Re: [PATCH] queue barrier support

[Jens Axboe <axboe@suse.de>]

On Wed, Feb 13 2002, Martin Dalecki wrote:
> Jens Axboe wrote:
> 
> >Patches attached, comments welcome.
> >
> >diff -Nru a/include/linux/ide.h b/include/linux/ide.h
> >--- a/include/linux/ide.h	Wed Feb 13 13:48:25 2002
> >+++ b/include/linux/ide.h	Wed Feb 13 13:48:25 2002
> >@@ -448,6 +448,7 @@
> >	byte		acoustic;	/* acoustic management */
> >	unsigned int	failures;	/* current failure count */
> >	unsigned int	max_failures;	/* maximum allowed failure count */
> >+	char		special_buf[4];	/* IDE_DRIVE_CMD, free use */
> >} ide_drive_t;
> >
> ide-barrier-1-c1.296:+  memset(drive->special_buf, 0, 
> sizeof(drive->special_buf));
> ide-barrier-1-c1.296:+  flush_rq->buffer = drive->special_buf;
> ide-barrier-1-c1.296:+  char            special_buf[4]; /* 
> IDE_DRIVE_CMD, free use */
> 
> I just don't see special_buf used anywhere. What is it supposed to be 
> used for?
> Is the intention to make it look like the SCSI code?

See ide.c:ide_queue_flush_cmd(), I'm only using 1 of the bytes but it
has room for 4 like that is typically used when issuing an ata command
directly. So yes, it is used, I'm not adding stuff for fun :-)

-- 
Jens Axboe