linux/fs/nilfs2/cpfile.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * NILFS checkpoint file.
 *
 * Copyright (C) 2006-2008 Nippon Telegraph and Telephone Corporation.
 *
 * Written by Koji Sato.
 */

#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/string.h>
#include <linux/buffer_head.h>
#include <linux/errno.h>
#include "mdt.h"
#include "cpfile.h"


static inline unsigned long
nilfs_cpfile_checkpoints_per_block(const struct inode *cpfile)
{ … }

/* block number from the beginning of the file */
static unsigned long
nilfs_cpfile_get_blkoff(const struct inode *cpfile, __u64 cno)
{ … }

/* offset in block */
static unsigned long
nilfs_cpfile_get_offset(const struct inode *cpfile, __u64 cno)
{ … }

static __u64 nilfs_cpfile_first_checkpoint_in_block(const struct inode *cpfile,
						    unsigned long blkoff)
{ … }

static unsigned long
nilfs_cpfile_checkpoints_in_block(const struct inode *cpfile,
				  __u64 curr,
				  __u64 max)
{ … }

static inline int nilfs_cpfile_is_in_first(const struct inode *cpfile,
					   __u64 cno)
{ … }

static unsigned int
nilfs_cpfile_block_add_valid_checkpoints(const struct inode *cpfile,
					 struct buffer_head *bh,
					 void *kaddr,
					 unsigned int n)
{ … }

static unsigned int
nilfs_cpfile_block_sub_valid_checkpoints(const struct inode *cpfile,
					 struct buffer_head *bh,
					 void *kaddr,
					 unsigned int n)
{ … }

static inline struct nilfs_cpfile_header *
nilfs_cpfile_block_get_header(const struct inode *cpfile,
			      struct buffer_head *bh,
			      void *kaddr)
{ … }

static struct nilfs_checkpoint *
nilfs_cpfile_block_get_checkpoint(const struct inode *cpfile, __u64 cno,
				  struct buffer_head *bh,
				  void *kaddr)
{ … }

static void nilfs_cpfile_block_init(struct inode *cpfile,
				    struct buffer_head *bh,
				    void *kaddr)
{ … }

static inline int nilfs_cpfile_get_header_block(struct inode *cpfile,
						struct buffer_head **bhp)
{ … }

static inline int nilfs_cpfile_get_checkpoint_block(struct inode *cpfile,
						    __u64 cno,
						    int create,
						    struct buffer_head **bhp)
{ … }

/**
 * nilfs_cpfile_find_checkpoint_block - find and get a buffer on cpfile
 * @cpfile: inode of cpfile
 * @start_cno: start checkpoint number (inclusive)
 * @end_cno: end checkpoint number (inclusive)
 * @cnop: place to store the next checkpoint number
 * @bhp: place to store a pointer to buffer_head struct
 *
 * Return Value: On success, it returns 0. On error, the following negative
 * error code is returned.
 *
 * %-ENOMEM - Insufficient memory available.
 *
 * %-EIO - I/O error
 *
 * %-ENOENT - no block exists in the range.
 */
static int nilfs_cpfile_find_checkpoint_block(struct inode *cpfile,
					      __u64 start_cno, __u64 end_cno,
					      __u64 *cnop,
					      struct buffer_head **bhp)
{ … }

static inline int nilfs_cpfile_delete_checkpoint_block(struct inode *cpfile,
						       __u64 cno)
{ … }

/**
 * nilfs_cpfile_read_checkpoint - read a checkpoint entry in cpfile
 * @cpfile: checkpoint file inode
 * @cno:    number of checkpoint entry to read
 * @root:   nilfs root object
 * @ifile:  ifile's inode to read and attach to @root
 *
 * This function imports checkpoint information from the checkpoint file and
 * stores it to the inode file given by @ifile and the nilfs root object
 * given by @root.
 *
 * Return: 0 on success, or the following negative error code on failure.
 * * %-EINVAL	- Invalid checkpoint.
 * * %-ENOMEM	- Insufficient memory available.
 * * %-EIO	- I/O error (including metadata corruption).
 */
int nilfs_cpfile_read_checkpoint(struct inode *cpfile, __u64 cno,
				 struct nilfs_root *root, struct inode *ifile)
{ … }

