FAILED: patch "[PATCH] smb: client: resolve SWN tcon from live registrations" failed to apply to 6.1-stable tree

index 9753a432d099..9951817d0d7f 100644
@@ -28,10 +28,54 @@ struct cifs_swn_reg {
 	bool net_name_notify;
 	bool share_name_notify;
 	bool ip_notify;
-
-	struct cifs_tcon *tcon;
 };
 
+struct cifs_swn_reg_info {
+	int id;
+	unsigned int ref_count;
+	const char *net_name;
+	const char *share_name;
+	bool net_name_notify;
+	bool share_name_notify;
+	bool ip_notify;
+};
+
+static void cifs_swn_snapshot_reg(struct cifs_swn_reg *swnreg,
+				  struct cifs_swn_reg_info *info)
+{
+	info->id = swnreg->id;
+	info->ref_count = kref_read(&swnreg->ref_count);
+	info->net_name = swnreg->net_name;
+	info->share_name = swnreg->share_name;
+	info->net_name_notify = swnreg->net_name_notify;
+	info->share_name_notify = swnreg->share_name_notify;
+	info->ip_notify = swnreg->ip_notify;
+}
+
+static int cifs_swn_dup_reg(struct cifs_swn_reg *swnreg,
+			    struct cifs_swn_reg_info *info)
+{
+	cifs_swn_snapshot_reg(swnreg, info);
+
+	info->net_name = kstrdup(swnreg->net_name, GFP_KERNEL);
+	if (!info->net_name)
+		return -ENOMEM;
+
+	info->share_name = kstrdup(swnreg->share_name, GFP_KERNEL);
+	if (!info->share_name) {
+		kfree(info->net_name);
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+static void cifs_swn_free_reg_info(struct cifs_swn_reg_info *info)
+{
+	kfree(info->net_name);
+	kfree(info->share_name);
+}
+
 static int cifs_swn_auth_info_krb(struct cifs_tcon *tcon, struct sk_buff *skb)
 {
 	int ret;

@@ -73,7 +117,8 @@ static int cifs_swn_auth_info_ntlm(struct cifs_tcon *tcon, struct sk_buff *skb)
  * The authentication information to connect to the witness service is bundled
  * into the message.
  */
-static int cifs_swn_send_register_message(struct cifs_swn_reg *swnreg)
+static int cifs_swn_send_register_message(struct cifs_swn_reg_info *swnreg,
+					  struct cifs_tcon *tcon)
 {
 	struct sk_buff *skb;
 	struct genlmsghdr *hdr;

@@ -109,10 +154,10 @@ static int cifs_swn_send_register_message(struct cifs_swn_reg *swnreg)
 	 * told to switch to it (client move message). In these cases we unregister from the
 	 * server address and register to the new address when we receive the notification.
 	 */
-	if (swnreg->tcon->ses->server->use_swn_dstaddr)
-		addr = &swnreg->tcon->ses->server->swn_dstaddr;
+	if (tcon->ses->server->use_swn_dstaddr)
+		addr = &tcon->ses->server->swn_dstaddr;
 	else
-		addr = &swnreg->tcon->ses->server->dstaddr;
+		addr = &tcon->ses->server->dstaddr;
 
 	ret = nla_put(skb, CIFS_GENL_ATTR_SWN_IP, sizeof(struct sockaddr_storage), addr);
 	if (ret < 0)

@@ -136,10 +181,10 @@ static int cifs_swn_send_register_message(struct cifs_swn_reg *swnreg)
 			goto nlmsg_fail;
 	}
 
-	authtype = cifs_select_sectype(swnreg->tcon->ses->server, swnreg->tcon->ses->sectype);
+	authtype = cifs_select_sectype(tcon->ses->server, tcon->ses->sectype);
 	switch (authtype) {
 	case Kerberos:
-		ret = cifs_swn_auth_info_krb(swnreg->tcon, skb);
+		ret = cifs_swn_auth_info_krb(tcon, skb);
 		if (ret < 0) {
 			cifs_dbg(VFS, "%s: Failed to get kerberos auth info: %d\n", __func__, ret);
 			goto nlmsg_fail;

@@ -147,7 +192,7 @@ static int cifs_swn_send_register_message(struct cifs_swn_reg *swnreg)
 		break;
 	case NTLMv2:
 	case RawNTLMSSP:
-		ret = cifs_swn_auth_info_ntlm(swnreg->tcon, skb);
+		ret = cifs_swn_auth_info_ntlm(tcon, skb);
 		if (ret < 0) {
 			cifs_dbg(VFS, "%s: Failed to get NTLM auth info: %d\n", __func__, ret);
 			goto nlmsg_fail;

@@ -176,7 +221,8 @@ static int cifs_swn_send_register_message(struct cifs_swn_reg *swnreg)
 /*
  * Sends an uregister message to the userspace daemon based on the registration
  */
-static int cifs_swn_send_unregister_message(struct cifs_swn_reg *swnreg)
+static int cifs_swn_send_unregister_message(struct cifs_swn_reg_info *swnreg,
+					    struct cifs_tcon *tcon)
 {
 	struct sk_buff *skb;
 	struct genlmsghdr *hdr;

@@ -205,7 +251,7 @@ static int cifs_swn_send_unregister_message(struct cifs_swn_reg *swnreg)
 		goto nlmsg_fail;
 
 	ret = nla_put(skb, CIFS_GENL_ATTR_SWN_IP, sizeof(struct sockaddr_storage),
-			&swnreg->tcon->ses->server->dstaddr);
+			&tcon->ses->server->dstaddr);
 	if (ret < 0)
 		goto nlmsg_fail;
 

@@ -241,6 +287,88 @@ static int cifs_swn_send_unregister_message(struct cifs_swn_reg *swnreg)
 	return ret;
 }
 
+/*
+ * Allocation-free mirror of extract_hostname() + extract_sharename() from
+ * fs/smb/client/unc.c.  Those helpers kmalloc(GFP_KERNEL); this runs under
+ * cifs_tcp_ses_lock and tcon->tc_lock, both spinlocks, so we mirror their
+ * parsing in place against the caller's stable net_name/share_name strings.
+ * Keep in sync with unc.c.
+ */
+static bool cifs_swn_tcon_matches(struct cifs_tcon *tcon,
+				  const char *net_name,
+				  const char *share_name)
+{
+	const char *unc = tcon->tree_name;
+	const char *host, *share, *delim;
+	size_t host_len, share_len;
+
+	if (!tcon->use_witness)
+		return false;
+
+	/* extract_hostname: require strlen(unc) >= 3 */
+	if (strnlen(unc, 3) < 3)
+		return false;
+	/* extract_hostname: skip all leading '\' characters */
+	for (host = unc; *host == '\\'; host++)
+		;
+	if (!*host)
+		return false;
+	delim = strchr(host, '\\');
+	if (!delim)
+		return false;
+	host_len = delim - host;
+	if (strlen(net_name) != host_len ||
+	    strncasecmp(host, net_name, host_len))
+		return false;
+
+	/* extract_sharename: start at unc + 2, then first '\' onward */
+	share = unc + 2;
+	delim = strchr(share, '\\');
+	if (!delim)
+		return false;
+	share = delim + 1;
+	share_len = strlen(share);
+
+	return strlen(share_name) == share_len &&
+	       !strncasecmp(share, share_name, share_len);
+}
+
+/*
+ * One SWN registration id represents one net/share name pair.  Multiple
+ * mounted tcons can therefore share the id.  Pick a live representative at
+ * use time instead of caching the first tcon pointer in the registration.
+ */
+static struct cifs_tcon *cifs_swn_get_tcon(struct cifs_swn_reg_info *swnreg)
+{
+	struct TCP_Server_Info *server;
+	struct cifs_ses *ses;
+	struct cifs_tcon *tcon;
+
+	spin_lock(&cifs_tcp_ses_lock);
+	list_for_each_entry(server, &cifs_tcp_ses_list, tcp_ses_list) {
+		list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) {
+			list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
+				spin_lock(&tcon->tc_lock);
+				if (tcon->status == TID_EXITING ||
+				    !cifs_swn_tcon_matches(tcon, swnreg->net_name,
+							   swnreg->share_name)) {
+					spin_unlock(&tcon->tc_lock);
+					continue;
+				}
+				++tcon->tc_count;
+				trace_smb3_tcon_ref(tcon->debug_id,
+						    tcon->tc_count,
+						    netfs_trace_tcon_ref_get_swn_notify);
+				spin_unlock(&tcon->tc_lock);
+				spin_unlock(&cifs_tcp_ses_lock);
+				return tcon;
+			}
+		}
+	}
+	spin_unlock(&cifs_tcp_ses_lock);
+	return NULL;
+}
+
 /*
  * Try to find a matching registration for the tcon's server name and share name.
  * Calls to this function must be protected by cifs_swnreg_idr_mutex.

