[thirdparty/u-boot.git] / fs / ubifs / tnc_misc.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * This file is part of UBIFS.
 *
 * Copyright (C) 2006-2008 Nokia Corporation.
 *
 * Authors: Adrian Hunter
 *          Artem Bityutskiy (Битюцкий Артём)
 */

/*
 * This file contains miscelanious TNC-related functions shared betweend
 * different files. This file does not form any logically separate TNC
 * sub-system. The file was created because there is a lot of TNC code and
 * putting it all in one file would make that file too big and unreadable.
 */

#ifdef __UBOOT__
#include <linux/err.h>
#endif
#include "ubifs.h"

/**
 * ubifs_tnc_levelorder_next - next TNC tree element in levelorder traversal.
 * @zr: root of the subtree to traverse
 * @znode: previous znode
 *
 * This function implements levelorder TNC traversal. The LNC is ignored.
 * Returns the next element or %NULL if @znode is already the last one.
 */
struct ubifs_znode *ubifs_tnc_levelorder_next(struct ubifs_znode *zr,
					      struct ubifs_znode *znode)
{
	int level, iip, level_search = 0;
	struct ubifs_znode *zn;

	ubifs_assert(zr);

	if (unlikely(!znode))
		return zr;

	if (unlikely(znode == zr)) {
		if (znode->level == 0)
			return NULL;
		return ubifs_tnc_find_child(zr, 0);
	}

	level = znode->level;

	iip = znode->iip;
	while (1) {
		ubifs_assert(znode->level <= zr->level);

		/*
		 * First walk up until there is a znode with next branch to
		 * look at.
		 */
		while (znode->parent != zr && iip >= znode->parent->child_cnt) {
			znode = znode->parent;
			iip = znode->iip;
		}

		if (unlikely(znode->parent == zr &&
			     iip >= znode->parent->child_cnt)) {
			/* This level is done, switch to the lower one */
			level -= 1;
			if (level_search || level < 0)
				/*
				 * We were already looking for znode at lower
				 * level ('level_search'). As we are here
				 * again, it just does not exist. Or all levels
				 * were finished ('level < 0').
				 */
				return NULL;

			level_search = 1;
			iip = -1;
			znode = ubifs_tnc_find_child(zr, 0);
			ubifs_assert(znode);
		}

		/* Switch to the next index */
		zn = ubifs_tnc_find_child(znode->parent, iip + 1);
		if (!zn) {
			/* No more children to look at, we have walk up */
			iip = znode->parent->child_cnt;
			continue;
		}

		/* Walk back down to the level we came from ('level') */
		while (zn->level != level) {
			znode = zn;
			zn = ubifs_tnc_find_child(zn, 0);
			if (!zn) {
				/*
				 * This path is not too deep so it does not
				 * reach 'level'. Try next path.
				 */
				iip = znode->iip;
				break;
			}
		}

		if (zn) {
			ubifs_assert(zn->level >= 0);
			return zn;
		}
	}
}

/**
 * ubifs_search_zbranch - search znode branch.
 * @c: UBIFS file-system description object
 * @znode: znode to search in
 * @key: key to search for
 * @n: znode branch slot number is returned here
 *
 * This is a helper function which search branch with key @key in @znode using
 * binary search. The result of the search may be:
 *   o exact match, then %1 is returned, and the slot number of the branch is
 *     stored in @n;
 *   o no exact match, then %0 is returned and the slot number of the left
 *     closest branch is returned in @n; the slot if all keys in this znode are
 *     greater than @key, then %-1 is returned in @n.
 */
int ubifs_search_zbranch(const struct ubifs_info *c,
			 const struct ubifs_znode *znode,
			 const union ubifs_key *key, int *n)
{
	int beg = 0, end = znode->child_cnt, uninitialized_var(mid);
	int uninitialized_var(cmp);
	const struct ubifs_zbranch *zbr = &znode->zbranch[0];

	ubifs_assert(end > beg);

	while (end > beg) {
		mid = (beg + end) >> 1;
		cmp = keys_cmp(c, key, &zbr[mid].key);
		if (cmp > 0)
			beg = mid + 1;
		else if (cmp < 0)
			end = mid;
		else {
			*n = mid;
			return 1;
		}
	}

