UBI: rename scan.c to attach.c

Finally, rename the scan.c file. Now adding fastmap support won't look that
hacky anymore.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>

1 files changed, 0 insertions, 1615 deletions

diff --git a/drivers/mtd/ubi/scan.c b/drivers/mtd/ubi/scan.c
deleted file mode 100644
index f59f748caf23..000000000000
--- a/drivers/mtd/ubi/scan.c
+++ /dev/null
@@ -1,1615 +0,0 @@
-/*
- * Copyright (c) International Business Machines Corp., 2006
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
- *
- * Author: Artem Bityutskiy (Битюцкий Артём)
- */
-
-/*
- * UBI attaching sub-system.
- *
- * This sub-system is responsible for attaching MTD devices and it also
- * implements flash media scanning.
- *
- * The attaching information is represented by a &struct ubi_attach_info'
- * object. Information about volumes is represented by &struct ubi_ainf_volume
- * objects which are kept in volume RB-tree with root at the @volumes field.
- * The RB-tree is indexed by the volume ID.
- *
- * Logical eraseblocks are represented by &struct ubi_ainf_peb objects. These
- * objects are kept in per-volume RB-trees with the root at the corresponding
- * &struct ubi_ainf_volume object. To put it differently, we keep an RB-tree of
- * per-volume objects and each of these objects is the root of RB-tree of
- * per-LEB objects.
- *
- * Corrupted physical eraseblocks are put to the @corr list, free physical
- * eraseblocks are put to the @free list and the physical eraseblock to be
- * erased are put to the @erase list.
- *
- * About corruptions
- * ~~~~~~~~~~~~~~~~~
- *
- * UBI protects EC and VID headers with CRC-32 checksums, so it can detect
- * whether the headers are corrupted or not. Sometimes UBI also protects the
- * data with CRC-32, e.g., when it executes the atomic LEB change operation, or
- * when it moves the contents of a PEB for wear-leveling purposes.
- *
- * UBI tries to distinguish between 2 types of corruptions.
- *
- * 1. Corruptions caused by power cuts. These are expected corruptions and UBI
- * tries to handle them gracefully, without printing too many warnings and
- * error messages. The idea is that we do not lose important data in these
- * cases - we may lose only the data which were being written to the media just
- * before the power cut happened, and the upper layers (e.g., UBIFS) are
- * supposed to handle such data losses (e.g., by using the FS journal).
- *
- * When UBI detects a corruption (CRC-32 mismatch) in a PEB, and it looks like
- * the reason is a power cut, UBI puts this PEB to the @erase list, and all
- * PEBs in the @erase list are scheduled for erasure later.
- *
- * 2. Unexpected corruptions which are not caused by power cuts. During
- * attaching, such PEBs are put to the @corr list and UBI preserves them.
- * Obviously, this lessens the amount of available PEBs, and if at some  point
- * UBI runs out of free PEBs, it switches to R/O mode. UBI also loudly informs
- * about such PEBs every time the MTD device is attached.
- *
- * However, it is difficult to reliably distinguish between these types of
- * corruptions and UBI's strategy is as follows (in case of attaching by
- * scanning). UBI assumes corruption type 2 if the VID header is corrupted and
- * the data area does not contain all 0xFFs, and there were no bit-flips or
- * integrity errors (e.g., ECC errors in case of NAND) while reading the data
- * area.  Otherwise UBI assumes corruption type 1. So the decision criteria
- * are as follows.
- *   o If the data area contains only 0xFFs, there are no data, and it is safe
- *     to just erase this PEB - this is corruption type 1.
- *   o If the data area has bit-flips or data integrity errors (ECC errors on
- *     NAND), it is probably a PEB which was being erased when power cut
- *     happened, so this is corruption type 1. However, this is just a guess,
- *     which might be wrong.
- *   o Otherwise this it corruption type 2.
- */
-
-#include <linux/err.h>
-#include <linux/slab.h>
-#include <linux/crc32.h>
-#include <linux/math64.h>
-#include <linux/random.h>
-#include "ubi.h"
-
-static int self_check_ai(struct ubi_device *ubi, struct ubi_attach_info *ai);
-
-/* Temporary variables used during scanning */
-static struct ubi_ec_hdr *ech;
-static struct ubi_vid_hdr *vidh;
-
-/**
- * add_to_list - add physical eraseblock to a list.
- * @ai: attaching information
- * @pnum: physical eraseblock number to add
- * @ec: erase counter of the physical eraseblock
- * @to_head: if not zero, add to the head of the list
- * @list: the list to add to
- *
- * This function allocates a 'struct ubi_ainf_peb' object for physical
- * eraseblock @pnum and adds it to the "free", "erase", or "alien" lists.
- * If @to_head is not zero, PEB will be added to the head of the list, which
- * basically means it will be processed first later. E.g., we add corrupted
- * PEBs (corrupted due to power cuts) to the head of the erase list to make
- * sure we erase them first and get rid of corruptions ASAP. This function
- * returns zero in case of success and a negative error code in case of
- * failure.
- */
-static int add_to_list(struct ubi_attach_info *ai, int pnum, int ec,
-		       int to_head, struct list_head *list)
-{
-	struct ubi_ainf_peb *aeb;
-
-	if (list == &ai->free) {
-		dbg_bld("add to free: PEB %d, EC %d", pnum, ec);
-	} else if (list == &ai->erase) {
-		dbg_bld("add to erase: PEB %d, EC %d", pnum, ec);
-	} else if (list == &ai->alien) {
-		dbg_bld("add to alien: PEB %d, EC %d", pnum, ec);
-		ai->alien_peb_count += 1;
-	} else
-		BUG();
-
-	aeb = kmem_cache_alloc(ai->aeb_slab_cache, GFP_KERNEL);
-	if (!aeb)
-		return -ENOMEM;
-
-	aeb->pnum = pnum;
-	aeb->ec = ec;
-	if (to_head)
-		list_add(&aeb->u.list, list);
-	else
-		list_add_tail(&aeb->u.list, list);
-	return 0;
-}
-
-/**
- * add_corrupted - add a corrupted physical eraseblock.
- * @ai: attaching information
- * @pnum: physical eraseblock number to add
- * @ec: erase counter of the physical eraseblock
- *
- * This function allocates a 'struct ubi_ainf_peb' object for a corrupted
- * physical eraseblock @pnum and adds it to the 'corr' list.  The corruption
- * was presumably not caused by a power cut. Returns zero in case of success
- * and a negative error code in case of failure.
- */
-static int add_corrupted(struct ubi_attach_info *ai, int pnum, int ec)
-{
-	struct ubi_ainf_peb *aeb;
-
-	dbg_bld("add to corrupted: PEB %d, EC %d", pnum, ec);
-
-	aeb = kmem_cache_alloc(ai->aeb_slab_cache, GFP_KERNEL);
-	if (!aeb)
-		return -ENOMEM;
-
-	ai->corr_peb_count += 1;
-	aeb->pnum = pnum;
-	aeb->ec = ec;
-	list_add(&aeb->u.list, &ai->corr);
-	return 0;
-}
-
-/**
- * validate_vid_hdr - check volume identifier header.
