From mboxrd@z Thu Jan 1 00:00:00 1970 From: Miao Xie Subject: Re: [BUG] btrfs hangup when we run the "sync" command Date: Mon, 19 Jul 2010 14:17:38 +0800 Message-ID: <4C43EE02.8060306@cn.fujitsu.com> References: <4C3E7E1B.5000002@cn.fujitsu.com> <4C3ECFBB.40006@cn.fujitsu.com> <20100715161213.GG8623@think> <4C43B0B2.1040507@cn.fujitsu.com> <4C43B1F6.6070601@oracle.com> Reply-To: miaox@cn.fujitsu.com Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Cc: Chris Mason , Linux Btrfs To: "Yan, Zheng" Return-path: In-Reply-To: <4C43B1F6.6070601@oracle.com> List-ID: On Mon, 19 Jul 2010 10:01:26 +0800, Yan, Zheng wrote: > On 07/19/2010 09:56 AM, Miao Xie wrote: >> On Thu, 15 Jul 2010 12:12:13 -0400, Chris Mason 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