	*n = end - 1;

	/* The insert point is after *n */
	ubifs_assert(*n >= -1 && *n < znode->child_cnt);
	if (*n == -1)
		ubifs_assert(keys_cmp(c, key, &zbr[0].key) < 0);
	else
		ubifs_assert(keys_cmp(c, key, &zbr[*n].key) > 0);
	if (*n + 1 < znode->child_cnt)
		ubifs_assert(keys_cmp(c, key, &zbr[*n + 1].key) < 0);

	return 0;
}

/**
 * ubifs_tnc_postorder_first - find first znode to do postorder tree traversal.
 * @znode: znode to start at (root of the sub-tree to traverse)
 *
 * Find the lowest leftmost znode in a subtree of the TNC tree. The LNC is
 * ignored.
 */
struct ubifs_znode *ubifs_tnc_postorder_first(struct ubifs_znode *znode)
{
	if (unlikely(!znode))
		return NULL;

	while (znode->level > 0) {
		struct ubifs_znode *child;

		child = ubifs_tnc_find_child(znode, 0);
		if (!child)
			return znode;
		znode = child;
	}

	return znode;
}

/**
 * ubifs_tnc_postorder_next - next TNC tree element in postorder traversal.
 * @znode: previous znode
 *
 * This function implements postorder TNC traversal. The LNC is ignored.
 * Returns the next element or %NULL if @znode is already the last one.
 */
struct ubifs_znode *ubifs_tnc_postorder_next(struct ubifs_znode *znode)
{
	struct ubifs_znode *zn;

	ubifs_assert(znode);
	if (unlikely(!znode->parent))
		return NULL;

	/* Switch to the next index in the parent */
	zn = ubifs_tnc_find_child(znode->parent, znode->iip + 1);
	if (!zn)
		/* This is in fact the last child, return parent */
		return znode->parent;

	/* Go to the first znode in this new subtree */
	return ubifs_tnc_postorder_first(zn);
}

/**
 * ubifs_destroy_tnc_subtree - destroy all znodes connected to a subtree.
 * @znode: znode defining subtree to destroy
 *
 * This function destroys subtree of the TNC tree. Returns number of clean
 * znodes in the subtree.
 */
long ubifs_destroy_tnc_subtree(struct ubifs_znode *znode)
{
	struct ubifs_znode *zn = ubifs_tnc_postorder_first(znode);
	long clean_freed = 0;
	int n;

	ubifs_assert(zn);
	while (1) {
		for (n = 0; n < zn->child_cnt; n++) {
			if (!zn->zbranch[n].znode)
				continue;

			if (zn->level > 0 &&
			    !ubifs_zn_dirty(zn->zbranch[n].znode))
				clean_freed += 1;

			cond_resched();
			kfree(zn->zbranch[n].znode);
		}

		if (zn == znode) {
			if (!ubifs_zn_dirty(zn))
				clean_freed += 1;
			kfree(zn);
			return clean_freed;
		}

		zn = ubifs_tnc_postorder_next(zn);
	}
}

/**
 * read_znode - read an indexing node from flash and fill znode.
 * @c: UBIFS file-system description object
 * @lnum: LEB of the indexing node to read
 * @offs: node offset
 * @len: node length
 * @znode: znode to read to
 *
 * This function reads an indexing node from the flash media and fills znode
 * with the read data. Returns zero in case of success and a negative error
 * code in case of failure. The read indexing node is validated and if anything
 * is wrong with it, this function prints complaint messages and returns
 * %-EINVAL.
 */
static int read_znode(struct ubifs_info *c, int lnum, int offs, int len,
		      struct ubifs_znode *znode)
{
	int i, err, type, cmp;
	struct ubifs_idx_node *idx;

	idx = kmalloc(c->max_idx_node_sz, GFP_NOFS);
	if (!idx)
		return -ENOMEM;

	err = ubifs_read_node(c, idx, UBIFS_IDX_NODE, len, lnum, offs);
	if (err < 0) {
		kfree(idx);
		return err;
	}

	znode->child_cnt = le16_to_cpu(idx->child_cnt);
	znode->level = le16_to_cpu(idx->level);

