + cache->key.offset;
 634                 }
 635
 636                 idata->first_block = file_block;
 637                 idata->disk_block = disk_block;
 638                 idata->boundary = bytenr / root->sectorsize;
 639         }
 640         idata->num_blocks++;
 641 fail:
 642         return ret;
 643 }
 644
 645 static int __block_iterate_proc(ext2_filsys fs, blk_t *blocknr,
 646                                 e2_blkcnt_t blockcnt, blk_t ref_block,
 647                                 int ref_offset, void *priv_data)
 648 {
 649         int ret;
 650         struct blk_iterate_data *idata;
 651         idata = (struct blk_iterate_data *)priv_data;
 652         ret = block_iterate_proc(*blocknr, blockcnt, idata);
 653         if (ret) {
 654                 idata->errcode = ret;
 655                 return BLOCK_ABORT;
 656         }
 657         return 0;
 658 }
 659
 660 /*
 661  * traverse file's data blocks, record these data blocks as file extents.
 662  */
 663 static int create_file_extents(struct btrfs_trans_handle *trans,
 664                                struct btrfs_root *root, u64 objectid,
 665                                struct btrfs_inode_item *btrfs_inode,
 666                                ext2_filsys ext2_fs, ext2_ino_t ext2_ino,
 667                                int datacsum, int packing)
 668 {
 669         int ret;
 670         char *buffer = NULL;
 671         errcode_t err;
 672         u32 last_block;
 673         u32 sectorsize = root->sectorsize;
 674         u64 inode_size = btrfs_stack_inode_size(btrfs_inode);
 675         struct blk_iterate_data data;
 676
 677         init_blk_iterate_data(&data, trans, root, btrfs_inode, objectid,
 678                               datacsum);
 679
 680         err = ext2fs_block_iterate2(ext2_fs, ext2_ino, BLOCK_FLAG_DATA_ONLY,
 681                                     NULL, __block_iterate_proc, &data);
 682         if (err)
 683                 goto error;
 684         ret = data.errcode;
 685         if (ret)
 686                 goto fail;
 687         if (packing && data.first_block == 0 && data.num_blocks > 0 &&
 688             inode_size <= BTRFS_MAX_INLINE_DATA_SIZE(root)) {
 689                 u64 num_bytes = data.num_blocks * sectorsize;
 690                 u64 disk_bytenr = data.disk_block * sectorsize;
 691                 u64 nbytes;
 692
 693                 buffer = malloc(num_bytes);
 694                 if (!buffer)
 695                         return -ENOMEM;
 696                 ret = read_disk_extent(root, disk_bytenr, num_bytes, buffer);
 697                 if (ret)
 698                         goto fail;
 699                 if (num_bytes > inode_size)
 700                         num_bytes = inode_size;
 701                 ret = btrfs_insert_inline_extent(trans, root, objectid,
 702                                                  0, buffer, num_bytes);
 703                 if (ret)
 704                         goto fail;
 705                 nbytes = btrfs_stack_inode_nbytes(btrfs_inode) + num_bytes;
 706                 btrfs_set_stack_inode_nbytes(btrfs_inode, nbytes);
 707         } else if (data.num_blocks > 0) {
 708                 ret = record_file_blocks(&data, data.first_block,
 709                                          data.disk_block, data.num_blocks);
 710                 if (ret)
 711                         goto fail;
 712         }
 713         data.first_block += data.num_blocks;
 714         last_block = (inode_size + sectorsize - 1) / sectorsize;
 715         if (last_block > data.first_block) {
 716                 ret = record_file_blocks(&data, data.first_block, 0,
 717                                          last_block - data.first_block);
 718         }
 719 fail:
 720         free(buffer);
 721         return ret;
 722 error:
 723         fprintf(stderr, "ext2fs_block_iterate2: %s\n", error_message(err));
 724         return -1;
 725 }
 726
 727 static int create_symbol_link(struct btrfs_trans_handle *trans,
 728                               struct btrfs_root *root, u64 objectid,
 729                               struct btrfs_inode_item *btrfs_inode,
 730                               ext2_filsys ext2_fs, ext2_ino_t ext2_ino,
 731                               struct ext2_inode *ext2_inode)
 732 {
 733         int ret;
 734         char *pathname;
 735         u64 inode_size = btrfs_stack_inode_size(btrfs_inode);
 736         if (ext2fs_inode_data_blocks(ext2_fs, ext2_inode)) {
 737                 btrfs_set_stack_inode_size(btrfs_inode, inode_size + 1);
 738                 ret = create_file_extents(trans, root, objectid, btrfs_inode,
 739                                           ext2_fs, ext2_ino, 1, 1);
 740                 btrfs_set_stack_inode_size(btrfs_inode, inode_size);
 741                 return ret;
 742         }
 743
 744         pathname = (char *)&(ext2_inode->i_block[0]);
 745         BUG_ON(pathname[inode_size] != 0);
 746         ret = btrfs_insert_inline_extent(trans, root, objectid, 0,
 747                                          pathname, inode_size + 1);
 748         btrfs_set_stack_inode_nbytes(btrfs_inode, inode_size + 1);
 749         return ret;
 750 }
 751
 752 /*
 753  * Following xattr/acl related codes are based on codes in
 754  * fs/ext3/xattr.c and fs/ext3/acl.c
 755  */
 756 #define EXT2_XATTR_BHDR(ptr) ((struct ext2_ext_attr_header *)(ptr))
 757 #define EXT2_XATTR_BFIRST(ptr) \
 758         ((struct ext2_ext_attr_entry *)(EXT2_XATTR_BHDR(ptr) + 1))
 759 #define EXT2_XATTR_IHDR(inode) \
 760         ((struct ext2_ext_attr_header *) ((void *)(inode) + \
 761                 EXT2_GOOD_OLD_INODE_SIZE + (inode)->i_extra_isize))
 762 #define EXT2_XATTR_IFIRST(inode) \
 763         ((struct ext2_ext_attr_entry *) ((void *)EXT2_XATTR_IHDR(inode) + \
 764                 sizeof(EXT2_XATTR_IHDR(inode)->h_magic)))
 765
 766 static int ext2_xattr_check_names(struct ext2_ext_attr_entry *entry,
 767                                   const void *end)
 768 {
 769         struct ext2_ext_attr_entry *next;
 770
 771         while (!EXT2_EXT_IS_LAST_ENTRY(entry)) {
 772                 next = EXT2_EXT_ATTR_NEXT(entry);
 773                 if ((void *)next >= end)
 774                         return -EIO;
 775                 entry = next;
 776         }
 777         return 0;
 778 }
 779
 780 static int ext2_xattr_check_block(const char *buf, size_t size)
 781 {
 782         int error;
 783         struct ext2_ext_attr_header *header = EXT2_XATTR_BHDR(buf);
 784
 785         if (header->h_magic != EXT2_EXT_ATTR_MAGIC ||
 786             header->h_blocks != 1)
 787                 return -EIO;
 788         error = ext2_xattr_check_names(EXT2_XATTR_BFIRST(buf), buf + size);
 789         return error;
 790 }
 791
 792 static int ext2_xattr_check_entry(struct ext2_ext_attr_entry *entry,
 793                                   size_t size)
 794 {
 795         size_t value_size = entry->e_value_size;
 796
 797         if (entry->e_value_block != 0 || value_size > size ||
 798             entry->e_value_offs + value_size > size)
 799                 return -EIO;
 800         return 0;
 801 }
 802
 803 #define EXT2_ACL_VERSION        0x0001
 804
 805 /* 23.2.5 acl_tag_t values */
 806
 807 #define ACL_UNDEFINED_TAG       (0x00)
 808 #define ACL_USER_OBJ            (0x01)
 809 #define ACL_USER                (0x02)
 810 #define ACL_GROUP_OBJ           (0x04)
 811 #define ACL_GROUP               (0x08)
 812 #define ACL_MASK                (0x10)
 813 #define ACL_OTHER               (0x20)
 814
 815 /* 23.2.7 ACL qualifier constants */
 816
 817 #define ACL_UNDEFINED_ID        ((id_t)-1)
 818
 819 typedef struct {
 820         __le16          e_tag;
 821         __le16          e_perm;
 822         __le32          e_id;
 823 } ext2_acl_entry;
 824
 825 typedef struct {
 826         __le16          e_tag;
 827         __le16          e_perm;
 828 } ext2_acl_entry_short;
 829
 830 typedef struct {
 831         __le32          a_version;
 832 } ext2_acl_header;
 833
 834 static inline int ext2_acl_count(size_t size)
 835 {
 836         ssize_t s;
 837         size -= sizeof(ext2_acl_header);
 838         s = size - 4 * sizeof(ext2_acl_entry_short);
 839         if (s < 0) {
 840                 if (size % sizeof(ext2_acl_entry_short))
 841                         return -1;
 842                 return size / sizeof(ext2_acl_entry_short);
 843         } else {
 844                 if (s % sizeof(ext2_acl_entry))
 845                         return -1;
 846                 return s / sizeof(ext2_acl_entry) + 4;
 847         }
 848 }
 849
 850 #define ACL_EA_VERSION          0x0002
 851
 852 typedef struct {
 853         __le16          e_tag;
 854         __le16          e_perm;
 855         __le32          e_id;
 856 } acl_ea_entry;
 857
 858 typedef struct {
 859         __le32          a_version;
 860         acl_ea_entry    a_entries[0];
 861 } acl_ea_header;
 862
 863 static inline size_t acl_ea_size(int count)
 864 {
 865         return sizeof(acl_ea_header) + count * sizeof(acl_ea_entry);
 866 }
 867
 868 static int ext2_acl_to_xattr(void *dst, const void *src,
 869                              size_t dst_size, size_t src_size)
 870 {
 871         int i, count;
 872         const void *end = src + src_size;
 873         acl_ea_header *ext_acl = (acl_ea_header *)dst;
 874         acl_ea_entry *dst_entry = ext_acl->a_entries;
 875         ext2_acl_entry *src_entry;
 876
 877         if (src_size < sizeof(ext2_acl_header))
 878                 goto fail;
 879         if (((ext2_acl_header *)src)->a_version !=
 880             cpu_to_le32(EXT2_ACL_VERSION))
 881                 goto fail;
 882         src += sizeof(ext2_acl_header);
 883         count = ext2_acl_count(src_size);
 884         if (count <= 0)
 885                 goto fail;
 886
 887         BUG_ON(dst_size < acl_ea_size(count));
 888         ext_acl->a_version = cpu_to_le32(ACL_EA_VERSION);
 889         for (i = 0; i < count; i++, dst_entry++) {
 890                 src_entry = (ext2_acl_entry *)src;
 891                 if (src + sizeof(ext2_acl_entry_short) > end)
 892                         goto fail;
 893                 dst_entry->e_tag = src_entry->e_tag;
 894                 dst_entry->e_perm = src_entry->e_perm;
 895                 switch (le16_to_cpu(src_entry->e_tag)) {
 896                 case ACL_USER_OBJ:
 897                 case ACL_GROUP_OBJ:
 898                 case ACL_MASK:
 899                 case ACL_OTHER:
 900                         src += sizeof(ext2_acl_entry_short);
 901                         dst_entry->e_id = cpu_to_le32(ACL_UNDEFINED_ID);
 902                         break;
 903                 case ACL_USER:
 904                 case ACL_GROUP:
 905                         src += sizeof(ext2_acl_entry);
 906                         if (src > end)
 907                                 goto fail;
 908                         dst_entry->e_id = src_entry->e_id;
 909                         break;
 910                 default:
 911                         goto fail;
 912                 }
 913         }
 914         if (src != end)
 915                 goto fail;
 916         return 0;
 917 fail:
 918         return -EINVAL;
 919 }
 920
 921 static char *xattr_prefix_table[] = {
 922         [1] =   "user.",
 923         [2] =   "system.posix_acl_access",
 924         [3] =   "system.posix_acl_default",
 925         [4] =   "trusted.",
 926         [6] =   "security.",
 927 };
 928
 929 static int copy_single_xattr(struct btrfs_trans_handle *trans,
 930                              struct btrfs_root *root, u64 objectid,
