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1/*
2 * linux/fs/hfs/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/pagemap.h>
12#include <linux/slab.h>
13#include <linux/log2.h>
14
15#include "btree.h"
16
17/* Get a reference to a B*Tree and do some initial checks */
18struct hfs_btree *hfs_btree_open(struct super_block *sb, u32 id, btree_keycmp keycmp)
19{
20 struct hfs_btree *tree;
21 struct hfs_btree_header_rec *head;
22 struct address_space *mapping;
23 struct page *page;
24 unsigned int size;
25
26 tree = kzalloc(sizeof(*tree), GFP_KERNEL);
27 if (!tree)
28 return NULL;
29
30 mutex_init(&tree->tree_lock);
31 spin_lock_init(&tree->hash_lock);
32 /* Set the correct compare function */
33 tree->sb = sb;
34 tree->cnid = id;
35 tree->keycmp = keycmp;
36
37 tree->inode = iget_locked(sb, id);
38 if (!tree->inode)
39 goto free_tree;
40 BUG_ON(!(tree->inode->i_state & I_NEW));
41 {
42 struct hfs_mdb *mdb = HFS_SB(sb)->mdb;
43 HFS_I(tree->inode)->flags = 0;
44 mutex_init(&HFS_I(tree->inode)->extents_lock);
45 switch (id) {
46 case HFS_EXT_CNID:
47 hfs_inode_read_fork(tree->inode, mdb->drXTExtRec, mdb->drXTFlSize,
48 mdb->drXTFlSize, be32_to_cpu(mdb->drXTClpSiz));
49 if (HFS_I(tree->inode)->alloc_blocks >
50 HFS_I(tree->inode)->first_blocks) {
51 pr_err("invalid btree extent records\n");
52 unlock_new_inode(tree->inode);
53 goto free_inode;
54 }
55
56 tree->inode->i_mapping->a_ops = &hfs_btree_aops;
57 break;
58 case HFS_CAT_CNID:
59 hfs_inode_read_fork(tree->inode, mdb->drCTExtRec, mdb->drCTFlSize,
60 mdb->drCTFlSize, be32_to_cpu(mdb->drCTClpSiz));
61
62 if (!HFS_I(tree->inode)->first_blocks) {
63 pr_err("invalid btree extent records (0 size)\n");
64 unlock_new_inode(tree->inode);
65 goto free_inode;
66 }
67
68 tree->inode->i_mapping->a_ops = &hfs_btree_aops;
69 break;
70 default:
71 BUG();
72 }
73 }
74 unlock_new_inode(tree->inode);
75
76 mapping = tree->inode->i_mapping;
77 page = read_mapping_page(mapping, 0, NULL);
78 if (IS_ERR(page))
79 goto free_inode;
80
81 /* Load the header */
82 head = (struct hfs_btree_header_rec *)(kmap(page) + sizeof(struct hfs_bnode_desc));
83 tree->root = be32_to_cpu(head->root);
84 tree->leaf_count = be32_to_cpu(head->leaf_count);
85 tree->leaf_head = be32_to_cpu(head->leaf_head);
86 tree->leaf_tail = be32_to_cpu(head->leaf_tail);
87 tree->node_count = be32_to_cpu(head->node_count);
88 tree->free_nodes = be32_to_cpu(head->free_nodes);
89 tree->attributes = be32_to_cpu(head->attributes);
90 tree->node_size = be16_to_cpu(head->node_size);
91 tree->max_key_len = be16_to_cpu(head->max_key_len);
92 tree->depth = be16_to_cpu(head->depth);
93
94 size = tree->node_size;
95 if (!is_power_of_2(size))
96 goto fail_page;
97 if (!tree->node_count)
98 goto fail_page;
99 switch (id) {
100 case HFS_EXT_CNID:
101 if (tree->max_key_len != HFS_MAX_EXT_KEYLEN) {
102 pr_err("invalid extent max_key_len %d\n",
103 tree->max_key_len);
104 goto fail_page;
105 }
106 break;
107 case HFS_CAT_CNID:
108 if (tree->max_key_len != HFS_MAX_CAT_KEYLEN) {
109 pr_err("invalid catalog max_key_len %d\n",
110 tree->max_key_len);
111 goto fail_page;
112 }
113 break;
114 default:
115 BUG();
116 }
117
118 tree->node_size_shift = ffs(size) - 1;
