[PATCH] Fix bug nfslock request sending fail will be process as blocked

[PATCH] Fix bug nfslock request sending fail will be process as blocked

[Mi Jinlong]

If local reason cause nfslock request send fail(means status < 0,
resp->status not be reset), the request will be process as blocked 
at first now.

This patch initialize resp->status to nlm_lck_denied_nolocks, it 
can make the following process correctly.

Signed-off-by: Mi Jinlong <mijinlong@cn.fujitsu.com>
---
 fs/lockd/clntproc.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/fs/lockd/clntproc.c b/fs/lockd/clntproc.c
index c81249f..a631582 100644
--- a/fs/lockd/clntproc.c
+++ b/fs/lockd/clntproc.c
@@ -535,7 +535,7 @@ again:
 	 * Initialise resp->status to a valid non-zero value,
 	 * since 0 == nlm_lck_granted
 	 */
-	resp->status = nlm_lck_blocked;
+	resp->status = nlm_lck_denied_nolocks;
 	for(;;) {
 		/* Reboot protection */
 		fl->fl_u.nfs_fl.state = host->h_state;
-- 
1.6.5.2

Re: [PATCH] Fix bug nfslock request sending fail will be process as blocked

[Trond Myklebust]

On Fri, 2010-03-12 at 18:17 +0800, Mi Jinlong wrote: 
> If local reason cause nfslock request send fail(means status < 0,
> resp->status not be reset), the request will be process as blocked 
> at first now.
> 
> This patch initialize resp->status to nlm_lck_denied_nolocks, it 
> can make the following process correctly.
> 
> Signed-off-by: Mi Jinlong <mijinlong@cn.fujitsu.com>
> ---
>  fs/lockd/clntproc.c |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
> 
> diff --git a/fs/lockd/clntproc.c b/fs/lockd/clntproc.c
> index c81249f..a631582 100644
> --- a/fs/lockd/clntproc.c
> +++ b/fs/lockd/clntproc.c
> @@ -535,7 +535,7 @@ again:
>  	 * Initialise resp->status to a valid non-zero value,
>  	 * since 0 == nlm_lck_granted
>  	 */
> -	resp->status = nlm_lck_blocked;
> +	resp->status = nlm_lck_denied_nolocks;
>  	for(;;) {
>  		/* Reboot protection */
>  		fl->fl_u.nfs_fl.state = host->h_state;

We _want_ to process it as being blocked if the RPC call was
interrupted. The above patch will cause the client to just abandon the
interrupted lock request without sending the CANCEL request...

Trond

Re: [PATCH] Fix bug nfslock request sending fail will be process as blocked

[Mi Jinlong]

Trond Myklebust =E5=86=99=E9=81=93:
> On Fri, 2010-03-12 at 18:17 +0800, Mi Jinlong wrote:=20
>> If local reason cause nfslock request send fail(means status < 0,
>> resp->status not be reset), the request will be process as blocked=20
>> at first now.
>>
>> This patch initialize resp->status to nlm_lck_denied_nolocks, it=20
>> can make the following process correctly.
>>
>> Signed-off-by: Mi Jinlong <mijinlong@cn.fujitsu.com>
>> ---
>>  fs/lockd/clntproc.c |    2 +-
>>  1 files changed, 1 insertions(+), 1 deletions(-)
>>
>> diff --git a/fs/lockd/clntproc.c b/fs/lockd/clntproc.c
>> index c81249f..a631582 100644
>> --- a/fs/lockd/clntproc.c
>> +++ b/fs/lockd/clntproc.c
>> @@ -535,7 +535,7 @@ again:
>>  	 * Initialise resp->status to a valid non-zero value,
>>  	 * since 0 =3D=3D nlm_lck_granted
>>  	 */
>> -	resp->status =3D nlm_lck_blocked;
>> +	resp->status =3D nlm_lck_denied_nolocks;
>>  	for(;;) {
>>  		/* Reboot protection */
>>  		fl->fl_u.nfs_fl.state =3D host->h_state;
>=20
> We _want_ to process it as being blocked if the RPC call was
> interrupted. The above patch will cause the client to just abandon th=
e
> interrupted lock request without sending the CANCEL request...

  No, the above patch don't just abandon the interrupted lock request,
  when the RPC call was interrupted, client will send an UNLOCK request=
 for status < 0.
   ...
   583         if (status < 0)
   584                 goto out_unlock;
   ...

  And, I think an UNLOCK request is more advisable than a CANCEL reques=
t.
  If a LOCK request was succeed when CANCEL request coming, it's useles=
s;
  the lock should be unlocked.