- * @vid_hdr: the volume identifier header to check
- * @av: information about the volume this logical eraseblock belongs to
- * @pnum: physical eraseblock number the VID header came from
- *
- * This function checks that data stored in @vid_hdr is consistent. Returns
- * non-zero if an inconsistency was found and zero if not.
- *
- * Note, UBI does sanity check of everything it reads from the flash media.
- * Most of the checks are done in the I/O sub-system. Here we check that the
- * information in the VID header is consistent to the information in other VID
- * headers of the same volume.
- */
-static int validate_vid_hdr(const struct ubi_vid_hdr *vid_hdr,
-			    const struct ubi_ainf_volume *av, int pnum)
-{
-	int vol_type = vid_hdr->vol_type;
-	int vol_id = be32_to_cpu(vid_hdr->vol_id);
-	int used_ebs = be32_to_cpu(vid_hdr->used_ebs);
-	int data_pad = be32_to_cpu(vid_hdr->data_pad);
-
-	if (av->leb_count != 0) {
-		int av_vol_type;
-
-		/*
-		 * This is not the first logical eraseblock belonging to this
-		 * volume. Ensure that the data in its VID header is consistent
-		 * to the data in previous logical eraseblock headers.
-		 */
-
-		if (vol_id != av->vol_id) {
-			ubi_err("inconsistent vol_id");
-			goto bad;
-		}
-
-		if (av->vol_type == UBI_STATIC_VOLUME)
-			av_vol_type = UBI_VID_STATIC;
-		else
-			av_vol_type = UBI_VID_DYNAMIC;
-
-		if (vol_type != av_vol_type) {
-			ubi_err("inconsistent vol_type");
-			goto bad;
-		}
-
-		if (used_ebs != av->used_ebs) {
-			ubi_err("inconsistent used_ebs");
-			goto bad;
-		}
-
-		if (data_pad != av->data_pad) {
-			ubi_err("inconsistent data_pad");
-			goto bad;
-		}
-	}
-
-	return 0;
-
-bad:
-	ubi_err("inconsistent VID header at PEB %d", pnum);
-	ubi_dump_vid_hdr(vid_hdr);
-	ubi_dump_av(av);
-	return -EINVAL;
-}
-
-/**
- * add_volume - add volume to the attaching information.
- * @ai: attaching information
- * @vol_id: ID of the volume to add
- * @pnum: physical eraseblock number
- * @vid_hdr: volume identifier header
- *
- * If the volume corresponding to the @vid_hdr logical eraseblock is already
- * present in the attaching information, this function does nothing. Otherwise
- * it adds corresponding volume to the attaching information. Returns a pointer
- * to the allocated "av" object in case of success and a negative error code in
- * case of failure.
- */
-static struct ubi_ainf_volume *add_volume(struct ubi_attach_info *ai,
-					  int vol_id, int pnum,
-					  const struct ubi_vid_hdr *vid_hdr)
-{
-	struct ubi_ainf_volume *av;
-	struct rb_node **p = &ai->volumes.rb_node, *parent = NULL;
-
-	ubi_assert(vol_id == be32_to_cpu(vid_hdr->vol_id));
-
-	/* Walk the volume RB-tree to look if this volume is already present */
-	while (*p) {
-		parent = *p;
-		av = rb_entry(parent, struct ubi_ainf_volume, rb);
-
-		if (vol_id == av->vol_id)
-			return av;
-
-		if (vol_id > av->vol_id)
-			p = &(*p)->rb_left;
-		else
-			p = &(*p)->rb_right;
-	}
-
-	/* The volume is absent - add it */
-	av = kmalloc(sizeof(struct ubi_ainf_volume), GFP_KERNEL);
-	if (!av)
-		return ERR_PTR(-ENOMEM);
-
-	av->highest_lnum = av->leb_count = 0;
-	av->vol_id = vol_id;
-	av->root = RB_ROOT;
-	av->used_ebs = be32_to_cpu(vid_hdr->used_ebs);
-	av->data_pad = be32_to_cpu(vid_hdr->data_pad);
-	av->compat = vid_hdr->compat;
-	av->vol_type = vid_hdr->vol_type == UBI_VID_DYNAMIC ? UBI_DYNAMIC_VOLUME
-							    : UBI_STATIC_VOLUME;
-	if (vol_id > ai->highest_vol_id)
-		ai->highest_vol_id = vol_id;
-
-	rb_link_node(&av->rb, parent, p);
-	rb_insert_color(&av->rb, &ai->volumes);
-	ai->vols_found += 1;
-	dbg_bld("added volume %d", vol_id);
-	return av;
-}
-
-/**
- * compare_lebs - find out which logical eraseblock is newer.
- * @ubi: UBI device description object
- * @aeb: first logical eraseblock to compare
- * @pnum: physical eraseblock number of the second logical eraseblock to
- * compare
- * @vid_hdr: volume identifier header of the second logical eraseblock
- *
- * This function compares 2 copies of a LEB and informs which one is newer. In
- * case of success this function returns a positive value, in case of failure, a
- * negative error code is returned. The success return codes use the following
- * bits:
- *     o bit 0 is cleared: the first PEB (described by @aeb) is newer than the
- *       second PEB (described by @pnum and @vid_hdr);
- *     o bit 0 is set: the second PEB is newer;
- *     o bit 1 is cleared: no bit-flips were detected in the newer LEB;
- *     o bit 1 is set: bit-flips were detected in the newer LEB;
- *     o bit 2 is cleared: the older LEB is not corrupted;
- *     o bit 2 is set: the older LEB is corrupted.
- */
-static int compare_lebs(struct ubi_device *ubi, const struct ubi_ainf_peb *aeb,
-			int pnum, const struct ubi_vid_hdr *vid_hdr)
-{
-	void *buf;
-	int len, err, second_is_newer, bitflips = 0, corrupted = 0;
-	uint32_t data_crc, crc;
-	struct ubi_vid_hdr *vh = NULL;
-	unsigned long long sqnum2 = be64_to_cpu(vid_hdr->sqnum);
-
-	if (sqnum2 == aeb->sqnum) {
-		/*
-		 * This must be a really ancient UBI image which has been
-		 * created before sequence numbers support has been added. At
-		 * that times we used 32-bit LEB versions stored in logical
-		 * eraseblocks. That was before UBI got into mainline. We do not
-		 * support these images anymore. Well, those images still work,
-		 * but only if no unclean reboots happened.
-		 */
-		ubi_err("unsupported on-flash UBI format\n");
-		return -EINVAL;
-	}
-
-	/* Obviously the LEB with lower sequence counter is older */
-	second_is_newer = (sqnum2 > aeb->sqnum);
-
-	/*
-	 * Now we know which copy is newer. If the copy flag of the PEB with
-	 * newer version is not set, then we just return, otherwise we have to
-	 * check data CRC. For the second PEB we already have the VID header,
-	 * for the first one - we'll need to re-read it from flash.
-	 *
-	 * Note: this may be optimized so that we wouldn't read twice.
