[PATCH 4/5] thread_with_file: allow ioctls against these files

[Darrick J. Wong]

From: Darrick J. Wong <djwong@xxxxxxxxxx>

Make it so that a thread_with_stdio user can handle ioctls against the
file descriptor.

Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx>
Signed-off-by: Kent Overstreet <kent.overstreet@xxxxxxxxx>
---
 include/linux/thread_with_file.h |    1 +
 lib/thread_with_file.c           |   12 ++++++++++++
 2 files changed, 13 insertions(+)


diff --git a/include/linux/thread_with_file.h b/include/linux/thread_with_file.h
index 445b1b12a0bd6..33770938d5d9a 100644
--- a/include/linux/thread_with_file.h
+++ b/include/linux/thread_with_file.h
@@ -57,6 +57,7 @@ struct thread_with_stdio;
 struct thread_with_stdio_ops {
 	void (*exit)(struct thread_with_stdio *);
 	void (*fn)(struct thread_with_stdio *);
+	long (*unlocked_ioctl)(struct thread_with_stdio *, unsigned int, unsigned long);
 };
 
 struct thread_with_stdio {
diff --git a/lib/thread_with_file.c b/lib/thread_with_file.c
index 2edf33c3e7dc5..8b129744a48a3 100644
--- a/lib/thread_with_file.c
+++ b/lib/thread_with_file.c
@@ -379,12 +379,23 @@ static __poll_t thread_with_stdout_poll(struct file *file, struct poll_table_str
 	return mask;
 }
 
+static long thread_with_stdio_ioctl(struct file *file, unsigned int cmd, unsigned long p)
+{
+	struct thread_with_stdio *thr =
+		container_of(file->private_data, struct thread_with_stdio, thr);
+
+	if (thr->ops->unlocked_ioctl)
+		return thr->ops->unlocked_ioctl(thr, cmd, p);
+	return -ENOTTY;
+}
+
 static const struct file_operations thread_with_stdio_fops = {
 	.llseek		= no_llseek,
 	.read		= thread_with_stdio_read,
 	.write		= thread_with_stdio_write,
 	.poll		= thread_with_stdio_poll,
 	.release	= thread_with_stdio_release,
+	.unlocked_ioctl	= thread_with_stdio_ioctl,
 };
 
 static const struct file_operations thread_with_stdout_fops = {
@@ -392,6 +403,7 @@ static const struct file_operations thread_with_stdout_fops = {
 	.read		= thread_with_stdio_read,
 	.poll		= thread_with_stdout_poll,
 	.release	= thread_with_stdio_release,
+	.unlocked_ioctl	= thread_with_stdio_ioctl,
 };
 
 static int thread_with_stdio_fn(void *arg)