[PATCH 4.9 93/94] xfs: fix unaligned access in xfs_btree_visit_blocks

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Eric Sandeen <sandeen@xxxxxxxxxxx>

commit a4d768e702de224cc85e0c8eac9311763403b368 upstream.

This structure copy was throwing unaligned access warnings on sparc64:

Kernel unaligned access at TPC[1043c088] xfs_btree_visit_blocks+0x88/0xe0 [xfs]

xfs_btree_copy_ptrs does a memcpy, which avoids it.

Signed-off-by: Eric Sandeen <sandeen@xxxxxxxxxx>
Reviewed-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 fs/xfs/libxfs/xfs_btree.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/fs/xfs/libxfs/xfs_btree.c
+++ b/fs/xfs/libxfs/xfs_btree.c
@@ -4376,7 +4376,7 @@ xfs_btree_visit_blocks(
 			xfs_btree_readahead_ptr(cur, ptr, 1);
 
 			/* save for the next iteration of the loop */
-			lptr = *ptr;
+			xfs_btree_copy_ptrs(cur, &lptr, ptr, 1);
 		}
 
 		/* for each buffer in the level */