[PATCH 07/24] ibtrs: client: sysfs interface functions

[Roman Pen <roman.penyaev@profitbricks.com>]

This is the sysfs interface to IBTRS sessions on client side:

  /sys/kernel/ibtrs_client/<SESS-NAME>/
    *** IBTRS session created by ibtrs_clt_open() API call
    |
    |- max_reconnect_attempts
    |  *** number of reconnect attempts for session
    |
    |- add_path
    |  *** adds another connection path into IBTRS session
    |
    |- paths/<DEST-IP>/
       *** established paths to server in a session
       |
       |- disconnect
       |  *** disconnect path
       |
       |- reconnect
       |  *** reconnect path
       |
       |- remove_path
       |  *** remove current path
       |
       |- state
       |  *** retrieve current path state
       |
       |- stats/
          *** current path statistics
          |
	  |- cpu_migration
	  |- rdma
	  |- rdma_lat
	  |- reconnects
	  |- reset_all
	  |- sg_entries
	  |- wc_completions

Signed-off-by: Roman Pen <roman.penyaev@profitbricks.com>
Signed-off-by: Danil Kipnis <danil.kipnis@profitbricks.com>
Cc: Jack Wang <jinpu.wang@profitbricks.com>
---
 drivers/infiniband/ulp/ibtrs/ibtrs-clt-sysfs.c | 519 +++++++++++++++++++++++++
 1 file changed, 519 insertions(+)

diff --git a/drivers/infiniband/ulp/ibtrs/ibtrs-clt-sysfs.c b/drivers/infiniband/ulp/ibtrs/ibtrs-clt-sysfs.c
new file mode 100644
index 000000000000..04949d6d796b
--- /dev/null
+++ b/drivers/infiniband/ulp/ibtrs/ibtrs-clt-sysfs.c
@@ -0,0 +1,519 @@
+/*
+ * InfiniBand Transport Layer
+ *
+ * Copyright (c) 2014 - 2017 ProfitBricks GmbH. All rights reserved.
+ * Authors: Fabian Holler <mail@fholler.de>
+ *          Jack Wang <jinpu.wang@profitbricks.com>
+ *          Kleber Souza <kleber.souza@profitbricks.com>
+ *          Danil Kipnis <danil.kipnis@profitbricks.com>
+ *          Roman Penyaev <roman.penyaev@profitbricks.com>
+ *          Milind Dumbare <Milind.dumbare@gmail.com>
+ *
+ * Copyright (c) 2017 - 2018 ProfitBricks GmbH. All rights reserved.
+ * Authors: Danil Kipnis <danil.kipnis@profitbricks.com>
+ *          Roman Penyaev <roman.penyaev@profitbricks.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#undef pr_fmt
+#define pr_fmt(fmt) KBUILD_MODNAME " L" __stringify(__LINE__) ": " fmt
+
+#include "ibtrs-pri.h"
+#include "ibtrs-clt.h"
+#include "ibtrs-log.h"
+
+static struct kobject *ibtrs_kobj;
+
+#define MIN_MAX_RECONN_ATT -1
+#define MAX_MAX_RECONN_ATT 9999
+
+static struct kobj_type ktype = {
+	.sysfs_ops = &kobj_sysfs_ops,
+};
+
+static ssize_t ibtrs_clt_max_reconn_attempts_show(struct kobject *kobj,
+						  struct kobj_attribute *attr,
+						  char *page)
+{
+	struct ibtrs_clt *clt;
+
+	clt = container_of(kobj, struct ibtrs_clt, kobj);
+
+	return sprintf(page, "%d\n", ibtrs_clt_get_max_reconnect_attempts(clt));
+}
+
+static ssize_t ibtrs_clt_max_reconn_attempts_store(struct kobject *kobj,
+						   struct kobj_attribute *attr,
+						   const char *buf,
+						   size_t count)
+{
+	struct ibtrs_clt *clt;
+	int value;
+	int ret;
+
+	clt = container_of(kobj, struct ibtrs_clt, kobj);
+
+	ret = kstrtoint(buf, 10, &value);
+	if (unlikely(ret)) {
