From: Pavel Begunkov Date: Mon, 1 Mar 2021 13:02:15 +0000 (+0000) Subject: io_uring: kill sqo_dead and sqo submission halting X-Git-Tag: microblaze-v5.14~446^2~18 X-Git-Url: http://git.monstr.eu/?a=commitdiff_plain;h=70aacfe66136809d7f080f89c492c278298719f4;p=linux-2.6-microblaze.git io_uring: kill sqo_dead and sqo submission halting As SQPOLL task doesn't poke into ->sqo_task anymore, there is no need to kill the sqo when the master task exits. Before it was necessary to avoid races accessing sqo_task->files with removing them. Signed-off-by: Pavel Begunkov [axboe: don't forget to enable SQPOLL before exit, if started disabled] Signed-off-by: Jens Axboe --- diff --git a/fs/io_uring.c b/fs/io_uring.c index eb4bc8967178..6090a380e903 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -338,7 +338,6 @@ struct io_ring_ctx { unsigned int drain_next: 1; unsigned int eventfd_async: 1; unsigned int restricted: 1; - unsigned int sqo_dead: 1; unsigned int sqo_exec: 1; /* @@ -1967,7 +1966,7 @@ static void __io_req_task_submit(struct io_kiocb *req) /* ctx stays valid until unlock, even if we drop all ours ctx->refs */ mutex_lock(&ctx->uring_lock); - if (!ctx->sqo_dead && !(current->flags & PF_EXITING) && !current->in_execve) + if (!(current->flags & PF_EXITING) && !current->in_execve) __io_queue_sqe(req); else __io_req_task_cancel(req, -EFAULT); @@ -6578,8 +6577,7 @@ static int __io_sq_thread(struct io_ring_ctx *ctx, bool cap_entries) if (!list_empty(&ctx->iopoll_list)) io_do_iopoll(ctx, &nr_events, 0); - if (to_submit && !ctx->sqo_dead && - likely(!percpu_ref_is_dying(&ctx->refs))) + if (to_submit && likely(!percpu_ref_is_dying(&ctx->refs))) ret = io_submit_sqes(ctx, to_submit); mutex_unlock(&ctx->uring_lock); } @@ -7818,7 +7816,7 @@ static int io_sq_thread_fork(struct io_sq_data *sqd, struct io_ring_ctx *ctx) clear_bit(IO_SQ_THREAD_SHOULD_STOP, &sqd->state); reinit_completion(&sqd->completion); - ctx->sqo_dead = ctx->sqo_exec = 0; + ctx->sqo_exec = 0; sqd->task_pid = current->pid; current->flags |= PF_IO_WORKER; ret = io_wq_fork_thread(io_sq_thread, sqd); @@ -8529,10 +8527,6 @@ static void io_ring_ctx_wait_and_kill(struct io_ring_ctx *ctx) { mutex_lock(&ctx->uring_lock); percpu_ref_kill(&ctx->refs); - - if (WARN_ON_ONCE((ctx->flags & IORING_SETUP_SQPOLL) && !ctx->sqo_dead)) - ctx->sqo_dead = 1; - /* if force is set, the ring is going away. always drop after that */ ctx->cq_overflow_flushed = 1; if (ctx->rings) @@ -8692,19 +8686,6 @@ static void io_uring_cancel_files(struct io_ring_ctx *ctx, } } -static void io_disable_sqo_submit(struct io_ring_ctx *ctx) -{ - mutex_lock(&ctx->uring_lock); - ctx->sqo_dead = 1; - if (ctx->flags & IORING_SETUP_R_DISABLED) - io_sq_offload_start(ctx); - mutex_unlock(&ctx->uring_lock); - - /* make sure callers enter the ring to get error */ - if (ctx->rings) - io_ring_set_wakeup_flag(ctx); -} - /* * We need to iteratively cancel requests, in case a request has dependent * hard links. These persist even for failure of cancelations, hence keep @@ -8717,7 +8698,11 @@ static void io_uring_cancel_task_requests(struct io_ring_ctx *ctx, bool did_park = false; if ((ctx->flags & IORING_SETUP_SQPOLL) && ctx->sq_data) { - io_disable_sqo_submit(ctx); + /* never started, nothing to cancel */ + if (ctx->flags & IORING_SETUP_R_DISABLED) { + io_sq_offload_start(ctx); + return; + } did_park = io_sq_thread_park(ctx->sq_data); if (did_park) { task = ctx->sq_data->thread; @@ -8838,7 +8823,6 @@ static void io_uring_cancel_sqpoll(struct io_ring_ctx *ctx) if (!sqd) return; - io_disable_sqo_submit(ctx); if (!io_sq_thread_park(sqd)) return; tctx = ctx->sq_data->thread->io_uring; @@ -8883,7 +8867,6 @@ void __io_uring_task_cancel(void) /* make sure overflow events are dropped */ atomic_inc(&tctx->in_idle); - /* trigger io_disable_sqo_submit() */ if (tctx->sqpoll) { struct file *file; unsigned long index; @@ -8996,22 +8979,14 @@ static int io_sqpoll_wait_sq(struct io_ring_ctx *ctx) do { if (!io_sqring_full(ctx)) break; - prepare_to_wait(&ctx->sqo_sq_wait, &wait, TASK_INTERRUPTIBLE); - if (unlikely(ctx->sqo_dead)) { - ret = -EOWNERDEAD; - goto out; - } - if (!io_sqring_full(ctx)) break; - schedule(); } while (!signal_pending(current)); finish_wait(&ctx->sqo_sq_wait, &wait); -out: return ret; } @@ -9093,8 +9068,6 @@ SYSCALL_DEFINE6(io_uring_enter, unsigned int, fd, u32, to_submit, ctx->sqo_exec = 0; } ret = -EOWNERDEAD; - if (unlikely(ctx->sqo_dead)) - goto out; if (flags & IORING_ENTER_SQ_WAKEUP) wake_up(&ctx->sq_data->wait); if (flags & IORING_ENTER_SQ_WAIT) { @@ -9466,7 +9439,6 @@ static int io_uring_create(unsigned entries, struct io_uring_params *p, */ ret = io_uring_install_fd(ctx, file); if (ret < 0) { - io_disable_sqo_submit(ctx); /* fput will clean it up */ fput(file); return ret; @@ -9475,7 +9447,6 @@ static int io_uring_create(unsigned entries, struct io_uring_params *p, trace_io_uring_create(ret, ctx, p->sq_entries, p->cq_entries, p->flags); return ret; err: - io_disable_sqo_submit(ctx); io_ring_ctx_wait_and_kill(ctx); return ret; }