119 tree->pages_per_bnode = (tree->node_size + PAGE_SIZE - 1) >> PAGE_SHIFT;
120
121 kunmap(page);
122 put_page(page);
123 return tree;
124
125fail_page:
126 put_page(page);
127free_inode:
128 tree->inode->i_mapping->a_ops = &hfs_aops;
129 iput(tree->inode);
130free_tree:
131 kfree(tree);
132 return NULL;
133}
134
135/* Release resources used by a btree */
136void hfs_btree_close(struct hfs_btree *tree)
137{
138 struct hfs_bnode *node;
139 int i;
140
141 if (!tree)
142 return;
143
144 for (i = 0; i < NODE_HASH_SIZE; i++) {
145 while ((node = tree->node_hash[i])) {
146 tree->node_hash[i] = node->next_hash;
147 if (atomic_read(&node->refcnt))
148 pr_err("node %d:%d still has %d user(s)!\n",
149 node->tree->cnid, node->this,
150 atomic_read(&node->refcnt));
151 hfs_bnode_free(node);
152 tree->node_hash_cnt--;
153 }
154 }
155 iput(tree->inode);
156 kfree(tree);
157}
158
159void hfs_btree_write(struct hfs_btree *tree)
160{
161 struct hfs_btree_header_rec *head;
162 struct hfs_bnode *node;
163 struct page *page;
164
165 node = hfs_bnode_find(tree, 0);
166 if (IS_ERR(node))
167 /* panic? */
168 return;
169 /* Load the header */
170 page = node->page[0];
171 head = (struct hfs_btree_header_rec *)(kmap(page) + sizeof(struct hfs_bnode_desc));
172
173 head->root = cpu_to_be32(tree->root);
174 head->leaf_count = cpu_to_be32(tree->leaf_count);
175 head->leaf_head = cpu_to_be32(tree->leaf_head);
176 head->leaf_tail = cpu_to_be32(tree->leaf_tail);
177 head->node_count = cpu_to_be32(tree->node_count);
178 head->free_nodes = cpu_to_be32(tree->free_nodes);
179 head->attributes = cpu_to_be32(tree->attributes);
180 head->depth = cpu_to_be16(tree->depth);
181
182 kunmap(page);
183 set_page_dirty(page);
184 hfs_bnode_put(node);
185}
186
187static struct hfs_bnode *hfs_bmap_new_bmap(struct hfs_bnode *prev, u32 idx)
188{
189 struct hfs_btree *tree = prev->tree;
190 struct hfs_bnode *node;
191 struct hfs_bnode_desc desc;
192 __be32 cnid;
193
194 node = hfs_bnode_create(tree, idx);
195 if (IS_ERR(node))
196 return node;
197
198 if (!tree->free_nodes)
199 panic("FIXME!!!");
200 tree->free_nodes--;
201 prev->next = idx;
202 cnid = cpu_to_be32(idx);
203 hfs_bnode_write(prev, &cnid, offsetof(struct hfs_bnode_desc, next), 4);
204
205 node->type = HFS_NODE_MAP;
206 node->num_recs = 1;
207 hfs_bnode_clear(node, 0, tree->node_size);
208 desc.next = 0;
209 desc.prev = 0;
210 desc.type = HFS_NODE_MAP;
211 desc.height = 0;
212 desc.num_recs = cpu_to_be16(1);
213 desc.reserved = 0;
214 hfs_bnode_write(node, &desc, 0, sizeof(desc));
215 hfs_bnode_write_u16(node, 14, 0x8000);
216 hfs_bnode_write_u16(node, tree->node_size - 2, 14);
217 hfs_bnode_write_u16(node, tree->node_size - 4, tree->node_size - 6);
218
219 return node;
220}
221
222struct hfs_bnode *hfs_bmap_alloc(struct hfs_btree *tree)
223{
224 struct hfs_bnode *node, *next_node;
225 struct page **pagep;
226 u32 nidx, idx;
227 unsigned off;
228 u16 off16;
229 u16 len;
230 u8 *data, byte, m;
231 int i;
232
233 while (!tree->free_nodes) {
234 struct inode *inode = tree->inode;
235 u32 count;
236 int res;
237
238 res = hfs_extend_file(inode);
239 if (res)
240 return ERR_PTR(res);
241 HFS_I(inode)->phys_size = inode->i_size =
242 (loff_t)HFS_I(inode)->alloc_blocks *
