linux-ext4 - Re: [PATCH 27/27] direct-io: remove random prefetches

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:   Tue, 19 Apr 2022 14:55:17 +0200
From:   David Sterba <dsterba@...e.cz>
To:     Christoph Hellwig <hch@....de>
Cc:     Jens Axboe <axboe@...nel.dk>, dm-devel@...hat.com,
        linux-xfs@...r.kernel.org, linux-fsdevel@...r.kernel.org,
        linux-um@...ts.infradead.org, linux-block@...r.kernel.org,
        drbd-dev@...ts.linbit.com, nbd@...er.debian.org,
        ceph-devel@...r.kernel.org,
        virtualization@...ts.linux-foundation.org,
        xen-devel@...ts.xenproject.org, linux-bcache@...r.kernel.org,
        linux-raid@...r.kernel.org, linux-mmc@...r.kernel.org,
        linux-mtd@...ts.infradead.org, linux-nvme@...ts.infradead.org,
        linux-s390@...r.kernel.org, linux-scsi@...r.kernel.org,
        target-devel@...r.kernel.org, linux-btrfs@...r.kernel.org,
        linux-ext4@...r.kernel.org, linux-f2fs-devel@...ts.sourceforge.net,
        cluster-devel@...hat.com, jfs-discussion@...ts.sourceforge.net,
        linux-nilfs@...r.kernel.org, ntfs3@...ts.linux.dev,
        ocfs2-devel@....oracle.com, linux-mm@...ck.org
Subject: Re: [PATCH 27/27] direct-io: remove random prefetches

On Fri, Apr 15, 2022 at 06:52:58AM +0200, Christoph Hellwig wrote:
> Randomly poking into block device internals for manual prefetches isn't
> exactly a very maintainable thing to do.  And none of the performance
> criticil direct I/O implementations still use this library function
> anyway, so just drop it.
> 
> Signed-off-by: Christoph Hellwig <hch@....de>

That the direct io function needed a valid bdev just for the prefetch
but nothing else was one of the reasons we had to keep the latest_bdev
in btrfs, so good riddance.

You may want to add the reference to the patch that added the prefetch,
65dd2aa90aa1 ("dio: optimize cache misses in the submission path") and
also remove #include <linux/prefetch.h> as there are no more uses of
prefetch in the file.

With that

Reviewed-by: David Sterba <dsterba@...e.com>