Merge branch 'master' into pr6866

5 files changed, 520 insertions, 37 deletions

diff --git a/runtime/staprun/common.c b/runtime/staprun/common.c
index fd16b4b8..8200ec9d 100644
--- a/runtime/staprun/common.c
+++ b/runtime/staprun/common.c
@@ -27,6 +27,9 @@ int attach_mod;
 int delete_mod;
 int load_only;
 int need_uprobes;
+int daemon_mode;
+off_t fsize_max;
+int fnum_max;
 
 /* module variables */
 char *modname = NULL;
@@ -35,9 +38,132 @@ char *modoptions[MAXMODOPTIONS];
 
 int control_channel = -1; /* NB: fd==0 possible */
 
+static char path_buf[PATH_MAX];
+static char *get_abspath(char *path)
+{
+	int len;
+	if (path[0] == '/')
+		return path;
+
+	len = strlen(getcwd(path_buf, PATH_MAX));
+	if (len + 2 + strlen(path) >= PATH_MAX)
+		return NULL;
+	path_buf[len] = '/';
+	strcpy(&path_buf[len + 1], path);
+	return path_buf;
+}
+
+int stap_strfloctime(char *buf, size_t max, const char *fmt, time_t t)
+{
+	char *c = buf;
+	const char *c2 = fmt, *end = buf + max;
+	int ret, num;
+	struct tm tm;
+	if (buf == NULL || fmt == NULL || max <= 1)
+		return -EINVAL;
+	localtime_r(&t, &tm);
+
+	while (*c2 != '\0'){
+		if (c + 1 >= end)
+			return -EINVAL;
+		if (*c2 != '%') {
+			*c++ = *c2++;
+			continue;
+		}
+		c2++;
+		switch (*c2++) {
+		case '%':
+			*c++ = '%';
+			break;
+		case 'Y':
+			num = tm.tm_year + 1900;
+			goto numbering;
+		case 'y':
+			num = tm.tm_year % 100;
+			goto numbering02;
+		case 'C':
+			num = ((tm.tm_year + 1900 - 1) / 100) + 1;
+			goto numbering;
+		case 'm':
+			num = tm.tm_mon + 1;
+			goto numbering02;
+		case 'd':
+			num = tm.tm_mday;
+			goto numbering02;
+		case 'e':
+			num = tm.tm_mday;
+			goto numbering;
+		case 'F':
+			ret = snprintf(c, end - c, "%d-%02d-%02d",
+				tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday);
+			if (ret < 0) return ret;
+			c += ret;
+			break;
+		case 'H':
+			num = tm.tm_hour;
+			goto numbering02;
+		case 'I':
+			num = tm.tm_hour % 12;
+			if (num == 0) num = 12;
+			goto numbering02;
+		case 'j':
+			ret = snprintf(c, end - c, "%03d", tm.tm_yday);
+			if (ret < 0) return ret;
+			c += ret;
+			break;
+		case 'k':
+			num = tm.tm_hour;
+			goto numbering;
+		case 'l':
+			num = tm.tm_hour % 12;
+			if (num == 0) num = 12;
+			goto numbering;
+		case 'M':
+			num = tm.tm_min;
+			goto numbering02;
+		case 'S':
+			num = tm.tm_sec;
+			goto numbering02;
+		case 'R':
+			ret = snprintf(c, end - c, "%02d:%02d",
+					tm.tm_hour, tm.tm_min);
+			if (ret < 0) return ret;
+			c += ret;
+			break;
+		case 'T':
+			ret = snprintf(c, end - c, "%02d:%02d:%02d",
+					tm.tm_hour, tm.tm_min, tm.tm_sec);
+			if (ret < 0) return ret;
+			c += ret;
+			break;
+		case 'u':
+			num = tm.tm_wday == 0 ? 7 : tm.tm_wday;
+			goto numbering;
+		case 'w':
+			num = tm.tm_wday;
+			goto numbering;
+		default:
+			return -EINVAL;
+		}
+		continue;
+numbering:
+		ret = snprintf(c, end - c, "%d", num);
+		if (ret < 0) return ret;
+		c += ret;
+		continue;
+numbering02:
+		ret = snprintf(c, end - c, "%02d", num);
+		if (ret < 0) return ret;
+		c += ret;
+	}
+	*c = '\0';
+	return c - buf;
+}
+
 void parse_args(int argc, char **argv)
 {
 	int c;
+	char *s;
 
