commit 74f2c6e9a47cf4e508198c8594626cc82906a13d upstream.

Since PEB erasure is asynchornous it can happen that there is
more than one Fastmap on the MTD. This is fine because the attach logic
will pick the Fastmap data structure with the highest sequence number.

On a not so well configured MTD stack spurious ECC errors are common.
Causes can be different, bad hardware, wrong operating modes, etc...
If the most current Fastmap renders bad due to ECC errors UBI might
pick an older Fastmap to attach from.
While this can only happen on an anyway broken setup it will show
completely different sympthoms and makes finding the root cause much
more difficult.
So, be debug friendly and fall back to scanning mode of we're facing
an ECC error while scanning for Fastmap.

Signed-off-by: Richard Weinberger <richard@nod.at>
[bwh: Backported to 3.16:
 - In scan_fast(), use 'ai' instead of 'scan_ai'
 - Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 8eef7d70f7c6772c3490f410ee2bceab3b543fa1 upstream.

We are completely discarding the earlier value of 'bitflips', which
could reflect a bitflip found in ubi_io_read_vid_hdr(). Let's use the
bitwise OR of header and data 'bitflip' statuses instead.

Coverity CID #1226856

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>

Set the return variable to an error code as done elsewhere in the function.

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

// <smpl>
(
if@p1 (\(ret < 0\|ret != 0\))
 { ... return ret; }
|
ret@p1 = 0
)
... when != ret = e1
    when != &ret
*if(...)
{
  ... when != ret = e2
      when forall
 return ret;
}

// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Reviewed-by: Richard Weinberger <richard@nod.at>

The test:
if (!a && b)
  a = b;
can be symplified in:
if (!a)
  a = b;

And there's no need to test if ubi->image_seq is not null, because if it is,
it is set to image_seq.
So, we just test if image_seq is not null.

Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>

If we find an invalid fastmap we have to scan from the very beginning.
Otherwise we leak the first 64 PEBs.

Reported-and-tested-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Artem 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: Ezequiel Garcia <elezegarcia@gmail.com>
Signed-off-by: Artem 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: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>

- Export compare_lebs() as fastmap needs this function.
- Implement fastmap scan logic.

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

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem 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: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>