UBIFS failed to recover master node

[Artem Bityutskiy]

On Mon, 2010-05-24 at 11:22 -0400, twebb wrote:
> I've had several cases where our MLC NAND flash appears corrupted in
> such a way that one of three UBIFS volumes can not be mounted due to
> "failed to recover master node".  I haven't been able to reproduce the
> problem, but we've had at least 5 incidents where this has occurred.
> (A partial capture from one of the failures is below.)
> 
> I'm starting to investigate this problem and don't know if this is a
> UBIFS/UBI problem or a NAND driver problem.  I'm starting the process
> of back-porting the latest UBIFS code to our 2.6.29 kernel - hoping
> that new UBIFS code will solve the problem.  However, this may also be
> a driver problem and I wonder if I also need to update that driver
> (pxa3xx_nand).  Any suggestions for debugging this problem?
> 
> Thanks,
> twebb
> 
> 
> capture:
> [root at ESIedge mtd-utils]# mount -t ubifs ubi0_0 /mnt/
> [  239.605869] UBI error: ubi_io_read: error -74 while reading 516096
> bytes from PEB 4:8192, read 516096 bytes
> [  239.616317] UBIFS error (pid 676): ubifs_scan: corrupt empty space
> at LEB 2:268135
> [  239.623996] UBIFS error (pid 676): ubifs_scanned_corruption:
> corruption at LEB 2:268135
> [  239.642101] UBIFS error (pid 676): ubifs_scan: LEB 2 scanning failed
> [  239.976396] UBI error: ubi_io_read: error -74 while reading 516096
> bytes from PEB 4:8192, read 516096 bytes
> [  239.986742] UBIFS error (pid 676): ubifs_recover_master_node:
> failed to recover master node
> mount: mounting ubi0_0 on /mnt/ failed: Invalid argument

And BTW, it is a good idea not to erase/re-flash this device if you want
to fix this problem.

-- 
Best Regards,
Artem Bityutskiy (Артём Битюцкий)