2019-04-09 11:37:35

by Xiubo Li

[permalink] [raw]
Subject: [PATCH] svc_run: make sure only one svc_run loop runs in one process

From: Xiubo Li <[email protected]>

In gluster-block project and there are 2 separate threads, both
of which will run the svc_run loop, this could work well in glibc
version, but in libtirpc we are hitting the random crash and stuck
issues.

More detail please see:
https://github.com/gluster/gluster-block/pull/182

Signed-off-by: Xiubo Li <[email protected]>
---
src/svc_run.c | 19 +++++++++++++++++++
1 file changed, 19 insertions(+)

diff --git a/src/svc_run.c b/src/svc_run.c
index f40314b..b295755 100644
--- a/src/svc_run.c
+++ b/src/svc_run.c
@@ -38,12 +38,17 @@
#include <string.h>
#include <unistd.h>
#include <sys/poll.h>
+#include <syslog.h>
+#include <stdbool.h>


#include <rpc/rpc.h>
#include "rpc_com.h"
#include <sys/select.h>

+static bool svc_loop_running = false;
+static pthread_mutex_t svc_run_lock = PTHREAD_MUTEX_INITIALIZER;
+
void
svc_run()
{
@@ -51,6 +56,16 @@ svc_run()
struct pollfd *my_pollfd = NULL;
int last_max_pollfd = 0;

+ pthread_mutex_lock(&svc_run_lock);
+ if (svc_loop_running) {
+ pthread_mutex_unlock(&svc_run_lock);
+ syslog (LOG_ERR, "svc_run: svc loop is already running in current process %d", getpid());
+ return;
+ }
+
+ svc_loop_running = true;
+ pthread_mutex_unlock(&svc_run_lock);
+
for (;;) {
int max_pollfd = svc_max_pollfd;
if (max_pollfd == 0 && svc_pollfd == NULL)
@@ -111,4 +126,8 @@ svc_exit()
svc_pollfd = NULL;
svc_max_pollfd = 0;
rwlock_unlock(&svc_fd_lock);
+
+ pthread_mutex_lock(&svc_run_lock);
+ svc_loop_running = false;
+ pthread_mutex_unlock(&svc_run_lock);
}
--
1.8.3.1



2019-05-16 02:57:19

by Xiubo Li

[permalink] [raw]
Subject: Re: [PATCH] svc_run: make sure only one svc_run loop runs in one process

Hey ping.

What's the state of this patch and will it make sense here?

Thanks
BRs

On 2019/4/9 19:37, [email protected] wrote:
> From: Xiubo Li <[email protected]>
>
> In gluster-block project and there are 2 separate threads, both
> of which will run the svc_run loop, this could work well in glibc
> version, but in libtirpc we are hitting the random crash and stuck
> issues.
>
> More detail please see:
> https://github.com/gluster/gluster-block/pull/182
>
> Signed-off-by: Xiubo Li <[email protected]>
> ---
> src/svc_run.c | 19 +++++++++++++++++++
> 1 file changed, 19 insertions(+)
>
> diff --git a/src/svc_run.c b/src/svc_run.c
> index f40314b..b295755 100644
> --- a/src/svc_run.c
> +++ b/src/svc_run.c
> @@ -38,12 +38,17 @@
> #include <string.h>
> #include <unistd.h>
> #include <sys/poll.h>
> +#include <syslog.h>
> +#include <stdbool.h>
>
>
> #include <rpc/rpc.h>
> #include "rpc_com.h"
> #include <sys/select.h>
>
> +static bool svc_loop_running = false;
> +static pthread_mutex_t svc_run_lock = PTHREAD_MUTEX_INITIALIZER;
> +
> void
> svc_run()
> {
> @@ -51,6 +56,16 @@ svc_run()
> struct pollfd *my_pollfd = NULL;
> int last_max_pollfd = 0;
>
> + pthread_mutex_lock(&svc_run_lock);
> + if (svc_loop_running) {
> + pthread_mutex_unlock(&svc_run_lock);
> + syslog (LOG_ERR, "svc_run: svc loop is already running in current process %d", getpid());
> + return;
> + }
> +
> + svc_loop_running = true;
> + pthread_mutex_unlock(&svc_run_lock);
> +
> for (;;) {
> int max_pollfd = svc_max_pollfd;
> if (max_pollfd == 0 && svc_pollfd == NULL)
> @@ -111,4 +126,8 @@ svc_exit()
> svc_pollfd = NULL;
> svc_max_pollfd = 0;
> rwlock_unlock(&svc_fd_lock);
> +
> + pthread_mutex_lock(&svc_run_lock);
> + svc_loop_running = false;
> + pthread_mutex_unlock(&svc_run_lock);
> }


