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Commit 762dfd10 authored by Pavel Shilovsky's avatar Pavel Shilovsky Committed by Steve French
Browse files

CIFS: Cleanup demupltiplex thread exiting code 



Reviewed-and-Tested-by: default avatarJeff Layton <jlayton@redhat.com>
Signed-off-by: default avatarPavel Shilovsky <piastryyy@gmail.com>
Signed-off-by: default avatarSteve French <sfrench@us.ibm.com>
parent ad69bae1

fs/cifs/connect.c

+96 −77
Original line number Diff line number Diff line
@@ -531,6 +531,101 @@ multi_t2_fnd: 
	return ret;

}



static void clean_demultiplex_info(struct TCP_Server_Info *server)

{

	int length;



	/* take it off the list, if it's not already */

	spin_lock(&cifs_tcp_ses_lock);

	list_del_init(&server->tcp_ses_list);

	spin_unlock(&cifs_tcp_ses_lock);



	spin_lock(&GlobalMid_Lock);

	server->tcpStatus = CifsExiting;

	spin_unlock(&GlobalMid_Lock);

	wake_up_all(&server->response_q);



	/*

	 * Check if we have blocked requests that need to free. Note that

	 * cifs_max_pending is normally 50, but can be set at module install

	 * time to as little as two.

	 */

	spin_lock(&GlobalMid_Lock);

	if (atomic_read(&server->inFlight) >= cifs_max_pending)

		atomic_set(&server->inFlight, cifs_max_pending - 1);

	/*

	 * We do not want to set the max_pending too low or we could end up

	 * with the counter going negative.

	 */

	spin_unlock(&GlobalMid_Lock);

	/*

	 * Although there should not be any requests blocked on this queue it

	 * can not hurt to be paranoid and try to wake up requests that may

	 * haven been blocked when more than 50 at time were on the wire to the

	 * same server - they now will see the session is in exit state and get

	 * out of SendReceive.

	 */

	wake_up_all(&server->request_q);

	/* give those requests time to exit */

	msleep(125);



	if (server->ssocket) {

		sock_release(server->ssocket);

		server->ssocket = NULL;

	}



	if (!list_empty(&server->pending_mid_q)) {

		struct list_head dispose_list;

		struct mid_q_entry *mid_entry;

		struct list_head *tmp, *tmp2;



		INIT_LIST_HEAD(&dispose_list);

		spin_lock(&GlobalMid_Lock);

		list_for_each_safe(tmp, tmp2, &server->pending_mid_q) {

			mid_entry = list_entry(tmp, struct mid_q_entry, qhead);

			cFYI(1, "Clearing mid 0x%x", mid_entry->mid);

			mid_entry->midState = MID_SHUTDOWN;

			list_move(&mid_entry->qhead, &dispose_list);

		}

		spin_unlock(&GlobalMid_Lock);



		/* now walk dispose list and issue callbacks */

		list_for_each_safe(tmp, tmp2, &dispose_list) {

			mid_entry = list_entry(tmp, struct mid_q_entry, qhead);

			cFYI(1, "Callback mid 0x%x", mid_entry->mid);

			list_del_init(&mid_entry->qhead);

			mid_entry->callback(mid_entry);

		}

		/* 1/8th of sec is more than enough time for them to exit */

		msleep(125);

	}



	if (!list_empty(&server->pending_mid_q)) {

		/*

		 * mpx threads have not exited yet give them at least the smb

		 * send timeout time for long ops.

		 *

		 * Due to delays on oplock break requests, we need to wait at

		 * least 45 seconds before giving up on a request getting a

		 * response and going ahead and killing cifsd.

		 */

		cFYI(1, "Wait for exit from demultiplex thread");

		msleep(46000);

		/*

		 * If threads still have not exited they are probably never

		 * coming home not much else we can do but free the memory.

