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v4.6
 
  1/*
  2 *  linux/fs/hfs/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
 11#include "btree.h"
 12
 13static struct hfs_bnode *hfs_bnode_split(struct hfs_find_data *fd);
 14static int hfs_brec_update_parent(struct hfs_find_data *fd);
 15static int hfs_btree_inc_height(struct hfs_btree *tree);
 16
 17/* Get the length and offset of the given record in the given node */
 18u16 hfs_brec_lenoff(struct hfs_bnode *node, u16 rec, u16 *off)
 19{
 20	__be16 retval[2];
 21	u16 dataoff;
 22
 23	dataoff = node->tree->node_size - (rec + 2) * 2;
 24	hfs_bnode_read(node, retval, dataoff, 4);
 25	*off = be16_to_cpu(retval[1]);
 26	return be16_to_cpu(retval[0]) - *off;
 27}
 28
 29/* Get the length of the key from a keyed record */
 30u16 hfs_brec_keylen(struct hfs_bnode *node, u16 rec)
 31{
 32	u16 retval, recoff;
 33
 34	if (node->type != HFS_NODE_INDEX && node->type != HFS_NODE_LEAF)
 35		return 0;
 36
 37	if ((node->type == HFS_NODE_INDEX) &&
 38	   !(node->tree->attributes & HFS_TREE_VARIDXKEYS)) {
 39		if (node->tree->attributes & HFS_TREE_BIGKEYS)
 40			retval = node->tree->max_key_len + 2;
 41		else
 42			retval = node->tree->max_key_len + 1;
 43	} else {
 44		recoff = hfs_bnode_read_u16(node, node->tree->node_size - (rec + 1) * 2);
 45		if (!recoff)
 46			return 0;
 47		if (node->tree->attributes & HFS_TREE_BIGKEYS) {
 48			retval = hfs_bnode_read_u16(node, recoff) + 2;
 49			if (retval > node->tree->max_key_len + 2) {
 50				pr_err("keylen %d too large\n", retval);
 51				retval = 0;
 52			}
 53		} else {
 54			retval = (hfs_bnode_read_u8(node, recoff) | 1) + 1;
 55			if (retval > node->tree->max_key_len + 1) {
 56				pr_err("keylen %d too large\n", retval);
 57				retval = 0;
 58			}
 59		}
 60	}
 61	return retval;
 62}
 63
 64int hfs_brec_insert(struct hfs_find_data *fd, void *entry, int entry_len)
 65{
 66	struct hfs_btree *tree;
 67	struct hfs_bnode *node, *new_node;
 68	int size, key_len, rec;
 69	int data_off, end_off;
 70	int idx_rec_off, data_rec_off, end_rec_off;
 71	__be32 cnid;
 72
 73	tree = fd->tree;
 74	if (!fd->bnode) {
 75		if (!tree->root)
 76			hfs_btree_inc_height(tree);
 77		fd->bnode = hfs_bnode_find(tree, tree->leaf_head);
 78		if (IS_ERR(fd->bnode))
 79			return PTR_ERR(fd->bnode);
 
 80		fd->record = -1;
 81	}
 82	new_node = NULL;
 83	key_len = (fd->search_key->key_len | 1) + 1;
 84again:
 85	/* new record idx and complete record size */
 86	rec = fd->record + 1;
 87	size = key_len + entry_len;
 88
 89	node = fd->bnode;
 90	hfs_bnode_dump(node);
 91	/* get last offset */
 92	end_rec_off = tree->node_size - (node->num_recs + 1) * 2;
 93	end_off = hfs_bnode_read_u16(node, end_rec_off);
 94	end_rec_off -= 2;
 95	hfs_dbg(BNODE_MOD, "insert_rec: %d, %d, %d, %d\n",
 96		rec, size, end_off, end_rec_off);
 97	if (size > end_rec_off - end_off) {
 98		if (new_node)
 99			panic("not enough room!\n");
100		new_node = hfs_bnode_split(fd);
101		if (IS_ERR(new_node))
102			return PTR_ERR(new_node);
103		goto again;
104	}
105	if (node->type == HFS_NODE_LEAF) {
106		tree->leaf_count++;
107		mark_inode_dirty(tree->inode);
108	}
109	node->num_recs++;
110	/* write new last offset */
111	hfs_bnode_write_u16(node, offsetof(struct hfs_bnode_desc, num_recs), node->num_recs);
112	hfs_bnode_write_u16(node, end_rec_off, end_off + size);
113	data_off = end_off;
114	data_rec_off = end_rec_off + 2;
115	idx_rec_off = tree->node_size - (rec + 1) * 2;
116	if (idx_rec_off == data_rec_off)
117		goto skip;
118	/* move all following entries */
119	do {
120		data_off = hfs_bnode_read_u16(node, data_rec_off + 2);
121		hfs_bnode_write_u16(node, data_rec_off, data_off + size);
122		data_rec_off += 2;
123	} while (data_rec_off < idx_rec_off);
124
125	/* move data away */
126	hfs_bnode_move(node, data_off + size, data_off,
127		       end_off - data_off);
