mm/gup: move try_get_compound_head() to top, fix minor issues

An upcoming patch uses try_get_compound_head() more widely, so move it to
the top of gup.c.

Also fix a tiny spelling error and a checkpatch.pl warning.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: John Hubbard <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Reviewed-by: Jan Kara <[email protected]>
Reviewed-by: Ira Weiny <[email protected]>
Cc: Alex Williamson <[email protected]>
Cc: Aneesh Kumar K.V <[email protected]>
Cc: Björn Töpel <[email protected]>
Cc: Daniel Vetter <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: Hans Verkuil <[email protected]>
Cc: Jason Gunthorpe <[email protected]>
Cc: Jason Gunthorpe <[email protected]>
Cc: Jens Axboe <[email protected]>
Cc: Jerome Glisse <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Kirill A. Shutemov <[email protected]>
Cc: Leon Romanovsky <[email protected]>
Cc: Mauro Carvalho Chehab <[email protected]>
Cc: Mike Rapoport <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

1 files changed, 15 insertions, 14 deletions

diff --git a/mm/gup.c b/mm/gup.c
index 706f85b84f47..c40e977f33c9 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -29,6 +29,21 @@ struct follow_page_context {
 	unsigned int page_mask;
 };
 
+/*
+ * Return the compound head page with ref appropriately incremented,
+ * or NULL if that failed.
+ */
+static inline struct page *try_get_compound_head(struct page *page, int refs)
+{
+	struct page *head = compound_head(page);
+
+	if (WARN_ON_ONCE(page_ref_count(head) < 0))
+		return NULL;
+	if (unlikely(!page_cache_add_speculative(head, refs)))
+		return NULL;
+	return head;
+}
+
 /**
  * put_user_pages_dirty_lock() - release and optionally dirty gup-pinned pages
  * @pages:  array of pages to be maybe marked dirty, and definitely released.
@@ -1807,20 +1822,6 @@ static void __maybe_unused undo_dev_pagemap(int *nr, int nr_start,
 	}
 }
 
-/*
- * Return the compund head page with ref appropriately incremented,
- * or NULL if that failed.
- */
-static inline struct page *try_get_compound_head(struct page *page, int refs)
-{
-	struct page *head = compound_head(page);
-	if (WARN_ON_ONCE(page_ref_count(head) < 0))
-		return NULL;
-	if (unlikely(!page_cache_add_speculative(head, refs)))
-		return NULL;
-	return head;
-}
-
 #ifdef CONFIG_ARCH_HAS_PTE_SPECIAL
 static int gup_pte_range(pmd_t pmd, unsigned long addr, unsigned long end,
 			 unsigned int flags, struct page **pages, int *nr)