[people/ms/u-boot.git] / fs / ubifs / scan.c

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

/*
 * This file implements the scan which is a general-purpose function for
 * determining what nodes are in an eraseblock. The scan is used to replay the
 * journal, to do garbage collection. for the TNC in-the-gaps method, and by
 * debugging functions.
 */

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

/**
 * scan_padding_bytes - scan for padding bytes.
 * @buf: buffer to scan
 * @len: length of buffer
 *
 * This function returns the number of padding bytes on success and
 * %SCANNED_GARBAGE on failure.
 */
static int scan_padding_bytes(void *buf, int len)
{
	int pad_len = 0, max_pad_len = min_t(int, UBIFS_PAD_NODE_SZ, len);
	uint8_t *p = buf;

	dbg_scan("not a node");

	while (pad_len < max_pad_len && *p++ == UBIFS_PADDING_BYTE)
		pad_len += 1;

	if (!pad_len || (pad_len & 7))
		return SCANNED_GARBAGE;

	dbg_scan("%d padding bytes", pad_len);

	return pad_len;
}

/**
 * ubifs_scan_a_node - scan for a node or padding.
 * @c: UBIFS file-system description object
 * @buf: buffer to scan
 * @len: length of buffer
 * @lnum: logical eraseblock number
 * @offs: offset within the logical eraseblock
 * @quiet: print no messages
 *
 * This function returns a scanning code to indicate what was scanned.
 */
int ubifs_scan_a_node(const struct ubifs_info *c, void *buf, int len, int lnum,
		      int offs, int quiet)
{
	struct ubifs_ch *ch = buf;
	uint32_t magic;

	magic = le32_to_cpu(ch->magic);

	if (magic == 0xFFFFFFFF) {
		dbg_scan("hit empty space at LEB %d:%d", lnum, offs);
		return SCANNED_EMPTY_SPACE;
	}

	if (magic != UBIFS_NODE_MAGIC)
		return scan_padding_bytes(buf, len);

	if (len < UBIFS_CH_SZ)
		return SCANNED_GARBAGE;

	dbg_scan("scanning %s at LEB %d:%d",
		 dbg_ntype(ch->node_type), lnum, offs);

	if (ubifs_check_node(c, buf, lnum, offs, quiet, 1))
		return SCANNED_A_CORRUPT_NODE;

	if (ch->node_type == UBIFS_PAD_NODE) {
		struct ubifs_pad_node *pad = buf;
		int pad_len = le32_to_cpu(pad->pad_len);
		int node_len = le32_to_cpu(ch->len);

		/* Validate the padding node */
		if (pad_len < 0 ||
		    offs + node_len + pad_len > c->leb_size) {
			if (!quiet) {
				ubifs_err(c, "bad pad node at LEB %d:%d",
					  lnum, offs);
				ubifs_dump_node(c, pad);
			}
			return SCANNED_A_BAD_PAD_NODE;
		}

		/* Make the node pads to 8-byte boundary */
		if ((node_len + pad_len) & 7) {
			if (!quiet)
				ubifs_err(c, "bad padding length %d - %d",
					  offs, offs + node_len + pad_len);
			return SCANNED_A_BAD_PAD_NODE;
		}

		dbg_scan("%d bytes padded at LEB %d:%d, offset now %d", pad_len,
			 lnum, offs, ALIGN(offs + node_len + pad_len, 8));

		return node_len + pad_len;
	}

	return SCANNED_A_NODE;
}

/**
 * ubifs_start_scan - create LEB scanning information at start of scan.
 * @c: UBIFS file-system description object
 * @lnum: logical eraseblock number
 * @offs: offset to start at (usually zero)
 * @sbuf: scan buffer (must be c->leb_size)
 *
 * This function returns the scanned information on success and a negative error
 * code on failure.
 */
struct ubifs_scan_leb *ubifs_start_scan(const struct ubifs_info *c, int lnum,
					int offs, void *sbuf)
{
	struct ubifs_scan_leb *sleb;
	int err;

