> You ignored my feedback from earlier patch.
> It seems you are adding a lot more here that is necessary.

I split the changes into two separate patches, where [PATCH v2 1/2] 
addresses
the IOV_MAX limit issue and where I've incorporated your feedback + 
added a unit
test that tests this situation. if I did something wrong, let me know.

The problem of partial writig is addressed in the second patch [PATCH v2 
2/2]

On 29/07/2022 17:58, Stephen Hemminger wrote:
> On Fri, 29 Jul 2022 09:18:39 +0200
> Mário Kuka <kuka@cesnet.cz> wrote:
>
>> This patchset contains fixes for some issues that occur when writing a
>> large burst of packets at once, such as writing more packets than the
>> IOV_MAX limit and the problem of partial writing of a packet to a file
>> if the writev() system call performs a partial write.
>>
>> The typical use of pcapng in our cases is to copy the packets into a
>> separate buffer and the process of writing to the file is done in some
>> slow path, for example by writing in a separate thread or at the end of
>> the application, where we don't mind the limitation of the typically
>> slow speed of the storage medium.
>>
>> Mário Kuka (2):
>>    pcapng: fix write more packets than IOV_MAX limit
>>    pcapng: check if writev() returns a partial write
>>
>>   app/test/test_pcapng.c  | 42 +++++++++++++++++-
>>   lib/pcapng/rte_pcapng.c | 96 +++++++++++++++++++++++++++++++++--------
>>   2 files changed, 120 insertions(+), 18 deletions(-)
>>
> You ignored my feedback from earlier patch.
> It seems you are adding a lot more here that is necessary.