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

[liubo <liubo2009@cn.fujitsu.com>]

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:
> 

Sorry, I messed up BTRFS_FIRST_FREE_OBJECTID and BTRFS_LAST_FREE_OBJECTID,
plz ignore this.

> ===
> based on 3.0, commit d6c0cb379c5198487e4ac124728cbb2346d63b1f
> ===
> diff --git a/fs/btrfs/inode-map.c b/fs/btrfs/inode-map.c
> index 0009705..ebc2a7b 100644
> --- a/fs/btrfs/inode-map.c
> +++ b/fs/btrfs/inode-map.c
> @@ -372,6 +372,10 @@ int btrfs_save_ino_cache(struct btrfs_root *root,
>  	int prealloc;
>  	bool retry = false;
>  
> +	if (root->root_key.objectid != BTRFS_FS_TREE_OBJECTID &&
> +	    root->root_key.objectid < BTRFS_FIRST_FREE_OBJECTID)
> +		return 0;
> +
>  	path = btrfs_alloc_path();
>  	if (!path)
>  		return -ENOMEM;
> 
> 
> 
> thanks,
> liubo
>