+		ibtrs_err(clt, "%s: failed to convert string '%s' to int\n",
+			  attr->attr.name, buf);
+		return ret;
+	}
+	if (unlikely(value > MAX_MAX_RECONN_ATT ||
+		     value < MIN_MAX_RECONN_ATT)) {
+		ibtrs_err(clt, "%s: invalid range"
+			  " (provided: '%s', accepted: min: %d, max: %d)\n",
+			  attr->attr.name, buf, MIN_MAX_RECONN_ATT,
+			  MAX_MAX_RECONN_ATT);
+		return -EINVAL;
+	}
+	ibtrs_clt_set_max_reconnect_attempts(clt, value);
+
+	return count;
+}
+
+static struct kobj_attribute ibtrs_clt_max_reconnect_attempts_attr =
+	__ATTR(max_reconnect_attempts, 0644,
+	       ibtrs_clt_max_reconn_attempts_show,
+	       ibtrs_clt_max_reconn_attempts_store);
+
+static ssize_t ibtrs_clt_mp_policy_show(struct kobject *kobj,
+					struct kobj_attribute *attr,
+					char *page)
+{
+	struct ibtrs_clt *clt;
+
+	clt = container_of(kobj, struct ibtrs_clt, kobj);
+
+	switch (clt->mp_policy) {
+	case MP_POLICY_RR:
+		return sprintf(page, "round-robin (RR: %d)\n", clt->mp_policy);
+	case MP_POLICY_MIN_INFLIGHT:
+		return sprintf(page, "min-inflight (MI: %d)\n", clt->mp_policy);
+	default:
+		return sprintf(page, "Unknown (%d)\n", clt->mp_policy);
+	}
+}
+
+static ssize_t ibtrs_clt_mp_policy_store(struct kobject *kobj,
+					 struct kobj_attribute *attr,
+					 const char *buf,
+					 size_t count)
+{
+	struct ibtrs_clt *clt;
+	int value;
+	int ret;
+
+	clt = container_of(kobj, struct ibtrs_clt, kobj);
+
+	ret = kstrtoint(buf, 10, &value);
+	if (!ret && (value == MP_POLICY_RR || value == MP_POLICY_MIN_INFLIGHT)) {
+		clt->mp_policy = value;
+		return count;
+	}
+
+	if (!strncasecmp(buf, "round-robin", 11) ||
+	    !strncasecmp(buf, "rr", 2))
+		clt->mp_policy = MP_POLICY_RR;
+	else if (!strncasecmp(buf, "min-inflight", 12) ||
+		 !strncasecmp(buf, "mi", 2))
+		clt->mp_policy = MP_POLICY_MIN_INFLIGHT;
+	else
+		return -EINVAL;
+
+	return count;
+}
+
+static struct kobj_attribute ibtrs_clt_mp_policy_attr =
+	__ATTR(mp_policy, 0644,
+	       ibtrs_clt_mp_policy_show,
+	       ibtrs_clt_mp_policy_store);
+
+static ssize_t ibtrs_clt_state_show(struct kobject *kobj,
+				    struct kobj_attribute *attr, char *page)
+{
+	struct ibtrs_clt_sess *sess;
+
+	sess = container_of(kobj, struct ibtrs_clt_sess, kobj);
+	if (ibtrs_clt_sess_is_connected(sess))
+		return sprintf(page, "connected\n");
+
+	return sprintf(page, "disconnected\n");
+}
+
+static struct kobj_attribute ibtrs_clt_state_attr =
+	__ATTR(state, 0444, ibtrs_clt_state_show, NULL);
+
+static ssize_t ibtrs_clt_reconnect_show(struct kobject *kobj,
+					struct kobj_attribute *attr,
+					char *page)
+{
+	return scnprintf(page, PAGE_SIZE, "Usage: echo 1 > %s\n",
+			 attr->attr.name);
+}
+
+static ssize_t ibtrs_clt_reconnect_store(struct kobject *kobj,
+					 struct kobj_attribute *attr,
+					 const char *buf, size_t count)
+{
+	struct ibtrs_clt_sess *sess;
+	int ret;
+
+	sess = container_of(kobj, struct ibtrs_clt_sess, kobj);
+	if (!sysfs_streq(buf, "1")) {
+		ibtrs_err(sess, "%s: unknown value: '%s'\n",
+			  attr->attr.name, buf);
+		return -EINVAL;
+	}
+	ret = ibtrs_clt_reconnect_from_sysfs(sess);
+	if (unlikely(ret))
+		return ret;
