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1da177e4 LT |
1 | /* |
2 | * Copyright (C) International Business Machines Corp., 2000-2004 | |
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 | ||
19 | #include <linux/fs.h> | |
20 | #include "jfs_incore.h" | |
21 | #include "jfs_superblock.h" | |
22 | #include "jfs_dmap.h" | |
23 | #include "jfs_imap.h" | |
24 | #include "jfs_lock.h" | |
25 | #include "jfs_metapage.h" | |
26 | #include "jfs_debug.h" | |
27 | ||
1da177e4 LT |
28 | /* |
29 | * SERIALIZATION of the Block Allocation Map. | |
30 | * | |
31 | * the working state of the block allocation map is accessed in | |
32 | * two directions: | |
33 | * | |
34 | * 1) allocation and free requests that start at the dmap | |
35 | * level and move up through the dmap control pages (i.e. | |
36 | * the vast majority of requests). | |
37 | * | |
38 | * 2) allocation requests that start at dmap control page | |
39 | * level and work down towards the dmaps. | |
40 | * | |
41 | * the serialization scheme used here is as follows. | |
42 | * | |
43 | * requests which start at the bottom are serialized against each | |
44 | * other through buffers and each requests holds onto its buffers | |
45 | * as it works it way up from a single dmap to the required level | |
46 | * of dmap control page. | |
47 | * requests that start at the top are serialized against each other | |
48 | * and request that start from the bottom by the multiple read/single | |
49 | * write inode lock of the bmap inode. requests starting at the top | |
50 | * take this lock in write mode while request starting at the bottom | |
51 | * take the lock in read mode. a single top-down request may proceed | |
52 | * exclusively while multiple bottoms-up requests may proceed | |
53 | * simultaneously (under the protection of busy buffers). | |
54 | * | |
55 | * in addition to information found in dmaps and dmap control pages, | |
56 | * the working state of the block allocation map also includes read/ | |
57 | * write information maintained in the bmap descriptor (i.e. total | |
58 | * free block count, allocation group level free block counts). | |
59 | * a single exclusive lock (BMAP_LOCK) is used to guard this information | |
60 | * in the face of multiple-bottoms up requests. | |
61 | * (lock ordering: IREAD_LOCK, BMAP_LOCK); | |
62 | * | |
63 | * accesses to the persistent state of the block allocation map (limited | |
64 | * to the persistent bitmaps in dmaps) is guarded by (busy) buffers. | |
65 | */ | |
66 | ||
67 | #define BMAP_LOCK_INIT(bmp) init_MUTEX(&bmp->db_bmaplock) | |
68 | #define BMAP_LOCK(bmp) down(&bmp->db_bmaplock) | |
69 | #define BMAP_UNLOCK(bmp) up(&bmp->db_bmaplock) | |
70 | ||
71 | /* | |
72 | * forward references | |
73 | */ | |
74 | static void dbAllocBits(struct bmap * bmp, struct dmap * dp, s64 blkno, | |
75 | int nblocks); | |
76 | static void dbSplit(dmtree_t * tp, int leafno, int splitsz, int newval); | |
b6a47fd8 | 77 | static int dbBackSplit(dmtree_t * tp, int leafno); |
56d12549 | 78 | static int dbJoin(dmtree_t * tp, int leafno, int newval); |
1da177e4 LT |
79 | static void dbAdjTree(dmtree_t * tp, int leafno, int newval); |
80 | static int dbAdjCtl(struct bmap * bmp, s64 blkno, int newval, int alloc, | |
81 | int level); | |
82 | static int dbAllocAny(struct bmap * bmp, s64 nblocks, int l2nb, s64 * results); | |
83 | static int dbAllocNext(struct bmap * bmp, struct dmap * dp, s64 blkno, | |
84 | int nblocks); | |
85 | static int dbAllocNear(struct bmap * bmp, struct dmap * dp, s64 blkno, | |
86 | int nblocks, | |
87 | int l2nb, s64 * results); | |
88 | static int dbAllocDmap(struct bmap * bmp, struct dmap * dp, s64 blkno, | |
89 | int nblocks); | |
90 | static int dbAllocDmapLev(struct bmap * bmp, struct dmap * dp, int nblocks, | |
91 | int l2nb, | |
92 | s64 * results); | |
93 | static int dbAllocAG(struct bmap * bmp, int agno, s64 nblocks, int l2nb, | |
94 | s64 * results); | |
95 | static int dbAllocCtl(struct bmap * bmp, s64 nblocks, int l2nb, s64 blkno, | |
96 | s64 * results); | |
97 | static int dbExtend(struct inode *ip, s64 blkno, s64 nblocks, s64 addnblocks); | |
98 | static int dbFindBits(u32 word, int l2nb); | |
99 | static int dbFindCtl(struct bmap * bmp, int l2nb, int level, s64 * blkno); | |
100 | static int dbFindLeaf(dmtree_t * tp, int l2nb, int *leafidx); | |
56d12549 DK |
101 | static int dbFreeBits(struct bmap * bmp, struct dmap * dp, s64 blkno, |
102 | int nblocks); | |
1da177e4 LT |
103 | static int dbFreeDmap(struct bmap * bmp, struct dmap * dp, s64 blkno, |
104 | int nblocks); | |
105 | static int dbMaxBud(u8 * cp); | |
106 | s64 dbMapFileSizeToMapSize(struct inode *ipbmap); | |
107 | static int blkstol2(s64 nb); | |
108 | ||
109 | static int cntlz(u32 value); | |
110 | static int cnttz(u32 word); | |
111 | ||
112 | static int dbAllocDmapBU(struct bmap * bmp, struct dmap * dp, s64 blkno, | |
113 | int nblocks); | |
114 | static int dbInitDmap(struct dmap * dp, s64 blkno, int nblocks); | |
115 | static int dbInitDmapTree(struct dmap * dp); | |
116 | static int dbInitTree(struct dmaptree * dtp); | |
117 | static int dbInitDmapCtl(struct dmapctl * dcp, int level, int i); | |
118 | static int dbGetL2AGSize(s64 nblocks); | |
119 | ||
120 | /* | |
121 | * buddy table | |
122 | * | |
123 | * table used for determining buddy sizes within characters of | |
124 | * dmap bitmap words. the characters themselves serve as indexes | |
125 | * into the table, with the table elements yielding the maximum | |
126 | * binary buddy of free bits within the character. | |
127 | */ | |
128 | static s8 budtab[256] = { | |
129 | 3, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, | |
130 | 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, | |
131 | 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, | |
132 | 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, | |
133 | 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, | |
134 | 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, | |
135 | 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, | |
136 | 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, | |
137 | 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, | |
138 | 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, | |
139 | 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, | |
140 | 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, | |
141 | 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, | |
142 | 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, | |
143 | 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, | |
144 | 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, -1 | |
145 | }; | |
146 | ||
147 | ||
148 | /* | |
149 | * NAME: dbMount() | |
150 | * | |
151 | * FUNCTION: initializate the block allocation map. | |
152 | * | |
153 | * memory is allocated for the in-core bmap descriptor and | |
154 | * the in-core descriptor is initialized from disk. | |
155 | * | |
156 | * PARAMETERS: | |
157 | * ipbmap - pointer to in-core inode for the block map. | |
158 | * | |
159 | * RETURN VALUES: | |
160 | * 0 - success | |
161 | * -ENOMEM - insufficient memory | |
162 | * -EIO - i/o error | |
163 | */ | |
164 | int dbMount(struct inode *ipbmap) | |
165 | { | |
166 | struct bmap *bmp; | |
167 | struct dbmap_disk *dbmp_le; | |
168 | struct metapage *mp; | |
169 | int i; | |
170 | ||
171 | /* | |
172 | * allocate/initialize the in-memory bmap descriptor | |
173 | */ | |
174 | /* allocate memory for the in-memory bmap descriptor */ | |
175 | bmp = kmalloc(sizeof(struct bmap), GFP_KERNEL); | |
176 | if (bmp == NULL) | |
177 | return -ENOMEM; | |
178 | ||
179 | /* read the on-disk bmap descriptor. */ | |
180 | mp = read_metapage(ipbmap, | |
181 | BMAPBLKNO << JFS_SBI(ipbmap->i_sb)->l2nbperpage, | |
182 | PSIZE, 0); | |
183 | if (mp == NULL) { | |
184 | kfree(bmp); | |
185 | return -EIO; | |
186 | } | |
187 | ||
188 | /* copy the on-disk bmap descriptor to its in-memory version. */ | |
189 | dbmp_le = (struct dbmap_disk *) mp->data; | |
190 | bmp->db_mapsize = le64_to_cpu(dbmp_le->dn_mapsize); | |
191 | bmp->db_nfree = le64_to_cpu(dbmp_le->dn_nfree); | |
192 | bmp->db_l2nbperpage = le32_to_cpu(dbmp_le->dn_l2nbperpage); | |
193 | bmp->db_numag = le32_to_cpu(dbmp_le->dn_numag); | |
194 | bmp->db_maxlevel = le32_to_cpu(dbmp_le->dn_maxlevel); | |
195 | bmp->db_maxag = le32_to_cpu(dbmp_le->dn_maxag); | |
196 | bmp->db_agpref = le32_to_cpu(dbmp_le->dn_agpref); | |
197 | bmp->db_aglevel = le32_to_cpu(dbmp_le->dn_aglevel); | |
198 | bmp->db_agheigth = le32_to_cpu(dbmp_le->dn_agheigth); | |
199 | bmp->db_agwidth = le32_to_cpu(dbmp_le->dn_agwidth); | |
200 | bmp->db_agstart = le32_to_cpu(dbmp_le->dn_agstart); | |
201 | bmp->db_agl2size = le32_to_cpu(dbmp_le->dn_agl2size); | |
202 | for (i = 0; i < MAXAG; i++) | |
203 | bmp->db_agfree[i] = le64_to_cpu(dbmp_le->dn_agfree[i]); | |
204 | bmp->db_agsize = le64_to_cpu(dbmp_le->dn_agsize); | |
205 | bmp->db_maxfreebud = dbmp_le->dn_maxfreebud; | |
206 | ||
207 | /* release the buffer. */ | |
208 | release_metapage(mp); | |
209 | ||
210 | /* bind the bmap inode and the bmap descriptor to each other. */ | |
211 | bmp->db_ipbmap = ipbmap; | |
212 | JFS_SBI(ipbmap->i_sb)->bmap = bmp; | |
213 | ||
214 | memset(bmp->db_active, 0, sizeof(bmp->db_active)); | |
1da177e4 LT |
215 | |
216 | /* | |
217 | * allocate/initialize the bmap lock | |
218 | */ | |
219 | BMAP_LOCK_INIT(bmp); | |
220 | ||
221 | return (0); | |
222 | } | |
223 | ||
224 | ||
225 | /* | |
226 | * NAME: dbUnmount() | |
227 | * | |
228 | * FUNCTION: terminate the block allocation map in preparation for | |
229 | * file system unmount. | |
230 | * | |
231 | * the in-core bmap descriptor is written to disk and | |
232 | * the memory for this descriptor is freed. | |
233 | * | |
234 | * PARAMETERS: | |
235 | * ipbmap - pointer to in-core inode for the block map. | |
236 | * | |
237 | * RETURN VALUES: | |
238 | * 0 - success | |
239 | * -EIO - i/o error | |
240 | */ | |
241 | int dbUnmount(struct inode *ipbmap, int mounterror) | |
242 | { | |
243 | struct bmap *bmp = JFS_SBI(ipbmap->i_sb)->bmap; | |
1da177e4 LT |
244 | |
245 | if (!(mounterror || isReadOnly(ipbmap))) | |
246 | dbSync(ipbmap); | |
247 | ||
248 | /* | |
249 | * Invalidate the page cache buffers | |
250 | */ | |
251 | truncate_inode_pages(ipbmap->i_mapping, 0); | |
252 | ||
1da177e4 LT |
253 | /* free the memory for the in-memory bmap. */ |
254 | kfree(bmp); | |
255 | ||
256 | return (0); | |
257 | } | |
258 | ||
259 | /* | |
260 | * dbSync() | |
261 | */ | |
262 | int dbSync(struct inode *ipbmap) | |
263 | { | |
264 | struct dbmap_disk *dbmp_le; | |
265 | struct bmap *bmp = JFS_SBI(ipbmap->i_sb)->bmap; | |
266 | struct metapage *mp; | |
267 | int i; | |
268 | ||
269 | /* | |
270 | * write bmap global control page | |
271 | */ | |
272 | /* get the buffer for the on-disk bmap descriptor. */ | |
273 | mp = read_metapage(ipbmap, | |
274 | BMAPBLKNO << JFS_SBI(ipbmap->i_sb)->l2nbperpage, | |
275 | PSIZE, 0); | |
276 | if (mp == NULL) { | |
277 | jfs_err("dbSync: read_metapage failed!"); | |
278 | return -EIO; | |
279 | } | |
280 | /* copy the in-memory version of the bmap to the on-disk version */ | |
281 | dbmp_le = (struct dbmap_disk *) mp->data; | |
282 | dbmp_le->dn_mapsize = cpu_to_le64(bmp->db_mapsize); | |
283 | dbmp_le->dn_nfree = cpu_to_le64(bmp->db_nfree); | |
284 | dbmp_le->dn_l2nbperpage = cpu_to_le32(bmp->db_l2nbperpage); | |
285 | dbmp_le->dn_numag = cpu_to_le32(bmp->db_numag); | |
286 | dbmp_le->dn_maxlevel = cpu_to_le32(bmp->db_maxlevel); | |
287 | dbmp_le->dn_maxag = cpu_to_le32(bmp->db_maxag); | |
288 | dbmp_le->dn_agpref = cpu_to_le32(bmp->db_agpref); | |
289 | dbmp_le->dn_aglevel = cpu_to_le32(bmp->db_aglevel); | |
290 | dbmp_le->dn_agheigth = cpu_to_le32(bmp->db_agheigth); | |
291 | dbmp_le->dn_agwidth = cpu_to_le32(bmp->db_agwidth); | |
292 | dbmp_le->dn_agstart = cpu_to_le32(bmp->db_agstart); | |
293 | dbmp_le->dn_agl2size = cpu_to_le32(bmp->db_agl2size); | |
294 | for (i = 0; i < MAXAG; i++) | |
295 | dbmp_le->dn_agfree[i] = cpu_to_le64(bmp->db_agfree[i]); | |
296 | dbmp_le->dn_agsize = cpu_to_le64(bmp->db_agsize); | |
297 | dbmp_le->dn_maxfreebud = bmp->db_maxfreebud; | |
298 | ||
299 | /* write the buffer */ | |
300 | write_metapage(mp); | |
301 | ||
302 | /* | |
303 | * write out dirty pages of bmap | |
304 | */ | |
305 | filemap_fdatawrite(ipbmap->i_mapping); | |
306 | filemap_fdatawait(ipbmap->i_mapping); | |
307 | ||
1da177e4 LT |
308 | diWriteSpecial(ipbmap, 0); |
309 | ||
310 | return (0); | |
311 | } | |
312 | ||
313 | ||
314 | /* | |
315 | * NAME: dbFree() | |
316 | * | |
317 | * FUNCTION: free the specified block range from the working block | |
318 | * allocation map. | |
319 | * | |
320 | * the blocks will be free from the working map one dmap | |
321 | * at a time. | |
322 | * | |
323 | * PARAMETERS: | |
324 | * ip - pointer to in-core inode; | |
325 | * blkno - starting block number to be freed. | |
326 | * nblocks - number of blocks to be freed. | |
327 | * | |
328 | * RETURN VALUES: | |
329 | * 0 - success | |
330 | * -EIO - i/o error | |
331 | */ | |
332 | int dbFree(struct inode *ip, s64 blkno, s64 nblocks) | |
333 | { | |
334 | struct metapage *mp; | |
335 | struct dmap *dp; | |
336 | int nb, rc; | |
337 | s64 lblkno, rem; | |
338 | struct inode *ipbmap = JFS_SBI(ip->i_sb)->ipbmap; | |
339 | struct bmap *bmp = JFS_SBI(ip->i_sb)->bmap; | |
340 | ||
341 | IREAD_LOCK(ipbmap); | |
342 | ||
343 | /* block to be freed better be within the mapsize. */ | |
344 | if (unlikely((blkno == 0) || (blkno + nblocks > bmp->db_mapsize))) { | |
345 | IREAD_UNLOCK(ipbmap); | |
346 | printk(KERN_ERR "blkno = %Lx, nblocks = %Lx\n", | |
347 | (unsigned long long) blkno, | |
348 | (unsigned long long) nblocks); | |
349 | jfs_error(ip->i_sb, | |
350 | "dbFree: block to be freed is outside the map"); | |
351 | return -EIO; | |
352 | } | |
353 | ||
354 | /* | |
355 | * free the blocks a dmap at a time. | |
356 | */ | |
357 | mp = NULL; | |
358 | for (rem = nblocks; rem > 0; rem -= nb, blkno += nb) { | |
359 | /* release previous dmap if any */ | |
360 | if (mp) { | |
361 | write_metapage(mp); | |
362 | } | |
363 | ||
364 | /* get the buffer for the current dmap. */ | |
365 | lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage); | |
366 | mp = read_metapage(ipbmap, lblkno, PSIZE, 0); | |
367 | if (mp == NULL) { | |
368 | IREAD_UNLOCK(ipbmap); | |
369 | return -EIO; | |
370 | } | |
371 | dp = (struct dmap *) mp->data; | |
372 | ||
373 | /* determine the number of blocks to be freed from | |
374 | * this dmap. | |
375 | */ | |
376 | nb = min(rem, BPERDMAP - (blkno & (BPERDMAP - 1))); | |
377 | ||
1da177e4 LT |
378 | /* free the blocks. */ |
379 | if ((rc = dbFreeDmap(bmp, dp, blkno, nb))) { | |
56d12549 | 380 | jfs_error(ip->i_sb, "dbFree: error in block map\n"); |
1da177e4 LT |
381 | release_metapage(mp); |
382 | IREAD_UNLOCK(ipbmap); | |
383 | return (rc); | |
384 | } | |
1da177e4 LT |
385 | } |
386 | ||
387 | /* write the last buffer. */ | |
388 | write_metapage(mp); | |
389 | ||
390 | IREAD_UNLOCK(ipbmap); | |
391 | ||
392 | return (0); | |
393 | } | |
394 | ||
395 | ||
396 | /* | |
397 | * NAME: dbUpdatePMap() | |
398 | * | |
399 | * FUNCTION: update the allocation state (free or allocate) of the | |
400 | * specified block range in the persistent block allocation map. | |
401 | * | |
402 | * the blocks will be updated in the persistent map one | |
403 | * dmap at a time. | |
404 | * | |
405 | * PARAMETERS: | |
406 | * ipbmap - pointer to in-core inode for the block map. | |
407 | * free - TRUE if block range is to be freed from the persistent | |
408 | * map; FALSE if it is to be allocated. | |
409 | * blkno - starting block number of the range. | |
410 | * nblocks - number of contiguous blocks in the range. | |
411 | * tblk - transaction block; | |
412 | * | |
413 | * RETURN VALUES: | |
414 | * 0 - success | |
415 | * -EIO - i/o error | |
416 | */ | |
417 | int | |
418 | dbUpdatePMap(struct inode *ipbmap, | |
419 | int free, s64 blkno, s64 nblocks, struct tblock * tblk) | |
420 | { | |
421 | int nblks, dbitno, wbitno, rbits; | |
422 | int word, nbits, nwords; | |
423 | struct bmap *bmp = JFS_SBI(ipbmap->i_sb)->bmap; | |
424 | s64 lblkno, rem, lastlblkno; | |
425 | u32 mask; | |
426 | struct dmap *dp; | |
427 | struct metapage *mp; | |
428 | struct jfs_log *log; | |
429 | int lsn, difft, diffp; | |
7fab479b | 430 | unsigned long flags; |
1da177e4 LT |
431 | |
432 | /* the blocks better be within the mapsize. */ | |
433 | if (blkno + nblocks > bmp->db_mapsize) { | |
434 | printk(KERN_ERR "blkno = %Lx, nblocks = %Lx\n", | |
435 | (unsigned long long) blkno, | |
436 | (unsigned long long) nblocks); | |
437 | jfs_error(ipbmap->i_sb, | |
438 | "dbUpdatePMap: blocks are outside the map"); | |
439 | return -EIO; | |
440 | } | |
441 | ||
442 | /* compute delta of transaction lsn from log syncpt */ | |
443 | lsn = tblk->lsn; | |
444 | log = (struct jfs_log *) JFS_SBI(tblk->sb)->log; | |
445 | logdiff(difft, lsn, log); | |
446 | ||
447 | /* | |
448 | * update the block state a dmap at a time. | |
449 | */ | |
450 | mp = NULL; | |
451 | lastlblkno = 0; | |
452 | for (rem = nblocks; rem > 0; rem -= nblks, blkno += nblks) { | |
453 | /* get the buffer for the current dmap. */ | |
454 | lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage); | |
455 | if (lblkno != lastlblkno) { | |
456 | if (mp) { | |
457 | write_metapage(mp); | |
458 | } | |
459 | ||
460 | mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, | |
461 | 0); | |
462 | if (mp == NULL) | |
463 | return -EIO; | |
7fab479b | 464 | metapage_wait_for_io(mp); |
1da177e4 LT |
465 | } |
466 | dp = (struct dmap *) mp->data; | |
467 | ||
468 | /* determine the bit number and word within the dmap of | |
469 | * the starting block. also determine how many blocks | |
470 | * are to be updated within this dmap. | |
471 | */ | |
472 | dbitno = blkno & (BPERDMAP - 1); | |
473 | word = dbitno >> L2DBWORD; | |
474 | nblks = min(rem, (s64)BPERDMAP - dbitno); | |
475 | ||
476 | /* update the bits of the dmap words. the first and last | |
477 | * words may only have a subset of their bits updated. if | |
478 | * this is the case, we'll work against that word (i.e. | |
479 | * partial first and/or last) only in a single pass. a | |
