After re-naming the 'struct ubi_scan_volume' we should adjust all variables
named 'sv' to something else, because 'sv' stands for "scanning volume".
Let's rename it to 'av' which stands for "attaching volume" which is
a bit more consistent and has the same length, which makes re-naming easy.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@linux.intel.com>
After re-naming the 'struct ubi_scan_leb' we should adjust all variables
named 'seb' to something else, because 'seb' stands for "scanning eraseblock".
Let's rename it to 'aeb' which stands for "attaching eraseblock" which is
a bit more consistend and has the same length.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@linux.intel.com>
Rename 'struct ubi_scan_volume' to 'struct ubi_ainf_volume'. This is part
of the code re-structuring I am trying to do in order to add fastmap
in a more logical way. Fastmap can share a lot with scanning, including
the attach-time data structures, which all now have "scan" word in the
name. Let's get rid of this word and use "ainf" instead which stands
for "attach information". It has the same length as "scan" so re-naming
is trivial.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@linux.intel.com>
Rename 'struct ubi_scan_leb' to 'struct ubi_ainf_leb'. This is part
of the code re-structuring I am trying to do in order to add fastmap
in a more logical way. Fastmap can share a lot with scanning, including
the attach-time data structures, which all now have "scan" word in the
name. Let's get rid of this word and use "ainf" instead which stands
for "attach information". It has the same length as "scan" so re-naming
is trivial.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@linux.intel.com>
This patch removes the 'dbg_err()' macro and we now use 'ubi_err' instead.
The idea of 'dbg_err()' was to compile out some error message to make the
binary a bit smaller - but I think it was a bad idea.
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
This patch kills the UBI debugging Kconfig option completely and makes all the
debugging stuff to be always compiled-in. It was pain in the neck to maintain
this useless option because all users I am aware of have debugging enabled
anyway - how else will you diagnose errors otherwise?
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
I am going to remove the "UBI debugging" compilation option and make the
debugging stuff to be always compiled it. This patch is a preparation
which renames 'ubi_dbg_dump_mkvol_req()' to 'ubi_dump_mkvol_req()'.
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
I am going to remove the "UBI debugging" compilation option and make the
debugging stuff to be always compiled it. This patch is a preparation
which renames 'ubi_dbg_dump_seb()' to 'ubi_dump_seb()'.
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
I am going to remove the "UBI debugging" compilation option and make the
debugging stuff to be always compiled it. This patch is a preparation
which renames 'ubi_dbg_dump_sv()' to 'ubi_dump_sv()'.
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
I am going to remove the "UBI debugging" compilation option and make the
debugging stuff to be always compiled it. This patch is a preparation
which renames 'ubi_dbg_dump_vtbl_record()' to 'ubi_dump_vtbl_record()'.
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
I am going to remove the "UBI debugging" compilation option and make the
debugging stuff to be always compiled it. This patch is a preparation
which renames 'ubi_dbg_dump_vol_info()' to 'ubi_dump_vol_info()'.
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
UBI (and UBIFS) are a bit over-engineered WRT debugging. The idea was to
link as few as possible when debugging is disabled, but the downside is
that most people produce bug reports which are difficult to understand.
Always dump the VID and EC headers' contents in case of errors when it
is helpful.
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
UBI (and UBIFS) are a bit over-engineered WRT debugging. The idea was to
link as few as possible when debugging is disabled, but the downside is
that most people produce bug reports which are difficult to understand.
Always dump the flash contents in case of errors, not only when debugging is
enabled.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@linux.intel.com>
UBI (and UBIFS) are a bit over-engineered WRT debugging. The idea was to
link as few as possible when debugging is disabled, but the downside is
that most people produce bug reports which are difficult to understand.
This patch weeds out the 'ubi_dbg_dump_stack()' function and turns it
into 'dump_stack()' - it is always useful to have stack dump in case of
an error.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@linux.intel.com>
Patch ab50ff6847 broke UBI debugging messages:
before that commit when UBI debugging was enabled, users saw few useful
debugging messages after attaching an MTD device. However, that patch turned
'dbg_msg()' into 'pr_debug()', so to enable the debugging messages users have
to enable them first via /sys/kernel/debug/dynamic_debug/control, which is
very impractical.
