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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 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) +
55 sizeof(struct hfs_bnode_desc));
56 tree->root = be32_to_cpu(head->root);
57 tree->leaf_count = be32_to_cpu(head->leaf_count);
58 tree->leaf_head = be32_to_cpu(head->leaf_head);
59 tree->leaf_tail = be32_to_cpu(head->leaf_tail);
60 tree->node_count = be32_to_cpu(head->node_count);
61 tree->free_nodes = be32_to_cpu(head->free_nodes);
62 tree->attributes = be32_to_cpu(head->attributes);
63 tree->node_size = be16_to_cpu(head->node_size);
64 tree->max_key_len = be16_to_cpu(head->max_key_len);
65 tree->depth = be16_to_cpu(head->depth);
66
67 /* Verify the tree and set the correct compare function */
68 switch (id) {
69 case HFSPLUS_EXT_CNID:
70 if (tree->max_key_len != HFSPLUS_EXT_KEYLEN - sizeof(u16)) {
71 printk(KERN_ERR "hfs: invalid extent max_key_len %d\n",
72 tree->max_key_len);
73 goto fail_page;
74 }
75 if (tree->attributes & HFS_TREE_VARIDXKEYS) {
76 printk(KERN_ERR "hfs: invalid extent btree flag\n");
77 goto fail_page;
78 }
79
80 tree->keycmp = hfsplus_ext_cmp_key;
81 break;
82 case HFSPLUS_CAT_CNID:
83 if (tree->max_key_len != HFSPLUS_CAT_KEYLEN - sizeof(u16)) {
84 printk(KERN_ERR "hfs: invalid catalog max_key_len %d\n",
85 tree->max_key_len);
86 goto fail_page;
87 }
88 if (!(tree->attributes & HFS_TREE_VARIDXKEYS)) {
89 printk(KERN_ERR "hfs: invalid catalog btree flag\n");
90 goto fail_page;
91 }
92
93 if (test_bit(HFSPLUS_SB_HFSX, &HFSPLUS_SB(sb)->flags) &&
94 (head->key_type == HFSPLUS_KEY_BINARY))
95 tree->keycmp = hfsplus_cat_bin_cmp_key;
96 else {
97 tree->keycmp = hfsplus_cat_case_cmp_key;
98 set_bit(HFSPLUS_SB_CASEFOLD, &HFSPLUS_SB(sb)->flags);
99 }
100 break;
101 default:
102 printk(KERN_ERR "hfs: unknown B*Tree requested\n");
103 goto fail_page;
104 }
105
106 if (!(tree->attributes & HFS_TREE_BIGKEYS)) {
107 printk(KERN_ERR "hfs: invalid btree flag\n");
108 goto fail_page;
109 }
110
111 size = tree->node_size;
112 if (!is_power_of_2(size))
113 goto fail_page;
114 if (!tree->node_count)
115 goto fail_page;
116
117 tree->node_size_shift = ffs(size) - 1;
118
119 tree->pages_per_bnode =
120 (tree->node_size + PAGE_CACHE_SIZE - 1) >>
121 PAGE_CACHE_SHIFT;
122
123 kunmap(page);
124 page_cache_release(page);
125 return tree;
126
127 fail_page:
128 page_cache_release(page);
129 free_inode:
130 tree->inode->i_mapping->a_ops = &hfsplus_aops;
131 iput(tree->inode);
132 free_tree:
133 kfree(tree);
134 return NULL;
135}
136
137/* Release resources used by a btree */
138void hfs_btree_close(struct hfs_btree *tree)
139{
140 struct hfs_bnode *node;
141 int i;
142
143 if (!tree)
144 return;
145
146 for (i = 0; i < NODE_HASH_SIZE; i++) {
147 while ((node = tree->node_hash[i])) {
148 tree->node_hash[i] = node->next_hash;
149 if (atomic_read(&node->refcnt))
150 printk(KERN_CRIT "hfs: node %d:%d "
151 "still has %d user(s)!\n",
152 node->tree->cnid, node->this,
153 atomic_read(&node->refcnt));
154 hfs_bnode_free(node);
155 tree->node_hash_cnt--;
156 }
157 }
158 iput(tree->inode);
159 kfree(tree);
160}
161
