mkfs.c

   1 #define _XOPEN_SOURCE 500
   2 #ifndef __CHECKER__
   3 #include <sys/ioctl.h>
   4 #include <sys/mount.h>
   5 #endif
   6 #include <stdio.h>
   7 #include <stdlib.h>
   8 #include <sys/types.h>
   9 #include <sys/stat.h>
  10 #include <fcntl.h>
  11 #include <unistd.h>
  12 #include <uuid/uuid.h>
  13 #include "kerncompat.h"
  14 #include "radix-tree.h"
  15 #include "ctree.h"
  16 #include "disk-io.h"
  17 #include "transaction.h"
  18
  19 #ifdef __CHECKER__
  20 #define BLKGETSIZE64 0
  21 static inline int ioctl(int fd, int define, u64 *size) { return 0; }
  22 #endif
  23
  24 static int __make_root_dir(struct btrfs_trans_handle *trans,
  25                            struct btrfs_root *root, u64 objectid)
  26 {
  27         int ret;
  28         char buf[8];
  29         struct btrfs_key inode_map;
  30         struct btrfs_inode_item inode_item;
  31
  32         buf[0] = '.';
  33         buf[1] = '.';
  34
  35         inode_map.objectid = objectid;
  36         inode_map.flags = 0;
  37         btrfs_set_key_type(&inode_map, BTRFS_INODE_ITEM_KEY);
  38         inode_map.offset = 0;
  39
  40         memset(&inode_item, 0, sizeof(inode_item));
  41         btrfs_set_inode_generation(&inode_item, root->fs_info->generation);
  42         btrfs_set_inode_size(&inode_item, 6);
  43         btrfs_set_inode_nlink(&inode_item, 1);
  44         btrfs_set_inode_nblocks(&inode_item, 1);
  45         btrfs_set_inode_mode(&inode_item, S_IFDIR | 0555);
  46
  47         if (root->fs_info->tree_root == root)
  48                 btrfs_set_super_root_dir(root->fs_info->disk_super, objectid);
  49
  50         ret = btrfs_insert_inode(trans, root, objectid, &inode_item);
  51         if (ret)
  52                 goto error;
  53         ret = btrfs_insert_dir_item(trans, root, buf, 1, objectid,
  54                                     &inode_map, 1);
  55         if (ret)
  56                 goto error;
  57         ret = btrfs_insert_dir_item(trans, root, buf, 2, objectid,
  58                                     &inode_map, 1);
  59         if (ret)
  60                 goto error;
  61         btrfs_set_root_dirid(&root->root_item, objectid);
  62         ret = 0;
  63 error:
  64         return ret;
  65 }
  66
  67 static int make_block_groups(struct btrfs_trans_handle *trans,
  68                              struct btrfs_root *root)
  69 {
  70         u64 group_size_blocks;
  71         u64 total_blocks;
  72         u64 cur_start;
  73         int ret;
  74         struct btrfs_block_group_cache *cache;
  75
  76         root = root->fs_info->extent_root;
  77         /* first we bootstrap the things into cache */
  78         group_size_blocks = BTRFS_BLOCK_GROUP_SIZE / root->blocksize;
  79         cache = malloc(sizeof(*cache));
  80         cache->key.objectid = 0;
  81         cache->key.offset = group_size_blocks;
  82         cache->key.flags = 0;
  83         btrfs_set_key_type(&cache->key, BTRFS_BLOCK_GROUP_ITEM_KEY);
  84         memset(&cache->item, 0, sizeof(cache->item));
  85         btrfs_set_block_group_used(&cache->item,
  86                            btrfs_super_blocks_used(root->fs_info->disk_super));
  87         ret = radix_tree_insert(&root->fs_info->block_group_radix,
  88                                 group_size_blocks - 1, (void *)cache);
  89         BUG_ON(ret);
  90
  91         total_blocks = btrfs_super_total_blocks(root->fs_info->disk_super);
  92         cur_start = group_size_blocks;
  93         while(cur_start < total_blocks) {
  94                 cache = malloc(sizeof(*cache));
