@@ -58,6 +58,25 @@ void io_msg_ring_cleanup(struct io_kiocb *req)
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);
+
+ 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);
@@ -96,15 +115,8 @@ static int io_msg_ring_data(struct io_kiocb *req, unsigned int issue_flags)
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_msg_need_remote(target_ctx))
+ return io_msg_exec_remote(req, io_msg_tw_complete);
ret = -EOVERFLOW;
if (target_ctx->flags & IORING_SETUP_IOPOLL) {
@@ -202,14 +214,8 @@ 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);
}
There is a couple of problems with queueing a tw in io_msg_ring_data() for remote execution. First, once we queue it the target ring can go away and so setting IORING_SQ_TASKRUN there is not safe. Secondly, the userspace might not expect IORING_SQ_TASKRUN. Extract a helper and uniformly use TWA_SIGNAL without TWA_SIGNAL_NO_IPI tricks for now, just as it was done in the original patch. Fixes: 6d043ee1164ca ("io_uring: do msg_ring in target task via tw") Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> --- io_uring/msg_ring.c | 40 +++++++++++++++++++++++----------------- 1 file changed, 23 insertions(+), 17 deletions(-)