	dbg_scan("scan LEB %d:%d", lnum, offs);

	sleb = kzalloc(sizeof(struct ubifs_scan_leb), GFP_NOFS);
	if (!sleb)
		return ERR_PTR(-ENOMEM);

	sleb->lnum = lnum;
	INIT_LIST_HEAD(&sleb->nodes);
	sleb->buf = sbuf;

	err = ubifs_leb_read(c, lnum, sbuf + offs, offs, c->leb_size - offs, 0);
	if (err && err != -EBADMSG) {
		ubifs_err(c, "cannot read %d bytes from LEB %d:%d, error %d",
			  c->leb_size - offs, lnum, offs, err);
		kfree(sleb);
		return ERR_PTR(err);
	}

	/*
	 * Note, we ignore integrity errors (EBASMSG) because all the nodes are
	 * protected by CRC checksums.
	 */
	return sleb;
}

/**
 * ubifs_end_scan - update LEB scanning information at end of scan.
 * @c: UBIFS file-system description object
 * @sleb: scanning information
 * @lnum: logical eraseblock number
 * @offs: offset to start at (usually zero)
 */
void ubifs_end_scan(const struct ubifs_info *c, struct ubifs_scan_leb *sleb,
		    int lnum, int offs)
{
	lnum = lnum;
	dbg_scan("stop scanning LEB %d at offset %d", lnum, offs);
	ubifs_assert(offs % c->min_io_size == 0);

	sleb->endpt = ALIGN(offs, c->min_io_size);
}

/**
 * ubifs_add_snod - add a scanned node to LEB scanning information.
 * @c: UBIFS file-system description object
 * @sleb: scanning information
 * @buf: buffer containing node
 * @offs: offset of node on flash
 *
 * This function returns %0 on success and a negative error code on failure.
 */
int ubifs_add_snod(const struct ubifs_info *c, struct ubifs_scan_leb *sleb,
		   void *buf, int offs)
{
	struct ubifs_ch *ch = buf;
	struct ubifs_ino_node *ino = buf;
	struct ubifs_scan_node *snod;

	snod = kmalloc(sizeof(struct ubifs_scan_node), GFP_NOFS);
	if (!snod)
		return -ENOMEM;

	snod->sqnum = le64_to_cpu(ch->sqnum);
	snod->type = ch->node_type;
	snod->offs = offs;
	snod->len = le32_to_cpu(ch->len);
	snod->node = buf;

	switch (ch->node_type) {
	case UBIFS_INO_NODE:
	case UBIFS_DENT_NODE:
	case UBIFS_XENT_NODE:
	case UBIFS_DATA_NODE:
		/*
		 * The key is in the same place in all keyed
		 * nodes.
		 */
		key_read(c, &ino->key, &snod->key);
		break;
	default:
		invalid_key_init(c, &snod->key);
		break;
	}
	list_add_tail(&snod->list, &sleb->nodes);
	sleb->nodes_cnt += 1;
	return 0;
}

/**
 * ubifs_scanned_corruption - print information after UBIFS scanned corruption.
 * @c: UBIFS file-system description object
 * @lnum: LEB number of corruption
 * @offs: offset of corruption
 * @buf: buffer containing corruption
 */
void ubifs_scanned_corruption(const struct ubifs_info *c, int lnum, int offs,
			      void *buf)
{
	int len;

	ubifs_err(c, "corruption at LEB %d:%d", lnum, offs);
	len = c->leb_size - offs;
	if (len > 8192)
		len = 8192;
	ubifs_err(c, "first %d bytes from LEB %d:%d", len, lnum, offs);
	print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 4, buf, len, 1);
}