128
129skip:
130	hfs_bnode_write(node, fd->search_key, data_off, key_len);
131	hfs_bnode_write(node, entry, data_off + key_len, entry_len);
132	hfs_bnode_dump(node);
133
134	/*
135	 * update parent key if we inserted a key
136	 * at the start of the node and it is not the new node
137	 */
138	if (!rec && new_node != node) {
139		hfs_bnode_read_key(node, fd->search_key, data_off + size);
140		hfs_brec_update_parent(fd);
141	}
142
143	if (new_node) {
144		hfs_bnode_put(fd->bnode);
145		if (!new_node->parent) {
146			hfs_btree_inc_height(tree);
147			new_node->parent = tree->root;
148		}
149		fd->bnode = hfs_bnode_find(tree, new_node->parent);
150
151		/* create index data entry */
152		cnid = cpu_to_be32(new_node->this);
153		entry = &cnid;
154		entry_len = sizeof(cnid);
155
156		/* get index key */
157		hfs_bnode_read_key(new_node, fd->search_key, 14);
158		__hfs_brec_find(fd->bnode, fd);
159
160		hfs_bnode_put(new_node);
161		new_node = NULL;
162
163		if (tree->attributes & HFS_TREE_VARIDXKEYS)
164			key_len = fd->search_key->key_len + 1;
165		else {
166			fd->search_key->key_len = tree->max_key_len;
167			key_len = tree->max_key_len + 1;
168		}
169		goto again;
170	}
171
172	return 0;
173}
174
175int hfs_brec_remove(struct hfs_find_data *fd)
176{
177	struct hfs_btree *tree;
178	struct hfs_bnode *node, *parent;
179	int end_off, rec_off, data_off, size;
180
181	tree = fd->tree;
182	node = fd->bnode;
183again:
184	rec_off = tree->node_size - (fd->record + 2) * 2;
185	end_off = tree->node_size - (node->num_recs + 1) * 2;
186
187	if (node->type == HFS_NODE_LEAF) {
188		tree->leaf_count--;
189		mark_inode_dirty(tree->inode);
190	}
191	hfs_bnode_dump(node);
192	hfs_dbg(BNODE_MOD, "remove_rec: %d, %d\n",
193		fd->record, fd->keylength + fd->entrylength);
194	if (!--node->num_recs) {
195		hfs_bnode_unlink(node);
196		if (!node->parent)
197			return 0;
198		parent = hfs_bnode_find(tree, node->parent);
199		if (IS_ERR(parent))
200			return PTR_ERR(parent);
201		hfs_bnode_put(node);
202		node = fd->bnode = parent;
203
204		__hfs_brec_find(node, fd);
205		goto again;
206	}
207	hfs_bnode_write_u16(node, offsetof(struct hfs_bnode_desc, num_recs), node->num_recs);
208
209	if (rec_off == end_off)
210		goto skip;
211	size = fd->keylength + fd->entrylength;
212
213	do {
214		data_off = hfs_bnode_read_u16(node, rec_off);
215		hfs_bnode_write_u16(node, rec_off + 2, data_off - size);
216		rec_off -= 2;
217	} while (rec_off >= end_off);
218
219	/* fill hole */
220	hfs_bnode_move(node, fd->keyoffset, fd->keyoffset + size,
221		       data_off - fd->keyoffset - size);
222skip:
223	hfs_bnode_dump(node);
224	if (!fd->record)
225		hfs_brec_update_parent(fd);
226	return 0;
227}
228
229static struct hfs_bnode *hfs_bnode_split(struct hfs_find_data *fd)
230{
231	struct hfs_btree *tree;
232	struct hfs_bnode *node, *new_node, *next_node;
233	struct hfs_bnode_desc node_desc;
234	int num_recs, new_rec_off, new_off, old_rec_off;
235	int data_start, data_end, size;
236
237	tree = fd->tree;
238	node = fd->bnode;
239	new_node = hfs_bmap_alloc(tree);
240	if (IS_ERR(new_node))
241		return new_node;
242	hfs_bnode_get(node);
243	hfs_dbg(BNODE_MOD, "split_nodes: %d - %d - %d\n",
244		node->this, new_node->this, node->next);
245	new_node->next = node->next;
246	new_node->prev = node->this;
247	new_node->parent = node->parent;
248	new_node->type = node->type;
249	new_node->height = node->height;
250
251	if (node->next)
252		next_node = hfs_bnode_find(tree, node->next);
253	else
254		next_node = NULL;
255
256	if (IS_ERR(next_node)) {
257		hfs_bnode_put(node);
258		hfs_bnode_put(new_node);
259		return next_node;
260	}
261
262	size = tree->node_size / 2 - node->num_recs * 2 - 14;
263	old_rec_off = tree->node_size - 4;
264	num_recs = 1;
265	for (;;) {
266		data_start = hfs_bnode_read_u16(node, old_rec_off);
267		if (data_start > size)
