[PATCH v3 0/3] mtd: Add sysfs entries and account BBT blocks properly

[PATCH v3 0/3] mtd: Add sysfs entries and account BBT blocks properly

[Ezequiel Garcia]

Here's a new round of the patchset to add sysfs entries for the ECC stats
struct fields. See the discussion around previous version for context:

http://lists.infradead.org/pipermail/linux-mtd/2014-March/052804.html

Changes from v2:

  * As suggested by Pekon Gupta, use "ecc_failures" instead of
    "uncorrectable_errors".

  * Added documentation for the new sysfs ABI as requested by Greg KH.

Changes from v1:

  * As agreed I've added a sysfs file per field to replace the ecc_stats
    sysfs file. The current proposal follows the "one file per value" sysfs
    rule, adding the following device attributes:
    - corrected_bits (ecc_stats.corrected)
    - uncorrectable_errors (ecc_stats.failed)
    - bad_blocks (ecc_stats.badblocks)
    - bbt_blocks (ecc_stats.bbtblocks)

  * Following Brian's request, added small wrapper nand_block_isreserved()
    that checks if the NAND has a bad block table before querying the number
    of reserved blocks.

  * Finally, this new series drops patch: "nand: Account the blocks used by
    the BBT in the ecc_stats". It's not yet clear how to best deal with the
    current inconsistencies in MTD master and partition handling.

The first patch adds the sysfs entries. The rest of the patches fixes the
bbtblock accounting and allows to keep track of the reserved blocks correctly.

This is a very old issue, probably around since the dawn of time,
and nobody seemed to care much about it. However, with the introduction of
the sysfs access, it's easier to access this stats and easier to
see the issue.

Ezequiel Garcia (3):
  mtd: Add sysfs attributes to expose the ECC stats fields
  mtd: Introduce mtd_block_isreserved()
  mtd: Account for BBT blocks when a partition is being allocated

 Documentation/ABI/testing/sysfs-class-mtd | 38 ++++++++++++++++++++
 drivers/mtd/mtdcore.c                     | 59 +++++++++++++++++++++++++++++--
 drivers/mtd/mtdpart.c                     | 13 ++++++-
 drivers/mtd/nand/nand_base.c              | 18 ++++++++++
 drivers/mtd/nand/nand_bbt.c               | 14 ++++++++
 include/linux/mtd/mtd.h                   |  2 ++
 include/linux/mtd/nand.h                  |  1 +
 7 files changed, 142 insertions(+), 3 deletions(-)

-- 
1.9.1

[PATCH v3 1/3] mtd: Add sysfs attributes to expose the ECC stats fields

[Ezequiel Garcia]

These new sysfs device attributes allows to retrieve the ECC
and bad block stats by poking a sysfs file, which is often more convenient
than using the ioctl.

Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
---
 Documentation/ABI/testing/sysfs-class-mtd | 38 ++++++++++++++++++++++++++
 drivers/mtd/mtdcore.c                     | 45 +++++++++++++++++++++++++++++++
 2 files changed, 83 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-class-mtd b/Documentation/ABI/testing/sysfs-class-mtd
index 1399bb2..176cf02 100644
--- a/Documentation/ABI/testing/sysfs-class-mtd
+++ b/Documentation/ABI/testing/sysfs-class-mtd
@@ -184,3 +184,41 @@ Description:
 
