/*

   * f2fs debugging statistics
   *
   * Copyright (c) 2012 Samsung Electronics Co., Ltd.
   *             http://www.samsung.com/
   * Copyright (c) 2012 Linux Foundation
   * Copyright (c) 2012 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License version 2 as
   * published by the Free Software Foundation.
   */
  
  #include <linux/fs.h>
  #include <linux/backing-dev.h>

  #include <linux/f2fs_fs.h>
  #include <linux/blkdev.h>
  #include <linux/debugfs.h>
  #include <linux/seq_file.h>
  
  #include "f2fs.h"
  #include "node.h"
  #include "segment.h"
  #include "gc.h"
  
  static LIST_HEAD(f2fs_stat_list);
  static struct dentry *debugfs_root;

  static DEFINE_MUTEX(f2fs_stat_mutex);

  static void update_general_status(struct f2fs_sb_info *sbi)

  {
  	struct f2fs_stat_info *si = sbi->stat_info;
  	int i;
  
  	/* valid check of the segment numbers */
  	si->hit_ext = sbi->read_hit_ext;
  	si->total_ext = sbi->total_hit_ext;
  	si->ndirty_node = get_pages(sbi, F2FS_DIRTY_NODES);
  	si->ndirty_dent = get_pages(sbi, F2FS_DIRTY_DENTS);
  	si->ndirty_dirs = sbi->n_dirty_dirs;
  	si->ndirty_meta = get_pages(sbi, F2FS_DIRTY_META);
  	si->total_count = (int)sbi->user_block_count / sbi->blocks_per_seg;
  	si->rsvd_segs = reserved_segments(sbi);
  	si->overp_segs = overprovision_segments(sbi);
  	si->valid_count = valid_user_blocks(sbi);
  	si->valid_node_count = valid_node_count(sbi);
  	si->valid_inode_count = valid_inode_count(sbi);
  	si->utilization = utilization(sbi);
  
  	si->free_segs = free_segments(sbi);
  	si->free_secs = free_sections(sbi);
  	si->prefree_count = prefree_segments(sbi);
  	si->dirty_count = dirty_segments(sbi);
  	si->node_pages = sbi->node_inode->i_mapping->nrpages;
  	si->meta_pages = sbi->meta_inode->i_mapping->nrpages;
  	si->nats = NM_I(sbi)->nat_cnt;
  	si->sits = SIT_I(sbi)->dirty_sentries;
  	si->fnids = NM_I(sbi)->fcnt;
  	si->bg_gc = sbi->bg_gc;
  	si->util_free = (int)(free_user_blocks(sbi) >> sbi->log_blocks_per_seg)
  		* 100 / (int)(sbi->user_block_count >> sbi->log_blocks_per_seg)
  		/ 2;
  	si->util_valid = (int)(written_block_count(sbi) >>
  						sbi->log_blocks_per_seg)
  		* 100 / (int)(sbi->user_block_count >> sbi->log_blocks_per_seg)
  		/ 2;
  	si->util_invalid = 50 - si->util_free - si->util_valid;
  	for (i = CURSEG_HOT_DATA; i <= CURSEG_COLD_NODE; i++) {
  		struct curseg_info *curseg = CURSEG_I(sbi, i);
  		si->curseg[i] = curseg->segno;
  		si->cursec[i] = curseg->segno / sbi->segs_per_sec;
  		si->curzone[i] = si->cursec[i] / sbi->secs_per_zone;
  	}
  
  	for (i = 0; i < 2; i++) {
  		si->segment_count[i] = sbi->segment_count[i];
  		si->block_count[i] = sbi->block_count[i];
  	}
  }

