qeth: serialize sysfs-triggered device configurations

This patch serializes device removal and other sysfs-triggered
configurations by moving removal of sysfs-attributes to the beginning
of the remove functions. And it serializes online/offline setting
and discipline-switching (causing reestablishing of the net_device)
by making use of a new discipline mutex.

Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: Frank Blaschka <frank.blaschka@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

5 files changed, 22 insertions, 7 deletions

diff --git a/drivers/s390/net/qeth_core.h b/drivers/s390/net/qeth_core.h
index e7e99e6cad21..41ddf86c3421 100644
--- a/drivers/s390/net/qeth_core.h
+++ b/drivers/s390/net/qeth_core.h
@@ -747,6 +747,7 @@ struct qeth_card {
         struct qdio_ssqd_desc ssqd;
         debug_info_t *debug;
         struct mutex conf_mutex;
+        struct mutex discipline_mutex;
 };
 
 struct qeth_card_list_struct {
diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c
index 844935fbe6a8..f33da45c35ef 100644
--- a/drivers/s390/net/qeth_core_main.c
+++ b/drivers/s390/net/qeth_core_main.c
@@ -1084,6 +1084,7 @@ static int qeth_setup_card(struct qeth_card *card)
         spin_lock_init(&card->ip_lock);
         spin_lock_init(&card->thread_mask_lock);
         mutex_init(&card->conf_mutex);
+        mutex_init(&card->discipline_mutex);
         card->thread_start_mask = 0;
         card->thread_allowed_mask = 0;
         card->thread_running_mask = 0;
@@ -4348,16 +4349,18 @@ static void qeth_core_remove_device(struct ccwgroup_device *gdev)
         struct qeth_card *card = dev_get_drvdata(&gdev->dev);
 
         QETH_DBF_TEXT(SETUP, 2, "removedv");
-        if (card->discipline.ccwgdriver) {
-                card->discipline.ccwgdriver->remove(gdev);
-                qeth_core_free_discipline(card);
-        }
 
         if (card->info.type == QETH_CARD_TYPE_OSN) {
                 qeth_core_remove_osn_attributes(&gdev->dev);
         } else {
                 qeth_core_remove_device_attributes(&gdev->dev);
         }
+
+        if (card->discipline.ccwgdriver) {
+                card->discipline.ccwgdriver->remove(gdev);
+                qeth_core_free_discipline(card);
+        }
+
         debug_unregister(card->debug);
         write_lock_irqsave(&qeth_core_card_list.rwlock, flags);
         list_del(&card->list);
diff --git a/drivers/s390/net/qeth_core_sys.c b/drivers/s390/net/qeth_core_sys.c
index 6b7fd88e8e4d..42fa783a70c8 100644
--- a/drivers/s390/net/qeth_core_sys.c
+++ b/drivers/s390/net/qeth_core_sys.c
@@ -411,7 +411,7 @@ static ssize_t qeth_dev_layer2_store(struct device *dev,
         if (!card)
                 return -EINVAL;
 
-        mutex_lock(&card->conf_mutex);
+        mutex_lock(&card->discipline_mutex);
         if (card->state != CARD_STATE_DOWN) {
                 rc = -EPERM;
                 goto out;
@@ -446,7 +446,7 @@ static ssize_t qeth_dev_layer2_store(struct device *dev,
 
         rc = card->discipline.ccwgdriver->probe(card->gdev);
 out:
-        mutex_unlock(&card->conf_mutex);
+        mutex_unlock(&card->discipline_mutex);
         return rc ? rc : count;
 }
 
diff --git a/drivers/s390/net/qeth_l2_main.c b/drivers/s390/net/qeth_l2_main.c
index 32d07c2dcc67..5e66333a8bea 100644
--- a/drivers/s390/net/qeth_l2_main.c
+++ b/drivers/s390/net/qeth_l2_main.c
@@ -935,6 +935,7 @@ static int __qeth_l2_set_online(struct ccwgroup_device *gdev, int recovery_mode)
         enum qeth_card_states recover_flag;
 
