svlogd: do not set O_NONBLOCK on stdin permanently - that can
affect other processes!
diff --git a/runit/svlogd.c b/runit/svlogd.c
index 59b1e57..a0e562b 100644
--- a/runit/svlogd.c
+++ b/runit/svlogd.c
@@ -44,15 +44,19 @@
static struct taia trotate;
static char *line;
-static unsigned exitasap;
-static unsigned rotateasap;
-static unsigned reopenasap;
-static unsigned linecomplete = 1;
-static unsigned tmaxflag;
-static iopause_fd input;
+static smallint exitasap;
+static smallint rotateasap;
+static smallint reopenasap;
+static smallint linecomplete = 1;
-static const char *replace = "";
+static smallint tmaxflag;
+
static char repl;
+static const char *replace = "";
+
+sigset_t blocked_sigset;
+static iopause_fd input;
+static int fl_flag_0;
static struct logdir {
//// char *btmp;
@@ -333,7 +337,7 @@
if (len > (ld->sizemax - ld->size))
len = ld->sizemax - ld->size;
}
- while ((i = write(ld->fdcur, s, len)) == -1) {
+ while ((i = full_write(ld->fdcur, s, len)) == -1) {
if ((errno == ENOSPC) && (ld->nmin < ld->nmax)) {
DIR *d;
struct dirent *f;
@@ -585,6 +589,17 @@
if (!ok) fatalx("no functional log directories");
}
+/* Will look good in libbb one day */
+static ssize_t ndelay_read(int fd, void *buf, size_t count)
+{
+ if (!(fl_flag_0 & O_NONBLOCK))
+ fcntl(fd, F_SETFL, fl_flag_0 | O_NONBLOCK);
+ count = safe_read(fd, buf, count);
+ if (!(fl_flag_0 & O_NONBLOCK))
+ fcntl(fd, F_SETFL, fl_flag_0);
+ return count;
+}
+
/* Used for reading stdin */
static int buffer_pread(int fd, char *s, unsigned len)
{
@@ -617,17 +632,10 @@
}
while (1) {
- /* Comment? */
- sig_unblock(SIGTERM);
- sig_unblock(SIGCHLD);
- sig_unblock(SIGALRM);
- sig_unblock(SIGHUP);
+ sigprocmask(SIG_UNBLOCK, &blocked_sigset, NULL);
iopause(&input, 1, &trotate, &now);
- sig_block(SIGTERM);
- sig_block(SIGCHLD);
- sig_block(SIGALRM);
- sig_block(SIGHUP);
- i = safe_read(fd, s, len);
+ sigprocmask(SIG_BLOCK, &blocked_sigset, NULL);
+ i = ndelay_read(fd, s, len);
if (i >= 0) break;
if (errno != EAGAIN) {
warn("cannot read standard input");
@@ -775,14 +783,17 @@
fndir = argv;
input.fd = 0;
input.events = IOPAUSE_READ;
- /* I be damned. Linux 2.6.18: this somehow affects
- * OTHER processes! Konsole starts to redraw itself much slower!
- * This persists even after svlogd exits */
- ndelay_on(input.fd);
- sig_block(SIGTERM);
- sig_block(SIGCHLD);
- sig_block(SIGALRM);
- sig_block(SIGHUP);
+ /* We cannot set NONBLOCK on fd #0 permanently - this setting
+ * _isn't_ per-process! It is shared among all other processes
+ * with the same stdin */
+ fl_flag_0 = fcntl(0, F_GETFL, 0);
+
+ sigemptyset(&blocked_sigset);
+ sigaddset(&blocked_sigset, SIGTERM);
+ sigaddset(&blocked_sigset, SIGCHLD);
+ sigaddset(&blocked_sigset, SIGALRM);
+ sigaddset(&blocked_sigset, SIGHUP);
+ sigprocmask(SIG_BLOCK, &blocked_sigset, NULL);
sig_catch(SIGTERM, sig_term_handler);
sig_catch(SIGCHLD, sig_child_handler);
sig_catch(SIGALRM, sig_alarm_handler);
@@ -850,8 +861,13 @@
/* linelen == no of chars incl. '\n' (or == stdin_cnt) */
ch = lineptr[linelen-1];
- /* write out lineptr[0..linelen-1] to each log destination */
- /* (or lineptr[-26..linelen-1] if timestamping) */
+ /* TODO: biggest performance hit is coming from the fact
+ * that we do not buffer writes. We may read many lines
+ * in one read() above, but will do one write()
+ * per line below. Should we use stdio? */
+
+ /* write out lineptr[0..linelen-1] to each log destination
+ * (or lineptr[-26..linelen-1] if timestamping) */
printlen = linelen;
printptr = lineptr;
if (timestamp) {