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 18unsigned hfsplus_pages_per_bnode; 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 inode *inode; 26 struct page *page; 27 unsigned int size; 28 29 tree = kzalloc(sizeof(*tree), GFP_KERNEL); 30 if (!tree) 31 return NULL; 32 33 mutex_init(&tree->tree_lock); 34 spin_lock_init(&tree->hash_lock); 35 tree->sb = sb; 36 tree->cnid = id; 37 inode = hfsplus_iget(sb, id); 38 if (IS_ERR(inode)) 39 goto free_tree; 40 tree->inode = inode; 41 42 if (!HFSPLUS_I(tree->inode).first_blocks) { 43 printk(KERN_ERR 44 "hfs: invalid btree extent records (0 size).\n"); 45 goto free_inode; 46 } 47 48 mapping = tree->inode->i_mapping; 49 page = read_mapping_page(mapping, 0, NULL); 50 if (IS_ERR(page)) 51 goto free_inode; 52 53 /* Load the header */ 54 head = (struct hfs_btree_header_rec *)(kmap(page) + sizeof(struct hfs_bnode_desc)); 55 tree->root = be32_to_cpu(head->root); 56 tree->leaf_count = be32_to_cpu(head->leaf_count); 57 tree->leaf_head = be32_to_cpu(head->leaf_head); 58 tree->leaf_tail = be32_to_cpu(head->leaf_tail); 59 tree->node_count = be32_to_cpu(head->node_count); 60 tree->free_nodes = be32_to_cpu(head->free_nodes); 61 tree->attributes = be32_to_cpu(head->attributes); 62 tree->node_size = be16_to_cpu(head->node_size); 63 tree->max_key_len = be16_to_cpu(head->max_key_len); 64 tree->depth = be16_to_cpu(head->depth); 65 66 /* Verify the tree and set the correct compare function */ 67 switch (id) { 68 case HFSPLUS_EXT_CNID: 69 if (tree->max_key_len != HFSPLUS_EXT_KEYLEN - sizeof(u16)) { 70 printk(KERN_ERR "hfs: invalid extent max_key_len %d\n", 71 tree->max_key_len); 72 goto fail_page; 73 } 74 if (tree->attributes & HFS_TREE_VARIDXKEYS) { 75 printk(KERN_ERR "hfs: invalid extent btree flag\n"); 76 goto fail_page; 77 } 78 79 tree->keycmp = hfsplus_ext_cmp_key; 80 break; 81 case HFSPLUS_CAT_CNID: 82 if (tree->max_key_len != HFSPLUS_CAT_KEYLEN - sizeof(u16)) { 83 printk(KERN_ERR "hfs: invalid catalog max_key_len %d\n", 84 tree->max_key_len); 85 goto fail_page; 86 } 87 if (!(tree->attributes & HFS_TREE_VARIDXKEYS)) { 88 printk(KERN_ERR "hfs: invalid catalog btree flag\n"); 89 goto fail_page; 90 } 91 92 if (test_bit(HFSPLUS_SB_HFSX, &HFSPLUS_SB(sb).flags) && 93 (head->key_type == HFSPLUS_KEY_BINARY)) 94 tree->keycmp = hfsplus_cat_bin_cmp_key; 95 else { 96 tree->keycmp = hfsplus_cat_case_cmp_key; 97 set_bit(HFSPLUS_SB_CASEFOLD, &HFSPLUS_SB(sb).flags); 98 } 99 break; 100 default: 101 printk(KERN_ERR "hfs: unknown B*Tree requested\n"); 102 goto fail_page; 103 } 104 105 if (!(tree->attributes & HFS_TREE_BIGKEYS)) { 106 printk(KERN_ERR "hfs: invalid btree flag\n"); 107 goto fail_page; 108 } 109 110 size = tree->node_size; 111 if (!is_power_of_2(size)) 112 goto fail_page; 113 if (!tree->node_count) 114 goto fail_page; 115 tree->node_size_shift = ffs(size) - 1; 116 117 tree->pages_per_bnode = (tree->node_size + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; 118hfsplus_pages_per_bnode=tree->pages_per_bnode; 119 kunmap(page); 120 page_cache_release(page); 121 return tree; 122 123 fail_page: 124 tree->inode->i_mapping->a_ops = &hfsplus_aops; 125 page_cache_release(page); 126 free_inode: 127 iput(tree->inode); 128 free_tree: 129 kfree(tree); 130 return NULL; 131} 132 133/* Release resources used by a btree */ 134void hfs_btree_close(struct hfs_btree *tree) 135{ 136 struct hfs_bnode *node; 137 int i; 138 139 if (!tree) 140 return; 141 142 for (i = 0; i < NODE_HASH_SIZE; i++) { 143 while ((node = tree->node_hash[i])) { 144 tree->node_hash[i] = node->next_hash; 145 if (atomic_read(&node->refcnt)) 146 printk(KERN_CRIT "hfs: node %d:%d still has %d user(s)!