Commit 53db8a71 authored by Jens Axboe's avatar Jens Axboe
Browse files

io_uring: add support for IORING_OP_PIPE 



This works just like pipe2(2), except it also supports fixed file
descriptors. Used in a similar fashion as for other fd instantiating
opcodes (like accept, socket, open, etc), where sqe->file_slot is set
appropriately if two direct descriptors are desired rather than a set
of normal file descriptors.

sqe->addr must be set to a pointer to an array of 2 integers, which
is where the fixed/normal file descriptors are copied to.

sqe->pipe_flags contains flags, same as what is allowed for pipe2(2).

Future expansion of per-op private flags can go in sqe->ioprio,
like we do for other opcodes that take both a "syscall" flag set and
an io_uring opcode specific flag set.

Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent bd32923e

include/uapi/linux/io_uring.h

+2 −0
Original line number Diff line number Diff line
@@ -73,6 +73,7 @@ struct io_uring_sqe { 
		__u32		futex_flags;

		__u32		install_fd_flags;

		__u32		nop_flags;

		__u32		pipe_flags;

	};

	__u64	user_data;	/* data to be passed back at completion time */

	/* pack this to avoid bogus arm OABI complaints */
@@ -283,6 +284,7 @@ enum io_uring_op { 
	IORING_OP_EPOLL_WAIT,

	IORING_OP_READV_FIXED,

	IORING_OP_WRITEV_FIXED,

	IORING_OP_PIPE,



	/* this goes last, obviously */

	IORING_OP_LAST,

io_uring/opdef.c

+7 −0
Original line number Diff line number Diff line
@@ -569,6 +569,10 @@ const struct io_issue_def io_issue_defs[] = { 
		.prep			= io_prep_writev_fixed,

		.issue			= io_write,

	},

	[IORING_OP_PIPE] = {

		.prep			= io_pipe_prep,

		.issue			= io_pipe,

	},

};



const struct io_cold_def io_cold_defs[] = {
@@ -815,6 +819,9 @@ const struct io_cold_def io_cold_defs[] = { 
		.cleanup		= io_readv_writev_cleanup,

		.fail			= io_rw_fail,

	},

	[IORING_OP_PIPE] = {

		.name			= "PIPE",

	},

};



const char *io_uring_get_opcode(u8 opcode)

io_uring/openclose.c

+133 −0
Original line number Diff line number Diff line
@@ -6,6 +6,8 @@ 
#include <linux/fdtable.h>

#include <linux/fsnotify.h>

#include <linux/namei.h>

#include <linux/pipe_fs_i.h>

#include <linux/watch_queue.h>

#include <linux/io_uring.h>



#include <uapi/linux/io_uring.h>
@@ -302,3 +304,134 @@ int io_install_fixed_fd(struct io_kiocb *req, unsigned int issue_flags) 
	io_req_set_res(req, ret, 0);

	return IOU_OK;

}



struct io_pipe {

	struct file *file;

	int __user *fds;

	int flags;

	int file_slot;

	unsigned long nofile;

};



int io_pipe_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)

{

	struct io_pipe *p = io_kiocb_to_cmd(req, struct io_pipe);



	if (sqe->fd || sqe->off || sqe->addr3)

		return -EINVAL;



	p->fds = u64_to_user_ptr(READ_ONCE(sqe->addr));

	p->flags = READ_ONCE(sqe->pipe_flags);

	if (p->flags & ~(O_CLOEXEC | O_NONBLOCK | O_DIRECT | O_NOTIFICATION_PIPE))

		return -EINVAL;



	p->file_slot = READ_ONCE(sqe->file_index);

	p->nofile = rlimit(RLIMIT_NOFILE);

	return 0;

}



static int io_pipe_fixed(struct io_kiocb *req, struct file **files,

			 unsigned int issue_flags)

{

	struct io_pipe *p = io_kiocb_to_cmd(req, struct io_pipe);

	struct io_ring_ctx *ctx = req->ctx;

	int ret, fds[2] = { -1, -1 };

	int slot = p->file_slot;



	if (p->flags & O_CLOEXEC)

		return -EINVAL;



	io_ring_submit_lock(ctx, issue_flags);



	ret = __io_fixed_fd_install(ctx, files[0], slot);

	if (ret < 0)

		goto err;

	fds[0] = ret;

	files[0] = NULL;



	/*

	 * If a specific slot is given, next one will be used for

	 * the write side.

	 */

	if (slot != IORING_FILE_INDEX_ALLOC)

		slot++;



	ret = __io_fixed_fd_install(ctx, files[1], slot);

	if (ret < 0)

		goto err;

	fds[1] = ret;

	files[1] = NULL;



	io_ring_submit_unlock(ctx, issue_flags);



	if (!copy_to_user(p->fds, fds, sizeof(fds)))

		return 0;



	ret = -EFAULT;

	io_ring_submit_lock(ctx, issue_flags);

err:

	if (fds[0] != -1)

		io_fixed_fd_remove(ctx, fds[0]);

	if (fds[1] != -1)

		io_fixed_fd_remove(ctx, fds[1]);

	io_ring_submit_unlock(ctx, issue_flags);

	return ret;

}



static int io_pipe_fd(struct io_kiocb *req, struct file **files)

{

	struct io_pipe *p = io_kiocb_to_cmd(req, struct io_pipe);

	int ret, fds[2] = { -1, -1 };



	ret = __get_unused_fd_flags(p->flags, p->nofile);

	if (ret < 0)

		goto err;

	fds[0] = ret;



	ret = __get_unused_fd_flags(p->flags, p->nofile);

	if (ret < 0)

		goto err;

	fds[1] = ret;



	if (!copy_to_user(p->fds, fds, sizeof(fds))) {

		fd_install(fds[0], files[0]);

		fd_install(fds[1], files[1]);

		return 0;

	}

	ret = -EFAULT;

err:

	if (fds[0] != -1)

		put_unused_fd(fds[0]);

	if (fds[1] != -1)

		put_unused_fd(fds[1]);

	return ret;

}



int io_pipe(struct io_kiocb *req, unsigned int issue_flags)

{

	struct io_pipe *p = io_kiocb_to_cmd(req, struct io_pipe);

	struct file *files[2];

	int ret;



	ret = create_pipe_files(files, p->flags);

	if (ret)

		return ret;

	files[0]->f_mode |= FMODE_NOWAIT;

	files[1]->f_mode |= FMODE_NOWAIT;



	if (!!p->file_slot)

		ret = io_pipe_fixed(req, files, issue_flags);

	else

		ret = io_pipe_fd(req, files);



	io_req_set_res(req, ret, 0);

	if (!ret)

		return IOU_OK;



	req_set_fail(req);

	if (files[0])

		fput(files[0]);

	if (files[1])

		fput(files[1]);

	return ret;

}

io_uring/openclose.h

+3 −0
Original line number Diff line number Diff line
@@ -13,5 +13,8 @@ int io_openat2(struct io_kiocb *req, unsigned int issue_flags); 
int io_close_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe);

int io_close(struct io_kiocb *req, unsigned int issue_flags);



int io_pipe_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe);

int io_pipe(struct io_kiocb *req, unsigned int issue_flags);



int io_install_fixed_fd_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe);

int io_install_fixed_fd(struct io_kiocb *req, unsigned int issue_flags);