runsvdir: fx a recent vda's buglet (was pausing even if not signaled).

 stop spawning children immediately if signaled. Kill one global.

diff --git a/runit/runsvdir.c b/runit/runsvdir.c
index 29e747f..e7f8d5a 100644 (file)
--- a/runit/runsvdir.c
+++ b/runit/runsvdir.c
@@ -58,7 +58,6 @@ struct globals {
        struct pollfd pfd[1];
        unsigned stamplog;
 #endif
-       smallint need_rescan; /* = 1; */
        smallint set_pgrp;
 };
 #define G (*(struct globals*)&bb_common_bufsiz1)
@@ -70,10 +69,8 @@ struct globals {
 #define logpipe     (G.logpipe     )
 #define pfd         (G.pfd         )
 #define stamplog    (G.stamplog    )
-#define need_rescan (G.need_rescan )
 #define set_pgrp    (G.set_pgrp    )
 #define INIT_G() do { \
-       need_rescan = 1; \
 } while (0)
 
 static void fatal2_cannot(const char *m1, const char *m2)
@@ -96,21 +93,27 @@ static void warnx(const char *m1)
 }
 #endif
 
-static void runsv(int no, const char *name)
+/* inlining + vfork -> bigger code */
+static NOINLINE pid_t runsv(const char *name)
 {
-       pid_t pid = vfork();
+       pid_t pid;
+
+       /* If we got signaled, stop spawning children at once! */
+       if (bb_got_signal)
+               return 0;
 
+       pid = vfork();
        if (pid == -1) {
                warn2_cannot("vfork", "");
-               return;
+               return 0;
        }
        if (pid == 0) {
                /* child */
                if (set_pgrp)
                        setsid();
 /* man execv:
- * Signals set to be caught by the calling process image
- * shall be set to the default action in the new process image.
+ * "Signals set to be caught by the calling process image
+ *  shall be set to the default action in the new process image."
  * Therefore, we do not need this: */
 #if 0
                bb_signals(0
@@ -121,20 +124,22 @@ static void runsv(int no, const char *name)
                execlp("runsv", "runsv", name, NULL);
                fatal2_cannot("start runsv ", name);
        }
-       sv[no].pid = pid;
+       return pid;
 }
 
-static void do_rescan(void)
+/* gcc 4.3.0 does better with NOINLINE */
+static NOINLINE int do_rescan(void)
 {
        DIR *dir;
        direntry *d;
        int i;
        struct stat s;
+       int need_rescan = 0;
 
        dir = opendir(".");
        if (!dir) {
                warn2_cannot("open directory ", svdir);
-               return;
+               return 1; /* need to rescan again soon */
        }
        for (i = 0; i < svnum; i++)
                sv[i].isgone = 1;
@@ -152,47 +157,47 @@ static void do_rescan(void)
                }
                if (!S_ISDIR(s.st_mode))
                        continue;
+               /* Do we have this service listed already? */
                for (i = 0; i < svnum; i++) {
                        if ((sv[i].ino == s.st_ino)
 #if CHECK_DEVNO_TOO
                         && (sv[i].dev == s.st_dev)
 #endif
                        ) {
-                               sv[i].isgone = 0;
-                               if (!sv[i].pid)
-                                       runsv(i, d->d_name);
-                               break;
+                               if (sv[i].pid == 0) /* restart if it has died */
+                                       goto run_ith_sv;
+                               sv[i].isgone = 0; /* "we still see you" */
+                               goto next_dentry;
                        }
                }
-               if (i == svnum) {
-                       /* new service */
+               { /* Not found, make new service */
                        struct service *svnew = realloc(sv, (i+1) * sizeof(*sv));
                        if (!svnew) {
                                warn2_cannot("start runsv ", d->d_name);
+                               need_rescan = 1;
                                continue;
                        }
                        sv = svnew;
                        svnum++;
-                       memset(&sv[i], 0, sizeof(sv[i]));
-                       sv[i].ino = s.st_ino;
 #if CHECK_DEVNO_TOO
                        sv[i].dev = s.st_dev;
 #endif
-                       /*sv[i].pid = 0;*/
-                       /*sv[i].isgone = 0;*/
-                       runsv(i, d->d_name);
-                       need_rescan = 1;
+                       sv[i].ino = s.st_ino;
+ run_ith_sv:
+                       sv[i].pid = runsv(d->d_name);
+                       sv[i].isgone = 0;
                }
+ next_dentry: ;
        }
        i = errno;
        closedir(dir);
-       if (i) {
+       if (i) { /* readdir failed */
                warn2_cannot("read directory ", svdir);
-               need_rescan = 1;
-               return;
+               return 1; /* need to rescan again soon */
        }
 
-       /* Send SIGTERM to runsv whose directories were not found (removed) */
+       /* Send SIGTERM to runsv whose directories
+        * were no longer found (-> must have been removed) */
        for (i = 0; i < svnum; i++) {
                if (!sv[i].isgone)
                        continue;
@@ -201,8 +206,8 @@ static void do_rescan(void)
                svnum--;
                sv[i] = sv[svnum];
                i--; /* so that we don't skip new sv[i] (bug was here!) */
-               need_rescan = 1;
        }
+       return need_rescan;
 }
 
 int runsvdir_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
@@ -219,6 +224,7 @@ int runsvdir_main(int argc UNUSED_PARAM, char **argv)
        unsigned now;
        unsigned stampcheck;
        int i;
+       int need_rescan = 1;
 
        INIT_G();
 
@@ -284,10 +290,9 @@ int runsvdir_main(int argc UNUSED_PARAM, char **argv)
                                break;
                        for (i = 0; i < svnum; i++) {
                                if (pid == sv[i].pid) {
-                                       /* runsv has gone */
+                                       /* runsv has died */
                                        sv[i].pid = 0;
                                        need_rescan = 1;
-                                       break;
                                }
                        }
                }
@@ -306,19 +311,20 @@ int runsvdir_main(int argc UNUSED_PARAM, char **argv)
                                                last_mtime = s.st_mtime;
                                                last_dev = s.st_dev;
                                                last_ino = s.st_ino;
-                                               need_rescan = 0;
                                                //if (now <= mtime)
                                                //      sleep(1);
-                                               do_rescan();
+                                               need_rescan = do_rescan();
                                                while (fchdir(curdir) == -1) {
                                                        warn2_cannot("change directory, pausing", "");
                                                        sleep(5);
                                                }
-                                       } else
+                                       } else {
                                                warn2_cannot("change directory to ", svdir);
+                                       }
                                }
-                       } else
+                       } else {
                                warn2_cannot("stat ", svdir);
+                       }
                }
 
 #if ENABLE_FEATURE_RUNSVDIR_LOG
@@ -354,6 +360,8 @@ int runsvdir_main(int argc UNUSED_PARAM, char **argv)
                }
 #endif
                switch (bb_got_signal) {
+               case 0: /* we are not signaled, business as usual */
+                       break;
                case SIGHUP:
                        for (i = 0; i < svnum; i++)
                                if (sv[i].pid)