recovery.c | Explore in Territory

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

#include <linux/buffer_head.h>
#include <linux/blkdev.h>
#include <linux/swap.h>
#include <linux/slab.h>
#include <linux/crc32.h>
#include "nilfs.h"
#include "segment.h"
#include "sufile.h"
#include "page.h"
#include "segbuf.h"

/*
 * Segment check result
 */
enum { … };

/* work structure for recovery */
struct nilfs_recovery_block { … };


static int nilfs_warn_segment_error(struct super_block *sb, int err)
{ … }

/**
 * nilfs_compute_checksum - compute checksum of blocks continuously
 * @nilfs: nilfs object
 * @bhs: buffer head of start block
 * @sum: place to store result
 * @offset: offset bytes in the first block
 * @check_bytes: number of bytes to be checked
 * @start: DBN of start block
 * @nblock: number of blocks to be checked
 */
static int nilfs_compute_checksum(struct the_nilfs *nilfs,
				  struct buffer_head *bhs, u32 *sum,
				  unsigned long offset, u64 check_bytes,
				  sector_t start, unsigned long nblock)
{ … }

/**
 * nilfs_read_super_root_block - read super root block
 * @nilfs: nilfs object
 * @sr_block: disk block number of the super root block
 * @pbh: address of a buffer_head pointer to return super root buffer
 * @check: CRC check flag
 */
int nilfs_read_super_root_block(struct the_nilfs *nilfs, sector_t sr_block,
				struct buffer_head **pbh, int check)
{ … }

/**
 * nilfs_read_log_header - read summary header of the specified log
 * @nilfs: nilfs object
 * @start_blocknr: start block number of the log
 * @sum: pointer to return segment summary structure
 */
static struct buffer_head *
nilfs_read_log_header(struct the_nilfs *nilfs, sector_t start_blocknr,
		      struct nilfs_segment_summary **sum)
{ … }

/**
 * nilfs_validate_log - verify consistency of log
 * @nilfs: nilfs object
 * @seg_seq: sequence number of segment
 * @bh_sum: buffer head of summary block
 * @sum: segment summary struct
 */
static int nilfs_validate_log(struct the_nilfs *nilfs, u64 seg_seq,
			      struct buffer_head *bh_sum,
			      struct nilfs_segment_summary *sum)
{ … }

/**
 * nilfs_read_summary_info - read an item on summary blocks of a log
 * @nilfs: nilfs object
 * @pbh: the current buffer head on summary blocks [in, out]
 * @offset: the current byte offset on summary blocks [in, out]
 * @bytes: byte size of the item to be read
 */
static void *nilfs_read_summary_info(struct the_nilfs *nilfs,
				     struct buffer_head **pbh,
				     unsigned int *offset, unsigned int bytes)
{ … }

/**
 * nilfs_skip_summary_info - skip items on summary blocks of a log
 * @nilfs: nilfs object
 * @pbh: the current buffer head on summary blocks [in, out]
 * @offset: the current byte offset on summary blocks [in, out]
 * @bytes: byte size of the item to be skipped
 * @count: number of items to be skipped
 */
static void nilfs_skip_summary_info(struct the_nilfs *nilfs,
				    struct buffer_head **pbh,
				    unsigned int *offset, unsigned int bytes,
				    unsigned long count)
{ … }

/**
 * nilfs_scan_dsync_log - get block information of a log written for data sync
 * @nilfs: nilfs object
 * @start_blocknr: start block number of the log
 * @sum: log summary information
 * @head: list head to add nilfs_recovery_block struct
 */
static int nilfs_scan_dsync_log(struct the_nilfs *nilfs, sector_t start_blocknr,
				struct nilfs_segment_summary *sum,
				struct list_head *head)
{ … }

static void dispose_recovery_list(struct list_head *head)
{ … }

struct nilfs_segment_entry { … };

static int nilfs_segment_list_add(struct list_head *head, __u64 segnum)
{ … }

void nilfs_dispose_segment_list(struct list_head *head)
{ … }

static int nilfs_prepare_segment_for_recovery(struct the_nilfs *nilfs,
					      struct super_block *sb,
					      struct nilfs_recovery_info *ri)
{ … }

static int nilfs_recovery_copy_block(struct the_nilfs *nilfs,
				     struct nilfs_recovery_block *rb,
				     loff_t pos, struct page *page)
{ … }

static int nilfs_recover_dsync_blocks(struct the_nilfs *nilfs,
				      struct super_block *sb,
				      struct nilfs_root *root,
				      struct list_head *head,
				      unsigned long *nr_salvaged_blocks)
{ … }

/**
 * nilfs_do_roll_forward - salvage logical segments newer than the latest
 * checkpoint
 * @nilfs: nilfs object
 * @sb: super block instance
 * @root: NILFS root instance
 * @ri: pointer to a nilfs_recovery_info
 */
static int nilfs_do_roll_forward(struct the_nilfs *nilfs,
				 struct super_block *sb,
				 struct nilfs_root *root,
				 struct nilfs_recovery_info *ri)
{ … }

static void nilfs_finish_roll_forward(struct the_nilfs *nilfs,
				      struct nilfs_recovery_info *ri)
{ … }

/**
 * nilfs_salvage_orphan_logs - salvage logs written after the latest checkpoint
 * @nilfs: nilfs object
 * @sb: super block instance
 * @ri: pointer to a nilfs_recovery_info struct to store search results.
 *
 * Return Value: On success, 0 is returned.  On error, one of the following
 * negative error code is returned.
 *
 * %-EINVAL - Inconsistent filesystem state.
 *
 * %-EIO - I/O error
 *
 * %-ENOSPC - No space left on device (only in a panic state).
 *
 * %-ERESTARTSYS - Interrupted.
 *
 * %-ENOMEM - Insufficient memory available.
 */
int nilfs_salvage_orphan_logs(struct the_nilfs *nilfs,
			      struct super_block *sb,
			      struct nilfs_recovery_info *ri)
{ … }

/**
 * nilfs_search_super_root - search the latest valid super root
 * @nilfs: the_nilfs
 * @ri: pointer to a nilfs_recovery_info struct to store search results.
 *
 * nilfs_search_super_root() looks for the latest super-root from a partial
 * segment pointed by the superblock.  It sets up struct the_nilfs through
 * this search. It fills nilfs_recovery_info (ri) required for recovery.
 *
 * Return Value: On success, 0 is returned.  On error, one of the following
 * negative error code is returned.
 *
 * %-EINVAL - No valid segment found
 *
 * %-EIO - I/O error
 *
 * %-ENOMEM - Insufficient memory available.
 */
int nilfs_search_super_root(struct the_nilfs *nilfs,
			    struct nilfs_recovery_info *ri)
{ … }
linux/fs/nilfs2/recovery.c
