From: Sukadev Bhattiprolu <sukadev@xxxxxxxxxxxxxxxxxx>
Date: Mon, 1 Mar 2010 20:04:12 -0800
Subject: [PATCH 04/13][user-cr]: restart: Use ckpt_msg() to log
Rather than implicitly redirecting messages to 'stdout' or 'stderr'
use global variables, 'global_ulogfd' and 'global_uerrfd'. That would
make it easier to implement additional command line options to redirect
these fds to other files, If we also later implement a library interface
to this restart code, it would enable callers to specify fds other than
'stdout' and 'stderr'.
Signed-off-by: Sukadev Bhattiprolu <sukadev@xxxxxxxxxxxxxxxxxx>
---
restart.c | 90 ++++++++++++++++++++++++++++++++++++++++++------------------
1 files changed, 63 insertions(+), 27 deletions(-)
diff --git a/restart.c b/restart.c
index 1839330..c4c2158 100644
--- a/restart.c
+++ b/restart.c
@@ -31,6 +31,7 @@
#include <sys/syscall.h>
#include <sys/prctl.h>
#include <sys/mount.h>
+#include <stdarg.h>
#include <linux/sched.h>
#include <linux/checkpoint.h>
@@ -101,16 +102,38 @@ static char usage_str[] =
* of the checkpoint image stream.
*/
+#define BUFSIZE (4 * 4096)
+
+static inline void ckpt_msg(int fd, char *format, ...)
+{
+ va_list ap;
+ char *bufp;
+ if (fd < 0)
+ return;
+
+ va_start(ap, format);
+
+ bufp = malloc(BUFSIZE);
+ if(bufp) {
+ vsnprintf(bufp, BUFSIZE, format, ap);
+ write(fd, bufp, strlen(bufp));
+ }
+ free(bufp);
+
+ va_end(ap);
+}
+
#ifdef CHECKPOINT_DEBUG
#define ckpt_dbg(_format, _args...) \
do { \
if (global_debug) \
- fprintf(stderr, "<%d>" _format, _gettid(), ##_args); \
+ ckpt_msg(global_uerrfd, "<%d>" _format, \
+ _gettid(), ##_args); \
} while (0)
-#define ckpt_dbg_cont(_format, _args...) \
- do { \
- if (global_debug) \
- fprintf(stderr, _format, ##_args); \
+#define ckpt_dbg_cont(_format, _args...) \
+ do { \
+ if (global_debug) \
+ ckpt_msg(global_uerrfd, _format, ##_args); \
} while (0)
#else
#define ckpt_dbg(_format, _args...) \
@@ -120,12 +143,12 @@ static char usage_str[] =
#endif
#define ckpt_err(...) \
- fprintf(stderr, __VA_ARGS__)
+ ckpt_msg(global_uerrfd, __VA_ARGS__)
-#define ckpt_verbose(...) \
- do { \
- if (global_verbose) \
- printf(__VA_ARGS__); \
+#define ckpt_verbose(...) \
+ do { \
+ if (global_verbose) \
+ ckpt_msg(global_ulogfd, __VA_ARGS__); \
} while(0)
#define SIGNAL_ENTRY(signal) { SIG ## signal, #signal }
@@ -196,8 +219,6 @@ inline static int restart(pid_t pid, int fd, unsigned long flags, int klogfd)
return syscall(__NR_restart, pid, fd, flags, klogfd);
}
-#define BUFSIZE (4 * 4096)
-
struct hashent {
long key;
void *data;
@@ -270,6 +291,12 @@ struct ckpt_ctx {
char *freezer;
};
+/*
+ * TODO: Do we need to direct user-space restart messages to two different
+ * fds (like stdout and stderr) or can we just use one ?