/**
 * ubifs_scan - scan a logical eraseblock.
 * @c: UBIFS file-system description object
 * @lnum: logical eraseblock number
 * @offs: offset to start at (usually zero)
 * @sbuf: scan buffer (must be of @c->leb_size bytes in size)
 * @quiet: print no messages
 *
 * This function scans LEB number @lnum and returns complete information about
 * its contents. Returns the scanned information in case of success and,
 * %-EUCLEAN if the LEB neads recovery, and other negative error codes in case
 * of failure.
 *
 * If @quiet is non-zero, this function does not print large and scary
 * error messages and flash dumps in case of errors.
 */
struct ubifs_scan_leb *ubifs_scan(const struct ubifs_info *c, int lnum,
				  int offs, void *sbuf, int quiet)
{
	void *buf = sbuf + offs;
	int err, len = c->leb_size - offs;
	struct ubifs_scan_leb *sleb;

	sleb = ubifs_start_scan(c, lnum, offs, sbuf);
	if (IS_ERR(sleb))
		return sleb;

	while (len >= 8) {
		struct ubifs_ch *ch = buf;
		int node_len, ret;

		dbg_scan("look at LEB %d:%d (%d bytes left)",
			 lnum, offs, len);

		cond_resched();

		ret = ubifs_scan_a_node(c, buf, len, lnum, offs, quiet);
		if (ret > 0) {
			/* Padding bytes or a valid padding node */
			offs += ret;
			buf += ret;
			len -= ret;
			continue;
		}

		if (ret == SCANNED_EMPTY_SPACE)
			/* Empty space is checked later */
			break;

		switch (ret) {
		case SCANNED_GARBAGE:
			ubifs_err(c, "garbage");
			goto corrupted;
		case SCANNED_A_NODE:
			break;
		case SCANNED_A_CORRUPT_NODE:
		case SCANNED_A_BAD_PAD_NODE:
			ubifs_err(c, "bad node");
			goto corrupted;
		default:
			ubifs_err(c, "unknown");
			err = -EINVAL;
			goto error;
		}

		err = ubifs_add_snod(c, sleb, buf, offs);
		if (err)
			goto error;

		node_len = ALIGN(le32_to_cpu(ch->len), 8);
		offs += node_len;
		buf += node_len;
		len -= node_len;
	}

	if (offs % c->min_io_size) {
		if (!quiet)
			ubifs_err(c, "empty space starts at non-aligned offset %d",
				  offs);
		goto corrupted;
	}

	ubifs_end_scan(c, sleb, lnum, offs);

	for (; len > 4; offs += 4, buf = buf + 4, len -= 4)
		if (*(uint32_t *)buf != 0xffffffff)
			break;
	for (; len; offs++, buf++, len--)
		if (*(uint8_t *)buf != 0xff) {
			if (!quiet)
				ubifs_err(c, "corrupt empty space at LEB %d:%d",
					  lnum, offs);
			goto corrupted;
		}

	return sleb;

corrupted:
	if (!quiet) {
		ubifs_scanned_corruption(c, lnum, offs, buf);
		ubifs_err(c, "LEB %d scanning failed", lnum);
	}
	err = -EUCLEAN;
	ubifs_scan_destroy(sleb);
	return ERR_PTR(err);

error:
	ubifs_err(c, "LEB %d scanning failed, error %d", lnum, err);
	ubifs_scan_destroy(sleb);
	return ERR_PTR(err);
}

/**
 * ubifs_scan_destroy - destroy LEB scanning information.
 * @sleb: scanning information to free
 */
void ubifs_scan_destroy(struct ubifs_scan_leb *sleb)
{
	struct ubifs_scan_node *node;
	struct list_head *head;