 	/* Initialize option variables. */
 	verbose = 0;
@@ -49,8 +175,11 @@ void parse_args(int argc, char **argv)
 	delete_mod = 0;
 	load_only = 0;
 	need_uprobes = 0;
+	daemon_mode = 0;
+	fsize_max = 0;
+	fnum_max = 0;
 
-	while ((c = getopt(argc, argv, "ALuvb:t:dc:o:x:")) != EOF) {
+	while ((c = getopt(argc, argv, "ALuvb:t:dc:o:x:S:D")) != EOF) {
 		switch (c) {
 		case 'u':
 			need_uprobes = 1;
@@ -85,11 +214,38 @@ void parse_args(int argc, char **argv)
 		case 'L':
 			load_only = 1;
 			break;
+		case 'D':
+			daemon_mode = 1;
+			break;
+		case 'S':
+			fsize_max = strtoul(optarg, &s, 10);
+			fsize_max <<= 20;
+			if (s[0] == ',')
+				fnum_max = (int)strtoul(&s[1], &s, 10);
+			if (s[0] != '\0') {
+				err("Invalid file size option '%s'.\n", optarg);
+				usage(argv[0]);
+			}
+			break;
 		default:
 			usage(argv[0]);
 		}
 	}
-
+	if (outfile_name) {
+		char tmp[PATH_MAX];
+		int ret;
+		outfile_name = get_abspath(outfile_name);
+		if (outfile_name == NULL) {
+			err("File name is too long.\n");
+			usage(argv[0]);
+		}
+		ret = stap_strfloctime(tmp, PATH_MAX - 18, /* = _cpuNNN.SSSSSSSSSS */
+				       outfile_name, time(NULL));
+		if (ret < 0) {
+			err("Filename format is invalid or too long.\n");
+			usage(argv[0]);
+		}
+	}
 	if (attach_mod && load_only) {
 		err("You can't specify the '-A' and '-L' options together.\n");
 		usage(argv[0]);
@@ -118,18 +274,41 @@ void parse_args(int argc, char **argv)
 		err("You can't specify the '-c' and '-x' options together.\n");
 		usage(argv[0]);
 	}
+
+	if (daemon_mode && load_only) {
+		err("You can't specify the '-D' and '-L' options together.\n");
+		usage(argv[0]);
+	}
+	if (daemon_mode && delete_mod) {
+		err("You can't specify the '-D' and '-d' options together.\n");
+		usage(argv[0]);
+	}
+	if (daemon_mode && target_cmd) {
+		err("You can't specify the '-D' and '-c' options together.\n");
+		usage(argv[0]);
+	}
+	if (daemon_mode && outfile_name == NULL) {
+		err("You have to specify output FILE with '-D' option.\n");
+		usage(argv[0]);
+	}
+	if (outfile_name == NULL && fsize_max != 0) {
+		err("You have to specify output FILE with '-S' option.\n");
+		usage(argv[0]);
+	}
 }
 
