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linux / linux / kernel / git / dhowells / linux-fs / refs/heads/afs-experimental / . / drivers / mtd / ubi / attach.c
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/*
* 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 is 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);
#define AV_FIND BIT(0)
#define AV_ADD BIT(1)
#define AV_FIND_OR_ADD (AV_FIND | AV_ADD)
/**
* find_or_add_av - internal function to find a volume, add a volume or do
* both (find and add if missing).
* @ai: attaching information
* @vol_id: the requested volume ID
* @flags: a combination of the %AV_FIND and %AV_ADD flags describing the
* expected operation. If only %AV_ADD is set, -EEXIST is returned
* if the volume already exists. If only %AV_FIND is set, NULL is
* returned if the volume does not exist. And if both flags are
* set, the helper first tries to find an existing volume, and if
* it does not exist it creates a new one.
* @created: in value used to inform the caller whether it"s a newly created
* volume or not.
*
* This function returns a pointer to a volume description or an ERR_PTR if
* the operation failed. It can also return NULL if only %AV_FIND is set and
* the volume does not exist.
*/
static struct ubi_ainf_volume *find_or_add_av(struct ubi_attach_info *ai,
int vol_id, unsigned int flags,
bool *created)
{
struct ubi_ainf_volume *av;
struct rb_node **p = &ai->volumes.rb_node, *parent = NULL;
/* 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) {
*created = false;
if (!(flags & AV_FIND))
return ERR_PTR(-EEXIST);
return av;
}
if (vol_id > av->vol_id)
p = &(*p)->rb_left;
else
p = &(*p)->rb_right;
}
if (!(flags & AV_ADD))
return NULL;
/* The volume is absent - add it */
av = kzalloc(sizeof(*av), GFP_KERNEL);
if (!av)
return ERR_PTR(-ENOMEM);
av->vol_id = vol_id;
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;
*created = true;
dbg_bld("added volume %d", vol_id);
return av;
}
/**
* ubi_find_or_add_av - search for a volume in the attaching information and
* add one if it does not exist.
* @ai: attaching information
* @vol_id: the requested volume ID
* @created: whether the volume has been created or not
*
* This function returns a pointer to the new volume description or an
* ERR_PTR if the operation failed.
*/
static struct ubi_ainf_volume *ubi_find_or_add_av(struct ubi_attach_info *ai,
int vol_id, bool *created)
{
return find_or_add_av(ai, vol_id, AV_FIND_OR_ADD, created);
}
/**
* ubi_alloc_aeb - allocate an aeb element
* @ai: attaching information
* @pnum: physical eraseblock number
* @ec: erase counter of the physical eraseblock
*
* Allocate an aeb object and initialize the pnum and ec information.
* vol_id and lnum are set to UBI_UNKNOWN, and the other fields are
* initialized to zero.
* Note that the element is not added in any list or RB tree.
*/
struct ubi_ainf_peb *ubi_alloc_aeb(struct ubi_attach_info *ai, int pnum,
int ec)
{
struct ubi_ainf_peb *aeb;
aeb = kmem_cache_zalloc(ai->aeb_slab_cache, GFP_KERNEL);
if (!aeb)
return NULL;
aeb->pnum = pnum;
aeb->ec = ec;
aeb->vol_id = UBI_UNKNOWN;
aeb->lnum = UBI_UNKNOWN;
return aeb;
}
/**
* ubi_free_aeb - free an aeb element
* @ai: attaching information
* @aeb: the element to free
*
* Free an aeb object. The caller must have removed the element from any list
* or RB tree.
*/
void ubi_free_aeb(struct ubi_attach_info *ai, struct ubi_ainf_peb *aeb)
{
kmem_cache_free(ai->aeb_slab_cache, aeb);
}
/**
* add_to_list - add physical eraseblock to a list.
* @ai: attaching information
* @pnum: physical eraseblock number to add
* @vol_id: the last used volume id for the PEB
* @lnum: the last used LEB number for the PEB
* @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.
* It stores the @lnum and @vol_id alongside, which can both be
* %UBI_UNKNOWN if they are not available, not readable, or not assigned.