268			break;
269		old_rec_off -= 2;
270		if (++num_recs < node->num_recs)
271			continue;
272		/* panic? */
273		hfs_bnode_put(node);
274		hfs_bnode_put(new_node);
275		if (next_node)
276			hfs_bnode_put(next_node);
277		return ERR_PTR(-ENOSPC);
278	}
279
280	if (fd->record + 1 < num_recs) {
281		/* new record is in the lower half,
282		 * so leave some more space there
283		 */
284		old_rec_off += 2;
285		num_recs--;
286		data_start = hfs_bnode_read_u16(node, old_rec_off);
287	} else {
288		hfs_bnode_put(node);
289		hfs_bnode_get(new_node);
290		fd->bnode = new_node;
291		fd->record -= num_recs;
292		fd->keyoffset -= data_start - 14;
293		fd->entryoffset -= data_start - 14;
294	}
295	new_node->num_recs = node->num_recs - num_recs;
296	node->num_recs = num_recs;
297
298	new_rec_off = tree->node_size - 2;
299	new_off = 14;
300	size = data_start - new_off;
301	num_recs = new_node->num_recs;
302	data_end = data_start;
303	while (num_recs) {
304		hfs_bnode_write_u16(new_node, new_rec_off, new_off);
305		old_rec_off -= 2;
306		new_rec_off -= 2;
307		data_end = hfs_bnode_read_u16(node, old_rec_off);
308		new_off = data_end - size;
309		num_recs--;
310	}
311	hfs_bnode_write_u16(new_node, new_rec_off, new_off);
312	hfs_bnode_copy(new_node, 14, node, data_start, data_end - data_start);
313
314	/* update new bnode header */
315	node_desc.next = cpu_to_be32(new_node->next);
316	node_desc.prev = cpu_to_be32(new_node->prev);
317	node_desc.type = new_node->type;
318	node_desc.height = new_node->height;
319	node_desc.num_recs = cpu_to_be16(new_node->num_recs);
320	node_desc.reserved = 0;
321	hfs_bnode_write(new_node, &node_desc, 0, sizeof(node_desc));
322
323	/* update previous bnode header */
324	node->next = new_node->this;
325	hfs_bnode_read(node, &node_desc, 0, sizeof(node_desc));
326	node_desc.next = cpu_to_be32(node->next);
327	node_desc.num_recs = cpu_to_be16(node->num_recs);
328	hfs_bnode_write(node, &node_desc, 0, sizeof(node_desc));
329
330	/* update next bnode header */
331	if (next_node) {
332		next_node->prev = new_node->this;
333		hfs_bnode_read(next_node, &node_desc, 0, sizeof(node_desc));
334		node_desc.prev = cpu_to_be32(next_node->prev);
335		hfs_bnode_write(next_node, &node_desc, 0, sizeof(node_desc));
336		hfs_bnode_put(next_node);
337	} else if (node->this == tree->leaf_tail) {
338		/* if there is no next node, this might be the new tail */
339		tree->leaf_tail = new_node->this;
340		mark_inode_dirty(tree->inode);
341	}
342
343	hfs_bnode_dump(node);
344	hfs_bnode_dump(new_node);
345	hfs_bnode_put(node);
346
347	return new_node;
348}
349
350static int hfs_brec_update_parent(struct hfs_find_data *fd)
351{
352	struct hfs_btree *tree;
353	struct hfs_bnode *node, *new_node, *parent;
354	int newkeylen, diff;
355	int rec, rec_off, end_rec_off;
356	int start_off, end_off;
357
358	tree = fd->tree;
359	node = fd->bnode;
360	new_node = NULL;
361	if (!node->parent)
362		return 0;
363
364again:
365	parent = hfs_bnode_find(tree, node->parent);
366	if (IS_ERR(parent))
367		return PTR_ERR(parent);
368	__hfs_brec_find(parent, fd);
369	if (fd->record < 0)
370		return -ENOENT;
371	hfs_bnode_dump(parent);
372	rec = fd->record;
373
374	/* size difference between old and new key */
375	if (tree->attributes & HFS_TREE_VARIDXKEYS)
376		newkeylen = (hfs_bnode_read_u8(node, 14) | 1) + 1;
377	else
378		fd->keylength = newkeylen = tree->max_key_len + 1;
379	hfs_dbg(BNODE_MOD, "update_rec: %d, %d, %d\n",
380		rec, fd->keylength, newkeylen);
381
382	rec_off = tree->node_size - (rec + 2) * 2;
383	end_rec_off = tree->node_size - (parent->num_recs + 1) * 2;
384	diff = newkeylen - fd->keylength;
385	if (!diff)
386		goto skip;
387	if (diff > 0) {
388		end_off = hfs_bnode_read_u16(parent, end_rec_off);
389		if (end_rec_off - end_off < diff) {
390
391			printk(KERN_DEBUG "splitting index node...\n");
392			fd->bnode = parent;
