This patch introduces the %UBI_IO_BAD_HDR_READ return code for
the I/O level function. We will use this code in order to distinguish
between "corrupted header possibly because this is non-ubi data" and
"corrupted header possibly because of real data corruption and ECC error".

So far this patch does not introduce any functional change, just a
preparation.

This patch is pased on a patch from
Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Reviewed-by: NSebastian Andrzej Siewior <sebastian@breakpoint.cc>
Tested-by: NSebastian Andrzej Siewior <sebastian@breakpoint.cc>

We do not really need 2 separate error codes for indicating bad VID
and bad EC headers (UBI_IO_BAD_EC_HDR, UBI_IO_BAD_VID_HDR), it is
enough to have only one UBI_IO_BAD_HDR return code.

This patch does not introduce any functional change, only some
code simplification.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Reviewed-by: NSebastian Andrzej Siewior <sebastian@breakpoint.cc>
Tested-by: NSebastian Andrzej Siewior <sebastian@breakpoint.cc>

Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NShinya Kuribayashi <shinya.kuribayashi.px@renesas.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

Signed-off-by: NShinya Kuribayashi <shinya.kuribayashi.px@renesas.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

UBI can be built into the kernel or be compiled as a kernel module.
Further on the command line one can specify MTD devices to be attach to
UBI while loading. In the current implementation the UBI driver refuses
to load if one of the MTD devices cannot be attached.

Consider:
1) UBI compiled into the kernel and
2) a MTD device specified on the command line and
3) this MTD device contains bogus data (for whatever reason).

During init UBI tries to attach the MTD device is this fails the whole
UBI subsystem isn't initialized. Later the userspace cannot attach any
MTD to UBI because UBI isn't loaded.

This patch keeps the current behaviour: if UBI is compiled as a module
and a MTD device cannot be attached the UBI module cannot be loaded,
but changes it for the UBI-is-built-into-the-kernel usecase.

If UBI is builtin, a not attachable MTD device doen't stop UBI from
initializing. This slightly modifies the behaviour if multiple MTD
devices are specified on the command line. Now every MTD device is
probed and, if possible, attached, i.e. a faulty MTD device doesn't
stop the others from being attached.

Artem: tweaked the patch
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

The UBI reboot notifier causes problems with hibernation.  Move this
functionality into the low-level MTD driver instead.
Signed-off-by: NKevin Cernekee <cernekee@gmail.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: NTejun Heo <tj@kernel.org>
Guess-its-ok-by: NChristoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

Passing the attribute to the low level IO functions allows all kinds
of cleanups, by sharing low level IO code without requiring
an own function for every piece of data.

Also drivers can extend the attributes with own data fields
and use that in the low level function.

This makes the class attributes the same as sysdev_class attributes
and plain attributes.

This will allow further cleanups in drivers.

Full tree sweep converting all users.
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Add an extra debugging check function which validates writes.
After every write it reads the data back, compares it with the
original data, and complains if they mismatch.

Useful for debugging. No-op if extra debugging checks are disabled.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

UBI debugging functions were a little bit over-engineered and
returned more error codes than needed, and the callers had to
do useless checks. Simplify the return codes.

Impact: only debugging code is affected, which means that for
        non-developers this is a no-op patch.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

In the error path of 'ubi_attach_mtd_dev()' we have a tricky situation:
we have to release things differently depending on at which point
the failure happening. Namely, if @ubi->dev is not initialized, we have
to free everything ourselves. But if it was, we should not free the @ubi
object, because it will be freed in the 'dev_release()' function. And
we did not get this situation right.

This patch introduces additional argument to the 'uif_init()' function.
On exit, this argument indicates whether the final 'free(ubi)' will
happen in 'dev_release()' or not. So the caller always knows how to
properly release the resources.

Impact: all memory is now correctly released when UBI fails to attach
        an MTD device.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

This patch adds a capability to attach MTD devices by their character
device paths. For example, one can do:

$ modprobe ubi mtd=/dev/mtd0

to attach /dev/mtd0.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

The @mtd_devs and @mtd_dev_param variables are used only during the
initialization, and all functions that use the variables have
the __init prefix. This means we can safely mark the variables
as __initdata, which is a tiny optimization.

