/*
* segbuf.h - NILFS Segment buffer prototypes and definitions
*
* Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* Written by Ryusuke Konishi <ryusuke@osrg.net>
*
*/
#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>
#include <linux/backing-dev.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
* @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;
time_t ctime;
sector_t next;
};
/* macro for the flags */
#define NILFS_SEG_HAS_SR(sum) ((sum)->flags & NILFS_SS_SR)
#define NILFS_SEG_LOGBGN(sum) ((sum)->flags & NILFS_SS_LOGBGN)
#define NILFS_SEG_LOGEND(sum) ((sum)->flags & NILFS_SS_LOGEND)
#define NILFS_SEG_DSYNC(sum) ((sum)->flags & NILFS_SS_SYNDT)
#define NILFS_SEG_SIMPLEX(sum) \
(((sum)->flags & (NILFS_SS_LOGBGN | NILFS_SS_LOGEND)) == \
(NILFS_SS_LOGBGN | NILFS_SS_LOGEND))
#define NILFS_SEG_EMPTY(sum) ((sum)->nblocks == (sum)->nsumblk)
/**
* 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
* @sb_io_error: I/O error status
*/
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;
unsigned sb_rest_blocks;
/* Buffers */
struct list_head sb_segsum_buffers;
struct list_head sb_payload_buffers; /* including super root */
/* io status */
int sb_io_error;
};
#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)
int __init nilfs_init_segbuf_cache(void);
void nilfs_destroy_segbuf_cache(void);
struct nilfs_segment_buffer *nilfs_segbuf_new(struct super_block *);
void nilfs_segbuf_free(struct nilfs_segment_buffer *);
void nilfs_segbuf_map(struct nilfs_segment_buffer *, __u64, unsigned long,
struct the_nilfs *);
void nilfs_segbuf_set_next_segnum(struct nilfs_segment_buffer *, __u64,
struct the_nilfs *);
int nilfs_segbuf_reset(struct nilfs_segment_buffer *, unsigned, time_t);
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 *);
void nilfs_segbuf_fill_in_segsum_crc(struct nilfs_segment_buffer *, u32);
void nilfs_segbuf_fill_in_data_crc(struct nilfs_segment_buffer *, u32);
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++;
}
void nilfs_release_buffers(struct list_head *);
static inline void nilfs_segbuf_clear(struct nilfs_segment_buffer *segbuf)
{
nilfs_release_buffers(&segbuf->sb_segsum_buffers);
nilfs_release_buffers(&segbuf->sb_payload_buffers);
}
struct nilfs_write_info {
struct bio *bio;
int start, end; /* The region to be submitted */
int rest_blocks;
int max_pages;
int nr_vecs;
sector_t blocknr;
int nbio;
atomic_t err;
struct completion bio_event;
/* completion event of segment write */
/*
* The following fields must be set explicitly
*/
struct super_block *sb;
struct backing_dev_info *bdi; /* backing dev info */
struct buffer_head *bh_sr;
};
void nilfs_segbuf_prepare_write(struct nilfs_segment_buffer *,
struct nilfs_write_info *);
int nilfs_segbuf_write(struct nilfs_segment_buffer *,
struct nilfs_write_info *);
int nilfs_segbuf_wait(struct nilfs_segment_buffer *,
struct nilfs_write_info *);
#endif /* _NILFS_SEGBUF_H */
