[PATCH v7 18/25] block/rnbd: client: sysfs interface functions

Jack Wang
2020-01-16T12:59:50Z

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

This is the sysfs interface to rnbd block devices on client side:

/sys/devices/virtual/rnbd-client/ctl/
|- map_device
| *** maps remote device
|
|- devices/
*** all mapped devices

/sys/block/rnbd<N>/rnbd/
|- unmap_device
| *** unmaps device
|
|- state
| *** device state
|
|- session
| *** session name
|
|- mapping_path
*** path of the dev that was mapped on server

Signed-off-by: Danil Kipnis <danil.kipnis@cloud.ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@cloud.ionos.com>
---
drivers/block/rnbd/rnbd-clt-sysfs.c | 621 ++++++++++++++++++++++++++++
1 file changed, 621 insertions(+)
create mode 100644 drivers/block/rnbd/rnbd-clt-sysfs.c

diff --git a/drivers/block/rnbd/rnbd-clt-sysfs.c b/drivers/block/rnbd/rnbd-clt-sysfs.c
new file mode 100644
index 000000000000..bc2e223c42c4
--- /dev/null
+++ b/drivers/block/rnbd/rnbd-clt-sysfs.c
@@ -0,0 +1,621 @@
+// 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 <linux/types.h>
+#include <linux/ctype.h>
+#include <linux/parser.h>
+#include <linux/module.h>
+#include <linux/in6.h>
+#include <linux/fs.h>
+#include <linux/uaccess.h>
+#include <linux/device.h>
+#include <rdma/ib.h>
+#include <rdma/rdma_cm.h>
+
+#include "rnbd-clt.h"
+
+static struct device *rnbd_dev;
+static struct class *rnbd_dev_class;
+static struct kobject *rnbd_devs_kobj;
+
+enum {
+ RNBD_OPT_ERR = 0,
+ RNBD_OPT_PATH = 1 << 0,
+ RNBD_OPT_DEV_PATH = 1 << 1,
+ RNBD_OPT_ACCESS_MODE = 1 << 3,
+ RNBD_OPT_SESSNAME = 1 << 6,
+};
+
+static const unsigned int rnbd_opt_mandatory[] = {
+ RNBD_OPT_PATH,
+ RNBD_OPT_DEV_PATH,
+ RNBD_OPT_SESSNAME,
+};
+
+static const match_table_t rnbd_opt_tokens = {
+ {RNBD_OPT_PATH, "path=%s" },
+ {RNBD_OPT_DEV_PATH, "device_path=%s"},
+ {RNBD_OPT_ACCESS_MODE, "access_mode=%s"},
+ {RNBD_OPT_SESSNAME, "sessname=%s" },
+ {RNBD_OPT_ERR, NULL },
+};
+
+struct rnbd_map_options {
+ char *sessname;
+ struct rtrs_addr *paths;
+ size_t *path_cnt;
+ char *pathname;
+ enum rnbd_access_mode *access_mode;
+};
+
+static int rnbd_clt_parse_map_options(const char *buf, size_t max_path_cnt,
+ struct rnbd_map_options *opt)
+{
+ char *options, *sep_opt;
+ char *p;
+ substring_t args[MAX_OPT_ARGS];
+ int opt_mask = 0;
+ int token;
+ int ret = -EINVAL;
+ int i;
+ int p_cnt = 0;
+
+ options = kstrdup(buf, GFP_KERNEL);
+ if (!options)
+ return -ENOMEM;
+
+ sep_opt = strstrip(options);
+ while ((p = strsep(&sep_opt, " ")) != NULL) {
+ if (!*p)
+ continue;
+
+ token = match_token(p, rnbd_opt_tokens, args);
+ opt_mask |= token;
+
+ switch (token) {
+ case RNBD_OPT_SESSNAME:
+ p = match_strdup(args);
+ if (!p) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ if (strlen(p) > NAME_MAX) {
+ pr_err("map_device: sessname too long\n");
