On Wed, Jun 05, 2019 at 03:32:51PM -0300, Jason Gunthorpe wrote:
> From: Jason Gunthorpe <jgg@xxxxxxxxxxxx>
>
> Allow userspace to issue a netlink query against the ib_device for
> something like "uverbs" and get back the char dev name, inode major/minor,
> and interface ABI information for "uverbs0".
>
> Since we are now in netlink this can also trigger a module autoload to
> make the uverbs device come into existence.
>
> Largely this will let us replace searching and reading inside sysfs to
> setup devices, and provides an alternative (using driver_id) to device
> name based provider binding for things like rxe.
>
> Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxxxx>
> ---
> drivers/infiniband/core/core_priv.h | 9 +++
> drivers/infiniband/core/device.c | 88 ++++++++++++++++++++++++++++
> drivers/infiniband/core/nldev.c | 91 +++++++++++++++++++++++++++++
> include/rdma/ib_verbs.h | 4 ++
> include/rdma/rdma_netlink.h | 2 +
> include/uapi/rdma/rdma_netlink.h | 10 ++++
> 6 files changed, 204 insertions(+)
>
> diff --git a/drivers/infiniband/core/core_priv.h b/drivers/infiniband/core/core_priv.h
> index ff40a450b5d28e..a953c2fa2e7811 100644
> --- a/drivers/infiniband/core/core_priv.h
> +++ b/drivers/infiniband/core/core_priv.h
> @@ -88,6 +88,15 @@ typedef int (*nldev_callback)(struct ib_device *device,
> int ib_enum_all_devs(nldev_callback nldev_cb, struct sk_buff *skb,
> struct netlink_callback *cb);
>
> +struct ib_client_nl_info {
> + struct sk_buff *nl_msg;
> + struct device *cdev;
> + unsigned int port;
> + u64 abi;
> +};
> +int ib_get_client_nl_info(struct ib_device *ibdev, const char *client_name,
> + struct ib_client_nl_info *res);
> +
> enum ib_cache_gid_default_mode {
> IB_CACHE_GID_DEFAULT_MODE_SET,
> IB_CACHE_GID_DEFAULT_MODE_DELETE
> diff --git a/drivers/infiniband/core/device.c b/drivers/infiniband/core/device.c
> index 49e5ea3a530f53..80e7911951f6f6 100644
> --- a/drivers/infiniband/core/device.c
> +++ b/drivers/infiniband/core/device.c
> @@ -1749,6 +1749,94 @@ void ib_unregister_client(struct ib_client *client)
> }
> EXPORT_SYMBOL(ib_unregister_client);
>
> +static int __ib_get_client_nl_info(struct ib_device *ibdev,
> + const char *client_name,
> + struct ib_client_nl_info *res)
> +{
> + unsigned long index;
> + void *client_data;
> + int ret = -ENOENT;
> +
> + if (!ibdev) {
> + struct ib_client *client;
> +
> + down_read(&clients_rwsem);
> + xa_for_each_marked (&clients, index, client, CLIENT_REGISTERED) {
> + if (strcmp(client->name, client_name) != 0)
> + continue;
> + if (!client->get_global_nl_info) {
> + ret = -EOPNOTSUPP;
> + break;
> + }
> + ret = client->get_global_nl_info(res);
> + if (WARN_ON(ret == -ENOENT))
You are putting to much WARN_ON, sometimes printk can be enough.
> + ret = -EINVAL;
> + if (!ret && res->cdev)
> + get_device(res->cdev);
> + break;
> + }
> + up_read(&clients_rwsem);
> + return ret;
This flow is better to have in separate function, one function for
loaded client and another for no-loaded.
> + }
> +
> + down_read(&ibdev->client_data_rwsem);
> + xan_for_each_marked (&ibdev->client_data, index, client_data,
> + CLIENT_DATA_REGISTERED) {
> + struct ib_client *client = xa_load(&clients, index);
> +
> + if (!client || strcmp(client->name, client_name) != 0)
> + continue;
> + if (!client->get_nl_info) {
> + ret = -EOPNOTSUPP;
> + break;
> + }
> + ret = client->get_nl_info(ibdev, client_data, res);
> + if (WARN_ON(ret == -ENOENT))
Same comment
> + ret = -EINVAL;
> +
> + /*
> + * The cdev is guaranteed valid as long as we are inside the
> + * client_data_rwsem as remove_one can't be called. Keep it
> + * valid for the caller.
