关于块设备驱动程序的问题1 设备, 驱动程序

wangxd54292000

各位高手：
              小弟正在编写一个简单的块设备驱动。编译后加载该驱动，出现”insmod:cannot insert simple_block.ko’:cannot allocate memory”。请教出现此问题的原因。谢谢！驱动源码如下：
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/kernel.h>
/* printk() */
#include <linux/slab.h>
/* kmalloc() */
#include <linux/fs.h>
/* everything... */
#include <linux/errno.h>
/* error codes */
#include <linux/timer.h>
#include <linux/types.h>
/* size_t */
#include <linux/fcntl.h>
/* O_ACCMODE */
#include <linux/hdreg.h>
/* HDIO_GETGEO */
#include <linux/kdev_t.h>
#include <linux/vmalloc.h>
#include <linux/genhd.h>
#include <linux/blkdev.h>
#include <linux/buffer_head.h>
/* invalidate_bdev */
#include <linux/bio.h>

#define SIMP_BLKDEV_DEVICEMAJOR
COMPAQ_SMART2_MAJOR
#define SIMP_BLKDEV_DISKNAME
"simp_blkdev"
#define SIMP_BLKDEV_BYTES
(16*1024*1024)

unsigned char simp_blkdev_data[SIMP_BLKDEV_BYTES];

static struct request_queue *simp_blkdev_queue;
static struct gendisk *simp_blkdev_disk;

static void simp_blkdev_do_request(struct request_queue *q);

struct block_device_operations simp_blkdev_fops = {

.owner
= THIS_MODULE,
};

static void simp_blkdev_do_request(struct request_queue *q)
{

struct request *req;

while ((req = elv_next_request(q)) != NULL) {

if ((req->sector + req->current_nr_sectors) << 9

> SIMP_BLKDEV_BYTES) {

printk(KERN_ERR SIMP_BLKDEV_DISKNAME

": bad request: block=%llu, count=%u\n",

(unsigned long long)req->sector,

req->current_nr_sectors);

end_request(req, 0);

continue;

}


switch (rq_data_dir(req)) {

case READ:

memcpy(req->buffer,


simp_blkdev_data + (req->sector << 9),

req->current_nr_sectors << 9);

end_request(req, 1);

break;

case WRITE:

memcpy(simp_blkdev_data + (req->sector << 9),

req->buffer, req->current_nr_sectors << 9);

end_request(req, 1);

break;

default:

/* No default because rq_data_dir(req) is 1 bit */

break;

}

}
}

static int __init simp_blkdev_init(void)
{

int ret;


simp_blkdev_queue = blk_init_queue(simp_blkdev_do_request, NULL);

if (!simp_blkdev_queue) {

ret = -ENOMEM;

goto err_init_queue;

}
      

simp_blkdev_disk = alloc_disk(1);

if (!simp_blkdev_disk) {

ret = -ENOMEM;

goto err_alloc_disk;

}



strcpy(simp_blkdev_disk->disk_name, SIMP_BLKDEV_DISKNAME);

simp_blkdev_disk->major = SIMP_BLKDEV_DEVICEMAJOR;

simp_blkdev_disk->first_minor = 0;

simp_blkdev_disk->fops = &simp_blkdev_fops;

simp_blkdev_disk->queue = simp_blkdev_queue;

set_capacity(simp_blkdev_disk, SIMP_BLKDEV_BYTES>>9);

add_disk(simp_blkdev_disk);


return 0;

err_alloc_disk:

blk_cleanup_queue(simp_blkdev_queue);
err_init_queue:

return ret;
}

static void __exit simp_blkdev_exit(void)
{

del_gendisk(simp_blkdev_disk);

put_disk(simp_blkdev_disk);

blk_cleanup_queue(simp_blkdev_queue);
}

module_init(simp_blkdev_init);
module_exit(simp_blkdev_exit);