Merge tag 'nfsd-6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux

Pull nfsd updates from Chuck Lever:
 "Jeff Layton contributed a scalability improvement to NFSD's NFSv4
  backchannel session implementation. This improvement is intended to
  increase the rate at which NFSD can safely recall NFSv4 delegations
  from clients, to avoid the need to revoke them. Revoking requires a
  slow state recovery process.

  A wide variety of bug fixes and other incremental improvements make up
  the bulk of commits in this series. As always I am grateful to the
  NFSD contributors, reviewers, testers, and bug reporters who
  participated during this cycle"

* tag 'nfsd-6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux: (72 commits)
  nfsd: allow for up to 32 callback session slots
  nfs_common: must not hold RCU while calling nfsd_file_put_local
  nfsd: get rid of include ../internal.h
  nfsd: fix nfs4_openowner leak when concurrent nfsd4_open occur
  NFSD: Add nfsd4_copy time-to-live
  NFSD: Add a laundromat reaper for async copy state
  NFSD: Block DESTROY_CLIENTID only when there are ongoing async COPY operations
  NFSD: Handle an NFS4ERR_DELAY response to CB_OFFLOAD
  NFSD: Free async copy information in nfsd4_cb_offload_release()
  NFSD: Fix nfsd4_shutdown_copy()
  NFSD: Add a tracepoint to record canceled async COPY operations
  nfsd: make nfsd4_session->se_flags a bool
  nfsd: remove nfsd4_session->se_bchannel
  nfsd: make use of warning provided by refcount_t
  nfsd: Don't fail OP_SETCLIENTID when there are too many clients.
  svcrdma: fix miss destroy percpu_counter in svc_rdma_proc_init()
  xdrgen: Remove program_stat_to_errno() call sites
  xdrgen: Update the files included in client-side source code
  xdrgen: Remove check for "nfs_ok" in C templates
  xdrgen: Remove tracepoint call site
  ...

1 files changed, 93 insertions, 10 deletions

diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index d32f2dfd148f..f8a10f90bc7a 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -57,6 +57,8 @@ module_param(inter_copy_offload_enable, bool, 0644);
 MODULE_PARM_DESC(inter_copy_offload_enable,
 		 "Enable inter server to server copy offload. Default: false");
 
+static void cleanup_async_copy(struct nfsd4_copy *copy);
+
 #ifdef CONFIG_NFSD_V4_2_INTER_SSC
 static int nfsd4_ssc_umount_timeout = 900000;		/* default to 15 mins */
 module_param(nfsd4_ssc_umount_timeout, int, 0644);
@@ -1276,6 +1278,71 @@ out:
 	return status;
 }
 
+/**
+ * nfsd4_has_active_async_copies - Check for ongoing copy operations
+ * @clp: Client to be checked
+ *
+ * NFSD maintains state for async COPY operations after they complete,
+ * and this state remains in the nfs4_client's async_copies list.
+ * Ongoing copies should block the destruction of the nfs4_client, but
+ * completed copies should not.
+ *
+ * Return values:
+ *   %true: At least one active async COPY is ongoing
+ *   %false: No active async COPY operations were found
+ */
+bool nfsd4_has_active_async_copies(struct nfs4_client *clp)
+{
+	struct nfsd4_copy *copy;
+	bool result = false;
+
+	spin_lock(&clp->async_lock);
+	list_for_each_entry(copy, &clp->async_copies, copies) {
+		if (!test_bit(NFSD4_COPY_F_COMPLETED, &copy->cp_flags) &&
+		    !test_bit(NFSD4_COPY_F_STOPPED, &copy->cp_flags)) {
+			result = true;
+			break;
+		}
+	}
+	spin_unlock(&clp->async_lock);
+	return result;
+}
+
+/**
+ * nfsd4_async_copy_reaper - Purge completed copies
+ * @nn: Network namespace with possible active copy information
+ */
+void nfsd4_async_copy_reaper(struct nfsd_net *nn)
+{
+	struct nfs4_client *clp;
+	struct nfsd4_copy *copy;
+	LIST_HEAD(reaplist);
+
+	spin_lock(&nn->client_lock);
+	list_for_each_entry(clp, &nn->client_lru, cl_lru) {
+		struct list_head *pos, *next;
+
+		spin_lock(&clp->async_lock);
+		list_for_each_safe(pos, next, &clp->async_copies) {
+			copy = list_entry(pos, struct nfsd4_copy, copies);
+			if (test_bit(NFSD4_COPY_F_OFFLOAD_DONE, &copy->cp_flags)) {
+				if (--copy->cp_ttl) {
+					list_del_init(&copy->copies);
+					list_add(&copy->copies, &reaplist);
+				}
+			}
+		}
+		spin_unlock(&clp->async_lock);
+	}
+	spin_unlock(&nn->client_lock);
+
+	while (!list_empty(&reaplist)) {
+		copy = list_first_entry(&reaplist, struct nfsd4_copy, copies);
+		list_del_init(&copy->copies);
+		cleanup_async_copy(copy);
+	}
+}
+
 static void nfs4_put_copy(struct nfsd4_copy *copy)
 {
 	if (!refcount_dec_and_test(&copy->refcount))
@@ -1287,12 +1354,13 @@ static void nfs4_put_copy(struct nfsd4_copy *copy)
 
 static void nfsd4_stop_copy(struct nfsd4_copy *copy)
 {
+	trace_nfsd_copy_async_cancel(copy);
 	if (!test_and_set_bit(NFSD4_COPY_F_STOPPED, &copy->cp_flags))
 		kthread_stop(copy->copy_task);
 	nfs4_put_copy(copy);
 }
 
