[net-next-2.6.git] / fs / ubifs / scan.c

/*
 * This file is part of UBIFS.
 *
 * Copyright (C) 2006-2008 Nokia Corporation
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published by
 * the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program; if not, write to the Free Software Foundation, Inc., 51
 * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 *
 * 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.
 */

#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");
		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", dbg_ntype(ch->node_type));

	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("bad pad node at LEB %d:%d",
					  lnum, offs);
				dbg_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)
				dbg_err("bad padding length %d - %d",
					offs, offs + node_len + pad_len);
			return SCANNED_A_BAD_PAD_NODE;
		}

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

	if (err == -EBADMSG)
		sleb->ecc = 1;

	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)
 *
 * This function returns %0 on success and a negative error code on failure.
 */
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("corruption at LEB %d:%d", lnum, offs);
	if (dbg_failure_mode)
		return;
	len = c->leb_size - offs;
	if (len > 8192)
		len = 8192;
	dbg_err("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 scaned 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:
			dbg_err("garbage");
			goto corrupted;
		case SCANNED_A_NODE:
			break;
		case SCANNED_A_CORRUPT_NODE:
		case SCANNED_A_BAD_PAD_NODE:
			dbg_err("bad node");
			goto corrupted;
		default:
			dbg_err("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("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("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("LEB %d scanning failed", lnum);
	}
	err = -EUCLEAN;
	ubifs_scan_destroy(sleb);
	return ERR_PTR(err);

