qeth: synchronize configuration interface

Synchronize access to the drivers configuration interface.
Also do not allow configuration changes during online/offline
transition.

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

1 files changed, 91 insertions, 57 deletions

diff --git a/drivers/s390/net/qeth_core_sys.c b/drivers/s390/net/qeth_core_sys.c
index 25dfd5abd19b..cbac4050afb2 100644
--- a/drivers/s390/net/qeth_core_sys.c
+++ b/drivers/s390/net/qeth_core_sys.c
@@ -122,23 +122,32 @@ static ssize_t qeth_dev_portno_store(struct device *dev,
 	struct qeth_card *card = dev_get_drvdata(dev);
 	char *tmp;
 	unsigned int portno, limit;
+	int rc = 0;
 
 	if (!card)
 		return -EINVAL;
 
+	mutex_lock(&card->conf_mutex);
 	if ((card->state != CARD_STATE_DOWN) &&
-	    (card->state != CARD_STATE_RECOVER))
-		return -EPERM;
+	    (card->state != CARD_STATE_RECOVER)) {
+		rc = -EPERM;
+		goto out;
+	}
 
 	portno = simple_strtoul(buf, &tmp, 16);
-	if (portno > QETH_MAX_PORTNO)
-		return -EINVAL;
+	if (portno > QETH_MAX_PORTNO) {
+		rc = -EINVAL;
+		goto out;
+	}
 	limit = (card->ssqd.pcnt ? card->ssqd.pcnt - 1 : card->ssqd.pcnt);
-	if (portno > limit)
-		return -EINVAL;
-
+	if (portno > limit) {
+		rc = -EINVAL;
+		goto out;
+	}
 	card->info.portno = portno;
-	return count;
+out:
+	mutex_unlock(&card->conf_mutex);
+	return rc ? rc : count;
 }
 
 static DEVICE_ATTR(portno, 0644, qeth_dev_portno_show, qeth_dev_portno_store);
@@ -165,18 +174,23 @@ static ssize_t qeth_dev_portname_store(struct device *dev,
 {
 	struct qeth_card *card = dev_get_drvdata(dev);
 	char *tmp;
-	int i;
+	int i, rc = 0;
 
 	if (!card)
 		return -EINVAL;
 
+	mutex_lock(&card->conf_mutex);
 	if ((card->state != CARD_STATE_DOWN) &&
-	    (card->state != CARD_STATE_RECOVER))
-		return -EPERM;
+	    (card->state != CARD_STATE_RECOVER)) {
+		rc = -EPERM;
+		goto out;
+	}
 
 	tmp = strsep((char **) &buf, "\n");
-	if ((strlen(tmp) > 8) || (strlen(tmp) == 0))
-		return -EINVAL;
+	if ((strlen(tmp) > 8) || (strlen(tmp) == 0)) {
+		rc = -EINVAL;
+		goto out;
+	}
 
 	card->info.portname[0] = strlen(tmp);
 	/* for beauty reasons */
@@ -184,8 +198,9 @@ static ssize_t qeth_dev_portname_store(struct device *dev,
 		card->info.portname[i] = ' ';
 	strcpy(card->info.portname + 1, tmp);
 	ASCEBC(card->info.portname + 1, 8);
-
-	return count;
+out:
+	mutex_unlock(&card->conf_mutex);
+	return rc ? rc : count;
 }
 
 static DEVICE_ATTR(portname, 0644, qeth_dev_portname_show,
@@ -215,20 +230,25 @@ static ssize_t qeth_dev_prioqing_store(struct device *dev,
 {
 	struct qeth_card *card = dev_get_drvdata(dev);
 	char *tmp;
+	int rc = 0;
 
 	if (!card)
 		return -EINVAL;
 
+	mutex_lock(&card->conf_mutex);
 	if ((card->state != CARD_STATE_DOWN) &&
-	    (card->state != CARD_STATE_RECOVER))
-		return -EPERM;
+	    (card->state != CARD_STATE_RECOVER)) {
+		rc = -EPERM;
+		goto out;
+	}
 
 	/* check if 1920 devices are supported ,
 	 * if though we have to permit priority queueing
 	 */
 	if (card->qdio.no_out_queues == 1) {
 		card->qdio.do_prio_queueing = QETH_PRIOQ_DEFAULT;
-		return -EPERM;
+		rc = -EPERM;
+		goto out;
 	}
 
 	tmp = strsep((char **) &buf, "\n");
@@ -251,10 +271,11 @@ static ssize_t qeth_dev_prioqing_store(struct device *dev,
 	} else if (!strcmp(tmp, "no_prio_queueing")) {
 		card->qdio.do_prio_queueing = QETH_NO_PRIO_QUEUEING;
 		card->qdio.default_out_queue = QETH_DEFAULT_QUEUE;
-	} else {
-		return -EINVAL;
-	}
-	return count;
+	} else
+		rc = -EINVAL;
+out:
+	mutex_unlock(&card->conf_mutex);
+	return rc ? rc : count;
 }
 
 static DEVICE_ATTR(priority_queueing, 0644, qeth_dev_prioqing_show,
@@ -277,14 +298,17 @@ static ssize_t qeth_dev_bufcnt_store(struct device *dev,
 	struct qeth_card *card = dev_get_drvdata(dev);
 	char *tmp;
 	int cnt, old_cnt;
-	int rc;
+	int rc = 0;
 
 	if (!card)
 		return -EINVAL;
 
