Root/fs/jfs/jfs_dmap.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_DMAP
19#define _H_JFS_DMAP
20
21#include "jfs_txnmgr.h"
22
23#define BMAPVERSION 1 /* version number */
24#define TREESIZE (256+64+16+4+1) /* size of a dmap tree */
25#define LEAFIND (64+16+4+1) /* index of 1st leaf of a dmap tree */
26#define LPERDMAP 256 /* num leaves per dmap tree */
27#define L2LPERDMAP 8 /* l2 number of leaves per dmap tree */
28#define DBWORD 32 /* # of blks covered by a map word */
29#define L2DBWORD 5 /* l2 # of blks covered by a mword */
30#define BUDMIN L2DBWORD /* max free string in a map word */
31#define BPERDMAP (LPERDMAP * DBWORD) /* num of blks per dmap */
32#define L2BPERDMAP 13 /* l2 num of blks per dmap */
33#define CTLTREESIZE (1024+256+64+16+4+1) /* size of a dmapctl tree */
34#define CTLLEAFIND (256+64+16+4+1) /* idx of 1st leaf of a dmapctl tree */
35#define LPERCTL 1024 /* num of leaves per dmapctl tree */
36#define L2LPERCTL 10 /* l2 num of leaves per dmapctl tree */
37#define ROOT 0 /* index of the root of a tree */
38#define NOFREE ((s8) -1) /* no blocks free */
39#define MAXAG 128 /* max number of allocation groups */
40#define L2MAXAG 7 /* l2 max num of AG */
41#define L2MINAGSZ 25 /* l2 of minimum AG size in bytes */
42#define BMAPBLKNO 0 /* lblkno of bmap within the map */
43
44/*
45 * maximum l2 number of disk blocks at the various dmapctl levels.
46 */
47#define L2MAXL0SIZE (L2BPERDMAP + 1 * L2LPERCTL)
48#define L2MAXL1SIZE (L2BPERDMAP + 2 * L2LPERCTL)
49#define L2MAXL2SIZE (L2BPERDMAP + 3 * L2LPERCTL)
50
51/*
52 * maximum number of disk blocks at the various dmapctl levels.
53 */
54#define MAXL0SIZE ((s64)1 << L2MAXL0SIZE)
55#define MAXL1SIZE ((s64)1 << L2MAXL1SIZE)
56#define MAXL2SIZE ((s64)1 << L2MAXL2SIZE)
57
58#define MAXMAPSIZE MAXL2SIZE /* maximum aggregate map size */
59
60/*
61 * determine the maximum free string for four (lower level) nodes
62 * of the tree.
63 */
64static inline signed char TREEMAX(signed char *cp)
65{
66    signed char tmp1, tmp2;
67
68    tmp1 = max(*(cp+2), *(cp+3));
69    tmp2 = max(*(cp), *(cp+1));
70
71    return max(tmp1, tmp2);
72}
73
74/*
75 * convert disk block number to the logical block number of the dmap
76 * describing the disk block. s is the log2(number of logical blocks per page)
77 *
78 * The calculation figures out how many logical pages are in front of the dmap.
79 * - the number of dmaps preceding it
80 * - the number of L0 pages preceding its L0 page
81 * - the number of L1 pages preceding its L1 page
82 * - 3 is added to account for the L2, L1, and L0 page for this dmap
83 * - 1 is added to account for the control page of the map.
84 */
85#define BLKTODMAP(b,s) \
86    ((((b) >> 13) + ((b) >> 23) + ((b) >> 33) + 3 + 1) << (s))
87
88/*
89 * convert disk block number to the logical block number of the LEVEL 0
90 * dmapctl describing the disk block. s is the log2(number of logical blocks
91 * per page)
92 *
93 * The calculation figures out how many logical pages are in front of the L0.
94 * - the number of dmap pages preceding it
95 * - the number of L0 pages preceding it
96 * - the number of L1 pages preceding its L1 page
97 * - 2 is added to account for the L2, and L1 page for this L0
98 * - 1 is added to account for the control page of the map.
99 */
100#define BLKTOL0(b,s) \
101    (((((b) >> 23) << 10) + ((b) >> 23) + ((b) >> 33) + 2 + 1) << (s))
102
103/*
104 * convert disk block number to the logical block number of the LEVEL 1
105 * dmapctl describing the disk block. s is the log2(number of logical blocks
106 * per page)
107 *
108 * The calculation figures out how many logical pages are in front of the L1.
109 * - the number of dmap pages preceding it
110 * - the number of L0 pages preceding it
111 * - the number of L1 pages preceding it
112 * - 1 is added to account for the L2 page
113 * - 1 is added to account for the control page of the map.
