linux-kernel - Re: [PATCH 2/4] brd: Add getgeo to block ops

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <53E344DD.7020801@gmail.com>
Date:	Thu, 07 Aug 2014 12:20:29 +0300
From:	Boaz Harrosh <openosd@...il.com>
To:	Ross Zwisler <ross.zwisler@...ux.intel.com>,
	Boaz Harrosh <boaz@...xistor.com>
CC:	Jens Axboe <axboe@...nel.dk>,
	Matthew Wilcox <willy@...ux.intel.com>,
	linux-kernel <linux-kernel@...r.kernel.org>,
	linux-fsdevel <linux-fsdevel@...r.kernel.org>
Subject: Re: [PATCH 2/4] brd: Add getgeo to block ops

On 08/06/2014 08:52 PM, Ross Zwisler wrote:
> On Wed, 6 Aug 2014, Boaz Harrosh wrote:
>> From: Ross Zwisler <ross.zwisler@...ux.intel.com>
>>
>> Some programs require HDIO_GETGEO work, which requires we implement
>> getgeo.  Based off of the work done to the NVMe driver in this commit:
>>
<>
>> +static int brd_getgeo(struct block_device *bd, struct hd_geometry *geo)
>> +{
>> +	/* some standard values */
>> +	geo->heads = 1 << 6;
>> +	geo->sectors = 1 << 5;
>> +	geo->cylinders = get_capacity(bd->bd_disk) >> 11;
>> +	return 0;
>> +}
>> +
<> 
> This looks good.
> 

Actually this one is wrong. When I go into fdisk it always gives me
34 as the first possible sector. (And with my 4k patch it gives me
40)

But what I really want is just plain 8. All I want is to waist first
4k for partition table and enough is enough. So actually this above
is wrong.

All we need is :
+	geo->heads = 1 ;
+	geo->sectors = 1 ;
+	geo->cylinders = 1;

Now do not worry the capacity is never extracted from this 32bit structure
for a long time. The capacity is fetched else where, in all programs. This
here just gives you that wired HD math calculation for this 34 sectors
alignment crap.

I just tried it works perfectly with fdisk and gpart. So I'll post a patch.

Thanks
Boaz

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/