Commit Graph

224 Commits

Author SHA1 Message Date
Artem Bityutskiy
f9b0080e10 UBI: support attaching by MTD character device name
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: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2010-02-01 15:16:36 +02:00
Artem Bityutskiy
9e0c7ef3f6 UBI: mark few variables as __initdata
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: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2010-02-01 15:16:36 +02:00
Linus Torvalds
551e28dbe8 Merge branch 'for-linus' of git://git.infradead.org/ubi-2.6
* 'for-linus' of git://git.infradead.org/ubi-2.6:
  UBI: fix volume creation input checking
2010-01-28 12:57:50 -08:00
Mika Westerberg
c5ce5b46af UBI: fix volume creation input checking
Do not use an unchecked variable UBI_IOCMKVOL ioctl.

Signed-off-by: Mika Westerberg <ext-mika.1.westerberg@nokia.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Cc: stable@vger.kernel.org
2010-01-27 11:55:43 +02:00
Artem Bityutskiy
ebddd63b74 UBI: fix memory leak in update path
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: Marek Skuczynski <mareksk7@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Tested-by: Marek Skuczynski <mareksk7@gmail.com>
Cc: stable@kernel.org
2010-01-18 18:53:56 +02:00
Artem Bityutskiy
b531b55a7b UBI: add more checks to chdev open
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: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2010-01-12 13:19:15 +02:00
Peter Horton
ff99879328 UBI: initialise update marker
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: Peter Horton <zero@colonel-panic.org>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Cc: stable@kernel.org
2010-01-12 13:19:08 +02:00
Linus Torvalds
fc1495bf99 Merge git://git.infradead.org/ubifs-2.6
* git://git.infradead.org/ubifs-2.6:
  UBIFS: fix return code in check_leaf
  UBI: flush wl before clearing update marker
  MAINTAINERS: change e-mail of Artem Bityutskiy
  UBIFS: remove manual O_SYNC handling
  UBIFS: support mounting of UBI volume character devices
  UBI: Add ubi_open_volume_path
2009-12-10 09:31:45 -08:00
Sebastian Andrzej Siewior
6afaf8a484 UBI: flush wl before clearing update marker
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: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Cc: stable@kernel.org
2009-12-04 07:47:11 +02:00
Corentin Chary
b571028418 UBI: Add ubi_open_volume_path
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: Corentin Chary <corentincj@iksaif.net>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2009-11-24 08:18:54 +02:00
Michael Roth
fa3012318b Kconfig: Remove useless and sometimes wrong comments
Additionally, some excessive newlines removed.

Signed-off-by: Michael Roth <mroth@nessie.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-11-09 09:40:56 +01:00
Roel Kluin
774b138210 UBI: fix check on unsigned long
result is unsigned, the wrong check was used.

