The current ubi.mtd parsing logic will warn & continue on when attaching
the specified mtd device fails (for any reason).  It doesn't however skip
things when the specified mtd device can't be opened.

This scenario can be hit in a couple of different ways such as:
 - build NAND controller driver as a module
 - build UBI into the kernel
 - include ubi.mtd on the kernel command line
 - boot the system
 - MTD devices don't exist, so UBI init fails

This is problematic because failing init means the entire UBI layer is
unavailable until you reboot and modify the kernel command line.  If
we just warn and continue on, /dev/ubi_ctrl is available for userland
to add UBI volumes on the fly once it loads the NAND driver.
Signed-off-by: NMike Frysinger <vapier@gentoo.org>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

The ubi_err() macro automatically prefixes "UBI error" before the message.
By also using it here, we get a log like so:
	UBI error: ubi_init: UBI error: cannot initialize UBI, error -19
Signed-off-by: NMike Frysinger <vapier@gentoo.org>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Use more preferable function name which implies using a pseudo-random
number generator.
Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

ubi_debug_info struct was dynamically allocated which
is always suboptimal, for it tends to fragment memory
and make the code error-prone.
Fix this by embedding it in ubi_device struct.
Signed-off-by: NEzequiel Garcia <elezegarcia@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

With this patch code is a bit more readable and there's no
generated code or functionality impact.
Furthermore, this abstracts implementation details and
will allow to change ubi_debug_info in a less invasive way.
Signed-off-by: NEzequiel Garcia <elezegarcia@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

As ubi_self_check_all_ff() might sleep we are not allowed
to call it from atomic context.
For now we call it only from ubi_wl_get_peb().
There are some code paths where it would also make sense,
but these paths are currently atomic and only enabled
when fastmap is used.
Signed-off-by: NRichard Weinberger <richard@nod.at>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

If UBI is built without fastmap, get_peb_for_wl() has to
remove the PEB manially from the free tree.
Otherwise the requested PEB lives in two trees.
Reported-by: NZach Sadecki <zsadecki@itwatchdogs.com>
Signed-off-by: NRichard Weinberger <richard@nod.at>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

This kind of memcpy() is error-prone. Its replacement with a struct
assignment is prefered because it's type-safe and much easier to read.

Found by coccinelle. Hand patched and reviewed.
Tested by compilation only.

A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
@@
identifier struct_name;
struct struct_name to;
struct struct_name from;
expression E;
@@
-memcpy(&(to), &(from), E);
+to = from;
// </smpl>
Signed-off-by: NPeter Senna Tschudin <peter.senna@gmail.com>
Signed-off-by: NEzequiel Garcia <elezegarcia@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

This line of comment looks completely bogus.

It was introduced in:
commit d99383b0
Author: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Date:   Wed May 18 14:47:34 2011 +0300

    UBI: change the interface of a debugging check function

Remove it.
Signed-off-by: NEzequiel Garcia <elezegarcia@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

Both names 'total_read' and 'total_written' are actually used
as the number of bytes left to read and write.
Fix this confusion by renaming both to 'bytes_left'.
Signed-off-by: NEzequiel Garcia <elezegarcia@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

UBI reserves an LEB sized buffer for various needs. We can use this buffer
while scanning, instead of allocating another one. This patch was originally
created by Jan Luebbe <jlu@pengutronix.de>, but then he dropped it and I picked
up and tweaked a little bit.
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

Using list_move_tail() instead of list_del() + list_add_tail().

dpatch engine is used to auto generate this patch.
(https://github.com/weiyj/dpatch)
Signed-off-by: NWei Yongjun <yongjun_wei@trendmicro.com.cn>
Acked-by: NRichard Weinberger <richard@nod.at>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

Make fastmap known to Kconfig, UBI Makefile and MAINTAINERS.
Signed-off-by: NRichard Weinberger <richard@nod.at>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