-static struct nfsd4_copy *nfsd4_get_copy(struct nfs4_client *clp)
+static struct nfsd4_copy *nfsd4_unhash_copy(struct nfs4_client *clp)
 {
 	struct nfsd4_copy *copy = NULL;
 
@@ -1301,6 +1369,9 @@ static struct nfsd4_copy *nfsd4_get_copy(struct nfs4_client *clp)
 		copy = list_first_entry(&clp->async_copies, struct nfsd4_copy,
 					copies);
 		refcount_inc(&copy->refcount);
+		copy->cp_clp = NULL;
+		if (!list_empty(&copy->copies))
+			list_del_init(&copy->copies);
 	}
 	spin_unlock(&clp->async_lock);
 	return copy;
@@ -1310,7 +1381,7 @@ void nfsd4_shutdown_copy(struct nfs4_client *clp)
 {
 	struct nfsd4_copy *copy;
 
-	while ((copy = nfsd4_get_copy(clp)) != NULL)
+	while ((copy = nfsd4_unhash_copy(clp)) != NULL)
 		nfsd4_stop_copy(copy);
 }
 #ifdef CONFIG_NFSD_V4_2_INTER_SSC
@@ -1598,8 +1669,10 @@ static void nfsd4_cb_offload_release(struct nfsd4_callback *cb)
 {
 	struct nfsd4_cb_offload *cbo =
 		container_of(cb, struct nfsd4_cb_offload, co_cb);
+	struct nfsd4_copy *copy =
+		container_of(cbo, struct nfsd4_copy, cp_cb_offload);
 
-	kfree(cbo);
+	set_bit(NFSD4_COPY_F_OFFLOAD_DONE, &copy->cp_flags);
 }
 
 static int nfsd4_cb_offload_done(struct nfsd4_callback *cb,
@@ -1609,6 +1682,13 @@ static int nfsd4_cb_offload_done(struct nfsd4_callback *cb,
 		container_of(cb, struct nfsd4_cb_offload, co_cb);
 
 	trace_nfsd_cb_offload_done(&cbo->co_res.cb_stateid, task);
+	switch (task->tk_status) {
+	case -NFS4ERR_DELAY:
+		if (cbo->co_retries--) {
+			rpc_delay(task, 1 * HZ);
+			return 0;
+		}
+	}
 	return 1;
 }
 
@@ -1732,15 +1812,12 @@ static void cleanup_async_copy(struct nfsd4_copy *copy)
 
 static void nfsd4_send_cb_offload(struct nfsd4_copy *copy)
 {
-	struct nfsd4_cb_offload *cbo;
-
-	cbo = kzalloc(sizeof(*cbo), GFP_KERNEL);
-	if (!cbo)
-		return;
+	struct nfsd4_cb_offload *cbo = &copy->cp_cb_offload;
 
 	memcpy(&cbo->co_res, &copy->cp_res, sizeof(copy->cp_res));
 	memcpy(&cbo->co_fh, &copy->fh, sizeof(copy->fh));
 	cbo->co_nfserr = copy->nfserr;
+	cbo->co_retries = 5;
 
 	nfsd4_init_cb(&cbo->co_cb, copy->cp_clp, &nfsd4_cb_offload_ops,
 		      NFSPROC4_CLNT_CB_OFFLOAD);
@@ -1786,10 +1863,13 @@ static int nfsd4_do_async_copy(void *data)
 	}
 
 do_callback:
+	/* The kthread exits forthwith. Ensure that a subsequent
+	 * OFFLOAD_CANCEL won't try to kill it again. */
+	set_bit(NFSD4_COPY_F_STOPPED, &copy->cp_flags);
+
 	set_bit(NFSD4_COPY_F_COMPLETED, &copy->cp_flags);
 	trace_nfsd_copy_async_done(copy);
 	nfsd4_send_cb_offload(copy);
-	cleanup_async_copy(copy);
 	return 0;
 }
 
@@ -1843,6 +1923,7 @@ nfsd4_copy(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 		async_copy->cp_nn = nn;
 		INIT_LIST_HEAD(&async_copy->copies);
 		refcount_set(&async_copy->refcount, 1);
+		async_copy->cp_ttl = NFSD_COPY_INITIAL_TTL;
 		/* Arbitrary cap on number of pending async copy operations */
 		if (atomic_inc_return(&nn->pending_async_copies) >
 				(int)rqstp->rq_pool->sp_nrthreads)
@@ -2780,6 +2861,7 @@ nfsd4_proc_compound(struct svc_rqst *rqstp)
 		if (op->opdesc->op_get_currentstateid)
 			op->opdesc->op_get_currentstateid(cstate, &op->u);
 		op->status = op->opdesc->op_func(rqstp, cstate, &op->u);
+		trace_nfsd_compound_op_err(rqstp, op->opnum, op->status);
 
 		/* Only from SEQUENCE */
 		if (cstate->status == nfserr_replay_cache) {
@@ -2796,7 +2878,7 @@ nfsd4_proc_compound(struct svc_rqst *rqstp)
 
 			if (current_fh->fh_export &&
 					need_wrongsec_check(rqstp))
-				op->status = check_nfsd_access(current_fh->fh_export, rqstp);
+				op->status = check_nfsd_access(current_fh->fh_export, rqstp, false);
 		}
 encode_op:
 		if (op->status == nfserr_replay_me) {
@@ -3452,6 +3534,7 @@ static const struct nfsd4_operation nfsd4_ops[] = {
 	/* NFSv4.1 operations */
 	[OP_EXCHANGE_ID] = {
 		.op_func = nfsd4_exchange_id,
+		.op_release = nfsd4_exchange_id_release,
 		.op_flags = ALLOWED_WITHOUT_FH | ALLOWED_AS_FIRST_OP
 				| OP_MODIFIES_SOMETHING,
 		.op_name = "OP_EXCHANGE_ID",