stack: Reduce stack usage for local variables to store tmpfile names

This patch moves stack based PATH_MAX allocations for tmpfile
names, to heap allocated names instead. Reducing the impact on
stack space used and accruing benefits thereof.

Change-Id: I646d9cb091018de6768b3523902788fa2ba14d96
Updates: bz#1193929
Signed-off-by: ShyamsundarR <srangana@redhat.com>

1 files changed, 18 insertions, 5 deletions

diff --git a/xlators/mgmt/glusterd/src/glusterd-svc-helper.c b/xlators/mgmt/glusterd/src/glusterd-svc-helper.c
index abf979eada5..40726dbfb3e 100644
--- a/xlators/mgmt/glusterd/src/glusterd-svc-helper.c
+++ b/xlators/mgmt/glusterd/src/glusterd-svc-helper.c
@@ -162,7 +162,7 @@ glusterd_svc_check_volfile_identical (char *svc_name,
                                       gf_boolean_t *identical)
 {
         char            orgvol[PATH_MAX]        = {0,};
-        char            tmpvol[PATH_MAX]        = {0,};
+        char            *tmpvol                 = NULL;
         glusterd_conf_t *conf                   = NULL;
         xlator_t        *this                   = NULL;
         int             ret                     = -1;
@@ -178,7 +178,10 @@ glusterd_svc_check_volfile_identical (char *svc_name,
         glusterd_svc_build_volfile_path (svc_name, conf->workdir,
                                          orgvol, sizeof (orgvol));
 
-        snprintf (tmpvol, sizeof (tmpvol), "/tmp/g%s-XXXXXX", svc_name);
+        ret = gf_asprintf(&tmpvol, "/tmp/g%s-XXXXXX", svc_name);
+        if (ret < 0) {
+                goto out;
+        }
 
         /* coverity[secure_temp] mkstemp uses 0600 as the mode and is safe */
         tmp_fd = mkstemp (tmpvol);
@@ -186,6 +189,7 @@ glusterd_svc_check_volfile_identical (char *svc_name,
                 gf_msg (this->name, GF_LOG_WARNING, errno,
                         GD_MSG_FILE_OP_FAILED, "Unable to create temp file"
                         " %s:(%s)", tmpvol, strerror (errno));
+                ret = -1;
                 goto out;
         }
 
@@ -196,11 +200,13 @@ glusterd_svc_check_volfile_identical (char *svc_name,
                 goto out;
 
         ret = glusterd_check_files_identical (orgvol, tmpvol, identical);
-
 out:
         if (need_unlink)
                 sys_unlink (tmpvol);
 
+        if (tmpvol != NULL)
+                GF_FREE(tmpvol);
+
         if (tmp_fd >= 0)
                 sys_close (tmp_fd);
 
@@ -213,7 +219,7 @@ glusterd_svc_check_topology_identical (char *svc_name,
                                        gf_boolean_t *identical)
 {
         char            orgvol[PATH_MAX]        = {0,};
-        char            tmpvol[PATH_MAX]        = {0,};
+        char            *tmpvol                 = NULL;
         glusterd_conf_t *conf                   = NULL;
         xlator_t        *this                   = THIS;
         int             ret                     = -1;
@@ -231,13 +237,18 @@ glusterd_svc_check_topology_identical (char *svc_name,
                                          orgvol, sizeof (orgvol));
 
         /* Create the temporary volfile */
-        snprintf (tmpvol, sizeof (tmpvol), "/tmp/g%s-XXXXXX", svc_name);
+        ret = gf_asprintf(&tmpvol, "/tmp/g%s-XXXXXX", svc_name);
+        if (ret < 0) {
+                goto out;
+        }
+
         /* coverity[secure_temp] mkstemp uses 0600 as the mode and is safe */
         tmpfd = mkstemp (tmpvol);
         if (tmpfd < 0) {
                 gf_msg (this->name, GF_LOG_WARNING, errno,
                         GD_MSG_FILE_OP_FAILED, "Unable to create temp file"
                         " %s:(%s)", tmpvol, strerror (errno));
+                ret = -1;
                 goto out;
         }
 
@@ -256,5 +267,7 @@ out:
                 sys_close (tmpfd);
         if (tmpclean)
                 sys_unlink (tmpvol);
+        if (tmpvol != NULL)
+                GF_FREE(tmpvol);
         return ret;
 }