480 | * single pass will also be used to update all words that | |
481 | * are to have all their bits updated. | |
482 | */ | |
483 | for (rbits = nblks; rbits > 0; | |
484 | rbits -= nbits, dbitno += nbits) { | |
485 | /* determine the bit number within the word and | |
486 | * the number of bits within the word. | |
487 | */ | |
488 | wbitno = dbitno & (DBWORD - 1); | |
489 | nbits = min(rbits, DBWORD - wbitno); | |
490 | ||
491 | /* check if only part of the word is to be updated. */ | |
492 | if (nbits < DBWORD) { | |
493 | /* update (free or allocate) the bits | |
494 | * in this word. | |
495 | */ | |
496 | mask = | |
497 | (ONES << (DBWORD - nbits) >> wbitno); | |
498 | if (free) | |
499 | dp->pmap[word] &= | |
500 | cpu_to_le32(~mask); | |
501 | else | |
502 | dp->pmap[word] |= | |
503 | cpu_to_le32(mask); | |
504 | ||
505 | word += 1; | |
506 | } else { | |
507 | /* one or more words are to have all | |
508 | * their bits updated. determine how | |
509 | * many words and how many bits. | |
510 | */ | |
511 | nwords = rbits >> L2DBWORD; | |
512 | nbits = nwords << L2DBWORD; | |
513 | ||
514 | /* update (free or allocate) the bits | |
515 | * in these words. | |
516 | */ | |
517 | if (free) | |
518 | memset(&dp->pmap[word], 0, | |
519 | nwords * 4); | |
520 | else | |
521 | memset(&dp->pmap[word], (int) ONES, | |
522 | nwords * 4); | |
523 | ||
524 | word += nwords; | |
525 | } | |
526 | } | |
527 | ||
528 | /* | |
529 | * update dmap lsn | |
530 | */ | |
531 | if (lblkno == lastlblkno) | |
532 | continue; | |
533 | ||
534 | lastlblkno = lblkno; | |
535 | ||
536 | if (mp->lsn != 0) { | |
537 | /* inherit older/smaller lsn */ | |
538 | logdiff(diffp, mp->lsn, log); | |
7fab479b | 539 | LOGSYNC_LOCK(log, flags); |
1da177e4 LT |
540 | if (difft < diffp) { |
541 | mp->lsn = lsn; | |
542 | ||
543 | /* move bp after tblock in logsync list */ | |
1da177e4 | 544 | list_move(&mp->synclist, &tblk->synclist); |
1da177e4 LT |
545 | } |
546 | ||
547 | /* inherit younger/larger clsn */ | |
1da177e4 LT |
548 | logdiff(difft, tblk->clsn, log); |
549 | logdiff(diffp, mp->clsn, log); | |
550 | if (difft > diffp) | |
551 | mp->clsn = tblk->clsn; | |
7fab479b | 552 | LOGSYNC_UNLOCK(log, flags); |
1da177e4 LT |
553 | } else { |
554 | mp->log = log; | |
555 | mp->lsn = lsn; | |
556 | ||
557 | /* insert bp after tblock in logsync list */ | |
7fab479b | 558 | LOGSYNC_LOCK(log, flags); |
1da177e4 LT |
559 | |
560 | log->count++; | |
561 | list_add(&mp->synclist, &tblk->synclist); | |
562 | ||
563 | mp->clsn = tblk->clsn; | |
7fab479b | 564 | LOGSYNC_UNLOCK(log, flags); |
1da177e4 LT |
565 | } |
566 | } | |
567 | ||
568 | /* write the last buffer. */ | |
569 | if (mp) { | |
570 | write_metapage(mp); | |
571 | } | |
572 | ||
573 | return (0); | |
574 | } | |
575 | ||
576 | ||
577 | /* | |
578 | * NAME: dbNextAG() | |
579 | * | |
580 | * FUNCTION: find the preferred allocation group for new allocations. | |
581 | * | |
582 | * Within the allocation groups, we maintain a preferred | |
583 | * allocation group which consists of a group with at least | |
584 | * average free space. It is the preferred group that we target | |
585 | * new inode allocation towards. The tie-in between inode | |
586 | * allocation and block allocation occurs as we allocate the | |
587 | * first (data) block of an inode and specify the inode (block) | |
588 | * as the allocation hint for this block. | |
589 | * | |
590 | * We try to avoid having more than one open file growing in | |
591 | * an allocation group, as this will lead to fragmentation. | |
592 | * This differs from the old OS/2 method of trying to keep | |
593 | * empty ags around for large allocations. | |
594 | * | |
595 | * PARAMETERS: | |
596 | * ipbmap - pointer to in-core inode for the block map. | |
597 | * | |
598 | * RETURN VALUES: | |
599 | * the preferred allocation group number. | |
600 | */ | |
601 | int dbNextAG(struct inode *ipbmap) | |
602 | { | |
603 | s64 avgfree; | |
604 | int agpref; | |
605 | s64 hwm = 0; | |
606 | int i; | |
607 | int next_best = -1; | |
608 | struct bmap *bmp = JFS_SBI(ipbmap->i_sb)->bmap; | |
609 | ||
610 | BMAP_LOCK(bmp); | |
611 | ||
612 | /* determine the average number of free blocks within the ags. */ | |
613 | avgfree = (u32)bmp->db_nfree / bmp->db_numag; | |
614 | ||
615 | /* | |
616 | * if the current preferred ag does not have an active allocator | |
617 | * and has at least average freespace, return it | |
618 | */ | |
619 | agpref = bmp->db_agpref; | |
620 | if ((atomic_read(&bmp->db_active[agpref]) == 0) && | |
621 | (bmp->db_agfree[agpref] >= avgfree)) | |
622 | goto unlock; | |
623 | ||
624 | /* From the last preferred ag, find the next one with at least | |
625 | * average free space. | |
626 | */ | |
627 | for (i = 0 ; i < bmp->db_numag; i++, agpref++) { | |
628 | if (agpref == bmp->db_numag) | |
629 | agpref = 0; | |
630 | ||
631 | if (atomic_read(&bmp->db_active[agpref])) | |
632 | /* open file is currently growing in this ag */ | |
633 | continue; | |
634 | if (bmp->db_agfree[agpref] >= avgfree) { | |
635 | /* Return this one */ | |
636 | bmp->db_agpref = agpref; | |
637 | goto unlock; | |
638 | } else if (bmp->db_agfree[agpref] > hwm) { | |
639 | /* Less than avg. freespace, but best so far */ | |
640 | hwm = bmp->db_agfree[agpref]; | |
641 | next_best = agpref; | |
642 | } | |
643 | } | |
644 | ||
645 | /* | |
646 | * If no inactive ag was found with average freespace, use the | |
647 | * next best | |
648 | */ | |
649 | if (next_best != -1) | |
650 | bmp->db_agpref = next_best; | |
651 | /* else leave db_agpref unchanged */ | |
652 | unlock: | |
653 | BMAP_UNLOCK(bmp); | |
654 | ||
655 | /* return the preferred group. | |
656 | */ | |
657 | return (bmp->db_agpref); | |
658 | } | |
659 | ||
660 | /* | |
661 | * NAME: dbAlloc() | |
662 | * | |
663 | * FUNCTION: attempt to allocate a specified number of contiguous free | |
664 | * blocks from the working allocation block map. | |
665 | * | |
666 | * the block allocation policy uses hints and a multi-step | |
667 | * approach. | |
668 | * | |
669 | * for allocation requests smaller than the number of blocks | |
670 | * per dmap, we first try to allocate the new blocks | |
671 | * immediately following the hint. if these blocks are not | |
672 | * available, we try to allocate blocks near the hint. if | |
673 | * no blocks near the hint are available, we next try to | |
674 | * allocate within the same dmap as contains the hint. | |
675 | * | |
676 | * if no blocks are available in the dmap or the allocation | |
677 | * request is larger than the dmap size, we try to allocate | |
678 | * within the same allocation group as contains the hint. if | |
679 | * this does not succeed, we finally try to allocate anywhere | |
680 | * within the aggregate. | |
681 | * | |
682 | * we also try to allocate anywhere within the aggregate for | |
683 | * for allocation requests larger than the allocation group | |
684 | * size or requests that specify no hint value. | |
685 | * | |
686 | * PARAMETERS: | |
687 | * ip - pointer to in-core inode; | |
688 | * hint - allocation hint. | |
689 | * nblocks - number of contiguous blocks in the range. | |
690 | * results - on successful return, set to the starting block number | |
691 | * of the newly allocated contiguous range. | |
692 | * | |
693 | * RETURN VALUES: | |
694 | * 0 - success | |
695 | * -ENOSPC - insufficient disk resources | |
696 | * -EIO - i/o error | |
697 | */ | |
698 | int dbAlloc(struct inode *ip, s64 hint, s64 nblocks, s64 * results) | |
699 | { | |
700 | int rc, agno; | |
701 | struct inode *ipbmap = JFS_SBI(ip->i_sb)->ipbmap; | |
702 | struct bmap *bmp; | |
703 | struct metapage *mp; | |
704 | s64 lblkno, blkno; | |
705 | struct dmap *dp; | |
706 | int l2nb; | |
707 | s64 mapSize; | |
708 | int writers; | |
709 | ||
710 | /* assert that nblocks is valid */ | |
711 | assert(nblocks > 0); | |
712 | ||
713 | #ifdef _STILL_TO_PORT | |
714 | /* DASD limit check F226941 */ | |
715 | if (OVER_LIMIT(ip, nblocks)) | |
716 | return -ENOSPC; | |
717 | #endif /* _STILL_TO_PORT */ | |
718 | ||
719 | /* get the log2 number of blocks to be allocated. | |
720 | * if the number of blocks is not a log2 multiple, | |
721 | * it will be rounded up to the next log2 multiple. | |
722 | */ | |
723 | l2nb = BLKSTOL2(nblocks); | |
724 | ||
725 | bmp = JFS_SBI(ip->i_sb)->bmap; | |
726 | ||
727 | //retry: /* serialize w.r.t.extendfs() */ | |
728 | mapSize = bmp->db_mapsize; | |
729 | ||
730 | /* the hint should be within the map */ | |
731 | if (hint >= mapSize) { | |
732 | jfs_error(ip->i_sb, "dbAlloc: the hint is outside the map"); | |
733 | return -EIO; | |
734 | } | |
735 | ||
736 | /* if the number of blocks to be allocated is greater than the | |
737 | * allocation group size, try to allocate anywhere. | |
738 | */ | |
739 | if (l2nb > bmp->db_agl2size) { | |
740 | IWRITE_LOCK(ipbmap); | |
741 | ||
742 | rc = dbAllocAny(bmp, nblocks, l2nb, results); | |
1da177e4 LT |
743 | |
744 | goto write_unlock; | |
745 | } | |
746 | ||
747 | /* | |
748 | * If no hint, let dbNextAG recommend an allocation group | |
749 | */ | |
750 | if (hint == 0) | |
751 | goto pref_ag; | |
752 | ||
753 | /* we would like to allocate close to the hint. adjust the | |
754 | * hint to the block following the hint since the allocators | |
755 | * will start looking for free space starting at this point. | |
756 | */ | |
757 | blkno = hint + 1; | |
758 | ||
759 | if (blkno >= bmp->db_mapsize) | |
760 | goto pref_ag; | |
761 | ||
762 | agno = blkno >> bmp->db_agl2size; | |
763 | ||
764 | /* check if blkno crosses over into a new allocation group. | |
765 | * if so, check if we should allow allocations within this | |
766 | * allocation group. | |
767 | */ | |
768 | if ((blkno & (bmp->db_agsize - 1)) == 0) | |
769 | /* check if the AG is currenly being written to. | |
770 | * if so, call dbNextAG() to find a non-busy | |
771 | * AG with sufficient free space. | |
772 | */ | |
773 | if (atomic_read(&bmp->db_active[agno])) | |
774 | goto pref_ag; | |
775 | ||
776 | /* check if the allocation request size can be satisfied from a | |
777 | * single dmap. if so, try to allocate from the dmap containing | |
778 | * the hint using a tiered strategy. | |
779 | */ | |
780 | if (nblocks <= BPERDMAP) { | |
781 | IREAD_LOCK(ipbmap); | |
782 | ||
783 | /* get the buffer for the dmap containing the hint. | |
784 | */ | |
785 | rc = -EIO; | |
786 | lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage); | |
787 | mp = read_metapage(ipbmap, lblkno, PSIZE, 0); | |
788 | if (mp == NULL) | |
789 | goto read_unlock; | |
790 | ||
791 | dp = (struct dmap *) mp->data; | |
792 | ||
793 | /* first, try to satisfy the allocation request with the | |
794 | * blocks beginning at the hint. | |
795 | */ | |
796 | if ((rc = dbAllocNext(bmp, dp, blkno, (int) nblocks)) | |
797 | != -ENOSPC) { | |
798 | if (rc == 0) { | |
799 | *results = blkno; | |
1da177e4 LT |
800 | mark_metapage_dirty(mp); |
801 | } | |
802 | ||
803 | release_metapage(mp); | |
804 | goto read_unlock; | |
805 | } | |
806 | ||
807 | writers = atomic_read(&bmp->db_active[agno]); | |
808 | if ((writers > 1) || | |
809 | ((writers == 1) && (JFS_IP(ip)->active_ag != agno))) { | |
810 | /* | |
811 | * Someone else is writing in this allocation | |
812 | * group. To avoid fragmenting, try another ag | |
813 | */ | |
814 | release_metapage(mp); | |
815 | IREAD_UNLOCK(ipbmap); | |
816 | goto pref_ag; | |
817 | } | |
818 | ||
819 | /* next, try to satisfy the allocation request with blocks | |
820 | * near the hint. | |
821 | */ | |
822 | if ((rc = | |
823 | dbAllocNear(bmp, dp, blkno, (int) nblocks, l2nb, results)) | |
824 | != -ENOSPC) { | |
b38a3ab3 | 825 | if (rc == 0) |
1da177e4 | 826 | mark_metapage_dirty(mp); |
1da177e4 LT |
827 | |
828 | release_metapage(mp); | |
829 | goto read_unlock; | |
830 | } | |
831 | ||
832 | /* try to satisfy the allocation request with blocks within | |
833 | * the same dmap as the hint. | |
834 | */ | |
835 | if ((rc = dbAllocDmapLev(bmp, dp, (int) nblocks, l2nb, results)) | |
836 | != -ENOSPC) { | |
b38a3ab3 | 837 | if (rc == 0) |
1da177e4 | 838 | mark_metapage_dirty(mp); |
1da177e4 LT |
839 | |
840 | release_metapage(mp); | |
841 | goto read_unlock; | |
842 | } | |
843 | ||
844 | release_metapage(mp); | |
845 | IREAD_UNLOCK(ipbmap); | |
846 | } | |
847 | ||
848 | /* try to satisfy the allocation request with blocks within | |
849 | * the same allocation group as the hint. | |
850 | */ | |
851 | IWRITE_LOCK(ipbmap); | |
b38a3ab3 | 852 | if ((rc = dbAllocAG(bmp, agno, nblocks, l2nb, results)) != -ENOSPC) |
1da177e4 | 853 | goto write_unlock; |
b38a3ab3 | 854 | |
1da177e4 LT |
855 | IWRITE_UNLOCK(ipbmap); |
856 | ||
857 | ||
858 | pref_ag: | |
859 | /* | |
860 | * Let dbNextAG recommend a preferred allocation group | |
861 | */ | |
862 | agno = dbNextAG(ipbmap); | |
863 | IWRITE_LOCK(ipbmap); | |
864 | ||
865 | /* Try to allocate within this allocation group. if that fails, try to | |
866 | * allocate anywhere in the map. | |
867 | */ | |
868 | if ((rc = dbAllocAG(bmp, agno, nblocks, l2nb, results)) == -ENOSPC) | |
869 | rc = dbAllocAny(bmp, nblocks, l2nb, results); | |
1da177e4 LT |
870 | |
871 | write_unlock: | |
872 | IWRITE_UNLOCK(ipbmap); | |
873 | ||
874 | return (rc); | |
875 | ||
876 | read_unlock: | |
877 | IREAD_UNLOCK(ipbmap); | |
878 | ||
879 | return (rc); | |
880 | } | |
881 | ||
882 | #ifdef _NOTYET | |
883 | /* | |
884 | * NAME: dbAllocExact() | |
885 | * | |
886 | * FUNCTION: try to allocate the requested extent; | |
887 | * | |
888 | * PARAMETERS: | |
889 | * ip - pointer to in-core inode; | |
890 | * blkno - extent address; | |
891 | * nblocks - extent length; | |
892 | * | |
893 | * RETURN VALUES: | |
894 | * 0 - success | |
895 | * -ENOSPC - insufficient disk resources | |
896 | * -EIO - i/o error | |
897 | */ | |
898 | int dbAllocExact(struct inode *ip, s64 blkno, int nblocks) | |
899 | { | |
900 | int rc; | |
901 | struct inode *ipbmap = JFS_SBI(ip->i_sb)->ipbmap; | |
902 | struct bmap *bmp = JFS_SBI(ip->i_sb)->bmap; | |
903 | struct dmap *dp; | |
904 | s64 lblkno; | |
905 | struct metapage *mp; | |
906 | ||
907 | IREAD_LOCK(ipbmap); | |
908 | ||
909 | /* | |
910 | * validate extent request: | |
911 | * | |
912 | * note: defragfs policy: | |
913 | * max 64 blocks will be moved. | |
914 | * allocation request size must be satisfied from a single dmap. | |
915 | */ | |
916 | if (nblocks <= 0 || nblocks > BPERDMAP || blkno >= bmp->db_mapsize) { | |
917 | IREAD_UNLOCK(ipbmap); | |
918 | return -EINVAL; | |
919 | } | |
920 | ||
921 | if (nblocks > ((s64) 1 << bmp->db_maxfreebud)) { | |
922 | /* the free space is no longer available */ | |
923 | IREAD_UNLOCK(ipbmap); | |
924 | return -ENOSPC; | |
925 | } | |
926 | ||
927 | /* read in the dmap covering the extent */ | |
928 | lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage); | |
929 | mp = read_metapage(ipbmap, lblkno, PSIZE, 0); | |
930 | if (mp == NULL) { | |
931 | IREAD_UNLOCK(ipbmap); | |
932 | return -EIO; | |
933 | } | |
934 | dp = (struct dmap *) mp->data; | |
935 | ||
936 | /* try to allocate the requested extent */ | |
937 | rc = dbAllocNext(bmp, dp, blkno, nblocks); | |
938 | ||
939 | IREAD_UNLOCK(ipbmap); | |
940 | ||
b38a3ab3 | 941 | if (rc == 0) |
1da177e4 | 942 | mark_metapage_dirty(mp); |
b38a3ab3 | 943 | |
1da177e4 LT |
944 | release_metapage(mp); |
945 | ||
946 | return (rc); | |
947 | } | |
948 | #endif /* _NOTYET */ | |
949 | ||
950 | /* | |
951 | * NAME: dbReAlloc() | |
952 | * | |
953 | * FUNCTION: attempt to extend a current allocation by a specified | |
954 | * number of blocks. | |
955 | * | |
956 | * this routine attempts to satisfy the allocation request | |
957 | * by first trying to extend the existing allocation in | |
958 | * place by allocating the additional blocks as the blocks | |
959 | * immediately following the current allocation. if these | |
960 | * blocks are not available, this routine will attempt to | |
961 | * allocate a new set of contiguous blocks large enough | |
962 | * to cover the existing allocation plus the additional | |
963 | * number of blocks required. | |
964 | * | |
965 | * PARAMETERS: | |
966 | * ip - pointer to in-core inode requiring allocation. | |
967 | * blkno - starting block of the current allocation. | |
968 | * nblocks - number of contiguous blocks within the current | |
969 | * allocation. | |
970 | * addnblocks - number of blocks to add to the allocation. | |
971 | * results - on successful return, set to the starting block number | |
972 | * of the existing allocation if the existing allocation | |
973 | * was extended in place or to a newly allocated contiguous | |
974 | * range if the existing allocation could not be extended | |
975 | * in place. | |
976 | * | |
977 | * RETURN VALUES: | |
978 | * 0 - success | |
979 | * -ENOSPC - insufficient disk resources | |
980 | * -EIO - i/o error | |
981 | */ | |
982 | int | |
983 | dbReAlloc(struct inode *ip, | |
984 | s64 blkno, s64 nblocks, s64 addnblocks, s64 * results) | |
985 | { | |
986 | int rc; | |
987 | ||
988 | /* try to extend the allocation in place. | |
989 | */ | |
990 | if ((rc = dbExtend(ip, blkno, nblocks, addnblocks)) == 0) { | |
991 | *results = blkno; | |
992 | return (0); | |
993 | } else { | |
994 | if (rc != -ENOSPC) | |
995 | return (rc); | |
996 | } | |
997 | ||
998 | /* could not extend the allocation in place, so allocate a | |
999 | * new set of blocks for the entire request (i.e. try to get | |
1000 | * a range of contiguous blocks large enough to cover the | |
1001 | * existing allocation plus the additional blocks.) | |
1002 | */ | |
1003 | return (dbAlloc | |
1004 | (ip, blkno + nblocks - 1, addnblocks + nblocks, results)); | |
1005 | } | |
1006 | ||
1007 | ||
1008 | /* | |
1009 | * NAME: dbExtend() | |
1010 | * | |
1011 | * FUNCTION: attempt to extend a current allocation by a specified | |
1012 | * number of blocks. | |
1013 | * | |
1014 | * this routine attempts to satisfy the allocation request | |
1015 | * by first trying to extend the existing allocation in | |
1016 | * place by allocating the additional blocks as the blocks | |
1017 | * immediately following the current allocation. | |
1018 | * | |
1019 | * PARAMETERS: | |
1020 | * ip - pointer to in-core inode requiring allocation. | |