  95                 cache->key.objectid = cur_start;
  96                 cache->key.offset = group_size_blocks;
  97                 cache->key.flags = 0;
  98                 btrfs_set_key_type(&cache->key, BTRFS_BLOCK_GROUP_ITEM_KEY);
  99                 memset(&cache->item, 0, sizeof(cache->item));
 100                 ret = radix_tree_insert(&root->fs_info->block_group_radix,
 101                                         cur_start + group_size_blocks - 1,
 102                                         (void *)cache);
 103                 BUG_ON(ret);
 104                 cur_start += group_size_blocks;
 105         }
 106         /* then insert all the items */
 107         cur_start = 0;
 108         while(cur_start < total_blocks) {
 109                 cache = radix_tree_lookup(&root->fs_info->block_group_radix,
 110                                           cur_start + group_size_blocks - 1);
 111                 BUG_ON(!cache);
 112                 ret = btrfs_insert_block_group(trans, root, &cache->key,
 113                                                &cache->item);
 114                 BUG_ON(ret);
 115                 cur_start += group_size_blocks;
 116         }
 117         return 0;
 118 }
 119
 120 static int make_root_dir(int fd) {
 121         struct btrfs_root *root;
 122         struct btrfs_super_block super;
 123         struct btrfs_trans_handle *trans;
 124         int ret;
 125         struct btrfs_key location;
 126
 127         root = open_ctree_fd(fd, &super);
 128
 129         if (!root) {
 130                 fprintf(stderr, "ctree init failed\n");
 131                 return -1;
 132         }
 133         trans = btrfs_start_transaction(root, 1);
 134         ret = make_block_groups(trans, root);
 135         ret = __make_root_dir(trans, root->fs_info->tree_root,
 136                               BTRFS_ROOT_TREE_DIR_OBJECTID);
 137         if (ret)
 138                 goto err;
 139         ret = __make_root_dir(trans, root, BTRFS_FIRST_FREE_OBJECTID);
 140         if (ret)
 141                 goto err;
 142         memcpy(&location, &root->fs_info->fs_root->root_key, sizeof(location));
 143         location.offset = (u64)-1;
 144         ret = btrfs_insert_dir_item(trans, root->fs_info->tree_root,
 145                         "default", strlen("default"),
 146                         btrfs_super_root_dir(root->fs_info->disk_super),
 147                         &location, 1);
 148         if (ret)
 149                 goto err;
 150         btrfs_commit_transaction(trans, root, root->fs_info->disk_super);
 151         ret = close_ctree(root, &super);
 152 err:
 153         return ret;
 154 }
 155
 156 int mkfs(int fd, char *pathname, u64 num_blocks, u32 blocksize)
 157 {
 158         struct btrfs_super_block super;
 159         struct btrfs_leaf *empty_leaf;
 160         struct btrfs_root_item root_item;
 161         struct btrfs_item item;
 162         struct btrfs_extent_item extent_item;
 163         struct btrfs_inode_item *inode_item;
 164         struct btrfs_device_item dev_item;
 165         char *block;
 166         int ret;
 167         u32 itemoff;
 168         u32 start_block = BTRFS_SUPER_INFO_OFFSET / blocksize;
 169         u16 item_size;
 170
 171         btrfs_set_super_generation(&super, 1);
 172         btrfs_set_super_blocknr(&super, start_block);
 173         btrfs_set_super_root(&super, start_block + 1);
 174         strcpy((char *)(&super.magic), BTRFS_MAGIC);
 175         btrfs_set_super_blocksize(&super, blocksize);
 176         btrfs_set_super_total_blocks(&super, num_blocks);
