[PATCH net-next 10/15] batman-adv: tt: extract marking of a removed local entry

[Simon Wunderlich <sw@simonwunderlich.de>]

From: Sven Eckelmann <sven@narfation.org>

The first locked section of batadv_tt_local_remove() does three things at
once

* it snapshots the flags for the return value
* it marks the client as ROAMed
* it decides whether the entry has to survive until the next ttvn increment

But this complex locked section is in the middle of the function and cannot
be written as scoped_guard() due to goto's in this routine.

Move it to batadv_tt_local_mark_removed() and report the decision via its
return value. But leave the batadv_tt_local_set_pending_event() flag
assembly outside the function because it has no locking requirements.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
---
 net/batman-adv/translation-table.c | 48 ++++++++++++++++++++++--------
 1 file changed, 35 insertions(+), 13 deletions(-)

diff --git a/net/batman-adv/translation-table.c b/net/batman-adv/translation-table.c
index b3e45fb5e9dd4..f5b753ed1ae1a 100644
--- a/net/batman-adv/translation-table.c
+++ b/net/batman-adv/translation-table.c
@@ -1443,6 +1443,38 @@ batadv_tt_local_set_pending_event(struct batadv_priv *bat_priv,
 		   batadv_print_vid(tt_local_entry->common.vid), message);
 }
 
+/**
+ * batadv_tt_local_mark_removed() - mark a local entry as removed
+ * @tt_local_entry: local TT entry to mark
+ * @roaming: true if the deletion is due to a roaming event
+ * @curr_flags: pointer to store the flags of the entry before it was marked
+ *
+ * Return: true if the entry has to be kept in the local table until the next
+ * ttvn increment, false if it can be purged immediately.
+ */
+static bool
+batadv_tt_local_mark_removed(struct batadv_tt_local_entry *tt_local_entry,
+			     bool roaming, u16 *curr_flags)
+{
+	struct batadv_tt_common_entry *common = &tt_local_entry->common;
+	bool pending = false;
+
+	scoped_guard(spinlock_bh, &common->flags_lock) {
+		*curr_flags = common->flags;
+
+		/* mark the local client as ROAMed */
+		if (roaming)
+			common->flags |= BATADV_TT_CLIENT_ROAM;
+
+		if (!(common->flags & BATADV_TT_CLIENT_NEW)) {
+			common->flags |= BATADV_TT_CLIENT_PENDING;
+			pending = true;
+		}
+	}
+
+	return pending;
+}
+
 /**
  * batadv_tt_local_remove() - logically remove an entry from the local table
  * @bat_priv: the bat priv with all the mesh interface information
@@ -1467,26 +1499,16 @@ u16 batadv_tt_local_remove(struct batadv_priv *bat_priv, const u8 *addr,
 	if (!tt_local_entry)
 		goto out;
 
-	spin_lock_bh(&tt_local_entry->common.flags_lock);
-	curr_flags = tt_local_entry->common.flags;
-
 	flags = BATADV_TT_CLIENT_DEL;
 	/* if this global entry addition is due to a roaming, the node has to
 	 * mark the local entry as "roamed" in order to correctly reroute
 	 * packets later
 	 */
-	if (roaming) {
+	if (roaming)
 		flags |= BATADV_TT_CLIENT_ROAM;
-		/* mark the local client as ROAMed */
-		tt_local_entry->common.flags |= BATADV_TT_CLIENT_ROAM;
-	}
-
-	if (!(tt_local_entry->common.flags & BATADV_TT_CLIENT_NEW)) {
-		tt_local_entry->common.flags |= BATADV_TT_CLIENT_PENDING;
-		pending = true;
-	}
-	spin_unlock_bh(&tt_local_entry->common.flags_lock);
 
+	pending = batadv_tt_local_mark_removed(tt_local_entry, roaming,
+					       &curr_flags);
 	if (pending) {
 		batadv_tt_local_set_pending_event(bat_priv, tt_local_entry, flags,
 						  message);
-- 
2.47.3