[mirror_ubuntu-hirsute-kernel.git] / fs / hfsplus / bfind.c

// SPDX-License-Identifier: GPL-2.0
/*
 *  linux/fs/hfsplus/bfind.c
 *
 * Copyright (C) 2001
 * Brad Boyer (flar@allandria.com)
 * (C) 2003 Ardis Technologies <roman@ardistech.com>
 *
 * Search routines for btrees
 */

#include <linux/slab.h>
#include "hfsplus_fs.h"

int hfs_find_init(struct hfs_btree *tree, struct hfs_find_data *fd)
{
	void *ptr;

	fd->tree = tree;
	fd->bnode = NULL;
	ptr = kmalloc(tree->max_key_len * 2 + 4, GFP_KERNEL);
	if (!ptr)
		return -ENOMEM;
	fd->search_key = ptr;
	fd->key = ptr + tree->max_key_len + 2;
	hfs_dbg(BNODE_REFS, "find_init: %d (%p)\n",
		tree->cnid, __builtin_return_address(0));
	switch (tree->cnid) {
	case HFSPLUS_CAT_CNID:
		mutex_lock_nested(&tree->tree_lock, CATALOG_BTREE_MUTEX);
		break;
	case HFSPLUS_EXT_CNID:
		mutex_lock_nested(&tree->tree_lock, EXTENTS_BTREE_MUTEX);
		break;
	case HFSPLUS_ATTR_CNID:
		mutex_lock_nested(&tree->tree_lock, ATTR_BTREE_MUTEX);
		break;
	default:
		BUG();
	}
	return 0;
}

void hfs_find_exit(struct hfs_find_data *fd)
{
	hfs_bnode_put(fd->bnode);
	kfree(fd->search_key);
	hfs_dbg(BNODE_REFS, "find_exit: %d (%p)\n",
		fd->tree->cnid, __builtin_return_address(0));
	mutex_unlock(&fd->tree->tree_lock);
	fd->tree = NULL;
}

int hfs_find_1st_rec_by_cnid(struct hfs_bnode *bnode,
				struct hfs_find_data *fd,
				int *begin,
				int *end,
				int *cur_rec)
{
	__be32 cur_cnid;
	__be32 search_cnid;

	if (bnode->tree->cnid == HFSPLUS_EXT_CNID) {
		cur_cnid = fd->key->ext.cnid;
		search_cnid = fd->search_key->ext.cnid;
	} else if (bnode->tree->cnid == HFSPLUS_CAT_CNID) {
		cur_cnid = fd->key->cat.parent;
		search_cnid = fd->search_key->cat.parent;
	} else if (bnode->tree->cnid == HFSPLUS_ATTR_CNID) {
		cur_cnid = fd->key->attr.cnid;
		search_cnid = fd->search_key->attr.cnid;
	} else {
		cur_cnid = 0;	/* used-uninitialized warning */
		search_cnid = 0;
		BUG();
	}

	if (cur_cnid == search_cnid) {
		(*end) = (*cur_rec);
		if ((*begin) == (*end))
			return 1;
	} else {
		if (be32_to_cpu(cur_cnid) < be32_to_cpu(search_cnid))
			(*begin) = (*cur_rec) + 1;
		else
			(*end) = (*cur_rec) - 1;
	}

	return 0;
}

int hfs_find_rec_by_key(struct hfs_bnode *bnode,
				struct hfs_find_data *fd,
				int *begin,
				int *end,
				int *cur_rec)
{
	int cmpval;

	cmpval = bnode->tree->keycmp(fd->key, fd->search_key);
	if (!cmpval) {
		(*end) = (*cur_rec);
		return 1;
	}
	if (cmpval < 0)
		(*begin) = (*cur_rec) + 1;
	else
		*(end) = (*cur_rec) - 1;

	return 0;
}

/* Find the record in bnode that best matches key (not greater than...)*/
int __hfs_brec_find(struct hfs_bnode *bnode, struct hfs_find_data *fd,
					search_strategy_t rec_found)
{
	u16 off, len, keylen;
	int rec;
	int b, e;
	int res;

