fat: Fix ATTR_RO for directory

FAT has the ATTR_RO (read-only) attribute. But on Windows, the ATTR_RO
of the directory will be just ignored actually, and is used by only
applications as flag. E.g. it's setted for the customized folder by
Explorer.

http://msdn2.microsoft.com/en-us/library/aa969337.aspx

This adds "rodir" option. If user specified it, ATTR_RO is used as
read-only flag even if it's the directory. Otherwise, inode->i_mode
is not used to hold ATTR_RO (i.e. fat_mode_can_save_ro() returns 0).

Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 8 insertions, 0 deletions

diff --git a/Documentation/filesystems/vfat.txt b/Documentation/filesystems/vfat.txt
index dc9dc73d7d38..3a5ddc96901a 100644
--- a/Documentation/filesystems/vfat.txt
+++ b/Documentation/filesystems/vfat.txt
@@ -124,6 +124,14 @@ sys_immutable -- If set, ATTR_SYS attribute on FAT is handled as
 flush         -- If set, the filesystem will try to flush to disk more
                  early than normal. Not set by default.
 
+rodir         -- FAT has the ATTR_RO (read-only) attribute. But on Windows,
+                 the ATTR_RO of the directory will be just ignored actually,
+                 and is used by only applications as flag. E.g. it's setted
+                 for the customized folder.
+
+                 If you want to use ATTR_RO as read-only flag even for
+                 the directory, set this option.
+
 <bool>: 0,1,yes,no,true,false
 
 TODO