162void hfs_btree_write(struct hfs_btree *tree)
163{
164 struct hfs_btree_header_rec *head;
165 struct hfs_bnode *node;
166 struct page *page;
167
168 node = hfs_bnode_find(tree, 0);
169 if (IS_ERR(node))
170 /* panic? */
171 return;
172 /* Load the header */
173 page = node->page[0];
174 head = (struct hfs_btree_header_rec *)(kmap(page) +
175 sizeof(struct hfs_bnode_desc));
176
177 head->root = cpu_to_be32(tree->root);
178 head->leaf_count = cpu_to_be32(tree->leaf_count);
179 head->leaf_head = cpu_to_be32(tree->leaf_head);
180 head->leaf_tail = cpu_to_be32(tree->leaf_tail);
181 head->node_count = cpu_to_be32(tree->node_count);
182 head->free_nodes = cpu_to_be32(tree->free_nodes);
183 head->attributes = cpu_to_be32(tree->attributes);
184 head->depth = cpu_to_be16(tree->depth);
185
186 kunmap(page);
187 set_page_dirty(page);
188 hfs_bnode_put(node);
189}
190
191static struct hfs_bnode *hfs_bmap_new_bmap(struct hfs_bnode *prev, u32 idx)
192{
193 struct hfs_btree *tree = prev->tree;
194 struct hfs_bnode *node;
195 struct hfs_bnode_desc desc;
196 __be32 cnid;
197
198 node = hfs_bnode_create(tree, idx);
199 if (IS_ERR(node))
200 return node;
201
202 tree->free_nodes--;
203 prev->next = idx;
204 cnid = cpu_to_be32(idx);
205 hfs_bnode_write(prev, &cnid, offsetof(struct hfs_bnode_desc, next), 4);
206
207 node->type = HFS_NODE_MAP;
208 node->num_recs = 1;
209 hfs_bnode_clear(node, 0, tree->node_size);
210 desc.next = 0;
211 desc.prev = 0;
212 desc.type = HFS_NODE_MAP;
213 desc.height = 0;
214 desc.num_recs = cpu_to_be16(1);
215 desc.reserved = 0;
216 hfs_bnode_write(node, &desc, 0, sizeof(desc));
217 hfs_bnode_write_u16(node, 14, 0x8000);
218 hfs_bnode_write_u16(node, tree->node_size - 2, 14);
219 hfs_bnode_write_u16(node, tree->node_size - 4, tree->node_size - 6);
220
221 return node;
222}
223
224struct hfs_bnode *hfs_bmap_alloc(struct hfs_btree *tree)
225{
226 struct hfs_bnode *node, *next_node;
227 struct page **pagep;
228 u32 nidx, idx;
229 unsigned off;
230 u16 off16;
231 u16 len;
232 u8 *data, byte, m;
233 int i;
234
235 while (!tree->free_nodes) {
236 struct inode *inode = tree->inode;
237 struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
238 u32 count;
239 int res;
240
241 res = hfsplus_file_extend(inode);
242 if (res)
243 return ERR_PTR(res);
244 hip->phys_size = inode->i_size =
245 (loff_t)hip->alloc_blocks <<
246 HFSPLUS_SB(tree->sb)->alloc_blksz_shift;
247 hip->fs_blocks =
248 hip->alloc_blocks << HFSPLUS_SB(tree->sb)->fs_shift;
249 inode_set_bytes(inode, inode->i_size);
250 count = inode->i_size >> tree->node_size_shift;
251 tree->free_nodes = count - tree->node_count;
252 tree->node_count = count;
253 }
254
255 nidx = 0;
256 node = hfs_bnode_find(tree, nidx);
257 if (IS_ERR(node))
258 return node;
259 len = hfs_brec_lenoff(node, 2, &off16);
260 off = off16;
261
262 off += node->page_offset;
263 pagep = node->page + (off >> PAGE_CACHE_SHIFT);
264 data = kmap(*pagep);
265 off &= ~PAGE_CACHE_MASK;
266 idx = 0;
267
268 for (;;) {
269 while (len) {
270 byte = data[off];
271 if (byte != 0xff) {
272 for (m = 0x80, i = 0; i < 8; m >>= 1, i++) {
273 if (!(byte & m)) {