* 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 vol_id,
int lnum, 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 = ubi_alloc_aeb(ai, pnum, ec);
if (!aeb)
return -ENOMEM;
aeb->vol_id = vol_id;
aeb->lnum = lnum;
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 = ubi_alloc_aeb(ai, pnum, ec);
if (!aeb)
return -ENOMEM;
ai->corr_peb_count += 1;
list_add(&aeb->u.list, &ai->corr);
return 0;
}
/**
* add_fastmap - add a Fastmap related physical eraseblock.
* @ai: attaching information
* @pnum: physical eraseblock number the VID header came from
* @vid_hdr: the volume identifier header
* @ec: erase counter of the physical eraseblock
*
* This function allocates a 'struct ubi_ainf_peb' object for a Fastamp
* physical eraseblock @pnum and adds it to the 'fastmap' list.
* Such blocks can be Fastmap super and data blocks from both the most
* recent Fastmap we're attaching from or from old Fastmaps which will
* be erased.
*/
static int add_fastmap(struct ubi_attach_info *ai, int pnum,
struct ubi_vid_hdr *vid_hdr, int ec)
{
struct ubi_ainf_peb *aeb;
aeb = ubi_alloc_aeb(ai, pnum, ec);
if (!aeb)
return -ENOMEM;
aeb->vol_id = be32_to_cpu(vid_hdr->vol_id);
aeb->sqnum = be64_to_cpu(vid_hdr->sqnum);
list_add(&aeb->u.list, &ai->fastmap);
dbg_bld("add to fastmap list: PEB %d, vol_id %d, sqnum: %llu", pnum,
aeb->vol_id, aeb->sqnum);
return 0;
}
/**
* validate_vid_hdr - check volume identifier header.
* @ubi: UBI device description object
* @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_device *ubi,
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(ubi, "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(ubi, "inconsistent vol_type");
goto bad;
}
if (used_ebs != av->used_ebs) {
ubi_err(ubi, "inconsistent used_ebs");
goto bad;
}
if (data_pad != av->data_pad) {
ubi_err(ubi, "inconsistent data_pad");
goto bad;
}
}
return 0;
bad:
ubi_err(ubi, "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;
bool created;
ubi_assert(vol_id == be32_to_cpu(vid_hdr->vol_id));
av = ubi_find_or_add_av(ai, vol_id, &created);
if (IS_ERR(av) || !created)
return av;
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;
return av;
}
/**
* ubi_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.
*/
int ubi_compare_lebs(struct ubi_device *ubi, const struct ubi_ainf_peb *aeb,
int pnum, const struct ubi_vid_hdr *vid_hdr)
{
int len, err, second_is_newer, bitflips = 0, corrupted = 0;
uint32_t data_crc, crc;
struct ubi_vid_io_buf *vidb = 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(ubi, "unsupported on-flash UBI format");
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;
}
vidb = ubi_alloc_vid_buf(ubi, GFP_KERNEL);
if (!vidb)
return -ENOMEM;
pnum = aeb->pnum;
err = ubi_io_read_vid_hdr(ubi, pnum, vidb, 0);
if (err) {
if (err == UBI_IO_BITFLIPS)
bitflips = 1;
else {
ubi_err(ubi, "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 = ubi_get_vid_hdr(vidb);
}
/* Read the data of the copy and check the CRC */
len = be32_to_cpu(vid_hdr->data_size);
mutex_lock(&ubi->buf_mutex);
err = ubi_io_read_data(ubi, ubi->peb_buf, pnum, 0, len);
if (err && err != UBI_IO_BITFLIPS && !mtd_is_eccerr(err))
goto out_unlock;
data_crc = be32_to_cpu(vid_hdr->data_crc);
crc = crc32(UBI_CRC32_INIT, ubi->peb_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;
}
mutex_unlock(&ubi->buf_mutex);
ubi_free_vid_buf(vidb);
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_unlock:
mutex_unlock(&ubi->buf_mutex);
out_free_vidh:
ubi_free_vid_buf(vidb);
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
* 'ubi_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(ubi, "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 = ubi_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(ubi, vid_hdr, av, pnum);
if (err)
return err;
err = add_to_list(ai, aeb->pnum, aeb->vol_id,
aeb->lnum, aeb->ec, cmp_res & 4,
&ai->erase);
if (err)
return err;
aeb->ec = ec;
aeb->pnum = pnum;
aeb->vol_id = vol_id;
aeb->lnum = lnum;
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, vol_id, lnum, 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(ubi, vid_hdr, av, pnum);
if (err)
return err;
aeb = ubi_alloc_aeb(ai, pnum, ec);
if (!aeb)
return -ENOMEM;
aeb->vol_id = vol_id;
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_add_av - add volume to the attaching information.
