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From: Christoph Hellwig <hch@lst.de>
To: Charles Machalow <csm10495@gmail.com>
Cc: Sagi Grimberg <sagi@grimberg.me>,
	linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org,
	Jens Axboe <axboe@fb.com>,
	marta.rybczynska@kalray.eu, Keith Busch <kbusch@kernel.org>,
	Christoph Hellwig <hch@lst.de>
Subject: Re: [PATCH] nvme: change nvme_passthru_cmd64's result field.
Date: Thu, 31 Oct 2019 14:39:21 +0100	[thread overview]
Message-ID: <20191031133921.GA4763@lst.de> (raw)
In-Reply-To: <20191031050338.12700-1-csm10495@gmail.com>

On Wed, Oct 30, 2019 at 10:03:38PM -0700, Charles Machalow wrote:
> Changing nvme_passthru_cmd64's result field to be backwards compatible
> with the nvme_passthru_cmd/nvme_admin_cmd struct in terms of the result
> field. With this change the first 32 bits of result in either case
> point to CQE DW0. This allows userspace tools to use the new structure
> when using the old ADMIN/IO_CMD ioctls or new ADMIN/IO_CMD64 ioctls.

All that casting is a pretty bad idea.  please just add an explicit
reserved field before the result, and check that it always is zero
in the ioctl handler.

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WARNING: multiple messages have this Message-ID (diff)
From: Christoph Hellwig <hch@lst.de>
To: Charles Machalow <csm10495@gmail.com>
Cc: linux-nvme@lists.infradead.org, marta.rybczynska@kalray.eu,
	Keith Busch <kbusch@kernel.org>, Jens Axboe <axboe@fb.com>,
	Christoph Hellwig <hch@lst.de>, Sagi Grimberg <sagi@grimberg.me>,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] nvme: change nvme_passthru_cmd64's result field.
Date: Thu, 31 Oct 2019 14:39:21 +0100	[thread overview]
Message-ID: <20191031133921.GA4763@lst.de> (raw)
In-Reply-To: <20191031050338.12700-1-csm10495@gmail.com>

On Wed, Oct 30, 2019 at 10:03:38PM -0700, Charles Machalow wrote:
> Changing nvme_passthru_cmd64's result field to be backwards compatible
> with the nvme_passthru_cmd/nvme_admin_cmd struct in terms of the result
> field. With this change the first 32 bits of result in either case
> point to CQE DW0. This allows userspace tools to use the new structure
> when using the old ADMIN/IO_CMD ioctls or new ADMIN/IO_CMD64 ioctls.

All that casting is a pretty bad idea.  please just add an explicit
reserved field before the result, and check that it always is zero
in the ioctl handler.

  reply	other threads:[~2019-10-31 13:39 UTC|newest]

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-31  5:03 [PATCH] nvme: change nvme_passthru_cmd64's result field Charles Machalow
2019-10-31  5:03 ` Charles Machalow
2019-10-31 13:39 ` Christoph Hellwig [this message]
2019-10-31 13:39   ` Christoph Hellwig
     [not found]   ` <CANSCoS8rN6g7u6iG4SRTcXjdj68cbimvX1n1Ex+FBAkhAAivJA@mail.gmail.com>
2019-10-31 13:59     ` Christoph Hellwig
2019-10-31 13:59       ` Christoph Hellwig
2019-10-31 15:39       ` Charles Machalow
2019-10-31 15:39         ` Charles Machalow
2019-10-31 13:59   ` Charles Machalow
2019-10-31 13:59     ` Charles Machalow
2019-11-04 14:34   ` Marta Rybczynska
2019-11-04 14:34     ` Marta Rybczynska
2019-11-04 14:51     ` Charles Machalow
2019-11-04 14:51       ` Charles Machalow
2019-11-04 14:56       ` Marta Rybczynska
2019-11-04 14:56         ` Marta Rybczynska
2019-11-04 15:01         ` Keith Busch
2019-11-04 15:01           ` Keith Busch
2019-11-04 15:29           ` Christoph Hellwig
2019-11-04 15:29             ` Christoph Hellwig
2019-11-04 15:32             ` Keith Busch
2019-11-04 15:32               ` Keith Busch
2019-11-04 15:01         ` Charles Machalow
2019-11-04 15:01           ` Charles Machalow
2019-11-04 15:16           ` Marta Rybczynska
2019-11-04 15:16             ` Marta Rybczynska
2019-11-04 15:20             ` Charles Machalow
2019-11-04 15:20               ` Charles Machalow
2019-11-04 15:30               ` Christoph Hellwig
2019-11-04 15:30                 ` Christoph Hellwig

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