Re: [3.0-rc1] kernel BUG at fs/btrfs/relocation.c:4285!

[Tsutomu Itoh <t-itoh@jp.fujitsu.com>]

Hi liubo,

(2011/06/01 19:44), Tsutomu Itoh wrote:
> Hi, liubo,
> 
> (2011/06/01 18:42), liubo wrote:
>> On 06/01/2011 04:12 PM, liubo wrote:
>>> On 06/01/2011 03:44 PM, liubo wrote:
>>>>> On 05/31/2011 08:27 AM, Tsutomu Itoh wrote:
>>>>>>>>> The panic occurred when 'btrfs fi bal /test5' was executed.
>>>>>>>>>
>>>>>>>>> /test5 is as follows:
>>>>>>>>> # mount -o space_cache,compress=lzo /dev/sdc3 /test5
>>>>>>>>> #
>>>>>>>>> # btrfs fi sh /dev/sdc3
>>>>>>>>> Label: none  uuid: 38ec48b2-a64b-4225-8cc6-5eb08024dc64
>>>>>>>>>          Total devices 5 FS bytes used 7.87MB
>>>>>>>>>          devid    1 size 10.00GB used 2.02GB path /dev/sdc3
>>>>>>>>>          devid    2 size 15.01GB used 3.00GB path /dev/sdc5
>>>>>>>>>          devid    3 size 15.01GB used 3.00GB path /dev/sdc6
>>>>>>>>>          devid    4 size 20.01GB used 2.01GB path /dev/sdc7
>>>>>>>>>          devid    5 size 10.00GB used 2.01GB path /dev/sdc8
>>>>>>>>>
>>>>>>>>> Btrfs v0.19-50-ge6bd18d
>>>>>>>>> # btrfs fi df /test5
>>>>>>>>> Data, RAID0: total=10.00GB, used=3.52MB
>>>>>>>>> Data: total=8.00MB, used=1.60MB
>>>>>>>>> System, RAID1: total=8.00MB, used=4.00KB
>>>>>>>>> System: total=4.00MB, used=0.00
>>>>>>>>> Metadata, RAID1: total=1.00GB, used=216.00KB
>>>>>>>>> Metadata: total=8.00MB, used=0.00
>>>>>>>>>
>>>>>
>>>>> Hi, Itoh san,
>>>>>
>>>>> I've come up with a patch aiming to fix this bug.
>>>>> The problems is that the inode allocator stores one inode cache per root,
>>>>> which is at least not good for relocation tree, cause we only find
>>>>> new inode number from fs tree or file tree (subvol/snapshot).
>>>>>
>>>>> I've tested with your run.sh and it works well on my box, so you can try this:
>>>>>
>>
>> I've tested the following patch for about 1.5 hour, and nothing happened.
>> And would you please test this patch?
> 
> Thank you for your investigation.
> 
> I will also test again. but, I cannot test until next week because I
> will go to LinuxCon tomorrow and the day after tomorrow.
> 

I also tested.

The problem did not occur though I executed the test script for about
two hours.


> Thanks,
> Tsutomu
> 
> 
>>
>> thanks,
>>
>> From: Liu Bo<liubo2009@cn.fujitsu.com>
>>
>> [PATCH] Btrfs: fix save ino cache bug
>>
>> We just get new inode number from fs root or subvol/snap root,
>> so we'd like to save fs/subvol/snap root's inode cache into disk.
>>
>> Signed-off-by: Liu Bo<liubo2009@cn.fujitsu.com>
>> ---
>>   fs/btrfs/inode-map.c |    6 ++++++
>>   1 files changed, 6 insertions(+), 0 deletions(-)
>>
>> diff --git a/fs/btrfs/inode-map.c b/fs/btrfs/inode-map.c
>> index 0009705..8c0c25b 100644
>> --- a/fs/btrfs/inode-map.c
>> +++ b/fs/btrfs/inode-map.c
>> @@ -372,6 +372,12 @@ int btrfs_save_ino_cache(struct btrfs_root *root,
>>   	int prealloc;
>>   	bool retry = false;
>>
>> +	/* only fs tree and subvol/snap needs ino cache */
>> +	if (root->root_key.objectid != BTRFS_FS_TREE_OBJECTID&&
>> +	    (root->root_key.objectid<  BTRFS_FIRST_FREE_OBJECTID ||
>> +	     root->root_key.objectid>  BTRFS_LAST_FREE_OBJECTID))
>> +		return 0;
>> +
>>   	path = btrfs_alloc_path();
>>   	if (!path)
>>   		return -ENOMEM;
>