mm/shmem: make find_get_pages_range() work for huge page
authorYu Zhao <yuzhao@google.com>
Tue, 5 Mar 2019 23:49:17 +0000 (15:49 -0800)
committerLinus Torvalds <torvalds@linux-foundation.org>
Wed, 6 Mar 2019 05:07:20 +0000 (21:07 -0800)
commit5d3ee42f8f5fa5e7ccc8980878fe6e18a129b9ff
treef2450c2442939937da7fcb79282b14c0c6e96f55
parentafa00112893f4ca02777c3cf4f93011577af5ffc
mm/shmem: make find_get_pages_range() work for huge page

find_get_pages_range() and find_get_pages_range_tag() already correctly
increment reference count on head when seeing compound page, but they
may still use page index from tail.  Page index from tail is always
zero, so these functions don't work on huge shmem.  This hasn't been a
problem because, AFAIK, nobody calls these functions on (huge) shmem.
Fix them anyway just in case.

Link: http://lkml.kernel.org/r/20190110030838.84446-1-yuzhao@google.com
Signed-off-by: Yu Zhao <yuzhao@google.com>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Amir Goldstein <amir73il@gmail.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: "Darrick J . Wong" <darrick.wong@oracle.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Souptick Joarder <jrdr.linux@gmail.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/filemap.c