Orange Pi5 kernel

 // SPDX-License-Identifier: GPL-2.0-only
/*
 * This file is part of UBIFS.
 *
 * Copyright (C) 2006-2008 Nokia Corporation
 *
 * 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 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)
{
<------>dbg_scan("stop scanning LEB %d at offset %d", lnum, offs);
<------>ubifs_assert(c, 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);
}

	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* This file is part of UBIFS.
	*
	* Copyright (C) 2006-2008 Nokia Corporation
	*
	* 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 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)
	{
	<------>dbg_scan("stop scanning LEB %d at offset %d", lnum, offs);
	<------>ubifs_assert(c, 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);
	}