inftlmount.c

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/*
 * inftlmount.c -- INFTL mount code with extensive checks.
 *
 * Author: Greg Ungerer ([email protected])
 * Copyright © 2002-2003, Greg Ungerer ([email protected])
 *
 * Based heavily on the nftlmount.c code which is:
 * Author: Fabrice Bellard ([email protected])
 * Copyright © 2000 Netgem S.A.
 *
 * 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
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <asm/errno.h>
#include <asm/io.h>
#include <asm/uaccess.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/nftl.h>
#include <linux/mtd/inftl.h>

/*
 * find_boot_record: Find the INFTL Media Header and its Spare copy which
 *  contains the various device information of the INFTL partition and
 *  Bad Unit Table. Update the PUtable[] table according to the Bad
 *  Unit Table. PUtable[] is used for management of Erase Unit in
 *  other routines in inftlcore.c and inftlmount.c.
 */
static int find_boot_record(struct INFTLrecord *inftl)
{
    struct inftl_unittail h1;
    //struct inftl_oob oob;
    unsigned int i, block;
    u8 buf[SECTORSIZE];
    struct INFTLMediaHeader *mh = &inftl->MediaHdr;
    struct mtd_info *mtd = inftl->mbd.mtd;
    struct INFTLPartition *ip;
    size_t retlen;

    pr_debug("INFTL: find_boot_record(inftl=%p)\n", inftl);

        /*
     * Assume logical EraseSize == physical erasesize for starting the
     * scan. We'll sort it out later if we find a MediaHeader which says
     * otherwise.
     */
    inftl->EraseSize = inftl->mbd.mtd->erasesize;
        inftl->nb_blocks = (u32)inftl->mbd.mtd->size / inftl->EraseSize;

    inftl->MediaUnit = BLOCK_NIL;

    /* Search for a valid boot record */
    for (block = 0; block < inftl->nb_blocks; block++) {
        int ret;

        /*
         * Check for BNAND header first. Then whinge if it's found
         * but later checks fail.
         */
        ret = mtd_read(mtd, block * inftl->EraseSize, SECTORSIZE,
                   &retlen, buf);
        /* We ignore ret in case the ECC of the MediaHeader is invalid
           (which is apparently acceptable) */
        if (retlen != SECTORSIZE) {
            static int warncount = 5;

            if (warncount) {
                printk(KERN_WARNING "INFTL: block read at 0x%x "
                    "of mtd%d failed: %d\n",
                    block * inftl->EraseSize,
                    inftl->mbd.mtd->index, ret);
                if (!--warncount)
                    printk(KERN_WARNING "INFTL: further "
                        "failures for this block will "
                        "not be printed\n");
            }
            continue;
        }

        if (retlen < 6 || memcmp(buf, "BNAND", 6)) {
            /* BNAND\0 not found. Continue */
            continue;
        }

        /* To be safer with BIOS, also use erase mark as discriminant */
        ret = inftl_read_oob(mtd,
                     block * inftl->EraseSize + SECTORSIZE + 8,
                     8, &retlen,(char *)&h1);
        if (ret < 0) {
            printk(KERN_WARNING "INFTL: ANAND header found at "
                "0x%x in mtd%d, but OOB data read failed "
                "(err %d)\n", block * inftl->EraseSize,
                inftl->mbd.mtd->index, ret);
            continue;
        }


        /*
         * This is the first we've seen.
         * Copy the media header structure into place.
         */
        memcpy(mh, buf, sizeof(struct INFTLMediaHeader));

