/*
 * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
 * Copyright (C) 2004-2005 Red Hat, Inc.  All rights reserved.
 *
 * This copyrighted material is made available to anyone wishing to use,
 * modify, copy, or redistribute it subject to the terms and conditions
 * of the GNU General Public License v.2.
 */

#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/completion.h>
#include <linux/buffer_head.h>
#include <asm/semaphore.h>

#include "gfs2.h"
#include "glock.h"
#include "log.h"
#include "lops.h"
#include "meta_io.h"
#include "recovery.h"
#include "rgrp.h"
#include "trans.h"

static void glock_lo_add(struct gfs2_sbd *sdp, struct gfs2_log_element *le)
{
	struct gfs2_glock *gl;

	get_transaction->tr_touched = 1;

	if (!list_empty(&le->le_list))
		return;

	gl = container_of(le, struct gfs2_glock, gl_le);
	if (gfs2_assert_withdraw(sdp, gfs2_glock_is_held_excl(gl)))
		return;
	gfs2_glock_hold(gl);
	set_bit(GLF_DIRTY, &gl->gl_flags);

	gfs2_log_lock(sdp);
	sdp->sd_log_num_gl++;
	list_add(&le->le_list, &sdp->sd_log_le_gl);
	gfs2_log_unlock(sdp);
}

static void glock_lo_after_commit(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
{
	struct list_head *head = &sdp->sd_log_le_gl;
	struct gfs2_glock *gl;

	while (!list_empty(head)) {
		gl = list_entry(head->next, struct gfs2_glock, gl_le.le_list);
		list_del_init(&gl->gl_le.le_list);
		sdp->sd_log_num_gl--;

		gfs2_assert_withdraw(sdp, gfs2_glock_is_held_excl(gl));
		gfs2_glock_put(gl);
	}
	gfs2_assert_warn(sdp, !sdp->sd_log_num_gl);
}

static void buf_lo_add(struct gfs2_sbd *sdp, struct gfs2_log_element *le)
{
	struct gfs2_bufdata *bd = container_of(le, struct gfs2_bufdata, bd_le);
	struct gfs2_trans *tr;

	if (!list_empty(&bd->bd_list_tr))
		return;

	tr = get_transaction;
	tr->tr_touched = 1;
	tr->tr_num_buf++;
	list_add(&bd->bd_list_tr, &tr->tr_list_buf);

	if (!list_empty(&le->le_list))
		return;

	gfs2_trans_add_gl(bd->bd_gl);

	gfs2_meta_check(sdp, bd->bd_bh);
	gfs2_pin(sdp, bd->bd_bh);

	gfs2_log_lock(sdp);
	sdp->sd_log_num_buf++;
	list_add(&le->le_list, &sdp->sd_log_le_buf);
	gfs2_log_unlock(sdp);

	tr->tr_num_buf_new++;
}

static void buf_lo_incore_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
{
	struct list_head *head = &tr->tr_list_buf;
	struct gfs2_bufdata *bd;

	while (!list_empty(head)) {
		bd = list_entry(head->next, struct gfs2_bufdata, bd_list_tr);
		list_del_init(&bd->bd_list_tr);
		tr->tr_num_buf--;
	}
	gfs2_assert_warn(sdp, !tr->tr_num_buf);
}

static void buf_lo_before_commit(struct gfs2_sbd *sdp)
{
	struct buffer_head *bh;
	struct gfs2_log_descriptor *ld;
	struct gfs2_bufdata *bd1 = NULL, *bd2;
	unsigned int total = sdp->sd_log_num_buf;
	unsigned int offset = sizeof(struct gfs2_log_descriptor);
	unsigned int limit;
	unsigned int num;
	unsigned n;
	__be64 *ptr;

	offset += (sizeof(__be64) - 1);
	offset &= ~(sizeof(__be64) - 1);
	limit = (sdp->sd_sb.sb_bsize - offset)/sizeof(__be64);
	/* for 4k blocks, limit = 503 */

	bd1 = bd2 = list_prepare_entry(bd1, &sdp->sd_log_le_buf, bd_le.le_list);
	while(total) {
		num = total;
		if (total > limit)
			num = limit;
		bh = gfs2_log_get_buf(sdp);
		ld = (struct gfs2_log_descriptor *)bh->b_data;
		ptr = (__be64 *)(bh->b_data + offset);
		ld->ld_header.mh_magic = cpu_to_be32(GFS2_MAGIC);
		ld->ld_header.mh_type = cpu_to_be16(GFS2_METATYPE_LD);
		ld->ld_header.mh_format = cpu_to_be16(GFS2_FORMAT_LD);
		ld->ld_type = cpu_to_be32(GFS2_LOG_DESC_METADATA);
		ld->ld_length = cpu_to_be32(num + 1);
		ld->ld_data1 = cpu_to_be32(num);
		ld->ld_data2 = cpu_to_be32(0);
		memset(ld->ld_reserved, 0, sizeof(ld->ld_reserved));

