Commit 50c1df2b authored by Jens Axboe's avatar Jens Axboe
Browse files

io_uring: support CLOCK_BOOTTIME/REALTIME for timeouts 

Certain use cases want to use CLOCK_BOOTTIME or CLOCK_REALTIME rather than
CLOCK_MONOTONIC, instead of the default CLOCK_MONOTONIC.

Add an IORING_TIMEOUT_BOOTTIME and IORING_TIMEOUT_REALTIME flag that
allows timeouts and linked timeouts to use the selected clock source.

Only one clock source may be selected, and we -EINVAL the request if more
than one is given. If neither BOOTIME nor REALTIME are selected, the
previous default of MONOTONIC is used.

Link: https://github.com/axboe/liburing/issues/369


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 2e480058

fs/io_uring.c

+24 −3
Original line number Diff line number Diff line
@@ -508,6 +508,7 @@ struct io_timeout_data { 
	struct hrtimer			timer;

	struct timespec64		ts;

	enum hrtimer_mode		mode;

	u32				flags;

};



struct io_accept {
@@ -5712,6 +5713,22 @@ static int io_timeout_cancel(struct io_ring_ctx *ctx, __u64 user_data) 
	return 0;

}



static clockid_t io_timeout_get_clock(struct io_timeout_data *data)

{

	switch (data->flags & IORING_TIMEOUT_CLOCK_MASK) {

	case IORING_TIMEOUT_BOOTTIME:

		return CLOCK_BOOTTIME;

	case IORING_TIMEOUT_REALTIME:

		return CLOCK_REALTIME;

	default:

		/* can't happen, vetted at prep time */

		WARN_ON_ONCE(1);

		fallthrough;

	case 0:

		return CLOCK_MONOTONIC;

	}

}



static int io_timeout_update(struct io_ring_ctx *ctx, __u64 user_data,

			     struct timespec64 *ts, enum hrtimer_mode mode)

	__must_hold(&ctx->timeout_lock)
@@ -5725,7 +5742,7 @@ static int io_timeout_update(struct io_ring_ctx *ctx, __u64 user_data, 
	req->timeout.off = 0; /* noseq */

	data = req->async_data;

	list_add_tail(&req->timeout.list, &ctx->timeout_list);

	hrtimer_init(&data->timer, CLOCK_MONOTONIC, mode);

	hrtimer_init(&data->timer, io_timeout_get_clock(data), mode);

	data->timer.function = io_timeout_fn;

	hrtimer_start(&data->timer, timespec64_to_ktime(*ts), mode);

	return 0;
@@ -5807,7 +5824,10 @@ static int io_timeout_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe, 
	if (off && is_timeout_link)

		return -EINVAL;

	flags = READ_ONCE(sqe->timeout_flags);

	if (flags & ~IORING_TIMEOUT_ABS)

	if (flags & ~(IORING_TIMEOUT_ABS | IORING_TIMEOUT_CLOCK_MASK))

		return -EINVAL;

	/* more than one clock specified is invalid, obviously */

	if (hweight32(flags & IORING_TIMEOUT_CLOCK_MASK) > 1)

		return -EINVAL;



	req->timeout.off = off;
@@ -5819,12 +5839,13 @@ static int io_timeout_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe, 


	data = req->async_data;

	data->req = req;

	data->flags = flags;



	if (get_timespec64(&data->ts, u64_to_user_ptr(sqe->addr)))

		return -EFAULT;



	data->mode = io_translate_timeout_mode(flags);

	hrtimer_init(&data->timer, CLOCK_MONOTONIC, data->mode);

	hrtimer_init(&data->timer, io_timeout_get_clock(data), data->mode);



	if (is_timeout_link) {

		struct io_submit_link *link = &req->ctx->submit_state.link;

include/uapi/linux/io_uring.h

+3 −0
Original line number Diff line number Diff line
@@ -151,6 +151,9 @@ enum { 
 */

#define IORING_TIMEOUT_ABS	(1U << 0)

#define IORING_TIMEOUT_UPDATE	(1U << 1)

#define IORING_TIMEOUT_BOOTTIME	(1U << 2)

#define IORING_TIMEOUT_REALTIME	(1U << 3)

#define IORING_TIMEOUT_CLOCK_MASK	(IORING_TIMEOUT_BOOTTIME | IORING_TIMEOUT_REALTIME)



/*

 * sqe->splice_flags