/**
 * nilfs_cpfile_create_checkpoint - create a checkpoint entry on cpfile
 * @cpfile: checkpoint file inode
 * @cno:    number of checkpoint to set up
 *
 * This function creates a checkpoint with the number specified by @cno on
 * cpfile.  If the specified checkpoint entry already exists due to a past
 * failure, it will be reused without returning an error.
 * In either case, the buffer of the block containing the checkpoint entry
 * and the cpfile inode are made dirty for inclusion in the write log.
 *
 * Return: 0 on success, or the following negative error code on failure.
 * * %-ENOMEM	- Insufficient memory available.
 * * %-EIO	- I/O error (including metadata corruption).
 * * %-EROFS	- Read only filesystem
 */
int nilfs_cpfile_create_checkpoint(struct inode *cpfile, __u64 cno)
{ … }

/**
 * nilfs_cpfile_finalize_checkpoint - fill in a checkpoint entry in cpfile
 * @cpfile: checkpoint file inode
 * @cno:    checkpoint number
 * @root:   nilfs root object
 * @blkinc: number of blocks added by this checkpoint
 * @ctime:  checkpoint creation time
 * @minor:  minor checkpoint flag
 *
 * This function completes the checkpoint entry numbered by @cno in the
 * cpfile with the data given by the arguments @root, @blkinc, @ctime, and
 * @minor.
 *
 * Return: 0 on success, or the following negative error code on failure.
 * * %-ENOMEM	- Insufficient memory available.
 * * %-EIO	- I/O error (including metadata corruption).
 */
int nilfs_cpfile_finalize_checkpoint(struct inode *cpfile, __u64 cno,
				     struct nilfs_root *root, __u64 blkinc,
				     time64_t ctime, bool minor)
{ … }

/**
 * nilfs_cpfile_delete_checkpoints - delete checkpoints
 * @cpfile: inode of checkpoint file
 * @start: start checkpoint number
 * @end: end checkpoint number
 *
 * Description: nilfs_cpfile_delete_checkpoints() deletes the checkpoints in
 * the period from @start to @end, excluding @end itself. The checkpoints
 * which have been already deleted are ignored.
 *
 * Return Value: On success, 0 is returned. On error, one of the following
 * negative error codes is returned.
 *
 * %-EIO - I/O error.
 *
 * %-ENOMEM - Insufficient amount of memory available.
 *
 * %-EINVAL - invalid checkpoints.
 */
int nilfs_cpfile_delete_checkpoints(struct inode *cpfile,
				    __u64 start,
				    __u64 end)
{ … }

static void nilfs_cpfile_checkpoint_to_cpinfo(struct inode *cpfile,
					      struct nilfs_checkpoint *cp,
					      struct nilfs_cpinfo *ci)
{ … }

static ssize_t nilfs_cpfile_do_get_cpinfo(struct inode *cpfile, __u64 *cnop,
					  void *buf, unsigned int cisz,
					  size_t nci)
{ … }

static ssize_t nilfs_cpfile_do_get_ssinfo(struct inode *cpfile, __u64 *cnop,
					  void *buf, unsigned int cisz,
					  size_t nci)
{ … }

