1/* 2 * linux/fs/hfsplus/btree.c 3 * 4 * Copyright (C) 2001 5 * Brad Boyer (flar@allandria.com) 6 * (C) 2003 Ardis Technologies <roman@ardistech.com> 7 * 8 * Handle opening/closing btree 9 */ 10 11#include <linux/slab.h> 12#include <linux/pagemap.h> 13#include <linux/log2.h> 14 15#include "hfsplus_fs.h" 16#include "hfsplus_raw.h" 17 18 19/* Get a reference to a B*Tree and do some initial checks */ 20struct hfs_btree *hfs_btree_open(struct super_block *sb, u32 id) 21{ 22 struct hfs_btree *tree; 23 struct hfs_btree_header_rec *head; 24 struct address_space *mapping; 25 struct page *page; 26 unsigned int size; 27 28 tree = kzalloc(sizeof(*tree), GFP_KERNEL); 29 if (!tree) 30 return NULL; 31 32 init_MUTEX(&tree->tree_lock); 33 spin_lock_init(&tree->hash_lock); 34 tree->sb = sb; 35 tree->cnid = id; 36 tree->inode = iget(sb, id); 37 if (!tree->inode) { 38 printk("HFS+-fs: B*Tree inode is NULL\n"); 39 goto free_tree; 40 } 41 42 mapping = tree->inode->i_mapping; 43 page = read_mapping_page(mapping, 0, NULL); 44 if (IS_ERR(page)) { 45 printk("HFS+-fs: Error in reading page of B*Tree\n"); 46 goto free_tree; 47 } 48 49 /* Load the header */ 50 head = (struct hfs_btree_header_rec *)(kmap(page) + sizeof(struct hfs_bnode_desc)); 51 tree->root = be32_to_cpu(head->root); 52 tree->leaf_count = be32_to_cpu(head->leaf_count); 53 tree->leaf_head = be32_to_cpu(head->leaf_head); 54 tree->leaf_tail = be32_to_cpu(head->leaf_tail); 55 tree->node_count = be32_to_cpu(head->node_count); 56 tree->free_nodes = be32_to_cpu(head->free_nodes); 57 tree->attributes = be32_to_cpu(head->attributes); 58 tree->node_size = be16_to_cpu(head->node_size); 59 tree->max_key_len = be16_to_cpu(head->max_key_len); 60 tree->depth = be16_to_cpu(head->depth); 61 62 /* Set the correct compare function */ 63 if (id == HFSPLUS_EXT_CNID) { 64 tree->keycmp = hfsplus_ext_cmp_key; 65 } else if (id == HFSPLUS_CAT_CNID) { 66 if ((HFSPLUS_SB(sb).flags & HFSPLUS_SB_HFSX) && 67 (head->key_type == HFSPLUS_KEY_BINARY)) 68 tree->keycmp = hfsplus_cat_bin_cmp_key; 69 else 70 tree->keycmp = hfsplus_cat_case_cmp_key; 71 } else { 72 printk(KERN_ERR "hfs: unknown B*Tree requested\n"); 73 goto fail_page; 74 } 75 76 size = tree->node_size; 77 if (!is_power_of_2(size)) 78 goto fail_page; 79 if (!tree->node_count) { 80 printk("HFS+-fs: B*Tree node count zero\n"); 81 goto fail_page; 82 } 83 tree->node_size_shift = ffs(size) - 1; 84 85 tree->pages_per_bnode = (tree->node_size + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; 86 87 kunmap(page); 88 page_cache_release(page); 89 return tree; 90 91 fail_page: 92 tree->inode->i_mapping->a_ops = &hfsplus_aops; 93 page_cache_release(page); 94 free_tree: 95 iput(tree->inode); 96 kfree(tree); 97 return NULL; 98} 99 100/* Release resources used by a btree */ 101void hfs_btree_close(struct hfs_btree *tree) 102{ 103 struct hfs_bnode *node; 104 int i; 105 106 if (!tree) 107 return; 108 109 for (i = 0; i < NODE_HASH_SIZE; i++) { 110 while ((node = tree->node_hash[i])) { 111 tree->node_hash[i] = node->next_hash; 112 if (atomic_read(&node->refcnt)) 113 printk(KERN_CRIT "hfs: node %d:%d still has %d user(s)!