		n = 0;
		list_for_each_entry_continue(bd1, &sdp->sd_log_le_buf, bd_le.le_list) {
			*ptr++ = cpu_to_be64(bd1->bd_bh->b_blocknr);
			if (++n >= num)
				break;
		}

		set_buffer_dirty(bh);
		ll_rw_block(WRITE, 1, &bh);

		n = 0;
		list_for_each_entry_continue(bd2, &sdp->sd_log_le_buf, bd_le.le_list) {
			bh = gfs2_log_fake_buf(sdp, bd2->bd_bh);
			set_buffer_dirty(bh);
			ll_rw_block(WRITE, 1, &bh);
			if (++n >= num)
				break;
		}

		total -= num;
	}
}

static void buf_lo_after_commit(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
{
	struct list_head *head = &sdp->sd_log_le_buf;
	struct gfs2_bufdata *bd;

	while (!list_empty(head)) {
		bd = list_entry(head->next, struct gfs2_bufdata, bd_le.le_list);
		list_del_init(&bd->bd_le.le_list);
		sdp->sd_log_num_buf--;

		gfs2_unpin(sdp, bd->bd_bh, ai);
	}
	gfs2_assert_warn(sdp, !sdp->sd_log_num_buf);
}

static void buf_lo_before_scan(struct gfs2_jdesc *jd,
			       struct gfs2_log_header *head, int pass)
{
	struct gfs2_sbd *sdp = jd->jd_inode->i_sbd;

	if (pass != 0)
		return;

	sdp->sd_found_blocks = 0;
	sdp->sd_replayed_blocks = 0;
}

static int buf_lo_scan_elements(struct gfs2_jdesc *jd, unsigned int start,
				struct gfs2_log_descriptor *ld, __be64 *ptr,
				int pass)
{
	struct gfs2_sbd *sdp = jd->jd_inode->i_sbd;
	struct gfs2_glock *gl = jd->jd_inode->i_gl;
	unsigned int blks = be32_to_cpu(ld->ld_data1);
	struct buffer_head *bh_log, *bh_ip;
	uint64_t blkno;
	int error = 0;

	if (pass != 1 || be32_to_cpu(ld->ld_type) != GFS2_LOG_DESC_METADATA)
		return 0;

	gfs2_replay_incr_blk(sdp, &start);

	for (; blks; gfs2_replay_incr_blk(sdp, &start), blks--) {
		blkno = be64_to_cpu(*ptr++);

		sdp->sd_found_blocks++;

		if (gfs2_revoke_check(sdp, blkno, start))
			continue;

		error = gfs2_replay_read_block(jd, start, &bh_log);
                if (error)
                        return error;

		bh_ip = gfs2_meta_new(gl, blkno);
		memcpy(bh_ip->b_data, bh_log->b_data, bh_log->b_size);

		if (gfs2_meta_check(sdp, bh_ip))
			error = -EIO;
		else
			mark_buffer_dirty(bh_ip);

		brelse(bh_log);
		brelse(bh_ip);

		if (error)
			break;

		sdp->sd_replayed_blocks++;
	}

	return error;
}

static void buf_lo_after_scan(struct gfs2_jdesc *jd, int error, int pass)
{
	struct gfs2_sbd *sdp = jd->jd_inode->i_sbd;

	if (error) {
		gfs2_meta_sync(jd->jd_inode->i_gl, DIO_START | DIO_WAIT);
		return;
	}
	if (pass != 1)
		return;

	gfs2_meta_sync(jd->jd_inode->i_gl, DIO_START | DIO_WAIT);

	fs_info(sdp, "jid=%u: Replayed %u of %u blocks\n",
	        jd->jd_jid, sdp->sd_replayed_blocks, sdp->sd_found_blocks);
}

static void revoke_lo_add(struct gfs2_sbd *sdp, struct gfs2_log_element *le)
{
	struct gfs2_trans *tr;

	tr = get_transaction;
	tr->tr_touched = 1;
	tr->tr_num_revoke++;

	gfs2_log_lock(sdp);
	sdp->sd_log_num_revoke++;
	list_add(&le->le_list, &sdp->sd_log_le_revoke);
	gfs2_log_unlock(sdp);
}

static void revoke_lo_before_commit(struct gfs2_sbd *sdp)
{
	struct gfs2_log_descriptor *ld;
	struct gfs2_meta_header *mh;
	struct buffer_head *bh;
	unsigned int offset;
	struct list_head *head = &sdp->sd_log_le_revoke;
	struct gfs2_revoke *rv;

