diff options
Diffstat (limited to 'drivers/mtd/nftlmount.c')
| -rw-r--r-- | drivers/mtd/nftlmount.c | 678 |
1 files changed, 678 insertions, 0 deletions
diff --git a/drivers/mtd/nftlmount.c b/drivers/mtd/nftlmount.c new file mode 100644 index 000000000..d1f05930f --- /dev/null +++ b/drivers/mtd/nftlmount.c @@ -0,0 +1,678 @@ +/* + * NFTL mount code with extensive checks + * + * Author: Fabrice Bellard (fabrice.bellard@netgem.com) + * Copyright (C) 2000 Netgem S.A. + * + * $Id: nftlmount.c,v 1.11 2000/11/17 12:24:09 ollie Exp $ + * + * 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/config.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <asm/errno.h> +#include <asm/io.h> +#include <asm/uaccess.h> +#include <linux/miscdevice.h> +#include <linux/pci.h> +#include <linux/delay.h> +#include <linux/malloc.h> +#include <linux/sched.h> +#include <linux/init.h> +#include <linux/mtd/mtd.h> +#include <linux/mtd/nftl.h> +#include <linux/mtd/compatmac.h> + +#define SECTORSIZE 512 + +/* find_boot_record: Find the NFTL Media Header and its Spare copy which contains the + * various device information of the NFTL partition and Bad Unit Table. Update + * the ReplUnitTable[] table accroding to the Bad Unit Table. ReplUnitTable[] + * is used for management of Erase Unit in other routines in nftl.c and nftlmount.c + */ +static int find_boot_record(struct NFTLrecord *nftl) +{ + struct nftl_uci1 h1; + struct nftl_oob oob; + unsigned int block, boot_record_count; + int retlen; + u8 buf[SECTORSIZE]; + struct NFTLMediaHeader *mh = &nftl->MediaHdr; + + nftl->MediaUnit = BLOCK_NIL; + nftl->SpareMediaUnit = BLOCK_NIL; + boot_record_count = 0; + + /* search for a valid boot record */ + for (block = 0; block < nftl->nb_blocks; block++) { + unsigned int erase_mark; + + /* read ANAND header. To be safer with BIOS, also use erase mark as discriminant */ + if (MTD_READOOB(nftl->mtd, block * nftl->EraseSize + SECTORSIZE + 8, + 8, &retlen, (char *)&h1) < 0) + continue; + + erase_mark = le16_to_cpu ((h1.EraseMark | h1.EraseMark1)); + if (erase_mark != ERASE_MARK) + continue; + + if (MTD_READECC(nftl->mtd, block * nftl->EraseSize, SECTORSIZE, + &retlen, buf, (char *)&oob) < 0) + continue; + + memcpy(mh, buf, sizeof(struct NFTLMediaHeader)); + if (memcmp(mh->DataOrgID, "ANAND", 6) == 0) { + /* first boot record */ + if (boot_record_count == 0) { + unsigned int i; + /* header found : read the bad block table data */ + if (mh->UnitSizeFactor != 0xff) { + printk("Sorry, we don't support UnitSizeFactor " + "of != 1 yet\n"); + goto ReplUnitTable; + } + + nftl->nb_boot_blocks = le16_to_cpu(mh->FirstPhysicalEUN); + if ((nftl->nb_boot_blocks + 2) >= nftl->nb_blocks) + goto ReplUnitTable; /* small consistency check */ + + nftl->numvunits = le32_to_cpu(mh->FormattedSize) / nftl->EraseSize; + if (nftl->numvunits > (nftl->nb_blocks - nftl->nb_boot_blocks - 2)) + goto ReplUnitTable; /* small consistency check */ + + /* FixMe: with bad blocks, the total size available is not FormattedSize any + more !!! */ + nftl->nr_sects = nftl->numvunits * (nftl->EraseSize / SECTORSIZE); + nftl->MediaUnit = block; + + /* read the Bad Erase Unit Table and modify ReplUnitTable[] accordingly */ + for (i = 0; i < nftl->nb_blocks; i++) { + if ((i & (SECTORSIZE - 1)) == 0) { + /* read one sector for every SECTORSIZE of blocks */ + if (MTD_READECC(nftl->mtd, block * nftl->EraseSize + + i + SECTORSIZE, SECTORSIZE, + &retlen, buf, (char *)&oob) < 0) + goto ReplUnitTable; + } + /* mark the Bad Erase Unit as RESERVED in ReplUnitTable */ + if (buf[i & (SECTORSIZE - 1)] != 0xff) + nftl->ReplUnitTable[i] = BLOCK_RESERVED; + } + + boot_record_count++; + } else if (boot_record_count == 1) { + nftl->SpareMediaUnit = block; + boot_record_count++; + break; + } + } + ReplUnitTable: + } + + if (boot_record_count == 0) { + /* no boot record found */ + return -1; + } else { + return 0; + } +} + +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 NFTLrecord *nftl, unsigned int address, int len, + int check_oob) +{ + int i, retlen; + u8 buf[SECTORSIZE]; + + for (i = 0; i < len; i += SECTORSIZE) { + /* we want to read the sector without ECC check here since a free + sector does not have ECC syndrome on it yet */ + if (MTD_READ(nftl->mtd, address, SECTORSIZE, &retlen, buf) < 0) + return -1; + if (memcmpb(buf, 0xff, SECTORSIZE) != 0) + return -1; + + if (check_oob) { + if (MTD_READOOB(nftl->mtd, address, nftl->mtd->oobsize, + &retlen, buf) < 0) + return -1; + if (memcmpb(buf, 0xff, nftl->mtd->oobsize) != 0) + return -1; + } + address += SECTORSIZE; + } + + return 0; +} + +/* NFTL_format: format a Erase Unit by erasing ALL Erase Zones in the Erase Unit and + * Update NFTL metadata. Each erase operation is checked with check_free_sectors + * + * Return: 0 when succeed, -1 on error. + * + * ToDo: 1. Is it neceressary to check_free_sector after erasing ?? + * 2. UnitSizeFactor != 0xFF + */ +int NFTL_formatblock(struct NFTLrecord *nftl, int block) +{ + int retlen; + unsigned int nb_erases, erase_mark; + struct nftl_uci1 uci; + struct erase_info *instr = &nftl->instr; + + /* Read the Unit Control Information #1 for Wear-Leveling */ + if (MTD_READOOB(nftl->mtd, block * nftl->EraseSize + SECTORSIZE + 8, + 8, &retlen, (char *)&uci) < 0) + goto default_uci1; + + erase_mark = le16_to_cpu ((uci.EraseMark | uci.EraseMark1)); + if (erase_mark != ERASE_MARK) { + default_uci1: + uci.EraseMark = cpu_to_le16(ERASE_MARK); + uci.EraseMark1 = cpu_to_le16(ERASE_MARK); + uci.WearInfo = cpu_to_le32(0); + } + + memset(instr, 0, sizeof(struct erase_info)); + + /* XXX: use async erase interface, XXX: test return code */ + instr->addr = block * nftl->EraseSize; + instr->len = nftl->EraseSize; + MTD_ERASE(nftl->mtd, instr); + + if (instr->state == MTD_ERASE_FAILED) { + /* could not format, FixMe: We should update the BadUnitTable + both in memory and on disk */ + printk("Error while formatting block %d\n", block); + return -1; + } else { + /* increase and write Wear-Leveling info */ + nb_erases = le32_to_cpu(uci.WearInfo); + nb_erases++; + + /* wrap (almost impossible with current flashs) or free block */ + if (nb_erases == 0) + nb_erases = 1; + + /* 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(nftl, instr->addr, nftl->EraseSize, 1) != 0) + return -1; + + uci.WearInfo = le32_to_cpu(nb_erases); + if (MTD_WRITEOOB(nftl->mtd, block * nftl->EraseSize + SECTORSIZE + 8, 8, + &retlen, (char *)&uci) < 0) + return -1; + return 0; + } +} + +/* check_sectors_in_chain: Check that each sector of a Virtual Unit Chain is correct. + * Mark as 'IGNORE' each incorrect sector. This check is only done if the chain + * was being folded when NFTL was interrupted. + * + * The check_free_sectors in this function is neceressary. There is a possible + * situation that after writing the Data area, the Block Control Information