-	 */
-
-	if (second_is_newer) {
-		if (!vid_hdr->copy_flag) {
-			/* It is not a copy, so it is newer */
-			dbg_bld("second PEB %d is newer, copy_flag is unset",
-				pnum);
-			return 1;
-		}
-	} else {
-		if (!aeb->copy_flag) {
-			/* It is not a copy, so it is newer */
-			dbg_bld("first PEB %d is newer, copy_flag is unset",
-				pnum);
-			return bitflips << 1;
-		}
-
-		vh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
-		if (!vh)
-			return -ENOMEM;
-
-		pnum = aeb->pnum;
-		err = ubi_io_read_vid_hdr(ubi, pnum, vh, 0);
-		if (err) {
-			if (err == UBI_IO_BITFLIPS)
-				bitflips = 1;
-			else {
-				ubi_err("VID of PEB %d header is bad, but it "
-					"was OK earlier, err %d", pnum, err);
-				if (err > 0)
-					err = -EIO;
-
-				goto out_free_vidh;
-			}
-		}
-
-		vid_hdr = vh;
-	}
-
-	/* Read the data of the copy and check the CRC */
-
-	len = be32_to_cpu(vid_hdr->data_size);
-	buf = vmalloc(len);
-	if (!buf) {
-		err = -ENOMEM;
-		goto out_free_vidh;
-	}
-
-	err = ubi_io_read_data(ubi, buf, pnum, 0, len);
-	if (err && err != UBI_IO_BITFLIPS && !mtd_is_eccerr(err))
-		goto out_free_buf;
-
-	data_crc = be32_to_cpu(vid_hdr->data_crc);
-	crc = crc32(UBI_CRC32_INIT, buf, len);
-	if (crc != data_crc) {
-		dbg_bld("PEB %d CRC error: calculated %#08x, must be %#08x",
-			pnum, crc, data_crc);
-		corrupted = 1;
-		bitflips = 0;
-		second_is_newer = !second_is_newer;
-	} else {
-		dbg_bld("PEB %d CRC is OK", pnum);
-		bitflips = !!err;
-	}
-
-	vfree(buf);
-	ubi_free_vid_hdr(ubi, vh);
-
-	if (second_is_newer)
-		dbg_bld("second PEB %d is newer, copy_flag is set", pnum);
-	else
-		dbg_bld("first PEB %d is newer, copy_flag is set", pnum);
-
-	return second_is_newer | (bitflips << 1) | (corrupted << 2);
-
-out_free_buf:
-	vfree(buf);
-out_free_vidh:
-	ubi_free_vid_hdr(ubi, vh);
-	return err;
-}
-
-/**
- * ubi_add_to_av - add used physical eraseblock to the attaching information.
- * @ubi: UBI device description object
- * @ai: attaching information
- * @pnum: the physical eraseblock number
- * @ec: erase counter
- * @vid_hdr: the volume identifier header
- * @bitflips: if bit-flips were detected when this physical eraseblock was read
- *
- * This function adds information about a used physical eraseblock to the
- * 'used' tree of the corresponding volume. The function is rather complex
- * because it has to handle cases when this is not the first physical
- * eraseblock belonging to the same logical eraseblock, and the newer one has
- * to be picked, while the older one has to be dropped. This function returns
- * zero in case of success and a negative error code in case of failure.
- */
-int ubi_add_to_av(struct ubi_device *ubi, struct ubi_attach_info *ai, int pnum,
-		  int ec, const struct ubi_vid_hdr *vid_hdr, int bitflips)
-{
-	int err, vol_id, lnum;
-	unsigned long long sqnum;
-	struct ubi_ainf_volume *av;
-	struct ubi_ainf_peb *aeb;
-	struct rb_node **p, *parent = NULL;
-
-	vol_id = be32_to_cpu(vid_hdr->vol_id);
-	lnum = be32_to_cpu(vid_hdr->lnum);
-	sqnum = be64_to_cpu(vid_hdr->sqnum);
-
-	dbg_bld("PEB %d, LEB %d:%d, EC %d, sqnum %llu, bitflips %d",
-		pnum, vol_id, lnum, ec, sqnum, bitflips);
-
-	av = add_volume(ai, vol_id, pnum, vid_hdr);
-	if (IS_ERR(av))
-		return PTR_ERR(av);
-
-	if (ai->max_sqnum < sqnum)
-		ai->max_sqnum = sqnum;
-
-	/*
-	 * Walk the RB-tree of logical eraseblocks of volume @vol_id to look
-	 * if this is the first instance of this logical eraseblock or not.
-	 */
-	p = &av->root.rb_node;
-	while (*p) {
-		int cmp_res;
-
-		parent = *p;
-		aeb = rb_entry(parent, struct ubi_ainf_peb, u.rb);
-		if (lnum != aeb->lnum) {
-			if (lnum < aeb->lnum)
-				p = &(*p)->rb_left;
-			else
-				p = &(*p)->rb_right;
-			continue;
-		}
-
-		/*
-		 * There is already a physical eraseblock describing the same
-		 * logical eraseblock present.
-		 */
-
-		dbg_bld("this LEB already exists: PEB %d, sqnum %llu, EC %d",
-			aeb->pnum, aeb->sqnum, aeb->ec);
-
-		/*
-		 * Make sure that the logical eraseblocks have different
-		 * sequence numbers. Otherwise the image is bad.
-		 *
-		 * However, if the sequence number is zero, we assume it must
-		 * be an ancient UBI image from the era when UBI did not have
-		 * sequence numbers. We still can attach these images, unless
-		 * there is a need to distinguish between old and new
-		 * eraseblocks, in which case we'll refuse the image in
-		 * 'compare_lebs()'. In other words, we attach old clean
-		 * images, but refuse attaching old images with duplicated
-		 * logical eraseblocks because there was an unclean reboot.
-		 */
-		if (aeb->sqnum == sqnum && sqnum != 0) {
-			ubi_err("two LEBs with same sequence number %llu",
-				sqnum);
-			ubi_dump_aeb(aeb, 0);
-			ubi_dump_vid_hdr(vid_hdr);
-			return -EINVAL;
-		}
-
-		/*
-		 * Now we have to drop the older one and preserve the newer
-		 * one.
-		 */
-		cmp_res = compare_lebs(ubi, aeb, pnum, vid_hdr);
-		if (cmp_res < 0)
-			return cmp_res;
-
-		if (cmp_res & 1) {
-			/*
-			 * This logical eraseblock is newer than the one
-			 * found earlier.
-			 */
-			err = validate_vid_hdr(vid_hdr, av, pnum);
-			if (err)
-				return err;
-
-			err = add_to_list(ai, aeb->pnum, aeb->ec, cmp_res & 4,
-					  &ai->erase);
-			if (err)
-				return err;
-
-			aeb->ec = ec;
-			aeb->pnum = pnum;
-			aeb->scrub = ((cmp_res & 2) || bitflips);
-			aeb->copy_flag = vid_hdr->copy_flag;
-			aeb->sqnum = sqnum;
-
-			if (av->highest_lnum == lnum)
-				av->last_data_size =
-					be32_to_cpu(vid_hdr->data_size);
-
-			return 0;
-		} else {
-			/*
-			 * This logical eraseblock is older than the one found
-			 * previously.
-			 */
-			return add_to_list(ai, pnum, ec, cmp_res & 4,
-					   &ai->erase);
-		}
-	}
-
-	/*
-	 * We've met this logical eraseblock for the first time, add it to the
-	 * attaching information.
