Re: [PATCH] kni: fix rte_kni_update_link

[Igor Ryzhov <iryzhov@nfware.com>]

Hi again,

Sorry for bothering, I should have done more testing. It works as it is now.
So, self NACK on the patch.

Best regards,
Igor

On Mon, Jan 28, 2019 at 2:45 PM Igor Ryzhov <iryzhov@nfware.com> wrote:

> Hi Ferruh,
>
> Can you, please, take a look at this patch?
> The current implementation is broken, I think the patch should be merged
> into 19.02 and 18.11.1.
>
> Best regards,
> Igor
>
> On Thu, Jan 24, 2019 at 11:47 PM Igor Ryzhov <iryzhov@nfware.com> wrote:
>
>> After read, file offset must be set to 0 before write.
>> Otherwise, the third byte will be overwritten instead of the first.
>>
>> Fixes: c6fd54f28c24 ("kni: add function to set link state on kernel
>> interface")
>> Cc: stable@dpdk.org
>>
>> Signed-off-by: Igor Ryzhov <iryzhov@nfware.com>
>> ---
>>  lib/librte_kni/rte_kni.c | 6 ++++++
>>  1 file changed, 6 insertions(+)
>>
>> diff --git a/lib/librte_kni/rte_kni.c b/lib/librte_kni/rte_kni.c
>> index 73aeccccf..5899bb14a 100644
>> --- a/lib/librte_kni/rte_kni.c
>> +++ b/lib/librte_kni/rte_kni.c
>> @@ -746,6 +746,12 @@ rte_kni_update_link(struct rte_kni *kni, unsigned
>> int linkup)
>>         }
>>         old_linkup = (old_carrier[0] == '1');
>>
>> +       if (lseek(fd, 0, SEEK_SET) == -1) {
>> +               RTE_LOG(ERR, KNI, "Failed to change file position:
>> %s.\n", path);
>> +               close(fd);
>> +               return -1;
>> +       }
>> +
>>         new_carrier = linkup ? "1" : "0";
>>         ret = write(fd, new_carrier, 1);
>>         if (ret < 1) {
>> --
>> 2.20.1
>>
>>