[linux-block.git] / fs / ubifs / master.c

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

/* This file implements reading and writing the master node */

#include "ubifs.h"

/**
 * ubifs_compare_master_node - compare two UBIFS master nodes
 * @c: UBIFS file-system description object
 * @m1: the first node
 * @m2: the second node
 *
 * This function compares two UBIFS master nodes. Returns 0 if they are equal
 * and nonzero if not.
 */
int ubifs_compare_master_node(struct ubifs_info *c, void *m1, void *m2)
{
	int ret;
	int behind;
	int hmac_offs = offsetof(struct ubifs_mst_node, hmac);

	/*
	 * Do not compare the common node header since the sequence number and
	 * hence the CRC are different.
	 */
	ret = memcmp(m1 + UBIFS_CH_SZ, m2 + UBIFS_CH_SZ,
		     hmac_offs - UBIFS_CH_SZ);
	if (ret)
		return ret;

	/*
	 * Do not compare the embedded HMAC aswell which also must be different
	 * due to the different common node header.
	 */
	behind = hmac_offs + UBIFS_MAX_HMAC_LEN;

	if (UBIFS_MST_NODE_SZ > behind)
		return memcmp(m1 + behind, m2 + behind, UBIFS_MST_NODE_SZ - behind);

	return 0;
}

/* mst_node_check_hash - Check hash of a master node
 * @c: UBIFS file-system description object
 * @mst: The master node
 * @expected: The expected hash of the master node
 *
 * This checks the hash of a master node against a given expected hash.
 * Note that we have two master nodes on a UBIFS image which have different
 * sequence numbers and consequently different CRCs. To be able to match
 * both master nodes we exclude the common node header containing the sequence
 * number and CRC from the hash.
 *
 * Returns 0 if the hashes are equal, a negative error code otherwise.
 */
static int mst_node_check_hash(const struct ubifs_info *c,
			       const struct ubifs_mst_node *mst,
			       const u8 *expected)
{
	u8 calc[UBIFS_MAX_HASH_LEN];
	const void *node = mst;

	SHASH_DESC_ON_STACK(shash, c->hash_tfm);

	shash->tfm = c->hash_tfm;

	crypto_shash_digest(shash, node + sizeof(struct ubifs_ch),
			    UBIFS_MST_NODE_SZ - sizeof(struct ubifs_ch), calc);

	if (ubifs_check_hash(c, expected, calc))
		return -EPERM;

	return 0;
}

/**
 * scan_for_master - search the valid master node.
 * @c: UBIFS file-system description object
 *
 * This function scans the master node LEBs and search for the latest master
 * node. Returns zero in case of success, %-EUCLEAN if there master area is
 * corrupted and requires recovery, and a negative error code in case of
 * failure.
 */
static int scan_for_master(struct ubifs_info *c)
{
	struct ubifs_scan_leb *sleb;
	struct ubifs_scan_node *snod;
	int lnum, offs = 0, nodes_cnt, err;

	lnum = UBIFS_MST_LNUM;

	sleb = ubifs_scan(c, lnum, 0, c->sbuf, 1);
	if (IS_ERR(sleb))
		return PTR_ERR(sleb);
	nodes_cnt = sleb->nodes_cnt;
	if (nodes_cnt > 0) {
		snod = list_entry(sleb->nodes.prev, struct ubifs_scan_node,
				  list);
		if (snod->type != UBIFS_MST_NODE)
			goto out_dump;
		memcpy(c->mst_node, snod->node, snod->len);
		offs = snod->offs;
	}
	ubifs_scan_destroy(sleb);

	lnum += 1;

	sleb = ubifs_scan(c, lnum, 0, c->sbuf, 1);
	if (IS_ERR(sleb))
		return PTR_ERR(sleb);
	if (sleb->nodes_cnt != nodes_cnt)
		goto out;
	if (!sleb->nodes_cnt)
		goto out;
	snod = list_entry(sleb->nodes.prev, struct ubifs_scan_node, list);
	if (snod->type != UBIFS_MST_NODE)
		goto out_dump;
	if (snod->offs != offs)
		goto out;
	if (ubifs_compare_master_node(c, c->mst_node, snod->node))
		goto out;

	c->mst_offs = offs;
	ubifs_scan_destroy(sleb);

	if (!ubifs_authenticated(c))
		return 0;

	if (ubifs_hmac_zero(c, c->mst_node->hmac)) {
		err = mst_node_check_hash(c, c->mst_node,
					  c->sup_node->hash_mst);
		if (err)
			ubifs_err(c, "Failed to verify master node hash");
	} else {
		err = ubifs_node_verify_hmac(c, c->mst_node,
					sizeof(struct ubifs_mst_node),
					offsetof(struct ubifs_mst_node, hmac));
		if (err)
			ubifs_err(c, "Failed to verify master node HMAC");
	}

	if (err)
		return -EPERM;

	return 0;

out:
	ubifs_scan_destroy(sleb);
	return -EUCLEAN;

out_dump:
	ubifs_err(c, "unexpected node type %d master LEB %d:%d",
		  snod->type, lnum, snod->offs);
	ubifs_scan_destroy(sleb);
	return -EINVAL;
}