* @ai: attaching information
* @vol_id: the requested volume ID
*
* This function returns a pointer to the new volume description or an
* ERR_PTR if the operation failed.
*/
struct ubi_ainf_volume *ubi_add_av(struct ubi_attach_info *ai, int vol_id)
{
bool created;
return find_or_add_av(ai, vol_id, AV_ADD, &created);
}
/**
* 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)
{
bool created;
return find_or_add_av((struct ubi_attach_info *)ai, vol_id, AV_FIND,
&created);
}
static void destroy_av(struct ubi_attach_info *ai, struct ubi_ainf_volume *av,
struct list_head *list);
/**
* 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)
{
dbg_bld("remove attaching information about volume %d", av->vol_id);
rb_erase(&av->rb, &ai->volumes);
destroy_av(ai, av, &ai->erase);
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(ubi, "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(ubi, "no free eraseblocks");
return ERR_PTR(-ENOSPC);
}
/**
* check_corruption - check the data area of PEB.
* @ubi: UBI device description object
* @vid_hdr: 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(ubi, "PEB %d contains corrupted VID header, and the data does not contain all 0xFF",
pnum);
ubi_err(ubi, "this may be a non-UBI PEB or a severe VID header corruption which requires manual inspection");
ubi_dump_vid_hdr(vid_hdr);
pr_err("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;
}
static bool vol_ignored(int vol_id)
{
switch (vol_id) {
case UBI_LAYOUT_VOLUME_ID:
return true;
}
#ifdef CONFIG_MTD_UBI_FASTMAP
return ubi_is_fm_vol(vol_id);
#else
return false;
#endif
}
/**
* scan_peb - scan and process UBI headers of a PEB.
* @ubi: UBI device description object
* @ai: attaching information
* @pnum: the physical eraseblock number
* @fast: true if we're scanning for a Fastmap
*
* 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, bool fast)
{
struct ubi_ec_hdr *ech = ai->ech;
struct ubi_vid_io_buf *vidb = ai->vidb;
struct ubi_vid_hdr *vidh = ubi_get_vid_hdr(vidb);
long long ec;
int err, bitflips = 0, vol_id = -1, 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, UBI_UNKNOWN,
UBI_UNKNOWN, 0, &ai->erase);
case UBI_IO_FF_BITFLIPS:
ai->empty_peb_count += 1;
return add_to_list(ai, pnum, UBI_UNKNOWN, UBI_UNKNOWN,
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, "'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(ubi, "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(ubi, "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)
ubi->image_seq = image_seq;
if (image_seq && ubi->image_seq != image_seq) {
ubi_err(ubi, "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, vidb, 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 we're facing a bad VID header we have to drop *all*
* Fastmap data structures we find. The most recent Fastmap
* could be bad and therefore there is a chance that we attach
* from an old one. On a fine MTD stack a PEB must not render
* bad all of a sudden, but the reality is different.
* So, let's be paranoid and help finding the root cause by
* falling back to scanning mode instead of attaching with a
* bad EBA table and cause data corruption which is hard to
* analyze.