+ ret = -EINVAL;
+ kfree(p);
+ goto out;
+ }
+ strlcpy(opt->sessname, p, NAME_MAX);
+ kfree(p);
+ break;
+
+ case RNBD_OPT_PATH:
+ if (p_cnt >= max_path_cnt) {
+ pr_err("map_device: too many (> %zu) paths provided\n",
+ max_path_cnt);
+ ret = -ENOMEM;
+ goto out;
+ }
+ p = match_strdup(args);
+ if (!p) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ ret = rtrs_addr_to_sockaddr(p, strlen(p), RTRS_PORT,
+ &opt->paths[p_cnt]);
+ if (ret) {
+ pr_err("Can't parse path %s: %d\n", p, ret);
+ kfree(p);
+ goto out;
+ }
+
+ p_cnt++;
+
+ kfree(p);
+ break;
+
+ case RNBD_OPT_DEV_PATH:
+ p = match_strdup(args);
+ if (!p) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ if (strlen(p) > NAME_MAX) {
+ pr_err("map_device: Device path too long\n");
+ ret = -EINVAL;
+ kfree(p);
+ goto out;
+ }
+ strlcpy(opt->pathname, p, NAME_MAX);
+ kfree(p);
+ break;
+
+ case RNBD_OPT_ACCESS_MODE:
+ p = match_strdup(args);
+ if (!p) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ if (!strcmp(p, "ro")) {
+ *opt->access_mode = RNBD_ACCESS_RO;
+ } else if (!strcmp(p, "rw")) {
+ *opt->access_mode = RNBD_ACCESS_RW;
+ } else if (!strcmp(p, "migration")) {
+ *opt->access_mode = RNBD_ACCESS_MIGRATION;
+ } else {
+ pr_err("map_device: Invalid access_mode: '%s'\n",
+ p);
+ ret = -EINVAL;
+ kfree(p);
+ goto out;
+ }
+
+ kfree(p);
+ break;
+
+ default:
+ pr_err("map_device: Unknown parameter or missing value '%s'\n",
+ p);
+ ret = -EINVAL;
+ goto out;
+ }
+ }
+
+ for (i = 0; i < ARRAY_SIZE(rnbd_opt_mandatory); i++) {
+ if ((opt_mask & rnbd_opt_mandatory[i])) {
+ ret = 0;
+ } else {
+ pr_err("map_device: Parameters missing\n");
+ ret = -EINVAL;
+ break;
+ }
+ }
+
+out:
+ *opt->path_cnt = p_cnt;
+ kfree(options);
+ return ret;
+}
+
+static ssize_t state_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *page)
+{
+ struct rnbd_clt_dev *dev;
+
+ dev = container_of(kobj, struct rnbd_clt_dev, kobj);
+
+ switch (dev->dev_state) {
+ case DEV_STATE_INIT:
+ return snprintf(page, PAGE_SIZE, "init\n");
+ case DEV_STATE_MAPPED:
+ /* TODO fix cli tool before changing to proper state */
+ return snprintf(page, PAGE_SIZE, "open\n");
+ case DEV_STATE_MAPPED_DISCONNECTED:
+ /* TODO fix cli tool before changing to proper state */
+ return snprintf(page, PAGE_SIZE, "closed\n");
+ case DEV_STATE_UNMAPPED:
+ return snprintf(page, PAGE_SIZE, "unmapped\n");
+ default:
+ return snprintf(page, PAGE_SIZE, "unknown\n");
+ }
+}
+
+static struct kobj_attribute rnbd_clt_state_attr = __ATTR_RO(state);
+
+static ssize_t mapping_path_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *page)
+{
+ struct rnbd_clt_dev *dev;
+
+ dev = container_of(kobj, struct rnbd_clt_dev, kobj);
+
+ return scnprintf(page, PAGE_SIZE, "%s\n", dev->pathname);
+}
+
+static struct kobj_attribute rnbd_clt_mapping_path_attr =
+ __ATTR_RO(mapping_path);
+