393			new_node = hfs_bnode_split(fd);
394			if (IS_ERR(new_node))
395				return PTR_ERR(new_node);
396			parent = fd->bnode;
397			rec = fd->record;
398			rec_off = tree->node_size - (rec + 2) * 2;
399			end_rec_off = tree->node_size - (parent->num_recs + 1) * 2;
400		}
401	}
402
403	end_off = start_off = hfs_bnode_read_u16(parent, rec_off);
404	hfs_bnode_write_u16(parent, rec_off, start_off + diff);
405	start_off -= 4;	/* move previous cnid too */
406
407	while (rec_off > end_rec_off) {
408		rec_off -= 2;
409		end_off = hfs_bnode_read_u16(parent, rec_off);
410		hfs_bnode_write_u16(parent, rec_off, end_off + diff);
411	}
412	hfs_bnode_move(parent, start_off + diff, start_off,
413		       end_off - start_off);
414skip:
415	hfs_bnode_copy(parent, fd->keyoffset, node, 14, newkeylen);
416	if (!(tree->attributes & HFS_TREE_VARIDXKEYS))
417		hfs_bnode_write_u8(parent, fd->keyoffset, newkeylen - 1);
418	hfs_bnode_dump(parent);
419
420	hfs_bnode_put(node);
421	node = parent;
422
423	if (new_node) {
424		__be32 cnid;
425
 
 
 
 
426		fd->bnode = hfs_bnode_find(tree, new_node->parent);
427		/* create index key and entry */
428		hfs_bnode_read_key(new_node, fd->search_key, 14);
429		cnid = cpu_to_be32(new_node->this);
430
431		__hfs_brec_find(fd->bnode, fd);
432		hfs_brec_insert(fd, &cnid, sizeof(cnid));
433		hfs_bnode_put(fd->bnode);
434		hfs_bnode_put(new_node);
435
436		if (!rec) {
437			if (new_node == node)
438				goto out;
439			/* restore search_key */
440			hfs_bnode_read_key(node, fd->search_key, 14);
441		}
 
442	}
443
444	if (!rec && node->parent)
445		goto again;
446out:
447	fd->bnode = node;
448	return 0;
449}
450
451static int hfs_btree_inc_height(struct hfs_btree *tree)
452{
453	struct hfs_bnode *node, *new_node;
454	struct hfs_bnode_desc node_desc;
455	int key_size, rec;
456	__be32 cnid;
457
458	node = NULL;
459	if (tree->root) {
460		node = hfs_bnode_find(tree, tree->root);
461		if (IS_ERR(node))
462			return PTR_ERR(node);
463	}
464	new_node = hfs_bmap_alloc(tree);
465	if (IS_ERR(new_node)) {
466		hfs_bnode_put(node);
467		return PTR_ERR(new_node);
468	}
469
470	tree->root = new_node->this;
471	if (!tree->depth) {
472		tree->leaf_head = tree->leaf_tail = new_node->this;
473		new_node->type = HFS_NODE_LEAF;
474		new_node->num_recs = 0;
475	} else {
476		new_node->type = HFS_NODE_INDEX;
477		new_node->num_recs = 1;
478	}
479	new_node->parent = 0;
480	new_node->next = 0;
481	new_node->prev = 0;
482	new_node->height = ++tree->depth;
483
484	node_desc.next = cpu_to_be32(new_node->next);
485	node_desc.prev = cpu_to_be32(new_node->prev);
486	node_desc.type = new_node->type;
487	node_desc.height = new_node->height;
488	node_desc.num_recs = cpu_to_be16(new_node->num_recs);
489	node_desc.reserved = 0;
490	hfs_bnode_write(new_node, &node_desc, 0, sizeof(node_desc));
491
492	rec = tree->node_size - 2;
493	hfs_bnode_write_u16(new_node, rec, 14);
494
495	if (node) {
496		/* insert old root idx into new root */
497		node->parent = tree->root;
498		if (node->type == HFS_NODE_LEAF ||
499		    tree->attributes & HFS_TREE_VARIDXKEYS)
500			key_size = hfs_bnode_read_u8(node, 14) + 1;
501		else
502			key_size = tree->max_key_len + 1;
503		hfs_bnode_copy(new_node, 14, node, 14, key_size);
504
505		if (!(tree->attributes & HFS_TREE_VARIDXKEYS)) {
506			key_size = tree->max_key_len + 1;
507			hfs_bnode_write_u8(new_node, 14, tree->max_key_len);
508		}
509		key_size = (key_size + 1) & -2;
510		cnid = cpu_to_be32(node->this);
511		hfs_bnode_write(new_node, &cnid, 14 + key_size, 4);
512
513		rec -= 2;
514		hfs_bnode_write_u16(new_node, rec, 14 + key_size + 4);
515
516		hfs_bnode_put(node);
517	}
518	hfs_bnode_put(new_node);
519	mark_inode_dirty(tree->inode);
520
521	return 0;
522}
v6.13.7
  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 *  linux/fs/hfs/brec.c
  4 *
  5 * Copyright (C) 2001