Impact: tiny RAM consumption optimization when UBI is used as a kernel
        module.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

Do not use an unchecked variable UBI_IOCMKVOL ioctl.
Signed-off-by: NMika Westerberg <ext-mika.1.westerberg@nokia.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Cc: stable@vger.kernel.org

When truncating an UBI volume, UBI should allocates a PEB-sized
buffer but does not release it, which leads to memory leaks.
This patch fixes the issue.
Reported-by: NMarek Skuczynski <mareksk7@gmail.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Tested-by: NMarek Skuczynski <mareksk7@gmail.com>
Cc: stable@kernel.org

When opening UBI volumes by their character device names, make
sure we are opening character devices, not block devices or any
other inode type.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

The in kernel copy of a volume's update marker is not initialised from the
volume table. This means that volumes where an update was unfinnished will
not be treated as "forbidden to use". This is basically that the update
functionality was broken.
Signed-off-by: NPeter Horton <zero@colonel-panic.org>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Cc: stable@kernel.org

ubiupdatevol -t does the following:
- ubi_start_update()
  - set_update_marker()
  - for all LEBs ubi_eba_unmap_leb()
  - clear_update_marker()
  - ubi_wl_flush()

ubi_wl_flush() physically erases all PEB, once it returns all PEBs are
empty. clear_update_marker() has the update marker written after return.
If there is a power cut between the last two functions then the UBI
volume has no longer the "update" marker set and may have some valid
LEBs while some of them may be gone.
If that volume in question happens to be a UBIFS volume, then mount
will fail with

|UBIFS error (pid 1361): ubifs_read_node: bad node type (255 but expected 6)
|UBIFS error (pid 1361): ubifs_read_node: bad node at LEB 0:0
|Not a node, first 24 bytes:
|00000000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff

if there is at least one valid LEB and the wear-leveling worker managed
to clear LEB 0.

The patch waits for the wl worker to finish prior clearing the "update"
marker on flash. The two new LEB which are scheduled for erasing after
clear_update_marker() should not matter because they are only visible to
UBI.
Signed-off-by: NSebastian Andrzej Siewior <sebastian@breakpoint.cc>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Cc: stable@kernel.org

Add an 'ubi_open_volume_path(path, mode)' function which works like
'open_bdev_exclusive(path, mode, ...)' where path is the special file
representing the UBI volume, typically /dev/ubi0_0.

This is needed to teach UBIFS being able to mount UBI character devices.

[Comments and the patch were amended a bit by Artem]
Signed-off-by: NCorentin Chary <corentincj@iksaif.net>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

Additionally, some excessive newlines removed.
Signed-off-by: NMichael Roth <mroth@nessie.de>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

result is unsigned, the wrong check was used.
Signed-off-by: NRoel Kluin <roel.kluin@gmail.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

Commit 32bc4820 did not fully fix
the backward compatibility issues. We still fail to properly handle
situations when the first PEB contains non-zero image sequence
number, but one of the following PEBs contains zero image sequence
number. For example, this may happen if we mount a new image with
an old kernel, and then try to mount it in the new kernel.

This patch should fix the issue.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

Signed-off-by: NAnand Gadiyar <gadiyar@ti.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

More testing of NOR flash against power cuts showed that sometimes
eraseblocks may be unwritable, and we cannot really invalidate
them before erasure. But in this case the eraseblock probably
contains garbage anyway, and we do not have to invalidate the
headers. This assumption might be not true, but this is at least
what I have observed. So if we cannot invalidate the headers,
we make sure that the PEB does not contain valid VID header.
If this is true, everything is fine, otherwise we panic.

