333 строки
10 KiB
C
333 строки
10 KiB
C
/*
|
|
* the_nilfs.h - the_nilfs shared structure.
|
|
*
|
|
* 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 _THE_NILFS_H
|
|
#define _THE_NILFS_H
|
|
|
|
#include <linux/types.h>
|
|
#include <linux/buffer_head.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/blkdev.h>
|
|
#include <linux/backing-dev.h>
|
|
#include <linux/slab.h>
|
|
#include "sb.h"
|
|
|
|
/* the_nilfs struct */
|
|
enum {
|
|
THE_NILFS_INIT = 0, /* Information from super_block is set */
|
|
THE_NILFS_LOADED, /* Roll-back/roll-forward has done and
|
|
the latest checkpoint was loaded */
|
|
THE_NILFS_DISCONTINUED, /* 'next' pointer chain has broken */
|
|
THE_NILFS_GC_RUNNING, /* gc process is running */
|
|
THE_NILFS_SB_DIRTY, /* super block is dirty */
|
|
};
|
|
|
|
/**
|
|
* struct the_nilfs - struct to supervise multiple nilfs mount points
|
|
* @ns_flags: flags
|
|
* @ns_count: reference count
|
|
* @ns_list: list head for nilfs_list
|
|
* @ns_bdev: block device
|
|
* @ns_bdi: backing dev info
|
|
* @ns_writer: back pointer to writable nilfs_sb_info
|
|
* @ns_sem: semaphore for shared states
|
|
* @ns_super_sem: semaphore for global operations across super block instances
|
|
* @ns_mount_mutex: mutex protecting mount process of nilfs
|
|
* @ns_writer_sem: semaphore protecting ns_writer attach/detach
|
|
* @ns_current: back pointer to current mount
|
|
* @ns_sbh: buffer heads of on-disk super blocks
|
|
* @ns_sbp: pointers to super block data
|
|
* @ns_sbwtime: previous write time of super blocks
|
|
* @ns_sbsize: size of valid data in super block
|
|
* @ns_supers: list of nilfs super block structs
|
|
* @ns_seg_seq: segment sequence counter
|
|
* @ns_segnum: index number of the latest full segment.
|
|
* @ns_nextnum: index number of the full segment index to be used next
|
|
* @ns_pseg_offset: offset of next partial segment in the current full segment
|
|
* @ns_cno: next checkpoint number
|
|
* @ns_ctime: write time of the last segment
|
|
* @ns_nongc_ctime: write time of the last segment not for cleaner operation
|
|
* @ns_ndirtyblks: Number of dirty data blocks
|
|
* @ns_last_segment_lock: lock protecting fields for the latest segment
|
|
* @ns_last_pseg: start block number of the latest segment
|
|
* @ns_last_seq: sequence value of the latest segment
|
|
* @ns_last_cno: checkpoint number of the latest segment
|
|
* @ns_prot_seq: least sequence number of segments which must not be reclaimed
|
|
* @ns_free_segments_count: counter of free segments
|
|
* @ns_segctor_sem: segment constructor semaphore
|
|
* @ns_dat: DAT file inode
|
|
* @ns_cpfile: checkpoint file inode
|
|
* @ns_sufile: segusage file inode
|
|
* @ns_gc_dat: shadow inode of the DAT file inode for GC
|
|
* @ns_gc_inodes: dummy inodes to keep live blocks
|
|
* @ns_gc_inodes_h: hash list to keep dummy inode holding live blocks
|
|
* @ns_blocksize_bits: bit length of block size
|
|
* @ns_nsegments: number of segments in filesystem
|
|
* @ns_blocks_per_segment: number of blocks per segment
|
|
* @ns_r_segments_percentage: reserved segments percentage
|
|
* @ns_nrsvsegs: number of reserved segments
|
|
* @ns_first_data_block: block number of first data block
|
|
* @ns_inode_size: size of on-disk inode
|
|
* @ns_first_ino: first not-special inode number
|
|
* @ns_crc_seed: seed value of CRC32 calculation
|
|
*/
|
|
struct the_nilfs {
|
|
unsigned long ns_flags;
|
|
atomic_t ns_count;
|
|
struct list_head ns_list;
|
|
|
|
struct block_device *ns_bdev;
|
|
struct backing_dev_info *ns_bdi;
|
|
struct nilfs_sb_info *ns_writer;
|
|
struct rw_semaphore ns_sem;
|
|
struct rw_semaphore ns_super_sem;
|
|
struct mutex ns_mount_mutex;
|
|
struct rw_semaphore ns_writer_sem;
|
|
|
|
/*
|
|
* components protected by ns_super_sem
|
|
*/
|
|
struct nilfs_sb_info *ns_current;
|
|
struct list_head ns_supers;
|
|
|
|
/*
|
|
* used for
|
|
* - loading the latest checkpoint exclusively.
|
|
* - allocating a new full segment.
|
|
* - protecting s_dirt in the super_block struct
|
|
* (see nilfs_write_super) and the following fields.
