utils.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 #define _XOPEN_SOURCE 600
  20 #define __USE_XOPEN2K
  21 #include <stdio.h>
  22 #include <stdlib.h>
  23 #include <sys/types.h>
  24 #include <sys/stat.h>
  25 #include <uuid/uuid.h>
  26 #include <fcntl.h>
  27 #include <unistd.h>
  28 #include "kerncompat.h"
  29 #include "radix-tree.h"
  30 #include "ctree.h"
  31 #include "disk-io.h"
  32 #include "transaction.h"
  33 #include "crc32c.h"
  34 #include "utils.h"
  35 static u64 reference_root_table[4] = {
  36         [1] =   BTRFS_ROOT_TREE_OBJECTID,
  37         [2] =   BTRFS_EXTENT_TREE_OBJECTID,
  38         [3] =   BTRFS_FS_TREE_OBJECTID,
  39 };
  40
  41 int make_btrfs(int fd, u64 blocks[4], u64 num_bytes, u32 nodesize,
  42                u32 leafsize, u32 sectorsize, u32 stripesize)
  43 {
  44         struct btrfs_super_block super;
  45         struct extent_buffer *buf;
  46         struct btrfs_root_item root_item;
  47         struct btrfs_disk_key disk_key;
  48         struct btrfs_extent_ref *extent_ref;
  49         struct btrfs_extent_item *extent_item;
  50         struct btrfs_inode_item *inode_item;
  51         int i;
  52         int ret;
  53         u32 itemoff;
  54         u32 nritems = 0;
  55         u64 hash;
  56         u64 first_free;
  57         u64 ref_gen;
  58         u64 ref_root;
  59
  60         first_free = BTRFS_SUPER_INFO_OFFSET + sectorsize * 2 - 1;
  61         first_free &= ~((u64)sectorsize - 1);
  62
  63         num_bytes = (num_bytes / sectorsize) * sectorsize;
  64         uuid_generate(super.fsid);
  65         btrfs_set_super_bytenr(&super, blocks[0]);
  66         strncpy((char *)&super.magic, BTRFS_MAGIC, sizeof(super.magic));
  67         btrfs_set_super_generation(&super, 1);
  68         btrfs_set_super_root(&super, blocks[1]);
  69         btrfs_set_super_total_bytes(&super, num_bytes);
  70         btrfs_set_super_bytes_used(&super, first_free + 3 * leafsize);
  71         btrfs_set_super_root_dir(&super, 0);
  72         btrfs_set_super_sectorsize(&super, sectorsize);
  73         btrfs_set_super_leafsize(&super, leafsize);
  74         btrfs_set_super_nodesize(&super, nodesize);
  75         btrfs_set_super_stripesize(&super, stripesize);
  76         btrfs_set_super_root_level(&super, 0);
  77
  78         buf = malloc(sizeof(*buf) + max(sectorsize, leafsize));
  79
  80         BUG_ON(sizeof(super) > sectorsize);
  81         memset(buf->data, 0, sectorsize);
  82         memcpy(buf->data, &super, sizeof(super));
  83         ret = pwrite(fd, buf->data, sectorsize, blocks[0]);
  84         BUG_ON(ret != sectorsize);
  85
  86         /* create the tree of root objects */
  87         memset(buf->data, 0, leafsize);
  88         btrfs_set_header_bytenr(buf, blocks[1]);
  89         btrfs_set_header_nritems(buf, 2);
  90         btrfs_set_header_generation(buf, 1);
  91         btrfs_set_header_owner(buf, BTRFS_ROOT_TREE_OBJECTID);
  92         write_extent_buffer(buf, super.fsid, (unsigned long)
  93                             btrfs_header_fsid(buf), BTRFS_FSID_SIZE);
  94
  95         /* create the items for the root tree */
  96         memset(&root_item, 0, sizeof(root_item));
  97         inode_item = &root_item.inode;
  98         btrfs_set_stack_inode_generation(inode_item, 1);
  99         btrfs_set_stack_inode_size(inode_item, 3);
