Re: [PATCH 4/4] ide: preserve Host Protected Area by default

[Sergei Shtylyov <sshtylyov@ru.mvista.com>]

Hello.

Bartlomiej Zolnierkiewicz wrote:

>>From: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
>>Subject: [PATCH] ide: preserve Host Protected Area by default

>>From the perspective of most users of recent systems, disabling Host
>>Protected Area (HPA) can break vendor RAID formats, GPT partitions and
>>risks corrupting firmware or overwriting vendor system recovery tools.

>>Unfortunately the original (kernels < 2.6.30) behavior (unconditionally
>>disabling HPA and using full disk capacity) was introduced at the time
>>when the main use of HPA was to make the drive look small enough for the
>>BIOS to allow the system to boot with large capacity drives.

>>Thus to allow the maximum compatibility with the existing setups (using
>>HPA and partitioned with HPA disabled) we automatically disable HPA if
>>any partitions overlapping HPA are detected.  Additionally HPA can also
>>be disabled using the "nohpa" module parameter (i.e. "ide_core.nohpa=0.0"
>>to disable HPA on /dev/hda).

>>While at it:
>>- remove stale "idebus=" entry from Documentation/kernel-parameters.txt

>>Cc: Robert Hancock <hancockrwd@gmail.com>
>>Cc: Frans Pop <elendil@planet.nl>
>>Cc: "Andries E. Brouwer" <Andries.Brouwer@cwi.nl>
>>Cc: Al Viro <viro@zeniv.linux.org.uk>
>>[patch description was based on input from Alan Cox and Frans Pop]
>>Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Acked-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>

> v2 interdiff

> v2:
> Fix ->resume HPA support.

> diff -u b/drivers/ide/ide-disk.c b/drivers/ide/ide-disk.c
> --- b/drivers/ide/ide-disk.c
> +++ b/drivers/ide/ide-disk.c
> @@ -433,8 +433,11 @@
>  		goto out;
>  
>  	set = ide_disk_hpa_set_capacity(drive, set, lba48);
> -	if (set)
> +	if (set) {

    Well, this seems to be a useful check after all. :-)

> +		/* needed for ->resume to disable HPA */
> +		drive->dev_flags |= IDE_DFLAG_NOHPA;
>  		return set;
> +	}
>  out:
>  	return drive->capacity64;
>  }

MBR, Sergei