|
|
*/
|
|
struct buffer_head *ns_sbh[2];
|
|
struct nilfs_super_block *ns_sbp[2];
|
|
time_t ns_sbwtime[2];
|
|
unsigned ns_sbsize;
|
|
unsigned ns_mount_state;
|
|
|
|
/*
|
|
* Following fields are dedicated to a writable FS-instance.
|
|
* Except for the period seeking checkpoint, code outside the segment
|
|
* constructor must lock a segment semaphore while accessing these
|
|
* fields.
|
|
* The writable FS-instance is sole during a lifetime of the_nilfs.
|
|
*/
|
|
u64 ns_seg_seq;
|
|
__u64 ns_segnum;
|
|
__u64 ns_nextnum;
|
|
unsigned long ns_pseg_offset;
|
|
__u64 ns_cno;
|
|
time_t ns_ctime;
|
|
time_t ns_nongc_ctime;
|
|
atomic_t ns_ndirtyblks;
|
|
|
|
/*
|
|
* The following fields hold information on the latest partial segment
|
|
* written to disk with a super root. These fields are protected by
|
|
* ns_last_segment_lock.
|
|
*/
|
|
spinlock_t ns_last_segment_lock;
|
|
sector_t ns_last_pseg;
|
|
u64 ns_last_seq;
|
|
__u64 ns_last_cno;
|
|
u64 ns_prot_seq;
|
|
unsigned long ns_free_segments_count;
|
|
|
|
struct rw_semaphore ns_segctor_sem;
|
|
|
|
/*
|
|
* Following fields are lock free except for the period before
|
|
* the_nilfs is initialized.
|
|
*/
|
|
struct inode *ns_dat;
|
|
struct inode *ns_cpfile;
|
|
struct inode *ns_sufile;
|
|
struct inode *ns_gc_dat;
|
|
|
|
/* GC inode list and hash table head */
|
|
struct list_head ns_gc_inodes;
|
|
struct hlist_head *ns_gc_inodes_h;
|
|
|
|
/* Disk layout information (static) */
|
|
unsigned int ns_blocksize_bits;
|
|
unsigned long ns_nsegments;
|
|
unsigned long ns_blocks_per_segment;
|
|
unsigned long ns_r_segments_percentage;
|
|
unsigned long ns_nrsvsegs;
|
|
unsigned long ns_first_data_block;
|
|
int ns_inode_size;
|
|
int ns_first_ino;
|
|
u32 ns_crc_seed;
|
|
};
|
|
|
|
#define NILFS_GCINODE_HASH_BITS 8
|
|
#define NILFS_GCINODE_HASH_SIZE (1<<NILFS_GCINODE_HASH_BITS)
|
|
|
|
#define THE_NILFS_FNS(bit, name) \
|
|
static inline void set_nilfs_##name(struct the_nilfs *nilfs) \
|
|
{ \
|
|
set_bit(THE_NILFS_##bit, &(nilfs)->ns_flags); \
|
|
} \
|
|
static inline void clear_nilfs_##name(struct the_nilfs *nilfs) \
|
|
{ \
|
|
clear_bit(THE_NILFS_##bit, &(nilfs)->ns_flags); \
|
|
} \
|
|
static inline int nilfs_##name(struct the_nilfs *nilfs) \
|
|
{ \
|
|
return test_bit(THE_NILFS_##bit, &(nilfs)->ns_flags); \
|
|
}
|
|
|
|
THE_NILFS_FNS(INIT, init)
|
|
THE_NILFS_FNS(LOADED, loaded)
|
|
THE_NILFS_FNS(DISCONTINUED, discontinued)
|
|
THE_NILFS_FNS(GC_RUNNING, gc_running)
|
|
THE_NILFS_FNS(SB_DIRTY, sb_dirty)
|
|
|
|
/* Minimum interval of periodical update of superblocks (in seconds) */
|
|
#define NILFS_SB_FREQ 10
|
|
#define NILFS_ALTSB_FREQ 60 /* spare superblock */
|
|
|
|
static inline int nilfs_sb_need_update(struct the_nilfs *nilfs)
|
|
{
|
|
u64 t = get_seconds();
|
|
return t < nilfs->ns_sbwtime[0] ||
|
|
t > nilfs->ns_sbwtime[0] + NILFS_SB_FREQ;
|
|
}
|
|
|
|
static inline int nilfs_altsb_need_update(struct the_nilfs *nilfs)
|
|
{
|
|
u64 t = get_seconds();
|
|
struct nilfs_super_block **sbp = nilfs->ns_sbp;
|
|
return sbp[1] && t > nilfs->ns_sbwtime[1] + NILFS_ALTSB_FREQ;
|
|
}
|
|
|
|
void nilfs_set_last_segment(struct the_nilfs *, sector_t, u64, __u64);
|
|
struct the_nilfs *find_or_create_nilfs(struct block_device *);
|
|
void put_nilfs(struct the_nilfs *);
|
|
