brec.c 13 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424425426427428429430431432433434435436437438439440441442443444445446447448449450451452453454455456457458459460461462463464465466467468469470471472473474475476477478479480481482483484485486487488489490491
  1. /*
  2. * linux/fs/hfsplus/brec.c
  3. *
  4. * Copyright (C) 2001
  5. * Brad Boyer (flar@allandria.com)
  6. * (C) 2003 Ardis Technologies <roman@ardistech.com>
  7. *
  8. * Handle individual btree records
  9. */
  10. #include "hfsplus_fs.h"
  11. #include "hfsplus_raw.h"
  12. static struct hfs_bnode *hfs_bnode_split(struct hfs_find_data *fd);
  13. static int hfs_brec_update_parent(struct hfs_find_data *fd);
  14. static int hfs_btree_inc_height(struct hfs_btree *);
  15. /* Get the length and offset of the given record in the given node */
  16. u16 hfs_brec_lenoff(struct hfs_bnode *node, u16 rec, u16 *off)
  17. {
  18. __be16 retval[2];
  19. u16 dataoff;
  20. dataoff = node->tree->node_size - (rec + 2) * 2;
  21. hfs_bnode_read(node, retval, dataoff, 4);
  22. *off = be16_to_cpu(retval[1]);
  23. return be16_to_cpu(retval[0]) - *off;
  24. }
  25. /* Get the length of the key from a keyed record */
  26. u16 hfs_brec_keylen(struct hfs_bnode *node, u16 rec)
  27. {
  28. u16 retval, recoff;
  29. if (node->type != HFS_NODE_INDEX && node->type != HFS_NODE_LEAF)
  30. return 0;
  31. if ((node->type == HFS_NODE_INDEX) &&
  32. !(node->tree->attributes & HFS_TREE_VARIDXKEYS)) {
  33. retval = node->tree->max_key_len + 2;
  34. } else {
  35. recoff = hfs_bnode_read_u16(node, node->tree->node_size - (rec + 1) * 2);
  36. if (!recoff)
  37. return 0;
  38. if (node->tree->attributes & HFS_TREE_BIGKEYS)
  39. retval = hfs_bnode_read_u16(node, recoff) + 2;
  40. else
  41. retval = (hfs_bnode_read_u8(node, recoff) | 1) + 1;
  42. }
  43. return retval;
  44. }
  45. int hfs_brec_insert(struct hfs_find_data *fd, void *entry, int entry_len)
  46. {
  47. struct hfs_btree *tree;
  48. struct hfs_bnode *node, *new_node;
  49. int size, key_len, rec;
  50. int data_off, end_off;
  51. int idx_rec_off, data_rec_off, end_rec_off;
  52. __be32 cnid;
  53. tree = fd->tree;
  54. if (!fd->bnode) {
  55. if (!tree->root)
  56. hfs_btree_inc_height(tree);
  57. fd->bnode = hfs_bnode_find(tree, tree->leaf_head);
  58. if (IS_ERR(fd->bnode))
  59. return PTR_ERR(fd->bnode);
  60. fd->record = -1;
  61. }
  62. new_node = NULL;
  63. key_len = be16_to_cpu(fd->search_key->key_len) + 2;
  64. again:
  65. /* new record idx and complete record size */
  66. rec = fd->record + 1;
  67. size = key_len + entry_len;
  68. node = fd->bnode;
  69. hfs_bnode_dump(node);
  70. /* get last offset */
  71. end_rec_off = tree->node_size - (node->num_recs + 1) * 2;
  72. end_off = hfs_bnode_read_u16(node, end_rec_off);
  73. end_rec_off -= 2;
  74. dprint(DBG_BNODE_MOD, "insert_rec: %d, %d, %d, %d\n", rec, size, end_off, end_rec_off);
  75. if (size > end_rec_off - end_off) {
  76. if (new_node)
  77. panic("not enough room!\n");
  78. new_node = hfs_bnode_split(fd);
  79. if (IS_ERR(new_node))
  80. return PTR_ERR(new_node);
