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)

diff --git a/doc/arm/Bv9ARM-book.xml b/doc/arm/Bv9ARM-book.xml
index 9213ef588b96e6da94d3d0669b37280214ee297c..b18dee135634230cd806e5e23494311a088445b6 100644 (file)
--- a/doc/arm/Bv9ARM-book.xml
+++ b/doc/arm/Bv9ARM-book.xml
@@ -8253,7 +8253,8 @@ 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 8dd3018182bcf27299a4444ff70b6ded750fe259..6edb46d6d76b2f2df9f3d4edada85a4112faec3a 100644 (file)
--- a/lib/ns/client.c
+++ b/lib/ns/client.c
@@ -3428,8 +3428,9 @@ 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.
                 *
@@ -3443,7 +3444,8 @@ 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);