On Wed, 2 Feb 2011, Patrick McHardy wrote:

> On 01.02.2011 22:28, Jozsef Kadlecsik wrote:
> > On Tue, 1 Feb 2011, Jozsef Kadlecsik wrote:
> > 
> >>>> I guess you're relying on that the original message is appended to a
> >>>> nlmsgerr message. That doesn't seem right though, if you want to return
> >>>> something to userspace, you should construct a new message.
> >>>
> >>> The message we are processing here carried multiple commands (each having 
> >>> an attribute with the line number of the given command) and one failed 
> >>> from some reason. We have to notify the userspace which command, at what 
> >>> line failed. For this reason the multi-command messages have got an 
> >>> attribute, which can be filled out with the line number - that happens 
> >>> here. The attribute is already there, the message is not enlarged, just
> >>> the empty value is overwritten with the proper value.
> >>>
> >>> The line number reporting works this way, tested in the testsuite too.
> >>>
> >>> If I had to construct a completely new message and sent it, that'd be more 
> >>> or less the duplication of netlink_ack. Additionally I had to suppress 
> >>> netlink from sending an errmsg/ack too.
> >>
> >> Hm, if I lie -EINTR to netlink, then I can construct and send the error 
> >> message manually and keep NLM_F_ACK at the same time. What do you think?
> >> Please have a look at the attached patch.
> > 
> > Oops, mistypeing fixed, here follow the hopefully good version.
> 
> This looks fine to me. A comment about why it returns -EINTR would
> probably be a good idea though.

Attached is the patch with a comment line added why -EINTR is returned.
Please apply.

Best regards,
Jozsef
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