Re: [PATCH RFC 9/9] NFSD: Trace delegation revocations

[Jeff Layton <jlayton@kernel.org>]

On Wed, 2022-10-05 at 10:56 -0400, Chuck Lever wrote:
> Revocation is an exceptional event. Generate a trace record when it
> occurs so that other activity can be triggered.
> 
> Example:
> 
> nfsd-1104  [005]  1912.002544: nfsd_stid_revoke:        client 633c9343:4e82788d stateid 00000003:00000001 ref=2 type=DELEG
> 
> Trace infrastructure is provided for subsequent additional tracing
> related to nfs4_stid activity.
> 
> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
> ---
>  fs/nfsd/nfs4state.c |    2 ++
>  fs/nfsd/trace.h     |   55 +++++++++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 57 insertions(+)
> 
> diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
> index 06499b9481a6..349302afa7eb 100644
> --- a/fs/nfsd/nfs4state.c
> +++ b/fs/nfsd/nfs4state.c
> @@ -1404,6 +1404,8 @@ static void revoke_delegation(struct nfs4_delegation *dp)
>  
>  	WARN_ON(!list_empty(&dp->dl_recall_lru));
>  
> +	trace_nfsd_stid_revoke(&dp->dl_stid);
> +
>  	if (clp->cl_minorversion) {
>  		dp->dl_stid.sc_type = NFS4_REVOKED_DELEG_STID;
>  		refcount_inc(&dp->dl_stid.sc_count);
> diff --git a/fs/nfsd/trace.h b/fs/nfsd/trace.h
> index 4921144880d3..23fb39c957af 100644
> --- a/fs/nfsd/trace.h
> +++ b/fs/nfsd/trace.h
> @@ -561,6 +561,61 @@ DEFINE_EVENT(nfsd_stateseqid_class, nfsd_##name, \
>  DEFINE_STATESEQID_EVENT(preprocess);
>  DEFINE_STATESEQID_EVENT(open_confirm);
>  
> +TRACE_DEFINE_ENUM(NFS4_OPEN_STID);
> +TRACE_DEFINE_ENUM(NFS4_LOCK_STID);
> +TRACE_DEFINE_ENUM(NFS4_DELEG_STID);
> +TRACE_DEFINE_ENUM(NFS4_CLOSED_STID);
> +TRACE_DEFINE_ENUM(NFS4_REVOKED_DELEG_STID);
> +TRACE_DEFINE_ENUM(NFS4_CLOSED_DELEG_STID);
> +TRACE_DEFINE_ENUM(NFS4_LAYOUT_STID);
> +
> +#define show_stid_type(x)						\
> +	__print_flags(x, "|",						\
> +		{ NFS4_OPEN_STID,		"OPEN" },		\
> +		{ NFS4_LOCK_STID,		"LOCK" },		\
> +		{ NFS4_DELEG_STID,		"DELEG" },		\
> +		{ NFS4_CLOSED_STID,		"CLOSED" },		\
> +		{ NFS4_REVOKED_DELEG_STID,	"REVOKED" },		\
> +		{ NFS4_CLOSED_DELEG_STID,	"CLOSED_DELEG" },	\
> +		{ NFS4_LAYOUT_STID,		"LAYOUT" })
> +
> +DECLARE_EVENT_CLASS(nfsd_stid_class,
> +	TP_PROTO(
> +		const struct nfs4_stid *stid
> +	),
> +	TP_ARGS(stid),
> +	TP_STRUCT__entry(
> +		__field(unsigned long, sc_type)
> +		__field(int, sc_count)
> +		__field(u32, cl_boot)
> +		__field(u32, cl_id)
> +		__field(u32, si_id)
> +		__field(u32, si_generation)
> +	),
> +	TP_fast_assign(
> +		const stateid_t *stp = &stid->sc_stateid;
> +
> +		__entry->sc_type = stid->sc_type;
> +		__entry->sc_count = refcount_read(&stid->sc_count);
> +		__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;
> +	),
> +	TP_printk("client %08x:%08x stateid %08x:%08x ref=%d type=%s",
> +		__entry->cl_boot, __entry->cl_id,
> +		__entry->si_id, __entry->si_generation,
> +		__entry->sc_count, show_stid_type(__entry->sc_type)
> +	)
> +);
> +
> +#define DEFINE_STID_EVENT(name)					\
> +DEFINE_EVENT(nfsd_stid_class, nfsd_stid_##name,			\
> +	TP_PROTO(const struct nfs4_stid *stid),			\
> +	TP_ARGS(stid))
> +
> +DEFINE_STID_EVENT(revoke);
> +
>  DECLARE_EVENT_CLASS(nfsd_clientid_class,
>  	TP_PROTO(const clientid_t *clid),
>  	TP_ARGS(clid),
> 
> 

Reviewed-by: Jeff Layton <jlayton@kernel.org>