1021 | * blkno - starting block of the current allocation. | |
1022 | * nblocks - number of contiguous blocks within the current | |
1023 | * allocation. | |
1024 | * addnblocks - number of blocks to add to the allocation. | |
1025 | * | |
1026 | * RETURN VALUES: | |
1027 | * 0 - success | |
1028 | * -ENOSPC - insufficient disk resources | |
1029 | * -EIO - i/o error | |
1030 | */ | |
1031 | static int dbExtend(struct inode *ip, s64 blkno, s64 nblocks, s64 addnblocks) | |
1032 | { | |
1033 | struct jfs_sb_info *sbi = JFS_SBI(ip->i_sb); | |
1034 | s64 lblkno, lastblkno, extblkno; | |
1035 | uint rel_block; | |
1036 | struct metapage *mp; | |
1037 | struct dmap *dp; | |
1038 | int rc; | |
1039 | struct inode *ipbmap = sbi->ipbmap; | |
1040 | struct bmap *bmp; | |
1041 | ||
1042 | /* | |
1043 | * We don't want a non-aligned extent to cross a page boundary | |
1044 | */ | |
1045 | if (((rel_block = blkno & (sbi->nbperpage - 1))) && | |
1046 | (rel_block + nblocks + addnblocks > sbi->nbperpage)) | |
1047 | return -ENOSPC; | |
1048 | ||
1049 | /* get the last block of the current allocation */ | |
1050 | lastblkno = blkno + nblocks - 1; | |
1051 | ||
1052 | /* determine the block number of the block following | |
1053 | * the existing allocation. | |
1054 | */ | |
1055 | extblkno = lastblkno + 1; | |
1056 | ||
1057 | IREAD_LOCK(ipbmap); | |
1058 | ||
1059 | /* better be within the file system */ | |
1060 | bmp = sbi->bmap; | |
1061 | if (lastblkno < 0 || lastblkno >= bmp->db_mapsize) { | |
1062 | IREAD_UNLOCK(ipbmap); | |
1063 | jfs_error(ip->i_sb, | |
1064 | "dbExtend: the block is outside the filesystem"); | |
1065 | return -EIO; | |
1066 | } | |
1067 | ||
1068 | /* we'll attempt to extend the current allocation in place by | |
1069 | * allocating the additional blocks as the blocks immediately | |
1070 | * following the current allocation. we only try to extend the | |
1071 | * current allocation in place if the number of additional blocks | |
1072 | * can fit into a dmap, the last block of the current allocation | |
1073 | * is not the last block of the file system, and the start of the | |
1074 | * inplace extension is not on an allocation group boundary. | |
1075 | */ | |
1076 | if (addnblocks > BPERDMAP || extblkno >= bmp->db_mapsize || | |
1077 | (extblkno & (bmp->db_agsize - 1)) == 0) { | |
1078 | IREAD_UNLOCK(ipbmap); | |
1079 | return -ENOSPC; | |
1080 | } | |
1081 | ||
1082 | /* get the buffer for the dmap containing the first block | |
1083 | * of the extension. | |
1084 | */ | |
1085 | lblkno = BLKTODMAP(extblkno, bmp->db_l2nbperpage); | |
1086 | mp = read_metapage(ipbmap, lblkno, PSIZE, 0); | |
1087 | if (mp == NULL) { | |
1088 | IREAD_UNLOCK(ipbmap); | |
1089 | return -EIO; | |
1090 | } | |
1091 | ||
1da177e4 LT |
1092 | dp = (struct dmap *) mp->data; |
1093 | ||
1094 | /* try to allocate the blocks immediately following the | |
1095 | * current allocation. | |
1096 | */ | |
1097 | rc = dbAllocNext(bmp, dp, extblkno, (int) addnblocks); | |
1098 | ||
1099 | IREAD_UNLOCK(ipbmap); | |
1100 | ||
1101 | /* were we successful ? */ | |
b38a3ab3 | 1102 | if (rc == 0) |
1da177e4 | 1103 | write_metapage(mp); |
b38a3ab3 | 1104 | else |
1da177e4 LT |
1105 | /* we were not successful */ |
1106 | release_metapage(mp); | |
1107 | ||
1108 | ||
1109 | return (rc); | |
1110 | } | |
1111 | ||
1112 | ||
1113 | /* | |
1114 | * NAME: dbAllocNext() | |
1115 | * | |
1116 | * FUNCTION: attempt to allocate the blocks of the specified block | |
1117 | * range within a dmap. | |
1118 | * | |
1119 | * PARAMETERS: | |
1120 | * bmp - pointer to bmap descriptor | |
1121 | * dp - pointer to dmap. | |
1122 | * blkno - starting block number of the range. | |
1123 | * nblocks - number of contiguous free blocks of the range. | |
1124 | * | |
1125 | * RETURN VALUES: | |
1126 | * 0 - success | |
1127 | * -ENOSPC - insufficient disk resources | |
1128 | * -EIO - i/o error | |
1129 | * | |
1130 | * serialization: IREAD_LOCK(ipbmap) held on entry/exit; | |
1131 | */ | |
1132 | static int dbAllocNext(struct bmap * bmp, struct dmap * dp, s64 blkno, | |
1133 | int nblocks) | |
1134 | { | |
1135 | int dbitno, word, rembits, nb, nwords, wbitno, nw; | |
1136 | int l2size; | |
1137 | s8 *leaf; | |
1138 | u32 mask; | |
1139 | ||
1140 | if (dp->tree.leafidx != cpu_to_le32(LEAFIND)) { | |
1141 | jfs_error(bmp->db_ipbmap->i_sb, | |
1142 | "dbAllocNext: Corrupt dmap page"); | |
1143 | return -EIO; | |
1144 | } | |
1145 | ||
1146 | /* pick up a pointer to the leaves of the dmap tree. | |
1147 | */ | |
1148 | leaf = dp->tree.stree + le32_to_cpu(dp->tree.leafidx); | |
1149 | ||
1150 | /* determine the bit number and word within the dmap of the | |
1151 | * starting block. | |
1152 | */ | |
1153 | dbitno = blkno & (BPERDMAP - 1); | |
1154 | word = dbitno >> L2DBWORD; | |
1155 | ||
1156 | /* check if the specified block range is contained within | |
1157 | * this dmap. | |
1158 | */ | |
1159 | if (dbitno + nblocks > BPERDMAP) | |
1160 | return -ENOSPC; | |
1161 | ||
1162 | /* check if the starting leaf indicates that anything | |
1163 | * is free. | |
1164 | */ | |
1165 | if (leaf[word] == NOFREE) | |
1166 | return -ENOSPC; | |
1167 | ||
1168 | /* check the dmaps words corresponding to block range to see | |
1169 | * if the block range is free. not all bits of the first and | |
1170 | * last words may be contained within the block range. if this | |
1171 | * is the case, we'll work against those words (i.e. partial first | |
1172 | * and/or last) on an individual basis (a single pass) and examine | |
1173 | * the actual bits to determine if they are free. a single pass | |
1174 | * will be used for all dmap words fully contained within the | |
1175 | * specified range. within this pass, the leaves of the dmap | |
1176 | * tree will be examined to determine if the blocks are free. a | |
1177 | * single leaf may describe the free space of multiple dmap | |
1178 | * words, so we may visit only a subset of the actual leaves | |
1179 | * corresponding to the dmap words of the block range. | |
1180 | */ | |
1181 | for (rembits = nblocks; rembits > 0; rembits -= nb, dbitno += nb) { | |
1182 | /* determine the bit number within the word and | |
1183 | * the number of bits within the word. | |
1184 | */ | |
1185 | wbitno = dbitno & (DBWORD - 1); | |
1186 | nb = min(rembits, DBWORD - wbitno); | |
1187 | ||
1188 | /* check if only part of the word is to be examined. | |
1189 | */ | |
1190 | if (nb < DBWORD) { | |
1191 | /* check if the bits are free. | |
1192 | */ | |
1193 | mask = (ONES << (DBWORD - nb) >> wbitno); | |
1194 | if ((mask & ~le32_to_cpu(dp->wmap[word])) != mask) | |
1195 | return -ENOSPC; | |
1196 | ||
1197 | word += 1; | |
1198 | } else { | |
1199 | /* one or more dmap words are fully contained | |
1200 | * within the block range. determine how many | |
1201 | * words and how many bits. | |
1202 | */ | |
1203 | nwords = rembits >> L2DBWORD; | |
1204 | nb = nwords << L2DBWORD; | |
1205 | ||
1206 | /* now examine the appropriate leaves to determine | |
1207 | * if the blocks are free. | |
1208 | */ | |
1209 | while (nwords > 0) { | |
1210 | /* does the leaf describe any free space ? | |
1211 | */ | |
1212 | if (leaf[word] < BUDMIN) | |
1213 | return -ENOSPC; | |
1214 | ||
1215 | /* determine the l2 number of bits provided | |
1216 | * by this leaf. | |
1217 | */ | |
1218 | l2size = | |
1219 | min((int)leaf[word], NLSTOL2BSZ(nwords)); | |
1220 | ||
1221 | /* determine how many words were handled. | |
1222 | */ | |
1223 | nw = BUDSIZE(l2size, BUDMIN); | |
1224 | ||
1225 | nwords -= nw; | |
1226 | word += nw; | |
1227 | } | |
1228 | } | |
1229 | } | |
1230 | ||
1231 | /* allocate the blocks. | |
1232 | */ | |
1233 | return (dbAllocDmap(bmp, dp, blkno, nblocks)); | |
1234 | } | |
1235 | ||
1236 | ||
1237 | /* | |
1238 | * NAME: dbAllocNear() | |
1239 | * | |
1240 | * FUNCTION: attempt to allocate a number of contiguous free blocks near | |
1241 | * a specified block (hint) within a dmap. | |
1242 | * | |
1243 | * starting with the dmap leaf that covers the hint, we'll | |
1244 | * check the next four contiguous leaves for sufficient free | |
1245 | * space. if sufficient free space is found, we'll allocate | |
1246 | * the desired free space. | |
1247 | * | |
1248 | * PARAMETERS: | |
1249 | * bmp - pointer to bmap descriptor | |
1250 | * dp - pointer to dmap. | |
1251 | * blkno - block number to allocate near. | |
1252 | * nblocks - actual number of contiguous free blocks desired. | |
1253 | * l2nb - log2 number of contiguous free blocks desired. | |
1254 | * results - on successful return, set to the starting block number | |
1255 | * of the newly allocated range. | |
1256 | * | |
1257 | * RETURN VALUES: | |
1258 | * 0 - success | |
1259 | * -ENOSPC - insufficient disk resources | |
1260 | * -EIO - i/o error | |
1261 | * | |
1262 | * serialization: IREAD_LOCK(ipbmap) held on entry/exit; | |
1263 | */ | |
1264 | static int | |
1265 | dbAllocNear(struct bmap * bmp, | |
1266 | struct dmap * dp, s64 blkno, int nblocks, int l2nb, s64 * results) | |
1267 | { | |
1268 | int word, lword, rc; | |
1269 | s8 *leaf; | |
1270 | ||
1271 | if (dp->tree.leafidx != cpu_to_le32(LEAFIND)) { | |
1272 | jfs_error(bmp->db_ipbmap->i_sb, | |
1273 | "dbAllocNear: Corrupt dmap page"); | |
1274 | return -EIO; | |
1275 | } | |
1276 | ||
1277 | leaf = dp->tree.stree + le32_to_cpu(dp->tree.leafidx); | |
1278 | ||
1279 | /* determine the word within the dmap that holds the hint | |
1280 | * (i.e. blkno). also, determine the last word in the dmap | |
1281 | * that we'll include in our examination. | |
1282 | */ | |
1283 | word = (blkno & (BPERDMAP - 1)) >> L2DBWORD; | |
1284 | lword = min(word + 4, LPERDMAP); | |
1285 | ||
1286 | /* examine the leaves for sufficient free space. | |
1287 | */ | |
1288 | for (; word < lword; word++) { | |
1289 | /* does the leaf describe sufficient free space ? | |
1290 | */ | |
1291 | if (leaf[word] < l2nb) | |
1292 | continue; | |
1293 | ||
1294 | /* determine the block number within the file system | |
1295 | * of the first block described by this dmap word. | |
1296 | */ | |
1297 | blkno = le64_to_cpu(dp->start) + (word << L2DBWORD); | |
1298 | ||
1299 | /* if not all bits of the dmap word are free, get the | |
1300 | * starting bit number within the dmap word of the required | |
1301 | * string of free bits and adjust the block number with the | |
1302 | * value. | |
1303 | */ | |
1304 | if (leaf[word] < BUDMIN) | |
1305 | blkno += | |
1306 | dbFindBits(le32_to_cpu(dp->wmap[word]), l2nb); | |
1307 | ||
1308 | /* allocate the blocks. | |
1309 | */ | |
1310 | if ((rc = dbAllocDmap(bmp, dp, blkno, nblocks)) == 0) | |
1311 | *results = blkno; | |
1312 | ||
1313 | return (rc); | |
1314 | } | |
1315 | ||
1316 | return -ENOSPC; | |
1317 | } | |
1318 | ||
1319 | ||
1320 | /* | |
1321 | * NAME: dbAllocAG() | |
1322 | * | |
1323 | * FUNCTION: attempt to allocate the specified number of contiguous | |
1324 | * free blocks within the specified allocation group. | |
1325 | * | |
1326 | * unless the allocation group size is equal to the number | |
1327 | * of blocks per dmap, the dmap control pages will be used to | |
1328 | * find the required free space, if available. we start the | |
1329 | * search at the highest dmap control page level which | |
1330 | * distinctly describes the allocation group's free space | |
1331 | * (i.e. the highest level at which the allocation group's | |
1332 | * free space is not mixed in with that of any other group). | |
1333 | * in addition, we start the search within this level at a | |
1334 | * height of the dmapctl dmtree at which the nodes distinctly | |
1335 | * describe the allocation group's free space. at this height, | |
1336 | * the allocation group's free space may be represented by 1 | |
1337 | * or two sub-trees, depending on the allocation group size. | |
1338 | * we search the top nodes of these subtrees left to right for | |
1339 | * sufficient free space. if sufficient free space is found, | |
1340 | * the subtree is searched to find the leftmost leaf that | |
1341 | * has free space. once we have made it to the leaf, we | |
1342 | * move the search to the next lower level dmap control page | |
1343 | * corresponding to this leaf. we continue down the dmap control | |
1344 | * pages until we find the dmap that contains or starts the | |
1345 | * sufficient free space and we allocate at this dmap. | |
1346 | * | |
1347 | * if the allocation group size is equal to the dmap size, | |
1348 | * we'll start at the dmap corresponding to the allocation | |
1349 | * group and attempt the allocation at this level. | |
1350 | * | |
1351 | * the dmap control page search is also not performed if the | |
1352 | * allocation group is completely free and we go to the first | |
1353 | * dmap of the allocation group to do the allocation. this is | |
1354 | * done because the allocation group may be part (not the first | |
1355 | * part) of a larger binary buddy system, causing the dmap | |
1356 | * control pages to indicate no free space (NOFREE) within | |
1357 | * the allocation group. | |
1358 | * | |
1359 | * PARAMETERS: | |
1360 | * bmp - pointer to bmap descriptor | |
1361 | * agno - allocation group number. | |
1362 | * nblocks - actual number of contiguous free blocks desired. | |
1363 | * l2nb - log2 number of contiguous free blocks desired. | |
1364 | * results - on successful return, set to the starting block number | |
1365 | * of the newly allocated range. | |
1366 | * | |
1367 | * RETURN VALUES: | |
1368 | * 0 - success | |
1369 | * -ENOSPC - insufficient disk resources | |
1370 | * -EIO - i/o error | |
1371 | * | |
1372 | * note: IWRITE_LOCK(ipmap) held on entry/exit; | |
1373 | */ | |
1374 | static int | |
1375 | dbAllocAG(struct bmap * bmp, int agno, s64 nblocks, int l2nb, s64 * results) | |
1376 | { | |
1377 | struct metapage *mp; | |
1378 | struct dmapctl *dcp; | |
1379 | int rc, ti, i, k, m, n, agperlev; | |
1380 | s64 blkno, lblkno; | |
1381 | int budmin; | |
1382 | ||
1383 | /* allocation request should not be for more than the | |
1384 | * allocation group size. | |
1385 | */ | |
1386 | if (l2nb > bmp->db_agl2size) { | |
1387 | jfs_error(bmp->db_ipbmap->i_sb, | |
1388 | "dbAllocAG: allocation request is larger than the " | |
1389 | "allocation group size"); | |
1390 | return -EIO; | |
1391 | } | |
1392 | ||
1393 | /* determine the starting block number of the allocation | |
1394 | * group. | |
1395 | */ | |
1396 | blkno = (s64) agno << bmp->db_agl2size; | |
1397 | ||
1398 | /* check if the allocation group size is the minimum allocation | |
1399 | * group size or if the allocation group is completely free. if | |
1400 | * the allocation group size is the minimum size of BPERDMAP (i.e. | |
1401 | * 1 dmap), there is no need to search the dmap control page (below) | |
1402 | * that fully describes the allocation group since the allocation | |
1403 | * group is already fully described by a dmap. in this case, we | |
1404 | * just call dbAllocCtl() to search the dmap tree and allocate the | |
1405 | * required space if available. | |
1406 | * | |
1407 | * if the allocation group is completely free, dbAllocCtl() is | |
1408 | * also called to allocate the required space. this is done for | |
1409 | * two reasons. first, it makes no sense searching the dmap control | |
1410 | * pages for free space when we know that free space exists. second, | |
1411 | * the dmap control pages may indicate that the allocation group | |
1412 | * has no free space if the allocation group is part (not the first | |
1413 | * part) of a larger binary buddy system. | |
1414 | */ | |
1415 | if (bmp->db_agsize == BPERDMAP | |
1416 | || bmp->db_agfree[agno] == bmp->db_agsize) { | |
1417 | rc = dbAllocCtl(bmp, nblocks, l2nb, blkno, results); | |
1418 | if ((rc == -ENOSPC) && | |
1419 | (bmp->db_agfree[agno] == bmp->db_agsize)) { | |
1420 | printk(KERN_ERR "blkno = %Lx, blocks = %Lx\n", | |
1421 | (unsigned long long) blkno, | |
1422 | (unsigned long long) nblocks); | |
1423 | jfs_error(bmp->db_ipbmap->i_sb, | |
1424 | "dbAllocAG: dbAllocCtl failed in free AG"); | |
1425 | } | |
1426 | return (rc); | |
1427 | } | |
1428 | ||
1429 | /* the buffer for the dmap control page that fully describes the | |
1430 | * allocation group. | |
1431 | */ | |
1432 | lblkno = BLKTOCTL(blkno, bmp->db_l2nbperpage, bmp->db_aglevel); | |
1433 | mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0); | |
1434 | if (mp == NULL) | |
1435 | return -EIO; | |
1436 | dcp = (struct dmapctl *) mp->data; | |
1437 | budmin = dcp->budmin; | |
1438 | ||
1439 | if (dcp->leafidx != cpu_to_le32(CTLLEAFIND)) { | |
1440 | jfs_error(bmp->db_ipbmap->i_sb, | |
1441 | "dbAllocAG: Corrupt dmapctl page"); | |
1442 | release_metapage(mp); | |
1443 | return -EIO; | |
1444 | } | |
1445 | ||
1446 | /* search the subtree(s) of the dmap control page that describes | |
1447 | * the allocation group, looking for sufficient free space. to begin, | |
1448 | * determine how many allocation groups are represented in a dmap | |
1449 | * control page at the control page level (i.e. L0, L1, L2) that | |
1450 | * fully describes an allocation group. next, determine the starting | |
1451 | * tree index of this allocation group within the control page. | |
1452 | */ | |
1453 | agperlev = | |
1454 | (1 << (L2LPERCTL - (bmp->db_agheigth << 1))) / bmp->db_agwidth; | |
1455 | ti = bmp->db_agstart + bmp->db_agwidth * (agno & (agperlev - 1)); | |
1456 | ||
1457 | /* dmap control page trees fan-out by 4 and a single allocation | |
1458 | * group may be described by 1 or 2 subtrees within the ag level | |
1459 | * dmap control page, depending upon the ag size. examine the ag's | |
1460 | * subtrees for sufficient free space, starting with the leftmost | |
1461 | * subtree. | |
1462 | */ | |
1463 | for (i = 0; i < bmp->db_agwidth; i++, ti++) { | |
1464 | /* is there sufficient free space ? | |
1465 | */ | |
1466 | if (l2nb > dcp->stree[ti]) | |
1467 | continue; | |
1468 | ||
1469 | /* sufficient free space found in a subtree. now search down | |
1470 | * the subtree to find the leftmost leaf that describes this | |
1471 | * free space. | |
1472 | */ | |
1473 | for (k = bmp->db_agheigth; k > 0; k--) { | |
1474 | for (n = 0, m = (ti << 2) + 1; n < 4; n++) { | |
1475 | if (l2nb <= dcp->stree[m + n]) { | |
1476 | ti = m + n; | |
