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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (C) International Business Machines Corp., 2000-2004
4 * Portions Copyright (C) Tino Reichardt, 2012
5 */
6
7#include <linux/fs.h>
8#include <linux/slab.h>
9#include "jfs_incore.h"
10#include "jfs_superblock.h"
11#include "jfs_dmap.h"
12#include "jfs_imap.h"
13#include "jfs_lock.h"
14#include "jfs_metapage.h"
15#include "jfs_debug.h"
16#include "jfs_discard.h"
17
18/*
19 * SERIALIZATION of the Block Allocation Map.
20 *
21 * the working state of the block allocation map is accessed in
22 * two directions:
23 *
24 * 1) allocation and free requests that start at the dmap
25 * level and move up through the dmap control pages (i.e.
26 * the vast majority of requests).
27 *
28 * 2) allocation requests that start at dmap control page
29 * level and work down towards the dmaps.
30 *
31 * the serialization scheme used here is as follows.
32 *
33 * requests which start at the bottom are serialized against each
34 * other through buffers and each requests holds onto its buffers
35 * as it works it way up from a single dmap to the required level
36 * of dmap control page.
37 * requests that start at the top are serialized against each other
38 * and request that start from the bottom by the multiple read/single
39 * write inode lock of the bmap inode. requests starting at the top
40 * take this lock in write mode while request starting at the bottom
41 * take the lock in read mode. a single top-down request may proceed
42 * exclusively while multiple bottoms-up requests may proceed
43 * simultaneously (under the protection of busy buffers).
44 *
45 * in addition to information found in dmaps and dmap control pages,
46 * the working state of the block allocation map also includes read/
47 * write information maintained in the bmap descriptor (i.e. total
48 * free block count, allocation group level free block counts).
49 * a single exclusive lock (BMAP_LOCK) is used to guard this information
50 * in the face of multiple-bottoms up requests.
51 * (lock ordering: IREAD_LOCK, BMAP_LOCK);
52 *
53 * accesses to the persistent state of the block allocation map (limited
54 * to the persistent bitmaps in dmaps) is guarded by (busy) buffers.
55 */
56
57#define BMAP_LOCK_INIT(bmp) mutex_init(&bmp->db_bmaplock)
58#define BMAP_LOCK(bmp) mutex_lock(&bmp->db_bmaplock)
59#define BMAP_UNLOCK(bmp) mutex_unlock(&bmp->db_bmaplock)
60
61/*
62 * forward references
63 */
64static void dbAllocBits(struct bmap * bmp, struct dmap * dp, s64 blkno,
65 int nblocks);
66static void dbSplit(dmtree_t *tp, int leafno, int splitsz, int newval, bool is_ctl);
67static int dbBackSplit(dmtree_t *tp, int leafno, bool is_ctl);
68static int dbJoin(dmtree_t *tp, int leafno, int newval, bool is_ctl);
69static void dbAdjTree(dmtree_t *tp, int leafno, int newval, bool is_ctl);
70static int dbAdjCtl(struct bmap * bmp, s64 blkno, int newval, int alloc,
71 int level);
72static int dbAllocAny(struct bmap * bmp, s64 nblocks, int l2nb, s64 * results);
73static int dbAllocNext(struct bmap * bmp, struct dmap * dp, s64 blkno,
74 int nblocks);
75static int dbAllocNear(struct bmap * bmp, struct dmap * dp, s64 blkno,
76 int nblocks,
77 int l2nb, s64 * results);
78static int dbAllocDmap(struct bmap * bmp, struct dmap * dp, s64 blkno,
79 int nblocks);
80static int dbAllocDmapLev(struct bmap * bmp, struct dmap * dp, int nblocks,
81 int l2nb,
82 s64 * results);
83static int dbAllocAG(struct bmap * bmp, int agno, s64 nblocks, int l2nb,
84 s64 * results);
85static int dbAllocCtl(struct bmap * bmp, s64 nblocks, int l2nb, s64 blkno,
86 s64 * results);
87static int dbExtend(struct inode *ip, s64 blkno, s64 nblocks, s64 addnblocks);
88static int dbFindBits(u32 word, int l2nb);
89static int dbFindCtl(struct bmap * bmp, int l2nb, int level, s64 * blkno);
90static int dbFindLeaf(dmtree_t *tp, int l2nb, int *leafidx, bool is_ctl);
91static int dbFreeBits(struct bmap * bmp, struct dmap * dp, s64 blkno,
92 int nblocks);
93static int dbFreeDmap(struct bmap * bmp, struct dmap * dp, s64 blkno,
94 int nblocks);
95static int dbMaxBud(u8 * cp);
96static int blkstol2(s64 nb);
97
98static int cntlz(u32 value);
99static int cnttz(u32 word);
100
101static int dbAllocDmapBU(struct bmap * bmp, struct dmap * dp, s64 blkno,
102 int nblocks);
103static int dbInitDmap(struct dmap * dp, s64 blkno, int nblocks);
104static int dbInitDmapTree(struct dmap * dp);
105static int dbInitTree(struct dmaptree * dtp);
106static int dbInitDmapCtl(struct dmapctl * dcp, int level, int i);
107static int dbGetL2AGSize(s64 nblocks);
108
109/*
110 * buddy table
111 *
112 * table used for determining buddy sizes within characters of
113 * dmap bitmap words. the characters themselves serve as indexes
114 * into the table, with the table elements yielding the maximum
115 * binary buddy of free bits within the character.
116 */
117static const s8 budtab[256] = {
118 3, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
119 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
120 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
121 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
122 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
123 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0,
124 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0,
125 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0,
126 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
127 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0,
128 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0,
129 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0,
130 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
131 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0,
132 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0,
133 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, -1
134};
135
136/*
137 * NAME: dbMount()
138 *
139 * FUNCTION: initializate the block allocation map.
140 *
141 * memory is allocated for the in-core bmap descriptor and
142 * the in-core descriptor is initialized from disk.
143 *
144 * PARAMETERS:
145 * ipbmap - pointer to in-core inode for the block map.
146 *
147 * RETURN VALUES:
148 * 0 - success
149 * -ENOMEM - insufficient memory
150 * -EIO - i/o error
151 * -EINVAL - wrong bmap data
152 */
153int dbMount(struct inode *ipbmap)
154{
155 struct bmap *bmp;
156 struct dbmap_disk *dbmp_le;
157 struct metapage *mp;
158 int i, err;
159
160 /*
161 * allocate/initialize the in-memory bmap descriptor
162 */
163 /* allocate memory for the in-memory bmap descriptor */
164 bmp = kmalloc(sizeof(struct bmap), GFP_KERNEL);
165 if (bmp == NULL)
166 return -ENOMEM;
167
168 /* read the on-disk bmap descriptor. */
169 mp = read_metapage(ipbmap,
170 BMAPBLKNO << JFS_SBI(ipbmap->i_sb)->l2nbperpage,
171 PSIZE, 0);
172 if (mp == NULL) {
173 err = -EIO;
174 goto err_kfree_bmp;
175 }
176
177 /* copy the on-disk bmap descriptor to its in-memory version. */
178 dbmp_le = (struct dbmap_disk *) mp->data;
179 bmp->db_mapsize = le64_to_cpu(dbmp_le->dn_mapsize);
180 bmp->db_nfree = le64_to_cpu(dbmp_le->dn_nfree);
181
182 bmp->db_l2nbperpage = le32_to_cpu(dbmp_le->dn_l2nbperpage);
183 if (bmp->db_l2nbperpage > L2PSIZE - L2MINBLOCKSIZE ||
184 bmp->db_l2nbperpage < 0) {
185 err = -EINVAL;
186 goto err_release_metapage;
187 }
188
189 bmp->db_numag = le32_to_cpu(dbmp_le->dn_numag);
190 if (!bmp->db_numag) {
191 err = -EINVAL;
192 goto err_release_metapage;
193 }
194
195 bmp->db_maxlevel = le32_to_cpu(dbmp_le->dn_maxlevel);
196 bmp->db_maxag = le32_to_cpu(dbmp_le->dn_maxag);
197 bmp->db_agpref = le32_to_cpu(dbmp_le->dn_agpref);
198 if (bmp->db_maxag >= MAXAG || bmp->db_maxag < 0 ||
199 bmp->db_agpref >= MAXAG || bmp->db_agpref < 0) {
200 err = -EINVAL;
201 goto err_release_metapage;
202 }
203
204 bmp->db_aglevel = le32_to_cpu(dbmp_le->dn_aglevel);
205 bmp->db_agheight = le32_to_cpu(dbmp_le->dn_agheight);
206 bmp->db_agwidth = le32_to_cpu(dbmp_le->dn_agwidth);
207 bmp->db_agstart = le32_to_cpu(dbmp_le->dn_agstart);
208 bmp->db_agl2size = le32_to_cpu(dbmp_le->dn_agl2size);
209 if (bmp->db_agl2size > L2MAXL2SIZE - L2MAXAG ||
210 bmp->db_agl2size < 0) {
211 err = -EINVAL;
212 goto err_release_metapage;
213 }
214
215 if (((bmp->db_mapsize - 1) >> bmp->db_agl2size) > MAXAG) {
216 err = -EINVAL;
217 goto err_release_metapage;
218 }
219
220 for (i = 0; i < MAXAG; i++)
221 bmp->db_agfree[i] = le64_to_cpu(dbmp_le->dn_agfree[i]);
222 bmp->db_agsize = le64_to_cpu(dbmp_le->dn_agsize);
223 bmp->db_maxfreebud = dbmp_le->dn_maxfreebud;
224
225 /* release the buffer. */
226 release_metapage(mp);
227
228 /* bind the bmap inode and the bmap descriptor to each other. */
229 bmp->db_ipbmap = ipbmap;
230 JFS_SBI(ipbmap->i_sb)->bmap = bmp;
231
232 memset(bmp->db_active, 0, sizeof(bmp->db_active));
233
234 /*
235 * allocate/initialize the bmap lock
236 */
237 BMAP_LOCK_INIT(bmp);
238
239 return (0);
240
241err_release_metapage:
242 release_metapage(mp);
243err_kfree_bmp:
244 kfree(bmp);
245 return err;
246}
247
248
249/*
250 * NAME: dbUnmount()
251 *
252 * FUNCTION: terminate the block allocation map in preparation for
253 * file system unmount.
254 *
255 * the in-core bmap descriptor is written to disk and
256 * the memory for this descriptor is freed.
257 *
258 * PARAMETERS:
259 * ipbmap - pointer to in-core inode for the block map.
260 *
261 * RETURN VALUES:
262 * 0 - success
263 * -EIO - i/o error
264 */
265int dbUnmount(struct inode *ipbmap, int mounterror)
266{
267 struct bmap *bmp = JFS_SBI(ipbmap->i_sb)->bmap;
268
269 if (!(mounterror || isReadOnly(ipbmap)))
270 dbSync(ipbmap);
271
272 /*
273 * Invalidate the page cache buffers
274 */
275 truncate_inode_pages(ipbmap->i_mapping, 0);
276
277 /* free the memory for the in-memory bmap. */
278 kfree(bmp);
279 JFS_SBI(ipbmap->i_sb)->bmap = NULL;
280
281 return (0);
282}
283
284/*
285 * dbSync()
286 */
287int dbSync(struct inode *ipbmap)
288{
289 struct dbmap_disk *dbmp_le;
290 struct bmap *bmp = JFS_SBI(ipbmap->i_sb)->bmap;
291 struct metapage *mp;
292 int i;
293
294 /*
295 * write bmap global control page
296 */
297 /* get the buffer for the on-disk bmap descriptor. */
298 mp = read_metapage(ipbmap,
299 BMAPBLKNO << JFS_SBI(ipbmap->i_sb)->l2nbperpage,
300 PSIZE, 0);
301 if (mp == NULL) {
302 jfs_err("dbSync: read_metapage failed!");
303 return -EIO;
304 }
305 /* copy the in-memory version of the bmap to the on-disk version */
306 dbmp_le = (struct dbmap_disk *) mp->data;
307 dbmp_le->dn_mapsize = cpu_to_le64(bmp->db_mapsize);
308 dbmp_le->dn_nfree = cpu_to_le64(bmp->db_nfree);
309 dbmp_le->dn_l2nbperpage = cpu_to_le32(bmp->db_l2nbperpage);
310 dbmp_le->dn_numag = cpu_to_le32(bmp->db_numag);
311 dbmp_le->dn_maxlevel = cpu_to_le32(bmp->db_maxlevel);
312 dbmp_le->dn_maxag = cpu_to_le32(bmp->db_maxag);
313 dbmp_le->dn_agpref = cpu_to_le32(bmp->db_agpref);
314 dbmp_le->dn_aglevel = cpu_to_le32(bmp->db_aglevel);
315 dbmp_le->dn_agheight = cpu_to_le32(bmp->db_agheight);
316 dbmp_le->dn_agwidth = cpu_to_le32(bmp->db_agwidth);
317 dbmp_le->dn_agstart = cpu_to_le32(bmp->db_agstart);
318 dbmp_le->dn_agl2size = cpu_to_le32(bmp->db_agl2size);
319 for (i = 0; i < MAXAG; i++)
320 dbmp_le->dn_agfree[i] = cpu_to_le64(bmp->db_agfree[i]);
321 dbmp_le->dn_agsize = cpu_to_le64(bmp->db_agsize);
322 dbmp_le->dn_maxfreebud = bmp->db_maxfreebud;
323
324 /* write the buffer */
325 write_metapage(mp);
326
327 /*
328 * write out dirty pages of bmap
329 */
330 filemap_write_and_wait(ipbmap->i_mapping);
331
332 diWriteSpecial(ipbmap, 0);
333
334 return (0);
335}
336
337/*
338 * NAME: dbFree()
339 *
340 * FUNCTION: free the specified block range from the working block
341 * allocation map.
342 *
343 * the blocks will be free from the working map one dmap
344 * at a time.
345 *
346 * PARAMETERS:
347 * ip - pointer to in-core inode;
348 * blkno - starting block number to be freed.
349 * nblocks - number of blocks to be freed.
350 *
351 * RETURN VALUES:
352 * 0 - success
353 * -EIO - i/o error
354 */
355int dbFree(struct inode *ip, s64 blkno, s64 nblocks)
356{
357 struct metapage *mp;
358 struct dmap *dp;
359 int nb, rc;
360 s64 lblkno, rem;
361 struct inode *ipbmap = JFS_SBI(ip->i_sb)->ipbmap;
362 struct bmap *bmp = JFS_SBI(ip->i_sb)->bmap;
363 struct super_block *sb = ipbmap->i_sb;
364
365 IREAD_LOCK(ipbmap, RDWRLOCK_DMAP);
366
367 /* block to be freed better be within the mapsize. */
368 if (unlikely((blkno == 0) || (blkno + nblocks > bmp->db_mapsize))) {
369 IREAD_UNLOCK(ipbmap);
370 printk(KERN_ERR "blkno = %Lx, nblocks = %Lx\n",
371 (unsigned long long) blkno,
372 (unsigned long long) nblocks);
373 jfs_error(ip->i_sb, "block to be freed is outside the map\n");
374 return -EIO;
375 }
376
377 /**
378 * TRIM the blocks, when mounted with discard option
379 */
380 if (JFS_SBI(sb)->flag & JFS_DISCARD)
381 if (JFS_SBI(sb)->minblks_trim <= nblocks)
382 jfs_issue_discard(ipbmap, blkno, nblocks);
383
384 /*
385 * free the blocks a dmap at a time.
386 */
387 mp = NULL;
388 for (rem = nblocks; rem > 0; rem -= nb, blkno += nb) {
389 /* release previous dmap if any */
390 if (mp) {
391 write_metapage(mp);
392 }
393
394 /* get the buffer for the current dmap. */
395 lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage);
396 mp = read_metapage(ipbmap, lblkno, PSIZE, 0);
397 if (mp == NULL) {
398 IREAD_UNLOCK(ipbmap);
399 return -EIO;
400 }
401 dp = (struct dmap *) mp->data;
402
403 /* determine the number of blocks to be freed from
404 * this dmap.
405 */
406 nb = min(rem, BPERDMAP - (blkno & (BPERDMAP - 1)));
407
408 /* free the blocks. */
409 if ((rc = dbFreeDmap(bmp, dp, blkno, nb))) {
410 jfs_error(ip->i_sb, "error in block map\n");
411 release_metapage(mp);
412 IREAD_UNLOCK(ipbmap);
413 return (rc);
414 }
415 }
416
417 /* write the last buffer. */
418 if (mp)
419 write_metapage(mp);
420
421 IREAD_UNLOCK(ipbmap);
422
423 return (0);
424}
425
426
427/*
428 * NAME: dbUpdatePMap()
429 *
430 * FUNCTION: update the allocation state (free or allocate) of the
431 * specified block range in the persistent block allocation map.
432 *
433 * the blocks will be updated in the persistent map one
434 * dmap at a time.
435 *
436 * PARAMETERS:
437 * ipbmap - pointer to in-core inode for the block map.
438 * free - 'true' if block range is to be freed from the persistent
439 * map; 'false' if it is to be allocated.
440 * blkno - starting block number of the range.
441 * nblocks - number of contiguous blocks in the range.
442 * tblk - transaction block;
443 *
444 * RETURN VALUES:
445 * 0 - success
446 * -EIO - i/o error
447 */
448int
449dbUpdatePMap(struct inode *ipbmap,
450 int free, s64 blkno, s64 nblocks, struct tblock * tblk)
451{
452 int nblks, dbitno, wbitno, rbits;
453 int word, nbits, nwords;
454 struct bmap *bmp = JFS_SBI(ipbmap->i_sb)->bmap;
455 s64 lblkno, rem, lastlblkno;
456 u32 mask;
457 struct dmap *dp;
458 struct metapage *mp;
459 struct jfs_log *log;
460 int lsn, difft, diffp;
461 unsigned long flags;
462
463 /* the blocks better be within the mapsize. */
464 if (blkno + nblocks > bmp->db_mapsize) {
465 printk(KERN_ERR "blkno = %Lx, nblocks = %Lx\n",
466 (unsigned long long) blkno,
467 (unsigned long long) nblocks);
468 jfs_error(ipbmap->i_sb, "blocks are outside the map\n");
469 return -EIO;
470 }
471
472 /* compute delta of transaction lsn from log syncpt */
473 lsn = tblk->lsn;
474 log = (struct jfs_log *) JFS_SBI(tblk->sb)->log;
475 logdiff(difft, lsn, log);
476
477 /*
478 * update the block state a dmap at a time.
479 */
480 mp = NULL;
481 lastlblkno = 0;
482 for (rem = nblocks; rem > 0; rem -= nblks, blkno += nblks) {
483 /* get the buffer for the current dmap. */
484 lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage);
485 if (lblkno != lastlblkno) {
486 if (mp) {
487 write_metapage(mp);
488 }
489
490 mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE,
491 0);
492 if (mp == NULL)
493 return -EIO;
494 metapage_wait_for_io(mp);
495 }
496 dp = (struct dmap *) mp->data;
497
498 /* determine the bit number and word within the dmap of
499 * the starting block. also determine how many blocks
500 * are to be updated within this dmap.
501 */
502 dbitno = blkno & (BPERDMAP - 1);
503 word = dbitno >> L2DBWORD;
504 nblks = min(rem, (s64)BPERDMAP - dbitno);
505
506 /* update the bits of the dmap words. the first and last
507 * words may only have a subset of their bits updated. if
508 * this is the case, we'll work against that word (i.e.
509 * partial first and/or last) only in a single pass. a
510 * single pass will also be used to update all words that
511 * are to have all their bits updated.
512 */
513 for (rbits = nblks; rbits > 0;
514 rbits -= nbits, dbitno += nbits) {
515 /* determine the bit number within the word and
516 * the number of bits within the word.
517 */
518 wbitno = dbitno & (DBWORD - 1);
519 nbits = min(rbits, DBWORD - wbitno);
520
521 /* check if only part of the word is to be updated. */
522 if (nbits < DBWORD) {
523 /* update (free or allocate) the bits
524 * in this word.
525 */
526 mask =
527 (ONES << (DBWORD - nbits) >> wbitno);
528 if (free)
529 dp->pmap[word] &=
530 cpu_to_le32(~mask);
531 else
532 dp->pmap[word] |=
533 cpu_to_le32(mask);
534
535 word += 1;
536 } else {
537 /* one or more words are to have all
538 * their bits updated. determine how
539 * many words and how many bits.
540 */
541 nwords = rbits >> L2DBWORD;
542 nbits = nwords << L2DBWORD;
543
544 /* update (free or allocate) the bits
545 * in these words.