	head = &sleb->nodes;
	while (!list_empty(head)) {
		node = list_entry(head->next, struct ubifs_scan_node, list);
		list_del(&node->list);
		kfree(node);
	}
	kfree(sleb);
}
Commit	Line	Data
9eefe2a2 SR	1	/*
	2	* This file is part of UBIFS.
	3	*
	4	* Copyright (C) 2006-2008 Nokia Corporation
	5	*
ff94bc40	6	* SPDX-License-Identifier: GPL-2.0+
9eefe2a2 SR	7	*
	8	* Authors: Adrian Hunter
	9	* Artem Bityutskiy (Битюцкий Артём)
	10	*/
	11
	12	/*
	13	* This file implements the scan which is a general-purpose function for
	14	* determining what nodes are in an eraseblock. The scan is used to replay the
	15	* journal, to do garbage collection. for the TNC in-the-gaps method, and by
	16	* debugging functions.
	17	*/
	18
ff94bc40 HS	19	#ifdef __UBOOT__
	20	#include <linux/err.h>
	21	#endif
9eefe2a2 SR	22	#include "ubifs.h"
	23
	24	/**
	25	* scan_padding_bytes - scan for padding bytes.
	26	* @buf: buffer to scan
	27	* @len: length of buffer
	28	*
	29	* This function returns the number of padding bytes on success and
	30	* %SCANNED_GARBAGE on failure.
	31	*/
	32	static int scan_padding_bytes(void *buf, int len)
	33	{
	34	int pad_len = 0, max_pad_len = min_t(int, UBIFS_PAD_NODE_SZ, len);
	35	uint8_t *p = buf;
	36
	37	dbg_scan("not a node");
	38
	39	while (pad_len < max_pad_len && *p++ == UBIFS_PADDING_BYTE)
	40	pad_len += 1;
	41
	42	if (!pad_len \|\| (pad_len & 7))
	43	return SCANNED_GARBAGE;
	44
	45	dbg_scan("%d padding bytes", pad_len);
	46
	47	return pad_len;
	48	}
	49
	50	/**
	51	* ubifs_scan_a_node - scan for a node or padding.
	52	* @c: UBIFS file-system description object
	53	* @buf: buffer to scan
	54	* @len: length of buffer
	55	* @lnum: logical eraseblock number
	56	* @offs: offset within the logical eraseblock
	57	* @quiet: print no messages
	58	*
	59	* This function returns a scanning code to indicate what was scanned.
	60	*/
	61	int ubifs_scan_a_node(const struct ubifs_info c, void buf, int len, int lnum,
	62	int offs, int quiet)
	63	{
	64	struct ubifs_ch *ch = buf;
	65	uint32_t magic;
	66
	67	magic = le32_to_cpu(ch->magic);
	68
	69	if (magic == 0xFFFFFFFF) {
ff94bc40	70	dbg_scan("hit empty space at LEB %d:%d", lnum, offs);
9eefe2a2 SR	71	return SCANNED_EMPTY_SPACE;
	72	}
	73
	74	if (magic != UBIFS_NODE_MAGIC)
	75	return scan_padding_bytes(buf, len);
	76
	77	if (len < UBIFS_CH_SZ)
	78	return SCANNED_GARBAGE;
	79
ff94bc40 HS	80	dbg_scan("scanning %s at LEB %d:%d",
ff94bc40 HS	81	dbg_ntype(ch->node_type), lnum, offs);
9eefe2a2 SR	82
	83	if (ubifs_check_node(c, buf, lnum, offs, quiet, 1))
	84	return SCANNED_A_CORRUPT_NODE;
	85
	86	if (ch->node_type == UBIFS_PAD_NODE) {
	87	struct ubifs_pad_node *pad = buf;
	88	int pad_len = le32_to_cpu(pad->pad_len);
	89	int node_len = le32_to_cpu(ch->len);
	90
	91	/* Validate the padding node */
	92	if (pad_len < 0 \|\|
	93	offs + node_len + pad_len > c->leb_size) {