2019-06-11 15:02:49

by Steve Dickson

[permalink] [raw]
Subject: Re: [PATCH] svc_run: make sure only one svc_run loop runs in one process

Sorry for the delay....

On 5/15/19 10:55 PM, Xiubo Li wrote:
> Hey ping.
>
> What's the state of this patch and will it make sense here?
I'm not sure it does make sense.... Shouldn't the mutex lock
be in the call of svc_run()?

steved.

>
> Thanks
> BRs
>
> On 2019/4/9 19:37, [email protected] wrote:
>> From: Xiubo Li <[email protected]>
>>
>> In gluster-block project and there are 2 separate threads, both
>> of which will run the svc_run loop, this could work well in glibc
>> version, but in libtirpc we are hitting the random crash and stuck
>> issues.
>>
>> More detail please see:
>> https://github.com/gluster/gluster-block/pull/182
>>
>> Signed-off-by: Xiubo Li <[email protected]>
>> ---
>>   src/svc_run.c | 19 +++++++++++++++++++
>>   1 file changed, 19 insertions(+)
>>
>> diff --git a/src/svc_run.c b/src/svc_run.c
>> index f40314b..b295755 100644
>> --- a/src/svc_run.c
>> +++ b/src/svc_run.c
>> @@ -38,12 +38,17 @@
>>   #include <string.h>
>>   #include <unistd.h>
>>   #include <sys/poll.h>
>> +#include <syslog.h>
>> +#include <stdbool.h>
>>       #include <rpc/rpc.h>
>>   #include "rpc_com.h"
>>   #include <sys/select.h>
>>   +static bool svc_loop_running = false;
>> +static pthread_mutex_t svc_run_lock = PTHREAD_MUTEX_INITIALIZER;
>> +
>>   void
>>   svc_run()
>>   {
>> @@ -51,6 +56,16 @@ svc_run()
>>     struct pollfd *my_pollfd = NULL;
>>     int last_max_pollfd = 0;
>>   +  pthread_mutex_lock(&svc_run_lock);
>> +  if (svc_loop_running) {
>> +    pthread_mutex_unlock(&svc_run_lock);
>> +    syslog (LOG_ERR, "svc_run: svc loop is already running in current process %d", getpid());
>> +    return;
>> +  }
>> +
>> +  svc_loop_running = true;
>> +  pthread_mutex_unlock(&svc_run_lock);
>> +
>>     for (;;) {
>>       int max_pollfd = svc_max_pollfd;
>>       if (max_pollfd == 0 && svc_pollfd == NULL)
>> @@ -111,4 +126,8 @@ svc_exit()
>>       svc_pollfd = NULL;
>>       svc_max_pollfd = 0;
>>       rwlock_unlock(&svc_fd_lock);
>> +
>> +    pthread_mutex_lock(&svc_run_lock);
>> +    svc_loop_running = false;
>> +    pthread_mutex_unlock(&svc_run_lock);
>>   }
>
>
>
>
> _______________________________________________
> Libtirpc-devel mailing list
> [email protected]
> https://lists.sourceforge.net/lists/listinfo/libtirpc-devel

2019-06-12 07:45:15

by Xiubo Li

[permalink] [raw]
Subject: Re: [PATCH] svc_run: make sure only one svc_run loop runs in one process

On 2019/6/11 22:54, Steve Dickson wrote:
> Sorry for the delay....
>
> On 5/15/19 10:55 PM, Xiubo Li wrote:
>> Hey ping.
>>
>> What's the state of this patch and will it make sense here?
> I'm not sure it does make sense.... Shouldn't the mutex lock
> be in the call of svc_run()?

