The patch titled
Subject: mm/rmap.c: fix pgoff calculation to handle hugepage correctly
has been removed from the -mm tree. Its filename was
rmap-fix-pgoff-calculation-to-handle-hugepage-correctly.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
From: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
Subject: mm/rmap.c: fix pgoff calculation to handle hugepage correctly
I triggered VM_BUG_ON() in vma_address() when I try to migrate an
anonymous hugepage with mbind() in the kernel v3.16-rc3. This is because
pgoff's calculation in rmap_walk_anon() fails to consider compound_order()
only to have an incorrect value.
This patch introduces page_to_pgoff(), which gets the page's offset in
PAGE_CACHE_SIZE. Kirill pointed out that page cache tree should natively
handle hugepages, and in order to make hugetlbfs fit it, page->index of
hugetlbfs page should be in PAGE_CACHE_SIZE. This is beyond this patch,
but page_to_pgoff() contains the point to be fixed in a single function.
Signed-off-by: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
Acked-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxx>
Cc: Hillf Danton <dhillf@xxxxxxxxx>
Cc: Naoya Horiguchi <nao.horiguchi@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/pagemap.h | 12 ++++++++++++
mm/memory-failure.c | 4 ++--
mm/rmap.c | 10 +++-------
3 files changed, 17 insertions(+), 9 deletions(-)
diff -puN include/linux/pagemap.h~rmap-fix-pgoff-calculation-to-handle-hugepage-correctly include/linux/pagemap.h
--- a/include/linux/pagemap.h~rmap-fix-pgoff-calculation-to-handle-hugepage-correctly
+++ a/include/linux/pagemap.h
@@ -399,6 +399,18 @@ static inline struct page *read_mapping_
}
/*
+ * Get the offset in PAGE_SIZE.
+ * (TODO: hugepage should have ->index in PAGE_SIZE)
+ */
+static inline pgoff_t page_to_pgoff(struct page *page)
+{
+ if (unlikely(PageHeadHuge(page)))
+ return page->index << compound_order(page);
+ else
+ return page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
+}
+
+/*
* Return byte-offset into filesystem object for page.
*/
static inline loff_t page_offset(struct page *page)
diff -puN mm/memory-failure.c~rmap-fix-pgoff-calculation-to-handle-hugepage-correctly mm/memory-failure.c
--- a/mm/memory-failure.c~rmap-fix-pgoff-calculation-to-handle-hugepage-correctly
+++ a/mm/memory-failure.c
@@ -435,7 +435,7 @@ static void collect_procs_anon(struct pa
if (av == NULL) /* Not actually mapped anymore */
return;
- pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
+ pgoff = page_to_pgoff(page);
read_lock(&tasklist_lock);
for_each_process (tsk) {
struct anon_vma_chain *vmac;
@@ -469,7 +469,7 @@ static void collect_procs_file(struct pa
mutex_lock(&mapping->i_mmap_mutex);
read_lock(&tasklist_lock);
for_each_process(tsk) {
- pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
+ pgoff_t pgoff = page_to_pgoff(page);
struct task_struct *t = task_early_kill(tsk, force_early);
if (!t)
diff -puN mm/rmap.c~rmap-fix-pgoff-calculation-to-handle-hugepage-correctly mm/rmap.c
--- a/mm/rmap.c~rmap-fix-pgoff-calculation-to-handle-hugepage-correctly
+++ a/mm/rmap.c
@@ -517,11 +517,7 @@ void page_unlock_anon_vma_read(struct an
static inline unsigned long
__vma_address(struct page *page, struct vm_area_struct *vma)
{
- pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
-
- if (unlikely(is_vm_hugetlb_page(vma)))
- pgoff = page->index << huge_page_order(page_hstate(page));
-
+ pgoff_t pgoff = page_to_pgoff(page);
return vma->vm_start + ((pgoff - vma->vm_pgoff) << PAGE_SHIFT);
}
@@ -1639,7 +1635,7 @@ static struct anon_vma *rmap_walk_anon_l
static int rmap_walk_anon(struct page *page, struct rmap_walk_control *rwc)
{
struct anon_vma *anon_vma;
- pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
+ pgoff_t pgoff = page_to_pgoff(page);
struct anon_vma_chain *avc;
int ret = SWAP_AGAIN;
@@ -1680,7 +1676,7 @@ static int rmap_walk_anon(struct page *p
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_to_pgoff(page);
struct vm_area_struct *vma;
int ret = SWAP_AGAIN;
_
Patches currently in -mm which might be from n-horiguchi@xxxxxxxxxxxxx are
origin.patch
mm-memcontrol-rewrite-charge-api-fix-hugetlb-charging.patch
mm-memcontrol-use-page-lists-for-uncharge-batching-fix-hugetlb-page-lru.patch
mm-update-the-description-for-madvise_remove.patch
mm-hwpoison-injectc-remove-unnecessary-null-test-before-debugfs_remove_recursive.patch
hwpoison-fix-race-with-changing-page-during-offlining-v2.patch
mm-hugetlb-generalize-writes-to-nr_hugepages.patch
mm-hugetlb-generalize-writes-to-nr_hugepages-fix.patch
mm-hugetlb-remove-hugetlb_zero-and-hugetlb_infinity.patch
mm-refactor-page-index-offset-getters.patch
mm-refactor-page-index-offset-getters-fix.patch
mm-introduce-do_shared_fault-and-drop-do_fault-fix-fix.patch
do_shared_fault-check-that-mmap_sem-is-held.patch
linux-next.patch
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