/*
 * f2fs sysfs interface
 *
 * Copyright (c) 2012 Samsung Electronics Co., Ltd.
 *             http://www.samsung.com/
 * Copyright (c) 2017 Chao Yu <chao@kernel.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/proc_fs.h>
#include <linux/f2fs_fs.h>

#include "f2fs.h"
#include "segment.h"
#include "gc.h"

static struct proc_dir_entry *f2fs_proc_root;
static struct kset *f2fs_kset;

/* Sysfs support for f2fs */
enum {
	GC_THREAD,	/* struct f2fs_gc_thread */
	SM_INFO,	/* struct f2fs_sm_info */
	DCC_INFO,	/* struct discard_cmd_control */
	NM_INFO,	/* struct f2fs_nm_info */
	F2FS_SBI,	/* struct f2fs_sb_info */
#ifdef CONFIG_F2FS_FAULT_INJECTION
	FAULT_INFO_RATE,	/* struct f2fs_fault_info */
	FAULT_INFO_TYPE,	/* struct f2fs_fault_info */
#endif
	RESERVED_BLOCKS,
};

struct f2fs_attr {
	struct attribute attr;
	ssize_t (*show)(struct f2fs_attr *, struct f2fs_sb_info *, char *);
	ssize_t (*store)(struct f2fs_attr *, struct f2fs_sb_info *,
			 const char *, size_t);
	int struct_type;
	int offset;
};

static unsigned char *__struct_ptr(struct f2fs_sb_info *sbi, int struct_type)
{
	if (struct_type == GC_THREAD)
		return (unsigned char *)sbi->gc_thread;
	else if (struct_type == SM_INFO)
		return (unsigned char *)SM_I(sbi);
	else if (struct_type == DCC_INFO)
		return (unsigned char *)SM_I(sbi)->dcc_info;
	else if (struct_type == NM_INFO)
		return (unsigned char *)NM_I(sbi);
	else if (struct_type == F2FS_SBI || struct_type == RESERVED_BLOCKS)
		return (unsigned char *)sbi;
#ifdef CONFIG_F2FS_FAULT_INJECTION
	else if (struct_type == FAULT_INFO_RATE ||
					struct_type == FAULT_INFO_TYPE)
		return (unsigned char *)&sbi->fault_info;
#endif
	return NULL;
}

static ssize_t lifetime_write_kbytes_show(struct f2fs_attr *a,
		struct f2fs_sb_info *sbi, char *buf)
{
	struct super_block *sb = sbi->sb;

	if (!sb->s_bdev->bd_part)
		return snprintf(buf, PAGE_SIZE, "0\n");

	return snprintf(buf, PAGE_SIZE, "%llu\n",
		(unsigned long long)(sbi->kbytes_written +
			BD_PART_WRITTEN(sbi)));
}

static ssize_t f2fs_sbi_show(struct f2fs_attr *a,
			struct f2fs_sb_info *sbi, char *buf)
{
	unsigned char *ptr = NULL;
	unsigned int *ui;

	ptr = __struct_ptr(sbi, a->struct_type);
	if (!ptr)
		return -EINVAL;

	ui = (unsigned int *)(ptr + a->offset);

	return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
}

static ssize_t f2fs_sbi_store(struct f2fs_attr *a,
			struct f2fs_sb_info *sbi,
			const char *buf, size_t count)
{
	unsigned char *ptr;
	unsigned long t;
	unsigned int *ui;
	ssize_t ret;

	ptr = __struct_ptr(sbi, a->struct_type);
	if (!ptr)
		return -EINVAL;

	ui = (unsigned int *)(ptr + a->offset);

	ret = kstrtoul(skip_spaces(buf), 0, &t);
	if (ret < 0)
		return ret;
#ifdef CONFIG_F2FS_FAULT_INJECTION
	if (a->struct_type == FAULT_INFO_TYPE && t >= (1 << FAULT_MAX))
		return -EINVAL;
#endif
	if (a->struct_type == RESERVED_BLOCKS) {
		spin_lock(&sbi->stat_lock);
		if ((unsigned long)sbi->total_valid_block_count + t >
				(unsigned long)sbi->user_block_count) {
			spin_unlock(&sbi->stat_lock);
			return -EINVAL;
		}
		*ui = t;
		spin_unlock(&sbi->stat_lock);
		return count;
	}
	*ui = t;
	return count;
}

static ssize_t f2fs_attr_show(struct kobject *kobj,
				struct attribute *attr, char *buf)
{
	struct f2fs_sb_info *sbi = container_of(kobj, struct f2fs_sb_info,
								s_kobj);
	struct f2fs_attr *a = container_of(attr, struct f2fs_attr, attr);

	return a->show ? a->show(a, sbi, buf) : 0;
}

static ssize_t f2fs_attr_store(struct kobject *kobj, struct attribute *attr,
						const char *buf, size_t len)
{
	struct f2fs_sb_info *sbi = container_of(kobj, struct f2fs_sb_info,
									s_kobj);
	struct f2fs_attr *a = container_of(attr, struct f2fs_attr, attr);

	return a->store ? a->store(a, sbi, buf, len) : 0;
}

static void f2fs_sb_release(struct kobject *kobj)
{
	struct f2fs_sb_info *sbi = container_of(kobj, struct f2fs_sb_info,
								s_kobj);
	complete(&sbi->s_kobj_unregister);
}

