NFSD: Add callback operation lifetime trace points
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.
Examples include:
nfsd-955 [004] 650.013997: nfsd_cb_queue: addr=192.168.122.6:0 client 65b3c5b8:f541f749 cb=0xffff8881134b02f8 (first try)
kworker/u21:4-497 [004] 650.014050: nfsd_cb_seq_status: task:00000001@00000001 sessionid=65b3c5b8:f541f749:00000001:00000000 tk_status=-107 seq_status=1
kworker/u21:4-497 [004] 650.014051: nfsd_cb_restart: addr=192.168.122.6:0 client 65b3c5b8:f541f749 cb=0xffff88810e39f400 (first try)
kworker/u21:4-497 [004] 650.014066: nfsd_cb_queue: addr=192.168.122.6:0 client 65b3c5b8:f541f749 cb=0xffff88810e39f400 (need restart)
kworker/u16:0-10 [006] 650.065750: nfsd_cb_start: addr=192.168.122.6:0 client 65b3c5b8:f541f749 state=UNKNOWN
kworker/u16:0-10 [006] 650.065752: nfsd_cb_bc_update: addr=192.168.122.6:0 client 65b3c5b8:f541f749 cb=0xffff8881134b02f8 (first try)
kworker/u16:0-10 [006] 650.065754: nfsd_cb_bc_shutdown: addr=192.168.122.6:0 client 65b3c5b8:f541f749 cb=0xffff8881134b02f8 (first try)
kworker/u16:0-10 [006] 650.065810: nfsd_cb_new_state: addr=192.168.122.6:0 client 65b3c5b8:f541f749 state=DOWN
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c
index a63171c..b50ce54 100644
--- a/fs/nfsd/nfs4callback.c
+++ b/fs/nfsd/nfs4callback.c
@@ -887,12 +887,14 @@ 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_delayed_work(callback_wq, &cb->cb_work, 0);
}
static void nfsd4_queue_cb_delayed(struct nfsd4_callback *cb,
unsigned long msecs)
{
+ trace_nfsd_cb_queue(cb->cb_clp, cb);
queue_delayed_work(callback_wq, &cb->cb_work,
msecs_to_jiffies(msecs));
}
@@ -1113,6 +1115,7 @@ 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);
@@ -1227,6 +1230,7 @@ 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;
}
@@ -1340,11 +1344,14 @@ 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);
@@ -1356,6 +1363,7 @@ static void nfsd4_process_cb_update(struct nfsd4_callback *cb)
}
if (test_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags))
return;
+
spin_lock(&clp->cl_lock);
/*
* Only serialized callback code is allowed to clear these
diff --git a/fs/nfsd/trace.h b/fs/nfsd/trace.h
index 6003af2..9f9e58d 100644
--- a/fs/nfsd/trace.h
+++ b/fs/nfsd/trace.h
@@ -1443,6 +1443,48 @@ TRACE_EVENT(nfsd_cb_setup_err,
__entry->error)
);
+DECLARE_EVENT_CLASS(nfsd_cb_lifetime_class,
+ TP_PROTO(
+ const struct nfs4_client *clp,
+ const struct nfsd4_callback *cb
+ ),
+ TP_ARGS(clp, cb),
+ TP_STRUCT__entry(
+ __field(u32, cl_boot)
+ __field(u32, cl_id)
+ __field(const void *, cb)
+ __field(bool, need_restart)
+ __sockaddr(addr, clp->cl_cb_conn.cb_addrlen)
+ ),
+ TP_fast_assign(
+ __entry->cl_boot = clp->cl_clientid.cl_boot;
+ __entry->cl_id = clp->cl_clientid.cl_id;
+ __entry->cb = cb;
+ __entry->need_restart = cb->cb_need_restart;
+ __assign_sockaddr(addr, &clp->cl_cb_conn.cb_addr,
+ clp->cl_cb_conn.cb_addrlen)
+ ),
+ TP_printk("addr=%pISpc client %08x:%08x cb=%p%s",
+ __get_sockaddr(addr), __entry->cl_boot, __entry->cl_id,
+ __entry->cb, __entry->need_restart ?
+ " (need restart)" : " (first try)"
+ )
+);
+
+#define DEFINE_NFSD_CB_LIFETIME_EVENT(name) \
+DEFINE_EVENT(nfsd_cb_lifetime_class, nfsd_cb_##name, \
+ TP_PROTO( \
+ const struct nfs4_client *clp, \
+ const struct nfsd4_callback *cb \
+ ), \
+ TP_ARGS(clp, cb))
+
+DEFINE_NFSD_CB_LIFETIME_EVENT(queue);
+DEFINE_NFSD_CB_LIFETIME_EVENT(destroy);
+DEFINE_NFSD_CB_LIFETIME_EVENT(restart);
+DEFINE_NFSD_CB_LIFETIME_EVENT(bc_update);
+DEFINE_NFSD_CB_LIFETIME_EVENT(bc_shutdown);
+
TRACE_EVENT(nfsd_cb_seq_status,
TP_PROTO(
const struct rpc_task *task,
