linux-kernel - Re: [PATCH 00/16] support non power of 2 zoned devices

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] [day] [month] [year] [list]

Date:   Thu, 5 May 2022 09:28:43 +0200
From:   Pankaj Raghav <p.raghav@...sung.com>
To:     David Sterba <dsterba@...e.cz>
CC:     Johannes Thumshirn <Johannes.Thumshirn@....com>,
        "jaegeuk@...nel.org" <jaegeuk@...nel.org>,
        "axboe@...nel.dk" <axboe@...nel.dk>,
        "snitzer@...nel.org" <snitzer@...nel.org>,
        "hch@....de" <hch@....de>, "mcgrof@...nel.org" <mcgrof@...nel.org>,
        Naohiro Aota <Naohiro.Aota@....com>,
        "sagi@...mberg.me" <sagi@...mberg.me>,
        "damien.lemoal@...nsource.wdc.com" <damien.lemoal@...nsource.wdc.com>,
        "dsterba@...e.com" <dsterba@...e.com>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "linux-btrfs@...r.kernel.org" <linux-btrfs@...r.kernel.org>,
        "clm@...com" <clm@...com>,
        "gost.dev@...sung.com" <gost.dev@...sung.com>,
        "chao@...nel.org" <chao@...nel.org>,
        "linux-f2fs-devel@...ts.sourceforge.net" 
        <linux-f2fs-devel@...ts.sourceforge.net>,
        "josef@...icpanda.com" <josef@...icpanda.com>,
        "jonathan.derrick@...ux.dev" <jonathan.derrick@...ux.dev>,
        "agk@...hat.com" <agk@...hat.com>,
        "kbusch@...nel.org" <kbusch@...nel.org>,
        "kch@...dia.com" <kch@...dia.com>,
        "linux-nvme@...ts.infradead.org" <linux-nvme@...ts.infradead.org>,
        "dm-devel@...hat.com" <dm-devel@...hat.com>,
        "bvanassche@....org" <bvanassche@....org>,
        "jiangbo.365@...edance.com" <jiangbo.365@...edance.com>,
        "linux-fsdevel@...r.kernel.org" <linux-fsdevel@...r.kernel.org>,
        Matias Bjørling <Matias.Bjorling@....com>,
        "linux-block@...r.kernel.org" <linux-block@...r.kernel.org>
Subject: Re: [PATCH 00/16] support non power of 2 zoned devices

On 2022-05-04 23:14, David Sterba wrote:
>> This commit: `btrfs: zoned: relax the alignment constraint for zoned
>> devices` makes sure the zone size is BTRFS_STRIPE_LEN aligned (64K). So
>> even the npo2 zoned device should be aligned to `fs_info->sectorsize`,
>> which is typically 4k.
>>
>> This was one of the comment that came from David Sterba:
>> https://lore.kernel.org/all/20220315142740.GU12643@twin.jikos.cz/
>> where he suggested to have some sane alignment for the zone sizes.
> 
> My idea of 'sane' value would be 1M, that we have 4K for sectors is
> because of the 1:1 mapping to pages, but RAM sizes are on a different
> scale than storage devices. The 4K is absolute minimum but if the page
> size is taken as a basic constraint, ARM has 64K and there are some 256K
> arches.

That is a good point. I think it is safe to have 1MB as the minimum
alignment so that it covers all architecture's page sizes. Thanks. I
will queue this up.