Commit aaa4db12 authored by Pavel Begunkov's avatar Pavel Begunkov Committed by Jens Axboe
Browse files

io_uring: accept directly into fixed file table 



As done with open opcodes, allow accept to skip installing fd into
processes' file tables and put it directly into io_uring's fixed file
table. Same restrictions and design as for open.

Suggested-by: default avatarJosh Triplett <josh@joshtriplett.org>
Signed-off-by: default avatarPavel Begunkov <asml.silence@gmail.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
Link: https://lore.kernel.org/r/6d16163f376fac7ac26a656de6b42199143e9721.1629888991.git.asml.silence@gmail.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent a7083ad5

fs/io_uring.c

+18 −6
Original line number Diff line number Diff line
@@ -515,6 +515,7 @@ struct io_accept { 
	struct sockaddr __user		*addr;

	int __user			*addr_len;

	int				flags;

	u32				file_slot;

	unsigned long			nofile;

};
@@ -4803,7 +4804,7 @@ static int io_accept_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) 


	if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))

		return -EINVAL;

	if (sqe->ioprio || sqe->len || sqe->buf_index || sqe->splice_fd_in)

	if (sqe->ioprio || sqe->len || sqe->buf_index)

		return -EINVAL;



	accept->addr = u64_to_user_ptr(READ_ONCE(sqe->addr));
@@ -4811,6 +4812,10 @@ static int io_accept_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) 
	accept->flags = READ_ONCE(sqe->accept_flags);

	accept->nofile = rlimit(RLIMIT_NOFILE);



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

	if (accept->file_slot && ((req->open.how.flags & O_CLOEXEC) ||

				  (accept->flags & SOCK_CLOEXEC)))

		return -EINVAL;

	if (accept->flags & ~(SOCK_CLOEXEC | SOCK_NONBLOCK))

		return -EINVAL;

	if (SOCK_NONBLOCK != O_NONBLOCK && (accept->flags & SOCK_NONBLOCK))
@@ -4823,28 +4828,35 @@ static int io_accept(struct io_kiocb *req, unsigned int issue_flags) 
	struct io_accept *accept = &req->accept;

	bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;

	unsigned int file_flags = force_nonblock ? O_NONBLOCK : 0;

	bool fixed = !!accept->file_slot;

	struct file *file;

	int ret, fd;



	if (req->file->f_flags & O_NONBLOCK)

		req->flags |= REQ_F_NOWAIT;



	if (!fixed) {

		fd = __get_unused_fd_flags(accept->flags, accept->nofile);

		if (unlikely(fd < 0))

			return fd;



	}

	file = do_accept(req->file, file_flags, accept->addr, accept->addr_len,

			 accept->flags);

	if (IS_ERR(file)) {

		if (!fixed)

			put_unused_fd(fd);

		ret = PTR_ERR(file);

		if (ret == -EAGAIN && force_nonblock)

			return -EAGAIN;

		if (ret == -ERESTARTSYS)

			ret = -EINTR;

		req_set_fail(req);

	} else {

	} else if (!fixed) {

		fd_install(fd, file);

		ret = fd;

	} else {

		ret = io_install_fixed_file(req, file, issue_flags,

					    accept->file_slot - 1);

	}

	__io_req_complete(req, issue_flags, ret, 0);

	return 0;