		 */

	}



	kfree(server->hostname);

	kfree(server);



	length = atomic_dec_return(&tcpSesAllocCount);

	if (length > 0)

		mempool_resize(cifs_req_poolp, length + cifs_min_rcv,

				GFP_KERNEL);

}



static int

cifs_demultiplex_thread(void *p)

{
@@ -541,7 +636,6 @@ cifs_demultiplex_thread(void *p) 
	struct smb_hdr *smb_buffer = NULL;

	struct msghdr smb_msg;

	struct kvec iov;

	struct list_head *tmp, *tmp2;

	struct task_struct *task_to_wake = NULL;

	struct mid_q_entry *mid_entry;

	bool isLargeBuf = false;
@@ -678,88 +772,13 @@ incomplete_rcv: 
		}

	} /* end while !EXITING */



	/* take it off the list, if it's not already */

	spin_lock(&cifs_tcp_ses_lock);

	list_del_init(&server->tcp_ses_list);

	spin_unlock(&cifs_tcp_ses_lock);



	spin_lock(&GlobalMid_Lock);

	server->tcpStatus = CifsExiting;

	spin_unlock(&GlobalMid_Lock);

	wake_up_all(&server->response_q);



	/* check if we have blocked requests that need to free */

	/* Note that cifs_max_pending is normally 50, but

	can be set at module install time to as little as two */

	spin_lock(&GlobalMid_Lock);

	if (atomic_read(&server->inFlight) >= cifs_max_pending)

		atomic_set(&server->inFlight, cifs_max_pending - 1);

	/* We do not want to set the max_pending too low or we

	could end up with the counter going negative */

	spin_unlock(&GlobalMid_Lock);

	/* Although there should not be any requests blocked on

	this queue it can not hurt to be paranoid and try to wake up requests

	that may haven been blocked when more than 50 at time were on the wire

	to the same server - they now will see the session is in exit state

	and get out of SendReceive.  */

	wake_up_all(&server->request_q);

	/* give those requests time to exit */

	msleep(125);



	if (server->ssocket) {

		sock_release(server->ssocket);

		server->ssocket = NULL;

	}

	/* buffer usually freed in free_mid - need to free it here on exit */

	cifs_buf_release(bigbuf);

	if (smallbuf) /* no sense logging a debug message if NULL */

		cifs_small_buf_release(smallbuf);



	if (!list_empty(&server->pending_mid_q)) {

		struct list_head dispose_list;



		INIT_LIST_HEAD(&dispose_list);

		spin_lock(&GlobalMid_Lock);

		list_for_each_safe(tmp, tmp2, &server->pending_mid_q) {

			mid_entry = list_entry(tmp, struct mid_q_entry, qhead);

			cFYI(1, "Clearing mid 0x%x", mid_entry->mid);

			mid_entry->midState = MID_SHUTDOWN;

			list_move(&mid_entry->qhead, &dispose_list);

		}

		spin_unlock(&GlobalMid_Lock);



		/* now walk dispose list and issue callbacks */

		list_for_each_safe(tmp, tmp2, &dispose_list) {

			mid_entry = list_entry(tmp, struct mid_q_entry, qhead);

			cFYI(1, "Callback mid 0x%x", mid_entry->mid);

			list_del_init(&mid_entry->qhead);

			mid_entry->callback(mid_entry);

		}

		/* 1/8th of sec is more than enough time for them to exit */

		msleep(125);

	}



	if (!list_empty(&server->pending_mid_q)) {

		/* mpx threads have not exited yet give them

		at least the smb send timeout time for long ops */

		/* due to delays on oplock break requests, we need

		to wait at least 45 seconds before giving up

		on a request getting a response and going ahead

		and killing cifsd */

		cFYI(1, "Wait for exit from demultiplex thread");

		msleep(46000);

		/* if threads still have not exited they are probably never

		coming home not much else we can do but free the memory */

	}



	kfree(server->hostname);

	task_to_wake = xchg(&server->tsk, NULL);

	kfree(server);



	length = atomic_dec_return(&tcpSesAllocCount);

	if (length  > 0)

		mempool_resize(cifs_req_poolp, length + cifs_min_rcv,

				GFP_KERNEL);

	clean_demultiplex_info(server);



	/* if server->tsk was NULL then wait for a signal before exiting */

	if (!task_to_wake) {