@@ -347,8 +475,6 @@ static struct cifs_swn_reg *cifs_get_swn_reg(struct cifs_tcon *tcon)
 	reg->net_name_notify = true;
 	reg->share_name_notify = true;
 	reg->ip_notify = (tcon->capabilities & SMB2_SHARE_CAP_SCALEOUT);
-
-	reg->tcon = tcon;
 unlock:
 	mutex_unlock(&cifs_swnreg_idr_mutex);
 

@@ -368,11 +494,6 @@ static struct cifs_swn_reg *cifs_get_swn_reg(struct cifs_tcon *tcon)
 static void cifs_swn_reg_release(struct kref *ref)
 {
 	struct cifs_swn_reg *swnreg = container_of(ref, struct cifs_swn_reg, ref_count);
-	int ret;
-
-	ret = cifs_swn_send_unregister_message(swnreg);
-	if (ret < 0)
-		cifs_dbg(VFS, "%s: Failed to send unregister message: %d\n", __func__, ret);
 
 	idr_remove(&cifs_swnreg_idr, swnreg->id);
 	kfree(swnreg->net_name);

@@ -380,23 +501,33 @@ static void cifs_swn_reg_release(struct kref *ref)
 	kfree(swnreg);
 }
 
-static void cifs_put_swn_reg(struct cifs_swn_reg *swnreg)
+static void cifs_put_swn_reg_locked(struct cifs_swn_reg *swnreg,
+				    struct cifs_tcon *tcon)
 {
-	mutex_lock(&cifs_swnreg_idr_mutex);
+	if (kref_read(&swnreg->ref_count) == 1) {
+		struct cifs_swn_reg_info swnreg_info;
+		int ret;
+
+		cifs_swn_snapshot_reg(swnreg, &swnreg_info);
+		ret = cifs_swn_send_unregister_message(&swnreg_info, tcon);
+		if (ret < 0)
+			cifs_dbg(VFS, "%s: Failed to send unregister message: %d\n",
+				 __func__, ret);
+	}
+
 	kref_put(&swnreg->ref_count, cifs_swn_reg_release);
-	mutex_unlock(&cifs_swnreg_idr_mutex);
 }
 
-static int cifs_swn_resource_state_changed(struct cifs_swn_reg *swnreg, const char *name, int state)
+static int cifs_swn_resource_state_changed(struct cifs_tcon *tcon, const char *name, int state)
 {
 	switch (state) {
 	case CIFS_SWN_RESOURCE_STATE_UNAVAILABLE:
 		cifs_dbg(FYI, "%s: resource name '%s' become unavailable\n", __func__, name);
-		cifs_signal_cifsd_for_reconnect(swnreg->tcon->ses->server, true);
+		cifs_signal_cifsd_for_reconnect(tcon->ses->server, true);
 		break;
 	case CIFS_SWN_RESOURCE_STATE_AVAILABLE:
 		cifs_dbg(FYI, "%s: resource name '%s' become available\n", __func__, name);
-		cifs_signal_cifsd_for_reconnect(swnreg->tcon->ses->server, true);
+		cifs_signal_cifsd_for_reconnect(tcon->ses->server, true);
 		break;
 	case CIFS_SWN_RESOURCE_STATE_UNKNOWN:
 		cifs_dbg(FYI, "%s: resource name '%s' changed to unknown state\n", __func__, name);

@@ -502,7 +633,7 @@ static int cifs_swn_reconnect(struct cifs_tcon *tcon, struct sockaddr_storage *a
 	return ret;
 }
 
-static int cifs_swn_client_move(struct cifs_swn_reg *swnreg, struct sockaddr_storage *addr)
+static int cifs_swn_client_move(struct cifs_tcon *tcon, struct sockaddr_storage *addr)
 {
 	struct sockaddr_in *ipv4 = (struct sockaddr_in *)addr;
 	struct sockaddr_in6 *ipv6 = (struct sockaddr_in6 *)addr;

@@ -512,14 +643,17 @@ static int cifs_swn_client_move(struct cifs_swn_reg *swnreg, struct sockaddr_sto
 	else if (addr->ss_family == AF_INET6)
 		cifs_dbg(FYI, "%s: move to %pI6\n", __func__, &ipv6->sin6_addr);
 
-	return cifs_swn_reconnect(swnreg->tcon, addr);
+	return cifs_swn_reconnect(tcon, addr);
 }
 
 int cifs_swn_notify(struct sk_buff *skb, struct genl_info *info)
 {
 	struct cifs_swn_reg *swnreg;
+	struct cifs_swn_reg_info swnreg_info;
+	struct cifs_tcon *tcon;
 	char name[256];
 	int type;
+	int ret = 0;
 
 	if (info->attrs[CIFS_GENL_ATTR_SWN_REGISTRATION_ID]) {
 		int swnreg_id;

@@ -527,21 +661,34 @@ int cifs_swn_notify(struct sk_buff *skb, struct genl_info *info)
 		swnreg_id = nla_get_u32(info->attrs[CIFS_GENL_ATTR_SWN_REGISTRATION_ID]);
 		mutex_lock(&cifs_swnreg_idr_mutex);
 		swnreg = idr_find(&cifs_swnreg_idr, swnreg_id);
-		mutex_unlock(&cifs_swnreg_idr_mutex);
 		if (swnreg == NULL) {
+			mutex_unlock(&cifs_swnreg_idr_mutex);
 			cifs_dbg(FYI, "%s: registration id %d not found\n", __func__, swnreg_id);
 			return -EINVAL;
 		}
+		ret = cifs_swn_dup_reg(swnreg, &swnreg_info);
+		mutex_unlock(&cifs_swnreg_idr_mutex);
+		if (ret)
+			return ret;
 	} else {
 		cifs_dbg(FYI, "%s: missing registration id attribute\n", __func__);
 		return -EINVAL;
 	}
 
+	tcon = cifs_swn_get_tcon(&swnreg_info);
+	if (!tcon) {
+		cifs_dbg(FYI, "%s: registration id %d has no live tcon\n",
+			 __func__, swnreg_info.id);
+		ret = -ENODEV;
+		goto free_info;
+	}
+
 	if (info->attrs[CIFS_GENL_ATTR_SWN_NOTIFICATION_TYPE]) {
 		type = nla_get_u32(info->attrs[CIFS_GENL_ATTR_SWN_NOTIFICATION_TYPE]);
 	} else {
 		cifs_dbg(FYI, "%s: missing notification type attribute\n", __func__);
-		return -EINVAL;
+		ret = -EINVAL;
+		goto out;
 	}
 
 	switch (type) {

@@ -553,15 +700,18 @@ int cifs_swn_notify(struct sk_buff *skb, struct genl_info *info)
 					sizeof(name));
 		} else {
 			cifs_dbg(FYI, "%s: missing resource name attribute\n", __func__);
-			return -EINVAL;
+			ret = -EINVAL;
+			goto out;
 		}
 		if (info->attrs[CIFS_GENL_ATTR_SWN_RESOURCE_STATE]) {
 			state = nla_get_u32(info->attrs[CIFS_GENL_ATTR_SWN_RESOURCE_STATE]);
 		} else {
 			cifs_dbg(FYI, "%s: missing resource state attribute\n", __func__);
-			return -EINVAL;
+			ret = -EINVAL;
+			goto out;
 		}
-		return cifs_swn_resource_state_changed(swnreg, name, state);
+		ret = cifs_swn_resource_state_changed(tcon, name, state);
+		break;
 	}
 	case CIFS_SWN_NOTIFICATION_CLIENT_MOVE: {
 		struct sockaddr_storage addr;

@@ -570,28 +720,36 @@ int cifs_swn_notify(struct sk_buff *skb, struct genl_info *info)
 			nla_memcpy(&addr, info->attrs[CIFS_GENL_ATTR_SWN_IP], sizeof(addr));
 		} else {
 			cifs_dbg(FYI, "%s: missing IP address attribute\n", __func__);
-			return -EINVAL;
+			ret = -EINVAL;
+			goto out;
 		}
-		return cifs_swn_client_move(swnreg, &addr);
+		ret = cifs_swn_client_move(tcon, &addr);
+		break;
 	}
 	default:
 		cifs_dbg(FYI, "%s: unknown notification type %d\n", __func__, type);
 		break;
 	}
 
-	return 0;
+out:
+	cifs_put_tcon(tcon, netfs_trace_tcon_ref_put_swn_notify);
+free_info:
+	cifs_swn_free_reg_info(&swnreg_info);
+	return ret;
 }
 
 int cifs_swn_register(struct cifs_tcon *tcon)
 {
 	struct cifs_swn_reg *swnreg;
+	struct cifs_swn_reg_info swnreg_info;
 	int ret;
 
 	swnreg = cifs_get_swn_reg(tcon);
 	if (IS_ERR(swnreg))
 		return PTR_ERR(swnreg);
 
-	ret = cifs_swn_send_register_message(swnreg);
+	cifs_swn_snapshot_reg(swnreg, &swnreg_info);
+	ret = cifs_swn_send_register_message(&swnreg_info, tcon);
 	if (ret < 0) {
 		cifs_dbg(VFS, "%s: Failed to send swn register message: %d\n", __func__, ret);
 		/* Do not put the swnreg or return error, the echo task will retry */

@@ -612,35 +770,68 @@ int cifs_swn_unregister(struct cifs_tcon *tcon)
 		return PTR_ERR(swnreg);
 	}
 
+	cifs_put_swn_reg_locked(swnreg, tcon);
 	mutex_unlock(&cifs_swnreg_idr_mutex);
 