  6 * Brad Boyer (flar@allandria.com)
  7 * (C) 2003 Ardis Technologies <roman@ardistech.com>
  8 *
  9 * Handle individual btree records
 10 */
 11
 12#include "btree.h"
 13
 14static struct hfs_bnode *hfs_bnode_split(struct hfs_find_data *fd);
 15static int hfs_brec_update_parent(struct hfs_find_data *fd);
 16static int hfs_btree_inc_height(struct hfs_btree *tree);
 17
 18/* Get the length and offset of the given record in the given node */
 19u16 hfs_brec_lenoff(struct hfs_bnode *node, u16 rec, u16 *off)
 20{
 21	__be16 retval[2];
 22	u16 dataoff;
 23
 24	dataoff = node->tree->node_size - (rec + 2) * 2;
 25	hfs_bnode_read(node, retval, dataoff, 4);
 26	*off = be16_to_cpu(retval[1]);
 27	return be16_to_cpu(retval[0]) - *off;
 28}
 29
 30/* Get the length of the key from a keyed record */
 31u16 hfs_brec_keylen(struct hfs_bnode *node, u16 rec)
 32{
 33	u16 retval, recoff;
 34
 35	if (node->type != HFS_NODE_INDEX && node->type != HFS_NODE_LEAF)
 36		return 0;
 37
 38	if ((node->type == HFS_NODE_INDEX) &&
 39	   !(node->tree->attributes & HFS_TREE_VARIDXKEYS)) {
 40		if (node->tree->attributes & HFS_TREE_BIGKEYS)
 41			retval = node->tree->max_key_len + 2;
 42		else
 43			retval = node->tree->max_key_len + 1;
 44	} else {
 45		recoff = hfs_bnode_read_u16(node, node->tree->node_size - (rec + 1) * 2);
 46		if (!recoff)
 47			return 0;
 48		if (node->tree->attributes & HFS_TREE_BIGKEYS) {
 49			retval = hfs_bnode_read_u16(node, recoff) + 2;
 50			if (retval > node->tree->max_key_len + 2) {
 51				pr_err("keylen %d too large\n", retval);
 52				retval = 0;
 53			}
 54		} else {
 55			retval = (hfs_bnode_read_u8(node, recoff) | 1) + 1;
 56			if (retval > node->tree->max_key_len + 1) {
 57				pr_err("keylen %d too large\n", retval);
 58				retval = 0;
 59			}
 60		}
 61	}
 62	return retval;
 63}
 64
 65int hfs_brec_insert(struct hfs_find_data *fd, void *entry, int entry_len)
 66{
 67	struct hfs_btree *tree;
 68	struct hfs_bnode *node, *new_node;
 69	int size, key_len, rec;
 70	int data_off, end_off;
 71	int idx_rec_off, data_rec_off, end_rec_off;
 72	__be32 cnid;
 73
 74	tree = fd->tree;
 75	if (!fd->bnode) {
 76		if (!tree->root)
 77			hfs_btree_inc_height(tree);
 78		node = hfs_bnode_find(tree, tree->leaf_head);
 79		if (IS_ERR(node))
 80			return PTR_ERR(node);
 81		fd->bnode = node;
 82		fd->record = -1;
 83	}
 84	new_node = NULL;
 85	key_len = (fd->search_key->key_len | 1) + 1;
 86again:
 87	/* new record idx and complete record size */
 88	rec = fd->record + 1;
 89	size = key_len + entry_len;
 90
 91	node = fd->bnode;
 92	hfs_bnode_dump(node);
 93	/* get last offset */
 94	end_rec_off = tree->node_size - (node->num_recs + 1) * 2;
 95	end_off = hfs_bnode_read_u16(node, end_rec_off);
 96	end_rec_off -= 2;
 97	hfs_dbg(BNODE_MOD, "insert_rec: %d, %d, %d, %d\n",
 98		rec, size, end_off, end_rec_off);
 99	if (size > end_rec_off - end_off) {
100		if (new_node)
101			panic("not enough room!\n");
102		new_node = hfs_bnode_split(fd);
103		if (IS_ERR(new_node))
104			return PTR_ERR(new_node);
105		goto again;
106	}
107	if (node->type == HFS_NODE_LEAF) {
108		tree->leaf_count++;
109		mark_inode_dirty(tree->inode);
110	}
111	node->num_recs++;
112	/* write new last offset */
113	hfs_bnode_write_u16(node, offsetof(struct hfs_bnode_desc, num_recs), node->num_recs);
114	hfs_bnode_write_u16(node, end_rec_off, end_off + size);
115	data_off = end_off;
116	data_rec_off = end_rec_off + 2;
117	idx_rec_off = tree->node_size - (rec + 1) * 2;
118	if (idx_rec_off == data_rec_off)
119		goto skip;
120	/* move all following entries */
121	do {
122		data_off = hfs_bnode_read_u16(node, data_rec_off + 2);
123		hfs_bnode_write_u16(node, data_rec_off, data_off + size);
124		data_rec_off += 2;
125	} while (data_rec_off < idx_rec_off);
126
127	/* move data away */
128	hfs_bnode_move(node, data_off + size, data_off,
129		       end_off - data_off);
