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[oleg <overlayfs@xxxxxxxxx>]

Public bug reported:

rm -r * fails to delete directories when using overlayfs in a user-
namespace.

If overlayfs is mounted as follows,

   mount -n -t overlay overlay -o
lowerdir=lowerdir,upperdir=upperdir,workdir=workdir mntpt

and if lowerdir contains lowerdir/foo/bar.txt, then,

   rm -r mntpt/foo

fails with error message,

   "rm: cannot remove ‘mntpt/foo’: Operation not permitted"

strace shows,

    unlinkat(AT_FDCWD, "mntpt/foo", AT_REMOVEDIR) = -1 EPERM (Operation
not permitted)

OS details: 64-bit ubuntu 14.04.2 with the linux-generic-lts-vivid
kernel.

The bug does not occur with the default 3.13 kernel.  The bug occurs for any vanilla 3.18+ kernel to which the 1-line patch, "overlayfs: allow unprivileged mounts" is added.  (The patch is at, http://kernel.ubuntu.com/git/ubuntu/ubuntu-vivid.git/commit/?id=78ec45495b15d27d4cc6d05cc454e30ec5b587ea)
 
The bug occurs regardless of whether the underlying filesystem is tmpfs or ext4.

A script which reproduces the bug is attached and is also available at
http://paste.ubuntu.com/11974137/

Hardware: intel core2 duo processor in a macbook-4.1

** Affects: linux (Ubuntu)
     Importance: Undecided
         Status: New


** Tags: overlayfs

** Attachment added: "script to reproduce the bug"
   https://bugs.launchpad.net/bugs/1480411/+attachment/4437088/+files/overlayfs-bug.sh

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https://bugs.launchpad.net/bugs/1480411

Title:
  rm -r * fails to delete directories when using overlayfs in a user-
  namespace

Status in linux package in Ubuntu:
  New

Bug description:
  rm -r * fails to delete directories when using overlayfs in a user-
  namespace.

  If overlayfs is mounted as follows,

     mount -n -t overlay overlay -o
  lowerdir=lowerdir,upperdir=upperdir,workdir=workdir mntpt

  and if lowerdir contains lowerdir/foo/bar.txt, then,

     rm -r mntpt/foo

  fails with error message,

     "rm: cannot remove ‘mntpt/foo’: Operation not permitted"

  strace shows,

      unlinkat(AT_FDCWD, "mntpt/foo", AT_REMOVEDIR) = -1 EPERM
  (Operation not permitted)

  OS details: 64-bit ubuntu 14.04.2 with the linux-generic-lts-vivid
  kernel.

  The bug does not occur with the default 3.13 kernel.  The bug occurs for any vanilla 3.18+ kernel to which the 1-line patch, "overlayfs: allow unprivileged mounts" is added.  (The patch is at, http://kernel.ubuntu.com/git/ubuntu/ubuntu-vivid.git/commit/?id=78ec45495b15d27d4cc6d05cc454e30ec5b587ea)
   
  The bug occurs regardless of whether the underlying filesystem is tmpfs or ext4.

  A script which reproduces the bug is attached and is also available at
  http://paste.ubuntu.com/11974137/

  Hardware: intel core2 duo processor in a macbook-4.1

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