From 041474885e9707a38fad081abe30159eb6d463f9 Mon Sep 17 00:00:00 2001 From: Stefan Metzmacher Date: Sun, 7 Mar 2021 11:54:29 +0100 Subject: [PATCH] io_uring: kill io_sq_thread_fork() and return -EOWNERDEAD if the sq_thread is gone This brings the behavior back in line with what 5.11 and earlier did, and this is no longer needed with the improved handling of creds not needing to do unshare(). Signed-off-by: Stefan Metzmacher Signed-off-by: Jens Axboe --- fs/io_uring.c | 31 +++---------------------------- 1 file changed, 3 insertions(+), 28 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index 4d3333ca27a3..7cf96be691d8 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -336,7 +336,6 @@ struct io_ring_ctx { unsigned int drain_next: 1; unsigned int eventfd_async: 1; unsigned int restricted: 1; - unsigned int sqo_exec: 1; /* * Ring buffer of indices into array of io_uring_sqe, which is @@ -6786,7 +6785,6 @@ static int io_sq_thread(void *data) sqd->thread = NULL; list_for_each_entry(ctx, &sqd->ctx_list, sqd_list) { - ctx->sqo_exec = 1; io_ring_set_wakeup_flag(ctx); } @@ -7846,26 +7844,6 @@ void __io_uring_free(struct task_struct *tsk) tsk->io_uring = NULL; } -static int io_sq_thread_fork(struct io_sq_data *sqd, struct io_ring_ctx *ctx) -{ - struct task_struct *tsk; - int ret; - - clear_bit(IO_SQ_THREAD_SHOULD_STOP, &sqd->state); - reinit_completion(&sqd->parked); - ctx->sqo_exec = 0; - sqd->task_pid = current->pid; - tsk = create_io_thread(io_sq_thread, sqd, NUMA_NO_NODE); - if (IS_ERR(tsk)) - return PTR_ERR(tsk); - ret = io_uring_alloc_task_context(tsk, ctx); - if (ret) - set_bit(IO_SQ_THREAD_SHOULD_STOP, &sqd->state); - sqd->thread = tsk; - wake_up_new_task(tsk); - return ret; -} - static int io_sq_offload_create(struct io_ring_ctx *ctx, struct io_uring_params *p) { @@ -9199,13 +9177,10 @@ SYSCALL_DEFINE6(io_uring_enter, unsigned int, fd, u32, to_submit, if (ctx->flags & IORING_SETUP_SQPOLL) { io_cqring_overflow_flush(ctx, false, NULL, NULL); - if (unlikely(ctx->sqo_exec)) { - ret = io_sq_thread_fork(ctx->sq_data, ctx); - if (ret) - goto out; - ctx->sqo_exec = 0; - } ret = -EOWNERDEAD; + if (unlikely(ctx->sq_data->thread == NULL)) { + goto out; + } if (flags & IORING_ENTER_SQ_WAKEUP) wake_up(&ctx->sq_data->wait); if (flags & IORING_ENTER_SQ_WAIT) {