1477 | break; | |
1478 | } | |
1479 | } | |
1480 | if (n == 4) { | |
1481 | jfs_error(bmp->db_ipbmap->i_sb, | |
1482 | "dbAllocAG: failed descending stree"); | |
1483 | release_metapage(mp); | |
1484 | return -EIO; | |
1485 | } | |
1486 | } | |
1487 | ||
1488 | /* determine the block number within the file system | |
1489 | * that corresponds to this leaf. | |
1490 | */ | |
1491 | if (bmp->db_aglevel == 2) | |
1492 | blkno = 0; | |
1493 | else if (bmp->db_aglevel == 1) | |
1494 | blkno &= ~(MAXL1SIZE - 1); | |
1495 | else /* bmp->db_aglevel == 0 */ | |
1496 | blkno &= ~(MAXL0SIZE - 1); | |
1497 | ||
1498 | blkno += | |
1499 | ((s64) (ti - le32_to_cpu(dcp->leafidx))) << budmin; | |
1500 | ||
1501 | /* release the buffer in preparation for going down | |
1502 | * the next level of dmap control pages. | |
1503 | */ | |
1504 | release_metapage(mp); | |
1505 | ||
1506 | /* check if we need to continue to search down the lower | |
1507 | * level dmap control pages. we need to if the number of | |
1508 | * blocks required is less than maximum number of blocks | |
1509 | * described at the next lower level. | |
1510 | */ | |
1511 | if (l2nb < budmin) { | |
1512 | ||
1513 | /* search the lower level dmap control pages to get | |
1514 | * the starting block number of the the dmap that | |
1515 | * contains or starts off the free space. | |
1516 | */ | |
1517 | if ((rc = | |
1518 | dbFindCtl(bmp, l2nb, bmp->db_aglevel - 1, | |
1519 | &blkno))) { | |
1520 | if (rc == -ENOSPC) { | |
1521 | jfs_error(bmp->db_ipbmap->i_sb, | |
1522 | "dbAllocAG: control page " | |
1523 | "inconsistent"); | |
1524 | return -EIO; | |
1525 | } | |
1526 | return (rc); | |
1527 | } | |
1528 | } | |
1529 | ||
1530 | /* allocate the blocks. | |
1531 | */ | |
1532 | rc = dbAllocCtl(bmp, nblocks, l2nb, blkno, results); | |
1533 | if (rc == -ENOSPC) { | |
1534 | jfs_error(bmp->db_ipbmap->i_sb, | |
1535 | "dbAllocAG: unable to allocate blocks"); | |
1536 | rc = -EIO; | |
1537 | } | |
1538 | return (rc); | |
1539 | } | |
1540 | ||
1541 | /* no space in the allocation group. release the buffer and | |
1542 | * return -ENOSPC. | |
1543 | */ | |
1544 | release_metapage(mp); | |
1545 | ||
1546 | return -ENOSPC; | |
1547 | } | |
1548 | ||
1549 | ||
1550 | /* | |
1551 | * NAME: dbAllocAny() | |
1552 | * | |
1553 | * FUNCTION: attempt to allocate the specified number of contiguous | |
1554 | * free blocks anywhere in the file system. | |
1555 | * | |
1556 | * dbAllocAny() attempts to find the sufficient free space by | |
1557 | * searching down the dmap control pages, starting with the | |
1558 | * highest level (i.e. L0, L1, L2) control page. if free space | |
1559 | * large enough to satisfy the desired free space is found, the | |
1560 | * desired free space is allocated. | |
1561 | * | |
1562 | * PARAMETERS: | |
1563 | * bmp - pointer to bmap descriptor | |
1564 | * nblocks - actual number of contiguous free blocks desired. | |
1565 | * l2nb - log2 number of contiguous free blocks desired. | |
1566 | * results - on successful return, set to the starting block number | |
1567 | * of the newly allocated range. | |
1568 | * | |
1569 | * RETURN VALUES: | |
1570 | * 0 - success | |
1571 | * -ENOSPC - insufficient disk resources | |
1572 | * -EIO - i/o error | |
1573 | * | |
1574 | * serialization: IWRITE_LOCK(ipbmap) held on entry/exit; | |
1575 | */ | |
1576 | static int dbAllocAny(struct bmap * bmp, s64 nblocks, int l2nb, s64 * results) | |
1577 | { | |
1578 | int rc; | |
1579 | s64 blkno = 0; | |
1580 | ||
1581 | /* starting with the top level dmap control page, search | |
1582 | * down the dmap control levels for sufficient free space. | |
1583 | * if free space is found, dbFindCtl() returns the starting | |
1584 | * block number of the dmap that contains or starts off the | |
1585 | * range of free space. | |
1586 | */ | |
1587 | if ((rc = dbFindCtl(bmp, l2nb, bmp->db_maxlevel, &blkno))) | |
1588 | return (rc); | |
1589 | ||
1590 | /* allocate the blocks. | |
1591 | */ | |
1592 | rc = dbAllocCtl(bmp, nblocks, l2nb, blkno, results); | |
1593 | if (rc == -ENOSPC) { | |
1594 | jfs_error(bmp->db_ipbmap->i_sb, | |
1595 | "dbAllocAny: unable to allocate blocks"); | |
1596 | return -EIO; | |
1597 | } | |
1598 | return (rc); | |
1599 | } | |
1600 | ||
1601 | ||
1602 | /* | |
1603 | * NAME: dbFindCtl() | |
1604 | * | |
1605 | * FUNCTION: starting at a specified dmap control page level and block | |
1606 | * number, search down the dmap control levels for a range of | |
1607 | * contiguous free blocks large enough to satisfy an allocation | |
1608 | * request for the specified number of free blocks. | |
1609 | * | |
1610 | * if sufficient contiguous free blocks are found, this routine | |
1611 | * returns the starting block number within a dmap page that | |
1612 | * contains or starts a range of contiqious free blocks that | |
1613 | * is sufficient in size. | |
1614 | * | |
1615 | * PARAMETERS: | |
1616 | * bmp - pointer to bmap descriptor | |
1617 | * level - starting dmap control page level. | |
1618 | * l2nb - log2 number of contiguous free blocks desired. | |
1619 | * *blkno - on entry, starting block number for conducting the search. | |
1620 | * on successful return, the first block within a dmap page | |
1621 | * that contains or starts a range of contiguous free blocks. | |
1622 | * | |
1623 | * RETURN VALUES: | |
1624 | * 0 - success | |
1625 | * -ENOSPC - insufficient disk resources | |
1626 | * -EIO - i/o error | |
1627 | * | |
1628 | * serialization: IWRITE_LOCK(ipbmap) held on entry/exit; | |
1629 | */ | |
1630 | static int dbFindCtl(struct bmap * bmp, int l2nb, int level, s64 * blkno) | |
1631 | { | |
1632 | int rc, leafidx, lev; | |
1633 | s64 b, lblkno; | |
1634 | struct dmapctl *dcp; | |
1635 | int budmin; | |
1636 | struct metapage *mp; | |
1637 | ||
1638 | /* starting at the specified dmap control page level and block | |
1639 | * number, search down the dmap control levels for the starting | |
1640 | * block number of a dmap page that contains or starts off | |
1641 | * sufficient free blocks. | |
1642 | */ | |
1643 | for (lev = level, b = *blkno; lev >= 0; lev--) { | |
1644 | /* get the buffer of the dmap control page for the block | |
1645 | * number and level (i.e. L0, L1, L2). | |
1646 | */ | |
1647 | lblkno = BLKTOCTL(b, bmp->db_l2nbperpage, lev); | |
1648 | mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0); | |
1649 | if (mp == NULL) | |
1650 | return -EIO; | |
1651 | dcp = (struct dmapctl *) mp->data; | |
1652 | budmin = dcp->budmin; | |
1653 | ||
1654 | if (dcp->leafidx != cpu_to_le32(CTLLEAFIND)) { | |
1655 | jfs_error(bmp->db_ipbmap->i_sb, | |
1656 | "dbFindCtl: Corrupt dmapctl page"); | |
1657 | release_metapage(mp); | |
1658 | return -EIO; | |
1659 | } | |
1660 | ||
1661 | /* search the tree within the dmap control page for | |
1662 | * sufficent free space. if sufficient free space is found, | |
1663 | * dbFindLeaf() returns the index of the leaf at which | |
1664 | * free space was found. | |
1665 | */ | |
1666 | rc = dbFindLeaf((dmtree_t *) dcp, l2nb, &leafidx); | |
1667 | ||
1668 | /* release the buffer. | |
1669 | */ | |
1670 | release_metapage(mp); | |
1671 | ||
1672 | /* space found ? | |
1673 | */ | |
1674 | if (rc) { | |
1675 | if (lev != level) { | |
1676 | jfs_error(bmp->db_ipbmap->i_sb, | |
1677 | "dbFindCtl: dmap inconsistent"); | |
1678 | return -EIO; | |
1679 | } | |
1680 | return -ENOSPC; | |
1681 | } | |
1682 | ||
1683 | /* adjust the block number to reflect the location within | |
1684 | * the dmap control page (i.e. the leaf) at which free | |
1685 | * space was found. | |
1686 | */ | |
1687 | b += (((s64) leafidx) << budmin); | |
1688 | ||
1689 | /* we stop the search at this dmap control page level if | |
1690 | * the number of blocks required is greater than or equal | |
1691 | * to the maximum number of blocks described at the next | |
1692 | * (lower) level. | |
1693 | */ | |
1694 | if (l2nb >= budmin) | |
1695 | break; | |
1696 | } | |
1697 | ||
1698 | *blkno = b; | |
1699 | return (0); | |
1700 | } | |
1701 | ||
1702 | ||
1703 | /* | |
1704 | * NAME: dbAllocCtl() | |
1705 | * | |
1706 | * FUNCTION: attempt to allocate a specified number of contiguous | |
1707 | * blocks starting within a specific dmap. | |
1708 | * | |
1709 | * this routine is called by higher level routines that search | |
1710 | * the dmap control pages above the actual dmaps for contiguous | |
1711 | * free space. the result of successful searches by these | |
1712 | * routines are the starting block numbers within dmaps, with | |
1713 | * the dmaps themselves containing the desired contiguous free | |
1714 | * space or starting a contiguous free space of desired size | |
1715 | * that is made up of the blocks of one or more dmaps. these | |
1716 | * calls should not fail due to insufficent resources. | |
1717 | * | |
1718 | * this routine is called in some cases where it is not known | |
1719 | * whether it will fail due to insufficient resources. more | |
1720 | * specifically, this occurs when allocating from an allocation | |
1721 | * group whose size is equal to the number of blocks per dmap. | |
1722 | * in this case, the dmap control pages are not examined prior | |
1723 | * to calling this routine (to save pathlength) and the call | |
1724 | * might fail. | |
1725 | * | |
1726 | * for a request size that fits within a dmap, this routine relies | |
1727 | * upon the dmap's dmtree to find the requested contiguous free | |
1728 | * space. for request sizes that are larger than a dmap, the | |
1729 | * requested free space will start at the first block of the | |
1730 | * first dmap (i.e. blkno). | |
1731 | * | |
1732 | * PARAMETERS: | |
1733 | * bmp - pointer to bmap descriptor | |
1734 | * nblocks - actual number of contiguous free blocks to allocate. | |
1735 | * l2nb - log2 number of contiguous free blocks to allocate. | |
1736 | * blkno - starting block number of the dmap to start the allocation | |
1737 | * from. | |
1738 | * results - on successful return, set to the starting block number | |
1739 | * of the newly allocated range. | |
1740 | * | |
1741 | * RETURN VALUES: | |
1742 | * 0 - success | |
1743 | * -ENOSPC - insufficient disk resources | |
1744 | * -EIO - i/o error | |
1745 | * | |
1746 | * serialization: IWRITE_LOCK(ipbmap) held on entry/exit; | |
1747 | */ | |
1748 | static int | |
1749 | dbAllocCtl(struct bmap * bmp, s64 nblocks, int l2nb, s64 blkno, s64 * results) | |
1750 | { | |
1751 | int rc, nb; | |
1752 | s64 b, lblkno, n; | |
1753 | struct metapage *mp; | |
1754 | struct dmap *dp; | |
1755 | ||
1756 | /* check if the allocation request is confined to a single dmap. | |
1757 | */ | |
1758 | if (l2nb <= L2BPERDMAP) { | |
1759 | /* get the buffer for the dmap. | |
1760 | */ | |
1761 | lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage); | |
1762 | mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0); | |
1763 | if (mp == NULL) | |
1764 | return -EIO; | |
1765 | dp = (struct dmap *) mp->data; | |
1766 | ||
1767 | /* try to allocate the blocks. | |
1768 | */ | |
1769 | rc = dbAllocDmapLev(bmp, dp, (int) nblocks, l2nb, results); | |
1770 | if (rc == 0) | |
1771 | mark_metapage_dirty(mp); | |
1772 | ||
1773 | release_metapage(mp); | |
1774 | ||
1775 | return (rc); | |
1776 | } | |
1777 | ||
1778 | /* allocation request involving multiple dmaps. it must start on | |
1779 | * a dmap boundary. | |
1780 | */ | |
1781 | assert((blkno & (BPERDMAP - 1)) == 0); | |
1782 | ||
1783 | /* allocate the blocks dmap by dmap. | |
1784 | */ | |
1785 | for (n = nblocks, b = blkno; n > 0; n -= nb, b += nb) { | |
1786 | /* get the buffer for the dmap. | |
1787 | */ | |
1788 | lblkno = BLKTODMAP(b, bmp->db_l2nbperpage); | |
1789 | mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0); | |
1790 | if (mp == NULL) { | |
1791 | rc = -EIO; | |
1792 | goto backout; | |
1793 | } | |
1794 | dp = (struct dmap *) mp->data; | |
1795 | ||
1796 | /* the dmap better be all free. | |
1797 | */ | |
1798 | if (dp->tree.stree[ROOT] != L2BPERDMAP) { | |
1799 | release_metapage(mp); | |
1800 | jfs_error(bmp->db_ipbmap->i_sb, | |
1801 | "dbAllocCtl: the dmap is not all free"); | |
1802 | rc = -EIO; | |
1803 | goto backout; | |
1804 | } | |
1805 | ||
1806 | /* determine how many blocks to allocate from this dmap. | |
1807 | */ | |
1808 | nb = min(n, (s64)BPERDMAP); | |
1809 | ||
1810 | /* allocate the blocks from the dmap. | |
1811 | */ | |
1812 | if ((rc = dbAllocDmap(bmp, dp, b, nb))) { | |
1813 | release_metapage(mp); | |
1814 | goto backout; | |
1815 | } | |
1816 | ||
1817 | /* write the buffer. | |
1818 | */ | |
1819 | write_metapage(mp); | |
1820 | } | |
1821 | ||
1822 | /* set the results (starting block number) and return. | |
1823 | */ | |
1824 | *results = blkno; | |
1825 | return (0); | |
1826 | ||
1827 | /* something failed in handling an allocation request involving | |
1828 | * multiple dmaps. we'll try to clean up by backing out any | |
1829 | * allocation that has already happened for this request. if | |
1830 | * we fail in backing out the allocation, we'll mark the file | |
1831 | * system to indicate that blocks have been leaked. | |
1832 | */ | |
1833 | backout: | |
1834 | ||
1835 | /* try to backout the allocations dmap by dmap. | |
1836 | */ | |
1837 | for (n = nblocks - n, b = blkno; n > 0; | |
1838 | n -= BPERDMAP, b += BPERDMAP) { | |
1839 | /* get the buffer for this dmap. | |
1840 | */ | |
1841 | lblkno = BLKTODMAP(b, bmp->db_l2nbperpage); | |
1842 | mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0); | |
1843 | if (mp == NULL) { | |
1844 | /* could not back out. mark the file system | |
1845 | * to indicate that we have leaked blocks. | |
1846 | */ | |
1847 | jfs_error(bmp->db_ipbmap->i_sb, | |
1848 | "dbAllocCtl: I/O Error: Block Leakage."); | |
1849 | continue; | |
1850 | } | |
1851 | dp = (struct dmap *) mp->data; | |
1852 | ||
1853 | /* free the blocks is this dmap. | |
1854 | */ | |
1855 | if (dbFreeDmap(bmp, dp, b, BPERDMAP)) { | |
1856 | /* could not back out. mark the file system | |
1857 | * to indicate that we have leaked blocks. | |
1858 | */ | |
1859 | release_metapage(mp); | |
1860 | jfs_error(bmp->db_ipbmap->i_sb, | |
1861 | "dbAllocCtl: Block Leakage."); | |
1862 | continue; | |
1863 | } | |
1864 | ||
1865 | /* write the buffer. | |
1866 | */ | |
1867 | write_metapage(mp); | |
1868 | } | |
1869 | ||
1870 | return (rc); | |
1871 | } | |
1872 | ||
1873 | ||
1874 | /* | |
1875 | * NAME: dbAllocDmapLev() | |
1876 | * | |
1877 | * FUNCTION: attempt to allocate a specified number of contiguous blocks | |
1878 | * from a specified dmap. | |
1879 | * | |
1880 | * this routine checks if the contiguous blocks are available. | |
1881 | * if so, nblocks of blocks are allocated; otherwise, ENOSPC is | |
1882 | * returned. | |
1883 | * | |
1884 | * PARAMETERS: | |
1885 | * mp - pointer to bmap descriptor | |
1886 | * dp - pointer to dmap to attempt to allocate blocks from. | |
1887 | * l2nb - log2 number of contiguous block desired. | |
1888 | * nblocks - actual number of contiguous block desired. | |
1889 | * results - on successful return, set to the starting block number | |
1890 | * of the newly allocated range. | |
1891 | * | |
1892 | * RETURN VALUES: | |
1893 | * 0 - success | |
1894 | * -ENOSPC - insufficient disk resources | |
1895 | * -EIO - i/o error | |
1896 | * | |
1897 | * serialization: IREAD_LOCK(ipbmap), e.g., from dbAlloc(), or | |
1898 | * IWRITE_LOCK(ipbmap), e.g., dbAllocCtl(), held on entry/exit; | |
1899 | */ | |
1900 | static int | |
1901 | dbAllocDmapLev(struct bmap * bmp, | |
1902 | struct dmap * dp, int nblocks, int l2nb, s64 * results) | |
1903 | { | |
1904 | s64 blkno; | |
1905 | int leafidx, rc; | |
1906 | ||
1907 | /* can't be more than a dmaps worth of blocks */ | |
1908 | assert(l2nb <= L2BPERDMAP); | |
1909 | ||
1910 | /* search the tree within the dmap page for sufficient | |
1911 | * free space. if sufficient free space is found, dbFindLeaf() | |
1912 | * returns the index of the leaf at which free space was found. | |
1913 | */ | |
1914 | if (dbFindLeaf((dmtree_t *) & dp->tree, l2nb, &leafidx)) | |
1915 | return -ENOSPC; | |
1916 | ||
1917 | /* determine the block number within the file system corresponding | |
1918 | * to the leaf at which free space was found. | |
1919 | */ | |
1920 | blkno = le64_to_cpu(dp->start) + (leafidx << L2DBWORD); | |
1921 | ||
1922 | /* if not all bits of the dmap word are free, get the starting | |
1923 | * bit number within the dmap word of the required string of free | |
1924 | * bits and adjust the block number with this value. | |
1925 | */ | |
1926 | if (dp->tree.stree[leafidx + LEAFIND] < BUDMIN) | |
1927 | blkno += dbFindBits(le32_to_cpu(dp->wmap[leafidx]), l2nb); | |
1928 | ||
1929 | /* allocate the blocks */ | |
1930 | if ((rc = dbAllocDmap(bmp, dp, blkno, nblocks)) == 0) | |
1931 | *results = blkno; | |
1932 | ||
1933 | return (rc); | |
1934 | } | |
1935 | ||
1936 | ||
1937 | /* | |
1938 | * NAME: dbAllocDmap() | |
1939 | * | |
1940 | * FUNCTION: adjust the disk allocation map to reflect the allocation | |
1941 | * of a specified block range within a dmap. | |
1942 | * | |
1943 | * this routine allocates the specified blocks from the dmap | |
1944 | * through a call to dbAllocBits(). if the allocation of the | |
1945 | * block range causes the maximum string of free blocks within | |
1946 | * the dmap to change (i.e. the value of the root of the dmap's | |
1947 | * dmtree), this routine will cause this change to be reflected | |
1948 | * up through the appropriate levels of the dmap control pages | |
1949 | * by a call to dbAdjCtl() for the L0 dmap control page that | |
1950 | * covers this dmap. | |
1951 | * | |
1952 | * PARAMETERS: | |
1953 | * bmp - pointer to bmap descriptor | |
1954 | * dp - pointer to dmap to allocate the block range from. | |
1955 | * blkno - starting block number of the block to be allocated. | |
1956 | * nblocks - number of blocks to be allocated. | |
1957 | * | |
1958 | * RETURN VALUES: | |
1959 | * 0 - success | |
1960 | * -EIO - i/o error | |
1961 | * | |
1962 | * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit; | |
1963 | */ | |
1964 | static int dbAllocDmap(struct bmap * bmp, struct dmap * dp, s64 blkno, | |
1965 | int nblocks) | |
1966 | { | |
1967 | s8 oldroot; | |
1968 | int rc; | |
