/* -*- mode: c; c-basic-offset: 8; -*-
 * vim: noexpandtab sw=8 ts=8 sts=0:
 *
 * Copyright (C) 2009 Novell.  All rights reserved.
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public
 * License along with this program; if not, write to the
 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
 * Boston, MA  02110-1301 USA.
 *
 * --
 * Pass 5 tries to read as much data as possible from the global quota file.
 * (we are interested mainly in limits for users and groups). After that we
 * scan the filesystem and recompute quota usage for each user / group and
 * finally we dump all the information into freshly created quota files.
 *
 * At this pass, filesystem should be already sound, so we use libocfs2
 * functions for low-level operations.
 *
 * FIXME: We could also check node-local quota files and use limits there.
 *        For now we just discard them.
 */
#include <string.h>
#include <inttypes.h>
#include <time.h>

#include "ocfs2/ocfs2.h"
#include "ocfs2/bitops.h"
#include "ocfs2/byteorder.h"

#include "fsck.h"
#include "pass5.h"
#include "problem.h"
#include "o2fsck_strings.h"
#include "util.h"

static const char *whoami = "pass5";
static char *qbmp[MAXQUOTAS];
static ocfs2_quota_hash *qhash[MAXQUOTAS];

static char *type2name(int type)
{
	if (type == USRQUOTA)
		return "user";
	return "group";
}

static errcode_t o2fsck_release_dquot(ocfs2_cached_dquot *dquot, void *p)
{
	ocfs2_quota_hash *hash = p;

	ocfs2_remove_quota_hash(hash, dquot);
	ocfs2_free(&dquot);
	return 0;
}

static int check_blkref(uint32_t block, uint32_t maxblocks)
{
	if (block < QT_TREEOFF || block >= maxblocks)
		return 0;
	return 1;
}

static errcode_t o2fsck_validate_blk(ocfs2_filesys *fs, char *buf)
{
	struct ocfs2_disk_dqtrailer *dqt =
				ocfs2_block_dqtrailer(fs->fs_blocksize, buf);
	return ocfs2_validate_meta_ecc(fs, buf, &dqt->dq_check);
}

static int o2fsck_valid_quota_info(ocfs2_filesys *fs, int type,
				   struct ocfs2_disk_dqheader *header,
				   struct ocfs2_global_disk_dqinfo *info)
{
	uint32_t magics[MAXQUOTAS] = OCFS2_GLOBAL_QMAGICS;
	int versions[MAXQUOTAS] = OCFS2_GLOBAL_QVERSIONS;

	if (header->dqh_magic != magics[type] ||
	    header->dqh_version > versions[type])
		return 0;
	if (info->dqi_blocks !=
	    fs->qinfo[type].qi_inode->ci_inode->i_size / fs->fs_blocksize)
		return 0;
	if ((info->dqi_free_blk &&
	     !check_blkref(info->dqi_free_blk, info->dqi_blocks)) ||
	    (info->dqi_free_entry &&
	     !check_blkref(info->dqi_free_entry, info->dqi_blocks)))
		return 0;
	return 1;
}

static errcode_t o2fsck_read_blk(ocfs2_filesys *fs, int type, char *buf,
				 uint32_t blk)
{
	uint32_t got;
	errcode_t ret;

	ret = ocfs2_file_read(fs->qinfo[type].qi_inode, buf, fs->fs_blocksize,
			      blk * fs->fs_blocksize, &got);
	if (ret)
		return ret;
	if (got != fs->fs_blocksize)
		return OCFS2_ET_SHORT_READ;
	return 0;
}

static errcode_t o2fsck_check_info(o2fsck_state *ost, int type)
{
	errcode_t ret;
	ocfs2_filesys *fs = ost->ost_fs;
	char *buf;
	struct ocfs2_disk_dqheader *header;
	struct ocfs2_global_disk_dqinfo *info;
	uint64_t blocks;
	int checksum_valid;

