linux-kernel - Re: [PATCH 16/19] ataflop: use a separate gendisk for each media format

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]

Date:   Fri, 4 Sep 2020 12:29:05 +0200
From:   Hannes Reinecke <hare@...e.de>
To:     Christoph Hellwig <hch@....de>, Jens Axboe <axboe@...nel.dk>
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        "Rafael J. Wysocki" <rafael@...nel.org>,
        Denis Efremov <efremov@...ux.com>,
        "David S. Miller" <davem@...emloft.net>,
        Song Liu <song@...nel.org>, Al Viro <viro@...iv.linux.org.uk>,
        Finn Thain <fthain@...egraphics.com.au>,
        Michael Schmitz <schmitzmic@...il.com>,
        linux-block@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-ide@...r.kernel.org, linux-raid@...r.kernel.org,
        linux-scsi@...r.kernel.org, linux-m68k@...ts.linux-m68k.org
Subject: Re: [PATCH 16/19] ataflop: use a separate gendisk for each media
 format

On 9/3/20 10:01 AM, Christoph Hellwig wrote:
> The Atari floppy driver usually autodetects the media when used with the
> ormal /dev/fd? devices, which also are the only nodes created by udev.
> But it also supports various aliases that force a given media format.
> That is currently supported using the blk_register_region framework
> which finds the floppy gendisk even for a 'mismatched' dev_t.  The
> problem with this (besides the code complexity) is that it creates
> multiple struct block_device instances for the whole device of a
> single gendisk, which can lead to interesting issues in code not
> aware of that fact.
> 
> To fix this just create a separate gendisk for each of the aliases
> if they are accessed.
> 
> Signed-off-by: Christoph Hellwig <hch@....de>
> ---
>   drivers/block/ataflop.c | 135 +++++++++++++++++++++++++---------------
>   1 file changed, 86 insertions(+), 49 deletions(-)
> 
Reviewed-by: Hannes Reinecke <hare@...e.de>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                Kernel Storage Architect
hare@...e.de                              +49 911 74053 688
SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), Geschäftsführer: Felix Imendörffer