-	cifs_put_swn_reg(swnreg);
-
 	return 0;
 }
 
-void cifs_swn_dump(struct seq_file *m)
+/*
+ * Snapshot one registration under cifs_swnreg_idr_mutex and return.  Callers
+ * intentionally do the per-registration network/genlmsg work without the
+ * mutex held, both to keep the critical section short and to avoid nesting
+ * cifs_swnreg_idr_mutex inside the higher tc_lock when a live tcon is then
+ * pinned for the send.
+ */
+static int cifs_swn_get_next_reg_info(int *id, struct cifs_swn_reg_info *info)
 {
 	struct cifs_swn_reg *swnreg;
+	int ret = 0;
+
+	mutex_lock(&cifs_swnreg_idr_mutex);
+	swnreg = idr_get_next(&cifs_swnreg_idr, id);
+	if (swnreg) {
+		ret = cifs_swn_dup_reg(swnreg, info);
+		if (!ret) {
+			*id = swnreg->id + 1;
+			ret = 1;
+		}
+	}
+	mutex_unlock(&cifs_swnreg_idr_mutex);
+
+	return ret;
+}
+
+void cifs_swn_dump(struct seq_file *m)
+{
+	struct cifs_swn_reg_info swnreg_info;
+	struct cifs_tcon *tcon;
 	struct sockaddr_in *sa;
 	struct sockaddr_in6 *sa6;
-	int id;
+	int id = 0;
+	int ret;
 
 	seq_puts(m, "Witness registrations:");
 
-	mutex_lock(&cifs_swnreg_idr_mutex);
-	idr_for_each_entry(&cifs_swnreg_idr, swnreg, id) {
+	while ((ret = cifs_swn_get_next_reg_info(&id, &swnreg_info)) > 0) {
 		seq_printf(m, "\nId: %u Refs: %u Network name: '%s'%s Share name: '%s'%s Ip address: ",
-				id, kref_read(&swnreg->ref_count),
-				swnreg->net_name, swnreg->net_name_notify ? "(y)" : "(n)",
-				swnreg->share_name, swnreg->share_name_notify ? "(y)" : "(n)");
-		switch (swnreg->tcon->ses->server->dstaddr.ss_family) {
+			   swnreg_info.id, swnreg_info.ref_count,
+			   swnreg_info.net_name, swnreg_info.net_name_notify ? "(y)" : "(n)",
+			   swnreg_info.share_name, swnreg_info.share_name_notify ? "(y)" : "(n)");
+
+		tcon = cifs_swn_get_tcon(&swnreg_info);
+		if (!tcon) {
+			seq_puts(m, "(no live tcon)");
+			goto next;
+		}
+
+		switch (tcon->ses->server->dstaddr.ss_family) {
 		case AF_INET:
-			sa = (struct sockaddr_in *) &swnreg->tcon->ses->server->dstaddr;
+			sa = (struct sockaddr_in *)&tcon->ses->server->dstaddr;
 			seq_printf(m, "%pI4", &sa->sin_addr.s_addr);
 			break;
 		case AF_INET6:
-			sa6 = (struct sockaddr_in6 *) &swnreg->tcon->ses->server->dstaddr;
+			sa6 = (struct sockaddr_in6 *)&tcon->ses->server->dstaddr;
 			seq_printf(m, "%pI6", &sa6->sin6_addr.s6_addr);
 			if (sa6->sin6_scope_id)
 				seq_printf(m, "%%%u", sa6->sin6_scope_id);

@@ -648,23 +839,38 @@ void cifs_swn_dump(struct seq_file *m)
 		default:
 			seq_puts(m, "(unknown)");
 		}
-		seq_printf(m, "%s", swnreg->ip_notify ? "(y)" : "(n)");
+		cifs_put_tcon(tcon, netfs_trace_tcon_ref_put_swn_notify);
+next:
+		seq_printf(m, "%s", swnreg_info.ip_notify ? "(y)" : "(n)");
+		cifs_swn_free_reg_info(&swnreg_info);
 	}
-	mutex_unlock(&cifs_swnreg_idr_mutex);
+	if (ret < 0)
+		seq_printf(m, "\nFailed to snapshot witness registration: %d", ret);
 	seq_puts(m, "\n");
 }
 
 void cifs_swn_check(void)
 {
-	struct cifs_swn_reg *swnreg;
-	int id;
+	struct cifs_swn_reg_info swnreg_info;
+	struct cifs_tcon *tcon;
+	int id = 0;
 	int ret;
 
-	mutex_lock(&cifs_swnreg_idr_mutex);
-	idr_for_each_entry(&cifs_swnreg_idr, swnreg, id) {
-		ret = cifs_swn_send_register_message(swnreg);
+	while ((ret = cifs_swn_get_next_reg_info(&id, &swnreg_info)) > 0) {
+		tcon = cifs_swn_get_tcon(&swnreg_info);
+		if (!tcon) {
+			cifs_dbg(FYI, "%s: registration id %d has no live tcon\n",
+				 __func__, swnreg_info.id);
+			goto free_info;
+		}
+
+		ret = cifs_swn_send_register_message(&swnreg_info, tcon);
 		if (ret < 0)
 			cifs_dbg(FYI, "%s: Failed to send register message: %d\n", __func__, ret);
+		cifs_put_tcon(tcon, netfs_trace_tcon_ref_put_swn_notify);
+free_info:
+		cifs_swn_free_reg_info(&swnreg_info);
 	}
-	mutex_unlock(&cifs_swnreg_idr_mutex);
+	if (ret < 0)
+		cifs_dbg(FYI, "%s: Failed to snapshot registration: %d\n", __func__, ret);
 }

index b99ec5a417fa..5b21ad3c15fb 100644
@@ -181,6 +181,7 @@
 	EM(netfs_trace_tcon_ref_get_find,		"GET Find  ") \
 	EM(netfs_trace_tcon_ref_get_find_sess_tcon,	"GET FndSes") \
 	EM(netfs_trace_tcon_ref_get_reconnect_server,	"GET Reconn") \
+	EM(netfs_trace_tcon_ref_get_swn_notify,		"GET SwnNot") \
 	EM(netfs_trace_tcon_ref_new,			"NEW       ") \
 	EM(netfs_trace_tcon_ref_new_ipc,		"NEW Ipc   ") \
 	EM(netfs_trace_tcon_ref_new_reconnect_server,	"NEW Reconn") \

@@ -192,6 +193,7 @@
 	EM(netfs_trace_tcon_ref_put_mnt_ctx,		"PUT MntCtx") \
 	EM(netfs_trace_tcon_ref_put_dfs_refer,		"PUT DfsRfr") \
 	EM(netfs_trace_tcon_ref_put_reconnect_server,	"PUT Reconn") \
+	EM(netfs_trace_tcon_ref_put_swn_notify,		"PUT SwnNot") \
 	EM(netfs_trace_tcon_ref_put_tlink,		"PUT Tlink ") \
 	EM(netfs_trace_tcon_ref_see_cancelled_close,	"SEE Cn-Cls") \
 	EM(netfs_trace_tcon_ref_see_fscache_collision,	"SEE FV-CO!") \

index 3d5de31129e29d..8d8d7f150f695d 100644
@@ -639,6 +639,7 @@ struct TCP_Server_Info {
 	bool noautotune;		/* do not autotune send buf sizes */
 	bool nosharesock;
 	bool tcp_nodelay;
+	bool terminate;
 	unsigned int credits;  /* send no more requests at once */
 	unsigned int max_credits; /* can override large 32000 default at mnt */
 	unsigned int in_flight;  /* number of requests on the wire to server */

index 79ac8364d38750..7734e7ea5f4d8e 100644
@@ -662,6 +662,8 @@ cifs_chan_needs_reconnect(struct cifs_ses *ses,
 bool
 cifs_chan_is_iface_active(struct cifs_ses *ses,
 			  struct TCP_Server_Info *server);
+void
+cifs_disable_secondary_channels(struct cifs_ses *ses);
 int
 cifs_chan_update_iface(struct cifs_ses *ses, struct TCP_Server_Info *server);
 int

index a8f16cd8dca692..c9b166366da94e 100644
@@ -259,6 +259,14 @@ cifs_mark_tcp_ses_conns_for_reconnect(struct TCP_Server_Info *server,
 
 	spin_lock(&cifs_tcp_ses_lock);
 	list_for_each_entry_safe(ses, nses, &pserver->smb_ses_list, smb_ses_list) {
+		/*
+		 * if channel has been marked for termination, nothing to do
+		 * for the channel. in fact, we cannot find the channel for the
+		 * server. So safe to exit here
+		 */
+		if (server->terminate)
+			break;
+
 		spin_lock(&ses->ses_lock);
 		if (ses->ses_status == SES_EXITING) {
 			spin_unlock(&ses->ses_lock);

@@ -302,6 +310,8 @@ cifs_mark_tcp_ses_conns_for_reconnect(struct TCP_Server_Info *server,
 			spin_lock(&tcon->tc_lock);
 			tcon->status = TID_NEED_RECON;
 			spin_unlock(&tcon->tc_lock);
+
+			cancel_delayed_work(&tcon->query_interfaces);
 		}
 		if (ses->tcon_ipc) {
 			ses->tcon_ipc->need_reconnect = true;

85 lines not on this page · raw message

111 lines not on this page · raw message

index 8a0342bb3ebe7d..b72d12a24056cd 100644
@@ -1063,7 +1063,7 @@ struct TCP_Server_Info *cifs_pick_channel(struct cifs_ses *ses)
 	spin_lock(&ses->chan_lock);
 	for (i = 0; i < ses->chan_count; i++) {
 		server = ses->chans[i].server;
-		if (!server)
+		if (!server || server->terminate)
 			continue;
 
 		/*

index c9b166366da94e..605476fac102b4 100644
@@ -256,17 +256,21 @@ cifs_mark_tcp_ses_conns_for_reconnect(struct TCP_Server_Info *server,
 	/* If server is a channel, select the primary channel */
 	pserver = CIFS_SERVER_IS_CHAN(server) ? server->primary_server : server;
 
