[libvirt] [PATCH 1/2] apparmor: allow qemu to read max_segments

[Christian Ehrhardt]

Since qemu 2.9 via 9103f1ce "file-posix: Consider max_segments for
BlockLimits.max_transfer" this is a new access that is denied by the
qemu profile.

It is non fatal, but prevents the fix mentioned to actually work.
It should be safe to allow reading from that path.

Since qemu opens a symlink path we need to translate that for apparmor from
"/sys/dev/block/*/queue/max_segments" to
"/sys/devices/**/block/*/queue/max_segments"

Signed-off-by: Christian Ehrhardt <christian.ehrhardt at canonical.com>
---
 examples/apparmor/libvirt-qemu | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/examples/apparmor/libvirt-qemu b/examples/apparmor/libvirt-qemu
index 97dd2d4..064501f 100644
--- a/examples/apparmor/libvirt-qemu
+++ b/examples/apparmor/libvirt-qemu
@@ -169,6 +169,9 @@
   # for rbd
   /etc/ceph/ceph.conf r,
 
+  # for file-posix getting limits since 9103f1ce
+  /sys/devices/**/block/*/queue/max_segments r,
+
   # for ppc device-tree access
   @{PROC}/device-tree/ r,
   @{PROC}/device-tree/** r,
-- 
2.7.4