	BUG_ON(!rec_found);
	b = 0;
	e = bnode->num_recs - 1;
	res = -ENOENT;
	do {
		rec = (e + b) / 2;
		len = hfs_brec_lenoff(bnode, rec, &off);
		keylen = hfs_brec_keylen(bnode, rec);
		if (keylen == 0) {
			res = -EINVAL;
			goto fail;
		}
		hfs_bnode_read(bnode, fd->key, off, keylen);
		if (rec_found(bnode, fd, &b, &e, &rec)) {
			res = 0;
			goto done;
		}
	} while (b <= e);

	if (rec != e && e >= 0) {
		len = hfs_brec_lenoff(bnode, e, &off);
		keylen = hfs_brec_keylen(bnode, e);
		if (keylen == 0) {
			res = -EINVAL;
			goto fail;
		}
		hfs_bnode_read(bnode, fd->key, off, keylen);
	}

done:
	fd->record = e;
	fd->keyoffset = off;
	fd->keylength = keylen;
	fd->entryoffset = off + keylen;
	fd->entrylength = len - keylen;

fail:
	return res;
}

/* Traverse a B*Tree from the root to a leaf finding best fit to key */
/* Return allocated copy of node found, set recnum to best record */
int hfs_brec_find(struct hfs_find_data *fd, search_strategy_t do_key_compare)
{
	struct hfs_btree *tree;
	struct hfs_bnode *bnode;
	u32 nidx, parent;
	__be32 data;
	int height, res;

	tree = fd->tree;
	if (fd->bnode)
		hfs_bnode_put(fd->bnode);
	fd->bnode = NULL;
	nidx = tree->root;
	if (!nidx)
		return -ENOENT;
	height = tree->depth;
	res = 0;
	parent = 0;
	for (;;) {
		bnode = hfs_bnode_find(tree, nidx);
		if (IS_ERR(bnode)) {
			res = PTR_ERR(bnode);
			bnode = NULL;
			break;
		}
		if (bnode->height != height)
			goto invalid;
		if (bnode->type != (--height ? HFS_NODE_INDEX : HFS_NODE_LEAF))
			goto invalid;
		bnode->parent = parent;

		res = __hfs_brec_find(bnode, fd, do_key_compare);
		if (!height)
			break;
		if (fd->record < 0)
			goto release;

		parent = nidx;
		hfs_bnode_read(bnode, &data, fd->entryoffset, 4);
		nidx = be32_to_cpu(data);
		hfs_bnode_put(bnode);
	}
	fd->bnode = bnode;
	return res;

invalid:
	pr_err("inconsistency in B*Tree (%d,%d,%d,%u,%u)\n",
		height, bnode->height, bnode->type, nidx, parent);
	res = -EIO;
release:
	hfs_bnode_put(bnode);
	return res;
}

int hfs_brec_read(struct hfs_find_data *fd, void *rec, int rec_len)
{
	int res;

	res = hfs_brec_find(fd, hfs_find_rec_by_key);
	if (res)
		return res;
	if (fd->entrylength > rec_len)
		return -EINVAL;
	hfs_bnode_read(fd->bnode, rec, fd->entryoffset, fd->entrylength);
	return 0;
}

int hfs_brec_goto(struct hfs_find_data *fd, int cnt)
{
	struct hfs_btree *tree;
	struct hfs_bnode *bnode;
	int idx, res = 0;
	u16 off, len, keylen;

	bnode = fd->bnode;
	tree = bnode->tree;

	if (cnt < 0) {
		cnt = -cnt;
		while (cnt > fd->record) {
			cnt -= fd->record + 1;
			fd->record = bnode->num_recs - 1;
			idx = bnode->prev;
			if (!idx) {
				res = -ENOENT;
				goto out;
			}
			hfs_bnode_put(bnode);
			bnode = hfs_bnode_find(tree, idx);
			if (IS_ERR(bnode)) {
				res = PTR_ERR(bnode);
				bnode = NULL;
				goto out;
			}
		}
		fd->record -= cnt;
	} else {
		while (cnt >= bnode->num_recs - fd->record) {
			cnt -= bnode->num_recs - fd->record;
			fd->record = 0;
			idx = bnode->next;
			if (!idx) {
				res = -ENOENT;
				goto out;
			}
			hfs_bnode_put(bnode);
			bnode = hfs_bnode_find(tree, idx);
			if (IS_ERR(bnode)) {
				res = PTR_ERR(bnode);
				bnode = NULL;
				goto out;
			}
		}
		fd->record += cnt;
	}