  /*

   * This function calculates BDF of every segments
   */
  static void update_sit_info(struct f2fs_sb_info *sbi)
  {
  	struct f2fs_stat_info *si = sbi->stat_info;
  	unsigned int blks_per_sec, hblks_per_sec, total_vblocks, bimodal, dist;
  	struct sit_info *sit_i = SIT_I(sbi);
  	unsigned int segno, vblocks;
  	int ndirty = 0;
  
  	bimodal = 0;
  	total_vblocks = 0;
  	blks_per_sec = sbi->segs_per_sec * (1 << sbi->log_blocks_per_seg);
  	hblks_per_sec = blks_per_sec / 2;
  	mutex_lock(&sit_i->sentry_lock);
  	for (segno = 0; segno < TOTAL_SEGS(sbi); segno += sbi->segs_per_sec) {
  		vblocks = get_valid_blocks(sbi, segno, sbi->segs_per_sec);
  		dist = abs(vblocks - hblks_per_sec);
  		bimodal += dist * dist;
  
  		if (vblocks > 0 && vblocks < blks_per_sec) {
  			total_vblocks += vblocks;
  			ndirty++;
  		}
  	}
  	mutex_unlock(&sit_i->sentry_lock);

  	dist = TOTAL_SECS(sbi) * hblks_per_sec * hblks_per_sec / 100;

  	si->bimodal = bimodal / dist;
  	if (si->dirty_count)
  		si->avg_vblocks = total_vblocks / ndirty;
  	else
  		si->avg_vblocks = 0;
  }

  /*

   * This function calculates memory footprint.
   */
  static void update_mem_info(struct f2fs_sb_info *sbi)
  {
  	struct f2fs_stat_info *si = sbi->stat_info;
  	unsigned npages;
  
  	if (si->base_mem)
  		goto get_cache;
  
  	si->base_mem = sizeof(struct f2fs_sb_info) + sbi->sb->s_blocksize;
  	si->base_mem += 2 * sizeof(struct f2fs_inode_info);
  	si->base_mem += sizeof(*sbi->ckpt);
  
  	/* build sm */
  	si->base_mem += sizeof(struct f2fs_sm_info);
  
  	/* build sit */
  	si->base_mem += sizeof(struct sit_info);
  	si->base_mem += TOTAL_SEGS(sbi) * sizeof(struct seg_entry);
  	si->base_mem += f2fs_bitmap_size(TOTAL_SEGS(sbi));
  	si->base_mem += 2 * SIT_VBLOCK_MAP_SIZE * TOTAL_SEGS(sbi);
  	if (sbi->segs_per_sec > 1)

  		si->base_mem += TOTAL_SECS(sbi) * sizeof(struct sec_entry);

  	si->base_mem += __bitmap_size(sbi, SIT_BITMAP);
  
  	/* build free segmap */
  	si->base_mem += sizeof(struct free_segmap_info);
  	si->base_mem += f2fs_bitmap_size(TOTAL_SEGS(sbi));

  	si->base_mem += f2fs_bitmap_size(TOTAL_SECS(sbi));

  
  	/* build curseg */
  	si->base_mem += sizeof(struct curseg_info) * NR_CURSEG_TYPE;
  	si->base_mem += PAGE_CACHE_SIZE * NR_CURSEG_TYPE;
  
  	/* build dirty segmap */
  	si->base_mem += sizeof(struct dirty_seglist_info);
  	si->base_mem += NR_DIRTY_TYPE * f2fs_bitmap_size(TOTAL_SEGS(sbi));

  	si->base_mem += f2fs_bitmap_size(TOTAL_SECS(sbi));

  
  	/* buld nm */
  	si->base_mem += sizeof(struct f2fs_nm_info);
  	si->base_mem += __bitmap_size(sbi, NAT_BITMAP);
  
  	/* build gc */
  	si->base_mem += sizeof(struct f2fs_gc_kthread);
  
  get_cache:
  	/* free nids */
  	si->cache_mem = NM_I(sbi)->fcnt;
  	si->cache_mem += NM_I(sbi)->nat_cnt;
  	npages = sbi->node_inode->i_mapping->nrpages;
  	si->cache_mem += npages << PAGE_CACHE_SHIFT;
  	npages = sbi->meta_inode->i_mapping->nrpages;
  	si->cache_mem += npages << PAGE_CACHE_SHIFT;
  	si->cache_mem += sbi->n_orphans * sizeof(struct orphan_inode_entry);
  	si->cache_mem += sbi->n_dirty_dirs * sizeof(struct dir_inode_entry);
  }
  
  static int stat_show(struct seq_file *s, void *v)
  {
  	struct f2fs_stat_info *si, *next;
  	int i = 0;
  	int j;

  	mutex_lock(&f2fs_stat_mutex);

  	list_for_each_entry_safe(si, next, &f2fs_stat_list, stat_list) {

  		char devname[BDEVNAME_SIZE];

  		update_general_status(si->sbi);

  		seq_printf(s, "
  =====[ partition info(%s). #%d ]=====
  ",
  			bdevname(si->sbi->sb->s_bdev, devname), i++);

  		seq_printf(s, "[SB: 1] [CP: 2] [SIT: %d] [NAT: %d] ",
  			   si->sit_area_segs, si->nat_area_segs);

  		seq_printf(s, "[SSA: %d] [MAIN: %d",
  			   si->ssa_area_segs, si->main_area_segs);
  		seq_printf(s, "(OverProv:%d Resv:%d)]
  
