kni: fix rte_kni_update_link
Checks
Commit Message
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(+)
Comments
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
>
>
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
>>
>>
On 1/28/2019 1:49 PM, Igor Ryzhov wrote:
> Hi again,
>
> Sorry for bothering, I should have done more testing. It works as it is now.
> So, self NACK on the patch.
Thanks for the update Igor.
Since the file is pseudo-file, sysfs, I would expect no seek operation should be
required, your update confirms this.
Meanwhile there is a unit test 'kni_autotest' when you want to test link update.
Thanks,
ferruh
>
> 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
>>>
>>>
>
On Thu, 24 Jan 2019 23:47:49 +0300
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) {
Why not use pwrite() which is atomic?
@@ -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) {