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

[Miao Xie <miaox@cn.fujitsu.com>]

On Mon, 19 Jul 2010 10:01:26 +0800, Yan, Zheng <zheng.yan@oracle.com> wrote:
> 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.

I don't know how this bug was fixed up. I think if the btrfs doesn't support
the >PAGE_SIZE sectorsize, it should forbid mounting a filesystem with >PAGE_SIZE 
sectorsize. But in fact, we can mount.

So I think this bug has not been fixed up or the fix is not so good.

Thanks
Miao Xie