glusterd: statedump support

Although glusterd currently has statedump support but it doesn't dump its
context information. Implementing glusterd_dump_priv function to export per-node
glusterd information would be useful for debugging bugs. Once implemented, we
could enhance sos-report to fetch this information. This would potentially
reduce our time to root cause and data needed for debugability can be dumped
gradually.

Following is the main items of the dump list targeted in this patch :

    * Supported max/min op-version and current op-version
    * Information about peer list
    * Information about peer list involved while a transaction is going on
      (xaction_peers)
    * option dictionary in glusterd_conf_t
    * mgmt_v3_lock in glusterd_conf_t
    * List of connected clients
    * uuid of glusterd
    * A section of rpc related information like live connections and their
      statistics

There are couple of issues which were found during implementation and testing
phase:
 - xaction_peers of glusterd_conf_t was not initialized in init because of which
   traversing through this list head was crashing when there was no active
   transaction
 - gf_free was not setting the typestr to NULL if the the alloc count becomes 0
   for a mem-type earlier allocated.

Change-Id: Ic9bce2d57682fc1771cd2bc6af0b7316ecbc761f
BUG: 1139682
Signed-off-by: Atin Mukherjee <amukherj@redhat.com>
Reviewed-on: http://review.gluster.org/8665
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Kaushal M <kaushal@redhat.com>

3 files changed, 64 insertions, 25 deletions

diff --git a/libglusterfs/src/dict.c b/libglusterfs/src/dict.c
index 5062f509940..d55495c1ad2 100644
--- a/libglusterfs/src/dict.c
+++ b/libglusterfs/src/dict.c
@@ -29,6 +29,7 @@
 #include "compat.h"
 #include "byte-order.h"
 #include "globals.h"
+#include "statedump.h"
 
 data_t *
 get_new_data ()
@@ -2807,39 +2808,67 @@ out:
         return ret;
 }
 
+int
+dict_dump_to_str (dict_t *dict, char *dump, int dumpsize, char *format)
+{
+        int          ret                       = 0;
+        int          dumplen                   = 0;
+        data_pair_t *trav                      = NULL;
+
+        for (trav = dict->members_list; trav; trav = trav->next) {
+                ret = snprintf (&dump[dumplen], dumpsize - dumplen,
+                                format, trav->key, trav->value->data);
+                if ((ret == -1) || !ret)
+                        return ret;
+
+                dumplen += ret;
+        }
+        return 0;
+}
+
 void
-dict_dump (dict_t *this)
+dict_dump_to_log (dict_t *dict)
 {
-        int          ret     = 0;
-        int          dumplen = 0;
-        data_pair_t *trav    = NULL;
-        char         dump[64*1024]; /* This is debug only, hence
-                                       performance should not matter */
+        int          ret                       = -1;
+        char         dump[64*1024]             = {0,};
+        char        *format                    = "(%s:%s)";
 
-        if (!this) {
-                gf_log_callingfn ("dict", GF_LOG_WARNING, "dict NULL");
-                goto out;
+        if (!dict) {
+                gf_log_callingfn ("dict", GF_LOG_WARNING, "dict is NULL");
+                return;
         }
 
-        dump[0] = '\0'; /* the array is not initialized to '\0' */
+        ret = dict_dump_to_str (dict, dump, sizeof(dump), format);
+        if (ret) {
+                gf_log ("dict", GF_LOG_WARNING, "Failed to log dictionary");
+                return;
+        }
+        gf_log_callingfn ("dict", GF_LOG_INFO, "dict=%p (%s)", dict, dump);
 
-        /* There is a possibility of issues if data is binary, ignore it
-           for now as debugging is more important */
-        for (trav = this->members_list; trav; trav = trav->next) {
-                ret = snprintf (&dump[dumplen], ((64*1024) - dumplen - 1),
-                                "(%s:%s)", trav->key, trav->value->data);
-                if ((ret == -1) || !ret)
-                        break;
+        return;
+}
 
-                dumplen += ret;
-                /* snprintf doesn't append a trailing '\0', add it here */
-                dump[dumplen] = '\0';
+void
+dict_dump_to_statedump (dict_t *dict, char *dict_name, char *domain)
+{
+        int          ret                       = -1;
+        char         dump[64*1024]             = {0,};
+        char         key[4096]                 = {0,};
+        char        *format                    = "\n\t%s:%s";
+
+        if (!dict) {
+                gf_log_callingfn (domain, GF_LOG_WARNING, "dict is NULL");
+                return;
         }
 
-        if (dumplen)
-                gf_log_callingfn ("dict", GF_LOG_INFO,
-                                  "dict=%p (%s)", this, dump);
+        ret = dict_dump_to_str (dict, dump, sizeof(dump), format);
+        if (ret) {
+                gf_log (domain, GF_LOG_WARNING, "Failed to log dictionary %s",
+                        dict_name);
+                return;
+        }
+        gf_proc_dump_build_key (key, domain, dict_name);
+        gf_proc_dump_write (key, "%s", dump);
 
-out:
         return;
 }
diff --git a/libglusterfs/src/dict.h b/libglusterfs/src/dict.h
index 7fd45e1cf34..148eb0ef7ea 100644
--- a/libglusterfs/src/dict.h
+++ b/libglusterfs/src/dict.h
@@ -234,6 +234,12 @@ GF_MUST_CHECK int dict_get_str (dict_t *this, char *key, char **str);
 GF_MUST_CHECK int dict_get_str_boolean (dict_t *this, char *key, int default_val);
 GF_MUST_CHECK int dict_serialize_value_with_delim (dict_t *this, char *buf, int32_t *serz_len,
                                                     char delimiter);
+void
+dict_dump_to_statedump (dict_t *dict, char *dict_name, char *domain);
 
-void dict_dump (dict_t *dict);
+void
+dict_dump_to_log (dict_t *dict);
+
+int
+dict_dump_to_str (dict_t *dict, char *dump, int dumpsize, char *format);
 #endif
diff --git a/libglusterfs/src/mem-pool.c b/libglusterfs/src/mem-pool.c
index 093592ec056..019be95e37e 100644
--- a/libglusterfs/src/mem-pool.c
+++ b/libglusterfs/src/mem-pool.c
@@ -279,6 +279,10 @@ __gf_free (void *free_ptr)
         {
                 xl->mem_acct.rec[type].size -= req_size;
                 xl->mem_acct.rec[type].num_allocs--;
+                /* If all the instaces are freed up then ensure typestr is
+                 * set to NULL */
+                if (!xl->mem_acct.rec[type].num_allocs)
+                        xl->mem_acct.rec[type].typestr = NULL;
         }
         UNLOCK (&xl->mem_acct.rec[type].lock);
 free: