svn commit: r217828 - projects/graid/head/sys/geom/raid

[John Baldwin]

On Tuesday, January 25, 2011 10:34:07 am Alexander Motin wrote:
> Author: mav
> Date: Tue Jan 25 15:34:07 2011
> New Revision: 217828
> URL: http://svn.freebsd.org/changeset/base/217828
> 
> Log:
>   Implement kernel dumping to geom_raid volumes. Dumping mechanism supports
>   any RAID levels without any additional magic. Dumping to RAID0 and RAID1
>   verified to work right now.
> 
> Modified:
>   projects/graid/head/sys/geom/raid/g_raid.c
>   projects/graid/head/sys/geom/raid/g_raid.h
>   projects/graid/head/sys/geom/raid/md_intel.c
> 
> Modified: projects/graid/head/sys/geom/raid/g_raid.c
> 
==============================================================================
> --- projects/graid/head/sys/geom/raid/g_raid.c	Tue Jan 25 15:18:10 2011	
(r217827)
> +++ projects/graid/head/sys/geom/raid/g_raid.c	Tue Jan 25 15:34:07 2011	
(r217828)
> @@ -116,8 +116,10 @@ static int g_raid_update_subdisk(struct 
>  static int g_raid_update_volume(struct g_raid_volume *vol, u_int state);
>  static void g_raid_dumpconf(struct sbuf *sb, const char *indent,
>      struct g_geom *gp, struct g_consumer *cp, struct g_provider *pp);
> +static void g_raid_start(struct bio *bp);
>  static void g_raid_start_request(struct bio *bp);
>  static void g_raid_disk_done(struct bio *bp);
> +static void g_raid_poll(struct g_raid_softc *sc);
>  
>  static const char *
>  g_raid_disk_state2str(int state)
> @@ -714,6 +716,73 @@ g_raid_unidle(struct g_raid_volume *vol)
>  }
>  
>  static void
> +g_raid_dumpdone(struct bio *bp)
> +{
> +
> +	bp->bio_flags |= BIO_DONE;
> +}
> +
> +static int
> +g_raid_dump(void *arg,
> +    void *virtual, vm_offset_t physical, off_t offset, size_t length)
> +{
> +	struct g_raid_softc *sc;
> +	struct g_raid_volume *vol;
> +	struct bio *bp;
> +
> +	vol = (struct g_raid_volume *)arg;
> +	sc = vol->v_softc;
> +	G_RAID_DEBUG(3, "Dumping at off %llu len %llu.",
> +	    (long long unsigned)offset, (long long unsigned)length);
> +
> +	bp = g_alloc_bio();
> +	bp->bio_cmd = BIO_WRITE;
> +	bp->bio_done = g_raid_dumpdone;
> +	bp->bio_attribute = NULL;
> +	bp->bio_offset = offset;
> +	bp->bio_length = length;
> +	bp->bio_data = virtual;
> +	bp->bio_to = vol->v_provider;
> +
> +	g_raid_start(bp);
> +
> +	while (!(bp->bio_flags & BIO_DONE)) {
> +		G_RAID_DEBUG(4, "Poll...");
> +		g_raid_poll(sc);
> +		DELAY(10);
> +	}
> +
> +	G_RAID_DEBUG(3, "Dumping at off %llu len %llu done.",
> +	    (long long unsigned)offset, (long long unsigned)length);
> +
> +	g_destroy_bio(bp);
> +	return (0);
> +}

Hmm, so this allocates bio's to make the dump work.  I believer other dump 
routines in other drivers do not do this, but instead use pre-allocated 
commands to schedule dump I/O requests.  Would it be possible to pre-allocate 
the bio that is used here when dumping is enabled and reuse it for each 
g_raid_dump() call without free'ing it when the I/O is finished?

-- 
John Baldwin