Merge tag 'fixes-for-v3.8-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/balbi/usb into usb-linus

Felipe writes:

  usb: fixes for v3.8-rc5

  Finally we have a build fix for fsl-mxc-udc UDC driver.

  We also have a fix for ep0 maxburst setting on DWC3
  which could confuse the HW if we tell it we had way
  too many streams on that endpoint when it _has_ to be
  only one.

  cppi_dma support for MUSB got a fix when running as a
  module. By dropping the wrong __init annotation, the
  function will be available even when we're modules and
  we're done with .init.text section.

  Last, but not least, we have a fix on FunctionFS which
  was causing a bug on our option parsing algorithm.

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;
 }