userns: Convert jffs2 to use kuid and kgid where appropriate

- General routine uid/gid conversion work
- When storing posix acls treat ACL_USER and ACL_GROUP separately
  so I can call from_kuid or from_kgid as appropriate.
- When reading posix acls treat ACL_USER and ACL_GROUP separately
  so I can call make_kuid or make_kgid as appropriate.

Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

fs/jffs2/file.c

@@ -175,8 +175,8 @@ static int jffs2_write_begin(struct file *filp, struct address_space *mapping,
 		ri.ino = cpu_to_je32(f->inocache->ino);
 		ri.version = cpu_to_je32(++f->highest_version);
 		ri.mode = cpu_to_jemode(inode->i_mode);
-		ri.uid = cpu_to_je16(inode->i_uid);
-		ri.gid = cpu_to_je16(inode->i_gid);
+		ri.uid = cpu_to_je16(i_uid_read(inode));
+		ri.gid = cpu_to_je16(i_gid_read(inode));
 		ri.isize = cpu_to_je32(max((uint32_t)inode->i_size, pageofs));
 		ri.atime = ri.ctime = ri.mtime = cpu_to_je32(get_seconds());
 		ri.offset = cpu_to_je32(inode->i_size);
@@ -283,8 +283,8 @@ static int jffs2_write_end(struct file *filp, struct address_space *mapping,
 	/* Set the fields that the generic jffs2_write_inode_range() code can't find */
 	ri->ino = cpu_to_je32(inode->i_ino);
 	ri->mode = cpu_to_jemode(inode->i_mode);
-	ri->uid = cpu_to_je16(inode->i_uid);
-	ri->gid = cpu_to_je16(inode->i_gid);
+	ri->uid = cpu_to_je16(i_uid_read(inode));
+	ri->gid = cpu_to_je16(i_gid_read(inode));
 	ri->isize = cpu_to_je32((uint32_t)inode->i_size);
 	ri->atime = ri->ctime = ri->mtime = cpu_to_je32(get_seconds());