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); |
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