274 idx += i;
275 data[off] |= m;
276 set_page_dirty(*pagep);
277 kunmap(*pagep);
278 tree->free_nodes--;
279 mark_inode_dirty(tree->inode);
280 hfs_bnode_put(node);
281 return hfs_bnode_create(tree,
282 idx);
283 }
284 }
285 }
286 if (++off >= PAGE_CACHE_SIZE) {
287 kunmap(*pagep);
288 data = kmap(*++pagep);
289 off = 0;
290 }
291 idx += 8;
292 len--;
293 }
294 kunmap(*pagep);
295 nidx = node->next;
296 if (!nidx) {
297 dprint(DBG_BNODE_MOD, "hfs: create new bmap node.\n");
298 next_node = hfs_bmap_new_bmap(node, idx);
299 } else
300 next_node = hfs_bnode_find(tree, nidx);
301 hfs_bnode_put(node);
302 if (IS_ERR(next_node))
303 return next_node;
304 node = next_node;
305
306 len = hfs_brec_lenoff(node, 0, &off16);
307 off = off16;
308 off += node->page_offset;
309 pagep = node->page + (off >> PAGE_CACHE_SHIFT);
310 data = kmap(*pagep);
311 off &= ~PAGE_CACHE_MASK;
312 }
313}
314
315void hfs_bmap_free(struct hfs_bnode *node)
316{
317 struct hfs_btree *tree;
318 struct page *page;
319 u16 off, len;
320 u32 nidx;
321 u8 *data, byte, m;
322
323 dprint(DBG_BNODE_MOD, "btree_free_node: %u\n", node->this);
324 BUG_ON(!node->this);
325 tree = node->tree;
326 nidx = node->this;
327 node = hfs_bnode_find(tree, 0);
328 if (IS_ERR(node))
329 return;
330 len = hfs_brec_lenoff(node, 2, &off);
331 while (nidx >= len * 8) {
332 u32 i;
333
334 nidx -= len * 8;
335 i = node->next;
336 hfs_bnode_put(node);
337 if (!i) {
338 /* panic */;
339 printk(KERN_CRIT "hfs: unable to free bnode %u. "
340 "bmap not found!\n",
341 node->this);
342 return;
343 }
344 node = hfs_bnode_find(tree, i);
345 if (IS_ERR(node))
346 return;
347 if (node->type != HFS_NODE_MAP) {
348 /* panic */;
349 printk(KERN_CRIT "hfs: invalid bmap found! "
350 "(%u,%d)\n",
351 node->this, node->type);
352 hfs_bnode_put(node);
353 return;
354 }
355 len = hfs_brec_lenoff(node, 0, &off);
356 }
357 off += node->page_offset + nidx / 8;
358 page = node->page[off >> PAGE_CACHE_SHIFT];
359 data = kmap(page);
360 off &= ~PAGE_CACHE_MASK;
361 m = 1 << (~nidx & 7);
362 byte = data[off];
363 if (!(byte & m)) {
364 printk(KERN_CRIT "hfs: trying to free free bnode "
365 "%u(%d)\n",
366 node->this, node->type);
367 kunmap(page);
368 hfs_bnode_put(node);
369 return;
370 }
371 data[off] = byte & ~m;
372 set_page_dirty(page);
373 kunmap(page);
374 hfs_bnode_put(node);
375 tree->free_nodes++;
376 mark_inode_dirty(tree->inode);
377}
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 * Initial source code of clump size calculation is gotten
20 * from http://opensource.apple.com/tarballs/diskdev_cmds/
21 */
22#define CLUMP_ENTRIES 15
23
24static short clumptbl[CLUMP_ENTRIES * 3] = {
25/*
26 * Volume Attributes Catalog Extents
27 * Size Clump (MB) Clump (MB) Clump (MB)
28 */
29 /* 1GB */ 4, 4, 4,
30 /* 2GB */ 6, 6, 4,
31 /* 4GB */ 8, 8, 4,
32 /* 8GB */ 11, 11, 5,
33 /*
34 * For volumes 16GB and larger, we want to make sure that a full OS
35 * install won't require fragmentation of the Catalog or Attributes
36 * B-trees. We do this by making the clump sizes sufficiently large,
37 * and by leaving a gap after the B-trees for them to grow into.
