Re: [PATCH v9 1/3] xfs: fix the calculation of length and end

[Shiyang Ruan]

在 2023/2/5 19:42, Matthew Wilcox 写道:

On Sat, Feb 04, 2023 at 02:58:36PM +0000, Shiyang Ruan wrote:

@@ -222,8 +222,8 @@ xfs_dax_notify_failure(
                len -= ddev_start - offset;
                offset = 0;
        }
-       if (offset + len > ddev_end)
-               len -= ddev_end - offset;
+       if (offset + len - 1 > ddev_end)
+               len -= offset + len - 1 - ddev_end;

This _looks_ wrong.  Are you sure it shouldn't be:

                len = ddev_end - offset + 1;

It is to make sure the range won't beyond the end of device.

But actually, both of us are rgiht.
  Mine: len -= offset + len - 1 - ddev_end;
     => len = len - (offset + len - 1 - ddev_end);
     => len = len - offset - len + 1 + ddev_end;
     => len = ddev_end - offset + 1;          --> Yours

I forgot to simplify it.  Will fix.


--
Thanks,
Ruan.