linux/fs/btrfs/sysfs.c

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/*
* Copyright (C) 2007 Oracle. All rights reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License v2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this program; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 021110-1307, USA.
*/
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/completion.h>
#include <linux/buffer_head.h>
#include <linux/module.h>
#include <linux/kobject.h>
#include "ctree.h"
#include "disk-io.h"
#include "transaction.h"
static ssize_t root_blocks_used_show(struct btrfs_root *root, char *buf)
{
return snprintf(buf, PAGE_SIZE, "%llu\n",
(unsigned long long)btrfs_root_used(&root->root_item));
}
static ssize_t root_block_limit_show(struct btrfs_root *root, char *buf)
{
return snprintf(buf, PAGE_SIZE, "%llu\n",
(unsigned long long)btrfs_root_limit(&root->root_item));
}
static ssize_t super_blocks_used_show(struct btrfs_fs_info *fs, char *buf)
{
return snprintf(buf, PAGE_SIZE, "%llu\n",
(unsigned long long)btrfs_super_bytes_used(&fs->super_copy));
}
static ssize_t super_total_blocks_show(struct btrfs_fs_info *fs, char *buf)
{
return snprintf(buf, PAGE_SIZE, "%llu\n",
(unsigned long long)btrfs_super_total_bytes(&fs->super_copy));
}
static ssize_t super_blocksize_show(struct btrfs_fs_info *fs, char *buf)
{
return snprintf(buf, PAGE_SIZE, "%llu\n",
(unsigned long long)btrfs_super_sectorsize(&fs->super_copy));
}
/* this is for root attrs (subvols/snapshots) */
struct btrfs_root_attr {
struct attribute attr;
ssize_t (*show)(struct btrfs_root *, char *);
ssize_t (*store)(struct btrfs_root *, const char *, size_t);
};
#define ROOT_ATTR(name, mode, show, store) \
static struct btrfs_root_attr btrfs_root_attr_##name = __ATTR(name, mode, \
show, store)
ROOT_ATTR(blocks_used, 0444, root_blocks_used_show, NULL);
ROOT_ATTR(block_limit, 0644, root_block_limit_show, NULL);
static struct attribute *btrfs_root_attrs[] = {
&btrfs_root_attr_blocks_used.attr,
&btrfs_root_attr_block_limit.attr,
NULL,
};
/* this is for super attrs (actual full fs) */
struct btrfs_super_attr {
struct attribute attr;
ssize_t (*show)(struct btrfs_fs_info *, char *);
ssize_t (*store)(struct btrfs_fs_info *, const char *, size_t);
};
#define SUPER_ATTR(name, mode, show, store) \
static struct btrfs_super_attr btrfs_super_attr_##name = __ATTR(name, mode, \
show, store)
SUPER_ATTR(blocks_used, 0444, super_blocks_used_show, NULL);
SUPER_ATTR(total_blocks, 0444, super_total_blocks_show, NULL);
SUPER_ATTR(blocksize, 0444, super_blocksize_show, NULL);
static struct attribute *btrfs_super_attrs[] = {
&btrfs_super_attr_blocks_used.attr,
&btrfs_super_attr_total_blocks.attr,
&btrfs_super_attr_blocksize.attr,
NULL,
};
static ssize_t btrfs_super_attr_show(struct kobject *kobj,
struct attribute *attr, char *buf)
{
struct btrfs_fs_info *fs = container_of(kobj, struct btrfs_fs_info,
super_kobj);
struct btrfs_super_attr *a = container_of(attr,
struct btrfs_super_attr,
attr);
return a->show ? a->show(fs, buf) : 0;
}
static ssize_t btrfs_super_attr_store(struct kobject *kobj,
struct attribute *attr,
