Re: [PATCH RFC 09/21] NFSD: Add an nfsd_cb_offload tracepoint

[Olga Kornievskaia <aglo@xxxxxxxxx>]

Hi Chuck,

On Mon, May 10, 2021 at 12:05 PM Chuck Lever <chuck.lever@xxxxxxxxxx> wrote:
>
> Record the arguments of CB_OFFLOAD callbacks so we can better
> observe asynchronous copy-offload behavior. For example:
>
>             nfsd-995   [008]  7721.934222: nfsd_cb_offload:      addr=192.168.2.51:0 client 6092a47c:35a43fc1 fh_hash=0x8739113a

I like the idea but can we include copy->nfserr if there is one and/or
if not then size copied?

> Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
> Cc: Olga Kornievskaia <kolga@xxxxxxxxxx>
> Cc: Dai Ngo <Dai.Ngo@xxxxxxxxxx>
> ---
>  fs/nfsd/nfs4proc.c |    1 +
>  fs/nfsd/trace.h    |   30 ++++++++++++++++++++++++++++++
>  2 files changed, 31 insertions(+)
>
> diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
> index daf43b980d4b..7a13f6c848c6 100644
> --- a/fs/nfsd/nfs4proc.c
> +++ b/fs/nfsd/nfs4proc.c
> @@ -1497,6 +1497,7 @@ static int nfsd4_do_async_copy(void *data)
>         memcpy(&cb_copy->fh, &copy->fh, sizeof(copy->fh));
>         nfsd4_init_cb(&cb_copy->cp_cb, cb_copy->cp_clp,
>                         &nfsd4_cb_offload_ops, NFSPROC4_CLNT_CB_OFFLOAD);
> +       trace_nfsd_cb_offload(copy->cp_clp, &copy->cp_res.cb_stateid, &copy->fh);
>         nfsd4_run_cb(&cb_copy->cp_cb);
>  out:
>         if (!copy->cp_intra)
> diff --git a/fs/nfsd/trace.h b/fs/nfsd/trace.h
> index 1dce41b3bd4d..15cacbdac411 100644
> --- a/fs/nfsd/trace.h
> +++ b/fs/nfsd/trace.h
> @@ -1004,6 +1004,36 @@ TRACE_EVENT(nfsd_cb_notify_lock,
>                 __entry->fh_hash)
>  );
>
> +TRACE_EVENT(nfsd_cb_offload,
> +       TP_PROTO(
> +               const struct nfs4_client *clp,
> +               const stateid_t *stp,
> +               const struct knfsd_fh *fh
> +       ),
> +       TP_ARGS(clp, stp, fh),
> +       TP_STRUCT__entry(
> +               __field(u32, cl_boot)
> +               __field(u32, cl_id)
> +               __field(u32, si_id)
> +               __field(u32, si_generation)
> +               __field(u32, fh_hash)
> +               __array(unsigned char, addr, sizeof(struct sockaddr_in6))
> +       ),
> +       TP_fast_assign(
> +               __entry->cl_boot = stp->si_opaque.so_clid.cl_boot;
> +               __entry->cl_id = stp->si_opaque.so_clid.cl_id;
> +               __entry->si_id = stp->si_opaque.so_id;
> +               __entry->si_generation = stp->si_generation;
> +               __entry->fh_hash = knfsd_fh_hash(fh);
> +               memcpy(__entry->addr, &clp->cl_cb_conn.cb_addr,
> +                       sizeof(struct sockaddr_in6));
> +       ),
> +       TP_printk("addr=%pISpc client %08x:%08x stateid %08x:%08x fh_hash=0x%08x",
> +               __entry->addr, __entry->cl_boot, __entry->cl_id,
> +               __entry->si_id, __entry->si_generation,
> +               __entry->fh_hash)
> +);
> +
>  #endif /* _NFSD_TRACE_H */
>
>  #undef TRACE_INCLUDE_PATH
>
>