	dbg_tnc("LEB %d:%d, level %d, %d branch",
		lnum, offs, znode->level, znode->child_cnt);

	if (znode->child_cnt > c->fanout || znode->level > UBIFS_MAX_LEVELS) {
		ubifs_err(c, "current fanout %d, branch count %d",
			  c->fanout, znode->child_cnt);
		ubifs_err(c, "max levels %d, znode level %d",
			  UBIFS_MAX_LEVELS, znode->level);
		err = 1;
		goto out_dump;
	}

	for (i = 0; i < znode->child_cnt; i++) {
		const struct ubifs_branch *br = ubifs_idx_branch(c, idx, i);
		struct ubifs_zbranch *zbr = &znode->zbranch[i];

		key_read(c, &br->key, &zbr->key);
		zbr->lnum = le32_to_cpu(br->lnum);
		zbr->offs = le32_to_cpu(br->offs);
		zbr->len  = le32_to_cpu(br->len);
		zbr->znode = NULL;

		/* Validate branch */

		if (zbr->lnum < c->main_first ||
		    zbr->lnum >= c->leb_cnt || zbr->offs < 0 ||
		    zbr->offs + zbr->len > c->leb_size || zbr->offs & 7) {
			ubifs_err(c, "bad branch %d", i);
			err = 2;
			goto out_dump;
		}

		switch (key_type(c, &zbr->key)) {
		case UBIFS_INO_KEY:
		case UBIFS_DATA_KEY:
		case UBIFS_DENT_KEY:
		case UBIFS_XENT_KEY:
			break;
		default:
			ubifs_err(c, "bad key type at slot %d: %d",
				  i, key_type(c, &zbr->key));
			err = 3;
			goto out_dump;
		}

		if (znode->level)
			continue;

		type = key_type(c, &zbr->key);
		if (c->ranges[type].max_len == 0) {
			if (zbr->len != c->ranges[type].len) {
				ubifs_err(c, "bad target node (type %d) length (%d)",
					  type, zbr->len);
				ubifs_err(c, "have to be %d", c->ranges[type].len);
				err = 4;
				goto out_dump;
			}
		} else if (zbr->len < c->ranges[type].min_len ||
			   zbr->len > c->ranges[type].max_len) {
			ubifs_err(c, "bad target node (type %d) length (%d)",
				  type, zbr->len);
			ubifs_err(c, "have to be in range of %d-%d",
				  c->ranges[type].min_len,
				  c->ranges[type].max_len);
			err = 5;
			goto out_dump;
		}
	}

	/*
	 * Ensure that the next key is greater or equivalent to the
	 * previous one.
	 */
	for (i = 0; i < znode->child_cnt - 1; i++) {
		const union ubifs_key *key1, *key2;

		key1 = &znode->zbranch[i].key;
		key2 = &znode->zbranch[i + 1].key;

		cmp = keys_cmp(c, key1, key2);
		if (cmp > 0) {
			ubifs_err(c, "bad key order (keys %d and %d)", i, i + 1);
			err = 6;
			goto out_dump;
		} else if (cmp == 0 && !is_hash_key(c, key1)) {
			/* These can only be keys with colliding hash */
			ubifs_err(c, "keys %d and %d are not hashed but equivalent",
				  i, i + 1);
			err = 7;
			goto out_dump;
		}
	}

	kfree(idx);
	return 0;

out_dump:
	ubifs_err(c, "bad indexing node at LEB %d:%d, error %d", lnum, offs, err);
	ubifs_dump_node(c, idx);
	kfree(idx);
	return -EINVAL;
}

/**
 * ubifs_load_znode - load znode to TNC cache.
 * @c: UBIFS file-system description object
 * @zbr: znode branch
 * @parent: znode's parent
 * @iip: index in parent
 *
 * This function loads znode pointed to by @zbr into the TNC cache and
 * returns pointer to it in case of success and a negative error code in case
 * of failure.
 */
struct ubifs_znode *ubifs_load_znode(struct ubifs_info *c,
				     struct ubifs_zbranch *zbr,
				     struct ubifs_znode *parent, int iip)
{
	int err;
	struct ubifs_znode *znode;

	ubifs_assert(!zbr->znode);
	/*
	 * A slab cache is not presently used for znodes because the znode size
	 * depends on the fanout which is stored in the superblock.
	 */
	znode = kzalloc(c->max_znode_sz, GFP_NOFS);
	if (!znode)
		return ERR_PTR(-ENOMEM);

	err = read_znode(c, zbr->lnum, zbr->offs, zbr->len, znode);
	if (err)
		goto out;

	atomic_long_inc(&c->clean_zn_cnt);

