sh: get_user_pages_fast() must flush cache
authorStas Sergeev <stsp@list.ru>
Tue, 9 Sep 2014 21:50:53 +0000 (14:50 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Wed, 10 Sep 2014 22:42:12 +0000 (15:42 -0700)
commitcaac7e6d00d3ddc888bd8169e75a02f962efdcff
tree5ec62f272828ee9da5786013e37a586ae78692fc
parentc680e41b3a2e944185c74bf60531e3d316d3ecc4
sh: get_user_pages_fast() must flush cache

This patch avoids fuse hangs on sh4 by flushing the cache on
get_user_pages_fast().  This is not necessary a good thing to do, but
get_user_pages() does this, so get_user_pages_fast() should too.

Please note the patch for mips arch that addresses the similar problem:
  https://kernel.googlesource.com/pub/scm/linux/kernel/git/ralf/linux/+/linux-3.4.50%5E!/#F0

They basically simply disable get_user_pages_fast() at all, using a
fall-back to get_user_pages().  But my fix is different, it adds an
explicit cache flushes.

Signed-off-by: Stas Sergeev <stsp@users.sourceforge.net>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Kamal Dasu <kdasu.kdev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
arch/sh/mm/gup.c