Useful for debugging problems, compiled in only if UBI debugging
is enabled. This patch also makes the UBI writing function dump
the flash if it fails to write.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

The assignment to pos when rb is finally NULL is undefined behaviour.
Upon seeing that assignment, GCC may assume that rb is not NULL, and
the loop condition ``rb'' may be optimised away.
Signed-off-by: NPhil Carmody <ext-phil.2.carmody@nokia.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

There was a bug report recently where UBI prints:

UBI error: ubi_attach_mtd_dev: failed to attach by scanning, error -22

error messages and refuses to attach a PEB. It turned out to be a
buggy flash driver which returned garbage to almost every UBI read.
This patch makes UBI print a better message in such cases. Namely,
if UBI finds 8 or more corrupted PEBs, it prints a warning and
lists the corrupted PEBs.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

In case of NOR flash, UBI zeroes EC and VID headers' magic,
in order to detect interrupted erasures. It first zeroes out
the EC magic, then VID magic. However, if a power cut happens
in between, we'll end up with a corrupted EC header and a valid
VID header, in which case UBI accepts the PEB, but prints a
warning. This patch makes sure we first zero out the VID
magic, then the EC magic, not vice versa. This is just a
small amendment to prevent warning messages.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

If the EC header is corrupted, but the VID header is OK, UBI accepts the
PEB and treats it as "used". However, generally this should not happen.
Print a warning if this happens.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

Fall back onto thinking everything's OK if either of the sequence
numbers we are asked to compare is zero, which is what was used
before sequence numbers were introduced.

[ Artem: modified the patch to be applicable to upstream UBI, added
        big comment ]
Signed-off-by: NAdrian Hunter <ext-adrian.hunter@nokia.com>
Signed-off-by: NPhil Carmody <ext-phil.2.carmody@nokia.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

If we fail in 'ubi_eba_init_scan()', we free
'ubi->volumes[i]->eba_tbl' in there, but also later free it
in 'free_internal_volumes()'. Fix this by assigning NULL
to 'ubi->volumes[i]->eba_tbl' after it is freed.
Signed-off-by: NAdrian Hunter <adrian.hunter@nokia.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

This patch fixes a bug in the image seq. number handling in the
scanning level. The assignment of the image_seq was incorrect.
Signed-off-by: NHolger Brunck <holger.brunck@keymile.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

Do not forget to initialize 'gluebi->ubi_num' because otherwise
it will stay 0 even for ubi1 device, and gluebi will open
wrong UBI device when 'gluebi_get_device()' is called.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

The recent "UBI: fix NOR flash recovery" introduced compilation
warnings which were immediately spotted by our linux-next keeper.
This patch fixes them.
Reported-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

This commit fixes NOR flash recovery issues observed with Spansion
S29GL512N NOR.

When NOR erases, it first fills PEBs with zeroes, then sets all bytes
to 0xFF. Filling with zeroes starts from the end of the PEB. And when
power is cut, this results in PEBs containing correct EC and VID headers
but corrupted with zeros at the end. This confuses UBI and it mistakinly
accepts these PEBs and associate them with LEBs.

Fis this issue by zeroing EC and VID magics before erasing PEBs, to
make UBI later refuse zem.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

Move the image seq. number handling from I/O level to the scanning
lever, where it really belongs to. Move the @image_seq_set variable
to the @struct ubi_scan_info structure, which exists only during
scanning.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

An image sequence number is added to the UBI erase-counter header
to be able determine if the root file system contains a mixture
of old and new images (because the flashing failed to complete).

A change to nolo is also needed for this to take effect.
Signed-off-by: NAdrian Hunter <adrian.hunter@nokia.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

The 'paranoid_check_empty()' is bogus because, which is easilly
seen on NOR flash, which has long erase cycles, and which may
easilly end-up with half-erased eraseblocks. In this case the
paranoid check fails. I is just wrong to assume that PEBs which
do not have EC headers always contain all 0xFF. Such assumption
should not be made on the I/O level, which is quite low.

Thus, just kill the check.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

This patch adds code which makes sure eraseblocks contain all 0xFF
bytes before starting using them. The verification is done only when
debugging checks are enabled.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>