243 HFS_SB(tree->sb)->alloc_blksz;
244 HFS_I(inode)->fs_blocks = inode->i_size >>
245 tree->sb->s_blocksize_bits;
246 inode_set_bytes(inode, inode->i_size);
247 count = inode->i_size >> tree->node_size_shift;
248 tree->free_nodes = count - tree->node_count;
249 tree->node_count = count;
250 }
251
252 nidx = 0;
253 node = hfs_bnode_find(tree, nidx);
254 if (IS_ERR(node))
255 return node;
256 len = hfs_brec_lenoff(node, 2, &off16);
257 off = off16;
258
259 off += node->page_offset;
260 pagep = node->page + (off >> PAGE_SHIFT);
261 data = kmap(*pagep);
262 off &= ~PAGE_MASK;
263 idx = 0;
264
265 for (;;) {
266 while (len) {
267 byte = data[off];
268 if (byte != 0xff) {
269 for (m = 0x80, i = 0; i < 8; m >>= 1, i++) {
270 if (!(byte & m)) {
271 idx += i;
272 data[off] |= m;
273 set_page_dirty(*pagep);
274 kunmap(*pagep);
275 tree->free_nodes--;
276 mark_inode_dirty(tree->inode);
277 hfs_bnode_put(node);
278 return hfs_bnode_create(tree, idx);
279 }
280 }
281 }
282 if (++off >= PAGE_SIZE) {
283 kunmap(*pagep);
284 data = kmap(*++pagep);
285 off = 0;
286 }
287 idx += 8;
288 len--;
289 }
290 kunmap(*pagep);
291 nidx = node->next;
292 if (!nidx) {
293 printk(KERN_DEBUG "create new bmap node...\n");
294 next_node = hfs_bmap_new_bmap(node, idx);
295 } else
296 next_node = hfs_bnode_find(tree, nidx);
297 hfs_bnode_put(node);
298 if (IS_ERR(next_node))
299 return next_node;
300 node = next_node;
301
302 len = hfs_brec_lenoff(node, 0, &off16);
303 off = off16;
304 off += node->page_offset;
305 pagep = node->page + (off >> PAGE_SHIFT);
306 data = kmap(*pagep);
307 off &= ~PAGE_MASK;
308 }
309}
310
311void hfs_bmap_free(struct hfs_bnode *node)
312{
313 struct hfs_btree *tree;
314 struct page *page;
315 u16 off, len;
316 u32 nidx;
317 u8 *data, byte, m;
318
319 hfs_dbg(BNODE_MOD, "btree_free_node: %u\n", node->this);
320 tree = node->tree;
321 nidx = node->this;
322 node = hfs_bnode_find(tree, 0);
323 if (IS_ERR(node))
324 return;
325 len = hfs_brec_lenoff(node, 2, &off);
326 while (nidx >= len * 8) {
327 u32 i;
328
329 nidx -= len * 8;
330 i = node->next;
331 hfs_bnode_put(node);
332 if (!i) {
333 /* panic */;
334 pr_crit("unable to free bnode %u. bmap not found!\n",
335 node->this);
336 return;
337 }
338 node = hfs_bnode_find(tree, i);
339 if (IS_ERR(node))
340 return;
341 if (node->type != HFS_NODE_MAP) {
342 /* panic */;
343 pr_crit("invalid bmap found! (%u,%d)\n",
344 node->this, node->type);
345 hfs_bnode_put(node);
346 return;
347 }
348 len = hfs_brec_lenoff(node, 0, &off);
349 }
350 off += node->page_offset + nidx / 8;
351 page = node->page[off >> PAGE_SHIFT];
352 data = kmap(page);
353 off &= ~PAGE_MASK;
354 m = 1 << (~nidx & 7);
355 byte = data[off];
356 if (!(byte & m)) {
357 pr_crit("trying to free free bnode %u(%d)\n",
358 node->this, node->type);
359 kunmap(page);
360 hfs_bnode_put(node);
361 return;
362 }
363 data[off] = byte & ~m;
364 set_page_dirty(page);
365 kunmap(page);
366 hfs_bnode_put(node);
367 tree->free_nodes++;
368 mark_inode_dirty(tree->inode);
369}
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * linux/fs/hfs/btree.c
4 *
5 * Copyright (C) 2001
6 * Brad Boyer (flar@allandria.com)
7 * (C) 2003 Ardis Technologies <roman@ardistech.com>
8 *
