Implement permanent failure for services via ./finish exiting 125

7 files changed, 51 insertions, 16 deletions

diff --git a/doc/s6-supervise.html b/doc/s6-supervise.html
index 081aeae..55cba6f 100644
--- a/doc/s6-supervise.html
+++ b/doc/s6-supervise.html
@@ -56,6 +56,10 @@ s6-supervise kills it with a SIGKILL. This can be configured via the
  <li> When <tt>./finish</tt> dies (or is killed),
 s6-supervise sends a <tt>'D'</tt> event to <tt>./event</tt>. Then
 it restarts <tt>./run</tt> unless it has been told not to. </li>
+ <li> If <tt>./finish</tt> exits 125, then s6-supervise sends a <tt>'O'</tt> event
+to <tt>./event</tt> <em>before</em> the <tt>'D'</tt>, and it
+<strong>does not restart the service</strong>, as if <tt>s6-svc -O</tt> had
+been called. This can be used to signify permanent failure to start the service. </li>
  <li> There is a minimum 1-second delay between two <tt>./run</tt> spawns, to avoid busylooping
 if <tt>./run</tt> exits too quickly. </li>
  <li> When killed or asked to exit, it waits for the service to go down one last time, then
diff --git a/doc/servicedir.html b/doc/servicedir.html
index 98929bb..a0d98f0 100644
--- a/doc/servicedir.html
+++ b/doc/servicedir.html
@@ -87,15 +87,21 @@ is executed everytime the <tt>run</tt> script dies. Generally, its main
 purpose is to clean up non-volatile data such as the filesystem after the supervised
 process has been killed. If the <em>foo</em> service is supposed to be up,
 <em>foo</em><tt>/run</tt> is restarted
-after <em>foo</em><tt>/finish</tt> dies. By default, a finish script must do
-its work and exit in less than                              
+after <em>foo</em><tt>/finish</tt> dies.
+ <ul>
+  <li> By default, a finish script must do its work and exit in less than                              
 5 seconds; if it takes more than that, it is killed. (The point is that the run
 script, not the finish script, should be running; the finish script should really
 be short-lived.) The maximum duration of a <tt>finish</tt> execution can be
-configured via the <tt>timeout-finish</tt> file, see below. The finish script is
+configured via the <tt>timeout-finish</tt> file, see below. </li>
+  <li> The finish script is
 executed with two arguments: the exit code from the run script (resp. 256 if the
 run script was killed by a signal), and an undefined number (resp. the number of
 the signal that killed the run script). </li>
+  <li> If the finish script exits 125, then <a href="s6-supervise.html">s6-supervise</a>
+interprets this as a permanent failure for the service, and does not restart it,
+as if an <a href="s6-svc.html">s6-svc -O</a> command had been sent. </li>
+ </ul> </li>
  <li> A directory named <tt>supervise</tt>. It is automatically created by
 <a href="s6-supervise.html">s6-supervise</a> if it does not exist. This is where
 <a href="s6-supervise.html">s6-supervise</a> stores its information. The directory
diff --git a/src/supervision/s6-supervise.c b/src/supervision/s6-supervise.c
index 8bb55c8..2e8ce6a 100644
--- a/src/supervision/s6-supervise.c
+++ b/src/supervision/s6-supervise.c
@@ -436,7 +436,13 @@ static void finishtimeout (void)
 
 static void finish_z (void)
 {
-  set_down_and_ready("D", 1) ;
+  int wstat = (int)status.pid ;
+  if (WIFEXITED(wstat) && WEXITSTATUS(wstat) == 125)
+  {
+    status.flagwant = 0 ;
+    set_down_and_ready("OD", 2) ;
+  }
+  else set_down_and_ready("D", 1) ;
 }
 
