diff options
Diffstat (limited to 'io_uring/futex.c')
| -rw-r--r-- | io_uring/futex.c | 169 |
1 files changed, 160 insertions, 9 deletions
diff --git a/io_uring/futex.c b/io_uring/futex.c index eb4406ac46fb2..3c3575303c3d0 100644 --- a/io_uring/futex.c +++ b/io_uring/futex.c @@ -14,10 +14,16 @@ struct io_futex { struct file *file; - u32 __user *uaddr; + union { + u32 __user *uaddr; + struct futex_waitv __user *uwaitv; + }; unsigned long futex_val; unsigned long futex_mask; + unsigned long futexv_owned; u32 futex_flags; + unsigned int futex_nr; + bool futexv_unqueued; }; struct io_futex_data { @@ -44,6 +50,13 @@ void io_futex_cache_free(struct io_ring_ctx *ctx) io_alloc_cache_free(&ctx->futex_cache, io_futex_cache_entry_free); } +static void __io_futex_complete(struct io_kiocb *req, struct io_tw_state *ts) +{ + req->async_data = NULL; + hlist_del_init(&req->hash_node); + io_req_task_complete(req, ts); +} + static void io_futex_complete(struct io_kiocb *req, struct io_tw_state *ts) { struct io_futex_data *ifd = req->async_data; @@ -52,22 +65,56 @@ static void io_futex_complete(struct io_kiocb *req, struct io_tw_state *ts) io_tw_lock(ctx, ts); if (!io_alloc_cache_put(&ctx->futex_cache, &ifd->cache)) kfree(ifd); - req->async_data = NULL; - hlist_del_init(&req->hash_node); - io_req_task_complete(req, ts); + __io_futex_complete(req, ts); } -static bool __io_futex_cancel(struct io_ring_ctx *ctx, struct io_kiocb *req) +static void io_futexv_complete(struct io_kiocb *req, struct io_tw_state *ts) { - struct io_futex_data *ifd = req->async_data; + struct io_futex *iof = io_kiocb_to_cmd(req, struct io_futex); + struct futex_vector *futexv = req->async_data; - /* futex wake already done or in progress */ - if (!futex_unqueue(&ifd->q)) + io_tw_lock(req->ctx, ts); + + if (!iof->futexv_unqueued) { + int res; + + res = futex_unqueue_multiple(futexv, iof->futex_nr); + if (res != -1) + io_req_set_res(req, res, 0); + } + + kfree(req->async_data); + req->flags &= ~REQ_F_ASYNC_DATA; + __io_futex_complete(req, ts); +} + +static bool io_futexv_claim(struct io_futex *iof) +{ + if (test_bit(0, &iof->futexv_owned) || + test_and_set_bit_lock(0, &iof->futexv_owned)) return false; + return true; +} + +static bool __io_futex_cancel(struct io_ring_ctx *ctx, struct io_kiocb *req) +{ + /* futex wake already done or in progress */ + if (req->opcode == IORING_OP_FUTEX_WAIT) { + struct io_futex_data *ifd = req->async_data; + + if (!futex_unqueue(&ifd->q)) + return false; + req->io_task_work.func = io_futex_complete; + } else { + struct io_futex *iof = io_kiocb_to_cmd(req, struct io_futex); + + if (!io_futexv_claim(iof)) + return false; + req->io_task_work.func = io_futexv_complete; + } hlist_del_init(&req->hash_node); io_req_set_res(req, -ECANCELED, 0); - req->io_task_work.func = io_futex_complete; io_req_task_work_add(req); return true; } @@ -147,6 +194,55 @@ int io_futex_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) return 0; } +static void io_futex_wakev_fn(struct wake_q_head *wake_q, struct futex_q *q) +{ + struct io_kiocb *req = q->wake_data; + struct io_futex *iof = io_kiocb_to_cmd(req, struct io_futex); + + if (!io_futexv_claim(iof)) + return; + if (unlikely(!__futex_wake_mark(q))) + return; + + io_req_set_res(req, 0, 0); + req->io_task_work.func = io_futexv_complete; + io_req_task_work_add(req); +} + +int io_futexv_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_futex *iof = io_kiocb_to_cmd(req, struct io_futex); + struct futex_vector *futexv; + int ret; + + /* No flags or mask supported for waitv */ + if (unlikely(sqe->fd || sqe->buf_index || sqe->file_index || + sqe->addr2 || sqe->futex_flags || sqe->addr3)) + return -EINVAL; + + iof->uaddr = u64_to_user_ptr(READ_ONCE(sqe->addr)); + iof->futex_nr = READ_ONCE(sqe->len); + if (!iof->futex_nr || iof->futex_nr > FUTEX_WAITV_MAX) + return -EINVAL; + + futexv = kcalloc(iof->futex_nr, sizeof(*futexv), GFP_KERNEL); + if (!futexv) + return -ENOMEM; + + ret = futex_parse_waitv(futexv, iof->uwaitv, iof->futex_nr, + io_futex_wakev_fn, req); + if (ret) { + kfree(futexv); + return ret; + } + + iof->futexv_owned = 0; + iof->futexv_unqueued = 0; + req->flags |= REQ_F_ASYNC_DATA; + req->async_data = futexv; + return 0; +} + static void io_futex_wake_fn(struct wake_q_head *wake_q, struct futex_q *q) { struct io_futex_data *ifd = container_of(q, struct io_futex_data, q); @@ -171,6 +267,61 @@ static struct io_futex_data *io_alloc_ifd(struct io_ring_ctx *ctx) return kmalloc(sizeof(struct io_futex_data), GFP_NOWAIT); } +int io_futexv_wait(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_futex *iof = io_kiocb_to_cmd(req, struct io_futex); + struct futex_vector *futexv = req->async_data; + struct io_ring_ctx *ctx = req->ctx; + int ret, woken = -1; + + io_ring_submit_lock(ctx, issue_flags); + + ret = futex_wait_multiple_setup(futexv, iof->futex_nr, &woken); + + /* + * Error case, ret is < 0. Mark the request as failed. + */ + if (unlikely(ret < 0)) { + io_ring_submit_unlock(ctx, issue_flags); + req_set_fail(req); + io_req_set_res(req, ret, 0); + kfree(futexv); + req->async_data = NULL; + req->flags &= ~REQ_F_ASYNC_DATA; + return IOU_OK; + } + + /* + * 0 return means that we successfully setup the waiters, and that + * nobody triggered a wakeup while we were doing so. If the wakeup + * happened post setup, the task_work will be run post this issue and + * under the submission lock. 1 means We got woken while setting up, + * let that side do the completion. Note that + * futex_wait_multiple_setup() will have unqueued all the futexes in + * this case. Mark us as having done that already, since this is + * different from normal wakeup. + */ + if (!ret) { + /* + * If futex_wait_multiple_setup() returns 0 for a + * successful setup, then the task state will not be + * runnable. This is fine for the sync syscall, as + * it'll be blocking unless we already got one of the + * futexes woken, but it obviously won't work for an + * async invocation. Mark us runnable again. + */ + __set_current_state(TASK_RUNNING); + hlist_add_head(&req->hash_node, &ctx->futex_list); + } else { + iof->futexv_unqueued = 1; + if (woken != -1) + io_req_set_res(req, woken, 0); + } + + io_ring_submit_unlock(ctx, issue_flags); + return IOU_ISSUE_SKIP_COMPLETE; +} + int io_futex_wait(struct io_kiocb *req, unsigned int issue_flags) { struct io_futex *iof = io_kiocb_to_cmd(req, struct io_futex); |