114 */
115#define BLKTOL1(b,s) \
116     (((((b) >> 33) << 20) + (((b) >> 33) << 10) + ((b) >> 33) + 1 + 1) << (s))
117
118/*
119 * convert disk block number to the logical block number of the dmapctl
120 * at the specified level which describes the disk block.
121 */
122#define BLKTOCTL(b,s,l) \
123    (((l) == 2) ? 1 : ((l) == 1) ? BLKTOL1((b),(s)) : BLKTOL0((b),(s)))
124
125/*
126 * convert aggregate map size to the zero origin dmapctl level of the
127 * top dmapctl.
128 */
129#define BMAPSZTOLEV(size) \
130    (((size) <= MAXL0SIZE) ? 0 : ((size) <= MAXL1SIZE) ? 1 : 2)
131
132/* convert disk block number to allocation group number.
133 */
134#define BLKTOAG(b,sbi) ((b) >> ((sbi)->bmap->db_agl2size))
135
136/* convert allocation group number to starting disk block
137 * number.
138 */
139#define AGTOBLK(a,ip) \
140    ((s64)(a) << (JFS_SBI((ip)->i_sb)->bmap->db_agl2size))
141
142/*
143 * dmap summary tree
144 *
145 * dmaptree must be consistent with dmapctl.
146 */
147struct dmaptree {
148    __le32 nleafs; /* 4: number of tree leafs */
149    __le32 l2nleafs; /* 4: l2 number of tree leafs */
150    __le32 leafidx; /* 4: index of first tree leaf */
151    __le32 height; /* 4: height of the tree */
152    s8 budmin; /* 1: min l2 tree leaf value to combine */
153    s8 stree[TREESIZE]; /* TREESIZE: tree */
154    u8 pad[2]; /* 2: pad to word boundary */
155}; /* - 360 - */
156
157/*
158 * dmap page per 8K blocks bitmap
159 */
160struct dmap {
161    __le32 nblocks; /* 4: num blks covered by this dmap */
162    __le32 nfree; /* 4: num of free blks in this dmap */
163    __le64 start; /* 8: starting blkno for this dmap */
164    struct dmaptree tree; /* 360: dmap tree */
165    u8 pad[1672]; /* 1672: pad to 2048 bytes */
166    __le32 wmap[LPERDMAP]; /* 1024: bits of the working map */
167    __le32 pmap[LPERDMAP]; /* 1024: bits of the persistent map */
168}; /* - 4096 - */
169
170/*
171 * disk map control page per level.
172 *
173 * dmapctl must be consistent with dmaptree.
174 */
175struct dmapctl {
176    __le32 nleafs; /* 4: number of tree leafs */
177    __le32 l2nleafs; /* 4: l2 number of tree leafs */
178    __le32 leafidx; /* 4: index of the first tree leaf */
179    __le32 height; /* 4: height of tree */
180    s8 budmin; /* 1: minimum l2 tree leaf value */
181    s8 stree[CTLTREESIZE]; /* CTLTREESIZE: dmapctl tree */
182    u8 pad[2714]; /* 2714: pad to 4096 */
183}; /* - 4096 - */
184
185/*
186 * common definition for dmaptree within dmap and dmapctl
187 */
188typedef union dmtree {
189    struct dmaptree t1;
190    struct dmapctl t2;
191} dmtree_t;
192
193/* macros for accessing fields within dmtree */
194#define dmt_nleafs t1.nleafs
195#define dmt_l2nleafs t1.l2nleafs
196#define dmt_leafidx t1.leafidx
197#define dmt_height t1.height
198#define dmt_budmin t1.budmin
199#define dmt_stree t1.stree
200
201/*
202 * on-disk aggregate disk allocation map descriptor.