546 */
547 if (free)
548 memset(&dp->pmap[word], 0,
549 nwords * 4);
550 else
551 memset(&dp->pmap[word], (int) ONES,
552 nwords * 4);
553
554 word += nwords;
555 }
556 }
557
558 /*
559 * update dmap lsn
560 */
561 if (lblkno == lastlblkno)
562 continue;
563
564 lastlblkno = lblkno;
565
566 LOGSYNC_LOCK(log, flags);
567 if (mp->lsn != 0) {
568 /* inherit older/smaller lsn */
569 logdiff(diffp, mp->lsn, log);
570 if (difft < diffp) {
571 mp->lsn = lsn;
572
573 /* move bp after tblock in logsync list */
574 list_move(&mp->synclist, &tblk->synclist);
575 }
576
577 /* inherit younger/larger clsn */
578 logdiff(difft, tblk->clsn, log);
579 logdiff(diffp, mp->clsn, log);
580 if (difft > diffp)
581 mp->clsn = tblk->clsn;
582 } else {
583 mp->log = log;
584 mp->lsn = lsn;
585
586 /* insert bp after tblock in logsync list */
587 log->count++;
588 list_add(&mp->synclist, &tblk->synclist);
589
590 mp->clsn = tblk->clsn;
591 }
592 LOGSYNC_UNLOCK(log, flags);
593 }
594
595 /* write the last buffer. */
596 if (mp) {
597 write_metapage(mp);
598 }
599
600 return (0);
601}
602
603
604/*
605 * NAME: dbNextAG()
606 *
607 * FUNCTION: find the preferred allocation group for new allocations.
608 *
609 * Within the allocation groups, we maintain a preferred
610 * allocation group which consists of a group with at least
611 * average free space. It is the preferred group that we target
612 * new inode allocation towards. The tie-in between inode
613 * allocation and block allocation occurs as we allocate the
614 * first (data) block of an inode and specify the inode (block)
615 * as the allocation hint for this block.
616 *
617 * We try to avoid having more than one open file growing in
618 * an allocation group, as this will lead to fragmentation.
619 * This differs from the old OS/2 method of trying to keep
620 * empty ags around for large allocations.
621 *
622 * PARAMETERS:
623 * ipbmap - pointer to in-core inode for the block map.
624 *
625 * RETURN VALUES:
626 * the preferred allocation group number.
627 */
628int dbNextAG(struct inode *ipbmap)
629{
630 s64 avgfree;
631 int agpref;
632 s64 hwm = 0;
633 int i;
634 int next_best = -1;
635 struct bmap *bmp = JFS_SBI(ipbmap->i_sb)->bmap;
636
637 BMAP_LOCK(bmp);
638
639 /* determine the average number of free blocks within the ags. */
640 avgfree = (u32)bmp->db_nfree / bmp->db_numag;
641
642 /*
643 * if the current preferred ag does not have an active allocator
644 * and has at least average freespace, return it
645 */
646 agpref = bmp->db_agpref;
647 if ((atomic_read(&bmp->db_active[agpref]) == 0) &&
648 (bmp->db_agfree[agpref] >= avgfree))
649 goto unlock;
650
651 /* From the last preferred ag, find the next one with at least
652 * average free space.
653 */
654 for (i = 0 ; i < bmp->db_numag; i++, agpref++) {
655 if (agpref == bmp->db_numag)
656 agpref = 0;
657
658 if (atomic_read(&bmp->db_active[agpref]))
659 /* open file is currently growing in this ag */
660 continue;
661 if (bmp->db_agfree[agpref] >= avgfree) {
662 /* Return this one */
663 bmp->db_agpref = agpref;
664 goto unlock;
665 } else if (bmp->db_agfree[agpref] > hwm) {
666 /* Less than avg. freespace, but best so far */
667 hwm = bmp->db_agfree[agpref];
668 next_best = agpref;
669 }
670 }
671
672 /*
673 * If no inactive ag was found with average freespace, use the
674 * next best
675 */
676 if (next_best != -1)
677 bmp->db_agpref = next_best;
678 /* else leave db_agpref unchanged */
679unlock:
680 BMAP_UNLOCK(bmp);
681
682 /* return the preferred group.
683 */
684 return (bmp->db_agpref);
685}
686
687/*
688 * NAME: dbAlloc()
689 *
690 * FUNCTION: attempt to allocate a specified number of contiguous free
691 * blocks from the working allocation block map.
692 *
693 * the block allocation policy uses hints and a multi-step
694 * approach.
695 *
696 * for allocation requests smaller than the number of blocks
697 * per dmap, we first try to allocate the new blocks
698 * immediately following the hint. if these blocks are not
699 * available, we try to allocate blocks near the hint. if
700 * no blocks near the hint are available, we next try to
701 * allocate within the same dmap as contains the hint.
702 *
703 * if no blocks are available in the dmap or the allocation
704 * request is larger than the dmap size, we try to allocate
705 * within the same allocation group as contains the hint. if
706 * this does not succeed, we finally try to allocate anywhere
707 * within the aggregate.
708 *
709 * we also try to allocate anywhere within the aggregate
710 * for allocation requests larger than the allocation group
711 * size or requests that specify no hint value.
712 *
713 * PARAMETERS:
714 * ip - pointer to in-core inode;
715 * hint - allocation hint.
716 * nblocks - number of contiguous blocks in the range.
717 * results - on successful return, set to the starting block number
718 * of the newly allocated contiguous range.
719 *
720 * RETURN VALUES:
721 * 0 - success
722 * -ENOSPC - insufficient disk resources
723 * -EIO - i/o error
724 */
725int dbAlloc(struct inode *ip, s64 hint, s64 nblocks, s64 * results)
726{
727 int rc, agno;
728 struct inode *ipbmap = JFS_SBI(ip->i_sb)->ipbmap;
729 struct bmap *bmp;
730 struct metapage *mp;
731 s64 lblkno, blkno;
732 struct dmap *dp;
733 int l2nb;
734 s64 mapSize;
735 int writers;
736
737 /* assert that nblocks is valid */
738 assert(nblocks > 0);
739
740 /* get the log2 number of blocks to be allocated.
741 * if the number of blocks is not a log2 multiple,
742 * it will be rounded up to the next log2 multiple.
743 */
744 l2nb = BLKSTOL2(nblocks);
745
746 bmp = JFS_SBI(ip->i_sb)->bmap;
747
748 mapSize = bmp->db_mapsize;
749
750 /* the hint should be within the map */
751 if (hint >= mapSize) {
752 jfs_error(ip->i_sb, "the hint is outside the map\n");
753 return -EIO;
754 }
755
756 /* if the number of blocks to be allocated is greater than the
757 * allocation group size, try to allocate anywhere.
758 */
759 if (l2nb > bmp->db_agl2size) {
760 IWRITE_LOCK(ipbmap, RDWRLOCK_DMAP);
761
762 rc = dbAllocAny(bmp, nblocks, l2nb, results);
763
764 goto write_unlock;
765 }
766
767 /*
768 * If no hint, let dbNextAG recommend an allocation group
769 */
770 if (hint == 0)
771 goto pref_ag;
772
773 /* we would like to allocate close to the hint. adjust the
774 * hint to the block following the hint since the allocators
775 * will start looking for free space starting at this point.
776 */
777 blkno = hint + 1;
778
779 if (blkno >= bmp->db_mapsize)
780 goto pref_ag;
781
782 agno = blkno >> bmp->db_agl2size;
783
784 /* check if blkno crosses over into a new allocation group.
785 * if so, check if we should allow allocations within this
786 * allocation group.
787 */
788 if ((blkno & (bmp->db_agsize - 1)) == 0)
789 /* check if the AG is currently being written to.
790 * if so, call dbNextAG() to find a non-busy
791 * AG with sufficient free space.
792 */
793 if (atomic_read(&bmp->db_active[agno]))
794 goto pref_ag;
795
796 /* check if the allocation request size can be satisfied from a
797 * single dmap. if so, try to allocate from the dmap containing
798 * the hint using a tiered strategy.
799 */
800 if (nblocks <= BPERDMAP) {
801 IREAD_LOCK(ipbmap, RDWRLOCK_DMAP);
802
803 /* get the buffer for the dmap containing the hint.
804 */
805 rc = -EIO;
806 lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage);
807 mp = read_metapage(ipbmap, lblkno, PSIZE, 0);
808 if (mp == NULL)
809 goto read_unlock;
810
811 dp = (struct dmap *) mp->data;
812
813 /* first, try to satisfy the allocation request with the
814 * blocks beginning at the hint.
815 */
816 if ((rc = dbAllocNext(bmp, dp, blkno, (int) nblocks))
817 != -ENOSPC) {
818 if (rc == 0) {
819 *results = blkno;
820 mark_metapage_dirty(mp);
821 }
822
823 release_metapage(mp);
824 goto read_unlock;
825 }
826
827 writers = atomic_read(&bmp->db_active[agno]);
828 if ((writers > 1) ||
829 ((writers == 1) && (JFS_IP(ip)->active_ag != agno))) {
830 /*
831 * Someone else is writing in this allocation
832 * group. To avoid fragmenting, try another ag
833 */
834 release_metapage(mp);
835 IREAD_UNLOCK(ipbmap);
836 goto pref_ag;
837 }
838
839 /* next, try to satisfy the allocation request with blocks
840 * near the hint.
841 */
842 if ((rc =
843 dbAllocNear(bmp, dp, blkno, (int) nblocks, l2nb, results))
844 != -ENOSPC) {
845 if (rc == 0)
846 mark_metapage_dirty(mp);
847
848 release_metapage(mp);
849 goto read_unlock;
850 }
851
852 /* try to satisfy the allocation request with blocks within
853 * the same dmap as the hint.
854 */
855 if ((rc = dbAllocDmapLev(bmp, dp, (int) nblocks, l2nb, results))
856 != -ENOSPC) {
857 if (rc == 0)
858 mark_metapage_dirty(mp);
859
860 release_metapage(mp);
861 goto read_unlock;
862 }
863
864 release_metapage(mp);
865 IREAD_UNLOCK(ipbmap);
866 }
867
868 /* try to satisfy the allocation request with blocks within
869 * the same allocation group as the hint.
870 */
871 IWRITE_LOCK(ipbmap, RDWRLOCK_DMAP);
872 if ((rc = dbAllocAG(bmp, agno, nblocks, l2nb, results)) != -ENOSPC)
873 goto write_unlock;
874
875 IWRITE_UNLOCK(ipbmap);
876
877
878 pref_ag:
879 /*
880 * Let dbNextAG recommend a preferred allocation group
881 */
882 agno = dbNextAG(ipbmap);
883 IWRITE_LOCK(ipbmap, RDWRLOCK_DMAP);
884
885 /* Try to allocate within this allocation group. if that fails, try to
886 * allocate anywhere in the map.
887 */
888 if ((rc = dbAllocAG(bmp, agno, nblocks, l2nb, results)) == -ENOSPC)
889 rc = dbAllocAny(bmp, nblocks, l2nb, results);
890
891 write_unlock:
892 IWRITE_UNLOCK(ipbmap);
893
894 return (rc);
895
896 read_unlock:
897 IREAD_UNLOCK(ipbmap);
898
899 return (rc);
900}
901
902/*
903 * NAME: dbReAlloc()
904 *
905 * FUNCTION: attempt to extend a current allocation by a specified
906 * number of blocks.
907 *
908 * this routine attempts to satisfy the allocation request
909 * by first trying to extend the existing allocation in
910 * place by allocating the additional blocks as the blocks
911 * immediately following the current allocation. if these
912 * blocks are not available, this routine will attempt to
913 * allocate a new set of contiguous blocks large enough
914 * to cover the existing allocation plus the additional
915 * number of blocks required.
916 *
917 * PARAMETERS:
918 * ip - pointer to in-core inode requiring allocation.
919 * blkno - starting block of the current allocation.
920 * nblocks - number of contiguous blocks within the current
921 * allocation.
922 * addnblocks - number of blocks to add to the allocation.
923 * results - on successful return, set to the starting block number
924 * of the existing allocation if the existing allocation
925 * was extended in place or to a newly allocated contiguous
926 * range if the existing allocation could not be extended
927 * in place.
928 *
929 * RETURN VALUES:
930 * 0 - success
931 * -ENOSPC - insufficient disk resources
932 * -EIO - i/o error
933 */
934int
935dbReAlloc(struct inode *ip,
936 s64 blkno, s64 nblocks, s64 addnblocks, s64 * results)
937{
938 int rc;
939
940 /* try to extend the allocation in place.
941 */
942 if ((rc = dbExtend(ip, blkno, nblocks, addnblocks)) == 0) {
943 *results = blkno;
944 return (0);
945 } else {
946 if (rc != -ENOSPC)
947 return (rc);
948 }
949
950 /* could not extend the allocation in place, so allocate a
951 * new set of blocks for the entire request (i.e. try to get
952 * a range of contiguous blocks large enough to cover the
953 * existing allocation plus the additional blocks.)
954 */
955 return (dbAlloc
956 (ip, blkno + nblocks - 1, addnblocks + nblocks, results));
957}
958
959
960/*
961 * NAME: dbExtend()
962 *
963 * FUNCTION: attempt to extend a current allocation by a specified
964 * number of blocks.
965 *
966 * this routine attempts to satisfy the allocation request
967 * by first trying to extend the existing allocation in
968 * place by allocating the additional blocks as the blocks
969 * immediately following the current allocation.
970 *
971 * PARAMETERS:
972 * ip - pointer to in-core inode requiring allocation.
973 * blkno - starting block of the current allocation.
974 * nblocks - number of contiguous blocks within the current
975 * allocation.
976 * addnblocks - number of blocks to add to the allocation.
977 *
978 * RETURN VALUES:
979 * 0 - success
980 * -ENOSPC - insufficient disk resources
981 * -EIO - i/o error
982 */
983static int dbExtend(struct inode *ip, s64 blkno, s64 nblocks, s64 addnblocks)
984{
985 struct jfs_sb_info *sbi = JFS_SBI(ip->i_sb);
986 s64 lblkno, lastblkno, extblkno;
987 uint rel_block;
988 struct metapage *mp;
989 struct dmap *dp;
990 int rc;
991 struct inode *ipbmap = sbi->ipbmap;
992 struct bmap *bmp;
993
994 /*
995 * We don't want a non-aligned extent to cross a page boundary
996 */
997 if (((rel_block = blkno & (sbi->nbperpage - 1))) &&
998 (rel_block + nblocks + addnblocks > sbi->nbperpage))
999 return -ENOSPC;
1000
1001 /* get the last block of the current allocation */
1002 lastblkno = blkno + nblocks - 1;
1003
1004 /* determine the block number of the block following
1005 * the existing allocation.
1006 */
1007 extblkno = lastblkno + 1;
1008
1009 IREAD_LOCK(ipbmap, RDWRLOCK_DMAP);
1010
1011 /* better be within the file system */
1012 bmp = sbi->bmap;
1013 if (lastblkno < 0 || lastblkno >= bmp->db_mapsize) {
1014 IREAD_UNLOCK(ipbmap);
1015 jfs_error(ip->i_sb, "the block is outside the filesystem\n");
1016 return -EIO;
1017 }
1018
1019 /* we'll attempt to extend the current allocation in place by
1020 * allocating the additional blocks as the blocks immediately
1021 * following the current allocation. we only try to extend the
1022 * current allocation in place if the number of additional blocks
1023 * can fit into a dmap, the last block of the current allocation
1024 * is not the last block of the file system, and the start of the
1025 * inplace extension is not on an allocation group boundary.
1026 */
1027 if (addnblocks > BPERDMAP || extblkno >= bmp->db_mapsize ||
1028 (extblkno & (bmp->db_agsize - 1)) == 0) {
1029 IREAD_UNLOCK(ipbmap);
1030 return -ENOSPC;
1031 }
1032
1033 /* get the buffer for the dmap containing the first block
1034 * of the extension.
1035 */
1036 lblkno = BLKTODMAP(extblkno, bmp->db_l2nbperpage);
1037 mp = read_metapage(ipbmap, lblkno, PSIZE, 0);
1038 if (mp == NULL) {
1039 IREAD_UNLOCK(ipbmap);
1040 return -EIO;
1041 }
1042
1043 dp = (struct dmap *) mp->data;
1044
1045 /* try to allocate the blocks immediately following the
1046 * current allocation.
1047 */
1048 rc = dbAllocNext(bmp, dp, extblkno, (int) addnblocks);
1049
1050 IREAD_UNLOCK(ipbmap);
1051
1052 /* were we successful ? */
1053 if (rc == 0)
1054 write_metapage(mp);
1055 else
1056 /* we were not successful */
1057 release_metapage(mp);
1058
1059 return (rc);
1060}
1061
1062
1063/*
1064 * NAME: dbAllocNext()
1065 *
1066 * FUNCTION: attempt to allocate the blocks of the specified block
1067 * range within a dmap.
1068 *
1069 * PARAMETERS:
1070 * bmp - pointer to bmap descriptor
1071 * dp - pointer to dmap.
1072 * blkno - starting block number of the range.
1073 * nblocks - number of contiguous free blocks of the range.
1074 *
1075 * RETURN VALUES:
1076 * 0 - success
1077 * -ENOSPC - insufficient disk resources
1078 * -EIO - i/o error
1079 *
1080 * serialization: IREAD_LOCK(ipbmap) held on entry/exit;
1081 */
1082static int dbAllocNext(struct bmap * bmp, struct dmap * dp, s64 blkno,
1083 int nblocks)
1084{
1085 int dbitno, word, rembits, nb, nwords, wbitno, nw;
1086 int l2size;
1087 s8 *leaf;
1088 u32 mask;
1089
1090 if (dp->tree.leafidx != cpu_to_le32(LEAFIND)) {
1091 jfs_error(bmp->db_ipbmap->i_sb, "Corrupt dmap page\n");
1092 return -EIO;
1093 }
1094
1095 /* pick up a pointer to the leaves of the dmap tree.
1096 */
1097 leaf = dp->tree.stree + le32_to_cpu(dp->tree.leafidx);
1098
1099 /* determine the bit number and word within the dmap of the
1100 * starting block.
1101 */
1102 dbitno = blkno & (BPERDMAP - 1);
1103 word = dbitno >> L2DBWORD;
1104
1105 /* check if the specified block range is contained within
1106 * this dmap.
1107 */
1108 if (dbitno + nblocks > BPERDMAP)
1109 return -ENOSPC;
1110
1111 /* check if the starting leaf indicates that anything
1112 * is free.
1113 */
1114 if (leaf[word] == NOFREE)
1115 return -ENOSPC;
1116
1117 /* check the dmaps words corresponding to block range to see
1118 * if the block range is free. not all bits of the first and
1119 * last words may be contained within the block range. if this
1120 * is the case, we'll work against those words (i.e. partial first
1121 * and/or last) on an individual basis (a single pass) and examine
1122 * the actual bits to determine if they are free. a single pass
1123 * will be used for all dmap words fully contained within the
1124 * specified range. within this pass, the leaves of the dmap
1125 * tree will be examined to determine if the blocks are free. a
1126 * single leaf may describe the free space of multiple dmap
1127 * words, so we may visit only a subset of the actual leaves
1128 * corresponding to the dmap words of the block range.
1129 */
1130 for (rembits = nblocks; rembits > 0; rembits -= nb, dbitno += nb) {
1131 /* determine the bit number within the word and
1132 * the number of bits within the word.
1133 */
1134 wbitno = dbitno & (DBWORD - 1);
1135 nb = min(rembits, DBWORD - wbitno);
1136
1137 /* check if only part of the word is to be examined.
1138 */
1139 if (nb < DBWORD) {
1140 /* check if the bits are free.
1141 */
1142 mask = (ONES << (DBWORD - nb) >> wbitno);
1143 if ((mask & ~le32_to_cpu(dp->wmap[word])) != mask)
1144 return -ENOSPC;
1145
1146 word += 1;
1147 } else {
1148 /* one or more dmap words are fully contained
1149 * within the block range. determine how many
1150 * words and how many bits.
1151 */
1152 nwords = rembits >> L2DBWORD;
1153 nb = nwords << L2DBWORD;
1154
1155 /* now examine the appropriate leaves to determine
1156 * if the blocks are free.
1157 */
1158 while (nwords > 0) {
1159 /* does the leaf describe any free space ?
1160 */
1161 if (leaf[word] < BUDMIN)
1162 return -ENOSPC;
1163
1164 /* determine the l2 number of bits provided
1165 * by this leaf.
1166 */
1167 l2size =
1168 min_t(int, leaf[word], NLSTOL2BSZ(nwords));
1169
1170 /* determine how many words were handled.
1171 */
1172 nw = BUDSIZE(l2size, BUDMIN);
1173
1174 nwords -= nw;
1175 word += nw;
1176 }
1177 }
1178 }
1179
1180 /* allocate the blocks.
1181 */
1182 return (dbAllocDmap(bmp, dp, blkno, nblocks));
1183}
1184
1185
1186/*
1187 * NAME: dbAllocNear()
1188 *
1189 * FUNCTION: attempt to allocate a number of contiguous free blocks near
1190 * a specified block (hint) within a dmap.
1191 *
1192 * starting with the dmap leaf that covers the hint, we'll
1193 * check the next four contiguous leaves for sufficient free
1194 * space. if sufficient free space is found, we'll allocate
1195 * the desired free space.
1196 *
1197 * PARAMETERS:
1198 * bmp - pointer to bmap descriptor
1199 * dp - pointer to dmap.
1200 * blkno - block number to allocate near.
1201 * nblocks - actual number of contiguous free blocks desired.
1202 * l2nb - log2 number of contiguous free blocks desired.
