Add the notion of essential service

3 files changed, 34 insertions, 4 deletions

diff --git a/src/include/s6-rc/s6rc-db.h b/src/include/s6-rc/s6rc-db.h
index c0d282d..0f03967 100644
--- a/src/include/s6-rc/s6rc-db.h
+++ b/src/include/s6-rc/s6rc-db.h
@@ -12,6 +12,8 @@
 #define S6RC_DB_BANNER_END "\ns6rc-db: end\n"
 #define S6RC_DB_BANNER_END_LEN (sizeof(S6RC_DB_BANNER_END) - 1)
 
+#define S6RC_DB_FLAG_ESSENTIAL 0x00000001U
+
 
 typedef struct s6rc_oneshot_s s6rc_oneshot_t, *s6rc_oneshot_t_ref ;
 struct s6rc_oneshot_s
diff --git a/src/s6-rc/s6-rc-compile.c b/src/s6-rc/s6-rc-compile.c
index 9ce6240..f2b6a84 100644
--- a/src/s6-rc/s6-rc-compile.c
+++ b/src/s6-rc/s6-rc-compile.c
@@ -351,10 +351,30 @@ static uint32_t read_timeout (int dfd, char const *srcdir, char const *name, cha
   return timeout ;
 }
 
+static inline uint32_t read_flags (int dfd, char const *srcdir, char const *name)
+{
+  static char const *files[32] =
+  {
+    "flag-essential",
+    0
+  } ;
+  uint32_t flags = 0 ;
+  for (uint32_t i = 0 ; i < 32 ; i++)
+  {
+    if (!files[i]) break ;
+    if (access_at(dfd, files[i], F_OK, 0) < 0)
+    {
+      if (errno != ENOENT)
+        strerr_diefu6sys(111, "read ", srcdir, "/", name, "/", files[i]) ;
+    }
+    else flags |= i ;
+  }
+  return flags ;
+}
+
 static void add_common (before_t *be, int dfd, char const *srcdir, char const *name, common_t *common, servicetype_t svtype)
 {
   unsigned int dummy ;
-  common->annotation_flags = 0 ;
   add_name(be, srcdir, name, svtype, &dummy, &common->kname) ;
   if (!add_namelist(be, dfd, srcdir, name, "dependencies", &common->depindex, &common->ndeps))
   {
@@ -365,6 +385,7 @@ static void add_common (before_t *be, int dfd, char const *srcdir, char const *n
   }
   common->timeout[0] = read_timeout(dfd, srcdir, name, "timeout-down") ;
   common->timeout[1] = read_timeout(dfd, srcdir, name, "timeout-up") ;
+  common->annotation_flags = read_flags(dfd, srcdir, name) ;
 }
 
 static inline void add_oneshot (before_t *be, int dfd, char const *srcdir, char const *name)
diff --git a/src/s6-rc/s6-rc.c b/src/s6-rc/s6-rc.c
index 76e38da..455bf16 100644
--- a/src/s6-rc/s6-rc.c
+++ b/src/s6-rc/s6-rc.c
@@ -26,7 +26,7 @@
 #include <s6-rc/config.h>
 #include <s6-rc/s6rc.h>
 
-#define USAGE "s6-rc [ -v verbosity ] [ -n dryrunthrottle ] [ -t timeout ] [ -l live ] [ -b ] [ -u | -d ] [ -p ] [ -a ] help|list|listall|diff|change [ servicenames... ]"
+#define USAGE "s6-rc [ -v verbosity ] [ -n dryrunthrottle ] [ -t timeout ] [ -l live ] [ -b ] [ -u | -d | -D ] [ -p ] [ -a ] help|list|listall|diff|change [ servicenames... ]"
 #define dieusage() strerr_dieusage(100, USAGE)
 
 typedef struct pidindex_s pidindex_t ;
@@ -47,6 +47,7 @@ static unsigned char *state ;
 static unsigned int *pendingdeps ;
 static tain_t deadline ;
 static int lameduck = 0 ;
+static int forcestop = 0 ;
 static char dryrun[UINT_FMT] = "" ;
 
 static inline void announce (void)
@@ -261,6 +262,11 @@ static void examine (unsigned int i, int h)
         strerr_warni4x("service ", name, ": already ", h ? "up" : "down") ;
       broadcast_success(i, h) ;
     }
+    else if (!h && !forcestop && db->services[i].flags & S6RC_DB_FLAG_ESSENTIAL)
+    {
+      if (verbosity)
+        strerr_warnw3x("service ", name, " is marked as essential, not stopping it") ;
+    }
     else
     {
       pidindex[npids].pid = i < db->nlong ? start_longrun(i, h) : start_oneshot(i, h) ;
@@ -450,7 +456,7 @@ static inline void print_help (void)
 "s6-rc [ -l live ] [ -a ] list [ servicenames... ]\n"
 "s6-rc [ -l live ] [ -a ] [ -u | -d ] listall [ servicenames... ]\n"
 "s6-rc [ -l live ] diff\n"
-"s6-rc [ -l live ] [ -a ] [ -u | -d ] [ -p ] [ -v verbosity ] [ -t timeout ] [ -n dryrunthrottle ] change [ servicenames... ]\n" ;
+"s6-rc [ -l live ] [ -a ] [ -u | -d | -D ] [ -p ] [ -v verbosity ] [ -t timeout ] [ -n dryrunthrottle ] change [ servicenames... ]\n" ;
   if (buffer_putsflush(buffer_1, help) < 0)
     strerr_diefu1sys(111, "write to stdout") ;
 }
@@ -465,7 +471,7 @@ int main (int argc, char const *const *argv)
     subgetopt_t l = SUBGETOPT_ZERO ;
     for (;;)
     {
-      int opt = subgetopt_r(argc, argv, "v:n:t:l:udpaXb", &l) ;
+      int opt = subgetopt_r(argc, argv, "v:n:t:l:uDdpaXb", &l) ;
       if (opt == -1) break ;
       switch (opt)
       {
@@ -480,6 +486,7 @@ int main (int argc, char const *const *argv)
         case 't' : if (!uint0_scan(l.arg, &t)) dieusage() ; break ;
         case 'l' : live = l.arg ; break ;
         case 'u' : up = 1 ; break ;
+        case 'D' : forcestop = 1 ;
         case 'd' : up = 0 ; break ;
         case 'p' : prune = 1 ; break ;
         case 'a' : selectlive = 1 ; break ;