38 *
39 * For SnowLeopard 10A298, a FullNetInstall with all packages selected
40 * results in:
41 * Catalog B-tree Header
42 * nodeSize: 8192
43 * totalNodes: 31616
44 * freeNodes: 1978
45 * (used = 231.55 MB)
46 * Attributes B-tree Header
47 * nodeSize: 8192
48 * totalNodes: 63232
49 * freeNodes: 958
50 * (used = 486.52 MB)
51 *
52 * We also want Time Machine backup volumes to have a sufficiently
53 * large clump size to reduce fragmentation.
54 *
55 * The series of numbers for Catalog and Attribute form a geometric
56 * series. For Catalog (16GB to 512GB), each term is 8**(1/5) times
57 * the previous term. For Attributes (16GB to 512GB), each term is
58 * 4**(1/5) times the previous term. For 1TB to 16TB, each term is
59 * 2**(1/5) times the previous term.
60 */
61 /* 16GB */ 64, 32, 5,
62 /* 32GB */ 84, 49, 6,
63 /* 64GB */ 111, 74, 7,
64 /* 128GB */ 147, 111, 8,
65 /* 256GB */ 194, 169, 9,
66 /* 512GB */ 256, 256, 11,
67 /* 1TB */ 294, 294, 14,
68 /* 2TB */ 338, 338, 16,
69 /* 4TB */ 388, 388, 20,
70 /* 8TB */ 446, 446, 25,
71 /* 16TB */ 512, 512, 32
72};
73
74u32 hfsplus_calc_btree_clump_size(u32 block_size, u32 node_size,
75 u64 sectors, int file_id)
76{
77 u32 mod = max(node_size, block_size);
78 u32 clump_size;
79 int column;
80 int i;
81
82 /* Figure out which column of the above table to use for this file. */
83 switch (file_id) {
84 case HFSPLUS_ATTR_CNID:
85 column = 0;
86 break;
87 case HFSPLUS_CAT_CNID:
88 column = 1;
89 break;
90 default:
91 column = 2;
92 break;
93 }
94
95 /*
96 * The default clump size is 0.8% of the volume size. And
97 * it must also be a multiple of the node and block size.
98 */
99 if (sectors < 0x200000) {
100 clump_size = sectors << 2; /* 0.8 % */
101 if (clump_size < (8 * node_size))
102 clump_size = 8 * node_size;
103 } else {
104 /* turn exponent into table index... */
105 for (i = 0, sectors = sectors >> 22;
106 sectors && (i < CLUMP_ENTRIES - 1);
107 ++i, sectors = sectors >> 1) {
108 /* empty body */
109 }
110
111 clump_size = clumptbl[column + (i) * 3] * 1024 * 1024;
112 }
113
114 /*
115 * Round the clump size to a multiple of node and block size.
116 * NOTE: This rounds down.
117 */
118 clump_size /= mod;
119 clump_size *= mod;
120
121 /*
122 * Rounding down could have rounded down to 0 if the block size was
123 * greater than the clump size. If so, just use one block or node.
