inftlmount.c

基于linux-2.6.28的mtd驱动

		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) */
	inftl->mbd.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;

	printk("-------------------------------------------"
		"----------------------------------\n");

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

	printk("\n-------------------------------------------"
		"----------------------------------\n");

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

	printk("\n-------------------------------------------"
		"----------------------------------\n");

	printk("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);

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

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

	printk("-------------------------------------------"
		"----------------------------------\n");

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

	printk("-------------------------------------------"
		"----------------------------------\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;

	DEBUG(MTD_DEBUG_LEVEL3, "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.
	 */
	DEBUG(MTD_DEBUG_LEVEL3, "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;
	}

#ifdef CONFIG_MTD_DEBUG_VERBOSE
	if (CONFIG_MTD_DEBUG_VERBOSE >= 2)
		INFTL_dumptables(s);
#endif

	/*
	 * 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.
	 */
	DEBUG(MTD_DEBUG_LEVEL3, "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);
		}
	}

#ifdef CONFIG_MTD_DEBUG_VERBOSE
	if (CONFIG_MTD_DEBUG_VERBOSE >= 2)
		INFTL_dumptables(s);
	if (CONFIG_MTD_DEBUG_VERBOSE >= 2)
		INFTL_dumpVUchains(s);
#endif

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

	DEBUG(MTD_DEBUG_LEVEL3, "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;
}