-	 */
-
-	err = validate_vid_hdr(vid_hdr, av, pnum);
-	if (err)
-		return err;
-
-	aeb = kmem_cache_alloc(ai->aeb_slab_cache, GFP_KERNEL);
-	if (!aeb)
-		return -ENOMEM;
-
-	aeb->ec = ec;
-	aeb->pnum = pnum;
-	aeb->lnum = lnum;
-	aeb->scrub = bitflips;
-	aeb->copy_flag = vid_hdr->copy_flag;
-	aeb->sqnum = sqnum;
-
-	if (av->highest_lnum <= lnum) {
-		av->highest_lnum = lnum;
-		av->last_data_size = be32_to_cpu(vid_hdr->data_size);
-	}
-
-	av->leb_count += 1;
-	rb_link_node(&aeb->u.rb, parent, p);
-	rb_insert_color(&aeb->u.rb, &av->root);
-	return 0;
-}
-
-/**
- * ubi_find_av - find volume in the attaching information.
- * @ai: attaching information
- * @vol_id: the requested volume ID
- *
- * This function returns a pointer to the volume description or %NULL if there
- * are no data about this volume in the attaching information.
- */
-struct ubi_ainf_volume *ubi_find_av(const struct ubi_attach_info *ai,
-				    int vol_id)
-{
-	struct ubi_ainf_volume *av;
-	struct rb_node *p = ai->volumes.rb_node;
-
-	while (p) {
-		av = rb_entry(p, struct ubi_ainf_volume, rb);
-
-		if (vol_id == av->vol_id)
-			return av;
-
-		if (vol_id > av->vol_id)
-			p = p->rb_left;
-		else
-			p = p->rb_right;
-	}
-
-	return NULL;
-}
-
-/**
- * ubi_remove_av - delete attaching information about a volume.
- * @ai: attaching information
- * @av: the volume attaching information to delete
- */
-void ubi_remove_av(struct ubi_attach_info *ai, struct ubi_ainf_volume *av)
-{
-	struct rb_node *rb;
-	struct ubi_ainf_peb *aeb;
-
-	dbg_bld("remove attaching information about volume %d", av->vol_id);
-
-	while ((rb = rb_first(&av->root))) {
-		aeb = rb_entry(rb, struct ubi_ainf_peb, u.rb);
-		rb_erase(&aeb->u.rb, &av->root);
-		list_add_tail(&aeb->u.list, &ai->erase);
-	}
-
-	rb_erase(&av->rb, &ai->volumes);
-	kfree(av);
-	ai->vols_found -= 1;
-}
-
-/**
- * early_erase_peb - erase a physical eraseblock.
- * @ubi: UBI device description object
- * @ai: attaching information
- * @pnum: physical eraseblock number to erase;
- * @ec: erase counter value to write (%UBI_UNKNOWN if it is unknown)
- *
- * This function erases physical eraseblock 'pnum', and writes the erase
- * counter header to it. This function should only be used on UBI device
- * initialization stages, when the EBA sub-system had not been yet initialized.
- * This function returns zero in case of success and a negative error code in
- * case of failure.
- */
-static int early_erase_peb(struct ubi_device *ubi,
-			   const struct ubi_attach_info *ai, int pnum, int ec)
-{
-	int err;
-	struct ubi_ec_hdr *ec_hdr;
-
-	if ((long long)ec >= UBI_MAX_ERASECOUNTER) {
-		/*
-		 * Erase counter overflow. Upgrade UBI and use 64-bit
-		 * erase counters internally.
-		 */
-		ubi_err("erase counter overflow at PEB %d, EC %d", pnum, ec);
-		return -EINVAL;
-	}
-
-	ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
-	if (!ec_hdr)
-		return -ENOMEM;
-
-	ec_hdr->ec = cpu_to_be64(ec);
-
-	err = ubi_io_sync_erase(ubi, pnum, 0);
-	if (err < 0)
-		goto out_free;
-
-	err = ubi_io_write_ec_hdr(ubi, pnum, ec_hdr);
-
-out_free:
-	kfree(ec_hdr);
-	return err;
-}
-
-/**
- * ubi_early_get_peb - get a free physical eraseblock.
- * @ubi: UBI device description object
- * @ai: attaching information
- *
- * This function returns a free physical eraseblock. It is supposed to be
- * called on the UBI initialization stages when the wear-leveling sub-system is
- * not initialized yet. This function picks a physical eraseblocks from one of
- * the lists, writes the EC header if it is needed, and removes it from the
- * list.
- *
- * This function returns a pointer to the "aeb" of the found free PEB in case
- * of success and an error code in case of failure.
- */
-struct ubi_ainf_peb *ubi_early_get_peb(struct ubi_device *ubi,
-				       struct ubi_attach_info *ai)
-{
-	int err = 0;
-	struct ubi_ainf_peb *aeb, *tmp_aeb;
-
-	if (!list_empty(&ai->free)) {
-		aeb = list_entry(ai->free.next, struct ubi_ainf_peb, u.list);
-		list_del(&aeb->u.list);
-		dbg_bld("return free PEB %d, EC %d", aeb->pnum, aeb->ec);
-		return aeb;
-	}
-
-	/*
-	 * We try to erase the first physical eraseblock from the erase list
-	 * and pick it if we succeed, or try to erase the next one if not. And
-	 * so forth. We don't want to take care about bad eraseblocks here -
-	 * they'll be handled later.
-	 */
-	list_for_each_entry_safe(aeb, tmp_aeb, &ai->erase, u.list) {
-		if (aeb->ec == UBI_UNKNOWN)
-			aeb->ec = ai->mean_ec;
-
-		err = early_erase_peb(ubi, ai, aeb->pnum, aeb->ec+1);
-		if (err)
-			continue;
-
-		aeb->ec += 1;
-		list_del(&aeb->u.list);
-		dbg_bld("return PEB %d, EC %d", aeb->pnum, aeb->ec);
-		return aeb;
-	}
-
-	ubi_err("no free eraseblocks");
-	return ERR_PTR(-ENOSPC);
-}
-
-/**
- * check_corruption - check the data area of PEB.
- * @ubi: UBI device description object
- * @vid_hrd: the (corrupted) VID header of this PEB
- * @pnum: the physical eraseblock number to check
- *
- * This is a helper function which is used to distinguish between VID header
- * corruptions caused by power cuts and other reasons. If the PEB contains only
- * 0xFF bytes in the data area, the VID header is most probably corrupted
- * because of a power cut (%0 is returned in this case). Otherwise, it was
- * probably corrupted for some other reasons (%1 is returned in this case). A
- * negative error code is returned if a read error occurred.
- *
- * If the corruption reason was a power cut, UBI can safely erase this PEB.
- * Otherwise, it should preserve it to avoid possibly destroying important
- * information.
- */
-static int check_corruption(struct ubi_device *ubi, struct ubi_vid_hdr *vid_hdr,
-			    int pnum)
-{
-	int err;
-
-	mutex_lock(&ubi->buf_mutex);
-	memset(ubi->peb_buf, 0x00, ubi->leb_size);
-
-	err = ubi_io_read(ubi, ubi->peb_buf, pnum, ubi->leb_start,
-			  ubi->leb_size);
-	if (err == UBI_IO_BITFLIPS || mtd_is_eccerr(err)) {
-		/*
-		 * Bit-flips or integrity errors while reading the data area.
