bonding: add rtnl lock and remove read lock for bond sysfs

The bond_for_each_slave() will not be protected by read_lock(),
only protected by rtnl_lock(), so need to replace read_lock()
with rtnl_lock().

Signed-off-by: Ding Tianhong <dingtianhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 17 insertions, 13 deletions

diff --git a/drivers/net/bonding/bond_sysfs.c b/drivers/net/bonding/bond_sysfs.c
index e9249527e7e7..03bed0ca935e 100644
--- a/drivers/net/bonding/bond_sysfs.c
+++ b/drivers/net/bonding/bond_sysfs.c
@@ -179,7 +179,9 @@ static ssize_t bonding_show_slaves(struct device *d,
         struct slave *slave;
         int res = 0;
 
-        read_lock(&bond->lock);
+        if (!rtnl_trylock())
+                return restart_syscall();
+
         bond_for_each_slave(bond, slave, iter) {
                 if (res > (PAGE_SIZE - IFNAMSIZ)) {
                         /* not enough space for another interface name */
@@ -190,7 +192,9 @@ static ssize_t bonding_show_slaves(struct device *d,
                 }
                 res += sprintf(buf + res, "%s ", slave->dev->name);
         }
-        read_unlock(&bond->lock);
+
+        rtnl_unlock();
+
         if (res)
                 buf[res-1] = '\n'; /* eat the leftover space */
 
@@ -626,6 +630,9 @@ static ssize_t bonding_store_arp_targets(struct device *d,
         unsigned long *targets_rx;
         int ind, i, j, ret = -EINVAL;
 
+        if (!rtnl_trylock())
+                return restart_syscall();
+
         targets = bond->params.arp_targets;
         newtarget = in_aton(buf + 1);
         /* look for adds */
@@ -699,6 +706,7 @@ static ssize_t bonding_store_arp_targets(struct device *d,
 
         ret = count;
 out:
+        rtnl_unlock();
         return ret;
 }
 static DEVICE_ATTR(arp_ip_target, S_IRUGO | S_IWUSR , bonding_show_arp_targets, bonding_store_arp_targets);
@@ -1467,7 +1475,6 @@ static ssize_t bonding_show_queue_id(struct device *d,
         if (!rtnl_trylock())
                 return restart_syscall();
 
-        read_lock(&bond->lock);
         bond_for_each_slave(bond, slave, iter) {
                 if (res > (PAGE_SIZE - IFNAMSIZ - 6)) {
                         /* not enough space for another interface_name:queue_id pair */
@@ -1479,9 +1486,9 @@ static ssize_t bonding_show_queue_id(struct device *d,
                 res += sprintf(buf + res, "%s:%d ",
                                slave->dev->name, slave->queue_id);
         }
-        read_unlock(&bond->lock);
         if (res)
                 buf[res-1] = '\n'; /* eat the leftover space */
+
         rtnl_unlock();
 
         return res;
@@ -1530,8 +1537,6 @@ static ssize_t bonding_store_queue_id(struct device *d,
         if (!sdev)
                 goto err_no_cmd;
 
-        read_lock(&bond->lock);
-
         /* Search for thes slave and check for duplicate qids */
         update_slave = NULL;
         bond_for_each_slave(bond, slave, iter) {
@@ -1542,23 +1547,20 @@ static ssize_t bonding_store_queue_id(struct device *d,
                          */
                         update_slave = slave;
                 else if (qid && qid == slave->queue_id) {
-                        goto err_no_cmd_unlock;
+                        goto err_no_cmd;
                 }
         }
 
         if (!update_slave)
-                goto err_no_cmd_unlock;
+                goto err_no_cmd;
 
         /* Actually set the qids for the slave */
         update_slave->queue_id = qid;
 
-        read_unlock(&bond->lock);
 out:
         rtnl_unlock();
         return ret;
 
-err_no_cmd_unlock:
-        read_unlock(&bond->lock);
 err_no_cmd:
         pr_info("invalid input for queue_id set for %s.\n",
                 bond->dev->name);
@@ -1591,6 +1593,9 @@ static ssize_t bonding_store_slaves_active(struct device *d,
         struct list_head *iter;
         struct slave *slave;
 
+        if (!rtnl_trylock())
+                return restart_syscall();
+
         if (sscanf(buf, "%d", &new_value) != 1) {
                 pr_err("%s: no all_slaves_active value specified.\n",
                        bond->dev->name);
@@ -1610,7 +1615,6 @@ static ssize_t bonding_store_slaves_active(struct device *d,
                 goto out;
         }
 
-        read_lock(&bond->lock);
         bond_for_each_slave(bond, slave, iter) {
                 if (!bond_is_active_slave(slave)) {
                         if (new_value)
@@ -1619,8 +1623,8 @@ static ssize_t bonding_store_slaves_active(struct device *d,
                                 slave->inactive = 1;
                 }
         }
-        read_unlock(&bond->lock);
 out:
+        rtnl_unlock();
         return ret;
 }
 static DEVICE_ATTR(all_slaves_active, S_IRUGO | S_IWUSR,