NFSD: Convert the callback workqueue to use delayed_work

Normally, NFSv4 callback operations are supposed to be sent to the
client as soon as they are queued up.

In a moment, I will introduce a recovery path where the server has
to wait for the client to reconnect. We don't want a hard busy wait
here -- the callback should be requeued to try again in several
milliseconds.

For now, convert nfsd4_callback from struct work_struct to struct
delayed_work, and queue with a zero delay argument. This should
avoid behavior changes for current operation.

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 43b0a34a5d5b8a3244db9304a630800050f87fb9..1ed2512b364846476557cf840216a053d214ebe2 100644 (file)
--- a/fs/nfsd/nfs4callback.c
+++ b/fs/nfsd/nfs4callback.c
@@ -887,7 +887,7 @@ static struct workqueue_struct *callback_wq;
 
 static bool nfsd4_queue_cb(struct nfsd4_callback *cb)
 {
-       return queue_work(callback_wq, &cb->cb_work);
+       return queue_delayed_work(callback_wq, &cb->cb_work, 0);
 }
 
 static void nfsd41_cb_inflight_begin(struct nfs4_client *clp)
@@ -1370,7 +1370,7 @@ static void
 nfsd4_run_cb_work(struct work_struct *work)
 {
        struct nfsd4_callback *cb =
-               container_of(work, struct nfsd4_callback, cb_work);
+               container_of(work, struct nfsd4_callback, cb_work.work);
        struct nfs4_client *clp = cb->cb_clp;
        struct rpc_clnt *clnt;
        int flags;
@@ -1415,7 +1415,7 @@ void nfsd4_init_cb(struct nfsd4_callback *cb, struct nfs4_client *clp,
        cb->cb_msg.rpc_argp = cb;
        cb->cb_msg.rpc_resp = cb;
        cb->cb_ops = ops;
-       INIT_WORK(&cb->cb_work, nfsd4_run_cb_work);
+       INIT_DELAYED_WORK(&cb->cb_work, nfsd4_run_cb_work);
        cb->cb_seq_status = 1;
        cb->cb_status = 0;
        cb->cb_need_restart = false;

diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h
index 41bdc913fa715b55a20460426a671bea10404817..87c4372ba36a8d1385bfceb6807e3ab5f74995c4 100644 (file)
--- a/fs/nfsd/state.h
+++ b/fs/nfsd/state.h
@@ -68,7 +68,7 @@ struct nfsd4_callback {
        struct nfs4_client *cb_clp;
        struct rpc_message cb_msg;
        const struct nfsd4_callback_ops *cb_ops;
-       struct work_struct cb_work;
+       struct delayed_work cb_work;
        int cb_seq_status;
        int cb_status;
        bool cb_need_restart;