Re: [PATCH 13/17] NFS: Client implementation of Labeled-NFS

[Steve Dickson <SteveD@redhat.com>]

On 08/05/13 12:43, Myklebust, Trond wrote:
> On Wed, 2013-05-08 at 12:39 -0400, Steve Dickson wrote:
>>
>> On 01/05/13 15:03, Myklebust, Trond wrote:
>>>> @@ -2409,10 +2468,26 @@ static int _nfs4_server_capabilities(struct nfs_server *server, struct nfs_fh *f
>>>>>  			server->caps |= NFS_CAP_CTIME;
>>>>>  		if (res.attr_bitmask[1] & FATTR4_WORD1_TIME_MODIFY)
>>>>>  			server->caps |= NFS_CAP_MTIME;
>>>>> +#ifdef CONFIG_NFS_V4_SECURITY_LABEL
>>>>> +		if (res.attr_bitmask[2] & FATTR4_WORD2_SECURITY_LABEL)
>>>>> +			server->caps |= NFS_CAP_SECURITY_LABEL;
>>>>> +#endif
>>>>> +		memcpy(server->attr_bitmask_nl, res.attr_bitmask, 
>>>>> +				sizeof(server->attr_bitmask));
>>>>> +
>>>>> +		if (server->caps & NFS_CAP_SECURITY_LABEL)
>>>>> +			server->attr_bitmask_nl[2] &= ~FATTR4_WORD2_SECURITY_LABEL;
>>>>>  
>>>>>  		memcpy(server->cache_consistency_bitmask, res.attr_bitmask, sizeof(server->cache_consistency_bitmask));
>>>>>  		server->cache_consistency_bitmask[0] &= FATTR4_WORD0_CHANGE|FATTR4_WORD0_SIZE;
>>>>> -		server->cache_consistency_bitmask[1] &= FATTR4_WORD1_TIME_METADATA|FATTR4_WORD1_TIME_MODIFY;
>>>>> +		server->cache_consistency_bitmask[1] &= FATTR4_WORD1_TIME_METADATA |
>>>>> +							FATTR4_WORD1_TIME_MODIFY;
>>>>> +#ifdef CONFIG_NFS_V4_SECURITY_LABEL
>>>>> +		server->cache_consistency_bitmask[2] &= FATTR4_WORD2_SECURITY_LABEL;
>>> Why? How is the security label relevant to cache consistency?
>> Its used to the set label bit in the GETATTR that goes out with ACCESS compound.
> 
> The GETATTR that goes out with ACCESS is only there in order to get the
> change attribute so that we know when to invalidate the access cache. It
> is _only_ for cache consistency.
> 
> Why do we need to fetch the label too?
> 
I think I answer this in the other thread but in short 
access updates the inode and so it appears the goal 
is to synchronize inode updates and label updates.

steved.