 931                              struct ext2_ext_attr_entry *entry,
 932                              const void *data, u32 datalen)
 933 {
 934         int ret = 0;
 935         int name_len;
 936         int name_index;
 937         void *databuf = NULL;
 938         char namebuf[XATTR_NAME_MAX + 1];
 939
 940         name_index = entry->e_name_index;
 941         if (name_index >= ARRAY_SIZE(xattr_prefix_table) ||
 942             xattr_prefix_table[name_index] == NULL)
 943                 return -EOPNOTSUPP;
 944         name_len = strlen(xattr_prefix_table[name_index]) +
 945                    entry->e_name_len;
 946         if (name_len >= sizeof(namebuf))
 947                 return -ERANGE;
 948
 949         if (name_index == 2 || name_index == 3) {
 950                 size_t bufsize = acl_ea_size(ext2_acl_count(datalen));
 951                 databuf = malloc(bufsize);
 952                 if (!databuf)
 953                        return -ENOMEM;
 954                 ret = ext2_acl_to_xattr(databuf, data, bufsize, datalen);
 955                 if (ret)
 956                         goto out;
 957                 data = databuf;
 958                 datalen = bufsize;
 959         }
 960         strncpy(namebuf, xattr_prefix_table[name_index], XATTR_NAME_MAX);
 961         strncat(namebuf, EXT2_EXT_ATTR_NAME(entry), entry->e_name_len);
 962         if (name_len + datalen > BTRFS_LEAF_DATA_SIZE(root) -
 963             sizeof(struct btrfs_item) - sizeof(struct btrfs_dir_item)) {
 964                 fprintf(stderr, "skip large xattr on inode %Lu name %.*s\n",
 965                         objectid - INO_OFFSET, name_len, namebuf);
 966                 goto out;
 967         }
 968         ret = btrfs_insert_xattr_item(trans, root, namebuf, name_len,
 969                                       data, datalen, objectid);
 970 out:
 971         free(databuf);
 972         return ret;
 973 }
 974
 975 static int copy_extended_attrs(struct btrfs_trans_handle *trans,
 976                                struct btrfs_root *root, u64 objectid,
 977                                struct btrfs_inode_item *btrfs_inode,
 978                                ext2_filsys ext2_fs, ext2_ino_t ext2_ino)
 979 {
 980         int ret = 0;
 981         int inline_ea = 0;
 982         errcode_t err;
 983         u32 datalen;
 984         u32 block_size = ext2_fs->blocksize;
 985         u32 inode_size = EXT2_INODE_SIZE(ext2_fs->super);
 986         struct ext2_inode_large *ext2_inode;
 987         struct ext2_ext_attr_entry *entry;
 988         void *data;
 989         char *buffer = NULL;
 990         char inode_buf[EXT2_GOOD_OLD_INODE_SIZE];
 991
 992         if (inode_size <= EXT2_GOOD_OLD_INODE_SIZE) {
 993                 ext2_inode = (struct ext2_inode_large *)inode_buf;
 994         } else {
 995                 ext2_inode = (struct ext2_inode_large *)malloc(inode_size);
 996                 if (!ext2_inode)
 997                        return -ENOMEM;
 998         }
 999         err = ext2fs_read_inode_full(ext2_fs, ext2_ino, (void *)ext2_inode,
1000                                      inode_size);
1001         if (err) {
1002                 fprintf(stderr, "ext2fs_read_inode_full: %s\n",
1003                         error_message(err));
1004                 ret = -1;
1005                 goto out;
1006         }
1007
1008         if (ext2_ino > ext2_fs->super->s_first_ino &&
1009             inode_size > EXT2_GOOD_OLD_INODE_SIZE) {
1010                 if (EXT2_GOOD_OLD_INODE_SIZE +
1011                     ext2_inode->i_extra_isize > inode_size) {
1012                         ret = -EIO;
1013                         goto out;
1014                 }
1015                 if (ext2_inode->i_extra_isize != 0 &&
1016                     EXT2_XATTR_IHDR(ext2_inode)->h_magic ==
1017                     EXT2_EXT_ATTR_MAGIC) {
1018                         inline_ea = 1;
1019                 }
1020         }
1021         if (inline_ea) {
1022                 int total;
1023                 void *end = (void *)ext2_inode + inode_size;
1024                 entry = EXT2_XATTR_IFIRST(ext2_inode);
1025                 total = end - (void *)entry;
1026                 ret = ext2_xattr_check_names(entry, end);
1027                 if (ret)
1028                         goto out;
1029                 while (!EXT2_EXT_IS_LAST_ENTRY(entry)) {
1030                         ret = ext2_xattr_check_entry(entry, total);
1031                         if (ret)
1032                                 goto out;
1033                         data = (void *)EXT2_XATTR_IFIRST(ext2_inode) +
1034                                 entry->e_value_offs;
1035                         datalen = entry->e_value_size;
1036                         ret = copy_single_xattr(trans, root, objectid,
1037                                                 entry, data, datalen);
1038                         if (ret)
1039                                 goto out;
1040                         entry = EXT2_EXT_ATTR_NEXT(entry);
1041                 }
1042         }
1043
1044         if (ext2_inode->i_file_acl == 0)
1045                 goto out;
1046
1047         buffer = malloc(block_size);
1048         if (!buffer) {
1049                 ret = -ENOMEM;
1050                 goto out;
1051         }
1052         err = ext2fs_read_ext_attr(ext2_fs, ext2_inode->i_file_acl, buffer);
1053         if (err) {
1054                 fprintf(stderr, "ext2fs_read_ext_attr: %s\n",
1055                         error_message(err));
1056                 ret = -1;
1057                 goto out;
1058         }
1059         ret = ext2_xattr_check_block(buffer, block_size);
1060         if (ret)
1061                 goto out;
1062
1063         entry = EXT2_XATTR_BFIRST(buffer);
1064         while (!EXT2_EXT_IS_LAST_ENTRY(entry)) {
1065                 ret = ext2_xattr_check_entry(entry, block_size);
1066                 if (ret)
1067                         goto out;
1068                 data = buffer + entry->e_value_offs;
1069                 datalen = entry->e_value_size;
1070                 ret = copy_single_xattr(trans, root, objectid,
1071                                         entry, data, datalen);
1072                 if (ret)
1073                         goto out;
1074                 entry = EXT2_EXT_ATTR_NEXT(entry);
1075         }
1076 out:
1077         free(buffer);
1078         if ((void *)ext2_inode != inode_buf)
1079                 free(ext2_inode);
1080         return ret;
1081 }
1082 #define MINORBITS       20
1083 #define MKDEV(ma, mi)   (((ma) << MINORBITS) | (mi))
1084
1085 static inline dev_t old_decode_dev(u16 val)
1086 {
1087         return MKDEV((val >> 8) & 255, val & 255);
1088 }
1089
1090 static inline dev_t new_decode_dev(u32 dev)
1091 {
1092         unsigned major = (dev & 0xfff00) >> 8;
1093         unsigned minor = (dev & 0xff) | ((dev >> 12) & 0xfff00);
1094         return MKDEV(major, minor);
1095 }
1096
1097 static int copy_inode_item(struct btrfs_inode_item *dst,
1098                            struct ext2_inode *src, u32 blocksize)
1099 {
1100         btrfs_set_stack_inode_generation(dst, 1);
1101         btrfs_set_stack_inode_sequence(dst, 0);
1102         btrfs_set_stack_inode_transid(dst, 1);
1103         btrfs_set_stack_inode_size(dst, src->i_size);
1104         btrfs_set_stack_inode_nbytes(dst, 0);
1105         btrfs_set_stack_inode_block_group(dst, 0);
1106         btrfs_set_stack_inode_nlink(dst, src->i_links_count);
1107         btrfs_set_stack_inode_uid(dst, src->i_uid | (src->i_uid_high << 16));
1108         btrfs_set_stack_inode_gid(dst, src->i_gid | (src->i_gid_high << 16));
1109         btrfs_set_stack_inode_mode(dst, src->i_mode);
1110         btrfs_set_stack_inode_rdev(dst, 0);
1111         btrfs_set_stack_inode_flags(dst, 0);
1112         btrfs_set_stack_timespec_sec(&dst->atime, src->i_atime);
1113         btrfs_set_stack_timespec_nsec(&dst->atime, 0);
1114         btrfs_set_stack_timespec_sec(&dst->ctime, src->i_ctime);
1115         btrfs_set_stack_timespec_nsec(&dst->ctime, 0);
1116         btrfs_set_stack_timespec_sec(&dst->mtime, src->i_mtime);
1117         btrfs_set_stack_timespec_nsec(&dst->mtime, 0);
1118         btrfs_set_stack_timespec_sec(&dst->otime, 0);
1119         btrfs_set_stack_timespec_nsec(&dst->otime, 0);
1120
1121         if (S_ISDIR(src->i_mode)) {
1122                 btrfs_set_stack_inode_size(dst, 0);
1123                 btrfs_set_stack_inode_nlink(dst, 1);
1124         }
1125         if (S_ISREG(src->i_mode)) {
1126                 btrfs_set_stack_inode_size(dst, (u64)src->i_size_high << 32 |
1127                                            (u64)src->i_size);
1128         }
1129         if (!S_ISREG(src->i_mode) && !S_ISDIR(src->i_mode) &&
1130             !S_ISLNK(src->i_mode)) {
1131                 if (src->i_block[0]) {
1132                         btrfs_set_stack_inode_rdev(dst,
1133                                 old_decode_dev(src->i_block[0]));
1134                 } else {
1135                         btrfs_set_stack_inode_rdev(dst,
1136                                 new_decode_dev(src->i_block[1]));
1137                 }
1138         }
1139         memset(&dst->reserved, 0, sizeof(dst->reserved));
1140
1141         return 0;
1142 }
1143
1144 /*
1145  * copy a single inode. do all the required works, such as cloning
1146  * inode item, creating file extents and creating directory entries.
1147  */
1148 static int copy_single_inode(struct btrfs_trans_handle *trans,
1149                              struct btrfs_root *root, u64 objectid,
1150                              ext2_filsys ext2_fs, ext2_ino_t ext2_ino,
1151                              struct ext2_inode *ext2_inode,
1152                              int datacsum, int packing, int noxattr)
1153 {
1154         int ret;
1155         struct btrfs_inode_item btrfs_inode;
1156
1157         if (ext2_inode->i_links_count == 0)
1158                 return 0;
1159
1160         copy_inode_item(&btrfs_inode, ext2_inode, ext2_fs->blocksize);
1161         if (!datacsum && S_ISREG(ext2_inode->i_mode)) {
1162                 u32 flags = btrfs_stack_inode_flags(&btrfs_inode) |
1163                             BTRFS_INODE_NODATASUM;
1164                 btrfs_set_stack_inode_flags(&btrfs_inode, flags);
1165         }
1166
1167         switch (ext2_inode->i_mode & S_IFMT) {
1168         case S_IFREG:
1169                 ret = create_file_extents(trans, root, objectid, &btrfs_inode,
1170                                         ext2_fs, ext2_ino, datacsum, packing);
1171                 break;
1172         case S_IFDIR:
1173                 ret = create_dir_entries(trans, root, objectid, &btrfs_inode,
1174                                          ext2_fs, ext2_ino);
1175                 break;
1176         case S_IFLNK:
1177                 ret = create_symbol_link(trans, root, objectid, &btrfs_inode,
1178                                          ext2_fs, ext2_ino, ext2_inode);
1179                 break;
1180         default:
1181                 ret = 0;
1182                 break;
1183         }
1184         if (ret)
1185                 return ret;
1186
1187         if (!noxattr) {
1188                 ret = copy_extended_attrs(trans, root, objectid, &btrfs_inode,
1189                                           ext2_fs, ext2_ino);
1190                 if (ret)
1191                         return ret;
1192         }
1193         return btrfs_insert_inode(trans, root, objectid, &btrfs_inode);
1194 }
1195
1196 /*
1197  * scan ext2's inode bitmap and copy all used inodes.