+static ssize_t access_mode_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *page)
+{
+ struct rnbd_clt_dev *dev;
+
+ dev = container_of(kobj, struct rnbd_clt_dev, kobj);
+
+ return snprintf(page, PAGE_SIZE, "%s\n",
+ rnbd_access_mode_str(dev->access_mode));
+}
+
+static struct kobj_attribute rnbd_clt_access_mode =
+ __ATTR_RO(access_mode);
+
+static ssize_t rnbd_clt_unmap_dev_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *page)
+{
+ return scnprintf(page, PAGE_SIZE, "Usage: echo <normal|force> > %s\n",
+ attr->attr.name);
+}
+
+static ssize_t rnbd_clt_unmap_dev_store(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct rnbd_clt_dev *dev;
+ char *opt, *options;
+ bool force;
+ int err;
+
+ opt = kstrdup(buf, GFP_KERNEL);
+ if (!opt)
+ return -ENOMEM;
+
+ options = strstrip(opt);
+ dev = container_of(kobj, struct rnbd_clt_dev, kobj);
+ if (sysfs_streq(options, "normal")) {
+ force = false;
+ } else if (sysfs_streq(options, "force")) {
+ force = true;
+ } else {
+ rnbd_clt_err(dev,
+ "unmap_device: Invalid value: %s\n",
+ options);
+ err = -EINVAL;
+ goto out;
+ }
+
+ rnbd_clt_info(dev, "Unmapping device, option: %s.\n",
+ force ? "force" : "normal");
+
+ /*
+ * We take explicit module reference only for one reason: do not
+ * race with lockless rnbd_destroy_sessions().
+ */
+ if (!try_module_get(THIS_MODULE)) {
+ err = -ENODEV;
+ goto out;
+ }
+ err = rnbd_clt_unmap_device(dev, force, &attr->attr);
+ if (unlikely(err)) {
+ if (unlikely(err != -EALREADY))
+ rnbd_clt_err(dev, "unmap_device: %d\n", err);
+ goto module_put;
+ }
+
+ /*
+ * Here device can be vanished!
+ */
+
+ err = count;
+
+module_put:
+ module_put(THIS_MODULE);
+out:
+ kfree(opt);
+
+ return err;
+}
+
+static struct kobj_attribute rnbd_clt_unmap_device_attr =
+ __ATTR(unmap_device, 0644, rnbd_clt_unmap_dev_show,
+ rnbd_clt_unmap_dev_store);
+
+static ssize_t rnbd_clt_resize_dev_show(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ char *page)
+{
+ return scnprintf(page, PAGE_SIZE,
+ "Usage: echo <new size in sectors> > %s\n",
+ attr->attr.name);
+}
+
+static ssize_t rnbd_clt_resize_dev_store(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ const char *buf, size_t count)
+{
+ int ret;
+ unsigned long sectors;
+ struct rnbd_clt_dev *dev;
+
+ dev = container_of(kobj, struct rnbd_clt_dev, kobj);
+
+ ret = kstrtoul(buf, 0, &sectors);
+ if (ret)
+ return ret;
+
+ ret = rnbd_clt_resize_disk(dev, (size_t)sectors);
+ if (ret)
+ return ret;
+
+ return count;
+}
+
+static struct kobj_attribute rnbd_clt_resize_dev_attr =
+ __ATTR(resize, 0644, rnbd_clt_resize_dev_show,
+ rnbd_clt_resize_dev_store);
+
+static ssize_t rnbd_clt_remap_dev_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 rnbd_clt_remap_dev_store(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct rnbd_clt_dev *dev;
+ char *opt, *options;
+ int err;
+
+ opt = kstrdup(buf, GFP_KERNEL);