  81. goto again;
  82. }
  83. if (node->type == HFS_NODE_LEAF) {
  84. tree->leaf_count++;
  85. mark_inode_dirty(tree->inode);
  86. }
  87. node->num_recs++;
  88. /* write new last offset */
  89. hfs_bnode_write_u16(node, offsetof(struct hfs_bnode_desc, num_recs), node->num_recs);
  90. hfs_bnode_write_u16(node, end_rec_off, end_off + size);
  91. data_off = end_off;
  92. data_rec_off = end_rec_off + 2;
  93. idx_rec_off = tree->node_size - (rec + 1) * 2;
  94. if (idx_rec_off == data_rec_off)
  95. goto skip;
  96. /* move all following entries */
  97. do {
  98. data_off = hfs_bnode_read_u16(node, data_rec_off + 2);
  99. hfs_bnode_write_u16(node, data_rec_off, data_off + size);
  100. data_rec_off += 2;
  101. } while (data_rec_off < idx_rec_off);
  102. /* move data away */
  103. hfs_bnode_move(node, data_off + size, data_off,
  104. end_off - data_off);
  105. skip:
  106. hfs_bnode_write(node, fd->search_key, data_off, key_len);
  107. hfs_bnode_write(node, entry, data_off + key_len, entry_len);
  108. hfs_bnode_dump(node);
  109. if (new_node) {
  110. /* update parent key if we inserted a key
  111. * at the start of the first node
  112. */
  113. if (!rec && new_node != node)
  114. hfs_brec_update_parent(fd);
  115. hfs_bnode_put(fd->bnode);
  116. if (!new_node->parent) {
  117. hfs_btree_inc_height(tree);
  118. new_node->parent = tree->root;
  119. }
  120. fd->bnode = hfs_bnode_find(tree, new_node->parent);
  121. /* create index data entry */
  122. cnid = cpu_to_be32(new_node->this);
  123. entry = &cnid;
  124. entry_len = sizeof(cnid);
  125. /* get index key */
  126. hfs_bnode_read_key(new_node, fd->search_key, 14);
  127. __hfs_brec_find(fd->bnode, fd);
  128. hfs_bnode_put(new_node);
  129. new_node = NULL;
  130. if (tree->attributes & HFS_TREE_VARIDXKEYS)
  131. key_len = be16_to_cpu(fd->search_key->key_len) + 2;
  132. else {
  133. fd->search_key->key_len = cpu_to_be16(tree->max_key_len);
  134. key_len = tree->max_key_len + 2;
  135. }
  136. goto again;
  137. }
  138. if (!rec)
  139. hfs_brec_update_parent(fd);
  140. return 0;
  141. }
  142. int hfs_brec_remove(struct hfs_find_data *fd)
  143. {
  144. struct hfs_btree *tree;
  145. struct hfs_bnode *node, *parent;
  146. int end_off, rec_off, data_off, size;
  147. tree = fd->tree;
  148. node = fd->bnode;
  149. again:
  150. rec_off = tree->node_size - (fd->record + 2) * 2;
  151. end_off = tree->node_size - (node->num_recs + 1) * 2;
  152. if (node->type == HFS_NODE_LEAF) {
  153. tree->leaf_count--;
  154. mark_inode_dirty(tree->inode);
  155. }
  156. hfs_bnode_dump(node);
  157. dprint(DBG_BNODE_MOD, "remove_rec: %d, %d\n", fd->record, fd->keylength + fd->entrylength);
  158. if (!--node->num_recs) {
  159. hfs_bnode_unlink(node);
  160. if (!node->parent)
  161. return 0;
  162. parent = hfs_bnode_find(tree, node->parent);
  163. if (IS_ERR(parent))
  164. return PTR_ERR(parent);
  165. hfs_bnode_put(node);
  166. node = fd->bnode = parent;
  167. __hfs_brec_find(node, fd);
  168. goto again;
  169. }
  170. hfs_bnode_write_u16(node, offsetof(struct hfs_bnode_desc, num_recs), node->num_recs);