	/*
	 * Increment the global clean znode counter as well. It is OK that
	 * global and per-FS clean znode counters may be inconsistent for some
	 * short time (because we might be preempted at this point), the global
	 * one is only used in shrinker.
	 */
	atomic_long_inc(&ubifs_clean_zn_cnt);

	zbr->znode = znode;
	znode->parent = parent;
	znode->time = get_seconds();
	znode->iip = iip;

	return znode;

out:
	kfree(znode);
	return ERR_PTR(err);
}

/**
 * ubifs_tnc_read_node - read a leaf node from the flash media.
 * @c: UBIFS file-system description object
 * @zbr: key and position of the node
 * @node: node is returned here
 *
 * This function reads a node defined by @zbr from the flash media. Returns
 * zero in case of success or a negative negative error code in case of
 * failure.
 */
int ubifs_tnc_read_node(struct ubifs_info *c, struct ubifs_zbranch *zbr,
			void *node)
{
	union ubifs_key key1, *key = &zbr->key;
	int err, type = key_type(c, key);
	struct ubifs_wbuf *wbuf;

	/*
	 * 'zbr' has to point to on-flash node. The node may sit in a bud and
	 * may even be in a write buffer, so we have to take care about this.
	 */
	wbuf = ubifs_get_wbuf(c, zbr->lnum);
	if (wbuf)
		err = ubifs_read_node_wbuf(wbuf, node, type, zbr->len,
					   zbr->lnum, zbr->offs);
	else
		err = ubifs_read_node(c, node, type, zbr->len, zbr->lnum,
				      zbr->offs);

	if (err) {
		dbg_tnck(key, "key ");
		return err;
	}

	/* Make sure the key of the read node is correct */
	key_read(c, node + UBIFS_KEY_OFFSET, &key1);
	if (!keys_eq(c, key, &key1)) {
		ubifs_err(c, "bad key in node at LEB %d:%d",
			  zbr->lnum, zbr->offs);
		dbg_tnck(key, "looked for key ");
		dbg_tnck(&key1, "but found node's key ");
		ubifs_dump_node(c, node);
		return -EINVAL;
	}

