Root/fs/jfs/jfs_imap.h

1/*
2 * Copyright (C) International Business Machines Corp., 2000-2002
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
12 * the GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
17 */
18#ifndef _H_JFS_IMAP
19#define _H_JFS_IMAP
20
21#include "jfs_txnmgr.h"
22
23/*
24 * jfs_imap.h: disk inode manager
25 */
26
27#define EXTSPERIAG 128 /* number of disk inode extent per iag */
28#define IMAPBLKNO 0 /* lblkno of dinomap within inode map */
29#define SMAPSZ 4 /* number of words per summary map */
30#define EXTSPERSUM 32 /* number of extents per summary map entry */
31#define L2EXTSPERSUM 5 /* l2 number of extents per summary map */
32#define PGSPERIEXT 4 /* number of 4K pages per dinode extent */
33#define MAXIAGS ((1<<20)-1) /* maximum number of iags */
34#define MAXAG 128 /* maximum number of allocation groups */
35
36#define AMAPSIZE 512 /* bytes in the IAG allocation maps */
37#define SMAPSIZE 16 /* bytes in the IAG summary maps */
38
39/* convert inode number to iag number */
40#define INOTOIAG(ino) ((ino) >> L2INOSPERIAG)
41
42/* convert iag number to logical block number of the iag page */
43#define IAGTOLBLK(iagno,l2nbperpg) (((iagno) + 1) << (l2nbperpg))
44
45/* get the starting block number of the 4K page of an inode extent
46 * that contains ino.
47 */
48#define INOPBLK(pxd,ino,l2nbperpg) (addressPXD((pxd)) + \
49    ((((ino) & (INOSPEREXT-1)) >> L2INOSPERPAGE) << (l2nbperpg)))
50
51/*
52 * inode allocation map:
53 *
54 * inode allocation map consists of
55 * . the inode map control page and
56 * . inode allocation group pages (per 4096 inodes)
57 * which are addressed by standard JFS xtree.
58 */
59/*
60 * inode allocation group page (per 4096 inodes of an AG)
61 */
62struct iag {
63    __le64 agstart; /* 8: starting block of ag */
64    __le32 iagnum; /* 4: inode allocation group number */
65    __le32 inofreefwd; /* 4: ag inode free list forward */
66    __le32 inofreeback; /* 4: ag inode free list back */
67    __le32 extfreefwd; /* 4: ag inode extent free list forward */
68    __le32 extfreeback; /* 4: ag inode extent free list back */
69    __le32 iagfree; /* 4: iag free list */
70
71    /* summary map: 1 bit per inode extent */
72    __le32 inosmap[SMAPSZ]; /* 16: sum map of mapwords w/ free inodes;
73                 * note: this indicates free and backed
74                 * inodes, if the extent is not backed the
75                 * value will be 1. if the extent is
76                 * backed but all inodes are being used the
77                 * value will be 1. if the extent is
78                 * backed but at least one of the inodes is
79                 * free the value will be 0.
80                 */
81    __le32 extsmap[SMAPSZ]; /* 16: sum map of mapwords w/ free extents */
82    __le32 nfreeinos; /* 4: number of free inodes */
83    __le32 nfreeexts; /* 4: number of free extents */
84    /* (72) */
85    u8 pad[1976]; /* 1976: pad to 2048 bytes */
86    /* allocation bit map: 1 bit per inode (0 - free, 1 - allocated) */
87    __le32 wmap[EXTSPERIAG]; /* 512: working allocation map */
88    __le32 pmap[EXTSPERIAG]; /* 512: persistent allocation map */
89    pxd_t inoext[EXTSPERIAG]; /* 1024: inode extent addresses */
90}; /* (4096) */
91
92/*
93 * per AG control information (in inode map control page)
94 */
95struct iagctl_disk {
96    __le32 inofree; /* 4: free inode list anchor */
97    __le32 extfree; /* 4: free extent list anchor */
98    __le32 numinos; /* 4: number of backed inodes */
99    __le32 numfree; /* 4: number of free inodes */
100}; /* (16) */
101
102struct iagctl {
103    int inofree; /* free inode list anchor */
104    int extfree; /* free extent list anchor */
105    int numinos; /* number of backed inodes */
106    int numfree; /* number of free inodes */
107};
108
109/*
110 * per fileset/aggregate inode map control page
111 */
112struct dinomap_disk {
113    __le32 in_freeiag; /* 4: free iag list anchor */
114    __le32 in_nextiag; /* 4: next free iag number */
115    __le32 in_numinos; /* 4: num of backed inodes */
116    __le32 in_numfree; /* 4: num of free backed inodes */
117    __le32 in_nbperiext; /* 4: num of blocks per inode extent */
118    __le32 in_l2nbperiext; /* 4: l2 of in_nbperiext */
119    __le32 in_diskblock; /* 4: for standalone test driver */
120    __le32 in_maxag; /* 4: for standalone test driver */
121    u8 pad[2016]; /* 2016: pad to 2048 */
122    struct iagctl_disk in_agctl[MAXAG]; /* 2048: AG control information */
123}; /* (4096) */
124
125struct dinomap {
126    int in_freeiag; /* free iag list anchor */
127    int in_nextiag; /* next free iag number */
128    int in_numinos; /* num of backed inodes */
129    int in_numfree; /* num of free backed inodes */
130    int in_nbperiext; /* num of blocks per inode extent */
131    int in_l2nbperiext; /* l2 of in_nbperiext */
132    int in_diskblock; /* for standalone test driver */
133    int in_maxag; /* for standalone test driver */
134    struct iagctl in_agctl[MAXAG]; /* AG control information */
135};
136
137/*
138 * In-core inode map control page
139 */
140struct inomap {
141    struct dinomap im_imap; /* 4096: inode allocation control */
142    struct inode *im_ipimap; /* 4: ptr to inode for imap */
143    struct mutex im_freelock; /* 4: iag free list lock */
144    struct mutex im_aglock[MAXAG]; /* 512: per AG locks */
145    u32 *im_DBGdimap;
146    atomic_t im_numinos; /* num of backed inodes */
147    atomic_t im_numfree; /* num of free backed inodes */
148};
149
150#define im_freeiag im_imap.in_freeiag
151#define im_nextiag im_imap.in_nextiag
152#define im_agctl im_imap.in_agctl
153#define im_nbperiext im_imap.in_nbperiext
154#define im_l2nbperiext im_imap.in_l2nbperiext
155
156/* for standalone testdriver
157 */
158#define im_diskblock im_imap.in_diskblock
159#define im_maxag im_imap.in_maxag
160
161extern int diFree(struct inode *);
162extern int diAlloc(struct inode *, bool, struct inode *);
163extern int diSync(struct inode *);
164/* external references */
165extern int diUpdatePMap(struct inode *ipimap, unsigned long inum,
166            bool is_free, struct tblock * tblk);
167extern int diExtendFS(struct inode *ipimap, struct inode *ipbmap);
168extern int diMount(struct inode *);
169extern int diUnmount(struct inode *, int);
170extern int diRead(struct inode *);
171extern struct inode *diReadSpecial(struct super_block *, ino_t, int);
172extern void diWriteSpecial(struct inode *, int);
173extern void diFreeSpecial(struct inode *);
174extern int diWrite(tid_t tid, struct inode *);
175#endif /* _H_JFS_IMAP */
176

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