	94	if (!quiet) {
0195a7bb	95	ubifs_err(c, "bad pad node at LEB %d:%d",
9eefe2a2	96	lnum, offs);
ff94bc40	97	ubifs_dump_node(c, pad);
9eefe2a2 SR	98	}
	99	return SCANNED_A_BAD_PAD_NODE;
	100	}
	101
	102	/* Make the node pads to 8-byte boundary */
	103	if ((node_len + pad_len) & 7) {
ff94bc40	104	if (!quiet)
0195a7bb	105	ubifs_err(c, "bad padding length %d - %d",
ff94bc40	106	offs, offs + node_len + pad_len);
9eefe2a2 SR	107	return SCANNED_A_BAD_PAD_NODE;
	108	}
	109
ff94bc40 HS	110	dbg_scan("%d bytes padded at LEB %d:%d, offset now %d", pad_len,
ff94bc40 HS	111	lnum, offs, ALIGN(offs + node_len + pad_len, 8));
9eefe2a2 SR	112
	113	return node_len + pad_len;
	114	}
	115
	116	return SCANNED_A_NODE;
	117	}
	118
	119	/**
	120	* ubifs_start_scan - create LEB scanning information at start of scan.
	121	* @c: UBIFS file-system description object
	122	* @lnum: logical eraseblock number
	123	* @offs: offset to start at (usually zero)
	124	* @sbuf: scan buffer (must be c->leb_size)
	125	*
0195a7bb HS	126	* This function returns the scanned information on success and a negative error
0195a7bb HS	127	* code on failure.
9eefe2a2 SR	128	*/
	129	struct ubifs_scan_leb ubifs_start_scan(const struct ubifs_info c, int lnum,
	130	int offs, void *sbuf)
	131	{
	132	struct ubifs_scan_leb *sleb;
	133	int err;
	134
	135	dbg_scan("scan LEB %d:%d", lnum, offs);
	136
	137	sleb = kzalloc(sizeof(struct ubifs_scan_leb), GFP_NOFS);
	138	if (!sleb)
	139	return ERR_PTR(-ENOMEM);
	140
	141	sleb->lnum = lnum;
	142	INIT_LIST_HEAD(&sleb->nodes);
	143	sleb->buf = sbuf;
	144
ff94bc40	145	err = ubifs_leb_read(c, lnum, sbuf + offs, offs, c->leb_size - offs, 0);
9eefe2a2	146	if (err && err != -EBADMSG) {
0195a7bb	147	ubifs_err(c, "cannot read %d bytes from LEB %d:%d, error %d",
ff94bc40	148	c->leb_size - offs, lnum, offs, err);
9eefe2a2 SR	149	kfree(sleb);
	150	return ERR_PTR(err);
	151	}
	152
0195a7bb HS	153	/*
	154	* Note, we ignore integrity errors (EBASMSG) because all the nodes are
	155	* protected by CRC checksums.
	156	*/
9eefe2a2 SR	157	return sleb;
	158	}
	159
	160	/**
	161	* ubifs_end_scan - update LEB scanning information at end of scan.
	162	* @c: UBIFS file-system description object
	163	* @sleb: scanning information
	164	* @lnum: logical eraseblock number
	165	* @offs: offset to start at (usually zero)
9eefe2a2 SR	166	*/
	167	void ubifs_end_scan(const struct ubifs_info c, struct ubifs_scan_leb sleb,
	168	int lnum, int offs)
	169	{
	170	lnum = lnum;
	171	dbg_scan("stop scanning LEB %d at offset %d", lnum, offs);
	172	ubifs_assert(offs % c->min_io_size == 0);
	173
	174	sleb->endpt = ALIGN(offs, c->min_io_size);
	175	}
	176
	177	/**
	178	* ubifs_add_snod - add a scanned node to LEB scanning information.
	179	* @c: UBIFS file-system description object
	180	* @sleb: scanning information
	181	* @buf: buffer containing node