	len = hfs_brec_lenoff(bnode, fd->record, &off);
	keylen = hfs_brec_keylen(bnode, fd->record);
	if (keylen == 0) {
		res = -EINVAL;
		goto out;
	}
	fd->keyoffset = off;
	fd->keylength = keylen;
	fd->entryoffset = off + keylen;
	fd->entrylength = len - keylen;
	hfs_bnode_read(bnode, fd->key, off, keylen);
out:
	fd->bnode = bnode;
	return res;
}
Commit	Line	Data
b2441318	1	// SPDX-License-Identifier: GPL-2.0
1da177e4 LT	2	/*
	3	* linux/fs/hfsplus/bfind.c
	4	*
	5	* Copyright (C) 2001
	6	* Brad Boyer (flar@allandria.com)
	7	* (C) 2003 Ardis Technologies <roman@ardistech.com>
	8	*
	9	* Search routines for btrees
	10	*/
	11
	12	#include <linux/slab.h>
	13	#include "hfsplus_fs.h"
	14
	15	int hfs_find_init(struct hfs_btree tree, struct hfs_find_data fd)
	16	{
	17	void *ptr;
	18
	19	fd->tree = tree;
	20	fd->bnode = NULL;
	21	ptr = kmalloc(tree->max_key_len * 2 + 4, GFP_KERNEL);
	22	if (!ptr)
	23	return -ENOMEM;
	24	fd->search_key = ptr;
	25	fd->key = ptr + tree->max_key_len + 2;
c2b3e1f7	26	hfs_dbg(BNODE_REFS, "find_init: %d (%p)\n",
2753cc28	27	tree->cnid, __builtin_return_address(0));
324ef39a VD	28	switch (tree->cnid) {
	29	case HFSPLUS_CAT_CNID:
	30	mutex_lock_nested(&tree->tree_lock, CATALOG_BTREE_MUTEX);
	31	break;
	32	case HFSPLUS_EXT_CNID:
	33	mutex_lock_nested(&tree->tree_lock, EXTENTS_BTREE_MUTEX);
	34	break;
	35	case HFSPLUS_ATTR_CNID:
	36	mutex_lock_nested(&tree->tree_lock, ATTR_BTREE_MUTEX);
	37	break;
	38	default:
	39	BUG();
	40	}
1da177e4 LT	41	return 0;
	42	}
	43
	44	void hfs_find_exit(struct hfs_find_data *fd)
	45	{
	46	hfs_bnode_put(fd->bnode);
	47	kfree(fd->search_key);
c2b3e1f7	48	hfs_dbg(BNODE_REFS, "find_exit: %d (%p)\n",
2753cc28	49	fd->tree->cnid, __builtin_return_address(0));
467c3d9c	50	mutex_unlock(&fd->tree->tree_lock);
1da177e4 LT	51	fd->tree = NULL;
	52	}
	53
324ef39a VD	54	int hfs_find_1st_rec_by_cnid(struct hfs_bnode *bnode,
	55	struct hfs_find_data *fd,
	56	int *begin,
	57	int *end,
	58	int *cur_rec)
	59	{
5f3726f9 VD	60	__be32 cur_cnid;
5f3726f9 VD	61	__be32 search_cnid;
324ef39a VD	62
	63	if (bnode->tree->cnid == HFSPLUS_EXT_CNID) {
	64	cur_cnid = fd->key->ext.cnid;
	65	search_cnid = fd->search_key->ext.cnid;
	66	} else if (bnode->tree->cnid == HFSPLUS_CAT_CNID) {
	67	cur_cnid = fd->key->cat.parent;
	68	search_cnid = fd->search_key->cat.parent;
	69	} else if (bnode->tree->cnid == HFSPLUS_ATTR_CNID) {
	70	cur_cnid = fd->key->attr.cnid;
	71	search_cnid = fd->search_key->attr.cnid;
5f3726f9 VD	72	} else {
	73	cur_cnid = 0; /* used-uninitialized warning */
	74	search_cnid = 0;
324ef39a	75	BUG();
5f3726f9	76	}
324ef39a VD	77
	78	if (cur_cnid == search_cnid) {
	79	(end) = (cur_rec);