130
131skip:
132	hfs_bnode_write(node, fd->search_key, data_off, key_len);
133	hfs_bnode_write(node, entry, data_off + key_len, entry_len);
134	hfs_bnode_dump(node);
135
136	/*
137	 * update parent key if we inserted a key
138	 * at the start of the node and it is not the new node
139	 */
140	if (!rec && new_node != node) {
141		hfs_bnode_read_key(node, fd->search_key, data_off + size);
142		hfs_brec_update_parent(fd);
143	}
144
145	if (new_node) {
146		hfs_bnode_put(fd->bnode);
147		if (!new_node->parent) {
148			hfs_btree_inc_height(tree);
149			new_node->parent = tree->root;
150		}
151		fd->bnode = hfs_bnode_find(tree, new_node->parent);
152
153		/* create index data entry */
154		cnid = cpu_to_be32(new_node->this);
155		entry = &cnid;
156		entry_len = sizeof(cnid);
157
158		/* get index key */
159		hfs_bnode_read_key(new_node, fd->search_key, 14);
160		__hfs_brec_find(fd->bnode, fd);
161
162		hfs_bnode_put(new_node);
163		new_node = NULL;
164
165		if (tree->attributes & HFS_TREE_VARIDXKEYS)
166			key_len = fd->search_key->key_len + 1;
167		else {
168			fd->search_key->key_len = tree->max_key_len;
169			key_len = tree->max_key_len + 1;
170		}
171		goto again;
172	}
173
174	return 0;
175}
176
177int hfs_brec_remove(struct hfs_find_data *fd)
178{
179	struct hfs_btree *tree;
180	struct hfs_bnode *node, *parent;
181	int end_off, rec_off, data_off, size;
182
183	tree = fd->tree;
184	node = fd->bnode;
185again:
186	rec_off = tree->node_size - (fd->record + 2) * 2;
187	end_off = tree->node_size - (node->num_recs + 1) * 2;
188
189	if (node->type == HFS_NODE_LEAF) {
190		tree->leaf_count--;
191		mark_inode_dirty(tree->inode);
192	}
193	hfs_bnode_dump(node);
194	hfs_dbg(BNODE_MOD, "remove_rec: %d, %d\n",
195		fd->record, fd->keylength + fd->entrylength);
196	if (!--node->num_recs) {
197		hfs_bnode_unlink(node);
198		if (!node->parent)
199			return 0;
200		parent = hfs_bnode_find(tree, node->parent);
201		if (IS_ERR(parent))
202			return PTR_ERR(parent);
203		hfs_bnode_put(node);
204		node = fd->bnode = parent;
205
206		__hfs_brec_find(node, fd);
207		goto again;
208	}
209	hfs_bnode_write_u16(node, offsetof(struct hfs_bnode_desc, num_recs), node->num_recs);
210
211	if (rec_off == end_off)
212		goto skip;
213	size = fd->keylength + fd->entrylength;
214
215	do {
216		data_off = hfs_bnode_read_u16(node, rec_off);
217		hfs_bnode_write_u16(node, rec_off + 2, data_off - size);
218		rec_off -= 2;
219	} while (rec_off >= end_off);
220
221	/* fill hole */
222	hfs_bnode_move(node, fd->keyoffset, fd->keyoffset + size,
223		       data_off - fd->keyoffset - size);
224skip:
225	hfs_bnode_dump(node);
226	if (!fd->record)
227		hfs_brec_update_parent(fd);
228	return 0;
229}
230
231static struct hfs_bnode *hfs_bnode_split(struct hfs_find_data *fd)
232{
233	struct hfs_btree *tree;
234	struct hfs_bnode *node, *new_node, *next_node;
235	struct hfs_bnode_desc node_desc;
236	int num_recs, new_rec_off, new_off, old_rec_off;
237	int data_start, data_end, size;
238
239	tree = fd->tree;
240	node = fd->bnode;
241	new_node = hfs_bmap_alloc(tree);
242	if (IS_ERR(new_node))
243		return new_node;
244	hfs_bnode_get(node);
245	hfs_dbg(BNODE_MOD, "split_nodes: %d - %d - %d\n",
246		node->this, new_node->this, node->next);
247	new_node->next = node->next;
248	new_node->prev = node->this;
249	new_node->parent = node->parent;
250	new_node->type = node->type;
251	new_node->height = node->height;
252
253	if (node->next)
254		next_node = hfs_bnode_find(tree, node->next);
255	else
256		next_node = NULL;
257
258	if (IS_ERR(next_node)) {
259		hfs_bnode_put(node);
260		hfs_bnode_put(new_node);
261		return next_node;
262	}
263
264	size = tree->node_size / 2 - node->num_recs * 2 - 14;
265	old_rec_off = tree->node_size - 4;
266	num_recs = 1;
267	for (;;) {
268		data_start = hfs_bnode_read_u16(node, old_rec_off);
269		if (data_start > size)
