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/hfs/btree.c |
Linux-2.6.12-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/hfs/btree.c')
-rw-r--r-- | fs/hfs/btree.c | 327 |
1 files changed, 327 insertions, 0 deletions
diff --git a/fs/hfs/btree.c b/fs/hfs/btree.c new file mode 100644 index 000000000000..394725efa1c8 --- /dev/null +++ b/fs/hfs/btree.c | |||
@@ -0,0 +1,327 @@ | |||
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 | |||
13 | #include "btree.h" | ||
14 | |||
15 | /* Get a reference to a B*Tree and do some initial checks */ | ||
16 | struct hfs_btree *hfs_btree_open(struct super_block *sb, u32 id, btree_keycmp keycmp) | ||
17 | { | ||
18 | struct hfs_btree *tree; | ||
19 | struct hfs_btree_header_rec *head; | ||
20 | struct address_space *mapping; | ||
21 | struct page *page; | ||
22 | unsigned int size; | ||
23 | |||
24 | tree = kmalloc(sizeof(*tree), GFP_KERNEL); | ||
25 | if (!tree) | ||
26 | return NULL; | ||
27 | memset(tree, 0, sizeof(*tree)); | ||
28 | |||
29 | init_MUTEX(&tree->tree_lock); | ||
30 | spin_lock_init(&tree->hash_lock); | ||
31 | /* Set the correct compare function */ | ||
32 | tree->sb = sb; | ||
33 | tree->cnid = id; | ||
34 | tree->keycmp = keycmp; | ||
35 | |||
36 | tree->inode = iget_locked(sb, id); | ||
37 | if (!tree->inode) | ||
38 | goto free_tree; | ||
39 | if (!(tree->inode->i_state & I_NEW)) | ||
40 | BUG(); | ||
41 | { | ||
42 | struct hfs_mdb *mdb = HFS_SB(sb)->mdb; | ||
43 | HFS_I(tree->inode)->flags = 0; | ||
44 | init_MUTEX(&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 | tree->inode->i_mapping->a_ops = &hfs_btree_aops; | ||
50 | break; | ||
51 | case HFS_CAT_CNID: | ||
52 | hfs_inode_read_fork(tree->inode, mdb->drCTExtRec, mdb->drCTFlSize, | ||
53 | mdb->drCTFlSize, be32_to_cpu(mdb->drCTClpSiz)); | ||
54 | tree->inode->i_mapping->a_ops = &hfs_btree_aops; | ||
55 | break; | ||
56 | default: | ||
57 | BUG(); | ||
58 | } | ||
59 | } | ||
60 | unlock_new_inode(tree->inode); | ||
61 | |||
62 | mapping = tree->inode->i_mapping; | ||
63 | page = read_cache_page(mapping, 0, (filler_t *)mapping->a_ops->readpage, NULL); | ||
64 | if (IS_ERR(page)) | ||
65 | goto free_tree; | ||
66 | |||
67 | /* Load the header */ | ||
68 | head = (struct hfs_btree_header_rec *)(kmap(page) + sizeof(struct hfs_bnode_desc)); | ||
69 | tree->root = be32_to_cpu(head->root); | ||
70 | tree->leaf_count = be32_to_cpu(head->leaf_count); | ||
71 | tree->leaf_head = be32_to_cpu(head->leaf_head); | ||
72 | tree->leaf_tail = be32_to_cpu(head->leaf_tail); | ||
73 | tree->node_count = be32_to_cpu(head->node_count); | ||
74 | tree->free_nodes = be32_to_cpu(head->free_nodes); | ||
75 | tree->attributes = be32_to_cpu(head->attributes); | ||
76 | tree->node_size = be16_to_cpu(head->node_size); | ||
77 | tree->max_key_len = be16_to_cpu(head->max_key_len); | ||
78 | tree->depth = be16_to_cpu(head->depth); | ||
79 | |||
80 | size = tree->node_size; | ||
81 | if (!size || size & (size - 1)) | ||
82 | goto fail_page; | ||
83 | if (!tree->node_count) | ||
84 | goto fail_page; | ||
85 | tree->node_size_shift = ffs(size) - 1; | ||
86 | tree->pages_per_bnode = (tree->node_size + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; | ||
87 | |||
88 | kunmap(page); | ||
89 | page_cache_release(page); | ||
90 | return tree; | ||
91 | |||
92 | fail_page: | ||
93 | tree->inode->i_mapping->a_ops = &hfs_aops; | ||
94 | page_cache_release(page); | ||
95 | free_tree: | ||
96 | iput(tree->inode); | ||
97 | kfree(tree); | ||
98 | return NULL; | ||
99 | } | ||
100 | |||
101 | /* Release resources used by a btree */ | ||
102 | void hfs_btree_close(struct hfs_btree *tree) | ||
103 | { | ||