  ",
  			   si->overp_segs, si->rsvd_segs);
  		seq_printf(s, "Utilization: %d%% (%d valid blocks)
  ",
  			   si->utilization, si->valid_count);
  		seq_printf(s, "  - Node: %u (Inode: %u, ",
  			   si->valid_node_count, si->valid_inode_count);
  		seq_printf(s, "Other: %u)
    - Data: %u
  ",
  			   si->valid_node_count - si->valid_inode_count,
  			   si->valid_count - si->valid_node_count);
  		seq_printf(s, "
  Main area: %d segs, %d secs %d zones
  ",
  			   si->main_area_segs, si->main_area_sections,
  			   si->main_area_zones);
  		seq_printf(s, "  - COLD  data: %d, %d, %d
  ",
  			   si->curseg[CURSEG_COLD_DATA],
  			   si->cursec[CURSEG_COLD_DATA],
  			   si->curzone[CURSEG_COLD_DATA]);
  		seq_printf(s, "  - WARM  data: %d, %d, %d
  ",
  			   si->curseg[CURSEG_WARM_DATA],
  			   si->cursec[CURSEG_WARM_DATA],
  			   si->curzone[CURSEG_WARM_DATA]);
  		seq_printf(s, "  - HOT   data: %d, %d, %d
  ",
  			   si->curseg[CURSEG_HOT_DATA],
  			   si->cursec[CURSEG_HOT_DATA],
  			   si->curzone[CURSEG_HOT_DATA]);
  		seq_printf(s, "  - Dir   dnode: %d, %d, %d
  ",
  			   si->curseg[CURSEG_HOT_NODE],
  			   si->cursec[CURSEG_HOT_NODE],
  			   si->curzone[CURSEG_HOT_NODE]);
  		seq_printf(s, "  - File   dnode: %d, %d, %d
  ",
  			   si->curseg[CURSEG_WARM_NODE],
  			   si->cursec[CURSEG_WARM_NODE],
  			   si->curzone[CURSEG_WARM_NODE]);
  		seq_printf(s, "  - Indir nodes: %d, %d, %d
  ",
  			   si->curseg[CURSEG_COLD_NODE],
  			   si->cursec[CURSEG_COLD_NODE],
  			   si->curzone[CURSEG_COLD_NODE]);
  		seq_printf(s, "
    - Valid: %d
    - Dirty: %d
  ",
  			   si->main_area_segs - si->dirty_count -
  			   si->prefree_count - si->free_segs,
  			   si->dirty_count);
  		seq_printf(s, "  - Prefree: %d
    - Free: %d (%d)
  
  ",
  			   si->prefree_count, si->free_segs, si->free_secs);
  		seq_printf(s, "GC calls: %d (BG: %d)
  ",
  			   si->call_count, si->bg_gc);
  		seq_printf(s, "  - data segments : %d
  ", si->data_segs);
  		seq_printf(s, "  - node segments : %d
  ", si->node_segs);
  		seq_printf(s, "Try to move %d blocks
  ", si->tot_blks);
  		seq_printf(s, "  - data blocks : %d
  ", si->data_blks);
  		seq_printf(s, "  - node blocks : %d
  ", si->node_blks);
  		seq_printf(s, "
  Extent Hit Ratio: %d / %d
  ",
  			   si->hit_ext, si->total_ext);
  		seq_printf(s, "
  Balancing F2FS Async:
  ");
  		seq_printf(s, "  - nodes %4d in %4d
  ",
  			   si->ndirty_node, si->node_pages);
  		seq_printf(s, "  - dents %4d in dirs:%4d
  ",
  			   si->ndirty_dent, si->ndirty_dirs);
  		seq_printf(s, "  - meta %4d in %4d
  ",
  			   si->ndirty_meta, si->meta_pages);
  		seq_printf(s, "  - NATs %5d > %lu
  ",
  			   si->nats, NM_WOUT_THRESHOLD);
  		seq_printf(s, "  - SITs: %5d
    - free_nids: %5d
  ",
  			   si->sits, si->fnids);
  		seq_printf(s, "
  Distribution of User Blocks:");
  		seq_printf(s, " [ valid | invalid | free ]
  ");
  		seq_printf(s, "  [");
  
