[RFC][PATCH v2] configfs: Provide variants of config_*_init_type_name() that report errors

From: Louis Rilling
Date: Fri Jun 20 2008 - 11:04:24 EST

[ applies on top of http://lkml.org/lkml/2008/6/12/427 ]

config_item_set_name() may fail but its error code is not checked in
config_*_init_type_name(). Such uses of config_*_init_type_name() are still
valid as long as the new name is shorter than CONFIGFS_ITEM_NAME_LEN, but as
soon as the new name is provided by userspace, the name length is not
controlled.

This patch implements config_*_init_type_long_name() variants that report errors
and that must be used in place of config_*_init_type_name() for names of unknown
length. config_*_init_type_name() now BUG_ON() if they are used with names too
long. In-tree users and documentation examples are updated to report errors as
well.

Signed-off-by: Louis Rilling <louis.rilling@xxxxxxxxxxx>
---
.../filesystems/configfs/configfs_example.c | 18 ++++++--
drivers/net/netconsole.c | 8 +++-
fs/configfs/item.c | 44 +++++++++++++++++---
fs/dlm/config.c | 28 ++++++++++---
fs/ocfs2/cluster/heartbeat.c | 5 ++-
fs/ocfs2/cluster/nodemanager.c | 11 ++++-
include/linux/configfs.h | 6 +++
7 files changed, 99 insertions(+), 21 deletions(-)

diff --git a/Documentation/filesystems/configfs/configfs_example.c b/Documentation/filesystems/configfs/configfs_example.c
index 0b422ac..e3f407c 100644
--- a/Documentation/filesystems/configfs/configfs_example.c
+++ b/Documentation/filesystems/configfs/configfs_example.c
@@ -276,14 +276,19 @@ static inline struct simple_children *to_simple_children(struct config_item *ite
static int simple_children_make_item(struct config_group *group, const char *name, struct config_item **new_item)
{
struct simple_child *simple_child;
+ int ret;

simple_child = kzalloc(sizeof(struct simple_child), GFP_KERNEL);
if (!simple_child)
return -ENOMEM;


- config_item_init_type_name(&simple_child->item, name,
- &simple_child_type);
+ ret = config_item_init_type_long_name(&simple_child->item, name,
+ &simple_child_type);
+ if (ret) {
+ kfree(simple_child);
+ return ret;
+ }

simple_child->storeme = 0;

@@ -363,6 +368,7 @@ static struct configfs_subsystem simple_children_subsys = {
static int group_children_make_group(struct config_group *group, const char *name, struct config_group **new_group)
{
struct simple_children *simple_children;
+ int ret;

simple_children = kzalloc(sizeof(struct simple_children),
GFP_KERNEL);
@@ -370,8 +376,12 @@ static int group_children_make_group(struct config_group *group, const char *nam
return -ENOMEM;


- config_group_init_type_name(&simple_children->group, name,
- &simple_children_type);
+ ret = config_group_init_type_long_name(&simple_children->group, name,
+ &simple_children_type);
+ if (ret) {
+ kfree(simple_children);
+ return ret;
+ }

*new_group = &simple_children->group;
return 0;
diff --git a/drivers/net/netconsole.c b/drivers/net/netconsole.c
index 387a133..7208c4a 100644
--- a/drivers/net/netconsole.c
+++ b/drivers/net/netconsole.c
@@ -591,6 +591,7 @@ static int make_netconsole_target(struct config_group *group,
{
unsigned long flags;
struct netconsole_target *nt;
+ int ret;

/*
* Allocate and initialize with defaults.
@@ -609,7 +610,12 @@ static int make_netconsole_target(struct config_group *group,
memset(nt->np.remote_mac, 0xff, ETH_ALEN);

/* Initialize the config_item member */
- config_item_init_type_name(&nt->item, name, &netconsole_target_type);
+ ret = config_item_init_type_long_name(&nt->item, name,
+ &netconsole_target_type);
+ if (ret) {
+ kfree(nt);
+ return ret;
+ }

/* Adding, but it is disabled */
spin_lock_irqsave(&target_list_lock, flags);
diff --git a/fs/configfs/item.c b/fs/configfs/item.c
index 76dc4c3..4c3a002 100644
--- a/fs/configfs/item.c
+++ b/fs/configfs/item.c
@@ -112,22 +112,54 @@ int config_item_set_name(struct config_item * item, const char * fmt, ...)

