Can you explain what problem are you facing with this module ?
On 4/20/05, ganesh kumar <ganesh_kmr@xxxxxxxx> wrote:
>
>
> hi, i have attached the module. Can any one review it and tell me what was
> the problem in this. Basically, i am trying to write in a raw hard disk, i
> doubt in the blocknr and brsector value.
>
>
>
> #include <linux/fs.h>
> #include <linux/module.h>
> #include <linux/kernel.h>
> #include <linux/init.h>
> #include <linux/slab.h>
> #include <linux/blkdev.h>
> #define MINORBITS 8 //these two macros are used to find b_rdev value
> #define MKDEV(ma,mi) (((ma) << MINORBITS) | (mi))
> #define SIZE 512
> #define BLK_SIZE 512
> #define SECTOR_SIZE 512
>
>
> int dataWrite(void);
> void ioCompleteHandler(struct buffer_head *bh, int uptodate);
> int major_no;
> struct block_device_operations block_bdops;
>
> void ioCompleteHandler(struct buffer_head *bh, int uptodate)
> {
> printk(KERN_INFO"Freeing the memory in completeHandler function\n");
> mark_buffer_uptodate(bh, uptodate);
>
> kfree(bh->b_data);
> kfree(bh);
> printk(KERN_INFO"Memory freed in iocompleHandler function\n");
> }
>
> int dataWrite()
> {
> struct buffer_head *bh;
> char *datpot;
> printk(KERN_INFO" For testing\n");
> printk(KERN_INFO"size of buffer is %d\n",sizeof(struct
> buffer_head));
> bh=kmalloc(sizeof(struct buffer_head),GFP_KERNEL);
> if( NULL == bh)
> {
> printk(KERN_INFO" kmalloc failed\n");
> return -1 ;
> }
>
> bh->b_next = NULL;
> bh->b_next_free = NULL;
> bh->b_prev_free = NULL;
> bh->b_this_page = NULL;
> bh->b_reqnext = NULL;
> bh->b_pprev = NULL;
>
> set_bit (BH_Uptodate, &bh->b_state);
> set_bit (BH_Mapped, &bh->b_state); //set if the device is mapped
> set_bit (BH_Req, &bh->b_state);
> set_bit (BH_Dirty, &bh->b_state); //added
>
> bh->b_size=SIZE;
> bh->b_dev = MKDEV(8,16);
> bh->b_blocknr= 1; //not sure
> bh->b_rsector = bh->b_blocknr * (BLK_SIZE/SECTOR_SIZE); // not sure
> printk(KERN_INFO"allocating buffer the data\n");
> datpot = kmalloc(SIZE,GFP_KERNEL);
>
> if (NULL == datpot)
> {
> printk(KERN_INFO"data memory allocation failed\n");
> return -1;
> }
>
> bh->b_data=datpot;
> bh->b_page = virt_to_page(bh->b_data);
> printk(KERN_INFO"virtual to page done\n");
> bh->b_rdev= bh->b_dev;
> bh->b_end_io=ioCompleteHandler;
> // bh->b_private = bh;
> printk(KERN_INFO"calling generic make request\n");
> generic_make_request(WRITE,bh);
> printk(KERN_INFO" write done\n");
> return 0;
> }
>
> static int block_init(void)
> {
> int ret;
> major_no =
> register_blkdev(0,"block_data",&block_bdops);
> if ( major_no <0)
> {
> printk(KERN_INFO"Failed to register the module\n");
> return -1;
> }
> printk(KERN_INFO"Block_data Module inserted\n");
> ret = dataWrite();
> return 0;
> }
>
> static void block_exit()
> {
> int ret;
> ret = unregister_blkdev(major_no,"block_date");
> if( ret < 0 )
> {
> printk(KERN_INFO"failed to unregister the module\n");
> //return -1;
> }
>
> printk(KERN_INFO"Block_data Module removed\n");
> }
>
> module_init(block_init);
> module_exit(block_exit);
> MODULE_LICENSE("GPL");
>
> --
>
> ___________________________________________________________
> Sign-up for Ads Free at Mail.com
> http://www.mail.com/?sr=signup -- Kernelnewbies: Help each other learn
> about the Linux kernel. Archive:
> http://mail.nl.linux.org/kernelnewbies/ FAQ:
> http://kernelnewbies.org/faq/
--
Kernelnewbies: Help each other learn about the Linux kernel.
Archive: http://mail.nl.linux.org/kernelnewbies/
FAQ: http://kernelnewbies.org/faq/