*/
if (fast)
ai->force_full_scan = 1;
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, UBI_UNKNOWN,
UBI_UNKNOWN, 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, UBI_UNKNOWN, UBI_UNKNOWN,
ec, 1, &ai->erase);
if (err)
return err;
goto adjust_mean_ec;
case UBI_IO_FF:
if (ec_err || bitflips)
err = add_to_list(ai, pnum, UBI_UNKNOWN,
UBI_UNKNOWN, ec, 1, &ai->erase);
else
err = add_to_list(ai, pnum, UBI_UNKNOWN,
UBI_UNKNOWN, ec, 0, &ai->free);
if (err)
return err;
goto adjust_mean_ec;
default:
ubi_err(ubi, "'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_ignored(vol_id)) {
int lnum = be32_to_cpu(vidh->lnum);
/* Unsupported internal volume */
switch (vidh->compat) {
case UBI_COMPAT_DELETE:
ubi_msg(ubi, "\"delete\" compatible internal volume %d:%d found, will remove it",
vol_id, lnum);
err = add_to_list(ai, pnum, vol_id, lnum,
ec, 1, &ai->erase);
if (err)
return err;
return 0;
case UBI_COMPAT_RO:
ubi_msg(ubi, "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(ubi, "\"preserve\" compatible internal volume %d:%d found",
vol_id, lnum);
err = add_to_list(ai, pnum, vol_id, lnum,
ec, 0, &ai->alien);
if (err)
return err;
return 0;
case UBI_COMPAT_REJECT:
ubi_err(ubi, "incompatible internal volume %d:%d found",
vol_id, lnum);
return -EINVAL;
}
}
if (ec_err)
ubi_warn(ubi, "valid VID header but corrupted EC header at PEB %d",
pnum);
if (ubi_is_fm_vol(vol_id))
err = add_fastmap(ai, pnum, vidh, ec);
else
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(ubi, "%d PEBs are corrupted and preserved",
ai->corr_peb_count);
pr_err("Corrupted PEBs are:");
list_for_each_entry(aeb, &ai->corr, u.list)
pr_cont(" %d", aeb->pnum);
pr_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(ubi, "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(ubi, "empty MTD device detected");
get_random_bytes(&ubi->image_seq,
sizeof(ubi->image_seq));
} else {
ubi_err(ubi, "MTD device is not UBI-formatted and possibly contains non-UBI data - refusing it");
return -EINVAL;
}
}
return 0;
}
/**
* destroy_av - free volume attaching information.
* @av: volume attaching information
* @ai: attaching information
* @list: put the aeb elements in there if !NULL, otherwise free them
*
* This function destroys the volume attaching information.
*/
static void destroy_av(struct ubi_attach_info *ai, struct ubi_ainf_volume *av,
struct list_head *list)
{
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;
}
if (list)
list_add_tail(&aeb->u.list, list);
else
ubi_free_aeb(ai, aeb);
}
}
kfree(av);
}
/**
* destroy_ai - destroy attaching information.
* @ai: attaching information
*/
static void 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);
ubi_free_aeb(ai, aeb);
}
list_for_each_entry_safe(aeb, aeb_tmp, &ai->erase, u.list) {
list_del(&aeb->u.list);
ubi_free_aeb(ai, aeb);
}
list_for_each_entry_safe(aeb, aeb_tmp, &ai->corr, u.list) {
list_del(&aeb->u.list);
ubi_free_aeb(ai, aeb);
}
list_for_each_entry_safe(aeb, aeb_tmp, &ai->free, u.list) {
list_del(&aeb->u.list);
ubi_free_aeb(ai, aeb);
}
list_for_each_entry_safe(aeb, aeb_tmp, &ai->fastmap, u.list) {
list_del(&aeb->u.list);
ubi_free_aeb(ai, 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, NULL);
}
}
kmem_cache_destroy(ai->aeb_slab_cache);
kfree(ai);
}
/**
* scan_all - scan entire MTD device.
* @ubi: UBI device description object
* @ai: attach info object
* @start: start scanning at this PEB
*
* 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 int scan_all(struct ubi_device *ubi, struct ubi_attach_info *ai,
int start)
{
int err, pnum;
struct rb_node *rb1, *rb2;
struct ubi_ainf_volume *av;
struct ubi_ainf_peb *aeb;
err = -ENOMEM;
ai->ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
if (!ai->ech)
return err;
ai->vidb = ubi_alloc_vid_buf(ubi, GFP_KERNEL);
if (!ai->vidb)
goto out_ech;
for (pnum = start; pnum < ubi->peb_count; pnum++) {
cond_resched();
dbg_gen("process PEB %d", pnum);
err = scan_peb(ubi, ai, pnum, false);
if (err < 0)
goto out_vidh;
}
ubi_msg(ubi, "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_buf(ai->vidb);
kfree(ai->ech);
return 0;
out_vidh:
ubi_free_vid_buf(ai->vidb);
out_ech:
kfree(ai->ech);
return err;
}
static struct ubi_attach_info *alloc_ai(void)
{
struct ubi_attach_info *ai;
ai = kzalloc(sizeof(struct ubi_attach_info), GFP_KERNEL);
if (!ai)
return ai;
INIT_LIST_HEAD(&ai->corr);
INIT_LIST_HEAD(&ai->free);
INIT_LIST_HEAD(&ai->erase);
INIT_LIST_HEAD(&ai->alien);
INIT_LIST_HEAD(&ai->fastmap);
ai->volumes = RB_ROOT;
ai->aeb_slab_cache = kmem_cache_create("ubi_aeb_slab_cache",
sizeof(struct ubi_ainf_peb),
0, 0, NULL);
if (!ai->aeb_slab_cache) {
kfree(ai);
ai = NULL;
}
return ai;
}
#ifdef CONFIG_MTD_UBI_FASTMAP
/**
* scan_fast - try to find a fastmap and attach from it.