> + */
> + if (!ret && res->cdev)
> + get_device(res->cdev);
> + break;
> + }
> + up_read(&ibdev->client_data_rwsem);
> +
> + return ret;
> +}
> +
> +/**
> + * ib_get_client_nl_info - Fetch the nl_info from a client
> + * @device - IB device
> + * @client_name - Name of the client
> + * @res - Result of the query
> + */
> +int ib_get_client_nl_info(struct ib_device *ibdev, const char *client_name,
> + struct ib_client_nl_info *res)
> +{
> + int ret;
> +
> + ret = __ib_get_client_nl_info(ibdev, client_name, res);
> +#ifdef CONFIG_MODULES
> + if (ret == -ENOENT) {
> + request_module("rdma-client-%s", client_name);
Do our ib_clients have rdma-client-* names?
> + ret = __ib_get_client_nl_info(ibdev, client_name, res);
> + }
> +#endif
> + if (ret) {
> + if (ret == -ENOENT)
> + return -EOPNOTSUPP;
> + return ret;
> + }
> +
> + if (WARN_ON(!res->cdev))
> + return -EINVAL;
> + return 0;
> +}
> +
> /**
> * ib_set_client_data - Set IB client context
> * @device:Device to set context for
> diff --git a/drivers/infiniband/core/nldev.c b/drivers/infiniband/core/nldev.c
> index 69188cbbd99bd5..55eccea628e99f 100644
> --- a/drivers/infiniband/core/nldev.c
> +++ b/drivers/infiniband/core/nldev.c
> @@ -120,6 +120,9 @@ static const struct nla_policy nldev_policy[RDMA_NLDEV_ATTR_MAX] = {
> [RDMA_NLDEV_ATTR_DEV_PROTOCOL] = { .type = NLA_NUL_STRING,
> .len = RDMA_NLDEV_ATTR_ENTRY_STRLEN },
> [RDMA_NLDEV_NET_NS_FD] = { .type = NLA_U32 },
> + [RDMA_NLDEV_ATTR_CHARDEV_TYPE] = { .type = NLA_NUL_STRING,
> + .len = 128 },
> + [RDMA_NLDEV_ATTR_PORT_INDEX] = { .type = NLA_U32 },
> };
>
> static int put_driver_name_print_type(struct sk_buff *msg, const char *name,
> @@ -1347,6 +1350,91 @@ static int nldev_dellink(struct sk_buff *skb, struct nlmsghdr *nlh,
> return 0;
> }
>
> +static int nldev_get_chardev(struct sk_buff *skb, struct nlmsghdr *nlh,
> + struct netlink_ext_ack *extack)
> +{
> + struct nlattr *tb[RDMA_NLDEV_ATTR_MAX];
> + char client_name[IB_DEVICE_NAME_MAX];
> + struct ib_client_nl_info data = {};
> + struct ib_device *ibdev = NULL;
> + struct sk_buff *msg;
> + u32 index;
> + int err;
> +
> + err = nlmsg_parse(nlh, 0, tb, RDMA_NLDEV_ATTR_MAX - 1, nldev_policy,
> + extack);
> + if (err || !tb[RDMA_NLDEV_ATTR_CHARDEV_TYPE])
> + return -EINVAL;
> +
> + if (nla_strlcpy(client_name, tb[RDMA_NLDEV_ATTR_CHARDEV_TYPE],
> + sizeof(client_name)) >= sizeof(client_name))
> + return -EINVAL;
> +
> + if (tb[RDMA_NLDEV_ATTR_DEV_INDEX]) {
> + index = nla_get_u32(tb[RDMA_NLDEV_ATTR_DEV_INDEX]);
> + ibdev = ib_device_get_by_index(sock_net(skb->sk), index);
> + if (!ibdev)
> + return -EINVAL;
> +
> + if (tb[RDMA_NLDEV_ATTR_PORT_INDEX]) {
> + data.port = nla_get_u32(tb[RDMA_NLDEV_ATTR_PORT_INDEX]);
> + if (!rdma_is_port_valid(ibdev, data.port)) {
> + err = -EINVAL;
> + goto out_put;
> + }
> + } else {
> + data.port = -1;
> + }
> + } else if (tb[RDMA_NLDEV_ATTR_PORT_INDEX]) {
> + return -EINVAL;
> + }
> +
> + msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
> + if (!msg) {
> + err = -ENOMEM;
> + goto out_put;
> + }
> + nlh = nlmsg_put(msg, NETLINK_CB(skb).portid, nlh->nlmsg_seq,
> + RDMA_NL_GET_TYPE(RDMA_NL_NLDEV,
> + RDMA_NLDEV_CMD_GET_CHARDEV),
> + 0, 0);
> +
> + data.nl_msg = msg;
> + err = ib_get_client_nl_info(ibdev, client_name, &data);