+	/*
+	 * if the server has been marked for termination, there is a
+	 * chance that the remaining channels all need reconnect. To be
+	 * on the safer side, mark the session and trees for reconnect
+	 * for this scenario. This might cause a few redundant session
+	 * setup and tree connect requests, but it is better than not doing
+	 * a tree connect when needed, and all following requests failing
+	 */
+	if (server->terminate) {
+		mark_smb_session = true;
+		server = pserver;
+	}
 
 	spin_lock(&cifs_tcp_ses_lock);
 	list_for_each_entry_safe(ses, nses, &pserver->smb_ses_list, smb_ses_list) {
-		/*
-		 * if channel has been marked for termination, nothing to do
-		 * for the channel. in fact, we cannot find the channel for the
-		 * server. So safe to exit here
-		 */
-		if (server->terminate)
-			break;
-
 		spin_lock(&ses->ses_lock);
 		if (ses->ses_status == SES_EXITING) {
 			spin_unlock(&ses->ses_lock);

index 8d8d7f150f695d..a63de0ee134108 100644
@@ -1205,7 +1205,9 @@ struct cifs_tcon {
 	__u32 max_bytes_copy;
 #ifdef CONFIG_CIFS_FSCACHE
 	u64 resource_id;		/* server resource id */
+	bool fscache_acquired;		/* T if we've tried acquiring a cookie */
 	struct fscache_volume *fscache;	/* cookie for share */
+	struct mutex fscache_lock;	/* Prevent regetting a cookie */
 #endif
 	struct list_head pending_opens;	/* list of incomplete opens */
 	struct cached_fids *cfids;

index 6df4ab2a6e5dc4..fb47da1d96168f 100644
@@ -43,12 +43,23 @@ int cifs_fscache_get_super_cookie(struct cifs_tcon *tcon)
 	char *key;
 	int ret = -ENOMEM;
 
+	if (tcon->fscache_acquired)
+		return 0;
+
+	mutex_lock(&tcon->fscache_lock);
+	if (tcon->fscache_acquired) {
+		mutex_unlock(&tcon->fscache_lock);
+		return 0;
+	}
+	tcon->fscache_acquired = true;
+
 	tcon->fscache = NULL;
 	switch (sa->sa_family) {
 	case AF_INET:
 	case AF_INET6:
 		break;
 	default:
+		mutex_unlock(&tcon->fscache_lock);
 		cifs_dbg(VFS, "Unknown network family '%d'\n", sa->sa_family);
 		return -EINVAL;
 	}

@@ -57,6 +68,7 @@ int cifs_fscache_get_super_cookie(struct cifs_tcon *tcon)
 
 	sharename = extract_sharename(tcon->tree_name);
 	if (IS_ERR(sharename)) {
+		mutex_unlock(&tcon->fscache_lock);
 		cifs_dbg(FYI, "%s: couldn't extract sharename\n", __func__);
 		return PTR_ERR(sharename);
 	}

@@ -90,6 +102,7 @@ int cifs_fscache_get_super_cookie(struct cifs_tcon *tcon)
 	kfree(key);
 out:
 	kfree(sharename);
+	mutex_unlock(&tcon->fscache_lock);
 	return ret;
 }
 

index 049a14677c9106..db897c38970312 100644
@@ -139,6 +139,9 @@ tconInfoAlloc(void)
 	spin_lock_init(&ret_buf->stat_lock);
 	atomic_set(&ret_buf->num_local_opens, 0);
 	atomic_set(&ret_buf->num_remote_opens, 0);
+#ifdef CONFIG_CIFS_FSCACHE
+	mutex_init(&ret_buf->fscache_lock);
+#endif
 
 	return ret_buf;
 }

index 7233c6a7e6d70b..35a3e73c195806 100644
@@ -313,17 +313,15 @@ static struct cifs_swn_reg *cifs_get_swn_reg(struct cifs_tcon *tcon)
 	reg = cifs_find_swn_reg(tcon);
 	if (!IS_ERR(reg)) {
 		kref_get(&reg->ref_count);
-		mutex_unlock(&cifs_swnreg_idr_mutex);
-		return reg;
+		goto unlock;
 	} else if (PTR_ERR(reg) != -EEXIST) {
-		mutex_unlock(&cifs_swnreg_idr_mutex);
-		return reg;
+		goto unlock;
 	}
 
 	reg = kmalloc(sizeof(struct cifs_swn_reg), GFP_ATOMIC);
 	if (reg == NULL) {
-		mutex_unlock(&cifs_swnreg_idr_mutex);
-		return ERR_PTR(-ENOMEM);
+		ret = -ENOMEM;
+		goto fail_unlock;
 	}
 
 	kref_init(&reg->ref_count);

@@ -354,7 +352,7 @@ static struct cifs_swn_reg *cifs_get_swn_reg(struct cifs_tcon *tcon)
 	reg->ip_notify = (tcon->capabilities & SMB2_SHARE_CAP_SCALEOUT);
 
 	reg->tcon = tcon;
-
+unlock:
 	mutex_unlock(&cifs_swnreg_idr_mutex);
 
 	return reg;

@@ -365,6 +363,7 @@ static struct cifs_swn_reg *cifs_get_swn_reg(struct cifs_tcon *tcon)
 	idr_remove(&cifs_swnreg_idr, reg->id);
 fail:
 	kfree(reg);
+fail_unlock:
 	mutex_unlock(&cifs_swnreg_idr_mutex);
 	return ERR_PTR(ret);
 }

index c2a9d7004ff598..b76997b1188444 100644
@@ -747,6 +747,8 @@ static void cifs_umount_begin(struct super_block *sb)
 
 	spin_lock(&cifs_tcp_ses_lock);
 	spin_lock(&tcon->tc_lock);
+	trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count,
+			    netfs_trace_tcon_ref_see_umount);
 	if ((tcon->tc_count > 1) || (tcon->status == TID_EXITING)) {
 		/* we have other mounts to same share or we have
 		   already tried to umount this and woken up

index a63de0ee134108..0f404625c2f4ae 100644
@@ -1121,6 +1121,7 @@ struct cifs_fattr {
  */
 struct cifs_tcon {
 	struct list_head tcon_list;
+	int debug_id;		/* Debugging for tracing */
 	int tc_count;
 	struct list_head rlist; /* reconnect list */
 	spinlock_t tc_lock;  /* protect anything here that is not protected */

index 7734e7ea5f4d8e..8cfa504e6bd837 100644
@@ -305,7 +305,7 @@ cifs_get_tcp_session(struct smb3_fs_context *ctx,
 		     struct TCP_Server_Info *primary_server);
 extern void cifs_put_tcp_session(struct TCP_Server_Info *server,
 				 int from_reconnect);
-extern void cifs_put_tcon(struct cifs_tcon *tcon);
+extern void cifs_put_tcon(struct cifs_tcon *tcon, enum smb3_tcon_ref_trace trace);
 
 #if IS_ENABLED(CONFIG_CIFS_DFS_UPCALL)
 extern void cifs_dfs_release_automount_timer(void);

@@ -525,8 +525,8 @@ extern int CIFSSMBLogoff(const unsigned int xid, struct cifs_ses *ses);
 
 extern struct cifs_ses *sesInfoAlloc(void);
 extern void sesInfoFree(struct cifs_ses *);
-extern struct cifs_tcon *tconInfoAlloc(void);
-extern void tconInfoFree(struct cifs_tcon *);
+extern struct cifs_tcon *tconInfoAlloc(enum smb3_tcon_ref_trace trace);
+extern void tconInfoFree(struct cifs_tcon *tcon, enum smb3_tcon_ref_trace trace);
 
 extern int cifs_sign_rqst(struct smb_rqst *rqst, struct TCP_Server_Info *server,
 		   __u32 *pexpected_response_sequence_number);

@@ -719,8 +719,6 @@ static inline int cifs_create_options(struct cifs_sb_info *cifs_sb, int options)
 		return options;
 }
 
-struct super_block *cifs_get_tcon_super(struct cifs_tcon *tcon);
-void cifs_put_tcon_super(struct super_block *sb);
 int cifs_wait_for_server_reconnect(struct TCP_Server_Info *server, bool retry);
 
 static inline void release_mid(struct mid_q_entry *mid)

index 605476fac102b4..e7426896449ea9 100644
@@ -1985,7 +1985,7 @@ cifs_setup_ipc(struct cifs_ses *ses, struct smb3_fs_context *ctx)
 		}
 	}
 
-	tcon = tconInfoAlloc();
+	tcon = tconInfoAlloc(netfs_trace_tcon_ref_new_ipc);
 	if (tcon == NULL)
 		return -ENOMEM;
 

@@ -2002,7 +2002,7 @@ cifs_setup_ipc(struct cifs_ses *ses, struct smb3_fs_context *ctx)
 
 	if (rc) {
 		cifs_server_dbg(VFS, "failed to connect to IPC (rc=%d)\n", rc);
-		tconInfoFree(tcon);
+		tconInfoFree(tcon, netfs_trace_tcon_ref_free_ipc_fail);
 		goto out;
 	}
 

@@ -2085,7 +2085,7 @@ void cifs_put_smb_ses(struct cifs_ses *ses)
 	 * files on session close, as specified in MS-SMB2 3.3.5.6 Receiving an
 	 * SMB2 LOGOFF Request.
 	 */
-	tconInfoFree(tcon);
+	tconInfoFree(tcon, netfs_trace_tcon_ref_free_ipc);
 	if (do_logoff) {
 		xid = get_xid();
 		rc = server->ops->logoff(xid, ses);