        /* Read the spare media header at offset 4096 */
        mtd_read(mtd, block * inftl->EraseSize + 4096, SECTORSIZE,
             &retlen, buf);
        if (retlen != SECTORSIZE) {
            printk(KERN_WARNING "INFTL: Unable to read spare "
                   "Media Header\n");
            return -1;
        }
        /* Check if this one is the same as the first one we found. */
        if (memcmp(mh, buf, sizeof(struct INFTLMediaHeader))) {
            printk(KERN_WARNING "INFTL: Primary and spare Media "
                   "Headers disagree.\n");
            return -1;
        }

        mh->NoOfBootImageBlocks = le32_to_cpu(mh->NoOfBootImageBlocks);
        mh->NoOfBinaryPartitions = le32_to_cpu(mh->NoOfBinaryPartitions);
        mh->NoOfBDTLPartitions = le32_to_cpu(mh->NoOfBDTLPartitions);
        mh->BlockMultiplierBits = le32_to_cpu(mh->BlockMultiplierBits);
        mh->FormatFlags = le32_to_cpu(mh->FormatFlags);
        mh->PercentUsed = le32_to_cpu(mh->PercentUsed);

        pr_debug("INFTL: Media Header ->\n"
             "    bootRecordID          = %s\n"
             "    NoOfBootImageBlocks   = %d\n"
             "    NoOfBinaryPartitions  = %d\n"
             "    NoOfBDTLPartitions    = %d\n"
             "    BlockMultiplerBits    = %d\n"
             "    FormatFlgs            = %d\n"
             "    OsakVersion           = 0x%x\n"
             "    PercentUsed           = %d\n",
             mh->bootRecordID, mh->NoOfBootImageBlocks,
             mh->NoOfBinaryPartitions,
             mh->NoOfBDTLPartitions,
             mh->BlockMultiplierBits, mh->FormatFlags,
             mh->OsakVersion, mh->PercentUsed);

        if (mh->NoOfBDTLPartitions == 0) {
            printk(KERN_WARNING "INFTL: Media Header sanity check "
                "failed: NoOfBDTLPartitions (%d) == 0, "
                "must be at least 1\n", mh->NoOfBDTLPartitions);
            return -1;
        }

        if ((mh->NoOfBDTLPartitions + mh->NoOfBinaryPartitions) > 4) {
            printk(KERN_WARNING "INFTL: Media Header sanity check "
                "failed: Total Partitions (%d) > 4, "
                "BDTL=%d Binary=%d\n", mh->NoOfBDTLPartitions +
                mh->NoOfBinaryPartitions,
                mh->NoOfBDTLPartitions,
                mh->NoOfBinaryPartitions);
            return -1;
        }

        if (mh->BlockMultiplierBits > 1) {
            printk(KERN_WARNING "INFTL: sorry, we don't support "
                "UnitSizeFactor 0x%02x\n",
                mh->BlockMultiplierBits);
            return -1;
        } else if (mh->BlockMultiplierBits == 1) {
            printk(KERN_WARNING "INFTL: support for INFTL with "
                "UnitSizeFactor 0x%02x is experimental\n",
                mh->BlockMultiplierBits);
            inftl->EraseSize = inftl->mbd.mtd->erasesize <<
                mh->BlockMultiplierBits;
            inftl->nb_blocks = (u32)inftl->mbd.mtd->size / inftl->EraseSize;
            block >>= mh->BlockMultiplierBits;
        }

        /* Scan the partitions */
        for (i = 0; (i < 4); i++) {
            ip = &mh->Partitions[i];
            ip->virtualUnits = le32_to_cpu(ip->virtualUnits);
            ip->firstUnit = le32_to_cpu(ip->firstUnit);
            ip->lastUnit = le32_to_cpu(ip->lastUnit);
            ip->flags = le32_to_cpu(ip->flags);
            ip->spareUnits = le32_to_cpu(ip->spareUnits);
            ip->Reserved0 = le32_to_cpu(ip->Reserved0);

            pr_debug("    PARTITION[%d] ->\n"
                 "        virtualUnits    = %d\n"
                 "        firstUnit       = %d\n"
                 "        lastUnit        = %d\n"
                 "        flags           = 0x%x\n"
                 "        spareUnits      = %d\n",
                 i, ip->virtualUnits, ip->firstUnit,
                 ip->lastUnit, ip->flags,
                 ip->spareUnits);

            if (ip->Reserved0 != ip->firstUnit) {
                struct erase_info *instr = &inftl->instr;

                instr->mtd = inftl->mbd.mtd;