const char *buf, size_t len)
{
struct btrfs_fs_info *fs = container_of(kobj, struct btrfs_fs_info,
super_kobj);
struct btrfs_super_attr *a = container_of(attr,
struct btrfs_super_attr,
attr);
return a->store ? a->store(fs, buf, len) : 0;
}
static ssize_t btrfs_root_attr_show(struct kobject *kobj,
struct attribute *attr, char *buf)
{
struct btrfs_root *root = container_of(kobj, struct btrfs_root,
root_kobj);
struct btrfs_root_attr *a = container_of(attr,
struct btrfs_root_attr,
attr);
return a->show ? a->show(root, buf) : 0;
}
static ssize_t btrfs_root_attr_store(struct kobject *kobj,
struct attribute *attr,
const char *buf, size_t len)
{
struct btrfs_root *root = container_of(kobj, struct btrfs_root,
root_kobj);
struct btrfs_root_attr *a = container_of(attr,
struct btrfs_root_attr,
attr);
return a->store ? a->store(root, buf, len) : 0;
}
static void btrfs_super_release(struct kobject *kobj)
{
struct btrfs_fs_info *fs = container_of(kobj, struct btrfs_fs_info,
super_kobj);
complete(&fs->kobj_unregister);
}
static void btrfs_root_release(struct kobject *kobj)
{
struct btrfs_root *root = container_of(kobj, struct btrfs_root,
root_kobj);
complete(&root->kobj_unregister);
}
static const struct sysfs_ops btrfs_super_attr_ops = {
.show = btrfs_super_attr_show,
.store = btrfs_super_attr_store,
};
static const struct sysfs_ops btrfs_root_attr_ops = {
.show = btrfs_root_attr_show,
.store = btrfs_root_attr_store,
};
static struct kobj_type btrfs_root_ktype = {
.default_attrs = btrfs_root_attrs,
.sysfs_ops = &btrfs_root_attr_ops,
.release = btrfs_root_release,
};
static struct kobj_type btrfs_super_ktype = {
.default_attrs = btrfs_super_attrs,
.sysfs_ops = &btrfs_super_attr_ops,
.release = btrfs_super_release,
};
/* /sys/fs/btrfs/ entry */
static struct kset *btrfs_kset;
int btrfs_sysfs_add_super(struct btrfs_fs_info *fs)
{
int error;
char *name;
char c;
int len = strlen(fs->sb->s_id) + 1;
int i;
name = kmalloc(len, GFP_NOFS);
if (!name) {
error = -ENOMEM;
goto fail;
}
for (i = 0; i < len; i++) {
c = fs->sb->s_id[i];
if (c == '/' || c == '\\')
c = '!';
name[i] = c;
}
name[len] = '\0';
fs->super_kobj.kset = btrfs_kset;
error = kobject_init_and_add(&fs->super_kobj, &btrfs_super_ktype,
NULL, "%s", name);
kfree(name);
if (error)
goto fail;
return 0;
fail:
printk(KERN_ERR "btrfs: sysfs creation for super failed\n");
return error;
}
int btrfs_sysfs_add_root(struct btrfs_root *root)
{
int error;
error = kobject_init_and_add(&root->root_kobj, &btrfs_root_ktype,
&root->fs_info->super_kobj,
"%s", root->name);
if (error)
goto fail;
return 0;
fail:
printk(KERN_ERR "btrfs: sysfs creation for root failed\n");
return error;
}
void btrfs_sysfs_del_root(struct btrfs_root *root)
{
kobject_put(&root->root_kobj);
wait_for_completion(&root->kobj_unregister);
}
void btrfs_sysfs_del_super(struct btrfs_fs_info *fs)
{
kobject_put(&fs->super_kobj);
wait_for_completion(&fs->kobj_unregister);
}
int btrfs_init_sysfs(void)
{
btrfs_kset = kset_create_and_add("btrfs", NULL, fs_kobj);
if (!btrfs_kset)
return -ENOMEM;
return 0;
}
void btrfs_exit_sysfs(void)
{
kset_unregister(btrfs_kset);
}