1969 | ||
1970 | /* save the current value of the root (i.e. maximum free string) | |
1971 | * of the dmap tree. | |
1972 | */ | |
1973 | oldroot = dp->tree.stree[ROOT]; | |
1974 | ||
1975 | /* allocate the specified (blocks) bits */ | |
1976 | dbAllocBits(bmp, dp, blkno, nblocks); | |
1977 | ||
1978 | /* if the root has not changed, done. */ | |
1979 | if (dp->tree.stree[ROOT] == oldroot) | |
1980 | return (0); | |
1981 | ||
1982 | /* root changed. bubble the change up to the dmap control pages. | |
1983 | * if the adjustment of the upper level control pages fails, | |
1984 | * backout the bit allocation (thus making everything consistent). | |
1985 | */ | |
1986 | if ((rc = dbAdjCtl(bmp, blkno, dp->tree.stree[ROOT], 1, 0))) | |
1987 | dbFreeBits(bmp, dp, blkno, nblocks); | |
1988 | ||
1989 | return (rc); | |
1990 | } | |
1991 | ||
1992 | ||
1993 | /* | |
1994 | * NAME: dbFreeDmap() | |
1995 | * | |
1996 | * FUNCTION: adjust the disk allocation map to reflect the allocation | |
1997 | * of a specified block range within a dmap. | |
1998 | * | |
1999 | * this routine frees the specified blocks from the dmap through | |
2000 | * a call to dbFreeBits(). if the deallocation of the block range | |
2001 | * causes the maximum string of free blocks within the dmap to | |
2002 | * change (i.e. the value of the root of the dmap's dmtree), this | |
2003 | * routine will cause this change to be reflected up through the | |
2004 | * appropriate levels of the dmap control pages by a call to | |
2005 | * dbAdjCtl() for the L0 dmap control page that covers this dmap. | |
2006 | * | |
2007 | * PARAMETERS: | |
2008 | * bmp - pointer to bmap descriptor | |
2009 | * dp - pointer to dmap to free the block range from. | |
2010 | * blkno - starting block number of the block to be freed. | |
2011 | * nblocks - number of blocks to be freed. | |
2012 | * | |
2013 | * RETURN VALUES: | |
2014 | * 0 - success | |
2015 | * -EIO - i/o error | |
2016 | * | |
2017 | * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit; | |
2018 | */ | |
2019 | static int dbFreeDmap(struct bmap * bmp, struct dmap * dp, s64 blkno, | |
2020 | int nblocks) | |
2021 | { | |
2022 | s8 oldroot; | |
56d12549 | 2023 | int rc = 0, word; |
1da177e4 LT |
2024 | |
2025 | /* save the current value of the root (i.e. maximum free string) | |
2026 | * of the dmap tree. | |
2027 | */ | |
2028 | oldroot = dp->tree.stree[ROOT]; | |
2029 | ||
2030 | /* free the specified (blocks) bits */ | |
56d12549 | 2031 | rc = dbFreeBits(bmp, dp, blkno, nblocks); |
1da177e4 | 2032 | |
56d12549 DK |
2033 | /* if error or the root has not changed, done. */ |
2034 | if (rc || (dp->tree.stree[ROOT] == oldroot)) | |
2035 | return (rc); | |
1da177e4 LT |
2036 | |
2037 | /* root changed. bubble the change up to the dmap control pages. | |
2038 | * if the adjustment of the upper level control pages fails, | |
2039 | * backout the deallocation. | |
2040 | */ | |
2041 | if ((rc = dbAdjCtl(bmp, blkno, dp->tree.stree[ROOT], 0, 0))) { | |
2042 | word = (blkno & (BPERDMAP - 1)) >> L2DBWORD; | |
2043 | ||
2044 | /* as part of backing out the deallocation, we will have | |
2045 | * to back split the dmap tree if the deallocation caused | |
2046 | * the freed blocks to become part of a larger binary buddy | |
2047 | * system. | |
2048 | */ | |
2049 | if (dp->tree.stree[word] == NOFREE) | |
2050 | dbBackSplit((dmtree_t *) & dp->tree, word); | |
2051 | ||
2052 | dbAllocBits(bmp, dp, blkno, nblocks); | |
2053 | } | |
2054 | ||
2055 | return (rc); | |
2056 | } | |
2057 | ||
2058 | ||
2059 | /* | |
2060 | * NAME: dbAllocBits() | |
2061 | * | |
2062 | * FUNCTION: allocate a specified block range from a dmap. | |
2063 | * | |
2064 | * this routine updates the dmap to reflect the working | |
2065 | * state allocation of the specified block range. it directly | |
2066 | * updates the bits of the working map and causes the adjustment | |
2067 | * of the binary buddy system described by the dmap's dmtree | |
2068 | * leaves to reflect the bits allocated. it also causes the | |
2069 | * dmap's dmtree, as a whole, to reflect the allocated range. | |
2070 | * | |
2071 | * PARAMETERS: | |
2072 | * bmp - pointer to bmap descriptor | |
2073 | * dp - pointer to dmap to allocate bits from. | |
2074 | * blkno - starting block number of the bits to be allocated. | |
2075 | * nblocks - number of bits to be allocated. | |
2076 | * | |
2077 | * RETURN VALUES: none | |
2078 | * | |
2079 | * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit; | |
2080 | */ | |
2081 | static void dbAllocBits(struct bmap * bmp, struct dmap * dp, s64 blkno, | |
2082 | int nblocks) | |
2083 | { | |
2084 | int dbitno, word, rembits, nb, nwords, wbitno, nw, agno; | |
2085 | dmtree_t *tp = (dmtree_t *) & dp->tree; | |
2086 | int size; | |
2087 | s8 *leaf; | |
2088 | ||
2089 | /* pick up a pointer to the leaves of the dmap tree */ | |
2090 | leaf = dp->tree.stree + LEAFIND; | |
2091 | ||
2092 | /* determine the bit number and word within the dmap of the | |
2093 | * starting block. | |
2094 | */ | |
2095 | dbitno = blkno & (BPERDMAP - 1); | |
2096 | word = dbitno >> L2DBWORD; | |
2097 | ||
2098 | /* block range better be within the dmap */ | |
2099 | assert(dbitno + nblocks <= BPERDMAP); | |
2100 | ||
2101 | /* allocate the bits of the dmap's words corresponding to the block | |
2102 | * range. not all bits of the first and last words may be contained | |
2103 | * within the block range. if this is the case, we'll work against | |
2104 | * those words (i.e. partial first and/or last) on an individual basis | |
2105 | * (a single pass), allocating the bits of interest by hand and | |
2106 | * updating the leaf corresponding to the dmap word. a single pass | |
2107 | * will be used for all dmap words fully contained within the | |
2108 | * specified range. within this pass, the bits of all fully contained | |
2109 | * dmap words will be marked as free in a single shot and the leaves | |
2110 | * will be updated. a single leaf may describe the free space of | |
2111 | * multiple dmap words, so we may update only a subset of the actual | |
2112 | * leaves corresponding to the dmap words of the block range. | |
2113 | */ | |
2114 | for (rembits = nblocks; rembits > 0; rembits -= nb, dbitno += nb) { | |
2115 | /* determine the bit number within the word and | |
2116 | * the number of bits within the word. | |
2117 | */ | |
2118 | wbitno = dbitno & (DBWORD - 1); | |
2119 | nb = min(rembits, DBWORD - wbitno); | |
2120 | ||
2121 | /* check if only part of a word is to be allocated. | |
2122 | */ | |
2123 | if (nb < DBWORD) { | |
2124 | /* allocate (set to 1) the appropriate bits within | |
2125 | * this dmap word. | |
2126 | */ | |
2127 | dp->wmap[word] |= cpu_to_le32(ONES << (DBWORD - nb) | |
2128 | >> wbitno); | |
2129 | ||
2130 | /* update the leaf for this dmap word. in addition | |
2131 | * to setting the leaf value to the binary buddy max | |
2132 | * of the updated dmap word, dbSplit() will split | |
2133 | * the binary system of the leaves if need be. | |
2134 | */ | |
2135 | dbSplit(tp, word, BUDMIN, | |
2136 | dbMaxBud((u8 *) & dp->wmap[word])); | |
2137 | ||
2138 | word += 1; | |
2139 | } else { | |
2140 | /* one or more dmap words are fully contained | |
2141 | * within the block range. determine how many | |
2142 | * words and allocate (set to 1) the bits of these | |
2143 | * words. | |
2144 | */ | |
2145 | nwords = rembits >> L2DBWORD; | |
2146 | memset(&dp->wmap[word], (int) ONES, nwords * 4); | |
2147 | ||
2148 | /* determine how many bits. | |
2149 | */ | |
2150 | nb = nwords << L2DBWORD; | |
2151 | ||
2152 | /* now update the appropriate leaves to reflect | |
2153 | * the allocated words. | |
2154 | */ | |
2155 | for (; nwords > 0; nwords -= nw) { | |
2156 | if (leaf[word] < BUDMIN) { | |
2157 | jfs_error(bmp->db_ipbmap->i_sb, | |
2158 | "dbAllocBits: leaf page " | |
2159 | "corrupt"); | |
2160 | break; | |
2161 | } | |
2162 | ||
2163 | /* determine what the leaf value should be | |
2164 | * updated to as the minimum of the l2 number | |
2165 | * of bits being allocated and the l2 number | |
2166 | * of bits currently described by this leaf. | |
2167 | */ | |
2168 | size = min((int)leaf[word], NLSTOL2BSZ(nwords)); | |
2169 | ||
2170 | /* update the leaf to reflect the allocation. | |
2171 | * in addition to setting the leaf value to | |
2172 | * NOFREE, dbSplit() will split the binary | |
2173 | * system of the leaves to reflect the current | |
2174 | * allocation (size). | |
2175 | */ | |
2176 | dbSplit(tp, word, size, NOFREE); | |
2177 | ||
2178 | /* get the number of dmap words handled */ | |
2179 | nw = BUDSIZE(size, BUDMIN); | |
2180 | word += nw; | |
2181 | } | |
2182 | } | |
2183 | } | |
2184 | ||
2185 | /* update the free count for this dmap */ | |
2186 | dp->nfree = cpu_to_le32(le32_to_cpu(dp->nfree) - nblocks); | |
2187 | ||
2188 | BMAP_LOCK(bmp); | |
2189 | ||
2190 | /* if this allocation group is completely free, | |
2191 | * update the maximum allocation group number if this allocation | |
2192 | * group is the new max. | |
2193 | */ | |
2194 | agno = blkno >> bmp->db_agl2size; | |
2195 | if (agno > bmp->db_maxag) | |
2196 | bmp->db_maxag = agno; | |
2197 | ||
2198 | /* update the free count for the allocation group and map */ | |
2199 | bmp->db_agfree[agno] -= nblocks; | |
2200 | bmp->db_nfree -= nblocks; | |
2201 | ||
2202 | BMAP_UNLOCK(bmp); | |
2203 | } | |
2204 | ||
2205 | ||
2206 | /* | |
2207 | * NAME: dbFreeBits() | |
2208 | * | |
2209 | * FUNCTION: free a specified block range from a dmap. | |
2210 | * | |
2211 | * this routine updates the dmap to reflect the working | |
2212 | * state allocation of the specified block range. it directly | |
2213 | * updates the bits of the working map and causes the adjustment | |
2214 | * of the binary buddy system described by the dmap's dmtree | |
2215 | * leaves to reflect the bits freed. it also causes the dmap's | |
2216 | * dmtree, as a whole, to reflect the deallocated range. | |
2217 | * | |
2218 | * PARAMETERS: | |
2219 | * bmp - pointer to bmap descriptor | |
2220 | * dp - pointer to dmap to free bits from. | |
2221 | * blkno - starting block number of the bits to be freed. | |
2222 | * nblocks - number of bits to be freed. | |
2223 | * | |
56d12549 | 2224 | * RETURN VALUES: 0 for success |
1da177e4 LT |
2225 | * |
2226 | * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit; | |
2227 | */ | |
56d12549 | 2228 | static int dbFreeBits(struct bmap * bmp, struct dmap * dp, s64 blkno, |
1da177e4 LT |
2229 | int nblocks) |
2230 | { | |
2231 | int dbitno, word, rembits, nb, nwords, wbitno, nw, agno; | |
2232 | dmtree_t *tp = (dmtree_t *) & dp->tree; | |
56d12549 | 2233 | int rc = 0; |
1da177e4 LT |
2234 | int size; |
2235 | ||
2236 | /* determine the bit number and word within the dmap of the | |
2237 | * starting block. | |
2238 | */ | |
2239 | dbitno = blkno & (BPERDMAP - 1); | |
2240 | word = dbitno >> L2DBWORD; | |
2241 | ||
2242 | /* block range better be within the dmap. | |
2243 | */ | |
2244 | assert(dbitno + nblocks <= BPERDMAP); | |
2245 | ||
2246 | /* free the bits of the dmaps words corresponding to the block range. | |
2247 | * not all bits of the first and last words may be contained within | |
2248 | * the block range. if this is the case, we'll work against those | |
2249 | * words (i.e. partial first and/or last) on an individual basis | |
2250 | * (a single pass), freeing the bits of interest by hand and updating | |
2251 | * the leaf corresponding to the dmap word. a single pass will be used | |
2252 | * for all dmap words fully contained within the specified range. | |
2253 | * within this pass, the bits of all fully contained dmap words will | |
2254 | * be marked as free in a single shot and the leaves will be updated. a | |
2255 | * single leaf may describe the free space of multiple dmap words, | |
2256 | * so we may update only a subset of the actual leaves corresponding | |
2257 | * to the dmap words of the block range. | |
2258 | * | |
2259 | * dbJoin() is used to update leaf values and will join the binary | |
2260 | * buddy system of the leaves if the new leaf values indicate this | |
2261 | * should be done. | |
2262 | */ | |
2263 | for (rembits = nblocks; rembits > 0; rembits -= nb, dbitno += nb) { | |
2264 | /* determine the bit number within the word and | |
2265 | * the number of bits within the word. | |
2266 | */ | |
2267 | wbitno = dbitno & (DBWORD - 1); | |
2268 | nb = min(rembits, DBWORD - wbitno); | |
2269 | ||
2270 | /* check if only part of a word is to be freed. | |
2271 | */ | |
2272 | if (nb < DBWORD) { | |
2273 | /* free (zero) the appropriate bits within this | |
2274 | * dmap word. | |
2275 | */ | |
2276 | dp->wmap[word] &= | |
2277 | cpu_to_le32(~(ONES << (DBWORD - nb) | |
2278 | >> wbitno)); | |
2279 | ||
2280 | /* update the leaf for this dmap word. | |
2281 | */ | |
56d12549 DK |
2282 | rc = dbJoin(tp, word, |
2283 | dbMaxBud((u8 *) & dp->wmap[word])); | |
2284 | if (rc) | |
2285 | return rc; | |
1da177e4 LT |
2286 | |
2287 | word += 1; | |
2288 | } else { | |
2289 | /* one or more dmap words are fully contained | |
2290 | * within the block range. determine how many | |
2291 | * words and free (zero) the bits of these words. | |
2292 | */ | |
2293 | nwords = rembits >> L2DBWORD; | |
2294 | memset(&dp->wmap[word], 0, nwords * 4); | |
2295 | ||
2296 | /* determine how many bits. | |
2297 | */ | |
2298 | nb = nwords << L2DBWORD; | |
2299 | ||
2300 | /* now update the appropriate leaves to reflect | |
2301 | * the freed words. | |
2302 | */ | |
2303 | for (; nwords > 0; nwords -= nw) { | |
2304 | /* determine what the leaf value should be | |
2305 | * updated to as the minimum of the l2 number | |
2306 | * of bits being freed and the l2 (max) number | |
2307 | * of bits that can be described by this leaf. | |
2308 | */ | |
2309 | size = | |
2310 | min(LITOL2BSZ | |
2311 | (word, L2LPERDMAP, BUDMIN), | |
2312 | NLSTOL2BSZ(nwords)); | |
2313 | ||
2314 | /* update the leaf. | |
2315 | */ | |
56d12549 DK |
2316 | rc = dbJoin(tp, word, size); |
2317 | if (rc) | |
2318 | return rc; | |
1da177e4 LT |
2319 | |
2320 | /* get the number of dmap words handled. | |
2321 | */ | |
2322 | nw = BUDSIZE(size, BUDMIN); | |
2323 | word += nw; | |
2324 | } | |
2325 | } | |
2326 | } | |
2327 | ||
2328 | /* update the free count for this dmap. | |
2329 | */ | |
2330 | dp->nfree = cpu_to_le32(le32_to_cpu(dp->nfree) + nblocks); | |
2331 | ||
2332 | BMAP_LOCK(bmp); | |
2333 | ||
2334 | /* update the free count for the allocation group and | |
2335 | * map. | |
2336 | */ | |
2337 | agno = blkno >> bmp->db_agl2size; | |
2338 | bmp->db_nfree += nblocks; | |
2339 | bmp->db_agfree[agno] += nblocks; | |
2340 | ||
2341 | /* check if this allocation group is not completely free and | |
2342 | * if it is currently the maximum (rightmost) allocation group. | |
2343 | * if so, establish the new maximum allocation group number by | |
2344 | * searching left for the first allocation group with allocation. | |
2345 | */ | |
2346 | if ((bmp->db_agfree[agno] == bmp->db_agsize && agno == bmp->db_maxag) || | |
2347 | (agno == bmp->db_numag - 1 && | |
2348 | bmp->db_agfree[agno] == (bmp-> db_mapsize & (BPERDMAP - 1)))) { | |
2349 | while (bmp->db_maxag > 0) { | |
2350 | bmp->db_maxag -= 1; | |
2351 | if (bmp->db_agfree[bmp->db_maxag] != | |
2352 | bmp->db_agsize) | |
2353 | break; | |
2354 | } | |
2355 | ||
2356 | /* re-establish the allocation group preference if the | |
2357 | * current preference is right of the maximum allocation | |
2358 | * group. | |
2359 | */ | |
2360 | if (bmp->db_agpref > bmp->db_maxag) | |
2361 | bmp->db_agpref = bmp->db_maxag; | |
2362 | } | |
2363 | ||
2364 | BMAP_UNLOCK(bmp); | |
56d12549 DK |
2365 | |
2366 | return 0; | |
1da177e4 LT |
2367 | } |
2368 | ||
2369 | ||
2370 | /* | |
2371 | * NAME: dbAdjCtl() | |
2372 | * | |
2373 | * FUNCTION: adjust a dmap control page at a specified level to reflect | |
2374 | * the change in a lower level dmap or dmap control page's | |
2375 | * maximum string of free blocks (i.e. a change in the root | |
2376 | * of the lower level object's dmtree) due to the allocation | |
2377 | * or deallocation of a range of blocks with a single dmap. | |
2378 | * | |
2379 | * on entry, this routine is provided with the new value of | |
2380 | * the lower level dmap or dmap control page root and the | |
2381 | * starting block number of the block range whose allocation | |
2382 | * or deallocation resulted in the root change. this range | |
2383 | * is respresented by a single leaf of the current dmapctl | |
2384 | * and the leaf will be updated with this value, possibly | |
2385 | * causing a binary buddy system within the leaves to be | |
2386 | * split or joined. the update may also cause the dmapctl's | |
2387 | * dmtree to be updated. | |
2388 | * | |
2389 | * if the adjustment of the dmap control page, itself, causes its | |
2390 | * root to change, this change will be bubbled up to the next dmap | |
2391 | * control level by a recursive call to this routine, specifying | |
2392 | * the new root value and the next dmap control page level to | |
2393 | * be adjusted. | |
2394 | * PARAMETERS: | |
2395 | * bmp - pointer to bmap descriptor | |
2396 | * blkno - the first block of a block range within a dmap. it is | |
2397 | * the allocation or deallocation of this block range that | |
2398 | * requires the dmap control page to be adjusted. | |
2399 | * newval - the new value of the lower level dmap or dmap control | |
2400 | * page root. | |
2401 | * alloc - TRUE if adjustment is due to an allocation. | |
2402 | * level - current level of dmap control page (i.e. L0, L1, L2) to | |
2403 | * be adjusted. | |
2404 | * | |
2405 | * RETURN VALUES: | |
2406 | * 0 - success | |
2407 | * -EIO - i/o error | |
2408 | * | |
2409 | * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit; | |
2410 | */ | |
2411 | static int | |
2412 | dbAdjCtl(struct bmap * bmp, s64 blkno, int newval, int alloc, int level) | |
2413 | { | |
2414 | struct metapage *mp; | |
2415 | s8 oldroot; | |
2416 | int oldval; | |
2417 | s64 lblkno; | |
2418 | struct dmapctl *dcp; | |
2419 | int rc, leafno, ti; | |
2420 | ||
2421 | /* get the buffer for the dmap control page for the specified | |
2422 | * block number and control page level. | |