error:
	ubifs_err("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
1e51764a AB	1	/*
	2	* This file is part of UBIFS.
	3	*
	4	* Copyright (C) 2006-2008 Nokia Corporation
	5	*
	6	* This program is free software; you can redistribute it and/or modify it
	7	* under the terms of the GNU General Public License version 2 as published by
	8	* the Free Software Foundation.
	9	*
	10	* This program is distributed in the hope that it will be useful, but WITHOUT
	11	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	12	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
	13	* more details.
	14	*
	15	* You should have received a copy of the GNU General Public License along with
	16	* this program; if not, write to the Free Software Foundation, Inc., 51
	17	* Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
	18	*
	19	* Authors: Adrian Hunter
	20	* Artem Bityutskiy (Битюцкий Артём)
	21	*/
	22
	23	/*
	24	* This file implements the scan which is a general-purpose function for
	25	* determining what nodes are in an eraseblock. The scan is used to replay the
	26	* journal, to do garbage collection. for the TNC in-the-gaps method, and by
	27	* debugging functions.
	28	*/
	29
	30	#include "ubifs.h"
	31
	32	/**
	33	* scan_padding_bytes - scan for padding bytes.
	34	* @buf: buffer to scan
	35	* @len: length of buffer
	36	*
	37	* This function returns the number of padding bytes on success and
	38	* %SCANNED_GARBAGE on failure.
	39	*/
	40	static int scan_padding_bytes(void *buf, int len)
	41	{
	42	int pad_len = 0, max_pad_len = min_t(int, UBIFS_PAD_NODE_SZ, len);
	43	uint8_t *p = buf;
	44
	45	dbg_scan("not a node");
	46
	47	while (pad_len < max_pad_len && *p++ == UBIFS_PADDING_BYTE)
	48	pad_len += 1;
	49
	50	if (!pad_len \|\| (pad_len & 7))
	51	return SCANNED_GARBAGE;
	52
	53	dbg_scan("%d padding bytes", pad_len);
	54
	55	return pad_len;
	56	}
	57
	58	/**
	59	* ubifs_scan_a_node - scan for a node or padding.
	60	* @c: UBIFS file-system description object
	61	* @buf: buffer to scan
	62	* @len: length of buffer
	63	* @lnum: logical eraseblock number
	64	* @offs: offset within the logical eraseblock
65	* @quiet: print no messages
66	*
67	* This function returns a scanning code to indicate what was scanned.
68	*/
69	int ubifs_scan_a_node(const struct ubifs_info c, void buf, int len, int lnum,
70	int offs, int quiet)
71	{
72	struct ubifs_ch *ch = buf;
73	uint32_t magic;
74
75	magic = le32_to_cpu(ch->magic);
76
77	if (magic == 0xFFFFFFFF) {
78	dbg_scan("hit empty space");
79	return SCANNED_EMPTY_SPACE;
80	}
81
82	if (magic != UBIFS_NODE_MAGIC)
83	return scan_padding_bytes(buf, len);
84
85	if (len < UBIFS_CH_SZ)
86	return SCANNED_GARBAGE;
87
88	dbg_scan("scanning %s", dbg_ntype(ch->node_type));
89
2953e73f	90	if (ubifs_check_node(c, buf, lnum, offs, quiet, 1))
1e51764a AB	91	return SCANNED_A_CORRUPT_NODE;
	92
	93	if (ch->node_type == UBIFS_PAD_NODE) {
	94	struct ubifs_pad_node *pad = buf;
	95	int pad_len = le32_to_cpu(pad->pad_len);
	96	int node_len = le32_to_cpu(ch->len);
	97
	98	/* Validate the padding node */
	99	if (pad_len < 0 \|\|
	100	offs + node_len + pad_len > c->leb_size) {
	101	if (!quiet) {
	102	ubifs_err("bad pad node at LEB %d:%d",
	103	lnum, offs);
	104	dbg_dump_node(c, pad);
	105	}
	106	return SCANNED_A_BAD_PAD_NODE;
	107	}
	108
	109	/* Make the node pads to 8-byte boundary */
	110	if ((node_len + pad_len) & 7) {
348709ba	111	if (!quiet)
1e51764a AB	112	dbg_err("bad padding length %d - %d",
1e51764a AB	113	offs, offs + node_len + pad_len);
1e51764a AB	114	return SCANNED_A_BAD_PAD_NODE;
	115	}
	116
	117	dbg_scan("%d bytes padded, offset now %d",
	118	pad_len, ALIGN(offs + node_len + pad_len, 8));
	119
	120	return node_len + pad_len;
	121	}
	122
	123	return SCANNED_A_NODE;
	124	}
	125
	126	/**