1198  */
1199 static int ext2_copy_inodes(struct btrfs_convert_context *cctx,
1200                             struct btrfs_root *root,
1201                             int datacsum, int packing, int noxattr, struct task_ctx *p)
1202 {
1203         ext2_filsys ext2_fs = cctx->fs_data;
1204         int ret;
1205         errcode_t err;
1206         ext2_inode_scan ext2_scan;
1207         struct ext2_inode ext2_inode;
1208         ext2_ino_t ext2_ino;
1209         u64 objectid;
1210         struct btrfs_trans_handle *trans;
1211
1212         trans = btrfs_start_transaction(root, 1);
1213         if (!trans)
1214                 return -ENOMEM;
1215         err = ext2fs_open_inode_scan(ext2_fs, 0, &ext2_scan);
1216         if (err) {
1217                 fprintf(stderr, "ext2fs_open_inode_scan: %s\n", error_message(err));
1218                 return -1;
1219         }
1220         while (!(err = ext2fs_get_next_inode(ext2_scan, &ext2_ino,
1221                                              &ext2_inode))) {
1222                 /* no more inodes */
1223                 if (ext2_ino == 0)
1224                         break;
1225                 /* skip special inode in ext2fs */
1226                 if (ext2_ino < EXT2_GOOD_OLD_FIRST_INO &&
1227                     ext2_ino != EXT2_ROOT_INO)
1228                         continue;
1229                 objectid = ext2_ino + INO_OFFSET;
1230                 ret = copy_single_inode(trans, root,
1231                                         objectid, ext2_fs, ext2_ino,
1232                                         &ext2_inode, datacsum, packing,
1233                                         noxattr);
1234                 p->cur_copy_inodes++;
1235                 if (ret)
1236                         return ret;
1237                 if (trans->blocks_used >= 4096) {
1238                         ret = btrfs_commit_transaction(trans, root);
1239                         BUG_ON(ret);
1240                         trans = btrfs_start_transaction(root, 1);
1241                         BUG_ON(!trans);
1242                 }
1243         }
1244         if (err) {
1245                 fprintf(stderr, "ext2fs_get_next_inode: %s\n", error_message(err));
1246                 return -1;
1247         }
1248         ret = btrfs_commit_transaction(trans, root);
1249         BUG_ON(ret);
1250         ext2fs_close_inode_scan(ext2_scan);
1251
1252         return ret;
1253 }
1254
1255 static int create_image_file_range(struct btrfs_trans_handle *trans,
1256                                       struct btrfs_root *root,
1257                                       struct cache_tree *used,
1258                                       struct btrfs_inode_item *inode,
1259                                       u64 ino, u64 bytenr, u64 *ret_len,
1260                                       int datacsum)
1261 {
1262         struct cache_extent *cache;
1263         struct btrfs_block_group_cache *bg_cache;
1264         u64 len = *ret_len;
1265         u64 disk_bytenr;
1266         int i;
1267         int ret;
1268
1269         BUG_ON(bytenr != round_down(bytenr, root->sectorsize));
1270         BUG_ON(len != round_down(len, root->sectorsize));
1271         len = min_t(u64, len, BTRFS_MAX_EXTENT_SIZE);
1272
1273         /*
1274          * Skip sb ranges first
1275          * [0, 1M), [sb_offset(1), +64K), [sb_offset(2), +64K].
1276          *
1277          * Or we will insert a hole into current image file, and later
1278          * migrate block will fail as there is already a file extent.
1279          */
1280         if (bytenr < 1024 * 1024) {
1281                 *ret_len = 1024 * 1024 - bytenr;
1282                 return 0;
1283         }
1284         for (i = 1; i < BTRFS_SUPER_MIRROR_MAX; i++) {
1285                 u64 cur = btrfs_sb_offset(i);
1286
1287                 if (bytenr >= cur && bytenr < cur + BTRFS_STRIPE_LEN) {
1288                         *ret_len = cur + BTRFS_STRIPE_LEN - bytenr;
1289                         return 0;
1290                 }
1291         }
1292         for (i = 1; i < BTRFS_SUPER_MIRROR_MAX; i++) {
1293                 u64 cur = btrfs_sb_offset(i);
1294
1295                 /*
1296                  *      |--reserved--|
1297                  * |----range-------|
1298                  * May still need to go through file extent inserts
1299                  */
1300                 if (bytenr < cur && bytenr + len >= cur) {
1301                         len = min_t(u64, len, cur - bytenr);
1302                         break;
1303                 }
1304                 /*
1305                  * |--reserved--|
1306                  *      |---range---|
1307                  * Drop out, no need to insert anything
1308                  */
1309                 if (bytenr >= cur && bytenr < cur + BTRFS_STRIPE_LEN) {
1310                         *ret_len = cur + BTRFS_STRIPE_LEN - bytenr;
1311                         return 0;
1312                 }
1313         }
1314
1315         cache = search_cache_extent(used, bytenr);
1316         if (cache) {
1317                 if (cache->start <= bytenr) {
1318                         /*
1319                          * |///////Used///////|
1320                          *      |<--insert--->|
1321                          *      bytenr
1322                          */
1323                         len = min_t(u64, len, cache->start + cache->size -
1324                                     bytenr);
1325                         disk_bytenr = bytenr;
1326                 } else {
1327                         /*
1328                          *              |//Used//|
1329                          *  |<-insert-->|
1330                          *  bytenr
1331                          */
1332                         len = min(len, cache->start - bytenr);
1333                         disk_bytenr = 0;
1334                         datacsum = 0;
1335                 }
1336         } else {
1337                 /*
1338                  * |//Used//|           |EOF
1339                  *          |<-insert-->|
1340                  *          bytenr
1341                  */
1342                 disk_bytenr = 0;
1343                 datacsum = 0;
1344         }
1345
1346         if (disk_bytenr) {
1347                 /* Check if the range is in a data block group */
1348                 bg_cache = btrfs_lookup_block_group(root->fs_info, bytenr);
1349                 if (!bg_cache)
1350                         return -ENOENT;
1351                 if (!(bg_cache->flags & BTRFS_BLOCK_GROUP_DATA))
1352                         return -EINVAL;
1353
1354                 /* The extent should never cross block group boundary */
1355                 len = min_t(u64, len, bg_cache->key.objectid +
1356                             bg_cache->key.offset - bytenr);
1357         }
1358
1359         BUG_ON(len != round_down(len, root->sectorsize));
1360         ret = btrfs_record_file_extent(trans, root, ino, inode, bytenr,
1361                                        disk_bytenr, len);
1362         if (ret < 0)
1363                 return ret;
1364
1365         if (datacsum)
1366                 ret = csum_disk_extent(trans, root, bytenr, len);
1367         *ret_len = len;
1368         return ret;
1369 }
1370
1371
1372 /*
1373  * Relocate old fs data in one reserved ranges
1374  *
1375  * Since all old fs data in reserved range is not covered by any chunk nor
1376  * data extent, we don't need to handle any reference but add new
1377  * extent/reference, which makes codes more clear
1378  */
1379 static int migrate_one_reserved_range(struct btrfs_trans_handle *trans,
1380                                       struct btrfs_root *root,
1381                                       struct cache_tree *used,
1382                                       struct btrfs_inode_item *inode, int fd,
1383                                       u64 ino, u64 start, u64 len, int datacsum)
1384 {
1385         u64 cur_off = start;
1386         u64 cur_len = len;
1387         u64 hole_start = start;
1388         u64 hole_len;
1389         struct cache_extent *cache;
1390         struct btrfs_key key;
1391         struct extent_buffer *eb;
1392         int ret = 0;
1393
1394         while (cur_off < start + len) {
1395                 cache = lookup_cache_extent(used, cur_off, cur_len);
1396                 if (!cache)
1397                         break;
1398                 cur_off = max(cache->start, cur_off);
1399                 cur_len = min(cache->start + cache->size, start + len) -
1400                           cur_off;
1401                 BUG_ON(cur_len < root->sectorsize);
1402
1403                 /* reserve extent for the data */
1404                 ret = btrfs_reserve_extent(trans, root, cur_len, 0, 0, (u64)-1,
1405                                            &key, 1);
1406                 if (ret < 0)
1407                         break;
1408
1409                 eb = malloc(sizeof(*eb) + cur_len);
1410                 if (!eb) {
1411                         ret = -ENOMEM;
1412                         break;
1413                 }
1414
1415                 ret = pread(fd, eb->data, cur_len, cur_off);
1416                 if (ret < cur_len) {
1417                         ret = (ret < 0 ? ret : -EIO);
1418                         free(eb);
1419                         break;
1420                 }
1421                 eb->start = key.objectid;
1422                 eb->len = key.offset;
1423
1424                 /* Write the data */
1425                 ret = write_and_map_eb(trans, root, eb);
1426                 free(eb);
1427                 if (ret < 0)
1428                         break;
1429
1430                 /* Now handle extent item and file extent things */
1431                 ret = btrfs_record_file_extent(trans, root, ino, inode, cur_off,
1432                                                key.objectid, key.offset);
1433                 if (ret < 0)
1434                         break;
1435                 /* Finally, insert csum items */
1436                 if (datacsum)
1437                         ret = csum_disk_extent(trans, root, key.objectid,
1438                                                key.offset);
1439
1440                 /* Don't forget to insert hole */
1441                 hole_len = cur_off - hole_start;
1442                 if (hole_len) {
1443                         ret = btrfs_record_file_extent(trans, root, ino, inode,
1444                                         hole_start, 0, hole_len);
1445                         if (ret < 0)
1446                                 break;
1447                 }
1448
1449                 cur_off += key.offset;
1450                 hole_start = cur_off;
1451                 cur_len = start + len - cur_off;
1452         }
1453         /* Last hole */
1454         if (start + len - hole_start > 0)
1455                 ret = btrfs_record_file_extent(trans, root, ino, inode,
1456                                 hole_start, 0, start + len - hole_start);
1457         return ret;
1458 }
1459
1460 /*
1461  * Relocate the used ext2 data in reserved ranges
1462  * [0,1M)
1463  * [btrfs_sb_offset(1), +BTRFS_STRIPE_LEN)
1464  * [btrfs_sb_offset(2), +BTRFS_STRIPE_LEN)
1465  */
1466 static int migrate_reserved_ranges(struct btrfs_trans_handle *trans,
1467                                    struct btrfs_root *root,
1468                                    struct cache_tree *used,
1469                                    struct btrfs_inode_item *inode, int fd,
1470                                    u64 ino, u64 total_bytes, int datacsum)
1471 {
1472         u64 cur_off;
1473         u64 cur_len;
1474         int ret = 0;
1475
1476         /* 0 ~ 1M */
1477         cur_off = 0;
1478         cur_len = 1024 * 1024;
1479         ret = migrate_one_reserved_range(trans, root, used, inode, fd, ino,
1480                                          cur_off, cur_len, datacsum);
1481         if (ret < 0)
1482                 return ret;
1483
1484         /* second sb(fisrt sb is included in 0~1M) */
1485         cur_off = btrfs_sb_offset(1);
1486         cur_len = min(total_bytes, cur_off + BTRFS_STRIPE_LEN) - cur_off;
1487         if (cur_off > total_bytes)
1488                 return ret;
1489         ret = migrate_one_reserved_range(trans, root, used, inode, fd, ino,
1490                                          cur_off, cur_len, datacsum);
1491         if (ret < 0)
1492                 return ret;
1493
1494         /* Last sb */
1495         cur_off = btrfs_sb_offset(2);
1496         cur_len = min(total_bytes, cur_off + BTRFS_STRIPE_LEN) - cur_off;
1497         if (cur_off > total_bytes)
1498                 return ret;
1499         ret = migrate_one_reserved_range(trans, root, used, inode, fd, ino,
1500                                          cur_off, cur_len, datacsum);
1501         return ret;
1502 }
1503
1504 static int wipe_reserved_ranges(struct cache_tree *tree, u64 min_stripe_size,
1505                                 int ensure_size);
1506
1507 /*
1508  * Create the fs image file of old filesystem.
1509  *
1510  * This is completely fs independent as we have cctx->used, only
1511  * need to create file extents pointing to all the positions.
