Re: sg driver and Fedora Core 2

Jens Axboe
2004-05-29T17:29:36Z

On Sat, May 29 2004, Jeff Garzik wrote:
> Really what needs to happen is a generic userland tap attaches to a
> chrdev, issues an ioctl(2) to attach to a request_queue, and then does
> read(2)/write(2)/mmap(2) to communicate with the request_queue.
>
> :)
>
> Call it /dev/bsg, or somesuch.
>
> The SG_IO ioctl won't work for all cases, since some block devices may
> rightly wish to limit (or block) multiple openers on the blkdev itself.
> OTOH, the SG_IO ioctl does eliminate the userland app needing to
> worry about _any_ target/addressing information, since that is implicit
> in the dentry pointing to the blkdev's inode.

Hear, hear!

--
Jens Axboe