Commit a14c5738 authored by Namjae Jeon's avatar Namjae Jeon Committed by Steve French
Browse files

ksmbd: use wait_event instead of schedule_timeout() 



ksmbd threads eating masses of cputime when connection is disconnected.
If connection is disconnected, ksmbd thread waits for pending requests
to be processed using schedule_timeout. schedule_timeout() incorrectly
is used, and it is more efficient to use wait_event/wake_up than to check
r_count every time with timeout.

Signed-off-by: default avatarNamjae Jeon <linkinjeon@kernel.org>
Reviewed-by: default avatarHyunchul Lee <hyc.lee@gmail.com>
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
parent 17ea92a9

fs/ksmbd/connection.c

+3 −3
Original line number Diff line number Diff line
@@ -66,6 +66,7 @@ struct ksmbd_conn *ksmbd_conn_alloc(void) 
	conn->outstanding_credits = 0;



	init_waitqueue_head(&conn->req_running_q);

	init_waitqueue_head(&conn->r_count_q);

	INIT_LIST_HEAD(&conn->conns_list);

	INIT_LIST_HEAD(&conn->requests);

	INIT_LIST_HEAD(&conn->async_requests);
@@ -165,7 +166,6 @@ int ksmbd_conn_write(struct ksmbd_work *work) 
	struct kvec iov[3];

	int iov_idx = 0;



	ksmbd_conn_try_dequeue_request(work);

	if (!work->response_buf) {

		pr_err("NULL response header\n");

		return -EINVAL;
@@ -347,8 +347,8 @@ int ksmbd_conn_handler_loop(void *p) 


out:

	/* Wait till all reference dropped to the Server object*/

	while (atomic_read(&conn->r_count) > 0)

		schedule_timeout(HZ);

	wait_event(conn->r_count_q, atomic_read(&conn->r_count) == 0);





	unload_nls(conn->local_nls);

	if (default_conn_ops.terminate_fn)

fs/ksmbd/connection.h

+1 −0
Original line number Diff line number Diff line
@@ -65,6 +65,7 @@ struct ksmbd_conn { 
	unsigned int			outstanding_credits;

	spinlock_t			credits_lock;

	wait_queue_head_t		req_running_q;

	wait_queue_head_t		r_count_q;

	/* Lock to protect requests list*/

	spinlock_t			request_lock;

	struct list_head		requests;

fs/ksmbd/oplock.c

+22 −13
Original line number Diff line number Diff line
@@ -615,18 +615,13 @@ static void __smb2_oplock_break_noti(struct work_struct *wk) 
	struct ksmbd_file *fp;



	fp = ksmbd_lookup_durable_fd(br_info->fid);

	if (!fp) {

		atomic_dec(&conn->r_count);

		ksmbd_free_work_struct(work);

		return;

	}

	if (!fp)

		goto out;



	if (allocate_oplock_break_buf(work)) {

		pr_err("smb2_allocate_rsp_buf failed! ");

		atomic_dec(&conn->r_count);

		ksmbd_fd_put(work, fp);

		ksmbd_free_work_struct(work);

		return;

		goto out;

	}



	rsp_hdr = smb2_get_msg(work->response_buf);
@@ -667,8 +662,16 @@ static void __smb2_oplock_break_noti(struct work_struct *wk) 


	ksmbd_fd_put(work, fp);

	ksmbd_conn_write(work);



out:

	ksmbd_free_work_struct(work);

	atomic_dec(&conn->r_count);

	/*

	 * Checking waitqueue to dropping pending requests on

	 * disconnection. waitqueue_active is safe because it

	 * uses atomic operation for condition.

	 */

	if (!atomic_dec_return(&conn->r_count) && waitqueue_active(&conn->r_count_q))

		wake_up(&conn->r_count_q);

}



/**
@@ -731,9 +734,7 @@ static void __smb2_lease_break_noti(struct work_struct *wk) 


	if (allocate_oplock_break_buf(work)) {

		ksmbd_debug(OPLOCK, "smb2_allocate_rsp_buf failed! ");

		ksmbd_free_work_struct(work);

		atomic_dec(&conn->r_count);

		return;

		goto out;

	}



	rsp_hdr = smb2_get_msg(work->response_buf);
@@ -771,8 +772,16 @@ static void __smb2_lease_break_noti(struct work_struct *wk) 
	inc_rfc1001_len(work->response_buf, 44);



	ksmbd_conn_write(work);



out:

	ksmbd_free_work_struct(work);

	atomic_dec(&conn->r_count);

	/*

	 * Checking waitqueue to dropping pending requests on

	 * disconnection. waitqueue_active is safe because it

	 * uses atomic operation for condition.

	 */

	if (!atomic_dec_return(&conn->r_count) && waitqueue_active(&conn->r_count_q))

		wake_up(&conn->r_count_q);

}



/**

fs/ksmbd/server.c

+7 −1
Original line number Diff line number Diff line
@@ -261,7 +261,13 @@ static void handle_ksmbd_work(struct work_struct *wk) 


	ksmbd_conn_try_dequeue_request(work);

	ksmbd_free_work_struct(work);

	atomic_dec(&conn->r_count);

	/*

	 * Checking waitqueue to dropping pending requests on

	 * disconnection. waitqueue_active is safe because it

	 * uses atomic operation for condition.

	 */

	if (!atomic_dec_return(&conn->r_count) && waitqueue_active(&conn->r_count_q))

		wake_up(&conn->r_count_q);

}



/**