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Commit 13a83fc9 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Nicholas Bellinger
Browse files

ocfs2/cluster: move locking into attribute store methods 



The test and separate set bit scheme was racy to start with, so move to do
a test_and_set_bit after doing the earlier error checks inside the actual
store methods.  Also remove the locking for the local attribute which
already has a different scheme to synchronize.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
parent ea9ed9cf

fs/ocfs2/cluster/nodemanager.c

+19 −35
Original line number Original line Diff line number Diff line
@@ -188,7 +188,6 @@ enum { 
	O2NM_NODE_ATTR_NUM = 0,

	O2NM_NODE_ATTR_NUM = 0,

	O2NM_NODE_ATTR_PORT,

	O2NM_NODE_ATTR_PORT,

	O2NM_NODE_ATTR_ADDRESS,

	O2NM_NODE_ATTR_ADDRESS,

	O2NM_NODE_ATTR_LOCAL,

};

};





static ssize_t o2nm_node_num_write(struct o2nm_node *node, const char *page,

static ssize_t o2nm_node_num_write(struct o2nm_node *node, const char *page,
@@ -197,6 +196,7 @@ static ssize_t o2nm_node_num_write(struct o2nm_node *node, const char *page, 
	struct o2nm_cluster *cluster = to_o2nm_cluster_from_node(node);

	struct o2nm_cluster *cluster = to_o2nm_cluster_from_node(node);

	unsigned long tmp;

	unsigned long tmp;

	char *p = (char *)page;

	char *p = (char *)page;

	int ret = 0;





	tmp = simple_strtoul(p, &p, 0);

	tmp = simple_strtoul(p, &p, 0);

	if (!p || (*p && (*p != '\n')))

	if (!p || (*p && (*p != '\n')))
@@ -215,15 +215,18 @@ static ssize_t o2nm_node_num_write(struct o2nm_node *node, const char *page, 




	write_lock(&cluster->cl_nodes_lock);

	write_lock(&cluster->cl_nodes_lock);

	if (cluster->cl_nodes[tmp])

	if (cluster->cl_nodes[tmp])

		p = NULL;

		ret = -EEXIST;

	else if (test_and_set_bit(O2NM_NODE_ATTR_NUM,

			&node->nd_set_attributes))

		ret = -EBUSY;

	else  {

	else  {

		cluster->cl_nodes[tmp] = node;

		cluster->cl_nodes[tmp] = node;

		node->nd_num = tmp;

		node->nd_num = tmp;

		set_bit(tmp, cluster->cl_nodes_bitmap);

		set_bit(tmp, cluster->cl_nodes_bitmap);

	}

	}

	write_unlock(&cluster->cl_nodes_lock);

	write_unlock(&cluster->cl_nodes_lock);

	if (p == NULL)

	if (ret)

		return -EEXIST;

		return ret;





	return count;

	return count;

}

}
@@ -247,6 +250,8 @@ static ssize_t o2nm_node_ipv4_port_write(struct o2nm_node *node, 
	if (tmp >= (u16)-1)

	if (tmp >= (u16)-1)

		return -ERANGE;

		return -ERANGE;





	if (test_and_set_bit(O2NM_NODE_ATTR_PORT, &node->nd_set_attributes))

		return -EBUSY;

	node->nd_ipv4_port = htons(tmp);

	node->nd_ipv4_port = htons(tmp);





	return count;

	return count;
@@ -282,6 +287,9 @@ static ssize_t o2nm_node_ipv4_address_write(struct o2nm_node *node, 
	write_lock(&cluster->cl_nodes_lock);

	write_lock(&cluster->cl_nodes_lock);

	if (o2nm_node_ip_tree_lookup(cluster, ipv4_addr, &p, &parent))

	if (o2nm_node_ip_tree_lookup(cluster, ipv4_addr, &p, &parent))

		ret = -EEXIST;

		ret = -EEXIST;

	else if (test_and_set_bit(O2NM_NODE_ATTR_ADDRESS,

			&node->nd_set_attributes))

		ret = -EBUSY;

	else {

	else {

		rb_link_node(&node->nd_ip_node, parent, p);

		rb_link_node(&node->nd_ip_node, parent, p);

		rb_insert_color(&node->nd_ip_node, &cluster->cl_node_ip_tree);

		rb_insert_color(&node->nd_ip_node, &cluster->cl_node_ip_tree);
@@ -388,24 +396,13 @@ static struct o2nm_node_attribute o2nm_node_attr_local = { 
};

};





static struct configfs_attribute *o2nm_node_attrs[] = {

static struct configfs_attribute *o2nm_node_attrs[] = {

	[O2NM_NODE_ATTR_NUM] = &o2nm_node_attr_num.attr,

	&o2nm_node_attr_num.attr,

	[O2NM_NODE_ATTR_PORT] = &o2nm_node_attr_ipv4_port.attr,

	&o2nm_node_attr_ipv4_port.attr,

	[O2NM_NODE_ATTR_ADDRESS] = &o2nm_node_attr_ipv4_address.attr,

	&o2nm_node_attr_ipv4_address.attr,

	[O2NM_NODE_ATTR_LOCAL] = &o2nm_node_attr_local.attr,

	&o2nm_node_attr_local.attr,

	NULL,

	NULL,

};

};





static int o2nm_attr_index(struct configfs_attribute *attr)

{

	int i;

	for (i = 0; i < ARRAY_SIZE(o2nm_node_attrs); i++) {

		if (attr == o2nm_node_attrs[i])

			return i;

	}

	BUG();

	return 0;

}



static ssize_t o2nm_node_show(struct config_item *item,

static ssize_t o2nm_node_show(struct config_item *item,

			      struct configfs_attribute *attr,

			      struct configfs_attribute *attr,

			      char *page)

			      char *page)
@@ -427,24 +424,11 @@ static ssize_t o2nm_node_store(struct config_item *item, 
	struct o2nm_node *node = to_o2nm_node(item);

	struct o2nm_node *node = to_o2nm_node(item);

	struct o2nm_node_attribute *o2nm_node_attr =

	struct o2nm_node_attribute *o2nm_node_attr =

		container_of(attr, struct o2nm_node_attribute, attr);

		container_of(attr, struct o2nm_node_attribute, attr);

	ssize_t ret;

	int attr_index = o2nm_attr_index(attr);





	if (o2nm_node_attr->store == NULL) {

	if (o2nm_node_attr->store == NULL)

		ret = -EINVAL;

		return -EINVAL;

		goto out;

	}



	if (test_bit(attr_index, &node->nd_set_attributes))

		return -EBUSY;



	ret = o2nm_node_attr->store(node, page, count);

	if (ret < count)

		goto out;





	set_bit(attr_index, &node->nd_set_attributes);

	return o2nm_node_attr->store(node, page, count);

out:

	return ret;

}

}





static struct configfs_item_operations o2nm_node_item_ops = {

static struct configfs_item_operations o2nm_node_item_ops = {