nfsd: introduce nfsd4_callback_ops

Add a higher level abstraction than the rpc_ops for callback operations.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

3 files changed, 83 insertions, 71 deletions

diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c
index d97e2009e310..4fe4be1ee82e 100644
--- a/fs/nfsd/nfs4callback.c
+++ b/fs/nfsd/nfs4callback.c
@@ -824,18 +824,8 @@ static void nfsd4_cb_done(struct rpc_task *task, void *calldata)
                 dprintk("%s: freed slot, new seqid=%d\n", __func__,
                         clp->cl_cb_session->se_cb_seq_nr);
         }
-}
 
-static void nfsd4_cb_recall_done(struct rpc_task *task, void *calldata)
-{
-        struct nfsd4_callback *cb = calldata;
-        struct nfs4_delegation *dp = to_delegation(cb);
-        struct nfs4_client *clp = cb->cb_clp;
-        struct rpc_clnt *current_rpc_client = clp->cl_cb_client;
-
-        nfsd4_cb_done(task, calldata);
-
-        if (current_rpc_client != task->tk_client) {
+        if (clp->cl_cb_client != task->tk_client) {
                 /* We're shutting down or changing cl_cb_client; leave
                  * it to nfsd4_process_cb_update to restart the call if
                  * necessary. */
@@ -844,45 +834,42 @@ static void nfsd4_cb_recall_done(struct rpc_task *task, void *calldata)
 
         if (cb->cb_done)
                 return;
-        switch (task->tk_status) {
+
+        switch (cb->cb_ops->done(cb, task)) {
         case 0:
+                task->tk_status = 0;
+                rpc_restart_call_prepare(task);
+                return;
+        case 1:
                 break;
-        case -EBADHANDLE:
-        case -NFS4ERR_BAD_STATEID:
-                /* Race: client probably got cb_recall
-                 * before open reply granting delegation */
-                if (dp->dl_retries--) {
-                        rpc_delay(task, 2*HZ);
-                        task->tk_status = 0;
-                        rpc_restart_call_prepare(task);
-                        return;
-                }
-        default:
+        case -1:
                 /* Network partition? */
                 nfsd4_mark_cb_down(clp, task->tk_status);
+                break;
+        default:
+                BUG();
         }
         cb->cb_done = true;
 }
 
-static void nfsd4_cb_recall_release(void *calldata)
+static void nfsd4_cb_release(void *calldata)
 {
         struct nfsd4_callback *cb = calldata;
         struct nfs4_client *clp = cb->cb_clp;
 
         if (cb->cb_done) {
-                struct nfs4_delegation *dp = to_delegation(cb);
-
                 spin_lock(&clp->cl_lock);
                 list_del(&cb->cb_per_client);
                 spin_unlock(&clp->cl_lock);
-                nfs4_put_stid(&dp->dl_stid);
+
+                cb->cb_ops->release(cb);
         }
 }
 
-static const struct rpc_call_ops nfsd4_cb_recall_ops = {
+static const struct rpc_call_ops nfsd4_cb_ops = {
         .rpc_call_prepare = nfsd4_cb_prepare,
-        .rpc_call_done = nfsd4_cb_recall_done,
-        .rpc_release = nfsd4_cb_recall_release,
+        .rpc_call_done = nfsd4_cb_done,
+        .rpc_release = nfsd4_cb_release,
 };
 
 int nfsd4_create_callback_queue(void)
@@ -911,12 +898,6 @@ void nfsd4_shutdown_callback(struct nfs4_client *clp)
         flush_workqueue(callback_wq);
 }
 
-static void nfsd4_release_cb(struct nfsd4_callback *cb)
-{
-        if (cb->cb_ops->rpc_release)
-                cb->cb_ops->rpc_release(cb);
-}
-
 /* requires cl_lock: */
 static struct nfsd4_conn * __nfsd4_find_backchannel(struct nfs4_client *clp)
 {
@@ -983,54 +964,40 @@ static void nfsd4_process_cb_update(struct nfsd4_callback *cb)
 }
 
 static void
-nfsd4_run_callback_rpc(struct nfsd4_callback *cb)
+nfsd4_run_cb_work(struct work_struct *work)
 {
+        struct nfsd4_callback *cb =
+                container_of(work, struct nfsd4_callback, cb_work);
         struct nfs4_client *clp = cb->cb_clp;
         struct rpc_clnt *clnt;
 