	return 0;
}
Commit	Line	Data
83d290c5	1	// SPDX-License-Identifier: GPL-2.0+
9eefe2a2 SR	2	/*
	3	* This file is part of UBIFS.
	4	*
	5	* Copyright (C) 2006-2008 Nokia Corporation.
	6	*
9eefe2a2 SR	7	* Authors: Adrian Hunter
	8	* Artem Bityutskiy (Битюцкий Артём)
	9	*/
	10
	11	/*
	12	* This file contains miscelanious TNC-related functions shared betweend
	13	* different files. This file does not form any logically separate TNC
	14	* sub-system. The file was created because there is a lot of TNC code and
	15	* putting it all in one file would make that file too big and unreadable.
	16	*/
	17
ff94bc40 HS	18	#ifdef __UBOOT__
	19	#include <linux/err.h>
	20	#endif
9eefe2a2 SR	21	#include "ubifs.h"
	22
	23	/**
	24	* ubifs_tnc_levelorder_next - next TNC tree element in levelorder traversal.
	25	* @zr: root of the subtree to traverse
	26	* @znode: previous znode
	27	*
	28	* This function implements levelorder TNC traversal. The LNC is ignored.
	29	* Returns the next element or %NULL if @znode is already the last one.
	30	*/
	31	struct ubifs_znode ubifs_tnc_levelorder_next(struct ubifs_znode zr,
	32	struct ubifs_znode *znode)
	33	{
	34	int level, iip, level_search = 0;
	35	struct ubifs_znode *zn;
	36
	37	ubifs_assert(zr);
	38
	39	if (unlikely(!znode))
	40	return zr;
	41
	42	if (unlikely(znode == zr)) {
	43	if (znode->level == 0)
	44	return NULL;
	45	return ubifs_tnc_find_child(zr, 0);
	46	}
	47
	48	level = znode->level;
	49
	50	iip = znode->iip;
	51	while (1) {
	52	ubifs_assert(znode->level <= zr->level);
	53
	54	/*
	55	* First walk up until there is a znode with next branch to
	56	* look at.
	57	*/
	58	while (znode->parent != zr && iip >= znode->parent->child_cnt) {
	59	znode = znode->parent;
	60	iip = znode->iip;
	61	}
	62
	63	if (unlikely(znode->parent == zr &&
	64	iip >= znode->parent->child_cnt)) {
	65	/* This level is done, switch to the lower one */
	66	level -= 1;
	67	if (level_search \|\| level < 0)
	68	/*
	69	* We were already looking for znode at lower
	70	* level ('level_search'). As we are here
	71	* again, it just does not exist. Or all levels
	72	* were finished ('level < 0').
	73	*/
	74	return NULL;
	75
	76	level_search = 1;
	77	iip = -1;
	78	znode = ubifs_tnc_find_child(zr, 0);
	79	ubifs_assert(znode);
	80	}
	81
	82	/* Switch to the next index */
	83	zn = ubifs_tnc_find_child(znode->parent, iip + 1);
	84	if (!zn) {
85	/* No more children to look at, we have walk up */
86	iip = znode->parent->child_cnt;
87	continue;
88	}
89
90	/* Walk back down to the level we came from ('level') */
91	while (zn->level != level) {
92	znode = zn;
93	zn = ubifs_tnc_find_child(zn, 0);
94	if (!zn) {
95	/*
96	* This path is not too deep so it does not
97	* reach 'level'. Try next path.
98	*/
99	iip = znode->iip;
100	break;
101	}
102	}
103
104	if (zn) {
105	ubifs_assert(zn->level >= 0);
106	return zn;
107	}
108	}
109	}
110
111	/**
112	* ubifs_search_zbranch - search znode branch.
113	* @c: UBIFS file-system description object
114	* @znode: znode to search in
115	* @key: key to search for
116	* @n: znode branch slot number is returned here
117	*
118	* This is a helper function which search branch with key @key in @znode using
119	* binary search. The result of the search may be:
120	* o exact match, then %1 is returned, and the slot number of the branch is
121	* stored in @n;
122	* o no exact match, then %0 is returned and the slot number of the left
123	* closest branch is returned in @n; the slot if all keys in this znode are
124	* greater than @key, then %-1 is returned in @n.
125	*/