124 */
125 if (clump_size == 0)
126 clump_size = mod;
127
128 return clump_size;
129}
130
131/* Get a reference to a B*Tree and do some initial checks */
132struct hfs_btree *hfs_btree_open(struct super_block *sb, u32 id)
133{
134 struct hfs_btree *tree;
135 struct hfs_btree_header_rec *head;
136 struct address_space *mapping;
137 struct inode *inode;
138 struct page *page;
139 unsigned int size;
140
141 tree = kzalloc(sizeof(*tree), GFP_KERNEL);
142 if (!tree)
143 return NULL;
144
145 mutex_init(&tree->tree_lock);
146 spin_lock_init(&tree->hash_lock);
147 tree->sb = sb;
148 tree->cnid = id;
149 inode = hfsplus_iget(sb, id);
150 if (IS_ERR(inode))
151 goto free_tree;
152 tree->inode = inode;
153
154 if (!HFSPLUS_I(tree->inode)->first_blocks) {
155 pr_err("invalid btree extent records (0 size)\n");
156 goto free_inode;
157 }
158
159 mapping = tree->inode->i_mapping;
160 page = read_mapping_page(mapping, 0, NULL);
161 if (IS_ERR(page))
162 goto free_inode;
163
164 /* Load the header */
165 head = (struct hfs_btree_header_rec *)(kmap(page) +
166 sizeof(struct hfs_bnode_desc));
167 tree->root = be32_to_cpu(head->root);
168 tree->leaf_count = be32_to_cpu(head->leaf_count);
169 tree->leaf_head = be32_to_cpu(head->leaf_head);
170 tree->leaf_tail = be32_to_cpu(head->leaf_tail);
171 tree->node_count = be32_to_cpu(head->node_count);
172 tree->free_nodes = be32_to_cpu(head->free_nodes);
173 tree->attributes = be32_to_cpu(head->attributes);
174 tree->node_size = be16_to_cpu(head->node_size);
175 tree->max_key_len = be16_to_cpu(head->max_key_len);
176 tree->depth = be16_to_cpu(head->depth);
177
178 /* Verify the tree and set the correct compare function */
179 switch (id) {
180 case HFSPLUS_EXT_CNID:
181 if (tree->max_key_len != HFSPLUS_EXT_KEYLEN - sizeof(u16)) {
182 pr_err("invalid extent max_key_len %d\n",
183 tree->max_key_len);
184 goto fail_page;
185 }
186 if (tree->attributes & HFS_TREE_VARIDXKEYS) {
187 pr_err("invalid extent btree flag\n");
188 goto fail_page;
189 }
190
191 tree->keycmp = hfsplus_ext_cmp_key;
192 break;
193 case HFSPLUS_CAT_CNID:
194 if (tree->max_key_len != HFSPLUS_CAT_KEYLEN - sizeof(u16)) {
195 pr_err("invalid catalog max_key_len %d\n",
196 tree->max_key_len);
197 goto fail_page;
198 }
199 if (!(tree->attributes & HFS_TREE_VARIDXKEYS)) {
200 pr_err("invalid catalog btree flag\n");
201 goto fail_page;
202 }
203
204 if (test_bit(HFSPLUS_SB_HFSX, &HFSPLUS_SB(sb)->flags) &&
205 (head->key_type == HFSPLUS_KEY_BINARY))
206 tree->keycmp = hfsplus_cat_bin_cmp_key;
207 else {
208 tree->keycmp = hfsplus_cat_case_cmp_key;
209 set_bit(HFSPLUS_SB_CASEFOLD, &HFSPLUS_SB(sb)->flags);
210 }
211 break;
212 case HFSPLUS_ATTR_CNID:
213 if (tree->max_key_len != HFSPLUS_ATTR_KEYLEN - sizeof(u16)) {
214 pr_err("invalid attributes max_key_len %d\n",
215 tree->max_key_len);
216 goto fail_page;
217 }
218 tree->keycmp = hfsplus_attr_bin_cmp_key;
219 break;
220 default:
221 pr_err("unknown B*Tree requested\n");
222 goto fail_page;
223 }
224
225 if (!(tree->attributes & HFS_TREE_BIGKEYS)) {
226 pr_err("invalid btree flag\n");
227 goto fail_page;
228 }
229
230 size = tree->node_size;
231 if (!is_power_of_2(size))
232 goto fail_page;
233 if (!tree->node_count)
234 goto fail_page;
235