/**
 * validate_master - validate master node.
 * @c: UBIFS file-system description object
 *
 * This function validates data which was read from master node. Returns zero
 * if the data is all right and %-EINVAL if not.
 */
static int validate_master(const struct ubifs_info *c)
{
	long long main_sz;
	int err;

	if (c->max_sqnum >= SQNUM_WATERMARK) {
		err = 1;
		goto out;
	}

	if (c->cmt_no >= c->max_sqnum) {
		err = 2;
		goto out;
	}

	if (c->highest_inum >= INUM_WATERMARK) {
		err = 3;
		goto out;
	}

	if (c->lhead_lnum < UBIFS_LOG_LNUM ||
	    c->lhead_lnum >= UBIFS_LOG_LNUM + c->log_lebs ||
	    c->lhead_offs < 0 || c->lhead_offs >= c->leb_size ||
	    c->lhead_offs & (c->min_io_size - 1)) {
		err = 4;
		goto out;
	}

	if (c->zroot.lnum >= c->leb_cnt || c->zroot.lnum < c->main_first ||
	    c->zroot.offs >= c->leb_size || c->zroot.offs & 7) {
		err = 5;
		goto out;
	}

	if (c->zroot.len < c->ranges[UBIFS_IDX_NODE].min_len ||
	    c->zroot.len > c->ranges[UBIFS_IDX_NODE].max_len) {
		err = 6;
		goto out;
	}

	if (c->gc_lnum >= c->leb_cnt || c->gc_lnum < c->main_first) {
		err = 7;
		goto out;
	}

	if (c->ihead_lnum >= c->leb_cnt || c->ihead_lnum < c->main_first ||
	    c->ihead_offs % c->min_io_size || c->ihead_offs < 0 ||
	    c->ihead_offs > c->leb_size || c->ihead_offs & 7) {
		err = 8;
		goto out;
	}

	main_sz = (long long)c->main_lebs * c->leb_size;
	if (c->bi.old_idx_sz & 7 || c->bi.old_idx_sz >= main_sz) {
		err = 9;
		goto out;
	}

	if (c->lpt_lnum < c->lpt_first || c->lpt_lnum > c->lpt_last ||
	    c->lpt_offs < 0 || c->lpt_offs + c->nnode_sz > c->leb_size) {
		err = 10;
		goto out;
	}

	if (c->nhead_lnum < c->lpt_first || c->nhead_lnum > c->lpt_last ||
	    c->nhead_offs < 0 || c->nhead_offs % c->min_io_size ||
	    c->nhead_offs > c->leb_size) {
		err = 11;
		goto out;
	}

	if (c->ltab_lnum < c->lpt_first || c->ltab_lnum > c->lpt_last ||
	    c->ltab_offs < 0 ||
	    c->ltab_offs + c->ltab_sz > c->leb_size) {
		err = 12;
		goto out;
	}

	if (c->big_lpt && (c->lsave_lnum < c->lpt_first ||
	    c->lsave_lnum > c->lpt_last || c->lsave_offs < 0 ||
	    c->lsave_offs + c->lsave_sz > c->leb_size)) {
		err = 13;
		goto out;
	}

	if (c->lscan_lnum < c->main_first || c->lscan_lnum >= c->leb_cnt) {
		err = 14;
		goto out;
	}

	if (c->lst.empty_lebs < 0 || c->lst.empty_lebs > c->main_lebs - 2) {
		err = 15;
		goto out;
	}

	if (c->lst.idx_lebs < 0 || c->lst.idx_lebs > c->main_lebs - 1) {
		err = 16;
		goto out;
	}

	if (c->lst.total_free < 0 || c->lst.total_free > main_sz ||
	    c->lst.total_free & 7) {
		err = 17;
		goto out;
	}

	if (c->lst.total_dirty < 0 || (c->lst.total_dirty & 7)) {
		err = 18;
		goto out;
	}

	if (c->lst.total_used < 0 || (c->lst.total_used & 7)) {
		err = 19;
		goto out;
	}

	if (c->lst.total_free + c->lst.total_dirty +
	    c->lst.total_used > main_sz) {
		err = 20;
		goto out;
	}

