Merge tag 'v3.9-rc5' into wq/for-3.10

Writeback conversion to workqueue will be based on top of wq/for-3.10
branch to take advantage of custom attrs and NUMA support for unbound
workqueues.  Mainline currently contains two commits which result in
non-trivial merge conflicts with wq/for-3.10 and because
block/for-3.10/core is based on v3.9-rc3 which contains one of the
conflicting commits, we need a pre-merge-window merge anyway.  Let's
pull v3.9-rc5 into wq/for-3.10 so that the block tree doesn't suffer
from workqueue merge conflicts.

The two conflicts and their resolutions:

* e68035fb65 ("workqueue: convert to idr_alloc()") in mainline changes
  worker_pool_assign_id() to use idr_alloc() instead of the old idr
  interface.  worker_pool_assign_id() goes through multiple locking
  changes in wq/for-3.10 causing the following conflict.

  static int worker_pool_assign_id(struct worker_pool *pool)
  {
	  int ret;

  <<<<<<< HEAD
	  lockdep_assert_held(&wq_pool_mutex);

	  do {
		  if (!idr_pre_get(&worker_pool_idr, GFP_KERNEL))
			  return -ENOMEM;
		  ret = idr_get_new(&worker_pool_idr, pool, &pool->id);
	  } while (ret == -EAGAIN);
  =======
	  mutex_lock(&worker_pool_idr_mutex);
	  ret = idr_alloc(&worker_pool_idr, pool, 0, 0, GFP_KERNEL);
	  if (ret >= 0)
		  pool->id = ret;
	  mutex_unlock(&worker_pool_idr_mutex);
  >>>>>>> c67bf5361e7e66a0ff1f4caf95f89347d55dfb89

	  return ret < 0 ? ret : 0;
  }

  We want locking from the former and idr_alloc() usage from the
  latter, which can be combined to the following.

  static int worker_pool_assign_id(struct worker_pool *pool)
  {
	  int ret;

	  lockdep_assert_held(&wq_pool_mutex);

	  ret = idr_alloc(&worker_pool_idr, pool, 0, 0, GFP_KERNEL);
	  if (ret >= 0) {
		  pool->id = ret;
		  return 0;
	  }
	  return ret;
   }

* eb2834285c ("workqueue: fix possible pool stall bug in
  wq_unbind_fn()") updated wq_unbind_fn() such that it has single
  larger for_each_std_worker_pool() loop instead of two separate loops
  with a schedule() call inbetween.  wq/for-3.10 renamed
  pool->assoc_mutex to pool->manager_mutex causing the following
  conflict (earlier function body and comments omitted for brevity).

  static void wq_unbind_fn(struct work_struct *work)
  {
  ...
		  spin_unlock_irq(&pool->lock);
  <<<<<<< HEAD
		  mutex_unlock(&pool->manager_mutex);
	  }
  =======
		  mutex_unlock(&pool->assoc_mutex);
  >>>>>>> c67bf5361e7e66a0ff1f4caf95f89347d55dfb89

		  schedule();

  <<<<<<< HEAD
	  for_each_cpu_worker_pool(pool, cpu)
  =======
  >>>>>>> c67bf5361e7e66a0ff1f4caf95f89347d55dfb89
		  atomic_set(&pool->nr_running, 0);

		  spin_lock_irq(&pool->lock);
		  wake_up_worker(pool);
		  spin_unlock_irq(&pool->lock);
	  }
  }

  The resolution is mostly trivial.  We want the control flow of the
  latter with the rename of the former.

  static void wq_unbind_fn(struct work_struct *work)
  {
  ...
		  spin_unlock_irq(&pool->lock);
		  mutex_unlock(&pool->manager_mutex);

		  schedule();

		  atomic_set(&pool->nr_running, 0);

		  spin_lock_irq(&pool->lock);
		  wake_up_worker(pool);
		  spin_unlock_irq(&pool->lock);
	  }
  }

Signed-off-by: Tejun Heo <tj@kernel.org>

1 files changed, 28 insertions, 44 deletions

diff --git a/net/l2tp/l2tp_netlink.c b/net/l2tp/l2tp_netlink.c
index c1bab22db85..0825ff26e11 100644
--- a/net/l2tp/l2tp_netlink.c
+++ b/net/l2tp/l2tp_netlink.c
@@ -246,8 +246,6 @@ static int l2tp_nl_tunnel_send(struct sk_buff *skb, u32 portid, u32 seq, int fla
 #if IS_ENABLED(CONFIG_IPV6)
 	struct ipv6_pinfo *np = NULL;
 #endif
-	struct l2tp_stats stats;
-	unsigned int start;
 
 	hdr = genlmsg_put(skb, portid, seq, &l2tp_nl_family, flags,
 			  L2TP_CMD_TUNNEL_GET);
@@ -265,28 +263,22 @@ static int l2tp_nl_tunnel_send(struct sk_buff *skb, u32 portid, u32 seq, int fla
 	if (nest == NULL)
 		goto nla_put_failure;
 
