From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michael Walker Subject: NFS mounts being mounted read-only depending upon mount order??? Date: Fri, 17 Nov 2006 10:22:58 -0800 Message-ID: <455DFE02.7050801@Cassatt.COM> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Cc: michael.walker@cassatt.com Return-path: Received: from sc8-sf-mx1-b.sourceforge.net ([10.3.1.91] helo=mail.sourceforge.net) by sc8-sf-list2-new.sourceforge.net with esmtp (Exim 4.43) id 1Gl8Mk-0003Cw-F0 for nfs@lists.sourceforge.net; Fri, 17 Nov 2006 10:23:06 -0800 Received: from 63-192-139-32.cassatt.com ([63.192.139.32] helo=GREYHOUND.cassatt.com) by mail.sourceforge.net with esmtp (Exim 4.44) id 1Gl8Mj-0007G3-3E for nfs@lists.sourceforge.net; Fri, 17 Nov 2006 10:23:07 -0800 To: nfs@lists.sourceforge.net List-Id: "Discussion of NFS under Linux development, interoperability, and testing." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: nfs-bounces@lists.sourceforge.net Errors-To: nfs-bounces@lists.sourceforge.net All, I'm having problems with the latest version of FC5 which contains kernel 2.6.18 - the problem is that NFS mounts of read-write file-systems are being mounted read-only, sometimes. Whether a mount is mounted read-only or read-write seems to very depending upon what other directories were mounted from the same server and with what options. Take the following file-systems exported from my Linux Server server: root@polyslo:/proc/fs/nfs# cat /etc/exports /disk1/dir_ro *(ro,no_root_squash,sync,wdelay,no_subtree_check) /disk1/dir_rw *(rw,no_root_squash,sync,wdelay,no_subtree_check) root@polyslo:/proc/fs/nfs# showmount -e 10.20.20.48 Export list for 10.20.20.48: /disk1/dir_rw * /disk1/dir_ro * root@polyslo:/proc/fs/nfs# If I now do the following mounts (in this order): # Mount initial directory read-only - this is intentional mount -t nfs -o ro 10.20.20.48:/disk1/dir_ro /tmp/dir_ro # Attempt to mount second directory read-write mount -t nfs -o rw 10.20.20.48:/disk1/dir_rw /tmp/dir_rw # Now I attempt to touch a file in the rw directory: [root@vt-1 tmp]# touch /tmp/dir_rw/hello touch: cannot touch `/tmp/dir_rw/hello': Read-only file system # And if I take a look in the /proc/mounts directory - I see # that the directory was truly mounted read-only [root@vt-1 tmp]# grep 10.20.20.48 /proc/mounts 10.20.20.48:/disk1/dir_ro /tmp/dir_ro nfs ro,vers=3,rsize=32768,wsize=32768,hard,proto=tcp,timeo=600,retrans=2,sec=sys,addr=10.20.20.48 0 0 10.20.20.48:/disk1/dir_rw /tmp/dir_rw nfs ro,vers=3,rsize=32768,wsize=32768,hard,proto=tcp,timeo=600,retrans=2,sec=sys,addr=10.20.20.48 0 0 [root@vt-1 tmp]# The above seems wrong to me - can someone clarify what's going on. I know that this is new behavior that was not true in the past. My RHEL_4U4 server running 2.6.9 kernel does not have this problem. Notice that if I change the order of the mounts I get different behavior: # Initially mount the read-write directory: mount -t nfs -o rw 10.20.20.48:/disk1/dir_rw /tmp/dir_rw # Then mount the read-only directory: mount -t nfs -o ro 10.20.20.48:/disk1/dir_ro /tmp/dir_ro # Now the directories are mounted as I wish, I can write to the # read-write mount: [root@vt-1 tmp]# touch /tmp/dir_rw/hello [root@vt-1 tmp]# # And the read-only directory is read-only: [root@vt-1 tmp]# touch /tmp/dir_ro/hello touch: cannot touch `/tmp/dir_ro/hello': Read-only file system [root@vt-1 tmp]# # And the /proc/mounts file reflects the states I expect [root@vt-1 tmp]# grep 10.20.20.48 /proc/mounts 10.20.20.48:/disk1/dir_rw /tmp/dir_rw nfs rw,vers=3,rsize=32768,wsize=32768,hard,proto=tcp,timeo=600,retrans=2,sec=sys,addr=10.20.20.48 0 0 10.20.20.48:/disk1/dir_ro /tmp/dir_ro nfs rw,vers=3,rsize=32768,wsize=32768,hard,proto=tcp,timeo=600,retrans=2,sec=sys,addr=10.20.20.48 0 0 [root@vt-1 tmp]# Note that previously the order did not matter and the permissions always reflected the permissions of the individual mount requests. If someone could provide insights on what's going on above that would be great. This is a artificial test case - but it's actually hitting code we have in production and will be a significant issue for us. Thanx much! _Mike_ ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ NFS maillist - NFS@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/nfs