	ret = ocfs2_malloc_block(fs->fs_io, &buf);
	if (ret) {
		com_err(whoami, ret, "while allocating block buffer");
		goto set_default;
	}
	ret = o2fsck_read_blk(fs, type, buf, 0);
	if (ret) {
		com_err(whoami, ret, "while reading global %s quota info "
			"block", type2name(type));
		goto set_default;
	}
	checksum_valid = !o2fsck_validate_blk(fs, buf);
	header = (struct ocfs2_disk_dqheader *)buf;
	info = (struct ocfs2_global_disk_dqinfo *)(buf + OCFS2_GLOBAL_INFO_OFF);
	ocfs2_swap_quota_header(header);
	ocfs2_swap_quota_global_info(info);
	if ((!checksum_valid ||
	     !o2fsck_valid_quota_info(fs, type, header, info)) &&
	    !prompt(ost, PN, PR_QMAGIC_INVALID, "%s quota info looks corrupt."
		    " Use its content:\nBlock grace time: %"PRIu32" sec\n"
		    "Inode grace time: %"PRIu32" sec\n"
		    "Cluster quota sync time: %"PRIu32" ms\n",
		    type2name(type), info->dqi_bgrace, info->dqi_igrace,
		    info->dqi_syncms)) {
		goto set_default;
	}
	fs->qinfo[type].qi_info.dqi_bgrace = info->dqi_bgrace;
	fs->qinfo[type].qi_info.dqi_igrace = info->dqi_igrace;
	fs->qinfo[type].qi_info.dqi_syncms = info->dqi_syncms;
	goto set_blocks;
set_default:
	fs->qinfo[type].qi_info.dqi_bgrace = OCFS2_DEF_BLOCK_GRACE;
	fs->qinfo[type].qi_info.dqi_igrace = OCFS2_DEF_INODE_GRACE;
	fs->qinfo[type].qi_info.dqi_syncms = OCFS2_DEF_QUOTA_SYNC;
set_blocks:
	blocks = fs->qinfo[type].qi_inode->ci_inode->i_size / fs->fs_blocksize;
	if (blocks > (1ULL << 32) - 1)
		fs->qinfo[type].qi_info.dqi_blocks = (1ULL << 32) - 1;
	else
		fs->qinfo[type].qi_info.dqi_blocks = blocks;
	return ret;
}

/* Check whether a reference to a tree block is sane */
static int o2fsck_check_tree_ref(o2fsck_state *ost, int type, uint32_t blk,
				 int depth)
{
	ocfs2_filesys *fs = ost->ost_fs;
	uint32_t blocks = fs->qinfo[type].qi_info.dqi_blocks;

	/* Bogus block number? */
	if (!check_blkref(blk, blocks)) {
		verbosef("ignoring invalid %s quota block reference %"PRIu32,
			 type2name(type), blk);
		return 0;
	}
	/* Already scanned block? */
	if (depth < ocfs2_qtree_depth(fs->fs_blocksize) &&
	    ocfs2_test_bit(blk, qbmp[type])) {
		verbosef("ignoring duplicate %s quota block reference %"PRIu32,
			 type2name(type), blk);
		return 0;
	}
	return 1;
}

/* Read the block, check dquot structures in it */
static errcode_t o2fsck_check_data_blk(o2fsck_state *ost, int type,
				       uint32_t blk, char *buf)
{
	ocfs2_filesys *fs = ost->ost_fs;
	errcode_t ret;
	struct qt_disk_dqdbheader *dh = (struct qt_disk_dqdbheader *)buf;
	int str_in_blk = ocfs2_global_dqstr_in_blk(fs->fs_blocksize);
	int i;
	struct ocfs2_global_disk_dqblk *ddquot;
	ocfs2_cached_dquot *dquot;
	uint32_t blocks = fs->qinfo[type].qi_info.dqi_blocks;
	int valid = 1;