+
+	return count;
+}
+
+static struct kobj_attribute ibtrs_clt_reconnect_attr =
+	__ATTR(reconnect, 0644, ibtrs_clt_reconnect_show,
+	       ibtrs_clt_reconnect_store);
+
+static ssize_t ibtrs_clt_disconnect_show(struct kobject *kobj,
+					 struct kobj_attribute *attr,
+					 char *page)
+{
+	return scnprintf(page, PAGE_SIZE, "Usage: echo 1 > %s\n",
+			 attr->attr.name);
+}
+
+static ssize_t ibtrs_clt_disconnect_store(struct kobject *kobj,
+					  struct kobj_attribute *attr,
+					  const char *buf, size_t count)
+{
+	struct ibtrs_clt_sess *sess;
+	int ret;
+
+	sess = container_of(kobj, struct ibtrs_clt_sess, kobj);
+	if (!sysfs_streq(buf, "1")) {
+		ibtrs_err(sess, "%s: unknown value: '%s'\n",
+			  attr->attr.name, buf);
+		return -EINVAL;
+	}
+	ret = ibtrs_clt_disconnect_from_sysfs(sess);
+	if (unlikely(ret))
+		return ret;
+
+	return count;
+}
+
+static struct kobj_attribute ibtrs_clt_disconnect_attr =
+	__ATTR(disconnect, 0644, ibtrs_clt_disconnect_show,
+	       ibtrs_clt_disconnect_store);
+
+static ssize_t ibtrs_clt_remove_path_show(struct kobject *kobj,
+					  struct kobj_attribute *attr,
+					  char *page)
+{
+	return scnprintf(page, PAGE_SIZE, "Usage: echo 1 > %s\n",
+			 attr->attr.name);
+}
+
+static ssize_t ibtrs_clt_remove_path_store(struct kobject *kobj,
+					   struct kobj_attribute *attr,
+					   const char *buf, size_t count)
+{
+	struct ibtrs_clt_sess *sess;
+	int ret;
+
+	sess = container_of(kobj, struct ibtrs_clt_sess, kobj);
+	if (!sysfs_streq(buf, "1")) {
+		ibtrs_err(sess, "%s: unknown value: '%s'\n",
+			  attr->attr.name, buf);
+		return -EINVAL;
+	}
+	ret = ibtrs_clt_remove_path_from_sysfs(sess, &attr->attr);
+	if (unlikely(ret))
+		return ret;
+
+	return count;
+}
+
+static struct kobj_attribute ibtrs_clt_remove_path_attr =
+	__ATTR(remove_path, 0644, ibtrs_clt_remove_path_show,
+	       ibtrs_clt_remove_path_store);
+
+static ssize_t ibtrs_clt_add_path_show(struct kobject *kobj,
+				       struct kobj_attribute *attr, char *page)
+{
+	return scnprintf(page, PAGE_SIZE, "Usage: echo"
+			 " [<source addr>,]<destination addr> > %s\n\n"
+			"*addr ::= [ ip:<ipv4|ipv6> | gid:<gid> ]\n",
+			 attr->attr.name);
+}
+
+static ssize_t ibtrs_clt_add_path_store(struct kobject *kobj,
+					struct kobj_attribute *attr,
+					const char *buf, size_t count)
+{
+	struct sockaddr_storage srcaddr, dstaddr;
+	struct ibtrs_addr addr = {
+		.src = (struct sockaddr *)&srcaddr,
+		.dst = (struct sockaddr *)&dstaddr
+	};
+	struct ibtrs_clt *clt;
+	const char *nl;
+	size_t len;
+	int err;
+
+	clt = container_of(kobj, struct ibtrs_clt, kobj);
+
+	nl = strchr(buf, '\n');
+	if (nl)
+		len = nl - buf;
+	else
+		len = count;
+	err = ibtrs_addr_to_sockaddr(buf, len, clt->port, &addr);
+	if (unlikely(err))
+		return -EINVAL;
+
+	err = ibtrs_clt_create_path_from_sysfs(clt, &addr);
+	if (unlikely(err))
+		return err;
+
+	return count;
+}
+
+static struct kobj_attribute ibtrs_clt_add_path_attr =
+	__ATTR(add_path, 0644, ibtrs_clt_add_path_show,
+	       ibtrs_clt_add_path_store);
+
+STAT_ATTR(struct ibtrs_clt_sess, cpu_migration,
+	  ibtrs_clt_stats_migration_cnt_to_str,
