libceph, ceph: change ceph_calc_file_object_mapping() signature

- make it void
- xlen (object extent length) out parameter should be u32 because only
  a single stripe unit is mapped at a time

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Alex Elder <elder@linaro.org>

fs/ceph/addr.c

@@ -945,19 +945,15 @@ get_more_pages:
 			if (locked_pages == 0) {
 				u64 objnum;
 				u64 objoff;
+				u32 xlen;
 
 				/* prepare async write request */
 				offset = (u64)page_offset(page);
-				len = wsize;
-
-				rc = ceph_calc_file_object_mapping(&ci->i_layout,
-								offset, len,
-								&objnum, &objoff,
-								&len);
-				if (rc < 0) {
-					unlock_page(page);
-					break;
-				}
+				ceph_calc_file_object_mapping(&ci->i_layout,
+							      offset, wsize,
+							      &objnum, &objoff,
+							      &xlen);
+				len = xlen;
 
 				num_ops = 1;
 				strip_unit_end = page->index +

fs/ceph/ioctl.c

@@ -185,7 +185,7 @@ static long ceph_ioctl_get_dataloc(struct file *file, void __user *arg)
 		&ceph_sb_to_client(inode->i_sb)->client->osdc;
 	struct ceph_object_locator oloc;
 	CEPH_DEFINE_OID_ONSTACK(oid);
-	u64 len = 1, olen;
+	u32 xlen;
 	u64 tmp;
 	struct ceph_pg pgid;
 	int r;
@@ -195,13 +195,8 @@ static long ceph_ioctl_get_dataloc(struct file *file, void __user *arg)
 		return -EFAULT;
 
 	down_read(&osdc->lock);
-	r = ceph_calc_file_object_mapping(&ci->i_layout, dl.file_offset, len,
-					  &dl.object_no, &dl.object_offset,
-					  &olen);
-	if (r < 0) {
-		up_read(&osdc->lock);
-		return -EIO;
-	}
+	ceph_calc_file_object_mapping(&ci->i_layout, dl.file_offset, 1,
+				      &dl.object_no, &dl.object_offset, &xlen);
 	dl.file_offset -= dl.object_offset;
 	dl.object_size = ci->i_layout.object_size;
 	dl.block_size = ci->i_layout.stripe_unit;