Hi Steve,

Yeah, mutex lock should be in the call of svc_run(). This is exactly
what I do in this change.

If the libtirpc means to allow only one svc_run() loop in each process,
so IMO this change is needed. Or if we will allow more than one like the
glibc version does, so this should be one bug in libtirpc.

Thanks.
BRs
Xiubo


> steved.
>
>> Thanks
>> BRs
>>
>> On 2019/4/9 19:37, [email protected] wrote:
>>> From: Xiubo Li <[email protected]>
>>>
>>> In gluster-block project and there are 2 separate threads, both
>>> of which will run the svc_run loop, this could work well in glibc
>>> version, but in libtirpc we are hitting the random crash and stuck
>>> issues.
>>>
>>> More detail please see:
>>> https://github.com/gluster/gluster-block/pull/182
>>>
>>> Signed-off-by: Xiubo Li <[email protected]>
>>> ---
>>>   src/svc_run.c | 19 +++++++++++++++++++
>>>   1 file changed, 19 insertions(+)
>>>
>>> diff --git a/src/svc_run.c b/src/svc_run.c
>>> index f40314b..b295755 100644
>>> --- a/src/svc_run.c
>>> +++ b/src/svc_run.c
>>> @@ -38,12 +38,17 @@
>>>   #include <string.h>
>>>   #include <unistd.h>
>>>   #include <sys/poll.h>
>>> +#include <syslog.h>
>>> +#include <stdbool.h>
>>>       #include <rpc/rpc.h>
>>>   #include "rpc_com.h"
>>>   #include <sys/select.h>
>>>   +static bool svc_loop_running = false;
>>> +static pthread_mutex_t svc_run_lock = PTHREAD_MUTEX_INITIALIZER;
>>> +
>>>   void
>>>   svc_run()
>>>   {
>>> @@ -51,6 +56,16 @@ svc_run()
>>>     struct pollfd *my_pollfd = NULL;
>>>     int last_max_pollfd = 0;
>>>   +  pthread_mutex_lock(&svc_run_lock);
>>> +  if (svc_loop_running) {
>>> +    pthread_mutex_unlock(&svc_run_lock);
>>> +    syslog (LOG_ERR, "svc_run: svc loop is already running in current process %d", getpid());
>>> +    return;
>>> +  }
>>> +
>>> +  svc_loop_running = true;
>>> +  pthread_mutex_unlock(&svc_run_lock);
>>> +
>>>     for (;;) {
>>>       int max_pollfd = svc_max_pollfd;
>>>       if (max_pollfd == 0 && svc_pollfd == NULL)
>>> @@ -111,4 +126,8 @@ svc_exit()
>>>       svc_pollfd = NULL;
>>>       svc_max_pollfd = 0;
>>>       rwlock_unlock(&svc_fd_lock);
>>> +
>>> +    pthread_mutex_lock(&svc_run_lock);
>>> +    svc_loop_running = false;
>>> +    pthread_mutex_unlock(&svc_run_lock);
>>>   }
>>
>>
>>
>> _______________________________________________
>> Libtirpc-devel mailing list
>> [email protected]
>> https://lists.sourceforge.net/lists/listinfo/libtirpc-devel


2019-06-12 18:07:33

by Olga Kornievskaia

[permalink] [raw]
Subject: Re: [PATCH] svc_run: make sure only one svc_run loop runs in one process

On Wed, Jun 12, 2019 at 3:45 AM Xiubo Li <[email protected]> wrote:
>
> On 2019/6/11 22:54, Steve Dickson wrote:
> > Sorry for the delay....
> >
> > On 5/15/19 10:55 PM, Xiubo Li wrote:
> >> Hey ping.
> >>
> >> What's the state of this patch and will it make sense here?
> > I'm not sure it does make sense.... Shouldn't the mutex lock
> > be in the call of svc_run()?
>
> Hi Steve,
>
> Yeah, mutex lock should be in the call of svc_run(). This is exactly
> what I do in this change.
>
> If the libtirpc means to allow only one svc_run() loop in each process,
> so IMO this change is needed. Or if we will allow more than one like the
> glibc version does, so this should be one bug in libtirpc.

