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

[Coly Li]

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);
>>
>>   
> 

-- 
Coly Li
SuSE Labs