+	  ibtrs_clt_reset_cpu_migr_stats);
+
+STAT_ATTR(struct ibtrs_clt_sess, sg_entries,
+	  ibtrs_clt_stats_sg_list_distr_to_str,
+	  ibtrs_clt_reset_sg_list_distr_stats);
+
+STAT_ATTR(struct ibtrs_clt_sess, reconnects,
+	  ibtrs_clt_stats_reconnects_to_str,
+	  ibtrs_clt_reset_reconnects_stat);
+
+STAT_ATTR(struct ibtrs_clt_sess, rdma_lat,
+	  ibtrs_clt_stats_rdma_lat_distr_to_str,
+	  ibtrs_clt_reset_rdma_lat_distr_stats);
+
+STAT_ATTR(struct ibtrs_clt_sess, wc_completion,
+	  ibtrs_clt_stats_wc_completion_to_str,
+	  ibtrs_clt_reset_wc_comp_stats);
+
+STAT_ATTR(struct ibtrs_clt_sess, rdma,
+	  ibtrs_clt_stats_rdma_to_str,
+	  ibtrs_clt_reset_rdma_stats);
+
+STAT_ATTR(struct ibtrs_clt_sess, reset_all,
+	  ibtrs_clt_reset_all_help,
+	  ibtrs_clt_reset_all_stats);
+
+static struct attribute *ibtrs_clt_stats_attrs[] = {
+	&sg_entries_attr.attr,
+	&cpu_migration_attr.attr,
+	&reconnects_attr.attr,
+	&rdma_lat_attr.attr,
+	&wc_completion_attr.attr,
+	&rdma_attr.attr,
+	&reset_all_attr.attr,
+	NULL,
+};
+
+static struct attribute_group ibtrs_clt_stats_attr_group = {
+	.attrs = ibtrs_clt_stats_attrs,
+};
+
+static int ibtrs_clt_create_stats_files(struct kobject *kobj,
+					struct kobject *kobj_stats)
+{
+	int ret;
+
+	ret = kobject_init_and_add(kobj_stats, &ktype, kobj, "stats");
+	if (ret) {
+		pr_err("Failed to init and add stats kobject, err: %d\n",
+		       ret);
+		return ret;
+	}
+
+	ret = sysfs_create_group(kobj_stats, &ibtrs_clt_stats_attr_group);
+	if (ret) {
+		pr_err("failed to create stats sysfs group, err: %d\n",
+		       ret);
+		goto err;
+	}
+
+	return 0;
+
+err:
+	kobject_del(kobj_stats);
+	kobject_put(kobj_stats);
+
+	return ret;
+}
+
+static struct attribute *ibtrs_clt_sess_attrs[] = {
+	&ibtrs_clt_state_attr.attr,
+	&ibtrs_clt_reconnect_attr.attr,
+	&ibtrs_clt_disconnect_attr.attr,
+	&ibtrs_clt_remove_path_attr.attr,
+	NULL,
+};
+
+static struct attribute_group ibtrs_clt_sess_attr_group = {
+	.attrs = ibtrs_clt_sess_attrs,
+};
+
+int ibtrs_clt_create_sess_files(struct ibtrs_clt_sess *sess)
+{
+	struct ibtrs_clt *clt = sess->clt;
+	char str[MAXHOSTNAMELEN];
+	int err;
+
+	sockaddr_to_str((struct sockaddr *)&sess->s.dst_addr, str, sizeof(str));
+
+	err = kobject_init_and_add(&sess->kobj, &ktype, &clt->kobj_paths,
+				   "%s", str);
+	if (unlikely(err)) {
+		pr_err("kobject_init_and_add: %d\n", err);
+		return err;
+	}
+	err = sysfs_create_group(&sess->kobj, &ibtrs_clt_sess_attr_group);
+	if (unlikely(err)) {
+		pr_err("sysfs_create_group(): %d\n", err);
+		goto put_kobj;
+	}
+	err = ibtrs_clt_create_stats_files(&sess->kobj, &sess->kobj_stats);
+	if (unlikely(err))
+		goto put_kobj;
+
+	return 0;
+
+put_kobj:
+	kobject_del(&sess->kobj);
+	kobject_put(&sess->kobj);
+
+	return err;
+}
+
+static void ibtrs_sysfs_remove_file_self(struct kobject *kobj,
+					 const struct attribute *attr)
+{
+	struct device_attribute dattr = {
+		.attr.name = attr->name
+	};
+	struct device *device;
+
+	/*
+	 * Unfortunately original sysfs_remove_file_self() is not exported,
+	 * so consider this as a hack to call self removal of a sysfs entry
+	 * just using another "door".
