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-rw-r--r--mm/memory.c17
-rw-r--r--mm/migrate.c13
2 files changed, 26 insertions, 4 deletions
diff --git a/mm/memory.c b/mm/memory.c
index c1c6d59b2b03..2b73dbde2274 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1481,7 +1481,8 @@ struct page *follow_page_mask(struct vm_area_struct *vma,
if (pud_none(*pud))
goto no_page_table;
if (pud_huge(*pud) && vma->vm_flags & VM_HUGETLB) {
- BUG_ON(flags & FOLL_GET);
+ if (flags & FOLL_GET)
+ goto out;
page = follow_huge_pud(mm, address, pud, flags & FOLL_WRITE);
goto out;
}
@@ -1492,8 +1493,20 @@ struct page *follow_page_mask(struct vm_area_struct *vma,
if (pmd_none(*pmd))
goto no_page_table;
if (pmd_huge(*pmd) && vma->vm_flags & VM_HUGETLB) {
- BUG_ON(flags & FOLL_GET);
page = follow_huge_pmd(mm, address, pmd, flags & FOLL_WRITE);
+ if (flags & FOLL_GET) {
+ /*
+ * Refcount on tail pages are not well-defined and
+ * shouldn't be taken. The caller should handle a NULL
+ * return when trying to follow tail pages.
+ */
+ if (PageHead(page))
+ get_page(page);
+ else {
+ page = NULL;
+ goto out;
+ }
+ }
goto out;
}
if ((flags & FOLL_NUMA) && pmd_numa(*pmd))
diff --git a/mm/migrate.c b/mm/migrate.c
index 3ec47d3394c8..d3137375fa80 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1092,7 +1092,11 @@ static struct page *new_page_node(struct page *p, unsigned long private,
*result = &pm->status;
- return alloc_pages_exact_node(pm->node,
+ if (PageHuge(p))
+ return alloc_huge_page_node(page_hstate(compound_head(p)),
+ pm->node);
+ else
+ return alloc_pages_exact_node(pm->node,
GFP_HIGHUSER_MOVABLE | GFP_THISNODE, 0);
}
@@ -1152,6 +1156,11 @@ static int do_move_page_to_node_array(struct mm_struct *mm,
!migrate_all)
goto put_and_set;
+ if (PageHuge(page)) {
+ isolate_huge_page(page, &pagelist);
+ goto put_and_set;
+ }
+
err = isolate_lru_page(page);
if (!err) {
list_add_tail(&page->lru, &pagelist);
@@ -1174,7 +1183,7 @@ set_status:
err = migrate_pages(&pagelist, new_page_node,
(unsigned long)pm, MIGRATE_SYNC, MR_SYSCALL);
if (err)
- putback_lru_pages(&pagelist);
+ putback_movable_pages(&pagelist);
}
up_read(&mm->mmap_sem);