236 tree->node_size_shift = ffs(size) - 1;
237
238 tree->pages_per_bnode =
239 (tree->node_size + PAGE_CACHE_SIZE - 1) >>
240 PAGE_CACHE_SHIFT;
241
242 kunmap(page);
243 page_cache_release(page);
244 return tree;
245
246 fail_page:
247 page_cache_release(page);
248 free_inode:
249 tree->inode->i_mapping->a_ops = &hfsplus_aops;
250 iput(tree->inode);
251 free_tree:
252 kfree(tree);
253 return NULL;
254}
255
256/* Release resources used by a btree */
257void hfs_btree_close(struct hfs_btree *tree)
258{
259 struct hfs_bnode *node;
260 int i;
261
262 if (!tree)
263 return;
264
265 for (i = 0; i < NODE_HASH_SIZE; i++) {
266 while ((node = tree->node_hash[i])) {
267 tree->node_hash[i] = node->next_hash;
268 if (atomic_read(&node->refcnt))
269 pr_crit("node %d:%d "
270 "still has %d user(s)!\n",
271 node->tree->cnid, node->this,
272 atomic_read(&node->refcnt));
273 hfs_bnode_free(node);
274 tree->node_hash_cnt--;
275 }
276 }
277 iput(tree->inode);
278 kfree(tree);
279}
280
281int hfs_btree_write(struct hfs_btree *tree)
282{
283 struct hfs_btree_header_rec *head;
284 struct hfs_bnode *node;
285 struct page *page;
286
287 node = hfs_bnode_find(tree, 0);
288 if (IS_ERR(node))
289 /* panic? */
290 return -EIO;
291 /* Load the header */
292 page = node->page[0];
293 head = (struct hfs_btree_header_rec *)(kmap(page) +
294 sizeof(struct hfs_bnode_desc));
295
296 head->root = cpu_to_be32(tree->root);
297 head->leaf_count = cpu_to_be32(tree->leaf_count);
298 head->leaf_head = cpu_to_be32(tree->leaf_head);
299 head->leaf_tail = cpu_to_be32(tree->leaf_tail);
300 head->node_count = cpu_to_be32(tree->node_count);
301 head->free_nodes = cpu_to_be32(tree->free_nodes);
302 head->attributes = cpu_to_be32(tree->attributes);
303 head->depth = cpu_to_be16(tree->depth);
304
305 kunmap(page);
306 set_page_dirty(page);
307 hfs_bnode_put(node);
308 return 0;
309}
310
311static struct hfs_bnode *hfs_bmap_new_bmap(struct hfs_bnode *prev, u32 idx)
312{
313 struct hfs_btree *tree = prev->tree;
314 struct hfs_bnode *node;
315 struct hfs_bnode_desc desc;
316 __be32 cnid;
317
318 node = hfs_bnode_create(tree, idx);
319 if (IS_ERR(node))
320 return node;
321
322 tree->free_nodes--;
323 prev->next = idx;
324 cnid = cpu_to_be32(idx);
325 hfs_bnode_write(prev, &cnid, offsetof(struct hfs_bnode_desc, next), 4);
326
327 node->type = HFS_NODE_MAP;
328 node->num_recs = 1;
329 hfs_bnode_clear(node, 0, tree->node_size);
330 desc.next = 0;
331 desc.prev = 0;
332 desc.type = HFS_NODE_MAP;
333 desc.height = 0;
334 desc.num_recs = cpu_to_be16(1);
335 desc.reserved = 0;
336 hfs_bnode_write(node, &desc, 0, sizeof(desc));
337 hfs_bnode_write_u16(node, 14, 0x8000);
338 hfs_bnode_write_u16(node, tree->node_size - 2, 14);
339 hfs_bnode_write_u16(node, tree->node_size - 4, tree->node_size - 6);
340
341 return node;
342}
343
344struct hfs_bnode *hfs_bmap_alloc(struct hfs_btree *tree)
345{
346 struct hfs_bnode *node, *next_node;
347 struct page **pagep;
348 u32 nidx, idx;
349 unsigned off;
350 u16 off16;
351 u16 len;
352 u8 *data, byte, m;
353 int i;
354
355 while (!tree->free_nodes) {
356 struct inode *inode = tree->inode;
357 struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
358 u32 count;
359 int res;
360
361 res = hfsplus_file_extend(inode);
