diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /fs/hfsplus/btree.c |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'fs/hfsplus/btree.c')
-rw-r--r-- | fs/hfsplus/btree.c | 319 |
1 files changed, 319 insertions, 0 deletions
diff --git a/fs/hfsplus/btree.c b/fs/hfsplus/btree.c new file mode 100644 index 000000000000..44326aa2bd34 --- /dev/null +++ b/fs/hfsplus/btree.c | |||
@@ -0,0 +1,319 @@ | |||
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 | |||
14 | #include "hfsplus_fs.h" | ||
15 | #include "hfsplus_raw.h" | ||
16 | |||
17 | |||
18 | /* Get a reference to a B*Tree and do some initial checks */ | ||
19 | struct hfs_btree *hfs_btree_open(struct super_block *sb, u32 id) | ||
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 = kmalloc(sizeof(*tree), GFP_KERNEL); | ||
28 | if (!tree) | ||
29 | return NULL; | ||
30 | memset(tree, 0, sizeof(*tree)); | ||
31 | |||
32 | init_MUTEX(&tree->tree_lock); | ||
33 | spin_lock_init(&tree->hash_lock); | ||
34 | /* Set the correct compare function */ | ||
35 | tree->sb = sb; | ||
36 | tree->cnid = id; | ||
37 | if (id == HFSPLUS_EXT_CNID) { | ||
38 | tree->keycmp = hfsplus_ext_cmp_key; | ||
39 | } else if (id == HFSPLUS_CAT_CNID) { | ||
40 | tree->keycmp = hfsplus_cat_cmp_key; | ||
41 | } else { | ||
42 | printk("HFS+-fs: unknown B*Tree requested\n"); | ||
43 | goto free_tree; | ||
44 | } | ||
45 | tree->inode = iget(sb, id); | ||
46 | if (!tree->inode) | ||
47 | goto free_tree; | ||
48 | |||
49 | mapping = tree->inode->i_mapping; | ||
50 | page = read_cache_page(mapping, 0, (filler_t *)mapping->a_ops->readpage, NULL); | ||
51 | if (IS_ERR(page)) | ||
52 | goto free_tree; | ||
53 | |||
54 | /* Load the header */ | ||
55 | head = (struct hfs_btree_header_rec *)(kmap(page) + 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 | size = tree->node_size; | ||
68 | if (!size || size & (size - 1)) | ||
69 | goto fail_page; | ||
70 | if (!tree->node_count) | ||
71 | goto fail_page; | ||
72 | tree->node_size_shift = ffs(size) - 1; | ||
73 | |||
74 | tree->pages_per_bnode = (tree->node_size + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; | ||
75 | |||
76 | kunmap(page); | ||
77 | page_cache_release(page); | ||
78 | return tree; | ||
79 | |||
80 | fail_page: | ||
81 | tree->inode->i_mapping->a_ops = &hfsplus_aops; | ||
82 | page_cache_release(page); | ||
83 | free_tree: | ||
84 | iput(tree->inode); | ||
85 | kfree(tree); | ||
86 | return NULL; | ||
87 | } | ||
88 | |||
89 | /* Release resources used by a btree */ | ||
90 | void hfs_btree_close(struct hfs_btree *tree) | ||
91 | { | ||
92 | struct hfs_bnode *node; | ||
93 | int i; | ||
94 | |||
95 | if (!tree) | ||
96 | return; | ||
97 | |||
98 | for (i = 0; i < NODE_HASH_SIZE; i++) { | ||
99 | while ((node = tree->node_hash[i])) { | ||
100 | tree->node_hash[i] = node->next_hash; | ||
101 | if (atomic_read(&node->refcnt)) | ||
102 | printk("HFS+: node %d:%d still has %d user(s)!\n", | ||
103 | node->tree->cnid, node->this, atomic_read(&node->refcnt)); | ||
104 | hfs_bnode_free(node); | ||
105 | tree->node_hash_cnt--; | ||
106 | } | ||
107 | } | ||
108 | iput(tree->inode); | ||
109 | kfree(tree); | ||
110 | } | ||
111 | |||
112 | void hfs_btree_write(struct hfs_btree *tree) | ||
113 | { | ||
114 | struct hfs_btree_header_rec *head; | ||
115 | struct hfs_bnode *node; | ||
116 | struct page *page; | ||