	if (c->lst.total_dead + c->lst.total_dark +
	    c->lst.total_used + c->bi.old_idx_sz > main_sz) {
		err = 21;
		goto out;
	}

	if (c->lst.total_dead < 0 ||
	    c->lst.total_dead > c->lst.total_free + c->lst.total_dirty ||
	    c->lst.total_dead & 7) {
		err = 22;
		goto out;
	}

	if (c->lst.total_dark < 0 ||
	    c->lst.total_dark > c->lst.total_free + c->lst.total_dirty ||
	    c->lst.total_dark & 7) {
		err = 23;
		goto out;
	}

	return 0;

out:
	ubifs_err(c, "bad master node at offset %d error %d", c->mst_offs, err);
	ubifs_dump_node(c, c->mst_node);
	return -EINVAL;
}

/**
 * ubifs_read_master - read master node.
 * @c: UBIFS file-system description object
 *
 * This function finds and reads the master node during file-system mount. If
 * the flash is empty, it creates default master node as well. Returns zero in
 * case of success and a negative error code in case of failure.
 */
int ubifs_read_master(struct ubifs_info *c)
{
	int err, old_leb_cnt;

	c->mst_node = kzalloc(c->mst_node_alsz, GFP_KERNEL);
	if (!c->mst_node)
		return -ENOMEM;

	err = scan_for_master(c);
	if (err) {
		if (err == -EUCLEAN)
			err = ubifs_recover_master_node(c);
		if (err)
			/*
			 * Note, we do not free 'c->mst_node' here because the
			 * unmount routine will take care of this.
			 */
			return err;
	}

	/* Make sure that the recovery flag is clear */
	c->mst_node->flags &= cpu_to_le32(~UBIFS_MST_RCVRY);

	c->max_sqnum       = le64_to_cpu(c->mst_node->ch.sqnum);
	c->highest_inum    = le64_to_cpu(c->mst_node->highest_inum);
	c->cmt_no          = le64_to_cpu(c->mst_node->cmt_no);
	c->zroot.lnum      = le32_to_cpu(c->mst_node->root_lnum);
	c->zroot.offs      = le32_to_cpu(c->mst_node->root_offs);
	c->zroot.len       = le32_to_cpu(c->mst_node->root_len);
	c->lhead_lnum      = le32_to_cpu(c->mst_node->log_lnum);
	c->gc_lnum         = le32_to_cpu(c->mst_node->gc_lnum);
	c->ihead_lnum      = le32_to_cpu(c->mst_node->ihead_lnum);
	c->ihead_offs      = le32_to_cpu(c->mst_node->ihead_offs);
	c->bi.old_idx_sz   = le64_to_cpu(c->mst_node->index_size);
	c->lpt_lnum        = le32_to_cpu(c->mst_node->lpt_lnum);
	c->lpt_offs        = le32_to_cpu(c->mst_node->lpt_offs);
	c->nhead_lnum      = le32_to_cpu(c->mst_node->nhead_lnum);
	c->nhead_offs      = le32_to_cpu(c->mst_node->nhead_offs);
	c->ltab_lnum       = le32_to_cpu(c->mst_node->ltab_lnum);
	c->ltab_offs       = le32_to_cpu(c->mst_node->ltab_offs);
	c->lsave_lnum      = le32_to_cpu(c->mst_node->lsave_lnum);
	c->lsave_offs      = le32_to_cpu(c->mst_node->lsave_offs);
	c->lscan_lnum      = le32_to_cpu(c->mst_node->lscan_lnum);
	c->lst.empty_lebs  = le32_to_cpu(c->mst_node->empty_lebs);
	c->lst.idx_lebs    = le32_to_cpu(c->mst_node->idx_lebs);
	old_leb_cnt        = le32_to_cpu(c->mst_node->leb_cnt);
	c->lst.total_free  = le64_to_cpu(c->mst_node->total_free);
	c->lst.total_dirty = le64_to_cpu(c->mst_node->total_dirty);
	c->lst.total_used  = le64_to_cpu(c->mst_node->total_used);
	c->lst.total_dead  = le64_to_cpu(c->mst_node->total_dead);
	c->lst.total_dark  = le64_to_cpu(c->mst_node->total_dark);

	ubifs_copy_hash(c, c->mst_node->hash_root_idx, c->zroot.hash);

	c->calc_idx_sz = c->bi.old_idx_sz;

	if (c->mst_node->flags & cpu_to_le32(UBIFS_MST_NO_ORPHS))
		c->no_orphs = 1;

	if (old_leb_cnt != c->leb_cnt) {
		/* The file system has been resized */
		int growth = c->leb_cnt - old_leb_cnt;

		if (c->leb_cnt < old_leb_cnt ||
		    c->leb_cnt < UBIFS_MIN_LEB_CNT) {
			ubifs_err(c, "bad leb_cnt on master node");
			ubifs_dump_node(c, c->mst_node);
			return -EINVAL;
		}

		dbg_mnt("Auto resizing (master) from %d LEBs to %d LEBs",
			old_leb_cnt, c->leb_cnt);
		c->lst.empty_lebs += growth;
		c->lst.total_free += growth * (long long)c->leb_size;
		c->lst.total_dark += growth * (long long)c->dark_wm;

