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, 14 insertions, 13 deletions

diff --git a/kernel/audit_tree.c b/kernel/audit_tree.c
index f4fcf58f20f..b898814fe4a 100644
--- a/kernel/audit_tree.c
+++ b/kernel/audit_tree.c
@@ -549,7 +549,7 @@ void audit_trim_trees(void)
 		if (err)
 			goto skip_it;
 
-		root_mnt = collect_mounts(nd.mnt, nd.dentry);
+		root_mnt = collect_mounts(nd.path.mnt, nd.path.dentry);
 		path_release(&nd);
 		if (!root_mnt)
 			goto skip_it;
@@ -583,17 +583,17 @@ skip_it:
 static int is_under(struct vfsmount *mnt, struct dentry *dentry,
 		    struct nameidata *nd)
 {
-	if (mnt != nd->mnt) {
+	if (mnt != nd->path.mnt) {
 		for (;;) {
 			if (mnt->mnt_parent == mnt)
 				return 0;
-			if (mnt->mnt_parent == nd->mnt)
+			if (mnt->mnt_parent == nd->path.mnt)
 					break;
 			mnt = mnt->mnt_parent;
 		}
 		dentry = mnt->mnt_mountpoint;
 	}
-	return is_subdir(dentry, nd->dentry);
+	return is_subdir(dentry, nd->path.dentry);
 }
 
 int audit_make_tree(struct audit_krule *rule, char *pathname, u32 op)
@@ -641,7 +641,7 @@ int audit_add_tree_rule(struct audit_krule *rule)
 	err = path_lookup(tree->pathname, 0, &nd);
 	if (err)
 		goto Err;
-	mnt = collect_mounts(nd.mnt, nd.dentry);
+	mnt = collect_mounts(nd.path.mnt, nd.path.dentry);
 	path_release(&nd);
 	if (!mnt) {
 		err = -ENOMEM;
@@ -701,7 +701,7 @@ int audit_tag_tree(char *old, char *new)
 	err = path_lookup(new, 0, &nd);
 	if (err)
 		return err;
-	tagged = collect_mounts(nd.mnt, nd.dentry);
+	tagged = collect_mounts(nd.path.mnt, nd.path.dentry);
 	path_release(&nd);
 	if (!tagged)
 		return -ENOMEM;
@@ -711,8 +711,8 @@ int audit_tag_tree(char *old, char *new)
 		drop_collected_mounts(tagged);
 		return err;
 	}
-	mnt = mntget(nd.mnt);
-	dentry = dget(nd.dentry);
+	mnt = mntget(nd.path.mnt);
+	dentry = dget(nd.path.dentry);
 	path_release(&nd);
 
 	if (dentry == tagged->mnt_root && dentry == mnt->mnt_root)
diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
index 6f19fd477aa..a36e66797c3 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -169,8 +169,8 @@ static struct audit_parent *audit_init_parent(struct nameidata *ndp)
 	inotify_init_watch(&parent->wdata);
 	/* grab a ref so inotify watch hangs around until we take audit_filter_mutex */
 	get_inotify_watch(&parent->wdata);
-	wd = inotify_add_watch(audit_ih, &parent->wdata, ndp->dentry->d_inode,
-			       AUDIT_IN_WATCH);
+	wd = inotify_add_watch(audit_ih, &parent->wdata,
+			       ndp->path.dentry->d_inode, AUDIT_IN_WATCH);
 	if (wd < 0) {
 		audit_free_parent(&parent->wdata);
 		return ERR_PTR(wd);
@@ -1214,8 +1214,8 @@ static int audit_add_watch(struct audit_krule *krule, struct nameidata *ndp,
 
 	/* update watch filter fields */
 	if (ndw) {
-		watch->dev = ndw->dentry->d_inode->i_sb->s_dev;
-		watch->ino = ndw->dentry->d_inode->i_ino;
+		watch->dev = ndw->path.dentry->d_inode->i_sb->s_dev;
+		watch->ino = ndw->path.dentry->d_inode->i_ino;
 	}
 
 	/* The audit_filter_mutex must not be held during inotify calls because
@@ -1225,7 +1225,8 @@ static int audit_add_watch(struct audit_krule *krule, struct nameidata *ndp,
 	 */
 	mutex_unlock(&audit_filter_mutex);
 
-	if (inotify_find_watch(audit_ih, ndp->dentry->d_inode, &i_watch) < 0) {
+	if (inotify_find_watch(audit_ih, ndp->path.dentry->d_inode,
+			       &i_watch) < 0) {
 		parent = audit_init_parent(ndp);
 		if (IS_ERR(parent)) {
 			/* caller expects mutex locked */