-		 * It is difficult to say for sure what type of corruption is
-		 * this, but presumably a power cut happened while this PEB was
-		 * erased, so it became unstable and corrupted, and should be
-		 * erased.
-		 */
-		err = 0;
-		goto out_unlock;
-	}
-
-	if (err)
-		goto out_unlock;
-
-	if (ubi_check_pattern(ubi->peb_buf, 0xFF, ubi->leb_size))
-		goto out_unlock;
-
-	ubi_err("PEB %d contains corrupted VID header, and the data does not "
-		"contain all 0xFF, this may be a non-UBI PEB or a severe VID "
-		"header corruption which requires manual inspection", pnum);
-	ubi_dump_vid_hdr(vid_hdr);
-	dbg_msg("hexdump of PEB %d offset %d, length %d",
-		pnum, ubi->leb_start, ubi->leb_size);
-	ubi_dbg_print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1,
-			       ubi->peb_buf, ubi->leb_size, 1);
-	err = 1;
-
-out_unlock:
-	mutex_unlock(&ubi->buf_mutex);
-	return err;
-}
-
-/**
- * scan_peb - scan and process UBI headers of a PEB.
- * @ubi: UBI device description object
- * @ai: attaching information
- * @pnum: the physical eraseblock number
- *
- * This function reads UBI headers of PEB @pnum, checks them, and adds
- * information about this PEB to the corresponding list or RB-tree in the
- * "attaching info" structure. Returns zero if the physical eraseblock was
- * successfully handled and a negative error code in case of failure.
- */
-static int scan_peb(struct ubi_device *ubi, struct ubi_attach_info *ai,
-		    int pnum)
-{
-	long long uninitialized_var(ec);
-	int err, bitflips = 0, vol_id, ec_err = 0;
-
-	dbg_bld("scan PEB %d", pnum);
-
-	/* Skip bad physical eraseblocks */
-	err = ubi_io_is_bad(ubi, pnum);
-	if (err < 0)
-		return err;
-	else if (err) {
-		ai->bad_peb_count += 1;
-		return 0;
-	}
-
-	err = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
-	if (err < 0)
-		return err;
-	switch (err) {
-	case 0:
-		break;
-	case UBI_IO_BITFLIPS:
-		bitflips = 1;
-		break;
-	case UBI_IO_FF:
-		ai->empty_peb_count += 1;
-		return add_to_list(ai, pnum, UBI_UNKNOWN, 0,
-				   &ai->erase);
-	case UBI_IO_FF_BITFLIPS:
-		ai->empty_peb_count += 1;
-		return add_to_list(ai, pnum, UBI_UNKNOWN, 1,
-				   &ai->erase);
-	case UBI_IO_BAD_HDR_EBADMSG:
-	case UBI_IO_BAD_HDR:
-		/*
-		 * We have to also look at the VID header, possibly it is not
-		 * corrupted. Set %bitflips flag in order to make this PEB be
-		 * moved and EC be re-created.
-		 */
-		ec_err = err;
-		ec = UBI_UNKNOWN;
-		bitflips = 1;
-		break;
-	default:
-		ubi_err("'ubi_io_read_ec_hdr()' returned unknown code %d", err);
-		return -EINVAL;
-	}
-
-	if (!ec_err) {
-		int image_seq;
-
-		/* Make sure UBI version is OK */
-		if (ech->version != UBI_VERSION) {
-			ubi_err("this UBI version is %d, image version is %d",
-				UBI_VERSION, (int)ech->version);
-			return -EINVAL;
-		}
-
-		ec = be64_to_cpu(ech->ec);
-		if (ec > UBI_MAX_ERASECOUNTER) {
-			/*
-			 * Erase counter overflow. The EC headers have 64 bits
-			 * reserved, but we anyway make use of only 31 bit
-			 * values, as this seems to be enough for any existing
-			 * flash. Upgrade UBI and use 64-bit erase counters
-			 * internally.
-			 */
-			ubi_err("erase counter overflow, max is %d",
-				UBI_MAX_ERASECOUNTER);
-			ubi_dump_ec_hdr(ech);
-			return -EINVAL;
-		}
-
-		/*
-		 * Make sure that all PEBs have the same image sequence number.
-		 * This allows us to detect situations when users flash UBI
-		 * images incorrectly, so that the flash has the new UBI image
-		 * and leftovers from the old one. This feature was added
-		 * relatively recently, and the sequence number was always
-		 * zero, because old UBI implementations always set it to zero.
-		 * For this reasons, we do not panic if some PEBs have zero
-		 * sequence number, while other PEBs have non-zero sequence
-		 * number.
-		 */
-		image_seq = be32_to_cpu(ech->image_seq);
-		if (!ubi->image_seq && image_seq)
-			ubi->image_seq = image_seq;
-		if (ubi->image_seq && image_seq &&
-		    ubi->image_seq != image_seq) {
-			ubi_err("bad image sequence number %d in PEB %d, "
-				"expected %d", image_seq, pnum, ubi->image_seq);
-			ubi_dump_ec_hdr(ech);
-			return -EINVAL;
-		}
-	}
-
-	/* OK, we've done with the EC header, let's look at the VID header */
-
-	err = ubi_io_read_vid_hdr(ubi, pnum, vidh, 0);
-	if (err < 0)
-		return err;
-	switch (err) {
-	case 0:
-		break;
-	case UBI_IO_BITFLIPS:
-		bitflips = 1;
-		break;
-	case UBI_IO_BAD_HDR_EBADMSG:
-		if (ec_err == UBI_IO_BAD_HDR_EBADMSG)
-			/*
-			 * Both EC and VID headers are corrupted and were read
-			 * with data integrity error, probably this is a bad
-			 * PEB, bit it is not marked as bad yet. This may also
-			 * be a result of power cut during erasure.
-			 */
-			ai->maybe_bad_peb_count += 1;
-	case UBI_IO_BAD_HDR:
-		if (ec_err)
-			/*
-			 * Both headers are corrupted. There is a possibility
-			 * that this a valid UBI PEB which has corresponding
-			 * LEB, but the headers are corrupted. However, it is
-			 * impossible to distinguish it from a PEB which just
-			 * contains garbage because of a power cut during erase
-			 * operation. So we just schedule this PEB for erasure.
-			 *
-			 * Besides, in case of NOR flash, we deliberately
-			 * corrupt both headers because NOR flash erasure is
-			 * slow and can start from the end.
-			 */
-			err = 0;
-		else
-			/*
-			 * The EC was OK, but the VID header is corrupted. We
-			 * have to check what is in the data area.
