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>
diff --git a/lib/rhashtable.c b/lib/rhashtable.c
index ddd7dde..1935e86 100644
--- a/lib/rhashtable.c
+++ b/lib/rhashtable.c
@@ -732,7 +732,7 @@ void rhashtable_walk_exit(struct rhashtable_iter *iter)
EXPORT_SYMBOL_GPL(rhashtable_walk_exit);
/**
- * rhashtable_walk_start - Start a hash table walk
+ * rhashtable_walk_start_check - Start a hash table walk
* @iter: Hash table iterator
*
* Start a hash table walk at the current iterator position. Note that we take
@@ -744,8 +744,12 @@ EXPORT_SYMBOL_GPL(rhashtable_walk_exit);
* Returns -EAGAIN if resize event occured. Note that the iterator
* will rewind back to the beginning and you may use it immediately
* by calling rhashtable_walk_next.
+ *
+ * rhashtable_walk_start is defined as an inline variant that returns
+ * void. This is preferred in cases where the caller would ignore
+ * resize events and always continue.
*/
-int rhashtable_walk_start(struct rhashtable_iter *iter)
+int rhashtable_walk_start_check(struct rhashtable_iter *iter)
__acquires(RCU)
{
struct rhashtable *ht = iter->ht;
@@ -764,7 +768,7 @@ int rhashtable_walk_start(struct rhashtable_iter *iter)
return 0;
}
-EXPORT_SYMBOL_GPL(rhashtable_walk_start);
+EXPORT_SYMBOL_GPL(rhashtable_walk_start_check);
/**
* rhashtable_walk_next - Return the next object and advance the iterator