	80	if ((begin) == (end))
	81	return 1;
	82	} else {
	83	if (be32_to_cpu(cur_cnid) < be32_to_cpu(search_cnid))
	84	(begin) = (cur_rec) + 1;
	85	else
	86	(end) = (cur_rec) - 1;
	87	}
	88
	89	return 0;
	90	}
	91
	92	int hfs_find_rec_by_key(struct hfs_bnode *bnode,
	93	struct hfs_find_data *fd,
	94	int *begin,
	95	int *end,
	96	int *cur_rec)
1da177e4 LT	97	{
1da177e4 LT	98	int cmpval;
324ef39a VD	99
	100	cmpval = bnode->tree->keycmp(fd->key, fd->search_key);
	101	if (!cmpval) {
	102	(end) = (cur_rec);
	103	return 1;
	104	}
	105	if (cmpval < 0)
	106	(begin) = (cur_rec) + 1;
	107	else
	108	(end) = (cur_rec) - 1;
	109
	110	return 0;
	111	}
	112
	113	/* Find the record in bnode that best matches key (not greater than...)*/
	114	int __hfs_brec_find(struct hfs_bnode bnode, struct hfs_find_data fd,
	115	search_strategy_t rec_found)
	116	{
1da177e4 LT	117	u16 off, len, keylen;
	118	int rec;
	119	int b, e;
	120	int res;
	121
7ce844a2	122	BUG_ON(!rec_found);
1da177e4 LT	123	b = 0;
	124	e = bnode->num_recs - 1;
	125	res = -ENOENT;
	126	do {
	127	rec = (e + b) / 2;
	128	len = hfs_brec_lenoff(bnode, rec, &off);
	129	keylen = hfs_brec_keylen(bnode, rec);
9250f925 ES	130	if (keylen == 0) {
	131	res = -EINVAL;
	132	goto fail;
	133	}
1da177e4	134	hfs_bnode_read(bnode, fd->key, off, keylen);
324ef39a	135	if (rec_found(bnode, fd, &b, &e, &rec)) {
1da177e4 LT	136	res = 0;
	137	goto done;
	138	}
1da177e4	139	} while (b <= e);
324ef39a	140
1da177e4 LT	141	if (rec != e && e >= 0) {
	142	len = hfs_brec_lenoff(bnode, e, &off);
	143	keylen = hfs_brec_keylen(bnode, e);
9250f925 ES	144	if (keylen == 0) {
	145	res = -EINVAL;
	146	goto fail;
	147	}
1da177e4 LT	148	hfs_bnode_read(bnode, fd->key, off, keylen);
1da177e4 LT	149	}
324ef39a	150
1da177e4 LT	151	done:
	152	fd->record = e;
	153	fd->keyoffset = off;
	154	fd->keylength = keylen;
	155	fd->entryoffset = off + keylen;
	156	fd->entrylength = len - keylen;
324ef39a	157
9250f925	158	fail:
1da177e4 LT	159	return res;
	160	}
	161
	162	/* Traverse a BTree from the root to a leaf finding best fit to key /
	163	/* Return allocated copy of node found, set recnum to best record */
324ef39a	164	int hfs_brec_find(struct hfs_find_data *fd, search_strategy_t do_key_compare)
1da177e4 LT	165	{
	166	struct hfs_btree *tree;
	167	struct hfs_bnode *bnode;
	168	u32 nidx, parent;
	169	__be32 data;
	170	int height, res;
	171
	172	tree = fd->tree;
	173	if (fd->bnode)
	174	hfs_bnode_put(fd->bnode);
	175	fd->bnode = NULL;
	176	nidx = tree->root;
	177	if (!nidx)
	178	return -ENOENT;
	179	height = tree->depth;
	180	res = 0;
	181	parent = 0;
	182	for (;;) {
	183	bnode = hfs_bnode_find(tree, nidx);
	184	if (IS_ERR(bnode)) {
