linux-kernel - Re: [PATCH 03/13 V2] blk: make the bioset rescue

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: <CACVXFVOL1G44gmNxQrV5V6PZXOoZWGj_beoQaxQXZWntZEoVsg@mail.gmail.com>
Date:   Wed, 3 May 2017 11:24:51 +0800
From:   Ming Lei <tom.leiming@...il.com>
To:     NeilBrown <neilb@...e.com>
Cc:     Jens Axboe <axboe@...nel.dk>,
        linux-block <linux-block@...r.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        Christoph Hellwig <hch@....de>
Subject: Re: [PATCH 03/13 V2] blk: make the bioset rescue_workqueue optional.

On Wed, May 3, 2017 at 6:34 AM, NeilBrown <neilb@...e.com> wrote:
> From 09017acf74ec4df674b78ca66f0924187f10d8a4 Mon Sep 17 00:00:00 2001
> From: NeilBrown <neilb@...e.com>
> Date: Fri, 10 Mar 2017 13:59:50 +1100
> Subject: [PATCH] blk: make the bioset rescue_workqueue optional.
>
> This patch converts bioset_create() to not create a workqueue by
> default, so alloctions will never trigger punt_bios_to_rescuer().  It
> also introduces a new flag BIOSET_NEED_RESCUER() which tells
> bioset_create() to preserve the old behavior.
>
> All callers of bioset_create() that are inside block device drivers,
> are given the BIOSET_NEED_RESCUER().
>
> biosets used by filesystems or other top-level users do not
> need rescuing as the bio can never be queued behind other
> bios.  This includes fs_bio_set, blkdev_dio_pool,
> btrfs_bioset, xfs_ioend_bioset, and one allocated by
> target_core_iblock.c.
>
> biosets used by md/raid do not need rescuing as
> their usage was recently audited and revised to never
> risk deadlock.
>
> It is hoped that most, if not all, of the remaining biosets
> can end up being the non-rescued version.
>
> Reviewed-by: Christoph Hellwig <hch@....de>
> Credit-to: Ming Lei <ming.lei@...hat.com> (minor fixes)
> Signed-off-by: NeilBrown <neilb@...e.com>

Reviewed-by: Ming Lei <ming.lei@...hat.com>


Thanks,
Ming