segbuf.h 5.51 KB
Newer Older
1
/* SPDX-License-Identifier: GPL-2.0+ */
Ryusuke Konishi's avatar
Ryusuke Konishi committed
2 3 4 5 6
/*
 * segbuf.h - NILFS Segment buffer prototypes and definitions
 *
 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
 *
7
 * Written by Ryusuke Konishi.
Ryusuke Konishi's avatar
Ryusuke Konishi committed
8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26
 *
 */
#ifndef _NILFS_SEGBUF_H
#define _NILFS_SEGBUF_H

#include <linux/fs.h>
#include <linux/buffer_head.h>
#include <linux/bio.h>
#include <linux/completion.h>

/**
 * struct nilfs_segsum_info - On-memory segment summary
 * @flags: Flags
 * @nfinfo: Number of file information structures
 * @nblocks: Number of blocks included in the partial segment
 * @nsumblk: Number of summary blocks
 * @sumbytes: Byte count of segment summary
 * @nfileblk: Total number of file blocks
 * @seg_seq: Segment sequence number
27
 * @cno: Checkpoint number
Ryusuke Konishi's avatar
Ryusuke Konishi committed
28 29 30 31 32 33 34 35 36 37 38
 * @ctime: Creation time
 * @next: Block number of the next full segment
 */
struct nilfs_segsum_info {
	unsigned int		flags;
	unsigned long		nfinfo;
	unsigned long		nblocks;
	unsigned long		nsumblk;
	unsigned long		sumbytes;
	unsigned long		nfileblk;
	u64			seg_seq;
39
	__u64			cno;
40
	time64_t		ctime;
Ryusuke Konishi's avatar
Ryusuke Konishi committed
41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56
	sector_t		next;
};

/**
 * struct nilfs_segment_buffer - Segment buffer
 * @sb_super: back pointer to a superblock struct
 * @sb_list: List head to chain this structure
 * @sb_sum: On-memory segment summary
 * @sb_segnum: Index number of the full segment
 * @sb_nextnum: Index number of the next full segment
 * @sb_fseg_start: Start block number of the full segment
 * @sb_fseg_end: End block number of the full segment
 * @sb_pseg_start: Disk block number of partial segment
 * @sb_rest_blocks: Number of residual blocks in the current segment
 * @sb_segsum_buffers: List of buffers for segment summaries
 * @sb_payload_buffers: List of buffers for segment payload
57
 * @sb_super_root: Pointer to buffer storing a super root block (if exists)
58 59 60
 * @sb_nbio: Number of flying bio requests
 * @sb_err: I/O error status
 * @sb_bio_event: Completion event of log writing
Ryusuke Konishi's avatar
Ryusuke Konishi committed
61 62 63 64 65 66 67 68 69 70 71
 */
struct nilfs_segment_buffer {
	struct super_block     *sb_super;
	struct list_head	sb_list;

	/* Segment information */
	struct nilfs_segsum_info sb_sum;
	__u64			sb_segnum;
	__u64			sb_nextnum;
	sector_t		sb_fseg_start, sb_fseg_end;
	sector_t		sb_pseg_start;
72
	unsigned int		sb_rest_blocks;
Ryusuke Konishi's avatar
Ryusuke Konishi committed
73 74 75 76

	/* Buffers */
	struct list_head	sb_segsum_buffers;
	struct list_head	sb_payload_buffers; /* including super root */
77
	struct buffer_head     *sb_super_root;
Ryusuke Konishi's avatar
Ryusuke Konishi committed
78 79

	/* io status */
80 81 82
	int			sb_nbio;
	atomic_t		sb_err;
	struct completion	sb_bio_event;
Ryusuke Konishi's avatar
Ryusuke Konishi committed
83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103
};

#define NILFS_LIST_SEGBUF(head)  \
	list_entry((head), struct nilfs_segment_buffer, sb_list)
#define NILFS_NEXT_SEGBUF(segbuf)  NILFS_LIST_SEGBUF((segbuf)->sb_list.next)
#define NILFS_PREV_SEGBUF(segbuf)  NILFS_LIST_SEGBUF((segbuf)->sb_list.prev)
#define NILFS_LAST_SEGBUF(head)    NILFS_LIST_SEGBUF((head)->prev)
#define NILFS_FIRST_SEGBUF(head)   NILFS_LIST_SEGBUF((head)->next)
#define NILFS_SEGBUF_IS_LAST(segbuf, head)  ((segbuf)->sb_list.next == (head))