117 | |||
118 | node = hfs_bnode_find(tree, 0); | ||
119 | if (IS_ERR(node)) | ||
120 | /* panic? */ | ||
121 | return; | ||
122 | /* Load the header */ | ||
123 | page = node->page[0]; | ||
124 | head = (struct hfs_btree_header_rec *)(kmap(page) + sizeof(struct hfs_bnode_desc)); | ||
125 | |||
126 | head->root = cpu_to_be32(tree->root); | ||
127 | head->leaf_count = cpu_to_be32(tree->leaf_count); | ||
128 | head->leaf_head = cpu_to_be32(tree->leaf_head); | ||
129 | head->leaf_tail = cpu_to_be32(tree->leaf_tail); | ||
130 | head->node_count = cpu_to_be32(tree->node_count); | ||
131 | head->free_nodes = cpu_to_be32(tree->free_nodes); | ||
132 | head->attributes = cpu_to_be32(tree->attributes); | ||
133 | head->depth = cpu_to_be16(tree->depth); | ||
134 | |||
135 | kunmap(page); | ||
136 | set_page_dirty(page); | ||
137 | hfs_bnode_put(node); | ||
138 | } | ||
139 | |||
140 | static struct hfs_bnode *hfs_bmap_new_bmap(struct hfs_bnode *prev, u32 idx) | ||
141 | { | ||
142 | struct hfs_btree *tree = prev->tree; | ||
143 | struct hfs_bnode *node; | ||
144 | struct hfs_bnode_desc desc; | ||
145 | __be32 cnid; | ||
146 | |||
147 | node = hfs_bnode_create(tree, idx); | ||
148 | if (IS_ERR(node)) | ||
149 | return node; | ||
150 | |||
151 | tree->free_nodes--; | ||
152 | prev->next = idx; | ||
153 | cnid = cpu_to_be32(idx); | ||
154 | hfs_bnode_write(prev, &cnid, offsetof(struct hfs_bnode_desc, next), 4); | ||
155 | |||
156 | node->type = HFS_NODE_MAP; | ||
157 | node->num_recs = 1; | ||
158 | hfs_bnode_clear(node, 0, tree->node_size); | ||
159 | desc.next = 0; | ||
160 | desc.prev = 0; | ||
161 | desc.type = HFS_NODE_MAP; | ||
162 | desc.height = 0; | ||
163 | desc.num_recs = cpu_to_be16(1); | ||
164 | desc.reserved = 0; | ||
165 | hfs_bnode_write(node, &desc, 0, sizeof(desc)); | ||
166 | hfs_bnode_write_u16(node, 14, 0x8000); | ||
167 | hfs_bnode_write_u16(node, tree->node_size - 2, 14); | ||
168 | hfs_bnode_write_u16(node, tree->node_size - 4, tree->node_size - 6); | ||
169 | |||
170 | return node; | ||
171 | } | ||
172 | |||
173 | struct hfs_bnode *hfs_bmap_alloc(struct hfs_btree *tree) | ||
174 | { | ||
175 | struct hfs_bnode *node, *next_node; | ||
176 | struct page **pagep; | ||
177 | u32 nidx, idx; | ||
178 | u16 off, len; | ||
179 | u8 *data, byte, m; | ||
180 | int i; | ||
181 | |||
182 | while (!tree->free_nodes) { | ||
183 | struct inode *inode = tree->inode; | ||
184 | u32 count; | ||
185 | int res; | ||
186 | |||
187 | res = hfsplus_file_extend(inode); | ||
188 | if (res) | ||
189 | return ERR_PTR(res); | ||
190 | HFSPLUS_I(inode).phys_size = inode->i_size = | ||
191 | (loff_t)HFSPLUS_I(inode).alloc_blocks << | ||
192 | HFSPLUS_SB(tree->sb).alloc_blksz_shift; | ||
193 | HFSPLUS_I(inode).fs_blocks = HFSPLUS_I(inode).alloc_blocks << | ||
194 | HFSPLUS_SB(tree->sb).fs_shift; | ||
195 | inode_set_bytes(inode, inode->i_size); | ||
196 | count = inode->i_size >> tree->node_size_shift; | ||
197 | tree->free_nodes = count - tree->node_count; | ||
198 | tree->node_count = count; | ||
199 | } | ||
200 | |||
201 | nidx = 0; | ||
202 | node = hfs_bnode_find(tree, nidx); | ||
203 | if (IS_ERR(node)) | ||
204 | return node; | ||
205 | len = hfs_brec_lenoff(node, 2, &off); | ||
206 | |||
207 | off += node->page_offset; | ||
208 | pagep = node->page + (off >> PAGE_CACHE_SHIFT); | ||
209 | data = kmap(*pagep); | ||
