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* Copyright (C) 2011 Citrix Systems Inc.
* This file is part of Blktap2.
* Blktap2 is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2
* as published by the Free Software Foundation.
* Blktap2 is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* GNU General Public License version 2 for more details.
* You should have received a copy of the GNU General Public License
* version 2 along with Blktap2. If not, see
* <>.
#ifndef _BLKTAP_H_
#define _BLKTAP_H_
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/fs.h>
#include <linux/cdev.h>
#include <linux/init.h>
#include <linux/scatterlist.h>
#include "linux-blktap.h"
extern int blktap_debug_level;
extern int blktap_ring_major;
extern int blktap_device_major;
#define BTPRINTK(level, tag, force, _f, _a...) \
do { \
if (blktap_debug_level > level && \
(force || printk_ratelimit())) \
printk(tag "%s: " _f, __func__, ##_a); \
} while (0)
#define BTDBG(_f, _a...) BTPRINTK(8, KERN_DEBUG, 1, _f, ##_a)
#define BTINFO(_f, _a...) BTPRINTK(0, KERN_INFO, 0, _f, ##_a)
#define BTWARN(_f, _a...) BTPRINTK(0, KERN_WARNING, 0, _f, ##_a)
#define BTERR(_f, _a...) BTPRINTK(0, KERN_ERR, 0, _f, ##_a)
#define MAX_BLKTAP_DEVICE 1024
struct blktap_device {
spinlock_t lock;
struct gendisk *gd;
struct blktap_request;
struct blktap_ring {
struct task_struct *task;
struct vm_area_struct *vma;
struct blktap_front_ring ring;
unsigned long ring_vstart;
unsigned long user_vstart;
int n_pending;
struct blktap_request *pending[BLKTAP_RING_SIZE];
wait_queue_head_t poll_wait;
dev_t devno;
struct device *dev;
struct blktap_statistics {
unsigned long st_print;
int st_rd_req;
int st_wr_req;
int st_tr_req;
int st_oo_req;
int st_fl_req;
int st_rd_sect;
int st_wr_sect;
int st_tr_sect;
s64 st_rd_cnt;
s64 st_rd_sum_usecs;
s64 st_rd_max_usecs;
s64 st_wr_cnt;
s64 st_wr_sum_usecs;
s64 st_wr_max_usecs;
struct blktap_request {
struct blktap *tap;
struct request *rq;
int usr_idx;
int operation;
struct scatterlist sg_table[BLKTAP_SEGMENT_MAX];
struct page *pages[BLKTAP_SEGMENT_MAX];
int nr_pages;
#define blktap_for_each_sg(_sg, _req, _i) \
for (_sg = (_req)->sg_table, _i = 0; \
_i < (_req)->nr_pages; \
(_sg)++, (_i)++)
struct blktap {
int minor;
unsigned long dev_inuse;
struct blktap_ring ring;
struct blktap_device device;
struct blktap_page_pool *pool;
wait_queue_head_t remove_wait;
struct work_struct remove_work;
char name[BLKTAP_NAME_MAX];
struct blktap_statistics stats;
struct blktap_page_pool {
struct mempool_s *bufs;
spinlock_t lock;
struct kobject kobj;
wait_queue_head_t wait;
extern struct mutex blktap_lock;
extern struct blktap **blktaps;
extern int blktap_max_minor;
int blktap_control_destroy_tap(struct blktap *);
size_t blktap_control_debug(struct blktap *, char *, size_t);
int blktap_ring_init(void);
void blktap_ring_exit(void);
size_t blktap_ring_debug(struct blktap *, char *, size_t);
int blktap_ring_create(struct blktap *);
int blktap_ring_destroy(struct blktap *);
struct blktap_request *blktap_ring_make_request(struct blktap *);
void blktap_ring_free_request(struct blktap *,struct blktap_request *);
void blktap_ring_submit_request(struct blktap *, struct blktap_request *);
int blktap_ring_map_request(struct blktap *, struct file *, struct blktap_request *);
void blktap_ring_unmap_request(struct blktap *, struct blktap_request *);
void blktap_ring_set_message(struct blktap *, int);
void blktap_ring_kick_user(struct blktap *);
int blktap_sysfs_init(void);
void blktap_sysfs_exit(void);
int blktap_sysfs_create(struct blktap *);
void blktap_sysfs_destroy(struct blktap *);
int blktap_device_init(void);
void blktap_device_exit(void);
size_t blktap_device_debug(struct blktap *, char *, size_t);
int blktap_device_create(struct blktap *, struct blktap_device_info *);
int blktap_device_destroy(struct blktap *);
void blktap_device_destroy_sync(struct blktap *);
void blktap_device_run_queue(struct blktap *, struct file *);
void blktap_device_end_request(struct blktap *, struct blktap_request *, int);
int blktap_page_pool_init(struct kobject *);
void blktap_page_pool_exit(void);
struct blktap_page_pool *blktap_page_pool_get(const char *);
size_t blktap_request_debug(struct blktap *, char *, size_t);
struct blktap_request *blktap_request_alloc(struct blktap *);
int blktap_request_get_pages(struct blktap *, struct blktap_request *, int);
void blktap_request_free(struct blktap *, struct blktap_request *);
void blktap_request_bounce(struct blktap *, struct blktap_request *, int);