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: Jens Axboe <axboe@kernel.dk>
diff --git a/fs/io_uring.c b/fs/io_uring.c
index edbda88..1c99f01 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -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;
