[sheepdog] [PATCH 1/2] logger: allow sheep dump core file for non-root startup

[Liu Yuan]

From: Liu Yuan <tailai.ly at taobao.com>

As a side effect, the coredump file will be located /path/to/store dir
instead of previous '/'. We also don't overlap core file when multiple sheeps
run on the same machine.

Signed-off-by: Liu Yuan <tailai.ly at taobao.com>
---
 lib/logger.c |    8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/lib/logger.c b/lib/logger.c
index 5bce85c..04ba933 100644
--- a/lib/logger.c
+++ b/lib/logger.c
@@ -29,6 +29,7 @@
 #include <sys/wait.h>
 #include <sys/prctl.h>
 #include <pthread.h>
+#include <libgen.h>
 
 #include "logger.h"
 #include "util.h"
@@ -404,12 +405,15 @@ notrace int log_init(char *program_name, int size, int to_stdout, int level,
 {
 	off_t offset;
 	size_t log_size;
+	char log_dir[PATH_MAX];
 
 	log_level = level;
 
 	logdbg(stderr, "entering log_init\n");
 	log_name = program_name;
 	log_nowname = outfile;
+	strcpy(log_dir, outfile);
+	strcpy(log_dir, dirname(log_dir));
 
 	semkey = random();
 
@@ -465,8 +469,8 @@ notrace int log_init(char *program_name, int size, int to_stdout, int level,
 		dup2(fd, 1);
 		dup2(fd, 2);
 		setsid();
-		if (chdir("/") < 0) {
-			syslog(LOG_ERR, "failed to chdir to /: %m\n");
+		if (chdir(log_dir) < 0) {
+			syslog(LOG_ERR, "failed to chdir to %s: %m\n", log_dir);
 			exit(1);
 		}
 
-- 
1.7.10.2