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-rw-r--r--drivers/block/nbd.c108
-rw-r--r--include/uapi/linux/nbd-netlink.h25
2 files changed, 133 insertions, 0 deletions
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index c5f866bcfea6..cb45d799bc5c 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -45,6 +45,7 @@
static DEFINE_IDR(nbd_index_idr);
static DEFINE_MUTEX(nbd_index_mutex);
+static int nbd_total_devices = 0;
struct nbd_sock {
struct socket *sock;
@@ -130,6 +131,7 @@ static int nbd_dev_dbg_init(struct nbd_device *nbd);
static void nbd_dev_dbg_close(struct nbd_device *nbd);
static void nbd_config_put(struct nbd_device *nbd);
static void nbd_connect_reply(struct genl_info *info, int index);
+static int nbd_genl_status(struct sk_buff *skb, struct genl_info *info);
static void nbd_dead_link_work(struct work_struct *work);
static inline struct device *nbd_to_dev(struct nbd_device *nbd)
@@ -1457,6 +1459,7 @@ static int nbd_dev_add(int index)
sprintf(disk->disk_name, "nbd%d", index);
nbd_reset(nbd);
add_disk(disk);
+ nbd_total_devices++;
return index;
out_free_tags:
@@ -1493,12 +1496,22 @@ static struct nla_policy nbd_attr_policy[NBD_ATTR_MAX + 1] = {
[NBD_ATTR_CLIENT_FLAGS] = { .type = NLA_U64 },
[NBD_ATTR_SOCKETS] = { .type = NLA_NESTED},
[NBD_ATTR_DEAD_CONN_TIMEOUT] = { .type = NLA_U64 },
+ [NBD_ATTR_DEVICE_LIST] = { .type = NLA_NESTED},
};
static struct nla_policy nbd_sock_policy[NBD_SOCK_MAX + 1] = {
[NBD_SOCK_FD] = { .type = NLA_U32 },
};
+/* We don't use this right now since we don't parse the incoming list, but we
+ * still want it here so userspace knows what to expect.
+ */
+static struct nla_policy __attribute__((unused))
+nbd_device_policy[NBD_DEVICE_ATTR_MAX + 1] = {
+ [NBD_DEVICE_INDEX] = { .type = NLA_U32 },
+ [NBD_DEVICE_CONNECTED] = { .type = NLA_U8 },
+};
+
static int nbd_genl_connect(struct sk_buff *skb, struct genl_info *info)
{
struct nbd_device *nbd = NULL;
@@ -1764,6 +1777,11 @@ static const struct genl_ops nbd_connect_genl_ops[] = {
.policy = nbd_attr_policy,
.doit = nbd_genl_reconfigure,
},
+ {
+ .cmd = NBD_CMD_STATUS,
+ .policy = nbd_attr_policy,
+ .doit = nbd_genl_status,
+ },
};
static const struct genl_multicast_group nbd_mcast_grps[] = {
@@ -1782,6 +1800,96 @@ static struct genl_family nbd_genl_family __ro_after_init = {
.n_mcgrps = ARRAY_SIZE(nbd_mcast_grps),
};
+static int populate_nbd_status(struct nbd_device *nbd, struct sk_buff *reply)
+{
+ struct nlattr *dev_opt;
+ u8 connected = 0;
+ int ret;
+
+ /* This is a little racey, but for status it's ok. The
+ * reason we don't take a ref here is because we can't
+ * take a ref in the index == -1 case as we would need
+ * to put under the nbd_index_mutex, which could
+ * deadlock if we are configured to remove ourselves
+ * once we're disconnected.
