From: Chuck Lever Subject: Re: [PATCH 2/2] Enable v4 mounts when either "nfsvers=4" or "vers=4" option are set (vers-02) Date: Tue, 25 Aug 2009 15:32:36 -0400 Message-ID: <7AB7BC01-F9E5-4611-BB4B-2B6E27069631@oracle.com> References: <4A9424DB.2040303@RedHat.com> <4A942593.8030101@RedHat.com> <4A943914.9020104@RedHat.com> Mime-Version: 1.0 (Apple Message framework v936) Content-Type: text/plain; charset="us-ascii"; Format="flowed"; DelSp="yes" Cc: Linux NFS Mailing list , Linux NFSv4 mailing list To: Steve Dickson Return-path: In-Reply-To: <4A943914.9020104@RedHat.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: nfsv4-bounces@linux-nfs.org Errors-To: nfsv4-bounces@linux-nfs.org List-ID: On Aug 25, 2009, at 3:18 PM, Steve Dickson wrote: > On 08/25/2009 02:59 PM, Chuck Lever wrote: >> On Aug 25, 2009, at 1:55 PM, Steve Dickson wrote: >>> commit 1471d23d692efc7388794a8a3c3b9e548d1c5be8 >>> Author: Steve Dickson >>> Date: Tue Aug 25 12:15:18 2009 -0400 >>> >>> Make sure umount use correct fs type. >>> >>> umounts use the fs type in /etc/mtab to determine >>> which file system is being unmounted. The mtab >>> entry is create during the mount. To ensure the >>> correct entry is create when the fs type changes >>> due to the mount options, the address of the fs_type >>> variable has to be passed so it can be updated. >> >> In general, my policy is to record the user requested mount options >> in >> /etc/mtab, and let umount.nfs handle renegotiating as needed. For >> version/transport this means that the server's configuration can >> change >> between the mount and the umount, and the umount will still work. >> >> Perhaps this is not a consideration for NFSv4, but leaving the mount >> options as specified by the user would save the need to update the fs >> type, and would be a consistent policy for v2, v3, and v4. I think >> it >> would be cleaner to teach umount.nfs to do the right thing with "-t >> nfs >> -o v4" rather than rewriting the options in /etc/mtab. > Since nfs4 is truly a separate/different file system from nfs in the > kernel, I think we should continue making that distinction in system > files like mtab and /proc/mounts.... We are teaching mount.nfs not to care about nfs/nfs4 (at least externally). Why should umount.nfs? > Also note there is no '-o ' flag to umount so 'umount -t nfs -o v4' is > not valid... but 'umount -t nfs' is and works on both nfs4 and nfs > file systems. Sorry I wasn't clear. I meant that umount.nfs should be able to read a line in /etc/mtab that has "nfs" and "v4" and do the right thing... then you wouldn't have to change the fs_type in /etc/mtab at all. -- Chuck Lever chuck[dot]lever[at]oracle[dot]com