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>

1 files changed, 16 insertions, 15 deletions

diff --git a/fs/open.c b/fs/open.c
index 43fcd603196..279aacf2560 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -127,7 +127,7 @@ asmlinkage long sys_statfs(const char __user * path, struct statfs __user * buf)
 	error = user_path_walk(path, &nd);
 	if (!error) {
 		struct statfs tmp;
-		error = vfs_statfs_native(nd.dentry, &tmp);
+		error = vfs_statfs_native(nd.path.dentry, &tmp);
 		if (!error && copy_to_user(buf, &tmp, sizeof(tmp)))
 			error = -EFAULT;
 		path_release(&nd);
@@ -146,7 +146,7 @@ asmlinkage long sys_statfs64(const char __user *path, size_t sz, struct statfs64
 	error = user_path_walk(path, &nd);
 	if (!error) {
 		struct statfs64 tmp;
-		error = vfs_statfs64(nd.dentry, &tmp);
+		error = vfs_statfs64(nd.path.dentry, &tmp);
 		if (!error && copy_to_user(buf, &tmp, sizeof(tmp)))
 			error = -EFAULT;
 		path_release(&nd);
@@ -233,7 +233,7 @@ static long do_sys_truncate(const char __user * path, loff_t length)
 	error = user_path_walk(path, &nd);
 	if (error)
 		goto out;
-	inode = nd.dentry->d_inode;
+	inode = nd.path.dentry->d_inode;
 
 	/* For directories it's -EISDIR, for other non-regulars - -EINVAL */
 	error = -EISDIR;
@@ -271,7 +271,7 @@ static long do_sys_truncate(const char __user * path, loff_t length)
 	error = locks_verify_truncate(inode, NULL, length);
 	if (!error) {
 		DQUOT_INIT(inode);
-		error = do_truncate(nd.dentry, length, 0, NULL);
+		error = do_truncate(nd.path.dentry, length, 0, NULL);
 	}
 
 put_write_and_out:
@@ -455,10 +455,10 @@ asmlinkage long sys_faccessat(int dfd, const char __user *filename, int mode)
 	res = vfs_permission(&nd, mode);
 	/* SuS v2 requires we report a read only fs too */
 	if(res || !(mode & S_IWOTH) ||
-	   special_file(nd.dentry->d_inode->i_mode))
+	   special_file(nd.path.dentry->d_inode->i_mode))
 		goto out_path_release;
 
-	if(IS_RDONLY(nd.dentry->d_inode))
+	if(IS_RDONLY(nd.path.dentry->d_inode))
 		res = -EROFS;
 
 out_path_release:
@@ -490,7 +490,7 @@ asmlinkage long sys_chdir(const char __user * filename)
 	if (error)
 		goto dput_and_out;
 
-	set_fs_pwd(current->fs, nd.mnt, nd.dentry);
+	set_fs_pwd(current->fs, nd.path.mnt, nd.path.dentry);
 
 dput_and_out:
 	path_release(&nd);
@@ -545,7 +545,7 @@ asmlinkage long sys_chroot(const char __user * filename)
 	if (!capable(CAP_SYS_CHROOT))
 		goto dput_and_out;
 
-	set_fs_root(current->fs, nd.mnt, nd.dentry);
+	set_fs_root(current->fs, nd.path.mnt, nd.path.dentry);
 	set_fs_altroot();
 	error = 0;
 dput_and_out:
@@ -602,7 +602,7 @@ asmlinkage long sys_fchmodat(int dfd, const char __user *filename,
 	error = __user_walk_fd(dfd, filename, LOOKUP_FOLLOW, &nd);
 	if (error)
 		goto out;
-	inode = nd.dentry->d_inode;
+	inode = nd.path.dentry->d_inode;
 
 	error = -EROFS;
 	if (IS_RDONLY(inode))
@@ -617,7 +617,7 @@ asmlinkage long sys_fchmodat(int dfd, const char __user *filename,
 		mode = inode->i_mode;
 	newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO);
 	newattrs.ia_valid = ATTR_MODE | ATTR_CTIME;
-	error = notify_change(nd.dentry, &newattrs);
+	error = notify_change(nd.path.dentry, &newattrs);
 	mutex_unlock(&inode->i_mutex);
 
 dput_and_out:
@@ -675,7 +675,7 @@ asmlinkage long sys_chown(const char __user * filename, uid_t user, gid_t group)
 	error = user_path_walk(filename, &nd);
 	if (error)
 		goto out;
-	error = chown_common(nd.dentry, user, group);
+	error = chown_common(nd.path.dentry, user, group);
 	path_release(&nd);
 out:
 	return error;
@@ -695,7 +695,7 @@ asmlinkage long sys_fchownat(int dfd, const char __user *filename, uid_t user,
 	error = __user_walk_fd(dfd, filename, follow, &nd);
 	if (error)
 		goto out;
-	error = chown_common(nd.dentry, user, group);
+	error = chown_common(nd.path.dentry, user, group);
 	path_release(&nd);
 out:
 	return error;
@@ -709,7 +709,7 @@ asmlinkage long sys_lchown(const char __user * filename, uid_t user, gid_t group
 	error = user_path_walk_link(filename, &nd);
 	if (error)
 		goto out;
-	error = chown_common(nd.dentry, user, group);
+	error = chown_common(nd.path.dentry, user, group);
 	path_release(&nd);
 out:
 	return error;
@@ -863,7 +863,7 @@ struct file *lookup_instantiate_filp(struct nameidata *nd, struct dentry *dentry
 		goto out;
 	if (IS_ERR(dentry))
 		goto out_err;
-	nd->intent.open.file = __dentry_open(dget(dentry), mntget(nd->mnt),
+	nd->intent.open.file = __dentry_open(dget(dentry), mntget(nd->path.mnt),
 					     nd->intent.open.flags - 1,
 					     nd->intent.open.file,
 					     open);
@@ -891,7 +891,8 @@ struct file *nameidata_to_filp(struct nameidata *nd, int flags)
 	filp = nd->intent.open.file;
 	/* Has the filesystem initialised the file for us? */
 	if (filp->f_path.dentry == NULL)
-		filp = __dentry_open(nd->dentry, nd->mnt, flags, filp, NULL);
+		filp = __dentry_open(nd->path.dentry, nd->path.mnt, flags, filp,
+				     NULL);
 	else
 		path_release(nd);
 	return filp;