/*
  Copyright (c) 2008-2012 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.
*/


#ifndef _CONFIG_H
#define _CONFIG_H
#include "config.h"
#endif

/* TODO: add NS locking */

#include "glusterfs.h"
#include "xlator.h"
#include "dht-common.h"
#include "defaults.h"

#include <sys/time.h>


int
dht_du_info_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
		 int op_ret, int op_errno, struct statvfs *statvfs,
                 dict_t *xdata)
{
	dht_conf_t    *conf         = NULL;
	call_frame_t  *prev          = NULL;
	int            this_call_cnt = 0;
	int            i = 0;
	double         percent = 0;
	double         percent_inodes = 0;
	uint64_t       bytes = 0;

	conf = this->private;
	prev = cookie;

	if (op_ret == -1) {
		gf_log (this->name, GF_LOG_WARNING,
			"failed to get disk info from %s", prev->this->name);
		goto out;
	}

	if (statvfs && statvfs->f_blocks) {
		percent = (statvfs->f_bavail * 100) / statvfs->f_blocks;
		bytes = (statvfs->f_bavail * statvfs->f_frsize);
	}

	if (statvfs && statvfs->f_files) {
		percent_inodes = (statvfs->f_ffree * 100) / statvfs->f_files;
	} else {
		/* set percent inodes to 100 for dynamically allocated inode filesystems
		   this logic holds good so that, distribute has nothing to worry about
		   total inodes rather let the 'create()' to be scheduled on the hashed
		   subvol regardless of the total inodes. since we have no awareness on
		   loosing inodes this logic fits well
		*/
		percent_inodes = 100;
	}

	LOCK (&conf->subvolume_lock);
	{
		for (i = 0; i < conf->subvolume_cnt; i++)
			if (prev->this == conf->subvolumes[i]) {
				conf->du_stats[i].avail_percent = percent;
				conf->du_stats[i].avail_space   = bytes;
				conf->du_stats[i].avail_inodes  = percent_inodes;
				gf_log (this->name, GF_LOG_DEBUG,
					"on subvolume '%s': avail_percent is: "
					"%.2f and avail_space is: %"PRIu64" "
					"and avail_inodes is: %.2f",
					prev->this->name,
					conf->du_stats[i].avail_percent,
					conf->du_stats[i].avail_space,
					conf->du_stats[i].avail_inodes);
			}
	}
	UNLOCK (&conf->subvolume_lock);

out:
	this_call_cnt = dht_frame_return (frame);
	if (is_last_call (this_call_cnt))
		DHT_STACK_DESTROY (frame);

	return 0;
}

int
dht_get_du_info_for_subvol (xlator_t *this, int subvol_idx)
{
	dht_conf_t    *conf         = NULL;
	call_frame_t  *statfs_frame = NULL;
	dht_local_t   *statfs_local = NULL;
	call_pool_t   *pool         = NULL;
	loc_t          tmp_loc      = {0,};

	conf = this->private;
	pool = this->ctx->pool;

	statfs_frame = create_frame (this, pool);
	if (!statfs_frame) {
		goto err;
	}

	/* local->fop value is not used in this case */
	statfs_local = dht_local_init (statfs_frame, NULL, NULL,
				       GF_FOP_MAXVALUE);
	if (!statfs_local) {
		goto err;
	}

        /* make it root gfid, should be enough to get the proper info back */
        tmp_loc.gfid[15] = 1;

	statfs_local->call_cnt = 1;
	STACK_WIND (statfs_frame, dht_du_info_cbk,
		    conf->subvolumes[subvol_idx],
		    conf->subvolumes[subvol_idx]->fops->statfs,
		    &tmp_loc, NULL);

	return 0;
err:
	if (statfs_frame)
		DHT_STACK_DESTROY (statfs_frame);

	return -1;
}

int
dht_get_du_info (call_frame_t *frame, xlator_t *this, loc_t *loc)
{
	int            i            = 0;
	dht_conf_t    *conf         = NULL;
	call_frame_t  *statfs_frame = NULL;
	dht_local_t   *statfs_local = NULL;
	struct timeval tv           = {0,};
        loc_t          tmp_loc      = {0,};

	conf  = this->private;

	gettimeofday (&tv, NULL);