 		It will always be a non-negative integer.  In the case of
 		devices lacking any ECC capability, it is 0.
+
+What:		/sys/class/mtd/mtdX/ecc_failures
+Date:		June 2014
+KernelVersion:	3.17
+Contact:	linux-mtd@lists.infradead.org
+Description:
+		The number of failures reported by this device's ECC. Typically,
+		this failures are associated to failed read operations.
+
+		It will always be a non-negative integer.  In the case of
+		devices lacking any ECC capability, it is 0.
+
+What:		/sys/class/mtd/mtdX/corrected_bits
+Date:		June 2014
+KernelVersion:	3.17
+Contact:	linux-mtd@lists.infradead.org
+Description:
+		The number of bits that have been corrected by means of the
+		device's ECC.
+
+		It will always be a non-negative integer.  In the case of
+		devices lacking any ECC capability, it is 0.
+
+What:		/sys/class/mtd/mtdX/bad_blocks
+Date:		June 2014
+KernelVersion:	3.17
+Contact:	linux-mtd@lists.infradead.org
+Description:
+		The number of blocks marked as bad, is any, in this partition.
+
+What:		/sys/class/mtd/mtdX/bbt_blocks
+Date:		June 2014
+KernelVersion:	3.17
+Contact:	linux-mtd@lists.infradead.org
+Description:
+		The number of blocks that are marked as reserved, if any, in
+		this partition. These are typically used to store the in-flash
+		bad block table.
diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
index d201fee..11857fa 100644
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -298,6 +298,47 @@ static ssize_t mtd_ecc_step_size_show(struct device *dev,
 }
 static DEVICE_ATTR(ecc_step_size, S_IRUGO, mtd_ecc_step_size_show, NULL);
 
+static ssize_t mtd_ecc_stats_corrected_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct mtd_info *mtd = dev_get_drvdata(dev);
+	struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
+
+	return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->corrected);
+}
+static DEVICE_ATTR(corrected_bits, S_IRUGO,
+		   mtd_ecc_stats_corrected_show, NULL);
+
+static ssize_t mtd_ecc_stats_errors_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct mtd_info *mtd = dev_get_drvdata(dev);
+	struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
+
+	return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->failed);
+}
+static DEVICE_ATTR(ecc_failures, S_IRUGO, mtd_ecc_stats_errors_show, NULL);
+
+static ssize_t mtd_badblocks_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct mtd_info *mtd = dev_get_drvdata(dev);
+	struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
+
+	return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->badblocks);
+}
+static DEVICE_ATTR(bad_blocks, S_IRUGO, mtd_badblocks_show, NULL);
+
+static ssize_t mtd_bbtblocks_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct mtd_info *mtd = dev_get_drvdata(dev);
+	struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
+
+	return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->bbtblocks);
+}
+static DEVICE_ATTR(bbt_blocks, S_IRUGO, mtd_bbtblocks_show, NULL);
+
 static struct attribute *mtd_attrs[] = {
 	&dev_attr_type.attr,
 	&dev_attr_flags.attr,
@@ -310,6 +351,10 @@ static struct attribute *mtd_attrs[] = {
 	&dev_attr_name.attr,
 	&dev_attr_ecc_strength.attr,
 	&dev_attr_ecc_step_size.attr,
+	&dev_attr_corrected_bits.attr,
+	&dev_attr_ecc_failures.attr,
+	&dev_attr_bad_blocks.attr,
+	&dev_attr_bbt_blocks.attr,
 	&dev_attr_bitflip_threshold.attr,
 	NULL,
 };
-- 
1.9.1

Re: [PATCH v3 1/3] mtd: Add sysfs attributes to expose the ECC stats fields

[Brian Norris]

On Tue, Jun 24, 2014 at 10:55:50AM -0300, Ezequiel Garcia wrote:
> These new sysfs device attributes allows to retrieve the ECC
> and bad block stats by poking a sysfs file, which is often more convenient
> than using the ioctl.
> 
> Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
> ---
>  Documentation/ABI/testing/sysfs-class-mtd | 38 ++++++++++++++++++++++++++
>  drivers/mtd/mtdcore.c                     | 45 +++++++++++++++++++++++++++++++
>  2 files changed, 83 insertions(+)

I'm squashing in the following diff:

diff --git a/Documentation/ABI/testing/sysfs-class-mtd b/Documentation/ABI/testing/sysfs-class-mtd
index 66d5206df742..76ee192f80a0 100644
--- a/Documentation/ABI/testing/sysfs-class-mtd
+++ b/Documentation/ABI/testing/sysfs-class-mtd
@@ -191,7 +191,7 @@ KernelVersion:	3.17
 Contact:	linux-mtd@lists.infradead.org
 Description:
 		The number of failures reported by this device's ECC. Typically,
-		this failures are associated to failed read operations.
+		these failures are associated with failed read operations.
 
