[Ocfs2-devel] [PATCH] ocfs2: return f_fsid info in ocfs2_statfs()

[Sunil Mushran]

It's worse. As far as I can see, the s_uuid_hash is never populated.
So we have two problems. The second issue is urgent as we are
using it in xattr.

Coly Li wrote:
> Sunil Mushran Wrote:
>   
>> Wondering whether this id needs to be endian consistent.
>> For failover nfs setups maybe.
>>     
>
> IMHO, It is. Because osb->uuid_hash is fetched by:
>         osb->uuid_hash = le32_to_cpu(di->id2.i_super.s_uuid_hash);
> CMIIW, It should work in nfs failover.
>
>   
>> Coly Li wrote:
>>     
>>> Currently f_fsid of struct kstatfs returned from ocfs2_statfs() is
>>> undefined (at least it should be
>>> filled with 0). Since in some conditions, f_fsid value might be used
>>> as (f_fsid, ino) pare to
>>> uniquely identify a file, ocfs2 should return a defined unique f_fsid
>>> value from ocfs2_statfs().
>>>
>>> This patch uses uuid_hash as a unique ID to initiate f_fsid value, the
>>> 32bits width is enough for
>>> ocfs2 membership so far.
>>>
>>> Signed-off-by: Coly Li <coly.li at suse.de>
>>> ---
>>>  fs/ocfs2/super.c |    2 ++
>>>  1 files changed, 2 insertions(+), 0 deletions(-)
>>>
>>> diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c
>>> index 43ed113..fdab98a 100644
>>> --- a/fs/ocfs2/super.c
>>> +++ b/fs/ocfs2/super.c
>>> @@ -1425,6 +1425,8 @@ static int ocfs2_statfs(struct dentry *dentry,
>>> struct kstatfs *buf)
>>>      buf->f_bavail = buf->f_bfree;
>>>      buf->f_files = numbits;
>>>      buf->f_ffree = freebits;
>>> +    buf->f_fsid.val[0] = osb->uuid_hash & 0xFFFFFFFFUL;
>>> +    buf->f_fsid.val[1] = 0;
>>>
>>>      brelse(bh);
>>>
>>>   
>>>       
>
>