rhashtable: Change rhashtable_walk_start to return void

Most callers of rhashtable_walk_start don't care about a resize event
which is indicated by a return value of -EAGAIN. So calls to
rhashtable_walk_start are wrapped wih code to ignore -EAGAIN. Something
like this is common:

       ret = rhashtable_walk_start(rhiter);
       if (ret && ret != -EAGAIN)
               goto out;

Since zero and -EAGAIN are the only possible return values from the
function this check is pointless. The condition never evaluates to true.

This patch changes rhashtable_walk_start to return void. This simplifies
code for the callers that ignore -EAGAIN. For the few cases where the
caller cares about the resize event, particularly where the table can be
walked in mulitple parts for netlink or seq file dump, the function
rhashtable_walk_start_check has been added that returns -EAGAIN on a
resize event.

Signed-off-by: Tom Herbert <tom@quantonium.net>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 10 insertions, 24 deletions

diff --git a/net/mac80211/mesh_pathtbl.c b/net/mac80211/mesh_pathtbl.c
index 86c8dfef56a4..a5125624a76d 100644
--- a/net/mac80211/mesh_pathtbl.c
+++ b/net/mac80211/mesh_pathtbl.c
@@ -257,9 +257,7 @@ __mesh_path_lookup_by_idx(struct mesh_table *tbl, int idx)
 	if (ret)
 		return NULL;
 
-	ret = rhashtable_walk_start(&iter);
-	if (ret && ret != -EAGAIN)
-		goto err;
+	rhashtable_walk_start(&iter);
 
 	while ((mpath = rhashtable_walk_next(&iter))) {
 		if (IS_ERR(mpath) && PTR_ERR(mpath) == -EAGAIN)
@@ -269,7 +267,6 @@ __mesh_path_lookup_by_idx(struct mesh_table *tbl, int idx)
 		if (i++ == idx)
 			break;
 	}
-err:
 	rhashtable_walk_stop(&iter);
 	rhashtable_walk_exit(&iter);
 
@@ -513,9 +510,7 @@ void mesh_plink_broken(struct sta_info *sta)
 	if (ret)
 		return;
 
-	ret = rhashtable_walk_start(&iter);
-	if (ret && ret != -EAGAIN)
-		goto out;
+	rhashtable_walk_start(&iter);
 
 	while ((mpath = rhashtable_walk_next(&iter))) {
 		if (IS_ERR(mpath) && PTR_ERR(mpath) == -EAGAIN)
@@ -535,7 +530,6 @@ void mesh_plink_broken(struct sta_info *sta)
 				WLAN_REASON_MESH_PATH_DEST_UNREACHABLE, bcast);
 		}
 	}
-out:
 	rhashtable_walk_stop(&iter);
 	rhashtable_walk_exit(&iter);
 }
@@ -584,9 +578,7 @@ void mesh_path_flush_by_nexthop(struct sta_info *sta)
 	if (ret)
 		return;
 
-	ret = rhashtable_walk_start(&iter);
-	if (ret && ret != -EAGAIN)
-		goto out;
+	rhashtable_walk_start(&iter);
 
 	while ((mpath = rhashtable_walk_next(&iter))) {
 		if (IS_ERR(mpath) && PTR_ERR(mpath) == -EAGAIN)
@@ -597,7 +589,7 @@ void mesh_path_flush_by_nexthop(struct sta_info *sta)
 		if (rcu_access_pointer(mpath->next_hop) == sta)
 			__mesh_path_del(tbl, mpath);
 	}
-out:
+
 	rhashtable_walk_stop(&iter);
 	rhashtable_walk_exit(&iter);
 }
@@ -614,9 +606,7 @@ static void mpp_flush_by_proxy(struct ieee80211_sub_if_data *sdata,
 	if (ret)
 		return;
 
-	ret = rhashtable_walk_start(&iter);
-	if (ret && ret != -EAGAIN)
-		goto out;
+	rhashtable_walk_start(&iter);
 
 	while ((mpath = rhashtable_walk_next(&iter))) {
 		if (IS_ERR(mpath) && PTR_ERR(mpath) == -EAGAIN)
@@ -627,7 +617,7 @@ static void mpp_flush_by_proxy(struct ieee80211_sub_if_data *sdata,
 		if (ether_addr_equal(mpath->mpp, proxy))
 			__mesh_path_del(tbl, mpath);
 	}
-out:
+
 	rhashtable_walk_stop(&iter);
 	rhashtable_walk_exit(&iter);
 }
@@ -642,9 +632,7 @@ static void table_flush_by_iface(struct mesh_table *tbl)
 	if (ret)
 		return;
 
-	ret = rhashtable_walk_start(&iter);
-	if (ret && ret != -EAGAIN)
-		goto out;
+	rhashtable_walk_start(&iter);
 
 	while ((mpath = rhashtable_walk_next(&iter))) {
 		if (IS_ERR(mpath) && PTR_ERR(mpath) == -EAGAIN)
@@ -653,7 +641,7 @@ static void table_flush_by_iface(struct mesh_table *tbl)
 			break;
 		__mesh_path_del(tbl, mpath);
 	}
-out:
+
 	rhashtable_walk_stop(&iter);
 	rhashtable_walk_exit(&iter);
 }
@@ -873,9 +861,7 @@ void mesh_path_tbl_expire(struct ieee80211_sub_if_data *sdata,
 	if (ret)
 		return;
 
-	ret = rhashtable_walk_start(&iter);
-	if (ret && ret != -EAGAIN)
-		goto out;
+	rhashtable_walk_start(&iter);
 
 	while ((mpath = rhashtable_walk_next(&iter))) {
 		if (IS_ERR(mpath) && PTR_ERR(mpath) == -EAGAIN)
@@ -887,7 +873,7 @@ void mesh_path_tbl_expire(struct ieee80211_sub_if_data *sdata,
 		     time_after(jiffies, mpath->exp_time + MESH_PATH_EXPIRE))
 			__mesh_path_del(tbl, mpath);
 	}
-out:
+
 	rhashtable_walk_stop(&iter);
 	rhashtable_walk_exit(&iter);
 }