Commit 15b71abe authored by Jens Axboe's avatar Jens Axboe
Browse files

io_uring: add support for IORING_OP_OPENAT 



This works just like openat(2), except it can be performed async. For
the normal case of a non-blocking path lookup this will complete
inline. If we have to do IO to perform the open, it'll be done from
async context.

Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 35cb6d54

fs/io_uring.c

+93 −2
Original line number Diff line number Diff line
@@ -70,6 +70,8 @@ 
#include <linux/sizes.h>

#include <linux/hugetlb.h>

#include <linux/highmem.h>

#include <linux/namei.h>

#include <linux/fsnotify.h>



#define CREATE_TRACE_POINTS

#include <trace/events/io_uring.h>
@@ -353,6 +355,15 @@ struct io_sr_msg { 
	int				msg_flags;

};



struct io_open {

	struct file			*file;

	int				dfd;

	umode_t				mode;

	const char __user		*fname;

	struct filename			*filename;

	int				flags;

};



struct io_async_connect {

	struct sockaddr_storage		address;

};
@@ -371,12 +382,17 @@ struct io_async_rw { 
	ssize_t				size;

};



struct io_async_open {

	struct filename			*filename;

};



struct io_async_ctx {

	union {

		struct io_async_rw	rw;

		struct io_async_msghdr	msg;

		struct io_async_connect	connect;

		struct io_timeout_data	timeout;

		struct io_async_open	open;

	};

};
@@ -397,6 +413,7 @@ struct io_kiocb { 
		struct io_timeout	timeout;

		struct io_connect	connect;

		struct io_sr_msg	sr_msg;

		struct io_open		open;

	};



	struct io_async_ctx		*io;
@@ -2150,6 +2167,67 @@ static int io_fallocate(struct io_kiocb *req, struct io_kiocb **nxt, 
	return 0;

}



static int io_openat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)

{

	int ret;



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

		return -EINVAL;



	req->open.dfd = READ_ONCE(sqe->fd);

	req->open.mode = READ_ONCE(sqe->len);

	req->open.fname = u64_to_user_ptr(READ_ONCE(sqe->addr));

	req->open.flags = READ_ONCE(sqe->open_flags);



	req->open.filename = getname(req->open.fname);

	if (IS_ERR(req->open.filename)) {

		ret = PTR_ERR(req->open.filename);

		req->open.filename = NULL;

		return ret;

	}



	return 0;

}



static int io_openat(struct io_kiocb *req, struct io_kiocb **nxt,

		     bool force_nonblock)

{

	struct open_flags op;

	struct open_how how;

	struct file *file;

	int ret;



	if (force_nonblock) {

		req->work.flags |= IO_WQ_WORK_NEEDS_FILES;

		return -EAGAIN;

	}



	how = build_open_how(req->open.flags, req->open.mode);

	ret = build_open_flags(&how, &op);

	if (ret)

		goto err;



	ret = get_unused_fd_flags(how.flags);

	if (ret < 0)

		goto err;



	file = do_filp_open(req->open.dfd, req->open.filename, &op);

	if (IS_ERR(file)) {

		put_unused_fd(ret);

		ret = PTR_ERR(file);

	} else {

		fsnotify_open(file);

		fd_install(ret, file);

	}

err:

	putname(req->open.filename);

	if (ret < 0)

		req_set_fail_links(req);

	io_cqring_add_event(req, ret);

	io_put_req_find_next(req, nxt);

	return 0;

}



static int io_prep_sfr(struct io_kiocb *req, const struct io_uring_sqe *sqe)

{

	struct io_ring_ctx *ctx = req->ctx;
@@ -3175,6 +3253,9 @@ static int io_req_defer_prep(struct io_kiocb *req, 
	case IORING_OP_FALLOCATE:

		ret = io_fallocate_prep(req, sqe);

		break;

	case IORING_OP_OPENAT:

		ret = io_openat_prep(req, sqe);

		break;

	default:

		printk_once(KERN_WARNING "io_uring: unhandled opcode %d\n",

				req->opcode);
@@ -3337,6 +3418,14 @@ static int io_issue_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe, 
		}

		ret = io_fallocate(req, nxt, force_nonblock);

		break;

	case IORING_OP_OPENAT:

		if (sqe) {

			ret = io_openat_prep(req, sqe);

			if (ret)

				break;

		}

		ret = io_openat(req, nxt, force_nonblock);

		break;

	default:

		ret = -EINVAL;

		break;
@@ -3409,7 +3498,7 @@ static bool io_req_op_valid(int op) 
	return op >= IORING_OP_NOP && op < IORING_OP_LAST;

}



static int io_req_needs_file(struct io_kiocb *req)

static int io_req_needs_file(struct io_kiocb *req, int fd)

{

	switch (req->opcode) {

	case IORING_OP_NOP:
@@ -3419,6 +3508,8 @@ static int io_req_needs_file(struct io_kiocb *req) 
	case IORING_OP_ASYNC_CANCEL:

	case IORING_OP_LINK_TIMEOUT:

		return 0;

	case IORING_OP_OPENAT:

		return fd != -1;

	default:

		if (io_req_op_valid(req->opcode))

			return 1;
@@ -3448,7 +3539,7 @@ static int io_req_set_file(struct io_submit_state *state, struct io_kiocb *req, 
	if (flags & IOSQE_IO_DRAIN)

		req->flags |= REQ_F_IO_DRAIN;



	ret = io_req_needs_file(req);

	ret = io_req_needs_file(req, fd);

	if (ret <= 0)

		return ret;

include/uapi/linux/io_uring.h

+2 −0
Original line number Diff line number Diff line
@@ -34,6 +34,7 @@ struct io_uring_sqe { 
		__u32		timeout_flags;

		__u32		accept_flags;

		__u32		cancel_flags;

		__u32		open_flags;

	};

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

	union {
@@ -77,6 +78,7 @@ enum { 
	IORING_OP_LINK_TIMEOUT,

	IORING_OP_CONNECT,

	IORING_OP_FALLOCATE,

	IORING_OP_OPENAT,



	/* this goes last, obviously */

	IORING_OP_LAST,

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