Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753893AbXKCLNT (ORCPT ); Sat, 3 Nov 2007 07:13:19 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751858AbXKCLNE (ORCPT ); Sat, 3 Nov 2007 07:13:04 -0400 Received: from mx1.redhat.com ([66.187.233.31]:43439 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751763AbXKCLNB (ORCPT ); Sat, 3 Nov 2007 07:13:01 -0400 Message-ID: <472C56E5.1040901@RedHat.com> Date: Sat, 03 Nov 2007 07:09:25 -0400 From: Steve Dickson User-Agent: Thunderbird 2.0.0.5 (X11/20070727) MIME-Version: 1.0 To: Alexander Viro , Christoph Hellwig CC: linux-fsdevel@vger.kernel.org, linux-kernel Subject: [PATCH] NFS: Stop sillyname renames and unmounts from racing Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3997 Lines: 123 The following patch stops NFS sillyname renames and umounts from racing. I have a test script does the following: 1) start nfs server 2) mount loopback 3) open file in background 4) remove file 5) stop nfs server 6) kill -9 process which has file open 7) restart nfs server 8) umount looback mount. After umount I got the "VFS: Busy inodes after unmount" message because the processing of the rename has not finished. Below is a patch that the uses the new silly_count mechanism to synchronize sillyname processing and umounts. The patch introduces a nfs_put_super() routine that waits until the nfsi->silly_count count is zero. A side-effect of finding and waiting for all the inode to find the sillyname processing, is I need to traverse the sb->s_inodes list in the supper block. To do that safely the inode_lock spin lock has to be held. So for modules to be able to "see" that lock I needed to EXPORT_SYMBOL_GPL() it. Any objections to exporting the inode_lock spin lock? If so, how should modules _safely_ access the s_inode list? steved. Author: Steve Dickson Date: Wed Oct 31 12:19:26 2007 -0400 Close a unlink/sillyname rename and umount race by added a nfs_put_super routine that will run through all the inode currently on the super block, waiting for those that are in the middle of a sillyname rename or removal. This patch stop the infamous "VFS: Busy inodes after unmount... " warning during umounts. Signed-off-by: Steve Dickson diff --git a/fs/inode.c b/fs/inode.c index ed35383..da9034a 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -81,6 +81,7 @@ static struct hlist_head *inode_hashtable __read_mostly; * the i_state of an inode while it is in use.. */ DEFINE_SPINLOCK(inode_lock); +EXPORT_SYMBOL_GPL(inode_lock); /* * iprune_mutex provides exclusion between the kswapd or try_to_free_pages diff --git a/fs/nfs/super.c b/fs/nfs/super.c index fa517ae..2ac3c34 100644 --- a/fs/nfs/super.c +++ b/fs/nfs/super.c @@ -48,6 +48,7 @@ #include #include #include +#include #include #include @@ -202,6 +203,7 @@ static int nfs_get_sb(struct file_system_type *, int, const char *, void *, stru static int nfs_xdev_get_sb(struct file_system_type *fs_type, int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt); static void nfs_kill_super(struct super_block *); +static void nfs_put_super(struct super_block *); static struct file_system_type nfs_fs_type = { .owner = THIS_MODULE, @@ -223,6 +225,7 @@ static const struct super_operations nfs_sops = { .alloc_inode = nfs_alloc_inode, .destroy_inode = nfs_destroy_inode, .write_inode = nfs_write_inode, + .put_super = nfs_put_super, .statfs = nfs_statfs, .clear_inode = nfs_clear_inode, .umount_begin = nfs_umount_begin, @@ -1767,6 +1770,30 @@ static void nfs4_kill_super(struct super_block *sb) nfs_free_server(server); } +void nfs_put_super(struct super_block *sb) +{ + struct inode *inode; + struct nfs_inode *nfsi; + /* + * Make sure there are no outstanding renames + */ +relock: + spin_lock(&inode_lock); + list_for_each_entry(inode, &sb->s_inodes, i_sb_list) { + nfsi = NFS_I(inode); + if (atomic_read(&nfsi->silly_count) > 0) { + /* Keep this inode around during the wait */ + atomic_inc(&inode->i_count); + spin_unlock(&inode_lock); + wait_event(nfsi->waitqueue, + atomic_read(&nfsi->silly_count) == 1); + iput(inode); + goto relock; + } + } + spin_unlock(&inode_lock); +} + /* * Clone an NFS4 server record on xdev traversal (FSID-change) */ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/