bonding: add sysfs /slave dir for bond slave devices.

Add sub-directory under /sys/class/net/<interface>/slave with
read-only attributes for slave.  Directory only appears when
<interface> is a slave.

$ tree /sys/class/net/eth2/slave/
/sys/class/net/eth2/slave/
├── ad_aggregator_id
├── link_failure_count
├── mii_status
├── perm_hwaddr
├── queue_id
└── state

$ cat /sys/class/net/eth2/slave/*
2
0
up
40:02:10:ef:06:01
0
active

Signed-off-by: Scott Feldman <sfeldma@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

5 files changed, 176 insertions, 13 deletions

diff --git a/drivers/net/bonding/Makefile b/drivers/net/bonding/Makefile
index 5a5d720da929..6f4e80853ed4 100644
--- a/drivers/net/bonding/Makefile
+++ b/drivers/net/bonding/Makefile
@@ -4,7 +4,7 @@
 
 obj-$(CONFIG_BONDING) += bonding.o
 
-bonding-objs := bond_main.o bond_3ad.o bond_alb.o bond_sysfs.o bond_debugfs.o bond_netlink.o bond_options.o
+bonding-objs := bond_main.o bond_3ad.o bond_alb.o bond_sysfs.o bond_sysfs_slave.o bond_debugfs.o bond_netlink.o bond_options.o
 
 proc-$(CONFIG_PROC_FS) += bond_procfs.o
 bonding-objs += $(proc-y)
diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index f00dd45b0308..df85cec3e5d9 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -466,6 +466,22 @@ static void bond_update_speed_duplex(struct slave *slave)
         return;
 }
 
+const char *bond_slave_link_status(s8 link)
+{
+        switch (link) {
+        case BOND_LINK_UP:
+                return "up";
+        case BOND_LINK_FAIL:
+                return "going down";
+        case BOND_LINK_DOWN:
+                return "down";
+        case BOND_LINK_BACK:
+                return "going back";
+        default:
+                return "unknown";
+        }
+}
+
 /*
  * if <dev> supports MII link status reporting, check its link status.
  *
@@ -1576,6 +1592,12 @@ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev)
                 goto err_unregister;
         }
 
+        res = bond_sysfs_slave_add(new_slave);
+        if (res) {
+                pr_debug("Error %d calling bond_sysfs_slave_add\n", res);
+                goto err_upper_unlink;
+        }
+
         bond->slave_cnt++;
         bond_compute_features(bond);
         bond_set_carrier(bond);
@@ -1595,6 +1617,9 @@ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev)
         return 0;
 
 /* Undo stages on error */
+err_upper_unlink:
+        bond_upper_dev_unlink(bond_dev, slave_dev);
+
 err_unregister:
         netdev_rx_handler_unregister(slave_dev);
 
@@ -1687,6 +1712,8 @@ static int __bond_release_one(struct net_device *bond_dev,
         /* release the slave from its bond */
         bond->slave_cnt--;
 
+        bond_sysfs_slave_del(slave);
+
         bond_upper_dev_unlink(bond_dev, slave_dev);
         /* unregister rx_handler early so bond_handle_frame wouldn't be called
          * for this slave anymore.
diff --git a/drivers/net/bonding/bond_procfs.c b/drivers/net/bonding/bond_procfs.c
index fb868d6c22da..8515b3442583 100644
--- a/drivers/net/bonding/bond_procfs.c
+++ b/drivers/net/bonding/bond_procfs.c
@@ -159,18 +159,6 @@ static void bond_info_show_master(struct seq_file *seq)
         }
 }
 