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2009-10-20 10:13:49 +03:00
Artem Bityutskiy
2eadaad67b UBI: fix backward compatibility
Commit 32bc482028 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: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2009-10-20 10:13:04 +03:00
Linus Torvalds
342ff1a1b5 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (34 commits)
  trivial: fix typo in aic7xxx comment
  trivial: fix comment typo in drivers/ata/pata_hpt37x.c
  trivial: typo in kernel-parameters.txt
  trivial: fix typo in tracing documentation
  trivial: add __init/__exit macros in drivers/gpio/bt8xxgpio.c
  trivial: add __init macro/ fix of __exit macro location in ipmi_poweroff.c
  trivial: remove unnecessary semicolons
  trivial: Fix duplicated word "options" in comment
  trivial: kbuild: remove extraneous blank line after declaration of usage()
  trivial: improve help text for mm debug config options
  trivial: doc: hpfall: accept disk device to unload as argument
  trivial: doc: hpfall: reduce risk that hpfall can do harm
  trivial: SubmittingPatches: Fix reference to renumbered step
  trivial: fix typos "man[ae]g?ment" -> "management"
  trivial: media/video/cx88: add __init/__exit macros to cx88 drivers
  trivial: fix typo in CONFIG_DEBUG_FS in gcov doc
  trivial: fix missing printk space in amd_k7_smp_check
  trivial: fix typo s/ketymap/keymap/ in comment
  trivial: fix typo "to to" in multiple files
  trivial: fix typos in comments s/DGBU/DBGU/
  ...
2009-09-22 07:51:45 -07:00
Anand Gadiyar
fd589a8f0a trivial: fix typo "to to" in multiple files
Signed-off-by: Anand Gadiyar <gadiyar@ti.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-09-21 15:14:55 +02:00
Artem Bityutskiy
de75c771b4 UBI: improve NOR flash erasure quirk
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.
2009-08-14 20:02:20 +03:00
Artem Bityutskiy
867996b15c UBI: introduce flash dump helper
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: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2009-08-14 20:02:20 +03:00
Phil Carmody
758d8e4634 UBI: eliminate possible undefined behaviour
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: Phil Carmody <ext-phil.2.carmody@nokia.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2009-08-14 20:01:36 +03:00
Artem Bityutskiy
4a406856ea UBI: print a warning if too many PEBs are corrupted
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: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2009-08-14 20:01:36 +03:00
Artem Bityutskiy
5b289b562f UBI: amend NOR flash pre-erase quirk
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: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2009-08-14 20:01:36 +03:00
Artem Bityutskiy
29a88c99d2 UBI: print a message if ECH is corrupted and VIDH is ok
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: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2009-08-14 20:01:35 +03:00
Adrian Hunter
32bc482028 UBI: compatible fallback in absense of sequence numbers
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: Adrian Hunter <ext-adrian.hunter@nokia.com>
Signed-off-by: Phil Carmody <ext-phil.2.carmody@nokia.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2009-07-24 20:08:52 +03:00
Adrian Hunter
7194e6f9c0 UBI: fix double free on error path
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: Adrian Hunter <adrian.hunter@nokia.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2009-07-24 20:08:52 +03:00
Holger Brunck
3dc948da78 UBI: fix bug in image sequence number handling
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: Holger Brunck <holger.brunck@keymile.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2009-07-15 11:30:59 +03:00
Artem Bityutskiy
c8cc452501 UBI: gluebi: initialize ubi_num field
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: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2009-07-15 11:30:55 +03:00
Artem Bityutskiy
83c2099f5e UBI: fix compilation warnings
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: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2009-07-08 10:15:41 +03:00
Artem Bityutskiy
ebf53f4213 UBI: fix NOR flash recovery
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: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2009-07-07 11:37:45 +03:00
Artem Bityutskiy
fe96efc1a3 UBI: nicify image sequence number handling
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: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2009-07-05 18:47:08 +03:00
Adrian Hunter
0c6c7fa131 UBI: add image sequence number to EC header
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: Adrian Hunter <adrian.hunter@nokia.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2009-07-05 18:47:07 +03:00
Artem Bityutskiy
1398788fe7 UBI: remove bogus debugging checks
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: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2009-07-05 18:47:05 +03:00
Artem Bityutskiy
40a71a87fa UBI: add empty eraseblocks verification
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: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2009-07-05 18:47:03 +03:00
Kevin Cernekee
d9dd0887cc UBI: add reboot notifier
Terminate the UBI background thread prior to restarting the system.

[Artem: amended comments a little]

Signed-off-by: Kevin Cernekee <kpc.mtd@gmail.com>
Tested-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2009-06-10 16:50:50 +03:00
Artem Bityutskiy
6b5c94c6b4 UBI: handle more error codes
The UBIFS WL worker may encounter read errors and there is logic
which makes a decision whether we should do one of:

1. cancel the operation and move the PEB with the read errors to
   the 'erroneous' list;
2. switch to R/O mode.

ATM, only -EIO errors trigger 1., other errors trigger 2. The idea
is that if we know we encountered an I/O error, do 1. Otherwise,
we do not know how to react, and do 2., just in case. E.g., if
the underlying driver became crazy because of a bug, we do not
want to harm any data, and switch to R/O mode.