	185	res = PTR_ERR(bnode);
	186	bnode = NULL;
	187	break;
	188	}
	189	if (bnode->height != height)
	190	goto invalid;
	191	if (bnode->type != (--height ? HFS_NODE_INDEX : HFS_NODE_LEAF))
	192	goto invalid;
	193	bnode->parent = parent;
	194
324ef39a	195	res = __hfs_brec_find(bnode, fd, do_key_compare);
1da177e4 LT	196	if (!height)
	197	break;
	198	if (fd->record < 0)
	199	goto release;
	200
	201	parent = nidx;
	202	hfs_bnode_read(bnode, &data, fd->entryoffset, 4);
	203	nidx = be32_to_cpu(data);
	204	hfs_bnode_put(bnode);
	205	}
	206	fd->bnode = bnode;
	207	return res;
	208
	209	invalid:
d6142673	210	pr_err("inconsistency in B*Tree (%d,%d,%d,%u,%u)\n",
1da177e4 LT	211	height, bnode->height, bnode->type, nidx, parent);
	212	res = -EIO;
	213	release:
	214	hfs_bnode_put(bnode);
	215	return res;
	216	}
	217
	218	int hfs_brec_read(struct hfs_find_data fd, void rec, int rec_len)
	219	{
	220	int res;
	221
324ef39a	222	res = hfs_brec_find(fd, hfs_find_rec_by_key);
1da177e4 LT	223	if (res)
	224	return res;
	225	if (fd->entrylength > rec_len)
	226	return -EINVAL;
	227	hfs_bnode_read(fd->bnode, rec, fd->entryoffset, fd->entrylength);
	228	return 0;
	229	}
	230
	231	int hfs_brec_goto(struct hfs_find_data *fd, int cnt)
	232	{
	233	struct hfs_btree *tree;
	234	struct hfs_bnode *bnode;
	235	int idx, res = 0;
	236	u16 off, len, keylen;
	237
	238	bnode = fd->bnode;
	239	tree = bnode->tree;
	240
	241	if (cnt < 0) {
	242	cnt = -cnt;
	243	while (cnt > fd->record) {
	244	cnt -= fd->record + 1;
	245	fd->record = bnode->num_recs - 1;
	246	idx = bnode->prev;
	247	if (!idx) {
	248	res = -ENOENT;
	249	goto out;
	250	}
	251	hfs_bnode_put(bnode);
	252	bnode = hfs_bnode_find(tree, idx);
	253	if (IS_ERR(bnode)) {
	254	res = PTR_ERR(bnode);
	255	bnode = NULL;
	256	goto out;
	257	}
	258	}
	259	fd->record -= cnt;
	260	} else {
	261	while (cnt >= bnode->num_recs - fd->record) {
	262	cnt -= bnode->num_recs - fd->record;
	263	fd->record = 0;
	264	idx = bnode->next;
	265	if (!idx) {
	266	res = -ENOENT;
	267	goto out;
	268	}
	269	hfs_bnode_put(bnode);
	270	bnode = hfs_bnode_find(tree, idx);
	271	if (IS_ERR(bnode)) {
	272	res = PTR_ERR(bnode);
	273	bnode = NULL;
	274	goto out;
	275	}
	276	}
	277	fd->record += cnt;
	278	}
	279
	280	len = hfs_brec_lenoff(bnode, fd->record, &off);
	281	keylen = hfs_brec_keylen(bnode, fd->record);
9250f925 ES	282	if (keylen == 0) {
	283	res = -EINVAL;
	284	goto out;
	285	}
1da177e4 LT	286	fd->keyoffset = off;
	287	fd->keylength = keylen;
	288	fd->entryoffset = off + keylen;
	289	fd->entrylength = len - keylen;
	290	hfs_bnode_read(bnode, fd->key, off, keylen);
	291	out:
	292	fd->bnode = bnode;
	293	return res;
	294	}