 177         btrfs_set_super_blocks_used(&super, start_block + 5);
 178         btrfs_set_super_device_block_start(&super, 0);
 179         btrfs_set_super_device_num_blocks(&super, num_blocks);
 180         btrfs_set_super_device_root(&super, start_block + 2);
 181         btrfs_set_super_device_id(&super, 1);
 182         btrfs_set_super_last_device_id(&super, 1);
 183         uuid_generate(super.fsid);
 184
 185         block = malloc(blocksize);
 186         memset(block, 0, blocksize);
 187         BUG_ON(sizeof(super) > blocksize);
 188         memcpy(block, &super, sizeof(super));
 189         ret = pwrite(fd, block, blocksize, BTRFS_SUPER_INFO_OFFSET);
 190         BUG_ON(ret != blocksize);
 191
 192         /* create the tree of root objects */
 193         empty_leaf = malloc(blocksize);
 194         memset(empty_leaf, 0, blocksize);
 195         btrfs_set_header_blocknr(&empty_leaf->header, start_block + 1);
 196         btrfs_set_header_nritems(&empty_leaf->header, 2);
 197         btrfs_set_header_generation(&empty_leaf->header, 0);
 198         btrfs_set_header_owner(&empty_leaf->header, BTRFS_ROOT_TREE_OBJECTID);
 199         memcpy(empty_leaf->header.fsid, super.fsid,
 200                sizeof(empty_leaf->header.fsid));
 201
 202         /* create the items for the root tree */
 203         inode_item = &root_item.inode;
 204         memset(inode_item, 0, sizeof(*inode_item));
 205         btrfs_set_inode_generation(inode_item, 1);
 206         btrfs_set_inode_size(inode_item, 3);
 207         btrfs_set_inode_nlink(inode_item, 1);
 208         btrfs_set_inode_nblocks(inode_item, 1);
 209         btrfs_set_inode_mode(inode_item, S_IFDIR | 0755);
 210
 211         btrfs_set_root_dirid(&root_item, 0);
 212         btrfs_set_root_refs(&root_item, 1);
 213         btrfs_set_disk_key_offset(&item.key, 0);
 214         btrfs_set_disk_key_flags(&item.key, 0);
 215         btrfs_set_item_size(&item, sizeof(root_item));
 216         btrfs_set_disk_key_type(&item.key, BTRFS_ROOT_ITEM_KEY);
 217
 218         itemoff = __BTRFS_LEAF_DATA_SIZE(blocksize) - sizeof(root_item);
 219         btrfs_set_root_blocknr(&root_item, start_block + 3);
 220         btrfs_set_item_offset(&item, itemoff);
 221         btrfs_set_disk_key_objectid(&item.key, BTRFS_EXTENT_TREE_OBJECTID);
 222         memcpy(empty_leaf->items, &item, sizeof(item));
 223         memcpy(btrfs_leaf_data(empty_leaf) + itemoff,
 224                 &root_item, sizeof(root_item));
 225
 226         btrfs_set_root_blocknr(&root_item, start_block + 4);
 227         itemoff = itemoff - sizeof(root_item);
 228         btrfs_set_item_offset(&item, itemoff);
 229         btrfs_set_disk_key_objectid(&item.key, BTRFS_FS_TREE_OBJECTID);
 230         memcpy(empty_leaf->items + 1, &item, sizeof(item));
 231         memcpy(btrfs_leaf_data(empty_leaf) + itemoff,
 232                 &root_item, sizeof(root_item));
 233         ret = pwrite(fd, empty_leaf, blocksize, (start_block + 1) * blocksize);
 234
 235         /* create the item for the dev tree */
 236         btrfs_set_header_blocknr(&empty_leaf->header, start_block + 2);
 237         btrfs_set_header_nritems(&empty_leaf->header, 1);
 238         btrfs_set_disk_key_objectid(&item.key, 0);
 239         btrfs_set_disk_key_offset(&item.key, num_blocks);
 240         btrfs_set_disk_key_flags(&item.key, 0);
 241         btrfs_set_disk_key_type(&item.key, BTRFS_DEV_ITEM_KEY);
 242
 243         item_size = sizeof(struct btrfs_device_item) + strlen(pathname);
 244         itemoff = __BTRFS_LEAF_DATA_SIZE(blocksize) - item_size;
 245         btrfs_set_item_offset(&item, itemoff);