 		It will always be a non-negative integer.  In the case of
 		devices lacking any ECC capability, it is 0.
@@ -212,7 +212,7 @@ Date:		June 2014
 KernelVersion:	3.17
 Contact:	linux-mtd@lists.infradead.org
 Description:
-		The number of blocks marked as bad, is any, in this partition.
+		The number of blocks marked as bad, if any, in this partition.
 
 What:		/sys/class/mtd/mtdX/bbt_blocks
 Date:		June 2014
@@ -221,4 +221,4 @@ Contact:	linux-mtd@lists.infradead.org
 Description:
 		The number of blocks that are marked as reserved, if any, in
 		this partition. These are typically used to store the in-flash
-		bad block table.
+		bad block table (BBT).

[PATCH v3 2/3] mtd: Introduce mtd_block_isreserved()

[Ezequiel Garcia]

In addition to mtd_block_isbad(), which checks if a block is bad or reserved,
it's needed to check if a block is reserved only (but not bad). This commit
adds an MTD interface for it, in a similar fashion to mtd_block_isbad().

While here, fix mtd_block_isbad() so the out-of-bounds checking is done the
callback check.

Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
---
 drivers/mtd/mtdcore.c        | 14 ++++++++++++--
 drivers/mtd/mtdpart.c        |  9 +++++++++
 drivers/mtd/nand/nand_base.c | 18 ++++++++++++++++++
 drivers/mtd/nand/nand_bbt.c  | 14 ++++++++++++++
 include/linux/mtd/mtd.h      |  2 ++
 include/linux/mtd/nand.h     |  1 +
 6 files changed, 56 insertions(+), 2 deletions(-)

diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
index 11857fa..e4831b4 100644
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -1043,12 +1043,22 @@ int mtd_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 }
 EXPORT_SYMBOL_GPL(mtd_is_locked);
 
-int mtd_block_isbad(struct mtd_info *mtd, loff_t ofs)
+int mtd_block_isreserved(struct mtd_info *mtd, loff_t ofs)
 {
-	if (!mtd->_block_isbad)
+	if (ofs < 0 || ofs > mtd->size)
+		return -EINVAL;
+	if (!mtd->_block_isreserved)
 		return 0;
+	return mtd->_block_isreserved(mtd, ofs);
+}
+EXPORT_SYMBOL_GPL(mtd_block_isreserved);
+
+int mtd_block_isbad(struct mtd_info *mtd, loff_t ofs)
+{
 	if (ofs < 0 || ofs > mtd->size)
 		return -EINVAL;
+	if (!mtd->_block_isbad)
+		return 0;
 	return mtd->_block_isbad(mtd, ofs);
 }
 EXPORT_SYMBOL_GPL(mtd_block_isbad);
diff --git a/drivers/mtd/mtdpart.c b/drivers/mtd/mtdpart.c
index 1ca9aec..921e8c6 100644
--- a/drivers/mtd/mtdpart.c
+++ b/drivers/mtd/mtdpart.c
@@ -290,6 +290,13 @@ static void part_resume(struct mtd_info *mtd)
 	part->master->_resume(part->master);
 }
 