         BUG_ON(!card);
+        mutex_lock(&card->discipline_mutex);
         mutex_lock(&card->conf_mutex);
         QETH_DBF_TEXT(SETUP, 2, "setonlin");
         QETH_DBF_HEX(SETUP, 2, &card, sizeof(void *));
@@ -1012,6 +1013,7 @@ static int __qeth_l2_set_online(struct ccwgroup_device *gdev, int recovery_mode)
         kobject_uevent(&gdev->dev.kobj, KOBJ_CHANGE);
 out:
         mutex_unlock(&card->conf_mutex);
+        mutex_unlock(&card->discipline_mutex);
         return 0;
 
 out_remove:
@@ -1025,6 +1027,7 @@ out_remove:
         else
                 card->state = CARD_STATE_DOWN;
         mutex_unlock(&card->conf_mutex);
+        mutex_unlock(&card->discipline_mutex);
         return rc;
 }
 
@@ -1040,6 +1043,7 @@ static int __qeth_l2_set_offline(struct ccwgroup_device *cgdev,
         int rc = 0, rc2 = 0, rc3 = 0;
         enum qeth_card_states recover_flag;
 
+        mutex_lock(&card->discipline_mutex);
         mutex_lock(&card->conf_mutex);
         QETH_DBF_TEXT(SETUP, 3, "setoffl");
         QETH_DBF_HEX(SETUP, 3, &card, sizeof(void *));
@@ -1060,6 +1064,7 @@ static int __qeth_l2_set_offline(struct ccwgroup_device *cgdev,
         /* let user_space know that device is offline */
         kobject_uevent(&cgdev->dev.kobj, KOBJ_CHANGE);
         mutex_unlock(&card->conf_mutex);
+        mutex_unlock(&card->discipline_mutex);
         return 0;
 }
 
diff --git a/drivers/s390/net/qeth_l3_main.c b/drivers/s390/net/qeth_l3_main.c
index 15b5ca82bd26..e22ae248f613 100644
--- a/drivers/s390/net/qeth_l3_main.c
+++ b/drivers/s390/net/qeth_l3_main.c
@@ -3354,6 +3354,8 @@ static void qeth_l3_remove_device(struct ccwgroup_device *cgdev)
 {
         struct qeth_card *card = dev_get_drvdata(&cgdev->dev);
 
+        qeth_l3_remove_device_attributes(&cgdev->dev);
+
         qeth_set_allowed_threads(card, 0, 1);
         wait_event(card->wait_q, qeth_threads_running(card, 0xffffffff) == 0);
 
@@ -3367,7 +3369,6 @@ static void qeth_l3_remove_device(struct ccwgroup_device *cgdev)
                 card->dev = NULL;
         }
 
-        qeth_l3_remove_device_attributes(&cgdev->dev);
         qeth_l3_clear_ip_list(card, 0, 0);
         qeth_l3_clear_ipato_list(card);
         return;
@@ -3380,6 +3381,7 @@ static int __qeth_l3_set_online(struct ccwgroup_device *gdev, int recovery_mode)
         enum qeth_card_states recover_flag;
 
         BUG_ON(!card);
+        mutex_lock(&card->discipline_mutex);
         mutex_lock(&card->conf_mutex);
         QETH_DBF_TEXT(SETUP, 2, "setonlin");
         QETH_DBF_HEX(SETUP, 2, &card, sizeof(void *));
@@ -3461,6 +3463,7 @@ static int __qeth_l3_set_online(struct ccwgroup_device *gdev, int recovery_mode)
         kobject_uevent(&gdev->dev.kobj, KOBJ_CHANGE);
 out:
         mutex_unlock(&card->conf_mutex);
+        mutex_unlock(&card->discipline_mutex);
         return 0;
 out_remove:
         card->use_hard_stop = 1;
@@ -3473,6 +3476,7 @@ out_remove:
         else
                 card->state = CARD_STATE_DOWN;
         mutex_unlock(&card->conf_mutex);
+        mutex_unlock(&card->discipline_mutex);
         return rc;
 }
 
@@ -3488,6 +3492,7 @@ static int __qeth_l3_set_offline(struct ccwgroup_device *cgdev,
         int rc = 0, rc2 = 0, rc3 = 0;
         enum qeth_card_states recover_flag;
 
+        mutex_lock(&card->discipline_mutex);
         mutex_lock(&card->conf_mutex);
         QETH_DBF_TEXT(SETUP, 3, "setoffl");
         QETH_DBF_HEX(SETUP, 3, &card, sizeof(void *));
@@ -3508,6 +3513,7 @@ static int __qeth_l3_set_offline(struct ccwgroup_device *cgdev,
         /* let user_space know that device is offline */
         kobject_uevent(&cgdev->dev.kobj, KOBJ_CHANGE);
         mutex_unlock(&card->conf_mutex);
+        mutex_unlock(&card->discipline_mutex);
         return 0;
 }