 100         btrfs_set_stack_inode_nlink(inode_item, 1);
 101         btrfs_set_stack_inode_nblocks(inode_item, 1);
 102         btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755);
 103         btrfs_set_root_refs(&root_item, 1);
 104         btrfs_set_root_used(&root_item, leafsize);
 105
 106         memset(&disk_key, 0, sizeof(disk_key));
 107         btrfs_set_disk_key_type(&disk_key, BTRFS_ROOT_ITEM_KEY);
 108         btrfs_set_disk_key_offset(&disk_key, 0);
 109
 110         itemoff = __BTRFS_LEAF_DATA_SIZE(leafsize) - sizeof(root_item);
 111         btrfs_set_root_bytenr(&root_item, blocks[2]);
 112         btrfs_set_disk_key_objectid(&disk_key, BTRFS_EXTENT_TREE_OBJECTID);
 113         btrfs_set_item_key(buf, &disk_key, 0);
 114         btrfs_set_item_offset(buf, btrfs_item_nr(buf, 0), itemoff);
 115         btrfs_set_item_size(buf, btrfs_item_nr(buf, 0), sizeof(root_item));
 116         write_extent_buffer(buf, &root_item, btrfs_item_ptr_offset(buf, 0),
 117                             sizeof(root_item));
 118
 119         itemoff = itemoff - sizeof(root_item);
 120         btrfs_set_root_bytenr(&root_item, blocks[3]);
 121         btrfs_set_disk_key_objectid(&disk_key, BTRFS_FS_TREE_OBJECTID);
 122         btrfs_set_item_key(buf, &disk_key, 1);
 123         btrfs_set_item_offset(buf, btrfs_item_nr(buf, 1), itemoff);
 124         btrfs_set_item_size(buf, btrfs_item_nr(buf, 1), sizeof(root_item));
 125         write_extent_buffer(buf, &root_item, btrfs_item_ptr_offset(buf, 1),
 126                             sizeof(root_item));
 127         ret = pwrite(fd, buf->data, leafsize, blocks[1]);
 128         BUG_ON(ret != leafsize);
 129
 130         /* create the items for the extent tree */
 131         itemoff = __BTRFS_LEAF_DATA_SIZE(leafsize) -
 132                   sizeof(struct btrfs_extent_item);
 133         btrfs_set_disk_key_objectid(&disk_key, 0);
 134         btrfs_set_disk_key_offset(&disk_key, first_free);
 135         btrfs_set_disk_key_type(&disk_key, BTRFS_EXTENT_ITEM_KEY);
 136         btrfs_set_item_key(buf, &disk_key, nritems);
 137         btrfs_set_item_offset(buf, btrfs_item_nr(buf, nritems), itemoff);
 138         btrfs_set_item_size(buf, btrfs_item_nr(buf,  nritems),
 139                             sizeof(struct btrfs_extent_item));
 140         extent_item = btrfs_item_ptr(buf, nritems, struct btrfs_extent_item);
 141         btrfs_set_extent_refs(buf, extent_item, 1);
 142         nritems++;
 143         for (i = 1; i < 4; i++) {
 144                 BUG_ON(blocks[i] < first_free);
 145                 BUG_ON(blocks[i] < blocks[i - 1]);
 146
 147                 /* create extent item */
 148                 itemoff = itemoff - sizeof(struct btrfs_extent_item);
 149                 btrfs_set_disk_key_objectid(&disk_key, blocks[i]);
 150                 btrfs_set_disk_key_offset(&disk_key, leafsize);
 151                 btrfs_set_disk_key_type(&disk_key, BTRFS_EXTENT_ITEM_KEY);
 152                 btrfs_set_item_key(buf, &disk_key, nritems);
 153                 btrfs_set_item_offset(buf, btrfs_item_nr(buf, nritems),
 154                                       itemoff);
 155                 btrfs_set_item_size(buf, btrfs_item_nr(buf, nritems),
 156                                     sizeof(struct btrfs_extent_item));
 157                 extent_item = btrfs_item_ptr(buf, nritems,
