linux.git/drivers/mtd/mtdpart.c, branch v4.16

mtd: Remove duplicate checks on mtd_oob_ops parameter

2018-01-16T14:23:22+00:00

Some of the check done in custom ->_read/write_oob() implementation are
already done by the core (in mtd_check_oob_ops()).

Suggested-by: Peter Pan 
[Remove redundant checks done in mtdpart.c]
Signed-off-by: Boris Brezillon 
Tested-by: Ladislav Michl

mtd: Fallback to ->_read/write_oob() when ->_read/write() is missing

2018-01-16T14:23:21+00:00

Some MTD sublayers/drivers are implementing ->_read/write_oob() and
provide dummy wrappers for their ->_read/write() implementations.
Let the core handle this case instead of duplicating the logic.

Signed-off-by: Boris Brezillon 
Acked-by: Robert Jarzmik 
Acked-by: Brian Norris 
Reviewed-by: Miquel Raynal 
Tested-by: Ladislav Michl

mtd: mtdpart: Make ECC stat handling consistent

2018-01-16T14:23:21+00:00

part_read() and part_read_oob() were counting ECC failures and
bitflips differently. Adjust part_read_oob() to mimic what is done in
part_read(). This is needed to use ->_read_oob() as a fallback when
when ->_read() is not implemented.

Note that bitflips and ECC failure accounting on MTD partitions is
broken by design, because nothing prevents concurrent accesses to the
underlying master MTD device between the moment we save the stats in a
local variable and the moment master->_read[_oob]() returns. It's not
something that can easily be fixed, so leave it like that for now.

Suggested-by: Brian Norris 
Signed-off-by: Boris Brezillon 
Tested-by: Ladislav Michl

mtd: remove the get_unmapped_area method

2017-11-13T20:39:18+00:00

It is now unused.

Signed-off-by: Nicolas Pitre 
Reviewed-by: Richard Weinberger 
Acked-by: Boris Brezillon 
Tested-by: Chris Brandt 
Signed-off-by: Richard Weinberger

mtd: Fix partition alignment check on multi-erasesize devices

2017-09-27T11:53:20+00:00

Commit 1eeef2d7483a ("mtd: handle partitioning on devices with 0
erasesize") introduced a regression on heterogeneous erase region
devices. Alignment of the partition was tested against the master
eraseblock size which can be bigger than the slave one, thus leading
to some partitions being marked as read-only.

Update wr_alignment to match this slave erasesize after this erasesize
has been determined by picking the biggest erasesize of all the regions
embedded in the MTD partition.

Reported-by: Mathias Thore 
Fixes: 1eeef2d7483a ("mtd: handle partitioning on devices with 0 erasesize")
Cc: 
Signed-off-by: Boris Brezillon 
Tested-by: Mathias Thore 
Reviewed-by: Mathias Thore

mtd: partitions: fixup some allocate_partition() whitespace

2017-06-23T17:52:15+00:00

Some recent patches caused churn around this area, and checkpatch
noticed the existing issues.

Signed-off-by: Brian Norris

mtd: partitions: add support for partition parsers

2017-06-22T20:13:09+00:00

Some devices have partitions that are kind of containers with extra
subpartitions / volumes instead of e.g. a simple filesystem data. To
support such cases we need to first create normal flash device
partitions and then take care of these special ones.

It's very common case for home routers. Depending on the vendor there
are formats like TRX, Seama, TP-Link, WRGG & more. All of them are used
to embed few partitions into a single one / single firmware file.

Ideally all vendors would use some well documented / standardized format
like UBI (and some probably start doing so), but there are still
countless devices on the market using these poor vendor specific
formats.

This patch extends MTD subsystem by allowing to specify list of parsers
that should be tried for a given partition. Supporting such poor formats
is highly unlikely to be the top priority so these changes try to
minimize maintenance cost to the minimum. It reuses existing code for
these new parsers and just adds a one property and one new function.

This implementation requires setting partition parsers in a flash
parser. A proper change of bcm47xxpart will follow and in the future we
will hopefully also find a solution for doing it with ofpart
("fixed-partitions").

Signed-off-by: Rafał Miłecki 
Signed-off-by: Brian Norris

mtd: partitions: add support for subpartitions

2017-06-22T20:13:08+00:00

Some flash device partitions can be containers with extra subpartitions
(volumes). All callbacks are already capable of this additional level of
indirection.

This patch makes sure we always display subpartitions using a tree
structure and takes care of deleting subpartitions when parent gets
removed.

Signed-off-by: Rafał Miłecki 
Signed-off-by: Brian Norris

mtd: partitions: rename "master" to the "parent" where appropriate

2017-06-22T20:13:07+00:00

This prepares mtd subsystem for the new feature: subpartitions. In some
cases flash device partition can be a container with extra subpartitions
(volumes).

So far there was a flat structure implemented. One master (flash device)
could be partitioned into few partitions. Every partition got its master
and it was enough to get things running.

To support subpartitions we need to store pointer to the parent for each
partition. This is required to implement more natural tree structure and
handle all recursion and offsets calculation.

To make code consistent this patch renamed "master" to the "parent" in
places where we can be dealing with subpartitions.

Signed-off-by: Rafał Miłecki 
Signed-off-by: Brian Norris

mtd: partitions: remove sysfs files when deleting all master's partitions

2017-06-22T20:13:06+00:00

When support for sysfs "offset" file was added it missed to update the
del_mtd_partitions function. It deletes partitions just like
mtd_del_partition does so both should also take care of removing sysfs
files.

This change moves sysfs_remove_files call to the shared function to fix
this issue.

Fixes: a62c24d755291 ("mtd: part: Add sysfs variable for offset of partition")
Cc: Dan Ehrenberg 
Signed-off-by: Rafał Miłecki 
Signed-off-by: Brian Norris