@@ -2459,6 +2459,8 @@ cifs_find_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx)
 			continue;
 		}
 		++tcon->tc_count;
+		trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count,
+				    netfs_trace_tcon_ref_get_find);
 		spin_unlock(&tcon->tc_lock);
 		spin_unlock(&cifs_tcp_ses_lock);
 		return tcon;

@@ -2468,7 +2470,7 @@ cifs_find_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx)
 }
 
 void
-cifs_put_tcon(struct cifs_tcon *tcon)
+cifs_put_tcon(struct cifs_tcon *tcon, enum smb3_tcon_ref_trace trace)
 {
 	unsigned int xid;
 	struct cifs_ses *ses;

@@ -2484,6 +2486,7 @@ cifs_put_tcon(struct cifs_tcon *tcon)
 	cifs_dbg(FYI, "%s: tc_count=%d\n", __func__, tcon->tc_count);
 	spin_lock(&cifs_tcp_ses_lock);
 	spin_lock(&tcon->tc_lock);
+	trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count - 1, trace);
 	if (--tcon->tc_count > 0) {
 		spin_unlock(&tcon->tc_lock);
 		spin_unlock(&cifs_tcp_ses_lock);

@@ -2517,7 +2520,7 @@ cifs_put_tcon(struct cifs_tcon *tcon)
 	_free_xid(xid);
 
 	cifs_fscache_release_super_cookie(tcon);
-	tconInfoFree(tcon);
+	tconInfoFree(tcon, netfs_trace_tcon_ref_free);
 	cifs_put_smb_ses(ses);
 }
 

@@ -2565,7 +2568,7 @@ cifs_get_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx)
 		goto out_fail;
 	}
 
-	tcon = tconInfoAlloc();
+	tcon = tconInfoAlloc(netfs_trace_tcon_ref_new);
 	if (tcon == NULL) {
 		rc = -ENOMEM;
 		goto out_fail;

@@ -2762,7 +2765,7 @@ cifs_get_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx)
 	return tcon;
 
 out_fail:
-	tconInfoFree(tcon);
+	tconInfoFree(tcon, netfs_trace_tcon_ref_free_fail);
 	return ERR_PTR(rc);
 }
 

@@ -2779,7 +2782,7 @@ cifs_put_tlink(struct tcon_link *tlink)
 	}
 
 	if (!IS_ERR(tlink_tcon(tlink)))
-		cifs_put_tcon(tlink_tcon(tlink));
+		cifs_put_tcon(tlink_tcon(tlink), netfs_trace_tcon_ref_put_tlink);
 	kfree(tlink);
 	return;
 }

@@ -3338,7 +3341,7 @@ static inline void mount_put_conns(struct mount_ctx *mnt_ctx)
 	int rc = 0;
 
 	if (mnt_ctx->tcon)
-		cifs_put_tcon(mnt_ctx->tcon);
+		cifs_put_tcon(mnt_ctx->tcon, netfs_trace_tcon_ref_put_mnt_ctx);
 	else if (mnt_ctx->ses)
 		cifs_put_smb_ses(mnt_ctx->ses);
 	else if (mnt_ctx->server)

index 3bc1d3494be3a5..0c88408d369aa4 100644
@@ -1564,7 +1564,7 @@ static void refresh_mounts(struct cifs_ses **sessions)
 		}
 		mutex_unlock(&server->refpath_lock);
 
-		cifs_put_tcon(tcon);
+		cifs_put_tcon(tcon, netfs_trace_tcon_ref_put_dfs_refer);
 	}
 }
 

index fb47da1d96168f..0ebf144ea825fe 100644
@@ -94,6 +94,11 @@ int cifs_fscache_get_super_cookie(struct cifs_tcon *tcon)
 		}
 		pr_err("Cache volume key already in use (%s)\n", key);
 		vcookie = NULL;
+		trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count,
+				    netfs_trace_tcon_ref_see_fscache_collision);
+	} else {
+		trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count,
+				    netfs_trace_tcon_ref_see_fscache_okay);
 	}
 
 	tcon->fscache = vcookie;

@@ -115,6 +120,8 @@ void cifs_fscache_release_super_cookie(struct cifs_tcon *tcon)
 	cifs_fscache_fill_volume_coherency(tcon, &cd);
 	fscache_relinquish_volume(tcon->fscache, &cd, false);
 	tcon->fscache = NULL;
+	trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count,
+			    netfs_trace_tcon_ref_see_fscache_relinq);
 }
 
 void cifs_fscache_get_inode_cookie(struct inode *inode)

index db897c38970312..5d44e951bde085 100644
@@ -116,9 +116,10 @@ sesInfoFree(struct cifs_ses *buf_to_free)
 }
 
 struct cifs_tcon *
-tconInfoAlloc(void)
+tconInfoAlloc(enum smb3_tcon_ref_trace trace)
 {
 	struct cifs_tcon *ret_buf;
+	static atomic_t tcon_debug_id;
 
 	ret_buf = kzalloc(sizeof(*ret_buf), GFP_KERNEL);
 	if (!ret_buf)

@@ -131,7 +132,8 @@ tconInfoAlloc(void)
 
 	atomic_inc(&tconInfoAllocCount);
 	ret_buf->status = TID_NEW;
-	++ret_buf->tc_count;
+	ret_buf->debug_id = atomic_inc_return(&tcon_debug_id);
+	ret_buf->tc_count = 1;
 	spin_lock_init(&ret_buf->tc_lock);
 	INIT_LIST_HEAD(&ret_buf->openFileList);
 	INIT_LIST_HEAD(&ret_buf->tcon_list);

@@ -142,17 +144,19 @@ tconInfoAlloc(void)
 #ifdef CONFIG_CIFS_FSCACHE
 	mutex_init(&ret_buf->fscache_lock);
 #endif
+	trace_smb3_tcon_ref(ret_buf->debug_id, ret_buf->tc_count, trace);
 
 	return ret_buf;
 }
 
 void
-tconInfoFree(struct cifs_tcon *tcon)
+tconInfoFree(struct cifs_tcon *tcon, enum smb3_tcon_ref_trace trace)
 {
 	if (tcon == NULL) {
 		cifs_dbg(FYI, "Null buffer passed to tconInfoFree\n");
 		return;
 	}
+	trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count, trace);
 	free_cached_dirs(tcon->cfids);
 	atomic_dec(&tconInfoAllocCount);
 	kfree(tcon->nativeFileSystem);

@@ -848,7 +852,7 @@ void cifs_close_all_deferred_files_sb(struct cifs_sb_info *cifs_sb)
 	list_for_each_entry_safe(tmp_list, q, &tcon_head, entry) {
 		cifs_close_all_deferred_files(tmp_list->tcon);
 		list_del(&tmp_list->entry);
-		cifs_put_tcon(tmp_list->tcon);
+		cifs_put_tcon(tmp_list->tcon, netfs_trace_tcon_ref_put_tlink);
 		kfree(tmp_list);
 	}
 }

index cc6fa92a39eeb5..acecba5c5f4848 100644
@@ -768,7 +768,7 @@ smb2_cancelled_close_fid(struct work_struct *work)
 	if (rc)
 		cifs_tcon_dbg(VFS, "Close cancelled mid failed rc:%d\n", rc);
 
-	cifs_put_tcon(tcon);
+	cifs_put_tcon(tcon, netfs_trace_tcon_ref_put_cancelled_close_fid);
 	kfree(cancelled);
 }
 

@@ -812,6 +812,8 @@ smb2_handle_cancelled_close(struct cifs_tcon *tcon, __u64 persistent_fid,
 	if (tcon->tc_count <= 0) {
 		struct TCP_Server_Info *server = NULL;
 
+		trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count,
+				    netfs_trace_tcon_ref_see_cancelled_close);
 		WARN_ONCE(tcon->tc_count < 0, "tcon refcount is negative");
 		spin_unlock(&cifs_tcp_ses_lock);
 

@@ -825,12 +827,14 @@ smb2_handle_cancelled_close(struct cifs_tcon *tcon, __u64 persistent_fid,
 		return 0;
 	}
 	tcon->tc_count++;
+	trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count,
+			    netfs_trace_tcon_ref_get_cancelled_close);
 	spin_unlock(&cifs_tcp_ses_lock);
 
 	rc = __smb2_handle_cancelled_cmd(tcon, SMB2_CLOSE_HE, 0,
 					 persistent_fid, volatile_fid);
 	if (rc)
-		cifs_put_tcon(tcon);
+		cifs_put_tcon(tcon, netfs_trace_tcon_ref_put_cancelled_close);
 
 	return rc;
 }

@@ -858,7 +862,7 @@ smb2_handle_cancelled_mid(struct mid_q_entry *mid, struct TCP_Server_Info *serve
 					 rsp->PersistentFileId,
 					 rsp->VolatileFileId);
 	if (rc)
-		cifs_put_tcon(tcon);
+		cifs_put_tcon(tcon, netfs_trace_tcon_ref_put_cancelled_mid);
 
 	return rc;
 }

index 8bcecd19e901c9..842465eff5824c 100644
@@ -2847,8 +2847,11 @@ smb2_get_dfs_refer(const unsigned int xid, struct cifs_ses *ses,
 		tcon = list_first_entry_or_null(&ses->tcon_list,
 						struct cifs_tcon,
 						tcon_list);
-		if (tcon)
+		if (tcon) {
 			tcon->tc_count++;
+			trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count,
+					    netfs_trace_tcon_ref_get_dfs_refer);
+		}
 		spin_unlock(&cifs_tcp_ses_lock);
 	}
 