> + if (err)
> + goto out_nlmsg;
> +
> + err = nla_put_u64_64bit(msg, RDMA_NLDEV_ATTR_CHARDEV,
> + huge_encode_dev(data.cdev->devt),
> + RDMA_NLDEV_ATTR_PAD);
> + if (err)
> + goto out_data;
> + err = nla_put_u64_64bit(msg, RDMA_NLDEV_ATTR_CHARDEV_ABI, data.abi,
> + RDMA_NLDEV_ATTR_PAD);
> + if (err)
> + goto out_data;
> + if (nla_put_string(msg, RDMA_NLDEV_ATTR_CHARDEV_NAME,
> + dev_name(data.cdev))) {
> + err = -EMSGSIZE;
> + goto out_data;
> + }
> +
> + nlmsg_end(msg, nlh);
> + put_device(data.cdev);
> + if (ibdev)
> + ib_device_put(ibdev);
> + return rdma_nl_unicast(msg, NETLINK_CB(skb).portid);
> +
> +out_data:
> + put_device(data.cdev);
> +out_nlmsg:
> + nlmsg_free(msg);
> +out_put:
> + if (ibdev)
> + ib_device_put(ibdev);
> + return err;
> +}
> +
> static int nldev_sys_get_doit(struct sk_buff *skb, struct nlmsghdr *nlh,
> struct netlink_ext_ack *extack)
> {
> @@ -1404,6 +1492,9 @@ static const struct rdma_nl_cbs nldev_cb_table[RDMA_NLDEV_NUM_OPS] = {
> .doit = nldev_get_doit,
> .dump = nldev_get_dumpit,
> },
> + [RDMA_NLDEV_CMD_GET_CHARDEV] = {
> + .doit = nldev_get_chardev,
> + },
> [RDMA_NLDEV_CMD_SET] = {
> .doit = nldev_set_doit,
> .flags = RDMA_NL_ADMIN_PERM,
> diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
> index d5dd3cb7fcf702..b93135a783eec0 100644
> --- a/include/rdma/ib_verbs.h
> +++ b/include/rdma/ib_verbs.h
> @@ -2684,11 +2684,15 @@ struct ib_device {
> u32 iw_driver_flags;
> };
>
> +struct ib_client_nl_info;
> struct ib_client {
> const char *name;
> void (*add) (struct ib_device *);
> void (*remove)(struct ib_device *, void *client_data);
> void (*rename)(struct ib_device *dev, void *client_data);
> + int (*get_nl_info)(struct ib_device *ibdev, void *client_data,
> + struct ib_client_nl_info *res);
> + int (*get_global_nl_info)(struct ib_client_nl_info *res);
>
> /* Returns the net_dev belonging to this ib_client and matching the
> * given parameters.
> diff --git a/include/rdma/rdma_netlink.h b/include/rdma/rdma_netlink.h
> index 10732ab31ba2f9..c7acbe08342828 100644
> --- a/include/rdma/rdma_netlink.h
> +++ b/include/rdma/rdma_netlink.h
> @@ -110,4 +110,6 @@ void rdma_link_register(struct rdma_link_ops *ops);
> void rdma_link_unregister(struct rdma_link_ops *ops);
>
> #define MODULE_ALIAS_RDMA_LINK(type) MODULE_ALIAS("rdma-link-" type)
> +#define MODULE_ALIAS_RDMA_CLIENT(type) MODULE_ALIAS("rdma-client-" type)
> +
> #endif /* _RDMA_NETLINK_H */
> diff --git a/include/uapi/rdma/rdma_netlink.h b/include/uapi/rdma/rdma_netlink.h
> index f588e8551c6cea..15eb861d1324f4 100644
> --- a/include/uapi/rdma/rdma_netlink.h
> +++ b/include/uapi/rdma/rdma_netlink.h
> @@ -279,6 +279,8 @@ enum rdma_nldev_command {
>
> RDMA_NLDEV_CMD_RES_PD_GET, /* can dump */
>
> + RDMA_NLDEV_CMD_GET_CHARDEV,
> +
> RDMA_NLDEV_NUM_OPS
> };
>
> @@ -491,6 +493,14 @@ enum rdma_nldev_attr {
> */
> RDMA_NLDEV_NET_NS_FD, /* u32 */
>
> + /*
> + * Information about a chardev
> + */
> + RDMA_NLDEV_ATTR_CHARDEV_TYPE, /* string */
> + RDMA_NLDEV_ATTR_CHARDEV_NAME, /* string */
> + RDMA_NLDEV_ATTR_CHARDEV_ABI, /* u64 */
> + RDMA_NLDEV_ATTR_CHARDEV, /* u64 */
Please document them, especially RDMA_NLDEV_ATTR_CHARDEV and
RDMA_NLDEV_ATTR_CHARDEV_TYPE.
> +
> /*
> * Always the end
> */
> --
> 2.21.0
>
