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References: <20230503183821.1473305-1-john.g.garry@oracle.com> <20230503183821.1473305-2-john.g.garry@oracle.com>
In-Reply-To: <20230503183821.1473305-2-john.g.garry@oracle.com>
From:   Mike Snitzer <snitzer@kernel.org>
Date:   Mon, 8 May 2023 20:19:46 -0400
Message-ID: <CAH6w=ay1NNxh=9mQv5PCcDi3OY0mgvRXO_0VrmKBLAd1dcUQqQ@mail.gmail.com>
Subject: Re: [PATCH RFC 01/16] block: Add atomic write operations to
 request_queue limits
To:     John Garry <john.g.garry@oracle.com>
Cc:     axboe@kernel.dk, kbusch@kernel.org, hch@lst.de, sagi@grimberg.me,
        martin.petersen@oracle.com, djwong@kernel.org,
        viro@zeniv.linux.org.uk, brauner@kernel.org, dchinner@redhat.com,
        jejb@linux.ibm.com, linux-block@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org,
        linux-scsi@vger.kernel.org, linux-xfs@vger.kernel.org,
        linux-fsdevel@vger.kernel.org,
        linux-security-module@vger.kernel.org, paul@paul-moore.com,
        jmorris@namei.org, serge@hallyn.com,
        Himanshu Madhani <himanshu.madhani@oracle.com>,
        dm-devel@redhat.com
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On Wed, May 3, 2023 at 2:40=E2=80=AFPM John Garry <john.g.garry@oracle.com>=
 wrote:
>
> From: Himanshu Madhani <himanshu.madhani@oracle.com>
>
> Add the following limits:
> - atomic_write_boundary
> - atomic_write_max_bytes
> - atomic_write_unit_max
> - atomic_write_unit_min
>
> Signed-off-by: Himanshu Madhani <himanshu.madhani@oracle.com>
> Signed-off-by: John Garry <john.g.garry@oracle.com>
> ---
>  Documentation/ABI/stable/sysfs-block | 42 +++++++++++++++++++++
>  block/blk-settings.c                 | 56 ++++++++++++++++++++++++++++
>  block/blk-sysfs.c                    | 33 ++++++++++++++++
>  include/linux/blkdev.h               | 23 ++++++++++++
>  4 files changed, 154 insertions(+)
>

...

> diff --git a/block/blk-settings.c b/block/blk-settings.c
> index 896b4654ab00..e21731715a12 100644
> --- a/block/blk-settings.c
> +++ b/block/blk-settings.c
> @@ -59,6 +59,9 @@ void blk_set_default_limits(struct queue_limits *lim)
>         lim->zoned =3D BLK_ZONED_NONE;
>         lim->zone_write_granularity =3D 0;
>         lim->dma_alignment =3D 511;
> +       lim->atomic_write_unit_min =3D lim->atomic_write_unit_max =3D 1;
> +       lim->atomic_write_max_bytes =3D 512;
> +       lim->atomic_write_boundary =3D 0;
>  }

Not seeing required changes to blk_set_stacking_limits() nor blk_stack_limi=
ts().

Sorry to remind you of DM and MD limits stacking requirements. ;)

Mike