EXPORT_SYMBOL(config_item_set_name);

+int config_item_init_type_long_name(struct config_item *item,
+ const char *name,
+ struct config_item_type *type)
+{
+ int error;
+
+ error = config_item_set_name(item, name);
+ if (error)
+ return error;
+ item->ci_type = type;
+ config_item_init(item);
+ return 0;
+}
+EXPORT_SYMBOL(config_item_init_type_long_name);
+
void config_item_init_type_name(struct config_item *item,
const char *name,
struct config_item_type *type)
{
- config_item_set_name(item, name);
- item->ci_type = type;
- config_item_init(item);
+ int error;
+
+ error = config_item_init_type_long_name(item, name, type);
+ BUG_ON(error);
}
EXPORT_SYMBOL(config_item_init_type_name);

-void config_group_init_type_name(struct config_group *group, const char *name,
- struct config_item_type *type)
+int config_group_init_type_long_name(struct config_group *group,
+ const char *name,
+ struct config_item_type *type)
{
- config_item_set_name(&group->cg_item, name);
+ int error;
+
+ error = config_item_set_name(&group->cg_item, name);
+ if (error)
+ return error;
group->cg_item.ci_type = type;
config_group_init(group);
+ return 0;
+}
+EXPORT_SYMBOL(config_group_init_type_long_name);
+
+void config_group_init_type_name(struct config_group *group, const char *name,
+ struct config_item_type *type)
+{
+ int error;
+
+ error = config_group_init_type_long_name(group, name, type);
+ BUG_ON(error);
}
EXPORT_SYMBOL(config_group_init_type_name);

diff --git a/fs/dlm/config.c b/fs/dlm/config.c
index 492d8ca..1f61b71 100644
--- a/fs/dlm/config.c
+++ b/fs/dlm/config.c
@@ -403,6 +403,7 @@ static int make_cluster(struct config_group *g, const char *name,
struct spaces *sps = NULL;
struct comms *cms = NULL;
void *gps = NULL;
+ int ret = -ENOMEM;

cl = kzalloc(sizeof(struct cluster), GFP_KERNEL);
gps = kcalloc(3, sizeof(struct config_group *), GFP_KERNEL);
@@ -412,7 +413,9 @@ static int make_cluster(struct config_group *g, const char *name,
if (!cl || !gps || !sps || !cms)
goto fail;

- config_group_init_type_name(&cl->group, name, &cluster_type);
+ ret = config_group_init_type_long_name(&cl->group, name, &cluster_type);
+ if (ret)
+ goto fail;
config_group_init_type_name(&sps->ss_group, "spaces", &spaces_type);
config_group_init_type_name(&cms->cs_group, "comms", &comms_type);

@@ -443,7 +446,7 @@ static int make_cluster(struct config_group *g, const char *name,
kfree(gps);
kfree(sps);
kfree(cms);
- return -ENOMEM;
+ return ret;
}

static void drop_cluster(struct config_group *g, struct config_item *i)
@@ -477,6 +480,7 @@ static int make_space(struct config_group *g, const char *name,
struct space *sp = NULL;
struct nodes *nds = NULL;
void *gps = NULL;
+ int ret = -ENOMEM;

sp = kzalloc(sizeof(struct space), GFP_KERNEL);
gps = kcalloc(2, sizeof(struct config_group *), GFP_KERNEL);
@@ -485,7 +489,9 @@ static int make_space(struct config_group *g, const char *name,
if (!sp || !gps || !nds)
goto fail;

- config_group_init_type_name(&sp->group, name, &space_type);
+ ret = config_group_init_type_long_name(&sp->group, name, &space_type);
+ if (ret)
+ goto fail;
config_group_init_type_name(&nds->ns_group, "nodes", &nodes_type);

sp->group.default_groups = gps;
@@ -502,7 +508,7 @@ static int make_space(struct config_group *g, const char *name,
kfree(sp);
kfree(gps);
kfree(nds);
- return -ENOMEM;
+ return ret;
}

static void drop_space(struct config_group *g, struct config_item *i)
@@ -533,12 +539,17 @@ static int make_comm(struct config_group *g, const char *name,
struct config_item **new_i)
{
struct comm *cm;
+ int ret;

cm = kzalloc(sizeof(struct comm), GFP_KERNEL);
if (!cm)
return -ENOMEM;