		/*
		 * Reflect changes back onto the master node. N.B. the master
		 * node gets written immediately whenever mounting (or
		 * remounting) in read-write mode, so we do not need to write it
		 * here.
		 */
		c->mst_node->leb_cnt = cpu_to_le32(c->leb_cnt);
		c->mst_node->empty_lebs = cpu_to_le32(c->lst.empty_lebs);
		c->mst_node->total_free = cpu_to_le64(c->lst.total_free);
		c->mst_node->total_dark = cpu_to_le64(c->lst.total_dark);
	}

	err = validate_master(c);
	if (err)
		return err;

	err = dbg_old_index_check_init(c, &c->zroot);

	return err;
}

/**
 * ubifs_write_master - write master node.
 * @c: UBIFS file-system description object
 *
 * This function writes the master node. Returns zero in case of success and a
 * negative error code in case of failure. The master node is written twice to
 * enable recovery.
 */
int ubifs_write_master(struct ubifs_info *c)
{
	int err, lnum, offs, len;

	ubifs_assert(c, !c->ro_media && !c->ro_mount);
	if (c->ro_error)
		return -EROFS;

	lnum = UBIFS_MST_LNUM;
	offs = c->mst_offs + c->mst_node_alsz;
	len = UBIFS_MST_NODE_SZ;

	if (offs + UBIFS_MST_NODE_SZ > c->leb_size) {
		err = ubifs_leb_unmap(c, lnum);
		if (err)
			return err;
		offs = 0;
	}

	c->mst_offs = offs;
	c->mst_node->highest_inum = cpu_to_le64(c->highest_inum);

	ubifs_copy_hash(c, c->zroot.hash, c->mst_node->hash_root_idx);
	err = ubifs_write_node_hmac(c, c->mst_node, len, lnum, offs,
				    offsetof(struct ubifs_mst_node, hmac));
	if (err)
		return err;

	lnum += 1;

	if (offs == 0) {
		err = ubifs_leb_unmap(c, lnum);
		if (err)
			return err;
	}
	err = ubifs_write_node_hmac(c, c->mst_node, len, lnum, offs,
				    offsetof(struct ubifs_mst_node, hmac));