126	int ubifs_search_zbranch(const struct ubifs_info *c,
127	const struct ubifs_znode *znode,
128	const union ubifs_key key, int n)
129	{
130	int beg = 0, end = znode->child_cnt, uninitialized_var(mid);
131	int uninitialized_var(cmp);
132	const struct ubifs_zbranch *zbr = &znode->zbranch[0];
133
134	ubifs_assert(end > beg);
135
136	while (end > beg) {
137	mid = (beg + end) >> 1;
138	cmp = keys_cmp(c, key, &zbr[mid].key);
139	if (cmp > 0)
140	beg = mid + 1;
141	else if (cmp < 0)
142	end = mid;
143	else {
144	*n = mid;
145	return 1;
146	}
147	}
148
149	*n = end - 1;
150
151	/* The insert point is after n /
152	ubifs_assert(n >= -1 && n < znode->child_cnt);
153	if (*n == -1)
154	ubifs_assert(keys_cmp(c, key, &zbr[0].key) < 0);
155	else
156	ubifs_assert(keys_cmp(c, key, &zbr[*n].key) > 0);
157	if (*n + 1 < znode->child_cnt)
158	ubifs_assert(keys_cmp(c, key, &zbr[*n + 1].key) < 0);
159
160	return 0;
161	}
162
163	/**
164	* ubifs_tnc_postorder_first - find first znode to do postorder tree traversal.
165	* @znode: znode to start at (root of the sub-tree to traverse)
166	*
167	* Find the lowest leftmost znode in a subtree of the TNC tree. The LNC is
168	* ignored.
169	*/
170	struct ubifs_znode ubifs_tnc_postorder_first(struct ubifs_znode znode)
171	{
172	if (unlikely(!znode))
173	return NULL;
174
175	while (znode->level > 0) {
176	struct ubifs_znode *child;
177
178	child = ubifs_tnc_find_child(znode, 0);
179	if (!child)
180	return znode;
181	znode = child;
182	}
183
184	return znode;
185	}
186
187	/**
188	* ubifs_tnc_postorder_next - next TNC tree element in postorder traversal.
189	* @znode: previous znode
190	*
191	* This function implements postorder TNC traversal. The LNC is ignored.
192	* Returns the next element or %NULL if @znode is already the last one.
193	*/
194	struct ubifs_znode ubifs_tnc_postorder_next(struct ubifs_znode znode)
195	{
196	struct ubifs_znode *zn;
197
198	ubifs_assert(znode);
199	if (unlikely(!znode->parent))
200	return NULL;
201
202	/* Switch to the next index in the parent */
203	zn = ubifs_tnc_find_child(znode->parent, znode->iip + 1);
204	if (!zn)
205	/* This is in fact the last child, return parent */
206	return znode->parent;
207
208	/* Go to the first znode in this new subtree */
209	return ubifs_tnc_postorder_first(zn);
210	}
211
ff94bc40 HS	212	/**
	213	* ubifs_destroy_tnc_subtree - destroy all znodes connected to a subtree.
	214	* @znode: znode defining subtree to destroy
	215	*
	216	* This function destroys subtree of the TNC tree. Returns number of clean
	217	* znodes in the subtree.
	218	*/
	219	long ubifs_destroy_tnc_subtree(struct ubifs_znode *znode)
	220	{
	221	struct ubifs_znode *zn = ubifs_tnc_postorder_first(znode);
	222	long clean_freed = 0;
	223	int n;
	224
	225	ubifs_assert(zn);
	226	while (1) {
	227	for (n = 0; n < zn->child_cnt; n++) {
	228	if (!zn->zbranch[n].znode)
	229	continue;
	230
	231	if (zn->level > 0 &&
	232	!ubifs_zn_dirty(zn->zbranch[n].znode))
	233	clean_freed += 1;
	234
	235	cond_resched();
	236	kfree(zn->zbranch[n].znode);
	237	}
	238
	239	if (zn == znode) {
	240	if (!ubifs_zn_dirty(zn))
	241	clean_freed += 1;
	242	kfree(zn);
	243	return clean_freed;
	244	}
	245
	246	zn = ubifs_tnc_postorder_next(zn);
	247	}
	248	}
	249
9eefe2a2 SR	250	/**
	251	* read_znode - read an indexing node from flash and fill znode.
	252	* @c: UBIFS file-system description object
	253	* @lnum: LEB of the indexing node to read
	254	* @offs: node offset
	255	* @len: node length
	256	* @znode: znode to read to
	257	*
	258	* This function reads an indexing node from the flash media and fills znode