This patch does 2 things:
1. Makes sure reads from the source PEB always cause 1. This is
   more consistent with other reads which come from the upper
   layers and never cause R/O.
2. Teaches UBI to do 1. also on -EBADMSG, UBI_IO_BAD_VID_HDR,
   -ENOMEM, and -ETIMEOUT. But this is only when reading the
   target PEB.

This preblems were hunted by Adrian Hunter.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2009-06-10 16:13:28 +03:00
Artem Bityutskiy
815bc5f8fe UBI: fix multiple spelling typos
Some of the typos were indicated by Adrian Hunter,
some by 'aspell'.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2009-06-10 16:13:27 +03:00
Artem Bityutskiy
21d08bbcb1 UBI: fix kmem_cache_free on error patch
'kmem_cache_free()' oopeses if NULL is passed, and there is
one error-path place where UBI may call it with NULL object.
This problem was pointed to by Adrian Hunter.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2009-06-10 16:13:27 +03:00
Artem Bityutskiy
52b605d107 UBI: print amount of reserved PEBs
When marking a PEB as bad, print how many PEBs are left reserved.
This is very useful information.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2009-06-09 18:49:51 +03:00
Artem Bityutskiy
9c259a52fa UBI: improve messages in the WL worker
Print not only the PEB number, but also the LEB number and volume id,
which is very useful for bug hunting.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2009-06-08 13:05:43 +03:00
Dmitry Pervushin
2ba3d76a1e UBI: make gluebi a separate module
[Artem: re-worked the patch: made it release resources when the
module is unloaded, made it do module referencing, made it really
independent on UBI, tested it with the UBI test-suite which can
be found in ubi-2.6.git/tests/ubi-tests, re-named most of the
funcs/variables to get rid of the "ubi" word and make names
consistent.]

Signed-off-by: Dmitry Pervushin <dpervushin@embeddedalley.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2009-06-03 17:45:23 +03:00
Dmitry Pervushin
518ceef0c9 UBI: remove built-in gluebi
Remove built-in gluebi support. This is a preparation for a
standalone glubi module support

Signed-off-by: Dmitry Pervushin <dpervushin@embeddedalley.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2009-06-02 13:53:35 +03:00
Dmitry Pervushin
0e0ee1cc33 UBI: add notification API
UBI volume notifications are intended to create the API to get clients
notified about volume creation/deletion, renaming and re-sizing. A
client can subscribe to these notifications using 'ubi_volume_register()'
and cancel the subscription using 'ubi_volume_unregister()'. When UBI
volumes change, a blocking notifier is called. Clients also can request
"added" events on all volumes that existed before client subscribed
to the notifications.

If we use notifications instead of calling functions like 'ubi_gluebi_xxx()',
we can make the MTD emulation layer to be more flexible: build it as a
separate module and load/unload it on demand.

[Artem: many cleanups, rework locking, add "updated" event, provide
 device/volume info in notifiers]

Signed-off-by: Dmitry Pervushin <dpervushin@embeddedalley.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2009-06-02 13:53:35 +03:00
Artem Bityutskiy
b86a2c56e5 UBI: do not switch to R/O mode on read errors
This patch improves UBI errors handling. ATM UBI switches to
R/O mode when the WL worker fails to read the source PEB.
This means that the upper layers (e.g., UBIFS) has no
chances to unmap the erroneous PEB and fix the error.
This patch changes this behaviour and makes UBI put PEBs
like this into a separate RB-tree, thus preventing the
WL worker from hitting the same read errors again and
again.

But there is a 10% limit on a maximum amount of PEBs like this.
If there are too much of them, UBI switches to R/O mode.

Additionally, this patch teaches UBI not to panic and
switch to R/O mode if after a PEB has been copied, the
target LEB cannot be read back. Instead, now UBI cancels
the operation and schedules the target PEB for torturing.

