[PATCH v7 22/25] block/rnbd: server: sysfs interface functions

Jack Wang
2020-01-16T12:59:51Z

From: Jack Wang <jinpu.wang@cloud.ionos.com>

This is the sysfs interface to rnbd mapped devices on server side:

/sys/devices/virtual/rnbd-server/ctl/devices/<device_name>/
|- block_dev
| *** link pointing to the corresponding block device sysfs entry
|
|- sessions/<session-name>/
| *** sessions directory
|
|- read_only
| *** is devices mapped as read only
|
|- mapping_path
*** relative device path provided by the client during mapping

Signed-off-by: Danil Kipnis <danil.kipnis@cloud.ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@cloud.ionos.com>
---
drivers/block/rnbd/rnbd-srv-sysfs.c | 213 ++++++++++++++++++++++++++++
1 file changed, 213 insertions(+)
create mode 100644 drivers/block/rnbd/rnbd-srv-sysfs.c

diff --git a/drivers/block/rnbd/rnbd-srv-sysfs.c b/drivers/block/rnbd/rnbd-srv-sysfs.c
new file mode 100644
index 000000000000..b0b871b5105c
--- /dev/null
+++ b/drivers/block/rnbd/rnbd-srv-sysfs.c
@@ -0,0 +1,213 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * RDMA Network Block Driver
+ *
+ * Copyright (c) 2014 - 2018 ProfitBricks GmbH. All rights reserved.
+ *
+ * Copyright (c) 2018 - 2019 1&1 IONOS Cloud GmbH. All rights reserved.
+ *
+ * Copyright (c) 2019 - 2020 1&1 IONOS SE. All rights reserved.
+ */
+#undef pr_fmt
+#define pr_fmt(fmt) KBUILD_MODNAME " L" __stringify(__LINE__) ": " fmt
+
+#include <uapi/linux/limits.h>
+#include <linux/kobject.h>
+#include <linux/sysfs.h>
+#include <linux/stat.h>
+#include <linux/genhd.h>
+#include <linux/list.h>
+#include <linux/moduleparam.h>
+#include <linux/device.h>
+
+#include "rnbd-srv.h"
+
+static struct device *rnbd_dev;
+static struct class *rnbd_dev_class;
+static struct kobject *rnbd_devs_kobj;
+
+static struct kobj_type ktype = {
+ .sysfs_ops = &kobj_sysfs_ops,
+};
+
+int rnbd_srv_create_dev_sysfs(struct rnbd_srv_dev *dev,
+ struct block_device *bdev,
+ const char *dir_name)
+{
+ struct kobject *bdev_kobj;
+ int ret;
+
+ ret = kobject_init_and_add(&dev->dev_kobj, &ktype,
+ rnbd_devs_kobj, dir_name);
+ if (ret)
+ return ret;
+
+ ret = kobject_init_and_add(&dev->dev_sessions_kobj,
+ &ktype,
+ &dev->dev_kobj, "sessions");
+ if (ret)
+ goto err;
+
+ bdev_kobj = &disk_to_dev(bdev->bd_disk)->kobj;
+ ret = sysfs_create_link(&dev->dev_kobj, bdev_kobj, "block_dev");
+ if (ret)
+ goto err2;
+
+ return 0;
+
+err2:
+ kobject_put(&dev->dev_sessions_kobj);
+err:
+ kobject_put(&dev->dev_kobj);
+ return ret;
+}
+
+void rnbd_srv_destroy_dev_sysfs(struct rnbd_srv_dev *dev)
+{
+ sysfs_remove_link(&dev->dev_kobj, "block_dev");
+ kobject_del(&dev->dev_sessions_kobj);
+ kobject_put(&dev->dev_sessions_kobj);
+ kobject_del(&dev->dev_kobj);
+ kobject_put(&dev->dev_kobj);
+}
+
+static ssize_t read_only_show(struct kobject *kobj, struct kobj_attribute *attr,
+ char *page)
+{
+ struct rnbd_srv_sess_dev *sess_dev;
+
+ sess_dev = container_of(kobj, struct rnbd_srv_sess_dev, kobj);
+
+ return scnprintf(page, PAGE_SIZE, "%s\n",
+ (sess_dev->open_flags & FMODE_WRITE) ? "0" : "1");
+}
+
+static struct kobj_attribute rnbd_srv_dev_session_ro_attr =
+ __ATTR_RO(read_only);