                /*
                 *  Most likely this is using the
                 *  undocumented qiuck mount feature.
                 *  We don't support that, we will need
                 *  to erase the hidden block for full
                 *  compatibility.
                 */
                instr->addr = ip->Reserved0 * inftl->EraseSize;
                instr->len = inftl->EraseSize;
                mtd_erase(mtd, instr);
            }
            if ((ip->lastUnit - ip->firstUnit + 1) < ip->virtualUnits) {
                printk(KERN_WARNING "INFTL: Media Header "
                    "Partition %d sanity check failed\n"
                    "    firstUnit %d : lastUnit %d  >  "
                    "virtualUnits %d\n", i, ip->lastUnit,
                    ip->firstUnit, ip->Reserved0);
                return -1;
            }
            if (ip->Reserved1 != 0) {
                printk(KERN_WARNING "INFTL: Media Header "
                    "Partition %d sanity check failed: "
                    "Reserved1 %d != 0\n",
                    i, ip->Reserved1);
                return -1;
            }

            if (ip->flags & INFTL_BDTL)
                break;
        }

        if (i >= 4) {
            printk(KERN_WARNING "INFTL: Media Header Partition "
                "sanity check failed:\n       No partition "
                "marked as Disk Partition\n");
            return -1;
        }

        inftl->nb_boot_blocks = ip->firstUnit;
        inftl->numvunits = ip->virtualUnits;
        if (inftl->numvunits > (inftl->nb_blocks -
            inftl->nb_boot_blocks - 2)) {
            printk(KERN_WARNING "INFTL: Media Header sanity check "
                "failed:\n        numvunits (%d) > nb_blocks "
                "(%d) - nb_boot_blocks(%d) - 2\n",
                inftl->numvunits, inftl->nb_blocks,
                inftl->nb_boot_blocks);
            return -1;
        }

        inftl->mbd.size  = inftl->numvunits *
            (inftl->EraseSize / SECTORSIZE);

        /*
         * Block count is set to last used EUN (we won't need to keep
         * any meta-data past that point).
         */
        inftl->firstEUN = ip->firstUnit;
        inftl->lastEUN = ip->lastUnit;
        inftl->nb_blocks = ip->lastUnit + 1;

        /* Memory alloc */
        inftl->PUtable = kmalloc(inftl->nb_blocks * sizeof(u16), GFP_KERNEL);
        if (!inftl->PUtable) {
            printk(KERN_WARNING "INFTL: allocation of PUtable "
                "failed (%zd bytes)\n",
                inftl->nb_blocks * sizeof(u16));
            return -ENOMEM;
        }

        inftl->VUtable = kmalloc(inftl->nb_blocks * sizeof(u16), GFP_KERNEL);
        if (!inftl->VUtable) {
            kfree(inftl->PUtable);
            printk(KERN_WARNING "INFTL: allocation of VUtable "
                "failed (%zd bytes)\n",
                inftl->nb_blocks * sizeof(u16));
            return -ENOMEM;
        }

        /* Mark the blocks before INFTL MediaHeader as reserved */
        for (i = 0; i < inftl->nb_boot_blocks; i++)
            inftl->PUtable[i] = BLOCK_RESERVED;
        /* Mark all remaining blocks as potentially containing data */
        for (; i < inftl->nb_blocks; i++)
            inftl->PUtable[i] = BLOCK_NOTEXPLORED;

        /* Mark this boot record (NFTL MediaHeader) block as reserved */
        inftl->PUtable[block] = BLOCK_RESERVED;