	182	* @offs: offset of node on flash
	183	*
	184	* This function returns %0 on success and a negative error code on failure.
	185	*/
	186	int ubifs_add_snod(const struct ubifs_info c, struct ubifs_scan_leb sleb,
	187	void *buf, int offs)
	188	{
	189	struct ubifs_ch *ch = buf;
	190	struct ubifs_ino_node *ino = buf;
	191	struct ubifs_scan_node *snod;
	192
ff94bc40	193	snod = kmalloc(sizeof(struct ubifs_scan_node), GFP_NOFS);
9eefe2a2 SR	194	if (!snod)
	195	return -ENOMEM;
	196
	197	snod->sqnum = le64_to_cpu(ch->sqnum);
	198	snod->type = ch->node_type;
	199	snod->offs = offs;
	200	snod->len = le32_to_cpu(ch->len);
	201	snod->node = buf;
	202
	203	switch (ch->node_type) {
	204	case UBIFS_INO_NODE:
	205	case UBIFS_DENT_NODE:
	206	case UBIFS_XENT_NODE:
	207	case UBIFS_DATA_NODE:
9eefe2a2 SR	208	/*
	209	* The key is in the same place in all keyed
	210	* nodes.
	211	*/
	212	key_read(c, &ino->key, &snod->key);
	213	break;
ff94bc40 HS	214	default:
	215	invalid_key_init(c, &snod->key);
	216	break;
9eefe2a2 SR	217	}
	218	list_add_tail(&snod->list, &sleb->nodes);
	219	sleb->nodes_cnt += 1;
	220	return 0;
	221	}
	222
	223	/**
	224	* ubifs_scanned_corruption - print information after UBIFS scanned corruption.
	225	* @c: UBIFS file-system description object
	226	* @lnum: LEB number of corruption
	227	* @offs: offset of corruption
	228	* @buf: buffer containing corruption
	229	*/
	230	void ubifs_scanned_corruption(const struct ubifs_info *c, int lnum, int offs,
	231	void *buf)
	232	{
	233	int len;
	234
0195a7bb	235	ubifs_err(c, "corruption at LEB %d:%d", lnum, offs);
9eefe2a2	236	len = c->leb_size - offs;
ff94bc40 HS	237	if (len > 8192)
ff94bc40 HS	238	len = 8192;
0195a7bb	239	ubifs_err(c, "first %d bytes from LEB %d:%d", len, lnum, offs);
9eefe2a2 SR	240	print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 4, buf, len, 1);
	241	}
	242
	243	/**
	244	* ubifs_scan - scan a logical eraseblock.
	245	* @c: UBIFS file-system description object
	246	* @lnum: logical eraseblock number
	247	* @offs: offset to start at (usually zero)
ff94bc40 HS	248	* @sbuf: scan buffer (must be of @c->leb_size bytes in size)
ff94bc40 HS	249	* @quiet: print no messages
9eefe2a2 SR	250	*
9eefe2a2 SR	251	* This function scans LEB number @lnum and returns complete information about
0195a7bb	252	* its contents. Returns the scanned information in case of success and,
ff94bc40 HS	253	* %-EUCLEAN if the LEB neads recovery, and other negative error codes in case
	254	* of failure.
	255	*
	256	* If @quiet is non-zero, this function does not print large and scary
	257	* error messages and flash dumps in case of errors.
9eefe2a2 SR	258	*/
9eefe2a2 SR	259	struct ubifs_scan_leb ubifs_scan(const struct ubifs_info c, int lnum,
ff94bc40	260	int offs, void *sbuf, int quiet)
9eefe2a2 SR	261	{
	262	void *buf = sbuf + offs;
	263	int err, len = c->leb_size - offs;
