[U-Boot] request for ubifs recovery support

[Albert ARIBAUD]

Le 17/11/2010 17:01, Quotient Remainder a écrit :
> Ar Aoine, 2010-09-17 ag 12:44 -0400, scríobh Eric Cooper:
>> But I just discovered that it has a fatal disadvantage.  My device
>> can't reboot when the ubifs is corrupted, which happened today after a
>> power failure:
>>
>>      UBIFS: recovery needed
>>      Error reading superblock on volume 'ubi:root'!
>>
>> Ubifs includes recovery code, but since u-boot treats it as a
>> read-only mount, this is never performed.  Once I booted Linux,
>> everything was fine.
>>
>> I'd like to request that the read-only flag be removed (at least to
>> allow recovery) so that the ubifs-only scheme can be used reliably.
>>
>
> Has this received any attention or is there an existing way to recover
> from these types of error?
>
> In devices I'm using, the problem is most apparent when the UBIFS RFS is
> mounted with "rootflags=sync" and a large file is copied into that RFS
> in Linux.  When the unit's power is cycled immediately on the "cp"
> command returning, the ubifsload command in U-Boot fails with the same
> error as mentioned by Eric Cooper above.

I don't know ubifs very well to say the least, but something strikes me 
in what you describe: ''the unit's power is cycled immediately on the 
"cp" command returning''.

Do you mean that, in Linux, you do a power cycle without (syncing and) 
unmounting a file system that will be critical to properly booting later 
on? If so, what is the rationale behind this too-quick power cycle?

Seems to me you should start by the preventive measure of avoiding the 
corruption in the first place (do a cp; sync; umount...) rather than 
relying on a curative measure of recovery attempts.

Amicalement,
-- 
Albert.