Index: vfs_bio.c
===================================================================
--- vfs_bio.c	(revision 338036)
+++ vfs_bio.c	(working copy)
@@ -4188,6 +4188,7 @@
 		}
 		return;
 	}
+	newbsize = round_page(newbsize);
 	vm_hold_free_pages(bp, newbsize);
 	bufspace_adjust(bp, newbsize);
 }
@@ -4218,6 +4219,7 @@
 		bufmallocadjust(bp, newbsize);
 		return;
 	}
+	newbsize = round_page(newbsize);
 
 	/*
 	 * If the buffer is growing on its other-than-first
@@ -4272,8 +4274,6 @@
 
 	newbsize = roundup2(size, DEV_BSIZE);
 	if ((bp->b_flags & B_VMIO) == 0) {
-		if ((bp->b_flags & B_MALLOC) == 0)
-			newbsize = round_page(newbsize);
 		/*
 		 * Just get anonymous memory from the kernel.  Don't
 		 * mess with B_CACHE.