1e20d96d6SChris Mason #include <linux/module.h> 2e20d96d6SChris Mason #include <linux/fs.h> 3d98237b3SChris Mason #include <linux/blkdev.h> 4eb60ceacSChris Mason #include "ctree.h" 5eb60ceacSChris Mason #include "disk-io.h" 6e089f05cSChris Mason #include "transaction.h" 7eb60ceacSChris Mason 8d98237b3SChris Mason 9e20d96d6SChris Mason static int check_tree_block(struct btrfs_root *root, struct buffer_head *buf) 10eb60ceacSChris Mason { 11e20d96d6SChris Mason struct btrfs_node *node = btrfs_buffer_node(buf); 12d98237b3SChris Mason if (buf->b_blocknr != btrfs_header_blocknr(&node->header)) { 139a8dd150SChris Mason BUG(); 14d98237b3SChris Mason } 15e20d96d6SChris Mason if (root->node && btrfs_header_parentid(&node->header) != 16df2ce34cSChris Mason btrfs_header_parentid(btrfs_buffer_header(root->node))) { 177f5c1516SChris Mason BUG(); 18df2ce34cSChris Mason } 199a8dd150SChris Mason return 0; 20eb60ceacSChris Mason } 21eb60ceacSChris Mason 22d98237b3SChris Mason struct buffer_head *btrfs_find_tree_block(struct btrfs_root *root, u64 blocknr) 23ed2ff2cbSChris Mason { 24d98237b3SChris Mason struct address_space *mapping = root->fs_info->btree_inode->i_mapping; 25d98237b3SChris Mason int blockbits = root->fs_info->sb->s_blocksize_bits; 26d98237b3SChris Mason unsigned long index = blocknr >> (PAGE_CACHE_SHIFT - blockbits); 27d98237b3SChris Mason struct page *page; 28d98237b3SChris Mason struct buffer_head *bh; 29d98237b3SChris Mason struct buffer_head *head; 30d98237b3SChris Mason struct buffer_head *ret = NULL; 31d98237b3SChris Mason 32d98237b3SChris Mason page = find_lock_page(mapping, index); 33d98237b3SChris Mason if (!page) 34d98237b3SChris Mason return NULL; 35d98237b3SChris Mason 36d98237b3SChris Mason if (!page_has_buffers(page)) 37d98237b3SChris Mason goto out_unlock; 38d98237b3SChris Mason 39d98237b3SChris Mason head = page_buffers(page); 40d98237b3SChris Mason bh = head; 41d98237b3SChris Mason do { 42d98237b3SChris Mason if (buffer_mapped(bh) && bh->b_blocknr == blocknr) { 43d98237b3SChris Mason ret = bh; 44d98237b3SChris Mason get_bh(bh); 45d98237b3SChris Mason goto out_unlock; 46d98237b3SChris Mason } 47d98237b3SChris Mason bh = bh->b_this_page; 48d98237b3SChris Mason } while (bh != head); 49d98237b3SChris Mason out_unlock: 50d98237b3SChris Mason unlock_page(page); 51d98237b3SChris Mason page_cache_release(page); 52d98237b3SChris Mason return ret; 53ed2ff2cbSChris Mason } 54ed2ff2cbSChris Mason 55d98237b3SChris Mason struct buffer_head *btrfs_find_create_tree_block(struct btrfs_root *root, 56d98237b3SChris Mason u64 blocknr) 57eb60ceacSChris Mason { 58d98237b3SChris Mason struct address_space *mapping = root->fs_info->btree_inode->i_mapping; 59d98237b3SChris Mason int blockbits = root->fs_info->sb->s_blocksize_bits; 60d98237b3SChris Mason unsigned long index = blocknr >> (PAGE_CACHE_SHIFT - blockbits); 61d98237b3SChris Mason struct page *page; 62d98237b3SChris Mason struct buffer_head *bh; 63d98237b3SChris Mason struct buffer_head *head; 64d98237b3SChris Mason struct buffer_head *ret = NULL; 65d98237b3SChris Mason u64 first_block = index << (PAGE_CACHE_SHIFT - blockbits); 66d98237b3SChris Mason page = grab_cache_page(mapping, index); 67d98237b3SChris Mason if (!page) 68d98237b3SChris Mason return NULL; 69d98237b3SChris Mason 70d98237b3SChris Mason wait_on_page_writeback(page); 71d98237b3SChris Mason if (!page_has_buffers(page)) 72d98237b3SChris Mason