From e9c0de80531cd372d1c560f753c03df0573dc273 Mon Sep 17 00:00:00 2001
From: Donald Buczek <buczek@molgen.mpg.de>
Date: Wed, 15 Apr 2020 15:25:06 +0200
Subject: [PATCH] mxqd: Only start jobs we are qualified for

Check, whether this server is qualified to start jobs from a group.

Lazy-evaluate qualification criteria defined in the group and cache the result.

The qualification criteria need to be reevaluated  when the active groups
were reloaded, because they may be changed by the user in existing
groups.

For now, the only qualification criteria are the groups blacklist and
whitelist. If a group has a whitelist, the short or long hostname of the
mxqd server needs to be on that list, otherwise the server is not
qualified for the group.

If the servers name is on the blacklist of the group, the server is not
qualified for the group.

Don't start jobs we are not qualified for.

This can later be expanded to additional criteria (e.g. hostconfig or
processor flags).
---
 mxqd.c         | 47 +++++++++++++++++++++++++++++++++++++++++++++++
 mxqd.h         |  4 ++++
 mxqd_control.c |  3 +++
 3 files changed, 54 insertions(+)

diff --git a/mxqd.c b/mxqd.c
index c1106aba..73d2eaaa 100644
--- a/mxqd.c
+++ b/mxqd.c
@@ -43,6 +43,7 @@
 #include "mxq.h"
 
 #include "mxqd_control.h"
+#include "keywordset.h"
 
 #ifndef MXQ_INITIAL_PATH
 #  define MXQ_INITIAL_PATH      "/sbin:/bin:/usr/sbin:/usr/bin:/usr/local/sbin:/usr/local/bin"
@@ -546,6 +547,16 @@ int server_init(struct mxq_server *server, int argc, char *argv[])
     }
 
     server->hostname = arg_hostname;
+    {
+        char *dot=index(arg_hostname,'.');
+        if (dot) {
+            server->hostname_short = mx_malloc_forever(dot-arg_hostname+1);
+            strncpy(server->hostname_short, arg_hostname, dot-arg_hostname);
+            server->hostname_short[dot-arg_hostname] = 0;
+        } else
+            server->hostname_short = mx_strdup_forever(arg_hostname);
+    }
+
     server->daemon_name = arg_daemon_name;
     server->initial_path = arg_initial_path;
     server->initial_tmpdir = arg_initial_tmpdir;
@@ -1277,6 +1288,39 @@ unsigned long start_job(struct mxq_group_list *glist)
 
 /**********************************************************************/
 
+static int server_is_qualified(struct mxq_server *server, struct mxq_group *group) {
+
+    int is_qualified;
+
+    if (*group->group_whitelist != 0) {
+        is_qualified = 0;
+        struct keywordset *kws = keywordset_new(group->group_whitelist);
+        if ( keywordset_ismember(kws, server->hostname_short)
+                || keywordset_ismember(kws, server->hostname) )
+            is_qualified = 1;
+        keywordset_free(kws);
+    } else {
+        is_qualified = 1;
+    }
+
+    if (*group->group_blacklist != 0) {
+        struct keywordset *kws = keywordset_new(group->group_blacklist);
+        if ( keywordset_ismember(kws, server->hostname_short)
+                || keywordset_ismember(kws, server->hostname) )
+            is_qualified = 0;
+        keywordset_free(kws);
+    }
+    return (is_qualified);
+}
+
+static int server_is_qualified_cached(struct mxq_server *server, struct mxq_group_list *glist) {
+    if (!glist->server_is_qualified_evaluated) {
+        glist->server_is_qualified = server_is_qualified(server, &glist->group);
+        glist->server_is_qualified_evaluated = 1;
+    }
+    return glist->server_is_qualified;
+}
+
 unsigned long start_user(struct mxq_user_list *ulist, long slots_to_start)
 {
     struct mxq_server *server;
@@ -1319,6 +1363,8 @@ unsigned long start_user(struct mxq_user_list *ulist, long slots_to_start)
         if (df_scratch/1024/1024/1024 < group->job_tmpdir_size + 20) {
             continue;
         }
+        if (!server_is_qualified_cached(server, glist))
+            continue;
 
         mx_log_info("  group=%s(%d):%lu slots_to_start=%ld slots_per_job=%lu :: trying to start job for group.",
                 group->user_name, group->user_uid, group->group_id, slots_to_start, glist->slots_per_job);
@@ -1472,6 +1518,7 @@ void server_free(struct mxq_server *server)
     mx_free_null(server->finished_jobsdir);
     mx_flock_free(server->flock);
     mx_free_null(server->supgid);
+    mx_free_null(server->hostname_short);
 
     mx_log_finish();
 }
diff --git a/mxqd.h b/mxqd.h
index 5c9ce7e3..87aa2236 100644
--- a/mxqd.h
+++ b/mxqd.h
@@ -43,6 +43,9 @@ struct mxq_group_list {
     unsigned long global_threads_running;
     unsigned long global_slots_running;
 
+    int        server_is_qualified_evaluated;
+    int        server_is_qualified;
+
     short orphaned;
 };
 
@@ -95,6 +98,7 @@ struct mxq_server {
     unsigned long long int starttime;
     char *host_id;
     char *hostname;
+    char *hostname_short;
     char *daemon_name;
     char *pidfilename;
     char *finished_jobsdir;
diff --git a/mxqd_control.c b/mxqd_control.c
index 36814e26..bbbd8549 100644
--- a/mxqd_control.c
+++ b/mxqd_control.c
@@ -103,6 +103,9 @@ static void _group_list_init(struct mxq_group_list *glist)
     glist->slots_max  = slots_max;
     glist->memory_max = memory_max;
 
+    glist->server_is_qualified_evaluated = 0;
+    glist->server_is_qualified = 0;
+
     glist->orphaned = 0;
 }