 void usage(char *prog)
 {
-	err("\n%s [-v]  [-c cmd ] [-x pid] [-u user]\n"
-                "\t[-A|-L] [-b bufsize] [-o FILE] MODULE [module-options]\n", prog);
+	err("\n%s [-v]  [-c cmd ] [-x pid] [-u user] [-A|-L|-d]\n"
+                "\t[-b bufsize] [-o FILE [-D] [-S size[,N]]] MODULE [module-options]\n", prog);
 	err("-v              Increase verbosity.\n");
 	err("-c cmd          Command \'cmd\' will be run and staprun will\n");
 	err("                exit when it does.  The '_stp_target' variable\n");
 	err("                will contain the pid for the command.\n");
 	err("-x pid          Sets the '_stp_target' variable to pid.\n");
-	err("-o FILE         Send output to FILE.\n");
+	err("-o FILE         Send output to FILE. This supports a subset of\n");
+	err("                strftime(3) (%%%%,%%C,%%Y,%%y,%%m,%%d,%%e,%%F,%%H,%%I\n");
+	err("                %%j,%%k,%%l,%%M,%%S,%%R,%%T,%%u,%%w) for FILE.\n");
 	err("-b buffer size  The systemtap module specifies a buffer size.\n");
 	err("                Setting one here will override that value.  The\n");
 	err("                value should be an integer between 1 and 4095 \n");
@@ -140,6 +319,14 @@ void usage(char *prog)
 	err("-d              Delete a module.  Only detached or unused modules\n");
 	err("                the user has permission to access will be deleted. Use \"*\"\n");
 	err("                (quoted) to delete all unused modules.\n");
+	err("-D              Run in background. This requires '-o' option.\n");
+	err("-S size[,N]     Switches output file to next file when the size\n");
+	err("                of file reaches the specified size. The value\n");
+	err("                should be an integer greater than 1 which is\n");
+	err("                assumed to be the maximum file size in MB.\n");
+	err("                When the number of output files reaches N, it\n");
+	err("                switches to the first output file. You can omit\n");
+	err("                the second argument.\n");
 	err("MODULE can be either a module name or a module path.  If a\n");
 	err("module name is used, it is looked for in the following\n");
 	err("directory: /lib/modules/`uname -r`/systemtap\n");
@@ -344,3 +531,24 @@ int send_request(int type, void *data, int len)
         if (rc < 0) return rc;
         return (rc != len+4);
 }
+
+#include <stdarg.h>
+
+static int use_syslog = 0;
+
+void eprintf(const char *fmt, ...)
+{
+	va_list va;
+	va_start(va, fmt);
+	if (use_syslog)
+		vsyslog(LOG_ERR, fmt, va);
+	else
+		vfprintf(stderr, fmt, va);
+	va_end(va);
+}
+
+void switch_syslog(const char *name)
+{
+	openlog(name, LOG_PID, LOG_DAEMON);
+	use_syslog = 1;
+}
diff --git a/runtime/staprun/mainloop.c b/runtime/staprun/mainloop.c
index db6ef6b7..c80bbba4 100644
--- a/runtime/staprun/mainloop.c
+++ b/runtime/staprun/mainloop.c
@@ -318,6 +318,41 @@ int init_stapio(void)
   if (target_cmd)
     start_cmd();
 
+  /* Run in background */
+  if (daemon_mode) {
+    pid_t pid;
+    int ret;
+    dbug(2, "daemonizing stapio\n");
+
+    /* daemonize */
+    ret = daemon(0, 1); /* don't close stdout at this time. */
+    if (ret) {
+      err("Failed to daemonize stapio\n");
+      return -1;
+    }
+
+    /* change error messages to syslog. */
+    switch_syslog("stapio");
+
+    /* show new pid */
+    pid = getpid();
+    fprintf(stdout, "%d\n", pid);
+    fflush(stdout);
+
+    /* redirect all outputs to /dev/null */
+    ret = open("/dev/null", O_RDWR);
+    if (ret < 0) {
+      err("Failed to open /dev/null\n");
+      return -1;
+    }
+    close(STDIN_FILENO);
+    close(STDOUT_FILENO);
+    close(STDERR_FILENO);
+    dup2(ret, STDOUT_FILENO);
+    dup2(ret, STDERR_FILENO);
+    close(ret);
+  }
+
   return 0;
 }
 