	264	struct ubifs_scan_leb *sleb;
	265
	266	sleb = ubifs_start_scan(c, lnum, offs, sbuf);
	267	if (IS_ERR(sleb))
	268	return sleb;
	269
	270	while (len >= 8) {
	271	struct ubifs_ch *ch = buf;
	272	int node_len, ret;
	273
	274	dbg_scan("look at LEB %d:%d (%d bytes left)",
	275	lnum, offs, len);
	276
	277	cond_resched();
	278
ff94bc40	279	ret = ubifs_scan_a_node(c, buf, len, lnum, offs, quiet);
9eefe2a2 SR	280	if (ret > 0) {
	281	/* Padding bytes or a valid padding node */
	282	offs += ret;
	283	buf += ret;
	284	len -= ret;
	285	continue;
	286	}
	287
	288	if (ret == SCANNED_EMPTY_SPACE)
	289	/* Empty space is checked later */
	290	break;
	291
	292	switch (ret) {
	293	case SCANNED_GARBAGE:
0195a7bb	294	ubifs_err(c, "garbage");
9eefe2a2 SR	295	goto corrupted;
	296	case SCANNED_A_NODE:
	297	break;
	298	case SCANNED_A_CORRUPT_NODE:
	299	case SCANNED_A_BAD_PAD_NODE:
0195a7bb	300	ubifs_err(c, "bad node");
9eefe2a2 SR	301	goto corrupted;
9eefe2a2 SR	302	default:
0195a7bb	303	ubifs_err(c, "unknown");
ff94bc40 HS	304	err = -EINVAL;
ff94bc40 HS	305	goto error;
9eefe2a2 SR	306	}
	307
	308	err = ubifs_add_snod(c, sleb, buf, offs);
	309	if (err)
	310	goto error;
	311
	312	node_len = ALIGN(le32_to_cpu(ch->len), 8);
	313	offs += node_len;
	314	buf += node_len;
	315	len -= node_len;
	316	}
	317
ff94bc40 HS	318	if (offs % c->min_io_size) {
ff94bc40 HS	319	if (!quiet)
0195a7bb	320	ubifs_err(c, "empty space starts at non-aligned offset %d",
ff94bc40	321	offs);
9eefe2a2	322	goto corrupted;
ff94bc40	323	}
9eefe2a2 SR	324
	325	ubifs_end_scan(c, sleb, lnum, offs);
	326
	327	for (; len > 4; offs += 4, buf = buf + 4, len -= 4)
	328	if ((uint32_t )buf != 0xffffffff)
	329	break;
	330	for (; len; offs++, buf++, len--)
	331	if ((uint8_t )buf != 0xff) {
ff94bc40	332	if (!quiet)
0195a7bb	333	ubifs_err(c, "corrupt empty space at LEB %d:%d",
ff94bc40	334	lnum, offs);
9eefe2a2 SR	335	goto corrupted;
	336	}
	337
	338	return sleb;
	339
	340	corrupted:
ff94bc40 HS	341	if (!quiet) {
ff94bc40 HS	342	ubifs_scanned_corruption(c, lnum, offs, buf);
0195a7bb	343	ubifs_err(c, "LEB %d scanning failed", lnum);
ff94bc40	344	}
9eefe2a2	345	err = -EUCLEAN;
ff94bc40 HS	346	ubifs_scan_destroy(sleb);
	347	return ERR_PTR(err);
	348
9eefe2a2	349	error:
0195a7bb	350	ubifs_err(c, "LEB %d scanning failed, error %d", lnum, err);
9eefe2a2 SR	351	ubifs_scan_destroy(sleb);
	352	return ERR_PTR(err);
	353	}
	354
	355	/**
	356	* ubifs_scan_destroy - destroy LEB scanning information.
	357	* @sleb: scanning information to free
	358	*/
	359	void ubifs_scan_destroy(struct ubifs_scan_leb *sleb)
	360	{
	361	struct ubifs_scan_node *node;
	362	struct list_head *head;
	363
	364	head = &sleb->nodes;
	365	while (!list_empty(head)) {
	366	node = list_entry(head->next, struct ubifs_scan_node, list);
	367	list_del(&node->list);
	368	kfree(node);
	369	}
	370	kfree(sleb);
	371	}