9 * Handle opening/closing btree
10 */
11
12#include <linux/pagemap.h>
13#include <linux/slab.h>
14#include <linux/log2.h>
15
16#include "btree.h"
17
18/* Get a reference to a B*Tree and do some initial checks */
19struct hfs_btree *hfs_btree_open(struct super_block *sb, u32 id, btree_keycmp keycmp)
20{
21 struct hfs_btree *tree;
22 struct hfs_btree_header_rec *head;
23 struct address_space *mapping;
24 struct page *page;
25 unsigned int size;
26
27 tree = kzalloc(sizeof(*tree), GFP_KERNEL);
28 if (!tree)
29 return NULL;
30
31 mutex_init(&tree->tree_lock);
32 spin_lock_init(&tree->hash_lock);
33 /* Set the correct compare function */
34 tree->sb = sb;
35 tree->cnid = id;
36 tree->keycmp = keycmp;
37
38 tree->inode = iget_locked(sb, id);
39 if (!tree->inode)
40 goto free_tree;
41 BUG_ON(!(tree->inode->i_state & I_NEW));
42 {
43 struct hfs_mdb *mdb = HFS_SB(sb)->mdb;
44 HFS_I(tree->inode)->flags = 0;
45 mutex_init(&HFS_I(tree->inode)->extents_lock);
46 switch (id) {
47 case HFS_EXT_CNID:
48 hfs_inode_read_fork(tree->inode, mdb->drXTExtRec, mdb->drXTFlSize,
49 mdb->drXTFlSize, be32_to_cpu(mdb->drXTClpSiz));
50 if (HFS_I(tree->inode)->alloc_blocks >
51 HFS_I(tree->inode)->first_blocks) {
52 pr_err("invalid btree extent records\n");
53 unlock_new_inode(tree->inode);
54 goto free_inode;
55 }
56
57 tree->inode->i_mapping->a_ops = &hfs_btree_aops;
58 break;
59 case HFS_CAT_CNID:
60 hfs_inode_read_fork(tree->inode, mdb->drCTExtRec, mdb->drCTFlSize,
61 mdb->drCTFlSize, be32_to_cpu(mdb->drCTClpSiz));
62
63 if (!HFS_I(tree->inode)->first_blocks) {
64 pr_err("invalid btree extent records (0 size)\n");
65 unlock_new_inode(tree->inode);
66 goto free_inode;
67 }
68
69 tree->inode->i_mapping->a_ops = &hfs_btree_aops;
70 break;
71 default:
72 BUG();
73 }
74 }
75 unlock_new_inode(tree->inode);
76
77 mapping = tree->inode->i_mapping;
78 page = read_mapping_page(mapping, 0, NULL);
79 if (IS_ERR(page))
80 goto free_inode;
81
82 /* Load the header */
83 head = (struct hfs_btree_header_rec *)(kmap(page) + sizeof(struct hfs_bnode_desc));
84 tree->root = be32_to_cpu(head->root);
85 tree->leaf_count = be32_to_cpu(head->leaf_count);
86 tree->leaf_head = be32_to_cpu(head->leaf_head);
87 tree->leaf_tail = be32_to_cpu(head->leaf_tail);
88 tree->node_count = be32_to_cpu(head->node_count);
89 tree->free_nodes = be32_to_cpu(head->free_nodes);
90 tree->attributes = be32_to_cpu(head->attributes);
91 tree->node_size = be16_to_cpu(head->node_size);
92 tree->max_key_len = be16_to_cpu(head->max_key_len);
93 tree->depth = be16_to_cpu(head->depth);
94
95 size = tree->node_size;
96 if (!is_power_of_2(size))
97 goto fail_page;
98 if (!tree->node_count)
99 goto fail_page;
100 switch (id) {
101 case HFS_EXT_CNID:
102 if (tree->max_key_len != HFS_MAX_EXT_KEYLEN) {
103 pr_err("invalid extent max_key_len %d\n",
104 tree->max_key_len);
105 goto fail_page;
106 }
107 break;
108 case HFS_CAT_CNID:
109 if (tree->max_key_len != HFS_MAX_CAT_KEYLEN) {
110 pr_err("invalid catalog max_key_len %d\n",
111 tree->max_key_len);
112 goto fail_page;
113 }
114 break;
115 default:
116 BUG();
117 }
118
119 tree->node_size_shift = ffs(size) - 1;
120 tree->pages_per_bnode = (tree->node_size + PAGE_SIZE - 1) >> PAGE_SHIFT;
121