@@ -454,21 +489,14 @@ int stp_main_loop(void)
     switch (type) {
 #ifdef STP_OLD_TRANSPORT
     case STP_REALTIME_DATA:
-      {
-        ssize_t bw = write(out_fd[0], data, nb);
-        if (bw >= 0 && bw != nb) {
-          nb = nb - bw;
-          bw = write(out_fd[0], data, nb);
-        }
-        if (bw != nb) {
-          _perr("write error (nb=%ld)", (long)nb);
-          cleanup_and_exit(0);
-        }
-        break;
+      if (write_realtime_data(data, nb)) {
+        _perr("write error (nb=%ld)", (long)nb);
+        cleanup_and_exit(0);
       }
+      break;
 #endif
     case STP_OOB_DATA:
-      fputs((char *)data, stderr);
+      eprintf("%s", (char *)data);
       break;
     case STP_EXIT:
       {
diff --git a/runtime/staprun/relay.c b/runtime/staprun/relay.c
index 19621933..50f295b5 100644
--- a/runtime/staprun/relay.c
+++ b/runtime/staprun/relay.c
@@ -17,6 +17,9 @@ static pthread_t reader[NR_CPUS];
 static int relay_fd[NR_CPUS];
 static int bulkmode = 0;
 static volatile int stop_threads = 0;
+static time_t *time_backlog[NR_CPUS];
+static int backlog_order=0;
+#define BACKLOG_MASK ((1 << backlog_order) - 1)
 
 /*
  * ppoll exists in glibc >= 2.4
@@ -44,6 +47,90 @@ static int ppoll(struct pollfd *fds, nfds_t nfds,
 }
 #endif
 
+int init_backlog(int cpu)
+{
+	int order = 0;
+	if (!fnum_max)
+		return 0;
+	while (fnum_max >> order) order++;
+	if (fnum_max == 1<<(order-1)) order--;
+	time_backlog[cpu] = (time_t *)calloc(1<<order, sizeof(time_t));
+	if (time_backlog[cpu] == NULL) {
+		_err("Memory allocation failed\n");
+		return -1;
+	}
+	backlog_order = order;
+	return 0;
+}
+
+void write_backlog(int cpu, int fnum, time_t t)
+{
+	time_backlog[cpu][fnum & BACKLOG_MASK] = t;
+}
+
+time_t read_backlog(int cpu, int fnum)
+{
+	return time_backlog[cpu][fnum & BACKLOG_MASK];
+}
+
+int make_outfile_name(char *buf, int max, int fnum, int cpu, time_t t)
+{
+	int len;
+	len = stap_strfloctime(buf, max, outfile_name, t);
+	if (len < 0) {
+		err("Invalid FILE name format\n");
+  		return -1;
+  	}
+	if (bulkmode) {
+		/* special case: for testing we sometimes want to write to /dev/null */
+		if (strcmp(outfile_name, "/dev/null") == 0) {
+			strcpy(buf, "/dev/null");
+		} else {
+			if (snprintf_chk(&buf[len], PATH_MAX - len,
+					 "_cpu%d.%d", cpu, fnum))
+				return -1;
+		}
+	} else {
+		/* stream mode */
+		if (snprintf_chk(&buf[len], PATH_MAX - len, ".%d", fnum))
+			return -1;
+	}
+	return 0;
+}
+
+static int open_outfile(int fnum, int cpu, int remove_file)
+{
+	char buf[PATH_MAX];
+	time_t t;
+	if (!outfile_name) {
+		_err("-S is set without -o. Please file a bug report.\n");
+		return -1;
+	}
+
+	time(&t);
+	if (fnum_max) {
+		if (remove_file) {
+			 /* remove oldest file */
+			if (make_outfile_name(buf, PATH_MAX, fnum - fnum_max,
+				 cpu, read_backlog(cpu, fnum - fnum_max)) < 0)
+				return -1;
+			remove(buf); /* don't care */
+		}
+		write_backlog(cpu, fnum, t);
+	}
+
+	if (make_outfile_name(buf, PATH_MAX, fnum, cpu, t) < 0)
+		return -1;
+	out_fd[cpu] = open (buf, O_CREAT|O_TRUNC|O_WRONLY, 0666);
+	if (out_fd[cpu] < 0) {
+		perr("Couldn't open output file %s", buf);
+		return -1;
+	}
+	if (set_clexec(out_fd[cpu]) < 0)
+		return -1;
+	return 0;
+}
+
 /**
  *	reader_thread - per-cpu channel buffer reader
  */
@@ -57,6 +144,9 @@ static void *reader_thread(void *data)
 	struct timespec tim = {.tv_sec=0, .tv_nsec=200000000}, *timeout = &tim;
 	sigset_t sigs;
 	struct sigaction sa;
+	off_t wsize = 0;
+	int fnum = 0;
+	int remove_file = 0;
 
