/*
 *	vfsv0 quota IO operations on file
 */

#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/mount.h>
#include <linux/dqblk_v2.h>
#include <linux/quotaio_v2.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/slab.h>

#include <asm/byteorder.h>

MODULE_AUTHOR("Jan Kara");
MODULE_DESCRIPTION("Quota format v2 support");
MODULE_LICENSE("GPL");

#define __QUOTA_V2_PARANOIA

typedef char *dqbuf_t;

#define GETIDINDEX(id, depth) (((id) >> ((V2_DQTREEDEPTH-(depth)-1)*8)) & 0xff)
#define GETENTRIES(buf) ((struct v2_disk_dqblk *)(((char *)buf)+sizeof(struct v2_disk_dqdbheader)))

/* Check whether given file is really vfsv0 quotafile */
static int v2_check_quota_file(struct super_block *sb, int type)
{
	struct v2_disk_dqheader dqhead;
	ssize_t size;
	static const uint quota_magics[] = V2_INITQMAGICS;
	static const uint quota_versions[] = V2_INITQVERSIONS;
 
	size = sb->s_op->quota_read(sb, type, (char *)&dqhead, sizeof(struct v2_disk_dqheader), 0);
	if (size != sizeof(struct v2_disk_dqheader)) {
		printk("quota_v2: failed read expected=%zd got=%zd\n",
			sizeof(struct v2_disk_dqheader), size);
		return 0;
	}
	if (le32_to_cpu(dqhead.dqh_magic) != quota_magics[type] ||
	    le32_to_cpu(dqhead.dqh_version) != quota_versions[type])
		return 0;
	return 1;
}

/* Read information header from quota file */
static int v2_read_file_info(struct super_block *sb, int type)
{
	struct v2_disk_dqinfo dinfo;
	struct mem_dqinfo *info = sb_dqopt(sb)->info+type;
	ssize_t size;

	size = sb->s_op->quota_read(sb, type, (char *)&dinfo,
	       sizeof(struct v2_disk_dqinfo), V2_DQINFOOFF);
	if (size != sizeof(struct v2_disk_dqinfo)) {
		printk(KERN_WARNING "Can't read info structure on device %s.\n",
			sb->s_id);
		return -1;
	}
	/* limits are stored as unsigned 32-bit data */
	info->dqi_maxblimit = 0xffffffff;
	info->dqi_maxilimit = 0xffffffff;
	info->dqi_bgrace = le32_to_cpu(dinfo.dqi_bgrace);
	info->dqi_igrace = le32_to_cpu(dinfo.dqi_igrace);
	info->dqi_flags = le32_to_cpu(dinfo.dqi_flags);
	info->u.v2_i.dqi_blocks = le32_to_cpu(dinfo.dqi_blocks);
	info->u.v2_i.dqi_free_blk = le32_to_cpu(dinfo.dqi_free_blk);
	info->u.v2_i.dqi_free_entry = le32_to_cpu(dinfo.dqi_free_entry);
	return 0;
}

/* Write information header to quota file */
static int v2_write_file_info(struct super_block *sb, int type)
{
	struct v2_disk_dqinfo dinfo;
	struct mem_dqinfo *info = sb_dqopt(sb)->info+type;
	ssize_t size;

	spin_lock(&dq_data_lock);
	info->dqi_flags &= ~DQF_INFO_DIRTY;
	dinfo.dqi_bgrace = cpu_to_le32(info->dqi_bgrace);
	dinfo.dqi_igrace = cpu_to_le32(info->dqi_igrace);
	dinfo.dqi_flags = cpu_to_le32(info->dqi_flags & DQF_MASK);
	spin_unlock(&dq_data_lock);
	dinfo.dqi_blocks = cpu_to_le32(info->u.v2_i.dqi_blocks);
	dinfo.dqi_free_blk = cpu_to_le32(info->u.v2_i.dqi_free_blk);
	dinfo.dqi_free_entry = cpu_to_le32(info->u.v2_i.dqi_free_entry);