mm: use swp_offset as key in shmem_replace_page()
authorYu Zhao <yuzhao@google.com>
Fri, 30 Nov 2018 22:09:03 +0000 (14:09 -0800)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 5 Dec 2018 18:42:41 +0000 (19:42 +0100)
commit3c470638b6a61e30b753715d2e546456dccd9437
tree4135c8b10b55ebcd3f138dfb6e2958bd77ed687f
parent06c2233ac246507e98022809ea4752dbfead9337
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>
mm/shmem.c