        /* Read Bad Erase Unit Table and modify PUtable[] accordingly */
        for (i = 0; i < inftl->nb_blocks; i++) {
            int physblock;
            /* If any of the physical eraseblocks are bad, don't
               use the unit. */
            for (physblock = 0; physblock < inftl->EraseSize; physblock += inftl->mbd.mtd->erasesize) {
                if (mtd_block_isbad(inftl->mbd.mtd,
                            i * inftl->EraseSize + physblock))
                    inftl->PUtable[i] = BLOCK_RESERVED;
            }
        }

        inftl->MediaUnit = block;
        return 0;
    }

    /* Not found. */
    return -1;
}

static int memcmpb(void *a, int c, int n)
{
    int i;
    for (i = 0; i < n; i++) {
        if (c != ((unsigned char *)a)[i])
            return 1;
    }
    return 0;
}

/*
 * check_free_sector: check if a free sector is actually FREE,
 *  i.e. All 0xff in data and oob area.
 */
static int check_free_sectors(struct INFTLrecord *inftl, unsigned int address,
    int len, int check_oob)
{
    u8 buf[SECTORSIZE + inftl->mbd.mtd->oobsize];
    struct mtd_info *mtd = inftl->mbd.mtd;
    size_t retlen;
    int i;

    for (i = 0; i < len; i += SECTORSIZE) {
        if (mtd_read(mtd, address, SECTORSIZE, &retlen, buf))
            return -1;
        if (memcmpb(buf, 0xff, SECTORSIZE) != 0)
            return -1;

        if (check_oob) {
            if(inftl_read_oob(mtd, address, mtd->oobsize,
                      &retlen, &buf[SECTORSIZE]) < 0)
                return -1;
            if (memcmpb(buf + SECTORSIZE, 0xff, mtd->oobsize) != 0)
                return -1;
        }
        address += SECTORSIZE;
    }

    return 0;
}

/*
 * INFTL_format: format a Erase Unit by erasing ALL Erase Zones in the Erase
 *       Unit and Update INFTL metadata. Each erase operation is
 *       checked with check_free_sectors.
 *
 * Return: 0 when succeed, -1 on error.
 *
 * ToDo: 1. Is it necessary to check_free_sector after erasing ??
 */
int INFTL_formatblock(struct INFTLrecord *inftl, int block)
{
    size_t retlen;
    struct inftl_unittail uci;
    struct erase_info *instr = &inftl->instr;
    struct mtd_info *mtd = inftl->mbd.mtd;
    int physblock;

    pr_debug("INFTL: INFTL_formatblock(inftl=%p,block=%d)\n", inftl, block);

    memset(instr, 0, sizeof(struct erase_info));

    /* FIXME: Shouldn't we be setting the 'discarded' flag to zero
       _first_? */

    /* Use async erase interface, test return code */
    instr->mtd = inftl->mbd.mtd;
    instr->addr = block * inftl->EraseSize;
    instr->len = inftl->mbd.mtd->erasesize;
    /* Erase one physical eraseblock at a time, even though the NAND api
       allows us to group them.  This way we if we have a failure, we can
       mark only the failed block in the bbt. */
    for (physblock = 0; physblock < inftl->EraseSize;
         physblock += instr->len, instr->addr += instr->len) {
        mtd_erase(inftl->mbd.mtd, instr);

        if (instr->state == MTD_ERASE_FAILED) {
            printk(KERN_WARNING "INFTL: error while formatting block %d\n",
                block);
            goto fail;
        }

        /*
         * Check the "freeness" of Erase Unit before updating metadata.
         * FixMe: is this check really necessary? Since we have check
         * the return code after the erase operation.
         */
        if (check_free_sectors(inftl, instr->addr, instr->len, 1) != 0)
            goto fail;
    }

    uci.EraseMark = cpu_to_le16(ERASE_MARK);
    uci.EraseMark1 = cpu_to_le16(ERASE_MARK);
    uci.Reserved[0] = 0;
    uci.Reserved[1] = 0;
    uci.Reserved[2] = 0;
    uci.Reserved[3] = 0;
    instr->addr = block * inftl->EraseSize + SECTORSIZE * 2;
    if (inftl_write_oob(mtd, instr->addr + 8, 8, &retlen, (char *)&uci) < 0)
        goto fail;
    return 0;
fail:
    /* could not format, update the bad block table (caller is responsible
       for setting the PUtable to BLOCK_RESERVED on failure) */
    mtd_block_markbad(inftl->mbd.mtd, instr->addr);
    return -1;
}