        /* make it root gfid, should be enough to get the proper
           info back */
        tmp_loc.gfid[15] = 1;

	if (tv.tv_sec > (conf->refresh_interval
			 + conf->last_stat_fetch.tv_sec)) {

		statfs_frame = copy_frame (frame);
		if (!statfs_frame) {
			goto err;
		}

		/* In this case, 'local->fop' is not used */
		statfs_local = dht_local_init (statfs_frame, loc, NULL,
					       GF_FOP_MAXVALUE);
		if (!statfs_local) {
			goto err;
		}

		statfs_local->call_cnt = conf->subvolume_cnt;
		for (i = 0; i < conf->subvolume_cnt; i++) {
			STACK_WIND (statfs_frame, dht_du_info_cbk,
				    conf->subvolumes[i],
				    conf->subvolumes[i]->fops->statfs,
				    &tmp_loc, NULL);
		}

		conf->last_stat_fetch.tv_sec = tv.tv_sec;
	}
	return 0;
err:
	if (statfs_frame)
		DHT_STACK_DESTROY (statfs_frame);

	return -1;
}


gf_boolean_t
dht_is_subvol_filled (xlator_t *this, xlator_t *subvol)
{
	int         i = 0;
	dht_conf_t *conf = NULL;
	gf_boolean_t subvol_filled_inodes = _gf_false;
	gf_boolean_t subvol_filled_space = _gf_false;
	gf_boolean_t is_subvol_filled = _gf_false;

	conf = this->private;

	/* Check for values above specified percent or free disk */
	LOCK (&conf->subvolume_lock);
	{
		for (i = 0; i < conf->subvolume_cnt; i++) {
			if (subvol == conf->subvolumes[i]) {
				if (conf->disk_unit == 'p') {
					if (conf->du_stats[i].avail_percent <
					    conf->min_free_disk) {
						subvol_filled_space = _gf_true;
						break;
					}

				} else {
					if (conf->du_stats[i].avail_space <
					    conf->min_free_disk) {
						subvol_filled_space = _gf_true;
						break;
					}
				}
				if (conf->du_stats[i].avail_inodes <
				    conf->min_free_inodes) {
					subvol_filled_inodes = _gf_true;
					break;
				}
			}
		}
	}
	UNLOCK (&conf->subvolume_lock);

	if (subvol_filled_space && conf->subvolume_status[i]) {
		if (!(conf->du_stats[i].log++ % (GF_UNIVERSAL_ANSWER * 10))) {
			gf_log (this->name, GF_LOG_WARNING,
				"disk space on subvolume '%s' is getting "
				"full (%.2f %%), consider adding more nodes",
				subvol->name,
				(100 - conf->du_stats[i].avail_percent));
		}
	}

	if (subvol_filled_inodes && conf->subvolume_status[i]) {
		if (!(conf->du_stats[i].log++ % (GF_UNIVERSAL_ANSWER * 10))) {
			gf_log (this->name, GF_LOG_CRITICAL,
				"inodes on subvolume '%s' are at "
				"(%.2f %%), consider adding more nodes",
				subvol->name,
				(100 - conf->du_stats[i].avail_inodes));
		}
	}

	is_subvol_filled = (subvol_filled_space || subvol_filled_inodes);

	return is_subvol_filled;
}


/*Get the best subvolume to create the file in*/
xlator_t *
dht_free_disk_available_subvol (xlator_t *this, xlator_t *subvol,
                                dht_local_t *local)
{
	xlator_t   *avail_subvol = NULL;
	dht_conf_t *conf = NULL;
        dht_layout_t *layout = NULL;
        loc_t      *loc = NULL;

	conf = this->private;
        if (!local)
                goto out;
        loc = &local->loc;
        if (!local->layout) {
                layout = dht_layout_get (this, loc->parent);

                if (!layout) {
                        gf_log (this->name, GF_LOG_DEBUG,
                                "layout missing path=%s parent=%s",
                                loc->path, uuid_utoa (loc->parent->gfid));
                        goto out;
                }
        } else {
                layout = dht_layout_ref (this, local->layout);
        }

