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)
  26 {
  27         int ret;
  28         char buf[8];
  29         u64 objectid;
  30         struct btrfs_key inode_map;
  31         struct btrfs_inode_item inode_item;
  32
  33         buf[0] = '.';
  34         buf[1] = '.';
  35
  36         ret = btrfs_find_free_objectid(trans, root, 1, &objectid);
  37         if (ret)
  38                 goto error;
  39
  40         inode_map.objectid = objectid;
  41         inode_map.flags = 0;
  42         btrfs_set_key_type(&inode_map, BTRFS_INODE_ITEM_KEY);
  43         inode_map.offset = 0;
  44
  45         ret = btrfs_insert_inode_map(trans, root, objectid, &inode_map);
  46         if (ret)
  47                 goto error;
  48
  49         memset(&inode_item, 0, sizeof(inode_item));
  50         btrfs_set_inode_generation(&inode_item, root->fs_info->generation);
  51         btrfs_set_inode_size(&inode_item, 3);
  52         btrfs_set_inode_nlink(&inode_item, 1);
  53         btrfs_set_inode_nblocks(&inode_item, 1);
  54         btrfs_set_inode_mode(&inode_item, S_IFDIR | 0555);
  55
  56         if (root->fs_info->tree_root == root)
  57                 btrfs_set_super_root_dir(root->fs_info->disk_super, objectid);
  58
  59         ret = btrfs_insert_inode(trans, root, objectid, &inode_item);
  60         if (ret)
  61                 goto error;
  62         ret = btrfs_insert_dir_item(trans, root, buf, 1, objectid,
  63                                     &inode_map, 1);
  64         if (ret)
  65                 goto error;
  66         ret = btrfs_insert_dir_item(trans, root, buf, 2, objectid,
  67                                     &inode_map, 1);
  68         if (ret)
  69                 goto error;
  70         btrfs_set_root_dirid(&root->root_item, objectid);
  71         ret = 0;
  72 error:
  73         return ret;
  74 }
  75
  76 static int make_root_dir(int fd) {
  77         struct btrfs_root *root;
  78         struct btrfs_super_block super;
  79         struct btrfs_trans_handle *trans;
  80         int ret;
  81         struct btrfs_key location;
  82
  83         root = open_ctree_fd(fd, &super);
  84
  85         if (!root) {
  86                 fprintf(stderr, "ctree init failed\n");
  87                 return -1;
  88         }
  89         trans = btrfs_start_transaction(root, 1);
  90         ret = __make_root_dir(trans, root->fs_info->tree_root);
  91         if (ret)
  92                 goto err;
  93         ret = __make_root_dir(trans, root);
  94         if (ret)
  95                 goto err;
  96         memcpy(&location, &root->fs_info->fs_root->root_key, sizeof(location));
  97         location.offset = (u64)-1;
  98         ret = btrfs_insert_dir_item(trans, root->fs_info->tree_root,
  99                         "default", strlen("default"),
 100                         btrfs_super_root_dir(root->fs_info->disk_super),
 101                         &location, 1);
 102         if (ret)
 103                 goto err;
 104         btrfs_commit_transaction(trans, root, root->fs_info->disk_super);
 105         ret = close_ctree(root, &super);
 106 err:
 107         return ret;
 108 }
 109
 110 int mkfs(int fd, u64 num_blocks, u32 blocksize)
 111 {
 112         struct btrfs_super_block super;
 113         struct btrfs_leaf *empty_leaf;
 114         struct btrfs_root_item root_item;
 115         struct btrfs_item item;
 116         struct btrfs_extent_item extent_item;
 117         struct btrfs_inode_item *inode_item;
 118         char *block;
 119         int ret;
 120         u32 itemoff;
 121         u32 start_block = BTRFS_SUPER_INFO_OFFSET / blocksize;
 122
