[PATCH 21/23] 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: Christoph Hellwig
---
fs/ocfs2/cluster/nodemanager.c | 54 +++---
1 file changed, 19 insertions(+), 35 deletions(-)
diff --git a/fs/ocfs2/cluster/nodemanager.c b/fs/ocfs2/cluster/nodemanager.c
index 441c84e..7a398f6 100644
--- a/fs/ocfs2/cluster/nodemanager.c
+++ b/fs/ocfs2/cluster/nodemanager.c
@@ -188,7 +188,6 @@ enum {
O2NM_NODE_ATTR_NUM = 0,
O2NM_NODE_ATTR_PORT,
O2NM_NODE_ATTR_ADDRESS,
- O2NM_NODE_ATTR_LOCAL,
};
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);
unsigned long tmp;
char *p = (char *)page;
+ int ret = 0;
tmp = simple_strtoul(p, &p, 0);
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);
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 {
cluster->cl_nodes[tmp] = node;
node->nd_num = tmp;
set_bit(tmp, cluster->cl_nodes_bitmap);
}
write_unlock(&cluster->cl_nodes_lock);
- if (p == NULL)
- return -EEXIST;
+ if (ret)
+ return ret;
return count;
}
@@ -247,6 +250,8 @@ static ssize_t o2nm_node_ipv4_port_write(struct o2nm_node
*node,
if (tmp >= (u16)-1)
return -ERANGE;
+ if (test_and_set_bit(O2NM_NODE_ATTR_PORT, &node->nd_set_attributes))
+ return -EBUSY;
node->nd_ipv4_port = htons(tmp);
return count;
@@ -282,6 +287,9 @@ static ssize_t o2nm_node_ipv4_address_write(struct
o2nm_node *node,
write_lock(&cluster->cl_nodes_lock);
if (o2nm_node_ip_tree_lookup(cluster, ipv4_addr, &p, &parent))
ret = -EEXIST;
+ else if (test_and_set_bit(O2NM_NODE_ATTR_ADDRESS,
+ &node->nd_set_attributes))
+ ret = -EBUSY;
else {
rb_link_node(&node->nd_ip_node, parent, p);
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[] = {
- [O2NM_NODE_ATTR_NUM] = &o2nm_node_attr_num.attr,
- [O2NM_NODE_ATTR_PORT] = &o2nm_node_attr_ipv4_port.attr,
- [O2NM_NODE_ATTR_ADDRESS] = &o2nm_node_attr_ipv4_address.attr,
- [O2NM_NODE_ATTR_LOCAL] = &o2nm_node_attr_local.attr,
+ &o2nm_node_attr_num.attr,
+ &o2nm_node_attr_ipv4_port.attr,
+ &o2nm_node_attr_ipv4_address.attr,
+ &o2nm_node_attr_local.attr,
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,
struct configfs_attribute *attr,
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_attribute *o2nm_node_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) {
- ret = -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;
+ if (o2nm_node_attr->store == NULL)
+ return -EINVAL;
- set_bit(attr_index, &node->nd_set_attributes);
-out:
- return ret;
+ return o2nm_node_attr->store(node, page, count);
}
static struct configfs_item_operations o2nm_node_item_ops = {
--
1.9.1
--
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[PATCH 21/23] 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: Christoph Hellwig
---
fs/ocfs2/cluster/nodemanager.c | 54 +++---
1 file changed, 19 insertions(+), 35 deletions(-)
diff --git a/fs/ocfs2/cluster/nodemanager.c b/fs/ocfs2/cluster/nodemanager.c
index 441c84e..7a398f6 100644
--- a/fs/ocfs2/cluster/nodemanager.c
+++ b/fs/ocfs2/cluster/nodemanager.c
@@ -188,7 +188,6 @@ enum {
O2NM_NODE_ATTR_NUM = 0,
O2NM_NODE_ATTR_PORT,
O2NM_NODE_ATTR_ADDRESS,
- O2NM_NODE_ATTR_LOCAL,
};
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);
unsigned long tmp;
char *p = (char *)page;
+ int ret = 0;
tmp = simple_strtoul(p, &p, 0);
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);
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 {
cluster->cl_nodes[tmp] = node;
node->nd_num = tmp;
set_bit(tmp, cluster->cl_nodes_bitmap);
}
write_unlock(&cluster->cl_nodes_lock);
- if (p == NULL)
- return -EEXIST;
+ if (ret)
+ return ret;
return count;
}
@@ -247,6 +250,8 @@ static ssize_t o2nm_node_ipv4_port_write(struct o2nm_node
*node,
if (tmp >= (u16)-1)
return -ERANGE;
+ if (test_and_set_bit(O2NM_NODE_ATTR_PORT, &node->nd_set_attributes))
+ return -EBUSY;
node->nd_ipv4_port = htons(tmp);
return count;
@@ -282,6 +287,9 @@ static ssize_t o2nm_node_ipv4_address_write(struct
o2nm_node *node,
write_lock(&cluster->cl_nodes_lock);
if (o2nm_node_ip_tree_lookup(cluster, ipv4_addr, &p, &parent))
ret = -EEXIST;
+ else if (test_and_set_bit(O2NM_NODE_ATTR_ADDRESS,
+ &node->nd_set_attributes))
+ ret = -EBUSY;
else {
rb_link_node(&node->nd_ip_node, parent, p);
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[] = {
- [O2NM_NODE_ATTR_NUM] = &o2nm_node_attr_num.attr,
- [O2NM_NODE_ATTR_PORT] = &o2nm_node_attr_ipv4_port.attr,
- [O2NM_NODE_ATTR_ADDRESS] = &o2nm_node_attr_ipv4_address.attr,
- [O2NM_NODE_ATTR_LOCAL] = &o2nm_node_attr_local.attr,
+ &o2nm_node_attr_num.attr,
+ &o2nm_node_attr_ipv4_port.attr,
+ &o2nm_node_attr_ipv4_address.attr,
+ &o2nm_node_attr_local.attr,
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,
struct configfs_attribute *attr,
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_attribute *o2nm_node_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) {
- ret = -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;
+ if (o2nm_node_attr->store == NULL)
+ return -EINVAL;
- set_bit(attr_index, &node->nd_set_attributes);
-out:
- return ret;
+ return o2nm_node_attr->store(node, page, count);
}
static struct configfs_item_operations o2nm_node_item_ops = {
--
1.9.1
--
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