Bug 762724 (GLUSTER-992)

There is a memory leak in afr_sh_algo_diff. This is the valgrind report showing the mem-leak


 1,536 bytes in 48 blocks are definitely lost in loss record 123 of 145
==4084==    at 0x4C2414B: calloc (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==4084==    by 0x668AB3F: afr_sh_algo_diff (afr-self-heal-algorithm.c:1051)
==4084==    by 0x66753E7: afr_sh_data_sync_prepare (afr-self-heal-data.c:644)
==4084==    by 0x6675979: afr_sh_data_fix (afr-self-heal-data.c:758)
==4084==    by 0x6675C2D: afr_sh_data_fstat_cbk (afr-self-heal-data.c:829)
==4084==    by 0x6430A8B: client_fstat_cbk (client-protocol.c:4379)
==4084==    by 0x64379DB: protocol_client_interpret (client-protocol.c:6571)
==4084==    by 0x64386A1: protocol_client_pollin (client-protocol.c:6869)
==4084==    by 0x6438D15: notify (client-protocol.c:6988)
==4084==    by 0x4E422F9: xlator_notify (xlator.c:929)
==4084==    by 0x7F35256: socket_event_poll_in (socket.c:771)
==4084==    by 0x7F35550: socket_event_handler (socket.c:871)


in afr_sh_algo_diff function memory is allocated in this way:

 for (i = 0; i < priv->data_self_heal_window_size; i++) {
                sh_priv->loops[i]               = CALLOC (1, sizeof (*sh_priv->loops[i]));

                sh_priv->loops[i]->checksum     = CALLOC (priv->child_count,
                                                          MD5_DIGEST_LEN);
                sh_priv->loops[i]->write_needed = CALLOC (priv->child_count,
                                                          sizeof (*sh_priv->loops[i]->write_needed));
        }

        sh_diff_loop_driver (frame, this);

        return 0;
  sh_priv = sh->private;

        for (i = 0; i < priv->data_self_heal_window_size; i++) {
                if (sh_priv->loops[i]) {
                        if (sh_priv->loops[i]->write_needed)
                                FREE (sh_priv->loops[i]->write_needed);

                        if (sh_priv->loops[i]->checksum)
                                FREE (sh_priv->loops[i]->checksum);
                }
        }

        if (sh_priv) {
                if (sh_priv->loops)
                        FREE (sh_priv->loops);

                FREE (sh_priv);
        }


sh_priv->loops[i] is not freed thus causing a memory leak.


In sh_diff_loop_driver function it calls sh_diff_private_cleanup function which frees the sh_private structures in the following manner.

PATCH: http://patches.gluster.com/patch/3412 in release-3.0 (free sh_priv->loops to avoid memory leak)

PATCH: http://patches.gluster.com/patch/3840 in master (free sh_priv->loops[i] in afr-self-heal-algorithm.c to avoid memory leak)