2423 | */ | |
2424 | lblkno = BLKTOCTL(blkno, bmp->db_l2nbperpage, level); | |
2425 | mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0); | |
2426 | if (mp == NULL) | |
2427 | return -EIO; | |
2428 | dcp = (struct dmapctl *) mp->data; | |
2429 | ||
2430 | if (dcp->leafidx != cpu_to_le32(CTLLEAFIND)) { | |
2431 | jfs_error(bmp->db_ipbmap->i_sb, | |
2432 | "dbAdjCtl: Corrupt dmapctl page"); | |
2433 | release_metapage(mp); | |
2434 | return -EIO; | |
2435 | } | |
2436 | ||
2437 | /* determine the leaf number corresponding to the block and | |
2438 | * the index within the dmap control tree. | |
2439 | */ | |
2440 | leafno = BLKTOCTLLEAF(blkno, dcp->budmin); | |
2441 | ti = leafno + le32_to_cpu(dcp->leafidx); | |
2442 | ||
2443 | /* save the current leaf value and the current root level (i.e. | |
2444 | * maximum l2 free string described by this dmapctl). | |
2445 | */ | |
2446 | oldval = dcp->stree[ti]; | |
2447 | oldroot = dcp->stree[ROOT]; | |
2448 | ||
2449 | /* check if this is a control page update for an allocation. | |
2450 | * if so, update the leaf to reflect the new leaf value using | |
2451 | * dbSplit(); otherwise (deallocation), use dbJoin() to udpate | |
2452 | * the leaf with the new value. in addition to updating the | |
2453 | * leaf, dbSplit() will also split the binary buddy system of | |
2454 | * the leaves, if required, and bubble new values within the | |
2455 | * dmapctl tree, if required. similarly, dbJoin() will join | |
2456 | * the binary buddy system of leaves and bubble new values up | |
2457 | * the dmapctl tree as required by the new leaf value. | |
2458 | */ | |
2459 | if (alloc) { | |
2460 | /* check if we are in the middle of a binary buddy | |
2461 | * system. this happens when we are performing the | |
2462 | * first allocation out of an allocation group that | |
2463 | * is part (not the first part) of a larger binary | |
2464 | * buddy system. if we are in the middle, back split | |
2465 | * the system prior to calling dbSplit() which assumes | |
2466 | * that it is at the front of a binary buddy system. | |
2467 | */ | |
2468 | if (oldval == NOFREE) { | |
b6a47fd8 DK |
2469 | rc = dbBackSplit((dmtree_t *) dcp, leafno); |
2470 | if (rc) | |
2471 | return rc; | |
1da177e4 LT |
2472 | oldval = dcp->stree[ti]; |
2473 | } | |
2474 | dbSplit((dmtree_t *) dcp, leafno, dcp->budmin, newval); | |
2475 | } else { | |
56d12549 DK |
2476 | rc = dbJoin((dmtree_t *) dcp, leafno, newval); |
2477 | if (rc) | |
2478 | return rc; | |
1da177e4 LT |
2479 | } |
2480 | ||
2481 | /* check if the root of the current dmap control page changed due | |
2482 | * to the update and if the current dmap control page is not at | |
2483 | * the current top level (i.e. L0, L1, L2) of the map. if so (i.e. | |
2484 | * root changed and this is not the top level), call this routine | |
2485 | * again (recursion) for the next higher level of the mapping to | |
2486 | * reflect the change in root for the current dmap control page. | |
2487 | */ | |
2488 | if (dcp->stree[ROOT] != oldroot) { | |
2489 | /* are we below the top level of the map. if so, | |
2490 | * bubble the root up to the next higher level. | |
2491 | */ | |
2492 | if (level < bmp->db_maxlevel) { | |
2493 | /* bubble up the new root of this dmap control page to | |
2494 | * the next level. | |
2495 | */ | |
2496 | if ((rc = | |
2497 | dbAdjCtl(bmp, blkno, dcp->stree[ROOT], alloc, | |
2498 | level + 1))) { | |
2499 | /* something went wrong in bubbling up the new | |
2500 | * root value, so backout the changes to the | |
2501 | * current dmap control page. | |
2502 | */ | |
2503 | if (alloc) { | |
2504 | dbJoin((dmtree_t *) dcp, leafno, | |
2505 | oldval); | |
2506 | } else { | |
2507 | /* the dbJoin() above might have | |
2508 | * caused a larger binary buddy system | |
2509 | * to form and we may now be in the | |
2510 | * middle of it. if this is the case, | |
2511 | * back split the buddies. | |
2512 | */ | |
2513 | if (dcp->stree[ti] == NOFREE) | |
2514 | dbBackSplit((dmtree_t *) | |
2515 | dcp, leafno); | |
2516 | dbSplit((dmtree_t *) dcp, leafno, | |
2517 | dcp->budmin, oldval); | |
2518 | } | |
2519 | ||
2520 | /* release the buffer and return the error. | |
2521 | */ | |
2522 | release_metapage(mp); | |
2523 | return (rc); | |
2524 | } | |
2525 | } else { | |
2526 | /* we're at the top level of the map. update | |
2527 | * the bmap control page to reflect the size | |
2528 | * of the maximum free buddy system. | |
2529 | */ | |
2530 | assert(level == bmp->db_maxlevel); | |
2531 | if (bmp->db_maxfreebud != oldroot) { | |
2532 | jfs_error(bmp->db_ipbmap->i_sb, | |
2533 | "dbAdjCtl: the maximum free buddy is " | |
2534 | "not the old root"); | |
2535 | } | |
2536 | bmp->db_maxfreebud = dcp->stree[ROOT]; | |
2537 | } | |
2538 | } | |
2539 | ||
2540 | /* write the buffer. | |
2541 | */ | |
2542 | write_metapage(mp); | |
2543 | ||
2544 | return (0); | |
2545 | } | |
2546 | ||
2547 | ||
2548 | /* | |
2549 | * NAME: dbSplit() | |
2550 | * | |
2551 | * FUNCTION: update the leaf of a dmtree with a new value, splitting | |
2552 | * the leaf from the binary buddy system of the dmtree's | |
2553 | * leaves, as required. | |
2554 | * | |
2555 | * PARAMETERS: | |
2556 | * tp - pointer to the tree containing the leaf. | |
2557 | * leafno - the number of the leaf to be updated. | |
2558 | * splitsz - the size the binary buddy system starting at the leaf | |
2559 | * must be split to, specified as the log2 number of blocks. | |
2560 | * newval - the new value for the leaf. | |
2561 | * | |
2562 | * RETURN VALUES: none | |
2563 | * | |
2564 | * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit; | |
2565 | */ | |
2566 | static void dbSplit(dmtree_t * tp, int leafno, int splitsz, int newval) | |
2567 | { | |
2568 | int budsz; | |
2569 | int cursz; | |
2570 | s8 *leaf = tp->dmt_stree + le32_to_cpu(tp->dmt_leafidx); | |
2571 | ||
2572 | /* check if the leaf needs to be split. | |
2573 | */ | |
2574 | if (leaf[leafno] > tp->dmt_budmin) { | |
2575 | /* the split occurs by cutting the buddy system in half | |
2576 | * at the specified leaf until we reach the specified | |
2577 | * size. pick up the starting split size (current size | |
2578 | * - 1 in l2) and the corresponding buddy size. | |
2579 | */ | |
2580 | cursz = leaf[leafno] - 1; | |
2581 | budsz = BUDSIZE(cursz, tp->dmt_budmin); | |
2582 | ||
2583 | /* split until we reach the specified size. | |
2584 | */ | |
2585 | while (cursz >= splitsz) { | |
2586 | /* update the buddy's leaf with its new value. | |
2587 | */ | |
2588 | dbAdjTree(tp, leafno ^ budsz, cursz); | |
2589 | ||
2590 | /* on to the next size and buddy. | |
2591 | */ | |
2592 | cursz -= 1; | |
2593 | budsz >>= 1; | |
2594 | } | |
2595 | } | |
2596 | ||
2597 | /* adjust the dmap tree to reflect the specified leaf's new | |
2598 | * value. | |
2599 | */ | |
2600 | dbAdjTree(tp, leafno, newval); | |
2601 | } | |
2602 | ||
2603 | ||
2604 | /* | |
2605 | * NAME: dbBackSplit() | |
2606 | * | |
2607 | * FUNCTION: back split the binary buddy system of dmtree leaves | |
2608 | * that hold a specified leaf until the specified leaf | |
2609 | * starts its own binary buddy system. | |
2610 | * | |
2611 | * the allocators typically perform allocations at the start | |
2612 | * of binary buddy systems and dbSplit() is used to accomplish | |
2613 | * any required splits. in some cases, however, allocation | |
2614 | * may occur in the middle of a binary system and requires a | |
2615 | * back split, with the split proceeding out from the middle of | |
2616 | * the system (less efficient) rather than the start of the | |
2617 | * system (more efficient). the cases in which a back split | |
2618 | * is required are rare and are limited to the first allocation | |
2619 | * within an allocation group which is a part (not first part) | |
2620 | * of a larger binary buddy system and a few exception cases | |
2621 | * in which a previous join operation must be backed out. | |
2622 | * | |
2623 | * PARAMETERS: | |
2624 | * tp - pointer to the tree containing the leaf. | |
2625 | * leafno - the number of the leaf to be updated. | |
2626 | * | |
2627 | * RETURN VALUES: none | |
2628 | * | |
2629 | * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit; | |
2630 | */ | |
b6a47fd8 | 2631 | static int dbBackSplit(dmtree_t * tp, int leafno) |
1da177e4 LT |
2632 | { |
2633 | int budsz, bud, w, bsz, size; | |
2634 | int cursz; | |
2635 | s8 *leaf = tp->dmt_stree + le32_to_cpu(tp->dmt_leafidx); | |
2636 | ||
2637 | /* leaf should be part (not first part) of a binary | |
2638 | * buddy system. | |
2639 | */ | |
2640 | assert(leaf[leafno] == NOFREE); | |
2641 | ||
2642 | /* the back split is accomplished by iteratively finding the leaf | |
2643 | * that starts the buddy system that contains the specified leaf and | |
2644 | * splitting that system in two. this iteration continues until | |
2645 | * the specified leaf becomes the start of a buddy system. | |
2646 | * | |
2647 | * determine maximum possible l2 size for the specified leaf. | |
2648 | */ | |
2649 | size = | |
2650 | LITOL2BSZ(leafno, le32_to_cpu(tp->dmt_l2nleafs), | |
2651 | tp->dmt_budmin); | |
2652 | ||
2653 | /* determine the number of leaves covered by this size. this | |
2654 | * is the buddy size that we will start with as we search for | |
2655 | * the buddy system that contains the specified leaf. | |
2656 | */ | |
2657 | budsz = BUDSIZE(size, tp->dmt_budmin); | |
2658 | ||
2659 | /* back split. | |
2660 | */ | |
2661 | while (leaf[leafno] == NOFREE) { | |
2662 | /* find the leftmost buddy leaf. | |
2663 | */ | |
2664 | for (w = leafno, bsz = budsz;; bsz <<= 1, | |
2665 | w = (w < bud) ? w : bud) { | |
b6a47fd8 DK |
2666 | if (bsz >= le32_to_cpu(tp->dmt_nleafs)) { |
2667 | jfs_err("JFS: block map error in dbBackSplit"); | |
2668 | return -EIO; | |
2669 | } | |
1da177e4 LT |
2670 | |
2671 | /* determine the buddy. | |
2672 | */ | |
2673 | bud = w ^ bsz; | |
2674 | ||
2675 | /* check if this buddy is the start of the system. | |
2676 | */ | |
2677 | if (leaf[bud] != NOFREE) { | |
2678 | /* split the leaf at the start of the | |
2679 | * system in two. | |
2680 | */ | |
2681 | cursz = leaf[bud] - 1; | |
2682 | dbSplit(tp, bud, cursz, cursz); | |
2683 | break; | |
2684 | } | |
2685 | } | |
2686 | } | |
2687 | ||
b6a47fd8 DK |
2688 | if (leaf[leafno] != size) { |
2689 | jfs_err("JFS: wrong leaf value in dbBackSplit"); | |
2690 | return -EIO; | |
2691 | } | |
2692 | return 0; | |
1da177e4 LT |
2693 | } |
2694 | ||
2695 | ||
2696 | /* | |
2697 | * NAME: dbJoin() | |
2698 | * | |
2699 | * FUNCTION: update the leaf of a dmtree with a new value, joining | |
2700 | * the leaf with other leaves of the dmtree into a multi-leaf | |
2701 | * binary buddy system, as required. | |
2702 | * | |
2703 | * PARAMETERS: | |
2704 | * tp - pointer to the tree containing the leaf. | |
2705 | * leafno - the number of the leaf to be updated. | |
2706 | * newval - the new value for the leaf. | |
2707 | * | |
2708 | * RETURN VALUES: none | |
2709 | */ | |
56d12549 | 2710 | static int dbJoin(dmtree_t * tp, int leafno, int newval) |
1da177e4 LT |
2711 | { |
2712 | int budsz, buddy; | |
2713 | s8 *leaf; | |
2714 | ||
2715 | /* can the new leaf value require a join with other leaves ? | |
2716 | */ | |
2717 | if (newval >= tp->dmt_budmin) { | |
2718 | /* pickup a pointer to the leaves of the tree. | |
2719 | */ | |
2720 | leaf = tp->dmt_stree + le32_to_cpu(tp->dmt_leafidx); | |
2721 | ||
2722 | /* try to join the specified leaf into a large binary | |
2723 | * buddy system. the join proceeds by attempting to join | |
2724 | * the specified leafno with its buddy (leaf) at new value. | |
2725 | * if the join occurs, we attempt to join the left leaf | |
2726 | * of the joined buddies with its buddy at new value + 1. | |
2727 | * we continue to join until we find a buddy that cannot be | |
2728 | * joined (does not have a value equal to the size of the | |
2729 | * last join) or until all leaves have been joined into a | |
2730 | * single system. | |
2731 | * | |
2732 | * get the buddy size (number of words covered) of | |
2733 | * the new value. | |
2734 | */ | |
2735 | budsz = BUDSIZE(newval, tp->dmt_budmin); | |
2736 | ||
2737 | /* try to join. | |
2738 | */ | |
2739 | while (budsz < le32_to_cpu(tp->dmt_nleafs)) { | |
2740 | /* get the buddy leaf. | |
2741 | */ | |
2742 | buddy = leafno ^ budsz; | |
2743 | ||
2744 | /* if the leaf's new value is greater than its | |
2745 | * buddy's value, we join no more. | |
2746 | */ | |
2747 | if (newval > leaf[buddy]) | |
2748 | break; | |
2749 | ||
56d12549 DK |
2750 | /* It shouldn't be less */ |
2751 | if (newval < leaf[buddy]) | |
2752 | return -EIO; | |
1da177e4 LT |
2753 | |
2754 | /* check which (leafno or buddy) is the left buddy. | |
2755 | * the left buddy gets to claim the blocks resulting | |
2756 | * from the join while the right gets to claim none. | |
2757 | * the left buddy is also eligable to participate in | |
2758 | * a join at the next higher level while the right | |
2759 | * is not. | |
2760 | * | |
2761 | */ | |
2762 | if (leafno < buddy) { | |
2763 | /* leafno is the left buddy. | |
2764 | */ | |
2765 | dbAdjTree(tp, buddy, NOFREE); | |
2766 | } else { | |
2767 | /* buddy is the left buddy and becomes | |
2768 | * leafno. | |
2769 | */ | |
2770 | dbAdjTree(tp, leafno, NOFREE); | |
2771 | leafno = buddy; | |
2772 | } | |
2773 | ||
2774 | /* on to try the next join. | |
2775 | */ | |
2776 | newval += 1; | |
2777 | budsz <<= 1; | |
2778 | } | |
2779 | } | |
2780 | ||
2781 | /* update the leaf value. | |
2782 | */ | |
2783 | dbAdjTree(tp, leafno, newval); | |
56d12549 DK |
2784 | |
2785 | return 0; | |
1da177e4 LT |
2786 | } |
2787 | ||
2788 | ||
2789 | /* | |
2790 | * NAME: dbAdjTree() | |
2791 | * | |
2792 | * FUNCTION: update a leaf of a dmtree with a new value, adjusting | |
2793 | * the dmtree, as required, to reflect the new leaf value. | |
2794 | * the combination of any buddies must already be done before | |
2795 | * this is called. | |
2796 | * | |
2797 | * PARAMETERS: | |
2798 | * tp - pointer to the tree to be adjusted. | |
2799 | * leafno - the number of the leaf to be updated. | |
2800 | * newval - the new value for the leaf. | |
2801 | * | |
2802 | * RETURN VALUES: none | |
2803 | */ | |
2804 | static void dbAdjTree(dmtree_t * tp, int leafno, int newval) | |
2805 | { | |
2806 | int lp, pp, k; | |
2807 | int max; | |
2808 | ||
2809 | /* pick up the index of the leaf for this leafno. | |
2810 | */ | |
2811 | lp = leafno + le32_to_cpu(tp->dmt_leafidx); | |
2812 | ||
2813 | /* is the current value the same as the old value ? if so, | |
2814 | * there is nothing to do. | |
2815 | */ | |
2816 | if (tp->dmt_stree[lp] == newval) | |
2817 | return; | |
2818 | ||
2819 | /* set the new value. | |
2820 | */ | |
2821 | tp->dmt_stree[lp] = newval; | |
2822 | ||
2823 | /* bubble the new value up the tree as required. | |
2824 | */ | |
2825 | for (k = 0; k < le32_to_cpu(tp->dmt_height); k++) { | |
2826 | /* get the index of the first leaf of the 4 leaf | |
2827 | * group containing the specified leaf (leafno). | |
2828 | */ | |
2829 | lp = ((lp - 1) & ~0x03) + 1; | |
2830 | ||
2831 | /* get the index of the parent of this 4 leaf group. | |
2832 | */ | |
2833 | pp = (lp - 1) >> 2; | |
2834 | ||
2835 | /* determine the maximum of the 4 leaves. | |
2836 | */ | |
2837 | max = TREEMAX(&tp->dmt_stree[lp]); | |
2838 | ||
2839 | /* if the maximum of the 4 is the same as the | |
2840 | * parent's value, we're done. | |
2841 | */ | |
2842 | if (tp->dmt_stree[pp] == max) | |
2843 | break; | |
2844 | ||
2845 | /* parent gets new value. | |
2846 | */ | |
2847 | tp->dmt_stree[pp] = max; | |
2848 | ||
2849 | /* parent becomes leaf for next go-round. | |
2850 | */ | |
2851 | lp = pp; | |
2852 | } | |
2853 | } | |
2854 | ||
2855 | ||
2856 | /* | |
2857 | * NAME: dbFindLeaf() | |
2858 | * | |
2859 | * FUNCTION: search a dmtree_t for sufficient free blocks, returning | |
2860 | * the index of a leaf describing the free blocks if | |
2861 | * sufficient free blocks are found. | |
2862 | * | |
2863 | * the search starts at the top of the dmtree_t tree and | |
2864 | * proceeds down the tree to the leftmost leaf with sufficient | |
2865 | * free space. | |
2866 | * | |
2867 | * PARAMETERS: | |
2868 | * tp - pointer to the tree to be searched. | |
2869 | * l2nb - log2 number of free blocks to search for. | |
2870 | * leafidx - return pointer to be set to the index of the leaf | |
2871 | * describing at least l2nb free blocks if sufficient | |
2872 | * free blocks are found. | |
2873 | * | |
2874 | * RETURN VALUES: | |
2875 | * 0 - success | |
2876 | * -ENOSPC - insufficient free blocks. | |
2877 | */ | |
2878 | static int dbFindLeaf(dmtree_t * tp, int l2nb, int *leafidx) | |
2879 | { | |
2880 | int ti, n = 0, k, x = 0; | |
2881 | ||
2882 | /* first check the root of the tree to see if there is | |
2883 | * sufficient free space. | |
2884 | */ | |
2885 | if (l2nb > tp->dmt_stree[ROOT]) | |
2886 | return -ENOSPC; | |
2887 | ||
2888 | /* sufficient free space available. now search down the tree | |
2889 | * starting at the next level for the leftmost leaf that | |
2890 | * describes sufficient free space. | |
2891 | */ | |
2892 | for (k = le32_to_cpu(tp->dmt_height), ti = 1; | |
2893 | k > 0; k--, ti = ((ti + n) << 2) + 1) { | |
2894 | /* search the four nodes at this level, starting from | |
2895 | * the left. | |
2896 | */ | |
2897 | for (x = ti, n = 0; n < 4; n++) { | |
2898 | /* sufficient free space found. move to the next | |
2899 | * level (or quit if this is the last level). | |
2900 | */ | |
2901 | if (l2nb <= tp->dmt_stree[x + n]) | |
2902 | break; | |
2903 | } | |
2904 | ||
2905 | /* better have found something since the higher | |
2906 | * levels of the tree said it was here. | |
2907 | */ | |
2908 | assert(n < 4); | |
2909 | } | |
2910 | ||
2911 | /* set the return to the leftmost leaf describing sufficient | |
2912 | * free space. | |
2913 | */ | |
2914 | *leafidx = x + n - le32_to_cpu(tp->dmt_leafidx); | |
2915 | ||
2916 | return (0); | |
2917 | } | |
2918 | ||
2919 | ||
2920 | /* | |
2921 | * NAME: dbFindBits() | |
2922 | * | |
2923 | * FUNCTION: find a specified number of binary buddy free bits within a | |
2924 | * dmap bitmap word value. | |
2925 | * | |
