xlator: make 'xlator_api' mandatory

* Remove the options to load old symbol.
* keep only 'xlator_api' symbol from being exported using xlator.sym
* add xlator_api to all the xlators where its missing

NOTE: This covers all the xlators which has at least a test case
to validate its loading. If there is a translator, which doesn't
have any test, then we should probably remove that from codebase.

fixes: #164
Change-Id: Ibcdc8c9844cda6b4463d907a15813745d14c1ebb
Signed-off-by: Amar Tumballi <amarts@redhat.com>

2 files changed, 16 insertions, 145 deletions

diff --git a/libglusterfs/src/glusterfs/xlator.h b/libglusterfs/src/glusterfs/xlator.h
index 12d507bc021..0c39f4bd3cc 100644
--- a/libglusterfs/src/glusterfs/xlator.h
+++ b/libglusterfs/src/glusterfs/xlator.h
@@ -866,13 +866,6 @@ struct _xlator {
     uint32_t notify_down;
 };
 
-typedef struct {
-    int32_t (*init)(xlator_t *this);
-    void (*fini)(xlator_t *this);
-    int32_t (*reconfigure)(xlator_t *this, dict_t *options);
-    event_notify_fn_t notify;
-} class_methods_t;
-
 /* This would be the only structure which needs to be exported by
    the translators. For the backward compatibility, in 4.x series
    even the old exported fields will be supported */
diff --git a/libglusterfs/src/xlator.c b/libglusterfs/src/xlator.c
index 13213d55994..3dc0c648177 100644
--- a/libglusterfs/src/xlator.c
+++ b/libglusterfs/src/xlator.c
@@ -214,26 +214,16 @@ xlator_volopt_dynload(char *xlator_type, void **dl_handle,
     /* check new struct first, and then check this */
     xlapi = dlsym(handle, "xlator_api");
     if (!xlapi) {
-        gf_msg("xlator", GF_LOG_DEBUG, 0, LG_MSG_DLSYM_ERROR,
-               "dlsym(xlator_api) on %s. "
-               "Fall back to old symbols",
-               dlerror());
-        /* This case is not an error for now, so allow it
-           to fall back to old methods. */
-        opt_list->given_opt = dlsym(handle, "options");
-        if (!opt_list->given_opt) {
-            dlerror();
-            gf_msg("xlator", GF_LOG_ERROR, 0, LG_MSG_LOAD_FAILED,
-                   "Failed to load xlator opt table");
-            goto out;
-        }
-    } else {
-        opt_list->given_opt = xlapi->options;
-        if (!opt_list->given_opt) {
-            gf_msg("xlator", GF_LOG_ERROR, 0, LG_MSG_LOAD_FAILED,
-                   "Failed to load xlator options table");
-            goto out;
-        }
+        gf_msg("xlator", GF_LOG_ERROR, 0, LG_MSG_DLSYM_ERROR,
+               "dlsym(xlator_api) missing: %s", dlerror());
+        goto out;
+    }
+
+    opt_list->given_opt = xlapi->options;
+    if (!opt_list->given_opt) {
+        gf_msg("xlator", GF_LOG_ERROR, 0, LG_MSG_LOAD_FAILED,
+               "Failed to load xlator options table");
+        goto out;
     }
 
