libglusterfs/xlator: undefined symbol xlator_api

Issue:
On executiing the command gluster vol set help, an error
comes up in glusterd logs stating `undefined symbol: xlator_api`.
This issue is seen for the rpc-transport/socket.so file.

Fix:
The symbol `xlator_api` is not found in rpc-transport/socket.so
file as it is not a xlator but a shared object for transport.
In the `xlator.c` file, there is a function `xlator_volopt_dynload`,
which looks for the default values of the options available in gluster,
which is stored inside the respective xlator files for different voltypes.
In each of these files the `options` object is present which contains
the default values, which is therefore referenced from the `options` data
member of `xlator_api` object in case of xlators.But, since
`rpc-transport/socket.so` is not an xlator we don't have the `xlator_api`
object present to point to that object. So, in case of
`rpc-transport/socket.so` type we are accesing the `options` object
directly from the `xlator_volopt_dynload` function to fetch the default
values for the available options.

Fixes: #827
Change-Id: I3b2b0c1f2a11896be250aaca1a33a65b044991d5
Signed-off-by: nik-redhat <nladha@redhat.com>

1 files changed, 27 insertions, 12 deletions

diff --git a/libglusterfs/src/xlator.c b/libglusterfs/src/xlator.c
index e793e1e3d68..539da7f4716 100644
--- a/libglusterfs/src/xlator.c
+++ b/libglusterfs/src/xlator.c
@@ -184,9 +184,11 @@ xlator_volopt_dynload(char *xlator_type, void **dl_handle,
                       volume_opt_list_t *opt_list)
 {
     int ret = -1;
+    int flag = 0;
     char *name = NULL;
     void *handle = NULL;
     xlator_api_t *xlapi = NULL;
+    volume_option_t *opt = NULL;
 
     GF_VALIDATE_OR_GOTO("xlator", xlator_type, out);
 
@@ -194,8 +196,10 @@ xlator_volopt_dynload(char *xlator_type, void **dl_handle,
      * need this check */
     if (!strstr(xlator_type, "rpc-transport"))
         ret = gf_asprintf(&name, "%s/%s.so", XLATORDIR, xlator_type);
-    else
+    else {
+        flag = 1;
         ret = gf_asprintf(&name, "%s/%s.so", XLATORPARENTDIR, xlator_type);
+    }
     if (-1 == ret) {
         goto out;
     }
@@ -211,18 +215,29 @@ xlator_volopt_dynload(char *xlator_type, void **dl_handle,
         goto out;
     }
 
-    /* check new struct first, and then check this */
-    xlapi = dlsym(handle, "xlator_api");
-    if (!xlapi) {
-        gf_smsg("xlator", GF_LOG_ERROR, 0, LG_MSG_DLSYM_ERROR, "error=%s",
-                dlerror(), NULL);
-        goto out;
-    }
+    if (flag == 0) {
+        /* check new struct first, and then check this */
+        xlapi = dlsym(handle, "xlator_api");
+        if (!xlapi) {
+            gf_smsg("xlator", GF_LOG_ERROR, 0, LG_MSG_DLSYM_ERROR, "error=%s",
+                    dlerror(), NULL);
+            goto out;
+        }
 
-    opt_list->given_opt = xlapi->options;
-    if (!opt_list->given_opt) {
-        gf_smsg("xlator", GF_LOG_ERROR, 0, LG_MSG_LOAD_FAILED, NULL);
-        goto out;
+        opt_list->given_opt = xlapi->options;
+        if (!opt_list->given_opt) {
+            gf_smsg("xlator", GF_LOG_ERROR, 0, LG_MSG_LOAD_FAILED, NULL);
+            goto out;
+        }
+    } else {
+        opt = dlsym(handle, "options");
+        if (!opt) {
+            gf_smsg("xlator", GF_LOG_ERROR, 0, LG_MSG_DLSYM_ERROR, "error=%s",
+                    dlerror(), NULL);
+            goto out;
+        }
+
+        opt_list->given_opt = opt;
     }
 
     *dl_handle = handle;