/*
 * format_chain: Format an invalid Virtual Unit chain. It frees all the Erase
 *  Units in a Virtual Unit Chain, i.e. all the units are disconnected.
 *
 *  Since the chain is invalid then we will have to erase it from its
 *  head (normally for INFTL we go from the oldest). But if it has a
 *  loop then there is no oldest...
 */
static void format_chain(struct INFTLrecord *inftl, unsigned int first_block)
{
    unsigned int block = first_block, block1;

    printk(KERN_WARNING "INFTL: formatting chain at block %d\n",
        first_block);

    for (;;) {
        block1 = inftl->PUtable[block];

        printk(KERN_WARNING "INFTL: formatting block %d\n", block);
        if (INFTL_formatblock(inftl, block) < 0) {
            /*
             * Cannot format !!!! Mark it as Bad Unit,
             */
            inftl->PUtable[block] = BLOCK_RESERVED;
        } else {
            inftl->PUtable[block] = BLOCK_FREE;
        }

        /* Goto next block on the chain */
        block = block1;

        if (block == BLOCK_NIL || block >= inftl->lastEUN)
            break;
    }
}

void INFTL_dumptables(struct INFTLrecord *s)
{
    int i;

    pr_debug("-------------------------------------------"
        "----------------------------------\n");

    pr_debug("VUtable[%d] ->", s->nb_blocks);
    for (i = 0; i < s->nb_blocks; i++) {
        if ((i % 8) == 0)
            pr_debug("\n%04x: ", i);
        pr_debug("%04x ", s->VUtable[i]);
    }

    pr_debug("\n-------------------------------------------"
        "----------------------------------\n");

    pr_debug("PUtable[%d-%d=%d] ->", s->firstEUN, s->lastEUN, s->nb_blocks);
    for (i = 0; i <= s->lastEUN; i++) {
        if ((i % 8) == 0)
            pr_debug("\n%04x: ", i);
        pr_debug("%04x ", s->PUtable[i]);
    }

    pr_debug("\n-------------------------------------------"
        "----------------------------------\n");

    pr_debug("INFTL ->\n"
        "  EraseSize       = %d\n"
        "  h/s/c           = %d/%d/%d\n"
        "  numvunits       = %d\n"
        "  firstEUN        = %d\n"
        "  lastEUN         = %d\n"
        "  numfreeEUNs     = %d\n"
        "  LastFreeEUN     = %d\n"
        "  nb_blocks       = %d\n"
        "  nb_boot_blocks  = %d",
        s->EraseSize, s->heads, s->sectors, s->cylinders,
        s->numvunits, s->firstEUN, s->lastEUN, s->numfreeEUNs,
        s->LastFreeEUN, s->nb_blocks, s->nb_boot_blocks);

    pr_debug("\n-------------------------------------------"
        "----------------------------------\n");
}

void INFTL_dumpVUchains(struct INFTLrecord *s)
{
    int logical, block, i;

    pr_debug("-------------------------------------------"
        "----------------------------------\n");

    pr_debug("INFTL Virtual Unit Chains:\n");
    for (logical = 0; logical < s->nb_blocks; logical++) {
        block = s->VUtable[logical];
        if (block > s->nb_blocks)
            continue;
        pr_debug("  LOGICAL %d --> %d ", logical, block);
        for (i = 0; i < s->nb_blocks; i++) {
            if (s->PUtable[block] == BLOCK_NIL)
                break;
            block = s->PUtable[block];
            pr_debug("%d ", block);
        }
        pr_debug("\n");
    }

    pr_debug("-------------------------------------------"
        "----------------------------------\n");
}

int INFTL_mount(struct INFTLrecord *s)
{
    struct mtd_info *mtd = s->mbd.mtd;
    unsigned int block, first_block, prev_block, last_block;
    unsigned int first_logical_block, logical_block, erase_mark;
    int chain_length, do_format_chain;
    struct inftl_unithead1 h0;
    struct inftl_unittail h1;
    size_t retlen;
    int i;
    u8 *ANACtable, ANAC;

    pr_debug("INFTL: INFTL_mount(inftl=%p)\n", s);