122 kunmap(page);
123 put_page(page);
124 return tree;
125
126fail_page:
127 put_page(page);
128free_inode:
129 tree->inode->i_mapping->a_ops = &hfs_aops;
130 iput(tree->inode);
131free_tree:
132 kfree(tree);
133 return NULL;
134}
135
136/* Release resources used by a btree */
137void hfs_btree_close(struct hfs_btree *tree)
138{
139 struct hfs_bnode *node;
140 int i;
141
142 if (!tree)
143 return;
144
145 for (i = 0; i < NODE_HASH_SIZE; i++) {
146 while ((node = tree->node_hash[i])) {
147 tree->node_hash[i] = node->next_hash;
148 if (atomic_read(&node->refcnt))
149 pr_err("node %d:%d still has %d user(s)!\n",
150 node->tree->cnid, node->this,
151 atomic_read(&node->refcnt));
152 hfs_bnode_free(node);
153 tree->node_hash_cnt--;
154 }
155 }
156 iput(tree->inode);
157 kfree(tree);
158}
159
160void hfs_btree_write(struct hfs_btree *tree)
161{
162 struct hfs_btree_header_rec *head;
163 struct hfs_bnode *node;
164 struct page *page;
165
166 node = hfs_bnode_find(tree, 0);
167 if (IS_ERR(node))
168 /* panic? */
169 return;
170 /* Load the header */
171 page = node->page[0];
172 head = (struct hfs_btree_header_rec *)(kmap(page) + sizeof(struct hfs_bnode_desc));
173
174 head->root = cpu_to_be32(tree->root);
175 head->leaf_count = cpu_to_be32(tree->leaf_count);
176 head->leaf_head = cpu_to_be32(tree->leaf_head);
177 head->leaf_tail = cpu_to_be32(tree->leaf_tail);
178 head->node_count = cpu_to_be32(tree->node_count);
179 head->free_nodes = cpu_to_be32(tree->free_nodes);
180 head->attributes = cpu_to_be32(tree->attributes);
181 head->depth = cpu_to_be16(tree->depth);
182
183 kunmap(page);
184 set_page_dirty(page);
185 hfs_bnode_put(node);
186}
187
188static struct hfs_bnode *hfs_bmap_new_bmap(struct hfs_bnode *prev, u32 idx)
189{
190 struct hfs_btree *tree = prev->tree;
191 struct hfs_bnode *node;
192 struct hfs_bnode_desc desc;
193 __be32 cnid;
194
195 node = hfs_bnode_create(tree, idx);
196 if (IS_ERR(node))
197 return node;
198
199 if (!tree->free_nodes)
200 panic("FIXME!!!");
201 tree->free_nodes--;
202 prev->next = idx;
203 cnid = cpu_to_be32(idx);
204 hfs_bnode_write(prev, &cnid, offsetof(struct hfs_bnode_desc, next), 4);
205
206 node->type = HFS_NODE_MAP;
207 node->num_recs = 1;
208 hfs_bnode_clear(node, 0, tree->node_size);
209 desc.next = 0;
210 desc.prev = 0;
211 desc.type = HFS_NODE_MAP;
212 desc.height = 0;
213 desc.num_recs = cpu_to_be16(1);
214 desc.reserved = 0;
215 hfs_bnode_write(node, &desc, 0, sizeof(desc));
216 hfs_bnode_write_u16(node, 14, 0x8000);
217 hfs_bnode_write_u16(node, tree->node_size - 2, 14);
218 hfs_bnode_write_u16(node, tree->node_size - 4, tree->node_size - 6);
219
220 return node;
221}
222
223/* Make sure @tree has enough space for the @rsvd_nodes */
224int hfs_bmap_reserve(struct hfs_btree *tree, int rsvd_nodes)
225{
226 struct inode *inode = tree->inode;
227 u32 count;
228 int res;
229
230 while (tree->free_nodes < rsvd_nodes) {
231 res = hfs_extend_file(inode);
232 if (res)
233 return res;
234 HFS_I(inode)->phys_size = inode->i_size =
235 (loff_t)HFS_I(inode)->alloc_blocks *
236 HFS_SB(tree->sb)->alloc_blksz;
237 HFS_I(inode)->fs_blocks = inode->i_size >>
238 tree->sb->s_blocksize_bits;
239 inode_set_bytes(inode, inode->i_size);