+	mutex_lock(&card->conf_mutex);
 	if ((card->state != CARD_STATE_DOWN) &&
-	    (card->state != CARD_STATE_RECOVER))
-		return -EPERM;
+	    (card->state != CARD_STATE_RECOVER)) {
+		rc = -EPERM;
+		goto out;
+	}
 
 	old_cnt = card->qdio.in_buf_pool.buf_count;
 	cnt = simple_strtoul(buf, &tmp, 10);
@@ -293,7 +317,9 @@ static ssize_t qeth_dev_bufcnt_store(struct device *dev,
 	if (old_cnt != cnt) {
 		rc = qeth_realloc_buffer_pool(card, cnt);
 	}
-	return count;
+out:
+	mutex_unlock(&card->conf_mutex);
+	return rc ? rc : count;
 }
 
 static DEVICE_ATTR(buffer_count, 0644, qeth_dev_bufcnt_show,
@@ -337,25 +363,27 @@ static ssize_t qeth_dev_performance_stats_store(struct device *dev,
 {
 	struct qeth_card *card = dev_get_drvdata(dev);
 	char *tmp;
-	int i;
+	int i, rc = 0;
 
 	if (!card)
 		return -EINVAL;
 
+	mutex_lock(&card->conf_mutex);
 	i = simple_strtoul(buf, &tmp, 16);
 	if ((i == 0) || (i == 1)) {
 		if (i == card->options.performance_stats)
-			return count;
+			goto out;;
 		card->options.performance_stats = i;
 		if (i == 0)
 			memset(&card->perf_stats, 0,
 				sizeof(struct qeth_perf_stats));
 		card->perf_stats.initial_rx_packets = card->stats.rx_packets;
 		card->perf_stats.initial_tx_packets = card->stats.tx_packets;
-	} else {
-		return -EINVAL;
-	}
-	return count;
+	} else
+		rc = -EINVAL;
+out:
+	mutex_unlock(&card->conf_mutex);
+	return rc ? rc : count;
 }
 
 static DEVICE_ATTR(performance_stats, 0644, qeth_dev_performance_stats_show,
@@ -377,15 +405,17 @@ static ssize_t qeth_dev_layer2_store(struct device *dev,
 {
 	struct qeth_card *card = dev_get_drvdata(dev);
 	char *tmp;
-	int i, rc;
+	int i, rc = 0;
 	enum qeth_discipline_id newdis;
 
 	if (!card)
 		return -EINVAL;
 
-	if (((card->state != CARD_STATE_DOWN) &&
-	     (card->state != CARD_STATE_RECOVER)))
-		return -EPERM;
+	mutex_lock(&card->conf_mutex);
+	if (card->state != CARD_STATE_DOWN) {
+		rc = -EPERM;
+		goto out;
+	}
 
 	i = simple_strtoul(buf, &tmp, 16);
 	switch (i) {
@@ -396,12 +426,13 @@ static ssize_t qeth_dev_layer2_store(struct device *dev,
 		newdis = QETH_DISCIPLINE_LAYER2;
 		break;
 	default:
-		return -EINVAL;
+		rc = -EINVAL;
+		goto out;
 	}
 
-	if (card->options.layer2 == newdis) {
-		return count;
-	} else {
+	if (card->options.layer2 == newdis)
+		goto out;
+	else {
 		if (card->discipline.ccwgdriver) {
 			card->discipline.ccwgdriver->remove(card->gdev);
 			qeth_core_free_discipline(card);
@@ -410,12 +441,12 @@ static ssize_t qeth_dev_layer2_store(struct device *dev,
 
 	rc = qeth_core_load_discipline(card, newdis);
 	if (rc)
-		return rc;
+		goto out;
 
 	rc = card->discipline.ccwgdriver->probe(card->gdev);
-	if (rc)
-		return rc;
-	return count;
+out:
+	mutex_unlock(&card->conf_mutex);
+	return rc ? rc : count;
 }
 
 static DEVICE_ATTR(layer2, 0644, qeth_dev_layer2_show,
@@ -454,11 +485,10 @@ static ssize_t qeth_dev_isolation_store(struct device *dev,
 	char *tmp, *curtoken;
 	curtoken = (char *) buf;
 
-	if (!card) {
-		rc = -EINVAL;
-		goto out;
-	}
+	if (!card)
+		return -EINVAL;
 
+	mutex_lock(&card->conf_mutex);
 	/* check for unknown, too, in case we do not yet know who we are */
 	if (card->info.type != QETH_CARD_TYPE_OSAE &&
 	    card->info.type != QETH_CARD_TYPE_UNKNOWN) {
@@ -491,6 +521,7 @@ static ssize_t qeth_dev_isolation_store(struct device *dev,
 			rc = ipa_rc;
 	}
 out:
+	mutex_unlock(&card->conf_mutex);
 	return rc;
 }
 
@@ -510,22 +541,25 @@ static ssize_t qeth_dev_blkt_store(struct qeth_card *card,
 		const char *buf, size_t count, int *value, int max_value)
 {
 	char *tmp;
-	int i;
+	int i, rc = 0;
 
 	if (!card)
 		return -EINVAL;
 
+	mutex_lock(&card->conf_mutex);
 	if ((card->state != CARD_STATE_DOWN) &&
-	    (card->state != CARD_STATE_RECOVER))
-		return -EPERM;
-
+	    (card->state != CARD_STATE_RECOVER)) {
+		rc = -EPERM;
+		goto out;
+	}
 	i = simple_strtoul(buf, &tmp, 10);
-	if (i <= max_value) {
+	if (i <= max_value)
 		*value = i;
-	} else {
-		return -EINVAL;
-	}
-	return count;
+	else
+		rc = -EINVAL;
+out:
+	mutex_unlock(&card->conf_mutex);
+	return rc ? rc : count;
 }
 
 static ssize_t qeth_dev_blkt_total_show(struct device *dev,