[PATCH V3 01/10] block: pass page to xen_biovec_phys_mergeable

[Ming Lei <ming.lei@redhat.com>]

xen_biovec_phys_mergeable() only needs .bv_page of the 2nd bio bvec
for checking if the two bvecs can be merged, so pass page to
xen_biovec_phys_mergeable() directly.

No function change.

Cc: ris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: xen-devel@lists.xenproject.org
Cc: Omar Sandoval <osandov@fb.com>
Cc: Christoph Hellwig <hch@lst.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
---
 block/blk.h            | 2 +-
 drivers/xen/biomerge.c | 5 +++--
 include/xen/xen.h      | 4 +++-
 3 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/block/blk.h b/block/blk.h
index 5d636ee41663..e27fd1512e4b 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -75,7 +75,7 @@ static inline bool biovec_phys_mergeable(struct request_queue *q,
 
 	if (addr1 + vec1->bv_len != addr2)
 		return false;
-	if (xen_domain() && !xen_biovec_phys_mergeable(vec1, vec2))
+	if (xen_domain() && !xen_biovec_phys_mergeable(vec1, vec2->bv_page))
 		return false;
 	if ((addr1 | mask) != ((addr2 + vec2->bv_len - 1) | mask))
 		return false;
diff --git a/drivers/xen/biomerge.c b/drivers/xen/biomerge.c
index f3fbb700f569..05a286d24f14 100644
--- a/drivers/xen/biomerge.c
+++ b/drivers/xen/biomerge.c
@@ -4,12 +4,13 @@
 #include <xen/xen.h>
 #include <xen/page.h>
 
+/* check if @page can be merged with 'vec1' */
 bool xen_biovec_phys_mergeable(const struct bio_vec *vec1,
-			       const struct bio_vec *vec2)
+			       const struct page *page)
 {
 #if XEN_PAGE_SIZE == PAGE_SIZE
 	unsigned long bfn1 = pfn_to_bfn(page_to_pfn(vec1->bv_page));
-	unsigned long bfn2 = pfn_to_bfn(page_to_pfn(vec2->bv_page));
+	unsigned long bfn2 = pfn_to_bfn(page_to_pfn(page));
 
 	return bfn1 + PFN_DOWN(vec1->bv_offset + vec1->bv_len) == bfn2;
 #else
diff --git a/include/xen/xen.h b/include/xen/xen.h
index 19d032373de5..19a72f591e2b 100644
--- a/include/xen/xen.h
+++ b/include/xen/xen.h
@@ -43,8 +43,10 @@ extern struct hvm_start_info pvh_start_info;
 #endif	/* CONFIG_XEN_DOM0 */
 
 struct bio_vec;
+struct page;
+
 bool xen_biovec_phys_mergeable(const struct bio_vec *vec1,
-		const struct bio_vec *vec2);
+		const struct page *page);
 
 #if defined(CONFIG_MEMORY_HOTPLUG) && defined(CONFIG_XEN_BALLOON)
 extern u64 xen_saved_max_mem_size;
-- 
2.9.5