This commit makes 'dbg_msg()' to use 'printk()' instead of 'pr_debug()', just
as it was before the breakage.
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Cc: stable@kernel.org [3.0+]
Michal Marek spotted the same issue in UBIFS and this patch fixes UBI,
see "UBIFS: not build debug messages with CONFIG_UBIFS_FS_DEBUG disabled"
When UBI debugging is disabled, we have debugging messages defined as:
if (0)
pr_debug()
But pr_debug macro defines data structures with debugging data and makes
the linux binary larger, even though we have "if (0)".
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@intel.com>
Kill the UBI 'debug_tsts' module parameter and switch to debugfs. Create
per-test mode files there. E.g., to enable bit-flips emulation you may just do:
echo 1 > /sys/kernel/debug/ubi/ubi0/tst_emulate_bitflips
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Current layout does not allow us to add inline functions to debug.h which use
the 'struct ubi_device' object, because it is undefined there. Move
'#include "debug.h"' in "ubi.h" down so to make 'struct ubi_device" be defined.
Additionally, this makes it possible to remove a bunch of forward declarations
in "debug.h". This is a preparation to the next patch.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
We'll need the 'struct ubi_device *ubi' pointer in every debugging function (to
access the ->dbg field), so add this pointer to all the functions implementing
UBI debugging test modes like 'ubi_dbg_is_bitflip()' etc.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
This patch introduces debugfs support to UBI. All the UBI stuff is kept in the
"ubi" debugfs directory, which contains per-UBI device "ubi/ubiX"
sub-directories, containing debugging files. This file also creates
"ubi/ubiX/chk_gen" and "ubi/ubiX/chk_io" knobs for switching general and I/O
extra checks on and off. And it removes the 'debug_chks' UBI module parameters.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Remove custom dynamic prints and the module parameter to toggle them and use
the generic kernel dynamic printk infrastructure.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Similarly as we have done for UBIFS in
1dcffad741, turn the debugging macros into static
inline functions, for the same reasons: to avoid gcc 4.5 warnings.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
When debugging is disabled, define debugging prints as if (0) printk() to make
sure that the compiler still the format string in debugging messages even if
debugging is disabled.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Similarly to the debugging checks and message, make the test modes
be dynamically selected via the "debug_tsts" module parameter or
via the "/sys/module/ubi/parameters/debug_tsts" sysfs file. This
is consistent with UBIFS as well.
And now, since all the Kconfig knobs became dynamic, we can remove
the Kconfig.debug file completely.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
This patch adds a possibility to dynamically switch UBI self-checks
on and off, instead of toggling them compile-time from the configuration
menu. This is much more flexible, and consistent with UBIFS, and this
also simplifies UBI Kconfig menu and the code.
This patch introduces two levels of self-checks - general, which
includes all self-checks which are relatively fast, and I/O, which
includes write-verify checks and erase-verify checks, which are
relatively slow and involve flash I/O.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
This patch adds a possibility to dynamically select UBI debugging
messages, instead of selecting them compile-time from the configuration
menu. This is much more flexible, and consistent with UBIFS, and this
also simplifies UBI Kconfig menu and the code.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
This additional little macro is used to print a bit more messages
while scanning the media. However, we have the 'dbg_bld()' macro
for this, so we better us 'dbg_bld()' and kill UBI_IO_DEBUG. This
simplifies the code a tiny bit.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Introduce a helper function to print hexdump: 'ubi_dbg_print_hex_dump()'.
It is compiled out if debugging is enabled. Will be used in the next patch.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
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: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
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>
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>
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>
Hch asked not to use "unit" for sub-systems, let it be so.
Also some other commentaries modifications.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
__FUNCTION__ is gcc-specific, use __func__
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Make I/O function to be always verbose when about CRC errors
and magic number errors when I/O debugging is enabled.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
When volume creation fails, we have to set ubi->volumes[vol_id]
back to NULL.
