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Diffstat (limited to 'fs/io_uring.c')
-rw-r--r--fs/io_uring.c62
1 files changed, 53 insertions, 9 deletions
diff --git a/fs/io_uring.c b/fs/io_uring.c
index f39671a0d84f..2f305c097bd5 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -262,6 +262,7 @@ struct io_ring_ctx {
 		unsigned int		drain_next: 1;
 		unsigned int		eventfd_async: 1;
 		unsigned int		restricted: 1;
+		unsigned int		sqo_dead: 1;
 
 		/*
 		 * Ring buffer of indices into array of io_uring_sqe, which is
@@ -2160,12 +2161,11 @@ static void io_req_task_cancel(struct callback_head *cb)
 static void __io_req_task_submit(struct io_kiocb *req)
 {
 	struct io_ring_ctx *ctx = req->ctx;
-	bool fail;
 
-	fail = __io_sq_thread_acquire_mm(ctx) ||
-		__io_sq_thread_acquire_files(ctx);
 	mutex_lock(&ctx->uring_lock);
-	if (!fail)
+	if (!ctx->sqo_dead &&
+	    !__io_sq_thread_acquire_mm(ctx) &&
+	    !__io_sq_thread_acquire_files(ctx))
 		__io_queue_sqe(req, NULL);
 	else
 		__io_req_task_cancel(req, -EFAULT);
@@ -6954,7 +6954,8 @@ 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 && likely(!percpu_ref_is_dying(&ctx->refs)))
+		if (to_submit && !ctx->sqo_dead &&
+		    likely(!percpu_ref_is_dying(&ctx->refs)))
 			ret = io_submit_sqes(ctx, to_submit);
 		mutex_unlock(&ctx->uring_lock);
 	}
@@ -8712,6 +8713,10 @@ 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)
@@ -8874,6 +8879,18 @@ static void __io_uring_cancel_task_requests(struct io_ring_ctx *ctx,
 	}
 }
 
+static void io_disable_sqo_submit(struct io_ring_ctx *ctx)
+{
+	WARN_ON_ONCE(ctx->sqo_task != current);
+
+	mutex_lock(&ctx->uring_lock);
+	ctx->sqo_dead = 1;
+	mutex_unlock(&ctx->uring_lock);
+
+	/* make sure callers enter the ring to get error */
+	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
@@ -8885,6 +8902,8 @@ static void io_uring_cancel_task_requests(struct io_ring_ctx *ctx,
 	struct task_struct *task = current;
 
 	if ((ctx->flags & IORING_SETUP_SQPOLL) && ctx->sq_data) {
+		/* for SQPOLL only sqo_task has task notes */
+		io_disable_sqo_submit(ctx);
 		task = ctx->sq_data->thread;
 		atomic_inc(&task->io_uring->in_idle);
 		io_sq_thread_park(ctx->sq_data);
@@ -9056,6 +9075,7 @@ void __io_uring_task_cancel(void)
 static int io_uring_flush(struct file *file, void *data)
 {
 	struct io_uring_task *tctx = current->io_uring;
+	struct io_ring_ctx *ctx = file->private_data;
 
 	if (!tctx)
 		return 0;
@@ -9071,7 +9091,16 @@ static int io_uring_flush(struct file *file, void *data)
 	if (atomic_long_read(&file->f_count) != 2)
 		return 0;
 
-	io_uring_del_task_file(file);
+	if (ctx->flags & IORING_SETUP_SQPOLL) {
+		/* there is only one file note, which is owned by sqo_task */
+		WARN_ON_ONCE((ctx->sqo_task == current) ==
+			     !xa_load(&tctx->xa, (unsigned long)file));
+
+		io_disable_sqo_submit(ctx);
+	}
+
+	if (!(ctx->flags & IORING_SETUP_SQPOLL) || ctx->sqo_task == current)
+		io_uring_del_task_file(file);
 	return 0;
 }
 
@@ -9145,8 +9174,9 @@ static unsigned long io_uring_nommu_get_unmapped_area(struct file *file,
 
 #endif /* !CONFIG_MMU */
 
-static void io_sqpoll_wait_sq(struct io_ring_ctx *ctx)
+static int io_sqpoll_wait_sq(struct io_ring_ctx *ctx)
 {
+	int ret = 0;
 	DEFINE_WAIT(wait);
 
 	do {
@@ -9155,6 +9185,11 @@ static void io_sqpoll_wait_sq(struct io_ring_ctx *ctx)
 
 		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;
 
@@ -9162,6 +9197,8 @@ static void io_sqpoll_wait_sq(struct io_ring_ctx *ctx)
 	} while (!signal_pending(current));
 
 	finish_wait(&ctx->sqo_sq_wait, &wait);
+out:
+	return ret;
 }
 
 static int io_get_ext_arg(unsigned flags, const void __user *argp, size_t *argsz,
@@ -9235,10 +9272,16 @@ 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);
 
+		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)
-			io_sqpoll_wait_sq(ctx);
+		if (flags & IORING_ENTER_SQ_WAIT) {
+			ret = io_sqpoll_wait_sq(ctx);
+			if (ret)
+				goto out;
+		}
 		submitted = to_submit;
 	} else if (to_submit) {
 		ret = io_uring_add_task_file(ctx, f.file);
@@ -9665,6 +9708,7 @@ 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;
 }