  171. if (rec_off == end_off)
  172. goto skip;
  173. size = fd->keylength + fd->entrylength;
  174. do {
  175. data_off = hfs_bnode_read_u16(node, rec_off);
  176. hfs_bnode_write_u16(node, rec_off + 2, data_off - size);
  177. rec_off -= 2;
  178. } while (rec_off >= end_off);
  179. /* fill hole */
  180. hfs_bnode_move(node, fd->keyoffset, fd->keyoffset + size,
  181. data_off - fd->keyoffset - size);
  182. skip:
  183. hfs_bnode_dump(node);
  184. if (!fd->record)
  185. hfs_brec_update_parent(fd);
  186. return 0;
  187. }
  188. static struct hfs_bnode *hfs_bnode_split(struct hfs_find_data *fd)
  189. {
  190. struct hfs_btree *tree;
  191. struct hfs_bnode *node, *new_node;
  192. struct hfs_bnode_desc node_desc;
  193. int num_recs, new_rec_off, new_off, old_rec_off;
  194. int data_start, data_end, size;
  195. tree = fd->tree;
  196. node = fd->bnode;
  197. new_node = hfs_bmap_alloc(tree);
  198. if (IS_ERR(new_node))
  199. return new_node;
  200. hfs_bnode_get(node);
  201. dprint(DBG_BNODE_MOD, "split_nodes: %d - %d - %d\n",
  202. node->this, new_node->this, node->next);
  203. new_node->next = node->next;
  204. new_node->prev = node->this;
  205. new_node->parent = node->parent;
  206. new_node->type = node->type;
  207. new_node->height = node->height;
  208. size = tree->node_size / 2 - node->num_recs * 2 - 14;
  209. old_rec_off = tree->node_size - 4;
  210. num_recs = 1;
  211. for (;;) {
  212. data_start = hfs_bnode_read_u16(node, old_rec_off);
  213. if (data_start > size)
  214. break;
  215. old_rec_off -= 2;
  216. if (++num_recs < node->num_recs)
  217. continue;
  218. /* panic? */
  219. hfs_bnode_put(node);
  220. hfs_bnode_put(new_node);
  221. return ERR_PTR(-ENOSPC);
  222. }
  223. if (fd->record + 1 < num_recs) {
  224. /* new record is in the lower half,
  225. * so leave some more space there
  226. */
  227. old_rec_off += 2;
  228. num_recs--;
  229. data_start = hfs_bnode_read_u16(node, old_rec_off);
  230. } else {
  231. hfs_bnode_put(node);
  232. hfs_bnode_get(new_node);
  233. fd->bnode = new_node;
  234. fd->record -= num_recs;
  235. fd->keyoffset -= data_start - 14;
  236. fd->entryoffset -= data_start - 14;
  237. }
  238. new_node->num_recs = node->num_recs - num_recs;
  239. node->num_recs = num_recs;
  240. new_rec_off = tree->node_size - 2;
  241. new_off = 14;
  242. size = data_start - new_off;
  243. num_recs = new_node->num_recs;
  244. data_end = data_start;
  245. while (num_recs) {
  246. hfs_bnode_write_u16(new_node, new_rec_off, new_off);
  247. old_rec_off -= 2;
  248. new_rec_off -= 2;
  249. data_end = hfs_bnode_read_u16(node, old_rec_off);
  250. new_off = data_end - size;
  251. num_recs--;
  252. }
  253. hfs_bnode_write_u16(new_node, new_rec_off, new_off);
  254. hfs_bnode_copy(new_node, 14, node, data_start, data_end - data_start);
  255. /* update new bnode header */
  256. node_desc.next = cpu_to_be32(new_node->next);
  257. node_desc.prev = cpu_to_be32(new_node->prev);
  258. node_desc.type = new_node->type;
  259. node_desc.height = new_node->height;