	259	* with the read data. Returns zero in case of success and a negative error
	260	* code in case of failure. The read indexing node is validated and if anything
	261	* is wrong with it, this function prints complaint messages and returns
	262	* %-EINVAL.
	263	*/
	264	static int read_znode(struct ubifs_info *c, int lnum, int offs, int len,
	265	struct ubifs_znode *znode)
	266	{
	267	int i, err, type, cmp;
	268	struct ubifs_idx_node *idx;
	269
	270	idx = kmalloc(c->max_idx_node_sz, GFP_NOFS);
	271	if (!idx)
	272	return -ENOMEM;
	273
	274	err = ubifs_read_node(c, idx, UBIFS_IDX_NODE, len, lnum, offs);
	275	if (err < 0) {
	276	kfree(idx);
	277	return err;
	278	}
	279
	280	znode->child_cnt = le16_to_cpu(idx->child_cnt);
	281	znode->level = le16_to_cpu(idx->level);
	282
	283	dbg_tnc("LEB %d:%d, level %d, %d branch",
	284	lnum, offs, znode->level, znode->child_cnt);
	285
	286	if (znode->child_cnt > c->fanout \|\| znode->level > UBIFS_MAX_LEVELS) {
0195a7bb	287	ubifs_err(c, "current fanout %d, branch count %d",
ff94bc40	288	c->fanout, znode->child_cnt);
0195a7bb	289	ubifs_err(c, "max levels %d, znode level %d",
ff94bc40	290	UBIFS_MAX_LEVELS, znode->level);
9eefe2a2 SR	291	err = 1;
	292	goto out_dump;
	293	}
	294
	295	for (i = 0; i < znode->child_cnt; i++) {
	296	const struct ubifs_branch *br = ubifs_idx_branch(c, idx, i);
	297	struct ubifs_zbranch *zbr = &znode->zbranch[i];
	298
	299	key_read(c, &br->key, &zbr->key);
	300	zbr->lnum = le32_to_cpu(br->lnum);
	301	zbr->offs = le32_to_cpu(br->offs);
	302	zbr->len = le32_to_cpu(br->len);
	303	zbr->znode = NULL;
	304
	305	/* Validate branch */
	306
	307	if (zbr->lnum < c->main_first \|\|
	308	zbr->lnum >= c->leb_cnt \|\| zbr->offs < 0 \|\|
	309	zbr->offs + zbr->len > c->leb_size \|\| zbr->offs & 7) {
0195a7bb	310	ubifs_err(c, "bad branch %d", i);
9eefe2a2 SR	311	err = 2;
	312	goto out_dump;
	313	}
	314
	315	switch (key_type(c, &zbr->key)) {
	316	case UBIFS_INO_KEY:
	317	case UBIFS_DATA_KEY:
	318	case UBIFS_DENT_KEY:
	319	case UBIFS_XENT_KEY:
	320	break;
	321	default:
0195a7bb	322	ubifs_err(c, "bad key type at slot %d: %d",
ff94bc40	323	i, key_type(c, &zbr->key));
9eefe2a2 SR	324	err = 3;
	325	goto out_dump;
	326	}
	327
	328	if (znode->level)
	329	continue;
	330
	331	type = key_type(c, &zbr->key);
	332	if (c->ranges[type].max_len == 0) {
	333	if (zbr->len != c->ranges[type].len) {
0195a7bb	334	ubifs_err(c, "bad target node (type %d) length (%d)",
ff94bc40	335	type, zbr->len);
0195a7bb	336	ubifs_err(c, "have to be %d", c->ranges[type].len);
9eefe2a2 SR	337	err = 4;
	338	goto out_dump;
	339	}
	340	} else if (zbr->len < c->ranges[type].min_len \|\|
	341	zbr->len > c->ranges[type].max_len) {
0195a7bb	342	ubifs_err(c, "bad target node (type %d) length (%d)",
ff94bc40	343	type, zbr->len);
0195a7bb	344	ubifs_err(c, "have to be in range of %d-%d",
ff94bc40 HS	345	c->ranges[type].min_len,
ff94bc40 HS	346	c->ranges[type].max_len);
9eefe2a2 SR	347	err = 5;
	348	goto out_dump;
	349	}
	350	}
	351
	352	/*
	353	* Ensure that the next key is greater or equivalent to the
	354	* previous one.
	355	*/
	356	for (i = 0; i < znode->child_cnt - 1; i++) {
	357	const union ubifs_key key1, key2;
	358
	359	key1 = &znode->zbranch[i].key;
	360	key2 = &znode->zbranch[i + 1].key;
	361
	362	cmp = keys_cmp(c, key1, key2);
	363	if (cmp > 0) {
0195a7bb	364	ubifs_err(c, "bad key order (keys %d and %d)", i, i + 1);
9eefe2a2 SR	365	err = 6;
	366	goto out_dump;
	367	} else if (cmp == 0 && !is_hash_key(c, key1)) {
	368	/* These can only be keys with colliding hash */