2926 | * this routine searches the bitmap value for (1 << l2nb) free | |
2927 | * bits at (1 << l2nb) alignments within the value. | |
2928 | * | |
2929 | * PARAMETERS: | |
2930 | * word - dmap bitmap word value. | |
2931 | * l2nb - number of free bits specified as a log2 number. | |
2932 | * | |
2933 | * RETURN VALUES: | |
2934 | * starting bit number of free bits. | |
2935 | */ | |
2936 | static int dbFindBits(u32 word, int l2nb) | |
2937 | { | |
2938 | int bitno, nb; | |
2939 | u32 mask; | |
2940 | ||
2941 | /* get the number of bits. | |
2942 | */ | |
2943 | nb = 1 << l2nb; | |
2944 | assert(nb <= DBWORD); | |
2945 | ||
2946 | /* complement the word so we can use a mask (i.e. 0s represent | |
2947 | * free bits) and compute the mask. | |
2948 | */ | |
2949 | word = ~word; | |
2950 | mask = ONES << (DBWORD - nb); | |
2951 | ||
2952 | /* scan the word for nb free bits at nb alignments. | |
2953 | */ | |
2954 | for (bitno = 0; mask != 0; bitno += nb, mask >>= nb) { | |
2955 | if ((mask & word) == mask) | |
2956 | break; | |
2957 | } | |
2958 | ||
2959 | ASSERT(bitno < 32); | |
2960 | ||
2961 | /* return the bit number. | |
2962 | */ | |
2963 | return (bitno); | |
2964 | } | |
2965 | ||
2966 | ||
2967 | /* | |
2968 | * NAME: dbMaxBud(u8 *cp) | |
2969 | * | |
2970 | * FUNCTION: determine the largest binary buddy string of free | |
2971 | * bits within 32-bits of the map. | |
2972 | * | |
2973 | * PARAMETERS: | |
2974 | * cp - pointer to the 32-bit value. | |
2975 | * | |
2976 | * RETURN VALUES: | |
2977 | * largest binary buddy of free bits within a dmap word. | |
2978 | */ | |
2979 | static int dbMaxBud(u8 * cp) | |
2980 | { | |
2981 | signed char tmp1, tmp2; | |
2982 | ||
2983 | /* check if the wmap word is all free. if so, the | |
2984 | * free buddy size is BUDMIN. | |
2985 | */ | |
2986 | if (*((uint *) cp) == 0) | |
2987 | return (BUDMIN); | |
2988 | ||
2989 | /* check if the wmap word is half free. if so, the | |
2990 | * free buddy size is BUDMIN-1. | |
2991 | */ | |
2992 | if (*((u16 *) cp) == 0 || *((u16 *) cp + 1) == 0) | |
2993 | return (BUDMIN - 1); | |
2994 | ||
2995 | /* not all free or half free. determine the free buddy | |
2996 | * size thru table lookup using quarters of the wmap word. | |
2997 | */ | |
2998 | tmp1 = max(budtab[cp[2]], budtab[cp[3]]); | |
2999 | tmp2 = max(budtab[cp[0]], budtab[cp[1]]); | |
3000 | return (max(tmp1, tmp2)); | |
3001 | } | |
3002 | ||
3003 | ||
3004 | /* | |
3005 | * NAME: cnttz(uint word) | |
3006 | * | |
3007 | * FUNCTION: determine the number of trailing zeros within a 32-bit | |
3008 | * value. | |
3009 | * | |
3010 | * PARAMETERS: | |
3011 | * value - 32-bit value to be examined. | |
3012 | * | |
3013 | * RETURN VALUES: | |
3014 | * count of trailing zeros | |
3015 | */ | |
3016 | static int cnttz(u32 word) | |
3017 | { | |
3018 | int n; | |
3019 | ||
3020 | for (n = 0; n < 32; n++, word >>= 1) { | |
3021 | if (word & 0x01) | |
3022 | break; | |
3023 | } | |
3024 | ||
3025 | return (n); | |
3026 | } | |
3027 | ||
3028 | ||
3029 | /* | |
3030 | * NAME: cntlz(u32 value) | |
3031 | * | |
3032 | * FUNCTION: determine the number of leading zeros within a 32-bit | |
3033 | * value. | |
3034 | * | |
3035 | * PARAMETERS: | |
3036 | * value - 32-bit value to be examined. | |
3037 | * | |
3038 | * RETURN VALUES: | |
3039 | * count of leading zeros | |
3040 | */ | |
3041 | static int cntlz(u32 value) | |
3042 | { | |
3043 | int n; | |
3044 | ||
3045 | for (n = 0; n < 32; n++, value <<= 1) { | |
3046 | if (value & HIGHORDER) | |
3047 | break; | |
3048 | } | |
3049 | return (n); | |
3050 | } | |
3051 | ||
3052 | ||
3053 | /* | |
3054 | * NAME: blkstol2(s64 nb) | |
3055 | * | |
3056 | * FUNCTION: convert a block count to its log2 value. if the block | |
3057 | * count is not a l2 multiple, it is rounded up to the next | |
3058 | * larger l2 multiple. | |
3059 | * | |
3060 | * PARAMETERS: | |
3061 | * nb - number of blocks | |
3062 | * | |
3063 | * RETURN VALUES: | |
3064 | * log2 number of blocks | |
3065 | */ | |
6cb1269b | 3066 | static int blkstol2(s64 nb) |
1da177e4 LT |
3067 | { |
3068 | int l2nb; | |
3069 | s64 mask; /* meant to be signed */ | |
3070 | ||
3071 | mask = (s64) 1 << (64 - 1); | |
3072 | ||
3073 | /* count the leading bits. | |
3074 | */ | |
3075 | for (l2nb = 0; l2nb < 64; l2nb++, mask >>= 1) { | |
3076 | /* leading bit found. | |
3077 | */ | |
3078 | if (nb & mask) { | |
3079 | /* determine the l2 value. | |
3080 | */ | |
3081 | l2nb = (64 - 1) - l2nb; | |
3082 | ||
3083 | /* check if we need to round up. | |
3084 | */ | |
3085 | if (~mask & nb) | |
3086 | l2nb++; | |
3087 | ||
3088 | return (l2nb); | |
3089 | } | |
3090 | } | |
3091 | assert(0); | |
3092 | return 0; /* fix compiler warning */ | |
3093 | } | |
3094 | ||
3095 | ||
3096 | /* | |
3097 | * NAME: dbAllocBottomUp() | |
3098 | * | |
3099 | * FUNCTION: alloc the specified block range from the working block | |
3100 | * allocation map. | |
3101 | * | |
3102 | * the blocks will be alloc from the working map one dmap | |
3103 | * at a time. | |
3104 | * | |
3105 | * PARAMETERS: | |
3106 | * ip - pointer to in-core inode; | |
3107 | * blkno - starting block number to be freed. | |
3108 | * nblocks - number of blocks to be freed. | |
3109 | * | |
3110 | * RETURN VALUES: | |
3111 | * 0 - success | |
3112 | * -EIO - i/o error | |
3113 | */ | |
3114 | int dbAllocBottomUp(struct inode *ip, s64 blkno, s64 nblocks) | |
3115 | { | |
3116 | struct metapage *mp; | |
3117 | struct dmap *dp; | |
3118 | int nb, rc; | |
3119 | s64 lblkno, rem; | |
3120 | struct inode *ipbmap = JFS_SBI(ip->i_sb)->ipbmap; | |
3121 | struct bmap *bmp = JFS_SBI(ip->i_sb)->bmap; | |
3122 | ||
3123 | IREAD_LOCK(ipbmap); | |
3124 | ||
3125 | /* block to be allocated better be within the mapsize. */ | |
3126 | ASSERT(nblocks <= bmp->db_mapsize - blkno); | |
3127 | ||
3128 | /* | |
3129 | * allocate the blocks a dmap at a time. | |
3130 | */ | |
3131 | mp = NULL; | |
3132 | for (rem = nblocks; rem > 0; rem -= nb, blkno += nb) { | |
3133 | /* release previous dmap if any */ | |
3134 | if (mp) { | |
3135 | write_metapage(mp); | |
3136 | } | |
3137 | ||
3138 | /* get the buffer for the current dmap. */ | |
3139 | lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage); | |
3140 | mp = read_metapage(ipbmap, lblkno, PSIZE, 0); | |
3141 | if (mp == NULL) { | |
3142 | IREAD_UNLOCK(ipbmap); | |
3143 | return -EIO; | |
3144 | } | |
3145 | dp = (struct dmap *) mp->data; | |
3146 | ||
3147 | /* determine the number of blocks to be allocated from | |
3148 | * this dmap. | |
3149 | */ | |
3150 | nb = min(rem, BPERDMAP - (blkno & (BPERDMAP - 1))); | |
3151 | ||
1da177e4 LT |
3152 | /* allocate the blocks. */ |
3153 | if ((rc = dbAllocDmapBU(bmp, dp, blkno, nb))) { | |
3154 | release_metapage(mp); | |
3155 | IREAD_UNLOCK(ipbmap); | |
3156 | return (rc); | |
3157 | } | |
1da177e4 LT |
3158 | } |
3159 | ||
3160 | /* write the last buffer. */ | |
3161 | write_metapage(mp); | |
3162 | ||
3163 | IREAD_UNLOCK(ipbmap); | |
3164 | ||
3165 | return (0); | |
3166 | } | |
3167 | ||
3168 | ||
3169 | static int dbAllocDmapBU(struct bmap * bmp, struct dmap * dp, s64 blkno, | |
3170 | int nblocks) | |
3171 | { | |
3172 | int rc; | |
3173 | int dbitno, word, rembits, nb, nwords, wbitno, agno; | |
3174 | s8 oldroot, *leaf; | |
3175 | struct dmaptree *tp = (struct dmaptree *) & dp->tree; | |
3176 | ||
3177 | /* save the current value of the root (i.e. maximum free string) | |
3178 | * of the dmap tree. | |
3179 | */ | |
3180 | oldroot = tp->stree[ROOT]; | |
3181 | ||
3182 | /* pick up a pointer to the leaves of the dmap tree */ | |
3183 | leaf = tp->stree + LEAFIND; | |
3184 | ||
3185 | /* determine the bit number and word within the dmap of the | |
3186 | * starting block. | |
3187 | */ | |
3188 | dbitno = blkno & (BPERDMAP - 1); | |
3189 | word = dbitno >> L2DBWORD; | |
3190 | ||
3191 | /* block range better be within the dmap */ | |
3192 | assert(dbitno + nblocks <= BPERDMAP); | |
3193 | ||
3194 | /* allocate the bits of the dmap's words corresponding to the block | |
3195 | * range. not all bits of the first and last words may be contained | |
3196 | * within the block range. if this is the case, we'll work against | |
3197 | * those words (i.e. partial first and/or last) on an individual basis | |
3198 | * (a single pass), allocating the bits of interest by hand and | |
3199 | * updating the leaf corresponding to the dmap word. a single pass | |
3200 | * will be used for all dmap words fully contained within the | |
3201 | * specified range. within this pass, the bits of all fully contained | |
3202 | * dmap words will be marked as free in a single shot and the leaves | |
3203 | * will be updated. a single leaf may describe the free space of | |
3204 | * multiple dmap words, so we may update only a subset of the actual | |
3205 | * leaves corresponding to the dmap words of the block range. | |
3206 | */ | |
3207 | for (rembits = nblocks; rembits > 0; rembits -= nb, dbitno += nb) { | |
3208 | /* determine the bit number within the word and | |
3209 | * the number of bits within the word. | |
3210 | */ | |
3211 | wbitno = dbitno & (DBWORD - 1); | |
3212 | nb = min(rembits, DBWORD - wbitno); | |
3213 | ||
3214 | /* check if only part of a word is to be allocated. | |
3215 | */ | |
3216 | if (nb < DBWORD) { | |
3217 | /* allocate (set to 1) the appropriate bits within | |
3218 | * this dmap word. | |
3219 | */ | |
3220 | dp->wmap[word] |= cpu_to_le32(ONES << (DBWORD - nb) | |
3221 | >> wbitno); | |
3222 | ||
3223 | word++; | |
3224 | } else { | |
3225 | /* one or more dmap words are fully contained | |
3226 | * within the block range. determine how many | |
3227 | * words and allocate (set to 1) the bits of these | |
3228 | * words. | |
3229 | */ | |
3230 | nwords = rembits >> L2DBWORD; | |
3231 | memset(&dp->wmap[word], (int) ONES, nwords * 4); | |
3232 | ||
3233 | /* determine how many bits */ | |
3234 | nb = nwords << L2DBWORD; | |
3235 | word += nwords; | |
3236 | } | |
3237 | } | |
3238 | ||
3239 | /* update the free count for this dmap */ | |
3240 | dp->nfree = cpu_to_le32(le32_to_cpu(dp->nfree) - nblocks); | |
3241 | ||
3242 | /* reconstruct summary tree */ | |
3243 | dbInitDmapTree(dp); | |
3244 | ||
3245 | BMAP_LOCK(bmp); | |
3246 | ||
3247 | /* if this allocation group is completely free, | |
3248 | * update the highest active allocation group number | |
3249 | * if this allocation group is the new max. | |
3250 | */ | |
3251 | agno = blkno >> bmp->db_agl2size; | |
3252 | if (agno > bmp->db_maxag) | |
3253 | bmp->db_maxag = agno; | |
3254 | ||
3255 | /* update the free count for the allocation group and map */ | |
3256 | bmp->db_agfree[agno] -= nblocks; | |
3257 | bmp->db_nfree -= nblocks; | |
3258 | ||
3259 | BMAP_UNLOCK(bmp); | |
3260 | ||
3261 | /* if the root has not changed, done. */ | |
3262 | if (tp->stree[ROOT] == oldroot) | |
3263 | return (0); | |
3264 | ||
3265 | /* root changed. bubble the change up to the dmap control pages. | |
3266 | * if the adjustment of the upper level control pages fails, | |
3267 | * backout the bit allocation (thus making everything consistent). | |
3268 | */ | |
3269 | if ((rc = dbAdjCtl(bmp, blkno, tp->stree[ROOT], 1, 0))) | |
3270 | dbFreeBits(bmp, dp, blkno, nblocks); | |
3271 | ||
3272 | return (rc); | |
3273 | } | |
3274 | ||
3275 | ||
3276 | /* | |
3277 | * NAME: dbExtendFS() | |
3278 | * | |
3279 | * FUNCTION: extend bmap from blkno for nblocks; | |
3280 | * dbExtendFS() updates bmap ready for dbAllocBottomUp(); | |
3281 | * | |
3282 | * L2 | |
3283 | * | | |
3284 | * L1---------------------------------L1 | |
3285 | * | | | |
3286 | * L0---------L0---------L0 L0---------L0---------L0 | |
3287 | * | | | | | | | |
3288 | * d0,...,dn d0,...,dn d0,...,dn d0,...,dn d0,...,dn d0,.,dm; | |
3289 | * L2L1L0d0,...,dnL0d0,...,dnL0d0,...,dnL1L0d0,...,dnL0d0,...,dnL0d0,..dm | |
3290 | * | |
3291 | * <---old---><----------------------------extend-----------------------> | |
3292 | */ | |
3293 | int dbExtendFS(struct inode *ipbmap, s64 blkno, s64 nblocks) | |
3294 | { | |
3295 | struct jfs_sb_info *sbi = JFS_SBI(ipbmap->i_sb); | |
3296 | int nbperpage = sbi->nbperpage; | |
3297 | int i, i0 = TRUE, j, j0 = TRUE, k, n; | |
3298 | s64 newsize; | |
3299 | s64 p; | |
3300 | struct metapage *mp, *l2mp, *l1mp = NULL, *l0mp = NULL; | |
3301 | struct dmapctl *l2dcp, *l1dcp, *l0dcp; | |
3302 | struct dmap *dp; | |
3303 | s8 *l0leaf, *l1leaf, *l2leaf; | |
3304 | struct bmap *bmp = sbi->bmap; | |
3305 | int agno, l2agsize, oldl2agsize; | |
3306 | s64 ag_rem; | |
3307 | ||
3308 | newsize = blkno + nblocks; | |
3309 | ||
3310 | jfs_info("dbExtendFS: blkno:%Ld nblocks:%Ld newsize:%Ld", | |
3311 | (long long) blkno, (long long) nblocks, (long long) newsize); | |
3312 | ||
3313 | /* | |
3314 | * initialize bmap control page. | |
3315 | * | |
3316 | * all the data in bmap control page should exclude | |
3317 | * the mkfs hidden dmap page. | |
3318 | */ | |
3319 | ||
3320 | /* update mapsize */ | |
3321 | bmp->db_mapsize = newsize; | |
3322 | bmp->db_maxlevel = BMAPSZTOLEV(bmp->db_mapsize); | |
3323 | ||
3324 | /* compute new AG size */ | |
3325 | l2agsize = dbGetL2AGSize(newsize); | |
3326 | oldl2agsize = bmp->db_agl2size; | |
3327 | ||
3328 | bmp->db_agl2size = l2agsize; | |
3329 | bmp->db_agsize = 1 << l2agsize; | |
3330 | ||
3331 | /* compute new number of AG */ | |
3332 | agno = bmp->db_numag; | |
3333 | bmp->db_numag = newsize >> l2agsize; | |
3334 | bmp->db_numag += ((u32) newsize % (u32) bmp->db_agsize) ? 1 : 0; | |
3335 | ||
3336 | /* | |
3337 | * reconfigure db_agfree[] | |
3338 | * from old AG configuration to new AG configuration; | |
3339 | * | |
3340 | * coalesce contiguous k (newAGSize/oldAGSize) AGs; | |
3341 | * i.e., (AGi, ..., AGj) where i = k*n and j = k*(n+1) - 1 to AGn; | |
3342 | * note: new AG size = old AG size * (2**x). | |
3343 | */ | |
3344 | if (l2agsize == oldl2agsize) | |
3345 | goto extend; | |
3346 | k = 1 << (l2agsize - oldl2agsize); | |
3347 | ag_rem = bmp->db_agfree[0]; /* save agfree[0] */ | |
3348 | for (i = 0, n = 0; i < agno; n++) { | |
3349 | bmp->db_agfree[n] = 0; /* init collection point */ | |
3350 | ||
3351 | /* coalesce cotiguous k AGs; */ | |
3352 | for (j = 0; j < k && i < agno; j++, i++) { | |
3353 | /* merge AGi to AGn */ | |
3354 | bmp->db_agfree[n] += bmp->db_agfree[i]; | |
3355 | } | |
3356 | } | |
3357 | bmp->db_agfree[0] += ag_rem; /* restore agfree[0] */ | |
3358 | ||
3359 | for (; n < MAXAG; n++) | |
3360 | bmp->db_agfree[n] = 0; | |
3361 | ||
3362 | /* | |
3363 | * update highest active ag number | |
3364 | */ | |
3365 | ||
3366 | bmp->db_maxag = bmp->db_maxag / k; | |
3367 | ||
3368 | /* | |
3369 | * extend bmap | |
3370 | * | |
3371 | * update bit maps and corresponding level control pages; | |
3372 | * global control page db_nfree, db_agfree[agno], db_maxfreebud; | |
3373 | */ | |
3374 | extend: | |
3375 | /* get L2 page */ | |
3376 | p = BMAPBLKNO + nbperpage; /* L2 page */ | |
3377 | l2mp = read_metapage(ipbmap, p, PSIZE, 0); | |
3378 | if (!l2mp) { | |
3379 | jfs_error(ipbmap->i_sb, "dbExtendFS: L2 page could not be read"); | |
3380 | return -EIO; | |
3381 | } | |
3382 | l2dcp = (struct dmapctl *) l2mp->data; | |
3383 | ||
3384 | /* compute start L1 */ | |
3385 | k = blkno >> L2MAXL1SIZE; | |
3386 | l2leaf = l2dcp->stree + CTLLEAFIND + k; | |
3387 | p = BLKTOL1(blkno, sbi->l2nbperpage); /* L1 page */ | |
3388 | ||
3389 | /* | |
3390 | * extend each L1 in L2 | |
3391 | */ | |
3392 | for (; k < LPERCTL; k++, p += nbperpage) { | |
3393 | /* get L1 page */ | |
3394 | if (j0) { | |
3395 | /* read in L1 page: (blkno & (MAXL1SIZE - 1)) */ | |
3396 | l1mp = read_metapage(ipbmap, p, PSIZE, 0); | |
3397 | if (l1mp == NULL) | |
3398 | goto errout; | |
3399 | l1dcp = (struct dmapctl *) l1mp->data; | |
3400 | ||
3401 | /* compute start L0 */ | |
3402 | j = (blkno & (MAXL1SIZE - 1)) >> L2MAXL0SIZE; | |
3403 | l1leaf = l1dcp->stree + CTLLEAFIND + j; | |
3404 | p = BLKTOL0(blkno, sbi->l2nbperpage); | |
3405 | j0 = FALSE; | |
3406 | } else { | |
3407 | /* assign/init L1 page */ | |
3408 | l1mp = get_metapage(ipbmap, p, PSIZE, 0); | |
3409 | if (l1mp == NULL) | |
3410 | goto errout; | |
3411 | ||
3412 | l1dcp = (struct dmapctl *) l1mp->data; | |
3413 | ||
3414 | /* compute start L0 */ | |
3415 | j = 0; | |
3416 | l1leaf = l1dcp->stree + CTLLEAFIND; | |
3417 | p += nbperpage; /* 1st L0 of L1.k */ | |
3418 | } | |
3419 | ||
3420 | /* | |
3421 | * extend each L0 in L1 | |
3422 | */ | |
3423 | for (; j < LPERCTL; j++) { | |
3424 | /* get L0 page */ | |
3425 | if (i0) { | |
3426 | /* read in L0 page: (blkno & (MAXL0SIZE - 1)) */ | |
3427 | ||
3428 | l0mp = read_metapage(ipbmap, p, PSIZE, 0); | |
3429 | if (l0mp == NULL) | |
3430 | goto errout; | |
3431 | l0dcp = (struct dmapctl *) l0mp->data; | |
3432 | ||
3433 | /* compute start dmap */ | |
3434 | i = (blkno & (MAXL0SIZE - 1)) >> | |
3435 | L2BPERDMAP; | |
3436 | l0leaf = l0dcp->stree + CTLLEAFIND + i; | |
3437 | p = BLKTODMAP(blkno, | |
3438 | sbi->l2nbperpage); | |
3439 | i0 = FALSE; | |
3440 | } else { | |
3441 | /* assign/init L0 page */ | |
3442 | l0mp = get_metapage(ipbmap, p, PSIZE, 0); | |
3443 | if (l0mp == NULL) | |
3444 | goto errout; | |
3445 | ||
3446 | l0dcp = (struct dmapctl *) l0mp->data; | |
3447 | ||
3448 | /* compute start dmap */ | |
3449 | i = 0; | |
3450 | l0leaf = l0dcp->stree + CTLLEAFIND; | |
3451 | p += nbperpage; /* 1st dmap of L0.j */ | |
3452 | } | |
3453 | ||
3454 | /* | |
3455 | * extend each dmap in L0 | |
3456 | */ | |
3457 | for (; i < LPERCTL; i++) { | |
3458 | /* | |
3459 | * reconstruct the dmap page, and | |
3460 | * initialize corresponding parent L0 leaf | |
3461 | */ | |
3462 | if ((n = blkno & (BPERDMAP - 1))) { | |
3463 | /* read in dmap page: */ | |
3464 | mp = read_metapage(ipbmap, p, | |
3465 | PSIZE, 0); | |
3466 | if (mp == NULL) | |
3467 | goto errout; | |
3468 | n = min(nblocks, (s64)BPERDMAP - n); | |
3469 | } else { | |
3470 | /* assign/init dmap page */ | |
3471 | mp = read_metapage(ipbmap, p, | |
3472 | PSIZE, 0); | |
3473 | if (mp == NULL) | |
3474 | goto errout; | |
3475 | ||
3476 | n = min(nblocks, (s64)BPERDMAP); | |
3477 | } | |
3478 | ||
3479 | dp = (struct dmap *) mp->data; | |
3480 | *l0leaf = dbInitDmap(dp, blkno, n); | |
3481 | ||
3482 | bmp->db_nfree += n; | |
3483 | agno = le64_to_cpu(dp->start) >> l2agsize; | |