The error paths has been tested by ingecting errors
into 'ubi_eba_copy_leb()'.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2009-06-02 13:53:35 +03:00
Artem Bityutskiy
87960c0b12 UBI: fix and clean-up error paths in WL worker
This patch fixes the error path in the WL worker - in same cases
UBI oopses when 'goto out_error' happens and e1 or e2 are NULL.
This patch also cleans up the error paths a little. And I have
tested nearly all error paths in the WL worker.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2009-06-02 13:53:35 +03:00
Artem Bityutskiy
90bf0265e5 UBI: introduce new constants
This patch is a clean-up and a preparation for the following
patches. It introduece constants for the return values of the
'ubi_eba_copy_leb()' function.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2009-06-02 13:53:35 +03:00
Artem Bityutskiy
ddbd3b6170 UBI: fix race condition
This patch fixes a minor problem where we may fail to wake
upe the UBI background thread. This is not fatal at all,
it may just result at sligtly worse performace for a short
period of time, just because the thread will be woken up
when real I/O on the UBI starts.

Anywey, the issue is the race condition between
'ubi_attach_mtd_dev()' and 'ubi_thread()'. If we do not
serialize them, the 'wake_up_process()' call may be done
before 'ubi_thread()' went seep, but after it checked
'ubi->thread_enabled'.

This issue was spotted by Shin Hong <hongshin@gmail.com>

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2009-05-26 12:47:47 +03:00
Artem Bityutskiy
95c9c1da79 UBI: minor serialization fix
The @vol->upd_marker should be protected by the @ubi->device_mutex,
otherwise 'paranoid_check_volume()' complains sometimes because
vol->upd_marker is 1 while vtbl_rec->upd_marker is 0.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2009-05-18 12:28:26 +03:00
Artem Bityutskiy
d38dce5bfb UBI: do not panic if volume check fails
If a volume paranoid check fails, do not return an error
code to the caller, but just print error messages and go
forward. The primary reason for this is that it is difficult
to recover and cancel the operation at that stage.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2009-05-18 12:28:26 +03:00
Artem Bityutskiy
cfcf0ec84b UBI: add dump_stack in checking code
I am experiencing an error in 'paranoid_check_volume()'. Add
dump_stack() there to make it easier to identify the reasons
of the error.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2009-05-18 12:28:26 +03:00
Artem Bityutskiy
ffb6b7e4fd UBI: fix races in I/O debugging checks
When paranoid checs are enabled, the 'io_paral' test from the
'mtd-utils' package fails. The symptoms are:

UBI error: paranoid_check_all_ff: flash region at PEB 3973:512, length 15872 does not contain all 0xFF bytes
UBI error: paranoid_check_all_ff: paranoid check failed for PEB 3973
UBI: hex dump of the 512-16384 region

It turned out to be a bug in the checking function. Suppose there
are 2 tasks - A and B. Task A is the wear-levelling working
('wear_leveling_worker()'). It is reading the VID header to find
which LEB this PEB belongs to. Say, task A is reading header
of PEB X. Suppose PEB X is unmapped, and has no VID header.
Task B is trying to write to PEB X.

Task A: in 'ubi_io_read_vid_hdr()': reads the VID header from PEB X.
        The read data contain all 0xFF bytes.
Task B: writes VID header and some data to PEB X
Task A: assumes PEB X is empty, calls 'paranoid_check_all_ff()', which
        fails.

The solution for this problem is to make 'paranoid_check_all_ff()'
re-read the VID header, re-check it, and only if it is not there,
check the rest. This now implemented by the 'paranoid_check_empty()'
function.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2009-05-18 12:28:25 +03:00
Artem Bityutskiy
2cb81e218f UBI: small debugging code optimization
The @ubi->dbg_peb_buf is needed only when paranoid checks are
enabled, not when debugging in general is enabled.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2009-05-18 12:28:25 +03:00
Artem Bityutskiy
e1cf7e6dd4 UBI: improve debugging messages
Various minor improvements to the debugging messages which
I found useful while hunting problems.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2009-05-18 12:28:25 +03:00