0195a7bb	369	ubifs_err(c, "keys %d and %d are not hashed but equivalent",
ff94bc40	370	i, i + 1);
9eefe2a2 SR	371	err = 7;
	372	goto out_dump;
	373	}
	374	}
	375
	376	kfree(idx);
	377	return 0;
	378
	379	out_dump:
0195a7bb	380	ubifs_err(c, "bad indexing node at LEB %d:%d, error %d", lnum, offs, err);
ff94bc40	381	ubifs_dump_node(c, idx);
9eefe2a2 SR	382	kfree(idx);
	383	return -EINVAL;
	384	}
	385
	386	/**
	387	* ubifs_load_znode - load znode to TNC cache.
	388	* @c: UBIFS file-system description object
	389	* @zbr: znode branch
	390	* @parent: znode's parent
	391	* @iip: index in parent
	392	*
	393	* This function loads znode pointed to by @zbr into the TNC cache and
	394	* returns pointer to it in case of success and a negative error code in case
	395	* of failure.
	396	*/
	397	struct ubifs_znode ubifs_load_znode(struct ubifs_info c,
	398	struct ubifs_zbranch *zbr,
	399	struct ubifs_znode *parent, int iip)
	400	{
	401	int err;
	402	struct ubifs_znode *znode;
	403
	404	ubifs_assert(!zbr->znode);
	405	/*
	406	* A slab cache is not presently used for znodes because the znode size
	407	* depends on the fanout which is stored in the superblock.
	408	*/
	409	znode = kzalloc(c->max_znode_sz, GFP_NOFS);
	410	if (!znode)
	411	return ERR_PTR(-ENOMEM);
	412
	413	err = read_znode(c, zbr->lnum, zbr->offs, zbr->len, znode);
	414	if (err)
	415	goto out;
	416
ff94bc40 HS	417	atomic_long_inc(&c->clean_zn_cnt);
	418
	419	/*
	420	* Increment the global clean znode counter as well. It is OK that
	421	* global and per-FS clean znode counters may be inconsistent for some
	422	* short time (because we might be preempted at this point), the global
	423	* one is only used in shrinker.
	424	*/
	425	atomic_long_inc(&ubifs_clean_zn_cnt);
	426
9eefe2a2 SR	427	zbr->znode = znode;
	428	znode->parent = parent;
	429	znode->time = get_seconds();
	430	znode->iip = iip;
	431
	432	return znode;
	433
	434	out:
	435	kfree(znode);
	436	return ERR_PTR(err);
	437	}
	438
	439	/**
	440	* ubifs_tnc_read_node - read a leaf node from the flash media.
	441	* @c: UBIFS file-system description object
	442	* @zbr: key and position of the node
	443	* @node: node is returned here
	444	*
	445	* This function reads a node defined by @zbr from the flash media. Returns
	446	* zero in case of success or a negative negative error code in case of
	447	* failure.
	448	*/
	449	int ubifs_tnc_read_node(struct ubifs_info c, struct ubifs_zbranch zbr,
	450	void *node)
	451	{
	452	union ubifs_key key1, *key = &zbr->key;
	453	int err, type = key_type(c, key);
ff94bc40	454	struct ubifs_wbuf *wbuf;
9eefe2a2	455
ff94bc40 HS	456	/*
	457	* 'zbr' has to point to on-flash node. The node may sit in a bud and
	458	* may even be in a write buffer, so we have to take care about this.
	459	*/
	460	wbuf = ubifs_get_wbuf(c, zbr->lnum);
	461	if (wbuf)
	462	err = ubifs_read_node_wbuf(wbuf, node, type, zbr->len,
	463	zbr->lnum, zbr->offs);
	464	else
	465	err = ubifs_read_node(c, node, type, zbr->len, zbr->lnum,
	466	zbr->offs);
9eefe2a2 SR	467
9eefe2a2 SR	468	if (err) {
ff94bc40	469	dbg_tnck(key, "key ");
9eefe2a2 SR	470	return err;
	471	}
	472
	473	/* Make sure the key of the read node is correct */
	474	key_read(c, node + UBIFS_KEY_OFFSET, &key1);
	475	if (!keys_eq(c, key, &key1)) {
0195a7bb	476	ubifs_err(c, "bad key in node at LEB %d:%d",
9eefe2a2	477	zbr->lnum, zbr->offs);
ff94bc40 HS	478	dbg_tnck(key, "looked for key ");
	479	dbg_tnck(&key1, "but found node's key ");
	480	ubifs_dump_node(c, node);
9eefe2a2 SR	481	return -EINVAL;
	482	}
	483
	484	return 0;
	485	}