1512  */
1513 static int create_image(struct btrfs_root *root,
1514                            struct btrfs_mkfs_config *cfg,
1515                            struct btrfs_convert_context *cctx, int fd,
1516                            u64 size, char *name, int datacsum)
1517 {
1518         struct btrfs_inode_item buf;
1519         struct btrfs_trans_handle *trans;
1520         struct btrfs_path *path = NULL;
1521         struct btrfs_key key;
1522         struct cache_extent *cache;
1523         struct cache_tree used_tmp;
1524         u64 cur;
1525         u64 ino;
1526         int ret;
1527
1528         trans = btrfs_start_transaction(root, 1);
1529         if (!trans)
1530                 return -ENOMEM;
1531
1532         cache_tree_init(&used_tmp);
1533
1534         ret = btrfs_find_free_objectid(trans, root, BTRFS_FIRST_FREE_OBJECTID,
1535                                        &ino);
1536         if (ret < 0)
1537                 goto out;
1538         ret = btrfs_new_inode(trans, root, ino, 0600 | S_IFREG);
1539         if (ret < 0)
1540                 goto out;
1541         ret = btrfs_add_link(trans, root, ino, BTRFS_FIRST_FREE_OBJECTID, name,
1542                              strlen(name), BTRFS_FT_REG_FILE, NULL, 1);
1543         if (ret < 0)
1544                 goto out;
1545
1546         path = btrfs_alloc_path();
1547         if (!path) {
1548                 ret = -ENOMEM;
1549                 goto out;
1550         }
1551         key.objectid = ino;
1552         key.type = BTRFS_INODE_ITEM_KEY;
1553         key.offset = 0;
1554
1555         ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1556         if (ret) {
1557                 ret = (ret > 0 ? -ENOENT : ret);
1558                 goto out;
1559         }
1560         read_extent_buffer(path->nodes[0], &buf,
1561                         btrfs_item_ptr_offset(path->nodes[0], path->slots[0]),
1562                         sizeof(buf));
1563         btrfs_release_path(path);
1564
1565         /*
1566          * Create a new used space cache, which doesn't contain the reserved
1567          * range
1568          */
1569         for (cache = first_cache_extent(&cctx->used); cache;
1570              cache = next_cache_extent(cache)) {
1571                 ret = add_cache_extent(&used_tmp, cache->start, cache->size);
1572                 if (ret < 0)
1573                         goto out;
1574         }
1575         ret = wipe_reserved_ranges(&used_tmp, 0, 0);
1576         if (ret < 0)
1577                 goto out;
1578
1579         /*
1580          * Start from 1M, as 0~1M is reserved, and create_image_file_range()
1581          * can't handle bytenr 0(will consider it as a hole)
1582          */
1583         cur = 1024 * 1024;
1584         while (cur < size) {
1585                 u64 len = size - cur;
1586
1587                 ret = create_image_file_range(trans, root, &used_tmp,
1588                                                 &buf, ino, cur, &len, datacsum);
1589                 if (ret < 0)
1590                         goto out;
1591                 cur += len;
1592         }
1593         /* Handle the reserved ranges */
1594         ret = migrate_reserved_ranges(trans, root, &cctx->used, &buf, fd, ino,
1595                                       cfg->num_bytes, datacsum);
1596
1597
1598         key.objectid = ino;
1599         key.type = BTRFS_INODE_ITEM_KEY;
1600         key.offset = 0;
1601         ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1602         if (ret) {
1603                 ret = (ret > 0 ? -ENOENT : ret);
1604                 goto out;
1605         }
1606         btrfs_set_stack_inode_size(&buf, cfg->num_bytes);
1607         write_extent_buffer(path->nodes[0], &buf,
1608                         btrfs_item_ptr_offset(path->nodes[0], path->slots[0]),
1609                         sizeof(buf));
1610 out:
1611         free_extent_cache_tree(&used_tmp);
1612         btrfs_free_path(path);
1613         btrfs_commit_transaction(trans, root);
1614         return ret;
1615 }
1616
1617 static struct btrfs_root * link_subvol(struct btrfs_root *root,
1618                 const char *base, u64 root_objectid)
1619 {
1620         struct btrfs_trans_handle *trans;
1621         struct btrfs_fs_info *fs_info = root->fs_info;
1622         struct btrfs_root *tree_root = fs_info->tree_root;
1623         struct btrfs_root *new_root = NULL;
1624         struct btrfs_path *path;
1625         struct btrfs_inode_item *inode_item;
1626         struct extent_buffer *leaf;
1627         struct btrfs_key key;
1628         u64 dirid = btrfs_root_dirid(&root->root_item);
1629         u64 index = 2;
1630         char buf[BTRFS_NAME_LEN + 1]; /* for snprintf null */
1631         int len;
1632         int i;
1633         int ret;
1634
1635         len = strlen(base);
1636         if (len == 0 || len > BTRFS_NAME_LEN)
1637                 return NULL;
1638
1639         path = btrfs_alloc_path();
1640         BUG_ON(!path);
1641
1642         key.objectid = dirid;
1643         key.type = BTRFS_DIR_INDEX_KEY;
1644         key.offset = (u64)-1;
1645
1646         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1647         BUG_ON(ret <= 0);
1648
1649         if (path->slots[0] > 0) {
1650                 path->slots[0]--;
1651                 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1652                 if (key.objectid == dirid && key.type == BTRFS_DIR_INDEX_KEY)
1653                         index = key.offset + 1;
1654         }
1655         btrfs_release_path(path);
1656
1657         trans = btrfs_start_transaction(root, 1);
1658         BUG_ON(!trans);
1659
1660         key.objectid = dirid;
1661         key.offset = 0;
1662         key.type =  BTRFS_INODE_ITEM_KEY;
1663
1664         ret = btrfs_lookup_inode(trans, root, path, &key, 1);
1665         BUG_ON(ret);
1666         leaf = path->nodes[0];
1667         inode_item = btrfs_item_ptr(leaf, path->slots[0],
1668                                     struct btrfs_inode_item);
1669
1670         key.objectid = root_objectid;
1671         key.offset = (u64)-1;
1672         key.type = BTRFS_ROOT_ITEM_KEY;
1673
1674         memcpy(buf, base, len);
1675         for (i = 0; i < 1024; i++) {
1676                 ret = btrfs_insert_dir_item(trans, root, buf, len,
1677                                             dirid, &key, BTRFS_FT_DIR, index);
1678                 if (ret != -EEXIST)
1679                         break;
1680                 len = snprintf(buf, ARRAY_SIZE(buf), "%s%d", base, i);
1681                 if (len < 1 || len > BTRFS_NAME_LEN) {
1682                         ret = -EINVAL;
1683                         break;
1684                 }
1685         }
1686         if (ret)
1687                 goto fail;
1688
1689         btrfs_set_inode_size(leaf, inode_item, len * 2 +
1690                              btrfs_inode_size(leaf, inode_item));
1691         btrfs_mark_buffer_dirty(leaf);
1692         btrfs_release_path(path);
1693
1694         /* add the backref first */
1695         ret = btrfs_add_root_ref(trans, tree_root, root_objectid,
1696                                  BTRFS_ROOT_BACKREF_KEY,
1697                                  root->root_key.objectid,
1698                                  dirid, index, buf, len);
1699         BUG_ON(ret);
1700
1701         /* now add the forward ref */
1702         ret = btrfs_add_root_ref(trans, tree_root, root->root_key.objectid,
1703                                  BTRFS_ROOT_REF_KEY, root_objectid,
1704                                  dirid, index, buf, len);
1705
1706         ret = btrfs_commit_transaction(trans, root);
1707         BUG_ON(ret);
1708
1709         new_root = btrfs_read_fs_root(fs_info, &key);
1710         if (IS_ERR(new_root))
1711                 new_root = NULL;
1712 fail:
1713         btrfs_free_path(path);
1714         return new_root;
1715 }
1716
1717 static int create_subvol(struct btrfs_trans_handle *trans,
1718                          struct btrfs_root *root, u64 root_objectid)
1719 {
1720         struct extent_buffer *tmp;
1721         struct btrfs_root *new_root;
1722         struct btrfs_key key;
1723         struct btrfs_root_item root_item;
1724         int ret;
1725
1726         ret = btrfs_copy_root(trans, root, root->node, &tmp,
1727                               root_objectid);
1728         BUG_ON(ret);
1729
1730         memcpy(&root_item, &root->root_item, sizeof(root_item));
1731         btrfs_set_root_bytenr(&root_item, tmp->start);
1732         btrfs_set_root_level(&root_item, btrfs_header_level(tmp));
1733         btrfs_set_root_generation(&root_item, trans->transid);
1734         free_extent_buffer(tmp);
1735
1736         key.objectid = root_objectid;
1737         key.type = BTRFS_ROOT_ITEM_KEY;
1738         key.offset = trans->transid;
1739         ret = btrfs_insert_root(trans, root->fs_info->tree_root,
1740                                 &key, &root_item);
1741
1742         key.offset = (u64)-1;
1743         new_root = btrfs_read_fs_root(root->fs_info, &key);
1744         BUG_ON(!new_root || IS_ERR(new_root));
1745
1746         ret = btrfs_make_root_dir(trans, new_root, BTRFS_FIRST_FREE_OBJECTID);
1747         BUG_ON(ret);
1748
1749         return 0;
1750 }
1751
1752 /*
1753  * New make_btrfs() has handle system and meta chunks quite well.
1754  * So only need to add remaining data chunks.
1755  */
1756 static int make_convert_data_block_groups(struct btrfs_trans_handle *trans,
1757                                           struct btrfs_fs_info *fs_info,
1758                                           struct btrfs_mkfs_config *cfg,
1759                                           struct btrfs_convert_context *cctx)
1760 {
1761         struct btrfs_root *extent_root = fs_info->extent_root;
1762         struct cache_tree *data_chunks = &cctx->data_chunks;
1763         struct cache_extent *cache;
1764         u64 max_chunk_size;
1765         int ret = 0;
1766
1767         /*
1768          * Don't create data chunk over 10% of the convert device
1769          * And for single chunk, don't create chunk larger than 1G.
1770          */
1771         max_chunk_size = cfg->num_bytes / 10;
1772         max_chunk_size = min((u64)(1024 * 1024 * 1024), max_chunk_size);
1773         max_chunk_size = round_down(max_chunk_size, extent_root->sectorsize);
1774
1775         for (cache = first_cache_extent(data_chunks); cache;
1776              cache = next_cache_extent(cache)) {
1777                 u64 cur = cache->start;
1778
1779                 while (cur < cache->start + cache->size) {
1780                         u64 len;
1781                         u64 cur_backup = cur;
1782
1783                         len = min(max_chunk_size,
1784                                   cache->start + cache->size - cur);
1785                         ret = btrfs_alloc_data_chunk(trans, extent_root,
1786                                         &cur_backup, len,
1787                                         BTRFS_BLOCK_GROUP_DATA, 1);
1788                         if (ret < 0)
1789                                 break;
1790                         ret = btrfs_make_block_group(trans, extent_root, 0,
1791                                         BTRFS_BLOCK_GROUP_DATA,
1792                                         BTRFS_FIRST_CHUNK_TREE_OBJECTID,
1793                                         cur, len);
1794                         if (ret < 0)
1795                                 break;
1796                         cur += len;
1797                 }
1798         }
1799         return ret;
1800 }
1801
1802 /*
1803  * Init the temp btrfs to a operational status.
1804  *
1805  * It will fix the extent usage accounting(XXX: Do we really need?) and
1806  * insert needed data chunks, to ensure all old fs data extents are covered
1807  * by DATA chunks, preventing wrong chunks are allocated.
1808  *
1809  * And also create convert image subvolume and relocation tree.
1810  * (XXX: Not need again?)
1811  * But the convert image subvolume is *NOT* linked to fs tree yet.
1812  */
1813 static int init_btrfs(struct btrfs_mkfs_config *cfg, struct btrfs_root *root,
1814                          struct btrfs_convert_context *cctx, int datacsum,
1815                          int packing, int noxattr)
1816 {
1817         struct btrfs_key location;
1818         struct btrfs_trans_handle *trans;
1819         struct btrfs_fs_info *fs_info = root->fs_info;
1820         int ret;
1821
1822         /*
1823          * Don't alloc any metadata/system chunk, as we don't want
1824          * any meta/sys chunk allcated before all data chunks are inserted.