+static int part_block_isreserved(struct mtd_info *mtd, loff_t ofs)
+{
+	struct mtd_part *part = PART(mtd);
+	ofs += part->offset;
+	return part->master->_block_isreserved(part->master, ofs);
+}
+
 static int part_block_isbad(struct mtd_info *mtd, loff_t ofs)
 {
 	struct mtd_part *part = PART(mtd);
@@ -422,6 +429,8 @@ static struct mtd_part *allocate_partition(struct mtd_info *master,
 		slave->mtd._unlock = part_unlock;
 	if (master->_is_locked)
 		slave->mtd._is_locked = part_is_locked;
+	if (master->_block_isreserved)
+		slave->mtd._block_isreserved = part_block_isreserved;
 	if (master->_block_isbad)
 		slave->mtd._block_isbad = part_block_isbad;
 	if (master->_block_markbad)
diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index 41167e9..0c505dd 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -488,6 +488,23 @@ static int nand_check_wp(struct mtd_info *mtd)
  * nand_block_checkbad - [GENERIC] Check if a block is marked bad
  * @mtd: MTD device structure
  * @ofs: offset from device start
+ *
+ * Check if the block is mark as reserved.
+ */
+static int nand_block_isreserved(struct mtd_info *mtd, loff_t ofs)
+{
+	struct nand_chip *chip = mtd->priv;
+
+	if (!chip->bbt)
+		return 0;
+	/* Return info from the table */
+	return nand_isreserved_bbt(mtd, ofs);
+}
+
+/**
+ * nand_block_checkbad - [GENERIC] Check if a block is marked bad
+ * @mtd: MTD device structure
+ * @ofs: offset from device start
  * @getchip: 0, if the chip is already selected
  * @allowbbt: 1, if its allowed to access the bbt area
  *
@@ -4111,6 +4128,7 @@ int nand_scan_tail(struct mtd_info *mtd)
 	mtd->_unlock = NULL;
 	mtd->_suspend = nand_suspend;
 	mtd->_resume = nand_resume;
+	mtd->_block_isreserved = nand_block_isreserved;
 	mtd->_block_isbad = nand_block_isbad;
 	mtd->_block_markbad = nand_block_markbad;
 	mtd->writebufsize = mtd->writesize;
diff --git a/drivers/mtd/nand/nand_bbt.c b/drivers/mtd/nand/nand_bbt.c
index 7f0c3b4..443fa82 100644
--- a/drivers/mtd/nand/nand_bbt.c
+++ b/drivers/mtd/nand/nand_bbt.c
@@ -1311,6 +1311,20 @@ int nand_default_bbt(struct mtd_info *mtd)
 }
 
 /**
+ * nand_isreserved_bbt - [NAND Interface] Check if a block is reserved
+ * @mtd: MTD device structure
+ * @offs: offset in the device
+ */
+int nand_isreserved_bbt(struct mtd_info *mtd, loff_t offs)
+{
+	struct nand_chip *this = mtd->priv;
+	int block;
+
+	block = (int)(offs >> this->bbt_erase_shift);
+	return bbt_get_entry(this, block) == BBT_BLOCK_RESERVED;
+}
+
+/**
  * nand_isbad_bbt - [NAND Interface] Check if a block is bad
  * @mtd: MTD device structure
  * @offs: offset in the device
diff --git a/include/linux/mtd/mtd.h b/include/linux/mtd/mtd.h
index a1b0b4c..031ff3a 100644
--- a/include/linux/mtd/mtd.h
+++ b/include/linux/mtd/mtd.h
@@ -222,6 +222,7 @@ struct mtd_info {
 	int (*_lock) (struct mtd_info *mtd, loff_t ofs, uint64_t len);
 	int (*_unlock) (struct mtd_info *mtd, loff_t ofs, uint64_t len);
 	int (*_is_locked) (struct mtd_info *mtd, loff_t ofs, uint64_t len);
+	int (*_block_isreserved) (struct mtd_info *mtd, loff_t ofs);
 	int (*_block_isbad) (struct mtd_info *mtd, loff_t ofs);
 	int (*_block_markbad) (struct mtd_info *mtd, loff_t ofs);
 	int (*_suspend) (struct mtd_info *mtd);
@@ -302,6 +303,7 @@ static inline void mtd_sync(struct mtd_info *mtd)
 int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len);
 int mtd_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len);
 int mtd_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len);
+int mtd_block_isreserved(struct mtd_info *mtd, loff_t ofs);
 int mtd_block_isbad(struct mtd_info *mtd, loff_t ofs);
 int mtd_block_markbad(struct mtd_info *mtd, loff_t ofs);
 
diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h
index 2f0af28..1cff329 100644
--- a/include/linux/mtd/nand.h
+++ b/include/linux/mtd/nand.h
@@ -810,6 +810,7 @@ extern struct nand_manufacturers nand_manuf_ids[];
 extern int nand_scan_bbt(struct mtd_info *mtd, struct nand_bbt_descr *bd);
 extern int nand_default_bbt(struct mtd_info *mtd);
 extern int nand_markbad_bbt(struct mtd_info *mtd, loff_t offs);
+extern int nand_isreserved_bbt(struct mtd_info *mtd, loff_t offs);
 extern int nand_isbad_bbt(struct mtd_info *mtd, loff_t offs, int allowbbt);
 extern int nand_erase_nand(struct mtd_info *mtd, struct erase_info *instr,
 			   int allowbbt);
-- 
1.9.1

[PATCH v3 3/3] mtd: Account for BBT blocks when a partition is being allocated

[Ezequiel Garcia]

With the introduction of mtd_block_isreserved(), it's now possible
to fix the bad and reserved block distribution exposed by ecc_stats,
instead of accounting all the bad or reserved blocks as 'bad'.

Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
---
 drivers/mtd/mtdpart.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/mtd/mtdpart.c b/drivers/mtd/mtdpart.c
index 921e8c6..a3e3a7d 100644
--- a/drivers/mtd/mtdpart.c
+++ b/drivers/mtd/mtdpart.c
@@ -535,7 +535,9 @@ static struct mtd_part *allocate_partition(struct mtd_info *master,
 		uint64_t offs = 0;
 
 		while (offs < slave->mtd.size) {
-			if (mtd_block_isbad(master, offs + slave->offset))
+			if (mtd_block_isreserved(master, offs + slave->offset))
+				slave->mtd.ecc_stats.bbtblocks++;
+			else if (mtd_block_isbad(master, offs + slave->offset))
 				slave->mtd.ecc_stats.badblocks++;
 			offs += slave->mtd.erasesize;
 		}
-- 
1.9.1

RE: [PATCH v3 0/3] mtd: Add sysfs entries and account BBT blocks properly

[Gupta, Pekon]

>From: Ezequiel Garcia [mailto:ezequiel.garcia@free-electrons.com]
>
>Here's a new round of the patchset to add sysfs entries for the ECC stats
>struct fields. See the discussion around previous version for context:
>
>http://lists.infradead.org/pipermail/linux-mtd/2014-March/052804.html
>
>Changes from v2:
>
>  * As suggested by Pekon Gupta, use "ecc_failures" instead of
>    "uncorrectable_errors".
>
>  * Added documentation for the new sysfs ABI as requested by Greg KH.
>
>Changes from v1:
>
>  * As agreed I've added a sysfs file per field to replace the ecc_stats
>    sysfs file. The current proposal follows the "one file per value" sysfs
>    rule, adding the following device attributes:
>    - corrected_bits (ecc_stats.corrected)
>    - uncorrectable_errors (ecc_stats.failed)
>    - bad_blocks (ecc_stats.badblocks)
>    - bbt_blocks (ecc_stats.bbtblocks)
>
>  * Following Brian's request, added small wrapper nand_block_isreserved()
>    that checks if the NAND has a bad block table before querying the number
>    of reserved blocks.
>
>  * Finally, this new series drops patch: "nand: Account the blocks used by
>    the BBT in the ecc_stats". It's not yet clear how to best deal with the
>    current inconsistencies in MTD master and partition handling.
>
>The first patch adds the sysfs entries. The rest of the patches fixes the
>bbtblock accounting and allows to keep track of the reserved blocks correctly.
>
>This is a very old issue, probably around since the dawn of time,
>and nobody seemed to care much about it. However, with the introduction of
>the sysfs access, it's easier to access this stats and easier to
>see the issue.
>
>Ezequiel Garcia (3):
>  mtd: Add sysfs attributes to expose the ECC stats fields
>  mtd: Introduce mtd_block_isreserved()
>  mtd: Account for BBT blocks when a partition is being allocated
>
> Documentation/ABI/testing/sysfs-class-mtd | 38 ++++++++++++++++++++
> drivers/mtd/mtdcore.c                     | 59 +++++++++++++++++++++++++++++--
> drivers/mtd/mtdpart.c                     | 13 ++++++-
> drivers/mtd/nand/nand_base.c              | 18 ++++++++++
> drivers/mtd/nand/nand_bbt.c               | 14 ++++++++
> include/linux/mtd/mtd.h                   |  2 ++
> include/linux/mtd/nand.h                  |  1 +
> 7 files changed, 142 insertions(+), 3 deletions(-)
>
>--
>1.9.1

