error: too few arguments to function ‘blk_get_request’

Question

In Block Device Drivers coding, I am trying to implement Disk on file code, I am getting error:

In function ‘mydisk_request’:
/home/lab/DD/main.c:223:20: error: too few arguments to function ‘blk_get_request’
     while ((req =  blk_get_request(queue)) != NULL)
                    ^~~~~~~~~~~~~~~
In file included from /home/lab/DD/main.c:5:0:
./include/linux/blkdev.h:854:24: note: declared here
 extern struct request *blk_get_request(struct request_queue *, unsigned int op,
                        ^~~~~~~~~~~~~~~
/home/lab/DD/main.c:228:9: error: implicit declaration of function ‘__blk_end_request_all’; did you mean ‘blk_get_request’? [-Werror=implicit-function-declaration]
         __blk_end_request_all(req,ret);
         ^~~~~~~~~~~~~~~~~~~~~
         blk_get_request
/home/lab/DD/main.c: In function ‘mydisk_init’:
/home/lab/DD/main.c:266:24: error: implicit declaration of function ‘blk_init_queue’; did you mean ‘blk_put_queue’? [-Werror=implicit-function-declaration]
     mydisk_dev.queue = blk_init_queue(mydisk_request, &mydisk_dev.lock);
                        ^~~~~~~~~~~~~~
                        blk_put_queue
/home/lab/DD/main.c:266:22: warning: assignment makes pointer from integer without a cast [-Wint-conversion]
     mydisk_dev.queue = blk_init_queue(mydisk_request, &mydisk_dev.lock);
                      ^

Can anyone pls. help me with this?

I think its asking me to replace blk_get_request(queue) function with blk_get_request and blk_init_queue(mydisk_request, &mydisk_dev.lock); function with blk_put_queue respectively. But once I am replacing I am getting the error that too few arguments for those functions.

Answer 1

I suggest you to downgrade your kernel version from 4.6 to 4.19, then all functions will work.

Answer 2

blk_get_request takes 3 argument.
struct request *blk_get_request(struct request_queue *q, unsigned int op, blk_mq_req_flags_t flags)