	127	* ubifs_start_scan - create LEB scanning information at start of scan.
	128	* @c: UBIFS file-system description object
	129	* @lnum: logical eraseblock number
	130	* @offs: offset to start at (usually zero)
	131	* @sbuf: scan buffer (must be c->leb_size)
	132	*
	133	* This function returns %0 on success and a negative error code on failure.
	134	*/
	135	struct ubifs_scan_leb ubifs_start_scan(const struct ubifs_info c, int lnum,
	136	int offs, void *sbuf)
	137	{
	138	struct ubifs_scan_leb *sleb;
	139	int err;
	140
	141	dbg_scan("scan LEB %d:%d", lnum, offs);
	142
	143	sleb = kzalloc(sizeof(struct ubifs_scan_leb), GFP_NOFS);
	144	if (!sleb)
	145	return ERR_PTR(-ENOMEM);
	146
	147	sleb->lnum = lnum;
	148	INIT_LIST_HEAD(&sleb->nodes);
	149	sleb->buf = sbuf;
	150
	151	err = ubi_read(c->ubi, lnum, sbuf + offs, offs, c->leb_size - offs);
	152	if (err && err != -EBADMSG) {
	153	ubifs_err("cannot read %d bytes from LEB %d:%d,"
	154	" error %d", c->leb_size - offs, lnum, offs, err);
	155	kfree(sleb);
	156	return ERR_PTR(err);
	157	}
	158
	159	if (err == -EBADMSG)
	160	sleb->ecc = 1;
	161
	162	return sleb;
	163	}
	164
	165	/**
	166	* ubifs_end_scan - update LEB scanning information at end of scan.
	167	* @c: UBIFS file-system description object
	168	* @sleb: scanning information
	169	* @lnum: logical eraseblock number
	170	* @offs: offset to start at (usually zero)
	171	*
	172	* This function returns %0 on success and a negative error code on failure.
	173	*/
	174	void ubifs_end_scan(const struct ubifs_info c, struct ubifs_scan_leb sleb,
	175	int lnum, int offs)
	176	{
	177	lnum = lnum;
178	dbg_scan("stop scanning LEB %d at offset %d", lnum, offs);
179	ubifs_assert(offs % c->min_io_size == 0);
180
181	sleb->endpt = ALIGN(offs, c->min_io_size);
182	}
183
184	/**
185	* ubifs_add_snod - add a scanned node to LEB scanning information.
186	* @c: UBIFS file-system description object
187	* @sleb: scanning information
188	* @buf: buffer containing node
189	* @offs: offset of node on flash
190	*
191	* This function returns %0 on success and a negative error code on failure.
192	*/
193	int ubifs_add_snod(const struct ubifs_info c, struct ubifs_scan_leb sleb,
194	void *buf, int offs)
195	{
196	struct ubifs_ch *ch = buf;
197	struct ubifs_ino_node *ino = buf;
198	struct ubifs_scan_node *snod;
199
ba2f48f7	200	snod = kmalloc(sizeof(struct ubifs_scan_node), GFP_NOFS);
1e51764a AB	201	if (!snod)
	202	return -ENOMEM;
	203
	204	snod->sqnum = le64_to_cpu(ch->sqnum);
	205	snod->type = ch->node_type;
	206	snod->offs = offs;
	207	snod->len = le32_to_cpu(ch->len);
	208	snod->node = buf;
	209
	210	switch (ch->node_type) {
	211	case UBIFS_INO_NODE:
	212	case UBIFS_DENT_NODE:
	213	case UBIFS_XENT_NODE:
	214	case UBIFS_DATA_NODE:
1e51764a AB	215	/*
	216	* The key is in the same place in all keyed
	217	* nodes.
	218	*/
	219	key_read(c, &ino->key, &snod->key);
	220	break;
ba2f48f7 AB	221	default:
	222	invalid_key_init(c, &snod->key);
	223	break;
1e51764a AB	224	}
	225	list_add_tail(&snod->list, &sleb->nodes);
	226	sleb->nodes_cnt += 1;
	227	return 0;
	228	}
	229
	230	/**
	231	* ubifs_scanned_corruption - print information after UBIFS scanned corruption.
	232	* @c: UBIFS file-system description object
	233	* @lnum: LEB number of corruption
	234	* @offs: offset of corruption
	235	* @buf: buffer containing corruption
	236	*/
	237	void ubifs_scanned_corruption(const struct ubifs_info *c, int lnum, int offs,
	238	void *buf)
	239	{
	240	int len;
	241
086b3640	242	ubifs_err("corruption at LEB %d:%d", lnum, offs);
1e51764a AB	243	if (dbg_failure_mode)
	244	return;
	245	len = c->leb_size - offs;
086b3640 AB	246	if (len > 8192)
086b3640 AB	247	len = 8192;
1e51764a AB	248	dbg_err("first %d bytes from LEB %d:%d", len, lnum, offs);