* @ubi: UBI device description object
* @ai: attach info object
*
* Returns 0 on success, negative return values indicate an internal
* error.
* UBI_NO_FASTMAP denotes that no fastmap was found.
* UBI_BAD_FASTMAP denotes that the found fastmap was invalid.
*/
static int scan_fast(struct ubi_device *ubi, struct ubi_attach_info **ai)
{
int err, pnum;
struct ubi_attach_info *scan_ai;
err = -ENOMEM;
scan_ai = alloc_ai();
if (!scan_ai)
goto out;
scan_ai->ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
if (!scan_ai->ech)
goto out_ai;
scan_ai->vidb = ubi_alloc_vid_buf(ubi, GFP_KERNEL);
if (!scan_ai->vidb)
goto out_ech;
for (pnum = 0; pnum < UBI_FM_MAX_START; pnum++) {
cond_resched();
dbg_gen("process PEB %d", pnum);
err = scan_peb(ubi, scan_ai, pnum, true);
if (err < 0)
goto out_vidh;
}
ubi_free_vid_buf(scan_ai->vidb);
kfree(scan_ai->ech);
if (scan_ai->force_full_scan)
err = UBI_NO_FASTMAP;
else
err = ubi_scan_fastmap(ubi, *ai, scan_ai);
if (err) {
/*
* Didn't attach via fastmap, do a full scan but reuse what
* we've aready scanned.
*/
destroy_ai(*ai);
*ai = scan_ai;
} else
destroy_ai(scan_ai);
return err;
out_vidh:
ubi_free_vid_buf(scan_ai->vidb);
out_ech:
kfree(scan_ai->ech);
out_ai:
destroy_ai(scan_ai);
out:
return err;
}
#endif
/**
* ubi_attach - attach an MTD device.
* @ubi: UBI device descriptor
* @force_scan: if set to non-zero attach by scanning
*
* 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 force_scan)
{
int err;
struct ubi_attach_info *ai;
ai = alloc_ai();
if (!ai)
return -ENOMEM;
#ifdef CONFIG_MTD_UBI_FASTMAP
/* On small flash devices we disable fastmap in any case. */
if ((int)mtd_div_by_eb(ubi->mtd->size, ubi->mtd) <= UBI_FM_MAX_START) {
ubi->fm_disabled = 1;
force_scan = 1;
}
if (force_scan)
err = scan_all(ubi, ai, 0);
else {
err = scan_fast(ubi, &ai);
if (err > 0 || mtd_is_eccerr(err)) {
if (err != UBI_NO_FASTMAP) {
destroy_ai(ai);
ai = alloc_ai();
if (!ai)
return -ENOMEM;
err = scan_all(ubi, ai, 0);
} else {
err = scan_all(ubi, ai, UBI_FM_MAX_START);
}
}
}
#else
err = scan_all(ubi, ai, 0);
#endif
if (err)
goto out_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;
dbg_gen("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;
#ifdef CONFIG_MTD_UBI_FASTMAP
if (ubi->fm && ubi_dbg_chk_fastmap(ubi)) {
struct ubi_attach_info *scan_ai;
scan_ai = alloc_ai();
if (!scan_ai) {
err = -ENOMEM;
goto out_wl;
}
err = scan_all(ubi, scan_ai, 0);
if (err) {
destroy_ai(scan_ai);
goto out_wl;
}
err = self_check_eba(ubi, ai, scan_ai);
destroy_ai(scan_ai);
if (err)
goto out_wl;
}
#endif
destroy_ai(ai);
return 0;
out_wl:
ubi_wl_close(ubi);
out_vtbl:
ubi_free_internal_volumes(ubi);
vfree(ubi->vtbl);
out_ai:
destroy_ai(ai);
return err;
}
/**
* 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)
{
struct ubi_vid_io_buf *vidb = ai->vidb;
struct ubi_vid_hdr *vidh = ubi_get_vid_hdr(vidb);
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(ubi))
