/* Busyboxed by Denys Vlasenko <vda.linux@googlemail.com> */
/* TODO: depends on runit_lib.c - review and reduce/eliminate */
-#include <sys/poll.h>
+//usage:#define runsvdir_trivial_usage
+//usage: "[-P] [-s SCRIPT] DIR"
+//usage:#define runsvdir_full_usage "\n\n"
+//usage: "Start a runsv process for each subdirectory. If it exits, restart it.\n"
+//usage: "\n -P Put each runsv in a new session"
+//usage: "\n -s SCRIPT Run SCRIPT <signo> after signal is processed"
+
#include <sys/file.h>
#include "libbb.h"
#include "runit_lib.h"
struct pollfd pfd[1];
unsigned stamplog;
#endif
- smallint need_rescan; /* = 1; */
- smallint set_pgrp;
-};
+} FIX_ALIASING;
#define G (*(struct globals*)&bb_common_bufsiz1)
#define sv (G.sv )
#define svdir (G.svdir )
#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)
+#define INIT_G() do { } while (0)
static void fatal2_cannot(const char *m1, const char *m2)
{
- bb_perror_msg_and_die("%s: fatal: cannot %s%s", svdir, m1, m2);
+ bb_perror_msg_and_die("%s: fatal: can't %s%s", svdir, m1, m2);
/* was exiting 100 */
}
static void warn3x(const char *m1, const char *m2, const char *m3)
}
static void warn2_cannot(const char *m1, const char *m2)
{
- warn3x("cannot ", m1, m2);
+ warn3x("can't ", m1, m2);
}
#if ENABLE_FEATURE_RUNSVDIR_LOG
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;
- char *prog[3];
- prog[0] = (char*)"runsv";
- prog[1] = (char*)name;
- prog[2] = NULL;
+ /* 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)
+ if (option_mask32 & 1) /* -P option? */
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."
+ * Therefore, we do not need this: */
+#if 0
bb_signals(0
- + (1 << SIGHUP)
- + (1 << SIGTERM)
+ | (1 << SIGHUP)
+ | (1 << SIGTERM)
, SIG_DFL);
- execvp(prog[0], prog);
+#endif
+ execlp("runsv", "runsv", name, (char *) 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;
+ struct dirent *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;
}
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;
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;
time_t last_mtime = 0;
int wstat;
int curdir;
- int pid;
+ pid_t pid;
unsigned deadline;
unsigned now;
unsigned stampcheck;
int i;
+ int need_rescan = 1;
+ char *opt_s_argv[3];
INIT_G();
opt_complementary = "-1";
- set_pgrp = getopt32(argv, "P");
+ opt_s_argv[0] = NULL;
+ opt_s_argv[2] = NULL;
+ getopt32(argv, "Ps:", &opt_s_argv[0]);
argv += optind;
- bb_signals_recursive((1 << SIGTERM) | (1 << SIGHUP), record_signo);
+ bb_signals(0
+ | (1 << SIGTERM)
+ | (1 << SIGHUP)
+ /* For busybox's init, SIGTERM == reboot,
+ * SIGUSR1 == halt
+ * SIGUSR2 == poweroff
+ * so we need to intercept SIGUSRn too.
+ * Note that we do not implement actual reboot
+ * (killall(TERM) + umount, etc), we just pause
+ * respawing and avoid exiting (-> making kernel oops).
+ * The user is responsible for the rest. */
+ | (getpid() == 1 ? ((1 << SIGUSR1) | (1 << SIGUSR2)) : 0)
+ , record_signo);
svdir = *argv++;
#if ENABLE_FEATURE_RUNSVDIR_LOG
if (rploglen < 7) {
warnx("log must have at least seven characters");
} else if (piped_pair(logpipe)) {
- warnx("cannot create pipe for log");
+ warnx("can't create pipe for log");
} else {
close_on_exec_on(logpipe.rd);
close_on_exec_on(logpipe.wr);
ndelay_on(logpipe.rd);
ndelay_on(logpipe.wr);
if (dup2(logpipe.wr, 2) == -1) {
- warnx("cannot set filedescriptor for log");
+ warnx("can't set filedescriptor for log");
} else {
pfd[0].fd = logpipe.rd;
pfd[0].events = POLLIN;
rplog = NULL;
warnx("log service disabled");
}
-run:
+ run:
#endif
- curdir = open_read(".");
+ curdir = open(".", O_RDONLY|O_NDELAY);
if (curdir == -1)
fatal2_cannot("open current directory", "");
close_on_exec_on(curdir);
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;
}
}
}
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();
+ /* if the svdir changed this very second, wait until the
+ * next second, because we won't be able to detect more
+ * changes within this second */
+ while (time(NULL) == last_mtime)
+ usleep(100000);
+ 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
}
pfd[0].revents = 0;
#endif
- sig_block(SIGCHLD);
deadline = (need_rescan ? 1 : 5);
+ sig_block(SIGCHLD);
#if ENABLE_FEATURE_RUNSVDIR_LOG
if (rplog)
poll(pfd, 1, deadline*1000);
if (pfd[0].revents & POLLIN) {
char ch;
while (read(logpipe.rd, &ch, 1) > 0) {
- if (ch) {
- for (i = 6; i < rploglen; i++)
- rplog[i-1] = rplog[i];
- rplog[rploglen-1] = ch;
- }
+ if (ch < ' ')
+ ch = ' ';
+ for (i = 6; i < rploglen; i++)
+ rplog[i-1] = rplog[i];
+ rplog[rploglen-1] = ch;
}
}
#endif
- switch (bb_got_signal) {
- case SIGHUP:
+ if (!bb_got_signal)
+ continue;
+
+ /* -s SCRIPT: useful if we are init.
+ * In this case typically script never returns,
+ * it halts/powers off/reboots the system. */
+ if (opt_s_argv[0]) {
+ /* Single parameter: signal# */
+ opt_s_argv[1] = utoa(bb_got_signal);
+ pid = spawn(opt_s_argv);
+ if (pid > 0) {
+ /* Remembering to wait for _any_ children,
+ * not just pid */
+ while (wait(NULL) != pid)
+ continue;
+ }
+ }
+
+ if (bb_got_signal == SIGHUP) {
for (i = 0; i < svnum; i++)
if (sv[i].pid)
kill(sv[i].pid, SIGTERM);
- // N.B. fall through
- case SIGTERM:
- _exit((SIGHUP == bb_got_signal) ? 111 : EXIT_SUCCESS);
}
- }
- /* not reached */
- return 0;
+ /* SIGHUP or SIGTERM (or SIGUSRn if we are init) */
+ /* Exit unless we are init */
+ if (getpid() != 1)
+ return (SIGHUP == bb_got_signal) ? 111 : EXIT_SUCCESS;
+
+ /* init continues to monitor services forever */
+ bb_got_signal = 0;
+ } /* for (;;) */
}
projects / platform / upstream / busybox.git / blobdiff