1 files changed, 228 insertions, 0 deletions

diff --git a/drivers/staging/lustre/lustre/obdclass/genops.c b/drivers/staging/lustre/lustre/obdclass/genops.c
index cf8bb2a..fa0d38d 100644
--- a/drivers/staging/lustre/lustre/obdclass/genops.c
+++ b/drivers/staging/lustre/lustre/obdclass/genops.c
@@ -907,6 +907,8 @@ struct obd_import *class_new_import(struct obd_device *obd)
 	INIT_LIST_HEAD(&imp->imp_sending_list);
 	INIT_LIST_HEAD(&imp->imp_delayed_list);
 	INIT_LIST_HEAD(&imp->imp_committed_list);
+	INIT_LIST_HEAD(&imp->imp_unreplied_list);
+	imp->imp_known_replied_xid = 0;
 	imp->imp_replay_cursor = &imp->imp_committed_list;
 	spin_lock_init(&imp->imp_lock);
 	imp->imp_last_success_conn = 0;
@@ -1408,13 +1410,33 @@ EXPORT_SYMBOL(obd_get_max_rpcs_in_flight);
 int obd_set_max_rpcs_in_flight(struct client_obd *cli, __u32 max)
 {
 	struct obd_request_slot_waiter *orsw;
+	const char *typ_name;
 	__u32 old;
 	int diff;
+	int rc;
 	int i;
 
 	if (max > OBD_MAX_RIF_MAX || max < 1)
 		return -ERANGE;
 
+	typ_name = cli->cl_import->imp_obd->obd_type->typ_name;
+	if (!strcmp(typ_name, LUSTRE_MDC_NAME)) {
+		/*
+		 * adjust max_mod_rpcs_in_flight to ensure it is always
+		 * strictly lower that max_rpcs_in_flight
+		 */
+		if (max < 2) {
+			CERROR("%s: cannot set max_rpcs_in_flight to 1 because it must be higher than max_mod_rpcs_in_flight value\n",
+			       cli->cl_import->imp_obd->obd_name);
+			return -ERANGE;
+		}
+		if (max <= cli->cl_max_mod_rpcs_in_flight) {
+			rc = obd_set_max_mod_rpcs_in_flight(cli, max - 1);
+			if (rc)
+				return rc;
+		}
+	}
+
 	spin_lock(&cli->cl_loi_list_lock);
 	old = cli->cl_max_rpcs_in_flight;
 	cli->cl_max_rpcs_in_flight = max;
@@ -1436,3 +1458,209 @@ int obd_set_max_rpcs_in_flight(struct client_obd *cli, __u32 max)
 	return 0;
 }
 EXPORT_SYMBOL(obd_set_max_rpcs_in_flight);
+
+int obd_set_max_mod_rpcs_in_flight(struct client_obd *cli, __u16 max)
+{
+	struct obd_connect_data *ocd;
+	u16 maxmodrpcs;
+	u16 prev;
+
+	if (max > OBD_MAX_RIF_MAX || max < 1)
+		return -ERANGE;
+
+	/* cannot exceed or equal max_rpcs_in_flight */
+	if (max >= cli->cl_max_rpcs_in_flight) {
+		CERROR("%s: can't set max_mod_rpcs_in_flight to a value (%hu) higher or equal to max_rpcs_in_flight value (%u)\n",
+		       cli->cl_import->imp_obd->obd_name,
+		       max, cli->cl_max_rpcs_in_flight);
+		return -ERANGE;
+	}
+
+	/* cannot exceed max modify RPCs in flight supported by the server */
+	ocd = &cli->cl_import->imp_connect_data;
+	if (ocd->ocd_connect_flags & OBD_CONNECT_MULTIMODRPCS)
+		maxmodrpcs = ocd->ocd_maxmodrpcs;
+	else
+		maxmodrpcs = 1;
+	if (max > maxmodrpcs) {
+		CERROR("%s: can't set max_mod_rpcs_in_flight to a value (%hu) higher than max_mod_rpcs_per_client value (%hu) returned by the server at connection\n",
+		       cli->cl_import->imp_obd->obd_name,