203 */
204struct dbmap_disk {
205    __le64 dn_mapsize; /* 8: number of blocks in aggregate */
206    __le64 dn_nfree; /* 8: num free blks in aggregate map */
207    __le32 dn_l2nbperpage; /* 4: number of blks per page */
208    __le32 dn_numag; /* 4: total number of ags */
209    __le32 dn_maxlevel; /* 4: number of active ags */
210    __le32 dn_maxag; /* 4: max active alloc group number */
211    __le32 dn_agpref; /* 4: preferred alloc group (hint) */
212    __le32 dn_aglevel; /* 4: dmapctl level holding the AG */
213    __le32 dn_agheight; /* 4: height in dmapctl of the AG */
214    __le32 dn_agwidth; /* 4: width in dmapctl of the AG */
215    __le32 dn_agstart; /* 4: start tree index at AG height */
216    __le32 dn_agl2size; /* 4: l2 num of blks per alloc group */
217    __le64 dn_agfree[MAXAG];/* 8*MAXAG: per AG free count */
218    __le64 dn_agsize; /* 8: num of blks per alloc group */
219    s8 dn_maxfreebud; /* 1: max free buddy system */
220    u8 pad[3007]; /* 3007: pad to 4096 */
221}; /* - 4096 - */
222
223struct dbmap {
224    s64 dn_mapsize; /* number of blocks in aggregate */
225    s64 dn_nfree; /* num free blks in aggregate map */
226    int dn_l2nbperpage; /* number of blks per page */
227    int dn_numag; /* total number of ags */
228    int dn_maxlevel; /* number of active ags */
229    int dn_maxag; /* max active alloc group number */
230    int dn_agpref; /* preferred alloc group (hint) */
231    int dn_aglevel; /* dmapctl level holding the AG */
232    int dn_agheight; /* height in dmapctl of the AG */
233    int dn_agwidth; /* width in dmapctl of the AG */
234    int dn_agstart; /* start tree index at AG height */
235    int dn_agl2size; /* l2 num of blks per alloc group */
236    s64 dn_agfree[MAXAG]; /* per AG free count */
237    s64 dn_agsize; /* num of blks per alloc group */
238    signed char dn_maxfreebud; /* max free buddy system */
239}; /* - 4096 - */
240/*
241 * in-memory aggregate disk allocation map descriptor.
242 */
243struct bmap {
244    struct dbmap db_bmap; /* on-disk aggregate map descriptor */
245    struct inode *db_ipbmap; /* ptr to aggregate map incore inode */
246    struct mutex db_bmaplock; /* aggregate map lock */
247    atomic_t db_active[MAXAG]; /* count of active, open files in AG */
248    u32 *db_DBmap;
249};
250
251/* macros for accessing fields within in-memory aggregate map descriptor */
252#define db_mapsize db_bmap.dn_mapsize
253#define db_nfree db_bmap.dn_nfree
254#define db_agfree db_bmap.dn_agfree
255#define db_agsize db_bmap.dn_agsize
256#define db_agl2size db_bmap.dn_agl2size
257#define db_agwidth db_bmap.dn_agwidth
258#define db_agheight db_bmap.dn_agheight
259#define db_agstart db_bmap.dn_agstart
260#define db_numag db_bmap.dn_numag
261#define db_maxlevel db_bmap.dn_maxlevel
262#define db_aglevel db_bmap.dn_aglevel
263#define db_agpref db_bmap.dn_agpref
264#define db_maxag db_bmap.dn_maxag
265#define db_maxfreebud db_bmap.dn_maxfreebud
266#define db_l2nbperpage db_bmap.dn_l2nbperpage
267
268/*
269 * macros for various conversions needed by the allocators.
270 * blkstol2(), cntlz(), and cnttz() are operating system dependent functions.
271 */
272/* convert number of blocks to log2 number of blocks, rounding up to
273 * the next log2 value if blocks is not a l2 multiple.
274 */
275#define BLKSTOL2(d) (blkstol2(d))
276
277/* convert number of leafs to log2 leaf value */
278#define NLSTOL2BSZ(n) (31 - cntlz((n)) + BUDMIN)
279
280/* convert leaf index to log2 leaf value */
281#define LITOL2BSZ(n,m,b) ((((n) == 0) ? (m) : cnttz((n))) + (b))
282
283/* convert a block number to a dmap control leaf index */
284#define BLKTOCTLLEAF(b,m) \
285    (((b) & (((s64)1 << ((m) + L2LPERCTL)) - 1)) >> (m))
286
287/* convert log2 leaf value to buddy size */
288#define BUDSIZE(s,m) (1 << ((s) - (m)))
289
290/*
291 * external references.
292 */
293extern int dbMount(struct inode *ipbmap);
294
295extern int dbUnmount(struct inode *ipbmap, int mounterror);
296
297extern int dbFree(struct inode *ipbmap, s64 blkno, s64 nblocks);
298
299extern int dbUpdatePMap(struct inode *ipbmap,
300            int free, s64 blkno, s64 nblocks, struct tblock * tblk);
301
302extern int dbNextAG(struct inode *ipbmap);
303
304extern int dbAlloc(struct inode *ipbmap, s64 hint, s64 nblocks, s64 * results);
305
306extern int dbReAlloc(struct inode *ipbmap,
307             s64 blkno, s64 nblocks, s64 addnblocks, s64 * results);
308
309extern int dbSync(struct inode *ipbmap);
310extern int dbAllocBottomUp(struct inode *ip, s64 blkno, s64 nblocks);
311extern int dbExtendFS(struct inode *ipbmap, s64 blkno, s64 nblocks);
312extern void dbFinalizeBmap(struct inode *ipbmap);
313extern s64 dbMapFileSizeToMapSize(struct inode *ipbmap);
314#endif /* _H_JFS_DMAP */
315

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