270			break;
271		old_rec_off -= 2;
272		if (++num_recs < node->num_recs)
273			continue;
274		/* panic? */
275		hfs_bnode_put(node);
276		hfs_bnode_put(new_node);
277		if (next_node)
278			hfs_bnode_put(next_node);
279		return ERR_PTR(-ENOSPC);
280	}
281
282	if (fd->record + 1 < num_recs) {
283		/* new record is in the lower half,
284		 * so leave some more space there
285		 */
286		old_rec_off += 2;
287		num_recs--;
288		data_start = hfs_bnode_read_u16(node, old_rec_off);
289	} else {
290		hfs_bnode_put(node);
291		hfs_bnode_get(new_node);
292		fd->bnode = new_node;
293		fd->record -= num_recs;
294		fd->keyoffset -= data_start - 14;
295		fd->entryoffset -= data_start - 14;
296	}
297	new_node->num_recs = node->num_recs - num_recs;
298	node->num_recs = num_recs;
299
300	new_rec_off = tree->node_size - 2;
301	new_off = 14;
302	size = data_start - new_off;
303	num_recs = new_node->num_recs;
304	data_end = data_start;
305	while (num_recs) {
306		hfs_bnode_write_u16(new_node, new_rec_off, new_off);
307		old_rec_off -= 2;
308		new_rec_off -= 2;
309		data_end = hfs_bnode_read_u16(node, old_rec_off);
310		new_off = data_end - size;
311		num_recs--;
312	}
313	hfs_bnode_write_u16(new_node, new_rec_off, new_off);
314	hfs_bnode_copy(new_node, 14, node, data_start, data_end - data_start);
315
316	/* update new bnode header */
317	node_desc.next = cpu_to_be32(new_node->next);
318	node_desc.prev = cpu_to_be32(new_node->prev);
319	node_desc.type = new_node->type;
320	node_desc.height = new_node->height;
321	node_desc.num_recs = cpu_to_be16(new_node->num_recs);
322	node_desc.reserved = 0;
323	hfs_bnode_write(new_node, &node_desc, 0, sizeof(node_desc));
324
325	/* update previous bnode header */
326	node->next = new_node->this;
327	hfs_bnode_read(node, &node_desc, 0, sizeof(node_desc));
328	node_desc.next = cpu_to_be32(node->next);
329	node_desc.num_recs = cpu_to_be16(node->num_recs);
330	hfs_bnode_write(node, &node_desc, 0, sizeof(node_desc));
331
332	/* update next bnode header */
333	if (next_node) {
334		next_node->prev = new_node->this;
335		hfs_bnode_read(next_node, &node_desc, 0, sizeof(node_desc));
336		node_desc.prev = cpu_to_be32(next_node->prev);
337		hfs_bnode_write(next_node, &node_desc, 0, sizeof(node_desc));
338		hfs_bnode_put(next_node);
339	} else if (node->this == tree->leaf_tail) {
340		/* if there is no next node, this might be the new tail */
341		tree->leaf_tail = new_node->this;
342		mark_inode_dirty(tree->inode);
343	}
344
345	hfs_bnode_dump(node);
346	hfs_bnode_dump(new_node);
347	hfs_bnode_put(node);
348
349	return new_node;
350}
351
352static int hfs_brec_update_parent(struct hfs_find_data *fd)
353{
354	struct hfs_btree *tree;
355	struct hfs_bnode *node, *new_node, *parent;
356	int newkeylen, diff;
357	int rec, rec_off, end_rec_off;
358	int start_off, end_off;
359
360	tree = fd->tree;
361	node = fd->bnode;
362	new_node = NULL;
363	if (!node->parent)
364		return 0;
365
366again:
367	parent = hfs_bnode_find(tree, node->parent);
368	if (IS_ERR(parent))
369		return PTR_ERR(parent);
370	__hfs_brec_find(parent, fd);
371	if (fd->record < 0)
372		return -ENOENT;
373	hfs_bnode_dump(parent);
374	rec = fd->record;
375
376	/* size difference between old and new key */
377	if (tree->attributes & HFS_TREE_VARIDXKEYS)
378		newkeylen = (hfs_bnode_read_u8(node, 14) | 1) + 1;
379	else
380		fd->keylength = newkeylen = tree->max_key_len + 1;
381	hfs_dbg(BNODE_MOD, "update_rec: %d, %d, %d\n",
382		rec, fd->keylength, newkeylen);
383
384	rec_off = tree->node_size - (rec + 2) * 2;
385	end_rec_off = tree->node_size - (parent->num_recs + 1) * 2;
386	diff = newkeylen - fd->keylength;
387	if (!diff)
388		goto skip;
389	if (diff > 0) {
390		end_off = hfs_bnode_read_u16(parent, end_rec_off);
391		if (end_rec_off - end_off < diff) {
392
393			printk(KERN_DEBUG "splitting index node...\n");
394			fd->bnode = parent;
