path: root/fs/nilfs2/the_nilfs.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * the_nilfs shared structure.
 *
 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
 *
 * Written by Ryusuke Konishi.
 *
 */

#include <linux/buffer_head.h>
#include <linux/slab.h>
#include <linux/blkdev.h>
#include <linux/backing-dev.h>
#include <linux/log2.h>
#include <linux/crc32.h>
#include "nilfs.h"
#include "segment.h"
#include "alloc.h"
#include "cpfile.h"
#include "sufile.h"
#include "dat.h"
#include "segbuf.h"


static int nilfs_valid_sb(struct nilfs_super_block *sbp);

void nilfs_set_last_segment(struct the_nilfs *nilfs,
			    sector_t start_blocknr, u64 seq, __u64 cno)
{
	spin_lock(&nilfs->ns_last_segment_lock);
	nilfs->ns_last_pseg = start_blocknr;
	nilfs->ns_last_seq = seq;
	nilfs->ns_last_cno = cno;

	if (!nilfs_sb_dirty(nilfs)) {
		if (nilfs->ns_prev_seq == nilfs->ns_last_seq)
			goto stay_cursor;

		set_nilfs_sb_dirty(nilfs);
	}
	nilfs->ns_prev_seq = nilfs->ns_last_seq;

 stay_cursor:
	spin_unlock(&nilfs->ns_last_segment_lock);
}

/**
 * alloc_nilfs - allocate a nilfs object
 * @sb: super block instance
 *
 * Return: a pointer to the allocated nilfs object on success, or NULL on
 * failure.
 */
struct the_nilfs *alloc_nilfs(struct super_block *sb)
{
	struct the_nilfs *nilfs;

	nilfs = kzalloc(sizeof(*nilfs), GFP_KERNEL);
	if (!nilfs)
		return NULL;

	nilfs->ns_sb = sb;
	nilfs->ns_bdev = sb->s_bdev;
	atomic_set(&nilfs->ns_ndirtyblks, 0);
	init_rwsem(&nilfs->ns_sem);
	mutex_init(&nilfs->ns_snapshot_mount_mutex);
	INIT_LIST_HEAD(&nilfs->ns_dirty_files);
	INIT_LIST_HEAD(&nilfs->ns_gc_inodes);
	spin_lock_init(&nilfs->ns_inode_lock);
	spin_lock_init(&nilfs->ns_last_segment_lock);
	nilfs->ns_cptree = RB_ROOT;
	spin_lock_init(&nilfs->ns_cptree_lock);
	init_rwsem(&nilfs->ns_segctor_sem);
	nilfs->ns_sb_update_freq = NILFS_SB_FREQ;

	return nilfs;
}

/**
 * destroy_nilfs - destroy nilfs object
 * @nilfs: nilfs object to be released
 */
void destroy_nilfs(struct the_nilfs *nilfs)
{
	might_sleep();
	if (nilfs_init(nilfs)) {
		brelse(nilfs->ns_sbh[0]);
		brelse(nilfs->ns_sbh[1]);
	}
	kfree(nilfs);
}

static int nilfs_load_super_root(struct the_nilfs *nilfs,
				 struct super_block *sb, sector_t sr_block)
{
	struct buffer_head *bh_sr;
	struct nilfs_super_root *raw_sr;
	struct nilfs_super_block **sbp = nilfs->ns_sbp;
	struct nilfs_inode *rawi;
	unsigned int dat_entry_size, segment_usage_size, checkpoint_size;
	unsigned int inode_size;
	int err;

	err = nilfs_read_super_root_block(nilfs, sr_block, &bh_sr, 1);
	if (unlikely(err))
		return err;

	down_read(&nilfs->ns_sem);
	dat_entry_size = le16_to_cpu(sbp[0]->s_dat_entry_size);
	checkpoint_size = le16_to_cpu(sbp[0]->s_checkpoint_size);
	segment_usage_size = le16_to_cpu(sbp[0]->s_segment_usage_size);
	up_read(&nilfs->ns_sem);

	inode_size = nilfs->ns_inode_size;

	rawi = (void *)bh_sr->b_data + NILFS_SR_DAT_OFFSET(inode_size);
	err = nilfs_dat_read(sb, dat_entry_size, rawi, &nilfs->ns_dat);
	if (err)
		goto failed;

	rawi = (void *)bh_sr->b_data + NILFS_SR_CPFILE_OFFSET(inode_size);
	err = nilfs_cpfile_read(sb, checkpoint_size, rawi, &nilfs->ns_cpfile);
	if (err)
		goto failed_dat;

	rawi = (void *)bh_sr->b_data + NILFS_SR_SUFILE_OFFSET(inode_size);
	err = nilfs_sufile_read(sb, segment_usage_size, rawi,
				&nilfs->ns_sufile);
	if (err)
		goto failed_cpfile;

	raw_sr = (struct nilfs_super_root *)bh_sr->b_data;
	nilfs->ns_nongc_ctime = le64_to_cpu(raw_sr->sr_nongc_ctime);

 failed:
	brelse(bh_sr);
	return err;

 failed_cpfile:
	iput(nilfs->ns_cpfile);

 failed_dat:
	iput(nilfs->ns_dat);
	goto failed;
}

static void nilfs_init_recovery_info(struct nilfs_recovery_info *ri)
{
	memset(ri, 0, sizeof(*ri));
	INIT_LIST_HEAD(&ri->ri_used_segments);
}

static void nilfs_clear_recovery_info(struct nilfs_recovery_info *ri)
{
	nilfs_dispose_segment_list(&ri