rmap: recompute pgoff for unmapping huge page

We have to recompute pgoff if the given page is huge, since result based
on HPAGE_SIZE is not approapriate for scanning the vma interval tree, as
shown by commit 36e4f20af833 ("hugetlb: do not use vma_hugecache_offset()
for vma_prio_tree_foreach").

Signed-off-by: Hillf Danton <dhillf@gmail.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Michel Lespinasse <walken@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 3 insertions, 0 deletions

diff --git a/mm/rmap.c b/mm/rmap.c
index 807c96bf0dc6..6280da86b5d6 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -1513,6 +1513,9 @@ static int try_to_unmap_file(struct page *page, enum ttu_flags flags)
         unsigned long max_nl_size = 0;
         unsigned int mapcount;
 
+        if (PageHuge(page))
+                pgoff = page->index << compound_order(page);
+
         mutex_lock(&mapping->i_mmap_mutex);
         vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff, pgoff) {
                 unsigned long address = vma_address(page, vma);