240 count = inode->i_size >> tree->node_size_shift;
241 tree->free_nodes += count - tree->node_count;
242 tree->node_count = count;
243 }
244 return 0;
245}
246
247struct hfs_bnode *hfs_bmap_alloc(struct hfs_btree *tree)
248{
249 struct hfs_bnode *node, *next_node;
250 struct page **pagep;
251 u32 nidx, idx;
252 unsigned off;
253 u16 off16;
254 u16 len;
255 u8 *data, byte, m;
256 int i, res;
257
258 res = hfs_bmap_reserve(tree, 1);
259 if (res)
260 return ERR_PTR(res);
261
262 nidx = 0;
263 node = hfs_bnode_find(tree, nidx);
264 if (IS_ERR(node))
265 return node;
266 len = hfs_brec_lenoff(node, 2, &off16);
267 off = off16;
268
269 off += node->page_offset;
270 pagep = node->page + (off >> PAGE_SHIFT);
271 data = kmap(*pagep);
272 off &= ~PAGE_MASK;
273 idx = 0;
274
275 for (;;) {
276 while (len) {
277 byte = data[off];
278 if (byte != 0xff) {
279 for (m = 0x80, i = 0; i < 8; m >>= 1, i++) {
280 if (!(byte & m)) {
281 idx += i;
282 data[off] |= m;
283 set_page_dirty(*pagep);
284 kunmap(*pagep);
285 tree->free_nodes--;
286 mark_inode_dirty(tree->inode);
287 hfs_bnode_put(node);
288 return hfs_bnode_create(tree, idx);
289 }
290 }
291 }
292 if (++off >= PAGE_SIZE) {
293 kunmap(*pagep);
294 data = kmap(*++pagep);
295 off = 0;
296 }
297 idx += 8;
298 len--;
299 }
300 kunmap(*pagep);
301 nidx = node->next;
302 if (!nidx) {
303 printk(KERN_DEBUG "create new bmap node...\n");
304 next_node = hfs_bmap_new_bmap(node, idx);
305 } else
306 next_node = hfs_bnode_find(tree, nidx);
307 hfs_bnode_put(node);
308 if (IS_ERR(next_node))
309 return next_node;
310 node = next_node;
311
312 len = hfs_brec_lenoff(node, 0, &off16);
313 off = off16;
314 off += node->page_offset;
315 pagep = node->page + (off >> PAGE_SHIFT);
316 data = kmap(*pagep);
317 off &= ~PAGE_MASK;
318 }
319}
320
321void hfs_bmap_free(struct hfs_bnode *node)
322{
323 struct hfs_btree *tree;
324 struct page *page;
325 u16 off, len;
326 u32 nidx;
327 u8 *data, byte, m;
328
329 hfs_dbg(BNODE_MOD, "btree_free_node: %u\n", node->this);
330 tree = node->tree;
331 nidx = node->this;
332 node = hfs_bnode_find(tree, 0);
333 if (IS_ERR(node))
334 return;
335 len = hfs_brec_lenoff(node, 2, &off);
336 while (nidx >= len * 8) {
337 u32 i;
338
339 nidx -= len * 8;
340 i = node->next;
341 if (!i) {
342 /* panic */;
343 pr_crit("unable to free bnode %u. bmap not found!\n",
344 node->this);
345 hfs_bnode_put(node);
346 return;
347 }
348 hfs_bnode_put(node);
349 node = hfs_bnode_find(tree, i);
350 if (IS_ERR(node))
351 return;
352 if (node->type != HFS_NODE_MAP) {
353 /* panic */;
354 pr_crit("invalid bmap found! (%u,%d)\n",
355 node->this, node->type);
356 hfs_bnode_put(node);
357 return;
358 }
359 len = hfs_brec_lenoff(node, 0, &off);
360 }
361 off += node->page_offset + nidx / 8;
362 page = node->page[off >> PAGE_SHIFT];
363 data = kmap(page);
364 off &= ~PAGE_MASK;
365 m = 1 << (~nidx & 7);
366 byte = data[off];
367 if (!(byte & m)) {
368 pr_crit("trying to free free bnode %u(%d)\n",
369 node->this, node->type);
370 kunmap(page);
371 hfs_bnode_put(node);
372 return;
373 }
374 data[off] = byte & ~m;
375 set_page_dirty(page);
376 kunmap(page);
377 hfs_bnode_put(node);
378 tree->free_nodes++;
379 mark_inode_dirty(tree->inode);
380}