	if (!sdp->sd_log_num_revoke)
		return;

	bh = gfs2_log_get_buf(sdp);
	ld = (struct gfs2_log_descriptor *)bh->b_data;
	ld->ld_header.mh_magic = cpu_to_be32(GFS2_MAGIC);
	ld->ld_header.mh_type = cpu_to_be16(GFS2_METATYPE_LD);
	ld->ld_header.mh_format = cpu_to_be16(GFS2_FORMAT_LD);
	ld->ld_type = cpu_to_be32(GFS2_LOG_DESC_REVOKE);
	ld->ld_length = cpu_to_be32(gfs2_struct2blk(sdp, sdp->sd_log_num_revoke, sizeof(uint64_t)));
	ld->ld_data1 = cpu_to_be32(sdp->sd_log_num_revoke);
	ld->ld_data2 = cpu_to_be32(0);
	memset(ld->ld_reserved, 0, sizeof(ld->ld_reserved));
	offset = sizeof(struct gfs2_log_descriptor);

	while (!list_empty(head)) {
		rv = list_entry(head->next, struct gfs2_revoke, rv_le.le_list);
		list_del(&rv->rv_le.le_list);
		sdp->sd_log_num_revoke--;

		if (offset + sizeof(uint64_t) > sdp->sd_sb.sb_bsize) {
			set_buffer_dirty(bh);
			ll_rw_block(WRITE, 1, &bh);

			bh = gfs2_log_get_buf(sdp);
			mh = (struct gfs2_meta_header *)bh->b_data;
			mh->mh_magic = cpu_to_be32(GFS2_MAGIC);
			mh->mh_type = cpu_to_be16(GFS2_METATYPE_LB);
			mh->mh_format = cpu_to_be16(GFS2_FORMAT_LB);
			offset = sizeof(struct gfs2_meta_header);
		}

		*(__be64 *)(bh->b_data + offset) = cpu_to_be64(rv->rv_blkno);
		kfree(rv);

		offset += sizeof(uint64_t);
	}
	gfs2_assert_withdraw(sdp, !sdp->sd_log_num_revoke);

	set_buffer_dirty(bh);
	ll_rw_block(WRITE, 1, &bh);
}

static void revoke_lo_before_scan(struct gfs2_jdesc *jd,
				  struct gfs2_log_header *head, int pass)
{
	struct gfs2_sbd *sdp = jd->jd_inode->i_sbd;

	if (pass != 0)
		return;

	sdp->sd_found_revokes = 0;
	sdp->sd_replay_tail = head->lh_tail;
}

static int revoke_lo_scan_elements(struct gfs2_jdesc *jd, unsigned int start,
				   struct gfs2_log_descriptor *ld, __be64 *ptr,
				   int pass)
{
	struct gfs2_sbd *sdp = jd->jd_inode->i_sbd;
	unsigned int blks = be32_to_cpu(ld->ld_length);
	unsigned int revokes = be32_to_cpu(ld->ld_data1);
	struct buffer_head *bh;
	unsigned int offset;
	uint64_t blkno;
	int first = 1;
	int error;

	if (pass != 0 || be32_to_cpu(ld->ld_type) != GFS2_LOG_DESC_REVOKE)
		return 0;

	offset = sizeof(struct gfs2_log_descriptor);

	for (; blks; gfs2_replay_incr_blk(sdp, &start), blks--) {
		error = gfs2_replay_read_block(jd, start, &bh);
		if (error)
			return error;

		if (!first)
			gfs2_metatype_check(sdp, bh, GFS2_METATYPE_LB);

		while (offset + sizeof(uint64_t) <= sdp->sd_sb.sb_bsize) {
			blkno = be64_to_cpu(*(__be64 *)(bh->b_data + offset));

			error = gfs2_revoke_add(sdp, blkno, start);
			if (error < 0)
				return error;
			else if (error)
				sdp->sd_found_revokes++;

			if (!--revokes)
				break;
			offset += sizeof(uint64_t);
		}

		brelse(bh);
		offset = sizeof(struct gfs2_meta_header);
		first = 0;
	}

	return 0;
}

static void revoke_lo_after_scan(struct gfs2_jdesc *jd, int error, int pass)
{
	struct gfs2_sbd *sdp = jd->jd_inode->i_sbd;

	if (error) {
		gfs2_revoke_clean(sdp);
		return;
	}
	if (pass != 1)
		return;

	fs_info(sdp, "jid=%u: Found %u revoke tags\n",
	        jd->jd_jid, sdp->sd_found_revokes);