	ocfs2_set_bit(blk, qbmp[type]);
	ret = o2fsck_read_blk(fs, type, buf, blk);
	if (ret) {
		com_err(whoami, ret,
			"while reading %s quota file block %"PRIu32,
			type2name(type), blk);
		return ret;
	}
	ret = o2fsck_validate_blk(fs, buf);
	if (ret) {
		verbosef("%s: invalid checksum in %s quota leaf block (block %"
			 PRIu32")", error_message(ret), type2name(type), blk);
		valid = 0;
	}
	ocfs2_swap_quota_leaf_block_header(dh);
	if ((dh->dqdh_next_free && !check_blkref(dh->dqdh_next_free, blocks)) ||
	    (dh->dqdh_prev_free && !check_blkref(dh->dqdh_prev_free, blocks)) ||
	    dh->dqdh_entries > str_in_blk) {
		verbosef("corrupt %s quota leaf block header (block %"PRIu32")",
			 type2name(type), blk);
		valid = 0;
	}
	ddquot = (struct ocfs2_global_disk_dqblk *)(buf +
			sizeof(struct qt_disk_dqdbheader));
	for (i = 0; i < str_in_blk; i++, ddquot++) {
		if (ocfs2_qtree_entry_unused(ddquot))
			continue;
		ocfs2_swap_quota_global_dqblk(ddquot);
		ret = ocfs2_find_quota_hash(qhash[type], ddquot->dqb_id,
					    &dquot);
		if (ret) {
			com_err(whoami, ret,
				"while searching in %s quota hash",
				type2name(type));
			return ret;
		}
		if (dquot && valid) {
			if (!prompt(ost, PY, PR_DUP_DQBLK_VALID,
				    "Duplicate %s quota structure for id %"
				    PRIu32":\nCurrent quota limits: Inode: %"
				    PRIu64" %"PRIu64" Space: %"PRIu64" %"
				    PRIu64"\nFound quota limits: Inode: %"
				    PRIu64" %"PRIu64" Space: %"PRIu64" %"
				    PRIu64"\nUse found limits?",
				    type2name(type), ddquot->dqb_id,
				    (uint64_t)dquot->d_ddquot.dqb_isoftlimit,
				    (uint64_t)dquot->d_ddquot.dqb_ihardlimit,
				    (uint64_t)dquot->d_ddquot.dqb_bsoftlimit,
				    (uint64_t)dquot->d_ddquot.dqb_bhardlimit,
				    (uint64_t)ddquot->dqb_isoftlimit,
				    (uint64_t)ddquot->dqb_ihardlimit,
				    (uint64_t)ddquot->dqb_bsoftlimit,
				    (uint64_t)ddquot->dqb_bhardlimit))
				continue;
		} else if (dquot && !valid) {
			if (!prompt(ost, PN, PR_DUP_DQBLK_INVALID,
				    "Found %s quota structure for id %"PRIu32
				    " in a corrupted block and already have "
				    "values for this id:\nCurrent quota "
				    "limits: Inode: %"PRIu64" %"PRIu64" Space:"
				    " %"PRIu64" %"PRIu64"\nFound quota limits:"
				    " Inode: %"PRIu64" %"PRIu64" Space: %"
				    PRIu64" %"PRIu64"\nUse found limits?",
				    type2name(type), ddquot->dqb_id,
				    (uint64_t)dquot->d_ddquot.dqb_isoftlimit,
				    (uint64_t)dquot->d_ddquot.dqb_ihardlimit,
				    (uint64_t)dquot->d_ddquot.dqb_bsoftlimit,
				    (uint64_t)dquot->d_ddquot.dqb_bhardlimit,
				    (uint64_t)ddquot->dqb_isoftlimit,
				    (uint64_t)ddquot->dqb_ihardlimit,
				    (uint64_t)ddquot->dqb_bsoftlimit,
				    (uint64_t)ddquot->dqb_bhardlimit))
				continue;
		} else if (!dquot && !valid) {
			if (!prompt(ost, PN, PR_DQBLK_INVALID,
				    "Found corrupted %s quota structure for id"
				    " %"PRIu32":\nFound quota limits: Inode: %"
				    PRIu64" %"PRIu64" Space: %"PRIu64" %"
				    PRIu64"\nUse found limits?",
				    type2name(type), ddquot->dqb_id,
				    (uint64_t)ddquot->dqb_isoftlimit,
				    (uint64_t)ddquot->dqb_ihardlimit,
				    (uint64_t)ddquot->dqb_bsoftlimit,
				    (uint64_t)ddquot->dqb_bhardlimit))
				continue;
		}

		if (!dquot) {
			ret = ocfs2_find_create_quota_hash(qhash[type],
					ddquot->dqb_id, &dquot);
			if (ret) {
				com_err(whoami, ret, "while inserting quota"
					" structure into hash");
				return ret;
			}
		}
		memcpy(&dquot->d_ddquot, ddquot,
				sizeof(struct ocfs2_global_disk_dqblk));
		dquot->d_ddquot.dqb_use_count = 0;
		dquot->d_ddquot.dqb_curinodes = 0;
		dquot->d_ddquot.dqb_curspace = 0;
	}
	return 0;
}