- Thanks Ezequiel, This will be helpful for NAND Flash users while debugging issues,
   And checking NAND flash quality (bit-flips numbers) during production.
- Tested on Beaglebone-Black using 4K NAND cape..
- Needed following fix in OMAP NAND driver to enable BBT creation and scanning.
------------- 
diff --git a/drivers/mtd/nand/omap2.c b/drivers/mtd/nand/omap2.c
index f0ed92e..2ad7451 100644
--- a/drivers/mtd/nand/omap2.c
+++ b/drivers/mtd/nand/omap2.c
@@ -1663,7 +1663,7 @@ static int omap_nand_probe(struct platform_device *pdev)
        mtd->owner              = THIS_MODULE;
        nand_chip               = &info->nand;
        nand_chip->ecc.priv     = NULL;
-       nand_chip->options      |= NAND_SKIP_BBTSCAN;
+       nand_chip->bbt_options  |= NAND_BBT_USE_FLASH;

        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        nand_chip->IO_ADDR_R = devm_ioremap_resource(&pdev->dev, res);
------------- 

So for whole series
Tested-by: Pekon Gupta <pekon@ti.com>


with regards, pekon

Re: [PATCH v3 0/3] mtd: Add sysfs entries and account BBT blocks properly

[Brian Norris]

On Tue, Jun 24, 2014 at 10:55:49AM -0300, Ezequiel Garcia wrote:
> Here's a new round of the patchset to add sysfs entries for the ECC stats
> struct fields. See the discussion around previous version for context:
> 
> http://lists.infradead.org/pipermail/linux-mtd/2014-March/052804.html
> 
> Changes from v2:
> 
>   * As suggested by Pekon Gupta, use "ecc_failures" instead of
>     "uncorrectable_errors".
> 
>   * Added documentation for the new sysfs ABI as requested by Greg KH.
> 
> Changes from v1:
> 
>   * As agreed I've added a sysfs file per field to replace the ecc_stats
>     sysfs file. The current proposal follows the "one file per value" sysfs
>     rule, adding the following device attributes:
>     - corrected_bits (ecc_stats.corrected)
>     - uncorrectable_errors (ecc_stats.failed)
>     - bad_blocks (ecc_stats.badblocks)
>     - bbt_blocks (ecc_stats.bbtblocks)
> 
>   * Following Brian's request, added small wrapper nand_block_isreserved()
>     that checks if the NAND has a bad block table before querying the number
>     of reserved blocks.
> 
>   * Finally, this new series drops patch: "nand: Account the blocks used by
>     the BBT in the ecc_stats". It's not yet clear how to best deal with the
>     current inconsistencies in MTD master and partition handling.
> 
> The first patch adds the sysfs entries. The rest of the patches fixes the
> bbtblock accounting and allows to keep track of the reserved blocks correctly.
> 
> This is a very old issue, probably around since the dawn of time,
> and nobody seemed to care much about it. However, with the introduction of
> the sysfs access, it's easier to access this stats and easier to
> see the issue.

Pushed to l2-mtd.git, with the small tweaks I noted for patch 1. Thanks!

Brian