+        if (cb->cb_ops && cb->cb_ops->prepare)
+                cb->cb_ops->prepare(cb);
+
         if (clp->cl_flags & NFSD4_CLIENT_CB_FLAG_MASK)
                 nfsd4_process_cb_update(cb);
 
         clnt = clp->cl_cb_client;
         if (!clnt) {
                 /* Callback channel broken, or client killed; give up: */
-                nfsd4_release_cb(cb);
+                if (cb->cb_ops && cb->cb_ops->release)
+                        cb->cb_ops->release(cb);
                 return;
         }
         cb->cb_msg.rpc_cred = clp->cl_cb_cred;
         rpc_call_async(clnt, &cb->cb_msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN,
-                        cb->cb_ops, cb);
-}
-
-void
-nfsd4_run_cb_null(struct work_struct *w)
-{
-        struct nfsd4_callback *cb = container_of(w, struct nfsd4_callback,
-                                                        cb_work);
-        nfsd4_run_callback_rpc(cb);
-}
-
-void
-nfsd4_run_cb_recall(struct work_struct *w)
-{
-        struct nfsd4_callback *cb = container_of(w, struct nfsd4_callback,
-                                                        cb_work);
-
-        nfsd4_prepare_cb_recall(to_delegation(cb));
-        nfsd4_run_callback_rpc(cb);
+                        cb->cb_ops ? &nfsd4_cb_ops : &nfsd4_cb_probe_ops, cb);
 }
 
 void nfsd4_init_cb(struct nfsd4_callback *cb, struct nfs4_client *clp,
-                enum nfsd4_cb_op op)
+                struct nfsd4_callback_ops *ops, enum nfsd4_cb_op op)
 {
         cb->cb_clp = clp;
         cb->cb_msg.rpc_proc = &nfs4_cb_procedures[op];
         cb->cb_msg.rpc_argp = cb;
         cb->cb_msg.rpc_resp = cb;
-        if (op == NFSPROC4_CLNT_CB_NULL)
-                cb->cb_ops = &nfsd4_cb_probe_ops;
-        else
-                cb->cb_ops = &nfsd4_cb_recall_ops;
+        cb->cb_ops = ops;
+        INIT_WORK(&cb->cb_work, nfsd4_run_cb_work);
         INIT_LIST_HEAD(&cb->cb_per_client);
         cb->cb_done = true;
 }
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index a0ead0c57268..551f32d7f5c7 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -96,6 +96,8 @@ static struct kmem_cache *deleg_slab;
 
 static void free_session(struct nfsd4_session *);
 
+static struct nfsd4_callback_ops nfsd4_cb_recall_ops;
+
 static bool is_session_dead(struct nfsd4_session *ses)
 {
         return ses->se_flags & NFS4_SESSION_DEAD;
@@ -647,8 +649,7 @@ alloc_init_deleg(struct nfs4_client *clp, struct svc_fh *current_fh)
         dp->dl_type = NFS4_OPEN_DELEGATE_READ;
         dp->dl_retries = 1;
         nfsd4_init_cb(&dp->dl_recall, dp->dl_stid.sc_client,
-                 NFSPROC4_CLNT_CB_RECALL);
-        INIT_WORK(&dp->dl_recall.cb_work, nfsd4_run_cb_recall);
+                      &nfsd4_cb_recall_ops, NFSPROC4_CLNT_CB_RECALL);
         return dp;
 out_dec:
         atomic_long_dec(&num_delegations);
@@ -1872,8 +1873,7 @@ static struct nfs4_client *create_client(struct xdr_netobj name,
                 free_client(clp);
                 return NULL;
         }
-        nfsd4_init_cb(&clp->cl_cb_null, clp, NFSPROC4_CLNT_CB_NULL);
-        INIT_WORK(&clp->cl_cb_null.cb_work, nfsd4_run_cb_null);
+        nfsd4_init_cb(&clp->cl_cb_null, clp, NULL, NFSPROC4_CLNT_CB_NULL);
         clp->cl_time = get_seconds();
         clear_bit(0, &clp->cl_cb_slot_busy);
         copy_verf(clp, verf);
@@ -3360,8 +3360,12 @@ nfs4_share_conflict(struct svc_fh *current_fh, unsigned int deny_type)
         return ret;
 }
 