 123         btrfs_set_super_blocknr(&super, start_block);
 124         btrfs_set_super_root(&super, start_block + 1);
 125         strcpy((char *)(&super.magic), BTRFS_MAGIC);
 126         btrfs_set_super_blocksize(&super, blocksize);
 127         btrfs_set_super_total_blocks(&super, num_blocks);
 128         btrfs_set_super_blocks_used(&super, start_block + 5);
 129         uuid_generate(super.fsid);
 130
 131         block = malloc(blocksize);
 132         memset(block, 0, blocksize);
 133         BUG_ON(sizeof(super) > blocksize);
 134         memcpy(block, &super, sizeof(super));
 135         ret = pwrite(fd, block, blocksize, BTRFS_SUPER_INFO_OFFSET);
 136         BUG_ON(ret != blocksize);
 137
 138         /* create the tree of root objects */
 139         empty_leaf = malloc(blocksize);
 140         memset(empty_leaf, 0, blocksize);
 141         btrfs_set_header_parentid(&empty_leaf->header,
 142                                   BTRFS_ROOT_TREE_OBJECTID);
 143         btrfs_set_header_blocknr(&empty_leaf->header, start_block + 1);
 144         btrfs_set_header_nritems(&empty_leaf->header, 3);
 145         btrfs_set_header_generation(&empty_leaf->header, 0);
 146         memcpy(empty_leaf->header.fsid, super.fsid,
 147                sizeof(empty_leaf->header.fsid));
 148
 149         /* create the items for the root tree */
 150         inode_item = &root_item.inode;
 151         memset(inode_item, 0, sizeof(*inode_item));
 152         btrfs_set_inode_generation(inode_item, 1);
 153         btrfs_set_inode_size(inode_item, 3);
 154         btrfs_set_inode_nlink(inode_item, 1);
 155         btrfs_set_inode_nblocks(inode_item, 1);
 156         btrfs_set_inode_mode(inode_item, S_IFDIR | 0755);
 157
 158         btrfs_set_root_dirid(&root_item, 0);
 159         btrfs_set_root_blocknr(&root_item, start_block + 2);
 160         btrfs_set_root_refs(&root_item, 1);
 161         itemoff = __BTRFS_LEAF_DATA_SIZE(blocksize) - sizeof(root_item);
 162         btrfs_set_item_offset(&item, itemoff);
 163         btrfs_set_item_size(&item, sizeof(root_item));
 164         btrfs_set_disk_key_objectid(&item.key, BTRFS_EXTENT_TREE_OBJECTID);
 165         btrfs_set_disk_key_offset(&item.key, 0);
 166         btrfs_set_disk_key_flags(&item.key, 0);
 167         btrfs_set_disk_key_type(&item.key, BTRFS_ROOT_ITEM_KEY);
 168         memcpy(empty_leaf->items, &item, sizeof(item));
 169         memcpy(btrfs_leaf_data(empty_leaf) + itemoff,
 170                 &root_item, sizeof(root_item));
 171
 172         btrfs_set_root_blocknr(&root_item, start_block + 3);
 173         itemoff = itemoff - sizeof(root_item);
 174         btrfs_set_item_offset(&item, itemoff);
 175         btrfs_set_disk_key_objectid(&item.key, BTRFS_INODE_MAP_OBJECTID);
 176         memcpy(empty_leaf->items + 1, &item, sizeof(item));
 177         memcpy(btrfs_leaf_data(empty_leaf) + itemoff,
 178                 &root_item, sizeof(root_item));
 179
 180         btrfs_set_root_blocknr(&root_item, start_block + 4);
 181         itemoff = itemoff - sizeof(root_item);
 182         btrfs_set_item_offset(&item, itemoff);
 183         btrfs_set_disk_key_objectid(&item.key, BTRFS_FS_TREE_OBJECTID);
 184         memcpy(empty_leaf->items + 2, &item, sizeof(item));
 185         memcpy(btrfs_leaf_data(empty_leaf) + itemoff,
 186                 &root_item, sizeof(root_item));
 187         ret = pwrite(fd, empty_leaf, blocksize, (start_block + 1) * blocksize);
 188
 189         /* create the items for the extent tree */
 190         btrfs_set_header_parentid(&empty_leaf->header,
 191                                   BTRFS_EXTENT_TREE_OBJECTID);
 192         btrfs_set_header_blocknr(&empty_leaf->header, start_block + 2);