+		       max, maxmodrpcs);
+		return -ERANGE;
+	}
+
+	spin_lock(&cli->cl_mod_rpcs_lock);
+
+	prev = cli->cl_max_mod_rpcs_in_flight;
+	cli->cl_max_mod_rpcs_in_flight = max;
+
+	/* wakeup waiters if limit has been increased */
+	if (cli->cl_max_mod_rpcs_in_flight > prev)
+		wake_up(&cli->cl_mod_rpcs_waitq);
+
+	spin_unlock(&cli->cl_mod_rpcs_lock);
+
+	return 0;
+}
+EXPORT_SYMBOL(obd_set_max_mod_rpcs_in_flight);
+
+#define pct(a, b) (b ? (a * 100) / b : 0)
+
+int obd_mod_rpc_stats_seq_show(struct client_obd *cli, struct seq_file *seq)
+{
+	unsigned long mod_tot = 0, mod_cum;
+	struct timespec64 now;
+	int i;
+
+	ktime_get_real_ts64(&now);
+
+	spin_lock(&cli->cl_mod_rpcs_lock);
+
+	seq_printf(seq, "snapshot_time:		%llu.%9lu (secs.nsecs)\n",
+		   (s64)now.tv_sec, (unsigned long)now.tv_nsec);
+	seq_printf(seq, "modify_RPCs_in_flight:  %hu\n",
+		   cli->cl_mod_rpcs_in_flight);
+
+	seq_puts(seq, "\n\t\t\tmodify\n");
+	seq_puts(seq, "rpcs in flight        rpcs   %% cum %%\n");
+
+	mod_tot = lprocfs_oh_sum(&cli->cl_mod_rpcs_hist);
+
+	mod_cum = 0;
+	for (i = 0; i < OBD_HIST_MAX; i++) {
+		unsigned long mod = cli->cl_mod_rpcs_hist.oh_buckets[i];
+
+		mod_cum += mod;
+		seq_printf(seq, "%d:\t\t%10lu %3lu %3lu\n",
+			   i, mod, pct(mod, mod_tot),
+			   pct(mod_cum, mod_tot));
+		if (mod_cum == mod_tot)
+			break;
+	}
+
+	spin_unlock(&cli->cl_mod_rpcs_lock);
+
+	return 0;
+}
+EXPORT_SYMBOL(obd_mod_rpc_stats_seq_show);
+#undef pct
+
+/*
+ * The number of modify RPCs sent in parallel is limited
+ * because the server has a finite number of slots per client to
+ * store request result and ensure reply reconstruction when needed.
+ * On the client, this limit is stored in cl_max_mod_rpcs_in_flight
+ * that takes into account server limit and cl_max_rpcs_in_flight
+ * value.
+ * On the MDC client, to avoid a potential deadlock (see Bugzilla 3462),
+ * one close request is allowed above the maximum.
+ */
+static inline bool obd_mod_rpc_slot_avail_locked(struct client_obd *cli,
+						 bool close_req)
+{
+	bool avail;
+
+	/* A slot is available if
+	 * - number of modify RPCs in flight is less than the max
+	 * - it's a close RPC and no other close request is in flight
+	 */
+	avail = cli->cl_mod_rpcs_in_flight < cli->cl_max_mod_rpcs_in_flight ||
+		(close_req && !cli->cl_close_rpcs_in_flight);
+
+	return avail;
+}
+
+static inline bool obd_mod_rpc_slot_avail(struct client_obd *cli,
+					  bool close_req)
+{
+	bool avail;
+
+	spin_lock(&cli->cl_mod_rpcs_lock);
+	avail = obd_mod_rpc_slot_avail_locked(cli, close_req);
+	spin_unlock(&cli->cl_mod_rpcs_lock);
+	return avail;
+}
+
+/* Get a modify RPC slot from the obd client @cli according
+ * to the kind of operation @opc that is going to be sent
+ * and the intent @it of the operation if it applies.