1825          * Or we screw up the chunk layout just like the old implement.
1826          */
1827         fs_info->avoid_sys_chunk_alloc = 1;
1828         fs_info->avoid_meta_chunk_alloc = 1;
1829         trans = btrfs_start_transaction(root, 1);
1830         BUG_ON(!trans);
1831         ret = btrfs_fix_block_accounting(trans, root);
1832         if (ret)
1833                 goto err;
1834         ret = make_convert_data_block_groups(trans, fs_info, cfg, cctx);
1835         if (ret)
1836                 goto err;
1837         ret = btrfs_make_root_dir(trans, fs_info->tree_root,
1838                                   BTRFS_ROOT_TREE_DIR_OBJECTID);
1839         if (ret)
1840                 goto err;
1841         memcpy(&location, &root->root_key, sizeof(location));
1842         location.offset = (u64)-1;
1843         ret = btrfs_insert_dir_item(trans, fs_info->tree_root, "default", 7,
1844                                 btrfs_super_root_dir(fs_info->super_copy),
1845                                 &location, BTRFS_FT_DIR, 0);
1846         if (ret)
1847                 goto err;
1848         ret = btrfs_insert_inode_ref(trans, fs_info->tree_root, "default", 7,
1849                                 location.objectid,
1850                                 btrfs_super_root_dir(fs_info->super_copy), 0);
1851         if (ret)
1852                 goto err;
1853         btrfs_set_root_dirid(&fs_info->fs_root->root_item,
1854                              BTRFS_FIRST_FREE_OBJECTID);
1855
1856         /* subvol for fs image file */
1857         ret = create_subvol(trans, root, CONV_IMAGE_SUBVOL_OBJECTID);
1858         if (ret < 0)
1859                 goto err;
1860         /* subvol for data relocation tree */
1861         ret = create_subvol(trans, root, BTRFS_DATA_RELOC_TREE_OBJECTID);
1862         if (ret < 0)
1863                 goto err;
1864
1865         ret = btrfs_commit_transaction(trans, root);
1866         fs_info->avoid_sys_chunk_alloc = 0;
1867         fs_info->avoid_meta_chunk_alloc = 0;
1868 err:
1869         return ret;
1870 }
1871
1872 /*
1873  * Migrate super block to its default position and zero 0 ~ 16k
1874  */
1875 static int migrate_super_block(int fd, u64 old_bytenr, u32 sectorsize)
1876 {
1877         int ret;
1878         struct extent_buffer *buf;
1879         struct btrfs_super_block *super;
1880         u32 len;
1881         u32 bytenr;
1882
1883         BUG_ON(sectorsize < sizeof(*super));
1884         buf = malloc(sizeof(*buf) + sectorsize);
1885         if (!buf)
1886                 return -ENOMEM;
1887
1888         buf->len = sectorsize;
1889         ret = pread(fd, buf->data, sectorsize, old_bytenr);
1890         if (ret != sectorsize)
1891                 goto fail;
1892
1893         super = (struct btrfs_super_block *)buf->data;
1894         BUG_ON(btrfs_super_bytenr(super) != old_bytenr);
1895         btrfs_set_super_bytenr(super, BTRFS_SUPER_INFO_OFFSET);
1896
1897         csum_tree_block_size(buf, BTRFS_CRC32_SIZE, 0);
1898         ret = pwrite(fd, buf->data, sectorsize, BTRFS_SUPER_INFO_OFFSET);
1899         if (ret != sectorsize)
1900                 goto fail;
1901
1902         ret = fsync(fd);
1903         if (ret)
1904                 goto fail;
1905
1906         memset(buf->data, 0, sectorsize);
1907         for (bytenr = 0; bytenr < BTRFS_SUPER_INFO_OFFSET; ) {
1908                 len = BTRFS_SUPER_INFO_OFFSET - bytenr;
1909                 if (len > sectorsize)
1910                         len = sectorsize;
1911                 ret = pwrite(fd, buf->data, len, bytenr);
1912                 if (ret != len) {
1913                         fprintf(stderr, "unable to zero fill device\n");
1914                         break;
1915                 }
1916                 bytenr += len;
1917         }
1918         ret = 0;
1919         fsync(fd);
1920 fail:
1921         free(buf);
1922         if (ret > 0)
1923                 ret = -1;
1924         return ret;
1925 }
1926
1927 static int prepare_system_chunk_sb(struct btrfs_super_block *super)
1928 {
1929         struct btrfs_chunk *chunk;
1930         struct btrfs_disk_key *key;
1931         u32 sectorsize = btrfs_super_sectorsize(super);
1932
1933         key = (struct btrfs_disk_key *)(super->sys_chunk_array);
1934         chunk = (struct btrfs_chunk *)(super->sys_chunk_array +
1935                                        sizeof(struct btrfs_disk_key));
1936
1937         btrfs_set_disk_key_objectid(key, BTRFS_FIRST_CHUNK_TREE_OBJECTID);
1938         btrfs_set_disk_key_type(key, BTRFS_CHUNK_ITEM_KEY);
1939         btrfs_set_disk_key_offset(key, 0);
1940
1941         btrfs_set_stack_chunk_length(chunk, btrfs_super_total_bytes(super));
1942         btrfs_set_stack_chunk_owner(chunk, BTRFS_EXTENT_TREE_OBJECTID);
1943         btrfs_set_stack_chunk_stripe_len(chunk, BTRFS_STRIPE_LEN);
1944         btrfs_set_stack_chunk_type(chunk, BTRFS_BLOCK_GROUP_SYSTEM);
1945         btrfs_set_stack_chunk_io_align(chunk, sectorsize);
1946         btrfs_set_stack_chunk_io_width(chunk, sectorsize);
1947         btrfs_set_stack_chunk_sector_size(chunk, sectorsize);
1948         btrfs_set_stack_chunk_num_stripes(chunk, 1);
1949         btrfs_set_stack_chunk_sub_stripes(chunk, 0);
1950         chunk->stripe.devid = super->dev_item.devid;
1951         btrfs_set_stack_stripe_offset(&chunk->stripe, 0);
1952         memcpy(chunk->stripe.dev_uuid, super->dev_item.uuid, BTRFS_UUID_SIZE);
1953         btrfs_set_super_sys_array_size(super, sizeof(*key) + sizeof(*chunk));
1954         return 0;
1955 }
1956
1957 static const struct btrfs_convert_operations ext2_convert_ops = {
1958         .name                   = "ext2",
1959         .open_fs                = ext2_open_fs,
1960         .read_used_space        = ext2_read_used_space,
1961         .copy_inodes            = ext2_copy_inodes,
1962         .close_fs               = ext2_close_fs,
1963 };
1964
1965 static const struct btrfs_convert_operations *convert_operations[] = {
1966         &ext2_convert_ops,
1967 };
1968
1969 static int convert_open_fs(const char *devname,
1970                            struct btrfs_convert_context *cctx)
1971 {
1972         int i;
1973
1974         memset(cctx, 0, sizeof(*cctx));
1975
1976         for (i = 0; i < ARRAY_SIZE(convert_operations); i++) {
1977                 int ret = convert_operations[i]->open_fs(cctx, devname);
1978
1979                 if (ret == 0) {
1980                         cctx->convert_ops = convert_operations[i];
1981                         return ret;
1982                 }
1983         }
1984
1985         fprintf(stderr, "No file system found to convert.\n");
1986         return -1;
1987 }
1988
1989 /*
1990  * Helper for expand and merge extent_cache for wipe_one_reserved_range() to
1991  * handle wiping a range that exists in cache.
1992  */
1993 static int _expand_extent_cache(struct cache_tree *tree,
1994                                 struct cache_extent *entry,
1995                                 u64 min_stripe_size, int backward)
1996 {
1997         struct cache_extent *ce;
1998         int diff;
1999
2000         if (entry->size >= min_stripe_size)
2001                 return 0;
2002         diff = min_stripe_size - entry->size;
2003
2004         if (backward) {
2005                 ce = prev_cache_extent(entry);
2006                 if (!ce)
2007                         goto expand_back;
2008                 if (ce->start + ce->size >= entry->start - diff) {
2009                         /* Directly merge with previous extent */
2010                         ce->size = entry->start + entry->size - ce->start;
2011                         remove_cache_extent(tree, entry);
2012                         free(entry);
2013                         return 0;
2014                 }
2015 expand_back:
2016                 /* No overlap, normal extent */
2017                 if (entry->start < diff) {
2018                         error("cannot find space for data chunk layout");
2019                         return -ENOSPC;
2020                 }
2021                 entry->start -= diff;
2022                 entry->size += diff;
2023                 return 0;
2024         }
2025         ce = next_cache_extent(entry);
2026         if (!ce)
2027                 goto expand_after;
2028         if (entry->start + entry->size + diff >= ce->start) {
2029                 /* Directly merge with next extent */
2030                 entry->size = ce->start + ce->size - entry->start;
2031                 remove_cache_extent(tree, ce);
2032                 free(ce);
2033                 return 0;
2034         }
2035 expand_after:
2036         entry->size += diff;
2037         return 0;
2038 }
2039
2040 /*
2041  * Remove one reserve range from given cache tree
2042  * if min_stripe_size is non-zero, it will ensure for split case,
2043  * all its split cache extent is no smaller than @min_strip_size / 2.