1203 * results - on successful return, set to the starting block number
1204 * of the newly allocated range.
1205 *
1206 * RETURN VALUES:
1207 * 0 - success
1208 * -ENOSPC - insufficient disk resources
1209 * -EIO - i/o error
1210 *
1211 * serialization: IREAD_LOCK(ipbmap) held on entry/exit;
1212 */
1213static int
1214dbAllocNear(struct bmap * bmp,
1215 struct dmap * dp, s64 blkno, int nblocks, int l2nb, s64 * results)
1216{
1217 int word, lword, rc;
1218 s8 *leaf;
1219
1220 if (dp->tree.leafidx != cpu_to_le32(LEAFIND)) {
1221 jfs_error(bmp->db_ipbmap->i_sb, "Corrupt dmap page\n");
1222 return -EIO;
1223 }
1224
1225 leaf = dp->tree.stree + le32_to_cpu(dp->tree.leafidx);
1226
1227 /* determine the word within the dmap that holds the hint
1228 * (i.e. blkno). also, determine the last word in the dmap
1229 * that we'll include in our examination.
1230 */
1231 word = (blkno & (BPERDMAP - 1)) >> L2DBWORD;
1232 lword = min(word + 4, LPERDMAP);
1233
1234 /* examine the leaves for sufficient free space.
1235 */
1236 for (; word < lword; word++) {
1237 /* does the leaf describe sufficient free space ?
1238 */
1239 if (leaf[word] < l2nb)
1240 continue;
1241
1242 /* determine the block number within the file system
1243 * of the first block described by this dmap word.
1244 */
1245 blkno = le64_to_cpu(dp->start) + (word << L2DBWORD);
1246
1247 /* if not all bits of the dmap word are free, get the
1248 * starting bit number within the dmap word of the required
1249 * string of free bits and adjust the block number with the
1250 * value.
1251 */
1252 if (leaf[word] < BUDMIN)
1253 blkno +=
1254 dbFindBits(le32_to_cpu(dp->wmap[word]), l2nb);
1255
1256 /* allocate the blocks.
1257 */
1258 if ((rc = dbAllocDmap(bmp, dp, blkno, nblocks)) == 0)
1259 *results = blkno;
1260
1261 return (rc);
1262 }
1263
1264 return -ENOSPC;
1265}
1266
1267
1268/*
1269 * NAME: dbAllocAG()
1270 *
1271 * FUNCTION: attempt to allocate the specified number of contiguous
1272 * free blocks within the specified allocation group.
1273 *
1274 * unless the allocation group size is equal to the number
1275 * of blocks per dmap, the dmap control pages will be used to
1276 * find the required free space, if available. we start the
1277 * search at the highest dmap control page level which
1278 * distinctly describes the allocation group's free space
1279 * (i.e. the highest level at which the allocation group's
1280 * free space is not mixed in with that of any other group).
1281 * in addition, we start the search within this level at a
1282 * height of the dmapctl dmtree at which the nodes distinctly
1283 * describe the allocation group's free space. at this height,
1284 * the allocation group's free space may be represented by 1
1285 * or two sub-trees, depending on the allocation group size.
1286 * we search the top nodes of these subtrees left to right for
1287 * sufficient free space. if sufficient free space is found,
1288 * the subtree is searched to find the leftmost leaf that
1289 * has free space. once we have made it to the leaf, we
1290 * move the search to the next lower level dmap control page
1291 * corresponding to this leaf. we continue down the dmap control
1292 * pages until we find the dmap that contains or starts the
1293 * sufficient free space and we allocate at this dmap.
1294 *
1295 * if the allocation group size is equal to the dmap size,
1296 * we'll start at the dmap corresponding to the allocation
1297 * group and attempt the allocation at this level.
1298 *
1299 * the dmap control page search is also not performed if the
1300 * allocation group is completely free and we go to the first
1301 * dmap of the allocation group to do the allocation. this is
1302 * done because the allocation group may be part (not the first
1303 * part) of a larger binary buddy system, causing the dmap
1304 * control pages to indicate no free space (NOFREE) within
1305 * the allocation group.
1306 *
1307 * PARAMETERS:
1308 * bmp - pointer to bmap descriptor
1309 * agno - allocation group number.
1310 * nblocks - actual number of contiguous free blocks desired.
1311 * l2nb - log2 number of contiguous free blocks desired.
1312 * results - on successful return, set to the starting block number
1313 * of the newly allocated range.
1314 *
1315 * RETURN VALUES:
1316 * 0 - success
1317 * -ENOSPC - insufficient disk resources
1318 * -EIO - i/o error
1319 *
1320 * note: IWRITE_LOCK(ipmap) held on entry/exit;
1321 */
1322static int
1323dbAllocAG(struct bmap * bmp, int agno, s64 nblocks, int l2nb, s64 * results)
1324{
1325 struct metapage *mp;
1326 struct dmapctl *dcp;
1327 int rc, ti, i, k, m, n, agperlev;
1328 s64 blkno, lblkno;
1329 int budmin;
1330
1331 /* allocation request should not be for more than the
1332 * allocation group size.
1333 */
1334 if (l2nb > bmp->db_agl2size) {
1335 jfs_error(bmp->db_ipbmap->i_sb,
1336 "allocation request is larger than the allocation group size\n");
1337 return -EIO;
1338 }
1339
1340 /* determine the starting block number of the allocation
1341 * group.
1342 */
1343 blkno = (s64) agno << bmp->db_agl2size;
1344
1345 /* check if the allocation group size is the minimum allocation
1346 * group size or if the allocation group is completely free. if
1347 * the allocation group size is the minimum size of BPERDMAP (i.e.
1348 * 1 dmap), there is no need to search the dmap control page (below)
1349 * that fully describes the allocation group since the allocation
1350 * group is already fully described by a dmap. in this case, we
1351 * just call dbAllocCtl() to search the dmap tree and allocate the
1352 * required space if available.
1353 *
1354 * if the allocation group is completely free, dbAllocCtl() is
1355 * also called to allocate the required space. this is done for
1356 * two reasons. first, it makes no sense searching the dmap control
1357 * pages for free space when we know that free space exists. second,
1358 * the dmap control pages may indicate that the allocation group
1359 * has no free space if the allocation group is part (not the first
1360 * part) of a larger binary buddy system.
1361 */
1362 if (bmp->db_agsize == BPERDMAP
1363 || bmp->db_agfree[agno] == bmp->db_agsize) {
1364 rc = dbAllocCtl(bmp, nblocks, l2nb, blkno, results);
1365 if ((rc == -ENOSPC) &&
1366 (bmp->db_agfree[agno] == bmp->db_agsize)) {
1367 printk(KERN_ERR "blkno = %Lx, blocks = %Lx\n",
1368 (unsigned long long) blkno,
1369 (unsigned long long) nblocks);
1370 jfs_error(bmp->db_ipbmap->i_sb,
1371 "dbAllocCtl failed in free AG\n");
1372 }
1373 return (rc);
1374 }
1375
1376 /* the buffer for the dmap control page that fully describes the
1377 * allocation group.
1378 */
1379 lblkno = BLKTOCTL(blkno, bmp->db_l2nbperpage, bmp->db_aglevel);
1380 mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0);
1381 if (mp == NULL)
1382 return -EIO;
1383 dcp = (struct dmapctl *) mp->data;
1384 budmin = dcp->budmin;
1385
1386 if (dcp->leafidx != cpu_to_le32(CTLLEAFIND)) {
1387 jfs_error(bmp->db_ipbmap->i_sb, "Corrupt dmapctl page\n");
1388 release_metapage(mp);
1389 return -EIO;
1390 }
1391
1392 /* search the subtree(s) of the dmap control page that describes
1393 * the allocation group, looking for sufficient free space. to begin,
1394 * determine how many allocation groups are represented in a dmap
1395 * control page at the control page level (i.e. L0, L1, L2) that
1396 * fully describes an allocation group. next, determine the starting
1397 * tree index of this allocation group within the control page.
1398 */
1399 agperlev =
1400 (1 << (L2LPERCTL - (bmp->db_agheight << 1))) / bmp->db_agwidth;
1401 ti = bmp->db_agstart + bmp->db_agwidth * (agno & (agperlev - 1));
1402
1403 /* dmap control page trees fan-out by 4 and a single allocation
1404 * group may be described by 1 or 2 subtrees within the ag level
1405 * dmap control page, depending upon the ag size. examine the ag's
1406 * subtrees for sufficient free space, starting with the leftmost
1407 * subtree.
1408 */
1409 for (i = 0; i < bmp->db_agwidth; i++, ti++) {
1410 /* is there sufficient free space ?
1411 */
1412 if (l2nb > dcp->stree[ti])
1413 continue;
1414
1415 /* sufficient free space found in a subtree. now search down
1416 * the subtree to find the leftmost leaf that describes this
1417 * free space.
1418 */
1419 for (k = bmp->db_agheight; k > 0; k--) {
1420 for (n = 0, m = (ti << 2) + 1; n < 4; n++) {
1421 if (l2nb <= dcp->stree[m + n]) {
1422 ti = m + n;
1423 break;
1424 }
1425 }
1426 if (n == 4) {
1427 jfs_error(bmp->db_ipbmap->i_sb,
1428 "failed descending stree\n");
1429 release_metapage(mp);
1430 return -EIO;
1431 }
1432 }
1433
1434 /* determine the block number within the file system
1435 * that corresponds to this leaf.
1436 */
1437 if (bmp->db_aglevel == 2)
1438 blkno = 0;
1439 else if (bmp->db_aglevel == 1)
1440 blkno &= ~(MAXL1SIZE - 1);
1441 else /* bmp->db_aglevel == 0 */
1442 blkno &= ~(MAXL0SIZE - 1);
1443
1444 blkno +=
1445 ((s64) (ti - le32_to_cpu(dcp->leafidx))) << budmin;
1446
1447 /* release the buffer in preparation for going down
1448 * the next level of dmap control pages.
1449 */
1450 release_metapage(mp);
1451
1452 /* check if we need to continue to search down the lower
1453 * level dmap control pages. we need to if the number of
1454 * blocks required is less than maximum number of blocks
1455 * described at the next lower level.
1456 */
1457 if (l2nb < budmin) {
1458
1459 /* search the lower level dmap control pages to get
1460 * the starting block number of the dmap that
1461 * contains or starts off the free space.
1462 */
1463 if ((rc =
1464 dbFindCtl(bmp, l2nb, bmp->db_aglevel - 1,
1465 &blkno))) {
1466 if (rc == -ENOSPC) {
1467 jfs_error(bmp->db_ipbmap->i_sb,
1468 "control page inconsistent\n");
1469 return -EIO;
1470 }
1471 return (rc);
1472 }
1473 }
1474
1475 /* allocate the blocks.
1476 */
1477 rc = dbAllocCtl(bmp, nblocks, l2nb, blkno, results);
1478 if (rc == -ENOSPC) {
1479 jfs_error(bmp->db_ipbmap->i_sb,
1480 "unable to allocate blocks\n");
1481 rc = -EIO;
1482 }
1483 return (rc);
1484 }
1485
1486 /* no space in the allocation group. release the buffer and
1487 * return -ENOSPC.
1488 */
1489 release_metapage(mp);
1490
1491 return -ENOSPC;
1492}
1493
1494
1495/*
1496 * NAME: dbAllocAny()
1497 *
1498 * FUNCTION: attempt to allocate the specified number of contiguous
1499 * free blocks anywhere in the file system.
1500 *
1501 * dbAllocAny() attempts to find the sufficient free space by
1502 * searching down the dmap control pages, starting with the
1503 * highest level (i.e. L0, L1, L2) control page. if free space
1504 * large enough to satisfy the desired free space is found, the
1505 * desired free space is allocated.
1506 *
1507 * PARAMETERS:
1508 * bmp - pointer to bmap descriptor
1509 * nblocks - actual number of contiguous free blocks desired.
1510 * l2nb - log2 number of contiguous free blocks desired.
1511 * results - on successful return, set to the starting block number
1512 * of the newly allocated range.
1513 *
1514 * RETURN VALUES:
1515 * 0 - success
1516 * -ENOSPC - insufficient disk resources
1517 * -EIO - i/o error
1518 *
1519 * serialization: IWRITE_LOCK(ipbmap) held on entry/exit;
1520 */
1521static int dbAllocAny(struct bmap * bmp, s64 nblocks, int l2nb, s64 * results)
1522{
1523 int rc;
1524 s64 blkno = 0;
1525
1526 /* starting with the top level dmap control page, search
1527 * down the dmap control levels for sufficient free space.
1528 * if free space is found, dbFindCtl() returns the starting
1529 * block number of the dmap that contains or starts off the
1530 * range of free space.
1531 */
1532 if ((rc = dbFindCtl(bmp, l2nb, bmp->db_maxlevel, &blkno)))
1533 return (rc);
1534
1535 /* allocate the blocks.
1536 */
1537 rc = dbAllocCtl(bmp, nblocks, l2nb, blkno, results);
1538 if (rc == -ENOSPC) {
1539 jfs_error(bmp->db_ipbmap->i_sb, "unable to allocate blocks\n");
1540 return -EIO;
1541 }
1542 return (rc);
1543}
1544
1545
1546/*
1547 * NAME: dbDiscardAG()
1548 *
1549 * FUNCTION: attempt to discard (TRIM) all free blocks of specific AG
1550 *
1551 * algorithm:
1552 * 1) allocate blocks, as large as possible and save them
1553 * while holding IWRITE_LOCK on ipbmap
1554 * 2) trim all these saved block/length values
1555 * 3) mark the blocks free again
1556 *
1557 * benefit:
1558 * - we work only on one ag at some time, minimizing how long we
1559 * need to lock ipbmap
1560 * - reading / writing the fs is possible most time, even on
1561 * trimming
1562 *
1563 * downside:
1564 * - we write two times to the dmapctl and dmap pages
1565 * - but for me, this seems the best way, better ideas?
1566 * /TR 2012
1567 *
1568 * PARAMETERS:
1569 * ip - pointer to in-core inode
1570 * agno - ag to trim
1571 * minlen - minimum value of contiguous blocks
1572 *
1573 * RETURN VALUES:
1574 * s64 - actual number of blocks trimmed
1575 */
1576s64 dbDiscardAG(struct inode *ip, int agno, s64 minlen)
1577{
1578 struct inode *ipbmap = JFS_SBI(ip->i_sb)->ipbmap;
1579 struct bmap *bmp = JFS_SBI(ip->i_sb)->bmap;
1580 s64 nblocks, blkno;
1581 u64 trimmed = 0;
1582 int rc, l2nb;
1583 struct super_block *sb = ipbmap->i_sb;
1584
1585 struct range2trim {
1586 u64 blkno;
1587 u64 nblocks;
1588 } *totrim, *tt;
1589
1590 /* max blkno / nblocks pairs to trim */
1591 int count = 0, range_cnt;
1592 u64 max_ranges;
1593
1594 /* prevent others from writing new stuff here, while trimming */
1595 IWRITE_LOCK(ipbmap, RDWRLOCK_DMAP);
1596
1597 nblocks = bmp->db_agfree[agno];
1598 max_ranges = nblocks;
1599 do_div(max_ranges, minlen);
1600 range_cnt = min_t(u64, max_ranges + 1, 32 * 1024);
1601 totrim = kmalloc_array(range_cnt, sizeof(struct range2trim), GFP_NOFS);
1602 if (totrim == NULL) {
1603 jfs_error(bmp->db_ipbmap->i_sb, "no memory for trim array\n");
1604 IWRITE_UNLOCK(ipbmap);
1605 return 0;
1606 }
1607
1608 tt = totrim;
1609 while (nblocks >= minlen) {
1610 l2nb = BLKSTOL2(nblocks);
1611
1612 /* 0 = okay, -EIO = fatal, -ENOSPC -> try smaller block */
1613 rc = dbAllocAG(bmp, agno, nblocks, l2nb, &blkno);
1614 if (rc == 0) {
1615 tt->blkno = blkno;
1616 tt->nblocks = nblocks;
1617 tt++; count++;
1618
1619 /* the whole ag is free, trim now */
1620 if (bmp->db_agfree[agno] == 0)
1621 break;
1622
1623 /* give a hint for the next while */
1624 nblocks = bmp->db_agfree[agno];
1625 continue;
1626 } else if (rc == -ENOSPC) {
1627 /* search for next smaller log2 block */
1628 l2nb = BLKSTOL2(nblocks) - 1;
1629 nblocks = 1LL << l2nb;
1630 } else {
1631 /* Trim any already allocated blocks */
1632 jfs_error(bmp->db_ipbmap->i_sb, "-EIO\n");
1633 break;
1634 }
1635
1636 /* check, if our trim array is full */
1637 if (unlikely(count >= range_cnt - 1))
1638 break;
1639 }
1640 IWRITE_UNLOCK(ipbmap);
1641
1642 tt->nblocks = 0; /* mark the current end */
1643 for (tt = totrim; tt->nblocks != 0; tt++) {
1644 /* when mounted with online discard, dbFree() will
1645 * call jfs_issue_discard() itself */
1646 if (!(JFS_SBI(sb)->flag & JFS_DISCARD))
1647 jfs_issue_discard(ip, tt->blkno, tt->nblocks);
1648 dbFree(ip, tt->blkno, tt->nblocks);
1649 trimmed += tt->nblocks;
1650 }
1651 kfree(totrim);
1652
1653 return trimmed;
1654}
1655
1656/*
1657 * NAME: dbFindCtl()
1658 *
1659 * FUNCTION: starting at a specified dmap control page level and block
1660 * number, search down the dmap control levels for a range of
1661 * contiguous free blocks large enough to satisfy an allocation
1662 * request for the specified number of free blocks.
1663 *
1664 * if sufficient contiguous free blocks are found, this routine
1665 * returns the starting block number within a dmap page that
1666 * contains or starts a range of contiqious free blocks that
1667 * is sufficient in size.
1668 *
1669 * PARAMETERS:
1670 * bmp - pointer to bmap descriptor
1671 * level - starting dmap control page level.
1672 * l2nb - log2 number of contiguous free blocks desired.
1673 * *blkno - on entry, starting block number for conducting the search.
1674 * on successful return, the first block within a dmap page
1675 * that contains or starts a range of contiguous free blocks.
1676 *
1677 * RETURN VALUES:
1678 * 0 - success
1679 * -ENOSPC - insufficient disk resources
1680 * -EIO - i/o error
1681 *
1682 * serialization: IWRITE_LOCK(ipbmap) held on entry/exit;
1683 */
1684static int dbFindCtl(struct bmap * bmp, int l2nb, int level, s64 * blkno)
1685{
1686 int rc, leafidx, lev;
1687 s64 b, lblkno;
1688 struct dmapctl *dcp;
1689 int budmin;
1690 struct metapage *mp;
1691
1692 /* starting at the specified dmap control page level and block
1693 * number, search down the dmap control levels for the starting
1694 * block number of a dmap page that contains or starts off
1695 * sufficient free blocks.
1696 */
1697 for (lev = level, b = *blkno; lev >= 0; lev--) {
1698 /* get the buffer of the dmap control page for the block
1699 * number and level (i.e. L0, L1, L2).
1700 */
1701 lblkno = BLKTOCTL(b, bmp->db_l2nbperpage, lev);
1702 mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0);
1703 if (mp == NULL)
1704 return -EIO;
1705 dcp = (struct dmapctl *) mp->data;
1706 budmin = dcp->budmin;
1707
1708 if (dcp->leafidx != cpu_to_le32(CTLLEAFIND)) {
1709 jfs_error(bmp->db_ipbmap->i_sb,
1710 "Corrupt dmapctl page\n");
1711 release_metapage(mp);
1712 return -EIO;
1713 }
1714
1715 /* search the tree within the dmap control page for
1716 * sufficient free space. if sufficient free space is found,
1717 * dbFindLeaf() returns the index of the leaf at which
1718 * free space was found.
1719 */
1720 rc = dbFindLeaf((dmtree_t *) dcp, l2nb, &leafidx, true);
1721
1722 /* release the buffer.
1723 */
1724 release_metapage(mp);
1725
1726 /* space found ?
1727 */
1728 if (rc) {
1729 if (lev != level) {
1730 jfs_error(bmp->db_ipbmap->i_sb,
1731 "dmap inconsistent\n");
1732 return -EIO;
1733 }
1734 return -ENOSPC;
1735 }
1736
1737 /* adjust the block number to reflect the location within
1738 * the dmap control page (i.e. the leaf) at which free
1739 * space was found.
1740 */
1741 b += (((s64) leafidx) << budmin);
1742
1743 /* we stop the search at this dmap control page level if
1744 * the number of blocks required is greater than or equal
1745 * to the maximum number of blocks described at the next
1746 * (lower) level.
1747 */
1748 if (l2nb >= budmin)
1749 break;
1750 }
1751
1752 *blkno = b;
1753 return (0);
1754}
1755
1756
1757/*
1758 * NAME: dbAllocCtl()
1759 *
1760 * FUNCTION: attempt to allocate a specified number of contiguous
1761 * blocks starting within a specific dmap.