 	sigemptyset(&sigs);
 	sigaddset(&sigs,SIGUSR2);
@@ -99,6 +189,19 @@ static void *reader_thread(void *data)
                         }
                 }
 		while ((rc = read(relay_fd[cpu], buf, sizeof(buf))) > 0) {
+			wsize += rc;
+			/* Switching file */
+			if (fsize_max && wsize > fsize_max) {
+				close(out_fd[cpu]);
+				fnum++;
+				if (fnum_max && fnum == fnum_max)
+					remove_file = 1;
+				if (open_outfile(fnum, cpu, remove_file) < 0) {
+					perr("Couldn't open file for cpu %d, exiting.", cpu);
+					return(NULL);
+				}
+				wsize = 0;
+			}
 			if (write(out_fd[cpu], buf, rc) != rc) {
 				perr("Couldn't write to output %d for cpu %d, exiting.", out_fd[cpu], cpu);
 				return(NULL);
@@ -116,7 +219,7 @@ static void *reader_thread(void *data)
  */
 int init_relayfs(void)
 {
-	int i;
+	int i, len;
 	struct statfs st;
 	char rqbuf[128];
 	char buf[PATH_MAX], relay_filebase[PATH_MAX];
@@ -163,14 +266,29 @@ int init_relayfs(void)
 		return -1;
 	}
 
-	if (bulkmode) {
+	if (fsize_max) {
+		/* switch file mode */
+		for (i = 0; i < ncpus; i++) {
+			if (init_backlog(i) < 0)
+				return -1;
+  			if (open_outfile(0, i, 0) < 0)
+  				return -1;
+		}
+	} else if (bulkmode) {
 		for (i = 0; i < ncpus; i++) {
 			if (outfile_name) {
 				/* special case: for testing we sometimes want to write to /dev/null */
 				if (strcmp(outfile_name, "/dev/null") == 0) {
 					strcpy(buf, "/dev/null");
 				} else {
-					if (sprintf_chk(buf, "%s_%d", outfile_name, i))
+					len = stap_strfloctime(buf, PATH_MAX,
+						 outfile_name, time(NULL));
+					if (len < 0) {
+						err("Invalid FILE name format\n");
+						return -1;
+					}
+					if (snprintf_chk(&buf[len],
+						PATH_MAX - len, "_%d", i))
 						return -1;
 				}
 			} else {
@@ -189,9 +307,15 @@ int init_relayfs(void)
 	} else {
 		/* stream mode */
 		if (outfile_name) {
-			out_fd[0] = open (outfile_name, O_CREAT|O_TRUNC|O_WRONLY, 0666);
+			len = stap_strfloctime(buf, PATH_MAX,
+						 outfile_name, time(NULL));
+			if (len < 0) {
+				err("Invalid FILE name format\n");
+				return -1;
+			}
+			out_fd[0] = open (buf, O_CREAT|O_TRUNC|O_WRONLY, 0666);
 			if (out_fd[0] < 0) {
-				perr("Couldn't open output file %s", outfile_name);
+				perr("Couldn't open output file %s", buf);
 				return -1;
 			}
 			if (set_clexec(out_fd[i]) < 0)
diff --git a/runtime/staprun/relay_old.c b/runtime/staprun/relay_old.c
index bd746f19..ef8fd0da 100644
--- a/runtime/staprun/relay_old.c
+++ b/runtime/staprun/relay_old.c
@@ -23,6 +23,14 @@ static int bulkmode = 0;
 unsigned subbuf_size = 0;
 unsigned n_subbufs = 0;
 