is + * not updated according (due to power failure or something) which leaves the block + * in an umconsistent state. So we have to check if a block is really FREE in this + * case. */ +static void check_sectors_in_chain(struct NFTLrecord *nftl, unsigned int first_block) +{ + unsigned int block, i, status; + struct nftl_bci bci; + int sectors_per_block, retlen; + + sectors_per_block = nftl->EraseSize / SECTORSIZE; + block = first_block; + for (;;) { + for (i = 0; i < sectors_per_block; i++) { + if (MTD_READOOB(nftl->mtd, block * nftl->EraseSize + i * SECTORSIZE, + 8, &retlen, (char *)&bci) < 0) + status = SECTOR_IGNORE; + else + status = bci.Status | bci.Status1; + + switch(status) { + case SECTOR_FREE: + /* verify that the sector is really free. If not, mark + as ignore */ + if (memcmpb(&bci, 0xff, 8) != 0 || + check_free_sectors(nftl, block * nftl->EraseSize + i * SECTORSIZE, + SECTORSIZE, 0) != 0) { + printk("Incorrect free sector %d in block %d: " + "marking it as ignored\n", + i, block); + + /* sector not free actually : mark it as SECTOR_IGNORE */ + bci.Status = SECTOR_IGNORE; + bci.Status1 = SECTOR_IGNORE; + MTD_WRITEOOB(nftl->mtd, + block * nftl->EraseSize + i * SECTORSIZE, + 8, &retlen, (char *)&bci); + } + break; + default: + break; + } + } + + /* proceed to next Erase Unit on the chain */ + block = nftl->ReplUnitTable[block]; + if (!(block == BLOCK_NIL || block < nftl->nb_blocks)) + printk("incorrect ReplUnitTable[] : %d\n", block); + if (block == BLOCK_NIL || block >= nftl->nb_blocks) + break; + } +} + +/* calc_chain_lenght: Walk through a Virtual Unit Chain and estimate chain length */ +static int calc_chain_length(struct NFTLrecord *nftl, unsigned int first_block) +{ + unsigned int length = 0, block = first_block; + + for (;;) { + length++; + /* avoid infinite loops, although this is guaranted not to + happen because of the previous checks */ + if (length >= nftl->nb_blocks) { + printk("nftl: length too long %d !\n", length); + break; + } + + block = nftl->ReplUnitTable[block]; + if (!(block == BLOCK_NIL || block < nftl->nb_blocks)) + printk("incorrect ReplUnitTable[] : %d\n", block); + if (block == BLOCK_NIL || block >= nftl->nb_blocks) + break; + } + return length; +} + +/* 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. + * + * It is not stricly correct to begin from the first block of the chain because + * if we stop the code, we may see again a valid chain if there was a first_block + * flag in a block inside it. But is it really a problem ? + * + * FixMe: Figure out what the last statesment means. What if power failure when we are + * in the for (;;) loop formatting blocks ?? + */ +static void format_chain(struct NFTLrecord *nftl, unsigned int first_block) +{ + unsigned int block = first_block, block1; + + printk("Formatting chain at block %d\n", first_block); + + for (;;) { + block1 = nftl->ReplUnitTable[block]; + + printk("Formatting block %d\n", block); + if (NFTL_formatblock(nftl, block) < 0) { + /* cannot format !!!! Mark it as Bad Unit, + FixMe: update the BadUnitTable on disk */ + nftl->ReplUnitTable[block] = BLOCK_RESERVED; + } else { + nftl->ReplUnitTable[block] = BLOCK_FREE; + } + + /* goto next block on the chain */ + block = block1; + + if (!