And one other
From other mailing I see you send patch to Denys Fedoryshchenko this patch is :
diff --git a/drivers/net/ppp/ppp_generic.c
b/drivers/net/ppp/ppp_generic.c
index 255a5def56e9..2acf4b0eabd1 100644
--- a/drivers/net/ppp/ppp_generic.c
+++ b/drivers/net/ppp/ppp_generic.c
@@ -3161,6 +3161,15 @@ ppp_connect_channel(struct channel *pch, int
unit)
goto outl;
ppp_lock(ppp);
+ spin_lock_bh(>downl);
+ if (!pch->chan) {
+ /* Don't connect unregistered channels */
+ ppp_unlock(ppp);
+ spin_unlock_bh(>downl);
+ ret = -ENOTCONN;
+ goto outl;
+ }
+ spin_unlock_bh(>downl);
if (pch->file.hdrlen > ppp->file.hdrlen)
ppp->file.hdrlen = pch->file.hdrlen;
hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */
But in official stable kernel three In ppp_generic.c is this :
spin_lock_bh(&pch->downl);
if (!pch->chan) {
/* Don't connect unregistered channels */
spin_unlock_bh(&pch->downl);
ppp_unlock(ppp);
ret = -ENOTCONN;
goto outl; }
spin_unlock_bh(&pch->downl);
It is normal to unlock ppp after spin_unlock ?
shouldn't it be as you wrote it?
In your patch first :
+ ppp_unlock(ppp);
+ spin_unlock_bh(>downl);
But in stable kernel is :
spin_unlock_bh(&pch->downl);
ppp_unlock(ppp);
> On 9 Dec 2020, at 20:10, Guillaume Nault <gna...@redhat.com> wrote:
>
> On Wed, Dec 09, 2020 at 06:57:44PM +0200, Martin Zaharinov wrote:
>>> On 9 Dec 2020, at 18:40, Guillaume Nault <gna...@redhat.com> wrote:
>>> On Wed, Dec 09, 2020 at 04:47:52PM +0200, Martin Zaharinov wrote:
>>>> Hi All
>>>>
>>>> I have problem with latest kernel release
>>>> And the problem is base on this late problem :
>>>>
>>>>
>>>> https://www.mail-archive.com/search?l=netdev@vger.kernel.org&q=subject:%22Re%5C%3A+ppp%5C%2Fpppoe%2C+still+panic+4.15.3+in+ppp_push%22&o=newest&f=1
>>>>
>>>> I have same problem in kernel 5.6 > now I use kernel 5.9.13 and have same
>>>> problem.
>>>>
>>>>
>>>> In kernel 5.9.13 now don’t have any crashes in dimes but in one moment
>>>> accel service stop with defunct and in log have many of this line :
>>>>
>>>>
>>>> error: vlan608: ioctl(PPPIOCCONNECT): Transport endpoint is not connected
>>>> error: vlan617: ioctl(PPPIOCCONNECT): Transport endpoint is not connected
>>>> error: vlan679: ioctl(PPPIOCCONNECT): Transport endpoint is not connected
>>>>
>>>> In one moment connected user bump double or triple and after that service
>>>> defunct and need wait to drop all session to start .
>>>>
>>>> I talk with accel-ppp team and they said this is kernel related problem
>>>> and to back to kernel 4.14 there is not this problem.
>>>>
>>>> Problem is come after kernel 4.15 > and not have solution to this moment.
>>>
>>> I'm sorry, I don't understand.
>>> Do you mean that v4.14 worked fine (no crash, no ioctl() error)?
>>> Did the problem start appearing in v4.15? Or did v4.15 work and the
>>> problem appeared in v4.16?
>>
>> In Telegram group I talk with Sergey and Dimka and told my the problem is
>> come after changes from 4.14 to 4.15
>> Sergey write this : "as I know, there was a similar issue in kernel 4.15 so
>> maybe it is still not fixed"
>
> Ok, but what is your experience? Do you have a kernel version where
> accel-ppp reports no ioctl() error and doesn't crash the kernel?
>
> There wasn't a lot of changes between 4.14 and 4.15 for PPP.
> The only PPP patch I can see that might have been risky is commit
> 0171c4183559 ("ppp: unlock all_ppp_mutex before registering device").
>
>> I don’t have options to test with this old kernel 4.14.xxx i don’t have
>> support for them.
>>
>>
>>>
>>>> Please help to find the problem.
>>>>
>>>> Last time in link I see is make changes in ppp_generic.c
>>>>
>>>> ppp_lock(ppp);
>>>> spin_lock_bh(&pch->downl);
>>>> if (!pch->chan) {
>>>> /* Don't connect unregistered channels */
>>>> spin_unlock_bh(&pch->downl);
>>>> ppp_unlock(ppp);
>>>> ret = -ENOTCONN;
>>>> goto outl;
>>>> }
>>>> spin_unlock_bh(&pch->downl);
>>>>
>>>>
>>>> But this fix only to don’t display error and freeze system
>>>> The problem is stay and is to big.
>>>
>>> Do you use accel-ppp's unit-cache option? Does the problem go away if
>>> you stop using it?
>>>
>>
>> No I don’t use unit-cache , if I set unit-cache accel-ppp defunct same but
>> user Is connect and disconnet more fast.
>>
>> The problem is same with unit and without .
>> Only after this patch I don’t see error in dimes but this is not solution.
>
> Soryy, what's "in dimes"?
> Do you mean that reverting commit 77f840e3e5f0 ("ppp: prevent
> unregistered channels from connecting to PPP units") fixes your problem?
>
>> In network have customer what have power cut problem, when drop 600 user and
>> back Is normal but in this moment kernel is locking and start to make this :
>> sessions:
>> starting: 4235
>> active: 3882
>> finishing: 378
>> The problem is starting session is not real user normal user in this server
>> is ~4k customers .
>
> What type of session is it? L2TP, PPPoE, PPTP?
>
>> I use pppd_compat .
>>
>> Any idea ?
>>
>>>>
>>>> Please help to fix.
>> Martin
