[PATCH] autofs3: Make sure all dentries refs are released before calling kill_anon_super()

Make sure all dentries refs are released before calling kill_anon_super()
so that the assumption that generic_shutdown_super() can completely destroy
the dentry tree for there will be no external references holds true.

What was being done in the put_super() superblock op, is now done in the
kill_sb() filesystem op instead, prior to calling kill_anon_super().

The call to shrink_dcache_sb() is removed as it is redundant since
shrink_dcache_for_umount() will now be called after the cleanup routine.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Ian Kent <raven@themaw.net>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

fs/autofs/autofs_i.h

@@ -149,6 +149,7 @@ extern const struct file_operations autofs_root_operations;
 /* Initializing function */
 
 int autofs_fill_super(struct super_block *, void *, int);
+void autofs_kill_sb(struct super_block *sb);
 
 /* Queue management functions */
 

fs/autofs/dirhash.c

@@ -246,5 +246,4 @@ void autofs_hash_nuke(struct autofs_sb_info *sbi)
 			kfree(ent);
 		}
 	}
-	shrink_dcache_sb(sbi->sb);
 }

fs/autofs/init.c

@@ -24,7 +24,7 @@ static struct file_system_type autofs_fs_type = {
 	.owner		= THIS_MODULE,
 	.name		= "autofs",
 	.get_sb		= autofs_get_sb,
-	.kill_sb	= kill_anon_super,
+	.kill_sb	= autofs_kill_sb,
 };
 
 static int __init init_autofs_fs(void)

fs/autofs/inode.c

@@ -20,7 +20,7 @@
 #include "autofs_i.h"
 #include <linux/module.h>
 
-static void autofs_put_super(struct super_block *sb)
+void autofs_kill_sb(struct super_block *sb)
 {
 	struct autofs_sb_info *sbi = autofs_sbi(sb);
 	unsigned int n;
@@ -37,13 +37,13 @@ static void autofs_put_super(struct super_block *sb)
 	kfree(sb->s_fs_info);
 
 	DPRINTK(("autofs: shutting down\n"));
+	kill_anon_super(sb);
 }
 
 static void autofs_read_inode(struct inode *inode);
 
 static struct super_operations autofs_sops = {
 	.read_inode	= autofs_read_inode,
-	.put_super	= autofs_put_super,
 	.statfs		= simple_statfs,
 };