[PATCH] tun: fix blocking read

From: Timur Celik
Date: Sat Feb 23 2019 - 06:53:37 EST


This patch moves setting of the current state into the loop. Otherwise
the task may end up in a busy wait loop if none of the break conditions
are met.

Signed-off-by: Timur Celik <mail@xxxxxxxxxxxxx>
---
drivers/net/tun.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index fed298c0cb39..d291762b9e9d 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -2167,9 +2167,9 @@ static void *tun_ring_recv(struct tun_file *tfile, int noblock, int *err)
}

add_wait_queue(&tfile->wq.wait, &wait);
- current->state = TASK_INTERRUPTIBLE;

while (1) {
+ set_current_state(TASK_INTERRUPTIBLE);
ptr = ptr_ring_consume(&tfile->tx_ring);
if (ptr)
break;
@@ -2185,7 +2185,7 @@ static void *tun_ring_recv(struct tun_file *tfile, int noblock, int *err)
schedule();
}

- current->state = TASK_RUNNING;
+ set_current_state(TASK_RUNNING);
remove_wait_queue(&tfile->wq.wait, &wait);

out:
--
2.20.1