dm vdo: add sysfs support for setting parameters and fetching stats

Add data and methods setting run time parameters via sysfs, and to
make state and statistics information available through sysfs.
Co-developed-by: J. corwin Coburn <corwin@hurlbutnet.net>
Signed-off-by: J. corwin Coburn <corwin@hurlbutnet.net>
Co-developed-by: Michael Sclafani <dm-devel@lists.linux.dev>
Signed-off-by: Michael Sclafani <dm-devel@lists.linux.dev>
Co-developed-by: Sweet Tea Dorminy <sweettea-kernel@dorminy.me>
Signed-off-by: Sweet Tea Dorminy <sweettea-kernel@dorminy.me>
Co-developed-by: Bruce Johnston <bjohnsto@redhat.com>
Signed-off-by: Bruce Johnston <bjohnsto@redhat.com>
Signed-off-by: Matthew Sakai <msakai@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>

drivers/md/dm-vdo/pool-sysfs.c

+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright 2023 Red Hat
+ */
+
+#include "pool-sysfs.h"
+
+#include <linux/kstrtox.h>
+
+#include "memory-alloc.h"
+#include "string-utils.h"
+
+#include "data-vio.h"
+#include "dedupe.h"
+#include "vdo.h"
+
+struct pool_attribute {
+	struct attribute attr;
+	ssize_t (*show)(struct vdo *vdo, char *buf);
+	ssize_t (*store)(struct vdo *vdo, const char *value, size_t count);
+};
+
+static ssize_t vdo_pool_attr_show(struct kobject *directory, struct attribute *attr,
+				  char *buf)
+{
+	struct pool_attribute *pool_attr = container_of(attr, struct pool_attribute,
+							attr);
+	struct vdo *vdo = container_of(directory, struct vdo, vdo_directory);
+
+	if (pool_attr->show == NULL)
+		return -EINVAL;
+	return pool_attr->show(vdo, buf);
+}
+
+static ssize_t vdo_pool_attr_store(struct kobject *directory, struct attribute *attr,
+				   const char *buf, size_t length)
+{
+	struct pool_attribute *pool_attr = container_of(attr, struct pool_attribute,
+							attr);
+	struct vdo *vdo = container_of(directory, struct vdo, vdo_directory);
+
+	if (pool_attr->store == NULL)
+		return -EINVAL;
+	return pool_attr->store(vdo, buf, length);
+}
+
+static const struct sysfs_ops vdo_pool_sysfs_ops = {
+	.show = vdo_pool_attr_show,
+	.store = vdo_pool_attr_store,
+};
+
+static ssize_t pool_compressing_show(struct vdo *vdo, char *buf)
+{
+	return sprintf(buf, "%s\n", (vdo_get_compressing(vdo) ? "1" : "0"));
+}
+
+static ssize_t pool_discards_active_show(struct vdo *vdo, char *buf)
+{
+	return sprintf(buf, "%u\n",
+		       get_data_vio_pool_active_discards(vdo->data_vio_pool));
+}
+
+static ssize_t pool_discards_limit_show(struct vdo *vdo, char *buf)
+{
+	return sprintf(buf, "%u\n", get_data_vio_pool_discard_limit(vdo->data_vio_pool));
+}
+
+static ssize_t pool_discards_limit_store(struct vdo *vdo, const char *buf, size_t length)
+{
+	unsigned int value;
+	int result;
+
+	if ((length > 12) || (kstrtouint(buf, 10, &value) < 0) || (value < 1))
+		return -EINVAL;
+
+	result = set_data_vio_pool_discard_limit(vdo->data_vio_pool, value);
+	if (result != VDO_SUCCESS)
+		return -EINVAL;
+
+	return length;
+}
+
+static ssize_t pool_discards_maximum_show(struct vdo *vdo, char *buf)
+{
+	return sprintf(buf, "%u\n",
+		       get_data_vio_pool_maximum_discards(vdo->data_vio_pool));
+}
+
+static ssize_t pool_instance_show(struct vdo *vdo, char *buf)
+{
+	return sprintf(buf, "%u\n", vdo->instance);
+}
+
+static ssize_t pool_requests_active_show(struct vdo *vdo, char *buf)
+{
+	return sprintf(buf, "%u\n",
+		       get_data_vio_pool_active_requests(vdo->data_vio_pool));
+}
+
+static ssize_t pool_requests_limit_show(struct vdo *vdo, char *buf)
+{
+	return sprintf(buf, "%u\n", get_data_vio_pool_request_limit(vdo->data_vio_pool));
+}
+
+static ssize_t pool_requests_maximum_show(struct vdo *vdo, char *buf)
+{
+	return sprintf(buf, "%u\n",
+		       get_data_vio_pool_maximum_requests(vdo->data_vio_pool));
+}
+
+static void vdo_pool_release(struct kobject *directory)
+{
+	uds_free(container_of(directory, struct vdo, vdo_directory));
+}
+
+static struct pool_attribute vdo_pool_compressing_attr = {
+	.attr = {
+			.name = "compressing",
+			.mode = 0444,
+		},
+	.show = pool_compressing_show,
+};
+
+static struct pool_attribute vdo_pool_discards_active_attr = {
+	.attr = {
+			.name = "discards_active",
+			.mode = 0444,
+		},
+	.show = pool_discards_active_show,
+};
+
+static struct pool_attribute vdo_pool_discards_limit_attr = {
+	.attr = {
+			.name = "discards_limit",
+			.mode = 0644,
+		},
+	.show = pool_discards_limit_show,
+	.store = pool_discards_limit_store,
+};
+
+static struct pool_attribute vdo_pool_discards_maximum_attr = {
+	.attr = {
+			.name = "discards_maximum",
+			.mode = 0444,
+		},
+	.show = pool_discards_maximum_show,
+};
+
+static struct pool_attribute vdo_pool_instance_attr = {
+	.attr = {
+			.name = "instance",
+			.mode = 0444,
+		},
+	.show = pool_instance_show,
+};
+
+static struct pool_attribute vdo_pool_requests_active_attr = {
+	.attr = {
+			.name = "requests_active",
+			.mode = 0444,
+		},
+	.show = pool_requests_active_show,
+};
+
+static struct pool_attribute vdo_pool_requests_limit_attr = {
+	.attr = {
+			.name = "requests_limit",
+			.mode = 0444,
+		},
+	.show = pool_requests_limit_show,
+};
+
+static struct pool_attribute vdo_pool_requests_maximum_attr = {
+	.attr = {
+			.name = "requests_maximum",
+			.mode = 0444,
+		},
+	.show = pool_requests_maximum_show,
+};
+
+static struct attribute *pool_attrs[] = {
+	&vdo_pool_compressing_attr.attr,
+	&vdo_pool_discards_active_attr.attr,
+	&vdo_pool_discards_limit_attr.attr,
+	&vdo_pool_discards_maximum_attr.attr,
+	&vdo_pool_instance_attr.attr,
+	&vdo_pool_requests_active_attr.attr,
+	&vdo_pool_requests_limit_attr.attr,
+	&vdo_pool_requests_maximum_attr.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(pool);
+
+const struct kobj_type vdo_directory_type = {
+	.release = vdo_pool_release,
+	.sysfs_ops = &vdo_pool_sysfs_ops,
+	.default_groups = pool_groups,
+};