create_empty_buffers(page, root->fs_info->sb->s_blocksize, 0); 73d98237b3SChris Mason head = page_buffers(page); 74d98237b3SChris Mason bh = head; 75d98237b3SChris Mason do { 76d98237b3SChris Mason if (!buffer_mapped(bh)) { 77d98237b3SChris Mason bh->b_bdev = root->fs_info->sb->s_bdev; 78d98237b3SChris Mason bh->b_blocknr = first_block; 79d98237b3SChris Mason set_buffer_mapped(bh); 80e20d96d6SChris Mason } 81d98237b3SChris Mason if (bh->b_blocknr == blocknr) { 82d98237b3SChris Mason ret = bh; 83d98237b3SChris Mason get_bh(bh); 84d98237b3SChris Mason goto out_unlock; 85d98237b3SChris Mason } 86d98237b3SChris Mason bh = bh->b_this_page; 87d98237b3SChris Mason first_block++; 88d98237b3SChris Mason } while (bh != head); 89d98237b3SChris Mason out_unlock: 90d98237b3SChris Mason unlock_page(page); 91d98237b3SChris Mason page_cache_release(page); 92d98237b3SChris Mason return ret; 93d98237b3SChris Mason } 94d98237b3SChris Mason 95d98237b3SChris Mason static sector_t max_block(struct block_device *bdev) 96d98237b3SChris Mason { 97d98237b3SChris Mason sector_t retval = ~((sector_t)0); 98d98237b3SChris Mason loff_t sz = i_size_read(bdev->bd_inode); 99d98237b3SChris Mason 100d98237b3SChris Mason if (sz) { 101d98237b3SChris Mason unsigned int size = block_size(bdev); 102d98237b3SChris Mason unsigned int sizebits = blksize_bits(size); 103d98237b3SChris Mason retval = (sz >> sizebits); 104d98237b3SChris Mason } 105d98237b3SChris Mason return retval; 106d98237b3SChris Mason } 107d98237b3SChris Mason 108d98237b3SChris Mason static int btree_get_block(struct inode *inode, sector_t iblock, 109d98237b3SChris Mason struct buffer_head *bh, int create) 110d98237b3SChris Mason { 111d98237b3SChris Mason if (iblock >= max_block(inode->i_sb->s_bdev)) { 112d98237b3SChris Mason if (create) 113d98237b3SChris Mason return -EIO; 114d98237b3SChris Mason 115d98237b3SChris Mason /* 116d98237b3SChris Mason * for reads, we're just trying to fill a partial page. 117d98237b3SChris Mason * return a hole, they will have to call get_block again 118d98237b3SChris Mason * before they can fill it, and they will get -EIO at that 119d98237b3SChris Mason * time 120d98237b3SChris Mason */ 121d98237b3SChris Mason return 0; 122d98237b3SChris Mason } 123d98237b3SChris Mason bh->b_bdev = inode->i_sb->s_bdev; 124d98237b3SChris Mason bh->b_blocknr = iblock; 125d98237b3SChris Mason set_buffer_mapped(bh); 126d98237b3SChris Mason return 0; 127d98237b3SChris Mason } 128d98237b3SChris Mason 129d98237b3SChris Mason static int btree_writepage(struct page *page, struct writeback_control *wbc) 130d98237b3SChris Mason { 131d98237b3SChris Mason return block_write_full_page(page, btree_get_block, wbc); 132d98237b3SChris Mason } 133d98237b3SChris Mason 134d98237b3SChris Mason static int btree_readpage(struct file * file, struct page * page) 135d98237b3SChris Mason { 136d98237b3SChris Mason return block_read_full_page(page, btree_get_block); 137d98237b3SChris Mason } 138d98237b3SChris Mason 139d98237b3SChris Mason static struct address_space_operations btree_aops = { 140d98237b3SChris Mason .readpage = btree_readpage, 141d98237b3SChris Mason .writepage = btree_writepage, 142d98237b3SChris Mason .sync_page = block_sync_page, 143d98237b3SChris Mason }; 144123abc88SChris Mason 145e20d96d6SChris Mason struct buffer_head *read_tree_block(struct btrfs_root *root, u64 blocknr) 146e20d96d6SChris Mason { 147d98237b3SChris Mason struct buffer_head *bh = NULL; 