 193         btrfs_set_header_nritems(&empty_leaf->header, 5);
 194
 195         /* item1, reserve blocks 0-16 */
 196         btrfs_set_disk_key_objectid(&item.key, 0);
 197         btrfs_set_disk_key_offset(&item.key, start_block + 1);
 198         btrfs_set_disk_key_flags(&item.key, 0);
 199         btrfs_set_disk_key_type(&item.key, BTRFS_EXTENT_ITEM_KEY);
 200         itemoff = __BTRFS_LEAF_DATA_SIZE(blocksize) -
 201                         sizeof(struct btrfs_extent_item);
 202         btrfs_set_item_offset(&item, itemoff);
 203         btrfs_set_item_size(&item, sizeof(struct btrfs_extent_item));
 204         btrfs_set_extent_refs(&extent_item, 1);
 205         btrfs_set_extent_owner(&extent_item, 0);
 206         memcpy(empty_leaf->items, &item, sizeof(item));
 207         memcpy(btrfs_leaf_data(empty_leaf) + btrfs_item_offset(&item),
 208                 &extent_item, btrfs_item_size(&item));
 209
 210         /* item2, give block 17 to the root */
 211         btrfs_set_disk_key_objectid(&item.key, start_block + 1);
 212         btrfs_set_disk_key_offset(&item.key, 1);
 213         itemoff = itemoff - sizeof(struct btrfs_extent_item);
 214         btrfs_set_item_offset(&item, itemoff);
 215         btrfs_set_extent_owner(&extent_item, BTRFS_ROOT_TREE_OBJECTID);
 216         memcpy(empty_leaf->items + 1, &item, sizeof(item));
 217         memcpy(btrfs_leaf_data(empty_leaf) + btrfs_item_offset(&item),
 218                 &extent_item, btrfs_item_size(&item));
 219
 220         /* item3, give block 18 to the extent root */
 221         btrfs_set_disk_key_objectid(&item.key, start_block + 2);
 222         btrfs_set_disk_key_offset(&item.key, 1);
 223         itemoff = itemoff - sizeof(struct btrfs_extent_item);
 224         btrfs_set_item_offset(&item, itemoff);
 225         btrfs_set_extent_owner(&extent_item, BTRFS_EXTENT_TREE_OBJECTID);
 226         memcpy(empty_leaf->items + 2, &item, sizeof(item));
 227         memcpy(btrfs_leaf_data(empty_leaf) + btrfs_item_offset(&item),
 228                 &extent_item, btrfs_item_size(&item));
 229
 230         /* item4, give block 19 to the inode map */
 231         btrfs_set_disk_key_objectid(&item.key, start_block + 3);
 232         btrfs_set_disk_key_offset(&item.key, 1);
 233         itemoff = itemoff - sizeof(struct btrfs_extent_item);
 234         btrfs_set_item_offset(&item, itemoff);
 235         btrfs_set_extent_owner(&extent_item, BTRFS_INODE_MAP_OBJECTID);
 236         memcpy(empty_leaf->items + 3, &item, sizeof(item));
 237         memcpy(btrfs_leaf_data(empty_leaf) + btrfs_item_offset(&item),
 238                 &extent_item, btrfs_item_size(&item));
 239         ret = pwrite(fd, empty_leaf, blocksize, (start_block + 2) * blocksize);
 240         if (ret != blocksize)
 241                 return -1;
 242
 243         /* item5, give block 20 to the FS root */
 244         btrfs_set_disk_key_objectid(&item.key, start_block + 4);
 245         btrfs_set_disk_key_offset(&item.key, 1);
 246         itemoff = itemoff - sizeof(struct btrfs_extent_item);
 247         btrfs_set_item_offset(&item, itemoff);
 248         btrfs_set_extent_owner(&extent_item, BTRFS_FS_TREE_OBJECTID);
 249         memcpy(empty_leaf->items + 4, &item, sizeof(item));
 250         memcpy(btrfs_leaf_data(empty_leaf) + btrfs_item_offset(&item),
 251                 &extent_item, btrfs_item_size(&item));
 252         ret = pwrite(fd, empty_leaf, blocksize, (start_block + 2) * blocksize);
 253         if (ret != blocksize)
 254                 return -1;
 255
 256         /* create the inode map */
 257         btrfs_set_header_parentid(&empty_leaf->header,
