From: Jens Axboe <[email protected]>
To: Anuj Gupta <[email protected]>, [email protected], [email protected]
Cc: [email protected], [email protected],
[email protected], [email protected],
[email protected], Kanchan Joshi <[email protected]>
Subject: Re: [PATCH for-next v12 02/12] io_uring: introduce fixed buffer support for io_uring_cmd
Date: Fri, 30 Sep 2022 07:42:04 -0600 [thread overview]
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>
On 9/30/22 12:27 AM, Anuj Gupta wrote:
> Add IORING_URING_CMD_FIXED flag that is to be used for sending io_uring
> command with previously registered buffers. User-space passes the buffer
> index in sqe->buf_index, same as done in read/write variants that uses
> fixed buffers.
>
> Signed-off-by: Anuj Gupta <[email protected]>
> Signed-off-by: Kanchan Joshi <[email protected]>
> ---
> include/linux/io_uring.h | 2 +-
> include/uapi/linux/io_uring.h | 9 +++++++++
> io_uring/uring_cmd.c | 18 +++++++++++++++++-
> 3 files changed, 27 insertions(+), 2 deletions(-)
>
> diff --git a/include/linux/io_uring.h b/include/linux/io_uring.h
> index 1dbf51115c30..e10c5cc81082 100644
> --- a/include/linux/io_uring.h
> +++ b/include/linux/io_uring.h
> @@ -28,7 +28,7 @@ struct io_uring_cmd {
> void *cookie;
> };
> u32 cmd_op;
> - u32 pad;
> + u32 flags;
> u8 pdu[32]; /* available inline for free use */
> };
>
> diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h
> index 92f29d9505a6..ab7458033ee3 100644
> --- a/include/uapi/linux/io_uring.h
> +++ b/include/uapi/linux/io_uring.h
> @@ -56,6 +56,7 @@ struct io_uring_sqe {
> __u32 hardlink_flags;
> __u32 xattr_flags;
> __u32 msg_ring_flags;
> + __u32 uring_cmd_flags;
> };
> __u64 user_data; /* data to be passed back at completion time */
> /* pack this to avoid bogus arm OABI complaints */
> @@ -219,6 +220,14 @@ enum io_uring_op {
> IORING_OP_LAST,
> };
>
> +/*
> + * sqe->uring_cmd_flags
> + * IORING_URING_CMD_FIXED use registered buffer; pass thig flag
> + * along with setting sqe->buf_index.
> + */
> +#define IORING_URING_CMD_FIXED (1U << 0)
> +
> +
> /*
> * sqe->fsync_flags
> */
> diff --git a/io_uring/uring_cmd.c b/io_uring/uring_cmd.c
> index 6a6d69523d75..05e8ad8cef87 100644
> --- a/io_uring/uring_cmd.c
> +++ b/io_uring/uring_cmd.c
> @@ -4,6 +4,7 @@
> #include <linux/file.h>
> #include <linux/io_uring.h>
> #include <linux/security.h>
> +#include <linux/nospec.h>
>
> #include <uapi/linux/io_uring.h>
>
> @@ -77,7 +78,22 @@ int io_uring_cmd_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
> {
> struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd);
>
> - if (sqe->rw_flags || sqe->__pad1)
> + if (sqe->__pad1)
> + return -EINVAL;
> +
> + ioucmd->flags = READ_ONCE(sqe->uring_cmd_flags);
> + if (ioucmd->flags & IORING_URING_CMD_FIXED) {
> + struct io_ring_ctx *ctx = req->ctx;
> + u16 index;
> +
> + req->buf_index = READ_ONCE(sqe->buf_index);
> + if (unlikely(req->buf_index >= ctx->nr_user_bufs))
> + return -EFAULT;
> + index = array_index_nospec(req->buf_index, ctx->nr_user_bufs);
> + req->imu = ctx->user_bufs[index];
> + io_req_set_rsrc_node(req, ctx, 0);
> + }
> + if (ioucmd->flags & ~IORING_URING_CMD_FIXED)
> return -EINVAL;
Not that it _really_ matters, but why isn't this check the first thing
that is done after reading the flags? No need to respin, I can just move
it myself.
