ceph: check PG_Private flag before accessing page->private
authorYan, Zheng <zheng.z.yan@intel.com>
Mon, 28 May 2012 06:44:30 +0000 (14:44 +0800)
committerAlex Elder <elder@inktank.com>
Wed, 20 Jun 2012 12:43:48 +0000 (07:43 -0500)
commit61600ef8483924039dcdec8b4717ca32bd3353c6
tree3bb61de61e148b7adcae79b978c8b644a2582691
parentf40759e7041498577235192727322186b43aa216
ceph: check PG_Private flag before accessing page->private

I got lots of NULL pointer dereference Oops when compiling kernel on ceph.
The bug is because the kernel page migration routine replaces some pages
in the page cache with new pages, these new pages' private can be non-zero.

Signed-off-by: Zheng Yan <zheng.z.yan@intel.com>
Signed-off-by: Sage Weil <sage@inktank.com>
(cherry picked from commit 28c0254ede13ab575d2df5c6585ed3d4817c3e6b)
fs/ceph/addr.c