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From: Jens Axboe <axboe@kernel.dk>
To: io-uring@vger.kernel.org
Cc: Jens Axboe <axboe@kernel.dk>
Subject: [PATCH 5/9] io_uring: add non-vectored read/write commands
Date: Sat, 28 Dec 2019 12:21:14 -0700
Message-ID: <20191228192118.4005-6-axboe@kernel.dk> (raw)
In-Reply-To: <20191228192118.4005-1-axboe@kernel.dk>

For uses cases that don't already naturally have an iovec, it's easier
(or more convenient) to just use a buffer address + length. This is
particular true if the use case is from languages that want to create
a memory safe abstraction on top of io_uring, and where introducing
the need for the iovec may impose an ownership issue. For those cases,
they currently need an indirection buffer, which means allocating data
just for this purpose.

Add basic read/write that don't require the iovec.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 fs/io_uring.c                 | 23 +++++++++++++++++++++++
 include/uapi/linux/io_uring.h |  2 ++
 2 files changed, 25 insertions(+)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 0ee9115a599d..464ca73f2dd3 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -656,6 +656,18 @@ static const struct io_op_def io_op_defs[IORING_OP_LAST] = {
 		.needs_file		= 1,
 		.fd_non_neg		= 1,
 	},
+	{
+		/* IORING_OP_READ */
+		.needs_mm		= 1,
+		.needs_file		= 1,
+		.unbound_nonreg_file	= 1,
+	},
+	{
+		/* IORING_OP_WRITE */
+		.needs_mm		= 1,
+		.needs_file		= 1,
+		.unbound_nonreg_file	= 1,
+	},
 };
 
 static void io_wq_submit_work(struct io_wq_work **workptr);
@@ -1869,6 +1881,13 @@ static ssize_t io_import_iovec(int rw, struct io_kiocb *req,
 	if (req->rw.kiocb.private)
 		return -EINVAL;
 
+	if (opcode == IORING_OP_READ || opcode == IORING_OP_WRITE) {
+		ssize_t ret;
+		ret = import_single_range(rw, buf, sqe_len, *iovec, iter);
+		*iovec = NULL;
+		return ret;
+	}
+
 	if (req->io) {
 		struct io_async_rw *iorw = &req->io->rw;
 
@@ -3635,10 +3654,12 @@ static int io_req_defer_prep(struct io_kiocb *req,
 		break;
 	case IORING_OP_READV:
 	case IORING_OP_READ_FIXED:
+	case IORING_OP_READ:
 		ret = io_read_prep(req, sqe, true);
 		break;
 	case IORING_OP_WRITEV:
 	case IORING_OP_WRITE_FIXED:
+	case IORING_OP_WRITE:
 		ret = io_write_prep(req, sqe, true);
 		break;
 	case IORING_OP_POLL_ADD:
@@ -3742,6 +3763,7 @@ static int io_issue_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe,
 		break;
 	case IORING_OP_READV:
 	case IORING_OP_READ_FIXED:
+	case IORING_OP_READ:
 		if (sqe) {
 			ret = io_read_prep(req, sqe, force_nonblock);
 			if (ret < 0)
@@ -3751,6 +3773,7 @@ static int io_issue_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe,
 		break;
 	case IORING_OP_WRITEV:
 	case IORING_OP_WRITE_FIXED:
+	case IORING_OP_WRITE:
 		if (sqe) {
 			ret = io_write_prep(req, sqe, force_nonblock);
 			if (ret < 0)
diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h
index 762a63a49af1..03d2dde46152 100644
--- a/include/uapi/linux/io_uring.h
+++ b/include/uapi/linux/io_uring.h
@@ -84,6 +84,8 @@ enum {
 	IORING_OP_CLOSE,
 	IORING_OP_FILES_UPDATE,
 	IORING_OP_STATX,
+	IORING_OP_READ,
+	IORING_OP_WRITE,
 
 	/* this goes last, obviously */
 	IORING_OP_LAST,
-- 
2.24.1


  parent reply index

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-12-28 19:21 [PATCHSET 0/9] cleanups, improvements, additions Jens Axboe
2019-12-28 19:21 ` [PATCH 1/9] io_uring: remove two unnecessary function declarations Jens Axboe
2019-12-28 19:21 ` [PATCH 2/9] io_uring: add lookup table for various opcode needs Jens Axboe
2019-12-28 19:21 ` [PATCH 3/9] io_uring: split overflow state into SQ and CQ side Jens Axboe
2019-12-28 19:21 ` [PATCH 4/9] io_uring: improve poll completion performance Jens Axboe
2019-12-28 19:21 ` Jens Axboe [this message]
2019-12-28 19:21 ` [PATCH 6/9] io_uring: allow use of offset == -1 to mean file position Jens Axboe
2019-12-28 19:21 ` [PATCH 7/9] io_uring: add IORING_OP_FADVISE Jens Axboe
2019-12-28 19:21 ` [PATCH 8/9] mm: make do_madvise() available internally Jens Axboe
2019-12-28 19:21 ` [PATCH 9/9] io_uring: add IORING_OP_MADVISE Jens Axboe

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