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

Bruce Fields
2021-05-25T20:58:49Z

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.

--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