#define nilfs_for_each_segbuf_before(s, t, h) \
	for ((s) = NILFS_FIRST_SEGBUF(h); (s) != (t); \
	     (s) = NILFS_NEXT_SEGBUF(s))

#define NILFS_SEGBUF_FIRST_BH(head)  \
	(list_entry((head)->next, struct buffer_head, b_assoc_buffers))
#define NILFS_SEGBUF_NEXT_BH(bh)  \
	(list_entry((bh)->b_assoc_buffers.next, struct buffer_head, \
		    b_assoc_buffers))
#define NILFS_SEGBUF_BH_IS_LAST(bh, head)  ((bh)->b_assoc_buffers.next == head)

104
extern struct kmem_cache *nilfs_segbuf_cachep;
Ryusuke Konishi's avatar
Ryusuke Konishi committed
105 106 107

struct nilfs_segment_buffer *nilfs_segbuf_new(struct super_block *);
void nilfs_segbuf_free(struct nilfs_segment_buffer *);
108 109
void nilfs_segbuf_map(struct nilfs_segment_buffer *, __u64, unsigned long,
		      struct the_nilfs *);
110 111
void nilfs_segbuf_map_cont(struct nilfs_segment_buffer *segbuf,
			   struct nilfs_segment_buffer *prev);
Ryusuke Konishi's avatar
Ryusuke Konishi committed
112 113
void nilfs_segbuf_set_next_segnum(struct nilfs_segment_buffer *, __u64,
				  struct the_nilfs *);
114
int nilfs_segbuf_reset(struct nilfs_segment_buffer *, unsigned int, time64_t,
115
		       __u64);
Ryusuke Konishi's avatar
Ryusuke Konishi committed
116 117 118 119 120
int nilfs_segbuf_extend_segsum(struct nilfs_segment_buffer *);
int nilfs_segbuf_extend_payload(struct nilfs_segment_buffer *,
				struct buffer_head **);
void nilfs_segbuf_fill_in_segsum(struct nilfs_segment_buffer *);

121 122 123 124 125 126 127 128 129 130 131 132 133
static inline int nilfs_segbuf_simplex(struct nilfs_segment_buffer *segbuf)
{
	unsigned int flags = segbuf->sb_sum.flags;

	return (flags & (NILFS_SS_LOGBGN | NILFS_SS_LOGEND)) ==
		(NILFS_SS_LOGBGN | NILFS_SS_LOGEND);
}

static inline int nilfs_segbuf_empty(struct nilfs_segment_buffer *segbuf)
{
	return segbuf->sb_sum.nblocks == segbuf->sb_sum.nsumblk;
}

Ryusuke Konishi's avatar
Ryusuke Konishi committed
134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159
static inline void
nilfs_segbuf_add_segsum_buffer(struct nilfs_segment_buffer *segbuf,
			       struct buffer_head *bh)
{
	list_add_tail(&bh->b_assoc_buffers, &segbuf->sb_segsum_buffers);
	segbuf->sb_sum.nblocks++;
	segbuf->sb_sum.nsumblk++;
}

static inline void
nilfs_segbuf_add_payload_buffer(struct nilfs_segment_buffer *segbuf,
				struct buffer_head *bh)
{
	list_add_tail(&bh->b_assoc_buffers, &segbuf->sb_payload_buffers);
	segbuf->sb_sum.nblocks++;
}

static inline void
nilfs_segbuf_add_file_buffer(struct nilfs_segment_buffer *segbuf,
			     struct buffer_head *bh)
{
	get_bh(bh);
	nilfs_segbuf_add_payload_buffer(segbuf, bh);
	segbuf->sb_sum.nfileblk++;
}

160 161 162
void nilfs_clear_logs(struct list_head *logs);
void nilfs_truncate_logs(struct list_head *logs,
			 struct nilfs_segment_buffer *last);
163
int nilfs_write_logs(struct list_head *logs, struct the_nilfs *nilfs);
164
int nilfs_wait_on_logs(struct list_head *logs);
165
void nilfs_add_checksums_on_logs(struct list_head *logs, u32 seed);
166 167 168 169 170 171

static inline void nilfs_destroy_logs(struct list_head *logs)
{
	nilfs_truncate_logs(logs, NULL);
}

Ryusuke Konishi's avatar
Ryusuke Konishi committed
172
#endif /* _NILFS_SEGBUF_H */