Signed-off-by: NRichard Weinberger <richard@nod.at>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

To make fastmap possible the WL sub-system needs some
changes.
Mostly to support fastmaps pools.
Signed-off-by: NRichard Weinberger <richard@nod.at>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

- Export compare_lebs() as fastmap needs this function.
- Implement fastmap scan logic.
Signed-off-by: NRichard Weinberger <richard@nod.at>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

Fastmap uses ->fm_sem to stop EBA changes while writing
a new fastmap.
Signed-off-by: NRichard Weinberger <richard@nod.at>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

Signed-off-by: NRichard Weinberger <richard@nod.at>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

self_check_eba() compares two ubi_attach_info objects.
Fastmap uses this function for self checks.
Signed-off-by: NRichard Weinberger <richard@nod.at>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

Fastmap needs next_sqnum(), rename it to ubi_next_sqnum()
and make it non-static.
Signed-off-by: NRichard Weinberger <richard@nod.at>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

This patch adds fastmap specific data structures to ubi.h.
It moves also struct ubi_work to ubi.h as it is now needed
for more than one c file.
Signed-off-by: NRichard Weinberger <richard@nod.at>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

Add the on-flash data structures neeed by fastmap
to ubi-media.h
Signed-off-by: NRichard Weinberger <richard@nod.at>
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@linux.intel.com>

Use 'late_initcall()' in UBI to make sure it initializes after MTD drivers.
Signed-off-by: NJiang Lu <lu.jiang@windriver.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

UBI was mistakingly using 'kfree()' instead of 'kmem_cache_free()' when
freeing "attach eraseblock" structures in vtbl.c. Thankfully, this happened
only when we were doing auto-format, so many systems were unaffected. However,
there are still many users affected.

It is strange, but the system did not crash and nothing bad happened when
the SLUB memory allocator was used. However, in case of SLOB we observed an
crash right away.

This problem was introduced in 2.6.39 by commit
"6c1e875c UBI: add slab cache for ubi_scan_leb objects"

A note for stable trees:
  Because variable were renamed, this won't cleanly apply to older kernels.
  Changing names like this should help:
	1. ai -> si
	2. aeb_slab_cache -> seb_slab_cache
	3. new_aeb -> new_seb
Reported-by: NRichard Genoud <richard.genoud@gmail.com>
Tested-by: NRichard Genoud <richard.genoud@gmail.com>
Tested-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Cc: stable@vger.kernel.org [v2.6.39+]
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

UBI currently prints a lot of information when it mounts a volume, which
bothers some people. Make it less chatty - print only important information
by default.

Get rid of 'dbg_msg()' macro completely.
Reported-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

Use 'pr_err()' instead of 'printk(KERN_ERR', etc.
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

Join all the split printk lines in order to stop checkpatch complaining.
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

Without this patch, these PEB are not scrubbed until we put data in them.
Bitflip can accumulate latter and we can loose the EC header (but VID header
should be intact and allow to recover data).
Signed-off-by: NMatthieu Castet <matthieu.castet@parrot.com>
Cc: stable@vger.kernel.org
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

Currently UBI fails in autoresize when it is in R/O mode (e.g., because the
underlying MTD device is R/O). This patch fixes the issue - we just skip
autoresize and print a warning.
Reported-by: NPali Rohár <pali.rohar@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

This patch provides a possibility to set the "maximum expected number of
bad blocks per 1024 blocks" (max_beb_per1024) for each mtd device using
the UBI_IOCATT ioctl.
Signed-off-by: NRichard Genoud <richard.genoud@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

This patch provides the possibility to adjust the "maximum expected number of
bad blocks per 1024 blocks" (max_beb_per1024) for each mtd device.

