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// SPDX-License-Identifier: GPL-2.0
/*
* This file is part of the Distributed Network Block Device 3
*
* Copyright(c) 2011-2012 Johann Latocha <johann@latocha.de>
*
* This file may be licensed under the terms of the
* GNU General Public License Version 2 (the ``GPL'').
*
* Software distributed under the License is distributed
* on an ``AS IS'' basis, WITHOUT WARRANTY OF ANY KIND, either
* express or implied. See the GPL for the specific language
* governing rights and limitations.
*
* You should have received a copy of the GPL along with this
* program. If not, go to http://www.gnu.org/licenses/gpl.html
* or write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
*/
#include <linux/kobject.h>
#include "sysfs.h"
#ifndef MIN
#define MIN(a, b) ((a) < (b) ? (a) : (b))
#endif
/**
* Print currently connected server IP:PORT
*/
ssize_t show_cur_server_addr(char *buf, dnbd3_device_t *dev)
{
ssize_t ret;
spin_lock(&dev->blk_lock);
ret = MIN(snprintf(buf, PAGE_SIZE, "%pISpc\n", &dev->cur_server.host), PAGE_SIZE);
spin_unlock(&dev->blk_lock);
return ret;
}
/**
* List alt servers. One line per server, format is:
* IP:PORT RTT consecutive_failures best_count
*/
ssize_t show_alt_servers(char *buf, dnbd3_device_t *dev)
{
int i, size = PAGE_SIZE;
ssize_t ret;
if (mutex_lock_interruptible(&dev->alt_servers_lock) != 0)
return 0;
for (i = 0; i < NUMBER_SERVERS; ++i) {
if (dev->alt_servers[i].host.ss_family == 0)
continue;
ret = MIN(snprintf(buf, size, "%pISpc %llu %d %d\n", &dev->alt_servers[i].host,
(unsigned long long)((dev->alt_servers[i].rtts[0] +
dev->alt_servers[i].rtts[1] +
dev->alt_servers[i].rtts[2] +
dev->alt_servers[i].rtts[3]) / 4),
(int)dev->alt_servers[i].failures,
(int)dev->alt_servers[i].best_count),
size);
size -= ret;
buf += ret;
if (size <= 0) {
size = 0;
break;
}
}
mutex_unlock(&dev->alt_servers_lock);
return PAGE_SIZE - size;
}
/**
* Show name of image in use
*/
ssize_t show_image_name(char *buf, dnbd3_device_t *dev)
{
ssize_t ret;
spin_lock(&dev->blk_lock);
ret = MIN(snprintf(buf, PAGE_SIZE, "%s\n", dev->imgname), PAGE_SIZE);
spin_unlock(&dev->blk_lock);
return ret;
}
/**
* Show rid of image in use
*/
ssize_t show_rid(char *buf, dnbd3_device_t *dev)
{
// No locking here, primitive type, no pointer to allocated memory
return MIN(snprintf(buf, PAGE_SIZE, "%d\n", dev->rid), PAGE_SIZE);
}
ssize_t show_update_available(char *buf, dnbd3_device_t *dev)
{
// Same story
return MIN(snprintf(buf, PAGE_SIZE, "%d\n", dev->update_available), PAGE_SIZE);
}
device_attr_t cur_server_addr = {
.attr = { .name = "cur_server_addr", .mode = 0444 },
.show = show_cur_server_addr,
.store = NULL,
};
device_attr_t alt_servers = {
.attr = { .name = "alt_servers", .mode = 0444 },
.show = show_alt_servers,
.store = NULL,
};
device_attr_t image_name = {
.attr = { .name = "image_name", .mode = 0444 },
.show = show_image_name,
.store = NULL,
};
device_attr_t rid = {
.attr = { .name = "rid", .mode = 0444 },
.show = show_rid,
.store = NULL,
};
device_attr_t update_available = {
.attr = { .name = "update_available", .mode = 0444 },
.show = show_update_available,
.store = NULL,
};
ssize_t device_show(struct kobject *kobj, struct attribute *attr, char *buf)
{
device_attr_t *device_attr = container_of(attr, device_attr_t, attr);
dnbd3_device_t *dev = container_of(kobj, dnbd3_device_t, kobj);
return device_attr->show(buf, dev);
}
struct attribute *device_attrs[] = {
&cur_server_addr.attr,
&alt_servers.attr,
&image_name.attr, &rid.attr,
&update_available.attr,
NULL,
};
#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 15, 0)
ATTRIBUTE_GROUPS(device);
#endif
const struct sysfs_ops device_ops = {
.show = device_show,
};
void release(struct kobject *kobj)
{
kobj->state_initialized = 0;
}
struct kobj_type device_ktype = {
#if LINUX_VERSION_CODE < KERNEL_VERSION(5, 15, 0)
.default_attrs = device_attrs,
#else
.default_groups = device_groups,
#endif
.sysfs_ops = &device_ops,
.release = release,
};
void dnbd3_sysfs_init(dnbd3_device_t *dev)
{
int error;
struct kobject *kobj = &dev->kobj;
struct kobj_type *ktype = &device_ktype;
struct kobject *parent = &disk_to_dev(dev->disk)->kobj;
error = kobject_init_and_add(kobj, ktype, parent, "%s", "net");
if (error)
dev_err(dnbd3_device_to_dev(dev), "initializing sysfs for device failed!\n");
}
void dnbd3_sysfs_exit(dnbd3_device_t *dev)
{
kobject_put(&dev->kobj);
}
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