linux-kernel - Re: [PATCH v3 4/4] io_uring: add support for zone-append

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: <20200710131054.GB7491@infradead.org>
Date:   Fri, 10 Jul 2020 14:10:54 +0100
From:   Christoph Hellwig <hch@...radead.org>
To:     Kanchan Joshi <joshiiitr@...il.com>
Cc:     Jens Axboe <axboe@...nel.dk>,
        Christoph Hellwig <hch@...radead.org>,
        Kanchan Joshi <joshi.k@...sung.com>, viro@...iv.linux.org.uk,
        bcrl@...ck.org, Damien.LeMoal@....com, asml.silence@...il.com,
        linux-fsdevel@...r.kernel.org, Matias Bj??rling <mb@...htnvm.io>,
        linux-kernel@...r.kernel.org, linux-aio@...ck.org,
        io-uring@...r.kernel.org, linux-block@...r.kernel.org,
        Selvakumar S <selvakuma.s1@...sung.com>,
        Nitesh Shetty <nj.shetty@...sung.com>,
        Javier Gonzalez <javier.gonz@...sung.com>
Subject: Re: [PATCH v3 4/4] io_uring: add support for zone-append

On Fri, Jul 10, 2020 at 12:35:43AM +0530, Kanchan Joshi wrote:
> Append required special treatment (conversion for sector to bytes) for io_uring.
> And we were planning a user-space wrapper to abstract that.
> 
> But good part (as it seems now) was: append result went along with cflags at
> virtually no additional cost. And uring code changes became super clean/minimal
> with further revisions.
> While indirect-offset requires doing allocation/mgmt in application,
> io-uring submission
> and in completion path (which seems trickier), and those CQE flags
> still get written
> user-space and serve no purpose for append-write.

I have to say that storing the results in the CQE generally make
so much more sense.  I wonder if we need a per-fd "large CGE" flag
that adds two extra u64s to the CQE, and some ops just require this
version.