We have a couple of initialization funcntionsn left which have "_scan" suffic -
rename them:

ubi_eba_init_scan() -> ubi_eba_init()
ubi_wl_init_scan() -> ubi_wl_init()
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

The old name is not logical anymore - rename it to 'ubi_move_aeb_to_list()'.
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>

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>

We do not need this feature and to our shame it even was not working
and there was a bug found very recently.
	-- Artem Bityutskiy

Without the data type hint UBI2 (fastmap) will be easier to implement.
Signed-off-by: NRichard Weinberger <richard@nod.at>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

While looking at a problem reported by UBI around the PEB moving area I
noticed that the 'MOVE_CANCEL_BITFLIPS' is a bit inconsistent name and
'MOVE_TARGET_BITFLIPS' better - let's rename it.
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>

Remove the pre-allocated 'peb_buf2' buffer because we do not really need it.
The only reason UBI has it is to check that the data were written correctly.
But we do not have to have 2 buffers for this and waste RAM - we can just
compare CRC checksums instead. This reduces UBI memory consumption.

Artem bityutskiy: massaged the patch and commit message
Signed-off-by: NJosselin Costanzi <josselin.costanzi@mobile-devices.fr>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

Under some cases, when scrubbing the PEB if we did not get the lock on
the PEB it fails to scrub. Add that PEB again to the scrub list

Artem: minor amendments.

Cc: stable@kernel.org [2.6.31+]
Signed-off-by: NBhavesh Parekh <bparekh@nvidia.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

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

Currently UBI erases all corrupted eraseblocks, irrespectively of the nature
of corruption: corruption due to power cuts and non-power cut corruption.
The former case is OK, but the latter is not, because UBI may destroy
potentially important data.

With this patch, during scanning, when UBI hits a PEB with corrupted VID
header, it checks whether this PEB contains only 0xFF data. If yes, it is
safe to erase this PEB and it is put to the 'erase' list. If not, this may
be important data and it is better to avoid erasing this PEB. Instead,
UBI puts it to the corr list and moves out of the pool of available PEB.
IOW, UBI preserves this PEB.

Such corrupted PEB lessen the amount of available PEBs. So the more of them
we accumulate, the less PEBs are available. The maximum amount of non-power
cut corrupted PEBs is 8.

This patch is a response to UBIFS problem where reporter
(Matthew L. Creech <mlcreech@gmail.com>) observes that UBIFS index points
to an unmapped LEB. The theory is that corresponding PEB somehow got
corrupted and UBI wiped it. This patch (actually a series of patches)
tries to make sure such PEBs are preserved - this would make it is easier
to analyze the corruption.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

Rename UBI_IO_BAD_HDR_READ into UBI_IO_BAD_HDR_EBADMSG which is presumably more
self-documenting and readable. Indeed, the '_READ' suffix does not tell much and
even confuses, while '_EBADMSG' tells about uncorrectable ECC error, because we
use -EBADMSG all over the place to represent ECC errors.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

Currently, when UBI attaches an MTD device and cannot reserve all 1% (by
default) of PEBs for bad eraseblocks handling, it prints a warning. However,
Matthew L. Creech <mlcreech@gmail.com> is not very happy to see this warning,
because he did reserve enough of PEB at the beginning, but with time some
PEBs became bad. The warning is not necessary in this case.

This patch makes UBI print the warning
 o if this is a new image
 o of this is used image and the amount of reserved PEBs is only 10% (or less)
   of the size of the reserved PEB pool.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

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

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>

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

Some of the typos were indicated by Adrian Hunter,
some by 'aspell'.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

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

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

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

- (better, more, bigger ...) then -> (...) than
Signed-off-by: NFrederik Schwarzer <schwarzerf@gmail.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

When a PEB is moved and a write error happens, UBI switches
to R/O mode, which is wrong, because we just copy the data
and may select a different PEB and re-try this. This patch
fixes WL worker's behavior.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

We cannot call 'ubi_wl_get_peb()' with @ubi->buf_mutex locked,
because 'ubi_wl_get_peb()' may force erasure, which, in turn,
may call 'torture_peb()' which also locks the @ubi->buf_mutex
and deadlocks.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

'ubi_io_read_data()' may return EBADMSG in case of an ECC error,
and we should not panic because of this. We have CRC32 checksum
and may check the data. So just ignore the EBADMSG error.