-			 */
-			err = check_corruption(ubi, vidh, pnum);
-
-		if (err < 0)
-			return err;
-		else if (!err)
-			/* This corruption is caused by a power cut */
-			err = add_to_list(ai, pnum, ec, 1, &ai->erase);
-		else
-			/* This is an unexpected corruption */
-			err = add_corrupted(ai, pnum, ec);
-		if (err)
-			return err;
-		goto adjust_mean_ec;
-	case UBI_IO_FF_BITFLIPS:
-		err = add_to_list(ai, pnum, ec, 1, &ai->erase);
-		if (err)
-			return err;
-		goto adjust_mean_ec;
-	case UBI_IO_FF:
-		if (ec_err)
-			err = add_to_list(ai, pnum, ec, 1, &ai->erase);
-		else
-			err = add_to_list(ai, pnum, ec, 0, &ai->free);
-		if (err)
-			return err;
-		goto adjust_mean_ec;
-	default:
-		ubi_err("'ubi_io_read_vid_hdr()' returned unknown code %d",
-			err);
-		return -EINVAL;
-	}
-
-	vol_id = be32_to_cpu(vidh->vol_id);
-	if (vol_id > UBI_MAX_VOLUMES && vol_id != UBI_LAYOUT_VOLUME_ID) {
-		int lnum = be32_to_cpu(vidh->lnum);
-
-		/* Unsupported internal volume */
-		switch (vidh->compat) {
-		case UBI_COMPAT_DELETE:
-			ubi_msg("\"delete\" compatible internal volume %d:%d"
-				" found, will remove it", vol_id, lnum);
-			err = add_to_list(ai, pnum, ec, 1, &ai->erase);
-			if (err)
-				return err;
-			return 0;
-
-		case UBI_COMPAT_RO:
-			ubi_msg("read-only compatible internal volume %d:%d"
-				" found, switch to read-only mode",
-				vol_id, lnum);
-			ubi->ro_mode = 1;
-			break;
-
-		case UBI_COMPAT_PRESERVE:
-			ubi_msg("\"preserve\" compatible internal volume %d:%d"
-				" found", vol_id, lnum);
-			err = add_to_list(ai, pnum, ec, 0, &ai->alien);
-			if (err)
-				return err;
-			return 0;
-
-		case UBI_COMPAT_REJECT:
-			ubi_err("incompatible internal volume %d:%d found",
-				vol_id, lnum);
-			return -EINVAL;
-		}
-	}
-
-	if (ec_err)
-		ubi_warn("valid VID header but corrupted EC header at PEB %d",
-			 pnum);
-	err = ubi_add_to_av(ubi, ai, pnum, ec, vidh, bitflips);
-	if (err)
-		return err;
-
-adjust_mean_ec:
-	if (!ec_err) {
-		ai->ec_sum += ec;
-		ai->ec_count += 1;
-		if (ec > ai->max_ec)
-			ai->max_ec = ec;
-		if (ec < ai->min_ec)
-			ai->min_ec = ec;
-	}
-
-	return 0;
-}
-
-/**
- * late_analysis - analyze the overall situation with PEB.
- * @ubi: UBI device description object
- * @ai: attaching information
- *
- * This is a helper function which takes a look what PEBs we have after we
- * gather information about all of them ("ai" is compete). It decides whether
- * the flash is empty and should be formatted of whether there are too many
- * corrupted PEBs and we should not attach this MTD device. Returns zero if we
- * should proceed with attaching the MTD device, and %-EINVAL if we should not.
- */
-static int late_analysis(struct ubi_device *ubi, struct ubi_attach_info *ai)
-{
-	struct ubi_ainf_peb *aeb;
-	int max_corr, peb_count;
-
-	peb_count = ubi->peb_count - ai->bad_peb_count - ai->alien_peb_count;
-	max_corr = peb_count / 20 ?: 8;
-
-	/*
-	 * Few corrupted PEBs is not a problem and may be just a result of
-	 * unclean reboots. However, many of them may indicate some problems
-	 * with the flash HW or driver.
-	 */
-	if (ai->corr_peb_count) {
-		ubi_err("%d PEBs are corrupted and preserved",
-			ai->corr_peb_count);
-		printk(KERN_ERR "Corrupted PEBs are:");
-		list_for_each_entry(aeb, &ai->corr, u.list)
-			printk(KERN_CONT " %d", aeb->pnum);
-		printk(KERN_CONT "\n");
-
-		/*
-		 * If too many PEBs are corrupted, we refuse attaching,
-		 * otherwise, only print a warning.
-		 */
-		if (ai->corr_peb_count >= max_corr) {
-			ubi_err("too many corrupted PEBs, refusing");
-			return -EINVAL;
-		}
-	}
-
-	if (ai->empty_peb_count + ai->maybe_bad_peb_count == peb_count) {
-		/*
-		 * All PEBs are empty, or almost all - a couple PEBs look like
-		 * they may be bad PEBs which were not marked as bad yet.
-		 *
-		 * This piece of code basically tries to distinguish between
-		 * the following situations:
-		 *
-		 * 1. Flash is empty, but there are few bad PEBs, which are not
-		 *    marked as bad so far, and which were read with error. We
-		 *    want to go ahead and format this flash. While formatting,
-		 *    the faulty PEBs will probably be marked as bad.
-		 *
-		 * 2. Flash contains non-UBI data and we do not want to format
-		 *    it and destroy possibly important information.
-		 */
-		if (ai->maybe_bad_peb_count <= 2) {
-			ai->is_empty = 1;
-			ubi_msg("empty MTD device detected");
-			get_random_bytes(&ubi->image_seq,
-					 sizeof(ubi->image_seq));
-		} else {
-			ubi_err("MTD device is not UBI-formatted and possibly "
-				"contains non-UBI data - refusing it");
-			return -EINVAL;
-		}
-
-	}
-
-	return 0;
-}
-
-/**
- * scan_all - scan entire MTD device.
- * @ubi: UBI device description object
- *
- * This function does full scanning of an MTD device and returns complete
- * information about it in form of a "struct ubi_attach_info" object. In case
- * of failure, an error code is returned.
- */
-static struct ubi_attach_info *scan_all(struct ubi_device *ubi)
-{
-	int err, pnum;
-	struct rb_node *rb1, *rb2;
-	struct ubi_ainf_volume *av;
-	struct ubi_ainf_peb *aeb;
-	struct ubi_attach_info *ai;
-
-	ai = kzalloc(sizeof(struct ubi_attach_info), GFP_KERNEL);
-	if (!ai)
-		return ERR_PTR(-ENOMEM);
-
-	INIT_LIST_HEAD(&ai->corr);
-	INIT_LIST_HEAD(&ai->free);
-	INIT_LIST_HEAD(&ai->erase);
-	INIT_LIST_HEAD(&ai->alien);
-	ai->volumes = RB_ROOT;
-
-	err = -ENOMEM;
-	ai->aeb_slab_cache = kmem_cache_create("ubi_aeb_slab_cache",
-					       sizeof(struct ubi_ainf_peb),
-					       0, 0, NULL);
-	if (!ai->aeb_slab_cache)
-		goto out_ai;
-
-	ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
-	if (!ech)
-		goto out_ai;
-
-	vidh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
-	if (!vidh)
-		goto out_ech;
-
-	for (pnum = 0; pnum < ubi->peb_count; pnum++) {
-		cond_resched();
-
-		dbg_gen("process PEB %d", pnum);
-		err = scan_peb(ubi, ai, pnum);
-		if (err < 0)
-			goto out_vidh;
-	}
-
-	dbg_msg("scanning is finished");
-
-	/* Calculate mean erase counter */
-	if (ai->ec_count)
-		ai->mean_ec = div_u64(ai->ec_sum, ai->ec_count);
-
-	err = late_analysis(ubi, ai);
-	if (err)
-		goto out_vidh;
-
-	/*
-	 * In case of unknown erase counter we use the mean erase counter
-	 * value.