 246         btrfs_set_item_size(&item, item_size);
 247         btrfs_set_device_pathlen(&dev_item, strlen(pathname));
 248         btrfs_set_device_id(&dev_item, 1);
 249         memcpy(empty_leaf->items, &item, sizeof(item));
 250         memcpy(btrfs_leaf_data(empty_leaf) + itemoff, &dev_item,
 251                sizeof(dev_item));
 252         memcpy(btrfs_leaf_data(empty_leaf) + itemoff + sizeof(dev_item),
 253                pathname, strlen(pathname));
 254         ret = pwrite(fd, empty_leaf, blocksize, (start_block + 2) * blocksize);
 255         if (ret != blocksize)
 256                 return -1;
 257
 258         /* create the items for the extent tree */
 259         btrfs_set_header_blocknr(&empty_leaf->header, start_block + 3);
 260         btrfs_set_header_nritems(&empty_leaf->header, 5);
 261
 262         /* item1, reserve blocks 0-16 */
 263         btrfs_set_disk_key_objectid(&item.key, 0);
 264         btrfs_set_disk_key_offset(&item.key, start_block + 1);
 265         btrfs_set_disk_key_flags(&item.key, 0);
 266         btrfs_set_disk_key_type(&item.key, BTRFS_EXTENT_ITEM_KEY);
 267         itemoff = __BTRFS_LEAF_DATA_SIZE(blocksize) -
 268                         sizeof(struct btrfs_extent_item);
 269         btrfs_set_item_offset(&item, itemoff);
 270         btrfs_set_item_size(&item, sizeof(struct btrfs_extent_item));
 271         btrfs_set_extent_refs(&extent_item, 1);
 272         btrfs_set_extent_owner(&extent_item, BTRFS_ROOT_TREE_OBJECTID);
 273         memcpy(empty_leaf->items, &item, sizeof(item));
 274         memcpy(btrfs_leaf_data(empty_leaf) + btrfs_item_offset(&item),
 275                 &extent_item, btrfs_item_size(&item));
 276
 277         /* item2, give block 17 to the root */
 278         btrfs_set_disk_key_objectid(&item.key, start_block + 1);
 279         btrfs_set_disk_key_offset(&item.key, 1);
 280         itemoff = itemoff - sizeof(struct btrfs_extent_item);
 281         btrfs_set_item_offset(&item, itemoff);
 282         memcpy(empty_leaf->items + 1, &item, sizeof(item));
 283         memcpy(btrfs_leaf_data(empty_leaf) + btrfs_item_offset(&item),
 284                 &extent_item, btrfs_item_size(&item));
 285
 286         /* item3, give block 18 to the dev root */
 287         btrfs_set_disk_key_objectid(&item.key, start_block + 2);
 288         btrfs_set_disk_key_offset(&item.key, 1);
 289         itemoff = itemoff - sizeof(struct btrfs_extent_item);
 290         btrfs_set_item_offset(&item, itemoff);
 291         memcpy(empty_leaf->items + 2, &item, sizeof(item));
 292         memcpy(btrfs_leaf_data(empty_leaf) + btrfs_item_offset(&item),
 293                 &extent_item, btrfs_item_size(&item));
 294
 295         /* item4, give block 19 to the extent root */
 296         btrfs_set_disk_key_objectid(&item.key, start_block + 3);
 297         btrfs_set_disk_key_offset(&item.key, 1);
 298         itemoff = itemoff - sizeof(struct btrfs_extent_item);
 299         btrfs_set_item_offset(&item, itemoff);
 300         memcpy(empty_leaf->items + 3, &item, sizeof(item));
 301         memcpy(btrfs_leaf_data(empty_leaf) + btrfs_item_offset(&item),
 302                 &extent_item, btrfs_item_size(&item));
 303
 304         /* item5, give block 20 to the FS root */
 305         btrfs_set_disk_key_objectid(&item.key, start_block + 4);
 306         btrfs_set_disk_key_offset(&item.key, 1);
 307         itemoff = itemoff - sizeof(struct btrfs_extent_item);
 308         btrfs_set_item_offset(&item, itemoff);
 309         memcpy(empty_leaf->items + 4, &item, sizeof(item));