+ */
+ if (refcount_read(&nbd->config_refs))
+ connected = 1;
+ dev_opt = nla_nest_start(reply, NBD_DEVICE_ITEM);
+ if (!dev_opt)
+ return -EMSGSIZE;
+ ret = nla_put_u32(reply, NBD_DEVICE_INDEX, nbd->index);
+ if (ret)
+ return -EMSGSIZE;
+ ret = nla_put_u8(reply, NBD_DEVICE_CONNECTED,
+ connected);
+ if (ret)
+ return -EMSGSIZE;
+ nla_nest_end(reply, dev_opt);
+ return 0;
+}
+
+static int status_cb(int id, void *ptr, void *data)
+{
+ struct nbd_device *nbd = ptr;
+ return populate_nbd_status(nbd, (struct sk_buff *)data);
+}
+
+static int nbd_genl_status(struct sk_buff *skb, struct genl_info *info)
+{
+ struct nlattr *dev_list;
+ struct sk_buff *reply;
+ void *reply_head;
+ size_t msg_size;
+ int index = -1;
+ int ret = -ENOMEM;
+
+ if (info->attrs[NBD_ATTR_INDEX])
+ index = nla_get_u32(info->attrs[NBD_ATTR_INDEX]);
+
+ mutex_lock(&nbd_index_mutex);
+
+ msg_size = nla_total_size(nla_attr_size(sizeof(u32)) +
+ nla_attr_size(sizeof(u8)));
+ msg_size *= (index == -1) ? nbd_total_devices : 1;
+
+ reply = genlmsg_new(msg_size, GFP_KERNEL);
+ if (!reply)
+ goto out;
+ reply_head = genlmsg_put_reply(reply, info, &nbd_genl_family, 0,
+ NBD_CMD_STATUS);
+ if (!reply_head) {
+ nlmsg_free(reply);
+ goto out;
+ }
+
+ dev_list = nla_nest_start(reply, NBD_ATTR_DEVICE_LIST);
+ if (index == -1) {
+ ret = idr_for_each(&nbd_index_idr, &status_cb, reply);
+ if (ret) {
+ nlmsg_free(reply);
+ goto out;
+ }
+ } else {
+ struct nbd_device *nbd;
+ nbd = idr_find(&nbd_index_idr, index);
+ if (nbd) {
+ ret = populate_nbd_status(nbd, reply);
+ if (ret) {
+ nlmsg_free(reply);
+ goto out;
+ }
+ }
+ }
+ nla_nest_end(reply, dev_list);
+ genlmsg_end(reply, reply_head);
+ genlmsg_reply(reply, info);
+ ret = 0;
+out:
+ mutex_unlock(&nbd_index_mutex);
+ return ret;
+}
+
static void nbd_connect_reply(struct genl_info *info, int index)
{
struct sk_buff *skb;
diff --git a/include/uapi/linux/nbd-netlink.h b/include/uapi/linux/nbd-netlink.h
index c2209c75626c..6f7ca3d63a65 100644
--- a/include/uapi/linux/nbd-netlink.h
+++ b/include/uapi/linux/nbd-netlink.h
@@ -33,11 +33,35 @@ enum {
NBD_ATTR_CLIENT_FLAGS,
NBD_ATTR_SOCKETS,
NBD_ATTR_DEAD_CONN_TIMEOUT,
+ NBD_ATTR_DEVICE_LIST,
__NBD_ATTR_MAX,
};
#define NBD_ATTR_MAX (__NBD_ATTR_MAX - 1)
/*
+ * This is the format for multiple devices with NBD_ATTR_DEVICE_LIST
+ *
+ * [NBD_ATTR_DEVICE_LIST]
+ * [NBD_DEVICE_ITEM]
+ * [NBD_DEVICE_INDEX]
+ * [NBD_DEVICE_CONNECTED]
+ */
+enum {
+ NBD_DEVICE_ITEM_UNSPEC,
+ NBD_DEVICE_ITEM,
+ __NBD_DEVICE_ITEM_MAX,
+};
+#define NBD_DEVICE_ITEM_MAX (__NBD_DEVICE_ITEM_MAX - 1)
+
+enum {
+ NBD_DEVICE_UNSPEC,
+ NBD_DEVICE_INDEX,
+ NBD_DEVICE_CONNECTED,
+ __NBD_DEVICE_MAX,
+};
+#define NBD_DEVICE_ATTR_MAX (__NBD_DEVICE_MAX - 1)
+
+/*
* This is the format for multiple sockets with NBD_ATTR_SOCKETS
*
* [NBD_ATTR_SOCKETS]
@@ -66,6 +90,7 @@ enum {
NBD_CMD_DISCONNECT,
NBD_CMD_RECONFIGURE,
NBD_CMD_LINK_DEAD,
+ NBD_CMD_STATUS,
__NBD_CMD_MAX,
};
#define NBD_CMD_MAX (__NBD_CMD_MAX - 1)