@@ -2912,6 +2915,8 @@ smb2_get_dfs_refer(const unsigned int xid, struct cifs_ses *ses,
 		/* ipc tcons are not refcounted */
 		spin_lock(&cifs_tcp_ses_lock);
 		tcon->tc_count--;
+		trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count,
+				    netfs_trace_tcon_ref_dec_dfs_refer);
 		/* tc_count can never go negative */
 		WARN_ON(tcon->tc_count < 0);
 		spin_unlock(&cifs_tcp_ses_lock);

index 961d37daf154df..c911a7db66ebc5 100644
@@ -3995,6 +3995,8 @@ void smb2_reconnect_server(struct work_struct *work)
 		list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
 			if (tcon->need_reconnect || tcon->need_reopen_files) {
 				tcon->tc_count++;
+				trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count,
+						    netfs_trace_tcon_ref_get_reconnect_server);
 				list_add_tail(&tcon->rlist, &tmp_list);
 				tcon_selected = tcon_exist = true;
 			}

@@ -4040,14 +4042,14 @@ void smb2_reconnect_server(struct work_struct *work)
 		if (tcon->ipc)
 			cifs_put_smb_ses(tcon->ses);
 		else
-			cifs_put_tcon(tcon);
+			cifs_put_tcon(tcon, netfs_trace_tcon_ref_put_reconnect_server);
 	}
 
 	if (!ses_exist)
 		goto done;
 
 	/* allocate a dummy tcon struct used for reconnect */
-	tcon = tconInfoAlloc();
+	tcon = tconInfoAlloc(netfs_trace_tcon_ref_new_reconnect_server);
 	if (!tcon) {
 		resched = true;
 		list_for_each_entry_safe(ses, ses2, &tmp_ses_list, rlist) {

@@ -4070,7 +4072,7 @@ void smb2_reconnect_server(struct work_struct *work)
 		list_del_init(&ses->rlist);
 		cifs_put_smb_ses(ses);
 	}
-	tconInfoFree(tcon);
+	tconInfoFree(tcon, netfs_trace_tcon_ref_free_reconnect_server);
 
 done:
 	cifs_dbg(FYI, "Reconnecting tcons and channels finished\n");

index 92eea7ba75c080..3a69f3500acdea 100644
@@ -189,6 +189,8 @@ smb2_find_smb_sess_tcon_unlocked(struct cifs_ses *ses, __u32  tid)
 		if (tcon->tid != tid)
 			continue;
 		++tcon->tc_count;
+		trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count,
+				    netfs_trace_tcon_ref_get_find_sess_tcon);
 		return tcon;
 	}
 

112 lines not on this page · raw message

index 35a3e73c195806..693f609512e6b5 100644
@@ -28,10 +28,54 @@ struct cifs_swn_reg {
 	bool net_name_notify;
 	bool share_name_notify;
 	bool ip_notify;
+};
 
-	struct cifs_tcon *tcon;
+struct cifs_swn_reg_info {
+	int id;
+	unsigned int ref_count;
+	const char *net_name;
+	const char *share_name;
+	bool net_name_notify;
+	bool share_name_notify;
+	bool ip_notify;
 };
 
+static void cifs_swn_snapshot_reg(struct cifs_swn_reg *swnreg,
+				  struct cifs_swn_reg_info *info)
+{
+	info->id = swnreg->id;
+	info->ref_count = kref_read(&swnreg->ref_count);
+	info->net_name = swnreg->net_name;
+	info->share_name = swnreg->share_name;
+	info->net_name_notify = swnreg->net_name_notify;
+	info->share_name_notify = swnreg->share_name_notify;
+	info->ip_notify = swnreg->ip_notify;
+}
+
+static int cifs_swn_dup_reg(struct cifs_swn_reg *swnreg,
+			    struct cifs_swn_reg_info *info)
+{
+	cifs_swn_snapshot_reg(swnreg, info);
+
+	info->net_name = kstrdup(swnreg->net_name, GFP_KERNEL);
+	if (!info->net_name)
+		return -ENOMEM;
+
+	info->share_name = kstrdup(swnreg->share_name, GFP_KERNEL);
+	if (!info->share_name) {
+		kfree(info->net_name);
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+static void cifs_swn_free_reg_info(struct cifs_swn_reg_info *info)
+{
+	kfree(info->net_name);
+	kfree(info->share_name);
+}
+
 static int cifs_swn_auth_info_krb(struct cifs_tcon *tcon, struct sk_buff *skb)
 {
 	int ret;

@@ -73,7 +117,8 @@ static int cifs_swn_auth_info_ntlm(struct cifs_tcon *tcon, struct sk_buff *skb)
  * The authentication information to connect to the witness service is bundled
  * into the message.
  */
-static int cifs_swn_send_register_message(struct cifs_swn_reg *swnreg)
+static int cifs_swn_send_register_message(struct cifs_swn_reg_info *swnreg,
+					  struct cifs_tcon *tcon)
 {
 	struct sk_buff *skb;
 	struct genlmsghdr *hdr;

@@ -111,10 +156,10 @@ static int cifs_swn_send_register_message(struct cifs_swn_reg *swnreg)
 	 * told to switch to it (client move message). In these cases we unregister from the
 	 * server address and register to the new address when we receive the notification.
 	 */
-	if (swnreg->tcon->ses->server->use_swn_dstaddr)
-		addr = &swnreg->tcon->ses->server->swn_dstaddr;
+	if (tcon->ses->server->use_swn_dstaddr)
+		addr = &tcon->ses->server->swn_dstaddr;
 	else
-		addr = &swnreg->tcon->ses->server->dstaddr;
+		addr = &tcon->ses->server->dstaddr;
 
 	ret = nla_put(skb, CIFS_GENL_ATTR_SWN_IP, sizeof(struct sockaddr_storage), addr);
 	if (ret < 0)

@@ -138,10 +183,10 @@ static int cifs_swn_send_register_message(struct cifs_swn_reg *swnreg)
 			goto nlmsg_fail;
 	}
 
-	authtype = cifs_select_sectype(swnreg->tcon->ses->server, swnreg->tcon->ses->sectype);
+	authtype = cifs_select_sectype(tcon->ses->server, tcon->ses->sectype);
 	switch (authtype) {
 	case Kerberos:
-		ret = cifs_swn_auth_info_krb(swnreg->tcon, skb);
+		ret = cifs_swn_auth_info_krb(tcon, skb);
 		if (ret < 0) {
 			cifs_dbg(VFS, "%s: Failed to get kerberos auth info: %d\n", __func__, ret);
 			goto nlmsg_fail;

@@ -149,7 +194,7 @@ static int cifs_swn_send_register_message(struct cifs_swn_reg *swnreg)
 		break;
 	case NTLMv2:
 	case RawNTLMSSP:
-		ret = cifs_swn_auth_info_ntlm(swnreg->tcon, skb);
+		ret = cifs_swn_auth_info_ntlm(tcon, skb);
 		if (ret < 0) {
 			cifs_dbg(VFS, "%s: Failed to get NTLM auth info: %d\n", __func__, ret);
 			goto nlmsg_fail;

@@ -179,7 +224,8 @@ static int cifs_swn_send_register_message(struct cifs_swn_reg *swnreg)
 /*
  * Sends an uregister message to the userspace daemon based on the registration
  */
-static int cifs_swn_send_unregister_message(struct cifs_swn_reg *swnreg)
+static int cifs_swn_send_unregister_message(struct cifs_swn_reg_info *swnreg,
+					    struct cifs_tcon *tcon)
 {
 	struct sk_buff *skb;
 	struct genlmsghdr *hdr;

@@ -208,7 +254,7 @@ static int cifs_swn_send_unregister_message(struct cifs_swn_reg *swnreg)
 		goto nlmsg_fail;
 
 	ret = nla_put(skb, CIFS_GENL_ATTR_SWN_IP, sizeof(struct sockaddr_storage),
-			&swnreg->tcon->ses->server->dstaddr);
+			&tcon->ses->server->dstaddr);
 	if (ret < 0)
 		goto nlmsg_fail;
 

@@ -244,6 +290,88 @@ static int cifs_swn_send_unregister_message(struct cifs_swn_reg *swnreg)
 	return ret;
 }
 