 static void finish_u (void)
diff --git a/src/supervision/s6-svlisten.c b/src/supervision/s6-svlisten.c
index f2191fd..d15557a 100644
--- a/src/supervision/s6-svlisten.c
+++ b/src/supervision/s6-svlisten.c
@@ -63,6 +63,7 @@ int main (int argc, char const **argv, char const *const *envp)
   {
     s6_svlisten_t foo = S6_SVLISTEN_ZERO ;
     pid_t pid ;
+    int e ;
     uint16_t ids[argc1] ;
     unsigned char upstate[bitarray_div8(argc1)] ;
     unsigned char readystate[bitarray_div8(argc1)] ;
@@ -71,10 +72,12 @@ int main (int argc, char const **argv, char const *const *envp)
     if (!pid) strerr_diefu2sys(111, "spawn ", argv[argc1 + 1]) ;
     if (wantrestart)
     {
-      argc1 = s6_svlisten_loop(&foo, 0, 1, or, &deadline, spfd, &s6_svlisten_signal_handler) ;
-      if (argc1) return argc1 ;
+      e = s6_svlisten_loop(&foo, 0, 1, or, &deadline, spfd, &s6_svlisten_signal_handler) ;
+      if (e) strerr_dief1x(e, "some services reported permanent failure") ;
       wantup = 1 ;
     }
-    return s6_svlisten_loop(&foo, wantup, wantready, or, &deadline, spfd, &s6_svlisten_signal_handler) ;
+    e = s6_svlisten_loop(&foo, wantup, wantready, or, &deadline, spfd, &s6_svlisten_signal_handler) ;
+    if (e) strerr_dief1x(e, "some services reported permanent failure") ;
   }
+  return 0 ;
 }
diff --git a/src/supervision/s6-svlisten1.c b/src/supervision/s6-svlisten1.c
index d9a5de4..af9959a 100644
--- a/src/supervision/s6-svlisten1.c
+++ b/src/supervision/s6-svlisten1.c
@@ -17,6 +17,7 @@ int main (int argc, char const *const *argv, char const *const *envp)
   tain_t deadline, tto ;
   pid_t pid ;
   int spfd ;
+  int e ;
   int wantup = 1, wantready = 0, wantrestart = 0 ;
   uint16_t id ;
   unsigned char upstate, readystate ;
@@ -52,9 +53,11 @@ int main (int argc, char const *const *argv, char const *const *envp)
   if (!pid) strerr_diefu2sys(111, "spawn ", argv[1]) ;
   if (wantrestart)
   {
-    int r = s6_svlisten_loop(&foo, 0, 1, 1, &deadline, spfd, &s6_svlisten_signal_handler) ;
-    if (r) return r ;
+    int e = s6_svlisten_loop(&foo, 0, 1, 1, &deadline, spfd, &s6_svlisten_signal_handler) ;
+    if (e) strerr_dief2x(1, argv[0], " failed permanently: the finish script exited 125") ;
     wantup = 1 ;
   }
-  return s6_svlisten_loop(&foo, wantup, wantready, 1, &deadline, spfd, &s6_svlisten_signal_handler) ;
+  e = s6_svlisten_loop(&foo, wantup, wantready, 1, &deadline, spfd, &s6_svlisten_signal_handler) ;
+  if (e) strerr_dief2x(1, argv[0], " failed permanently: the finish script exited 125") ;
+  return 0 ;
 }
diff --git a/src/supervision/s6-svwait.c b/src/supervision/s6-svwait.c
index 752da69..28d1c3d 100644
--- a/src/supervision/s6-svwait.c
+++ b/src/supervision/s6-svwait.c
@@ -46,10 +46,13 @@ int main (int argc, char const *const *argv)
 
   {
     s6_svlisten_t foo = S6_SVLISTEN_ZERO ;
+    int e ;
     uint16_t ids[argc] ;
     unsigned char upstate[bitarray_div8(argc)] ;
     unsigned char readystate[bitarray_div8(argc)] ;
     s6_svlisten_init(argc, argv, &foo, ids, upstate, readystate, &deadline) ;
-    return s6_svlisten_loop(&foo, wantup, wantready, or, &deadline, -1, 0) ;
+    e = s6_svlisten_loop(&foo, wantup, wantready, or, &deadline, -1, 0) ;
+    if (e) strerr_dief1x(e, "some services reported permanent failure") ; 
   }
+  return 0 ;
 }
diff --git a/src/supervision/s6_svlisten_loop.c b/src/supervision/s6_svlisten_loop.c
index 3cab3ff..942abf0 100644
--- a/src/supervision/s6_svlisten_loop.c
+++ b/src/supervision/s6_svlisten_loop.c
@@ -26,7 +26,7 @@ void s6_svlisten_init (int argc, char const *const *argv, s6_svlisten_t *foo, ui
     memcpy(s, argv[i], len) ;
     s[len] = '/' ;
     memcpy(s + len + 1, S6_SUPERVISE_EVENTDIR, sizeof(S6_SUPERVISE_EVENTDIR)) ;
-    foo->ids[i] = ftrigr_subscribe_g(&foo->a, s, "[DuUd]", FTRIGR_REPEAT, deadline) ;
+    foo->ids[i] = ftrigr_subscribe_g(&foo->a, s, "[DuUdO]", FTRIGR_REPEAT, deadline) ;
     if (!foo->ids[i]) strerr_diefu2sys(111, "subscribe to events for ", argv[i]) ;
     if (!s6_svstatus_read(argv[i], &status)) strerr_diefu1sys(111, "s6_svstatus_read") ;
     bitarray_poke(foo->upstate, i, status.pid && !status.flagfinishing) ;
@@ -47,6 +47,7 @@ static inline int got (s6_svlisten_t const *foo, int wantup, int wantready, int
 int s6_svlisten_loop (s6_svlisten_t *foo, int wantup, int wantready, int or, tain_t const *deadline, int spfd, action_func_t_ref handler)
 {
   iopause_fd x[2] = { { .fd = ftrigr_fd(&foo->a), .events = IOPAUSE_READ }, { .fd = spfd, .events = IOPAUSE_READ, .revents = 0 } } ;
+  unsigned int e = 0 ;
   while (!got(foo, wantup, wantready, or))
   {
     int r = iopause_g(x, 1 + (spfd >= 0), deadline) ;
@@ -64,12 +65,21 @@ int s6_svlisten_loop (s6_svlisten_t *foo, int wantup, int wantready, int or, tai
         if (r < 0) strerr_diefu1sys(111, "ftrigr_check") ;
         if (r)
         {
-          unsigned int d = byte_chr("dDuU", 4, what) ;
-          bitarray_poke(foo->upstate, i, d & 2) ;
-          bitarray_poke(foo->readystate, i, d & 1) ;
+          if (what == 'O')
+          {
+            bitarray_poke(foo->upstate, i, wantup) ;
+            bitarray_poke(foo->readystate, i, wantready) ;
+            e++ ;
+          }
+          else
+          {
+            unsigned int d = byte_chr("dDuU", 4, what) ;
+            bitarray_poke(foo->upstate, i, d & 2) ;
+            bitarray_poke(foo->readystate, i, d & 1) ;
+          }
         }
       }
     }
   }
-  return 0 ;
+  return e ;
 }