	return err;
}
Commit	Line	Data
2b27bdcc	1	// SPDX-License-Identifier: GPL-2.0-only
1e51764a AB	2	/*
	3	* This file is part of UBIFS.
	4	*
	5	* Copyright (C) 2006-2008 Nokia Corporation.
	6	*
1e51764a AB	7	* Authors: Artem Bityutskiy (Битюцкий Артём)
	8	* Adrian Hunter
	9	*/
	10
	11	/* This file implements reading and writing the master node */
	12
	13	#include "ubifs.h"
	14
625700cc SH	15	/**
	16	* ubifs_compare_master_node - compare two UBIFS master nodes
	17	* @c: UBIFS file-system description object
	18	* @m1: the first node
	19	* @m2: the second node
	20	*
	21	* This function compares two UBIFS master nodes. Returns 0 if they are equal
	22	* and nonzero if not.
	23	*/
	24	int ubifs_compare_master_node(struct ubifs_info c, void m1, void *m2)
	25	{
	26	int ret;
	27	int behind;
	28	int hmac_offs = offsetof(struct ubifs_mst_node, hmac);
	29
	30	/*
	31	* Do not compare the common node header since the sequence number and
	32	* hence the CRC are different.
	33	*/
	34	ret = memcmp(m1 + UBIFS_CH_SZ, m2 + UBIFS_CH_SZ,
	35	hmac_offs - UBIFS_CH_SZ);
	36	if (ret)
	37	return ret;
	38
	39	/*
	40	* Do not compare the embedded HMAC aswell which also must be different
	41	* due to the different common node header.
	42	*/
	43	behind = hmac_offs + UBIFS_MAX_HMAC_LEN;
	44
	45	if (UBIFS_MST_NODE_SZ > behind)
	46	return memcmp(m1 + behind, m2 + behind, UBIFS_MST_NODE_SZ - behind);
	47
	48	return 0;
	49	}
	50
817aa094 SH	51	/* mst_node_check_hash - Check hash of a master node
	52	* @c: UBIFS file-system description object
	53	* @mst: The master node
	54	* @expected: The expected hash of the master node
	55	*
	56	* This checks the hash of a master node against a given expected hash.
	57	* Note that we have two master nodes on a UBIFS image which have different
	58	* sequence numbers and consequently different CRCs. To be able to match
	59	* both master nodes we exclude the common node header containing the sequence
	60	* number and CRC from the hash.
	61	*
	62	* Returns 0 if the hashes are equal, a negative error code otherwise.
	63	*/
	64	static int mst_node_check_hash(const struct ubifs_info *c,
	65	const struct ubifs_mst_node *mst,
	66	const u8 *expected)
	67	{
	68	u8 calc[UBIFS_MAX_HASH_LEN];
	69	const void *node = mst;
	70
	71	SHASH_DESC_ON_STACK(shash, c->hash_tfm);
	72
	73	shash->tfm = c->hash_tfm;
	74
	75	crypto_shash_digest(shash, node + sizeof(struct ubifs_ch),
	76	UBIFS_MST_NODE_SZ - sizeof(struct ubifs_ch), calc);
	77
	78	if (ubifs_check_hash(c, expected, calc))
	79	return -EPERM;
	80
	81	return 0;
	82	}
	83
1e51764a AB	84	/**
	85	* scan_for_master - search the valid master node.
	86	* @c: UBIFS file-system description object
	87	*
	88	* This function scans the master node LEBs and search for the latest master
0dcd18e4 AB	89	* node. Returns zero in case of success, %-EUCLEAN if there master area is
0dcd18e4 AB	90	* corrupted and requires recovery, and a negative error code in case of
1e51764a AB	91	* failure.
	92	*/
	93	static int scan_for_master(struct ubifs_info *c)
	94	{
	95	struct ubifs_scan_leb *sleb;
	96	struct ubifs_scan_node *snod;
625700cc	97	int lnum, offs = 0, nodes_cnt, err;
1e51764a AB	98
	99	lnum = UBIFS_MST_LNUM;
	100
348709ba	101	sleb = ubifs_scan(c, lnum, 0, c->sbuf, 1);
1e51764a AB	102	if (IS_ERR(sleb))
	103	return PTR_ERR(sleb);
	104	nodes_cnt = sleb->nodes_cnt;
	105	if (nodes_cnt > 0) {
	106	snod = list_entry(sleb->nodes.prev, struct ubifs_scan_node,
	107	list);
	108	if (snod->type != UBIFS_MST_NODE)
0dcd18e4	109	goto out_dump;
1e51764a AB	110	memcpy(c->mst_node, snod->node, snod->len);
	111	offs = snod->offs;
	112	}
	113	ubifs_scan_destroy(sleb);
	114
	115	lnum += 1;
	116
348709ba	117	sleb = ubifs_scan(c, lnum, 0, c->sbuf, 1);