  260. node_desc.num_recs = cpu_to_be16(new_node->num_recs);
  261. node_desc.reserved = 0;
  262. hfs_bnode_write(new_node, &node_desc, 0, sizeof(node_desc));
  263. /* update previous bnode header */
  264. node->next = new_node->this;
  265. hfs_bnode_read(node, &node_desc, 0, sizeof(node_desc));
  266. node_desc.next = cpu_to_be32(node->next);
  267. node_desc.num_recs = cpu_to_be16(node->num_recs);
  268. hfs_bnode_write(node, &node_desc, 0, sizeof(node_desc));
  269. /* update next bnode header */
  270. if (new_node->next) {
  271. struct hfs_bnode *next_node = hfs_bnode_find(tree, new_node->next);
  272. next_node->prev = new_node->this;
  273. hfs_bnode_read(next_node, &node_desc, 0, sizeof(node_desc));
  274. node_desc.prev = cpu_to_be32(next_node->prev);
  275. hfs_bnode_write(next_node, &node_desc, 0, sizeof(node_desc));
  276. hfs_bnode_put(next_node);
  277. } else if (node->this == tree->leaf_tail) {
  278. /* if there is no next node, this might be the new tail */
  279. tree->leaf_tail = new_node->this;
  280. mark_inode_dirty(tree->inode);
  281. }
  282. hfs_bnode_dump(node);
  283. hfs_bnode_dump(new_node);
  284. hfs_bnode_put(node);
  285. return new_node;
  286. }
  287. static int hfs_brec_update_parent(struct hfs_find_data *fd)
  288. {
  289. struct hfs_btree *tree;
  290. struct hfs_bnode *node, *new_node, *parent;
  291. int newkeylen, diff;
  292. int rec, rec_off, end_rec_off;
  293. int start_off, end_off;
  294. tree = fd->tree;
  295. node = fd->bnode;
  296. new_node = NULL;
  297. if (!node->parent)
  298. return 0;
  299. again:
  300. parent = hfs_bnode_find(tree, node->parent);
  301. if (IS_ERR(parent))
  302. return PTR_ERR(parent);
  303. __hfs_brec_find(parent, fd);
  304. hfs_bnode_dump(parent);
  305. rec = fd->record;
  306. /* size difference between old and new key */
  307. if (tree->attributes & HFS_TREE_VARIDXKEYS)
  308. newkeylen = hfs_bnode_read_u16(node, 14) + 2;
  309. else
  310. fd->keylength = newkeylen = tree->max_key_len + 2;
  311. dprint(DBG_BNODE_MOD, "update_rec: %d, %d, %d\n", rec, fd->keylength, newkeylen);
  312. rec_off = tree->node_size - (rec + 2) * 2;
  313. end_rec_off = tree->node_size - (parent->num_recs + 1) * 2;
  314. diff = newkeylen - fd->keylength;
  315. if (!diff)
  316. goto skip;
  317. if (diff > 0) {
  318. end_off = hfs_bnode_read_u16(parent, end_rec_off);
  319. if (end_rec_off - end_off < diff) {
  320. printk(KERN_DEBUG "hfs: splitting index node...\n");
  321. fd->bnode = parent;
  322. new_node = hfs_bnode_split(fd);
  323. if (IS_ERR(new_node))
  324. return PTR_ERR(new_node);
  325. parent = fd->bnode;
  326. rec = fd->record;
  327. rec_off = tree->node_size - (rec + 2) * 2;
  328. end_rec_off = tree->node_size - (parent->num_recs + 1) * 2;
  329. }
  330. }
  331. end_off = start_off = hfs_bnode_read_u16(parent, rec_off);
  332. hfs_bnode_write_u16(parent, rec_off, start_off + diff);
  333. start_off -= 4; /* move previous cnid too */
  334. while (rec_off > end_rec_off) {
  335. rec_off -= 2;
  336. end_off = hfs_bnode_read_u16(parent, rec_off);
  337. hfs_bnode_write_u16(parent, rec_off, end_off + diff);
