Re: [PATCH] btrfs-progs: do not BUG_ON if btrfs_add_to_fsid succeeded to write superblock

[Su Yue <l@damenly.su>]

On Wed 12 May 2021 at 22:01, David Sterba <dsterba@suse.cz> wrote:

> On Tue, May 11, 2021 at 12:25:01PM +0800, Su Yue wrote:
>> Commit 8ef9313cf298 ("btrfs-progs: zoned: implement 
>> log-structured
>> superblock") changed to write BTRFS_SUPER_INFO_SIZE bytes to 
>> device.
>> The before num of bytes to be written is sectorsize.
>> It causes mkfs.btrfs failed on my 16k pagesize kvm:
>
> What architecture is that?
>
The host chip is Apple m1 so it's arm64 but only supporting 16k 
and 4k
pagesize. Since btrfs subpage work cares 64k pagesize for now, I 
usually
run xfstests with 16k pagesize and 16k sectorsize. So far, so 
good.

--
Su

>>
>>   $ /usr/bin/mkfs.btrfs -s 16k -f -mraid0 /dev/vdb2 /dev/vdb3
>>   btrfs-progs v5.12
>>   See http://btrfs.wiki.kernel.org for more information.
>>
>>   ERROR: superblock magic doesn't match
>>   ERROR: superblock magic doesn't match
>>   common/device-scan.c:195: btrfs_add_to_fsid: BUG_ON `ret != 
>>   sectorsize`
>>   triggered, value 1
>>   /usr/bin/mkfs.btrfs(btrfs_add_to_fsid+0x274)[0xaaab4fe8a5fc]
>>   /usr/bin/mkfs.btrfs(main+0x1188)[0xaaab4fe4dc8c]
>>   /usr/lib/libc.so.6(__libc_start_main+0xe8)[0xffff7223c538]
>>   /usr/bin/mkfs.btrfs(+0xc558)[0xaaab4fe4c558]
>>
>>   [1]    225842 abort (core dumped)  /usr/bin/mkfs.btrfs -s 16k 
>>   -f -mraid0
>>   /dev/vdb2 /dev/vdb3
>>
>> btrfs_add_to_fsid() now always calls sbwrite() to write
>> BTRFS_SUPER_INFO_SIZE bytes to device, so change condition of
>> the BUG_ON().
>> Also add comments for sbread() and sbwrite().
>>
>> Signed-off-by: Su Yue <l@damenly.su>
>
> Added to devel, thanks.