gf_system: fork/exec instead of system

* most of the glusterd 'system()' are replaced with 'gf_system()'

Signed-off-by: Amar Tumballi <amar@gluster.com>
Signed-off-by: Anand V. Avati <avati@dev.gluster.com>

BUG: 1292 ()
URL: http://bugs.gluster.com/cgi-bin/bugzilla3/show_bug.cgi?id=1292

4 files changed, 66 insertions, 8 deletions

diff --git a/libglusterfs/src/common-utils.c b/libglusterfs/src/common-utils.c
index 3b904f522..eef865ec5 100644
--- a/libglusterfs/src/common-utils.c
+++ b/libglusterfs/src/common-utils.c
@@ -36,6 +36,7 @@
 #include <time.h>
 #include <locale.h>
 #include <sys/socket.h>
+#include <sys/wait.h>
 #include <netinet/in.h>
 #include <arpa/inet.h>
 #include <signal.h>
@@ -1466,3 +1467,58 @@ get_checksum_for_file (int fd, uint32_t *checksum)
 
         return ret;
 }
+
+
+/* One should pass the command here with command with full path,
+   otherwise, execv will fail */
+int
+gf_system (const char *command)
+{
+        int    ret    = -1;
+        pid_t  pid    = 0;
+        int    status = 0;
+        int    idx    = 0;
+        char  *dupcmd = NULL;
+        char  *arg    = NULL;
+        char  *tmp    = NULL;
+        char  *argv[100] = { NULL, };
+
+        dupcmd = gf_strdup (command);
+        if (!dupcmd)
+                goto out;
+
+        pid = fork ();
+        if (pid < 0) {
+                /* failure */
+                goto out;
+        }
+        if (pid == 0) {
+                /* Child process */
+                /* Step 0: Prepare the argv */
+                arg = strtok_r (dupcmd, " ", &tmp);
+                while (arg) {
+                        argv[idx] = arg;
+                        arg = strtok_r (NULL, " ", &tmp);
+                        idx++;
+                }
+                /* Step 1: Close all 'fd' */
+                for (idx = 3; idx < 65536; idx++) {
+                        close (idx);
+                }
+                /* Step 2: execv (); */
+                ret = execvp (argv[0], argv);
+
+                /* Code will not come here at all */
+                gf_log ("", GF_LOG_ERROR, "execv of (%s) failed", command);
+        }
+        if (pid > 0) {
+                /* Current, ie, parent process */
+                pid = waitpid (pid, &status, 0);
+                ret = status;
+        }
+out:
+        if (dupcmd)
+                GF_FREE (dupcmd);
+
+        return ret;
+}
diff --git a/libglusterfs/src/common-utils.h b/libglusterfs/src/common-utils.h
index ab230993a..93d62f6cb 100644
--- a/libglusterfs/src/common-utils.h
+++ b/libglusterfs/src/common-utils.h
@@ -328,5 +328,7 @@ int gf_unlockfd (int fd);
 int get_checksum_for_file (int fd, uint32_t *checksum);
 int log_base2 (unsigned long x);
 
+int gf_system (const char *command);
+
 #endif /* _COMMON_UTILS_H */
 
diff --git a/xlators/mgmt/glusterd/src/glusterd-op-sm.c b/xlators/mgmt/glusterd/src/glusterd-op-sm.c
index d24a4f159..b243e7895 100644
--- a/xlators/mgmt/glusterd/src/glusterd-op-sm.c
+++ b/xlators/mgmt/glusterd/src/glusterd-op-sm.c
@@ -294,7 +294,7 @@ glusterd_volume_create_generate_volfiles (glusterd_volinfo_t *volinfo)
                                   " -c %s -r 1 %s -p %d --num-replica %d",
                                   GFS_PREFIX, volinfo->volname, path, bricks,
                                   volinfo->port, volinfo->sub_count);
-                        ret = system (cmd_str);
+                        ret = gf_system (cmd_str);
                         gf_log ("", 1, "%s", cmd_str);
                         break;
                 }
@@ -306,7 +306,7 @@ glusterd_volume_create_generate_volfiles (glusterd_volinfo_t *volinfo)
                                   " -c %s -r 0 %s -p %d --num-stripe %d",
                                   GFS_PREFIX, volinfo->volname, path, bricks,
                                   volinfo->port, volinfo->sub_count);
-                        ret = system (cmd_str);
+                        ret = gf_system (cmd_str);
                         gf_log ("", 1, "%s", cmd_str);
                         break;
                 }
@@ -318,7 +318,7 @@ glusterd_volume_create_generate_volfiles (glusterd_volinfo_t *volinfo)
                                   " -n %s -c %s %s -p %d",
                                   GFS_PREFIX, volinfo->volname, path, bricks,
                                   volinfo->port);
-                        ret = system (cmd_str);
+                        ret = gf_system (cmd_str);
                         gf_log ("", 1, "%s", cmd_str);
                         break;
                 }
@@ -1013,7 +1013,7 @@ rb_spawn_dst_brick (glusterd_volinfo_t *volinfo,
                   priv->workdir, volinfo->volname,
                   RB_DSTBRICK_PIDFILE);
 
-        ret = system (cmd_str);
+        ret = gf_system (cmd_str);
         if (ret) {
                 gf_log ("", GF_LOG_DEBUG,
                         "Could not start glusterfs");
@@ -1048,7 +1048,7 @@ rb_spawn_glusterfs_client (glusterd_volinfo_t *volinfo,
                   priv->workdir, volinfo->volname,
                   RB_CLIENT_MOUNTPOINT);
 
-        ret = system (cmd_str);
+        ret = gf_system (cmd_str);
         if (ret) {
                 gf_log ("", GF_LOG_DEBUG,
                         "Could not start glusterfs");
@@ -1255,11 +1255,11 @@ rb_destroy_maintainence_client (glusterd_volinfo_t *volinfo,
                 goto out;
         }
 
-        snprintf (cmd_str, 8192, "umount -f %s/vols/%s/%s",
+        snprintf (cmd_str, 8192, "/bin/umount -f %s/vols/%s/%s",
                   priv->workdir, volinfo->volname,
                   RB_CLIENT_MOUNTPOINT);
 
-        ret = system (cmd_str);
+        ret = gf_system (cmd_str);
         if (ret) {
                 gf_log ("", GF_LOG_DEBUG,
                         "umount failed on maintainence client");
diff --git a/xlators/mgmt/glusterd/src/glusterd-utils.c b/xlators/mgmt/glusterd/src/glusterd-utils.c
index 424c35f2f..35dfa3dfb 100644
--- a/xlators/mgmt/glusterd/src/glusterd-utils.c
+++ b/xlators/mgmt/glusterd/src/glusterd-utils.c
@@ -771,7 +771,7 @@ glusterd_volume_start_glusterfs (glusterd_volinfo_t  *volinfo,
                   "-s localhost --volfile-id %s -p %s --brick-name %s "
                   "--brick-port %d", GFS_PREFIX,
                   port, volfile, pidfile, brickinfo->path, port);
-        ret = system (cmd_str);
+        ret = gf_system (cmd_str);
 
         if (ret == 0) {
                 //pmap_registry_bind (THIS, port, brickinfo->path);