3484 | bmp->db_agfree[agno] += n; | |
3485 | ||
3486 | write_metapage(mp); | |
3487 | ||
3488 | l0leaf++; | |
3489 | p += nbperpage; | |
3490 | ||
3491 | blkno += n; | |
3492 | nblocks -= n; | |
3493 | if (nblocks == 0) | |
3494 | break; | |
3495 | } /* for each dmap in a L0 */ | |
3496 | ||
3497 | /* | |
3498 | * build current L0 page from its leaves, and | |
3499 | * initialize corresponding parent L1 leaf | |
3500 | */ | |
3501 | *l1leaf = dbInitDmapCtl(l0dcp, 0, ++i); | |
3502 | write_metapage(l0mp); | |
3503 | l0mp = NULL; | |
3504 | ||
3505 | if (nblocks) | |
3506 | l1leaf++; /* continue for next L0 */ | |
3507 | else { | |
3508 | /* more than 1 L0 ? */ | |
3509 | if (j > 0) | |
3510 | break; /* build L1 page */ | |
3511 | else { | |
3512 | /* summarize in global bmap page */ | |
3513 | bmp->db_maxfreebud = *l1leaf; | |
3514 | release_metapage(l1mp); | |
3515 | release_metapage(l2mp); | |
3516 | goto finalize; | |
3517 | } | |
3518 | } | |
3519 | } /* for each L0 in a L1 */ | |
3520 | ||
3521 | /* | |
3522 | * build current L1 page from its leaves, and | |
3523 | * initialize corresponding parent L2 leaf | |
3524 | */ | |
3525 | *l2leaf = dbInitDmapCtl(l1dcp, 1, ++j); | |
3526 | write_metapage(l1mp); | |
3527 | l1mp = NULL; | |
3528 | ||
3529 | if (nblocks) | |
3530 | l2leaf++; /* continue for next L1 */ | |
3531 | else { | |
3532 | /* more than 1 L1 ? */ | |
3533 | if (k > 0) | |
3534 | break; /* build L2 page */ | |
3535 | else { | |
3536 | /* summarize in global bmap page */ | |
3537 | bmp->db_maxfreebud = *l2leaf; | |
3538 | release_metapage(l2mp); | |
3539 | goto finalize; | |
3540 | } | |
3541 | } | |
3542 | } /* for each L1 in a L2 */ | |
3543 | ||
3544 | jfs_error(ipbmap->i_sb, | |
3545 | "dbExtendFS: function has not returned as expected"); | |
3546 | errout: | |
3547 | if (l0mp) | |
3548 | release_metapage(l0mp); | |
3549 | if (l1mp) | |
3550 | release_metapage(l1mp); | |
3551 | release_metapage(l2mp); | |
3552 | return -EIO; | |
3553 | ||
3554 | /* | |
3555 | * finalize bmap control page | |
3556 | */ | |
3557 | finalize: | |
3558 | ||
3559 | return 0; | |
3560 | } | |
3561 | ||
3562 | ||
3563 | /* | |
3564 | * dbFinalizeBmap() | |
3565 | */ | |
3566 | void dbFinalizeBmap(struct inode *ipbmap) | |
3567 | { | |
3568 | struct bmap *bmp = JFS_SBI(ipbmap->i_sb)->bmap; | |
3569 | int actags, inactags, l2nl; | |
3570 | s64 ag_rem, actfree, inactfree, avgfree; | |
3571 | int i, n; | |
3572 | ||
3573 | /* | |
3574 | * finalize bmap control page | |
3575 | */ | |
3576 | //finalize: | |
3577 | /* | |
3578 | * compute db_agpref: preferred ag to allocate from | |
3579 | * (the leftmost ag with average free space in it); | |
3580 | */ | |
3581 | //agpref: | |
3582 | /* get the number of active ags and inacitve ags */ | |
3583 | actags = bmp->db_maxag + 1; | |
3584 | inactags = bmp->db_numag - actags; | |
3585 | ag_rem = bmp->db_mapsize & (bmp->db_agsize - 1); /* ??? */ | |
3586 | ||
3587 | /* determine how many blocks are in the inactive allocation | |
3588 | * groups. in doing this, we must account for the fact that | |
3589 | * the rightmost group might be a partial group (i.e. file | |
3590 | * system size is not a multiple of the group size). | |
3591 | */ | |
3592 | inactfree = (inactags && ag_rem) ? | |
3593 | ((inactags - 1) << bmp->db_agl2size) + ag_rem | |
3594 | : inactags << bmp->db_agl2size; | |
3595 | ||
3596 | /* determine how many free blocks are in the active | |
3597 | * allocation groups plus the average number of free blocks | |
3598 | * within the active ags. | |
3599 | */ | |
3600 | actfree = bmp->db_nfree - inactfree; | |
3601 | avgfree = (u32) actfree / (u32) actags; | |
3602 | ||
3603 | /* if the preferred allocation group has not average free space. | |
3604 | * re-establish the preferred group as the leftmost | |
3605 | * group with average free space. | |
3606 | */ | |
3607 | if (bmp->db_agfree[bmp->db_agpref] < avgfree) { | |
3608 | for (bmp->db_agpref = 0; bmp->db_agpref < actags; | |
3609 | bmp->db_agpref++) { | |
3610 | if (bmp->db_agfree[bmp->db_agpref] >= avgfree) | |
3611 | break; | |
3612 | } | |
3613 | if (bmp->db_agpref >= bmp->db_numag) { | |
3614 | jfs_error(ipbmap->i_sb, | |
3615 | "cannot find ag with average freespace"); | |
3616 | } | |
3617 | } | |
3618 | ||
3619 | /* | |
3620 | * compute db_aglevel, db_agheigth, db_width, db_agstart: | |
3621 | * an ag is covered in aglevel dmapctl summary tree, | |
3622 | * at agheight level height (from leaf) with agwidth number of nodes | |
3623 | * each, which starts at agstart index node of the smmary tree node | |
3624 | * array; | |
3625 | */ | |
3626 | bmp->db_aglevel = BMAPSZTOLEV(bmp->db_agsize); | |
3627 | l2nl = | |
3628 | bmp->db_agl2size - (L2BPERDMAP + bmp->db_aglevel * L2LPERCTL); | |
3629 | bmp->db_agheigth = l2nl >> 1; | |
3630 | bmp->db_agwidth = 1 << (l2nl - (bmp->db_agheigth << 1)); | |
3631 | for (i = 5 - bmp->db_agheigth, bmp->db_agstart = 0, n = 1; i > 0; | |
3632 | i--) { | |
3633 | bmp->db_agstart += n; | |
3634 | n <<= 2; | |
3635 | } | |
3636 | ||
3637 | } | |
3638 | ||
3639 | ||
3640 | /* | |
3641 | * NAME: dbInitDmap()/ujfs_idmap_page() | |
3642 | * | |
3643 | * FUNCTION: initialize working/persistent bitmap of the dmap page | |
3644 | * for the specified number of blocks: | |
3645 | * | |
3646 | * at entry, the bitmaps had been initialized as free (ZEROS); | |
3647 | * The number of blocks will only account for the actually | |
3648 | * existing blocks. Blocks which don't actually exist in | |
3649 | * the aggregate will be marked as allocated (ONES); | |
3650 | * | |
3651 | * PARAMETERS: | |
3652 | * dp - pointer to page of map | |
3653 | * nblocks - number of blocks this page | |
3654 | * | |
3655 | * RETURNS: NONE | |
3656 | */ | |
3657 | static int dbInitDmap(struct dmap * dp, s64 Blkno, int nblocks) | |
3658 | { | |
3659 | int blkno, w, b, r, nw, nb, i; | |
3660 | ||
3661 | /* starting block number within the dmap */ | |
3662 | blkno = Blkno & (BPERDMAP - 1); | |
3663 | ||
3664 | if (blkno == 0) { | |
3665 | dp->nblocks = dp->nfree = cpu_to_le32(nblocks); | |
3666 | dp->start = cpu_to_le64(Blkno); | |
3667 | ||
3668 | if (nblocks == BPERDMAP) { | |
3669 | memset(&dp->wmap[0], 0, LPERDMAP * 4); | |
3670 | memset(&dp->pmap[0], 0, LPERDMAP * 4); | |
3671 | goto initTree; | |
3672 | } | |
3673 | } else { | |
3674 | dp->nblocks = | |
3675 | cpu_to_le32(le32_to_cpu(dp->nblocks) + nblocks); | |
3676 | dp->nfree = cpu_to_le32(le32_to_cpu(dp->nfree) + nblocks); | |
3677 | } | |
3678 | ||
3679 | /* word number containing start block number */ | |
3680 | w = blkno >> L2DBWORD; | |
3681 | ||
3682 | /* | |
3683 | * free the bits corresponding to the block range (ZEROS): | |
3684 | * note: not all bits of the first and last words may be contained | |
3685 | * within the block range. | |
3686 | */ | |
3687 | for (r = nblocks; r > 0; r -= nb, blkno += nb) { | |
3688 | /* number of bits preceding range to be freed in the word */ | |
3689 | b = blkno & (DBWORD - 1); | |
3690 | /* number of bits to free in the word */ | |
3691 | nb = min(r, DBWORD - b); | |
3692 | ||
3693 | /* is partial word to be freed ? */ | |
3694 | if (nb < DBWORD) { | |
3695 | /* free (set to 0) from the bitmap word */ | |
3696 | dp->wmap[w] &= cpu_to_le32(~(ONES << (DBWORD - nb) | |
3697 | >> b)); | |
3698 | dp->pmap[w] &= cpu_to_le32(~(ONES << (DBWORD - nb) | |
3699 | >> b)); | |
3700 | ||
3701 | /* skip the word freed */ | |
3702 | w++; | |
3703 | } else { | |
3704 | /* free (set to 0) contiguous bitmap words */ | |
3705 | nw = r >> L2DBWORD; | |
3706 | memset(&dp->wmap[w], 0, nw * 4); | |
3707 | memset(&dp->pmap[w], 0, nw * 4); | |
3708 | ||
3709 | /* skip the words freed */ | |
3710 | nb = nw << L2DBWORD; | |
3711 | w += nw; | |
3712 | } | |
3713 | } | |
3714 | ||
3715 | /* | |
3716 | * mark bits following the range to be freed (non-existing | |
3717 | * blocks) as allocated (ONES) | |
3718 | */ | |
3719 | ||
3720 | if (blkno == BPERDMAP) | |
3721 | goto initTree; | |
3722 | ||
3723 | /* the first word beyond the end of existing blocks */ | |
3724 | w = blkno >> L2DBWORD; | |
3725 | ||
3726 | /* does nblocks fall on a 32-bit boundary ? */ | |
3727 | b = blkno & (DBWORD - 1); | |
3728 | if (b) { | |
3729 | /* mark a partial word allocated */ | |
3730 | dp->wmap[w] = dp->pmap[w] = cpu_to_le32(ONES >> b); | |
3731 | w++; | |
3732 | } | |
3733 | ||
3734 | /* set the rest of the words in the page to allocated (ONES) */ | |
3735 | for (i = w; i < LPERDMAP; i++) | |
3736 | dp->pmap[i] = dp->wmap[i] = cpu_to_le32(ONES); | |
3737 | ||
3738 | /* | |
3739 | * init tree | |
3740 | */ | |
3741 | initTree: | |
3742 | return (dbInitDmapTree(dp)); | |
3743 | } | |
3744 | ||
3745 | ||
3746 | /* | |
3747 | * NAME: dbInitDmapTree()/ujfs_complete_dmap() | |
3748 | * | |
3749 | * FUNCTION: initialize summary tree of the specified dmap: | |
3750 | * | |
3751 | * at entry, bitmap of the dmap has been initialized; | |
3752 | * | |
3753 | * PARAMETERS: | |
3754 | * dp - dmap to complete | |
3755 | * blkno - starting block number for this dmap | |
3756 | * treemax - will be filled in with max free for this dmap | |
3757 | * | |
3758 | * RETURNS: max free string at the root of the tree | |
3759 | */ | |
3760 | static int dbInitDmapTree(struct dmap * dp) | |
3761 | { | |
3762 | struct dmaptree *tp; | |
3763 | s8 *cp; | |
3764 | int i; | |
3765 | ||
3766 | /* init fixed info of tree */ | |
3767 | tp = &dp->tree; | |
3768 | tp->nleafs = cpu_to_le32(LPERDMAP); | |
3769 | tp->l2nleafs = cpu_to_le32(L2LPERDMAP); | |
3770 | tp->leafidx = cpu_to_le32(LEAFIND); | |
3771 | tp->height = cpu_to_le32(4); | |
3772 | tp->budmin = BUDMIN; | |
3773 | ||
3774 | /* init each leaf from corresponding wmap word: | |
3775 | * note: leaf is set to NOFREE(-1) if all blocks of corresponding | |
3776 | * bitmap word are allocated. | |
3777 | */ | |
3778 | cp = tp->stree + le32_to_cpu(tp->leafidx); | |
3779 | for (i = 0; i < LPERDMAP; i++) | |
3780 | *cp++ = dbMaxBud((u8 *) & dp->wmap[i]); | |
3781 | ||
3782 | /* build the dmap's binary buddy summary tree */ | |
3783 | return (dbInitTree(tp)); | |
3784 | } | |
3785 | ||
3786 | ||
3787 | /* | |
3788 | * NAME: dbInitTree()/ujfs_adjtree() | |
3789 | * | |
3790 | * FUNCTION: initialize binary buddy summary tree of a dmap or dmapctl. | |
3791 | * | |
3792 | * at entry, the leaves of the tree has been initialized | |
3793 | * from corresponding bitmap word or root of summary tree | |
3794 | * of the child control page; | |
3795 | * configure binary buddy system at the leaf level, then | |
3796 | * bubble up the values of the leaf nodes up the tree. | |
3797 | * | |
3798 | * PARAMETERS: | |
3799 | * cp - Pointer to the root of the tree | |
3800 | * l2leaves- Number of leaf nodes as a power of 2 | |
3801 | * l2min - Number of blocks that can be covered by a leaf | |
3802 | * as a power of 2 | |
3803 | * | |
3804 | * RETURNS: max free string at the root of the tree | |
3805 | */ | |
3806 | static int dbInitTree(struct dmaptree * dtp) | |
3807 | { | |
3808 | int l2max, l2free, bsize, nextb, i; | |
3809 | int child, parent, nparent; | |
3810 | s8 *tp, *cp, *cp1; | |
3811 | ||
3812 | tp = dtp->stree; | |
3813 | ||
3814 | /* Determine the maximum free string possible for the leaves */ | |
3815 | l2max = le32_to_cpu(dtp->l2nleafs) + dtp->budmin; | |
3816 | ||
3817 | /* | |
3818 | * configure the leaf levevl into binary buddy system | |
3819 | * | |
3820 | * Try to combine buddies starting with a buddy size of 1 | |
3821 | * (i.e. two leaves). At a buddy size of 1 two buddy leaves | |
3822 | * can be combined if both buddies have a maximum free of l2min; | |
3823 | * the combination will result in the left-most buddy leaf having | |
3824 | * a maximum free of l2min+1. | |
3825 | * After processing all buddies for a given size, process buddies | |
3826 | * at the next higher buddy size (i.e. current size * 2) and | |
3827 | * the next maximum free (current free + 1). | |
3828 | * This continues until the maximum possible buddy combination | |
3829 | * yields maximum free. | |
3830 | */ | |
3831 | for (l2free = dtp->budmin, bsize = 1; l2free < l2max; | |
3832 | l2free++, bsize = nextb) { | |
3833 | /* get next buddy size == current buddy pair size */ | |
3834 | nextb = bsize << 1; | |
3835 | ||
3836 | /* scan each adjacent buddy pair at current buddy size */ | |
3837 | for (i = 0, cp = tp + le32_to_cpu(dtp->leafidx); | |
3838 | i < le32_to_cpu(dtp->nleafs); | |
3839 | i += nextb, cp += nextb) { | |
3840 | /* coalesce if both adjacent buddies are max free */ | |
3841 | if (*cp == l2free && *(cp + bsize) == l2free) { | |
3842 | *cp = l2free + 1; /* left take right */ | |
3843 | *(cp + bsize) = -1; /* right give left */ | |
3844 | } | |
3845 | } | |
3846 | } | |
3847 | ||
3848 | /* | |
3849 | * bubble summary information of leaves up the tree. | |
3850 | * | |
3851 | * Starting at the leaf node level, the four nodes described by | |
3852 | * the higher level parent node are compared for a maximum free and | |
3853 | * this maximum becomes the value of the parent node. | |
3854 | * when all lower level nodes are processed in this fashion then | |
3855 | * move up to the next level (parent becomes a lower level node) and | |
3856 | * continue the process for that level. | |
3857 | */ | |
3858 | for (child = le32_to_cpu(dtp->leafidx), | |
3859 | nparent = le32_to_cpu(dtp->nleafs) >> 2; | |
3860 | nparent > 0; nparent >>= 2, child = parent) { | |
3861 | /* get index of 1st node of parent level */ | |
3862 | parent = (child - 1) >> 2; | |
3863 | ||
3864 | /* set the value of the parent node as the maximum | |
3865 | * of the four nodes of the current level. | |
3866 | */ | |
3867 | for (i = 0, cp = tp + child, cp1 = tp + parent; | |
3868 | i < nparent; i++, cp += 4, cp1++) | |
3869 | *cp1 = TREEMAX(cp); | |
3870 | } | |
3871 | ||
3872 | return (*tp); | |
3873 | } | |
3874 | ||
3875 | ||
3876 | /* | |
3877 | * dbInitDmapCtl() | |
3878 | * | |
3879 | * function: initialize dmapctl page | |
3880 | */ | |
3881 | static int dbInitDmapCtl(struct dmapctl * dcp, int level, int i) | |
3882 | { /* start leaf index not covered by range */ | |
3883 | s8 *cp; | |
3884 | ||
3885 | dcp->nleafs = cpu_to_le32(LPERCTL); | |
3886 | dcp->l2nleafs = cpu_to_le32(L2LPERCTL); | |
3887 | dcp->leafidx = cpu_to_le32(CTLLEAFIND); | |
3888 | dcp->height = cpu_to_le32(5); | |
3889 | dcp->budmin = L2BPERDMAP + L2LPERCTL * level; | |
3890 | ||
3891 | /* | |
3892 | * initialize the leaves of current level that were not covered | |
3893 | * by the specified input block range (i.e. the leaves have no | |
3894 | * low level dmapctl or dmap). | |
3895 | */ | |
3896 | cp = &dcp->stree[CTLLEAFIND + i]; | |
3897 | for (; i < LPERCTL; i++) | |
3898 | *cp++ = NOFREE; | |
3899 | ||
3900 | /* build the dmap's binary buddy summary tree */ | |
3901 | return (dbInitTree((struct dmaptree *) dcp)); | |
3902 | } | |
3903 | ||
3904 | ||
3905 | /* | |
3906 | * NAME: dbGetL2AGSize()/ujfs_getagl2size() | |
3907 | * | |
3908 | * FUNCTION: Determine log2(allocation group size) from aggregate size | |
3909 | * | |
3910 | * PARAMETERS: | |
3911 | * nblocks - Number of blocks in aggregate | |
3912 | * | |
3913 | * RETURNS: log2(allocation group size) in aggregate blocks | |
3914 | */ | |
3915 | static int dbGetL2AGSize(s64 nblocks) | |
3916 | { | |
3917 | s64 sz; | |
3918 | s64 m; | |
3919 | int l2sz; | |
3920 | ||
3921 | if (nblocks < BPERDMAP * MAXAG) | |
3922 | return (L2BPERDMAP); | |
3923 | ||
3924 | /* round up aggregate size to power of 2 */ | |
3925 | m = ((u64) 1 << (64 - 1)); | |
3926 | for (l2sz = 64; l2sz >= 0; l2sz--, m >>= 1) { | |
3927 | if (m & nblocks) | |
3928 | break; | |
3929 | } | |
3930 | ||
3931 | sz = (s64) 1 << l2sz; | |
3932 | if (sz < nblocks) | |
3933 | l2sz += 1; | |
3934 | ||
3935 | /* agsize = roundupSize/max_number_of_ag */ | |
3936 | return (l2sz - L2MAXAG); | |
3937 | } | |
3938 | ||
3939 | ||
3940 | /* | |
3941 | * NAME: dbMapFileSizeToMapSize() | |
3942 | * | |
3943 | * FUNCTION: compute number of blocks the block allocation map file | |
3944 | * can cover from the map file size; | |
3945 | * | |
3946 | * RETURNS: Number of blocks which can be covered by this block map file; | |
3947 | */ | |
3948 | ||
3949 | /* | |
3950 | * maximum number of map pages at each level including control pages | |
3951 | */ | |
3952 | #define MAXL0PAGES (1 + LPERCTL) | |
3953 | #define MAXL1PAGES (1 + LPERCTL * MAXL0PAGES) | |
3954 | #define MAXL2PAGES (1 + LPERCTL * MAXL1PAGES) | |
3955 | ||
3956 | /* | |
3957 | * convert number of map pages to the zero origin top dmapctl level | |
3958 | */ | |
3959 | #define BMAPPGTOLEV(npages) \ | |
3960 | (((npages) <= 3 + MAXL0PAGES) ? 0 \ | |
3961 | : ((npages) <= 2 + MAXL1PAGES) ? 1 : 2) | |
3962 | ||
3963 | s64 dbMapFileSizeToMapSize(struct inode * ipbmap) | |
3964 | { | |
3965 | struct super_block *sb = ipbmap->i_sb; | |
3966 | s64 nblocks; | |
3967 | s64 npages, ndmaps; | |
3968 | int level, i; | |
3969 | int complete, factor; | |
3970 | ||
3971 | nblocks = ipbmap->i_size >> JFS_SBI(sb)->l2bsize; | |
3972 | npages = nblocks >> JFS_SBI(sb)->l2nbperpage; | |
3973 | level = BMAPPGTOLEV(npages); | |
3974 | ||
3975 | /* At each level, accumulate the number of dmap pages covered by | |
3976 | * the number of full child levels below it; | |
3977 | * repeat for the last incomplete child level. | |
3978 | */ | |
3979 | ndmaps = 0; | |
3980 | npages--; /* skip the first global control page */ | |
3981 | /* skip higher level control pages above top level covered by map */ | |
3982 | npages -= (2 - level); | |
3983 | npages--; /* skip top level's control page */ | |
3984 | for (i = level; i >= 0; i--) { | |
3985 | factor = | |
3986 | (i == 2) ? MAXL1PAGES : ((i == 1) ? MAXL0PAGES : 1); | |
3987 | complete = (u32) npages / factor; | |
3988 | ndmaps += complete * ((i == 2) ? LPERCTL * LPERCTL | |
3989 | : ((i == 1) ? LPERCTL : 1)); | |
3990 | ||
3991 | /* pages in last/incomplete child */ | |
3992 | npages = (u32) npages % factor; | |
3993 | /* skip incomplete child's level control page */ | |
3994 | npages--; | |
3995 | } | |
3996 | ||
3997 | /* convert the number of dmaps into the number of blocks | |
3998 | * which can be covered by the dmaps; | |
3999 | */ | |
4000 | nblocks = ndmaps << L2BPERDMAP; | |
4001 | ||
4002 | return (nblocks); | |
4003 | } |