\n", 114 node->tree->cnid, node->this, atomic_read(&node->refcnt)); 115 hfs_bnode_free(node); 116 tree->node_hash_cnt--; 117 } 118 } 119 iput(tree->inode); 120 kfree(tree); 121} 122 123void hfs_btree_write(hfsplus_handle_t *hfsplus_handle, struct hfs_btree *tree) 124{ 125 struct hfs_btree_header_rec *head; 126 struct hfs_bnode *node; 127 struct page *page; 128 129 node = hfs_bnode_find(hfsplus_handle, tree, 0); 130 if (IS_ERR(node)) 131 /* panic? */ 132 return; 133 /* Load the header */ 134 page = node->page[0]; 135 head = (struct hfs_btree_header_rec *)(kmap(page) + sizeof(struct hfs_bnode_desc)); 136 137 head->root = cpu_to_be32(tree->root); 138 head->leaf_count = cpu_to_be32(tree->leaf_count); 139 head->leaf_head = cpu_to_be32(tree->leaf_head); 140 head->leaf_tail = cpu_to_be32(tree->leaf_tail); 141 head->node_count = cpu_to_be32(tree->node_count); 142 head->free_nodes = cpu_to_be32(tree->free_nodes); 143 head->attributes = cpu_to_be32(tree->attributes); 144 head->depth = cpu_to_be16(tree->depth); 145 146 kunmap(page); 147 hfsplus_journalled_set_page_dirty(hfsplus_handle, page); 148 hfs_bnode_put(hfsplus_handle, node); 149} 150 151static struct hfs_bnode *hfs_bmap_new_bmap(hfsplus_handle_t *hfsplus_handle, struct hfs_bnode *prev, u32 idx) 152{ 153 struct hfs_btree *tree = prev->tree; 154 struct hfs_bnode *node; 155 struct hfs_bnode_desc desc; 156 __be32 cnid; 157 158 node = hfs_bnode_create(hfsplus_handle, tree, idx); 159 if (IS_ERR(node)) 160 return node; 161 162 tree->free_nodes--; 163 prev->next = idx; 164 cnid = cpu_to_be32(idx); 165 hfs_bnode_write(hfsplus_handle, prev, &cnid, offsetof(struct hfs_bnode_desc, next), 4); 166 167 node->type = HFS_NODE_MAP; 168 node->num_recs = 1; 169 hfs_bnode_clear(hfsplus_handle, node, 0, tree->node_size); 170 desc.next = 0; 171 desc.prev = 0; 172 desc.type = HFS_NODE_MAP; 173 desc.height = 0; 174 desc.num_recs = cpu_to_be16(1); 175 desc.reserved = 0; 176 hfs_bnode_write(hfsplus_handle, node, &desc, 0, sizeof(desc)); 177 hfs_bnode_write_u16(hfsplus_handle, node, 14, 0x8000); 178 hfs_bnode_write_u16(hfsplus_handle, node, tree->node_size - 2, 14); 179 hfs_bnode_write_u16(hfsplus_handle, node, tree->node_size - 4, tree->node_size - 6); 180 181 return node; 182} 183 184struct hfs_bnode *hfs_bmap_alloc(hfsplus_handle_t *hfsplus_handle, struct hfs_btree *tree) 185{ 186 struct hfs_bnode *node, *next_node; 187 struct page **pagep; 188 u32 nidx, idx; 189 u16 off, len; 190 u8 *data, byte, m; 191 int i; 192 193 while (!tree->free_nodes) { 194 struct inode *inode = tree->inode; 195 u32 count; 196 int res; 197 198 res = hfsplus_file_extend(hfsplus_handle, inode); 199 if (res) 200 return ERR_PTR(res); 201 HFSPLUS_I(inode).phys_size = inode->i_size = 202 (loff_t)HFSPLUS_I(inode).alloc_blocks << 203 HFSPLUS_SB(tree->sb).alloc_blksz_shift; 204 HFSPLUS_I(inode).fs_blocks = HFSPLUS_I(inode).alloc_blocks << 205 HFSPLUS_SB(tree->sb).fs_shift; 206 inode_set_bytes(inode, inode->i_size); 207 /* Foxconn added start pling 05/31/2010 */ 208 /* Set the i_blocks field properly */ 209 inode->i_blocks = inode->i_size/512; 210 if (inode->i_size % 512) 211 inode->i_blocks++; 212 /* Foxconn added end pling 05/31/2010 */ 213 count = inode->i_size >> tree->node_size_shift; 214 tree->free_nodes = count - tree->node_count; 215 tree->node_count = count; 216 } 217 218 nidx = 0; 219 node = hfs_bnode_find(hfsplus_handle, tree, nidx); 220 if (IS_ERR(node)) 221 return node; 222 len = hfs_brec_lenoff(node, 2, &off); 223 224 off += node->page_offset; 225 pagep = node->page + (off >> PAGE_CACHE_SHIFT); 226 data = kmap(*pagep); 227 off &= ~PAGE_CACHE_MASK; 228 idx = 0; 229 230 for (;;) { 231 while (len) { 232 byte = data[off]; 233 if (byte != 0xff) { 234 for (m = 0x80, i = 0; i < 8; m >>= 1, i++) { 235 if (!