Re: [PATCH v2 1/1] nfsd4: Expose the callback address and state of each NFS4 client

Chuck Lever III
2021-05-25T21:48:46Z

> On May 25, 2021, at 4:58 PM, Bruce Fields <bfields@fieldses.org> wrote:
>
> When I run trace-cmd report I get output like:
>
> [nfsd:nfsd_cb_state] function cb_state2str not defined
> [nfsd:nfsd_cb_shutdown] function cb_state2str not defined
> [nfsd:nfsd_cb_probe] function cb_state2str not defined
> [nfsd:nfsd_cb_lost] function cb_state2str not defined
>
> I don't know how this is supposed to work. Is it OK for tracepoint definitions
> to reference kernel functions if they're defined in the right way somehow? If
> not, I don't know what the solution would be for sharing this--define a macro
> that expands to the array literal and use that in both places? Or maybe just
> live with the the redundancy.

Living with the redundancy is OK with me.

> --b.
>
> On Mon, May 17, 2021 at 04:29:45PM -0400, Dave Wysochanski wrote:
>> In addition to the client's address, display the callback channel
>> state and address in the 'info' file. Define and use a common
>> function for this information that can be used by both callback
>> trace events and the NFS4 client 'info' file.
>>
>> Signed-off-by: Dave Wysochanski <dwysocha@redhat.com>
>> ---
>> fs/nfsd/nfs4state.c | 2 ++
>> fs/nfsd/trace.c | 15 +++++++++++++++
>> fs/nfsd/trace.h | 9 ++-------
>> 3 files changed, 19 insertions(+), 7 deletions(-)
>>
>> diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
>> index b2573d3ecd3c..f3b8221bb543 100644
>> --- a/fs/nfsd/nfs4state.c
>> +++ b/fs/nfsd/nfs4state.c
>> @@ -2385,6 +2385,8 @@ static int client_info_show(struct seq_file *m, void *v)
>> seq_printf(m, "\nImplementation time: [%lld, %ld]\n",
>> clp->cl_nii_time.tv_sec, clp->cl_nii_time.tv_nsec);
>> }
>> + seq_printf(m, "callback state: %s\n", cb_state2str(clp->cl_cb_state));
>> + seq_printf(m, "callback address: %pISpc\n", &clp->cl_cb_conn.cb_addr);
>> drop_client(clp);
>>
>> return 0;
>> diff --git a/fs/nfsd/trace.c b/fs/nfsd/trace.c
>> index f008b95ceec2..6291b5d10824 100644
>> --- a/fs/nfsd/trace.c
>> +++ b/fs/nfsd/trace.c
>> @@ -2,3 +2,18 @@
>>
>> #define CREATE_TRACE_POINTS
>> #include "trace.h"
>> +
>> +const char *cb_state2str(const int state)
>> +{
>> + switch (state) {
>> + case NFSD4_CB_UP:
>> + return "UP";
>> + case NFSD4_CB_UNKNOWN:
>> + return "UNKNOWN";
>> + case NFSD4_CB_DOWN:
>> + return "DOWN";
>> + case NFSD4_CB_FAULT:
>> + return "FAULT";
>> + }
>> + return "UNDEFINED";
>> +}
>> diff --git a/fs/nfsd/trace.h b/fs/nfsd/trace.h
>> index 10cc3aaf1089..8908d48b2aa6 100644
>> --- a/fs/nfsd/trace.h
>> +++ b/fs/nfsd/trace.h
>> @@ -876,12 +876,7 @@
>> TP_printk("client %08x:%08x", __entry->cl_boot, __entry->cl_id)
>> )
>>
>> -#define show_cb_state(val) \
>> - __print_symbolic(val, \
>> - { NFSD4_CB_UP, "UP" }, \
>> - { NFSD4_CB_UNKNOWN, "UNKNOWN" }, \
>> - { NFSD4_CB_DOWN, "DOWN" }, \
>> - { NFSD4_CB_FAULT, "FAULT"})
>> +const char *cb_state2str(const int state);
>>
>> DECLARE_EVENT_CLASS(nfsd_cb_class,
>> TP_PROTO(const struct nfs4_client *clp),
>> @@ -901,7 +896,7 @@
>> ),
>> TP_printk("addr=%pISpc client %08x:%08x state=%s",
>> __entry->addr, __entry->cl_boot, __entry->cl_id,
>> - show_cb_state(__entry->state))
>> + cb_state2str(__entry->state))
>> );
>>
>> #define DEFINE_NFSD_CB_EVENT(name) \
>> --
>> 1.8.3.1

--
Chuck Lever