+/*
+ * Allocation-free mirror of extract_hostname() + extract_sharename() from
+ * fs/smb/client/unc.c.  Those helpers kmalloc(GFP_KERNEL); this runs under
+ * cifs_tcp_ses_lock and tcon->tc_lock, both spinlocks, so we mirror their
+ * parsing in place against the caller's stable net_name/share_name strings.
+ * Keep in sync with unc.c.
+ */
+static bool cifs_swn_tcon_matches(struct cifs_tcon *tcon,
+				  const char *net_name,
+				  const char *share_name)
+{
+	const char *unc = tcon->tree_name;
+	const char *host, *share, *delim;
+	size_t host_len, share_len;
+
+	if (!tcon->use_witness)
+		return false;
+
+	/* extract_hostname: require strlen(unc) >= 3 */
+	if (strnlen(unc, 3) < 3)
+		return false;
+	/* extract_hostname: skip all leading '\' characters */
+	for (host = unc; *host == '\\'; host++)
+		;
+	if (!*host)
+		return false;
+	delim = strchr(host, '\\');
+	if (!delim)
+		return false;
+	host_len = delim - host;
+	if (strlen(net_name) != host_len ||
+	    strncasecmp(host, net_name, host_len))
+		return false;
+
+	/* extract_sharename: start at unc + 2, then first '\' onward */
+	share = unc + 2;
+	delim = strchr(share, '\\');
+	if (!delim)
+		return false;
+	share = delim + 1;
+	share_len = strlen(share);
+
+	return strlen(share_name) == share_len &&
+	       !strncasecmp(share, share_name, share_len);
+}
+
+/*
+ * One SWN registration id represents one net/share name pair.  Multiple
+ * mounted tcons can therefore share the id.  Pick a live representative at
+ * use time instead of caching the first tcon pointer in the registration.
+ */
+static struct cifs_tcon *cifs_swn_get_tcon(struct cifs_swn_reg_info *swnreg)
+{
+	struct TCP_Server_Info *server;
+	struct cifs_ses *ses;
+	struct cifs_tcon *tcon;
+
+	spin_lock(&cifs_tcp_ses_lock);
+	list_for_each_entry(server, &cifs_tcp_ses_list, tcp_ses_list) {
+		list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) {
+			list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
+				spin_lock(&tcon->tc_lock);
+				if (tcon->status == TID_EXITING ||
+				    !cifs_swn_tcon_matches(tcon, swnreg->net_name,
+							   swnreg->share_name)) {
+					spin_unlock(&tcon->tc_lock);
+					continue;
+				}
+				++tcon->tc_count;
+				trace_smb3_tcon_ref(tcon->debug_id,
+						    tcon->tc_count,
+						    netfs_trace_tcon_ref_get_swn_notify);
+				spin_unlock(&tcon->tc_lock);
+				spin_unlock(&cifs_tcp_ses_lock);
+				return tcon;
+			}
+		}
+	}
+	spin_unlock(&cifs_tcp_ses_lock);
+	return NULL;
+}
+
 /*
  * Try to find a matching registration for the tcon's server name and share name.
  * Calls to this function must be protected by cifs_swnreg_idr_mutex.

@@ -350,8 +478,6 @@ static struct cifs_swn_reg *cifs_get_swn_reg(struct cifs_tcon *tcon)
 	reg->net_name_notify = true;
 	reg->share_name_notify = true;
 	reg->ip_notify = (tcon->capabilities & SMB2_SHARE_CAP_SCALEOUT);
-
-	reg->tcon = tcon;
 unlock:
 	mutex_unlock(&cifs_swnreg_idr_mutex);
 

@@ -371,11 +497,6 @@ static struct cifs_swn_reg *cifs_get_swn_reg(struct cifs_tcon *tcon)
 static void cifs_swn_reg_release(struct kref *ref)
 {
 	struct cifs_swn_reg *swnreg = container_of(ref, struct cifs_swn_reg, ref_count);
-	int ret;
-
-	ret = cifs_swn_send_unregister_message(swnreg);
-	if (ret < 0)
-		cifs_dbg(VFS, "%s: Failed to send unregister message: %d\n", __func__, ret);
 
 	idr_remove(&cifs_swnreg_idr, swnreg->id);
 	kfree(swnreg->net_name);

@@ -383,23 +504,33 @@ static void cifs_swn_reg_release(struct kref *ref)
 	kfree(swnreg);
 }
 
-static void cifs_put_swn_reg(struct cifs_swn_reg *swnreg)
+static void cifs_put_swn_reg_locked(struct cifs_swn_reg *swnreg,
+				    struct cifs_tcon *tcon)
 {
-	mutex_lock(&cifs_swnreg_idr_mutex);
+	if (kref_read(&swnreg->ref_count) == 1) {
+		struct cifs_swn_reg_info swnreg_info;
+		int ret;
+
+		cifs_swn_snapshot_reg(swnreg, &swnreg_info);
+		ret = cifs_swn_send_unregister_message(&swnreg_info, tcon);
+		if (ret < 0)
+			cifs_dbg(VFS, "%s: Failed to send unregister message: %d\n",
+				 __func__, ret);
+	}
+
 	kref_put(&swnreg->ref_count, cifs_swn_reg_release);
-	mutex_unlock(&cifs_swnreg_idr_mutex);
 }
 
-static int cifs_swn_resource_state_changed(struct cifs_swn_reg *swnreg, const char *name, int state)
+static int cifs_swn_resource_state_changed(struct cifs_tcon *tcon, const char *name, int state)
 {
 	switch (state) {
 	case CIFS_SWN_RESOURCE_STATE_UNAVAILABLE:
 		cifs_dbg(FYI, "%s: resource name '%s' become unavailable\n", __func__, name);
-		cifs_signal_cifsd_for_reconnect(swnreg->tcon->ses->server, true);
+		cifs_signal_cifsd_for_reconnect(tcon->ses->server, true);
 		break;
 	case CIFS_SWN_RESOURCE_STATE_AVAILABLE:
 		cifs_dbg(FYI, "%s: resource name '%s' become available\n", __func__, name);
-		cifs_signal_cifsd_for_reconnect(swnreg->tcon->ses->server, true);
+		cifs_signal_cifsd_for_reconnect(tcon->ses->server, true);
 		break;
 	case CIFS_SWN_RESOURCE_STATE_UNKNOWN:
 		cifs_dbg(FYI, "%s: resource name '%s' changed to unknown state\n", __func__, name);

@@ -505,7 +636,7 @@ static int cifs_swn_reconnect(struct cifs_tcon *tcon, struct sockaddr_storage *a
 	return ret;
 }
 
-static int cifs_swn_client_move(struct cifs_swn_reg *swnreg, struct sockaddr_storage *addr)
+static int cifs_swn_client_move(struct cifs_tcon *tcon, struct sockaddr_storage *addr)
 {
 	struct sockaddr_in *ipv4 = (struct sockaddr_in *)addr;
 	struct sockaddr_in6 *ipv6 = (struct sockaddr_in6 *)addr;

@@ -515,14 +646,17 @@ static int cifs_swn_client_move(struct cifs_swn_reg *swnreg, struct sockaddr_sto
 	else if (addr->ss_family == AF_INET6)
 		cifs_dbg(FYI, "%s: move to %pI6\n", __func__, &ipv6->sin6_addr);
 
-	return cifs_swn_reconnect(swnreg->tcon, addr);
+	return cifs_swn_reconnect(tcon, addr);
 }
 
 int cifs_swn_notify(struct sk_buff *skb, struct genl_info *info)
 {
 	struct cifs_swn_reg *swnreg;
+	struct cifs_swn_reg_info swnreg_info;
+	struct cifs_tcon *tcon;
 	char name[256];
 	int type;
+	int ret = 0;
 
 	if (info->attrs[CIFS_GENL_ATTR_SWN_REGISTRATION_ID]) {
 		int swnreg_id;

@@ -530,21 +664,34 @@ int cifs_swn_notify(struct sk_buff *skb, struct genl_info *info)
 		swnreg_id = nla_get_u32(info->attrs[CIFS_GENL_ATTR_SWN_REGISTRATION_ID]);
 		mutex_lock(&cifs_swnreg_idr_mutex);
 		swnreg = idr_find(&cifs_swnreg_idr, swnreg_id);
-		mutex_unlock(&cifs_swnreg_idr_mutex);
 		if (swnreg == NULL) {
+			mutex_unlock(&cifs_swnreg_idr_mutex);
 			cifs_dbg(FYI, "%s: registration id %d not found\n", __func__, swnreg_id);
 			return -EINVAL;
 		}
+		ret = cifs_swn_dup_reg(swnreg, &swnreg_info);
+		mutex_unlock(&cifs_swnreg_idr_mutex);
+		if (ret)
+			return ret;
 	} else {
 		cifs_dbg(FYI, "%s: missing registration id attribute\n", __func__);
 		return -EINVAL;
 	}
 
+	tcon = cifs_swn_get_tcon(&swnreg_info);
+	if (!tcon) {
+		cifs_dbg(FYI, "%s: registration id %d has no live tcon\n",
+			 __func__, swnreg_info.id);
+		ret = -ENODEV;
+		goto free_info;
+	}
+
 	if (info->attrs[CIFS_GENL_ATTR_SWN_NOTIFICATION_TYPE]) {
 		type = nla_get_u32(info->attrs[CIFS_GENL_ATTR_SWN_NOTIFICATION_TYPE]);
 	} else {
 		cifs_dbg(FYI, "%s: missing notification type attribute\n", __func__);
-		return -EINVAL;
+		ret = -EINVAL;
+		goto out;
 	}
 
 	switch (type) {

@@ -556,15 +703,18 @@ int cifs_swn_notify(struct sk_buff *skb, struct genl_info *info)
 					sizeof(name));
 		} else {
 			cifs_dbg(FYI, "%s: missing resource name attribute\n", __func__);
-			return -EINVAL;
+			ret = -EINVAL;
+			goto out;
 		}
 		if (info->attrs[CIFS_GENL_ATTR_SWN_RESOURCE_STATE]) {
 			state = nla_get_u32(info->attrs[CIFS_GENL_ATTR_SWN_RESOURCE_STATE]);
 		} else {
 			cifs_dbg(FYI, "%s: missing resource state attribute\n", __func__);
-			return -EINVAL;
+			ret = -EINVAL;
+			goto out;
 		}
-		return cifs_swn_resource_state_changed(swnreg, name, state);
+		ret = cifs_swn_resource_state_changed(tcon, name, state);
+		break;
 	}
 	case CIFS_SWN_NOTIFICATION_CLIENT_MOVE: {
 		struct sockaddr_storage addr;