2044  */
2045 static int wipe_one_reserved_range(struct cache_tree *tree,
2046                                    u64 start, u64 len, u64 min_stripe_size,
2047                                    int ensure_size)
2048 {
2049         struct cache_extent *cache;
2050         int ret;
2051
2052         BUG_ON(ensure_size && min_stripe_size == 0);
2053         /*
2054          * The logical here is simplified to handle special cases only
2055          * So we don't need to consider merge case for ensure_size
2056          */
2057         BUG_ON(min_stripe_size && (min_stripe_size < len * 2 ||
2058                min_stripe_size / 2 < BTRFS_STRIPE_LEN));
2059
2060         /* Also, wipe range should already be aligned */
2061         BUG_ON(start != round_down(start, BTRFS_STRIPE_LEN) ||
2062                start + len != round_up(start + len, BTRFS_STRIPE_LEN));
2063
2064         min_stripe_size /= 2;
2065
2066         cache = lookup_cache_extent(tree, start, len);
2067         if (!cache)
2068                 return 0;
2069
2070         if (start <= cache->start) {
2071                 /*
2072                  *      |--------cache---------|
2073                  * |-wipe-|
2074                  */
2075                 BUG_ON(start + len <= cache->start);
2076
2077                 /*
2078                  * The wipe size is smaller than min_stripe_size / 2,
2079                  * so the result length should still meet min_stripe_size
2080                  * And no need to do alignment
2081                  */
2082                 cache->size -= (start + len - cache->start);
2083                 if (cache->size == 0) {
2084                         remove_cache_extent(tree, cache);
2085                         free(cache);
2086                         return 0;
2087                 }
2088
2089                 BUG_ON(ensure_size && cache->size < min_stripe_size);
2090
2091                 cache->start = start + len;
2092                 return 0;
2093         } else if (start > cache->start && start + len < cache->start +
2094                    cache->size) {
2095                 /*
2096                  * |-------cache-----|
2097                  *      |-wipe-|
2098                  */
2099                 u64 old_start = cache->start;
2100                 u64 old_len = cache->size;
2101                 u64 insert_start = start + len;
2102                 u64 insert_len;
2103
2104                 cache->size = start - cache->start;
2105                 /* Expand the leading half part if needed */
2106                 if (ensure_size && cache->size < min_stripe_size) {
2107                         ret = _expand_extent_cache(tree, cache,
2108                                         min_stripe_size, 1);
2109                         if (ret < 0)
2110                                 return ret;
2111                 }
2112
2113                 /* And insert the new one */
2114                 insert_len = old_start + old_len - start - len;
2115                 ret = add_merge_cache_extent(tree, insert_start, insert_len);
2116                 if (ret < 0)
2117                         return ret;
2118
2119                 /* Expand the last half part if needed */
2120                 if (ensure_size && insert_len < min_stripe_size) {
2121                         cache = lookup_cache_extent(tree, insert_start,
2122                                                     insert_len);
2123                         if (!cache || cache->start != insert_start ||
2124                             cache->size != insert_len)
2125                                 return -ENOENT;
2126                         ret = _expand_extent_cache(tree, cache,
2127                                         min_stripe_size, 0);
2128                 }
2129
2130                 return ret;
2131         }
2132         /*
2133          * |----cache-----|
2134          *              |--wipe-|
2135          * Wipe len should be small enough and no need to expand the
2136          * remaining extent
2137          */
2138         cache->size = start - cache->start;
2139         BUG_ON(ensure_size && cache->size < min_stripe_size);
2140         return 0;
2141 }
2142
2143 /*
2144  * Remove reserved ranges from given cache_tree
2145  *
2146  * It will remove the following ranges
2147  * 1) 0~1M
2148  * 2) 2nd superblock, +64K (make sure chunks are 64K aligned)
2149  * 3) 3rd superblock, +64K
2150  *
2151  * @min_stripe must be given for safety check
2152  * and if @ensure_size is given, it will ensure affected cache_extent will be
2153  * larger than min_stripe_size
2154  */
2155 static int wipe_reserved_ranges(struct cache_tree *tree, u64 min_stripe_size,
2156                                 int ensure_size)
2157 {
2158         int ret;
2159
2160         ret = wipe_one_reserved_range(tree, 0, 1024 * 1024, min_stripe_size,
2161                                       ensure_size);
2162         if (ret < 0)
2163                 return ret;
2164         ret = wipe_one_reserved_range(tree, btrfs_sb_offset(1),
2165                         BTRFS_STRIPE_LEN, min_stripe_size, ensure_size);
2166         if (ret < 0)
2167                 return ret;
2168         ret = wipe_one_reserved_range(tree, btrfs_sb_offset(2),
2169                         BTRFS_STRIPE_LEN, min_stripe_size, ensure_size);
2170         return ret;
2171 }
2172
2173 static int calculate_available_space(struct btrfs_convert_context *cctx)
2174 {
2175         struct cache_tree *used = &cctx->used;
2176         struct cache_tree *data_chunks = &cctx->data_chunks;
2177         struct cache_tree *free = &cctx->free;
2178         struct cache_extent *cache;
2179         u64 cur_off = 0;
2180         /*
2181          * Twice the minimal chunk size, to allow later wipe_reserved_ranges()
2182          * works without need to consider overlap
2183          */
2184         u64 min_stripe_size = 2 * 16 * 1024 * 1024;
2185         int ret;
2186
2187         /* Calculate data_chunks */
2188         for (cache = first_cache_extent(used); cache;
2189              cache = next_cache_extent(cache)) {
2190                 u64 cur_len;
2191
2192                 if (cache->start + cache->size < cur_off)
2193                         continue;
2194                 if (cache->start > cur_off + min_stripe_size)
2195                         cur_off = cache->start;
2196                 cur_len = max(cache->start + cache->size - cur_off,
2197                               min_stripe_size);
2198                 ret = add_merge_cache_extent(data_chunks, cur_off, cur_len);
2199                 if (ret < 0)
2200                         goto out;
2201                 cur_off += cur_len;
2202         }
2203         /*
2204          * remove reserved ranges, so we won't ever bother relocating an old
2205          * filesystem extent to other place.
2206          */
2207         ret = wipe_reserved_ranges(data_chunks, min_stripe_size, 1);
2208         if (ret < 0)
2209                 goto out;
2210
2211         cur_off = 0;
2212         /*
2213          * Calculate free space
2214          * Always round up the start bytenr, to avoid metadata extent corss
2215          * stripe boundary, as later mkfs_convert() won't have all the extent
2216          * allocation check
2217          */
2218         for (cache = first_cache_extent(data_chunks); cache;
2219              cache = next_cache_extent(cache)) {
2220                 if (cache->start < cur_off)
2221                         continue;
2222                 if (cache->start > cur_off) {
2223                         u64 insert_start;
2224                         u64 len;
2225
2226                         len = cache->start - round_up(cur_off,
2227                                                       BTRFS_STRIPE_LEN);
2228                         insert_start = round_up(cur_off, BTRFS_STRIPE_LEN);
2229
2230                         ret = add_merge_cache_extent(free, insert_start, len);
2231                         if (ret < 0)
2232                                 goto out;
2233                 }
2234                 cur_off = cache->start + cache->size;
2235         }
2236         /* Don't forget the last range */
2237         if (cctx->total_bytes > cur_off) {
2238                 u64 len = cctx->total_bytes - cur_off;
2239                 u64 insert_start;
2240
2241                 insert_start = round_up(cur_off, BTRFS_STRIPE_LEN);
2242
2243                 ret = add_merge_cache_extent(free, insert_start, len);
2244                 if (ret < 0)
2245                         goto out;
2246         }
2247
2248         /* Remove reserved bytes */
2249         ret = wipe_reserved_ranges(free, min_stripe_size, 0);
2250 out:
2251         return ret;
2252 }
2253 /*
2254  * Read used space, and since we have the used space,
2255  * calcuate data_chunks and free for later mkfs
2256  */
2257 static int convert_read_used_space(struct btrfs_convert_context *cctx)
2258 {
2259         int ret;
2260
2261         ret = cctx->convert_ops->read_used_space(cctx);
2262         if (ret)
2263                 return ret;
2264
2265         ret = calculate_available_space(cctx);
2266         return ret;
2267 }
2268
2269 static int do_convert(const char *devname, int datacsum, int packing,
2270                 int noxattr, u32 nodesize, int copylabel, const char *fslabel,
2271                 int progress, u64 features)
2272 {
2273         int ret;
2274         int fd = -1;
2275         int is_btrfs = 0;
2276         u32 blocksize;
2277         u64 total_bytes;
2278         struct btrfs_root *root;
2279         struct btrfs_root *image_root;
2280         struct btrfs_convert_context cctx;
2281         struct btrfs_key key;
2282         char *subvol_name = NULL;
2283         struct task_ctx ctx;
2284         char features_buf[64];
2285         struct btrfs_mkfs_config mkfs_cfg;
2286
2287         init_convert_context(&cctx);
2288         ret = convert_open_fs(devname, &cctx);
2289         if (ret)
2290                 goto fail;
2291         ret = convert_read_used_space(&cctx);
2292         if (ret)
2293                 goto fail;
2294
2295         blocksize = cctx.blocksize;
2296         total_bytes = (u64)blocksize * (u64)cctx.block_count;
2297         if (blocksize < 4096) {
2298                 fprintf(stderr, "block size is too small\n");
2299                 goto fail;
2300         }
2301         if (btrfs_check_nodesize(nodesize, blocksize, features))
2302                 goto fail;
2303         fd = open(devname, O_RDWR);
2304         if (fd < 0) {
2305                 fprintf(stderr, "unable to open %s\n", devname);
2306                 goto fail;
2307         }
2308         btrfs_parse_features_to_string(features_buf, features);
2309         if (features == BTRFS_MKFS_DEFAULT_FEATURES)
2310                 strcat(features_buf, " (default)");
2311
2312         printf("create btrfs filesystem:\n");
2313         printf("\tblocksize: %u\n", blocksize);
2314         printf("\tnodesize:  %u\n", nodesize);
2315         printf("\tfeatures:  %s\n", features_buf);
2316
2317         mkfs_cfg.label = cctx.volume_name;
2318         mkfs_cfg.num_bytes = total_bytes;
2319         mkfs_cfg.nodesize = nodesize;
2320         mkfs_cfg.sectorsize = blocksize;
2321         mkfs_cfg.stripesize = blocksize;
2322         mkfs_cfg.features = features;
2323         /* New convert need these space */
2324         mkfs_cfg.fs_uuid = malloc(BTRFS_UUID_UNPARSED_SIZE);
2325         mkfs_cfg.chunk_uuid = malloc(BTRFS_UUID_UNPARSED_SIZE);
2326         *(mkfs_cfg.fs_uuid) = '\0';
2327         *(mkfs_cfg.chunk_uuid) = '\0';
2328
2329         ret = make_btrfs(fd, &mkfs_cfg, &cctx);
2330         if (ret) {
2331                 fprintf(stderr, "unable to create initial ctree: %s\n",
2332                         strerror(-ret));
2333                 goto fail;
2334         }
2335
2336         root = open_ctree_fd(fd, devname, mkfs_cfg.super_bytenr,
2337                              OPEN_CTREE_WRITES);
2338         if (!root) {
2339                 fprintf(stderr, "unable to open ctree\n");
2340                 goto fail;
2341         }
2342         ret = init_btrfs(&mkfs_cfg, root, &cctx, datacsum, packing, noxattr);
2343         if (ret) {
2344                 fprintf(stderr, "unable to setup the root tree\n");
2345                 goto fail;
2346         }
2347
2348         printf("creating %s image file.\n", cctx.convert_ops->name);
2349         ret = asprintf(&subvol_name, "%s_saved", cctx.convert_ops->name);
2350         if (ret < 0) {
2351                 fprintf(stderr, "error allocating subvolume name: %s_saved\n",
2352                         cctx.convert_ops->name);
2353                 goto fail;
2354         }
2355         key.objectid = CONV_IMAGE_SUBVOL_OBJECTID;
2356         key.offset = (u64)-1;
2357         key.type = BTRFS_ROOT_ITEM_KEY;
2358         image_root = btrfs_read_fs_root(root->fs_info, &key);
2359         if (!image_root) {
2360                 fprintf(stderr, "unable to create subvol\n");
2361                 goto fail;
2362         }
2363         ret = create_image(image_root, &mkfs_cfg, &cctx, fd,
2364                               mkfs_cfg.num_bytes, "image", datacsum);
2365         if (ret) {
2366                 fprintf(stderr, "error during create_image %d\n", ret);
2367                 goto fail;
2368         }
2369
2370         printf("creating btrfs metadata.\n");
2371         ctx.max_copy_inodes = (cctx.inodes_count - cctx.free_inodes_count);
2372         ctx.cur_copy_inodes = 0;
2373
2374         if (progress) {
2375                 ctx.info = task_init(print_copied_inodes, after_copied_inodes,
2376                                      &ctx);
2377                 task_start(ctx.info);
2378         }
2379         ret = copy_inodes(&cctx, root, datacsum, packing, noxattr, &ctx);
2380         if (ret) {
2381                 fprintf(stderr, "error during copy_inodes %d\n", ret);
2382                 goto fail;
2383         }
2384         if (progress) {
2385                 task_stop(ctx.info);
2386                 task_deinit(ctx.info);
2387         }
2388
2389         image_root = link_subvol(root, subvol_name, CONV_IMAGE_SUBVOL_OBJECTID);
2390
2391         free(subvol_name);
2392
2393         memset(root->fs_info->super_copy->label, 0, BTRFS_LABEL_SIZE);
2394         if (copylabel == 1) {
2395                 __strncpy_null(root->fs_info->super_copy->label,
2396                                 cctx.volume_name, BTRFS_LABEL_SIZE - 1);
2397                 fprintf(stderr, "copy label '%s'\n",
2398                                 root->fs_info->super_copy->label);
2399         } else if (copylabel == -1) {
2400                 strcpy(root->fs_info->super_copy->label, fslabel);
2401                 fprintf(stderr, "set label to '%s'\n", fslabel);
2402         }
2403
2404         ret = close_ctree(root);
2405         if (ret) {
2406                 fprintf(stderr, "error during close_ctree %d\n", ret);
2407                 goto fail;
2408         }
2409         convert_close_fs(&cctx);
2410         clean_convert_context(&cctx);
2411
2412         /*
2413          * If this step succeed, we get a mountable btrfs. Otherwise
2414          * the source fs is left unchanged.