+ * If the maximum number of modify RPCs in flight is reached
+ * the thread is put to sleep.
+ * Returns the tag to be set in the request message. Tag 0
+ * is reserved for non-modifying requests.
+ */
+u16 obd_get_mod_rpc_slot(struct client_obd *cli, __u32 opc,
+			 struct lookup_intent *it)
+{
+	struct l_wait_info lwi = LWI_INTR(NULL, NULL);
+	bool close_req = false;
+	u16 i, max;
+
+	/* read-only metadata RPCs don't consume a slot on MDT
+	 * for reply reconstruction
+	 */
+	if (it && (it->it_op == IT_GETATTR || it->it_op == IT_LOOKUP ||
+		   it->it_op == IT_LAYOUT || it->it_op == IT_READDIR))
+		return 0;
+
+	if (opc == MDS_CLOSE)
+		close_req = true;
+
+	do {
+		spin_lock(&cli->cl_mod_rpcs_lock);
+		max = cli->cl_max_mod_rpcs_in_flight;
+		if (obd_mod_rpc_slot_avail_locked(cli, close_req)) {
+			/* there is a slot available */
+			cli->cl_mod_rpcs_in_flight++;
+			if (close_req)
+				cli->cl_close_rpcs_in_flight++;
+			lprocfs_oh_tally(&cli->cl_mod_rpcs_hist,
+					 cli->cl_mod_rpcs_in_flight);
+			/* find a free tag */
+			i = find_first_zero_bit(cli->cl_mod_tag_bitmap,
+						max + 1);
+			LASSERT(i < OBD_MAX_RIF_MAX);
+			LASSERT(!test_and_set_bit(i, cli->cl_mod_tag_bitmap));
+			spin_unlock(&cli->cl_mod_rpcs_lock);
+			/* tag 0 is reserved for non-modify RPCs */
+			return i + 1;
+		}
+		spin_unlock(&cli->cl_mod_rpcs_lock);
+
+		CDEBUG(D_RPCTRACE, "%s: sleeping for a modify RPC slot opc %u, max %hu\n",
+		       cli->cl_import->imp_obd->obd_name, opc, max);
+
+		l_wait_event(cli->cl_mod_rpcs_waitq,
+			     obd_mod_rpc_slot_avail(cli, close_req), &lwi);
+	} while (true);
+}
+EXPORT_SYMBOL(obd_get_mod_rpc_slot);
+
+/*
+ * Put a modify RPC slot from the obd client @cli according
+ * to the kind of operation @opc that has been sent and the
+ * intent @it of the operation if it applies.
+ */
+void obd_put_mod_rpc_slot(struct client_obd *cli, u32 opc,
+			  struct lookup_intent *it, u16 tag)
+{
+	bool close_req = false;
+
+	if (it && (it->it_op == IT_GETATTR || it->it_op == IT_LOOKUP ||
+		   it->it_op == IT_LAYOUT || it->it_op == IT_READDIR))
+		return;
+
+	if (opc == MDS_CLOSE)
+		close_req = true;
+
+	spin_lock(&cli->cl_mod_rpcs_lock);
+	cli->cl_mod_rpcs_in_flight--;
+	if (close_req)
+		cli->cl_close_rpcs_in_flight--;
+	/* release the tag in the bitmap */
+	LASSERT(tag - 1 < OBD_MAX_RIF_MAX);
+	LASSERT(test_and_clear_bit(tag - 1, cli->cl_mod_tag_bitmap) != 0);
+	spin_unlock(&cli->cl_mod_rpcs_lock);
+	wake_up(&cli->cl_mod_rpcs_waitq);
+}
+EXPORT_SYMBOL(obd_put_mod_rpc_slot);