148e20d96d6SChris Mason 149d98237b3SChris Mason bh = btrfs_find_create_tree_block(root, blocknr); 150d98237b3SChris Mason if (!bh) 151d98237b3SChris Mason return bh; 152d98237b3SChris Mason lock_buffer(bh); 153d98237b3SChris Mason if (!buffer_uptodate(bh)) { 154d98237b3SChris Mason get_bh(bh); 155d98237b3SChris Mason bh->b_end_io = end_buffer_read_sync; 156d98237b3SChris Mason submit_bh(READ, bh); 157d98237b3SChris Mason wait_on_buffer(bh); 158d98237b3SChris Mason if (!buffer_uptodate(bh)) 159d98237b3SChris Mason goto fail; 160d98237b3SChris Mason } else { 161d98237b3SChris Mason unlock_buffer(bh); 162d98237b3SChris Mason } 163d98237b3SChris Mason if (check_tree_block(root, bh)) 164cfaa7295SChris Mason BUG(); 165d98237b3SChris Mason return bh; 166d98237b3SChris Mason fail: 167d98237b3SChris Mason brelse(bh); 168d98237b3SChris Mason return NULL; 169d98237b3SChris Mason 170eb60ceacSChris Mason } 171eb60ceacSChris Mason 172e089f05cSChris Mason int dirty_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root, 173e20d96d6SChris Mason struct buffer_head *buf) 174ed2ff2cbSChris Mason { 175e20d96d6SChris Mason mark_buffer_dirty(buf); 176ed2ff2cbSChris Mason return 0; 177ed2ff2cbSChris Mason } 178ed2ff2cbSChris Mason 179e089f05cSChris Mason int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root, 180e20d96d6SChris Mason struct buffer_head *buf) 181ed2ff2cbSChris Mason { 182e20d96d6SChris Mason clear_buffer_dirty(buf); 183ed2ff2cbSChris Mason return 0; 184ed2ff2cbSChris Mason } 185ed2ff2cbSChris Mason 186123abc88SChris Mason static int __setup_root(struct btrfs_super_block *super, 1879f5fae2fSChris Mason struct btrfs_root *root, 1889f5fae2fSChris Mason struct btrfs_fs_info *fs_info, 189e20d96d6SChris Mason u64 objectid) 190d97e63b6SChris Mason { 191cfaa7295SChris Mason root->node = NULL; 192a28ec197SChris Mason root->commit_root = NULL; 193123abc88SChris Mason root->blocksize = btrfs_super_blocksize(super); 194123abc88SChris Mason root->ref_cows = 0; 1959f5fae2fSChris Mason root->fs_info = fs_info; 1963768f368SChris Mason memset(&root->root_key, 0, sizeof(root->root_key)); 1973768f368SChris Mason memset(&root->root_item, 0, sizeof(root->root_item)); 1983768f368SChris Mason return 0; 1993768f368SChris Mason } 2003768f368SChris Mason 201123abc88SChris Mason static int find_and_setup_root(struct btrfs_super_block *super, 2029f5fae2fSChris Mason struct btrfs_root *tree_root, 2039f5fae2fSChris Mason struct btrfs_fs_info *fs_info, 2049f5fae2fSChris Mason u64 objectid, 205e20d96d6SChris Mason struct btrfs_root *root) 2063768f368SChris Mason { 2073768f368SChris Mason int ret; 2083768f368SChris Mason 209e20d96d6SChris Mason __setup_root(super, root, fs_info, objectid); 2103768f368SChris Mason ret = btrfs_find_last_root(tree_root, objectid, 2113768f368SChris Mason &root->root_item, &root->root_key); 2123768f368SChris Mason BUG_ON(ret); 2133768f368SChris Mason 2143768f368SChris Mason root->node = read_tree_block(root, 2153768f368SChris Mason btrfs_root_blocknr(&root->root_item)); 2163768f368SChris Mason BUG_ON(!root->node); 217d97e63b6SChris Mason return 0; 218d97e63b6SChris Mason } 219d97e63b6SChris Mason 220e20d96d6SChris Mason struct btrfs_root *open_ctree(struct super_block *sb, 221e20d96d6SChris Mason struct buffer_head *sb_buffer, 222e20d96d6SChris Mason struct btrfs_super_block *disk_super) 223eb60ceacSChris Mason { 224e20d96d6SChris Mason struct btrfs_root *root = kmalloc(sizeof(struct