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
