From: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Date: Thu, 26 Jun 2014 00:42:35 +0000 (+1000)
Subject: mm-hugetlbfs-fix-rmapping-for-anonymous-hugepages-with-page_pgoff-v3
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=6bbeb810e2b5a84e5d2d67607434cac7b7345eb7;p=karo-tx-linux.git

mm-hugetlbfs-fix-rmapping-for-anonymous-hugepages-with-page_pgoff-v3

- add comment on page_size_order()
- use compound_order(compound_head(page)) instead of huge_page_size_order()
- use page_pgoff() in rmap_walk_file() too
- use page_size_order() in kill_proc()
- fix space indent

Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

diff --git a/include/linux/hugetlb_inline.h b/include/linux/hugetlb_inline.h
index e939975f0cba..4d60c82e9fda 100644
--- a/include/linux/hugetlb_inline.h
+++ b/include/linux/hugetlb_inline.h
@@ -11,7 +11,6 @@ static inline int is_vm_hugetlb_page(struct vm_area_struct *vma)
 }
 
 int PageHuge(struct page *page);
-unsigned int huge_page_size_order(struct page *page);
 
 #else
 
@@ -25,11 +24,6 @@ static inline int PageHuge(struct page *page)
 	return 0;
 }
 
-static inline unsigned int huge_page_size_order(struct page *page)
-{
-	return 0;
-}
-
 #endif
 
 #endif
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index c337d2af6199..54cb1eb98355 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -411,10 +411,22 @@ static inline loff_t page_file_offset(struct page *page)
 	return ((loff_t)page_file_index(page)) << PAGE_CACHE_SHIFT;
 }
 
+/*
+ * Getting page order of a given page in the context of the pagecache which
+ * each page belongs to.
+ *
+ * Pagecache unit size is not a fixed value (hugetlbfs is an example), but
+ * vma_interval_tree and anon_vma_internval_tree APIs assume that its indices
+ * are in PAGE_SIZE unit. So this routine helps us to get normalized indices.
+ *
+ * This page should be called only for pagecache pages/hugepages and anonymous
+ * pages/hugepages, because pagecache unit size is irrelevant except for those
+ * pages.
+ */
 static inline unsigned int page_size_order(struct page *page)
 {
 	return unlikely(PageHuge(page)) ?
-		huge_page_size_order(page) :
+		compound_order(compound_head(page)) :
 		(PAGE_CACHE_SHIFT - PAGE_SHIFT);
 }
 
@@ -424,7 +436,7 @@ static inline unsigned int page_size_order(struct page *page)
  */
 static inline pgoff_t page_pgoff(struct page *page)
 {
-        return page->index << page_size_order(page);
+	return page->index << page_size_order(page);
 }
 
 extern pgoff_t linear_hugepage_index(struct vm_area_struct *vma,
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index cccec2b4c073..7faab717ba19 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -982,11 +982,6 @@ pgoff_t __basepage_index(struct page *page)
 	return (index << compound_order(page_head)) + compound_idx;
 }
 
-unsigned int huge_page_size_order(struct page *page)
-{
-	return huge_page_order(page_hstate(page));
-}
-
 static struct page *alloc_fresh_huge_page_node(struct hstate *h, int nid)
 {
 	struct page *page;
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index d148b54f82a2..a7a89eb2f935 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -202,7 +202,7 @@ static int kill_proc(struct task_struct *t, unsigned long addr, int trapno,
 #ifdef __ARCH_SI_TRAPNO
 	si.si_trapno = trapno;
 #endif
-	si.si_addr_lsb = compound_order(compound_head(page)) + PAGE_SHIFT;
+	si.si_addr_lsb = page_size_order(page) + PAGE_SHIFT;
 
 	if ((flags & MF_ACTION_REQUIRED) && t->mm == current->mm) {
 		si.si_code = BUS_MCEERR_AR;
diff --git a/mm/rmap.c b/mm/rmap.c
index 672ee4cebe80..e4c9f7856cd1 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -1676,7 +1676,7 @@ static int rmap_walk_anon(struct page *page, struct rmap_walk_control *rwc)
 static int rmap_walk_file(struct page *page, struct rmap_walk_control *rwc)
 {
 	struct address_space *mapping = page->mapping;
-	pgoff_t pgoff = page->index << compound_order(page);
+	pgoff_t pgoff = page_pgoff(page);
 	struct vm_area_struct *vma;
 	int ret = SWAP_AGAIN;