 158                                              struct btrfs_extent_item);
 159                 btrfs_set_extent_refs(buf, extent_item, 1);
 160                 nritems++;
 161
 162                 /* create extent ref */
 163                 ref_root = reference_root_table[i];
 164                 if (ref_root == BTRFS_FS_TREE_OBJECTID)
 165                         ref_gen = 1;
 166                 else
 167                         ref_gen = 0;
 168
 169                 hash = btrfs_hash_extent_ref(ref_root, ref_gen, 0, 0);
 170                 itemoff = itemoff - sizeof(struct btrfs_extent_ref);
 171                 btrfs_set_disk_key_objectid(&disk_key, blocks[i]);
 172                 btrfs_set_disk_key_offset(&disk_key, hash);
 173                 btrfs_set_disk_key_type(&disk_key, BTRFS_EXTENT_REF_KEY);
 174                 btrfs_set_item_key(buf, &disk_key, nritems);
 175                 btrfs_set_item_offset(buf, btrfs_item_nr(buf, nritems),
 176                                       itemoff);
 177                 btrfs_set_item_size(buf, btrfs_item_nr(buf, nritems),
 178                                     sizeof(struct btrfs_extent_ref));
 179                 extent_ref = btrfs_item_ptr(buf, nritems,
 180                                              struct btrfs_extent_ref);
 181                 btrfs_set_ref_root(buf, extent_ref, ref_root);
 182                 btrfs_set_ref_generation(buf, extent_ref, ref_gen);
 183                 btrfs_set_ref_objectid(buf, extent_ref, 0);
 184                 btrfs_set_ref_offset(buf, extent_ref, 0);
 185                 nritems++;
 186         }
 187         btrfs_set_header_bytenr(buf, blocks[2]);
 188         btrfs_set_header_owner(buf, BTRFS_EXTENT_TREE_OBJECTID);
 189         btrfs_set_header_nritems(buf, nritems);
 190         ret = pwrite(fd, buf->data, leafsize, blocks[2]);
 191         BUG_ON(ret != leafsize);
 192
 193         /* finally create the FS root */
 194         btrfs_set_header_bytenr(buf, blocks[3]);
 195         btrfs_set_header_owner(buf, BTRFS_FS_TREE_OBJECTID);
 196         btrfs_set_header_nritems(buf, 0);
 197         ret = pwrite(fd, buf->data, leafsize, blocks[3]);
 198         BUG_ON(ret != leafsize);
 199
 200         free(buf);
 201         return 0;
 202 }
 203
 204 int btrfs_make_root_dir(struct btrfs_trans_handle *trans,
 205                         struct btrfs_root *root, u64 objectid)
 206 {
 207         int ret;
 208         struct btrfs_inode_item inode_item;
 209
 210         memset(&inode_item, 0, sizeof(inode_item));
 211         btrfs_set_stack_inode_generation(&inode_item, trans->transid);
 212         btrfs_set_stack_inode_size(&inode_item, 0);
 213         btrfs_set_stack_inode_nlink(&inode_item, 1);
 214         btrfs_set_stack_inode_nblocks(&inode_item, 1);
 215         btrfs_set_stack_inode_mode(&inode_item, S_IFDIR | 0555);
 216
 217         if (root->fs_info->tree_root == root)
 218                 btrfs_set_super_root_dir(&root->fs_info->super_copy, objectid);
 219
 220         ret = btrfs_insert_inode(trans, root, objectid, &inode_item);
 221         if (ret)
 222                 goto error;
 223
 224         ret = btrfs_insert_inode_ref(trans, root, "..", 2, objectid, objectid);
 225         if (ret)
 226                 goto error;
 227
 228         btrfs_set_root_dirid(&root->root_item, objectid);
 229         ret = 0;
 230 error:
 231         return ret;
 232 }