(block == BLOCK_NIL || block < nftl->nb_blocks)) + printk("incorrect ReplUnitTable[] : %d\n", block); + if (block == BLOCK_NIL || block >= nftl->nb_blocks) + break; + } +} + +/* check_and_mark_free_block: Verify that a block is free in the NFTL sense (valid erase mark) or + * totally free (only 0xff). + * + * Definition: Free Erase Unit -- A properly erased/formatted Free Erase Unit should have meet the + * following critia: + * 1. */ +static int check_and_mark_free_block(struct NFTLrecord *nftl, int block) +{ + struct nftl_uci1 h1; + unsigned int erase_mark; + int i, retlen; + unsigned char buf[SECTORSIZE]; + + /* check erase mark. */ + if (MTD_READOOB(nftl->mtd, block * nftl->EraseSize + SECTORSIZE + 8, 8, + &retlen, (char *)&h1) < 0) + return -1; + + erase_mark = le16_to_cpu ((h1.EraseMark | h1.EraseMark1)); + if (erase_mark != ERASE_MARK) { + /* if no erase mark, the block must be totally free. This is + possible in two cases : empty filsystem or interrupted erase (very unlikely) */ + if (check_free_sectors (nftl, block * nftl->EraseSize, nftl->EraseSize, 1) != 0) + return -1; + + /* free block : write erase mark */ + h1.EraseMark = cpu_to_le16(ERASE_MARK); + h1.EraseMark1 = cpu_to_le16(ERASE_MARK); + h1.WearInfo = cpu_to_le32(0); + if (MTD_WRITEOOB(nftl->mtd, block * nftl->EraseSize + SECTORSIZE + 8, 8, + &retlen, (char *)&h1) < 0) + return -1; + } else { +#if 0 + /* if erase mark present, need to skip it when doing check */ + for (i = 0; i < nftl->EraseSize; i += SECTORSIZE) { + /* check free sector */ + if (check_free_sectors (nftl, block * nftl->EraseSize + i, + SECTORSIZE, 0) != 0) + return -1; + + if (MTD_READOOB(nftl->mtd, block * nftl->EraseSize + i, + 16, &retlen, buf) < 0) + return -1; + if (i == SECTORSIZE) { + /* skip erase mark */ + if (memcmpb(buf, 0xff, 8)) + return -1; + } else { + if (memcmpb(buf, 0xff, 16)) + return -1; + } + } +#endif + } + + return 0; +} + +/* get_fold_mark: Read fold mark from Unit Control Information #2, we use FOLD_MARK_IN_PROGRESS + * to indicate that we are in the progression of a Virtual Unit Chain folding. If the UCI #2 + * is FOLD_MARK_IN_PROGRESS when mounting the NFTL, the (previous) folding process is interrupted + * for some reason. A clean up/check of the VUC is neceressary in this case. + * + * WARNING: return 0 if read error + */ +static int get_fold_mark(struct NFTLrecord *nftl, unsigned int block) +{ + struct nftl_uci2 uci; + int retlen; + + if (MTD_READOOB(nftl->mtd, block * nftl->EraseSize + 2 * SECTORSIZE + 8, + 8, &retlen, (char *)&uci) < 0) + return 0; + + return le16_to_cpu((uci.FoldMark | uci.FoldMark1)); +} + +int NFTL_mount(struct NFTLrecord *s) +{ + int i; + unsigned int first_logical_block, logical_block, rep_block, nb_erases, erase_mark; + unsigned int block, first_block, is_first_block; + int chain_length, do_format_chain; + struct nftl_uci0 h0; + struct nftl_uci1 h1; + int retlen; + + /* XXX: will be suppressed */ + s->lastEUN = s->nb_blocks - 1; + + /* memory alloc */ + s->EUNtable = kmalloc(s->nb_blocks * sizeof(u16), GFP_KERNEL); + s->ReplUnitTable = kmalloc(s->nb_blocks * sizeof(u16), GFP_KERNEL); + if (!s->EUNtable || !s->ReplUnitTable) { + fail: + if (s->EUNtable) + kfree(s->EUNtable); + if (s->ReplUnitTable) + kfree(s->ReplUnitTable); + return -1; + } + + /* mark all blocks as potentially containing data */ + for (i = 0; i < s->nb_blocks; i++) { + s->ReplUnitTable[i] = BLOCK_NOTEXPLORED; + } + + /* search for NFTL MediaHeader and Spare NFTL Media Header */ + if (find_boot_record(s) < 0) { + printk("Could not find valid boot record\n"); + goto