io_uring: cancel all task's requests on exit

to #28736503

commit 44e728b8aae0bb6d4229129083974f9dea43f50b upstream

If a process is going away, io_uring_flush() will cancel only 1
request with a matching pid. Cancel all of them
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NXiaoguang Wang <xiaoguang.wang@linux.alibaba.com>
Acked-by: NJoseph Qi <joseph.qi@linux.alibaba.com>

fs/io-wq.c

@@ -1024,20 +1024,6 @@ enum io_wq_cancel io_wq_cancel_work(struct io_wq *wq, struct io_wq_work *cwork)
 	return io_wq_cancel_cb(wq, io_wq_io_cb_cancel_data, (void *)cwork, false);
 }
 
-static bool io_wq_pid_match(struct io_wq_work *work, void *data)
-{
-	pid_t pid = (pid_t) (unsigned long) data;
-
-	return work->task_pid == pid;
-}
-
-enum io_wq_cancel io_wq_cancel_pid(struct io_wq *wq, pid_t pid)
-{
-	void *data = (void *) (unsigned long) pid;
-
-	return io_wq_cancel_cb(wq, io_wq_pid_match, data, false);
-}
-
 struct io_wq *io_wq_create(unsigned bounded, struct io_wq_data *data)
 {
 	int ret = -ENOMEM, node;

fs/io-wq.h

@@ -125,7 +125,6 @@ static inline bool io_wq_is_hashed(struct io_wq_work *work)
 
 void io_wq_cancel_all(struct io_wq *wq);
 enum io_wq_cancel io_wq_cancel_work(struct io_wq *wq, struct io_wq_work *cwork);
-enum io_wq_cancel io_wq_cancel_pid(struct io_wq *wq, pid_t pid);
 
 typedef bool (work_cancel_fn)(struct io_wq_work *, void *);
 

fs/io_uring.c

@@ -7400,6 +7400,13 @@ static void io_uring_cancel_files(struct io_ring_ctx *ctx,
 	}
 }
 
+static bool io_cancel_pid_cb(struct io_wq_work *work, void *data)
+{
+	pid_t pid = (pid_t) (unsigned long) data;
+
+	return work->task_pid == pid;
+}
+
 static int io_uring_flush(struct file *file, void *data)
 {
 	struct io_ring_ctx *ctx = file->private_data;
@@ -7409,8 +7416,11 @@ static int io_uring_flush(struct file *file, void *data)
 	/*
 	 * If the task is going away, cancel work it may have pending
 	 */
-	if (fatal_signal_pending(current) || (current->flags & PF_EXITING))
-		io_wq_cancel_pid(ctx->io_wq, task_pid_vnr(current));
+	if (fatal_signal_pending(current) || (current->flags & PF_EXITING)) {
+		void *data = (void *) (unsigned long)task_pid_vnr(current);
+
+		io_wq_cancel_cb(ctx->io_wq, io_cancel_pid_cb, data, true);
+	}
 
 	return 0;
 }