    /* Search for INFTL MediaHeader and Spare INFTL Media Header */
    if (find_boot_record(s) < 0) {
        printk(KERN_WARNING "INFTL: could not find valid boot record?\n");
        return -ENXIO;
    }

    /* Init the logical to physical table */
    for (i = 0; i < s->nb_blocks; i++)
        s->VUtable[i] = BLOCK_NIL;

    logical_block = block = BLOCK_NIL;

    /* Temporary buffer to store ANAC numbers. */
    ANACtable = kcalloc(s->nb_blocks, sizeof(u8), GFP_KERNEL);
    if (!ANACtable) {
        printk(KERN_WARNING "INFTL: allocation of ANACtable "
                "failed (%zd bytes)\n",
                s->nb_blocks * sizeof(u8));
        return -ENOMEM;
    }

    /*
     * First pass is to explore each physical unit, and construct the
     * virtual chains that exist (newest physical unit goes into VUtable).
     * Any block that is in any way invalid will be left in the
     * NOTEXPLORED state. Then at the end we will try to format it and
     * mark it as free.
     */
    pr_debug("INFTL: pass 1, explore each unit\n");
    for (first_block = s->firstEUN; first_block <= s->lastEUN; first_block++) {
        if (s->PUtable[first_block] != BLOCK_NOTEXPLORED)
            continue;

        do_format_chain = 0;
        first_logical_block = BLOCK_NIL;
        last_block = BLOCK_NIL;
        block = first_block;

        for (chain_length = 0; ; chain_length++) {

            if ((chain_length == 0) &&
                (s->PUtable[block] != BLOCK_NOTEXPLORED)) {
                /* Nothing to do here, onto next block */
                break;
            }

            if (inftl_read_oob(mtd, block * s->EraseSize + 8,
                       8, &retlen, (char *)&h0) < 0 ||
                inftl_read_oob(mtd, block * s->EraseSize +
                       2 * SECTORSIZE + 8, 8, &retlen,
                       (char *)&h1) < 0) {
                /* Should never happen? */
                do_format_chain++;
                break;
            }

            logical_block = le16_to_cpu(h0.virtualUnitNo);
            prev_block = le16_to_cpu(h0.prevUnitNo);
            erase_mark = le16_to_cpu((h1.EraseMark | h1.EraseMark1));
            ANACtable[block] = h0.ANAC;

            /* Previous block is relative to start of Partition */
            if (prev_block < s->nb_blocks)
                prev_block += s->firstEUN;

            /* Already explored partial chain? */
            if (s->PUtable[block] != BLOCK_NOTEXPLORED) {
                /* Check if chain for this logical */
                if (logical_block == first_logical_block) {
                    if (last_block != BLOCK_NIL)
                        s->PUtable[last_block] = block;
                }
                break;
            }

            /* Check for invalid block */
            if (erase_mark != ERASE_MARK) {
                printk(KERN_WARNING "INFTL: corrupt block %d "
                    "in chain %d, chain length %d, erase "
                    "mark 0x%x?\n", block, first_block,
                    chain_length, erase_mark);
                /*
                 * Assume end of chain, probably incomplete
                 * fold/erase...
                 */
                if (chain_length == 0)
                    do_format_chain++;
                break;
            }

            /* Check for it being free already then... */
            if ((logical_block == BLOCK_FREE) ||
                (logical_block == BLOCK_NIL)) {
                s->PUtable[block] = BLOCK_FREE;
                break;
            }