+ */
+int global_ulogfd;
+int global_uerrfd;
int global_debug;
int global_verbose;
pid_t global_child_pid;
@@ -372,7 +399,7 @@ struct args {
static void usage(char *str)
{
- fprintf(stderr, "%s", str);
+ ckpt_err("%s", str);
exit(1);
}
@@ -406,7 +433,7 @@ static long cond_to_mask(const char *cond)
if (!strcmp(cond, conditions[i].cond))
return conditions[i].mask;
- printf("restart: invalid warn/fail condition '%s'\n", cond);
+ ckpt_err("restart: invalid warn/fail condition '%s'\n", cond);
exit(1);
}
@@ -489,7 +516,7 @@ static void parse_args(struct args *args, int argc, char *argv[])
case 7:
args->infd = str2num(optarg);
if (args->infd < 0) {
- printf("restart: invalid file descriptor\n");
+ ckpt_err("restart: invalid file descriptor\n");
exit(1);
}
break;
@@ -499,7 +526,7 @@ static void parse_args(struct args *args, int argc, char *argv[])
case 8:
args->klogfd = str2num(optarg);
if (args->klogfd < 0) {
- printf("restart: invalid file descriptor\n");
+ ckpt_err("restart: invalid file descriptor\n");
exit(1);
}
break;
@@ -517,7 +544,7 @@ static void parse_args(struct args *args, int argc, char *argv[])
if (sig < 0)
sig = str2num(optarg);
if (sig < 0 || sig >= NSIG) {
- printf("restart: invalid signal\n");
+ ckpt_err("restart: invalid signal\n");
exit(1);
}
global_send_sigint = sig;
@@ -574,7 +601,7 @@ static void parse_args(struct args *args, int argc, char *argv[])
#ifndef CLONE_NEWPID
if (args->pidns) {
- printf("This version of restart was compiled without "
+ ckpt_err("This version of restart was compiled without "
"support for --pidns.\n");
exit(1);
}
@@ -582,7 +609,7 @@ static void parse_args(struct args *args, int argc, char *argv[])
#ifndef CHECKPOINT_DEBUG
if (global_debug) {
- printf("This version of restart was compiled without "
+ ckpt_err("This version of restart was compiled without "
"support for --debug.\n");
exit(1);
}
@@ -594,7 +621,7 @@ static void parse_args(struct args *args, int argc, char *argv[])
#if 0 /* Defered until __NR_eclone makes it to standard headers */
#ifndef __NR_eclone
if (args->pids) {
- printf("This version of restart was compiled without "
+ ckpt_err("This version of restart was compiled without "
"support for --pids.\n");
exit(1);
}
@@ -604,17 +631,17 @@ static void parse_args(struct args *args, int argc, char *argv[])
if (args->self &&
(args->pids || args->pidns || no_pidns ||
args->show_status || args->copy_status || args->freezer)) {
- printf("Invalid mix of --self with multiprocess options\n");
+ ckpt_err("Invalid mix of --self with multiprocess options\n");
exit(1);
}
if (args->input && args->infd >= 0) {
- printf("Invalid used of both -i/--input and --input-fd\n");
+ ckpt_err("Invalid use of both -i/--input and --input-fd\n");
exit(1);
}
if (klogfile && args->klogfd >= 0) {
- printf("Invalid used of both -l/--logfile and --logfile-fd\n");
+ ckpt_err("Invalid use of both -l/--logfile and --logfile-fd\n");
exit(1);
}
@@ -770,6 +797,15 @@ int main(int argc, char *argv[])
struct args args;
int ret;
+ /*
+ * Initialize the log/error fds early so even parse_args() errors
+ * are redirected here. Even if we later implement command line options
+ * that override these, any errors/messages that occur before those
+ * new options are parsed still go to stdout/stderr
+ */
+ global_ulogfd = fileno(stdout);
+ global_uerrfd = fileno(stderr);
+
memset(&ctx, 0, sizeof(ctx));
parse_args(&args, argc, argv);
@@ -891,16 +927,16 @@ static int ckpt_parse_status(int status, int mimic, int verbose)
int ret = 0;
if (verbose && global_sent_sigint)
- printf("Terminated\n");
+ ckpt_verbose("Terminated\n");
if (WIFSIGNALED(status)) {
sig = WTERMSIG(status);
if (verbose && !global_sent_sigint)
- printf("Killed %d\n", sig);
+ ckpt_verbose("Killed %d\n", sig);
ckpt_dbg("task terminated with signal %d\n", sig);
} else if (WIFEXITED(status)) {
ret = WEXITSTATUS(status);
if (verbose)
- printf("Exited %d\n", ret);
+ ckpt_verbose("Exited %d\n", ret);
ckpt_dbg("task exited with status %d\n", ret);
}
@@ -1172,7 +1208,7 @@ static int ckpt_coordinator_pidns(struct ckpt_ctx *ctx)
#else
static int ckpt_coordinator_pidns(struct ckpt_ctx *ctx)
{
- printf("logical error: ckpt_coordinator_pidns unexpected\n");
+ ckpt_err("logical error: ckpt_coordinator_pidns unexpected\n");
exit(1);
}
#endif
--
1.6.0.4
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