From: Steve Dickson <SteveD@redhat.com>
Date: Wed, 21 Nov 2007 11:42:19 -0500
Subject: [nfs] let rpciod finish sillyrename then umount
Message-id: 47445FEB.2050407@RedHat.com
O-Subject: [RHEL5.2/RHEL5.1-z] [5/5] NFS: silly rename races with umounts
Bugzilla: 253663

This patch stop the "Busy inode" warning by holding
off umount until the async rpciod daemon finishes
the silly rename processing.

commit 4fa2c6f5bfab435e41a3650e40b7e2aa2132106f
Author: Steve Dickson <steved@redhat.com>
Date:   Thu Nov 15 14:39:38 2007 -0500

    Initialize the active_wq queue and active count in the
    nfs_server structure for nfs4 mounts.

    Signed-off-by: Steve Dickson <steved@redhat.com>

commit 68ef300e375554f3dc9388ca529b7a39f15d36ef
Author: Steve Dickson <steved@redhat.com>
Date:   Wed Nov 7 14:54:59 2007 -0500

    Added an active/deactive mechanism to the nfs_server structure
    allowing async operations to hold off umount until the
    operations are done.

    Signed-off-by: Steve Dickson <steved@redhat.com>

diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index 1013b1a..8d5cdbd 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -761,6 +761,9 @@ static struct nfs_server *nfs_alloc_server(void)
 	INIT_LIST_HEAD(&server->client_link);
 	INIT_LIST_HEAD(&server->master_link);
 
+	init_waitqueue_head(&server->active_wq);
+	atomic_set(&server->active, 0);
+
 	server->io_stats = nfs_alloc_iostats();
 	if (!server->io_stats) {
 		kfree(server);
diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index 2fce9bd..10d477e 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -165,6 +165,8 @@ extern struct rpc_stat nfs_rpcstat;
 
 extern int __init register_nfs_fs(void);
 extern void __exit unregister_nfs_fs(void);
+extern void nfs_sb_active(struct nfs_server *server);
+extern void nfs_sb_deactive(struct nfs_server *server);
 
 /* namespace.c */
 extern char *nfs_path(const char *base,
diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index da1e9a0..753508d 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -64,6 +64,7 @@ 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,
@@ -85,6 +86,7 @@ static 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,
@@ -185,6 +187,28 @@ void __exit unregister_nfs_fs(void)
 	unregister_filesystem(&nfs_fs_type);
 }
 
+void nfs_sb_active(struct nfs_server *server)
+{
+	atomic_inc(&server->active);
+}
+
+void nfs_sb_deactive(struct nfs_server *server)
+{
+	if (atomic_dec_and_test(&server->active))
+		wake_up(&server->active_wq);
+}
+
+static void nfs_put_super(struct super_block *sb)
+{
+	struct nfs_server *server = NFS_SB(sb);
+	/*
+	 * Make sure there are no outstanding ops to this server.
+	 * If so, wait for them to finish before allowing the
+	 * unmount to continue.
+	 */
+	wait_event(server->active_wq, atomic_read(&server->active) == 0);
+}
+
 /*
  * Deliver file system statistics to userspace
  */
diff --git a/fs/nfs/unlink.c b/fs/nfs/unlink.c
index 8efd7a5..698402b 100644
--- a/fs/nfs/unlink.c
+++ b/fs/nfs/unlink.c
@@ -16,6 +16,8 @@
 
 
 
+#include "internal.h"
+
 struct nfs_unlinkdata {
 	struct hlist_node list;
 	struct nfs_removeargs args;
@@ -31,6 +33,7 @@ struct nfs_unlinkdata {
 static void
 nfs_free_unlinkdata(struct nfs_unlinkdata *data)
 {
+	nfs_sb_deactive(NFS_SERVER(data->dir));
 	iput(data->dir);
 	put_rpccred(data->cred);
 	kfree(data->args.name.name);
@@ -156,6 +159,7 @@ static int nfs_do_call_unlink(struct dentry *parent, struct inode *dir, struct n
 		nfs_dec_sillycount(dir);
 		return 0;
 	}
+	nfs_sb_active(NFS_SERVER(dir));
 	data->args.fh = NFS_FH(dir);
 	nfs_fattr_init(&data->res.dir_attr);
 
diff --git a/include/linux/nfs_fs_sb.h b/include/linux/nfs_fs_sb.h
index c44be53..aae61ca 100644
--- a/include/linux/nfs_fs_sb.h
+++ b/include/linux/nfs_fs_sb.h
@@ -3,8 +3,11 @@
 
 #include <linux/list.h>
 #include <linux/backing-dev.h>
+#include <linux/wait.h>
 #include <linux/fscache.h>
 
+#include <asm/atomic.h>
+
 struct nfs_iostats;
 
 /*
@@ -116,6 +119,9 @@ struct nfs_server {
 						   filesystem */
 #endif
 	void (*destroy)(struct nfs_server *);
+
+	atomic_t active; /* Keep trace of any activity to this server */
+	wait_queue_head_t active_wq;  /* Wait for any activity to stop  */
 };
 
 /* Server capabilities */