kevin/linux
1
Fork 0
Code
ccecee1e5e
linux/fs/nilfs2/segbuf.h
Ryusuke Konishi cece552074 nilfs2: simplify handling of active state of segments 
will reduce some lines of segment constructor.  Previously, the state was
complexly controlled through a list of segments in order to keep
consistency in meta data of usage state of segments.  Instead, this
presents ``calculated'' active flags to userland cleaner program and stop
maintaining its real flag on disk.

Only by this fake flag, the cleaner cannot exactly know if each segment is
reclaimable or not.  However, the recent extension of nilfs_sustat ioctl
struct (nilfs2-extend-nilfs_sustat-ioctl-struct.patch) can prevent the
cleaner from reclaiming in-use segment wrongly.

So, now I can apply this for simplification.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-07 08:31:20 -07:00

202 lines
6.6 KiB
C
Raw Blame History

/*
* 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 */
View Git Blame Copy Permalink