/* Read the block, check references in it */
static errcode_t o2fsck_check_tree_blk(o2fsck_state *ost, int type,
				       uint32_t blk, int depth,
				       char *buf)
{
	ocfs2_filesys *fs = ost->ost_fs;
	errcode_t ret;
	int epb = (fs->fs_blocksize - OCFS2_QBLK_RESERVED_SPACE) >> 2;
	int tree_depth = ocfs2_qtree_depth(fs->fs_blocksize);
	int i;
	uint32_t *refs = (uint32_t *)buf, actref;

	ocfs2_set_bit(blk, qbmp[type]);
	ret = o2fsck_read_blk(fs, type, buf, blk);
	if (ret) {
		com_err(whoami, ret,
			"while reading %s quota file block %"PRIu32,
			type2name(type), blk);
		goto out;
	}
	ret = o2fsck_validate_blk(fs, buf);
	if (ret &&
	    !prompt(ost, PN, PR_QTREE_BLK_INVALID, "Corrupted %s quota tree "
		    "block %"PRIu32" (checksum error: %s). Scan referenced "
		    "blocks anyway?", type2name(type), blk,
		    error_message(ret))) {
		goto out;
	}
	for (i = 0; i < epb; i++) {
		actref = le32_to_cpu(refs[i]);
		if (!actref)
			continue;
		/* Valid block reference? */
		if (o2fsck_check_tree_ref(ost, type, actref, depth + 1)) {
			if (depth + 1 < tree_depth) {
				ret = o2fsck_check_tree_blk(ost, type, actref,
					depth + 1, buf + fs->fs_blocksize);
			} else if (!ocfs2_test_bit(actref, qbmp[type])) {
				ret = o2fsck_check_data_blk(ost, type, actref,
					buf + fs->fs_blocksize);
			}
			if (ret)
				goto out;
		}
	}
out:
	return ret;
}

static errcode_t load_quota_file(o2fsck_state *ost, int type)
{
	ocfs2_filesys *fs = ost->ost_fs;
	char *buf = NULL;
	errcode_t ret;

	ret = ocfs2_init_fs_quota_info(fs, type);
	if (ret) {
		com_err(whoami, ret, "while looking up global %s quota file",
			type2name(type));
		goto out;
	}
	ret = o2fsck_check_info(ost, type);
	/* Some fatal error happened? */
	if (ret)
		goto out;

	ret = ocfs2_malloc0((fs->qinfo[type].qi_info.dqi_blocks + 7) / 8,
			    qbmp + type);
	if (ret) {
		com_err(whoami, ret, "while allocating %s quota file block "
			"bitmap", type2name(type));
		goto out;
	}
	ret = ocfs2_malloc_blocks(fs->fs_io,
				  ocfs2_qtree_depth(fs->fs_blocksize) + 1,
				  &buf);
	if (ret) {
		com_err(whoami, ret,
			"while allocating buffer for quota blocks");
		goto out;
	}

	if (!o2fsck_check_tree_ref(ost, type, QT_TREEOFF, 0))
		goto out;
	ret = o2fsck_check_tree_blk(ost, type, QT_TREEOFF, 0, buf);
out:
	if (qbmp[type])
		ocfs2_free(qbmp + type);
	if (buf)
		ocfs2_free(&buf);
	return ret;
}

/* You have to write the inode yourself after calling this function! */
static errcode_t truncate_cached_inode(ocfs2_filesys *fs,
				       ocfs2_cached_inode *ci)
{
	uint32_t new_clusters;
	errcode_t ret;

	ret = ocfs2_zero_tail_and_truncate(fs, ci, 0, &new_clusters);
	if (ret)
		return ret;
	ci->ci_inode->i_clusters = new_clusters;
	if (new_clusters == 0)
		ci->ci_inode->id2.i_list.l_tree_depth = 0;
	ci->ci_inode->i_size = 0;

