Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 776 insertions, 0 deletions

diff --git a/drivers/mtd/inftlmount.c b/drivers/mtd/inftlmount.c
new file mode 100644
index 000000000..87e246a6f
--- /dev/null
+++ b/drivers/mtd/inftlmount.c
@@ -0,0 +1,776 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * inftlmount.c -- INFTL mount code with extensive checks.
+ *
+ * Author: Greg Ungerer (gerg@snapgear.com)
+ * Copyright © 2002-2003, Greg Ungerer (gerg@snapgear.com)
+ *
+ * Based heavily on the nftlmount.c code which is:
+ * Author: Fabrice Bellard (fabrice.bellard@netgem.com)
+ * Copyright © 2000 Netgem S.A.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <asm/errno.h>
+#include <asm/io.h>
+#include <linux/uaccess.h>
+#include <linux/delay.h>
+#include <linux/slab.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) {
+				pr_warn("INFTL: block read at 0x%x "
+					"of mtd%d failed: %d\n",
+					block * inftl->EraseSize,
+					inftl->mbd.mtd->index, ret);
+				if (!--warncount)
+					pr_warn("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) {
+			pr_warn("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) {
+			pr_warn("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))) {
+			pr_warn("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"
+			 "    BlockMultiplierBits   = %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) {
+			pr_warn("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) {
+			pr_warn("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) {
+			pr_warn("INFTL: sorry, we don't support "
+				"UnitSizeFactor 0x%02x\n",
+				mh->BlockMultiplierBits);
+			return -1;
+		} else if (mh->BlockMultiplierBits == 1) {
+			pr_warn("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;
+
+				/*
+				 * 	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) {
+				pr_warn("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) {
+				pr_warn("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) {
+			pr_warn("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)) {
+			pr_warn("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_array(inftl->nb_blocks, sizeof(u16),
+					       GFP_KERNEL);
+		if (!inftl->PUtable)
+			return -ENOMEM;
+
+		inftl->VUtable = kmalloc_array(inftl->nb_blocks, sizeof(u16),
+					       GFP_KERNEL);
+		if (!inftl->VUtable) {
+			kfree(inftl->PUtable);
+			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)
+{
+	struct mtd_info *mtd = inftl->mbd.mtd;
+	size_t retlen;
+	int i, ret;
+	u8 *buf;
+
+	buf = kmalloc(SECTORSIZE + mtd->oobsize, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	ret = -1;
+	for (i = 0; i < len; i += SECTORSIZE) {
+		if (mtd_read(mtd, address, SECTORSIZE, &retlen, buf))
+			goto out;
+		if (memcmpb(buf, 0xff, SECTORSIZE) != 0)
+			goto out;
+
+		if (check_oob) {
+			if(inftl_read_oob(mtd, address, mtd->oobsize,
+					  &retlen, &buf[SECTORSIZE]) < 0)
+				goto out;
+			if (memcmpb(buf + SECTORSIZE, 0xff, mtd->oobsize) != 0)
+				goto out;
+		}
+		address += SECTORSIZE;
+	}
+
+	ret = 0;
+
+out:
+	kfree(buf);
+	return ret;
+}
+
+/*
+ * 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->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) {
+		int ret;
+
+		ret = mtd_erase(inftl->mbd.mtd, instr);
+		if (ret) {
+			pr_warn("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;
+
+	pr_warn("INFTL: formatting chain at block %d\n",
+		first_block);
+
+	for (;;) {
+		block1 = inftl->PUtable[block];
+
+		pr_warn("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) {
+		pr_warn("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)
+		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) {
+				pr_warn("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) {
+					pr_warn("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) {
+				pr_warn("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) {
+				pr_warn("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) {
+			pr_warn("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;
+}