The majority of NAND devices have their max_beb_per1024 equal to 20, but
sometimes it's more.
Now, we can adjust that via a kernel parameter:
ubi.mtd=<name|num|path>[,<vid_hdr_offs>[,max_beb_per1024]]
Signed-off-by: NRichard Genoud <richard.genoud@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

max_beb_per1024 shouldn't be negative, and a 0 value will be treated as
the default value. For the upper bound, 768/1024 should be enough.
Signed-off-by: NRichard Genoud <richard.genoud@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

This patch prepare the way for the addition of max_beb_per1024 module
parameter.  There's no functional change.
Signed-off-by: NRichard Genoud <richard.genoud@gmail.com>
Reviewed-by: NShmulik Ladkani <shmulik.ladkani@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

Signed-off-by: NRichard Genoud <richard.genoud@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

No functional changes here, just to prepare for next patch.
Signed-off-by: NRichard Genoud <richard.genoud@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

On NAND flash devices, UBI reserves some physical erase blocks (PEB) for
bad block handling. Today, the number of reserved PEB can only be set as a
percentage of the total number of PEB in each MTD partition. For example, for a
NAND flash with 128KiB PEB, 2 MTD partition of 20MiB (mtd0) and 100MiB (mtd1)
and 2% reserved PEB:
 - the UBI device on mtd0 will have 2 PEB reserved
 - the UBI device on mtd1 will have 16 PEB reserved

The problem with this behaviour is that NAND flash manufacturers give a
minimum number of valid block (NVB) during the endurance life of the
device, e.g.:

Parameter             Symbol    Min    Max    Unit      Notes
--------------------------------------------------------------
Valid block number     NVB     1004    1024   Blocks     1

From this number we can deduce the maximum number of bad PEB that a device will
contain during its endurance life: a 128MiB NAND flash (1024 PEB) will not have
less than 20 bad blocks during the flash endurance life.

But the manufacturer doesn't tell where those bad block will appear. He doesn't
say either if they will be equally disposed on the whole device (and I'm pretty
sure they won't). So, according to the datasheets, we should reserve the
maximum number of bad PEB for each UBI device (worst case scenario: 20 bad
blocks appears on the smallest MTD partition).

So this patch make UBI use the whole MTD device size to calculate the maximum
bad expected eraseblocks.

The Kconfig option is in per1024 blocks, thus it can have a default value of 20
which is *very* common for NAND devices.
Signed-off-by: NRichard Genoud <richard.genoud@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

CONFIG_MTD_UBI_BEB_RESERVE and MIN_RESEVED_PEBS are no longer used,
since the amount of reserved eraseblocks for bad PEB handling is now
derived from 'ubi->bad_peb_limit' (ubi's maximum expected bad
eraseblocks).
Signed-off-by: NShmulik Ladkani <shmulik.ladkani@gmail.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@linux.intel.com>

The existing mechanism of reserving PEBs for bad PEB handling has two
flaws:
- It is calculated as a percentage of good PEBs instead of total PEBs.
- There's no limit on the amount of PEBs UBI reserves for future bad
  eraseblock handling.

This patch changes the mechanism to overcome these flaws.

The desired level of PEBs reserved for bad PEB handling (beb_rsvd_level)
is set to the maximum expected bad eraseblocks (bad_peb_limit) minus the
existing number of bad eraseblocks (bad_peb_count).

The actual amount of PEBs reserved for bad PEB handling is usually set
to the desired level (but in some circumstances may be lower than the
desired level, e.g. when attaching to a device that has too few
available PEBs to satisfy the desired level).

In the case where the device has too many bad PEBs (above the expected
limit), then the desired level, and the actual amount of PEBs reserved
are set to zero. No PEBs will be set aside for future bad eraseblock
handling - even if some PEBs are made available (e.g. by shrinking a
volume).
If another PEB goes bad, and there are available PEBs, then the
eraseblock will be marked bad (consuming one available PEB). But if
there are no available PEBs, ubi will go into readonly mode.
Signed-off-by: NShmulik Ladkani <shmulik.ladkani@gmail.com>