  That's only my opinion.

thanks,
Mi Jinlong

Re: [PATCH] Fix bug nfslock request sending fail will be process as blocked

[Trond Myklebust]

On Tue, 2010-03-16 at 18:20 +0800, Mi Jinlong wrote:=20
>=20
> Trond Myklebust =E5=86=99=E9=81=93:
> > On Fri, 2010-03-12 at 18:17 +0800, Mi Jinlong wrote:=20
> >> If local reason cause nfslock request send fail(means status < 0,
> >> resp->status not be reset), the request will be process as blocked=
=20
> >> at first now.
> >>
> >> This patch initialize resp->status to nlm_lck_denied_nolocks, it=20
> >> can make the following process correctly.
> >>
> >> Signed-off-by: Mi Jinlong <mijinlong@cn.fujitsu.com>
> >> ---
> >>  fs/lockd/clntproc.c |    2 +-
> >>  1 files changed, 1 insertions(+), 1 deletions(-)
> >>
> >> diff --git a/fs/lockd/clntproc.c b/fs/lockd/clntproc.c
> >> index c81249f..a631582 100644
> >> --- a/fs/lockd/clntproc.c
> >> +++ b/fs/lockd/clntproc.c
> >> @@ -535,7 +535,7 @@ again:
> >>  	 * Initialise resp->status to a valid non-zero value,
> >>  	 * since 0 =3D=3D nlm_lck_granted
> >>  	 */
> >> -	resp->status =3D nlm_lck_blocked;
> >> +	resp->status =3D nlm_lck_denied_nolocks;
> >>  	for(;;) {
> >>  		/* Reboot protection */
> >>  		fl->fl_u.nfs_fl.state =3D host->h_state;
> >=20
> > We _want_ to process it as being blocked if the RPC call was
> > interrupted. The above patch will cause the client to just abandon =
the
> > interrupted lock request without sending the CANCEL request...
>=20
>   No, the above patch don't just abandon the interrupted lock request=
,
>   when the RPC call was interrupted, client will send an UNLOCK reque=
st for status < 0.
>    ...
>    583         if (status < 0)
>    584                 goto out_unlock;
>    ...
>=20
>   And, I think an UNLOCK request is more advisable than a CANCEL requ=
est.
>   If a LOCK request was succeed when CANCEL request coming, it's usel=
ess;
>   the lock should be unlocked.

An unlock does not guarantee that the server will cancel the blocked
lock request.

Trond

Re: [PATCH] Fix bug nfslock request sending fail will be process as blocked

[Mi Jinlong]

Trond Myklebust =E5=86=99=E9=81=93:
> On Tue, 2010-03-16 at 18:20 +0800, Mi Jinlong wrote:=20
>> Trond Myklebust =E5=86=99=E9=81=93:
>>> On Fri, 2010-03-12 at 18:17 +0800, Mi Jinlong wrote:=20
>>>> If local reason cause nfslock request send fail(means status < 0,
>>>> resp->status not be reset), the request will be process as blocked=
=20
>>>> at first now.
>>>>
>>>> This patch initialize resp->status to nlm_lck_denied_nolocks, it=20
>>>> can make the following process correctly.
>>>>
>>>> Signed-off-by: Mi Jinlong <mijinlong@cn.fujitsu.com>
>>>> ---
>>>>  fs/lockd/clntproc.c |    2 +-
>>>>  1 files changed, 1 insertions(+), 1 deletions(-)
>>>>
>>>> diff --git a/fs/lockd/clntproc.c b/fs/lockd/clntproc.c
>>>> index c81249f..a631582 100644
>>>> --- a/fs/lockd/clntproc.c
>>>> +++ b/fs/lockd/clntproc.c
>>>> @@ -535,7 +535,7 @@ again:
>>>>  	 * Initialise resp->status to a valid non-zero value,
>>>>  	 * since 0 =3D=3D nlm_lck_granted
>>>>  	 */
>>>> -	resp->status =3D nlm_lck_blocked;
>>>> +	resp->status =3D nlm_lck_denied_nolocks;
>>>>  	for(;;) {
>>>>  		/* Reboot protection */
>>>>  		fl->fl_u.nfs_fl.state =3D host->h_state;
>>> We _want_ to process it as being blocked if the RPC call was
>>> interrupted. The above patch will cause the client to just abandon =
the
>>> interrupted lock request without sending the CANCEL request...
>>   No, the above patch don't just abandon the interrupted lock reques=
t,
>>   when the RPC call was interrupted, client will send an UNLOCK requ=
est for status < 0.
>>    ...
>>    583         if (status < 0)
>>    584                 goto out_unlock;
>>    ...
>>
>>   And, I think an UNLOCK request is more advisable than a CANCEL req=
uest.
>>   If a LOCK request was succeed when CANCEL request coming, it's use=
less;
>>   the lock should be unlocked.
>=20
> An unlock does not guarantee that the server will cancel the blocked
> lock request.

  When server receive an UNLOCK request, it will try to cancel the lock=
 at first,
  codes as follows:
    ...
    567 nlmsvc_unlock(struct nlm_file *file, struct nlm_lock *lock)
    568 {
    ....
    578         /* First, cancel any lock that might be there */
    579         nlmsvc_cancel_blocked(file, lock);
    ...

  Server don't process the nlmsvc_cancel_blocked's return value, is it =
the problem=20
  that you said above ? or some other reason?

  Server cannot cancel the blocked lock request, it's acceptable someti=
mes, IMO,
  but client should work strongly itself.

thanks,
Mi Jinlong