[mirror_ubuntu-jammy-kernel.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;
}

/**
 * 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;

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