On Tue, Aug 25, 2015 at 10:15 PM, Steven Rostedt <rost...@goodmis.org> wrote: > On Tue, 25 Aug 2015 15:50:18 +0800 > Sean Fu <fxinr...@gmail.com> wrote: > >> On Tue, Aug 25, 2015 at 10:24 AM, Eric W. Biederman >> <ebied...@xmission.com> wrote: >> > >> > >> > On August 24, 2015 6:57:57 PM MDT, Sean Fu <fxinr...@gmail.com> wrote: >> >>An application from HuaWei which works fine on 2.6 encounters this >> >>issue on 3.0 or later kernel. >> > >> > My sympathies. Being stuck with a 3rd party application you can barely >> > talk about that has been broken for 5years and no one reported it. >> > >> > Ordinarily we would fix a regression like this. As it has been 5years the >> > challenge now is how do we tell if there are applications that depend on >> > the current behavior. >> > >> > Before we can change the behavior back we need a convincing argument that >> > we won't cause a regression in another application by making the change. >> > >> > I do not see how such an argument can be made. So you have my sympathies >> > but I do not see how we can help you. >> We should consider this patch basing on my following arguments. >> 1 Different version kernel should keep consistent on this behavior. > > The thing is, the above argument is against the patch. The behavior > changed 2 years ago, and nobody noticed. Changing it back only causes > more inconsistent behavior. It is impossible to cause more inconsistent behavior. it just enhance compatibility(support "xx...x\0"). This patch just modify "proc_wspace_sep" array. and "proc_wspace_sep" is static. Only "proc_get_long" used this array, "proc_get_long" is also static. There are only 4 place to call "proc_get_long" in kernel/sysctl.c. I will prove that these 4 callers have no bad impact later.
> > >> 2 This writting behavior on proc file should be same with writting on >> regular file as possible as we can. > > Writing to a proc file causes kernel actions. Writing to a regular file > just saves data. That's not an argument here. > >> 3 This patch does not have any potential compatibility risk with 3rd >> party application. > > How do you know that? I will prove that all other write usage is not impacted later. Thanks for all reply. Sean > > -- Steve > >> 4 Support writting "1...\0" to proc file. >> >> > >> > Eric >> > > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