	249	print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 4, buf, len, 1);
	250	}
	251
	252	/**
	253	* ubifs_scan - scan a logical eraseblock.
	254	* @c: UBIFS file-system description object
	255	* @lnum: logical eraseblock number
	256	* @offs: offset to start at (usually zero)
348709ba AB	257	* @sbuf: scan buffer (must be of @c->leb_size bytes in size)
348709ba AB	258	* @quiet: print no messages
1e51764a AB	259	*
1e51764a AB	260	* This function scans LEB number @lnum and returns complete information about
ed43f2f0 AB	261	* its contents. Returns the scaned information in case of success and,
	262	* %-EUCLEAN if the LEB neads recovery, and other negative error codes in case
	263	* of failure.
348709ba AB	264	*
	265	* If @quiet is non-zero, this function does not print large and scary
	266	* error messages and flash dumps in case of errors.
1e51764a AB	267	*/
1e51764a AB	268	struct ubifs_scan_leb ubifs_scan(const struct ubifs_info c, int lnum,
348709ba	269	int offs, void *sbuf, int quiet)
1e51764a AB	270	{
	271	void *buf = sbuf + offs;
	272	int err, len = c->leb_size - offs;
	273	struct ubifs_scan_leb *sleb;
	274
	275	sleb = ubifs_start_scan(c, lnum, offs, sbuf);
	276	if (IS_ERR(sleb))
	277	return sleb;
	278
	279	while (len >= 8) {
	280	struct ubifs_ch *ch = buf;
	281	int node_len, ret;
	282
	283	dbg_scan("look at LEB %d:%d (%d bytes left)",
	284	lnum, offs, len);
	285
	286	cond_resched();
	287
348709ba	288	ret = ubifs_scan_a_node(c, buf, len, lnum, offs, quiet);
1e51764a AB	289	if (ret > 0) {
	290	/* Padding bytes or a valid padding node */
	291	offs += ret;
	292	buf += ret;
	293	len -= ret;
	294	continue;
	295	}
	296
	297	if (ret == SCANNED_EMPTY_SPACE)
	298	/* Empty space is checked later */
	299	break;
	300
	301	switch (ret) {
	302	case SCANNED_GARBAGE:
	303	dbg_err("garbage");
	304	goto corrupted;
	305	case SCANNED_A_NODE:
	306	break;
	307	case SCANNED_A_CORRUPT_NODE:
	308	case SCANNED_A_BAD_PAD_NODE:
	309	dbg_err("bad node");
	310	goto corrupted;
	311	default:
	312	dbg_err("unknown");
ed43f2f0 AB	313	err = -EINVAL;
ed43f2f0 AB	314	goto error;
1e51764a AB	315	}
	316
	317	err = ubifs_add_snod(c, sleb, buf, offs);
	318	if (err)
	319	goto error;
	320
	321	node_len = ALIGN(le32_to_cpu(ch->len), 8);
	322	offs += node_len;
	323	buf += node_len;
	324	len -= node_len;
	325	}
	326
ed43f2f0	327	if (offs % c->min_io_size) {
348709ba AB	328	if (!quiet)
	329	ubifs_err("empty space starts at non-aligned offset %d",
	330	offs);
ed43f2f0 AB	331	goto corrupted;;
ed43f2f0 AB	332	}
1e51764a AB	333
	334	ubifs_end_scan(c, sleb, lnum, offs);
	335
	336	for (; len > 4; offs += 4, buf = buf + 4, len -= 4)
	337	if ((uint32_t )buf != 0xffffffff)
	338	break;
	339	for (; len; offs++, buf++, len--)
	340	if ((uint8_t )buf != 0xff) {
348709ba AB	341	if (!quiet)
	342	ubifs_err("corrupt empty space at LEB %d:%d",
	343	lnum, offs);
1e51764a AB	344	goto corrupted;
	345	}
	346
	347	return sleb;
	348
	349	corrupted:
348709ba AB	350	if (!quiet) {
	351	ubifs_scanned_corruption(c, lnum, offs, buf);
	352	ubifs_err("LEB %d scanning failed", lnum);
	353	}
1e51764a	354	err = -EUCLEAN;
348709ba AB	355	ubifs_scan_destroy(sleb);
	356	return ERR_PTR(err);
	357
1e51764a	358	error:
348709ba	359	ubifs_err("LEB %d scanning failed, error %d", lnum, err);
1e51764a AB	360	ubifs_scan_destroy(sleb);
	361	return ERR_PTR(err);
	362	}
	363
	364	/**
	365	* ubifs_scan_destroy - destroy LEB scanning information.
	366	* @sleb: scanning information to free
	367	*/
	368	void ubifs_scan_destroy(struct ubifs_scan_leb *sleb)
	369	{
	370	struct ubifs_scan_node *node;
	371	struct list_head *head;
	372
	373	head = &sleb->nodes;
	374	while (!list_empty(head)) {
	375	node = list_entry(head->next, struct ubifs_scan_node, list);
	376	list_del(&node->list);
	377	kfree(node);
	378	}
	379	kfree(sleb);
	380	}