-	 */
-	ubi_rb_for_each_entry(rb1, av, &ai->volumes, rb) {
-		ubi_rb_for_each_entry(rb2, aeb, &av->root, u.rb)
-			if (aeb->ec == UBI_UNKNOWN)
-				aeb->ec = ai->mean_ec;
-	}
-
-	list_for_each_entry(aeb, &ai->free, u.list) {
-		if (aeb->ec == UBI_UNKNOWN)
-			aeb->ec = ai->mean_ec;
-	}
-
-	list_for_each_entry(aeb, &ai->corr, u.list)
-		if (aeb->ec == UBI_UNKNOWN)
-			aeb->ec = ai->mean_ec;
-
-	list_for_each_entry(aeb, &ai->erase, u.list)
-		if (aeb->ec == UBI_UNKNOWN)
-			aeb->ec = ai->mean_ec;
-
-	err = self_check_ai(ubi, ai);
-	if (err)
-		goto out_vidh;
-
-	ubi_free_vid_hdr(ubi, vidh);
-	kfree(ech);
-
-	return ai;
-
-out_vidh:
-	ubi_free_vid_hdr(ubi, vidh);
-out_ech:
-	kfree(ech);
-out_ai:
-	ubi_destroy_ai(ai);
-	return ERR_PTR(err);
-}
-
-/**
- * ubi_attach - attach an MTD device.
- * @ubi: UBI device descriptor
- *
- * This function returns zero in case of success and a negative error code in
- * case of failure.
- */
-int ubi_attach(struct ubi_device *ubi)
-{
-	int err;
-	struct ubi_attach_info *ai;
-
-	ai = scan_all(ubi);
-	if (IS_ERR(ai))
-		return PTR_ERR(ai);
-
-	ubi->bad_peb_count = ai->bad_peb_count;
-	ubi->good_peb_count = ubi->peb_count - ubi->bad_peb_count;
-	ubi->corr_peb_count = ai->corr_peb_count;
-	ubi->max_ec = ai->max_ec;
-	ubi->mean_ec = ai->mean_ec;
-	ubi_msg("max. sequence number:       %llu", ai->max_sqnum);
-
-	err = ubi_read_volume_table(ubi, ai);
-	if (err)
-		goto out_ai;
-
-	err = ubi_wl_init(ubi, ai);
-	if (err)
-		goto out_vtbl;
-
-	err = ubi_eba_init(ubi, ai);
-	if (err)
-		goto out_wl;
-
-	ubi_destroy_ai(ai);
-	return 0;
-
-out_wl:
-	ubi_wl_close(ubi);
-out_vtbl:
-	ubi_free_internal_volumes(ubi);
-	vfree(ubi->vtbl);
-out_ai:
-	ubi_destroy_ai(ai);
-	return err;
-}
-
-/**
- * destroy_av - free volume attaching information.
- * @av: volume attaching information
- * @ai: attaching information
- *
- * This function destroys the volume attaching information.
- */
-static void destroy_av(struct ubi_attach_info *ai, struct ubi_ainf_volume *av)
-{
-	struct ubi_ainf_peb *aeb;
-	struct rb_node *this = av->root.rb_node;
-
-	while (this) {
-		if (this->rb_left)
-			this = this->rb_left;
-		else if (this->rb_right)
-			this = this->rb_right;
-		else {
-			aeb = rb_entry(this, struct ubi_ainf_peb, u.rb);
-			this = rb_parent(this);
-			if (this) {
-				if (this->rb_left == &aeb->u.rb)
-					this->rb_left = NULL;
-				else
-					this->rb_right = NULL;
-			}
-
-			kmem_cache_free(ai->aeb_slab_cache, aeb);
-		}
-	}
-	kfree(av);
-}
-
-/**
- * ubi_destroy_ai - destroy attaching information.
- * @ai: attaching information
- */
-void ubi_destroy_ai(struct ubi_attach_info *ai)
-{
-	struct ubi_ainf_peb *aeb, *aeb_tmp;
-	struct ubi_ainf_volume *av;
-	struct rb_node *rb;
-
-	list_for_each_entry_safe(aeb, aeb_tmp, &ai->alien, u.list) {
-		list_del(&aeb->u.list);
-		kmem_cache_free(ai->aeb_slab_cache, aeb);
-	}
-	list_for_each_entry_safe(aeb, aeb_tmp, &ai->erase, u.list) {
-		list_del(&aeb->u.list);
-		kmem_cache_free(ai->aeb_slab_cache, aeb);
-	}
-	list_for_each_entry_safe(aeb, aeb_tmp, &ai->corr, u.list) {
-		list_del(&aeb->u.list);
-		kmem_cache_free(ai->aeb_slab_cache, aeb);
-	}
-	list_for_each_entry_safe(aeb, aeb_tmp, &ai->free, u.list) {
-		list_del(&aeb->u.list);
-		kmem_cache_free(ai->aeb_slab_cache, aeb);
-	}
-
-	/* Destroy the volume RB-tree */
-	rb = ai->volumes.rb_node;
-	while (rb) {
-		if (rb->rb_left)
-			rb = rb->rb_left;
-		else if (rb->rb_right)
-			rb = rb->rb_right;
-		else {
-			av = rb_entry(rb, struct ubi_ainf_volume, rb);
-
-			rb = rb_parent(rb);
-			if (rb) {
-				if (rb->rb_left == &av->rb)
-					rb->rb_left = NULL;
-				else
-					rb->rb_right = NULL;
-			}
-
-			destroy_av(ai, av);
-		}
-	}
-
-	if (ai->aeb_slab_cache)
-		kmem_cache_destroy(ai->aeb_slab_cache);
-
-	kfree(ai);
-}
-
-/**
- * self_check_ai - check the attaching information.
- * @ubi: UBI device description object
- * @ai: attaching information
- *
- * This function returns zero if the attaching information is all right, and a
- * negative error code if not or if an error occurred.
- */
-static int self_check_ai(struct ubi_device *ubi, struct ubi_attach_info *ai)
-{
-	int pnum, err, vols_found = 0;
-	struct rb_node *rb1, *rb2;
-	struct ubi_ainf_volume *av;
-	struct ubi_ainf_peb *aeb, *last_aeb;
-	uint8_t *buf;
-
-	if (!ubi->dbg->chk_gen)
-		return 0;
-
-	/*
-	 * At first, check that attaching information is OK.
