[PATCH v2] nsfs: fix wrong error code returned for pidns ioctls

[Zhihao Cheng]

When executing NS_GET_PID_FROM_PIDNS (or similar pidns ioctls), if the
target task cannot be found in the corresponding pid_ns, the error code
should be ESRCH instead of ENOTTY.

This bug was introduced when the extensible ioctl handling was added.
Without proper return, ret would be overwritten by the default case in
the extensible ioctl switch statement.

Fixes: a1d220d9dafa8 ("nsfs: iterate through mount namespaces")
Signed-off-by: Zhihao Cheng <chengzhihao1@xxxxxxxxxx>
---
v1->v2: Delete unnecessary blank line.
 fs/nsfs.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/nsfs.c b/fs/nsfs.c
index 51e8c9430477..160018c4fb36 100644
--- a/fs/nsfs.c
+++ b/fs/nsfs.c
@@ -266,7 +266,7 @@ static long ns_ioctl(struct file *filp, unsigned int ioctl,
 		else
 			tsk = find_task_by_pid_ns(arg, pid_ns);
 		if (!tsk)
-			break;
+			return ret;
 
 		switch (ioctl) {
 		case NS_GET_PID_FROM_PIDNS:
-- 
2.52.0