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, 19 insertions, 16 deletions

diff --git a/fs/nfs/namespace.c b/fs/nfs/namespace.c
index be4ce1c..3b6d83dc 100644
--- a/fs/nfs/namespace.c
+++ b/fs/nfs/namespace.c
@@ -107,38 +107,40 @@ static void * nfs_follow_mountpoint(struct dentry *dentry, struct nameidata *nd)
 
 	BUG_ON(IS_ROOT(dentry));
 	dprintk("%s: enter\n", __FUNCTION__);
-	dput(nd->dentry);
-	nd->dentry = dget(dentry);
+	dput(nd->path.dentry);
+	nd->path.dentry = dget(dentry);
 
 	/* Look it up again */
-	parent = dget_parent(nd->dentry);
+	parent = dget_parent(nd->path.dentry);
 	err = server->nfs_client->rpc_ops->lookup(parent->d_inode,
-						  &nd->dentry->d_name,
+						  &nd->path.dentry->d_name,
 						  &fh, &fattr);
 	dput(parent);
 	if (err != 0)
 		goto out_err;
 
 	if (fattr.valid & NFS_ATTR_FATTR_V4_REFERRAL)
-		mnt = nfs_do_refmount(nd->mnt, nd->dentry);
+		mnt = nfs_do_refmount(nd->path.mnt, nd->path.dentry);
 	else
-		mnt = nfs_do_submount(nd->mnt, nd->dentry, &fh, &fattr);
+		mnt = nfs_do_submount(nd->path.mnt, nd->path.dentry, &fh,
+				      &fattr);
 	err = PTR_ERR(mnt);
 	if (IS_ERR(mnt))
 		goto out_err;
 
 	mntget(mnt);
-	err = do_add_mount(mnt, nd, nd->mnt->mnt_flags|MNT_SHRINKABLE, &nfs_automount_list);
+	err = do_add_mount(mnt, nd, nd->path.mnt->mnt_flags|MNT_SHRINKABLE,
+			   &nfs_automount_list);
 	if (err < 0) {
 		mntput(mnt);
 		if (err == -EBUSY)
 			goto out_follow;
 		goto out_err;
 	}
-	mntput(nd->mnt);
-	dput(nd->dentry);
-	nd->mnt = mnt;
-	nd->dentry = dget(mnt->mnt_root);
+	mntput(nd->path.mnt);
+	dput(nd->path.dentry);
+	nd->path.mnt = mnt;
+	nd->path.dentry = dget(mnt->mnt_root);
 	schedule_delayed_work(&nfs_automount_task, nfs_mountpoint_expiry_timeout);
 out:
 	dprintk("%s: done, returned %d\n", __FUNCTION__, err);
@@ -149,7 +151,8 @@ out_err:
 	path_release(nd);
 	goto out;
 out_follow:
-	while(d_mountpoint(nd->dentry) && follow_down(&nd->mnt, &nd->dentry))
+	while (d_mountpoint(nd->path.dentry) &&
+	       follow_down(&nd->path.mnt, &nd->path.dentry))
 		;
 	err = 0;
 	goto out;
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 027e109..7ce0786 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -1384,11 +1384,11 @@ out_close:
 struct dentry *
 nfs4_atomic_open(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
 {
-	struct dentry *parent;
 	struct path path = {
-		.mnt = nd->mnt,
+		.mnt = nd->path.mnt,
 		.dentry = dentry,
 	};
+	struct dentry *parent;
 	struct iattr attr;
 	struct rpc_cred *cred;
 	struct nfs4_state *state;
@@ -1433,7 +1433,7 @@ int
 nfs4_open_revalidate(struct inode *dir, struct dentry *dentry, int openflags, struct nameidata *nd)
 {
 	struct path path = {
-		.mnt = nd->mnt,
+		.mnt = nd->path.mnt,
 		.dentry = dentry,
 	};
 	struct rpc_cred *cred;
@@ -1885,7 +1885,7 @@ nfs4_proc_create(struct inode *dir, struct dentry *dentry, struct iattr *sattr,
                  int flags, struct nameidata *nd)
 {
 	struct path path = {
-		.mnt = nd->mnt,
+		.mnt = nd->path.mnt,
 		.dentry = dentry,
 	};
 	struct nfs4_state *state;