btrfs_root), 225e20d96d6SChris Mason GFP_NOFS); 226e20d96d6SChris Mason struct btrfs_root *extent_root = kmalloc(sizeof(struct btrfs_root), 227e20d96d6SChris Mason GFP_NOFS); 228e20d96d6SChris Mason struct btrfs_root *tree_root = kmalloc(sizeof(struct btrfs_root), 229e20d96d6SChris Mason GFP_NOFS); 230e20d96d6SChris Mason struct btrfs_root *inode_root = kmalloc(sizeof(struct btrfs_root), 231e20d96d6SChris Mason GFP_NOFS); 232e20d96d6SChris Mason struct btrfs_fs_info *fs_info = kmalloc(sizeof(*fs_info), 233e20d96d6SChris Mason GFP_NOFS); 234eb60ceacSChris Mason int ret; 235eb60ceacSChris Mason 236e20d96d6SChris Mason if (!btrfs_super_root(disk_super)) 237e20d96d6SChris Mason return NULL; 2388ef97622SChris Mason init_bit_radix(&fs_info->pinned_radix); 2398ef97622SChris Mason init_bit_radix(&fs_info->pending_del_radix); 240d98237b3SChris Mason sb_set_blocksize(sb, sb_buffer->b_size); 2419f5fae2fSChris Mason fs_info->running_transaction = NULL; 2429f5fae2fSChris Mason fs_info->fs_root = root; 2439f5fae2fSChris Mason fs_info->tree_root = tree_root; 2449f5fae2fSChris Mason fs_info->extent_root = extent_root; 2459f5fae2fSChris Mason fs_info->inode_root = inode_root; 2469f5fae2fSChris Mason fs_info->last_inode_alloc = 0; 2479f5fae2fSChris Mason fs_info->last_inode_alloc_dirid = 0; 248e20d96d6SChris Mason fs_info->disk_super = disk_super; 249e20d96d6SChris Mason fs_info->sb = sb; 250d98237b3SChris Mason fs_info->btree_inode = new_inode(sb); 251d98237b3SChris Mason fs_info->btree_inode->i_ino = 1; 252d98237b3SChris Mason fs_info->btree_inode->i_size = sb->s_bdev->bd_inode->i_size; 253d98237b3SChris Mason fs_info->btree_inode->i_mapping->a_ops = &btree_aops; 254d98237b3SChris Mason mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS); 255d98237b3SChris Mason 25679154b1bSChris Mason mutex_init(&fs_info->trans_mutex); 257d561c025SChris Mason mutex_init(&fs_info->fs_mutex); 2589f5fae2fSChris Mason memset(&fs_info->current_insert, 0, sizeof(fs_info->current_insert)); 2599f5fae2fSChris Mason memset(&fs_info->last_insert, 0, sizeof(fs_info->last_insert)); 2603768f368SChris Mason 261e20d96d6SChris Mason __setup_root(disk_super, tree_root, fs_info, BTRFS_ROOT_TREE_OBJECTID); 262d98237b3SChris Mason 263d98237b3SChris Mason fs_info->sb_buffer = read_tree_block(tree_root, sb_buffer->b_blocknr); 264d98237b3SChris Mason 265d98237b3SChris Mason if (!fs_info->sb_buffer) 266d98237b3SChris Mason return NULL; 267d98237b3SChris Mason 268d98237b3SChris Mason brelse(sb_buffer); 269d98237b3SChris Mason sb_buffer = NULL; 270d98237b3SChris Mason disk_super = (struct btrfs_super_block *)fs_info->sb_buffer->b_data; 271d98237b3SChris Mason fs_info->disk_super = disk_super; 272d98237b3SChris Mason 273e20d96d6SChris Mason tree_root->node = read_tree_block(tree_root, 274e20d96d6SChris Mason btrfs_super_root(disk_super)); 2753768f368SChris Mason BUG_ON(!tree_root->node); 2763768f368SChris Mason 277e20d96d6SChris Mason ret = find_and_setup_root(disk_super, tree_root, fs_info, 278e20d96d6SChris Mason BTRFS_EXTENT_TREE_OBJECTID, extent_root); 2793768f368SChris Mason BUG_ON(ret); 2803768f368SChris Mason 281e20d96d6SChris Mason ret = find_and_setup_root(disk_super, tree_root, fs_info, 282e20d96d6SChris Mason BTRFS_INODE_MAP_OBJECTID, inode_root); 2839f5fae2fSChris Mason BUG_ON(ret); 2849f5fae2fSChris Mason 285e20d96d6SChris Mason ret = find_and_setup_root(disk_super, tree_root, fs_info, 286e20d96d6SChris