 258                                   BTRFS_INODE_MAP_OBJECTID);
 259         btrfs_set_header_blocknr(&empty_leaf->header, start_block + 3);
 260         btrfs_set_header_nritems(&empty_leaf->header, 0);
 261         ret = pwrite(fd, empty_leaf, blocksize, (start_block + 3) * blocksize);
 262         if (ret != blocksize)
 263                 return -1;
 264
 265         /* finally create the FS root */
 266         btrfs_set_header_parentid(&empty_leaf->header, BTRFS_FS_TREE_OBJECTID);
 267         btrfs_set_header_blocknr(&empty_leaf->header, start_block + 4);
 268         btrfs_set_header_nritems(&empty_leaf->header, 0);
 269         ret = pwrite(fd, empty_leaf, blocksize, (start_block + 4) * blocksize);
 270         if (ret != blocksize)
 271                 return -1;
 272         return 0;
 273 }
 274
 275 u64 device_size(int fd, struct stat *st)
 276 {
 277         u64 size;
 278         if (S_ISREG(st->st_mode)) {
 279                 return st->st_size;
 280         }
 281         if (!S_ISBLK(st->st_mode)) {
 282                 return 0;
 283         }
 284         if (ioctl(fd, BLKGETSIZE64, &size) >= 0) {
 285                 return size;
 286         }
 287         return 0;
 288 }
 289
 290 int main(int ac, char **av)
 291 {
 292         char *file;
 293         u64 block_count = 0;
 294         int fd;
 295         struct stat st;
 296         int ret;
 297         int i;
 298         char *buf = malloc(4096);
 299
 300         radix_tree_init();
 301
 302         if (ac >= 2) {
 303                 file = av[1];
 304                 if (ac == 3) {
 305                         block_count = atoi(av[2]);
 306                         if (!block_count) {
 307                                 fprintf(stderr, "error finding block count\n");
 308                                 exit(1);
 309                         }
 310                 }
 311         } else {
 312                 fprintf(stderr, "usage: mkfs.btrfs file [block count]\n");
 313                 exit(1);
 314         }
 315         fd = open(file, O_RDWR);
 316         if (fd < 0) {
 317                 fprintf(stderr, "unable to open %s\n", file);
 318                 exit(1);
 319         }
 320         ret = fstat(fd, &st);
 321         if (ret < 0) {
 322                 fprintf(stderr, "unable to stat %s\n", file);
 323                 exit(1);
 324         }
 325         if (block_count == 0) {
 326                 block_count = device_size(fd, &st);
 327                 if (block_count == 0) {
 328                         fprintf(stderr, "unable to find %s size\n", file);
 329                         exit(1);
 330                 }
 331         }
 332         block_count /= 4096;
 333         if (block_count < 256) {
 334                 fprintf(stderr, "device %s is too small\n", file);
 335                 exit(1);
 336         }
 337         memset(buf, 0, 4096);
 338         for(i = 0; i < 16; i++) {
 339                 ret = write(fd, buf, 4096);
 340                 if (ret != 4096) {
 341                         fprintf(stderr, "unable to zero fill device\n");
 342                         exit(1);
 343                 }
 344         }
 345         ret = mkfs(fd, block_count, 4096);
 346         if (ret) {
 347                 fprintf(stderr, "error during mkfs %d\n", ret);
 348                 exit(1);
 349         }
 350         ret = make_root_dir(fd);
 351         if (ret) {
 352                 fprintf(stderr, "failed to setup the root directory\n");
 353                 exit(1);
 354         }
 355         printf("fs created on %s blocksize %d blocks %Lu\n",
 356                file, 4096, block_count);
 357         return 0;
 358 }
 359