Re: bad btree header at bucket xxx.

[Thierry De Leeuw <thierry-gY9mk9TZ+INg9hUCZPvPmw@public.gmane.org>]

Hi,

Any idea? I would like to come back to a sane situation as soon as possible.

Thanks!

Thierry
On 11/04/2013 12:39 AM, Thierry wrote:
> Hi,
>
> After a reboot, the bcache devices didn't appeared. Looking at dmesg I
> foud out the following entries:
> [ 12.182288] bcache: register_bdev() registered backing device dm-0
> [ 12.217379] bcache: register_bdev() registered backing device dm-1
> [ 12.253040] bcache: error on d8e791cc-47c2-449c-909a-1e4433a5de11: bad
> btree header at bucket 32018, block 0, 0 keys, disabling caching
> [ 12.253050] bcache: register_cache() registered cache device sdb1
> [ 12.253488] bcache: cache_set_free() Cache set
> d8e791cc-47c2-449c-909a-1e4433a5de11 unregistered
>
> Here is my device map
> NAME MAJ:MIN RM SIZE TYPE FSTYPE MOUNTPOINT UUID PARTUUID
> sda 8:0 0 931.5G disk
> ├─sda1 8:1 0 150M part ext2 0ced49ec-a9ec-4711-95b6-8ce01153ee3c
> 2a20f8be-8162-48db-9e51-d97e8fde21ae
> ├─sda2 8:2 0 49.9G part ext4 / 79f36847-8365-46da-85a1-cbab5ea9e30a
> 59d37a51-5f05-4356-857c-1937b793e9b1
> ├─sda3 8:3 0 881.5G part LVM2_member
> Vzf2b6-NmgQ-5Zff-QKRS-puR8-Dlhz-XIkY3t e337497b-b1e3-479e-ba29-e1b203434e97
> │ ├─vgDataNew-lvHome (dm-0) 254:0 0 50G lvm bcache
> ff11059e-0edf-428d-9657-37f255bac07e
> │ │ └─bcache0 252:0 0 50G disk ext4 /home
> 66bf41ef-174a-4770-b9ef-d37ab06d3f23
> │ ├─vgDataNew-lvVM (dm-1) 254:1 0 100G lvm bcache
> 9497600e-839f-4f59-862a-a7512cb59f0a
> │ │ └─bcache1 252:1 0 100G disk ext4 /data/vm
> 5ed8126a-2bda-465e-bedb-61272d878fde
> │ ├─vgDataNew-lvDownloads (dm-2) 254:2 0 50G lvm /home/xxx/xxx
> │ └─vgDataNew-lvSwap (dm-3) 254:3 0 12G lvm [SWAP]
> └─sda4 8:4 0 1007K part f6826e28-5dc0-4122-ba84-8ccaffd900fd
> sdb 8:16 0 223.6G disk
> └─sdb1 8:17 0 223.6G part bcache dff8e23e-7f9a-4a14-94a0-ec5b618a35c4
> ba9624c2-7fb7-4cfb-8d8a-1da6ca429820
> sr0
>
> Here is the output of bacache-super-show
>
> bcache-super-show /dev/sdb1
> sb.magic ok
> sb.first_sector 8 [match]
> sb.csum C161466F71949DD0 [match]
> sb.version 3 [cache device]
>
> dev.uuid dff8e23e-7f9a-4a14-94a0-ec5b618a35c4
> dev.sectors_per_block 8
> dev.sectors_per_bucket 1024
> dev.cache.first_sector 1024
> dev.cache.cache_sectors 468858880
> dev.cache.total_sectors 468859904
> dev.cache.discard yes
> dev.cache.pos 0
>
> cset.uuid d8e791cc-47c2-449c-909a-1e4433a5de11
>
>
> bcache-super-show /dev/vgDataNew/lvHome
> sb.magic ok
> sb.first_sector 8 [match]
> sb.csum ADBDC19FD7011CAB [match]
> sb.version 1 [backing device]
>
> dev.uuid ff11059e-0edf-428d-9657-37f255bac07e
> dev.sectors_per_block 8
> dev.sectors_per_bucket 1024
> dev.data.first_sector 16
> dev.data.cache_mode 3 [no caching]
> dev.data.cache_state 3 [inconsistent]
>
> cset.uuid d8e791cc-47c2-449c-909a-1e4433a5de11
>
>
> bcache-super-show /dev/vgDataNew/lvVM
> sb.magic ok
> sb.first_sector 8 [match]
> sb.csum BFD4613F155DD0D7 [match]
> sb.version 1 [backing device]
>
> dev.uuid 9497600e-839f-4f59-862a-a7512cb59f0a
> dev.sectors_per_block 8
> dev.sectors_per_bucket 1024
> dev.data.first_sector 16
> dev.data.cache_mode 3 [no caching]
> dev.data.cache_state 3 [inconsistent]
>
> cset.uuid d8e791cc-47c2-449c-909a-1e4433a5de11
>
> As you see I restarted the devices after having changed the cache mode
> to "none" followed by a echo 1 > running (The state of the 2 devices
> were dirty)
> e2fsck do not report any problem on any of the bcache device
>
> I am using gentoo kernel 3.11.6.
>
> Not sure it is related but the last operations before reboot were:
> * extend the lvDownloads (without FS resize)
> * erronously executed resize2fs /dev/bcache1 which resulted in a message
> that indicated that the device already had the maximum length.
>
> Are there other "emegency actions" I should take (cache is till reported
> as inconsistent)?
>
> Any idea what can be the cause of this corruption? Do you need more
> information to investigate the issue?
>
> How can I fix it now?
>
> Thanks!
>
> Thierry