(byte & m)) { 236 idx += i; 237 data[off] |= m; 238 hfsplus_journalled_set_page_dirty(hfsplus_handle, *pagep); 239 kunmap(*pagep); 240 tree->free_nodes--; 241 if (hfsplus_journalled_mark_inode_dirty(__FUNCTION__, hfsplus_handle, tree->inode)) 242 return NULL; 243 hfs_bnode_put(hfsplus_handle, node); 244 return hfs_bnode_create(hfsplus_handle, tree, idx); 245 } 246 } 247 } 248 if (++off >= PAGE_CACHE_SIZE) { 249 kunmap(*pagep); 250 data = kmap(*++pagep); 251 off = 0; 252 } 253 idx += 8; 254 len--; 255 } 256 kunmap(*pagep); 257 nidx = node->next; 258 if (!nidx) { 259 printk(KERN_DEBUG "hfs: create new bmap node...\n"); 260 next_node = hfs_bmap_new_bmap(hfsplus_handle, node, idx); 261 } else 262 next_node = hfs_bnode_find(hfsplus_handle, tree, nidx); 263 hfs_bnode_put(hfsplus_handle, node); 264 if (IS_ERR(next_node)) 265 return next_node; 266 node = next_node; 267 268 len = hfs_brec_lenoff(node, 0, &off); 269 off += node->page_offset; 270 pagep = node->page + (off >> PAGE_CACHE_SHIFT); 271 data = kmap(*pagep); 272 off &= ~PAGE_CACHE_MASK; 273 } 274} 275 276void hfs_bmap_free(hfsplus_handle_t *hfsplus_handle, struct hfs_bnode *node) 277{ 278 struct hfs_btree *tree; 279 struct page *page; 280 u16 off, len; 281 u32 nidx; 282 u8 *data, byte, m; 283 284 dprint(DBG_BNODE_MOD, "btree_free_node: %u\n", node->this); 285 BUG_ON(!node->this); 286 tree = node->tree; 287 nidx = node->this; 288 node = hfs_bnode_find(hfsplus_handle, tree, 0); 289 if (IS_ERR(node)) 290 return; 291 len = hfs_brec_lenoff(node, 2, &off); 292 while (nidx >= len * 8) { 293 u32 i; 294 295 nidx -= len * 8; 296 i = node->next; 297 hfs_bnode_put(hfsplus_handle, node); 298 if (!i) { 299 /* panic */; 300 printk(KERN_CRIT "hfs: unable to free bnode %u. bmap not found!\n", node->this); 301 return; 302 } 303 node = hfs_bnode_find(hfsplus_handle, tree, i); 304 if (IS_ERR(node)) 305 return; 306 if (node->type != HFS_NODE_MAP) { 307 /* panic */; 308 printk(KERN_CRIT "hfs: invalid bmap found! (%u,%d)\n", node->this, node->type); 309 hfs_bnode_put(hfsplus_handle, node); 310 return; 311 } 312 len = hfs_brec_lenoff(node, 0, &off); 313 } 314 off += node->page_offset + nidx / 8; 315 page = node->page[off >> PAGE_CACHE_SHIFT]; 316 data = kmap(page); 317 off &= ~PAGE_CACHE_MASK; 318 m = 1 << (~nidx & 7); 319 byte = data[off]; 320 if (!(byte & m)) { 321 printk(KERN_CRIT "hfs: trying to free free bnode %u(%d)\n", node->this, node->type); 322 kunmap(page); 323 hfs_bnode_put(hfsplus_handle, node); 324 return; 325 } 326 data[off] = byte & ~m; 327 hfsplus_journalled_set_page_dirty(hfsplus_handle, page); 328 kunmap(page); 329 hfs_bnode_put(hfsplus_handle, node); 330 tree->free_nodes++; 331 if (hfsplus_journalled_mark_inode_dirty(__FUNCTION__, hfsplus_handle, tree->inode)) 332 return; 333} 334