	gfs2_revoke_clean(sdp);
}

static void rg_lo_add(struct gfs2_sbd *sdp, struct gfs2_log_element *le)
{
	struct gfs2_rgrpd *rgd;

	get_transaction->tr_touched = 1;

	if (!list_empty(&le->le_list))
		return;

	rgd = container_of(le, struct gfs2_rgrpd, rd_le);
	gfs2_rgrp_bh_hold(rgd);

	gfs2_log_lock(sdp);
	sdp->sd_log_num_rg++;
	list_add(&le->le_list, &sdp->sd_log_le_rg);
	gfs2_log_unlock(sdp);	
}

static void rg_lo_after_commit(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
{
	struct list_head *head = &sdp->sd_log_le_rg;
	struct gfs2_rgrpd *rgd;

	while (!list_empty(head)) {
		rgd = list_entry(head->next, struct gfs2_rgrpd, rd_le.le_list);
		list_del_init(&rgd->rd_le.le_list);
		sdp->sd_log_num_rg--;

		gfs2_rgrp_repolish_clones(rgd);
		gfs2_rgrp_bh_put(rgd);
	}
	gfs2_assert_warn(sdp, !sdp->sd_log_num_rg);
}

static void databuf_lo_add(struct gfs2_sbd *sdp, struct gfs2_log_element *le)
{
	get_transaction->tr_touched = 1;

	gfs2_log_lock(sdp);
	sdp->sd_log_num_databuf++;
	list_add(&le->le_list, &sdp->sd_log_le_databuf);
	gfs2_log_unlock(sdp);
}

static void databuf_lo_before_commit(struct gfs2_sbd *sdp)
{
	struct list_head *head = &sdp->sd_log_le_databuf;
	LIST_HEAD(started);
	struct gfs2_bufdata *bd;
	struct buffer_head *bh;

	while (!list_empty(head)) {
		bd = list_entry(head->prev, struct gfs2_bufdata, bd_le.le_list);
		list_move(&bd->bd_le.le_list, &started);

		gfs2_log_lock(sdp);
		bh = bd->bd_bh;
		if (bh) {
			get_bh(bh);
			gfs2_log_unlock(sdp);
			if (buffer_dirty(bh)) {
				wait_on_buffer(bh);
				ll_rw_block(WRITE, 1, &bh);
			}
			brelse(bh);
		} else
			gfs2_log_unlock(sdp);
	}

	while (!list_empty(&started)) {
		bd = list_entry(started.next, struct gfs2_bufdata,
				bd_le.le_list);
		list_del(&bd->bd_le.le_list);
		sdp->sd_log_num_databuf--;

		gfs2_log_lock(sdp);
		bh = bd->bd_bh;
		if (bh) {
			set_v2bd(bh, NULL);
			gfs2_log_unlock(sdp);
			wait_on_buffer(bh);
			brelse(bh);
		} else
			gfs2_log_unlock(sdp);

		kfree(bd);
	}

	gfs2_assert_warn(sdp, !sdp->sd_log_num_databuf);
}

struct gfs2_log_operations gfs2_glock_lops = {
	.lo_add = glock_lo_add,
	.lo_after_commit = glock_lo_after_commit,
	.lo_name = "glock"
};

struct gfs2_log_operations gfs2_buf_lops = {
	.lo_add = buf_lo_add,
	.lo_incore_commit = buf_lo_incore_commit,
	.lo_before_commit = buf_lo_before_commit,
	.lo_after_commit = buf_lo_after_commit,
	.lo_before_scan = buf_lo_before_scan,
	.lo_scan_elements = buf_lo_scan_elements,
	.lo_after_scan = buf_lo_after_scan,
	.lo_name = "buf"
};

struct gfs2_log_operations gfs2_revoke_lops = {
	.lo_add = revoke_lo_add,
	.lo_before_commit = revoke_lo_before_commit,
	.lo_before_scan = revoke_lo_before_scan,
	.lo_scan_elements = revoke_lo_scan_elements,
	.lo_after_scan = revoke_lo_after_scan,
	.lo_name = "revoke"
};

struct gfs2_log_operations gfs2_rg_lops = {
	.lo_add = rg_lo_add,
	.lo_after_commit = rg_lo_after_commit,
	.lo_name = "rg"
};

struct gfs2_log_operations gfs2_databuf_lops = {
	.lo_add = databuf_lo_add,
	.lo_before_commit = databuf_lo_before_commit,
	.lo_name = "databuf"
};

struct gfs2_log_operations *gfs2_log_ops[] = {
	&gfs2_glock_lops,
	&gfs2_buf_lops,
	&gfs2_revoke_lops,
	&gfs2_rg_lops,
	&gfs2_databuf_lops,
	NULL
};