Description of problem: Currently, umount -l only works if there is no cached data waiting to be read/written to the mount point. This is a request to allow a way to forcefully unmount, not caring about data loss. For example, if the NFS server has gone away never to return, a hung NFS mount with data waiting should be allowed to be unmounted. Requesting that this be considered for RHEL Version-Release number of selected component (if applicable): util-linux-2.12a-16.EL4.6 How reproducible: Initiate a write to the mountpoint, then take the NFS server down. umount -l will report that the device is busy. Steps to Reproduce: 1. dd if=/dev/zero of=/mnt/point 2. take down NFS server 3. umount -l /mnt/point Actual results: umount: /mnt/point: device is busy Expected results: umount -l succeeds Additional info:
Created attachment 133014 [details] nfs-utils patch I've incorporated the changes to my patch against latest nfs-utils, which can be found at git://linux-nfs.org/nfs-utils
Created attachment 133149 [details] lazy umount fix1 Patch in comment #6 is for util-linux. My patch in comment #11 is for nfs-utils which is a complete patch that hasn't made it to the upstream + the changes required for this bug fix. Alternatively you can use the attached patch which is a fix for this bug on top of my patch for nfs-utils-1.0.9.
Created attachment 133403 [details] util-linux fix The bug needs fixing at two places in this case. 1. nfs-utils - if its is compiled with --enable-mount 2. util-linux - if nfs-utils is NOT compiled with --enable-mount --enable-mount configure option in nfs-utils generates mount.nfs binary which overrides all the NFS mount/umount operations which otherwise are performed by util-linux. Latest patches to nfs-utils in rawhide add this option, which has also been sent upstream. Fix 1 (for nfs-utils) is in comment #13. Attached patch, which is actually a port of patch in comment #6 to latest util-linux, is fix 2 (for util-linux).
fixed in util-linux-2.12a-16.EL4.21
This request was evaluated by Red Hat Product Management for inclusion in a Red Hat Enterprise Linux maintenance release. Product Management has requested further review of this request by Red Hat Engineering, for potential inclusion in a Red Hat Enterprise Linux Update release for currently deployed products. This request is not yet committed for inclusion in an Update release.
This fix is available in the latest RHEL-4.5 Beta. If the customer is in a position to test the beta, please ask for testing feedback. Thanks.
An advisory has been issued which should help the problem described in this bug report. This report is therefore being closed with a resolution of ERRATA. For more information on the solution and/or where to find the updated files, please follow the link below. You may reopen this bug report if the solution does not work for you. http://rhn.redhat.com/errata/RHSA-2007-0235.html