Embed a struct path into struct nameidata instead of nd->{dentry,mnt}

This is the central patch of a cleanup series. In most cases there is no good
reason why someone would want to use a dentry for itself. This series reflects
that fact and embeds a struct path into nameidata.

Together with the other patches of this series
- it enforced the correct order of getting/releasing the reference count on
  <dentry,vfsmount> pairs
- it prepares the VFS for stacking support since it is essential to have a
  struct path in every place where the stack can be traversed
- it reduces the overall code size:

without patch series:
   text    data     bss     dec     hex filename
5321639  858418  715768 6895825  6938d1 vmlinux

with patch series:
   text    data     bss     dec     hex filename
5320026  858418  715768 6894212  693284 vmlinux

This patch:

Switch from nd->{dentry,mnt} to nd->path.{dentry,mnt} everywhere.

[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: fix cifs]
[akpm@linux-foundation.org: fix smack]
Signed-off-by: Jan Blunck <jblunck@suse.de>
Signed-off-by: Andreas Gruenbacher <agruen@suse.de>
Acked-by: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 13 insertions, 12 deletions

diff --git a/net/sunrpc/rpc_pipe.c b/net/sunrpc/rpc_pipe.c
index 0e3ead7e11b9..6bc3babf6175 100644
--- a/net/sunrpc/rpc_pipe.c
+++ b/net/sunrpc/rpc_pipe.c
@@ -668,7 +668,8 @@ rpc_lookup_negative(char *path, struct nameidata *nd)
 
 	if ((error = rpc_lookup_parent(path, nd)) != 0)
 		return ERR_PTR(error);
-	dentry = rpc_lookup_create(nd->dentry, nd->last.name, nd->last.len, 1);
+	dentry = rpc_lookup_create(nd->path.dentry, nd->last.name, nd->last.len,
+				   1);
 	if (IS_ERR(dentry))
 		rpc_release_path(nd);
 	return dentry;
@@ -695,7 +696,7 @@ rpc_mkdir(char *path, struct rpc_clnt *rpc_client)
 	dentry = rpc_lookup_negative(path, &nd);
 	if (IS_ERR(dentry))
 		return dentry;
-	dir = nd.dentry->d_inode;
+	dir = nd.path.dentry->d_inode;
 	if ((error = __rpc_mkdir(dir, dentry)) != 0)
 		goto err_dput;
 	RPC_I(dentry->d_inode)->private = rpc_client;
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index eea75888805e..7c3323e8827b 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -718,14 +718,14 @@ static struct sock *unix_find_other(struct net *net,
 			goto put_fail;
 
 		err = -ECONNREFUSED;
-		if (!S_ISSOCK(nd.dentry->d_inode->i_mode))
+		if (!S_ISSOCK(nd.path.dentry->d_inode->i_mode))
 			goto put_fail;
-		u=unix_find_socket_byinode(net, nd.dentry->d_inode);
+		u = unix_find_socket_byinode(net, nd.path.dentry->d_inode);
 		if (!u)
 			goto put_fail;
 
 		if (u->sk_type == type)
-			touch_atime(nd.mnt, nd.dentry);
+			touch_atime(nd.path.mnt, nd.path.dentry);
 
 		path_release(&nd);
 
@@ -819,12 +819,12 @@ static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
 		 */
 		mode = S_IFSOCK |
 		       (SOCK_INODE(sock)->i_mode & ~current->fs->umask);
-		err = vfs_mknod(nd.dentry->d_inode, dentry, mode, 0);
+		err = vfs_mknod(nd.path.dentry->d_inode, dentry, mode, 0);
 		if (err)
 			goto out_mknod_dput;
-		mutex_unlock(&nd.dentry->d_inode->i_mutex);
-		dput(nd.dentry);
-		nd.dentry = dentry;
+		mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
+		dput(nd.path.dentry);
+		nd.path.dentry = dentry;
 
 		addr->hash = UNIX_HASH_SIZE;
 	}
@@ -842,8 +842,8 @@ static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
 		list = &unix_socket_table[addr->hash];
 	} else {
 		list = &unix_socket_table[dentry->d_inode->i_ino & (UNIX_HASH_SIZE-1)];
-		u->dentry = nd.dentry;
-		u->mnt    = nd.mnt;
+		u->dentry = nd.path.dentry;
+		u->mnt    = nd.path.mnt;
 	}
 
 	err = 0;
@@ -861,7 +861,7 @@ out:
 out_mknod_dput:
 	dput(dentry);
 out_mknod_unlock:
-	mutex_unlock(&nd.dentry->d_inode->i_mutex);
+	mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
 	path_release(&nd);
 out_mknod_parent:
 	if (err==-EEXIST)