[PATCH 28/29] ksmbd: sleep interruptibly in the durable handle scavenger

[Namjae Jeon <linkinjeon@kernel.org>]

The durable handle scavenger kthread waits up to DURABLE_HANDLE_MAX_TIMEOUT
(300 seconds) between scans using wait_event_timeout(), which sleeps in
TASK_UNINTERRUPTIBLE. When there are no durable handles pending expiry the
task stays in D state far longer than 120 seconds, so the hung task
detector prints a bogus "task ksmbd-durable-s blocked for more than 120
seconds" warning with a backtrace, even though the thread is only idle.

Use wait_event_interruptible_timeout() so the thread sleeps in
TASK_INTERRUPTIBLE, which the hung task detector ignores. This also suits
the already-freezable kthread. Treat a negative return (e.g. -ERESTARTSYS)
like a timeout when recomputing the next wake interval.

Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
---
 fs/smb/server/vfs_cache.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/smb/server/vfs_cache.c b/fs/smb/server/vfs_cache.c
index 7495166b0262..fde22742d193 100644
--- a/fs/smb/server/vfs_cache.c
+++ b/fs/smb/server/vfs_cache.c
@@ -1344,10 +1344,10 @@ static int ksmbd_durable_scavenger(void *dummy)
 		if (try_to_freeze())
 			continue;
 
-		remaining_jiffies = wait_event_timeout(dh_wq,
+		remaining_jiffies = wait_event_interruptible_timeout(dh_wq,
 				   ksmbd_durable_scavenger_alive() == false,
 				   __msecs_to_jiffies(min_timeout));
-		if (remaining_jiffies)
+		if ((long)remaining_jiffies > 0)
 			min_timeout = jiffies_to_msecs(remaining_jiffies);
 		else
 			min_timeout = DURABLE_HANDLE_MAX_TIMEOUT;
-- 
2.25.1