linux newbie question: where is elv_next_trequest?

eantoranz · 12-04-2010, 08:08 AM

Hi!

I'm working on developing a simple block device driver (just for the fun on it).

I'm using the sbull code from here:

http://www.kernel-labs.org/?q=blockdriver

So, when I compile it, I get some errors. I have corrected the first one and now I'm getting something about elv_next_request being first time used, blh blah.

So I have to find the .h file where elv_next_request is defined and include it. I'm checking at my "Understanding the linux kernel" book and it'ssomething related to elevator.

When I check for .h files that define that function, none is found. When I check for files with "elevator" in their names, I get linux/elevator.h but there's no such function. Has the API been changed and I have to use another function now?

Code:

$ uname -a
Linux ubuntu 2.6.32-21-generic #32-Ubuntu SMP Fri Apr 16 08:10:02 UTC 2010 i686 GNU/Linux

On a LiveUSB (Kubuntu Lucid)

Thanks in advance.

eantoranz · 12-04-2010, 08:59 AM

Well, well.... I found it... kind of.

After reading http://lwn.net/Articles/333221/ it seems I have to call blk_fetch_request instead of elv_next_request. blk_fetch_request is defined in linux/blkdev.h:

Code:

extern struct request *blk_fetch_request(struct request_queue *q);