io_uring: allow updating linked timeouts

We allow updating normal timeouts, add support for adjusting timings of
linked timeouts as well.

Reported-by: Victor Stewart <v@nametag.social>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/fs/io_uring.c b/fs/io_uring.c
index aa97829..7cc458e 100644 (file)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -552,6 +552,7 @@ struct io_timeout_rem {
        /* timeout update */
        struct timespec64               ts;
        u32                             flags;
+       bool                            ltimeout;
 };
 
 struct io_rw {
@@ -1069,6 +1070,7 @@ static int io_req_prep_async(struct io_kiocb *req);
 
 static int io_install_fixed_file(struct io_kiocb *req, struct file *file,
                                 unsigned int issue_flags, u32 slot_index);
+static enum hrtimer_restart io_link_timeout_fn(struct hrtimer *timer);
 
 static struct kmem_cache *req_cachep;
 
@@ -5732,6 +5734,31 @@ static clockid_t io_timeout_get_clock(struct io_timeout_data *data)
        }
 }
 
+static int io_linked_timeout_update(struct io_ring_ctx *ctx, __u64 user_data,
+                                   struct timespec64 *ts, enum hrtimer_mode mode)
+       __must_hold(&ctx->timeout_lock)
+{
+       struct io_timeout_data *io;
+       struct io_kiocb *req;
+       bool found = false;
+
+       list_for_each_entry(req, &ctx->ltimeout_list, timeout.list) {
+               found = user_data == req->user_data;
+               if (found)
+                       break;
+       }
+       if (!found)
+               return -ENOENT;
+
+       io = req->async_data;
+       if (hrtimer_try_to_cancel(&io->timer) == -1)
+               return -EALREADY;
+       hrtimer_init(&io->timer, io_timeout_get_clock(io), mode);
+       io->timer.function = io_link_timeout_fn;
+       hrtimer_start(&io->timer, timespec64_to_ktime(*ts), mode);
+       return 0;
+}
+
 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)
@@ -5763,10 +5790,15 @@ static int io_timeout_remove_prep(struct io_kiocb *req,
        if (sqe->ioprio || sqe->buf_index || sqe->len || sqe->splice_fd_in)
                return -EINVAL;
 
+       tr->ltimeout = false;
        tr->addr = READ_ONCE(sqe->addr);
        tr->flags = READ_ONCE(sqe->timeout_flags);
-       if (tr->flags & IORING_TIMEOUT_UPDATE) {
-               if (tr->flags & ~(IORING_TIMEOUT_UPDATE|IORING_TIMEOUT_ABS))
+       if (tr->flags & IORING_TIMEOUT_UPDATE_MASK) {
+               if (hweight32(tr->flags & IORING_TIMEOUT_CLOCK_MASK) > 1)
+                       return -EINVAL;
+               if (tr->flags & IORING_LINK_TIMEOUT_UPDATE)
+                       tr->ltimeout = true;
+               if (tr->flags & ~(IORING_TIMEOUT_UPDATE_MASK|IORING_TIMEOUT_ABS))
                        return -EINVAL;
                if (get_timespec64(&tr->ts, u64_to_user_ptr(sqe->addr2)))
                        return -EFAULT;
@@ -5800,9 +5832,13 @@ static int io_timeout_remove(struct io_kiocb *req, unsigned int issue_flags)
                spin_unlock_irq(&ctx->timeout_lock);
                spin_unlock(&ctx->completion_lock);
        } else {
+               enum hrtimer_mode mode = io_translate_timeout_mode(tr->flags);
+
                spin_lock_irq(&ctx->timeout_lock);
-               ret = io_timeout_update(ctx, tr->addr, &tr->ts,
-                                       io_translate_timeout_mode(tr->flags));
+               if (tr->ltimeout)
+                       ret = io_linked_timeout_update(ctx, tr->addr, &tr->ts, mode);
+               else
+                       ret = io_timeout_update(ctx, tr->addr, &tr->ts, mode);
                spin_unlock_irq(&ctx->timeout_lock);
        }
 

diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h
index b6d28d9..3caec91 100644 (file)
--- a/include/uapi/linux/io_uring.h
+++ b/include/uapi/linux/io_uring.h
@@ -149,12 +149,13 @@ enum {
 /*
  * sqe->timeout_flags
  */
-#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_ABS             (1U << 0)
+#define IORING_TIMEOUT_UPDATE          (1U << 1)
+#define IORING_TIMEOUT_BOOTTIME                (1U << 2)
+#define IORING_TIMEOUT_REALTIME                (1U << 3)
+#define IORING_LINK_TIMEOUT_UPDATE     (1U << 4)
 #define IORING_TIMEOUT_CLOCK_MASK      (IORING_TIMEOUT_BOOTTIME | IORING_TIMEOUT_REALTIME)
-
+#define IORING_TIMEOUT_UPDATE_MASK     (IORING_TIMEOUT_UPDATE | IORING_LINK_TIMEOUT_UPDATE)
 /*
  * sqe->splice_flags
  * extends splice(2) flags