restore allowance for tcp-clients < interfaces

in the "refactor tcpquota and pipeline refs" commit, the counting
of active interfaces was tightened in such a way that named could
fail to listen on an interface if there were more interfaces than
tcp-clients. when checking the quota to start accepting on an
interface, if the number of active clients was above zero, then
it was presumed that some other client was able to handle accepting
new connections. this, however, ignored the fact that the current client
could be included in that count, so if the quota was already exceeded
before all the interfaces were listening, some interfaces would never
listen.

we now check whether the current client has been marked active; if so,
then the number of active clients on the interface must be greater
than 1, not 0.

(cherry picked from commit 02365b87ea0b1ea5ea8b17376f6734c811c95e61)
(cherry picked from commit cae79e1bab677ed1c2ce3adc5d54163a78f0d30b)

diff --git a/doc/arm/Bv9ARM-book.xml b/doc/arm/Bv9ARM-book.xml
index f79264a873c025ea2d6ee0fc74aa81662a031ad0..03ed8b786e66cfd06350b429c6f87d8831fab10d 100644 (file)
--- a/doc/arm/Bv9ARM-book.xml
+++ b/doc/arm/Bv9ARM-book.xml
@@ -8252,7 +8252,8 @@ avoid-v6-udp-ports { 40000; range 50000 60000; };
                <para>
                  The number of file descriptors reserved for TCP, stdio,
                  etc.  This needs to be big enough to cover the number of
-                 interfaces <command>named</command> listens on, <command>tcp-clients</command> as well as
+                 interfaces <command>named</command> listens on plus
+                 <command>tcp-clients</command>, as well as
                  to provide room for outgoing TCP queries and incoming zone
                  transfers.  The default is <literal>512</literal>.
                  The minimum value is <literal>128</literal> and the

diff --git a/lib/ns/client.c b/lib/ns/client.c
index 223eb1267c14b0127e9d7d6bef189ecaf0e5b06c..6e58b7e3501f5929ed396d44668e3b4f7b555f24 100644 (file)
--- a/lib/ns/client.c
+++ b/lib/ns/client.c
@@ -3439,8 +3439,9 @@ client_accept(ns_client_t *client) {
                 *
                 * So, we check here to see if any other clients are
                 * already servicing TCP queries on this interface (whether
-                * accepting, reading, or processing). If we find at least
-                * one, then it's okay *not* to call accept - we can let this
+                * accepting, reading, or processing). If we find that at
+                * least one client other than this one is active, then
+                * it's okay *not* to call accept - we can let this
                 * client go inactive and another will take over when it's
                 * done.
                 *
@@ -3454,7 +3455,8 @@ client_accept(ns_client_t *client) {
                 * quota is tcp-clients plus the number of listening
                 * interfaces plus 1.)
                 */
-               exit = (atomic_load(&client->interface->ntcpactive) > 0U);
+               exit = (atomic_load(&client->interface->ntcpactive) >
+                       (client->tcpactive ? 1U : 0U));
                if (exit) {
                        client->newstate = NS_CLIENTSTATE_INACTIVE;
                        (void)exit_check(client);