1762 *
1763 * this routine is called by higher level routines that search
1764 * the dmap control pages above the actual dmaps for contiguous
1765 * free space. the result of successful searches by these
1766 * routines are the starting block numbers within dmaps, with
1767 * the dmaps themselves containing the desired contiguous free
1768 * space or starting a contiguous free space of desired size
1769 * that is made up of the blocks of one or more dmaps. these
1770 * calls should not fail due to insufficent resources.
1771 *
1772 * this routine is called in some cases where it is not known
1773 * whether it will fail due to insufficient resources. more
1774 * specifically, this occurs when allocating from an allocation
1775 * group whose size is equal to the number of blocks per dmap.
1776 * in this case, the dmap control pages are not examined prior
1777 * to calling this routine (to save pathlength) and the call
1778 * might fail.
1779 *
1780 * for a request size that fits within a dmap, this routine relies
1781 * upon the dmap's dmtree to find the requested contiguous free
1782 * space. for request sizes that are larger than a dmap, the
1783 * requested free space will start at the first block of the
1784 * first dmap (i.e. blkno).
1785 *
1786 * PARAMETERS:
1787 * bmp - pointer to bmap descriptor
1788 * nblocks - actual number of contiguous free blocks to allocate.
1789 * l2nb - log2 number of contiguous free blocks to allocate.
1790 * blkno - starting block number of the dmap to start the allocation
1791 * from.
1792 * results - on successful return, set to the starting block number
1793 * of the newly allocated range.
1794 *
1795 * RETURN VALUES:
1796 * 0 - success
1797 * -ENOSPC - insufficient disk resources
1798 * -EIO - i/o error
1799 *
1800 * serialization: IWRITE_LOCK(ipbmap) held on entry/exit;
1801 */
1802static int
1803dbAllocCtl(struct bmap * bmp, s64 nblocks, int l2nb, s64 blkno, s64 * results)
1804{
1805 int rc, nb;
1806 s64 b, lblkno, n;
1807 struct metapage *mp;
1808 struct dmap *dp;
1809
1810 /* check if the allocation request is confined to a single dmap.
1811 */
1812 if (l2nb <= L2BPERDMAP) {
1813 /* get the buffer for the dmap.
1814 */
1815 lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage);
1816 mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0);
1817 if (mp == NULL)
1818 return -EIO;
1819 dp = (struct dmap *) mp->data;
1820
1821 /* try to allocate the blocks.
1822 */
1823 rc = dbAllocDmapLev(bmp, dp, (int) nblocks, l2nb, results);
1824 if (rc == 0)
1825 mark_metapage_dirty(mp);
1826
1827 release_metapage(mp);
1828
1829 return (rc);
1830 }
1831
1832 /* allocation request involving multiple dmaps. it must start on
1833 * a dmap boundary.
1834 */
1835 assert((blkno & (BPERDMAP - 1)) == 0);
1836
1837 /* allocate the blocks dmap by dmap.
1838 */
1839 for (n = nblocks, b = blkno; n > 0; n -= nb, b += nb) {
1840 /* get the buffer for the dmap.
1841 */
1842 lblkno = BLKTODMAP(b, bmp->db_l2nbperpage);
1843 mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0);
1844 if (mp == NULL) {
1845 rc = -EIO;
1846 goto backout;
1847 }
1848 dp = (struct dmap *) mp->data;
1849
1850 /* the dmap better be all free.
1851 */
1852 if (dp->tree.stree[ROOT] != L2BPERDMAP) {
1853 release_metapage(mp);
1854 jfs_error(bmp->db_ipbmap->i_sb,
1855 "the dmap is not all free\n");
1856 rc = -EIO;
1857 goto backout;
1858 }
1859
1860 /* determine how many blocks to allocate from this dmap.
1861 */
1862 nb = min_t(s64, n, BPERDMAP);
1863
1864 /* allocate the blocks from the dmap.
1865 */
1866 if ((rc = dbAllocDmap(bmp, dp, b, nb))) {
1867 release_metapage(mp);
1868 goto backout;
1869 }
1870
1871 /* write the buffer.
1872 */
1873 write_metapage(mp);
1874 }
1875
1876 /* set the results (starting block number) and return.
1877 */
1878 *results = blkno;
1879 return (0);
1880
1881 /* something failed in handling an allocation request involving
1882 * multiple dmaps. we'll try to clean up by backing out any
1883 * allocation that has already happened for this request. if
1884 * we fail in backing out the allocation, we'll mark the file
1885 * system to indicate that blocks have been leaked.
1886 */
1887 backout:
1888
1889 /* try to backout the allocations dmap by dmap.
1890 */
1891 for (n = nblocks - n, b = blkno; n > 0;
1892 n -= BPERDMAP, b += BPERDMAP) {
1893 /* get the buffer for this dmap.
1894 */
1895 lblkno = BLKTODMAP(b, bmp->db_l2nbperpage);
1896 mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0);
1897 if (mp == NULL) {
1898 /* could not back out. mark the file system
1899 * to indicate that we have leaked blocks.
1900 */
1901 jfs_error(bmp->db_ipbmap->i_sb,
1902 "I/O Error: Block Leakage\n");
1903 continue;
1904 }
1905 dp = (struct dmap *) mp->data;
1906
1907 /* free the blocks is this dmap.
1908 */
1909 if (dbFreeDmap(bmp, dp, b, BPERDMAP)) {
1910 /* could not back out. mark the file system
1911 * to indicate that we have leaked blocks.
1912 */
1913 release_metapage(mp);
1914 jfs_error(bmp->db_ipbmap->i_sb, "Block Leakage\n");
1915 continue;
1916 }
1917
1918 /* write the buffer.
1919 */
1920 write_metapage(mp);
1921 }
1922
1923 return (rc);
1924}
1925
1926
1927/*
1928 * NAME: dbAllocDmapLev()
1929 *
1930 * FUNCTION: attempt to allocate a specified number of contiguous blocks
1931 * from a specified dmap.
1932 *
1933 * this routine checks if the contiguous blocks are available.
1934 * if so, nblocks of blocks are allocated; otherwise, ENOSPC is
1935 * returned.
1936 *
1937 * PARAMETERS:
1938 * mp - pointer to bmap descriptor
1939 * dp - pointer to dmap to attempt to allocate blocks from.
1940 * l2nb - log2 number of contiguous block desired.
1941 * nblocks - actual number of contiguous block desired.
1942 * results - on successful return, set to the starting block number
1943 * of the newly allocated range.
1944 *
1945 * RETURN VALUES:
1946 * 0 - success
1947 * -ENOSPC - insufficient disk resources
1948 * -EIO - i/o error
1949 *
1950 * serialization: IREAD_LOCK(ipbmap), e.g., from dbAlloc(), or
1951 * IWRITE_LOCK(ipbmap), e.g., dbAllocCtl(), held on entry/exit;
1952 */
1953static int
1954dbAllocDmapLev(struct bmap * bmp,
1955 struct dmap * dp, int nblocks, int l2nb, s64 * results)
1956{
1957 s64 blkno;
1958 int leafidx, rc;
1959
1960 /* can't be more than a dmaps worth of blocks */
1961 assert(l2nb <= L2BPERDMAP);
1962
1963 /* search the tree within the dmap page for sufficient
1964 * free space. if sufficient free space is found, dbFindLeaf()
1965 * returns the index of the leaf at which free space was found.
1966 */
1967 if (dbFindLeaf((dmtree_t *) &dp->tree, l2nb, &leafidx, false))
1968 return -ENOSPC;
1969
1970 if (leafidx < 0)
1971 return -EIO;
1972
1973 /* determine the block number within the file system corresponding
1974 * to the leaf at which free space was found.
1975 */
1976 blkno = le64_to_cpu(dp->start) + (leafidx << L2DBWORD);
1977
1978 /* if not all bits of the dmap word are free, get the starting
1979 * bit number within the dmap word of the required string of free
1980 * bits and adjust the block number with this value.
1981 */
1982 if (dp->tree.stree[leafidx + LEAFIND] < BUDMIN)
1983 blkno += dbFindBits(le32_to_cpu(dp->wmap[leafidx]), l2nb);
1984
1985 /* allocate the blocks */
1986 if ((rc = dbAllocDmap(bmp, dp, blkno, nblocks)) == 0)
1987 *results = blkno;
1988
1989 return (rc);
1990}
1991
1992
1993/*
1994 * NAME: dbAllocDmap()
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 allocates the specified blocks from the dmap
2000 * through a call to dbAllocBits(). if the allocation of the
2001 * block range causes the maximum string of free blocks within
2002 * the dmap to change (i.e. the value of the root of the dmap's
2003 * dmtree), this routine will cause this change to be reflected
2004 * up through the appropriate levels of the dmap control pages
2005 * by a call to dbAdjCtl() for the L0 dmap control page that
2006 * covers this dmap.
2007 *
2008 * PARAMETERS:
2009 * bmp - pointer to bmap descriptor
2010 * dp - pointer to dmap to allocate the block range from.
2011 * blkno - starting block number of the block to be allocated.
2012 * nblocks - number of blocks to be allocated.
2013 *
2014 * RETURN VALUES:
2015 * 0 - success
2016 * -EIO - i/o error
2017 *
2018 * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit;
2019 */
2020static int dbAllocDmap(struct bmap * bmp, struct dmap * dp, s64 blkno,
2021 int nblocks)
2022{
2023 s8 oldroot;
2024 int rc;
2025
2026 /* save the current value of the root (i.e. maximum free string)
2027 * of the dmap tree.
2028 */
2029 oldroot = dp->tree.stree[ROOT];
2030
2031 /* allocate the specified (blocks) bits */
2032 dbAllocBits(bmp, dp, blkno, nblocks);
2033
2034 /* if the root has not changed, done. */
2035 if (dp->tree.stree[ROOT] == oldroot)
2036 return (0);
2037
2038 /* root changed. bubble the change up to the dmap control pages.
2039 * if the adjustment of the upper level control pages fails,
2040 * backout the bit allocation (thus making everything consistent).
2041 */
2042 if ((rc = dbAdjCtl(bmp, blkno, dp->tree.stree[ROOT], 1, 0)))
2043 dbFreeBits(bmp, dp, blkno, nblocks);
2044
2045 return (rc);
2046}
2047
2048
2049/*
2050 * NAME: dbFreeDmap()
2051 *
2052 * FUNCTION: adjust the disk allocation map to reflect the allocation
2053 * of a specified block range within a dmap.
2054 *
2055 * this routine frees the specified blocks from the dmap through
2056 * a call to dbFreeBits(). if the deallocation of the block range
2057 * causes the maximum string of free blocks within the dmap to
2058 * change (i.e. the value of the root of the dmap's dmtree), this
2059 * routine will cause this change to be reflected up through the
2060 * appropriate levels of the dmap control pages by a call to
2061 * dbAdjCtl() for the L0 dmap control page that covers this dmap.
2062 *
2063 * PARAMETERS:
2064 * bmp - pointer to bmap descriptor
2065 * dp - pointer to dmap to free the block range from.
2066 * blkno - starting block number of the block to be freed.
2067 * nblocks - number of blocks to be freed.
2068 *
2069 * RETURN VALUES:
2070 * 0 - success
2071 * -EIO - i/o error
2072 *
2073 * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit;
2074 */
2075static int dbFreeDmap(struct bmap * bmp, struct dmap * dp, s64 blkno,
2076 int nblocks)
2077{
2078 s8 oldroot;
2079 int rc = 0, word;
2080
2081 /* save the current value of the root (i.e. maximum free string)
2082 * of the dmap tree.
2083 */
2084 oldroot = dp->tree.stree[ROOT];
2085
2086 /* free the specified (blocks) bits */
2087 rc = dbFreeBits(bmp, dp, blkno, nblocks);
2088
2089 /* if error or the root has not changed, done. */
2090 if (rc || (dp->tree.stree[ROOT] == oldroot))
2091 return (rc);
2092
2093 /* root changed. bubble the change up to the dmap control pages.
2094 * if the adjustment of the upper level control pages fails,
2095 * backout the deallocation.
2096 */
2097 if ((rc = dbAdjCtl(bmp, blkno, dp->tree.stree[ROOT], 0, 0))) {
2098 word = (blkno & (BPERDMAP - 1)) >> L2DBWORD;
2099
2100 /* as part of backing out the deallocation, we will have
2101 * to back split the dmap tree if the deallocation caused
2102 * the freed blocks to become part of a larger binary buddy
2103 * system.
2104 */
2105 if (dp->tree.stree[word] == NOFREE)
2106 dbBackSplit((dmtree_t *)&dp->tree, word, false);
2107
2108 dbAllocBits(bmp, dp, blkno, nblocks);
2109 }
2110
2111 return (rc);
2112}
2113
2114
2115/*
2116 * NAME: dbAllocBits()
2117 *
2118 * FUNCTION: allocate a specified block range from a dmap.
2119 *
2120 * this routine updates the dmap to reflect the working
2121 * state allocation of the specified block range. it directly
2122 * updates the bits of the working map and causes the adjustment
2123 * of the binary buddy system described by the dmap's dmtree
2124 * leaves to reflect the bits allocated. it also causes the
2125 * dmap's dmtree, as a whole, to reflect the allocated range.
2126 *
2127 * PARAMETERS:
2128 * bmp - pointer to bmap descriptor
2129 * dp - pointer to dmap to allocate bits from.
2130 * blkno - starting block number of the bits to be allocated.
2131 * nblocks - number of bits to be allocated.
2132 *
2133 * RETURN VALUES: none
2134 *
2135 * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit;
2136 */
2137static void dbAllocBits(struct bmap * bmp, struct dmap * dp, s64 blkno,
2138 int nblocks)
2139{
2140 int dbitno, word, rembits, nb, nwords, wbitno, nw, agno;
2141 dmtree_t *tp = (dmtree_t *) & dp->tree;
2142 int size;
2143 s8 *leaf;
2144
2145 /* pick up a pointer to the leaves of the dmap tree */
2146 leaf = dp->tree.stree + LEAFIND;
2147
2148 /* determine the bit number and word within the dmap of the
2149 * starting block.
2150 */
2151 dbitno = blkno & (BPERDMAP - 1);
2152 word = dbitno >> L2DBWORD;
2153
2154 /* block range better be within the dmap */
2155 assert(dbitno + nblocks <= BPERDMAP);
2156
2157 /* allocate the bits of the dmap's words corresponding to the block
2158 * range. not all bits of the first and last words may be contained
2159 * within the block range. if this is the case, we'll work against
2160 * those words (i.e. partial first and/or last) on an individual basis
2161 * (a single pass), allocating the bits of interest by hand and
2162 * updating the leaf corresponding to the dmap word. a single pass
2163 * will be used for all dmap words fully contained within the
2164 * specified range. within this pass, the bits of all fully contained
2165 * dmap words will be marked as free in a single shot and the leaves
2166 * will be updated. a single leaf may describe the free space of
2167 * multiple dmap words, so we may update only a subset of the actual
2168 * leaves corresponding to the dmap words of the block range.
2169 */
2170 for (rembits = nblocks; rembits > 0; rembits -= nb, dbitno += nb) {
2171 /* determine the bit number within the word and
2172 * the number of bits within the word.
2173 */
2174 wbitno = dbitno & (DBWORD - 1);
2175 nb = min(rembits, DBWORD - wbitno);
2176
2177 /* check if only part of a word is to be allocated.
2178 */
2179 if (nb < DBWORD) {
2180 /* allocate (set to 1) the appropriate bits within
2181 * this dmap word.
2182 */
2183 dp->wmap[word] |= cpu_to_le32(ONES << (DBWORD - nb)
2184 >> wbitno);
2185
2186 /* update the leaf for this dmap word. in addition
2187 * to setting the leaf value to the binary buddy max
2188 * of the updated dmap word, dbSplit() will split
2189 * the binary system of the leaves if need be.
2190 */
2191 dbSplit(tp, word, BUDMIN,
2192 dbMaxBud((u8 *)&dp->wmap[word]), false);
2193
2194 word += 1;
2195 } else {
2196 /* one or more dmap words are fully contained
2197 * within the block range. determine how many
2198 * words and allocate (set to 1) the bits of these
2199 * words.
2200 */
2201 nwords = rembits >> L2DBWORD;
2202 memset(&dp->wmap[word], (int) ONES, nwords * 4);
2203
2204 /* determine how many bits.
2205 */
2206 nb = nwords << L2DBWORD;
2207
2208 /* now update the appropriate leaves to reflect
2209 * the allocated words.
2210 */
2211 for (; nwords > 0; nwords -= nw) {
2212 if (leaf[word] < BUDMIN) {
2213 jfs_error(bmp->db_ipbmap->i_sb,
2214 "leaf page corrupt\n");
2215 break;
2216 }
2217
2218 /* determine what the leaf value should be
2219 * updated to as the minimum of the l2 number
2220 * of bits being allocated and the l2 number
2221 * of bits currently described by this leaf.
2222 */
2223 size = min_t(int, leaf[word],
2224 NLSTOL2BSZ(nwords));
2225
2226 /* update the leaf to reflect the allocation.
2227 * in addition to setting the leaf value to
2228 * NOFREE, dbSplit() will split the binary
2229 * system of the leaves to reflect the current
2230 * allocation (size).
2231 */
2232 dbSplit(tp, word, size, NOFREE, false);
2233
2234 /* get the number of dmap words handled */
2235 nw = BUDSIZE(size, BUDMIN);
2236 word += nw;
2237 }
2238 }
2239 }
2240
2241 /* update the free count for this dmap */
2242 le32_add_cpu(&dp->nfree, -nblocks);
2243
2244 BMAP_LOCK(bmp);
2245
2246 /* if this allocation group is completely free,
2247 * update the maximum allocation group number if this allocation
2248 * group is the new max.
2249 */
2250 agno = blkno >> bmp->db_agl2size;
2251 if (agno > bmp->db_maxag)
2252 bmp->db_maxag = agno;
2253
2254 /* update the free count for the allocation group and map */
2255 bmp->db_agfree[agno] -= nblocks;
2256 bmp->db_nfree -= nblocks;
2257
2258 BMAP_UNLOCK(bmp);
2259}
2260
2261
2262/*
2263 * NAME: dbFreeBits()
2264 *
2265 * FUNCTION: free a specified block range from a dmap.
2266 *
2267 * this routine updates the dmap to reflect the working
2268 * state allocation of the specified block range. it directly
2269 * updates the bits of the working map and causes the adjustment
2270 * of the binary buddy system described by the dmap's dmtree
2271 * leaves to reflect the bits freed. it also causes the dmap's
2272 * dmtree, as a whole, to reflect the deallocated range.
2273 *
2274 * PARAMETERS:
2275 * bmp - pointer to bmap descriptor
2276 * dp - pointer to dmap to free bits from.
2277 * blkno - starting block number of the bits to be freed.
2278 * nblocks - number of bits to be freed.
2279 *
2280 * RETURN VALUES: 0 for success
2281 *
2282 * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit;
2283 */
2284static int dbFreeBits(struct bmap * bmp, struct dmap * dp, s64 blkno,
2285 int nblocks)
2286{
2287 int dbitno, word, rembits, nb, nwords, wbitno, nw, agno;
2288 dmtree_t *tp = (dmtree_t *) & dp->tree;
2289 int rc = 0;
2290 int size;
2291
2292 /* determine the bit number and word within the dmap of the
2293 * starting block.
2294 */
2295 dbitno = blkno & (BPERDMAP - 1);
2296 word = dbitno >> L2DBWORD;
2297
2298 /* block range better be within the dmap.
2299 */
2300 assert(dbitno + nblocks <= BPERDMAP);
2301
2302 /* free the bits of the dmaps words corresponding to the block range.
2303 * not all bits of the first and last words may be contained within
2304 * the block range. if this is the case, we'll work against those
2305 * words (i.e. partial first and/or last) on an individual basis
2306 * (a single pass), freeing the bits of interest by hand and updating
2307 * the leaf corresponding to the dmap word. a single pass will be used
2308 * for all dmap words fully contained within the specified range.
2309 * within this pass, the bits of all fully contained dmap words will
2310 * be marked as free in a single shot and the leaves will be updated. a
2311 * single leaf may describe the free space of multiple dmap words,
2312 * so we may update only a subset of the actual leaves corresponding
2313 * to the dmap words of the block range.
2314 *
2315 * dbJoin() is used to update leaf values and will join the binary
2316 * buddy system of the leaves if the new leaf values indicate this
2317 * should be done.
2318 */
2319 for (rembits = nblocks; rembits > 0; rembits -= nb, dbitno += nb) {
2320 /* determine the bit number within the word and
2321 * the number of bits within the word.
2322 */
2323 wbitno = dbitno & (DBWORD - 1);
2324 nb = min(rembits, DBWORD - wbitno);
2325
2326 /* check if only part of a word is to be freed.
2327 */
2328 if (nb < DBWORD) {
2329 /* free (zero) the appropriate bits within this
2330 * dmap word.
2331 */
2332 dp->wmap[word] &=
2333 cpu_to_le32(~(ONES << (DBWORD - nb)
2334 >> wbitno));
2335
2336 /* update the leaf for this dmap word.
