commit 1dcddd4abd2c6df7f28928ad5cafa4a1cd20030b
author Al Viro <viro@zeniv.linux.org.uk> Thu Oct 03 13:22:44 2013 -0400
committer Al Viro <viro@zeniv.linux.org.uk> Thu Oct 24 23:43:28 2013 -0400
tree 5aad2d4a6ec078b16750b77217e10a8a3172d38a
parent cac45b062c67f86dc1d91d675128838773523243

ncpfs: rcu-delay unload_nls() and freeing ncp_server

makes ->d_hash() and ->d_compare() safety in RCU mode independent
from vfsmount_lock.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/ncpfs/inode.c

diff --git a/fs/ncpfs/inode.c b/fs/ncpfs/inode.c
index 4659da6..2cf2ebe 100644
--- a/fs/ncpfs/inode.c
+++ b/fs/ncpfs/inode.c
@@ -782,6 +782,17 @@
 	return error;
 }
 
+static void delayed_free(struct rcu_head *p)
+{
+	struct ncp_server *server = container_of(p, struct ncp_server, rcu);
+#ifdef CONFIG_NCPFS_NLS
+	/* unload the NLS charsets */
+	unload_nls(server->nls_vol);
+	unload_nls(server->nls_io);
+#endif /* CONFIG_NCPFS_NLS */
+	kfree(server);
+}
+
 static void ncp_put_super(struct super_block *sb)
 {
 	struct ncp_server *server = NCP_SBP(sb);
@@ -792,11 +803,6 @@
 
 	ncp_stop_tasks(server);
 
-#ifdef CONFIG_NCPFS_NLS
-	/* unload the NLS charsets */
-	unload_nls(server->nls_vol);
-	unload_nls(server->nls_io);
-#endif /* CONFIG_NCPFS_NLS */
 	mutex_destroy(&server->rcv.creq_mutex);
 	mutex_destroy(&server->root_setup_lock);
 	mutex_destroy(&server->mutex);
@@ -813,8 +819,7 @@
 	vfree(server->rxbuf);
 	vfree(server->txbuf);
 	vfree(server->packet);
-	sb->s_fs_info = NULL;
-	kfree(server);
+	call_rcu(&server->rcu, delayed_free);
 }
 
 static int ncp_statfs(struct dentry *dentry, struct kstatfs *buf)