Finally, rename the scan.c file. Now adding fastmap support won't look that
hacky anymore.
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

Rename the constant to UBI_UNKNOWN, for the same reason that we are going
to add nother attaching method and re-use the same data structures, so the
"SCAN" in the name becomes incorrect. I've also removed the "_EC" part because
Joel is going to use this constant for other fields in the attaching info data
structures.
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

Rename the 'attach_by_scanning()' function to 'ubi_attach()' and move it to
scan.c. Richard will plug his fastmap stuff there.
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

This patch amends commentaries in scan.[ch] to match the new logic. Reminder -
we did the restructuring to prepare the code for adding the fastmap. This patch
also renames a couple of functions - it was too difficult to separate out that
change and I decided that it is not too bad to have it in the same patch with
commentaries changes.
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

The old name is not logical anymore - rename it to 'aeb_slab_cache'.
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

The old name is not logical anymore - rename it to 'ubi_destroy_ai()'.
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

The old name is not logical anymore - rename it to 'ubi_early_get_peb()'.
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

The old name is not logical anymore - rename it to 'ubi_remove_av()'.
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

The old name is not logical anymore - rename it to 'ubi_find_av()'.
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

The old name is not logical anymore - rename it to 'ubi_add_to_av()'.
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

The 'ubi_scan_find_aeb()' function is unused and thus can be removed.
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

The 'ubi_scan_erase_peb()' is used only in scan.c so can be static. Also
re-name it to 'early_erase_peb()' because we tend to use "ubi_" prefix only for
non-static fuction and also because the new name is better.
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

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: NArtem Bityutskiy <Artem.Bityutskiy@linux.intel.com>

After re-naming the 'struct ubi_scan_info' we should adjust all variables
named 'si' to something else, because 'si' stands for "scanning info".
Let's rename it to 'ai' which stands for "attaching info" which is
a bit more consistent and has the same length, which makes re-naming easy.
Signed-off-by: NArtem 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: NArtem Bityutskiy <Artem.Bityutskiy@linux.intel.com>

Rename 'struct ubi_scan_info' to 'struct ubi_attach_info'. 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.
Signed-off-by: NArtem 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: NArtem 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: NArtem 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: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

We have the "sefl-check" feature in UBI, but for historical reasons many
corresponding functions and commentaries in the code use term "paranoid check"
instead. Let's clean this up and use "self-check" everywhere.

This patch renames functions, amends messages and kills several redundant
debugging messages.
Signed-off-by: NArtem 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: NArtem 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: NArtem 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: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

!!(x < y) and (x < y) are identical expressions.
Signed-off-by: NRichard Weinberger <richard@nod.at>
Signed-off-by: NArtem 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: NArtem 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: NArtem Bityutskiy <Artem.Bityutskiy@linux.intel.com>

Now we have only one buffer so let's rename it to just 'peb_buf1'.
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

Two bad things can happen in ubi_scan():
1. If kmem_cache_create() fails we jump to out_si and call
   ubi_scan_destroy_si() which calls kmem_cache_destroy().
   But si->scan_leb_slab is NULL.
2. If process_eb() fails we jump to out_vidh, call
   kmem_cache_destroy() and ubi_scan_destroy_si() which calls
   again kmem_cache_destroy().
Signed-off-by: NRichard Weinberger <richard@nod.at>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Cc: stable@kernel.org

Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@intel.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: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

Fix checkpatch.pl errors and warnings:

* space before tab
* line over 80 characters
* include linux/ioctl.h instead of asm/ioctl.h
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

Fixes generated by 'codespell' and manually reviewed.
Signed-off-by: NLucas De Marchi <lucas.demarchi@profusion.mobi>

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: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

Just make them a bit more readable and explanatory.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

During scanning UBI allocates one struct ubi_scan_leb object for each PEB,
so it can end up allocating thousands of them. Use slab cache to reduce
memory consumption for these 48-byte objects, because currently used
'kmalloc()' ends up allocating 64 bytes per object, instead of 48.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

My new shiny code for corrupted PEB detection has NOR specific bug.
We tread PEB as corrupted and preserve it, if

1. EC header is OK.
2. VID header is corrupted.
3. data area is not "all 0xFFs"

In case of NOR we have 'nor_erase_prepare()' quirk, which invalidates
the headers before erasing the PEB. And we invalidate first the VID
header, and then the EC header. So if a power cut happens after we have
invalidated the VID header, but before we have invalidated the EC
header, we end up with a PEB which satisfies the above 3 conditions,
and the scanning code will treat it as corrupted, and will print
scary warnings, wrongly.

This patch fixes the issue by firt invalidating the EC header, then
invalidating the VID header. In case of power cut inbetween, we still
just lose the EC header, and UBI can deal with this situation gracefully.

Thanks to Anatolij Gustschin <agust@denx.de> for tracking this down.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Reported-by: NAnatolij Gustschin <agust@denx.de>
Tested-by: NAnatolij Gustschin <agust@denx.de>

Commit 45aafd32 "UBI: tighten the corrupted PEB criteria"
introduced some return paths that didn't release the ubi->buf_mutex
Signed-off-by: NDan Carpenter <error27@gmail.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

If we get a bit-flip of ECC error while reading the data area, do not add it to
corrupted list, because it is possible that this is just unstable PEB with
corruptions caused by unclean reboots.

This patch also improves commentaries.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

When the data does not contain all 0xFF bytes, 'check_data_ff()' should return
1, not -EINVAL; Also, the caller ('process_eb()') should not add the PEB to the
"corrupted" list if there was a read error.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

While scanning the flash we read all VID headers and store some important
information in 'struct ubi_scan_leb'. Store also the 'copy_flag' value there
as it is needed when comparing LEBs. We do not increase memory consumption
because this is just one bit and we have plenty of spare bits in
'struct ubi_scan_leb' (sizeof(struct ubi_scan_leb) is 48 both with and
without this patch).
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>