+struct switchfile_ctrl_block {
+	off_t wsize;
+	int fnum;
+	int rmfile;
+};
+
+static struct switchfile_ctrl_block global_scb = {0, 0, 0};
+
 /* per-cpu buffer info */
 static struct buf_status
 {
@@ -70,6 +78,41 @@ void close_oldrelayfs(int detach)
 		close_relayfs_files(i);
 }
 
+static int open_oldoutfile(int fnum, int cpu, int remove_file)
+{
+	char buf[PATH_MAX];
+	time_t t;
+	if (outfile_name) {
+		time(&t);
+		if (fnum_max) {
+			if (remove_file) {
+				 /* remove oldest file */
+				if (make_outfile_name(buf, PATH_MAX, fnum - fnum_max,
+					 cpu, read_backlog(cpu, fnum - fnum_max)) < 0)
+					return -1;
+				remove(buf); /* don't care */
+			}
+			write_backlog(cpu, fnum, t);
+		}
+		if (make_outfile_name(buf, PATH_MAX, fnum, cpu, t) < 0)
+			return -1;
+	} else if (bulkmode) {
+		if (sprintf_chk(buf, "stpd_cpu%d.%d", cpu, fnum))
+			return -1;
+	} else { /* stream mode */
+		out_fd[cpu] = STDOUT_FILENO;
+		return 0;
+	}
+
+	out_fd[cpu] = open (buf, O_CREAT|O_TRUNC|O_WRONLY, 0666);
+	if (out_fd[cpu] < 0) {
+		perr("Couldn't open output file %s", buf);
+		return -1;
+	}
+	if (set_clexec(out_fd[cpu]) < 0)
+		return -1;
+	return 0;
+}
 /**
  *	open_relayfs_files - open and mmap buffer and open output file.
  *	Returns -1 on unexpected failure, 0 if file not found, 1 on success.
@@ -104,18 +147,31 @@ static int open_relayfs_files(int cpu, const char *relay_filebase, const char *p
 		return -1;
 	}
 
+	if (fsize_max) {
+		if (init_backlog(cpu) < 0)
+			goto err2;
+		if (open_oldoutfile(0, cpu, 0) < 0)
+			goto err2;
+		goto opened;
+	}
 	if (outfile_name) {
 		/* special case: for testing we sometimes want to
 		 * write to /dev/null */
 		if (strcmp(outfile_name, "/dev/null") == 0) {
 			strcpy(tmp, "/dev/null");
 		} else {
-			if (sprintf_chk(tmp, "%s_%d", outfile_name, cpu))
-				goto err1;
+			int len;
+			len = stap_strfloctime(tmp, PATH_MAX, outfile_name, time(NULL));
+			if (len < 0) {
+				err("Invalid FILE name format\n");
+				goto err2;
+			}
+			if (snprintf_chk(&tmp[len], PATH_MAX - len, "_%d", cpu))
+				goto err2;
 		}
 	} else {
 		if (sprintf_chk(tmp, "stpd_cpu%d", cpu))
-			goto err1;
+			goto err2;
 	}
 
 	if((percpu_tmpfile[cpu] = fopen(tmp, "w+")) == NULL) {
@@ -126,6 +182,7 @@ static int open_relayfs_files(int cpu, const char *relay_filebase, const char *p
 		perr("Couldn't open output file %s", tmp);
 		goto err2;
 	}
+opened:
 