     *dl_handle = handle;
@@ -249,110 +239,8 @@ out:
     return ret;
 }
 
-int
-xlator_dynload_oldway(xlator_t *xl)
-{
-    int i = 0;
-    int ret = -1;
-    void *handle = NULL;
-    volume_opt_list_t *vol_opt = NULL;
-    class_methods_t *vtbl = NULL;
-
-    handle = xl->dlhandle;
-
-    xl->fops = dlsym(handle, "fops");
-    if (!xl->fops) {
-        gf_msg("xlator", GF_LOG_WARNING, 0, LG_MSG_DLSYM_ERROR,
-               "dlsym(fops) on %s", dlerror());
-        goto out;
-    }
-
-    xl->cbks = dlsym(handle, "cbks");
-    if (!xl->cbks) {
-        gf_msg("xlator", GF_LOG_WARNING, 0, LG_MSG_DLSYM_ERROR,
-               "dlsym(cbks) on %s", dlerror());
-        goto out;
-    }
-
-    /*
-     * If class_methods exists, its contents override any definitions of
-     * init or fini for that translator.  Otherwise, we fall back to the
-     * older method of looking for init and fini directly.
-     */
-    vtbl = dlsym(handle, "class_methods");
-    if (vtbl) {
-        xl->init = vtbl->init;
-        xl->fini = vtbl->fini;
-        xl->reconfigure = vtbl->reconfigure;
-        xl->notify = vtbl->notify;
-    } else {
-        if (!(*VOID(&xl->init) = dlsym(handle, "init"))) {
-            gf_msg("xlator", GF_LOG_WARNING, 0, LG_MSG_DLSYM_ERROR,
-                   "dlsym(init) on %s", dlerror());
-            goto out;
-        }
-
-        if (!(*VOID(&(xl->fini)) = dlsym(handle, "fini"))) {
-            gf_msg("xlator", GF_LOG_WARNING, 0, LG_MSG_DLSYM_ERROR,
-                   "dlsym(fini) on %s", dlerror());
-            goto out;
-        }
-        if (!(*VOID(&(xl->reconfigure)) = dlsym(handle, "reconfigure"))) {
-            gf_msg_trace("xlator", 0,
-                         "dlsym(reconfigure) on %s "
-                         "-- neglecting",
-                         dlerror());
-        }
-        if (!(*VOID(&(xl->notify)) = dlsym(handle, "notify"))) {
-            gf_msg_trace("xlator", 0,
-                         "dlsym(notify) on %s -- "
-                         "neglecting",
-                         dlerror());
-        }
-    }
-
-    if (!(xl->dumpops = dlsym(handle, "dumpops"))) {
-        gf_msg_trace("xlator", 0,
-                     "dlsym(dumpops) on %s -- "
-                     "neglecting",
-                     dlerror());
-    }
-
-    if (!(*VOID(&(xl->mem_acct_init)) = dlsym(handle, "mem_acct_init"))) {
-        gf_msg_trace(xl->name, 0,
-                     "dlsym(mem_acct_init) on %s -- "
-                     "neglecting",
-                     dlerror());
-    }
-
-    vol_opt = GF_CALLOC(1, sizeof(volume_opt_list_t),
-                        gf_common_mt_volume_opt_list_t);
-
-    if (!vol_opt) {
-        goto out;
-    }
-
-    INIT_LIST_HEAD(&vol_opt->list);
-    vol_opt->given_opt = dlsym(handle, "options");
-    if (!vol_opt->given_opt) {
-        vol_opt->given_opt = default_options;
-    }
-    list_add_tail(&vol_opt->list, &xl->volume_options);
-
-    /* make sure 'min' is set to high value, so it would be
-       properly set later */
-    for (i = 0; i < GF_FOP_MAXVALUE; i++) {
-        xl->stats.interval.latencies[i].min = 0xffffffff;
-    }
-
-    ret = 0;
-
-out:
-    return ret;
-}
-
-int
-xlator_dynload_newway(xlator_t *xl)
+static int
+xlator_dynload_apis(xlator_t *xl)
 {
     int ret = -1;
     void *handle = NULL;
@@ -363,13 +251,9 @@ xlator_dynload_newway(xlator_t *xl)
 
     xlapi = dlsym(handle, "xlator_api");
     if (!xlapi) {
-        gf_msg("xlator", GF_LOG_INFO, 0, LG_MSG_DLSYM_ERROR,
-               "dlsym(xlator_api) on %s. "
-               "Fall back to old symbols",
-               dlerror());
-        /* This case is not an error for now, so allow it
-           to fall back to old methods. */
-        ret = 1;
+        gf_msg("xlator", GF_LOG_ERROR, 0, LG_MSG_DLSYM_ERROR,
+               "dlsym(xlator_api) missing: %s", dlerror());
+        ret = -1;
         goto out;
     }
 
@@ -492,15 +376,9 @@ xlator_dynload(xlator_t *xl)
     }
     xl->dlhandle = handle;
 
-    ret = xlator_dynload_newway(xl);
+    ret = xlator_dynload_apis(xl);
     if (-1 == ret)
         goto out;
-    if (1 == ret) {
-        /* it means we don't find the new symbol in xlator code */
-        ret = xlator_dynload_oldway(xl);
-        if (-1 == ret)
-            goto out;
-    }
 
     fill_defaults(xl);