--
Jens Axboe
next prev parent reply other threads:[~2022-09-30 13:42 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CGME20220930063754epcas5p2aff33c952032713a39604388eacda910@epcas5p2.samsung.com>
2022-09-30 6:27 ` [PATCH for-next v12 00/12] Fixed-buffer for uring-cmd/passthru Anuj Gupta
[not found] ` <CGME20220930063805epcas5p2c8eb80f32507f011baedc6d6b4d3f38d@epcas5p2.samsung.com>
2022-09-30 6:27 ` [PATCH for-next v12 01/12] io_uring: add io_uring_cmd_import_fixed Anuj Gupta
[not found] ` <CGME20220930063809epcas5p328b9e14ead49e9612b905e6f5b6682f7@epcas5p3.samsung.com>
2022-09-30 6:27 ` [PATCH for-next v12 02/12] io_uring: introduce fixed buffer support for io_uring_cmd Anuj Gupta
2022-09-30 13:42 ` Jens Axboe [this message]
2022-09-30 14:04 ` Anuj gupta
[not found] ` <CGME20220930063811epcas5p43cce58f5e1589c3e3780ce0cfd563986@epcas5p4.samsung.com>
2022-09-30 6:27 ` [PATCH for-next v12 03/12] block: add blk_rq_map_user_io Anuj Gupta
[not found] ` <CGME20220930063815epcas5p1e056d6a2a53949296a7657de804fd2ec@epcas5p1.samsung.com>
2022-09-30 6:27 ` [PATCH for-next v12 04/12] scsi: Use blk_rq_map_user_io helper Anuj Gupta
[not found] ` <CGME20220930063818epcas5p4e321f0efa5a53759ea19eb8f1c63deef@epcas5p4.samsung.com>
2022-09-30 6:27 ` [PATCH for-next v12 05/12] nvme: " Anuj Gupta
[not found] ` <CGME20220930063821epcas5p48d4ec5136d487ea779ac74e2c0b740ac@epcas5p4.samsung.com>
2022-09-30 6:27 ` [PATCH for-next v12 06/12] nvme: refactor nvme_add_user_metadata Anuj Gupta
[not found] ` <CGME20220930063824epcas5p4f829f3b8673e2603cdc9a799ca44ea6e@epcas5p4.samsung.com>
2022-09-30 6:27 ` [PATCH for-next v12 07/12] nvme: refactor nvme_alloc_request Anuj Gupta
[not found] ` <CGME20220930063826epcas5p491d9bc62214c1d7c8c24c883299edfb7@epcas5p4.samsung.com>
2022-09-30 6:27 ` [PATCH for-next v12 08/12] block: rename bio_map_put to blk_mq_map_bio_put Anuj Gupta
[not found] ` <CGME20220930063828epcas5p2bfddb254b0dffde77e99c2acc4440bde@epcas5p2.samsung.com>
2022-09-30 6:27 ` [PATCH for-next v12 09/12] block: factor out blk_rq_map_bio_alloc helper Anuj Gupta
[not found] ` <CGME20220930063831epcas5p4b6a8559dedd39ef423a0b9a317163969@epcas5p4.samsung.com>
2022-09-30 6:27 ` [PATCH for-next v12 10/12] block: extend functionality to map bvec iterator Anuj Gupta
[not found] ` <CGME20220930063833epcas5p40fbff95f9d132f5a42dda80d307426e9@epcas5p4.samsung.com>
2022-09-30 6:27 ` [PATCH for-next v12 11/12] nvme: pass ubuffer as an integer Anuj Gupta
[not found] ` <CGME20220930063835epcas5p2812f8e3d0758b19c01198034fcddc019@epcas5p2.samsung.com>
2022-09-30 6:27 ` [PATCH for-next v12 12/12] nvme: wire up fixed buffer support for nvme passthrough Anuj Gupta
2022-09-30 14:04 ` [PATCH for-next v12 00/12] Fixed-buffer for uring-cmd/passthru Jens Axboe
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