From e9c18ae6eb2b312f16c63e34b43ea23926daa398 Mon Sep 17 00:00:00 2001 From: Vitaly Kuznetsov Date: Sat, 4 Mar 2017 18:13:59 -0700 Subject: [PATCH] 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: 5a66fecbf6aa ("Drivers: hv: util: kvp: Fix a rescind processing issue") Fixes: 20951c7535b5 ("Drivers: hv: util: Fcopy: Fix a rescind processing issue") Fixes: d77044d142e9 ("Drivers: hv: util: Backup: Fix a rescind processing issue") Reported-by: Dexuan Cui Tested-by: Dexuan Cui Signed-off-by: Vitaly Kuznetsov Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman --- drivers/hv/hv_fcopy.c | 4 ---- drivers/hv/hv_kvp.c | 4 ---- drivers/hv/hv_snapshot.c | 4 ---- drivers/hv/hv_utils_transport.c | 12 ++++++++---- drivers/hv/hv_utils_transport.h | 1 + 5 files changed, 9 insertions(+), 16 deletions(-) diff --git a/drivers/hv/hv_fcopy.c b/drivers/hv/hv_fcopy.c index 9aee6014339d..a5596a642ed0 100644 --- a/drivers/hv/hv_fcopy.c +++ b/drivers/hv/hv_fcopy.c @@ -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); } diff --git a/drivers/hv/hv_kvp.c b/drivers/hv/hv_kvp.c index de263712e247..a1adfe2cfb34 100644 --- a/drivers/hv/hv_kvp.c +++ b/drivers/hv/hv_kvp.c @@ -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); } diff --git a/drivers/hv/hv_snapshot.c b/drivers/hv/hv_snapshot.c index bcc03f0748d6..e659d1b94a57 100644 --- a/drivers/hv/hv_snapshot.c +++ b/drivers/hv/hv_snapshot.c @@ -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); } diff --git a/drivers/hv/hv_utils_transport.c b/drivers/hv/hv_utils_transport.c index c235a9515267..4402a71e23f7 100644 --- a/drivers/hv/hv_utils_transport.c +++ b/drivers/hv/hv_utils_transport.c @@ -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) - hvt_transport_free(hvt); + if (mode_old == HVUTIL_TRANSPORT_CHARDEV) + wait_for_completion(&hvt->release); + + hvt_transport_free(hvt); } diff --git a/drivers/hv/hv_utils_transport.h b/drivers/hv/hv_utils_transport.h index d98f5225c3e6..79afb626e166 100644 --- a/drivers/hv/hv_utils_transport.h +++ b/drivers/hv/hv_utils_transport.h @@ -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, -- 2.20.1