int init_nilfs(struct the_nilfs *, struct nilfs_sb_info *, char *);
|
|
int load_nilfs(struct the_nilfs *, struct nilfs_sb_info *);
|
|
int nilfs_discard_segments(struct the_nilfs *, __u64 *, size_t);
|
|
int nilfs_count_free_blocks(struct the_nilfs *, sector_t *);
|
|
struct nilfs_sb_info *nilfs_find_sbinfo(struct the_nilfs *, int, __u64);
|
|
int nilfs_checkpoint_is_mounted(struct the_nilfs *, __u64, int);
|
|
int nilfs_near_disk_full(struct the_nilfs *);
|
|
void nilfs_fall_back_super_block(struct the_nilfs *);
|
|
void nilfs_swap_super_block(struct the_nilfs *);
|
|
|
|
|
|
static inline void get_nilfs(struct the_nilfs *nilfs)
|
|
{
|
|
/* Caller must have at least one reference of the_nilfs. */
|
|
atomic_inc(&nilfs->ns_count);
|
|
}
|
|
|
|
static inline void
|
|
nilfs_attach_writer(struct the_nilfs *nilfs, struct nilfs_sb_info *sbi)
|
|
{
|
|
down_write(&nilfs->ns_writer_sem);
|
|
nilfs->ns_writer = sbi;
|
|
up_write(&nilfs->ns_writer_sem);
|
|
}
|
|
|
|
static inline void
|
|
nilfs_detach_writer(struct the_nilfs *nilfs, struct nilfs_sb_info *sbi)
|
|
{
|
|
down_write(&nilfs->ns_writer_sem);
|
|
if (sbi == nilfs->ns_writer)
|
|
nilfs->ns_writer = NULL;
|
|
up_write(&nilfs->ns_writer_sem);
|
|
}
|
|
|
|
static inline void nilfs_put_sbinfo(struct nilfs_sb_info *sbi)
|
|
{
|
|
if (atomic_dec_and_test(&sbi->s_count))
|
|
kfree(sbi);
|
|
}
|
|
|
|
static inline int nilfs_valid_fs(struct the_nilfs *nilfs)
|
|
{
|
|
unsigned valid_fs;
|
|
|
|
down_read(&nilfs->ns_sem);
|
|
valid_fs = (nilfs->ns_mount_state & NILFS_VALID_FS);
|
|
up_read(&nilfs->ns_sem);
|
|
return valid_fs;
|
|
}
|
|
|
|
static inline void
|
|
nilfs_get_segment_range(struct the_nilfs *nilfs, __u64 segnum,
|
|
sector_t *seg_start, sector_t *seg_end)
|
|
{
|
|
*seg_start = (sector_t)nilfs->ns_blocks_per_segment * segnum;
|
|
*seg_end = *seg_start + nilfs->ns_blocks_per_segment - 1;
|
|
if (segnum == 0)
|
|
*seg_start = nilfs->ns_first_data_block;
|
|
}
|
|
|
|
static inline sector_t
|
|
nilfs_get_segment_start_blocknr(struct the_nilfs *nilfs, __u64 segnum)
|
|
{
|
|
return (segnum == 0) ? nilfs->ns_first_data_block :
|
|
(sector_t)nilfs->ns_blocks_per_segment * segnum;
|
|
}
|
|
|
|
static inline __u64
|
|
nilfs_get_segnum_of_block(struct the_nilfs *nilfs, sector_t blocknr)
|
|
{
|
|
sector_t segnum = blocknr;
|
|
|
|
sector_div(segnum, nilfs->ns_blocks_per_segment);
|
|
return segnum;
|
|
}
|
|
|
|
static inline void
|
|
nilfs_terminate_segment(struct the_nilfs *nilfs, sector_t seg_start,
|
|
sector_t seg_end)
|
|
{
|
|
/* terminate the current full segment (used in case of I/O-error) */
|
|
nilfs->ns_pseg_offset = seg_end - seg_start + 1;
|
|
}
|
|
|
|
static inline void nilfs_shift_to_next_segment(struct the_nilfs *nilfs)
|
|
{
|
|
/* move forward with a full segment */
|
|
nilfs->ns_segnum = nilfs->ns_nextnum;
|
|
nilfs->ns_pseg_offset = 0;
|
|
nilfs->ns_seg_seq++;
|
|
}
|
|
|
|
static inline __u64 nilfs_last_cno(struct the_nilfs *nilfs)
|
|
{
|
|
__u64 cno;
|
|
|
|
spin_lock(&nilfs->ns_last_segment_lock);
|
|
cno = nilfs->ns_last_cno;
|
|
spin_unlock(&nilfs->ns_last_segment_lock);
|
|
return cno;
|
|
}
|
|
|
|
static inline int nilfs_segment_is_active(struct the_nilfs *nilfs, __u64 n)
|
|
{
|
|
return n == nilfs->ns_segnum || n == nilfs->ns_nextnum;
|
|
}
|
|
|
|
#endif /* _THE_NILFS_H */
|