1e51764a AB	118	if (IS_ERR(sleb))
	119	return PTR_ERR(sleb);
	120	if (sleb->nodes_cnt != nodes_cnt)
	121	goto out;
	122	if (!sleb->nodes_cnt)
	123	goto out;
	124	snod = list_entry(sleb->nodes.prev, struct ubifs_scan_node, list);
	125	if (snod->type != UBIFS_MST_NODE)
0dcd18e4	126	goto out_dump;
1e51764a AB	127	if (snod->offs != offs)
1e51764a AB	128	goto out;
625700cc	129	if (ubifs_compare_master_node(c, c->mst_node, snod->node))
1e51764a	130	goto out;
625700cc	131
1e51764a AB	132	c->mst_offs = offs;
1e51764a AB	133	ubifs_scan_destroy(sleb);
625700cc SH	134
	135	if (!ubifs_authenticated(c))
	136	return 0;
	137
817aa094 SH	138	if (ubifs_hmac_zero(c, c->mst_node->hmac)) {
	139	err = mst_node_check_hash(c, c->mst_node,
	140	c->sup_node->hash_mst);
	141	if (err)
	142	ubifs_err(c, "Failed to verify master node hash");
	143	} else {
	144	err = ubifs_node_verify_hmac(c, c->mst_node,
	145	sizeof(struct ubifs_mst_node),
	146	offsetof(struct ubifs_mst_node, hmac));
	147	if (err)
	148	ubifs_err(c, "Failed to verify master node HMAC");
625700cc SH	149	}
625700cc SH	150
817aa094 SH	151	if (err)
	152	return -EPERM;
	153
1e51764a AB	154	return 0;
	155
	156	out:
	157	ubifs_scan_destroy(sleb);
0dcd18e4 AB	158	return -EUCLEAN;
	159
	160	out_dump:
235c362b	161	ubifs_err(c, "unexpected node type %d master LEB %d:%d",
0dcd18e4 AB	162	snod->type, lnum, snod->offs);
0dcd18e4 AB	163	ubifs_scan_destroy(sleb);
1e51764a AB	164	return -EINVAL;
	165	}
	166
	167	/**
	168	* validate_master - validate master node.
	169	* @c: UBIFS file-system description object
	170	*
	171	* This function validates data which was read from master node. Returns zero
	172	* if the data is all right and %-EINVAL if not.
	173	*/
	174	static int validate_master(const struct ubifs_info *c)
	175	{
	176	long long main_sz;
	177	int err;
	178
	179	if (c->max_sqnum >= SQNUM_WATERMARK) {
	180	err = 1;
	181	goto out;
	182	}
	183
	184	if (c->cmt_no >= c->max_sqnum) {
	185	err = 2;
	186	goto out;
	187	}
	188
	189	if (c->highest_inum >= INUM_WATERMARK) {
	190	err = 3;
	191	goto out;
	192	}
	193
	194	if (c->lhead_lnum < UBIFS_LOG_LNUM \|\|
	195	c->lhead_lnum >= UBIFS_LOG_LNUM + c->log_lebs \|\|
	196	c->lhead_offs < 0 \|\| c->lhead_offs >= c->leb_size \|\|
	197	c->lhead_offs & (c->min_io_size - 1)) {
	198	err = 4;
	199	goto out;
	200	}
	201
	202	if (c->zroot.lnum >= c->leb_cnt \|\| c->zroot.lnum < c->main_first \|\|
	203	c->zroot.offs >= c->leb_size \|\| c->zroot.offs & 7) {
	204	err = 5;
	205	goto out;
	206	}
	207
	208	if (c->zroot.len < c->ranges[UBIFS_IDX_NODE].min_len \|\|
	209	c->zroot.len > c->ranges[UBIFS_IDX_NODE].max_len) {
	210	err = 6;
	211	goto out;
	212	}
	213
	214	if (c->gc_lnum >= c->leb_cnt \|\| c->gc_lnum < c->main_first) {
	215	err = 7;
	216	goto out;
	217	}
	218
	219	if (c->ihead_lnum >= c->leb_cnt \|\| c->ihead_lnum < c->main_first \|\|
	220	c->ihead_offs % c->min_io_size \|\| c->ihead_offs < 0 \|\|
	221	c->ihead_offs > c->leb_size \|\| c->ihead_offs & 7) {
	222	err = 8;
	223	goto out;
	224	}
	225
	226	main_sz = (long long)c->main_lebs * c->leb_size;
b137545c	227	if (c->bi.old_idx_sz & 7 \|\| c->bi.old_idx_sz >= main_sz) {
1e51764a AB	228	err = 9;
	229	goto out;
	230	}
	231
	232	if (c->lpt_lnum < c->lpt_first \|\| c->lpt_lnum > c->lpt_last \|\|
	233	c->lpt_offs < 0 \|\| c->lpt_offs + c->nnode_sz > c->leb_size) {
	234	err = 10;
	235	goto out;
	236	}
	237
	238	if (c->nhead_lnum < c->lpt_first \|\| c->nhead_lnum > c->lpt_last \|\|
	239	c->nhead_offs < 0 \|\| c->nhead_offs % c->min_io_size \|\|
	240	c->nhead_offs > c->leb_size) {
	241	err = 11;
	242	goto out;
	243	}
	244
	245	if (c->ltab_lnum < c->lpt_first \|\| c->ltab_lnum > c->lpt_last \|\|
	246	c->ltab_offs < 0 \|\|