Has there been effort into made into investigating what's causing the
crashes? We perhaps should make an effort to see if svc_run() is
thread-safe and examine which functions it uses and which might not be
thread safe. You might be able to allow greater parallelism then 1
thread in a svc_run() function by just making some not-thread safe
functions wrapped in pthread locks.

>
> Thanks.
> BRs
> Xiubo
>
>
> > steved.
> >
> >> Thanks
> >> BRs
> >>
> >> On 2019/4/9 19:37, [email protected] wrote:
> >>> From: Xiubo Li <[email protected]>
> >>>
> >>> In gluster-block project and there are 2 separate threads, both
> >>> of which will run the svc_run loop, this could work well in glibc
> >>> version, but in libtirpc we are hitting the random crash and stuck
> >>> issues.
> >>>
> >>> More detail please see:
> >>> https://github.com/gluster/gluster-block/pull/182
> >>>
> >>> Signed-off-by: Xiubo Li <[email protected]>
> >>> ---
> >>> src/svc_run.c | 19 +++++++++++++++++++
> >>> 1 file changed, 19 insertions(+)
> >>>
> >>> diff --git a/src/svc_run.c b/src/svc_run.c
> >>> index f40314b..b295755 100644
> >>> --- a/src/svc_run.c
> >>> +++ b/src/svc_run.c
> >>> @@ -38,12 +38,17 @@
> >>> #include <string.h>
> >>> #include <unistd.h>
> >>> #include <sys/poll.h>
> >>> +#include <syslog.h>
> >>> +#include <stdbool.h>
> >>> #include <rpc/rpc.h>
> >>> #include "rpc_com.h"
> >>> #include <sys/select.h>
> >>> +static bool svc_loop_running = false;
> >>> +static pthread_mutex_t svc_run_lock = PTHREAD_MUTEX_INITIALIZER;
> >>> +
> >>> void
> >>> svc_run()
> >>> {
> >>> @@ -51,6 +56,16 @@ svc_run()
> >>> struct pollfd *my_pollfd = NULL;
> >>> int last_max_pollfd = 0;
> >>> + pthread_mutex_lock(&svc_run_lock);
> >>> + if (svc_loop_running) {
> >>> + pthread_mutex_unlock(&svc_run_lock);
> >>> + syslog (LOG_ERR, "svc_run: svc loop is already running in current process %d", getpid());
> >>> + return;
> >>> + }
> >>> +
> >>> + svc_loop_running = true;
> >>> + pthread_mutex_unlock(&svc_run_lock);
> >>> +
> >>> for (;;) {
> >>> int max_pollfd = svc_max_pollfd;
> >>> if (max_pollfd == 0 && svc_pollfd == NULL)
> >>> @@ -111,4 +126,8 @@ svc_exit()
> >>> svc_pollfd = NULL;
> >>> svc_max_pollfd = 0;
> >>> rwlock_unlock(&svc_fd_lock);
> >>> +
> >>> + pthread_mutex_lock(&svc_run_lock);
> >>> + svc_loop_running = false;
> >>> + pthread_mutex_unlock(&svc_run_lock);
> >>> }
> >>
> >>
> >>
> >> _______________________________________________
> >> Libtirpc-devel mailing list
> >> [email protected]
> >> https://lists.sourceforge.net/lists/listinfo/libtirpc-devel
>
>

2019-06-13 16:59:15

by Xiubo Li

[permalink] [raw]
Subject: Re: [PATCH] svc_run: make sure only one svc_run loop runs in one process

On 2019/6/13 0:46, Olga Kornievskaia wrote:
> On Wed, Jun 12, 2019 at 3:45 AM Xiubo Li <[email protected]> wrote:
>> On 2019/6/11 22:54, Steve Dickson wrote:
>>> Sorry for the delay....
>>>
>>> On 5/15/19 10:55 PM, Xiubo Li wrote:
>>>> Hey ping.
>>>>
>>>> What's the state of this patch and will it make sense here?
>>> I'm not sure it does make sense.... Shouldn't the mutex lock
>>> be in the call of svc_run()?
>> Hi Steve,
>>
>> Yeah, mutex lock should be in the call of svc_run(). This is exactly
>> what I do in this change.
>>
>> If the libtirpc means to allow only one svc_run() loop in each process,
>> so IMO this change is needed. Or if we will allow more than one like the
>> glibc version does, so this should be one bug in libtirpc.
> Has there been effort into made into investigating what's causing the
> crashes?