+
+static ssize_t access_mode_show(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ char *page)
+{
+ struct rnbd_srv_sess_dev *sess_dev;
+
+ sess_dev = container_of(kobj, struct rnbd_srv_sess_dev, kobj);
+
+ return scnprintf(page, PAGE_SIZE, "%s\n",
+ rnbd_access_mode_str(sess_dev->access_mode));
+}
+
+static struct kobj_attribute rnbd_srv_dev_session_access_mode_attr =
+ __ATTR_RO(access_mode);
+
+static ssize_t mapping_path_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *page)
+{
+ struct rnbd_srv_sess_dev *sess_dev;
+
+ sess_dev = container_of(kobj, struct rnbd_srv_sess_dev, kobj);
+
+ return scnprintf(page, PAGE_SIZE, "%s\n", sess_dev->pathname);
+}
+
+static struct kobj_attribute rnbd_srv_dev_session_mapping_path_attr =
+ __ATTR_RO(mapping_path);
+
+static struct attribute *rnbd_srv_default_dev_sessions_attrs[] = {
+ &rnbd_srv_dev_session_access_mode_attr.attr,
+ &rnbd_srv_dev_session_ro_attr.attr,
+ &rnbd_srv_dev_session_mapping_path_attr.attr,
+ NULL,
+};
+
+static struct attribute_group rnbd_srv_default_dev_session_attr_group = {
+ .attrs = rnbd_srv_default_dev_sessions_attrs,
+};
+
+void rnbd_srv_destroy_dev_session_sysfs(struct rnbd_srv_sess_dev *sess_dev)
+{
+ DECLARE_COMPLETION_ONSTACK(sysfs_compl);
+
+ sysfs_remove_group(&sess_dev->kobj,
+ &rnbd_srv_default_dev_session_attr_group);
+
+ sess_dev->sysfs_release_compl = &sysfs_compl;
+ kobject_del(&sess_dev->kobj);
+ kobject_put(&sess_dev->kobj);
+ wait_for_completion(&sysfs_compl);
+}
+
+static void rnbd_srv_sess_dev_release(struct kobject *kobj)
+{
+ struct rnbd_srv_sess_dev *sess_dev;
+
+ sess_dev = container_of(kobj, struct rnbd_srv_sess_dev, kobj);
+ if (sess_dev->sysfs_release_compl)
+ complete_all(sess_dev->sysfs_release_compl);
+}
+
+static struct kobj_type rnbd_srv_sess_dev_ktype = {
+ .sysfs_ops = &kobj_sysfs_ops,
+ .release = rnbd_srv_sess_dev_release,
+};
+
+int rnbd_srv_create_dev_session_sysfs(struct rnbd_srv_sess_dev *sess_dev)
+{
+ int ret;
+
+ ret = kobject_init_and_add(&sess_dev->kobj, &rnbd_srv_sess_dev_ktype,
+ &sess_dev->dev->dev_sessions_kobj, "%s",
+ sess_dev->sess->sessname);
+ if (ret)
+ return ret;
+
+ ret = sysfs_create_group(&sess_dev->kobj,
+ &rnbd_srv_default_dev_session_attr_group);
+ if (ret)
+ goto err;
+
+ return 0;
+
+err:
+ kobject_put(&sess_dev->kobj);
+
+ return ret;
+}
+
+int rnbd_srv_create_sysfs_files(void)
+{
+ int err;
+
+ rnbd_dev_class = class_create(THIS_MODULE, "rnbd-server");
+ if (IS_ERR(rnbd_dev_class))
+ return PTR_ERR(rnbd_dev_class);
+
+ rnbd_dev = device_create(rnbd_dev_class, NULL,
+ MKDEV(0, 0), NULL, "ctl");
+ if (IS_ERR(rnbd_dev)) {
+ err = PTR_ERR(rnbd_dev);
+ goto cls_destroy;
+ }
+ rnbd_devs_kobj = kobject_create_and_add("devices", &rnbd_dev->kobj);
+ if (unlikely(!rnbd_devs_kobj)) {
+ err = -ENOMEM;
+ goto dev_destroy;
+ }
+
+ return 0;
+
+dev_destroy:
+ device_destroy(rnbd_dev_class, MKDEV(0, 0));
+cls_destroy:
+ class_destroy(rnbd_dev_class);
+
+ return err;
+}
+
+void rnbd_srv_destroy_sysfs_files(void)
+{
+ kobject_del(rnbd_devs_kobj);
+ kobject_put(rnbd_devs_kobj);
+ device_destroy(rnbd_dev_class, MKDEV(0, 0));
+ class_destroy(rnbd_dev_class);
+}
--
2.17.1