+	 */
+
+	device = container_of(kobj, typeof(*device), kobj);
+	device_remove_file_self(device, &dattr);
+}
+
+void ibtrs_clt_destroy_sess_files(struct ibtrs_clt_sess *sess,
+				  const struct attribute *sysfs_self)
+{
+	if (sess->kobj.state_in_sysfs) {
+		kobject_del(&sess->kobj_stats);
+		kobject_put(&sess->kobj_stats);
+		if (sysfs_self)
+			/* To avoid deadlock firstly commit suicide */
+			ibtrs_sysfs_remove_file_self(&sess->kobj, sysfs_self);
+		kobject_del(&sess->kobj);
+		kobject_put(&sess->kobj);
+	}
+}
+
+static struct attribute *ibtrs_clt_attrs[] = {
+	&ibtrs_clt_max_reconnect_attempts_attr.attr,
+	&ibtrs_clt_mp_policy_attr.attr,
+	&ibtrs_clt_add_path_attr.attr,
+	NULL,
+};
+
+static struct attribute_group ibtrs_clt_attr_group = {
+	.attrs = ibtrs_clt_attrs,
+};
+
+int ibtrs_clt_create_sysfs_root_folders(struct ibtrs_clt *clt)
+{
+	int err;
+
+	err = kobject_init_and_add(&clt->kobj, &ktype, ibtrs_kobj,
+				   "%s", clt->sessname);
+	if (unlikely(err)) {
+		pr_err("kobject_init_and_add(): %d\n", err);
+		return err;
+	}
+	err = kobject_init_and_add(&clt->kobj_paths, &ktype,
+				   &clt->kobj, "paths");
+	if (unlikely(err)) {
+		pr_err("kobject_init_and_add(): %d\n", err);
+		goto put_kobj;
+	}
+
+	return 0;
+
+put_kobj:
+	kobject_del(&clt->kobj);
+	kobject_put(&clt->kobj);
+
+	return err;
+}
+
+int ibtrs_clt_create_sysfs_root_files(struct ibtrs_clt *clt)
+{
+	return sysfs_create_group(&clt->kobj, &ibtrs_clt_attr_group);
+}
+
+void ibtrs_clt_destroy_sysfs_root_folders(struct ibtrs_clt *clt)
+{
+	if (clt->kobj_paths.state_in_sysfs) {
+		kobject_del(&clt->kobj_paths);
+		kobject_put(&clt->kobj_paths);
+	}
+	if (clt->kobj.state_in_sysfs) {
+		kobject_del(&clt->kobj);
+		kobject_put(&clt->kobj);
+	}
+}
+
+void ibtrs_clt_destroy_sysfs_root_files(struct ibtrs_clt *clt)
+{
+	sysfs_remove_group(&clt->kobj, &ibtrs_clt_attr_group);
+}
+
+int ibtrs_clt_create_sysfs_module_files(void)
+{
+	ibtrs_kobj = kobject_create_and_add(KBUILD_MODNAME, kernel_kobj);
+	if (unlikely(!ibtrs_kobj))
+		return -ENOMEM;
+
+	return 0;
+}
+
+void ibtrs_clt_destroy_sysfs_module_files(void)
+{
+	kobject_del(ibtrs_kobj);
+	kobject_put(ibtrs_kobj);
+}
-- 
2.13.1