Before as our investigation and test, it was that if we ran two
svc_run() loop in one process, such as in pthread1 and pthread2, it
seems that pthread1 will receive the RPC connection/request which should
be handled by pthread2's svc_run loop and vice versa.

Then we can see many random crash for tons of different reasons, like
use after free and double free..., and almost every time the crash will
randomly in different places and different libraries, such as the
libtirpc, glusterfs and gluster-block...

After switching to multi processes instead of running two svc_run loop
in multi pthreads, this issue has been resolved we didn't dig it further.


> We perhaps should make an effort to see if svc_run() is
> thread-safe and examine which functions it uses and which might not be
> thread safe. You might be able to allow greater parallelism then 1
> thread in a svc_run() function by just making some not-thread safe
> functions wrapped in pthread locks.

Yeah, make sense.

Thanks.

BRs


>> Thanks.
>> BRs
>> Xiubo
>>
>>
>>> steved.
>>>
>>>> Thanks
>>>> BRs
>>>>
>>>> On 2019/4/9 19:37, [email protected] wrote:
>>>>> From: Xiubo Li <[email protected]>
>>>>>
>>>>> In gluster-block project and there are 2 separate threads, both
>>>>> of which will run the svc_run loop, this could work well in glibc
>>>>> version, but in libtirpc we are hitting the random crash and stuck
>>>>> issues.
>>>>>
>>>>> More detail please see:
>>>>> https://github.com/gluster/gluster-block/pull/182
>>>>>
>>>>> Signed-off-by: Xiubo Li <[email protected]>
>>>>> ---
>>>>> src/svc_run.c | 19 +++++++++++++++++++
>>>>> 1 file changed, 19 insertions(+)
>>>>>
>>>>> diff --git a/src/svc_run.c b/src/svc_run.c
>>>>> index f40314b..b295755 100644
>>>>> --- a/src/svc_run.c
>>>>> +++ b/src/svc_run.c
>>>>> @@ -38,12 +38,17 @@
>>>>> #include <string.h>
>>>>> #include <unistd.h>
>>>>> #include <sys/poll.h>
>>>>> +#include <syslog.h>
>>>>> +#include <stdbool.h>
>>>>> #include <rpc/rpc.h>
>>>>> #include "rpc_com.h"
>>>>> #include <sys/select.h>
>>>>> +static bool svc_loop_running = false;
>>>>> +static pthread_mutex_t svc_run_lock = PTHREAD_MUTEX_INITIALIZER;
>>>>> +
>>>>> void
>>>>> svc_run()
>>>>> {
>>>>> @@ -51,6 +56,16 @@ svc_run()
>>>>> struct pollfd *my_pollfd = NULL;
>>>>> int last_max_pollfd = 0;
>>>>> + pthread_mutex_lock(&svc_run_lock);
>>>>> + if (svc_loop_running) {
>>>>> + pthread_mutex_unlock(&svc_run_lock);
>>>>> + syslog (LOG_ERR, "svc_run: svc loop is already running in current process %d", getpid());
>>>>> + return;
>>>>> + }
>>>>> +
>>>>> + svc_loop_running = true;
>>>>> + pthread_mutex_unlock(&svc_run_lock);
>>>>> +
>>>>> for (;;) {
>>>>> int max_pollfd = svc_max_pollfd;
>>>>> if (max_pollfd == 0 && svc_pollfd == NULL)
>>>>> @@ -111,4 +126,8 @@ svc_exit()
>>>>> svc_pollfd = NULL;
>>>>> svc_max_pollfd = 0;
>>>>> rwlock_unlock(&svc_fd_lock);
>>>>> +
>>>>> + pthread_mutex_lock(&svc_run_lock);
>>>>> + svc_loop_running = false;
>>>>> + pthread_mutex_unlock(&svc_run_lock);
>>>>> }
>>>>
>>>>
>>>> _______________________________________________
>>>> Libtirpc-devel mailing list
>>>> [email protected]
>>>> https://lists.sourceforge.net/lists/listinfo/libtirpc-devel
>>