+ if (!opt)
+ return -ENOMEM;
+
+ options = strstrip(opt);
+ dev = container_of(kobj, struct rnbd_clt_dev, kobj);
+ if (!sysfs_streq(options, "1")) {
+ rnbd_clt_err(dev,
+ "remap_device: Invalid value: %s\n",
+ options);
+ err = -EINVAL;
+ goto out;
+ }
+ err = rnbd_clt_remap_device(dev);
+ if (likely(!err))
+ err = count;
+
+out:
+ kfree(opt);
+
+ return err;
+}
+
+static struct kobj_attribute rnbd_clt_remap_device_attr =
+ __ATTR(remap_device, 0644, rnbd_clt_remap_dev_show,
+ rnbd_clt_remap_dev_store);
+
+static ssize_t session_show(struct kobject *kobj, struct kobj_attribute *attr,
+ char *page)
+{
+ struct rnbd_clt_dev *dev;
+
+ dev = container_of(kobj, struct rnbd_clt_dev, kobj);
+
+ return scnprintf(page, PAGE_SIZE, "%s\n", dev->sess->sessname);
+}
+
+static struct kobj_attribute rnbd_clt_session_attr =
+ __ATTR_RO(session);
+
+static struct attribute *rnbd_dev_attrs[] = {
+ &rnbd_clt_unmap_device_attr.attr,
+ &rnbd_clt_resize_dev_attr.attr,
+ &rnbd_clt_remap_device_attr.attr,
+ &rnbd_clt_mapping_path_attr.attr,
+ &rnbd_clt_state_attr.attr,
+ &rnbd_clt_session_attr.attr,
+ &rnbd_clt_access_mode.attr,
+ NULL,
+};
+
+void rnbd_clt_remove_dev_symlink(struct rnbd_clt_dev *dev)
+{
+ /*
+ * The module_is_live() check is crucial and helps to avoid annoying
+ * sysfs warning raised in sysfs_remove_link(), when the whole sysfs
+ * path was just removed, see rnbd_close_sessions().
+ */
+ if (strlen(dev->blk_symlink_name) && module_is_live(THIS_MODULE))
+ sysfs_remove_link(rnbd_devs_kobj, dev->blk_symlink_name);
+}
+
+static struct kobj_type rnbd_dev_ktype = {
+ .sysfs_ops = &kobj_sysfs_ops,
+ .default_attrs = rnbd_dev_attrs,
+};
+
+static int rnbd_clt_add_dev_kobj(struct rnbd_clt_dev *dev)
+{
+ int ret;
+ struct kobject *gd_kobj = &disk_to_dev(dev->gd)->kobj;
+
+ ret = kobject_init_and_add(&dev->kobj, &rnbd_dev_ktype, gd_kobj, "%s",
+ "rnbd");
+ if (ret)
+ rnbd_clt_err(dev, "Failed to create device sysfs dir, err: %d\n",
+ ret);
+
+ return ret;
+}
+
+static ssize_t rnbd_clt_map_device_show(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ char *page)
+{
+ return scnprintf(page, PAGE_SIZE,
+ "Usage: echo \"sessname=<name of the rtrs session> path=<[srcaddr@]dstaddr> [path=<[srcaddr@]dstaddr>] device_path=<full path on remote side> [access_mode=<ro|rw|migration>]\" > %s\n\naddr ::= [ ip:<ipv4> | ip:<ipv6> | gid:<gid> ]\n",
+ attr->attr.name);
+}
+
+static int rnbd_clt_get_path_name(struct rnbd_clt_dev *dev, char *buf,
+ size_t len)
+{
+ int ret;
+ char pathname[NAME_MAX], *s;
+
+ strlcpy(pathname, dev->pathname, sizeof(pathname));
+ while ((s = strchr(pathname, '/')))
+ s[0] = '!';
+
+ ret = snprintf(buf, len, "%s", pathname);
+ if (ret >= len)
+ return -ENAMETOOLONG;
+
+ return 0;
+}
+
+static int rnbd_clt_add_dev_symlink(struct rnbd_clt_dev *dev)
+{
+ struct kobject *gd_kobj = &disk_to_dev(dev->gd)->kobj;