2337 */
2338 rc = dbJoin(tp, word,
2339 dbMaxBud((u8 *)&dp->wmap[word]), false);
2340 if (rc)
2341 return rc;
2342
2343 word += 1;
2344 } else {
2345 /* one or more dmap words are fully contained
2346 * within the block range. determine how many
2347 * words and free (zero) the bits of these words.
2348 */
2349 nwords = rembits >> L2DBWORD;
2350 memset(&dp->wmap[word], 0, nwords * 4);
2351
2352 /* determine how many bits.
2353 */
2354 nb = nwords << L2DBWORD;
2355
2356 /* now update the appropriate leaves to reflect
2357 * the freed words.
2358 */
2359 for (; nwords > 0; nwords -= nw) {
2360 /* determine what the leaf value should be
2361 * updated to as the minimum of the l2 number
2362 * of bits being freed and the l2 (max) number
2363 * of bits that can be described by this leaf.
2364 */
2365 size =
2366 min(LITOL2BSZ
2367 (word, L2LPERDMAP, BUDMIN),
2368 NLSTOL2BSZ(nwords));
2369
2370 /* update the leaf.
2371 */
2372 rc = dbJoin(tp, word, size, false);
2373 if (rc)
2374 return rc;
2375
2376 /* get the number of dmap words handled.
2377 */
2378 nw = BUDSIZE(size, BUDMIN);
2379 word += nw;
2380 }
2381 }
2382 }
2383
2384 /* update the free count for this dmap.
2385 */
2386 le32_add_cpu(&dp->nfree, nblocks);
2387
2388 BMAP_LOCK(bmp);
2389
2390 /* update the free count for the allocation group and
2391 * map.
2392 */
2393 agno = blkno >> bmp->db_agl2size;
2394 bmp->db_nfree += nblocks;
2395 bmp->db_agfree[agno] += nblocks;
2396
2397 /* check if this allocation group is not completely free and
2398 * if it is currently the maximum (rightmost) allocation group.
2399 * if so, establish the new maximum allocation group number by
2400 * searching left for the first allocation group with allocation.
2401 */
2402 if ((bmp->db_agfree[agno] == bmp->db_agsize && agno == bmp->db_maxag) ||
2403 (agno == bmp->db_numag - 1 &&
2404 bmp->db_agfree[agno] == (bmp-> db_mapsize & (BPERDMAP - 1)))) {
2405 while (bmp->db_maxag > 0) {
2406 bmp->db_maxag -= 1;
2407 if (bmp->db_agfree[bmp->db_maxag] !=
2408 bmp->db_agsize)
2409 break;
2410 }
2411
2412 /* re-establish the allocation group preference if the
2413 * current preference is right of the maximum allocation
2414 * group.
2415 */
2416 if (bmp->db_agpref > bmp->db_maxag)
2417 bmp->db_agpref = bmp->db_maxag;
2418 }
2419
2420 BMAP_UNLOCK(bmp);
2421
2422 return 0;
2423}
2424
2425
2426/*
2427 * NAME: dbAdjCtl()
2428 *
2429 * FUNCTION: adjust a dmap control page at a specified level to reflect
2430 * the change in a lower level dmap or dmap control page's
2431 * maximum string of free blocks (i.e. a change in the root
2432 * of the lower level object's dmtree) due to the allocation
2433 * or deallocation of a range of blocks with a single dmap.
2434 *
2435 * on entry, this routine is provided with the new value of
2436 * the lower level dmap or dmap control page root and the
2437 * starting block number of the block range whose allocation
2438 * or deallocation resulted in the root change. this range
2439 * is respresented by a single leaf of the current dmapctl
2440 * and the leaf will be updated with this value, possibly
2441 * causing a binary buddy system within the leaves to be
2442 * split or joined. the update may also cause the dmapctl's
2443 * dmtree to be updated.
2444 *
2445 * if the adjustment of the dmap control page, itself, causes its
2446 * root to change, this change will be bubbled up to the next dmap
2447 * control level by a recursive call to this routine, specifying
2448 * the new root value and the next dmap control page level to
2449 * be adjusted.
2450 * PARAMETERS:
2451 * bmp - pointer to bmap descriptor
2452 * blkno - the first block of a block range within a dmap. it is
2453 * the allocation or deallocation of this block range that
2454 * requires the dmap control page to be adjusted.
2455 * newval - the new value of the lower level dmap or dmap control
2456 * page root.
2457 * alloc - 'true' if adjustment is due to an allocation.
2458 * level - current level of dmap control page (i.e. L0, L1, L2) to
2459 * be adjusted.
2460 *
2461 * RETURN VALUES:
2462 * 0 - success
2463 * -EIO - i/o error
2464 *
2465 * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit;
2466 */
2467static int
2468dbAdjCtl(struct bmap * bmp, s64 blkno, int newval, int alloc, int level)
2469{
2470 struct metapage *mp;
2471 s8 oldroot;
2472 int oldval;
2473 s64 lblkno;
2474 struct dmapctl *dcp;
2475 int rc, leafno, ti;
2476
2477 /* get the buffer for the dmap control page for the specified
2478 * block number and control page level.
2479 */
2480 lblkno = BLKTOCTL(blkno, bmp->db_l2nbperpage, level);
2481 mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0);
2482 if (mp == NULL)
2483 return -EIO;
2484 dcp = (struct dmapctl *) mp->data;
2485
2486 if (dcp->leafidx != cpu_to_le32(CTLLEAFIND)) {
2487 jfs_error(bmp->db_ipbmap->i_sb, "Corrupt dmapctl page\n");
2488 release_metapage(mp);
2489 return -EIO;
2490 }
2491
2492 /* determine the leaf number corresponding to the block and
2493 * the index within the dmap control tree.
2494 */
2495 leafno = BLKTOCTLLEAF(blkno, dcp->budmin);
2496 ti = leafno + le32_to_cpu(dcp->leafidx);
2497
2498 /* save the current leaf value and the current root level (i.e.
2499 * maximum l2 free string described by this dmapctl).
2500 */
2501 oldval = dcp->stree[ti];
2502 oldroot = dcp->stree[ROOT];
2503
2504 /* check if this is a control page update for an allocation.
2505 * if so, update the leaf to reflect the new leaf value using
2506 * dbSplit(); otherwise (deallocation), use dbJoin() to update
2507 * the leaf with the new value. in addition to updating the
2508 * leaf, dbSplit() will also split the binary buddy system of
2509 * the leaves, if required, and bubble new values within the
2510 * dmapctl tree, if required. similarly, dbJoin() will join
2511 * the binary buddy system of leaves and bubble new values up
2512 * the dmapctl tree as required by the new leaf value.
2513 */
2514 if (alloc) {
2515 /* check if we are in the middle of a binary buddy
2516 * system. this happens when we are performing the
2517 * first allocation out of an allocation group that
2518 * is part (not the first part) of a larger binary
2519 * buddy system. if we are in the middle, back split
2520 * the system prior to calling dbSplit() which assumes
2521 * that it is at the front of a binary buddy system.
2522 */
2523 if (oldval == NOFREE) {
2524 rc = dbBackSplit((dmtree_t *)dcp, leafno, true);
2525 if (rc) {
2526 release_metapage(mp);
2527 return rc;
2528 }
2529 oldval = dcp->stree[ti];
2530 }
2531 dbSplit((dmtree_t *) dcp, leafno, dcp->budmin, newval, true);
2532 } else {
2533 rc = dbJoin((dmtree_t *) dcp, leafno, newval, true);
2534 if (rc) {
2535 release_metapage(mp);
2536 return rc;
2537 }
2538 }
2539
2540 /* check if the root of the current dmap control page changed due
2541 * to the update and if the current dmap control page is not at
2542 * the current top level (i.e. L0, L1, L2) of the map. if so (i.e.
2543 * root changed and this is not the top level), call this routine
2544 * again (recursion) for the next higher level of the mapping to
2545 * reflect the change in root for the current dmap control page.
2546 */
2547 if (dcp->stree[ROOT] != oldroot) {
2548 /* are we below the top level of the map. if so,
2549 * bubble the root up to the next higher level.
2550 */
2551 if (level < bmp->db_maxlevel) {
2552 /* bubble up the new root of this dmap control page to
2553 * the next level.
2554 */
2555 if ((rc =
2556 dbAdjCtl(bmp, blkno, dcp->stree[ROOT], alloc,
2557 level + 1))) {
2558 /* something went wrong in bubbling up the new
2559 * root value, so backout the changes to the
2560 * current dmap control page.
2561 */
2562 if (alloc) {
2563 dbJoin((dmtree_t *) dcp, leafno,
2564 oldval, true);
2565 } else {
2566 /* the dbJoin() above might have
2567 * caused a larger binary buddy system
2568 * to form and we may now be in the
2569 * middle of it. if this is the case,
2570 * back split the buddies.
2571 */
2572 if (dcp->stree[ti] == NOFREE)
2573 dbBackSplit((dmtree_t *)
2574 dcp, leafno, true);
2575 dbSplit((dmtree_t *) dcp, leafno,
2576 dcp->budmin, oldval, true);
2577 }
2578
2579 /* release the buffer and return the error.
2580 */
2581 release_metapage(mp);
2582 return (rc);
2583 }
2584 } else {
2585 /* we're at the top level of the map. update
2586 * the bmap control page to reflect the size
2587 * of the maximum free buddy system.
2588 */
2589 assert(level == bmp->db_maxlevel);
2590 if (bmp->db_maxfreebud != oldroot) {
2591 jfs_error(bmp->db_ipbmap->i_sb,
2592 "the maximum free buddy is not the old root\n");
2593 }
2594 bmp->db_maxfreebud = dcp->stree[ROOT];
2595 }
2596 }
2597
2598 /* write the buffer.
2599 */
2600 write_metapage(mp);
2601
2602 return (0);
2603}
2604
2605
2606/*
2607 * NAME: dbSplit()
2608 *
2609 * FUNCTION: update the leaf of a dmtree with a new value, splitting
2610 * the leaf from the binary buddy system of the dmtree's
2611 * leaves, as required.
2612 *
2613 * PARAMETERS:
2614 * tp - pointer to the tree containing the leaf.
2615 * leafno - the number of the leaf to be updated.
2616 * splitsz - the size the binary buddy system starting at the leaf
2617 * must be split to, specified as the log2 number of blocks.
2618 * newval - the new value for the leaf.
2619 *
2620 * RETURN VALUES: none
2621 *
2622 * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit;
2623 */
2624static void dbSplit(dmtree_t *tp, int leafno, int splitsz, int newval, bool is_ctl)
2625{
2626 int budsz;
2627 int cursz;
2628 s8 *leaf = tp->dmt_stree + le32_to_cpu(tp->dmt_leafidx);
2629
2630 /* check if the leaf needs to be split.
2631 */
2632 if (leaf[leafno] > tp->dmt_budmin) {
2633 /* the split occurs by cutting the buddy system in half
2634 * at the specified leaf until we reach the specified
2635 * size. pick up the starting split size (current size
2636 * - 1 in l2) and the corresponding buddy size.
2637 */
2638 cursz = leaf[leafno] - 1;
2639 budsz = BUDSIZE(cursz, tp->dmt_budmin);
2640
2641 /* split until we reach the specified size.
2642 */
2643 while (cursz >= splitsz) {
2644 /* update the buddy's leaf with its new value.
2645 */
2646 dbAdjTree(tp, leafno ^ budsz, cursz, is_ctl);
2647
2648 /* on to the next size and buddy.
2649 */
2650 cursz -= 1;
2651 budsz >>= 1;
2652 }
2653 }
2654
2655 /* adjust the dmap tree to reflect the specified leaf's new
2656 * value.
2657 */
2658 dbAdjTree(tp, leafno, newval, is_ctl);
2659}
2660
2661
2662/*
2663 * NAME: dbBackSplit()
2664 *
2665 * FUNCTION: back split the binary buddy system of dmtree leaves
2666 * that hold a specified leaf until the specified leaf
2667 * starts its own binary buddy system.
2668 *
2669 * the allocators typically perform allocations at the start
2670 * of binary buddy systems and dbSplit() is used to accomplish
2671 * any required splits. in some cases, however, allocation
2672 * may occur in the middle of a binary system and requires a
2673 * back split, with the split proceeding out from the middle of
2674 * the system (less efficient) rather than the start of the
2675 * system (more efficient). the cases in which a back split
2676 * is required are rare and are limited to the first allocation
2677 * within an allocation group which is a part (not first part)
2678 * of a larger binary buddy system and a few exception cases
2679 * in which a previous join operation must be backed out.
2680 *
2681 * PARAMETERS:
2682 * tp - pointer to the tree containing the leaf.
2683 * leafno - the number of the leaf to be updated.
2684 *
2685 * RETURN VALUES: none
2686 *
2687 * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit;
2688 */
2689static int dbBackSplit(dmtree_t *tp, int leafno, bool is_ctl)
2690{
2691 int budsz, bud, w, bsz, size;
2692 int cursz;
2693 s8 *leaf = tp->dmt_stree + le32_to_cpu(tp->dmt_leafidx);
2694
2695 /* leaf should be part (not first part) of a binary
2696 * buddy system.
2697 */
2698 assert(leaf[leafno] == NOFREE);
2699
2700 /* the back split is accomplished by iteratively finding the leaf
2701 * that starts the buddy system that contains the specified leaf and
2702 * splitting that system in two. this iteration continues until
2703 * the specified leaf becomes the start of a buddy system.
2704 *
2705 * determine maximum possible l2 size for the specified leaf.
2706 */
2707 size =
2708 LITOL2BSZ(leafno, le32_to_cpu(tp->dmt_l2nleafs),
2709 tp->dmt_budmin);
2710
2711 /* determine the number of leaves covered by this size. this
2712 * is the buddy size that we will start with as we search for
2713 * the buddy system that contains the specified leaf.
2714 */
2715 budsz = BUDSIZE(size, tp->dmt_budmin);
2716
2717 /* back split.
2718 */
2719 while (leaf[leafno] == NOFREE) {
2720 /* find the leftmost buddy leaf.
2721 */
2722 for (w = leafno, bsz = budsz;; bsz <<= 1,
2723 w = (w < bud) ? w : bud) {
2724 if (bsz >= le32_to_cpu(tp->dmt_nleafs)) {
2725 jfs_err("JFS: block map error in dbBackSplit");
2726 return -EIO;
2727 }
2728
2729 /* determine the buddy.
2730 */
2731 bud = w ^ bsz;
2732
2733 /* check if this buddy is the start of the system.
2734 */
2735 if (leaf[bud] != NOFREE) {
2736 /* split the leaf at the start of the
2737 * system in two.
2738 */
2739 cursz = leaf[bud] - 1;
2740 dbSplit(tp, bud, cursz, cursz, is_ctl);
2741 break;
2742 }
2743 }
2744 }
2745
2746 if (leaf[leafno] != size) {
2747 jfs_err("JFS: wrong leaf value in dbBackSplit");
2748 return -EIO;
2749 }
2750 return 0;
2751}
2752
2753
2754/*
2755 * NAME: dbJoin()
2756 *
2757 * FUNCTION: update the leaf of a dmtree with a new value, joining
2758 * the leaf with other leaves of the dmtree into a multi-leaf
2759 * binary buddy system, as required.
2760 *
2761 * PARAMETERS:
2762 * tp - pointer to the tree containing the leaf.
2763 * leafno - the number of the leaf to be updated.
2764 * newval - the new value for the leaf.
2765 *
2766 * RETURN VALUES: none
2767 */
2768static int dbJoin(dmtree_t *tp, int leafno, int newval, bool is_ctl)
2769{
2770 int budsz, buddy;
2771 s8 *leaf;
2772
2773 /* can the new leaf value require a join with other leaves ?
2774 */
2775 if (newval >= tp->dmt_budmin) {
2776 /* pickup a pointer to the leaves of the tree.
2777 */
2778 leaf = tp->dmt_stree + le32_to_cpu(tp->dmt_leafidx);
2779
2780 /* try to join the specified leaf into a large binary
2781 * buddy system. the join proceeds by attempting to join
2782 * the specified leafno with its buddy (leaf) at new value.
2783 * if the join occurs, we attempt to join the left leaf
2784 * of the joined buddies with its buddy at new value + 1.
2785 * we continue to join until we find a buddy that cannot be
2786 * joined (does not have a value equal to the size of the
2787 * last join) or until all leaves have been joined into a
2788 * single system.
2789 *
2790 * get the buddy size (number of words covered) of
2791 * the new value.
2792 */
2793 budsz = BUDSIZE(newval, tp->dmt_budmin);
2794
2795 /* try to join.
2796 */
2797 while (budsz < le32_to_cpu(tp->dmt_nleafs)) {
2798 /* get the buddy leaf.
2799 */
2800 buddy = leafno ^ budsz;
2801
2802 /* if the leaf's new value is greater than its
2803 * buddy's value, we join no more.
2804 */
2805 if (newval > leaf[buddy])
2806 break;
2807
2808 /* It shouldn't be less */
2809 if (newval < leaf[buddy])
2810 return -EIO;
2811
2812 /* check which (leafno or buddy) is the left buddy.
2813 * the left buddy gets to claim the blocks resulting
2814 * from the join while the right gets to claim none.
2815 * the left buddy is also eligible to participate in
2816 * a join at the next higher level while the right
2817 * is not.
2818 *
2819 */
2820 if (leafno < buddy) {
2821 /* leafno is the left buddy.
2822 */
2823 dbAdjTree(tp, buddy, NOFREE, is_ctl);
2824 } else {
2825 /* buddy is the left buddy and becomes
2826 * leafno.
2827 */
2828 dbAdjTree(tp, leafno, NOFREE, is_ctl);
2829 leafno = buddy;
2830 }
2831
2832 /* on to try the next join.
2833 */
2834 newval += 1;
2835 budsz <<= 1;
2836 }
2837 }
2838
2839 /* update the leaf value.
2840 */
2841 dbAdjTree(tp, leafno, newval, is_ctl);
2842
2843 return 0;
2844}
2845
2846
2847/*
2848 * NAME: dbAdjTree()
2849 *
2850 * FUNCTION: update a leaf of a dmtree with a new value, adjusting
2851 * the dmtree, as required, to reflect the new leaf value.
2852 * the combination of any buddies must already be done before
2853 * this is called.
2854 *
2855 * PARAMETERS:
2856 * tp - pointer to the tree to be adjusted.
2857 * leafno - the number of the leaf to be updated.
2858 * newval - the new value for the leaf.
2859 *
2860 * RETURN VALUES: none
2861 */
2862static void dbAdjTree(dmtree_t *tp, int leafno, int newval, bool is_ctl)
2863{
2864 int lp, pp, k;
2865 int max, size;
2866
2867 size = is_ctl ? CTLTREESIZE : TREESIZE;
2868
2869 /* pick up the index of the leaf for this leafno.
2870 */
2871 lp = leafno + le32_to_cpu(tp->dmt_leafidx);
2872
2873 if (WARN_ON_ONCE(lp >= size || lp < 0))
2874 return;
2875
2876 /* is the current value the same as the old value ? if so,
2877 * there is nothing to do.
2878 */
2879 if (tp->dmt_stree[lp] == newval)
2880 return;
2881
2882 /* set the new value.
2883 */
2884 tp->dmt_stree[lp] = newval;
2885
2886 /* bubble the new value up the tree as required.
2887 */
2888 for (k = 0; k < le32_to_cpu(tp->dmt_height); k++) {
2889 /* get the index of the first leaf of the 4 leaf
2890 * group containing the specified leaf (leafno).
2891 */
2892 lp = ((lp - 1) & ~0x03) + 1;
2893
2894 /* get the index of the parent of this 4 leaf group.
2895 */
2896 pp = (lp - 1) >> 2;
2897
2898 /* determine the maximum of the 4 leaves.
2899 */
2900 max = TREEMAX(&tp->dmt_stree[lp]);
2901
2902 /* if the maximum of the 4 is the same as the
2903 * parent's value, we're done.
2904 */
2905 if (tp->dmt_stree[pp] == max)
2906 break;
2907
2908 /* parent gets new value.
2909 */
2910 tp->dmt_stree[pp] = max;
2911
2912 /* parent becomes leaf for next go-round.
2913 */
2914 lp = pp;
2915 }
2916}
2917
2918
2919/*
2920 * NAME: dbFindLeaf()
2921 *
2922 * FUNCTION: search a dmtree_t for sufficient free blocks, returning
2923 * the index of a leaf describing the free blocks if
2924 * sufficient free blocks are found.
2925 *
2926 * the search starts at the top of the dmtree_t tree and
2927 * proceeds down the tree to the leftmost leaf with sufficient
2928 * free space.
2929 *
2930 * PARAMETERS:
2931 * tp - pointer to the tree to be searched.
2932 * l2nb - log2 number of free blocks to search for.
2933 * leafidx - return pointer to be set to the index of the leaf
2934 * describing at least l2nb free blocks if sufficient
2935 * free blocks are found.
2936 * is_ctl - determines if the tree is of type ctl
2937 *
2938 * RETURN VALUES:
2939 * 0 - success
2940 * -ENOSPC - insufficient free blocks.