2415          */
2416         ret = migrate_super_block(fd, mkfs_cfg.super_bytenr, blocksize);
2417         if (ret) {
2418                 fprintf(stderr, "unable to migrate super block\n");
2419                 goto fail;
2420         }
2421         is_btrfs = 1;
2422
2423         root = open_ctree_fd(fd, devname, 0, OPEN_CTREE_WRITES);
2424         if (!root) {
2425                 fprintf(stderr, "unable to open ctree\n");
2426                 goto fail;
2427         }
2428         close(fd);
2429
2430         printf("conversion complete.\n");
2431         return 0;
2432 fail:
2433         clean_convert_context(&cctx);
2434         if (fd != -1)
2435                 close(fd);
2436         if (is_btrfs)
2437                 fprintf(stderr,
2438                         "WARNING: an error occurred during chunk mapping fixup, filesystem mountable but not finalized\n");
2439         else
2440                 fprintf(stderr, "conversion aborted\n");
2441         return -1;
2442 }
2443
2444 /*
2445  * Check if a non 1:1 mapped chunk can be rolled back.
2446  * For new convert, it's OK while for old convert it's not.
2447  */
2448 static int may_rollback_chunk(struct btrfs_fs_info *fs_info, u64 bytenr)
2449 {
2450         struct btrfs_block_group_cache *bg;
2451         struct btrfs_key key;
2452         struct btrfs_path path;
2453         struct btrfs_root *extent_root = fs_info->extent_root;
2454         u64 bg_start;
2455         u64 bg_end;
2456         int ret;
2457
2458         bg = btrfs_lookup_first_block_group(fs_info, bytenr);
2459         if (!bg)
2460                 return -ENOENT;
2461         bg_start = bg->key.objectid;
2462         bg_end = bg->key.objectid + bg->key.offset;
2463
2464         key.objectid = bg_end;
2465         key.type = BTRFS_METADATA_ITEM_KEY;
2466         key.offset = 0;
2467         btrfs_init_path(&path);
2468
2469         ret = btrfs_search_slot(NULL, extent_root, &key, &path, 0, 0);
2470         if (ret < 0)
2471                 return ret;
2472
2473         while (1) {
2474                 struct btrfs_extent_item *ei;
2475
2476                 ret = btrfs_previous_extent_item(extent_root, &path, bg_start);
2477                 if (ret > 0) {
2478                         ret = 0;
2479                         break;
2480                 }
2481                 if (ret < 0)
2482                         break;
2483
2484                 btrfs_item_key_to_cpu(path.nodes[0], &key, path.slots[0]);
2485                 if (key.type == BTRFS_METADATA_ITEM_KEY)
2486                         continue;
2487                 /* Now it's EXTENT_ITEM_KEY only */
2488                 ei = btrfs_item_ptr(path.nodes[0], path.slots[0],
2489                                     struct btrfs_extent_item);
2490                 /*
2491                  * Found data extent, means this is old convert must follow 1:1
2492                  * mapping.
2493                  */
2494                 if (btrfs_extent_flags(path.nodes[0], ei)
2495                                 & BTRFS_EXTENT_FLAG_DATA) {
2496                         ret = -EINVAL;
2497                         break;
2498                 }
2499         }
2500         btrfs_release_path(&path);
2501         return ret;
2502 }
2503
2504 static int may_rollback(struct btrfs_root *root)
2505 {
2506         struct btrfs_fs_info *info = root->fs_info;
2507         struct btrfs_multi_bio *multi = NULL;
2508         u64 bytenr;
2509         u64 length;
2510         u64 physical;
2511         u64 total_bytes;
2512         int num_stripes;
2513         int ret;
2514
2515         if (btrfs_super_num_devices(info->super_copy) != 1)
2516                 goto fail;
2517
2518         bytenr = BTRFS_SUPER_INFO_OFFSET;
2519         total_bytes = btrfs_super_total_bytes(root->fs_info->super_copy);
2520
2521         while (1) {
2522                 ret = btrfs_map_block(&info->mapping_tree, WRITE, bytenr,
2523                                       &length, &multi, 0, NULL);
2524                 if (ret) {
2525                         if (ret == -ENOENT) {
2526                                 /* removed block group at the tail */
2527                                 if (length == (u64)-1)
2528                                         break;
2529
2530                                 /* removed block group in the middle */
2531                                 goto next;
2532                         }
2533                         goto fail;
2534                 }
2535
2536                 num_stripes = multi->num_stripes;
2537                 physical = multi->stripes[0].physical;
2538                 kfree(multi);
2539
2540                 if (num_stripes != 1) {
2541                         error("num stripes for bytenr %llu is not 1", bytenr);
2542                         goto fail;
2543                 }
2544
2545                 /*
2546                  * Extra check for new convert, as metadata chunk from new
2547                  * convert is much more free than old convert, it doesn't need
2548                  * to do 1:1 mapping.
2549                  */
2550                 if (physical != bytenr) {
2551                         /*
2552                          * Check if it's a metadata chunk and has only metadata
2553                          * extent.
2554                          */
2555                         ret = may_rollback_chunk(info, bytenr);
2556                         if (ret < 0)
2557                                 goto fail;
2558                 }
2559 next:
2560                 bytenr += length;
2561                 if (bytenr >= total_bytes)
2562                         break;
2563         }
2564         return 0;
2565 fail:
2566         return -1;
2567 }
2568
2569 static int do_rollback(const char *devname)
2570 {
2571         int fd = -1;
2572         int ret;
2573         int i;
2574         struct btrfs_root *root;
2575         struct btrfs_root *image_root;
2576         struct btrfs_root *chunk_root;
2577         struct btrfs_dir_item *dir;
2578         struct btrfs_inode_item *inode;
2579         struct btrfs_file_extent_item *fi;
2580         struct btrfs_trans_handle *trans;
2581         struct extent_buffer *leaf;
2582         struct btrfs_block_group_cache *cache1;
2583         struct btrfs_block_group_cache *cache2;
2584         struct btrfs_key key;
2585         struct btrfs_path path;
2586         struct extent_io_tree io_tree;
2587         char *buf = NULL;
2588         char *name;
2589         u64 bytenr;
2590         u64 num_bytes;
2591         u64 root_dir;
2592         u64 objectid;
2593         u64 offset;
2594         u64 start;
2595         u64 end;
2596         u64 sb_bytenr;
2597         u64 first_free;
2598         u64 total_bytes;
2599         u32 sectorsize;
2600
2601         extent_io_tree_init(&io_tree);
2602
2603         fd = open(devname, O_RDWR);
2604         if (fd < 0) {
2605                 fprintf(stderr, "unable to open %s\n", devname);
2606                 goto fail;
2607         }
2608         root = open_ctree_fd(fd, devname, 0, OPEN_CTREE_WRITES);
2609         if (!root) {
2610                 fprintf(stderr, "unable to open ctree\n");
2611                 goto fail;
2612         }
2613         ret = may_rollback(root);
2614         if (ret < 0) {
2615                 fprintf(stderr, "unable to do rollback\n");
2616                 goto fail;
2617         }
2618
2619         sectorsize = root->sectorsize;
2620         buf = malloc(sectorsize);
2621         if (!buf) {
2622                 fprintf(stderr, "unable to allocate memory\n");
2623                 goto fail;
2624         }
2625
2626         btrfs_init_path(&path);
2627
2628         key.objectid = CONV_IMAGE_SUBVOL_OBJECTID;
2629         key.type = BTRFS_ROOT_BACKREF_KEY;
2630         key.offset = BTRFS_FS_TREE_OBJECTID;
2631         ret = btrfs_search_slot(NULL, root->fs_info->tree_root, &key, &path, 0,
2632                                 0);
2633         btrfs_release_path(&path);
2634         if (ret > 0) {
2635                 fprintf(stderr,
2636                 "ERROR: unable to convert ext2 image subvolume, is it deleted?\n");
2637                 goto fail;
2638         } else if (ret < 0) {
2639                 fprintf(stderr,
2640                         "ERROR: unable to open ext2_saved, id=%llu: %s\n",
2641                         (unsigned long long)key.objectid, strerror(-ret));
2642                 goto fail;
2643         }
2644
2645         key.objectid = CONV_IMAGE_SUBVOL_OBJECTID;
2646         key.type = BTRFS_ROOT_ITEM_KEY;
2647         key.offset = (u64)-1;
2648         image_root = btrfs_read_fs_root(root->fs_info, &key);
2649         if (!image_root || IS_ERR(image_root)) {
2650                 fprintf(stderr, "unable to open subvol %llu\n",
2651                         (unsigned long long)key.objectid);
2652                 goto fail;
2653         }
2654
2655         name = "image";
2656         root_dir = btrfs_root_dirid(&root->root_item);
2657         dir = btrfs_lookup_dir_item(NULL, image_root, &path,
2658                                    root_dir, name, strlen(name), 0);
2659         if (!dir || IS_ERR(dir)) {
2660                 fprintf(stderr, "unable to find file %s\n", name);
2661                 goto fail;
2662         }
2663         leaf = path.nodes[0];
2664         btrfs_dir_item_key_to_cpu(leaf, dir, &key);
2665         btrfs_release_path(&path);
2666
2667         objectid = key.objectid;
2668
2669         ret = btrfs_lookup_inode(NULL, image_root, &path, &key, 0);
2670         if (ret) {
2671                 fprintf(stderr, "unable to find inode item\n");
2672                 goto fail;
2673         }
2674         leaf = path.nodes[0];
2675         inode = btrfs_item_ptr(leaf, path.slots[0], struct btrfs_inode_item);
2676         total_bytes = btrfs_inode_size(leaf, inode);
2677         btrfs_release_path(&path);
2678
2679         key.objectid = objectid;
2680         key.offset = 0;
2681         btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
2682         ret = btrfs_search_slot(NULL, image_root, &key, &path, 0, 0);
2683         if (ret != 0) {
2684                 fprintf(stderr, "unable to find first file extent\n");
2685                 btrfs_release_path(&path);
2686                 goto fail;
2687         }
2688
2689         /* build mapping tree for the relocated blocks */
2690         for (offset = 0; offset < total_bytes; ) {
2691                 leaf = path.nodes[0];
2692                 if (path.slots[0] >= btrfs_header_nritems(leaf)) {
2693                         ret = btrfs_next_leaf(root, &path);
2694                         if (ret != 0)
2695                                 break;
2696                         continue;
2697                 }
2698
2699                 btrfs_item_key_to_cpu(leaf, &key, path.slots[0]);
2700                 if (key.objectid != objectid || key.offset != offset ||
2701                     btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
2702                         break;
2703
2704                 fi = btrfs_item_ptr(leaf, path.slots[0],
2705                                     struct btrfs_file_extent_item);
2706                 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG)
2707                         break;
2708                 if (btrfs_file_extent_compression(leaf, fi) ||
2709                     btrfs_file_extent_encryption(leaf, fi) ||
2710                     btrfs_file_extent_other_encoding(leaf, fi))
2711                         break;
2712
2713                 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
2714                 /* skip holes and direct mapped extents */
2715                 if (bytenr == 0 || bytenr == offset)
2716                         goto next_extent;
2717
2718                 bytenr += btrfs_file_extent_offset(leaf, fi);
2719                 num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
2720
2721                 cache1 = btrfs_lookup_block_group(root->fs_info, offset);
2722                 cache2 = btrfs_lookup_block_group(root->fs_info,
2723                                                   offset + num_bytes - 1);
2724                 /*
2725                  * Here we must take consideration of old and new convert
2726                  * behavior.
2727                  * For old convert case, sign, there is no consist chunk type
2728                  * that will cover the extent. META/DATA/SYS are all possible.
2729                  * Just ensure relocate one is in SYS chunk.
2730                  * For new convert case, they are all covered by DATA chunk.
2731                  *
2732                  * So, there is not valid chunk type check for it now.