-static const char *bond_slave_link_status(s8 link)
-{
-        static const char * const status[] = {
-                [BOND_LINK_UP] = "up",
-                [BOND_LINK_FAIL] = "going down",
-                [BOND_LINK_DOWN] = "down",
-                [BOND_LINK_BACK] = "going back",
-        };
-
-        return status[link];
-}
-
 static void bond_info_show_slave(struct seq_file *seq,
                                  const struct slave *slave)
 {
diff --git a/drivers/net/bonding/bond_sysfs_slave.c b/drivers/net/bonding/bond_sysfs_slave.c
new file mode 100644
index 000000000000..7cb97de3cf63
--- /dev/null
+++ b/drivers/net/bonding/bond_sysfs_slave.c
@@ -0,0 +1,144 @@
+/*      Sysfs attributes of bond slaves
+ *
+ *      Copyright (c) 2014 Scott Feldman <sfeldma@cumulusnetworks.com>
+ *
+ *      This program is free software; you can redistribute it and/or
+ *      modify it under the terms of the GNU General Public License
+ *      as published by the Free Software Foundation; either version
+ *      2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/capability.h>
+#include <linux/kernel.h>
+#include <linux/netdevice.h>
+
+#include "bonding.h"
+
+struct slave_attribute {
+        struct attribute attr;
+        ssize_t (*show)(struct slave *, char *);
+};
+
+#define SLAVE_ATTR(_name, _mode, _show)                         \
+const struct slave_attribute slave_attr_##_name = {             \
+        .attr = {.name = __stringify(_name),                    \
+                 .mode = _mode },                               \
+        .show   = _show,                                        \
+};
+#define SLAVE_ATTR_RO(_name) \
+        SLAVE_ATTR(_name, S_IRUGO, _name##_show)
+
+static ssize_t state_show(struct slave *slave, char *buf)
+{
+        switch (bond_slave_state(slave)) {
+        case BOND_STATE_ACTIVE:
+                return sprintf(buf, "active\n");
+        case BOND_STATE_BACKUP:
+                return sprintf(buf, "backup\n");
+        default:
+                return sprintf(buf, "UNKONWN\n");
+        }
+}
+static SLAVE_ATTR_RO(state);
+
+static ssize_t mii_status_show(struct slave *slave, char *buf)
+{
+        return sprintf(buf, "%s\n", bond_slave_link_status(slave->link));
+}
+static SLAVE_ATTR_RO(mii_status);
+
+static ssize_t link_failure_count_show(struct slave *slave, char *buf)
+{
+        return sprintf(buf, "%d\n", slave->link_failure_count);
+}
+static SLAVE_ATTR_RO(link_failure_count);
+
+static ssize_t perm_hwaddr_show(struct slave *slave, char *buf)
+{
+        return sprintf(buf, "%pM\n", slave->perm_hwaddr);
+}
+static SLAVE_ATTR_RO(perm_hwaddr);
+
+static ssize_t queue_id_show(struct slave *slave, char *buf)
+{
+        return sprintf(buf, "%d\n", slave->queue_id);
+}
+static SLAVE_ATTR_RO(queue_id);
+
+static ssize_t ad_aggregator_id_show(struct slave *slave, char *buf)
+{
+        const struct aggregator *agg;
+
+        if (slave->bond->params.mode == BOND_MODE_8023AD) {
+                agg = SLAVE_AD_INFO(slave).port.aggregator;
+                if (agg)
+                        return sprintf(buf, "%d\n",
+                                       agg->aggregator_identifier);
+        }
+
+        return sprintf(buf, "N/A\n");
+}
+static SLAVE_ATTR_RO(ad_aggregator_id);
+
+static const struct slave_attribute *slave_attrs[] = {
+        &slave_attr_state,
+        &slave_attr_mii_status,
+        &slave_attr_link_failure_count,
+        &slave_attr_perm_hwaddr,
+        &slave_attr_queue_id,
+        &slave_attr_ad_aggregator_id,
+        NULL
+};
+
+#define to_slave_attr(_at) container_of(_at, struct slave_attribute, attr)
+#define to_slave(obj)   container_of(obj, struct slave, kobj)
+
+static ssize_t slave_show(struct kobject *kobj,
+                          struct attribute *attr, char *buf)
+{
+        struct slave_attribute *slave_attr = to_slave_attr(attr);
+        struct slave *slave = to_slave(kobj);
+
+        return slave_attr->show(slave, buf);
+}
+
+const struct sysfs_ops slave_sysfs_ops = {
+        .show = slave_show,
+};
+
+static struct kobj_type slave_ktype = {
+#ifdef CONFIG_SYSFS
+        .sysfs_ops = &slave_sysfs_ops,
+#endif
+};
+
+int bond_sysfs_slave_add(struct slave *slave)
+{
+        const struct slave_attribute **a;
+        int err;
+
+        err = kobject_init_and_add(&slave->kobj, &slave_ktype,
+                                   &(slave->dev->dev.kobj), "slave");
+        if (err)
+                return err;
+
+        for (a = slave_attrs; *a; ++a) {
+                err = sysfs_create_file(&slave->kobj, &((*a)->attr));
+                if (err) {
+                        kobject_del(&slave->kobj);
+                        return err;
+                }
+        }
+
+        return 0;
+}
+
+void bond_sysfs_slave_del(struct slave *slave)
+{
+        const struct slave_attribute **a;
+
+        for (a = slave_attrs; *a; ++a)
+                sysfs_remove_file(&slave->kobj, &((*a)->attr));
+
+        kobject_del(&slave->kobj);
+}
diff --git a/drivers/net/bonding/bonding.h b/drivers/net/bonding/bonding.h
index 955dc4839f1d..309757d8482b 100644
--- a/drivers/net/bonding/bonding.h
+++ b/drivers/net/bonding/bonding.h
@@ -203,6 +203,7 @@ struct slave {
 #ifdef CONFIG_NET_POLL_CONTROLLER
         struct netpoll *np;
 #endif
+        struct kobject kobj;
 };
 
 /*
@@ -421,6 +422,8 @@ int bond_create(struct net *net, const char *name);
 int bond_create_sysfs(struct bond_net *net);
 void bond_destroy_sysfs(struct bond_net *net);
 void bond_prepare_sysfs_group(struct bonding *bond);
+int bond_sysfs_slave_add(struct slave *slave);
+void bond_sysfs_slave_del(struct slave *slave);
 int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev);
 int bond_release(struct net_device *bond_dev, struct net_device *slave_dev);
 int bond_xmit_hash(struct bonding *bond, struct sk_buff *skb, int count);
@@ -469,6 +472,7 @@ int bond_option_lacp_rate_set(struct bonding *bond, int lacp_rate);
 int bond_option_ad_select_set(struct bonding *bond, int ad_select);
 struct net_device *bond_option_active_slave_get_rcu(struct bonding *bond);
 struct net_device *bond_option_active_slave_get(struct bonding *bond);
+const char *bond_slave_link_status(s8 link);
 
 struct bond_net {
         struct net *            net;    /* Associated network namespace */