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(ubi, "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(ubi, "negative values");
goto bad_av;
}
if (av->vol_id >= UBI_MAX_VOLUMES &&
av->vol_id < UBI_INTERNAL_VOL_START) {
ubi_err(ubi, "bad vol_id");
goto bad_av;
}
if (av->vol_id > ai->highest_vol_id) {
ubi_err(ubi, "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(ubi, "bad vol_type");
goto bad_av;
}
if (av->data_pad > ubi->leb_size / 2) {
ubi_err(ubi, "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(ubi, "negative values");
goto bad_aeb;
}
if (aeb->ec < ai->min_ec) {
ubi_err(ubi, "bad ai->min_ec (%d), %d found",
ai->min_ec, aeb->ec);
goto bad_aeb;
}
if (aeb->ec > ai->max_ec) {
ubi_err(ubi, "bad ai->max_ec (%d), %d found",
ai->max_ec, aeb->ec);
goto bad_aeb;
}
if (aeb->pnum >= ubi->peb_count) {
ubi_err(ubi, "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(ubi, "bad lnum or used_ebs");
goto bad_aeb;
}
} else {
if (av->used_ebs != 0) {
ubi_err(ubi, "non-zero used_ebs");
goto bad_aeb;
}
}
if (aeb->lnum > av->highest_lnum) {
ubi_err(ubi, "incorrect highest_lnum or lnum");
goto bad_aeb;
}
}
if (av->leb_count != leb_count) {
ubi_err(ubi, "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(ubi, "bad highest_lnum");
goto bad_aeb;
}
}
if (vols_found != ai->vols_found) {
ubi_err(ubi, "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, vidb, 1);
if (err && err != UBI_IO_BITFLIPS) {
ubi_err(ubi, "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(ubi, "bad vol_type");
goto bad_vid_hdr;
}
if (aeb->sqnum != be64_to_cpu(vidh->sqnum)) {
ubi_err(ubi, "bad sqnum %llu", aeb->sqnum);
goto bad_vid_hdr;
}
if (av->vol_id != be32_to_cpu(vidh->vol_id)) {
ubi_err(ubi, "bad vol_id %d", av->vol_id);
goto bad_vid_hdr;
}
if (av->compat != vidh->compat) {
ubi_err(ubi, "bad compat %d", vidh->compat);
goto bad_vid_hdr;
}
if (aeb->lnum != be32_to_cpu(vidh->lnum)) {
ubi_err(ubi, "bad lnum %d", aeb->lnum);
goto bad_vid_hdr;
}
if (av->used_ebs != be32_to_cpu(vidh->used_ebs)) {
ubi_err(ubi, "bad used_ebs %d", av->used_ebs);
goto bad_vid_hdr;
}
if (av->data_pad != be32_to_cpu(vidh->data_pad)) {
ubi_err(ubi, "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(ubi, "bad highest_lnum %d", av->highest_lnum);
goto bad_vid_hdr;
}
if (av->last_data_size != be32_to_cpu(vidh->data_size)) {
ubi_err(ubi, "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(ubi, "PEB %d is not referred", pnum);
err = 1;
}
kfree(buf);
if (err)
goto out;
return 0;
bad_aeb:
ubi_err(ubi, "bad attaching information about LEB %d", aeb->lnum);
ubi_dump_aeb(aeb, 0);
ubi_dump_av(av);
goto out;
bad_av:
ubi_err(ubi, "bad attaching information about volume %d", av->vol_id);
ubi_dump_av(av);
goto out;
bad_vid_hdr:
ubi_err(ubi, "bad attaching information about volume %d", av->vol_id);
ubi_dump_av(av);
ubi_dump_vid_hdr(vidh);
out:
dump_stack();
return -EINVAL;
}