diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index 2ac1cd8d23ea..0a4efada9b3c 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -3674,7 +3674,7 @@ static __cold int io_uring_create(unsigned entries, struct io_uring_params *p, if (ctx->flags & IORING_SETUP_SINGLE_ISSUER && !(ctx->flags & IORING_SETUP_R_DISABLED)) - ctx->submitter_task = get_task_struct(current); + WRITE_ONCE(ctx->submitter_task, get_task_struct(current)); file = io_uring_get_file(ctx); if (IS_ERR(file)) { @@ -3868,7 +3868,7 @@ static int io_register_enable_rings(struct io_ring_ctx *ctx) return -EBADFD; if (ctx->flags & IORING_SETUP_SINGLE_ISSUER && !ctx->submitter_task) - ctx->submitter_task = get_task_struct(current); + WRITE_ONCE(ctx->submitter_task, get_task_struct(current)); if (ctx->restrictions.registered) ctx->restricted = 1; diff --git a/io_uring/msg_ring.c b/io_uring/msg_ring.c index 2d3cd945a531..15602a136821 100644 --- a/io_uring/msg_ring.c +++ b/io_uring/msg_ring.c @@ -25,60 +25,7 @@ struct io_msg { u32 flags; }; -void io_msg_ring_cleanup(struct io_kiocb *req) -{ - struct io_msg *msg = io_kiocb_to_cmd(req, struct io_msg); - - if (WARN_ON_ONCE(!msg->src_file)) - return; - - fput(msg->src_file); - msg->src_file = NULL; -} - -static void io_msg_tw_complete(struct callback_head *head) -{ - struct io_msg *msg = container_of(head, struct io_msg, tw); - struct io_kiocb *req = cmd_to_io_kiocb(msg); - struct io_ring_ctx *target_ctx = req->file->private_data; - int ret = 0; - - if (current->flags & PF_EXITING) - ret = -EOWNERDEAD; - else if (!io_post_aux_cqe(target_ctx, msg->user_data, msg->len, 0)) - ret = -EOVERFLOW; - - if (ret < 0) - req_set_fail(req); - io_req_queue_tw_complete(req, ret); -} - -static int io_msg_ring_data(struct io_kiocb *req) -{ - struct io_ring_ctx *target_ctx = req->file->private_data; - struct io_msg *msg = io_kiocb_to_cmd(req, struct io_msg); - - if (msg->src_fd || msg->dst_fd || msg->flags) - return -EINVAL; - - if (target_ctx->task_complete && current != target_ctx->submitter_task) { - init_task_work(&msg->tw, io_msg_tw_complete); - if (task_work_add(target_ctx->submitter_task, &msg->tw, - TWA_SIGNAL_NO_IPI)) - return -EOWNERDEAD; - - atomic_or(IORING_SQ_TASKRUN, &target_ctx->rings->sq_flags); - return IOU_ISSUE_SKIP_COMPLETE; - } - - if (io_post_aux_cqe(target_ctx, msg->user_data, msg->len, 0)) - return 0; - - return -EOVERFLOW; -} - -static void io_double_unlock_ctx(struct io_ring_ctx *octx, - unsigned int issue_flags) +static void io_double_unlock_ctx(struct io_ring_ctx *octx) { mutex_unlock(&octx->uring_lock); } @@ -100,6 +47,97 @@ static int io_double_lock_ctx(struct io_ring_ctx *octx, return 0; } +void io_msg_ring_cleanup(struct io_kiocb *req) +{ + struct io_msg *msg = io_kiocb_to_cmd(req, struct io_msg); + + if (WARN_ON_ONCE(!msg->src_file)) + return; + + fput(msg->src_file); + msg->src_file = NULL; +} + +static inline bool io_msg_need_remote(struct io_ring_ctx *target_ctx) +{ + if (!target_ctx->task_complete) + return false; + return current != target_ctx->submitter_task; +} + +static int io_msg_exec_remote(struct io_kiocb *req, task_work_func_t func) +{ + struct io_ring_ctx *ctx = req->file->private_data; + struct io_msg *msg = io_kiocb_to_cmd(req, struct io_msg); + struct task_struct *task = READ_ONCE(ctx->submitter_task); + + if (unlikely(!task)) + return -EOWNERDEAD; + + init_task_work(&msg->tw, func); + if (task_work_add(ctx->submitter_task, &msg->tw, TWA_SIGNAL)) + return -EOWNERDEAD; + + return IOU_ISSUE_SKIP_COMPLETE; +} + +static void io_msg_tw_complete(struct callback_head *head) +{ + struct io_msg *msg = container_of(head, struct io_msg, tw); + struct io_kiocb *req = cmd_to_io_kiocb(msg); + struct io_ring_ctx *target_ctx = req->file->private_data; + int ret = 0; + + if (current->flags & PF_EXITING) { + ret = -EOWNERDEAD; + } else { + /* + * If the target ring is using IOPOLL mode, then we need to be + * holding the uring_lock for posting completions. Other ring + * types rely on the regular completion locking, which is + * handled while posting. + */ + if (target_ctx->flags & IORING_SETUP_IOPOLL) + mutex_lock(&target_ctx->uring_lock); + if (!io_post_aux_cqe(target_ctx, msg->user_data, msg->len, 0)) + ret = -EOVERFLOW; + if (target_ctx->flags & IORING_SETUP_IOPOLL) + mutex_unlock(&target_ctx->uring_lock); + } + + if (ret < 0) + req_set_fail(req); + io_req_queue_tw_complete(req, ret); +} + +static int io_msg_ring_data(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_ring_ctx *target_ctx = req->file->private_data; + struct io_msg *msg = io_kiocb_to_cmd(req, struct io_msg); + int ret; + + if (msg->src_fd || msg->dst_fd || msg->flags) + return -EINVAL; + if (target_ctx->flags & IORING_SETUP_R_DISABLED) + return -EBADFD; + + if (io_msg_need_remote(target_ctx)) + return io_msg_exec_remote(req, io_msg_tw_complete); + + ret = -EOVERFLOW; + if (target_ctx->flags & IORING_SETUP_IOPOLL) { + if (unlikely(io_double_lock_ctx(target_ctx, issue_flags))) + return -EAGAIN; + if (io_post_aux_cqe(target_ctx, msg->user_data, msg->len, 0)) + ret = 0; + io_double_unlock_ctx(target_ctx); + } else { + if (io_post_aux_cqe(target_ctx, msg->user_data, msg->len, 0)) + ret = 0; + } + return ret; +} + static struct file *io_msg_grab_file(struct io_kiocb *req, unsigned int issue_flags) { struct io_msg *msg = io_kiocb_to_cmd(req, struct io_msg); @@ -148,7 +186,7 @@ static int io_msg_install_complete(struct io_kiocb *req, unsigned int issue_flag if (!io_post_aux_cqe(target_ctx, msg->user_data, msg->len, 0)) ret = -EOVERFLOW; out_unlock: - io_double_unlock_ctx(target_ctx, issue_flags); + io_double_unlock_ctx(target_ctx); return ret; } @@ -174,6 +212,8 @@ static int io_msg_send_fd(struct io_kiocb *req, unsigned int issue_flags) if (target_ctx == ctx) return -EINVAL; + if (target_ctx->flags & IORING_SETUP_R_DISABLED) + return -EBADFD; if (!src_file) { src_file = io_msg_grab_file(req, issue_flags); if (!src_file) @@ -182,14 +222,8 @@ static int io_msg_send_fd(struct io_kiocb *req, unsigned int issue_flags) req->flags |= REQ_F_NEED_CLEANUP; } - if (target_ctx->task_complete && current != target_ctx->submitter_task) { - init_task_work(&msg->tw, io_msg_tw_fd_complete); - if (task_work_add(target_ctx->submitter_task, &msg->tw, - TWA_SIGNAL)) - return -EOWNERDEAD; - - return IOU_ISSUE_SKIP_COMPLETE; - } + if (io_msg_need_remote(target_ctx)) + return io_msg_exec_remote(req, io_msg_tw_fd_complete); return io_msg_install_complete(req, issue_flags); } @@ -224,7 +258,7 @@ int io_msg_ring(struct io_kiocb *req, unsigned int issue_flags) switch (msg->cmd) { case IORING_MSG_DATA: - ret = io_msg_ring_data(req); + ret = io_msg_ring_data(req, issue_flags); break; case IORING_MSG_SEND_FD: ret = io_msg_send_fd(req, issue_flags);