	247	c->ltab_offs + c->ltab_sz > c->leb_size) {
	248	err = 12;
	249	goto out;
	250	}
	251
	252	if (c->big_lpt && (c->lsave_lnum < c->lpt_first \|\|
	253	c->lsave_lnum > c->lpt_last \|\| c->lsave_offs < 0 \|\|
	254	c->lsave_offs + c->lsave_sz > c->leb_size)) {
	255	err = 13;
	256	goto out;
	257	}
	258
	259	if (c->lscan_lnum < c->main_first \|\| c->lscan_lnum >= c->leb_cnt) {
	260	err = 14;
	261	goto out;
	262	}
	263
	264	if (c->lst.empty_lebs < 0 \|\| c->lst.empty_lebs > c->main_lebs - 2) {
	265	err = 15;
	266	goto out;
	267	}
	268
	269	if (c->lst.idx_lebs < 0 \|\| c->lst.idx_lebs > c->main_lebs - 1) {
	270	err = 16;
	271	goto out;
	272	}
	273
	274	if (c->lst.total_free < 0 \|\| c->lst.total_free > main_sz \|\|
	275	c->lst.total_free & 7) {
	276	err = 17;
	277	goto out;
	278	}
	279
	280	if (c->lst.total_dirty < 0 \|\| (c->lst.total_dirty & 7)) {
	281	err = 18;
	282	goto out;
	283	}
	284
	285	if (c->lst.total_used < 0 \|\| (c->lst.total_used & 7)) {
	286	err = 19;
	287	goto out;
	288	}
	289
	290	if (c->lst.total_free + c->lst.total_dirty +
	291	c->lst.total_used > main_sz) {
292	err = 20;
293	goto out;
294	}
295
296	if (c->lst.total_dead + c->lst.total_dark +
b137545c	297	c->lst.total_used + c->bi.old_idx_sz > main_sz) {
1e51764a AB	298	err = 21;
	299	goto out;
	300	}
	301
	302	if (c->lst.total_dead < 0 \|\|
	303	c->lst.total_dead > c->lst.total_free + c->lst.total_dirty \|\|
	304	c->lst.total_dead & 7) {
	305	err = 22;
	306	goto out;
	307	}
	308
	309	if (c->lst.total_dark < 0 \|\|
	310	c->lst.total_dark > c->lst.total_free + c->lst.total_dirty \|\|
	311	c->lst.total_dark & 7) {
	312	err = 23;
	313	goto out;
	314	}
	315
	316	return 0;
	317
	318	out:
235c362b	319	ubifs_err(c, "bad master node at offset %d error %d", c->mst_offs, err);
edf6be24	320	ubifs_dump_node(c, c->mst_node);
1e51764a AB	321	return -EINVAL;
	322	}
	323
	324	/**
	325	* ubifs_read_master - read master node.
	326	* @c: UBIFS file-system description object
	327	*
	328	* This function finds and reads the master node during file-system mount. If
	329	* the flash is empty, it creates default master node as well. Returns zero in
	330	* case of success and a negative error code in case of failure.
	331	*/
	332	int ubifs_read_master(struct ubifs_info *c)
	333	{
	334	int err, old_leb_cnt;
	335
	336	c->mst_node = kzalloc(c->mst_node_alsz, GFP_KERNEL);
	337	if (!c->mst_node)
	338	return -ENOMEM;
	339
	340	err = scan_for_master(c);
	341	if (err) {
0dcd18e4 AB	342	if (err == -EUCLEAN)
0dcd18e4 AB	343	err = ubifs_recover_master_node(c);
1e51764a AB	344	if (err)
	345	/*
	346	* Note, we do not free 'c->mst_node' here because the
	347	* unmount routine will take care of this.
	348	*/
	349	return err;
	350	}
	351
	352	/* Make sure that the recovery flag is clear */
	353	c->mst_node->flags &= cpu_to_le32(~UBIFS_MST_RCVRY);
	354
	355	c->max_sqnum = le64_to_cpu(c->mst_node->ch.sqnum);
	356	c->highest_inum = le64_to_cpu(c->mst_node->highest_inum);
	357	c->cmt_no = le64_to_cpu(c->mst_node->cmt_no);
	358	c->zroot.lnum = le32_to_cpu(c->mst_node->root_lnum);
	359	c->zroot.offs = le32_to_cpu(c->mst_node->root_offs);
	360	c->zroot.len = le32_to_cpu(c->mst_node->root_len);
	361	c->lhead_lnum = le32_to_cpu(c->mst_node->log_lnum);
	362	c->gc_lnum = le32_to_cpu(c->mst_node->gc_lnum);
	363	c->ihead_lnum = le32_to_cpu(c->mst_node->ihead_lnum);
	364	c->ihead_offs = le32_to_cpu(c->mst_node->ihead_offs);
b137545c	365	c->bi.old_idx_sz = le64_to_cpu(c->mst_node->index_size);
1e51764a AB	366	c->lpt_lnum = le32_to_cpu(c->mst_node->lpt_lnum);
	367	c->lpt_offs = le32_to_cpu(c->mst_node->lpt_offs);
	368	c->nhead_lnum = le32_to_cpu(c->mst_node->nhead_lnum);
	369	c->nhead_offs = le32_to_cpu(c->mst_node->nhead_offs);