-void nfsd4_prepare_cb_recall(struct nfs4_delegation *dp)
+#define cb_to_delegation(cb) \
+        container_of(cb, struct nfs4_delegation, dl_recall)
+
+static void nfsd4_cb_recall_prepare(struct nfsd4_callback *cb)
 {
+        struct nfs4_delegation *dp = cb_to_delegation(cb);
         struct nfsd_net *nn = net_generic(dp->dl_stid.sc_client->net,
                                           nfsd_net_id);
 
@@ -3382,6 +3386,43 @@ void nfsd4_prepare_cb_recall(struct nfs4_delegation *dp)
         spin_unlock(&state_lock);
 }
 
+static int nfsd4_cb_recall_done(struct nfsd4_callback *cb,
+                struct rpc_task *task)
+{
+        struct nfs4_delegation *dp = cb_to_delegation(cb);
+
+        switch (task->tk_status) {
+        case 0:
+                return 1;
+        case -EBADHANDLE:
+        case -NFS4ERR_BAD_STATEID:
+                /*
+                 * Race: client probably got cb_recall before open reply
+                 * granting delegation.
+                 */
+                if (dp->dl_retries--) {
+                        rpc_delay(task, 2 * HZ);
+                        return 0;
+                }
+                /*FALLTHRU*/
+        default:
+                return -1;
+        }
+}
+
+static void nfsd4_cb_recall_release(struct nfsd4_callback *cb)
+{
+        struct nfs4_delegation *dp = cb_to_delegation(cb);
+
+        nfs4_put_stid(&dp->dl_stid);
+}
+
+static struct nfsd4_callback_ops nfsd4_cb_recall_ops = {
+        .prepare        = nfsd4_cb_recall_prepare,
+        .done           = nfsd4_cb_recall_done,
+        .release        = nfsd4_cb_recall_release,
+};
+
 static void nfsd_break_one_deleg(struct nfs4_delegation *dp)
 {
         /*
diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h
index 3c3a1903b4fa..bf52dc7b15e7 100644
--- a/fs/nfsd/state.h
+++ b/fs/nfsd/state.h
@@ -66,11 +66,17 @@ struct nfsd4_callback {
         struct list_head cb_per_client;
         u32 cb_minorversion;
         struct rpc_message cb_msg;
-        const struct rpc_call_ops *cb_ops;
+        struct nfsd4_callback_ops *cb_ops;
         struct work_struct cb_work;
         bool cb_done;
 };
 
+struct nfsd4_callback_ops {
+        void (*prepare)(struct nfsd4_callback *);
+        int (*done)(struct nfsd4_callback *, struct rpc_task *);
+        void (*release)(struct nfsd4_callback *);
+};
+
 /*
  * A core object that represents a "common" stateid. These are generally
  * embedded within the different (more specific) stateid objects and contain
@@ -538,13 +544,11 @@ extern struct nfs4_client_reclaim *nfsd4_find_reclaim_client(const char *recdir,
 extern __be32 nfs4_check_open_reclaim(clientid_t *clid,
                 struct nfsd4_compound_state *cstate, struct nfsd_net *nn);
 extern int set_callback_cred(void);
-void nfsd4_run_cb_null(struct work_struct *w);
-void nfsd4_run_cb_recall(struct work_struct *w);
 extern void nfsd4_probe_callback(struct nfs4_client *clp);
 extern void nfsd4_probe_callback_sync(struct nfs4_client *clp);
 extern void nfsd4_change_callback(struct nfs4_client *clp, struct nfs4_cb_conn *);
 extern void nfsd4_init_cb(struct nfsd4_callback *cb, struct nfs4_client *clp,
-                enum nfsd4_cb_op op);
+                struct nfsd4_callback_ops *ops, enum nfsd4_cb_op op);
 extern void nfsd4_run_cb(struct nfsd4_callback *cb);
 extern int nfsd4_create_callback_queue(void);
 extern void nfsd4_destroy_callback_queue(void);