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 be4ce1c3a3d8..3b6d83dc98a7 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 027e1095256e..7ce07862c2fb 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;