@@ -573,28 +723,36 @@ int cifs_swn_notify(struct sk_buff *skb, struct genl_info *info)
 			nla_memcpy(&addr, info->attrs[CIFS_GENL_ATTR_SWN_IP], sizeof(addr));
 		} else {
 			cifs_dbg(FYI, "%s: missing IP address attribute\n", __func__);
-			return -EINVAL;
+			ret = -EINVAL;
+			goto out;
 		}
-		return cifs_swn_client_move(swnreg, &addr);
+		ret = cifs_swn_client_move(tcon, &addr);
+		break;
 	}
 	default:
 		cifs_dbg(FYI, "%s: unknown notification type %d\n", __func__, type);
 		break;
 	}
 
-	return 0;
+out:
+	cifs_put_tcon(tcon, netfs_trace_tcon_ref_put_swn_notify);
+free_info:
+	cifs_swn_free_reg_info(&swnreg_info);
+	return ret;
 }
 
 int cifs_swn_register(struct cifs_tcon *tcon)
 {
 	struct cifs_swn_reg *swnreg;
+	struct cifs_swn_reg_info swnreg_info;
 	int ret;
 
 	swnreg = cifs_get_swn_reg(tcon);
 	if (IS_ERR(swnreg))
 		return PTR_ERR(swnreg);
 
-	ret = cifs_swn_send_register_message(swnreg);
+	cifs_swn_snapshot_reg(swnreg, &swnreg_info);
+	ret = cifs_swn_send_register_message(&swnreg_info, tcon);
 	if (ret < 0) {
 		cifs_dbg(VFS, "%s: Failed to send swn register message: %d\n", __func__, ret);
 		/* Do not put the swnreg or return error, the echo task will retry */

@@ -615,35 +773,68 @@ int cifs_swn_unregister(struct cifs_tcon *tcon)
 		return PTR_ERR(swnreg);
 	}
 
+	cifs_put_swn_reg_locked(swnreg, tcon);
 	mutex_unlock(&cifs_swnreg_idr_mutex);
 
-	cifs_put_swn_reg(swnreg);
-
 	return 0;
 }
 
-void cifs_swn_dump(struct seq_file *m)
+/*
+ * Snapshot one registration under cifs_swnreg_idr_mutex and return.  Callers
+ * intentionally do the per-registration network/genlmsg work without the
+ * mutex held, both to keep the critical section short and to avoid nesting
+ * cifs_swnreg_idr_mutex inside the higher tc_lock when a live tcon is then
+ * pinned for the send.
+ */
+static int cifs_swn_get_next_reg_info(int *id, struct cifs_swn_reg_info *info)
 {
 	struct cifs_swn_reg *swnreg;
+	int ret = 0;
+
+	mutex_lock(&cifs_swnreg_idr_mutex);
+	swnreg = idr_get_next(&cifs_swnreg_idr, id);
+	if (swnreg) {
+		ret = cifs_swn_dup_reg(swnreg, info);
+		if (!ret) {
+			*id = swnreg->id + 1;
+			ret = 1;
+		}
+	}
+	mutex_unlock(&cifs_swnreg_idr_mutex);
+
+	return ret;
+}
+
+void cifs_swn_dump(struct seq_file *m)
+{
+	struct cifs_swn_reg_info swnreg_info;
+	struct cifs_tcon *tcon;
 	struct sockaddr_in *sa;
 	struct sockaddr_in6 *sa6;
-	int id;
+	int id = 0;
+	int ret;
 
 	seq_puts(m, "Witness registrations:");
 
-	mutex_lock(&cifs_swnreg_idr_mutex);
-	idr_for_each_entry(&cifs_swnreg_idr, swnreg, id) {
+	while ((ret = cifs_swn_get_next_reg_info(&id, &swnreg_info)) > 0) {
 		seq_printf(m, "\nId: %u Refs: %u Network name: '%s'%s Share name: '%s'%s Ip address: ",
-				id, kref_read(&swnreg->ref_count),
-				swnreg->net_name, swnreg->net_name_notify ? "(y)" : "(n)",
-				swnreg->share_name, swnreg->share_name_notify ? "(y)" : "(n)");
-		switch (swnreg->tcon->ses->server->dstaddr.ss_family) {
+			   swnreg_info.id, swnreg_info.ref_count,
+			   swnreg_info.net_name, swnreg_info.net_name_notify ? "(y)" : "(n)",
+			   swnreg_info.share_name, swnreg_info.share_name_notify ? "(y)" : "(n)");
+
+		tcon = cifs_swn_get_tcon(&swnreg_info);
+		if (!tcon) {
+			seq_puts(m, "(no live tcon)");
+			goto next;
+		}
+
+		switch (tcon->ses->server->dstaddr.ss_family) {
 		case AF_INET:
-			sa = (struct sockaddr_in *) &swnreg->tcon->ses->server->dstaddr;
+			sa = (struct sockaddr_in *)&tcon->ses->server->dstaddr;
 			seq_printf(m, "%pI4", &sa->sin_addr.s_addr);
 			break;
 		case AF_INET6:
-			sa6 = (struct sockaddr_in6 *) &swnreg->tcon->ses->server->dstaddr;
+			sa6 = (struct sockaddr_in6 *)&tcon->ses->server->dstaddr;
 			seq_printf(m, "%pI6", &sa6->sin6_addr.s6_addr);
 			if (sa6->sin6_scope_id)
 				seq_printf(m, "%%%u", sa6->sin6_scope_id);

@@ -651,23 +842,38 @@ void cifs_swn_dump(struct seq_file *m)
 		default:
 			seq_puts(m, "(unknown)");
 		}
-		seq_printf(m, "%s", swnreg->ip_notify ? "(y)" : "(n)");
+		cifs_put_tcon(tcon, netfs_trace_tcon_ref_put_swn_notify);
+next:
+		seq_printf(m, "%s", swnreg_info.ip_notify ? "(y)" : "(n)");
+		cifs_swn_free_reg_info(&swnreg_info);
 	}
-	mutex_unlock(&cifs_swnreg_idr_mutex);
+	if (ret < 0)
+		seq_printf(m, "\nFailed to snapshot witness registration: %d", ret);
 	seq_puts(m, "\n");
 }
 
 void cifs_swn_check(void)
 {
-	struct cifs_swn_reg *swnreg;
-	int id;
+	struct cifs_swn_reg_info swnreg_info;
+	struct cifs_tcon *tcon;
+	int id = 0;
 	int ret;
 
-	mutex_lock(&cifs_swnreg_idr_mutex);
-	idr_for_each_entry(&cifs_swnreg_idr, swnreg, id) {
-		ret = cifs_swn_send_register_message(swnreg);
+	while ((ret = cifs_swn_get_next_reg_info(&id, &swnreg_info)) > 0) {
+		tcon = cifs_swn_get_tcon(&swnreg_info);
+		if (!tcon) {
+			cifs_dbg(FYI, "%s: registration id %d has no live tcon\n",
+				 __func__, swnreg_info.id);
+			goto free_info;
+		}
+
+		ret = cifs_swn_send_register_message(&swnreg_info, tcon);
 		if (ret < 0)
 			cifs_dbg(FYI, "%s: Failed to send register message: %d\n", __func__, ret);
+		cifs_put_tcon(tcon, netfs_trace_tcon_ref_put_swn_notify);
+free_info:
+		cifs_swn_free_reg_info(&swnreg_info);
 	}
-	mutex_unlock(&cifs_swnreg_idr_mutex);
+	if (ret < 0)
+		cifs_dbg(FYI, "%s: Failed to snapshot registration: %d\n", __func__, ret);
 }

index fb80bb28fdcffc..ef8e849c09f2c2 100644
@@ -32,6 +32,7 @@
 	EM(netfs_trace_tcon_ref_get_find,		"GET Find  ") \
 	EM(netfs_trace_tcon_ref_get_find_sess_tcon,	"GET FndSes") \
 	EM(netfs_trace_tcon_ref_get_reconnect_server,	"GET Reconn") \
+	EM(netfs_trace_tcon_ref_get_swn_notify,		"GET SwnNot") \
 	EM(netfs_trace_tcon_ref_new,			"NEW       ") \
 	EM(netfs_trace_tcon_ref_new_ipc,		"NEW Ipc   ") \
 	EM(netfs_trace_tcon_ref_new_reconnect_server,	"NEW Reconn") \

@@ -41,6 +42,7 @@
 	EM(netfs_trace_tcon_ref_put_mnt_ctx,		"PUT MntCtx") \
 	EM(netfs_trace_tcon_ref_put_dfs_refer,		"PUT DfsRfr") \
 	EM(netfs_trace_tcon_ref_put_reconnect_server,	"PUT Reconn") \
+	EM(netfs_trace_tcon_ref_put_swn_notify,		"PUT SwnNot") \
 	EM(netfs_trace_tcon_ref_put_tlink,		"PUT Tlink ") \
 	EM(netfs_trace_tcon_ref_see_cancelled_close,	"SEE Cn-Cls") \
 	EM(netfs_trace_tcon_ref_see_fscache_collision,	"SEE FV-CO!") \