- config_item_init_type_name(&cm->item, name, &comm_type);
+ ret = config_item_init_type_long_name(&cm->item, name, &comm_type);
+ if (ret) {
+ kfree(cm);
+ return ret;
+ }
cm->nodeid = -1;
cm->local = 0;
cm->addr_count = 0;
@@ -568,12 +579,17 @@ static int make_node(struct config_group *g, const char *name,
{
struct space *sp = to_space(g->cg_item.ci_parent);
struct node *nd;
+ int ret;

nd = kzalloc(sizeof(struct node), GFP_KERNEL);
if (!nd)
return -ENOMEM;

- config_item_init_type_name(&nd->item, name, &node_type);
+ ret = config_item_init_type_long_name(&nd->item, name, &node_type);
+ if (ret) {
+ kfree(nd);
+ return ret;
+ }
nd->nodeid = -1;
nd->weight = 1; /* default weight of 1 if none is set */
nd->new = 1; /* set to 0 once it's been read by dlm_nodeid_list() */
diff --git a/fs/ocfs2/cluster/heartbeat.c b/fs/ocfs2/cluster/heartbeat.c
index 443d108..99bb6ca 100644
--- a/fs/ocfs2/cluster/heartbeat.c
+++ b/fs/ocfs2/cluster/heartbeat.c
@@ -1502,7 +1502,10 @@ static int o2hb_heartbeat_group_make_item(struct config_group *group,
goto out;
}

- config_item_init_type_name(&reg->hr_item, name, &o2hb_region_type);
+ ret = config_item_init_type_long_name(&reg->hr_item, name,
+ &o2hb_region_type);
+ if (ret)
+ goto out;

*new_item = &reg->hr_item;

diff --git a/fs/ocfs2/cluster/nodemanager.c b/fs/ocfs2/cluster/nodemanager.c
index fe09cc3..82909e3 100644
--- a/fs/ocfs2/cluster/nodemanager.c
+++ b/fs/ocfs2/cluster/nodemanager.c
@@ -723,7 +723,10 @@ static int o2nm_node_group_make_item(struct config_group *group,
}

strcpy(node->nd_name, name); /* use item.ci_namebuf instead? */
- config_item_init_type_name(&node->nd_item, name, &o2nm_node_type);
+ ret = config_item_init_type_long_name(&node->nd_item, name,
+ &o2nm_node_type);
+ if (ret)
+ goto out;
spin_lock_init(&node->nd_lock);

*new_item = &node->nd_item;
@@ -842,8 +845,10 @@ static int o2nm_cluster_group_make_group(struct config_group *group,
goto out;
}

- config_group_init_type_name(&cluster->cl_group, name,
- &o2nm_cluster_type);
+ ret = config_group_init_type_long_name(&cluster->cl_group, name,
+ &o2nm_cluster_type);
+ if (ret)
+ goto out;
config_group_init_type_name(&ns->ns_group, "node",
&o2nm_node_group_type);

diff --git a/include/linux/configfs.h b/include/linux/configfs.h
index 0488f93..bf1aac8 100644
--- a/include/linux/configfs.h
+++ b/include/linux/configfs.h
@@ -74,6 +74,9 @@ extern void config_item_init(struct config_item *);
extern void config_item_init_type_name(struct config_item *item,
const char *name,
struct config_item_type *type);
+extern int config_item_init_type_long_name(struct config_item *item,
+ const char *name,
+ struct config_item_type *type);

extern struct config_item * config_item_get(struct config_item *);
extern void config_item_put(struct config_item *);
@@ -100,6 +103,9 @@ extern void config_group_init(struct config_group *group);
extern void config_group_init_type_name(struct config_group *group,
const char *name,
struct config_item_type *type);
+extern int config_group_init_type_long_name(struct config_group *group,
+ const char *name,
+ struct config_item_type *type);

static inline struct config_group *to_config_group(struct config_item *item)
{
--
1.5.5.3

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