Commit 1eb54f8f authored by Jack Wang's avatar Jack Wang Committed by Jason Gunthorpe

block/rnbd: client: sysfs interface functions

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

  /sys/class/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

Link: https://lore.kernel.org/r/20200511135131.27580-19-danil.kipnis@cloud.ionos.comSigned-off-by: default avatarDanil Kipnis <danil.kipnis@cloud.ionos.com>
Signed-off-by: default avatarJack Wang <jinpu.wang@cloud.ionos.com>
Reviewed-by: default avatarBart Van Assche <bvanassche@acm.org>
Acked-by: default avatarJens Axboe <axboe@kernel.dk>
Signed-off-by: default avatarJason Gunthorpe <jgg@mellanox.com>
parent f7a7a5c2
// 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_DEST_PORT = 1 << 0,
RNBD_OPT_PATH = 1 << 1,
RNBD_OPT_DEV_PATH = 1 << 2,
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_DEST_PORT, "dest_port=%d" },
{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;
u16 *dest_port;
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, dest_port;
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),
*opt->dest_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_DEST_PORT:
if (match_int(args, &dest_port) || dest_port < 0 ||
dest_port > 65535) {
pr_err("bad destination port number parameter '%d'\n",
dest_port);
ret = -EINVAL;
goto out;
}
*opt->dest_port = dest_port;
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 (err) {
if (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 \"[dest_port=server port number] 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;
u16 port_nr = RTRS_PORT;
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.dest_port = &port_nr;
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, port_nr, pathname,
access_mode);
if (IS_ERR(dev)) {
ret = PTR_ERR(dev);
goto out;
}
ret = rnbd_clt_add_dev_kobj(dev);
if (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 (!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);
}
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