\n", 147 node->tree->cnid, node->this, atomic_read(&node->refcnt)); 148 hfs_bnode_free(node); 149 tree->node_hash_cnt--; 150 } 151 } 152 iput(tree->inode); 153 kfree(tree); 154} 155 156int hfs_btree_write(hfsplus_handle_t *hfsplus_handle,struct hfs_btree *tree) 157{ 158 struct hfs_btree_header_rec *head; 159 struct hfs_bnode *node; 160 struct page *page; 161 162 node = hfs_bnode_find(hfsplus_handle, tree, 0); 163 if (IS_ERR(node)) 164 /* panic? */ 165 return -EIO; 166 /* Load the header */ 167 page = node->page[0]; 168 head = (struct hfs_btree_header_rec *)(kmap(page) + sizeof(struct hfs_bnode_desc)); 169 170 head->root = cpu_to_be32(tree->root); 171 head->leaf_count = cpu_to_be32(tree->leaf_count); 172 head->leaf_head = cpu_to_be32(tree->leaf_head); 173 head->leaf_tail = cpu_to_be32(tree->leaf_tail); 174 head->node_count = cpu_to_be32(tree->node_count); 175 head->free_nodes = cpu_to_be32(tree->free_nodes); 176 head->attributes = cpu_to_be32(tree->attributes); 177 head->depth = cpu_to_be16(tree->depth); 178 179 kunmap(page); 180 hfsplus_journalled_set_page_dirty(hfsplus_handle, page); 181 hfs_bnode_put(hfsplus_handle, node); 182 return 0; 183} 184 185static struct hfs_bnode *hfs_bmap_new_bmap(hfsplus_handle_t *hfsplus_handle, struct hfs_bnode *prev, u32 idx) 186{ 187 struct hfs_btree *tree = prev->tree; 188 struct hfs_bnode *node; 189 struct hfs_bnode_desc desc; 190 __be32 cnid; 191 192 node = hfs_bnode_create(hfsplus_handle, tree, idx); 193 if (IS_ERR(node)) 194 return node; 195 196 tree->free_nodes--; 197 prev->next = idx; 198 cnid = cpu_to_be32(idx); 199 hfs_bnode_write(hfsplus_handle, prev, &cnid, offsetof(struct hfs_bnode_desc, next), 4); 200 201 node->type = HFS_NODE_MAP; 202 node->num_recs = 1; 203 hfs_bnode_clear(hfsplus_handle, node, 0, tree->node_size); 204 desc.next = 0; 205 desc.prev = 0; 206 desc.type = HFS_NODE_MAP; 207 desc.height = 0; 208 desc.num_recs = cpu_to_be16(1); 209 desc.reserved = 0; 210 hfs_bnode_write(hfsplus_handle, node, &desc, 0, sizeof(desc)); 211 hfs_bnode_write_u16(hfsplus_handle, node, 14, 0x8000); 212 hfs_bnode_write_u16(hfsplus_handle, node, tree->node_size - 2, 14); 213 hfs_bnode_write_u16(hfsplus_handle, node, tree->node_size - 4, tree->node_size - 6); 214 215 return node; 216} 217 218struct hfs_bnode *hfs_bmap_alloc(hfsplus_handle_t *hfsplus_handle, struct hfs_btree *tree) 219{ 220 struct hfs_bnode *node, *next_node; 221 struct page **pagep; 222 u32 nidx, idx; 223 unsigned off; 224 u16 off16; 225 u16 len; 226 u8 *data, byte, m; 227 int i; 228 229 while (!tree->free_nodes) { 230 struct inode *inode = tree->inode; 231 u32 count; 232 int res; 233 234 res = hfsplus_file_extend(hfsplus_handle, inode); 235 if (res) 236 return ERR_PTR(res); 237 HFSPLUS_I(inode).phys_size = inode->i_size = 238 (loff_t)HFSPLUS_I(inode).alloc_blocks << 239 HFSPLUS_SB(tree->sb).alloc_blksz_shift; 240 HFSPLUS_I(inode).fs_blocks = HFSPLUS_I(inode).alloc_blocks << 241 HFSPLUS_SB(tree->sb).fs_shift; 242 inode_set_bytes(inode, inode->i_size); 243 /* Foxconn added start pling 05/31/2010 */ 244 /* Set the i_blocks field properly */ 245 inode->i_blocks = inode->i_size/512; 246 if (inode->i_size % 512) 247 inode->i_blocks++; 248 /* Foxconn