Mason BTRFS_FS_TREE_OBJECTID, root); 2873768f368SChris Mason BUG_ON(ret); 288a28ec197SChris Mason root->commit_root = root->node; 289e20d96d6SChris Mason get_bh(root->node); 2903768f368SChris Mason root->ref_cows = 1; 291293ffd5fSChris Mason root->fs_info->generation = root->root_key.offset + 1; 292eb60ceacSChris Mason return root; 293eb60ceacSChris Mason } 294eb60ceacSChris Mason 295e089f05cSChris Mason int write_ctree_super(struct btrfs_trans_handle *trans, struct btrfs_root 29679154b1bSChris Mason *root) 297cfaa7295SChris Mason { 298d5719762SChris Mason struct buffer_head *bh = root->fs_info->sb_buffer; 299d5719762SChris Mason btrfs_set_super_root(root->fs_info->disk_super, 300d5719762SChris Mason root->fs_info->tree_root->node->b_blocknr); 301d5719762SChris Mason lock_buffer(bh); 302d5719762SChris Mason clear_buffer_dirty(bh); 303d5719762SChris Mason bh->b_end_io = end_buffer_write_sync; 304d5719762SChris Mason get_bh(bh); 305d5719762SChris Mason submit_bh(WRITE, bh); 306d5719762SChris Mason wait_on_buffer(bh); 307d5719762SChris Mason if (!buffer_uptodate(bh)) { 308d5719762SChris Mason WARN_ON(1); 309d5719762SChris Mason return -EIO; 310cfaa7295SChris Mason } 311cfaa7295SChris Mason return 0; 312cfaa7295SChris Mason } 313cfaa7295SChris Mason 314e20d96d6SChris Mason int close_ctree(struct btrfs_root *root) 315eb60ceacSChris Mason { 3163768f368SChris Mason int ret; 317e089f05cSChris Mason struct btrfs_trans_handle *trans; 318e089f05cSChris Mason 31979154b1bSChris Mason trans = btrfs_start_transaction(root, 1); 32079154b1bSChris Mason btrfs_commit_transaction(trans, root); 32179154b1bSChris Mason /* run commit again to drop the original snapshot */ 32279154b1bSChris Mason trans = btrfs_start_transaction(root, 1); 32379154b1bSChris Mason btrfs_commit_transaction(trans, root); 32479154b1bSChris Mason ret = btrfs_write_and_wait_transaction(NULL, root); 3259f5fae2fSChris Mason BUG_ON(ret); 32679154b1bSChris Mason write_ctree_super(NULL, root); 327ed2ff2cbSChris Mason 328eb60ceacSChris Mason if (root->node) 329234b63a0SChris Mason btrfs_block_release(root, root->node); 3309f5fae2fSChris Mason if (root->fs_info->extent_root->node) 3319f5fae2fSChris Mason btrfs_block_release(root->fs_info->extent_root, 3329f5fae2fSChris Mason root->fs_info->extent_root->node); 3339f5fae2fSChris Mason if (root->fs_info->inode_root->node) 3349f5fae2fSChris Mason btrfs_block_release(root->fs_info->inode_root, 3359f5fae2fSChris Mason root->fs_info->inode_root->node); 3369f5fae2fSChris Mason if (root->fs_info->tree_root->node) 3379f5fae2fSChris Mason btrfs_block_release(root->fs_info->tree_root, 3389f5fae2fSChris Mason root->fs_info->tree_root->node); 339234b63a0SChris Mason btrfs_block_release(root, root->commit_root); 340e20d96d6SChris Mason btrfs_block_release(root, root->fs_info->sb_buffer); 341d98237b3SChris Mason iput(root->fs_info->btree_inode); 342e20d96d6SChris Mason kfree(root->fs_info->extent_root); 343e20d96d6SChris Mason kfree(root->fs_info->inode_root); 344e20d96d6SChris Mason kfree(root->fs_info->tree_root); 345e20d96d6SChris Mason kfree(root->fs_info); 346e20d96d6SChris Mason kfree(root); 347eb60ceacSChris Mason return 0; 348eb60ceacSChris Mason } 349eb60ceacSChris Mason 350e20d96d6SChris Mason void btrfs_block_release(struct btrfs_root *root, struct buffer_head *buf) 351eb60ceacSChris Mason { 352e20d96d6SChris Mason brelse(buf); 353eb60ceacSChris Mason } 354eb60ceacSChris Mason 355