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Commit e9c18ae6 authored by Vitaly Kuznetsov's avatar Vitaly Kuznetsov Committed by Greg Kroah-Hartman
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Drivers: hv: util: move waiting for release to hv_utils_transport itself 



Waiting for release_event in all three drivers introduced issues on release
as on_reset() hook is not always called. E.g. if the device was never
opened we will never get the completion.

Move the waiting code to hvutil_transport_destroy() and make sure it is
only called when the device is open. hvt->lock serialization should
guarantee the absence of races.

Fixes: 5a66fecb ("Drivers: hv: util: kvp: Fix a rescind processing issue")
Fixes: 20951c75 ("Drivers: hv: util: Fcopy: Fix a rescind processing issue")
Fixes: d77044d1 ("Drivers: hv: util: Backup: Fix a rescind processing issue")

Reported-by: default avatarDexuan Cui <decui@microsoft.com>
Tested-by: default avatarDexuan Cui <decui@microsoft.com>
Signed-off-by: default avatarVitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: default avatarK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent dad72a1d

drivers/hv/hv_fcopy.c

+0 −4
Original line number Diff line number Diff line
@@ -71,7 +71,6 @@ static DECLARE_WORK(fcopy_send_work, fcopy_send_data); 
static const char fcopy_devname[] = "vmbus/hv_fcopy";

static u8 *recv_buffer;

static struct hvutil_transport *hvt;

static struct completion release_event;

/*

 * This state maintains the version number registered by the daemon.

 */
@@ -331,7 +330,6 @@ static void fcopy_on_reset(void) 


	if (cancel_delayed_work_sync(&fcopy_timeout_work))

		fcopy_respond_to_host(HV_E_FAIL);

	complete(&release_event);

}



int hv_fcopy_init(struct hv_util_service *srv)
@@ -339,7 +337,6 @@ int hv_fcopy_init(struct hv_util_service *srv) 
	recv_buffer = srv->recv_buffer;

	fcopy_transaction.recv_channel = srv->channel;



	init_completion(&release_event);

	/*

	 * When this driver loads, the user level daemon that

	 * processes the host requests may not yet be running.
@@ -361,5 +358,4 @@ void hv_fcopy_deinit(void) 
	fcopy_transaction.state = HVUTIL_DEVICE_DYING;

	cancel_delayed_work_sync(&fcopy_timeout_work);

	hvutil_transport_destroy(hvt);

	wait_for_completion(&release_event);

}

drivers/hv/hv_kvp.c

+0 −4
Original line number Diff line number Diff line
@@ -101,7 +101,6 @@ static DECLARE_WORK(kvp_sendkey_work, kvp_send_key); 
static const char kvp_devname[] = "vmbus/hv_kvp";

static u8 *recv_buffer;

static struct hvutil_transport *hvt;

static struct completion release_event;

/*

 * Register the kernel component with the user-level daemon.

 * As part of this registration, pass the LIC version number.
@@ -714,7 +713,6 @@ static void kvp_on_reset(void) 
	if (cancel_delayed_work_sync(&kvp_timeout_work))

		kvp_respond_to_host(NULL, HV_E_FAIL);

	kvp_transaction.state = HVUTIL_DEVICE_INIT;

	complete(&release_event);

}



int
@@ -723,7 +721,6 @@ hv_kvp_init(struct hv_util_service *srv) 
	recv_buffer = srv->recv_buffer;

	kvp_transaction.recv_channel = srv->channel;



	init_completion(&release_event);

	/*

	 * When this driver loads, the user level daemon that

	 * processes the host requests may not yet be running.
@@ -747,5 +744,4 @@ void hv_kvp_deinit(void) 
	cancel_delayed_work_sync(&kvp_timeout_work);

	cancel_work_sync(&kvp_sendkey_work);

	hvutil_transport_destroy(hvt);

	wait_for_completion(&release_event);

}

drivers/hv/hv_snapshot.c

+0 −4
Original line number Diff line number Diff line
@@ -79,7 +79,6 @@ static int dm_reg_value; 
static const char vss_devname[] = "vmbus/hv_vss";

static __u8 *recv_buffer;

static struct hvutil_transport *hvt;

static struct completion release_event;



static void vss_timeout_func(struct work_struct *dummy);

static void vss_handle_request(struct work_struct *dummy);
@@ -361,13 +360,11 @@ static void vss_on_reset(void) 
	if (cancel_delayed_work_sync(&vss_timeout_work))

		vss_respond_to_host(HV_E_FAIL);

	vss_transaction.state = HVUTIL_DEVICE_INIT;

	complete(&release_event);

}



int

hv_vss_init(struct hv_util_service *srv)

{

	init_completion(&release_event);

	if (vmbus_proto_version < VERSION_WIN8_1) {

		pr_warn("Integration service 'Backup (volume snapshot)'"

			" not supported on this host version.\n");
@@ -400,5 +397,4 @@ void hv_vss_deinit(void) 
	cancel_delayed_work_sync(&vss_timeout_work);

	cancel_work_sync(&vss_handle_request_work);

	hvutil_transport_destroy(hvt);

	wait_for_completion(&release_event);

}

drivers/hv/hv_utils_transport.c

+8 −4
Original line number Diff line number Diff line
@@ -182,10 +182,11 @@ static int hvt_op_release(struct inode *inode, struct file *file) 
	 * connects back.

	 */

	hvt_reset(hvt);

	mutex_unlock(&hvt->lock);



	if (mode_old == HVUTIL_TRANSPORT_DESTROY)

		hvt_transport_free(hvt);

		complete(&hvt->release);



	mutex_unlock(&hvt->lock);



	return 0;

}
@@ -304,6 +305,7 @@ struct hvutil_transport *hvutil_transport_init(const char *name, 


	init_waitqueue_head(&hvt->outmsg_q);

	mutex_init(&hvt->lock);

	init_completion(&hvt->release);



	spin_lock(&hvt_list_lock);

	list_add(&hvt->list, &hvt_list);
@@ -351,6 +353,8 @@ void hvutil_transport_destroy(struct hvutil_transport *hvt) 
	if (hvt->cn_id.idx > 0 && hvt->cn_id.val > 0)

		cn_del_callback(&hvt->cn_id);



	if (mode_old != HVUTIL_TRANSPORT_CHARDEV)

	if (mode_old == HVUTIL_TRANSPORT_CHARDEV)

		wait_for_completion(&hvt->release);



	hvt_transport_free(hvt);

}

drivers/hv/hv_utils_transport.h

+1 −0
Original line number Diff line number Diff line
@@ -41,6 +41,7 @@ struct hvutil_transport { 
	int outmsg_len;                     /* its length */

	wait_queue_head_t outmsg_q;         /* poll/read wait queue */

	struct mutex lock;                  /* protects struct members */

	struct completion release;          /* synchronize with fd release */

};



struct hvutil_transport *hvutil_transport_init(const char *name,