On 25 Jan 2024, at 11:29, Chuck Lever wrote:
> From: Chuck Lever <chuck.lever@xxxxxxxxxx>
>
> Help observe the flow of callback operations.
>
> bc_shutdown() records exactly when the backchannel RPC client is
> destroyed and cl_cb_client is replaced with NULL.
>
> Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
> ---
> fs/nfsd/nfs4callback.c | 7 +++++++
> fs/nfsd/trace.h | 42 ++++++++++++++++++++++++++++++++++++++++++
> include/trace/misc/nfs.h | 34 ++++++++++++++++++++++++++++++++++
> 3 files changed, 83 insertions(+)
>
> diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c
> index 1c85426830b1..4d5a6370b92c 100644
> --- a/fs/nfsd/nfs4callback.c
> +++ b/fs/nfsd/nfs4callback.c
> @@ -887,6 +887,7 @@ static struct workqueue_struct *callback_wq;
>
> static bool nfsd4_queue_cb(struct nfsd4_callback *cb)
> {
> + trace_nfsd_cb_queue(cb->cb_clp, cb);
> return queue_work(callback_wq, &cb->cb_work);
> }
>
> @@ -1106,6 +1107,7 @@ static void nfsd41_destroy_cb(struct nfsd4_callback *cb)
> {
> struct nfs4_client *clp = cb->cb_clp;
>
> + trace_nfsd_cb_destroy(clp, cb);
> nfsd41_cb_release_slot(cb);
> if (cb->cb_ops && cb->cb_ops->release)
> cb->cb_ops->release(cb);
> @@ -1220,6 +1222,7 @@ static bool nfsd4_cb_sequence_done(struct rpc_task *task, struct nfsd4_callback
> goto out;
> need_restart:
> if (!test_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags)) {
> + trace_nfsd_cb_restart(clp, cb);
> task->tk_status = 0;
> cb->cb_need_restart = true;
I think you want to call the tracepoint /after/ setting cb_need_restart here..
> }
> @@ -1333,11 +1336,14 @@ static void nfsd4_process_cb_update(struct nfsd4_callback *cb)
> struct nfsd4_conn *c;
> int err;
>
> + trace_nfsd_cb_bc_update(clp, cb);
> +
> /*
> * This is either an update, or the client dying; in either case,
> * kill the old client:
> */
> if (clp->cl_cb_client) {
> + trace_nfsd_cb_bc_shutdown(clp, cb);
> rpc_shutdown_client(clp->cl_cb_client);
> clp->cl_cb_client = NULL;
> put_cred(clp->cl_cb_cred);
> @@ -1349,6 +1355,7 @@ static void nfsd4_process_cb_update(struct nfsd4_callback *cb)
> }
> if (test_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags))
> return;
> +
I'm in favor of this whitespace change, but did you mean to include it?
Ben
