UBIFS errors when file-system is full

[Richard Weinberger]

Am 22.07.2015 um 09:10 schrieb Bhuvanchandra DV:
> On 07/21/2015 11:44 AM, Richard Weinberger wrote:
> 
>> Hi!
>>
>> Am 21.07.2015 um 08:04 schrieb Bhuvanchandra DV:
>>> Ran the power cut tests with fm_debug enabled, no additional logs are observed.
>>> After few hundred power cuts U-Boot fails to mount with -22 and kernel fails
>>> mounting with stack trace when reading the node.
>> Why U-Boot? Has U-Boot fastmap enabled?
> 
> Yes, fastmap is enabled in U-Boot.

Please disable it.

> The same power cut tests are done by skipping the U-Boot to mount the UBIFS. Loaded
> the kernel via tftp and mount the rootfs with kernel. The power cut test passed.
> I think U-Boot might have some issues, but not very sure.

To my knowledge U-Boot's fastmap support is incomplete.
If you *really* need fastmap in U-Boot make sure that they have backported
all recent fastmap changes. Fastmap is still experimental and faced a lot of fixes
recently.

>>
>> Anyway, we need to sort out what is going on.
>> As fm_debug does not trigger it could also be a non-fastmap issue.
>> Did you try your test without fastmap being enabled?
>>
>> Does your target pass UBI tests too?
> 
> I'm not aware of UBI tests so far the driver passed all MTD tests.
> Can you please provide some pointers for UBI tests. Will run the UBI tests with
> driver.

They are in the mtd-utils source.

>>
>>> Log:
>> [...]
>>> [    2.847326] UBIFS error (ubi0:0 pid 1): ubifs_read_node: bad node type (255 but expected 3)
>>> [    2.866839] UBIFS error (ubi0:0 pid 1): ubifs_read_node: bad node at LEB 981:70368, LEB mapping status 1
>>> [    2.887961] Not a node, first 24 bytes:
>>> [    2.891864] 00000000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff                          ........................
>> Hmm, LEB1 is unmapped.
>> If you disable fastmap, does this target boot as expected?
>> Or is this a persistent corruption?
> 
> No, the corruption is persistent.
> - removed|fm_autoconvert from kernel args - removed the fastmap support from kernel Tested with above both cases, the corruption is persistent. |

Okay that is a clear hint that Linux's fastmap is only the messenger and not the evil doer.

Thanks,
//richard