fail; + } + + /* mark the bios blocks (blocks before NFTL MediaHeader) as reserved */ + for (i = 0; i < s->nb_boot_blocks; i++) + s->ReplUnitTable[i] = BLOCK_RESERVED; + + /* also mark the boot records (NFTL MediaHeader) blocks as reserved */ + if (s->MediaUnit != BLOCK_NIL) + s->ReplUnitTable[s->MediaUnit] = BLOCK_RESERVED; + if (s->SpareMediaUnit != BLOCK_NIL) + s->ReplUnitTable[s->SpareMediaUnit] = BLOCK_RESERVED; + + /* init the logical to physical table */ + for (i = 0; i < s->nb_blocks; i++) { + s->EUNtable[i] = BLOCK_NIL; + } + + /* first pass : explore each block chain */ + first_logical_block = 0; + for (first_block = 0; first_block < s->nb_blocks; first_block++) { + /* if the block was not already explored, we can look at it */ + if (s->ReplUnitTable[first_block] == BLOCK_NOTEXPLORED) { + block = first_block; + chain_length = 0; + do_format_chain = 0; + + for (;;) { + /* read the block header. If error, we format the chain */ + if (MTD_READOOB(s->mtd, block * s->EraseSize + 8, 8, + &retlen, (char *)&h0) < 0 || + MTD_READOOB(s->mtd, block * s->EraseSize + SECTORSIZE + 8, 8, + &retlen, (char *)&h1) < 0) { + s->ReplUnitTable[block] = BLOCK_NIL; + do_format_chain = 1; + break; + } + + logical_block = le16_to_cpu ((h0.VirtUnitNum | h0.SpareVirtUnitNum)); + rep_block = le16_to_cpu ((h0.ReplUnitNum | h0.SpareReplUnitNum)); + nb_erases = le32_to_cpu (h1.WearInfo); + erase_mark = le16_to_cpu ((h1.EraseMark | h1.EraseMark1)); + + is_first_block = !(logical_block >> 15); + logical_block = logical_block & 0x7fff; + + /* invalid/free block test */ + if (erase_mark != ERASE_MARK || logical_block >= s->nb_blocks) { + if (chain_length == 0) { + /* if not currently in a chain, we can handle it safely */ + if (check_and_mark_free_block(s, block) < 0) { + /* not really free: format it */ + printk("Formatting block %d\n", block); + if (NFTL_formatblock(s, block) < 0) { + /* could not format: reserve the block */ + s->ReplUnitTable[block] = BLOCK_RESERVED; + } else { + s->ReplUnitTable[block] = BLOCK_FREE; + } + } else { + /* free block: mark it */ + s->ReplUnitTable[block] = BLOCK_FREE; + } + /* directly examine the next block. */ + goto examine_ReplUnitTable; + } else { + /* the block was in a chain : this is bad. We + must format all the chain */ + printk("Block %d: free but referenced in chain %d\n", + block, first_block); + s->ReplUnitTable[block] = BLOCK_NIL; + do_format_chain = 1; + break; + } + } + + /* we accept only first blocks here */ + if (chain_length == 0) { + /* this block is not the first block in chain : + ignore it, it will be included in a chain + later, or marked as not explored */ + if (!is_first_block) + goto examine_ReplUnitTable; + first_logical_block = logical_block; + } else { + if (logical_block != first_logical_block) { + printk("Block %d: incorrect logical block: %d expected: %d\n", + block, logical_block, first_logical_block); + /* the chain is incorrect : we must format it, + but we need to read it completly */ + do_format_chain = 1; + } + if (is_first_block) { + /* we accept that a block is marked as first + block while being last block in a chain + only if the chain is being folded */ + if (get_fold_mark(s, block) != FOLD_MARK_IN_PROGRESS || + rep_block != 0xffff) { + printk("Block %d: incorrectly marked as first block in chain\n", + block); + /* the chain is incorrect : we must format it, + but we need to read it completly */ + do_format_chain = 1; + } else { + printk("Block %d: folding in progress - ignoring first block flag\n", + block); + } + } + } + chain_length++; + if (rep_block == 0xffff) { + /* no more blocks after */ + s->ReplUnitTable[block] = BLOCK_NIL; + break; + } else if (rep_block >= s->nb_blocks) { + printk("Block %d: referencing invalid block %d\n", + block, rep_block); + do_format_chain = 1; + s->ReplUnitTable[block] = BLOCK_NIL; + break; + } else if (s->ReplUnitTable[rep_block] != BLOCK_NOTEXPLORED) { + /* same problem as previous 'is_first_block' test: + we accept that the last block of a chain has + the first_block flag set if folding is in + progress. We handle here the case where the + last block appeared first */ + if (s->ReplUnitTable[rep_block] == BLOCK_NIL && + s->EUNtable[first_logical_block] == rep_block && + get_fold_mark(s, first_block) == FOLD_MARK_IN_PROGRESS) { + /* EUNtable[] will be set after */ + printk("Block %d: folding in progress - ignoring first block flag\n", + rep_block); + s->ReplUnitTable[block] = rep_block; + s->EUNtable[first_logical_block] = BLOCK_NIL; + } else { + printk("Block %d: referencing block %d already in another chain\n", + block, rep_block); + /* XXX: should handle correctly fold in progress chains */ + do_format_chain = 1; + s->ReplUnitTable[block] = BLOCK_NIL; + } + break; + } else { + /* this is OK */ + s->ReplUnitTable[block] = rep_block; + block = rep_block; + } + } + + /* the chain was completely explored. Now we can decide + what to do with it */ + if (do_format_chain) { + /* invalid chain : format it */ + format_chain(s, first_block); + } else { + unsigned int first_block1, chain_to_format, chain_length1; + int fold_mark; + + /* valid chain : get foldmark */ + fold_mark = get_fold_mark(s, first_block); + if (fold_mark == 0) { + /* cannot get foldmark : format the chain */ + printk("Could read foldmark at block %d\n", first_block); + format_chain(s, first_block); + } else { + if (fold_mark == FOLD_MARK_IN_PROGRESS) + check_sectors_in_chain(s, first_block); + + /* now handle the case where we find two chains at the + same virtual address : we select the longer one, + because the shorter one is the one which was being + folded if the folding was not done in place */ + first_block1 = s->EUNtable[first_logical_block]; + if (first_block1 != BLOCK_NIL) { + /* XXX: what to do if same length ? */ + chain_length1 = calc_chain_length(s, first_block1); + printk("Two chains at blocks %d (len=%d) and %d (len=%d)\n", + first_block1, chain_length1, first_block, chain_length); + + if (chain_length >= chain_length1) { + chain_to_format = first_block1; + s->EUNtable[first_logical_block] = first_block; + } else { + chain_to_format = first_block; + } + format_chain(s, chain_to_format); + } else { + s->EUNtable[first_logical_block] = first_block; + } + } + } + } + examine_ReplUnitTable: + } + + /* second pass to format unreferenced blocks and init free block count */ + s->numfreeEUNs = 0; + s->LastFreeEUN = BLOCK_NIL; + + for (block = 0; block < s->nb_blocks; block++) { + if (s->ReplUnitTable[block] == BLOCK_NOTEXPLORED) { + printk("Unreferenced block %d, formatting it\n", block); + if (NFTL_formatblock(s, block) < 0) + s->ReplUnitTable[block] = BLOCK_RESERVED; + else + s->ReplUnitTable[block] = BLOCK_FREE; + } + if (s->ReplUnitTable[block] == BLOCK_FREE) { + s->numfreeEUNs++; + s->LastFreeEUN = block; + } + } + + return 0; +} |