drivers/md/dm-vdo/pool-sysfs.h

+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright 2023 Red Hat
+ */
+
+#ifndef VDO_POOL_SYSFS_H
+#define VDO_POOL_SYSFS_H
+
+#include <linux/kobject.h>
+
+/* The kobj_type used for setting up the kernel layer kobject. */
+extern const struct kobj_type vdo_directory_type;
+
+/* The sysfs_ops used for the "statistics" subdirectory. */
+extern const struct sysfs_ops vdo_pool_stats_sysfs_ops;
+/* The attribute used for the "statistics" subdirectory. */
+extern struct attribute *vdo_pool_stats_attrs[];
+
+#endif /* VDO_POOL_SYSFS_H */

drivers/md/dm-vdo/sysfs.c

+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright 2023 Red Hat
+ */
+
+#include <linux/module.h>
+
+#include "logger.h"
+
+#include "constants.h"
+#include "dedupe.h"
+#include "vdo.h"
+
+static int vdo_log_level_show(char *buf, const struct kernel_param *kp)
+{
+	return sprintf(buf, "%s\n", uds_log_priority_to_string(uds_get_log_level()));
+}
+
+static int vdo_log_level_store(const char *buf, const struct kernel_param *kp)
+{
+	static char internal_buf[11];
+
+	int n = strlen(buf);
+
+	if (n > 10)
+		return -EINVAL;
+
+	memset(internal_buf, '\000', sizeof(internal_buf));
+	memcpy(internal_buf, buf, n);
+	if (internal_buf[n - 1] == '\n')
+		internal_buf[n - 1] = '\000';
+	uds_set_log_level(uds_log_string_to_priority(internal_buf));
+	return 0;
+}
+
+
+static int vdo_dedupe_timeout_interval_store(const char *buf,
+					     const struct kernel_param *kp)
+{
+	int result = param_set_uint(buf, kp);
+
+	if (result != 0)
+		return result;
+	vdo_set_dedupe_index_timeout_interval(*(uint *)kp->arg);
+	return 0;
+}
+
+static int vdo_min_dedupe_timer_interval_store(const char *buf,
+					       const struct kernel_param *kp)
+{
+	int result = param_set_uint(buf, kp);
+
+	if (result != 0)
+		return result;
+	vdo_set_dedupe_index_min_timer_interval(*(uint *)kp->arg);
+	return 0;
+}
+
+static const struct kernel_param_ops log_level_ops = {
+	.set = vdo_log_level_store,
+	.get = vdo_log_level_show,
+};
+
+
+static const struct kernel_param_ops dedupe_timeout_ops = {
+	.set = vdo_dedupe_timeout_interval_store,
+	.get = param_get_uint,
+};
+
+static const struct kernel_param_ops dedupe_timer_ops = {
+	.set = vdo_min_dedupe_timer_interval_store,
+	.get = param_get_uint,
+};
+
+module_param_cb(log_level, &log_level_ops, NULL, 0644);
+
+
+module_param_cb(deduplication_timeout_interval, &dedupe_timeout_ops,
+		&vdo_dedupe_index_timeout_interval, 0644);
+
+module_param_cb(min_deduplication_timer_interval, &dedupe_timer_ops,
+		&vdo_dedupe_index_min_timer_interval, 0644);