/*
  Copyright (c) 2012-2016 Red Hat, Inc. <http://www.redhat.com>
  This file is part of GlusterFS.

  This file is licensed to you under your choice of the GNU Lesser
  General Public License, version 3 or any later version (LGPLv3 or
  later), or the GNU General Public License, version 2 (GPLv2), in all
  cases as published by the Free Software Foundation.
*/

#include <unistd.h>
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <inttypes.h>
#include <limits.h>

#include <glusterfs/xlator.h>
#include <glusterfs/glusterfs.h>

#include "glfs-internal.h"
#include "glfs-mem-types.h"
#include "gfapi-messages.h"

int
graph_setup(struct glfs *fs, glusterfs_graph_t *graph)
{
    xlator_t *new_subvol = NULL;
    xlator_t *old_subvol = NULL;
    inode_table_t *itable = NULL;
    int ret = -1;

    new_subvol = graph->top;

    /* This is called in a bottom-up context, it should specifically
       NOT be glfs_lock()
    */
    pthread_mutex_lock(&fs->mutex);
    {
        if (new_subvol->switched || new_subvol == fs->active_subvol ||
            new_subvol == fs->next_subvol || new_subvol == fs->mip_subvol) {
            /* Spurious CHILD_UP event on old graph */
            ret = 0;
            goto unlock;
        }

        if (!new_subvol->itable) {
            itable = inode_table_new(131072, new_subvol);
            if (!itable) {
                errno = ENOMEM;
                ret = -1;
                goto unlock;
            }

            new_subvol->itable = itable;
        }

        old_subvol = fs->next_subvol;
        fs->next_subvol = new_subvol;
        fs->next_subvol->winds++; /* first ref */
        ret = 0;
    }
unlock:
    pthread_mutex_unlock(&fs->mutex);

    if (old_subvol)
        /* wasn't picked up so far, skip */
        glfs_subvol_done(fs, old_subvol);

    return ret;
}

int
notify(xlator_t *this, int event, void *data, ...)
{
    glusterfs_graph_t *graph = NULL;
    struct glfs *fs = NULL;

    graph = data;
    fs = this->private;

    switch (event) {
        case GF_EVENT_GRAPH_NEW:
            gf_msg(this->name, GF_LOG_INFO, 0, API_MSG_NEW_GRAPH,
                   "New graph %s (%d) coming up",
                   uuid_utoa((unsigned char *)graph->graph_uuid), graph->id);
            break;
        case GF_EVENT_CHILD_UP:
            pthread_mutex_lock(&fs->mutex);
            {
                graph->used = 1;
            }
            pthread_mutex_unlock(&fs->mutex);
            graph_setup(fs, graph);
            glfs_init_done(fs, 0);
            break;
        case GF_EVENT_CHILD_DOWN:
            pthread_mutex_lock(&fs->mutex);
            {
                graph->used = 0;
                pthread_cond_broadcast(&fs->child_down_cond);
            }
            pthread_mutex_unlock(&fs->mutex);
            glfs_init_done(fs, 1);
            break;
        case GF_EVENT_CHILD_CONNECTING:
            break;
        case GF_EVENT_UPCALL:
            glfs_process_upcall_event(fs, data);
            break;
        default:
            gf_msg_debug(this->name, 0, "got notify event %d", event);
            break;
    }

    return 0;
}

int
mem_acct_init(xlator_t *this)
{
    int ret = -1;

    if (!this)
        return ret;

    ret = xlator_mem_acct_init(this, glfs_mt_end + 1);
    if (ret) {
        gf_msg(this->name, GF_LOG_ERROR, ENOMEM, API_MSG_MEM_ACCT_INIT_FAILED,
               "Failed to initialise "
               "memory accounting");
        return ret;
    }

    return 0;
}

int
init(xlator_t *this)
{
    return 0;
}

void
fini(xlator_t *this)
{
}

/* place-holder fops */
int
glfs_forget(xlator_t *this, inode_t *inode)
{
    return 0;
}

int
glfs_release(xlator_t *this, fd_t *fd)
{
    return 0;
}

int
glfs_releasedir(xlator_t *this, fd_t *fd)
{
    return 0;
}

struct xlator_dumpops dumpops;

struct xlator_fops fops;

struct xlator_cbks cbks = {
    .forget = glfs_forget,
    .release = glfs_release,
    .releasedir = glfs_releasedir,
};

xlator_api_t xlator_api = {
    .init = init,
    .fini = fini,
    .notify = notify,
    .mem_acct_init = mem_acct_init,
    .op_version = {1},
    .dumpops = &dumpops,
    .fops = &fops,
    .cbks = &cbks,
    .identifier = "glfs-api",
    .category = GF_MAINTAINED,
};