added end pling 05/31/2010 */ 249 count = inode->i_size >> tree->node_size_shift; 250 tree->free_nodes = count - tree->node_count; 251 tree->node_count = count; 252 } 253 254 nidx = 0; 255 node = hfs_bnode_find(hfsplus_handle, tree, nidx); 256 if (IS_ERR(node)) 257 return node; 258 len = hfs_brec_lenoff(node, 2, &off16); 259 off = off16; 260 261 off += node->page_offset; 262 pagep = node->page + (off >> PAGE_CACHE_SHIFT); 263 data = kmap(*pagep); 264 off &= ~PAGE_CACHE_MASK; 265 idx = 0; 266 267 for (;;) { 268 while (len) { 269 byte = data[off]; 270 if (byte != 0xff) { 271 for (m = 0x80, i = 0; i < 8; m >>= 1, i++) { 272 if (!(byte & m)) { 273 idx += i; 274 data[off] |= m; 275 hfsplus_journalled_set_page_dirty(hfsplus_handle, *pagep); 276 kunmap(*pagep); 277 tree->free_nodes--; 278 if (hfsplus_journalled_mark_inode_dirty(__FUNCTION__, hfsplus_handle, tree->inode)) 279 return NULL; 280 hfs_bnode_put(hfsplus_handle, node); 281 return hfs_bnode_create(hfsplus_handle, tree, idx); 282 } 283 } 284 } 285 if (++off >= PAGE_CACHE_SIZE) { 286 kunmap(*pagep); 287 data = kmap(*++pagep); 288 off = 0; 289 } 290 idx += 8; 291 len--; 292 } 293 kunmap(*pagep); 294 nidx = node->next; 295 if (!nidx) { 296 printk(KERN_DEBUG "hfs: create new bmap node...\n"); 297 next_node = hfs_bmap_new_bmap(hfsplus_handle, node, idx); 298 } else 299 next_node = hfs_bnode_find(hfsplus_handle, tree, nidx); 300 hfs_bnode_put(hfsplus_handle, node); 301 if (IS_ERR(next_node)) 302 return next_node; 303 node = next_node; 304 305 len = hfs_brec_lenoff(node, 0, &off16); 306 off = off16; 307 off += node->page_offset; 308 pagep = node->page + (off >> PAGE_CACHE_SHIFT); 309 data = kmap(*pagep); 310 off &= ~PAGE_CACHE_MASK; 311 } 312} 313 314void hfs_bmap_free(hfsplus_handle_t *hfsplus_handle, struct hfs_bnode *node) 315{ 316 struct hfs_btree *tree; 317 struct page *page; 318 u16 off, len; 319 u32 nidx; 320 u8 *data, byte, m; 321 322 dprint(DBG_BNODE_MOD, "btree_free_node: %u\n", node->this); 323 BUG_ON(!node->this); 324 tree = node->tree; 325 nidx = node->this; 326 node = hfs_bnode_find(hfsplus_handle, tree, 0); 327 if (IS_ERR(node)) 328 return; 329 len = hfs_brec_lenoff(node, 2, &off); 330 while (nidx >= len * 8) { 331 u32 i; 332 333 nidx -= len * 8; 334 i = node->next; 335 hfs_bnode_put(hfsplus_handle, node); 336 if (!i) { 337 /* panic */; 338 printk(KERN_CRIT "hfs: unable to free bnode %u. bmap not found!\n", node->this); 339 return; 340 } 341 node = hfs_bnode_find(hfsplus_handle, tree, i); 342 if (IS_ERR(node)) 343 return; 344 if (node->type != HFS_NODE_MAP) { 345 /* panic */; 346 printk(KERN_CRIT "hfs: invalid bmap found! (%u,%d)\n", node->this, node->type); 347 hfs_bnode_put(hfsplus_handle, node); 348 return; 349 } 350 len = hfs_brec_lenoff(node, 0, &off); 351 } 352 off += node->page_offset + nidx / 8; 353 page = node->page[off >> PAGE_CACHE_SHIFT]; 354 data = kmap(page); 355 off &= ~PAGE_CACHE_MASK; 356 m = 1 << (~nidx & 7); 357 byte = data[off]; 358 if (!(byte & m)) { 359 printk(KERN_CRIT "hfs: trying to free free bnode %u(%d)\n", node->this, node->type); 360 kunmap(page); 361 hfs_bnode_put(hfsplus_handle, node); 362 return; 363 } 364 data[off] = byte & ~m; 365 hfsplus_journalled_set_page_dirty(hfsplus_handle, page); 366 kunmap(page); 367 hfs_bnode_put(hfsplus_handle, node); 368 tree->free_nodes++; 369 if (hfsplus_journalled_mark_inode_dirty(__FUNCTION__, hfsplus_handle, tree->inode)) 370 return; 371} 372