Hi Andrew,
Thanks for your suggestion.
On 2017/12/13 6:47, Andrew Morton wrote:
> On Mon, 11 Dec 2017 14:24:08 +0800 alex chen <alex.c...@huawei.com> wrote:
>
>> Using the OCFS2_XATTR_ROOT_SIZE macro improves the readability of the code.
>>
>> Signed-off-by: Alex Chen <alex.c...@huawei.com>
>> Reviewed-by: Jun Piao <piao...@huawei.com>
>> ---
>> fs/ocfs2/xattr.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/fs/ocfs2/xattr.c b/fs/ocfs2/xattr.c
>> index 5fdf269..ca3b61a 100644
>> --- a/fs/ocfs2/xattr.c
>> +++ b/fs/ocfs2/xattr.c
>> @@ -6415,7 +6415,7 @@ static int ocfs2_reflink_xattr_header(handle_t *handle,
>> * and then insert the extents one by one.
>> */
>> if (xv->xr_list.l_tree_depth) {
>> - memcpy(new_xv, &def_xv, sizeof(def_xv));
>> + memcpy(new_xv, &def_xv, OCFS2_XATTR_ROOT_SIZE);
>> vb->vb_xv = new_xv;
>> vb->vb_bh = value_bh;
>> ocfs2_init_xattr_value_extent_tree(&data_et,
>
> OK.
>
> But what's wrong with
>
> *new_xv = def_xv;
>
> ?
The type of new_xv is 'ocfs2_xattr_value_root' and the type of def_xv is
'ocfs2_xattr_def_value_root'.
The length of def_xv is larger than that of new_xv.
We initialize the new_xv to the empty default value root which have one extent
record.
If we use method you describe above to copy, we may missed a copy of one extent
record.
Thanks,
Alex
>
> That gets typechecked and the compiler may be able to perform
> some optimizations...
>
>
> .
>
_______________________________________________
Ocfs2-devel mailing list
Ocfs2-devel@oss.oracle.com
https://oss.oracle.com/mailman/listinfo/ocfs2-devel
