Re: hot scsi disk resize

[Christoph Hellwig <hch@infradead.org>]

On Mon, Mar 03, 2003 at 08:21:24PM +0300, Alex Tomas wrote:
> +		if (err >= 0)
> +			err = length;
> +	} else if (!strncmp("rescan", buffer + 5, 6)) {
> +		p = buffer + 12;
> +
> +		host = simple_strtoul(p, &p, 0);
> +		channel = simple_strtoul(p + 1, &p, 0);
> +		id = simple_strtoul(p + 1, &p, 0);
> +		lun = simple_strtoul(p + 1, &p, 0);
> +		err = scsi_rescan_single_device(host, channel, id, lun);
> +		if (err >= 0)
> +			err = length;

Please don't add more procfs option.  A resize attribute for the
sysfs node of the scsi_device is the better choice in my opinion.

> +		buffer = kmalloc(512, GFP_DMA);
> +	else
> +		buffer = kmalloc(512, GFP_KERNEL);
> +
> +    	sd_read_capacity(sdkp, gd->disk_name, SRpnt, buffer);
> +	set_capacity(gd, sdkp->capacity);	
> +	scsi_release_request(SRpnt);
> +	kfree(buffer);

Don't you need some kind of serialization here?

> --- linux/fs/block_dev.c	Mon Jan 20 02:23:49 2003
> +++ edited/fs/block_dev.c	Mon Mar  3 18:49:47 2003
> @@ -623,6 +623,8 @@
>  			up(&whole->bd_sem);
>  		}
>  	} else {
> +		if (!part)
> +			bd_set_size(bdev,(loff_t)get_capacity(disk)<<9);

This needs more explanation.