362 if (res)
363 return ERR_PTR(res);
364 hip->phys_size = inode->i_size =
365 (loff_t)hip->alloc_blocks <<
366 HFSPLUS_SB(tree->sb)->alloc_blksz_shift;
367 hip->fs_blocks =
368 hip->alloc_blocks << HFSPLUS_SB(tree->sb)->fs_shift;
369 inode_set_bytes(inode, inode->i_size);
370 count = inode->i_size >> tree->node_size_shift;
371 tree->free_nodes = count - tree->node_count;
372 tree->node_count = count;
373 }
374
375 nidx = 0;
376 node = hfs_bnode_find(tree, nidx);
377 if (IS_ERR(node))
378 return node;
379 len = hfs_brec_lenoff(node, 2, &off16);
380 off = off16;
381
382 off += node->page_offset;
383 pagep = node->page + (off >> PAGE_CACHE_SHIFT);
384 data = kmap(*pagep);
385 off &= ~PAGE_CACHE_MASK;
386 idx = 0;
387
388 for (;;) {
389 while (len) {
390 byte = data[off];
391 if (byte != 0xff) {
392 for (m = 0x80, i = 0; i < 8; m >>= 1, i++) {
393 if (!(byte & m)) {
394 idx += i;
395 data[off] |= m;
396 set_page_dirty(*pagep);
397 kunmap(*pagep);
398 tree->free_nodes--;
399 mark_inode_dirty(tree->inode);
400 hfs_bnode_put(node);
401 return hfs_bnode_create(tree,
402 idx);
403 }
404 }
405 }
406 if (++off >= PAGE_CACHE_SIZE) {
407 kunmap(*pagep);
408 data = kmap(*++pagep);
409 off = 0;
410 }
411 idx += 8;
412 len--;
413 }
414 kunmap(*pagep);
415 nidx = node->next;
416 if (!nidx) {
417 hfs_dbg(BNODE_MOD, "create new bmap node\n");
418 next_node = hfs_bmap_new_bmap(node, idx);
419 } else
420 next_node = hfs_bnode_find(tree, nidx);
421 hfs_bnode_put(node);
422 if (IS_ERR(next_node))
423 return next_node;
424 node = next_node;
425
426 len = hfs_brec_lenoff(node, 0, &off16);
427 off = off16;
428 off += node->page_offset;
429 pagep = node->page + (off >> PAGE_CACHE_SHIFT);
430 data = kmap(*pagep);
431 off &= ~PAGE_CACHE_MASK;
432 }
433}
434
435void hfs_bmap_free(struct hfs_bnode *node)
436{
437 struct hfs_btree *tree;
438 struct page *page;
439 u16 off, len;
440 u32 nidx;
441 u8 *data, byte, m;
442
443 hfs_dbg(BNODE_MOD, "btree_free_node: %u\n", node->this);
444 BUG_ON(!node->this);
445 tree = node->tree;
446 nidx = node->this;
447 node = hfs_bnode_find(tree, 0);
448 if (IS_ERR(node))
449 return;
450 len = hfs_brec_lenoff(node, 2, &off);
451 while (nidx >= len * 8) {
452 u32 i;
453
454 nidx -= len * 8;
455 i = node->next;
456 hfs_bnode_put(node);
457 if (!i) {
458 /* panic */;
459 pr_crit("unable to free bnode %u. "
460 "bmap not found!\n",
461 node->this);
462 return;
463 }
464 node = hfs_bnode_find(tree, i);
465 if (IS_ERR(node))
466 return;
467 if (node->type != HFS_NODE_MAP) {
468 /* panic */;
469 pr_crit("invalid bmap found! "
470 "(%u,%d)\n",
471 node->this, node->type);
472 hfs_bnode_put(node);
473 return;
474 }
475 len = hfs_brec_lenoff(node, 0, &off);
476 }
477 off += node->page_offset + nidx / 8;
478 page = node->page[off >> PAGE_CACHE_SHIFT];
479 data = kmap(page);
480 off &= ~PAGE_CACHE_MASK;
481 m = 1 << (~nidx & 7);
482 byte = data[off];
483 if (!(byte & m)) {
484 pr_crit("trying to free free bnode "
485 "%u(%d)\n",
486 node->this, node->type);
487 kunmap(page);
488 hfs_bnode_put(node);
489 return;
490 }
491 data[off] = byte & ~m;
492 set_page_dirty(page);
493 kunmap(page);
494 hfs_bnode_put(node);
495 tree->free_nodes++;
496 mark_inode_dirty(tree->inode);
497}