104 | struct hfs_bnode *node; | ||
105 | int i; | ||
106 | |||
107 | if (!tree) | ||
108 | return; | ||
109 | |||
110 | for (i = 0; i < NODE_HASH_SIZE; i++) { | ||
111 | while ((node = tree->node_hash[i])) { | ||
112 | tree->node_hash[i] = node->next_hash; | ||
113 | if (atomic_read(&node->refcnt)) | ||
114 | printk("HFS: node %d:%d still has %d user(s)!\n", | ||
115 | node->tree->cnid, node->this, atomic_read(&node->refcnt)); | ||
116 | hfs_bnode_free(node); | ||
117 | tree->node_hash_cnt--; | ||
118 | } | ||
119 | } | ||
120 | iput(tree->inode); | ||
121 | kfree(tree); | ||
122 | } | ||
123 | |||
124 | void hfs_btree_write(struct hfs_btree *tree) | ||
125 | { | ||
126 | struct hfs_btree_header_rec *head; | ||
127 | struct hfs_bnode *node; | ||
128 | struct page *page; | ||
129 | |||
130 | node = hfs_bnode_find(tree, 0); | ||
131 | if (IS_ERR(node)) | ||
132 | /* panic? */ | ||
133 | return; | ||
134 | /* Load the header */ | ||
135 | page = node->page[0]; | ||
136 | head = (struct hfs_btree_header_rec *)(kmap(page) + sizeof(struct hfs_bnode_desc)); | ||
137 | |||
138 | head->root = cpu_to_be32(tree->root); | ||
139 | head->leaf_count = cpu_to_be32(tree->leaf_count); | ||
140 | head->leaf_head = cpu_to_be32(tree->leaf_head); | ||
141 | head->leaf_tail = cpu_to_be32(tree->leaf_tail); | ||
142 | head->node_count = cpu_to_be32(tree->node_count); | ||
143 | head->free_nodes = cpu_to_be32(tree->free_nodes); | ||
144 | head->attributes = cpu_to_be32(tree->attributes); | ||
145 | head->depth = cpu_to_be16(tree->depth); | ||
146 | |||
147 | kunmap(page); | ||
148 | set_page_dirty(page); | ||
149 | hfs_bnode_put(node); | ||
150 | } | ||
151 | |||
152 | static struct hfs_bnode *hfs_bmap_new_bmap(struct hfs_bnode *prev, u32 idx) | ||
153 | { | ||
154 | struct hfs_btree *tree = prev->tree; | ||
155 | struct hfs_bnode *node; | ||
156 | struct hfs_bnode_desc desc; | ||
157 | __be32 cnid; | ||
158 | |||
159 | node = hfs_bnode_create(tree, idx); | ||
160 | if (IS_ERR(node)) | ||
161 | return node; | ||
162 | |||
163 | if (!tree->free_nodes) | ||
164 | panic("FIXME!!!"); | ||
165 | tree->free_nodes--; | ||
166 | prev->next = idx; | ||
167 | cnid = cpu_to_be32(idx); | ||
168 | hfs_bnode_write(prev, &cnid, offsetof(struct hfs_bnode_desc, next), 4); | ||
169 | |||
170 | node->type = HFS_NODE_MAP; | ||
171 | node->num_recs = 1; | ||
172 | hfs_bnode_clear(node, 0, tree->node_size); | ||
173 | desc.next = 0; | ||
174 | desc.prev = 0; | ||
175 | desc.type = HFS_NODE_MAP; | ||
176 | desc.height = 0; | ||
177 | desc.num_recs = cpu_to_be16(1); | ||
178 | desc.reserved = 0; | ||
179 | hfs_bnode_write(node, &desc, 0, sizeof(desc)); | ||
180 | hfs_bnode_write_u16(node, 14, 0x8000); | ||
181 | hfs_bnode_write_u16(node, tree->node_size - 2, 14); | ||
182 | hfs_bnode_write_u16(node, tree->node_size - 4, tree->node_size - 6); | ||
183 | |||
184 | return node; | ||
185 | } | ||
186 | |||
187 | struct hfs_bnode *hfs_bmap_alloc(struct hfs_btree *tree) | ||
188 | { | ||
189 | struct hfs_bnode *node, *next_node; | ||
190 | struct page **pagep; | ||
191 | u32 nidx, idx; | ||
192 | u16 off, len; | ||
193 | u8 *data, byte, m; | ||
194 | int i; | ||
195 | |||
196 | while (!tree->free_nodes) { | ||
197 | struct inode *inode = tree->inode; | ||
198 | u32 count; | ||
199 | int res; | ||
200 | |||
201 | res = hfs_extend_file(inode); | ||
202 | if (res) | ||
203 | return ERR_PTR(res); | ||
204 | HFS_I(inode)->phys_size = inode->i_size = | ||
205 | (loff_t)HFS_I(inode)->alloc_blocks * | ||
206 | HFS_SB(tree->sb)->alloc_blksz; | ||
207 | HFS_I(inode)->fs_blocks = inode->i_size >> | ||
208 | tree->sb->s_blocksize_bits; | ||
209 | inode_set_bytes(inode, inode->i_size); | ||