 	total_bufsize = subbuf_size * n_subbufs;
 	relay_buffer[cpu] = mmap(NULL, total_bufsize, PROT_READ,
@@ -155,7 +212,8 @@ err1:
 /**
  *	process_subbufs - write ready subbufs to disk
  */
-static int process_subbufs(struct _stp_buf_info *info)
+static int process_subbufs(struct _stp_buf_info *info,
+			   struct switchfile_ctrl_block *scb)
 {
 	unsigned subbufs_ready, start_subbuf, end_subbuf, subbuf_idx, i;
 	int len, cpu = info->cpu;
@@ -173,6 +231,18 @@ static int process_subbufs(struct _stp_buf_info *info)
 		padding = *((unsigned *)subbuf_ptr);
 		subbuf_ptr += sizeof(padding);
 		len = (subbuf_size - sizeof(padding)) - padding;
+		scb->wsize += len;
+		if (fsize_max && scb->wsize > fsize_max) {
+			fclose(percpu_tmpfile[cpu]);
+			scb->fnum ++;
+			if (fnum_max && scb->fnum == fnum_max)
+				scb->rmfile = 1;
+			if (open_oldoutfile(scb->fnum, cpu, scb->rmfile) < 0) {
+				perr("Couldn't open file for cpu %d, exiting.", cpu);
+				exit(1);
+			}
+			scb->wsize = 0;
+		}
 		if (len) {
 			if (fwrite_unlocked (subbuf_ptr, len, 1, percpu_tmpfile[cpu]) != 1) {
 				_perr("Couldn't write to output file for cpu %d, exiting:", cpu);
@@ -196,6 +266,7 @@ static void *reader_thread(void *data)
 	struct _stp_consumed_info consumed_info;
 	unsigned subbufs_consumed;
 	cpu_set_t cpu_mask;
+	struct switchfile_ctrl_block scb = {0, 0, 0};
 
 	CPU_ZERO(&cpu_mask);
 	CPU_SET(cpu, &cpu_mask);
@@ -217,7 +288,7 @@ static void *reader_thread(void *data)
 		}
 
 		rc = read(proc_fd[cpu], &status[cpu].info, sizeof(struct _stp_buf_info));
-		subbufs_consumed = process_subbufs(&status[cpu].info);
+		subbufs_consumed = process_subbufs(&status[cpu].info, &scb);
 		if (subbufs_consumed) {
 			if (subbufs_consumed > status[cpu].max_backlog)
 				status[cpu].max_backlog = subbufs_consumed;
@@ -233,6 +304,33 @@ static void *reader_thread(void *data)
 }
 
 /**
+ *	write_realtime_data - write realtime data packet to disk
+ */
+int write_realtime_data(void *data, ssize_t nb)
+{
+	ssize_t bw;
+	global_scb.wsize += nb;
+	if (fsize_max && global_scb.wsize > fsize_max) {
+		close(out_fd[0]);
+		global_scb.fnum++;
+		if (fnum_max && global_scb.fnum == fnum_max)
+			global_scb.rmfile = 1;
+		if (open_oldoutfile(global_scb.fnum, 0,
+				    global_scb.rmfile) < 0) {
+			perr("Couldn't open file, exiting.");
+			return -1;
+		}
+		global_scb.wsize = 0;
+	}
+	bw = write(out_fd[0], data, nb);
+	if (bw >= 0 && bw != nb) {
+		nb = nb - bw;
+		bw = write(out_fd[0], data, nb);
+	}
+	return bw != nb;
+}
+
+/**
  *	init_relayfs - create files and threads for relayfs processing
  *
  *	Returns 0 if successful, negative otherwise
@@ -249,10 +347,22 @@ int init_oldrelayfs(void)
 		bulkmode = 1;
  