2941 */
2942static int dbFindLeaf(dmtree_t *tp, int l2nb, int *leafidx, bool is_ctl)
2943{
2944 int ti, n = 0, k, x = 0;
2945 int max_size;
2946
2947 max_size = is_ctl ? CTLTREESIZE : TREESIZE;
2948
2949 /* first check the root of the tree to see if there is
2950 * sufficient free space.
2951 */
2952 if (l2nb > tp->dmt_stree[ROOT])
2953 return -ENOSPC;
2954
2955 /* sufficient free space available. now search down the tree
2956 * starting at the next level for the leftmost leaf that
2957 * describes sufficient free space.
2958 */
2959 for (k = le32_to_cpu(tp->dmt_height), ti = 1;
2960 k > 0; k--, ti = ((ti + n) << 2) + 1) {
2961 /* search the four nodes at this level, starting from
2962 * the left.
2963 */
2964 for (x = ti, n = 0; n < 4; n++) {
2965 /* sufficient free space found. move to the next
2966 * level (or quit if this is the last level).
2967 */
2968 if (x + n > max_size)
2969 return -ENOSPC;
2970 if (l2nb <= tp->dmt_stree[x + n])
2971 break;
2972 }
2973
2974 /* better have found something since the higher
2975 * levels of the tree said it was here.
2976 */
2977 assert(n < 4);
2978 }
2979
2980 /* set the return to the leftmost leaf describing sufficient
2981 * free space.
2982 */
2983 *leafidx = x + n - le32_to_cpu(tp->dmt_leafidx);
2984
2985 return (0);
2986}
2987
2988
2989/*
2990 * NAME: dbFindBits()
2991 *
2992 * FUNCTION: find a specified number of binary buddy free bits within a
2993 * dmap bitmap word value.
2994 *
2995 * this routine searches the bitmap value for (1 << l2nb) free
2996 * bits at (1 << l2nb) alignments within the value.
2997 *
2998 * PARAMETERS:
2999 * word - dmap bitmap word value.
3000 * l2nb - number of free bits specified as a log2 number.
3001 *
3002 * RETURN VALUES:
3003 * starting bit number of free bits.
3004 */
3005static int dbFindBits(u32 word, int l2nb)
3006{
3007 int bitno, nb;
3008 u32 mask;
3009
3010 /* get the number of bits.
3011 */
3012 nb = 1 << l2nb;
3013 assert(nb <= DBWORD);
3014
3015 /* complement the word so we can use a mask (i.e. 0s represent
3016 * free bits) and compute the mask.
3017 */
3018 word = ~word;
3019 mask = ONES << (DBWORD - nb);
3020
3021 /* scan the word for nb free bits at nb alignments.
3022 */
3023 for (bitno = 0; mask != 0; bitno += nb, mask >>= nb) {
3024 if ((mask & word) == mask)
3025 break;
3026 }
3027
3028 ASSERT(bitno < 32);
3029
3030 /* return the bit number.
3031 */
3032 return (bitno);
3033}
3034
3035
3036/*
3037 * NAME: dbMaxBud(u8 *cp)
3038 *
3039 * FUNCTION: determine the largest binary buddy string of free
3040 * bits within 32-bits of the map.
3041 *
3042 * PARAMETERS:
3043 * cp - pointer to the 32-bit value.
3044 *
3045 * RETURN VALUES:
3046 * largest binary buddy of free bits within a dmap word.
3047 */
3048static int dbMaxBud(u8 * cp)
3049{
3050 signed char tmp1, tmp2;
3051
3052 /* check if the wmap word is all free. if so, the
3053 * free buddy size is BUDMIN.
3054 */
3055 if (*((uint *) cp) == 0)
3056 return (BUDMIN);
3057
3058 /* check if the wmap word is half free. if so, the
3059 * free buddy size is BUDMIN-1.
3060 */
3061 if (*((u16 *) cp) == 0 || *((u16 *) cp + 1) == 0)
3062 return (BUDMIN - 1);
3063
3064 /* not all free or half free. determine the free buddy
3065 * size thru table lookup using quarters of the wmap word.
3066 */
3067 tmp1 = max(budtab[cp[2]], budtab[cp[3]]);
3068 tmp2 = max(budtab[cp[0]], budtab[cp[1]]);
3069 return (max(tmp1, tmp2));
3070}
3071
3072
3073/*
3074 * NAME: cnttz(uint word)
3075 *
3076 * FUNCTION: determine the number of trailing zeros within a 32-bit
3077 * value.
3078 *
3079 * PARAMETERS:
3080 * value - 32-bit value to be examined.
3081 *
3082 * RETURN VALUES:
3083 * count of trailing zeros
3084 */
3085static int cnttz(u32 word)
3086{
3087 int n;
3088
3089 for (n = 0; n < 32; n++, word >>= 1) {
3090 if (word & 0x01)
3091 break;
3092 }
3093
3094 return (n);
3095}
3096
3097
3098/*
3099 * NAME: cntlz(u32 value)
3100 *
3101 * FUNCTION: determine the number of leading zeros within a 32-bit
3102 * value.
3103 *
3104 * PARAMETERS:
3105 * value - 32-bit value to be examined.
3106 *
3107 * RETURN VALUES:
3108 * count of leading zeros
3109 */
3110static int cntlz(u32 value)
3111{
3112 int n;
3113
3114 for (n = 0; n < 32; n++, value <<= 1) {
3115 if (value & HIGHORDER)
3116 break;
3117 }
3118 return (n);
3119}
3120
3121
3122/*
3123 * NAME: blkstol2(s64 nb)
3124 *
3125 * FUNCTION: convert a block count to its log2 value. if the block
3126 * count is not a l2 multiple, it is rounded up to the next
3127 * larger l2 multiple.
3128 *
3129 * PARAMETERS:
3130 * nb - number of blocks
3131 *
3132 * RETURN VALUES:
3133 * log2 number of blocks
3134 */
3135static int blkstol2(s64 nb)
3136{
3137 int l2nb;
3138 s64 mask; /* meant to be signed */
3139
3140 mask = (s64) 1 << (64 - 1);
3141
3142 /* count the leading bits.
3143 */
3144 for (l2nb = 0; l2nb < 64; l2nb++, mask >>= 1) {
3145 /* leading bit found.
3146 */
3147 if (nb & mask) {
3148 /* determine the l2 value.
3149 */
3150 l2nb = (64 - 1) - l2nb;
3151
3152 /* check if we need to round up.
3153 */
3154 if (~mask & nb)
3155 l2nb++;
3156
3157 return (l2nb);
3158 }
3159 }
3160 assert(0);
3161 return 0; /* fix compiler warning */
3162}
3163
3164
3165/*
3166 * NAME: dbAllocBottomUp()
3167 *
3168 * FUNCTION: alloc the specified block range from the working block
3169 * allocation map.
3170 *
3171 * the blocks will be alloc from the working map one dmap
3172 * at a time.
3173 *
3174 * PARAMETERS:
3175 * ip - pointer to in-core inode;
3176 * blkno - starting block number to be freed.
3177 * nblocks - number of blocks to be freed.
3178 *
3179 * RETURN VALUES:
3180 * 0 - success
3181 * -EIO - i/o error
3182 */
3183int dbAllocBottomUp(struct inode *ip, s64 blkno, s64 nblocks)
3184{
3185 struct metapage *mp;
3186 struct dmap *dp;
3187 int nb, rc;
3188 s64 lblkno, rem;
3189 struct inode *ipbmap = JFS_SBI(ip->i_sb)->ipbmap;
3190 struct bmap *bmp = JFS_SBI(ip->i_sb)->bmap;
3191
3192 IREAD_LOCK(ipbmap, RDWRLOCK_DMAP);
3193
3194 /* block to be allocated better be within the mapsize. */
3195 ASSERT(nblocks <= bmp->db_mapsize - blkno);
3196
3197 /*
3198 * allocate the blocks a dmap at a time.
3199 */
3200 mp = NULL;
3201 for (rem = nblocks; rem > 0; rem -= nb, blkno += nb) {
3202 /* release previous dmap if any */
3203 if (mp) {
3204 write_metapage(mp);
3205 }
3206
3207 /* get the buffer for the current dmap. */
3208 lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage);
3209 mp = read_metapage(ipbmap, lblkno, PSIZE, 0);
3210 if (mp == NULL) {
3211 IREAD_UNLOCK(ipbmap);
3212 return -EIO;
3213 }
3214 dp = (struct dmap *) mp->data;
3215
3216 /* determine the number of blocks to be allocated from
3217 * this dmap.
3218 */
3219 nb = min(rem, BPERDMAP - (blkno & (BPERDMAP - 1)));
3220
3221 /* allocate the blocks. */
3222 if ((rc = dbAllocDmapBU(bmp, dp, blkno, nb))) {
3223 release_metapage(mp);
3224 IREAD_UNLOCK(ipbmap);
3225 return (rc);
3226 }
3227 }
3228
3229 /* write the last buffer. */
3230 write_metapage(mp);
3231
3232 IREAD_UNLOCK(ipbmap);
3233
3234 return (0);
3235}
3236
3237
3238static int dbAllocDmapBU(struct bmap * bmp, struct dmap * dp, s64 blkno,
3239 int nblocks)
3240{
3241 int rc;
3242 int dbitno, word, rembits, nb, nwords, wbitno, agno;
3243 s8 oldroot;
3244 struct dmaptree *tp = (struct dmaptree *) & dp->tree;
3245
3246 /* save the current value of the root (i.e. maximum free string)
3247 * of the dmap tree.
3248 */
3249 oldroot = tp->stree[ROOT];
3250
3251 /* determine the bit number and word within the dmap of the
3252 * starting block.
3253 */
3254 dbitno = blkno & (BPERDMAP - 1);
3255 word = dbitno >> L2DBWORD;
3256
3257 /* block range better be within the dmap */
3258 assert(dbitno + nblocks <= BPERDMAP);
3259
3260 /* allocate the bits of the dmap's words corresponding to the block
3261 * range. not all bits of the first and last words may be contained
3262 * within the block range. if this is the case, we'll work against
3263 * those words (i.e. partial first and/or last) on an individual basis
3264 * (a single pass), allocating the bits of interest by hand and
3265 * updating the leaf corresponding to the dmap word. a single pass
3266 * will be used for all dmap words fully contained within the
3267 * specified range. within this pass, the bits of all fully contained
3268 * dmap words will be marked as free in a single shot and the leaves
3269 * will be updated. a single leaf may describe the free space of
3270 * multiple dmap words, so we may update only a subset of the actual
3271 * leaves corresponding to the dmap words of the block range.
3272 */
3273 for (rembits = nblocks; rembits > 0; rembits -= nb, dbitno += nb) {
3274 /* determine the bit number within the word and
3275 * the number of bits within the word.
3276 */
3277 wbitno = dbitno & (DBWORD - 1);
3278 nb = min(rembits, DBWORD - wbitno);
3279
3280 /* check if only part of a word is to be allocated.
3281 */
3282 if (nb < DBWORD) {
3283 /* allocate (set to 1) the appropriate bits within
3284 * this dmap word.
3285 */
3286 dp->wmap[word] |= cpu_to_le32(ONES << (DBWORD - nb)
3287 >> wbitno);
3288
3289 word++;
3290 } else {
3291 /* one or more dmap words are fully contained
3292 * within the block range. determine how many
3293 * words and allocate (set to 1) the bits of these
3294 * words.
3295 */
3296 nwords = rembits >> L2DBWORD;
3297 memset(&dp->wmap[word], (int) ONES, nwords * 4);
3298
3299 /* determine how many bits */
3300 nb = nwords << L2DBWORD;
3301 word += nwords;
3302 }
3303 }
3304
3305 /* update the free count for this dmap */
3306 le32_add_cpu(&dp->nfree, -nblocks);
3307
3308 /* reconstruct summary tree */
3309 dbInitDmapTree(dp);
3310
3311 BMAP_LOCK(bmp);
3312
3313 /* if this allocation group is completely free,
3314 * update the highest active allocation group number
3315 * if this allocation group is the new max.
3316 */
3317 agno = blkno >> bmp->db_agl2size;
3318 if (agno > bmp->db_maxag)
3319 bmp->db_maxag = agno;
3320
3321 /* update the free count for the allocation group and map */
3322 bmp->db_agfree[agno] -= nblocks;
3323 bmp->db_nfree -= nblocks;
3324
3325 BMAP_UNLOCK(bmp);
3326
3327 /* if the root has not changed, done. */
3328 if (tp->stree[ROOT] == oldroot)
3329 return (0);
3330
3331 /* root changed. bubble the change up to the dmap control pages.
3332 * if the adjustment of the upper level control pages fails,
3333 * backout the bit allocation (thus making everything consistent).
3334 */
3335 if ((rc = dbAdjCtl(bmp, blkno, tp->stree[ROOT], 1, 0)))
3336 dbFreeBits(bmp, dp, blkno, nblocks);
3337
3338 return (rc);
3339}
3340
3341
3342/*
3343 * NAME: dbExtendFS()
3344 *
3345 * FUNCTION: extend bmap from blkno for nblocks;
3346 * dbExtendFS() updates bmap ready for dbAllocBottomUp();
3347 *
3348 * L2
3349 * |
3350 * L1---------------------------------L1
3351 * | |
3352 * L0---------L0---------L0 L0---------L0---------L0
3353 * | | | | | |
3354 * d0,...,dn d0,...,dn d0,...,dn d0,...,dn d0,...,dn d0,.,dm;
3355 * L2L1L0d0,...,dnL0d0,...,dnL0d0,...,dnL1L0d0,...,dnL0d0,...,dnL0d0,..dm
3356 *
3357 * <---old---><----------------------------extend----------------------->
3358 */
3359int dbExtendFS(struct inode *ipbmap, s64 blkno, s64 nblocks)
3360{
3361 struct jfs_sb_info *sbi = JFS_SBI(ipbmap->i_sb);
3362 int nbperpage = sbi->nbperpage;
3363 int i, i0 = true, j, j0 = true, k, n;
3364 s64 newsize;
3365 s64 p;
3366 struct metapage *mp, *l2mp, *l1mp = NULL, *l0mp = NULL;
3367 struct dmapctl *l2dcp, *l1dcp, *l0dcp;
3368 struct dmap *dp;
3369 s8 *l0leaf, *l1leaf, *l2leaf;
3370 struct bmap *bmp = sbi->bmap;
3371 int agno, l2agsize, oldl2agsize;
3372 s64 ag_rem;
3373
3374 newsize = blkno + nblocks;
3375
3376 jfs_info("dbExtendFS: blkno:%Ld nblocks:%Ld newsize:%Ld",
3377 (long long) blkno, (long long) nblocks, (long long) newsize);
3378
3379 /*
3380 * initialize bmap control page.
3381 *
3382 * all the data in bmap control page should exclude
3383 * the mkfs hidden dmap page.
3384 */
3385
3386 /* update mapsize */
3387 bmp->db_mapsize = newsize;
3388 bmp->db_maxlevel = BMAPSZTOLEV(bmp->db_mapsize);
3389
3390 /* compute new AG size */
3391 l2agsize = dbGetL2AGSize(newsize);
3392 oldl2agsize = bmp->db_agl2size;
3393
3394 bmp->db_agl2size = l2agsize;
3395 bmp->db_agsize = 1 << l2agsize;
3396
3397 /* compute new number of AG */
3398 agno = bmp->db_numag;
3399 bmp->db_numag = newsize >> l2agsize;
3400 bmp->db_numag += ((u32) newsize % (u32) bmp->db_agsize) ? 1 : 0;
3401
3402 /*
3403 * reconfigure db_agfree[]
3404 * from old AG configuration to new AG configuration;
3405 *
3406 * coalesce contiguous k (newAGSize/oldAGSize) AGs;
3407 * i.e., (AGi, ..., AGj) where i = k*n and j = k*(n+1) - 1 to AGn;
3408 * note: new AG size = old AG size * (2**x).
3409 */
3410 if (l2agsize == oldl2agsize)
3411 goto extend;
3412 k = 1 << (l2agsize - oldl2agsize);
3413 ag_rem = bmp->db_agfree[0]; /* save agfree[0] */
3414 for (i = 0, n = 0; i < agno; n++) {
3415 bmp->db_agfree[n] = 0; /* init collection point */
3416
3417 /* coalesce contiguous k AGs; */
3418 for (j = 0; j < k && i < agno; j++, i++) {
3419 /* merge AGi to AGn */
3420 bmp->db_agfree[n] += bmp->db_agfree[i];
3421 }
3422 }
3423 bmp->db_agfree[0] += ag_rem; /* restore agfree[0] */
3424
3425 for (; n < MAXAG; n++)
3426 bmp->db_agfree[n] = 0;
3427
3428 /*
3429 * update highest active ag number
3430 */
3431
3432 bmp->db_maxag = bmp->db_maxag / k;
3433
3434 /*
3435 * extend bmap
3436 *
3437 * update bit maps and corresponding level control pages;
3438 * global control page db_nfree, db_agfree[agno], db_maxfreebud;
3439 */
3440 extend:
3441 /* get L2 page */
3442 p = BMAPBLKNO + nbperpage; /* L2 page */
3443 l2mp = read_metapage(ipbmap, p, PSIZE, 0);
3444 if (!l2mp) {
3445 jfs_error(ipbmap->i_sb, "L2 page could not be read\n");
3446 return -EIO;
3447 }
3448 l2dcp = (struct dmapctl *) l2mp->data;
3449
3450 /* compute start L1 */
3451 k = blkno >> L2MAXL1SIZE;
3452 l2leaf = l2dcp->stree + CTLLEAFIND + k;
3453 p = BLKTOL1(blkno, sbi->l2nbperpage); /* L1 page */
3454
3455 /*
3456 * extend each L1 in L2
3457 */
3458 for (; k < LPERCTL; k++, p += nbperpage) {
3459 /* get L1 page */
3460 if (j0) {
3461 /* read in L1 page: (blkno & (MAXL1SIZE - 1)) */
3462 l1mp = read_metapage(ipbmap, p, PSIZE, 0);
3463 if (l1mp == NULL)
3464 goto errout;
3465 l1dcp = (struct dmapctl *) l1mp->data;
3466
3467 /* compute start L0 */
3468 j = (blkno & (MAXL1SIZE - 1)) >> L2MAXL0SIZE;
3469 l1leaf = l1dcp->stree + CTLLEAFIND + j;
3470 p = BLKTOL0(blkno, sbi->l2nbperpage);
3471 j0 = false;
3472 } else {
3473 /* assign/init L1 page */
3474 l1mp = get_metapage(ipbmap, p, PSIZE, 0);
3475 if (l1mp == NULL)
3476 goto errout;
3477
3478 l1dcp = (struct dmapctl *) l1mp->data;
3479
3480 /* compute start L0 */
3481 j = 0;
3482 l1leaf = l1dcp->stree + CTLLEAFIND;
3483 p += nbperpage; /* 1st L0 of L1.k */
3484 }
3485
3486 /*
3487 * extend each L0 in L1
3488 */
3489 for (; j < LPERCTL; j++) {
3490 /* get L0 page */
3491 if (i0) {
3492 /* read in L0 page: (blkno & (MAXL0SIZE - 1)) */
3493
3494 l0mp = read_metapage(ipbmap, p, PSIZE, 0);
3495 if (l0mp == NULL)
3496 goto errout;
3497 l0dcp = (struct dmapctl *) l0mp->data;
3498
3499 /* compute start dmap */
3500 i = (blkno & (MAXL0SIZE - 1)) >>
3501 L2BPERDMAP;
3502 l0leaf = l0dcp->stree + CTLLEAFIND + i;
3503 p = BLKTODMAP(blkno,
3504 sbi->l2nbperpage);
3505 i0 = false;
3506 } else {
3507 /* assign/init L0 page */
3508 l0mp = get_metapage(ipbmap, p, PSIZE, 0);
3509 if (l0mp == NULL)
3510 goto errout;
3511
3512 l0dcp = (struct dmapctl *) l0mp->data;
3513
3514 /* compute start dmap */
3515 i = 0;
3516 l0leaf = l0dcp->stree + CTLLEAFIND;
3517 p += nbperpage; /* 1st dmap of L0.j */
3518 }
3519
3520 /*
3521 * extend each dmap in L0
3522 */
3523 for (; i < LPERCTL; i++) {
3524 /*
3525 * reconstruct the dmap page, and
3526 * initialize corresponding parent L0 leaf
3527 */
3528 if ((n = blkno & (BPERDMAP - 1))) {
3529 /* read in dmap page: */
3530 mp = read_metapage(ipbmap, p,
3531 PSIZE, 0);
3532 if (mp == NULL)
3533 goto errout;
3534 n = min(nblocks, (s64)BPERDMAP - n);
3535 } else {
3536 /* assign/init dmap page */
3537 mp = read_metapage(ipbmap, p,
3538 PSIZE, 0);
3539 if (mp == NULL)
3540 goto errout;
3541
3542 n = min_t(s64, nblocks, BPERDMAP);
3543 }
3544
3545 dp = (struct dmap *) mp->data;
3546 *l0leaf = dbInitDmap(dp, blkno, n);
3547
3548 bmp->db_nfree += n;
3549 agno = le64_to_cpu(dp->start) >> l2agsize;
3550 bmp->db_agfree[agno] += n;
3551
3552 write_metapage(mp);
3553
3554 l0leaf++;
3555 p += nbperpage;
3556
3557 blkno += n;
3558 nblocks -= n;
3559 if (nblocks == 0)
3560 break;
3561 } /* for each dmap in a L0 */
3562
3563 /*
3564 * build current L0 page from its leaves, and
3565 * initialize corresponding parent L1 leaf
3566 */
3567 *l1leaf = dbInitDmapCtl(l0dcp, 0, ++i);
3568 write_metapage(l0mp);
3569 l0mp = NULL;
3570
3571 if (nblocks)
3572 l1leaf++; /* continue for next L0 */
3573 else {
3574 /* more than 1 L0 ? */
3575 if (j > 0)
3576 break; /* build L1 page */
3577 else {
3578 /* summarize in global bmap page */
3579 bmp->db_maxfreebud = *l1leaf;
3580 release_metapage(l1mp);
3581 release_metapage(l2mp);
3582 goto finalize;
3583 }
3584 }
3585 } /* for each L0 in a L1 */
3586
3587 /*
3588 * build current L1 page from its leaves, and
3589 * initialize corresponding parent L2 leaf
3590 */
3591 *l2leaf = dbInitDmapCtl(l1dcp, 1, ++j);
3592 write_metapage(l1mp);
3593 l1mp = NULL;
3594
3595 if (nblocks)
3596 l2leaf++; /* continue for next L1 */
3597 else {
3598 /* more than 1 L1 ? */
3599 if (k > 0)
3600 break; /* build L2 page */
3601 else {
3602 /* summarize in global bmap page */
3603 bmp->db_maxfreebud = *l2leaf;
3604 release_metapage(l2mp);
3605 goto finalize;
3606 }
3607 }
3608 } /* for each L1 in a L2 */
3609
3610 jfs_error(ipbmap->i_sb, "function has not returned as expected\n");
3611errout:
3612 if (l0mp)
3613 release_metapage(l0mp);
3614 if (l1mp)
3615 release_metapage(l1mp);
3616 release_metapage(l2mp);
3617 return -EIO;
3618
3619 /*
3620 * finalize bmap control page
3621 */
3622finalize:
3623
3624 return 0;
3625}
3626
3627
3628/*
3629 * dbFinalizeBmap()
3630 */
3631void dbFinalizeBmap(struct inode *ipbmap)
3632{
3633 struct bmap *bmp = JFS_SBI(ipbmap->i_sb)->bmap;
3634 int actags, inactags, l2nl;
3635 s64 ag_rem, actfree, inactfree, avgfree;
3636 int i, n;
3637
3638 /*
3639 * finalize bmap control page
3640 */
3641//finalize:
3642 /*
3643 * compute db_agpref: preferred ag to allocate from
3644 * (the leftmost ag with average free space in it);
3645 */
3646//agpref:
3647 /* get the number of active ags and inactive ags */
3648 actags = bmp->db_maxag + 1;
3649 inactags = bmp->db_numag - actags;
3650 ag_rem = bmp->db_mapsize & (bmp->db_agsize - 1); /* ??? */
3651
3652 /* determine how many blocks are in the inactive allocation
3653 * groups. in doing this, we must account for the fact that
3654 * the rightmost group might be a partial group (i.e. file
3655 * system size is not a multiple of the group size).