This patch also tweaks some debugging stuff.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
UBI (Latin: "where?") manages multiple logical volumes on a single
flash device, specifically supporting NAND flash devices. UBI provides
a flexible partitioning concept which still allows for wear-levelling
across the whole flash device.
In a sense, UBI may be compared to the Logical Volume Manager
(LVM). Whereas LVM maps logical sector numbers to physical HDD sector
numbers, UBI maps logical eraseblocks to physical eraseblocks.
More information may be found at
http://www.linux-mtd.infradead.org/doc/ubi.html
Partitioning/Re-partitioning
An UBI volume occupies a certain number of erase blocks. This is
limited by a configured maximum volume size, which could also be
viewed as the partition size. Each individual UBI volume's size can
be changed independently of the other UBI volumes, provided that the
sum of all volume sizes doesn't exceed a certain limit.
UBI supports dynamic volumes and static volumes. Static volumes are
read-only and their contents are protected by CRC check sums.
Bad eraseblocks handling
UBI transparently handles bad eraseblocks. When a physical
eraseblock becomes bad, it is substituted by a good physical
eraseblock, and the user does not even notice this.
Scrubbing
On a NAND flash bit flips can occur on any write operation,
sometimes also on read. If bit flips persist on the device, at first
they can still be corrected by ECC, but once they accumulate,
correction will become impossible. Thus it is best to actively scrub
the affected eraseblock, by first copying it to a free eraseblock
and then erasing the original. The UBI layer performs this type of
scrubbing under the covers, transparently to the UBI volume users.
Erase Counts
UBI maintains an erase count header per eraseblock. This frees
higher-level layers (like file systems) from doing this and allows
for centralized erase count management instead. The erase counts are
used by the wear-levelling algorithm in the UBI layer. The algorithm
itself is exchangeable.
Booting from NAND
For booting directly from NAND flash the hardware must at least be
capable of fetching and executing a small portion of the NAND
flash. Some NAND flash controllers have this kind of support. They
usually limit the window to a few kilobytes in erase block 0. This
"initial program loader" (IPL) must then contain sufficient logic to
load and execute the next boot phase.
Due to bad eraseblocks, which may be randomly scattered over the
flash device, it is problematic to store the "secondary program
loader" (SPL) statically. Also, due to bit-flips it may become
corrupted over time. UBI allows to solve this problem gracefully by
storing the SPL in a small static UBI volume.
UBI volumes vs. static partitions
UBI volumes are still very similar to static MTD partitions:
* both consist of eraseblocks (logical eraseblocks in case of UBI
volumes, and physical eraseblocks in case of static partitions;
* both support three basic operations - read, write, erase.
But UBI volumes have the following advantages over traditional
static MTD partitions:
* there are no eraseblock wear-leveling constraints in case of UBI
volumes, so the user should not care about this;
* there are no bit-flips and bad eraseblocks in case of UBI volumes.
So, UBI volumes may be considered as flash devices with relaxed
restrictions.
Where can it be found?
Documentation, kernel code and applications can be found in the MTD
gits.
What are the applications for?
The applications help to create binary flash images for two purposes: pfi
files (partial flash images) for in-system update of UBI volumes, and plain
binary images, with or without OOB data in case of NAND, for a manufacturing
step. Furthermore some tools are/and will be created that allow flash content
analysis after a system has crashed..
Who did UBI?
The original ideas, where UBI is based on, were developed by Andreas
Arnez, Frank Haverkamp and Thomas Gleixner. Josh W. Boyer and some others
were involved too. The implementation of the kernel layer was done by Artem
B. Bityutskiy. The user-space applications and tools were written by Oliver
Lohmann with contributions from Frank Haverkamp, Andreas Arnez, and Artem.
Joern Engel contributed a patch which modifies JFFS2 so that it can be run on
a UBI volume. Thomas Gleixner did modifications to the NAND layer. Alexander
Schmidt made some testing work as well as core functionality improvements.
Signed-off-by: Artem B. Bityutskiy <dedekind@linutronix.de>
Signed-off-by: Frank Haverkamp <haver@vnet.ibm.com>
Artem Bityutskiy