#define F2FS_ATTR_OFFSET(_struct_type, _name, _mode, _show, _store, _offset) \
static struct f2fs_attr f2fs_attr_##_name = {			\
	.attr = {.name = __stringify(_name), .mode = _mode },	\
	.show	= _show,					\
	.store	= _store,					\
	.struct_type = _struct_type,				\
	.offset = _offset					\
}

#define F2FS_RW_ATTR(struct_type, struct_name, name, elname)	\
	F2FS_ATTR_OFFSET(struct_type, name, 0644,		\
		f2fs_sbi_show, f2fs_sbi_store,			\
		offsetof(struct struct_name, elname))

#define F2FS_GENERAL_RO_ATTR(name) \
static struct f2fs_attr f2fs_attr_##name = __ATTR(name, 0444, name##_show, NULL)

F2FS_RW_ATTR(GC_THREAD, f2fs_gc_kthread, gc_min_sleep_time, min_sleep_time);
F2FS_RW_ATTR(GC_THREAD, f2fs_gc_kthread, gc_max_sleep_time, max_sleep_time);
F2FS_RW_ATTR(GC_THREAD, f2fs_gc_kthread, gc_no_gc_sleep_time, no_gc_sleep_time);
F2FS_RW_ATTR(GC_THREAD, f2fs_gc_kthread, gc_idle, gc_idle);
F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, reclaim_segments, rec_prefree_segments);
F2FS_RW_ATTR(DCC_INFO, discard_cmd_control, max_small_discards, max_discards);
F2FS_RW_ATTR(RESERVED_BLOCKS, f2fs_sb_info, reserved_blocks, reserved_blocks);
F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, batched_trim_sections, trim_sections);
F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, ipu_policy, ipu_policy);
F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, min_ipu_util, min_ipu_util);
F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, min_fsync_blocks, min_fsync_blocks);
F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, min_hot_blocks, min_hot_blocks);
F2FS_RW_ATTR(NM_INFO, f2fs_nm_info, ram_thresh, ram_thresh);
F2FS_RW_ATTR(NM_INFO, f2fs_nm_info, ra_nid_pages, ra_nid_pages);
F2FS_RW_ATTR(NM_INFO, f2fs_nm_info, dirty_nats_ratio, dirty_nats_ratio);
F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, max_victim_search, max_victim_search);
F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, dir_level, dir_level);
F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, cp_interval, interval_time[CP_TIME]);
F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, idle_interval, interval_time[REQ_TIME]);
#ifdef CONFIG_F2FS_FAULT_INJECTION
F2FS_RW_ATTR(FAULT_INFO_RATE, f2fs_fault_info, inject_rate, inject_rate);
F2FS_RW_ATTR(FAULT_INFO_TYPE, f2fs_fault_info, inject_type, inject_type);
#endif
F2FS_GENERAL_RO_ATTR(lifetime_write_kbytes);

#define ATTR_LIST(name) (&f2fs_attr_##name.attr)
static struct attribute *f2fs_attrs[] = {
	ATTR_LIST(gc_min_sleep_time),
	ATTR_LIST(gc_max_sleep_time),
	ATTR_LIST(gc_no_gc_sleep_time),
	ATTR_LIST(gc_idle),
	ATTR_LIST(reclaim_segments),
	ATTR_LIST(max_small_discards),
	ATTR_LIST(batched_trim_sections),
	ATTR_LIST(ipu_policy),
	ATTR_LIST(min_ipu_util),
	ATTR_LIST(min_fsync_blocks),
	ATTR_LIST(min_hot_blocks),
	ATTR_LIST(max_victim_search),
	ATTR_LIST(dir_level),
	ATTR_LIST(ram_thresh),
	ATTR_LIST(ra_nid_pages),
	ATTR_LIST(dirty_nats_ratio),
	ATTR_LIST(cp_interval),
	ATTR_LIST(idle_interval),
#ifdef CONFIG_F2FS_FAULT_INJECTION
	ATTR_LIST(inject_rate),
	ATTR_LIST(inject_type),
#endif
	ATTR_LIST(lifetime_write_kbytes),
	ATTR_LIST(reserved_blocks),
	NULL,
};

static const struct sysfs_ops f2fs_attr_ops = {
	.show	= f2fs_attr_show,
	.store	= f2fs_attr_store,
};