395			new_node = hfs_bnode_split(fd);
396			if (IS_ERR(new_node))
397				return PTR_ERR(new_node);
398			parent = fd->bnode;
399			rec = fd->record;
400			rec_off = tree->node_size - (rec + 2) * 2;
401			end_rec_off = tree->node_size - (parent->num_recs + 1) * 2;
402		}
403	}
404
405	end_off = start_off = hfs_bnode_read_u16(parent, rec_off);
406	hfs_bnode_write_u16(parent, rec_off, start_off + diff);
407	start_off -= 4;	/* move previous cnid too */
408
409	while (rec_off > end_rec_off) {
410		rec_off -= 2;
411		end_off = hfs_bnode_read_u16(parent, rec_off);
412		hfs_bnode_write_u16(parent, rec_off, end_off + diff);
413	}
414	hfs_bnode_move(parent, start_off + diff, start_off,
415		       end_off - start_off);
416skip:
417	hfs_bnode_copy(parent, fd->keyoffset, node, 14, newkeylen);
418	if (!(tree->attributes & HFS_TREE_VARIDXKEYS))
419		hfs_bnode_write_u8(parent, fd->keyoffset, newkeylen - 1);
420	hfs_bnode_dump(parent);
421
422	hfs_bnode_put(node);
423	node = parent;
424
425	if (new_node) {
426		__be32 cnid;
427
428		if (!new_node->parent) {
429			hfs_btree_inc_height(tree);
430			new_node->parent = tree->root;
431		}
432		fd->bnode = hfs_bnode_find(tree, new_node->parent);
433		/* create index key and entry */
434		hfs_bnode_read_key(new_node, fd->search_key, 14);
435		cnid = cpu_to_be32(new_node->this);
436
437		__hfs_brec_find(fd->bnode, fd);
438		hfs_brec_insert(fd, &cnid, sizeof(cnid));
439		hfs_bnode_put(fd->bnode);
440		hfs_bnode_put(new_node);
441
442		if (!rec) {
443			if (new_node == node)
444				goto out;
445			/* restore search_key */
446			hfs_bnode_read_key(node, fd->search_key, 14);
447		}
448		new_node = NULL;
449	}
450
451	if (!rec && node->parent)
452		goto again;
453out:
454	fd->bnode = node;
455	return 0;
456}
457
458static int hfs_btree_inc_height(struct hfs_btree *tree)
459{
460	struct hfs_bnode *node, *new_node;
461	struct hfs_bnode_desc node_desc;
462	int key_size, rec;
463	__be32 cnid;
464
465	node = NULL;
466	if (tree->root) {
467		node = hfs_bnode_find(tree, tree->root);
468		if (IS_ERR(node))
469			return PTR_ERR(node);
470	}
471	new_node = hfs_bmap_alloc(tree);
472	if (IS_ERR(new_node)) {
473		hfs_bnode_put(node);
474		return PTR_ERR(new_node);
475	}
476
477	tree->root = new_node->this;
478	if (!tree->depth) {
479		tree->leaf_head = tree->leaf_tail = new_node->this;
480		new_node->type = HFS_NODE_LEAF;
481		new_node->num_recs = 0;
482	} else {
483		new_node->type = HFS_NODE_INDEX;
484		new_node->num_recs = 1;
485	}
486	new_node->parent = 0;
487	new_node->next = 0;
488	new_node->prev = 0;
489	new_node->height = ++tree->depth;
490
491	node_desc.next = cpu_to_be32(new_node->next);
492	node_desc.prev = cpu_to_be32(new_node->prev);
493	node_desc.type = new_node->type;
494	node_desc.height = new_node->height;
495	node_desc.num_recs = cpu_to_be16(new_node->num_recs);
496	node_desc.reserved = 0;
497	hfs_bnode_write(new_node, &node_desc, 0, sizeof(node_desc));
498
499	rec = tree->node_size - 2;
500	hfs_bnode_write_u16(new_node, rec, 14);
501
502	if (node) {
503		/* insert old root idx into new root */
504		node->parent = tree->root;
505		if (node->type == HFS_NODE_LEAF ||
506		    tree->attributes & HFS_TREE_VARIDXKEYS)
507			key_size = hfs_bnode_read_u8(node, 14) + 1;
508		else
509			key_size = tree->max_key_len + 1;
510		hfs_bnode_copy(new_node, 14, node, 14, key_size);
511
512		if (!(tree->attributes & HFS_TREE_VARIDXKEYS)) {
513			key_size = tree->max_key_len + 1;
514			hfs_bnode_write_u8(new_node, 14, tree->max_key_len);
515		}
516		key_size = (key_size + 1) & -2;
517		cnid = cpu_to_be32(node->this);
518		hfs_bnode_write(new_node, &cnid, 14 + key_size, 4);
519
520		rec -= 2;
521		hfs_bnode_write_u16(new_node, rec, 14 + key_size + 4);
522
523		hfs_bnode_put(node);
524	}
525	hfs_bnode_put(new_node);
526	mark_inode_dirty(tree->inode);
527
528	return 0;
529}