tree 666c8eaad844df0447870f1e6fada4f0fb8007cd
parent 6b0cd00bc396daf5c2dcf17a8d82055335341f46
author Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> 1283908772 +0900
committer Andi Kleen <ak@linux.intel.com> 1286523164 +0200

hugetlb: fix metadata corruption in hugetlb_fault()

Since the PageHWPoison() check is for avoiding hwpoisoned page remained
in pagecache mapping to the process, it should be done in "found in pagecache"
branch, not in the common path.
Otherwise, metadata corruption occurs if memory failure happens between
alloc_huge_page() and lock_page() because page fault fails with metadata
changes remained (such as refcount, mapcount, etc.)

This patch moves the check to "found in pagecache" branch and fix the problem.

ChangeLog since v2:
- remove retry check in "new allocation" path.
- make description more detailed
- change patch name from "HWPOISON, hugetlb: move PG_HWPoison bit check"

Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Wu Fengguang <fengguang.wu@intel.com>
Reviewed-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>