Merge tag 'omap-for-v3.8-rc4/fixes-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap into fixes

From Tony Lindgren:
Minimal omap fixes for the -rc series:

- A build fix for recently merged omap DRM changes

- Regression fixes from the common clock framework conversion
  for omap4 audio and omap2 reboot

- Regression fix for pandaboard WLAN control UART muxing caused by
  u-boot only muxing essential pins nowadays

- Timer iteration fix for CONFIG_OF_DYNAMIC

- A section mismatch fix for ocp2scp init

* tag 'omap-for-v3.8-rc4/fixes-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap: (306 commits)
  ARM: OMAP2+: omap4-panda: add UART2 muxing for WiLink shared transport
  ARM: OMAP2+: DT node Timer iteration fix
  ARM: OMAP2+: Fix section warning for omap_init_ocp2scp()
  ARM: OMAP2+: fix build break for omapdrm
  ARM: OMAP2: Fix missing omap2xxx_clkt_vps_late_init function calls
  ARM: OMAP4: hwmod_data: Correct IDLEMODE for McPDM
  ARM: OMAP4: clock data: Lock ABE DPLL on all revisions
  + Linux 3.8-rc4

Signed-off-by: Olof Johansson <olof@lixom.net>

1 files changed, 13 insertions, 2 deletions

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 9e894edc7811..6001ee6347a9 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1819,9 +1819,19 @@ int split_huge_page(struct page *page)
 
 	BUG_ON(is_huge_zero_pfn(page_to_pfn(page)));
 	BUG_ON(!PageAnon(page));
-	anon_vma = page_lock_anon_vma_read(page);
+
+	/*
+	 * The caller does not necessarily hold an mmap_sem that would prevent
+	 * the anon_vma disappearing so we first we take a reference to it
+	 * and then lock the anon_vma for write. This is similar to
+	 * page_lock_anon_vma_read except the write lock is taken to serialise
+	 * against parallel split or collapse operations.
+	 */
+	anon_vma = page_get_anon_vma(page);
 	if (!anon_vma)
 		goto out;
+	anon_vma_lock_write(anon_vma);
+
 	ret = 0;
 	if (!PageCompound(page))
 		goto out_unlock;
@@ -1832,7 +1842,8 @@ int split_huge_page(struct page *page)
 
 	BUG_ON(PageCompound(page));
 out_unlock:
-	page_unlock_anon_vma_read(anon_vma);
+	anon_vma_unlock(anon_vma);
+	put_anon_vma(anon_vma);
 out:
 	return ret;
 }