> On Jun 10, 2021, at 10:50 AM, Olga Kornievskaia <olga.kornievskaia@xxxxxxxxx> wrote:
>
> On Thu, Jun 10, 2021 at 9:34 AM Chuck Lever III <chuck.lever@xxxxxxxxxx> wrote:
>>
>>
>>
>>> On Jun 9, 2021, at 5:53 PM, Olga Kornievskaia <olga.kornievskaia@xxxxxxxxx> wrote:
>>>
>>> From: Olga Kornievskaia <kolga@xxxxxxxxxx>
>>>
>>> To keep track of how many transports have already been added, add
>>> ability to query the number.
>>
>> Just a random thought: Would it make more sense to plug the
>> maximum allowed transports value into the struct rpc_clnt,
>> and then rpc_clnt_test_and_add_xprt() could prevent the
>> addition of the new xprt if the maximum would be exceeded?
>
> Sure that could be done. Then the value of maximum allowed transports
> should be defined at the RPC layer and not NFS?
The limits are defined by the upper layer (NFS) and enforced
by the RPC client.
> I currently check for
> upper bounds during the parsing of the mount option, would I be not
> doing that or exposing the RPC value to the NFS layer?
> Actually I think it might be nice to add some kind of warning in the
> log that a trunking transport wasn't created because the limit was
> reached but if we move things to the RPC, we can't distinguish between
> nconnect and trunking transports.
One or two new tracepoints might help in any case. I wouldn't
say admins need a log message, but someone debugging something
might want one.
>>> Signed-off-by: Olga Kornievskaia <kolga@xxxxxxxxxx>
>>> ---
>>> include/linux/sunrpc/clnt.h | 2 ++
>>> net/sunrpc/clnt.c | 13 +++++++++++++
>>> 2 files changed, 15 insertions(+)
>>>
>>> diff --git a/include/linux/sunrpc/clnt.h b/include/linux/sunrpc/clnt.h
>>> index 02e7a5863d28..27042f1e581f 100644
>>> --- a/include/linux/sunrpc/clnt.h
>>> +++ b/include/linux/sunrpc/clnt.h
>>> @@ -234,6 +234,8 @@ void rpc_clnt_xprt_switch_put(struct rpc_clnt *);
>>> void rpc_clnt_xprt_switch_add_xprt(struct rpc_clnt *, struct rpc_xprt *);
>>> bool rpc_clnt_xprt_switch_has_addr(struct rpc_clnt *clnt,
>>> const struct sockaddr *sap);
>>> +size_t rpc_clnt_xprt_switch_nactive(struct rpc_clnt *);
>>> +
>>> void rpc_cleanup_clids(void);
>>>
>>> static inline int rpc_reply_expected(struct rpc_task *task)
>>> diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
>>> index 42623d6b8f0e..b46262ffcf72 100644
>>> --- a/net/sunrpc/clnt.c
>>> +++ b/net/sunrpc/clnt.c
>>> @@ -2959,6 +2959,19 @@ bool rpc_clnt_xprt_switch_has_addr(struct rpc_clnt *clnt,
>>> }
>>> EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_has_addr);
>>>
>>> +size_t rpc_clnt_xprt_switch_nactive(struct rpc_clnt *clnt)
>>> +{
>>> + struct rpc_xprt_switch *xps;
>>> + size_t num;
>>> +
>>> + rcu_read_lock();
>>> + xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);
>>> + num = xps->xps_nactive;
>>> + rcu_read_unlock();
>>> + return num;
>>> +}
>>> +EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_nactive);
>>> +
>>> #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
>>> static void rpc_show_header(void)
>>> {
>>> --
>>> 2.27.0
>>>
>>
>> --
>> Chuck Lever
--
Chuck Lever