210 | off &= ~PAGE_CACHE_MASK; | ||
211 | idx = 0; | ||
212 | |||
213 | for (;;) { | ||
214 | while (len) { | ||
215 | byte = data[off]; | ||
216 | if (byte != 0xff) { | ||
217 | for (m = 0x80, i = 0; i < 8; m >>= 1, i++) { | ||
218 | if (!(byte & m)) { | ||
219 | idx += i; | ||
220 | data[off] |= m; | ||
221 | set_page_dirty(*pagep); | ||
222 | kunmap(*pagep); | ||
223 | tree->free_nodes--; | ||
224 | mark_inode_dirty(tree->inode); | ||
225 | hfs_bnode_put(node); | ||
226 | if (!idx) { | ||
227 | printk("unexpected idx %u (%u)\n", idx, node->this); | ||
228 | BUG(); | ||
229 | } | ||
230 | return hfs_bnode_create(tree, idx); | ||
231 | } | ||
232 | } | ||
233 | } | ||
234 | if (++off >= PAGE_CACHE_SIZE) { | ||
235 | kunmap(*pagep); | ||
236 | data = kmap(*++pagep); | ||
237 | off = 0; | ||
238 | } | ||
239 | idx += 8; | ||
240 | len--; | ||
241 | } | ||
242 | kunmap(*pagep); | ||
243 | nidx = node->next; | ||
244 | if (!nidx) { | ||
245 | printk("create new bmap node...\n"); | ||
246 | next_node = hfs_bmap_new_bmap(node, idx); | ||
247 | } else | ||
248 | next_node = hfs_bnode_find(tree, nidx); | ||
249 | hfs_bnode_put(node); | ||
250 | if (IS_ERR(next_node)) | ||
251 | return next_node; | ||
252 | node = next_node; | ||
253 | |||
254 | len = hfs_brec_lenoff(node, 0, &off); | ||
255 | off += node->page_offset; | ||
256 | pagep = node->page + (off >> PAGE_CACHE_SHIFT); | ||
257 | data = kmap(*pagep); | ||
258 | off &= ~PAGE_CACHE_MASK; | ||
259 | } | ||
260 | } | ||
261 | |||
262 | void hfs_bmap_free(struct hfs_bnode *node) | ||
263 | { | ||
264 | struct hfs_btree *tree; | ||
265 | struct page *page; | ||
266 | u16 off, len; | ||
267 | u32 nidx; | ||
268 | u8 *data, byte, m; | ||
269 | |||
270 | dprint(DBG_BNODE_MOD, "btree_free_node: %u\n", node->this); | ||
271 | if (!node->this) | ||
272 | BUG(); | ||
273 | tree = node->tree; | ||
274 | nidx = node->this; | ||
275 | node = hfs_bnode_find(tree, 0); | ||
276 | if (IS_ERR(node)) | ||
277 | return; | ||
278 | len = hfs_brec_lenoff(node, 2, &off); | ||
279 | while (nidx >= len * 8) { | ||
280 | u32 i; | ||
281 | |||
282 | nidx -= len * 8; | ||
283 | i = node->next; | ||
284 | hfs_bnode_put(node); | ||
285 | if (!i) { | ||
286 | /* panic */; | ||
287 | printk("HFS: unable to free bnode %u. bmap not found!\n", node->this); | ||
288 | return; | ||
289 | } | ||
290 | node = hfs_bnode_find(tree, i); | ||
291 | if (IS_ERR(node)) | ||
292 | return; | ||
293 | if (node->type != HFS_NODE_MAP) { | ||
294 | /* panic */; | ||
295 | printk("HFS: invalid bmap found! (%u,%d)\n", node->this, node->type); | ||
296 | hfs_bnode_put(node); | ||
297 | return; | ||
298 | } | ||
299 | len = hfs_brec_lenoff(node, 0, &off); | ||
300 | } | ||
301 | off += node->page_offset + nidx / 8; | ||
302 | page = node->page[off >> PAGE_CACHE_SHIFT]; | ||
303 | data = kmap(page); | ||
304 | off &= ~PAGE_CACHE_MASK; | ||
305 | m = 1 << (~nidx & 7); | ||
306 | byte = data[off]; | ||
307 | if (!(byte & m)) { | ||
308 | printk("HFS: trying to free free bnode %u(%d)\n", node->this, node->type); | ||
309 | kunmap(page); | ||
310 | hfs_bnode_put(node); | ||
311 | return; | ||
312 | } | ||
313 | data[off] = byte & ~m; | ||
314 | set_page_dirty(page); | ||
315 | kunmap(page); | ||
316 | hfs_bnode_put(node); | ||
317 | tree->free_nodes++; | ||
318 | mark_inode_dirty(tree->inode); | ||
319 | } | ||