2733                  */
2734                 if (cache1 != cache2)
2735                         break;
2736
2737                 set_extent_bits(&io_tree, offset, offset + num_bytes - 1,
2738                                 EXTENT_LOCKED, GFP_NOFS);
2739                 set_state_private(&io_tree, offset, bytenr);
2740 next_extent:
2741                 offset += btrfs_file_extent_num_bytes(leaf, fi);
2742                 path.slots[0]++;
2743         }
2744         btrfs_release_path(&path);
2745
2746         if (offset < total_bytes) {
2747                 fprintf(stderr, "unable to build extent mapping\n");
2748                 fprintf(stderr, "converted filesystem after balance is unable to rollback\n");
2749                 goto fail;
2750         }
2751
2752         first_free = BTRFS_SUPER_INFO_OFFSET + 2 * sectorsize - 1;
2753         first_free &= ~((u64)sectorsize - 1);
2754         /* backup for extent #0 should exist */
2755         if(!test_range_bit(&io_tree, 0, first_free - 1, EXTENT_LOCKED, 1)) {
2756                 fprintf(stderr, "no backup for the first extent\n");
2757                 goto fail;
2758         }
2759         /* force no allocation from system block group */
2760         root->fs_info->system_allocs = -1;
2761         trans = btrfs_start_transaction(root, 1);
2762         BUG_ON(!trans);
2763         /*
2764          * recow the whole chunk tree, this will remove all chunk tree blocks
2765          * from system block group
2766          */
2767         chunk_root = root->fs_info->chunk_root;
2768         memset(&key, 0, sizeof(key));
2769         while (1) {
2770                 ret = btrfs_search_slot(trans, chunk_root, &key, &path, 0, 1);
2771                 if (ret < 0)
2772                         break;
2773
2774                 ret = btrfs_next_leaf(chunk_root, &path);
2775                 if (ret)
2776                         break;
2777
2778                 btrfs_item_key_to_cpu(path.nodes[0], &key, path.slots[0]);
2779                 btrfs_release_path(&path);
2780         }
2781         btrfs_release_path(&path);
2782
2783         offset = 0;
2784         num_bytes = 0;
2785         while(1) {
2786                 cache1 = btrfs_lookup_block_group(root->fs_info, offset);
2787                 if (!cache1)
2788                         break;
2789
2790                 if (cache1->flags & BTRFS_BLOCK_GROUP_SYSTEM)
2791                         num_bytes += btrfs_block_group_used(&cache1->item);
2792
2793                 offset = cache1->key.objectid + cache1->key.offset;
2794         }
2795         /* only extent #0 left in system block group? */
2796         if (num_bytes > first_free) {
2797                 fprintf(stderr, "unable to empty system block group\n");
2798                 goto fail;
2799         }
2800         /* create a system chunk that maps the whole device */
2801         ret = prepare_system_chunk_sb(root->fs_info->super_copy);
2802         if (ret) {
2803                 fprintf(stderr, "unable to update system chunk\n");
2804                 goto fail;
2805         }
2806
2807         ret = btrfs_commit_transaction(trans, root);
2808         BUG_ON(ret);
2809
2810         ret = close_ctree(root);
2811         if (ret) {
2812                 fprintf(stderr, "error during close_ctree %d\n", ret);
2813                 goto fail;
2814         }
2815
2816         /* zero btrfs super block mirrors */
2817         memset(buf, 0, sectorsize);
2818         for (i = 1 ; i < BTRFS_SUPER_MIRROR_MAX; i++) {
2819                 bytenr = btrfs_sb_offset(i);
2820                 if (bytenr >= total_bytes)
2821                         break;
2822                 ret = pwrite(fd, buf, sectorsize, bytenr);
2823                 if (ret != sectorsize) {
2824                         fprintf(stderr,
2825                                 "error during zeroing superblock %d: %d\n",
2826                                 i, ret);
2827                         goto fail;
2828                 }
2829         }
2830
2831         sb_bytenr = (u64)-1;
2832         /* copy all relocated blocks back */
2833         while(1) {
2834                 ret = find_first_extent_bit(&io_tree, 0, &start, &end,
2835                                             EXTENT_LOCKED);
2836                 if (ret)
2837                         break;
2838
2839                 ret = get_state_private(&io_tree, start, &bytenr);
2840                 BUG_ON(ret);
2841
2842                 clear_extent_bits(&io_tree, start, end, EXTENT_LOCKED,
2843                                   GFP_NOFS);
2844
2845                 while (start <= end) {
2846                         if (start == BTRFS_SUPER_INFO_OFFSET) {
2847                                 sb_bytenr = bytenr;
2848                                 goto next_sector;
2849                         }
2850                         ret = pread(fd, buf, sectorsize, bytenr);
2851                         if (ret < 0) {
2852                                 fprintf(stderr, "error during pread %d\n", ret);
2853                                 goto fail;
2854                         }
2855                         BUG_ON(ret != sectorsize);
2856                         ret = pwrite(fd, buf, sectorsize, start);
2857                         if (ret < 0) {
2858                                 fprintf(stderr, "error during pwrite %d\n", ret);
2859                                 goto fail;
2860                         }
2861                         BUG_ON(ret != sectorsize);
2862 next_sector:
2863                         start += sectorsize;
2864                         bytenr += sectorsize;
2865                 }
2866         }
2867
2868         ret = fsync(fd);
2869         if (ret) {
2870                 fprintf(stderr, "error during fsync %d\n", ret);
2871                 goto fail;
2872         }
2873         /*
2874          * finally, overwrite btrfs super block.
2875          */
2876         ret = pread(fd, buf, sectorsize, sb_bytenr);
2877         if (ret < 0) {
2878                 fprintf(stderr, "error during pread %d\n", ret);
2879                 goto fail;
2880         }
2881         BUG_ON(ret != sectorsize);
2882         ret = pwrite(fd, buf, sectorsize, BTRFS_SUPER_INFO_OFFSET);
2883         if (ret < 0) {
2884                 fprintf(stderr, "error during pwrite %d\n", ret);
2885                 goto fail;
2886         }
2887         BUG_ON(ret != sectorsize);
2888         ret = fsync(fd);
2889         if (ret) {
2890                 fprintf(stderr, "error during fsync %d\n", ret);
2891                 goto fail;
2892         }
2893
2894         close(fd);
2895         free(buf);
2896         extent_io_tree_cleanup(&io_tree);
2897         printf("rollback complete.\n");
2898         return 0;
2899
2900 fail:
2901         if (fd != -1)
2902                 close(fd);
2903         free(buf);
2904         fprintf(stderr, "rollback aborted.\n");
2905         return -1;
2906 }
2907
2908 static void print_usage(void)
2909 {
2910         printf("usage: btrfs-convert [options] device\n");
2911         printf("options:\n");
2912         printf("\t-d|--no-datasum        disable data checksum, sets NODATASUM\n");
2913         printf("\t-i|--no-xattr          ignore xattrs and ACLs\n");
2914         printf("\t-n|--no-inline         disable inlining of small files to metadata\n");
2915         printf("\t-N|--nodesize SIZE     set filesystem metadata nodesize\n");
2916         printf("\t-r|--rollback          roll back to the original filesystem\n");
2917         printf("\t-l|--label LABEL       set filesystem label\n");
2918         printf("\t-L|--copy-label        use label from converted filesystem\n");
2919         printf("\t-p|--progress          show converting progress (default)\n");
2920         printf("\t-O|--features LIST     comma separated list of filesystem features\n");
2921         printf("\t--no-progress          show only overview, not the detailed progress\n");
2922 }
2923
2924 int main(int argc, char *argv[])
2925 {
2926         int ret;
2927         int packing = 1;
2928         int noxattr = 0;
2929         int datacsum = 1;
2930         u32 nodesize = max_t(u32, sysconf(_SC_PAGESIZE),
2931                         BTRFS_MKFS_DEFAULT_NODE_SIZE);
2932         int rollback = 0;
2933         int copylabel = 0;
2934         int usage_error = 0;
2935         int progress = 1;
2936         char *file;
2937         char fslabel[BTRFS_LABEL_SIZE];
2938         u64 features = BTRFS_MKFS_DEFAULT_FEATURES;
2939
2940         while(1) {
2941                 enum { GETOPT_VAL_NO_PROGRESS = 256 };
2942                 static const struct option long_options[] = {
2943                         { "no-progress", no_argument, NULL,
2944                                 GETOPT_VAL_NO_PROGRESS },
2945                         { "no-datasum", no_argument, NULL, 'd' },
2946                         { "no-inline", no_argument, NULL, 'n' },
2947                         { "no-xattr", no_argument, NULL, 'i' },
2948                         { "rollback", no_argument, NULL, 'r' },
2949                         { "features", required_argument, NULL, 'O' },
2950                         { "progress", no_argument, NULL, 'p' },
2951                         { "label", required_argument, NULL, 'l' },
2952                         { "copy-label", no_argument, NULL, 'L' },
2953                         { "nodesize", required_argument, NULL, 'N' },
2954                         { "help", no_argument, NULL, GETOPT_VAL_HELP},
2955                         { NULL, 0, NULL, 0 }
2956                 };
2957                 int c = getopt_long(argc, argv, "dinN:rl:LpO:", long_options, NULL);
2958
2959                 if (c < 0)
2960                         break;
2961                 switch(c) {
2962                         case 'd':
2963                                 datacsum = 0;
2964                                 break;
2965                         case 'i':
2966                                 noxattr = 1;
2967                                 break;
2968                         case 'n':
2969                                 packing = 0;
2970                                 break;
2971                         case 'N':
2972                                 nodesize = parse_size(optarg);
2973                                 break;
2974                         case 'r':
2975                                 rollback = 1;
2976                                 break;
2977                         case 'l':
2978                                 copylabel = -1;
2979                                 if (strlen(optarg) >= BTRFS_LABEL_SIZE) {
2980                                         fprintf(stderr,
2981                                 "WARNING: label too long, trimmed to %d bytes\n",
2982                                                 BTRFS_LABEL_SIZE - 1);
2983                                 }
2984                                 __strncpy_null(fslabel, optarg, BTRFS_LABEL_SIZE - 1);
2985                                 break;
2986                         case 'L':
2987                                 copylabel = 1;
2988                                 break;
2989                         case 'p':
2990                                 progress = 1;
2991                                 break;
2992                         case 'O': {
2993                                 char *orig = strdup(optarg);
2994                                 char *tmp = orig;
2995
2996                                 tmp = btrfs_parse_fs_features(tmp, &features);
2997                                 if (tmp) {
2998                                         fprintf(stderr,
2999                                                 "Unrecognized filesystem feature '%s'\n",
3000                                                         tmp);
3001                                         free(orig);
3002                                         exit(1);
3003                                 }
3004                                 free(orig);
3005                                 if (features & BTRFS_FEATURE_LIST_ALL) {
3006                                         btrfs_list_all_fs_features(
3007                                                 ~BTRFS_CONVERT_ALLOWED_FEATURES);
3008                                         exit(0);
3009                                 }
3010                                 if (features & ~BTRFS_CONVERT_ALLOWED_FEATURES) {
3011                                         char buf[64];
3012
3013                                         btrfs_parse_features_to_string(buf,
3014                                                 features & ~BTRFS_CONVERT_ALLOWED_FEATURES);
3015                                         fprintf(stderr,
3016                                                 "ERROR: features not allowed for convert: %s\n",
3017                                                 buf);
3018                                         exit(1);
3019                                 }
3020
3021                                 break;
3022                                 }
3023                         case GETOPT_VAL_NO_PROGRESS:
3024                                 progress = 0;
3025                                 break;
3026                         case GETOPT_VAL_HELP:
3027                         default:
3028                                 print_usage();
3029                                 return c != GETOPT_VAL_HELP;
3030                 }
3031         }
3032         set_argv0(argv);
3033         if (check_argc_exact(argc - optind, 1)) {
3034                 print_usage();
3035                 return 1;
3036         }
3037
3038         if (rollback && (!datacsum || noxattr || !packing)) {
3039                 fprintf(stderr,
3040                         "Usage error: -d, -i, -n options do not apply to rollback\n");
3041                 usage_error++;
3042         }
3043
3044         if (usage_error) {
3045                 print_usage();
3046                 return 1;
3047         }
3048
3049         file = argv[optind];
3050         ret = check_mounted(file);
3051         if (ret < 0) {
3052                 fprintf(stderr, "Could not check mount status: %s\n",
3053                         strerror(-ret));
3054                 return 1;
3055         } else if (ret) {
3056                 fprintf(stderr, "%s is mounted\n", file);
3057                 return 1;
3058         }
3059
3060         if (rollback) {
3061                 ret = do_rollback(file);
3062         } else {
3063                 ret = do_convert(file, datacsum, packing, noxattr, nodesize,
3064                                 copylabel, fslabel, progress, features);
3065         }
3066         if (ret)
3067                 return 1;
3068         return 0;
3069 }