  338. }
  339. hfs_bnode_move(parent, start_off + diff, start_off,
  340. end_off - start_off);
  341. skip:
  342. hfs_bnode_copy(parent, fd->keyoffset, node, 14, newkeylen);
  343. hfs_bnode_dump(parent);
  344. hfs_bnode_put(node);
  345. node = parent;
  346. if (new_node) {
  347. __be32 cnid;
  348. fd->bnode = hfs_bnode_find(tree, new_node->parent);
  349. /* create index key and entry */
  350. hfs_bnode_read_key(new_node, fd->search_key, 14);
  351. cnid = cpu_to_be32(new_node->this);
  352. __hfs_brec_find(fd->bnode, fd);
  353. hfs_brec_insert(fd, &cnid, sizeof(cnid));
  354. hfs_bnode_put(fd->bnode);
  355. hfs_bnode_put(new_node);
  356. if (!rec) {
  357. if (new_node == node)
  358. goto out;
  359. /* restore search_key */
  360. hfs_bnode_read_key(node, fd->search_key, 14);
  361. }
  362. }
  363. if (!rec && node->parent)
  364. goto again;
  365. out:
  366. fd->bnode = node;
  367. return 0;
  368. }
  369. static int hfs_btree_inc_height(struct hfs_btree *tree)
  370. {
  371. struct hfs_bnode *node, *new_node;
  372. struct hfs_bnode_desc node_desc;
  373. int key_size, rec;
  374. __be32 cnid;
  375. node = NULL;
  376. if (tree->root) {
  377. node = hfs_bnode_find(tree, tree->root);
  378. if (IS_ERR(node))
  379. return PTR_ERR(node);
  380. }
  381. new_node = hfs_bmap_alloc(tree);
  382. if (IS_ERR(new_node)) {
  383. hfs_bnode_put(node);
  384. return PTR_ERR(new_node);
  385. }
  386. tree->root = new_node->this;
  387. if (!tree->depth) {
  388. tree->leaf_head = tree->leaf_tail = new_node->this;
  389. new_node->type = HFS_NODE_LEAF;
  390. new_node->num_recs = 0;
  391. } else {
  392. new_node->type = HFS_NODE_INDEX;
  393. new_node->num_recs = 1;
  394. }
  395. new_node->parent = 0;
  396. new_node->next = 0;
  397. new_node->prev = 0;
  398. new_node->height = ++tree->depth;
  399. node_desc.next = cpu_to_be32(new_node->next);
  400. node_desc.prev = cpu_to_be32(new_node->prev);
  401. node_desc.type = new_node->type;
  402. node_desc.height = new_node->height;
  403. node_desc.num_recs = cpu_to_be16(new_node->num_recs);
  404. node_desc.reserved = 0;
  405. hfs_bnode_write(new_node, &node_desc, 0, sizeof(node_desc));
  406. rec = tree->node_size - 2;
  407. hfs_bnode_write_u16(new_node, rec, 14);
  408. if (node) {
  409. /* insert old root idx into new root */
  410. node->parent = tree->root;
  411. if (node->type == HFS_NODE_LEAF ||
  412. tree->attributes & HFS_TREE_VARIDXKEYS)
  413. key_size = hfs_bnode_read_u16(node, 14) + 2;
  414. else
  415. key_size = tree->max_key_len + 2;
  416. hfs_bnode_copy(new_node, 14, node, 14, key_size);
  417. if (!(tree->attributes & HFS_TREE_VARIDXKEYS)) {
  418. key_size = tree->max_key_len + 2;
  419. hfs_bnode_write_u16(new_node, 14, tree->max_key_len);
  420. }
  421. cnid = cpu_to_be32(node->this);
  422. hfs_bnode_write(new_node, &cnid, 14 + key_size, 4);
  423. rec -= 2;
  424. hfs_bnode_write_u16(new_node, rec, 14 + key_size + 4);
  425. hfs_bnode_put(node);
  426. }
  427. hfs_bnode_put(new_node);
  428. mark_inode_dirty(tree->inode);
  429. return 0;
  430. }