	return 0;
}

static errcode_t recreate_quota_files(ocfs2_filesys *fs, int type)
{
	ocfs2_cached_inode *ci = fs->qinfo[type].qi_inode;
	errcode_t ret;

	ret = truncate_cached_inode(fs, ci);
	if (ret) {
		com_err(whoami, ret, "while truncating global %s quota file",
			type2name(type));
		return ret;
	}

	ret = ocfs2_init_global_quota_file(fs, type);
	if (ret) {
		com_err(whoami, ret,
			"while reinitializing global %s quota file",
			type2name(type));
		return ret;
	}
	ret = ocfs2_write_release_dquots(fs, type, qhash[type]);
	if (ret) {
		com_err(whoami, ret, "while writing %s quota usage",
			type2name(type));
		return ret;
	}

	ret = ocfs2_init_local_quota_files(fs, type);
	if (ret) {
		com_err(whoami, ret,
			"while initializing local quota files");
		return ret;
	}
	return 0;
}

errcode_t o2fsck_pass5(o2fsck_state *ost)
{
	errcode_t ret;
	ocfs2_filesys *fs = ost->ost_fs;
	struct ocfs2_super_block *super = OCFS2_RAW_SB(fs->fs_super);
	int has_usrquota, has_grpquota;
	struct o2fsck_resource_track rt;

	has_usrquota = OCFS2_HAS_RO_COMPAT_FEATURE(super,
				OCFS2_FEATURE_RO_COMPAT_USRQUOTA);
	has_grpquota = OCFS2_HAS_RO_COMPAT_FEATURE(super,
				OCFS2_FEATURE_RO_COMPAT_GRPQUOTA);
	/* Nothing to check? */
	if (!has_usrquota && !has_grpquota)
		return 0;
	printf("Pass 5: Checking quota information\n");

	o2fsck_init_resource_track(&rt, fs->fs_io);

	if (has_usrquota) {
		ret = ocfs2_new_quota_hash(qhash + USRQUOTA);
		if (ret) {
			com_err(whoami, ret,
				"while allocating user quota hash");
			goto out;
		}
		ret = load_quota_file(ost, USRQUOTA);
		if (ret)
			goto out;
	}
	if (has_grpquota) {
		ret = ocfs2_new_quota_hash(qhash + GRPQUOTA);
		if (ret) {
			com_err(whoami, ret,
				"while allocating group quota hash");
			goto out;
		}
		ret = load_quota_file(ost, GRPQUOTA);
		if (ret)
			goto out;
	}
	ret = ocfs2_compute_quota_usage(fs, qhash[USRQUOTA], qhash[GRPQUOTA]);
	if (ret) {
		com_err(whoami, ret, "while computing quota usage");
		goto out;
	}
	if (has_usrquota && ost->ost_fs->fs_flags & OCFS2_FLAG_RW) {
		ret = recreate_quota_files(fs, USRQUOTA);
		if (ret)
			goto out;
		ret = ocfs2_free_quota_hash(qhash[USRQUOTA]);
		if (ret) {
			com_err(whoami, ret, "while release user quota hash");
			goto out;
		}
	}
	if (has_grpquota && ost->ost_fs->fs_flags & OCFS2_FLAG_RW) {
		ret = recreate_quota_files(fs, GRPQUOTA);
		if (ret)
			goto out;
		ret = ocfs2_free_quota_hash(qhash[GRPQUOTA]);
		if (ret) {
			com_err(whoami, ret, "while release group quota hash");
			goto out;
		}
	}

	o2fsck_compute_resource_track(&rt, fs->fs_io);
	o2fsck_print_resource_track("Pass 5", ost, &rt, fs->fs_io);
	o2fsck_add_resource_track(&ost->ost_rt, &rt);

	return 0;
out:
	if (qhash[USRQUOTA]) {
		ocfs2_iterate_quota_hash(qhash[USRQUOTA], o2fsck_release_dquot,
					 qhash[USRQUOTA]);
		ocfs2_free_quota_hash(qhash[USRQUOTA]);
	}
	if (qhash[GRPQUOTA]) {
		ocfs2_iterate_quota_hash(qhash[GRPQUOTA], o2fsck_release_dquot,
					 qhash[GRPQUOTA]);
		ocfs2_free_quota_hash(qhash[GRPQUOTA]);
	}
	return ret;
}