 	if (!bulkmode) {
+		int len;
+		char tmp[PATH_MAX];
+		if (fsize_max) {
+			if (init_backlog(0))
+				return -1;
+			return open_oldoutfile(0, 0, 0);
+		}
 		if (outfile_name) {
-			out_fd[0] = open (outfile_name, O_CREAT|O_TRUNC|O_WRONLY, 0666);
+			len = stap_strfloctime(tmp, PATH_MAX, outfile_name, time(NULL));
+			if (len < 0) {
+				err("Invalid FILE name format\n");
+				return -1;
+			}
+			out_fd[0] = open (tmp, O_CREAT|O_TRUNC|O_WRONLY, 0666);
 			if (out_fd[0] < 0 || set_clexec(out_fd[0]) < 0) {
-				perr("Couldn't open output file '%s'", outfile_name);
+				perr("Couldn't open output file '%s'", tmp);
 				return -1;
 			}
 		} else
diff --git a/runtime/staprun/staprun.h b/runtime/staprun/staprun.h
index 84cf63fc..acc533b2 100644
--- a/runtime/staprun/staprun.h
+++ b/runtime/staprun/staprun.h
@@ -9,7 +9,7 @@
  *
  * Copyright (C) 2005-2008 Red Hat Inc.
  */
-
+#define _FILE_OFFSET_BITS 64
 #include <stdio.h>
 #include <stdlib.h>
 #include <ctype.h>
@@ -33,31 +33,35 @@
 #include <sys/wait.h>
 #include <sys/statfs.h>
 #include <linux/version.h>
+#include <syslog.h>
 
 /* Include config.h to pick up dependency for --prefix usage. */
 #include "config.h"
 
-#define dbug(level, args...) {if (verbose>=level) {fprintf(stderr,"%s:%s:%d ",__name__,__FUNCTION__, __LINE__); fprintf(stderr,args);}}
+extern void eprintf(const char *fmt, ...);
+extern void switch_syslog(const char *name);
+
+#define dbug(level, args...) do {if (verbose>=level) {eprintf("%s:%s:%d ",__name__,__FUNCTION__, __LINE__); eprintf(args);}} while (0)
 
 extern char *__name__;
 
 /* print to stderr */
-#define err(args...) fprintf(stderr,args)
+#define err(args...) eprintf(args)
 
 /* better perror() */
 #define perr(args...) do {					\
 		int _errno = errno;				\
-		fputs("ERROR: ", stderr);			\
-		fprintf(stderr, args);				\
-		fprintf(stderr, ": %s\n", strerror(_errno));	\
+		eprintf("ERROR: ");				\
+		eprintf(args);					\
+		eprintf(": %s\n", strerror(_errno));		\
 	} while (0)
 
 /* Error messages. Use these for serious errors, not informational messages to stderr. */
-#define _err(args...) do {fprintf(stderr,"%s:%s:%d: ERROR: ",__name__, __FUNCTION__, __LINE__); fprintf(stderr,args);} while(0)
+#define _err(args...) do {eprintf("%s:%s:%d: ERROR: ",__name__, __FUNCTION__, __LINE__); eprintf(args);} while(0)
 #define _perr(args...) do {					\
 		int _errno = errno;				\
 		_err(args);					\
-		fprintf(stderr, ": %s\n", strerror(_errno));	\
+		eprintf(": %s\n", strerror(_errno));	\
 	} while (0)
 #define overflow_error() _err("Internal buffer overflow. Please file a bug report.\n")
 
@@ -113,7 +117,12 @@ int init_relayfs(void);
 void close_relayfs(void);
 int init_oldrelayfs(void);
 void close_oldrelayfs(int);
+int write_realtime_data(void *data, ssize_t nb);
 void setup_signals(void);
+int make_outfile_name(char *buf, int max, int fnum, int cpu, time_t t);
+int init_backlog(int cpu);
+void write_backlog(int cpu, int fnum, time_t t);
+time_t read_backlog(int cpu, int fnum);
 /* staprun_funcs.c */
 void setup_staprun_signals(void);
 const char *moderror(int err);
@@ -125,6 +134,7 @@ void start_symbol_thread(void);
 void stop_symbol_thread(void);
 
 /* common.c functions */
+int stap_strfloctime(char *buf, size_t max, const char *fmt, time_t t);
 void parse_args(int argc, char **argv);
 void usage(char *prog);
 void parse_modpath(const char *);
@@ -153,6 +163,9 @@ extern int attach_mod;
 extern int delete_mod;
 extern int load_only;
 extern int need_uprobes;
+extern int daemon_mode;
+extern off_t fsize_max;
+extern int fnum_max;
 
 /* getopt variables */
 extern char *optarg;