3656 */
3657 inactfree = (inactags && ag_rem) ?
3658 ((inactags - 1) << bmp->db_agl2size) + ag_rem
3659 : inactags << bmp->db_agl2size;
3660
3661 /* determine how many free blocks are in the active
3662 * allocation groups plus the average number of free blocks
3663 * within the active ags.
3664 */
3665 actfree = bmp->db_nfree - inactfree;
3666 avgfree = (u32) actfree / (u32) actags;
3667
3668 /* if the preferred allocation group has not average free space.
3669 * re-establish the preferred group as the leftmost
3670 * group with average free space.
3671 */
3672 if (bmp->db_agfree[bmp->db_agpref] < avgfree) {
3673 for (bmp->db_agpref = 0; bmp->db_agpref < actags;
3674 bmp->db_agpref++) {
3675 if (bmp->db_agfree[bmp->db_agpref] >= avgfree)
3676 break;
3677 }
3678 if (bmp->db_agpref >= bmp->db_numag) {
3679 jfs_error(ipbmap->i_sb,
3680 "cannot find ag with average freespace\n");
3681 }
3682 }
3683
3684 /*
3685 * compute db_aglevel, db_agheight, db_width, db_agstart:
3686 * an ag is covered in aglevel dmapctl summary tree,
3687 * at agheight level height (from leaf) with agwidth number of nodes
3688 * each, which starts at agstart index node of the smmary tree node
3689 * array;
3690 */
3691 bmp->db_aglevel = BMAPSZTOLEV(bmp->db_agsize);
3692 l2nl =
3693 bmp->db_agl2size - (L2BPERDMAP + bmp->db_aglevel * L2LPERCTL);
3694 bmp->db_agheight = l2nl >> 1;
3695 bmp->db_agwidth = 1 << (l2nl - (bmp->db_agheight << 1));
3696 for (i = 5 - bmp->db_agheight, bmp->db_agstart = 0, n = 1; i > 0;
3697 i--) {
3698 bmp->db_agstart += n;
3699 n <<= 2;
3700 }
3701
3702}
3703
3704
3705/*
3706 * NAME: dbInitDmap()/ujfs_idmap_page()
3707 *
3708 * FUNCTION: initialize working/persistent bitmap of the dmap page
3709 * for the specified number of blocks:
3710 *
3711 * at entry, the bitmaps had been initialized as free (ZEROS);
3712 * The number of blocks will only account for the actually
3713 * existing blocks. Blocks which don't actually exist in
3714 * the aggregate will be marked as allocated (ONES);
3715 *
3716 * PARAMETERS:
3717 * dp - pointer to page of map
3718 * nblocks - number of blocks this page
3719 *
3720 * RETURNS: NONE
3721 */
3722static int dbInitDmap(struct dmap * dp, s64 Blkno, int nblocks)
3723{
3724 int blkno, w, b, r, nw, nb, i;
3725
3726 /* starting block number within the dmap */
3727 blkno = Blkno & (BPERDMAP - 1);
3728
3729 if (blkno == 0) {
3730 dp->nblocks = dp->nfree = cpu_to_le32(nblocks);
3731 dp->start = cpu_to_le64(Blkno);
3732
3733 if (nblocks == BPERDMAP) {
3734 memset(&dp->wmap[0], 0, LPERDMAP * 4);
3735 memset(&dp->pmap[0], 0, LPERDMAP * 4);
3736 goto initTree;
3737 }
3738 } else {
3739 le32_add_cpu(&dp->nblocks, nblocks);
3740 le32_add_cpu(&dp->nfree, nblocks);
3741 }
3742
3743 /* word number containing start block number */
3744 w = blkno >> L2DBWORD;
3745
3746 /*
3747 * free the bits corresponding to the block range (ZEROS):
3748 * note: not all bits of the first and last words may be contained
3749 * within the block range.
3750 */
3751 for (r = nblocks; r > 0; r -= nb, blkno += nb) {
3752 /* number of bits preceding range to be freed in the word */
3753 b = blkno & (DBWORD - 1);
3754 /* number of bits to free in the word */
3755 nb = min(r, DBWORD - b);
3756
3757 /* is partial word to be freed ? */
3758 if (nb < DBWORD) {
3759 /* free (set to 0) from the bitmap word */
3760 dp->wmap[w] &= cpu_to_le32(~(ONES << (DBWORD - nb)
3761 >> b));
3762 dp->pmap[w] &= cpu_to_le32(~(ONES << (DBWORD - nb)
3763 >> b));
3764
3765 /* skip the word freed */
3766 w++;
3767 } else {
3768 /* free (set to 0) contiguous bitmap words */
3769 nw = r >> L2DBWORD;
3770 memset(&dp->wmap[w], 0, nw * 4);
3771 memset(&dp->pmap[w], 0, nw * 4);
3772
3773 /* skip the words freed */
3774 nb = nw << L2DBWORD;
3775 w += nw;
3776 }
3777 }
3778
3779 /*
3780 * mark bits following the range to be freed (non-existing
3781 * blocks) as allocated (ONES)
3782 */
3783
3784 if (blkno == BPERDMAP)
3785 goto initTree;
3786
3787 /* the first word beyond the end of existing blocks */
3788 w = blkno >> L2DBWORD;
3789
3790 /* does nblocks fall on a 32-bit boundary ? */
3791 b = blkno & (DBWORD - 1);
3792 if (b) {
3793 /* mark a partial word allocated */
3794 dp->wmap[w] = dp->pmap[w] = cpu_to_le32(ONES >> b);
3795 w++;
3796 }
3797
3798 /* set the rest of the words in the page to allocated (ONES) */
3799 for (i = w; i < LPERDMAP; i++)
3800 dp->pmap[i] = dp->wmap[i] = cpu_to_le32(ONES);
3801
3802 /*
3803 * init tree
3804 */
3805 initTree:
3806 return (dbInitDmapTree(dp));
3807}
3808
3809
3810/*
3811 * NAME: dbInitDmapTree()/ujfs_complete_dmap()
3812 *
3813 * FUNCTION: initialize summary tree of the specified dmap:
3814 *
3815 * at entry, bitmap of the dmap has been initialized;
3816 *
3817 * PARAMETERS:
3818 * dp - dmap to complete
3819 * blkno - starting block number for this dmap
3820 * treemax - will be filled in with max free for this dmap
3821 *
3822 * RETURNS: max free string at the root of the tree
3823 */
3824static int dbInitDmapTree(struct dmap * dp)
3825{
3826 struct dmaptree *tp;
3827 s8 *cp;
3828 int i;
3829
3830 /* init fixed info of tree */
3831 tp = &dp->tree;
3832 tp->nleafs = cpu_to_le32(LPERDMAP);
3833 tp->l2nleafs = cpu_to_le32(L2LPERDMAP);
3834 tp->leafidx = cpu_to_le32(LEAFIND);
3835 tp->height = cpu_to_le32(4);
3836 tp->budmin = BUDMIN;
3837
3838 /* init each leaf from corresponding wmap word:
3839 * note: leaf is set to NOFREE(-1) if all blocks of corresponding
3840 * bitmap word are allocated.
3841 */
3842 cp = tp->stree + le32_to_cpu(tp->leafidx);
3843 for (i = 0; i < LPERDMAP; i++)
3844 *cp++ = dbMaxBud((u8 *) & dp->wmap[i]);
3845
3846 /* build the dmap's binary buddy summary tree */
3847 return (dbInitTree(tp));
3848}
3849
3850
3851/*
3852 * NAME: dbInitTree()/ujfs_adjtree()
3853 *
3854 * FUNCTION: initialize binary buddy summary tree of a dmap or dmapctl.
3855 *
3856 * at entry, the leaves of the tree has been initialized
3857 * from corresponding bitmap word or root of summary tree
3858 * of the child control page;
3859 * configure binary buddy system at the leaf level, then
3860 * bubble up the values of the leaf nodes up the tree.
3861 *
3862 * PARAMETERS:
3863 * cp - Pointer to the root of the tree
3864 * l2leaves- Number of leaf nodes as a power of 2
3865 * l2min - Number of blocks that can be covered by a leaf
3866 * as a power of 2
3867 *
3868 * RETURNS: max free string at the root of the tree
3869 */
3870static int dbInitTree(struct dmaptree * dtp)
3871{
3872 int l2max, l2free, bsize, nextb, i;
3873 int child, parent, nparent;
3874 s8 *tp, *cp, *cp1;
3875
3876 tp = dtp->stree;
3877
3878 /* Determine the maximum free string possible for the leaves */
3879 l2max = le32_to_cpu(dtp->l2nleafs) + dtp->budmin;
3880
3881 /*
3882 * configure the leaf level into binary buddy system
3883 *
3884 * Try to combine buddies starting with a buddy size of 1
3885 * (i.e. two leaves). At a buddy size of 1 two buddy leaves
3886 * can be combined if both buddies have a maximum free of l2min;
3887 * the combination will result in the left-most buddy leaf having
3888 * a maximum free of l2min+1.
3889 * After processing all buddies for a given size, process buddies
3890 * at the next higher buddy size (i.e. current size * 2) and
3891 * the next maximum free (current free + 1).
3892 * This continues until the maximum possible buddy combination
3893 * yields maximum free.
3894 */
3895 for (l2free = dtp->budmin, bsize = 1; l2free < l2max;
3896 l2free++, bsize = nextb) {
3897 /* get next buddy size == current buddy pair size */
3898 nextb = bsize << 1;
3899
3900 /* scan each adjacent buddy pair at current buddy size */
3901 for (i = 0, cp = tp + le32_to_cpu(dtp->leafidx);
3902 i < le32_to_cpu(dtp->nleafs);
3903 i += nextb, cp += nextb) {
3904 /* coalesce if both adjacent buddies are max free */
3905 if (*cp == l2free && *(cp + bsize) == l2free) {
3906 *cp = l2free + 1; /* left take right */
3907 *(cp + bsize) = -1; /* right give left */
3908 }
3909 }
3910 }
3911
3912 /*
3913 * bubble summary information of leaves up the tree.
3914 *
3915 * Starting at the leaf node level, the four nodes described by
3916 * the higher level parent node are compared for a maximum free and
3917 * this maximum becomes the value of the parent node.
3918 * when all lower level nodes are processed in this fashion then
3919 * move up to the next level (parent becomes a lower level node) and
3920 * continue the process for that level.
3921 */
3922 for (child = le32_to_cpu(dtp->leafidx),
3923 nparent = le32_to_cpu(dtp->nleafs) >> 2;
3924 nparent > 0; nparent >>= 2, child = parent) {
3925 /* get index of 1st node of parent level */
3926 parent = (child - 1) >> 2;
3927
3928 /* set the value of the parent node as the maximum
3929 * of the four nodes of the current level.
3930 */
3931 for (i = 0, cp = tp + child, cp1 = tp + parent;
3932 i < nparent; i++, cp += 4, cp1++)
3933 *cp1 = TREEMAX(cp);
3934 }
3935
3936 return (*tp);
3937}
3938
3939
3940/*
3941 * dbInitDmapCtl()
3942 *
3943 * function: initialize dmapctl page
3944 */
3945static int dbInitDmapCtl(struct dmapctl * dcp, int level, int i)
3946{ /* start leaf index not covered by range */
3947 s8 *cp;
3948
3949 dcp->nleafs = cpu_to_le32(LPERCTL);
3950 dcp->l2nleafs = cpu_to_le32(L2LPERCTL);
3951 dcp->leafidx = cpu_to_le32(CTLLEAFIND);
3952 dcp->height = cpu_to_le32(5);
3953 dcp->budmin = L2BPERDMAP + L2LPERCTL * level;
3954
3955 /*
3956 * initialize the leaves of current level that were not covered
3957 * by the specified input block range (i.e. the leaves have no
3958 * low level dmapctl or dmap).
3959 */
3960 cp = &dcp->stree[CTLLEAFIND + i];
3961 for (; i < LPERCTL; i++)
3962 *cp++ = NOFREE;
3963
3964 /* build the dmap's binary buddy summary tree */
3965 return (dbInitTree((struct dmaptree *) dcp));
3966}
3967
3968
3969/*
3970 * NAME: dbGetL2AGSize()/ujfs_getagl2size()
3971 *
3972 * FUNCTION: Determine log2(allocation group size) from aggregate size
3973 *
3974 * PARAMETERS:
3975 * nblocks - Number of blocks in aggregate
3976 *
3977 * RETURNS: log2(allocation group size) in aggregate blocks
3978 */
3979static int dbGetL2AGSize(s64 nblocks)
3980{
3981 s64 sz;
3982 s64 m;
3983 int l2sz;
3984
3985 if (nblocks < BPERDMAP * MAXAG)
3986 return (L2BPERDMAP);
3987
3988 /* round up aggregate size to power of 2 */
3989 m = ((u64) 1 << (64 - 1));
3990 for (l2sz = 64; l2sz >= 0; l2sz--, m >>= 1) {
3991 if (m & nblocks)
3992 break;
3993 }
3994
3995 sz = (s64) 1 << l2sz;
3996 if (sz < nblocks)
3997 l2sz += 1;
3998
3999 /* agsize = roundupSize/max_number_of_ag */
4000 return (l2sz - L2MAXAG);
4001}
4002
4003
4004/*
4005 * NAME: dbMapFileSizeToMapSize()
4006 *
4007 * FUNCTION: compute number of blocks the block allocation map file
4008 * can cover from the map file size;
4009 *
4010 * RETURNS: Number of blocks which can be covered by this block map file;
4011 */
4012
4013/*
4014 * maximum number of map pages at each level including control pages
4015 */
4016#define MAXL0PAGES (1 + LPERCTL)
4017#define MAXL1PAGES (1 + LPERCTL * MAXL0PAGES)
4018
4019/*
4020 * convert number of map pages to the zero origin top dmapctl level
4021 */
4022#define BMAPPGTOLEV(npages) \
4023 (((npages) <= 3 + MAXL0PAGES) ? 0 : \
4024 ((npages) <= 2 + MAXL1PAGES) ? 1 : 2)
4025
4026s64 dbMapFileSizeToMapSize(struct inode * ipbmap)
4027{
4028 struct super_block *sb = ipbmap->i_sb;
4029 s64 nblocks;
4030 s64 npages, ndmaps;
4031 int level, i;
4032 int complete, factor;
4033
4034 nblocks = ipbmap->i_size >> JFS_SBI(sb)->l2bsize;
4035 npages = nblocks >> JFS_SBI(sb)->l2nbperpage;
4036 level = BMAPPGTOLEV(npages);
4037
4038 /* At each level, accumulate the number of dmap pages covered by
4039 * the number of full child levels below it;
4040 * repeat for the last incomplete child level.
4041 */
4042 ndmaps = 0;
4043 npages--; /* skip the first global control page */
4044 /* skip higher level control pages above top level covered by map */
4045 npages -= (2 - level);
4046 npages--; /* skip top level's control page */
4047 for (i = level; i >= 0; i--) {
4048 factor =
4049 (i == 2) ? MAXL1PAGES : ((i == 1) ? MAXL0PAGES : 1);
4050 complete = (u32) npages / factor;
4051 ndmaps += complete * ((i == 2) ? LPERCTL * LPERCTL :
4052 ((i == 1) ? LPERCTL : 1));
4053
4054 /* pages in last/incomplete child */
4055 npages = (u32) npages % factor;
4056 /* skip incomplete child's level control page */
4057 npages--;
4058 }
4059
4060 /* convert the number of dmaps into the number of blocks
4061 * which can be covered by the dmaps;
4062 */
4063 nblocks = ndmaps << L2BPERDMAP;
4064
4065 return (nblocks);
4066}
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (C) International Business Machines Corp., 2000-2004
4 * Portions Copyright (C) Tino Reichardt, 2012
5 */
6
7#include <linux/fs.h>
8#include <linux/slab.h>
9#include "jfs_incore.h"
10#include "jfs_superblock.h"
11#include "jfs_dmap.h"
12#include "jfs_imap.h"
13#include "jfs_lock.h"
14#include "jfs_metapage.h"
15#include "jfs_debug.h"
16#include "jfs_discard.h"
17
18/*
19 * SERIALIZATION of the Block Allocation Map.
20 *
21 * the working state of the block allocation map is accessed in
22 * two directions:
23 *
24 * 1) allocation and free requests that start at the dmap
25 * level and move up through the dmap control pages (i.e.
26 * the vast majority of requests).
27 *
28 * 2) allocation requests that start at dmap control page
29 * level and work down towards the dmaps.
30 *
31 * the serialization scheme used here is as follows.
32 *
33 * requests which start at the bottom are serialized against each
34 * other through buffers and each requests holds onto its buffers
35 * as it works it way up from a single dmap to the required level
36 * of dmap control page.
37 * requests that start at the top are serialized against each other
38 * and request that start from the bottom by the multiple read/single
39 * write inode lock of the bmap inode. requests starting at the top
40 * take this lock in write mode while request starting at the bottom
41 * take the lock in read mode. a single top-down request may proceed
42 * exclusively while multiple bottoms-up requests may proceed
43 * simultaneously (under the protection of busy buffers).
44 *
45 * in addition to information found in dmaps and dmap control pages,
46 * the working state of the block allocation map also includes read/
47 * write information maintained in the bmap descriptor (i.e. total
48 * free block count, allocation group level free block counts).
49 * a single exclusive lock (BMAP_LOCK) is used to guard this information
50 * in the face of multiple-bottoms up requests.
51 * (lock ordering: IREAD_LOCK, BMAP_LOCK);
52 *
53 * accesses to the persistent state of the block allocation map (limited
54 * to the persistent bitmaps in dmaps) is guarded by (busy) buffers.