210 | count = inode->i_size >> tree->node_size_shift; | ||
211 | tree->free_nodes = count - tree->node_count; | ||
212 | tree->node_count = count; | ||
213 | } | ||
214 | |||
215 | nidx = 0; | ||
216 | node = hfs_bnode_find(tree, nidx); | ||
217 | if (IS_ERR(node)) | ||
218 | return node; | ||
219 | len = hfs_brec_lenoff(node, 2, &off); | ||
220 | |||
221 | off += node->page_offset; | ||
222 | pagep = node->page + (off >> PAGE_CACHE_SHIFT); | ||
223 | data = kmap(*pagep); | ||
224 | off &= ~PAGE_CACHE_MASK; | ||
225 | idx = 0; | ||
226 | |||
227 | for (;;) { | ||
228 | while (len) { | ||
229 | byte = data[off]; | ||
230 | if (byte != 0xff) { | ||
231 | for (m = 0x80, i = 0; i < 8; m >>= 1, i++) { | ||
232 | if (!(byte & m)) { | ||
233 | idx += i; | ||
234 | data[off] |= m; | ||
235 | set_page_dirty(*pagep); | ||
236 | kunmap(*pagep); | ||
237 | tree->free_nodes--; | ||
238 | mark_inode_dirty(tree->inode); | ||
239 | hfs_bnode_put(node); | ||
240 | return hfs_bnode_create(tree, idx); | ||
241 | } | ||
242 | } | ||
243 | } | ||
244 | if (++off >= PAGE_CACHE_SIZE) { | ||
245 | kunmap(*pagep); | ||
246 | data = kmap(*++pagep); | ||
247 | off = 0; | ||
248 | } | ||
249 | idx += 8; | ||
250 | len--; | ||
251 | } | ||
252 | kunmap(*pagep); | ||
253 | nidx = node->next; | ||
254 | if (!nidx) { | ||
255 | printk("create new bmap node...\n"); | ||
256 | next_node = hfs_bmap_new_bmap(node, idx); | ||
257 | } else | ||
258 | next_node = hfs_bnode_find(tree, nidx); | ||
259 | hfs_bnode_put(node); | ||
260 | if (IS_ERR(next_node)) | ||
261 | return next_node; | ||
262 | node = next_node; | ||
263 | |||
264 | len = hfs_brec_lenoff(node, 0, &off); | ||
265 | off += node->page_offset; | ||
266 | pagep = node->page + (off >> PAGE_CACHE_SHIFT); | ||
267 | data = kmap(*pagep); | ||
268 | off &= ~PAGE_CACHE_MASK; | ||
269 | } | ||
270 | } | ||
271 | |||
272 | void hfs_bmap_free(struct hfs_bnode *node) | ||
273 | { | ||
274 | struct hfs_btree *tree; | ||
275 | struct page *page; | ||
276 | u16 off, len; | ||
277 | u32 nidx; | ||
278 | u8 *data, byte, m; | ||
279 | |||
280 | dprint(DBG_BNODE_MOD, "btree_free_node: %u\n", node->this); | ||
281 | tree = node->tree; | ||
282 | nidx = node->this; | ||
283 | node = hfs_bnode_find(tree, 0); | ||
284 | if (IS_ERR(node)) | ||
285 | return; | ||
286 | len = hfs_brec_lenoff(node, 2, &off); | ||
287 | while (nidx >= len * 8) { | ||
288 | u32 i; | ||
289 | |||
290 | nidx -= len * 8; | ||
291 | i = node->next; | ||
292 | hfs_bnode_put(node); | ||
293 | if (!i) { | ||
294 | /* panic */; | ||
295 | printk("HFS: unable to free bnode %u. bmap not found!\n", node->this); | ||
296 | return; | ||
297 | } | ||
298 | node = hfs_bnode_find(tree, i); | ||
299 | if (IS_ERR(node)) | ||
300 | return; | ||
301 | if (node->type != HFS_NODE_MAP) { | ||
302 | /* panic */; | ||
303 | printk("HFS: invalid bmap found! (%u,%d)\n", node->this, node->type); | ||
304 | hfs_bnode_put(node); | ||
305 | return; | ||
306 | } | ||
307 | len = hfs_brec_lenoff(node, 0, &off); | ||
308 | } | ||
309 | off += node->page_offset + nidx / 8; | ||
310 | page = node->page[off >> PAGE_CACHE_SHIFT]; | ||
311 | data = kmap(page); | ||
312 | off &= ~PAGE_CACHE_MASK; | ||
313 | m = 1 << (~nidx & 7); | ||
314 | byte = data[off]; | ||
315 | if (!(byte & m)) { | ||
316 | printk("HFS: trying to free free bnode %u(%d)\n", node->this, node->type); | ||
317 | kunmap(page); | ||
318 | hfs_bnode_put(node); | ||
319 | return; | ||
320 | } | ||
321 | data[off] = byte & ~m; | ||
322 | set_page_dirty(page); | ||
323 | kunmap(page); | ||
324 | hfs_bnode_put(node); | ||
325 | tree->free_nodes++; | ||
326 | mark_inode_dirty(tree->inode); | ||
327 | } | ||