mirror of https://gitee.com/openkylin/linux.git
105 lines
2.1 KiB
C
105 lines
2.1 KiB
C
/*
|
|
* Hypervisor filesystem for Linux on s390 - debugfs interface
|
|
*
|
|
* Copyright IBM Corp. 2010
|
|
* Author(s): Michael Holzheu <holzheu@linux.vnet.ibm.com>
|
|
*/
|
|
|
|
#include <linux/slab.h>
|
|
#include "hypfs.h"
|
|
|
|
static struct dentry *dbfs_dir;
|
|
|
|
static struct hypfs_dbfs_data *hypfs_dbfs_data_alloc(struct hypfs_dbfs_file *f)
|
|
{
|
|
struct hypfs_dbfs_data *data;
|
|
|
|
data = kmalloc(sizeof(*data), GFP_KERNEL);
|
|
if (!data)
|
|
return NULL;
|
|
data->dbfs_file = f;
|
|
return data;
|
|
}
|
|
|
|
static void hypfs_dbfs_data_free(struct hypfs_dbfs_data *data)
|
|
{
|
|
data->dbfs_file->data_free(data->buf_free_ptr);
|
|
kfree(data);
|
|
}
|
|
|
|
static ssize_t dbfs_read(struct file *file, char __user *buf,
|
|
size_t size, loff_t *ppos)
|
|
{
|
|
struct hypfs_dbfs_data *data;
|
|
struct hypfs_dbfs_file *df;
|
|
ssize_t rc;
|
|
|
|
if (*ppos != 0)
|
|
return 0;
|
|
|
|
df = file_inode(file)->i_private;
|
|
mutex_lock(&df->lock);
|
|
data = hypfs_dbfs_data_alloc(df);
|
|
if (!data) {
|
|
mutex_unlock(&df->lock);
|
|
return -ENOMEM;
|
|
}
|
|
rc = df->data_create(&data->buf, &data->buf_free_ptr, &data->size);
|
|
if (rc) {
|
|
mutex_unlock(&df->lock);
|
|
kfree(data);
|
|
return rc;
|
|
}
|
|
mutex_unlock(&df->lock);
|
|
|
|
rc = simple_read_from_buffer(buf, size, ppos, data->buf, data->size);
|
|
hypfs_dbfs_data_free(data);
|
|
return rc;
|
|
}
|
|
|
|
static long dbfs_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
|
|
{
|
|
struct hypfs_dbfs_file *df = file_inode(file)->i_private;
|
|
long rc;
|
|
|
|
mutex_lock(&df->lock);
|
|
if (df->unlocked_ioctl)
|
|
rc = df->unlocked_ioctl(file, cmd, arg);
|
|
else
|
|
rc = -ENOTTY;
|
|
mutex_unlock(&df->lock);
|
|
return rc;
|
|
}
|
|
|
|
static const struct file_operations dbfs_ops = {
|
|
.read = dbfs_read,
|
|
.llseek = no_llseek,
|
|
.unlocked_ioctl = dbfs_ioctl,
|
|
};
|
|
|
|
int hypfs_dbfs_create_file(struct hypfs_dbfs_file *df)
|
|
{
|
|
df->dentry = debugfs_create_file(df->name, 0400, dbfs_dir, df,
|
|
&dbfs_ops);
|
|
if (IS_ERR(df->dentry))
|
|
return PTR_ERR(df->dentry);
|
|
mutex_init(&df->lock);
|
|
return 0;
|
|
}
|
|
|
|
void hypfs_dbfs_remove_file(struct hypfs_dbfs_file *df)
|
|
{
|
|
debugfs_remove(df->dentry);
|
|
}
|
|
|
|
int hypfs_dbfs_init(void)
|
|
{
|
|
dbfs_dir = debugfs_create_dir("s390_hypfs", NULL);
|
|
return PTR_ERR_OR_ZERO(dbfs_dir);
|
|
}
|
|
|
|
void hypfs_dbfs_exit(void)
|
|
{
|
|
debugfs_remove(dbfs_dir);
|
|
}
|