Re: [BUG] btrfs hangup when we run the "sync" command

["Yan, Zheng" <zheng.yan@oracle.com>]

On 07/19/2010 09:56 AM, Miao Xie wrote:
> On Thu, 15 Jul 2010 12:12:13 -0400, Chris Mason <chris.mason@oracle.com> wrote:
>>>>> It seems that the btrfs doesn't support the sectorsize which is
>>>>> greater than the page size just like ext2/3/4, though we can use
>>>>> mkfs.btrfs to make a filesystem with a big sectorsize. Am I right?
>>>>>
>>>>> If yes, we must do more check in the mkfs.btrfs.
>>>>>
>>>>
>>>> yes, btrfs doesn't support the sectorsize>  PAGE_size.
>>>>
>>>
>>> So we must do more check in the mkfs.btrfs to avoid misuse, and I'll
>>> add some check of the sectorsize into the mkfs.btrfs.
>>
>> Yes, but this is fixed up with the raid code, we'll allow different page
>> sizes.
> 
> Is the raid code that you said the initialization code for the block devices?
> just like this:
> 
> fs/btrfs/volumes.c:1430
> int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
> {
> 	[snip]
> 	set_blocksize(device->bdev, 4096);
> 	[snip]
> }
> 
> If yes, it uses a hard-code value to initialize the blocksize of the block device,
> not the blocksize of the btrfs, so the btrfs doesn't check the blocksize of the btrfs.
> 

This is for btrfs super block, because size of btrfs super block is fixed.

Yan, Zheng