        LOCK (&conf->subvolume_lock);
	{
                avail_subvol = dht_subvol_with_free_space_inodes(this, subvol,
                                                                 layout);
                if(!avail_subvol)
                {
                        avail_subvol = dht_subvol_maxspace_nonzeroinode(this,
                                                                        subvol,
                                                                        layout);
                }

	}
	UNLOCK (&conf->subvolume_lock);
out:
	if (!avail_subvol) {
		gf_log (this->name,
                        GF_LOG_DEBUG,
			"no subvolume has enough free space and/or inodes\
                         to create");
                avail_subvol = subvol;
	}

        if (layout)
                dht_layout_unref (this, layout);
	return avail_subvol;
}

static inline
int32_t dht_subvol_has_err (xlator_t *this, dht_layout_t *layout)
{
        int ret = -1;
        int i   = 0;

        if (!this || !layout)
                goto out;

        /* check if subvol has layout errors, before selecting it */
        for (i = 0; i < layout->cnt; i++) {
                if (!strcmp (layout->list[i].xlator->name, this->name) &&
                     (layout->list[i].err != 0)) {
                        ret = -1;
                        goto out;
                }
        }
        ret = 0;
out:
        return ret;
}

/*Get subvolume which has both space and inodes more than the min criteria*/
xlator_t *
dht_subvol_with_free_space_inodes(xlator_t *this, xlator_t *subvol,
                                  dht_layout_t *layout)
{
        int i = 0;
        double max = 0;
        double max_inodes = 0;
        int    ignore_subvol = 0;

        xlator_t *avail_subvol = NULL;
        dht_conf_t *conf = NULL;

        conf = this->private;

        for(i=0; i < conf->subvolume_cnt; i++) {
                /* check if subvol has layout errors, before selecting it */
                ignore_subvol = dht_subvol_has_err (conf->subvolumes[i],
                                                    layout);
                if (ignore_subvol)
                        continue;

                if ((conf->disk_unit == 'p') &&
                    (conf->du_stats[i].avail_percent > conf->min_free_disk) &&
                    (conf->du_stats[i].avail_inodes  > conf->min_free_inodes)) {
                        if ((conf->du_stats[i].avail_inodes > max_inodes) ||
                            (conf->du_stats[i].avail_percent > max)) {
                                max = conf->du_stats[i].avail_percent;
                                max_inodes = conf->du_stats[i].avail_inodes;
                                avail_subvol = conf->subvolumes[i];
                        }
                }

                if ((conf->disk_unit != 'p') &&
                    (conf->du_stats[i].avail_space > conf->min_free_disk) &&
                    (conf->du_stats[i].avail_inodes  > conf->min_free_inodes)) {
                        if ((conf->du_stats[i].avail_inodes > max_inodes) ||
                            (conf->du_stats[i].avail_space > max)) {
                                max = conf->du_stats[i].avail_space;
                                max_inodes = conf->du_stats[i].avail_inodes;
                                avail_subvol = conf->subvolumes[i];
                        }
                }
        }

        return avail_subvol;
}


/* Get subvol which has atleast one inode and maximum space */
xlator_t *
dht_subvol_maxspace_nonzeroinode (xlator_t *this, xlator_t *subvol,
                                  dht_layout_t *layout)
{
        int         i = 0;
        double      max = 0;
        int         ignore_subvol = 0;

        xlator_t   *avail_subvol = NULL;
        dht_conf_t *conf = NULL;

        conf = this->private;

        for (i = 0; i < conf->subvolume_cnt; i++) {
                /* check if subvol has layout errors, before selecting it */
                ignore_subvol = dht_subvol_has_err (conf->subvolumes[i],
                                                    layout);
                if (ignore_subvol)
                        continue;

                if (conf->disk_unit == 'p') {
                        if ((conf->du_stats[i].avail_percent > max)
                            && (conf->du_stats[i].avail_inodes > 0 )) {
                                max = conf->du_stats[i].avail_percent;
                                avail_subvol = conf->subvolumes[i];
                        }
               } else {
                         if ((conf->du_stats[i].avail_space > max)
                            && (conf->du_stats[i].avail_inodes > 0)) {
                                 max = conf->du_stats[i].avail_space;
                                 avail_subvol = conf->subvolumes[i];
                         }
               }
        }

        return avail_subvol;
}