udf: Fix extension of the last extent in the file

When extending the last extent in the file within the last block, we
wrongly computed the length of the last extent. This is mostly a
cosmetical problem since the extent does not contain any data and the
length will be fixed up by following operations but still.

Fixes: 1f3868f06855 ("udf: Fix extending file within last block")
Signed-off-by: Jan Kara <jack@suse.cz>

diff --git a/fs/udf/inode.c b/fs/udf/inode.c
index 1d7c2a812fc19809630b70c2969021740bf12fee..f3e988928d1d877fbbd86a598f12eba1418fa715 100644 (file)
--- a/fs/udf/inode.c
+++ b/fs/udf/inode.c
@@ -595,7 +595,7 @@ static void udf_do_extend_final_block(struct inode *inode,
         */
        if (new_elen <= (last_ext->extLength & UDF_EXTENT_LENGTH_MASK))
                return;
-       added_bytes = (last_ext->extLength & UDF_EXTENT_LENGTH_MASK) - new_elen;
+       added_bytes = new_elen - (last_ext->extLength & UDF_EXTENT_LENGTH_MASK);
        last_ext->extLength += added_bytes;
        UDF_I(inode)->i_lenExtents += added_bytes;