/**
 * nilfs_cpfile_get_cpinfo - get information on checkpoints
 * @cpfile: checkpoint file inode
 * @cnop:   place to pass a starting checkpoint number and receive a
 *          checkpoint number to continue the search
 * @mode:   mode of checkpoints that the caller wants to retrieve
 * @buf:    buffer for storing checkpoints' information
 * @cisz:   byte size of one checkpoint info item in array
 * @nci:    number of checkpoint info items to retrieve
 *
 * nilfs_cpfile_get_cpinfo() searches for checkpoints in @mode state
 * starting from the checkpoint number stored in @cnop, and stores
 * information about found checkpoints in @buf.
 * The buffer pointed to by @buf must be large enough to store information
 * for @nci checkpoints.  If at least one checkpoint information is
 * successfully retrieved, @cnop is updated to point to the checkpoint
 * number to continue searching.
 *
 * Return: Count of checkpoint info items stored in the output buffer on
 * success, or the following negative error code on failure.
 * * %-EINVAL	- Invalid checkpoint mode.
 * * %-ENOMEM	- Insufficient memory available.
 * * %-EIO	- I/O error (including metadata corruption).
 * * %-ENOENT	- Invalid checkpoint number specified.
 */

ssize_t nilfs_cpfile_get_cpinfo(struct inode *cpfile, __u64 *cnop, int mode,
				void *buf, unsigned int cisz, size_t nci)
{ … }

/**
 * nilfs_cpfile_delete_checkpoint -
 * @cpfile:
 * @cno:
 */
int nilfs_cpfile_delete_checkpoint(struct inode *cpfile, __u64 cno)
{ … }

static struct nilfs_snapshot_list *
nilfs_cpfile_block_get_snapshot_list(const struct inode *cpfile,
				     __u64 cno,
				     struct buffer_head *bh,
				     void *kaddr)
{ … }

static int nilfs_cpfile_set_snapshot(struct inode *cpfile, __u64 cno)
{ … }

static int nilfs_cpfile_clear_snapshot(struct inode *cpfile, __u64 cno)
{ … }

/**
 * nilfs_cpfile_is_snapshot -
 * @cpfile: inode of checkpoint file
 * @cno: checkpoint number
 *
 * Description:
 *
 * Return Value: On success, 1 is returned if the checkpoint specified by
 * @cno is a snapshot, or 0 if not. On error, one of the following negative
 * error codes is returned.
 *
 * %-EIO - I/O error.
 *
 * %-ENOMEM - Insufficient amount of memory available.
 *
 * %-ENOENT - No such checkpoint.
 */
int nilfs_cpfile_is_snapshot(struct inode *cpfile, __u64 cno)
{ … }

/**
 * nilfs_cpfile_change_cpmode - change checkpoint mode
 * @cpfile: inode of checkpoint file
 * @cno: checkpoint number
 * @mode: mode of checkpoint
 *
 * Description: nilfs_change_cpmode() changes the mode of the checkpoint
 * specified by @cno. The mode @mode is NILFS_CHECKPOINT or NILFS_SNAPSHOT.
 *
 * Return Value: On success, 0 is returned. On error, one of the following
 * negative error codes is returned.
 *
 * %-EIO - I/O error.
 *
 * %-ENOMEM - Insufficient amount of memory available.
 *
 * %-ENOENT - No such checkpoint.
 */
int nilfs_cpfile_change_cpmode(struct inode *cpfile, __u64 cno, int mode)
{ … }

/**
 * nilfs_cpfile_get_stat - get checkpoint statistics
 * @cpfile: inode of checkpoint file
 * @cpstat: pointer to a structure of checkpoint statistics
 *
 * Description: nilfs_cpfile_get_stat() returns information about checkpoints.
 *
 * Return Value: On success, 0 is returned, and checkpoints information is
 * stored in the place pointed by @cpstat. On error, one of the following
 * negative error codes is returned.
 *
 * %-EIO - I/O error.
 *
 * %-ENOMEM - Insufficient amount of memory available.
 */
int nilfs_cpfile_get_stat(struct inode *cpfile, struct nilfs_cpstat *cpstat)
{ … }

/**
 * nilfs_cpfile_read - read or get cpfile inode
 * @sb: super block instance
 * @cpsize: size of a checkpoint entry
 * @raw_inode: on-disk cpfile inode
 * @inodep: buffer to store the inode
 */
int nilfs_cpfile_read(struct super_block *sb, size_t cpsize,
		      struct nilfs_inode *raw_inode, struct inode **inodep)
{ … }