From 9cda70f622cdcf049521a9c2886e5fd8a90a0591 Mon Sep 17 00:00:00 2001 From: Anuj Gupta Date: Fri, 30 Sep 2022 11:57:39 +0530 Subject: [PATCH] io_uring: introduce fixed buffer support for io_uring_cmd 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 Signed-off-by: Kanchan Joshi Link: https://lore.kernel.org/r/20220930062749.152261-3-anuj20.g@samsung.com [axboe: shuffle valid flags check before acting on it] Signed-off-by: Jens Axboe --- include/linux/io_uring.h | 2 +- include/uapi/linux/io_uring.h | 9 +++++++++ io_uring/uring_cmd.c | 19 ++++++++++++++++++- 3 files changed, 28 insertions(+), 2 deletions(-) diff --git a/include/linux/io_uring.h b/include/linux/io_uring.h index 1dbf511..e10c5cc 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 92f29d9..ab74580 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 */ @@ -220,6 +221,14 @@ enum io_uring_op { }; /* + * 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 */ #define IORING_FSYNC_DATASYNC (1U << 0) diff --git a/io_uring/uring_cmd.c b/io_uring/uring_cmd.c index 6a6d695..e50de0b 100644 --- a/io_uring/uring_cmd.c +++ b/io_uring/uring_cmd.c @@ -4,6 +4,7 @@ #include #include #include +#include #include @@ -77,8 +78,24 @@ 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) + return -EINVAL; + + 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); + } ioucmd->cmd = sqe->cmd; ioucmd->cmd_op = READ_ONCE(sqe->cmd_op); return 0; -- 2.7.4