bootchart: put the bootchart into the journal.

This bit of code is mostly stolen from coredump.c. We construct
a simple journal message and append the bootchart file in the
journal automatically.

You can extract the latest bootchart from the current boot with
something like:

$ journalctl -b MESSAGE_ID=9f26aa562cf440c2b16c773d0479b518 --field=BOOTCHART

which prints it to stdout.

None of the other logic is touched. The journal entry is created
even if bootchart was run manually, which is probably wrong.

Makefile.am

@@ -3080,7 +3080,8 @@ systemd_bootchart_SOURCES = \
 	src/bootchart/svg.h
 
 systemd_bootchart_LDADD = \
-	libsystemd-shared.la
+	libsystemd-shared.la \
+	libsystemd-journal.la
 
 rootlibexec_PROGRAMS += \
 	systemd-bootchart

src/bootchart/bootchart.c

@@ -48,6 +48,7 @@
 #include <errno.h>
 #include <fcntl.h>
 #include <stdbool.h>
+#include <systemd/sd-journal.h>
 
 #include "util.h"
 #include "fileio.h"
@@ -98,6 +99,8 @@ static void signal_handler(int sig) {
 
 #define BOOTCHART_CONF "/etc/systemd/bootchart.conf"
 
+#define BOOTCHART_MAX (16*1024*1024)
+
 static void parse_conf(void) {
         char *init = NULL, *output = NULL;
         const ConfigTableItem items[] = {
@@ -237,6 +240,54 @@ static int parse_args(int argc, char *argv[]) {
         return 0;
 }
 
+static void do_journal_append(char *file)
+{
+        struct iovec iovec[5];
+        int r, f, j = 0;
+        ssize_t n;
+        char _cleanup_free_ *bootchart_file = NULL, *bootchart_message = NULL,
+                *p = NULL;
+
+        bootchart_file = strappend("BOOTCHART_FILE=", file);
+        if (bootchart_file)
+                IOVEC_SET_STRING(iovec[j++], bootchart_file);
+
+        IOVEC_SET_STRING(iovec[j++], "MESSAGE_ID=9f26aa562cf440c2b16c773d0479b518");
+        IOVEC_SET_STRING(iovec[j++], "PRIORITY=7");
+        bootchart_message = strjoin("MESSAGE=Bootchart created: ", file, NULL);
+        if (bootchart_message)
+                IOVEC_SET_STRING(iovec[j++], bootchart_message);
+
+        p = malloc(9 + BOOTCHART_MAX);
+        if (!p) {
+                r = log_oom();
+                return;
+        }
+
+        memcpy(p, "BOOTCHART=", 10);
+
+        f = open(file, O_RDONLY);
+        if (f < 0) {
+                log_error("Failed to read bootchart data: %s\n", strerror(-errno));
+                return;
+        }
+        n = loop_read(f, p + 10, BOOTCHART_MAX, false);
+        if (n < 0) {
+                log_error("Failed to read bootchart data: %s\n", strerror(-n));
+                close(f);
+                return;
+        }
+        close(f);
+
+        iovec[j].iov_base = p;
+        iovec[j].iov_len = 10 + n;
+        j++;
+
+        r = sd_journal_sendv(iovec, j);
+        if (r < 0)
+                log_error("Failed to send bootchart: %s", strerror(-r));
+}
+
 int main(int argc, char *argv[]) {
         _cleanup_free_ char *build = NULL;
         struct sigaction sig = {
@@ -382,6 +433,8 @@ int main(int argc, char *argv[]) {
 
         fprintf(stderr, "systemd-bootchart wrote %s\n", output_file);
 
+        do_journal_append(output_file);
+
         if (of)
                 fclose(of);