 310         memcpy(btrfs_leaf_data(empty_leaf) + btrfs_item_offset(&item),
 311                 &extent_item, btrfs_item_size(&item));
 312         ret = pwrite(fd, empty_leaf, blocksize, (start_block + 3) * blocksize);
 313         if (ret != blocksize)
 314                 return -1;
 315
 316         /* finally create the FS root */
 317         btrfs_set_header_blocknr(&empty_leaf->header, start_block + 4);
 318         btrfs_set_header_nritems(&empty_leaf->header, 0);
 319         ret = pwrite(fd, empty_leaf, blocksize, (start_block + 4) * blocksize);
 320         if (ret != blocksize)
 321                 return -1;
 322         return 0;
 323 }
 324
 325 u64 device_size(int fd, struct stat *st)
 326 {
 327         u64 size;
 328         if (S_ISREG(st->st_mode)) {
 329                 return st->st_size;
 330         }
 331         if (!S_ISBLK(st->st_mode)) {
 332                 return 0;
 333         }
 334         if (ioctl(fd, BLKGETSIZE64, &size) >= 0) {
 335                 return size;
 336         }
 337         return 0; }
 338
 339 int main(int ac, char **av)
 340 {
 341         char *file;
 342         u64 block_count = 0;
 343         int fd;
 344         struct stat st;
 345         int ret;
 346         int i;
 347         char *buf = malloc(4096);
 348         char *realpath_name;
 349
 350         radix_tree_init();
 351
 352         if (ac >= 2) {
 353                 file = av[1];
 354                 if (ac == 3) {
 355                         block_count = atoi(av[2]);
 356                         if (!block_count) {
 357                                 fprintf(stderr, "error finding block count\n");
 358                                 exit(1);
 359                         }
 360                 }
 361         } else {
 362                 fprintf(stderr, "usage: mkfs.btrfs file [block count]\n");
 363                 exit(1);
 364         }
 365         fd = open(file, O_RDWR);
 366         if (fd < 0) {
 367                 fprintf(stderr, "unable to open %s\n", file);
 368                 exit(1);
 369         }
 370         ret = fstat(fd, &st);
 371         if (ret < 0) {
 372                 fprintf(stderr, "unable to stat %s\n", file);
 373                 exit(1);
 374         }
 375         if (block_count == 0) {
 376                 block_count = device_size(fd, &st);
 377                 if (block_count == 0) {
 378                         fprintf(stderr, "unable to find %s size\n", file);
 379                         exit(1);
 380                 }
 381         }
 382         block_count /= 4096;
 383         if (block_count < 256) {
 384                 fprintf(stderr, "device %s is too small\n", file);
 385                 exit(1);
 386         }
 387         memset(buf, 0, 4096);
 388         for(i = 0; i < 64; i++) {
 389                 ret = write(fd, buf, 4096);
 390                 if (ret != 4096) {
 391                         fprintf(stderr, "unable to zero fill device\n");
 392                         exit(1);
 393                 }
 394         }
 395         realpath_name = realpath(file, NULL);
 396         ret = mkfs(fd, realpath_name, block_count, 4096);
 397         if (ret) {
 398                 fprintf(stderr, "error during mkfs %d\n", ret);
 399                 exit(1);
 400         }
 401         ret = make_root_dir(fd);
 402         if (ret) {
 403                 fprintf(stderr, "failed to setup the root directory\n");
 404                 exit(1);
 405         }
 406         printf("fs created on %s blocksize %d blocks %Lu\n",
 407                file, 4096, block_count);
 408         return 0;
 409 }
 410