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authorYu Zhao <yuzhao@google.com>2018-11-30 14:09:03 -0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-12-05 19:42:41 +0100
commit3c470638b6a61e30b753715d2e546456dccd9437 (patch)
tree4135c8b10b55ebcd3f138dfb6e2958bd77ed687f
parent06c2233ac246507e98022809ea4752dbfead9337 (diff)
mm: use swp_offset as key in shmem_replace_page()
commit c1cb20d43728aa9b5393bd8d489bc85c142949b2 upstream. We changed the key of swap cache tree from swp_entry_t.val to swp_offset. We need to do so in shmem_replace_page() as well. Hugh said: "shmem_replace_page() has been wrong since the day I wrote it: good enough to work on swap "type" 0, which is all most people ever use (especially those few who need shmem_replace_page() at all), but broken once there are any non-0 swp_type bits set in the higher order bits" Link: http://lkml.kernel.org/r/20181121215442.138545-1-yuzhao@google.com Fixes: f6ab1f7f6b2d ("mm, swap: use offset of swap entry as key of swap cache") Signed-off-by: Yu Zhao <yuzhao@google.com> Reviewed-by: Matthew Wilcox <willy@infradead.org> Acked-by: Hugh Dickins <hughd@google.com> Cc: <stable@vger.kernel.org> [4.9+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--mm/shmem.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/mm/shmem.c b/mm/shmem.c
index 54911bbc74d6..9b17bd4cbc5e 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1494,11 +1494,13 @@ static int shmem_replace_page(struct page **pagep, gfp_t gfp,
{
struct page *oldpage, *newpage;
struct address_space *swap_mapping;
+ swp_entry_t entry;
pgoff_t swap_index;
int error;
oldpage = *pagep;
- swap_index = page_private(oldpage);
+ entry.val = page_private(oldpage);
+ swap_index = swp_offset(entry);
swap_mapping = page_mapping(oldpage);
/*
@@ -1517,7 +1519,7 @@ static int shmem_replace_page(struct page **pagep, gfp_t gfp,
__SetPageLocked(newpage);
__SetPageSwapBacked(newpage);
SetPageUptodate(newpage);
- set_page_private(newpage, swap_index);
+ set_page_private(newpage, entry.val);
SetPageSwapCache(newpage);
/*