static struct kobj_type f2fs_ktype = {
	.default_attrs	= f2fs_attrs,
	.sysfs_ops	= &f2fs_attr_ops,
	.release	= f2fs_sb_release,
};

static int segment_info_seq_show(struct seq_file *seq, void *offset)
{
	struct super_block *sb = seq->private;
	struct f2fs_sb_info *sbi = F2FS_SB(sb);
	unsigned int total_segs =
			le32_to_cpu(sbi->raw_super->segment_count_main);
	int i;

	seq_puts(seq, "format: segment_type|valid_blocks\n"
		"segment_type(0:HD, 1:WD, 2:CD, 3:HN, 4:WN, 5:CN)\n");

	for (i = 0; i < total_segs; i++) {
		struct seg_entry *se = get_seg_entry(sbi, i);

		if ((i % 10) == 0)
			seq_printf(seq, "%-10d", i);
		seq_printf(seq, "%d|%-3u", se->type,
					get_valid_blocks(sbi, i, false));
		if ((i % 10) == 9 || i == (total_segs - 1))
			seq_putc(seq, '\n');
		else
			seq_putc(seq, ' ');
	}

	return 0;
}

static int segment_bits_seq_show(struct seq_file *seq, void *offset)
{
	struct super_block *sb = seq->private;
	struct f2fs_sb_info *sbi = F2FS_SB(sb);
	unsigned int total_segs =
			le32_to_cpu(sbi->raw_super->segment_count_main);
	int i, j;

	seq_puts(seq, "format: segment_type|valid_blocks|bitmaps\n"
		"segment_type(0:HD, 1:WD, 2:CD, 3:HN, 4:WN, 5:CN)\n");

	for (i = 0; i < total_segs; i++) {
		struct seg_entry *se = get_seg_entry(sbi, i);

		seq_printf(seq, "%-10d", i);
		seq_printf(seq, "%d|%-3u|", se->type,
					get_valid_blocks(sbi, i, false));
		for (j = 0; j < SIT_VBLOCK_MAP_SIZE; j++)
			seq_printf(seq, " %.2x", se->cur_valid_map[j]);
		seq_putc(seq, '\n');
	}
	return 0;
}

#define F2FS_PROC_FILE_DEF(_name)					\
static int _name##_open_fs(struct inode *inode, struct file *file)	\
{									\
	return single_open(file, _name##_seq_show, PDE_DATA(inode));	\
}									\
									\
static const struct file_operations f2fs_seq_##_name##_fops = {		\
	.open = _name##_open_fs,					\
	.read = seq_read,						\
	.llseek = seq_lseek,						\
	.release = single_release,					\
};

F2FS_PROC_FILE_DEF(segment_info);
F2FS_PROC_FILE_DEF(segment_bits);

int __init f2fs_register_sysfs(void)
{
	f2fs_proc_root = proc_mkdir("fs/f2fs", NULL);

	f2fs_kset = kset_create_and_add("f2fs", NULL, fs_kobj);
	if (!f2fs_kset)
		return -ENOMEM;
	return 0;
}

void f2fs_unregister_sysfs(void)
{
	kset_unregister(f2fs_kset);
	remove_proc_entry("fs/f2fs", NULL);
}

int f2fs_init_sysfs(struct f2fs_sb_info *sbi)
{
	struct super_block *sb = sbi->sb;
	int err;

	if (f2fs_proc_root)
		sbi->s_proc = proc_mkdir(sb->s_id, f2fs_proc_root);

	if (sbi->s_proc) {
		proc_create_data("segment_info", S_IRUGO, sbi->s_proc,
				 &f2fs_seq_segment_info_fops, sb);
		proc_create_data("segment_bits", S_IRUGO, sbi->s_proc,
				 &f2fs_seq_segment_bits_fops, sb);
	}

	sbi->s_kobj.kset = f2fs_kset;
	init_completion(&sbi->s_kobj_unregister);
	err = kobject_init_and_add(&sbi->s_kobj, &f2fs_ktype, NULL,
							"%s", sb->s_id);
	if (err)
		goto err_out;
	return 0;
err_out:
	if (sbi->s_proc) {
		remove_proc_entry("segment_info", sbi->s_proc);
		remove_proc_entry("segment_bits", sbi->s_proc);
		remove_proc_entry(sb->s_id, f2fs_proc_root);
	}
	return err;
}

void f2fs_exit_sysfs(struct f2fs_sb_info *sbi)
{
	kobject_del(&sbi->s_kobj);
	kobject_put(&sbi->s_kobj);
	wait_for_completion(&sbi->s_kobj_unregister);

	if (sbi->s_proc) {
		remove_proc_entry("segment_info", sbi->s_proc);
		remove_proc_entry("segment_bits", sbi->s_proc);
		remove_proc_entry(sbi->sb->s_id, f2fs_proc_root);
	}
}