+ int ret;
+
+ ret = rnbd_clt_get_path_name(dev, dev->blk_symlink_name,
+ sizeof(dev->blk_symlink_name));
+ if (ret) {
+ rnbd_clt_err(dev, "Failed to get /sys/block symlink path, err: %d\n",
+ ret);
+ goto out_err;
+ }
+
+ ret = sysfs_create_link(rnbd_devs_kobj, gd_kobj,
+ dev->blk_symlink_name);
+ if (ret) {
+ rnbd_clt_err(dev, "Creating /sys/block symlink failed, err: %d\n",
+ ret);
+ goto out_err;
+ }
+
+ return 0;
+
+out_err:
+ dev->blk_symlink_name[0] = '\0';
+ return ret;
+}
+
+static ssize_t rnbd_clt_map_device_store(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct rnbd_clt_dev *dev;
+ struct rnbd_map_options opt;
+ int ret;
+ char pathname[NAME_MAX];
+ char sessname[NAME_MAX];
+ enum rnbd_access_mode access_mode = RNBD_ACCESS_RW;
+
+ struct sockaddr_storage *addrs;
+ struct rtrs_addr paths[6];
+ size_t path_cnt;
+
+ opt.sessname = sessname;
+ opt.paths = paths;
+ opt.path_cnt = &path_cnt;
+ opt.pathname = pathname;
+ opt.access_mode = &access_mode;
+ addrs = kcalloc(ARRAY_SIZE(paths) * 2, sizeof(*addrs), GFP_KERNEL);
+ if (!addrs)
+ return -ENOMEM;
+
+ for (path_cnt = 0; path_cnt < ARRAY_SIZE(paths); path_cnt++) {
+ paths[path_cnt].src = &addrs[path_cnt * 2];
+ paths[path_cnt].dst = &addrs[path_cnt * 2 + 1];
+ }
+
+ ret = rnbd_clt_parse_map_options(buf, ARRAY_SIZE(paths), &opt);
+ if (ret)
+ goto out;
+
+ pr_info("Mapping device %s on session %s, (access_mode: %s)\n",
+ pathname, sessname,
+ rnbd_access_mode_str(access_mode));
+
+ dev = rnbd_clt_map_device(sessname, paths, path_cnt, pathname,
+ access_mode);
+ if (IS_ERR(dev)) {
+ ret = PTR_ERR(dev);
+ goto out;
+ }
+
+ ret = rnbd_clt_add_dev_kobj(dev);
+ if (unlikely(ret))
+ goto unmap_dev;
+
+ ret = rnbd_clt_add_dev_symlink(dev);
+ if (ret)
+ goto unmap_dev;
+
+ kfree(addrs);
+ return count;
+
+unmap_dev:
+ rnbd_clt_unmap_device(dev, true, NULL);
+out:
+ kfree(addrs);
+ return ret;
+}
+
+static struct kobj_attribute rnbd_clt_map_device_attr =
+ __ATTR(map_device, 0644,
+ rnbd_clt_map_device_show, rnbd_clt_map_device_store);
+
+static struct attribute *default_attrs[] = {
+ &rnbd_clt_map_device_attr.attr,
+ NULL,
+};
+
+static struct attribute_group default_attr_group = {
+ .attrs = default_attrs,
+};
+
+static const struct attribute_group *default_attr_groups[] = {
+ &default_attr_group,
+ NULL,
+};
+
+int rnbd_clt_create_sysfs_files(void)
+{
+ int err;
+
+ rnbd_dev_class = class_create(THIS_MODULE, "rnbd-client");
+ if (IS_ERR(rnbd_dev_class))
+ return PTR_ERR(rnbd_dev_class);
+
+ rnbd_dev = device_create_with_groups(rnbd_dev_class, NULL,
+ MKDEV(0, 0), NULL,
+ default_attr_groups, "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_clt_destroy_default_group(void)
+{
+ sysfs_remove_group(&rnbd_dev->kobj, &default_attr_group);
+}
+
+void rnbd_clt_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