/*
  RAWFS: Raw file system for NAND flash
  Copyright (C) 2012-2015  Perry Hsu <perry.hsu@mediatek.com>"

  This program can be distributed under the terms of the GNU GPL.
  See the file COPYING.
*/

#if defined(CONFIG_MT_ENG_BUILD)
#define DEBUG 1
#endif

#include <linux/module.h>
#include <linux/fs.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/crc32.h>
#include "rawfs.h"

int rawfs_readdir(struct file *filp, struct dir_context *ctx)
{
	struct inode *inode = filp->f_path.dentry->d_inode;
	struct dentry *dentry = filp->f_path.dentry;
	struct super_block *sb = inode->i_sb;
	struct rawfs_sb_info *sbi = RAWFS_SB(sb);
	int total_cnt = 0;  /* Total entries we found in hlist */

	loff_t cpos;

	cpos = ctx->pos;

	/* Read dir will execute twice. */
	if (inode->i_ino == RAWFS_ROOT_INO)
		RAWFS_PRINT(RAWFS_DBG_DIR, "rawfs_readdir, root, pos %lld\n", cpos);
	else
		RAWFS_PRINT(RAWFS_DBG_DIR, "rawfs_readdir, %s, i_id %X, i_ino %X, pos %lld\n",
		dentry->d_name.name, RAWFS_I(inode)->i_id, (unsigned)inode->i_ino, cpos);

	switch (cpos) {
	case 0:
		if (!dir_emit_dot(filp, ctx))
			break;
		ctx->pos++;
		cpos++;
		/* fallthrough */
	case 1:
		if (!dir_emit_dotdot(filp, ctx))
			break;
		ctx->pos++;
		cpos++;
		/* fallthrough */
	default:
		{
			struct rawfs_file_list_entry *entry;
			struct list_head *lists[2];
			int i;

			lists[0] =  &sbi->folder_list;
			lists[1] =  &sbi->file_list;

			mutex_lock(&sbi->file_list_lock);

			for (i = 0; i < 2; i++)	{
				list_for_each_entry(entry, lists[i], list) {
					int name_len;

					/* Matching sub-directory */
					if (entry->file_info.i_parent_folder_id !=
						RAWFS_I(dentry->d_inode)->i_id) {
						RAWFS_PRINT(RAWFS_DBG_DIR,
							"readdir: skip %s, parent folder id %X, target folder %X\n",
						   entry->file_info.i_name,
						   entry->file_info.i_parent_folder_id,
						   RAWFS_I(dentry->d_inode)->i_id);
						continue;
					}

					total_cnt++;

					if ((total_cnt+2) <= cpos) { /* skip first N + 2 (. & ..)
						entiries, if cpos doesn't start from zero */
						RAWFS_PRINT(RAWFS_DBG_DIR,
						"readdir: cpos=%lld, total cnt=%d, %s\n", cpos, total_cnt,
						entry->file_info.i_name);
						continue;
					}

					name_len = strlen(entry->file_info.i_name);

					if (!dir_emit(ctx,
						entry->file_info.i_name,
						name_len,
						entry->file_info.i_id,
						(S_ISDIR(entry->file_info.i_mode)?DT_DIR:DT_REG)))
						goto out;

					ctx->pos++;
					cpos++;
				}
			}
		}

out:
			mutex_unlock(&sbi->file_list_lock);
			break;
	}

	return 0;
}
EXPORT_SYMBOL_GPL(rawfs_readdir);

int rawfs_file_sync(struct file *file, loff_t start, loff_t end,
	int datasync)
{
	RAWFS_PRINT(RAWFS_DBG_DIR, "fsync, i_ino %ld\n",
		file->f_path.dentry->d_inode->i_ino);
	return 0;
}
EXPORT_SYMBOL_GPL(rawfs_file_sync);

MODULE_AUTHOR("Perry Hsu <perry.hsu@mediatek.com>");
MODULE_DESCRIPTION("RAW file system for NAND flash");
MODULE_LICENSE("GPL");