  		for (j = 0; j < si->util_valid; j++)
  			seq_printf(s, "-");
  		seq_printf(s, "|");
  
  		for (j = 0; j < si->util_invalid; j++)
  			seq_printf(s, "-");
  		seq_printf(s, "|");
  
  		for (j = 0; j < si->util_free; j++)
  			seq_printf(s, "-");
  		seq_printf(s, "]
  
  ");
  		seq_printf(s, "SSR: %u blocks in %u segments
  ",
  			   si->block_count[SSR], si->segment_count[SSR]);
  		seq_printf(s, "LFS: %u blocks in %u segments
  ",
  			   si->block_count[LFS], si->segment_count[LFS]);
  
  		/* segment usage info */
  		update_sit_info(si->sbi);
  		seq_printf(s, "
  BDF: %u, avg. vblocks: %u
  ",
  			   si->bimodal, si->avg_vblocks);
  
  		/* memory footprint */
  		update_mem_info(si->sbi);
  		seq_printf(s, "
  Memory: %u KB = static: %u + cached: %u
  ",
  				(si->base_mem + si->cache_mem) >> 10,
  				si->base_mem >> 10, si->cache_mem >> 10);

  	}

  	mutex_unlock(&f2fs_stat_mutex);

  	return 0;
  }
  
  static int stat_open(struct inode *inode, struct file *file)
  {
  	return single_open(file, stat_show, inode->i_private);
  }
  
  static const struct file_operations stat_fops = {
  	.open = stat_open,
  	.read = seq_read,
  	.llseek = seq_lseek,
  	.release = single_release,
  };

  int f2fs_build_stats(struct f2fs_sb_info *sbi)

  {
  	struct f2fs_super_block *raw_super = F2FS_RAW_SUPER(sbi);
  	struct f2fs_stat_info *si;
  
  	sbi->stat_info = kzalloc(sizeof(struct f2fs_stat_info), GFP_KERNEL);
  	if (!sbi->stat_info)
  		return -ENOMEM;
  
  	si = sbi->stat_info;

  	si->all_area_segs = le32_to_cpu(raw_super->segment_count);
  	si->sit_area_segs = le32_to_cpu(raw_super->segment_count_sit);
  	si->nat_area_segs = le32_to_cpu(raw_super->segment_count_nat);
  	si->ssa_area_segs = le32_to_cpu(raw_super->segment_count_ssa);
  	si->main_area_segs = le32_to_cpu(raw_super->segment_count_main);
  	si->main_area_sections = le32_to_cpu(raw_super->section_count);
  	si->main_area_zones = si->main_area_sections /
  				le32_to_cpu(raw_super->secs_per_zone);
  	si->sbi = sbi;

  
  	mutex_lock(&f2fs_stat_mutex);
  	list_add_tail(&si->stat_list, &f2fs_stat_list);
  	mutex_unlock(&f2fs_stat_mutex);

  	return 0;
  }

  void f2fs_destroy_stats(struct f2fs_sb_info *sbi)
  {
  	struct f2fs_stat_info *si = sbi->stat_info;

  	mutex_lock(&f2fs_stat_mutex);

  	list_del(&si->stat_list);

  	mutex_unlock(&f2fs_stat_mutex);

  	kfree(sbi->stat_info);
  }

  void __init f2fs_create_root_stats(void)
  {
  	debugfs_root = debugfs_create_dir("f2fs", NULL);
  	if (debugfs_root)
  		debugfs_create_file("status", S_IRUGO, debugfs_root,
  					 NULL, &stat_fops);
  }
  
  void f2fs_destroy_root_stats(void)

  {
  	debugfs_remove_recursive(debugfs_root);
  	debugfs_root = NULL;
  }