-	 */
-	ubi_rb_for_each_entry(rb1, av, &ai->volumes, rb) {
-		int leb_count = 0;
-
-		cond_resched();
-
-		vols_found += 1;
-
-		if (ai->is_empty) {
-			ubi_err("bad is_empty flag");
-			goto bad_av;
-		}
-
-		if (av->vol_id < 0 || av->highest_lnum < 0 ||
-		    av->leb_count < 0 || av->vol_type < 0 || av->used_ebs < 0 ||
-		    av->data_pad < 0 || av->last_data_size < 0) {
-			ubi_err("negative values");
-			goto bad_av;
-		}
-
-		if (av->vol_id >= UBI_MAX_VOLUMES &&
-		    av->vol_id < UBI_INTERNAL_VOL_START) {
-			ubi_err("bad vol_id");
-			goto bad_av;
-		}
-
-		if (av->vol_id > ai->highest_vol_id) {
-			ubi_err("highest_vol_id is %d, but vol_id %d is there",
-				ai->highest_vol_id, av->vol_id);
-			goto out;
-		}
-
-		if (av->vol_type != UBI_DYNAMIC_VOLUME &&
-		    av->vol_type != UBI_STATIC_VOLUME) {
-			ubi_err("bad vol_type");
-			goto bad_av;
-		}
-
-		if (av->data_pad > ubi->leb_size / 2) {
-			ubi_err("bad data_pad");
-			goto bad_av;
-		}
-
-		last_aeb = NULL;
-		ubi_rb_for_each_entry(rb2, aeb, &av->root, u.rb) {
-			cond_resched();
-
-			last_aeb = aeb;
-			leb_count += 1;
-
-			if (aeb->pnum < 0 || aeb->ec < 0) {
-				ubi_err("negative values");
-				goto bad_aeb;
-			}
-
-			if (aeb->ec < ai->min_ec) {
-				ubi_err("bad ai->min_ec (%d), %d found",
-					ai->min_ec, aeb->ec);
-				goto bad_aeb;
-			}
-
-			if (aeb->ec > ai->max_ec) {
-				ubi_err("bad ai->max_ec (%d), %d found",
-					ai->max_ec, aeb->ec);
-				goto bad_aeb;
-			}
-
-			if (aeb->pnum >= ubi->peb_count) {
-				ubi_err("too high PEB number %d, total PEBs %d",
-					aeb->pnum, ubi->peb_count);
-				goto bad_aeb;
-			}
-
-			if (av->vol_type == UBI_STATIC_VOLUME) {
-				if (aeb->lnum >= av->used_ebs) {
-					ubi_err("bad lnum or used_ebs");
-					goto bad_aeb;
-				}
-			} else {
-				if (av->used_ebs != 0) {
-					ubi_err("non-zero used_ebs");
-					goto bad_aeb;
-				}
-			}
-
-			if (aeb->lnum > av->highest_lnum) {
-				ubi_err("incorrect highest_lnum or lnum");
-				goto bad_aeb;
-			}
-		}
-
-		if (av->leb_count != leb_count) {
-			ubi_err("bad leb_count, %d objects in the tree",
-				leb_count);
-			goto bad_av;
-		}
-
-		if (!last_aeb)
-			continue;
-
-		aeb = last_aeb;
-
-		if (aeb->lnum != av->highest_lnum) {
-			ubi_err("bad highest_lnum");
-			goto bad_aeb;
-		}
-	}
-
-	if (vols_found != ai->vols_found) {
-		ubi_err("bad ai->vols_found %d, should be %d",
-			ai->vols_found, vols_found);
-		goto out;
-	}
-
-	/* Check that attaching information is correct */
-	ubi_rb_for_each_entry(rb1, av, &ai->volumes, rb) {
-		last_aeb = NULL;
-		ubi_rb_for_each_entry(rb2, aeb, &av->root, u.rb) {
-			int vol_type;
-
-			cond_resched();
-
-			last_aeb = aeb;
-
-			err = ubi_io_read_vid_hdr(ubi, aeb->pnum, vidh, 1);
-			if (err && err != UBI_IO_BITFLIPS) {
-				ubi_err("VID header is not OK (%d)", err);
-				if (err > 0)
-					err = -EIO;
-				return err;
-			}
-
-			vol_type = vidh->vol_type == UBI_VID_DYNAMIC ?
-				   UBI_DYNAMIC_VOLUME : UBI_STATIC_VOLUME;
-			if (av->vol_type != vol_type) {
-				ubi_err("bad vol_type");
-				goto bad_vid_hdr;
-			}
-
-			if (aeb->sqnum != be64_to_cpu(vidh->sqnum)) {
-				ubi_err("bad sqnum %llu", aeb->sqnum);
-				goto bad_vid_hdr;
-			}
-
-			if (av->vol_id != be32_to_cpu(vidh->vol_id)) {
-				ubi_err("bad vol_id %d", av->vol_id);
-				goto bad_vid_hdr;
-			}
-
-			if (av->compat != vidh->compat) {
-				ubi_err("bad compat %d", vidh->compat);
-				goto bad_vid_hdr;
-			}
-
-			if (aeb->lnum != be32_to_cpu(vidh->lnum)) {
-				ubi_err("bad lnum %d", aeb->lnum);
-				goto bad_vid_hdr;
-			}
-
-			if (av->used_ebs != be32_to_cpu(vidh->used_ebs)) {
-				ubi_err("bad used_ebs %d", av->used_ebs);
-				goto bad_vid_hdr;
-			}
-
-			if (av->data_pad != be32_to_cpu(vidh->data_pad)) {
-				ubi_err("bad data_pad %d", av->data_pad);
-				goto bad_vid_hdr;
-			}
-		}
-
-		if (!last_aeb)
-			continue;
-
-		if (av->highest_lnum != be32_to_cpu(vidh->lnum)) {
-			ubi_err("bad highest_lnum %d", av->highest_lnum);
-			goto bad_vid_hdr;
-		}
-
-		if (av->last_data_size != be32_to_cpu(vidh->data_size)) {
-			ubi_err("bad last_data_size %d", av->last_data_size);
-			goto bad_vid_hdr;
-		}
-	}
-
-	/*
-	 * Make sure that all the physical eraseblocks are in one of the lists
-	 * or trees.
-	 */
-	buf = kzalloc(ubi->peb_count, GFP_KERNEL);
-	if (!buf)
-		return -ENOMEM;
-
-	for (pnum = 0; pnum < ubi->peb_count; pnum++) {
-		err = ubi_io_is_bad(ubi, pnum);
-		if (err < 0) {
-			kfree(buf);
-			return err;
-		} else if (err)
-			buf[pnum] = 1;
-	}
-
-	ubi_rb_for_each_entry(rb1, av, &ai->volumes, rb)
-		ubi_rb_for_each_entry(rb2, aeb, &av->root, u.rb)
-			buf[aeb->pnum] = 1;
-
-	list_for_each_entry(aeb, &ai->free, u.list)
-		buf[aeb->pnum] = 1;
-
-	list_for_each_entry(aeb, &ai->corr, u.list)
-		buf[aeb->pnum] = 1;
-
-	list_for_each_entry(aeb, &ai->erase, u.list)
-		buf[aeb->pnum] = 1;
-
-	list_for_each_entry(aeb, &ai->alien, u.list)
-		buf[aeb->pnum] = 1;
-
-	err = 0;
-	for (pnum = 0; pnum < ubi->peb_count; pnum++)
-		if (!buf[pnum]) {
-			ubi_err("PEB %d is not referred", pnum);
-			err = 1;
-		}
-
-	kfree(buf);
-	if (err)
-		goto out;
-	return 0;
-
-bad_aeb:
-	ubi_err("bad attaching information about LEB %d", aeb->lnum);
-	ubi_dump_aeb(aeb, 0);
-	ubi_dump_av(av);
-	goto out;
-
-bad_av:
-	ubi_err("bad attaching information about volume %d", av->vol_id);
-	ubi_dump_av(av);
-	goto out;
-
-bad_vid_hdr:
-	ubi_err("bad attaching information about volume %d", av->vol_id);
-	ubi_dump_av(av);
-	ubi_dump_vid_hdr(vidh);
-
-out:
-	dump_stack();
-	return -EINVAL;
-}