-	do {
-		start = u64_stats_fetch_begin(&tunnel->stats.syncp);
-		stats.tx_packets = tunnel->stats.tx_packets;
-		stats.tx_bytes = tunnel->stats.tx_bytes;
-		stats.tx_errors = tunnel->stats.tx_errors;
-		stats.rx_packets = tunnel->stats.rx_packets;
-		stats.rx_bytes = tunnel->stats.rx_bytes;
-		stats.rx_errors = tunnel->stats.rx_errors;
-		stats.rx_seq_discards = tunnel->stats.rx_seq_discards;
-		stats.rx_oos_packets = tunnel->stats.rx_oos_packets;
-	} while (u64_stats_fetch_retry(&tunnel->stats.syncp, start));
-
-	if (nla_put_u64(skb, L2TP_ATTR_TX_PACKETS, stats.tx_packets) ||
-	    nla_put_u64(skb, L2TP_ATTR_TX_BYTES, stats.tx_bytes) ||
-	    nla_put_u64(skb, L2TP_ATTR_TX_ERRORS, stats.tx_errors) ||
-	    nla_put_u64(skb, L2TP_ATTR_RX_PACKETS, stats.rx_packets) ||
-	    nla_put_u64(skb, L2TP_ATTR_RX_BYTES, stats.rx_bytes) ||
+	if (nla_put_u64(skb, L2TP_ATTR_TX_PACKETS,
+		    atomic_long_read(&tunnel->stats.tx_packets)) ||
+	    nla_put_u64(skb, L2TP_ATTR_TX_BYTES,
+		    atomic_long_read(&tunnel->stats.tx_bytes)) ||
+	    nla_put_u64(skb, L2TP_ATTR_TX_ERRORS,
+		    atomic_long_read(&tunnel->stats.tx_errors)) ||
+	    nla_put_u64(skb, L2TP_ATTR_RX_PACKETS,
+		    atomic_long_read(&tunnel->stats.rx_packets)) ||
+	    nla_put_u64(skb, L2TP_ATTR_RX_BYTES,
+		    atomic_long_read(&tunnel->stats.rx_bytes)) ||
 	    nla_put_u64(skb, L2TP_ATTR_RX_SEQ_DISCARDS,
-			stats.rx_seq_discards) ||
+		    atomic_long_read(&tunnel->stats.rx_seq_discards)) ||
 	    nla_put_u64(skb, L2TP_ATTR_RX_OOS_PACKETS,
-			stats.rx_oos_packets) ||
-	    nla_put_u64(skb, L2TP_ATTR_RX_ERRORS, stats.rx_errors))
+		    atomic_long_read(&tunnel->stats.rx_oos_packets)) ||
+	    nla_put_u64(skb, L2TP_ATTR_RX_ERRORS,
+		    atomic_long_read(&tunnel->stats.rx_errors)))
 		goto nla_put_failure;
 	nla_nest_end(skb, nest);
 
@@ -612,8 +604,6 @@ static int l2tp_nl_session_send(struct sk_buff *skb, u32 portid, u32 seq, int fl
 	struct nlattr *nest;
 	struct l2tp_tunnel *tunnel = session->tunnel;
 	struct sock *sk = NULL;
-	struct l2tp_stats stats;
-	unsigned int start;
 
 	sk = tunnel->sock;
 
@@ -656,28 +646,22 @@ static int l2tp_nl_session_send(struct sk_buff *skb, u32 portid, u32 seq, int fl
 	if (nest == NULL)
 		goto nla_put_failure;
 
-	do {
-		start = u64_stats_fetch_begin(&session->stats.syncp);
-		stats.tx_packets = session->stats.tx_packets;
-		stats.tx_bytes = session->stats.tx_bytes;
-		stats.tx_errors = session->stats.tx_errors;
-		stats.rx_packets = session->stats.rx_packets;
-		stats.rx_bytes = session->stats.rx_bytes;
-		stats.rx_errors = session->stats.rx_errors;
-		stats.rx_seq_discards = session->stats.rx_seq_discards;
-		stats.rx_oos_packets = session->stats.rx_oos_packets;
-	} while (u64_stats_fetch_retry(&session->stats.syncp, start));
-
-	if (nla_put_u64(skb, L2TP_ATTR_TX_PACKETS, stats.tx_packets) ||
-	    nla_put_u64(skb, L2TP_ATTR_TX_BYTES, stats.tx_bytes) ||
-	    nla_put_u64(skb, L2TP_ATTR_TX_ERRORS, stats.tx_errors) ||
-	    nla_put_u64(skb, L2TP_ATTR_RX_PACKETS, stats.rx_packets) ||
-	    nla_put_u64(skb, L2TP_ATTR_RX_BYTES, stats.rx_bytes) ||
+	if (nla_put_u64(skb, L2TP_ATTR_TX_PACKETS,
+		atomic_long_read(&session->stats.tx_packets)) ||
+	    nla_put_u64(skb, L2TP_ATTR_TX_BYTES,
+		atomic_long_read(&session->stats.tx_bytes)) ||
+	    nla_put_u64(skb, L2TP_ATTR_TX_ERRORS,
+		atomic_long_read(&session->stats.tx_errors)) ||
+	    nla_put_u64(skb, L2TP_ATTR_RX_PACKETS,
+		atomic_long_read(&session->stats.rx_packets)) ||
+	    nla_put_u64(skb, L2TP_ATTR_RX_BYTES,
+		atomic_long_read(&session->stats.rx_bytes)) ||
 	    nla_put_u64(skb, L2TP_ATTR_RX_SEQ_DISCARDS,
-			stats.rx_seq_discards) ||
+		atomic_long_read(&session->stats.rx_seq_discards)) ||
 	    nla_put_u64(skb, L2TP_ATTR_RX_OOS_PACKETS,
-			stats.rx_oos_packets) ||
-	    nla_put_u64(skb, L2TP_ATTR_RX_ERRORS, stats.rx_errors))
+		atomic_long_read(&session->stats.rx_oos_packets)) ||
+	    nla_put_u64(skb, L2TP_ATTR_RX_ERRORS,
+		atomic_long_read(&session->stats.rx_errors)))
 		goto nla_put_failure;
 	nla_nest_end(skb, nest);