This patch also fixes a minor spelling error at the same time.
Signed-off-by: NZoltan Sogor <weth@inf.u-szeged.hu>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

Just out or curiousity ran checkpatch.pl for whole UBI,
and discovered there are quite a few of stylistic issues.
Fix them.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

This is probably a copy-paste bug - we torture the old PEB
in the atomic LEB change function, but we should not do this.
Signed-off-by: NArtem 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: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

leb_read_unlock() may be called simultaniously by several tasks.
The would race at the following code:

 up_read(&le->mutex);
 if (free)
         kfree(le);

And it is possible that one task frees 'le' before the other tasks
do 'up_read()'. Fix this by doing up_read and free inside the
'ubi->ltree' lock. Below it the oops we had because of this:

BUG: spinlock bad magic on CPU#0, integck/7504
BUG: unable to handle kernel paging request at 6b6b6c4f
IP: [<c0211221>] spin_bug+0x5c/0xdb
*pde = 00000000 Oops: 0000 [#1] PREEMPT SMP Modules linked in: ubifs ubi nandsim nand nand_ids nand_ecc video output

Pid: 7504, comm: integck Not tainted (2.6.26-rc3ubifs26 #8)
EIP: 0060:[<c0211221>] EFLAGS: 00010002 CPU: 0
EIP is at spin_bug+0x5c/0xdb
EAX: 00000032 EBX: 6b6b6b6b ECX: 6b6b6b6b EDX: f7f7ce30
ESI: f76491dc EDI: c044f51f EBP: e8a736cc ESP: e8a736a8
DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
Process integck (pid: 7504, ti=e8a72000 task=f7f7ce30 task.ti=e8a72000)
Stack: c044f754 c044f51f 00000000 f7f7d024 00001d50 00000001 f76491dc 00000296       f6df50e0 e8a736d8 c02112f0 f76491dc e8a736e8 c039157a f7d9e830 f76491d8       e8a7370c c020b975 f76491dc 00000296 f76491f8 00000000 f76491d8 00000000 Call Trace:
[<c02112f0>] ? _raw_spin_unlock+0x50/0x7c
[<c039157a>] ? _spin_unlock_irqrestore+0x20/0x58
[<c020b975>] ? rwsem_wake+0x4b/0x122
[<c0390e0a>] ? call_rwsem_wake+0xa/0xc
[<c0139ee7>] ? up_read+0x28/0x31
[<f8873b3c>] ? leb_read_unlock+0x73/0x7b [ubi]
[<f88742a3>] ? ubi_eba_read_leb+0x195/0x2b0 [ubi]
[<f8872a04>] ? ubi_leb_read+0xaf/0xf8 [ubi]
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

ubi_free_volume() function sets ubi->volumes[] to NULL, so
ubi_eba_close() is useless, it does not free what has to be freed.
So zap it and free vol->eba_tbl at the volume release function.
Pointed-out-by: NAdrian Hunter <ext-adrian.hunter@nokia.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

UBI already checks that @min io size is the power of 2 at io_init.
It is save to use bit operations then.
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

ubi_eba_atomic_leb_change() has to just map the LEB to a free PEB
if data length is zero.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

Add more information about layout volume to make userspace tools
use the macros instead of constants. Also rename UBI_LAYOUT_VOL_ID
to make it consistent with other macros.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

The problem: NAND flashes have different amount of initial bad physical
eraseblocks (marked as bad by the manufacturer). For example, for 256MiB
Samsung OneNAND flash there might be from 0 to 40 bad initial eraseblocks,
which is about 2%. When UBI is used as the base system, one needs to know
the exact amount of good physical eraseblocks, because this number is
needed to create the UBI image which is put to the devices during
production. But this number is not know, which forces us to use the
minimum number of good physical eraseblocks. And UBI additionally
reserves some percentage of physical eraseblocks for bad block handling
(default is 1%), so we have 1-3% of PEBs reserved at the end, depending
on the amount of initial bad PEBs. But it is desired to always have
1% (or more, depending on the configuration).

Solution: this patch adds an "auto-resize" flag to the volume table.
The volume which has the "auto-resize" flag will automatically be re-sized
(enlarged) on the first UBI initialization. UBI clears the flag when
the volume is re-sized. Only one volume may have the "auto-resize" flag.

So, the production UBI image may have one volume with "auto-resize"
flag set, and its size is automatically adjusted on the first boot
of the device.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>