linux/fs/overlayfs
Miklos Szeredi 0956254a2d ovl: don't copy up opaqueness
When a copy up of a directory occurs which has the opaque xattr set, the
xattr remains in the upper directory. The immediate behavior with overlayfs
is that the upper directory is not treated as opaque, however after a
remount the opaque flag is used and upper directory is treated as opaque.
This causes files created in the lower layer to be hidden when using
multiple lower directories.

Fix by not copying up the opaque flag.

To reproduce:

 ----8<---------8<---------8<---------8<---------8<---------8<----
mkdir -p l/d/s u v w mnt
mount -t overlay overlay -olowerdir=l,upperdir=u,workdir=w mnt
rm -rf mnt/d/
mkdir -p mnt/d/n
umount mnt
mount -t overlay overlay -olowerdir=u:l,upperdir=v,workdir=w mnt
touch mnt/d/foo
umount mnt
mount -t overlay overlay -olowerdir=u:l,upperdir=v,workdir=w mnt
ls mnt/d
 ----8<---------8<---------8<---------8<---------8<---------8<----
 
output should be:  "foo  n"

Reported-by: Derek McGowan <dmcg@drizz.net>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=151291
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Cc: <stable@vger.kernel.org>
2016-08-08 15:08:49 +02:00
..
Kconfig ovl: rename filesystem type to "overlay" 2014-11-20 16:39:59 +01:00
Makefile ovl: rename filesystem type to "overlay" 2014-11-20 16:39:59 +01:00
copy_up.c ovl: don't copy up opaqueness 2016-08-08 15:08:49 +02:00
dir.c ovl: simplify empty checking 2016-07-29 12:05:25 +02:00
inode.c ovl: don't copy up opaqueness 2016-08-08 15:08:49 +02:00
overlayfs.h ovl: don't copy up opaqueness 2016-08-08 15:08:49 +02:00
readdir.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-05-27 17:14:05 -07:00
super.c qstr: constify instances in overlayfs 2016-07-29 12:05:24 +02:00