UBIFS failed to recover master node

[twebb]

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