            /* Sanity checks on block numbers */
            if ((logical_block >= s->nb_blocks) ||
                ((prev_block >= s->nb_blocks) &&
                 (prev_block != BLOCK_NIL))) {
                if (chain_length > 0) {
                    printk(KERN_WARNING "INFTL: corrupt "
                        "block %d in chain %d?\n",
                        block, first_block);
                    do_format_chain++;
                }
                break;
            }

            if (first_logical_block == BLOCK_NIL) {
                first_logical_block = logical_block;
            } else {
                if (first_logical_block != logical_block) {
                    /* Normal for folded chain... */
                    break;
                }
            }

            /*
             * Current block is valid, so if we followed a virtual
             * chain to get here then we can set the previous
             * block pointer in our PUtable now. Then move onto
             * the previous block in the chain.
             */
            s->PUtable[block] = BLOCK_NIL;
            if (last_block != BLOCK_NIL)
                s->PUtable[last_block] = block;
            last_block = block;
            block = prev_block;

            /* Check for end of chain */
            if (block == BLOCK_NIL)
                break;

            /* Validate next block before following it... */
            if (block > s->lastEUN) {
                printk(KERN_WARNING "INFTL: invalid previous "
                    "block %d in chain %d?\n", block,
                    first_block);
                do_format_chain++;
                break;
            }
        }

        if (do_format_chain) {
            format_chain(s, first_block);
            continue;
        }

        /*
         * Looks like a valid chain then. It may not really be the
         * newest block in the chain, but it is the newest we have
         * found so far. We might update it in later iterations of
         * this loop if we find something newer.
         */
        s->VUtable[first_logical_block] = first_block;
        logical_block = BLOCK_NIL;
    }

    INFTL_dumptables(s);

    /*
     * Second pass, check for infinite loops in chains. These are
     * possible because we don't update the previous pointers when
     * we fold chains. No big deal, just fix them up in PUtable.
     */
    pr_debug("INFTL: pass 2, validate virtual chains\n");
    for (logical_block = 0; logical_block < s->numvunits; logical_block++) {
        block = s->VUtable[logical_block];
        last_block = BLOCK_NIL;

        /* Check for free/reserved/nil */
        if (block >= BLOCK_RESERVED)
            continue;

        ANAC = ANACtable[block];
        for (i = 0; i < s->numvunits; i++) {
            if (s->PUtable[block] == BLOCK_NIL)
                break;
            if (s->PUtable[block] > s->lastEUN) {
                printk(KERN_WARNING "INFTL: invalid prev %d, "
                    "in virtual chain %d\n",
                    s->PUtable[block], logical_block);
                s->PUtable[block] = BLOCK_NIL;

            }
            if (ANACtable[block] != ANAC) {
                /*
                 * Chain must point back to itself. This is ok,
                 * but we will need adjust the tables with this
                 * newest block and oldest block.
                 */
                s->VUtable[logical_block] = block;
                s->PUtable[last_block] = BLOCK_NIL;
                break;
            }

            ANAC--;
            last_block = block;
            block = s->PUtable[block];
        }

        if (i >= s->nb_blocks) {
            /*
             * Uhoo, infinite chain with valid ANACS!
             * Format whole chain...
             */
            format_chain(s, first_block);
        }
    }

    INFTL_dumptables(s);
    INFTL_dumpVUchains(s);

    /*
     * Third pass, format unreferenced blocks and init free block count.
     */
    s->numfreeEUNs = 0;
    s->LastFreeEUN = BLOCK_NIL;

    pr_debug("INFTL: pass 3, format unused blocks\n");
    for (block = s->firstEUN; block <= s->lastEUN; block++) {
        if (s->PUtable[block] == BLOCK_NOTEXPLORED) {
            printk("INFTL: unreferenced block %d, formatting it\n",
                block);
            if (INFTL_formatblock(s, block) < 0)
                s->PUtable[block] = BLOCK_RESERVED;
            else
                s->PUtable[block] = BLOCK_FREE;
        }
        if (s->PUtable[block] == BLOCK_FREE) {
            s->numfreeEUNs++;
            if (s->LastFreeEUN == BLOCK_NIL)
                s->LastFreeEUN = block;
        }
    }

    kfree(ANACtable);
    return 0;
}