From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: linux-nfs-owner@vger.kernel.org Received: from mx1.redhat.com ([209.132.183.28]:2375 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751652Ab3ITPJH (ORCPT ); Fri, 20 Sep 2013 11:09:07 -0400 Subject: [RFC][PATCH 0/3] FS-Cache: NFS(/CIFS/Ceph/9P): Fix start-caching whilst writing race To: Trond.Myklebust@netapp.com, steved@redhat.com From: David Howells Cc: linux-cifs@vger.kernel.org, linux-nfs@vger.kernel.org, linux-kernel@vger.kernel.org, linux-cachefs@redhat.com, linux-fsdevel@vger.kernel.org, ceph-devel@vger.kernel.org Date: Fri, 20 Sep 2013 16:09:03 +0100 Message-ID: <20130920150902.16220.32737.stgit@warthog.procyon.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Sender: linux-nfs-owner@vger.kernel.org List-ID: Following this mail is a series of patches to fix an issue with NFS whereby caching can be enabled on a file that is open for writing by subsequently opening it for reading. This can be made to crash by opening it for writing again if you're quick enough. The patches mailed here may not apply directly. They are based on top of three fix patches as can be seen in the GIT branch here: http://git.kernel.org/cgit/linux/kernel/git/dhowells/linux-fs.git/log/?h=fscache The gist of the patchset is that the cookie should be acquired at inode creation only and subsequently enabled and disabled as appropriate (which dispenses with the backing objects when they're not needed). The extra synchronisation that NFS does can then be dispensed with as it is thenceforth managed by FS-Cache. This likely will need applying to CIFS, Ceph and 9P also once this is okayed for NFS. AFS is probably safe. David --- David Howells (3): FS-Cache: Add use/unuse/wake cookie wrappers FS-Cache: Provide the ability to enable/disable cookies NFS: Use i_writecount to control whether to get an fscache cookie in nfs_open() Documentation/filesystems/caching/netfs-api.txt | 73 +++++++-- fs/9p/cache.c | 6 - fs/afs/cell.c | 2 fs/afs/inode.c | 2 fs/afs/vlocation.c | 3 fs/afs/volume.c | 2 fs/cachefiles/interface.c | 2 fs/ceph/cache.c | 4 fs/cifs/fscache.c | 8 - fs/fscache/cookie.c | 193 +++++++++++++++++------ fs/fscache/fsdef.c | 1 fs/fscache/netfs.c | 1 fs/fscache/object.c | 7 + fs/fscache/page.c | 59 +++++-- fs/nfs/dir.c | 2 fs/nfs/fscache.c | 196 +++++++---------------- fs/nfs/fscache.h | 18 +- fs/nfs/inode.c | 6 - fs/nfs/nfs4file.c | 2 include/linux/fs.h | 5 + include/linux/fscache-cache.h | 50 ++---- include/linux/fscache.h | 113 ++++++++++++- include/linux/nfs_fs.h | 8 + 23 files changed, 462 insertions(+), 301 deletions(-)