	370	c->ltab_lnum = le32_to_cpu(c->mst_node->ltab_lnum);
	371	c->ltab_offs = le32_to_cpu(c->mst_node->ltab_offs);
	372	c->lsave_lnum = le32_to_cpu(c->mst_node->lsave_lnum);
	373	c->lsave_offs = le32_to_cpu(c->mst_node->lsave_offs);
	374	c->lscan_lnum = le32_to_cpu(c->mst_node->lscan_lnum);
	375	c->lst.empty_lebs = le32_to_cpu(c->mst_node->empty_lebs);
	376	c->lst.idx_lebs = le32_to_cpu(c->mst_node->idx_lebs);
	377	old_leb_cnt = le32_to_cpu(c->mst_node->leb_cnt);
	378	c->lst.total_free = le64_to_cpu(c->mst_node->total_free);
	379	c->lst.total_dirty = le64_to_cpu(c->mst_node->total_dirty);
	380	c->lst.total_used = le64_to_cpu(c->mst_node->total_used);
	381	c->lst.total_dead = le64_to_cpu(c->mst_node->total_dead);
	382	c->lst.total_dark = le64_to_cpu(c->mst_node->total_dark);
	383
16a26b20 SH	384	ubifs_copy_hash(c, c->mst_node->hash_root_idx, c->zroot.hash);
16a26b20 SH	385
b137545c	386	c->calc_idx_sz = c->bi.old_idx_sz;
1e51764a AB	387
	388	if (c->mst_node->flags & cpu_to_le32(UBIFS_MST_NO_ORPHS))
	389	c->no_orphs = 1;
	390
	391	if (old_leb_cnt != c->leb_cnt) {
	392	/* The file system has been resized */
	393	int growth = c->leb_cnt - old_leb_cnt;
	394
	395	if (c->leb_cnt < old_leb_cnt \|\|
	396	c->leb_cnt < UBIFS_MIN_LEB_CNT) {
235c362b	397	ubifs_err(c, "bad leb_cnt on master node");
edf6be24	398	ubifs_dump_node(c, c->mst_node);
1e51764a AB	399	return -EINVAL;
	400	}
	401
	402	dbg_mnt("Auto resizing (master) from %d LEBs to %d LEBs",
	403	old_leb_cnt, c->leb_cnt);
	404	c->lst.empty_lebs += growth;
	405	c->lst.total_free += growth * (long long)c->leb_size;
	406	c->lst.total_dark += growth * (long long)c->dark_wm;
	407
	408	/*
	409	* Reflect changes back onto the master node. N.B. the master
	410	* node gets written immediately whenever mounting (or
	411	* remounting) in read-write mode, so we do not need to write it
	412	* here.
	413	*/
	414	c->mst_node->leb_cnt = cpu_to_le32(c->leb_cnt);
	415	c->mst_node->empty_lebs = cpu_to_le32(c->lst.empty_lebs);
	416	c->mst_node->total_free = cpu_to_le64(c->lst.total_free);
	417	c->mst_node->total_dark = cpu_to_le64(c->lst.total_dark);
	418	}
	419
	420	err = validate_master(c);
	421	if (err)
	422	return err;
	423
	424	err = dbg_old_index_check_init(c, &c->zroot);
	425
	426	return err;
	427	}
	428
	429	/**
	430	* ubifs_write_master - write master node.
	431	* @c: UBIFS file-system description object
	432	*
07e19dff AB	433	* This function writes the master node. Returns zero in case of success and a
	434	* negative error code in case of failure. The master node is written twice to
	435	* enable recovery.
1e51764a AB	436	*/
	437	int ubifs_write_master(struct ubifs_info *c)
	438	{
	439	int err, lnum, offs, len;
	440
6eb61d58	441	ubifs_assert(c, !c->ro_media && !c->ro_mount);
2680d722	442	if (c->ro_error)
a2b9df3f	443	return -EROFS;
1e51764a AB	444
	445	lnum = UBIFS_MST_LNUM;
	446	offs = c->mst_offs + c->mst_node_alsz;
	447	len = UBIFS_MST_NODE_SZ;
	448
	449	if (offs + UBIFS_MST_NODE_SZ > c->leb_size) {
	450	err = ubifs_leb_unmap(c, lnum);
	451	if (err)
	452	return err;
	453	offs = 0;
	454	}
	455
	456	c->mst_offs = offs;
	457	c->mst_node->highest_inum = cpu_to_le64(c->highest_inum);
	458
16a26b20	459	ubifs_copy_hash(c, c->zroot.hash, c->mst_node->hash_root_idx);
625700cc SH	460	err = ubifs_write_node_hmac(c, c->mst_node, len, lnum, offs,
625700cc SH	461	offsetof(struct ubifs_mst_node, hmac));
1e51764a AB	462	if (err)
	463	return err;
	464
	465	lnum += 1;
	466
	467	if (offs == 0) {
	468	err = ubifs_leb_unmap(c, lnum);
	469	if (err)
	470	return err;
	471	}
625700cc SH	472	err = ubifs_write_node_hmac(c, c->mst_node, len, lnum, offs,
625700cc SH	473	offsetof(struct ubifs_mst_node, hmac));
1e51764a AB	474
	475	return err;
	476	}