[PATCH] namei fixes (4/19)

path.mnt in open_namei() set to mirror nd->mnt.

nd->mnt is set in 3 places in that function - path_lookup() in the beginning,
__follow_down() loop after do_last: and __do_follow_link() call after
do_link:.

We set path.mnt to nd->mnt after path_lookup() and __do_follow_link().  In
__follow_down() loop we use &path.mnt instead of &nd->mnt and set nd->mnt to
path.mnt immediately after that loop.

Obviously equivalent transformation.
Signed-off-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

fs/namei.c

@@ -1442,6 +1442,7 @@ int open_namei(const char * pathname, int flag, int mode, struct nameidata *nd)
 	nd->flags &= ~LOOKUP_PARENT;
 	down(&dir->d_inode->i_sem);
 	path.dentry = __lookup_hash(&nd->last, nd->dentry, nd);
+	path.mnt = nd->mnt;
 
 do_last:
 	error = PTR_ERR(path.dentry);
@@ -1479,7 +1480,8 @@ int open_namei(const char * pathname, int flag, int mode, struct nameidata *nd)
 		error = -ELOOP;
 		if (flag & O_NOFOLLOW)
 			goto exit_dput;
-		while (__follow_down(&nd->mnt,&path.dentry) && d_mountpoint(path.dentry));
+		while (__follow_down(&path.mnt,&path.dentry) && d_mountpoint(path.dentry));
+		nd->mnt = path.mnt;
 	}
 	error = -ENOENT;
 	if (!path.dentry->d_inode)
@@ -1524,6 +1526,7 @@ int open_namei(const char * pathname, int flag, int mode, struct nameidata *nd)
 		goto exit_dput;
 	error = __do_follow_link(path.dentry, nd);
 	dput(path.dentry);
+	path.mnt = nd->mnt;
 	if (error)
 		return error;
 	nd->flags &= ~LOOKUP_PARENT;