55 */
56
57#define BMAP_LOCK_INIT(bmp) mutex_init(&bmp->db_bmaplock)
58#define BMAP_LOCK(bmp) mutex_lock(&bmp->db_bmaplock)
59#define BMAP_UNLOCK(bmp) mutex_unlock(&bmp->db_bmaplock)
60
61/*
62 * forward references
63 */
64static void dbAllocBits(struct bmap * bmp, struct dmap * dp, s64 blkno,
65 int nblocks);
66static void dbSplit(dmtree_t *tp, int leafno, int splitsz, int newval, bool is_ctl);
67static int dbBackSplit(dmtree_t *tp, int leafno, bool is_ctl);
68static int dbJoin(dmtree_t *tp, int leafno, int newval, bool is_ctl);
69static void dbAdjTree(dmtree_t *tp, int leafno, int newval, bool is_ctl);
70static int dbAdjCtl(struct bmap * bmp, s64 blkno, int newval, int alloc,
71 int level);
72static int dbAllocAny(struct bmap * bmp, s64 nblocks, int l2nb, s64 * results);
73static int dbAllocNext(struct bmap * bmp, struct dmap * dp, s64 blkno,
74 int nblocks);
75static int dbAllocNear(struct bmap * bmp, struct dmap * dp, s64 blkno,
76 int nblocks,
77 int l2nb, s64 * results);
78static int dbAllocDmap(struct bmap * bmp, struct dmap * dp, s64 blkno,
79 int nblocks);
80static int dbAllocDmapLev(struct bmap * bmp, struct dmap * dp, int nblocks,
81 int l2nb,
82 s64 * results);
83static int dbAllocAG(struct bmap * bmp, int agno, s64 nblocks, int l2nb,
84 s64 * results);
85static int dbAllocCtl(struct bmap * bmp, s64 nblocks, int l2nb, s64 blkno,
86 s64 * results);
87static int dbExtend(struct inode *ip, s64 blkno, s64 nblocks, s64 addnblocks);
88static int dbFindBits(u32 word, int l2nb);
89static int dbFindCtl(struct bmap * bmp, int l2nb, int level, s64 * blkno);
90static int dbFindLeaf(dmtree_t *tp, int l2nb, int *leafidx, bool is_ctl);
91static int dbFreeBits(struct bmap * bmp, struct dmap * dp, s64 blkno,
92 int nblocks);
93static int dbFreeDmap(struct bmap * bmp, struct dmap * dp, s64 blkno,
94 int nblocks);
95static int dbMaxBud(u8 * cp);
96static int blkstol2(s64 nb);
97
98static int cntlz(u32 value);
99static int cnttz(u32 word);
100
101static int dbAllocDmapBU(struct bmap * bmp, struct dmap * dp, s64 blkno,
102 int nblocks);
103static int dbInitDmap(struct dmap * dp, s64 blkno, int nblocks);
104static int dbInitDmapTree(struct dmap * dp);
105static int dbInitTree(struct dmaptree * dtp);
106static int dbInitDmapCtl(struct dmapctl * dcp, int level, int i);
107static int dbGetL2AGSize(s64 nblocks);
108
109/*
110 * buddy table
111 *
112 * table used for determining buddy sizes within characters of
113 * dmap bitmap words. the characters themselves serve as indexes
114 * into the table, with the table elements yielding the maximum
115 * binary buddy of free bits within the character.
116 */
117static const s8 budtab[256] = {
118 3, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
119 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
120 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
121 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
122 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
123 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0,
124 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0,
125 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0,
126 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
127 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0,
128 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0,
129 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0,
130 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
131 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0,
132 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0,
133 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, -1
134};
135
136/*
137 * NAME: dbMount()
138 *
139 * FUNCTION: initializate the block allocation map.
140 *
141 * memory is allocated for the in-core bmap descriptor and
142 * the in-core descriptor is initialized from disk.
143 *
144 * PARAMETERS:
145 * ipbmap - pointer to in-core inode for the block map.
146 *
147 * RETURN VALUES:
148 * 0 - success
149 * -ENOMEM - insufficient memory
150 * -EIO - i/o error
151 * -EINVAL - wrong bmap data
152 */
153int dbMount(struct inode *ipbmap)
154{
155 struct bmap *bmp;
156 struct dbmap_disk *dbmp_le;
157 struct metapage *mp;
158 int i, err;
159
160 /*
161 * allocate/initialize the in-memory bmap descriptor
162 */
163 /* allocate memory for the in-memory bmap descriptor */
164 bmp = kmalloc(sizeof(struct bmap), GFP_KERNEL);
165 if (bmp == NULL)
166 return -ENOMEM;
167
168 /* read the on-disk bmap descriptor. */
169 mp = read_metapage(ipbmap,
170 BMAPBLKNO << JFS_SBI(ipbmap->i_sb)->l2nbperpage,
171 PSIZE, 0);
172 if (mp == NULL) {
173 err = -EIO;
174 goto err_kfree_bmp;
175 }
176
177 /* copy the on-disk bmap descriptor to its in-memory version. */
178 dbmp_le = (struct dbmap_disk *) mp->data;
179 bmp->db_mapsize = le64_to_cpu(dbmp_le->dn_mapsize);
180 bmp->db_nfree = le64_to_cpu(dbmp_le->dn_nfree);
181
182 bmp->db_l2nbperpage = le32_to_cpu(dbmp_le->dn_l2nbperpage);
183 if (bmp->db_l2nbperpage > L2PSIZE - L2MINBLOCKSIZE ||
184 bmp->db_l2nbperpage < 0) {
185 err = -EINVAL;
186 goto err_release_metapage;
187 }
188
189 bmp->db_numag = le32_to_cpu(dbmp_le->dn_numag);
190 if (!bmp->db_numag || bmp->db_numag > MAXAG) {
191 err = -EINVAL;
192 goto err_release_metapage;
193 }
194
195 bmp->db_maxlevel = le32_to_cpu(dbmp_le->dn_maxlevel);
196 bmp->db_maxag = le32_to_cpu(dbmp_le->dn_maxag);
197 bmp->db_agpref = le32_to_cpu(dbmp_le->dn_agpref);
198 if (bmp->db_maxag >= MAXAG || bmp->db_maxag < 0 ||
199 bmp->db_agpref >= MAXAG || bmp->db_agpref < 0) {
200 err = -EINVAL;
201 goto err_release_metapage;
202 }
203
204 bmp->db_aglevel = le32_to_cpu(dbmp_le->dn_aglevel);
205 bmp->db_agheight = le32_to_cpu(dbmp_le->dn_agheight);
206 bmp->db_agwidth = le32_to_cpu(dbmp_le->dn_agwidth);
207 bmp->db_agstart = le32_to_cpu(dbmp_le->dn_agstart);
208 bmp->db_agl2size = le32_to_cpu(dbmp_le->dn_agl2size);
209 if (bmp->db_agl2size > L2MAXL2SIZE - L2MAXAG ||
210 bmp->db_agl2size < 0) {
211 err = -EINVAL;
212 goto err_release_metapage;
213 }
214
215 if (((bmp->db_mapsize - 1) >> bmp->db_agl2size) > MAXAG) {
216 err = -EINVAL;
217 goto err_release_metapage;
218 }
219
220 for (i = 0; i < MAXAG; i++)
221 bmp->db_agfree[i] = le64_to_cpu(dbmp_le->dn_agfree[i]);
222 bmp->db_agsize = le64_to_cpu(dbmp_le->dn_agsize);
223 bmp->db_maxfreebud = dbmp_le->dn_maxfreebud;
224
225 /* release the buffer. */
226 release_metapage(mp);
227
228 /* bind the bmap inode and the bmap descriptor to each other. */
229 bmp->db_ipbmap = ipbmap;
230 JFS_SBI(ipbmap->i_sb)->bmap = bmp;
231
232 memset(bmp->db_active, 0, sizeof(bmp->db_active));
233
234 /*
235 * allocate/initialize the bmap lock
236 */
237 BMAP_LOCK_INIT(bmp);
238
239 return (0);
240
241err_release_metapage:
242 release_metapage(mp);
243err_kfree_bmp:
244 kfree(bmp);
245 return err;
246}
247
248
249/*
250 * NAME: dbUnmount()
251 *
252 * FUNCTION: terminate the block allocation map in preparation for
253 * file system unmount.
254 *
255 * the in-core bmap descriptor is written to disk and
256 * the memory for this descriptor is freed.
257 *
258 * PARAMETERS:
259 * ipbmap - pointer to in-core inode for the block map.
260 *
261 * RETURN VALUES:
262 * 0 - success
263 * -EIO - i/o error
264 */
265int dbUnmount(struct inode *ipbmap, int mounterror)
266{
267 struct bmap *bmp = JFS_SBI(ipbmap->i_sb)->bmap;
268
269 if (!(mounterror || isReadOnly(ipbmap)))
270 dbSync(ipbmap);
271
272 /*
273 * Invalidate the page cache buffers
274 */
275 truncate_inode_pages(ipbmap->i_mapping, 0);
276
277 /* free the memory for the in-memory bmap. */
278 kfree(bmp);
279 JFS_SBI(ipbmap->i_sb)->bmap = NULL;
280
281 return (0);
282}
283
284/*
285 * dbSync()
286 */
287int dbSync(struct inode *ipbmap)
288{
289 struct dbmap_disk *dbmp_le;
290 struct bmap *bmp = JFS_SBI(ipbmap->i_sb)->bmap;
291 struct metapage *mp;
292 int i;
293
294 /*
295 * write bmap global control page
296 */
297 /* get the buffer for the on-disk bmap descriptor. */
298 mp = read_metapage(ipbmap,
299 BMAPBLKNO << JFS_SBI(ipbmap->i_sb)->l2nbperpage,
300 PSIZE, 0);
301 if (mp == NULL) {
302 jfs_err("dbSync: read_metapage failed!");
303 return -EIO;
304 }
305 /* copy the in-memory version of the bmap to the on-disk version */
306 dbmp_le = (struct dbmap_disk *) mp->data;
307 dbmp_le->dn_mapsize = cpu_to_le64(bmp->db_mapsize);
308 dbmp_le->dn_nfree = cpu_to_le64(bmp->db_nfree);
309 dbmp_le->dn_l2nbperpage = cpu_to_le32(bmp->db_l2nbperpage);
310 dbmp_le->dn_numag = cpu_to_le32(bmp->db_numag);
311 dbmp_le->dn_maxlevel = cpu_to_le32(bmp->db_maxlevel);
312 dbmp_le->dn_maxag = cpu_to_le32(bmp->db_maxag);
313 dbmp_le->dn_agpref = cpu_to_le32(bmp->db_agpref);
314 dbmp_le->dn_aglevel = cpu_to_le32(bmp->db_aglevel);
315 dbmp_le->dn_agheight = cpu_to_le32(bmp->db_agheight);
316 dbmp_le->dn_agwidth = cpu_to_le32(bmp->db_agwidth);
317 dbmp_le->dn_agstart = cpu_to_le32(bmp->db_agstart);
318 dbmp_le->dn_agl2size = cpu_to_le32(bmp->db_agl2size);
319 for (i = 0; i < MAXAG; i++)
320 dbmp_le->dn_agfree[i] = cpu_to_le64(bmp->db_agfree[i]);
321 dbmp_le->dn_agsize = cpu_to_le64(bmp->db_agsize);
322 dbmp_le->dn_maxfreebud = bmp->db_maxfreebud;
323
324 /* write the buffer */
325 write_metapage(mp);
326
327 /*
328 * write out dirty pages of bmap
329 */
330 filemap_write_and_wait(ipbmap->i_mapping);
331
332 diWriteSpecial(ipbmap, 0);
333
334 return (0);
335}
336
337/*
338 * NAME: dbFree()
339 *
340 * FUNCTION: free the specified block range from the working block
341 * allocation map.
342 *
343 * the blocks will be free from the working map one dmap
344 * at a time.
345 *
346 * PARAMETERS:
347 * ip - pointer to in-core inode;
348 * blkno - starting block number to be freed.
349 * nblocks - number of blocks to be freed.
350 *
351 * RETURN VALUES:
352 * 0 - success
353 * -EIO - i/o error
354 */
355int dbFree(struct inode *ip, s64 blkno, s64 nblocks)
356{
357 struct metapage *mp;
358 struct dmap *dp;
359 int nb, rc;
360 s64 lblkno, rem;
361 struct inode *ipbmap = JFS_SBI(ip->i_sb)->ipbmap;
362 struct bmap *bmp = JFS_SBI(ip->i_sb)->bmap;
363 struct super_block *sb = ipbmap->i_sb;
364
365 IREAD_LOCK(ipbmap, RDWRLOCK_DMAP);
366
367 /* block to be freed better be within the mapsize. */
368 if (unlikely((blkno == 0) || (blkno + nblocks > bmp->db_mapsize))) {
369 IREAD_UNLOCK(ipbmap);
370 printk(KERN_ERR "blkno = %Lx, nblocks = %Lx\n",
371 (unsigned long long) blkno,
372 (unsigned long long) nblocks);
373 jfs_error(ip->i_sb, "block to be freed is outside the map\n");
374 return -EIO;
375 }
376
377 /**
378 * TRIM the blocks, when mounted with discard option
379 */
380 if (JFS_SBI(sb)->flag & JFS_DISCARD)
381 if (JFS_SBI(sb)->minblks_trim <= nblocks)
382 jfs_issue_discard(ipbmap, blkno, nblocks);
383
384 /*
385 * free the blocks a dmap at a time.
386 */
387 mp = NULL;
388 for (rem = nblocks; rem > 0; rem -= nb, blkno += nb) {
389 /* release previous dmap if any */
390 if (mp) {
391 write_metapage(mp);
392 }
393
394 /* get the buffer for the current dmap. */
395 lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage);
396 mp = read_metapage(ipbmap, lblkno, PSIZE, 0);
397 if (mp == NULL) {
398 IREAD_UNLOCK(ipbmap);
399 return -EIO;
400 }
401 dp = (struct dmap *) mp->data;
402
403 /* determine the number of blocks to be freed from
404 * this dmap.
405 */
406 nb = min(rem, BPERDMAP - (blkno & (BPERDMAP - 1)));
407
408 /* free the blocks. */
409 if ((rc = dbFreeDmap(bmp, dp, blkno, nb))) {
410 jfs_error(ip->i_sb, "error in block map\n");
411 release_metapage(mp);
412 IREAD_UNLOCK(ipbmap);
413 return (rc);
414 }
415 }
416
417 /* write the last buffer. */
418 if (mp)
419 write_metapage(mp);
420
421 IREAD_UNLOCK(ipbmap);
422
423 return (0);
424}
425
426
427/*
428 * NAME: dbUpdatePMap()
429 *
430 * FUNCTION: update the allocation state (free or allocate) of the
431 * specified block range in the persistent block allocation map.
432 *
433 * the blocks will be updated in the persistent map one
434 * dmap at a time.
435 *
436 * PARAMETERS:
437 * ipbmap - pointer to in-core inode for the block map.
438 * free - 'true' if block range is to be freed from the persistent
439 * map; 'false' if it is to be allocated.
440 * blkno - starting block number of the range.
441 * nblocks - number of contiguous blocks in the range.
442 * tblk - transaction block;
443 *
444 * RETURN VALUES:
445 * 0 - success
446 * -EIO - i/o error
447 */
448int
449dbUpdatePMap(struct inode *ipbmap,
450 int free, s64 blkno, s64 nblocks, struct tblock * tblk)
451{
452 int nblks, dbitno, wbitno, rbits;
453 int word, nbits, nwords;
454 struct bmap *bmp = JFS_SBI(ipbmap->i_sb)->bmap;
455 s64 lblkno, rem, lastlblkno;
456 u32 mask;
457 struct dmap *dp;
458 struct metapage *mp;
459 struct jfs_log *log;
460 int lsn, difft, diffp;
461 unsigned long flags;
462
463 /* the blocks better be within the mapsize. */
464 if (blkno + nblocks > bmp->db_mapsize) {
465 printk(KERN_ERR "blkno = %Lx, nblocks = %Lx\n",
466 (unsigned long long) blkno,
467 (unsigned long long) nblocks);
468 jfs_error(ipbmap->i_sb, "blocks are outside the map\n");
469 return -EIO;
470 }
471
472 /* compute delta of transaction lsn from log syncpt */
473 lsn = tblk->lsn;
474 log = (struct jfs_log *) JFS_SBI(tblk->sb)->log;
475 logdiff(difft, lsn, log);
476
477 /*
478 * update the block state a dmap at a time.
479 */
480 mp = NULL;
481 lastlblkno = 0;
482 for (rem = nblocks; rem > 0; rem -= nblks, blkno += nblks) {
483 /* get the buffer for the current dmap. */
484 lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage);
485 if (lblkno != lastlblkno) {
486 if (mp) {
487 write_metapage(mp);
488 }
489
490 mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE,
491 0);
492 if (mp == NULL)
493 return -EIO;
494 metapage_wait_for_io(mp);
495 }
496 dp = (struct dmap *) mp->data;
497
498 /* determine the bit number and word within the dmap of
499 * the starting block. also determine how many blocks
500 * are to be updated within this dmap.
501 */
502 dbitno = blkno & (BPERDMAP - 1);
503 word = dbitno >> L2DBWORD;
504 nblks = min(rem, (s64)BPERDMAP - dbitno);
505
506 /* update the bits of the dmap words. the first and last
507 * words may only have a subset of their bits updated. if
508 * this is the case, we'll work against that word (i.e.
509 * partial first and/or last) only in a single pass. a
510 * single pass will also be used to update all words that
511 * are to have all their bits updated.
512 */
513 for (rbits = nblks; rbits > 0;
514 rbits -= nbits, dbitno += nbits) {
515 /* determine the bit number within the word and
516 * the number of bits within the word.
517 */
518 wbitno = dbitno & (DBWORD - 1);
519 nbits = min(rbits, DBWORD - wbitno);
520
521 /* check if only part of the word is to be updated. */
522 if (nbits < DBWORD) {
523 /* update (free or allocate) the bits
524 * in this word.
525 */
526 mask =
527 (ONES << (DBWORD - nbits) >> wbitno);
528 if (free)
529 dp->pmap[word] &=
530 cpu_to_le32(~mask);
531 else
532 dp->pmap[word] |=
533 cpu_to_le32(mask);
534
535 word += 1;
536 } else {
537 /* one or more words are to have all
538 * their bits updated. determine how
539 * many words and how many bits.
540 */
541 nwords = rbits >> L2DBWORD;
542 nbits = nwords << L2DBWORD;
543
544 /* update (free or allocate) the bits
545 * in these words.
546 */
547 if (free)
548 memset(&dp->pmap[word], 0,
549 nwords * 4);
550 else
551 memset(&dp->pmap[word], (int) ONES,
552 nwords * 4);
553
554 word += nwords;
555 }
556 }
557
558 /*
559 * update dmap lsn
560 */
561 if (lblkno == lastlblkno)
562 continue;
563
564 lastlblkno = lblkno;
565
566 LOGSYNC_LOCK(log, flags);
567 if (mp->lsn != 0) {
568 /* inherit older/smaller lsn */
569 logdiff(diffp, mp->lsn, log);
570 if (difft < diffp) {
571 mp->lsn = lsn;
572
573 /* move bp after tblock in logsync list */
574 list_move(&mp->synclist, &tblk->synclist);
575 }
576
577 /* inherit younger/larger clsn */
578 logdiff(difft, tblk->clsn, log);
579 logdiff(diffp, mp->clsn, log);
580 if (difft > diffp)
581 mp->clsn = tblk->clsn;
582 } else {
583 mp->log = log;
584 mp->lsn = lsn;
585
586 /* insert bp after tblock in logsync list */
587 log->count++;
588 list_add(&mp->synclist, &tblk->synclist);
589
590 mp->clsn = tblk->clsn;
591 }
592 LOGSYNC_UNLOCK(log, flags);
593 }
594
595 /* write the last buffer. */
596 if (mp) {
597 write_metapage(mp);
598 }
599
600 return (0);
601}
602
603
604/*
605 * NAME: dbNextAG()
606 *
607 * FUNCTION: find the preferred allocation group for new allocations.
608 *
609 * Within the allocation groups, we maintain a preferred
610 * allocation group which consists of a group with at least
611 * average free space. It is the preferred group that we target
612 * new inode allocation towards. The tie-in between inode
613 * allocation and block allocation occurs as we allocate the
614 * first (data) block of an inode and specify the inode (block)
615 * as the allocation hint for this block.
616 *
617 * We try to avoid having more than one open file growing in
618 * an allocation group, as this will lead to fragmentation.
619 * This differs from the old OS/2 method of trying to keep
620 * empty ags around for large allocations.
621 *
622 * PARAMETERS:
623 * ipbmap - pointer to in-core inode for the block map.
624 *
625 * RETURN VALUES:
626 * the preferred allocation group number.
627 */
628int dbNextAG(struct inode *ipbmap)
629{
630 s64 avgfree;
631 int agpref;
632 s64 hwm = 0;
633 int i;
634 int next_best = -1;
635 struct bmap *bmp = JFS_SBI(ipbmap->i_sb)->bmap;
636
637 BMAP_LOCK(bmp);
638
639 /* determine the average number of free blocks within the ags. */
640 avgfree = (u32)bmp->db_nfree / bmp->db_numag;
641
642 /*
643 * if the current preferred ag does not have an active allocator
644 * and has at least average freespace, return it
645 */
646 agpref = bmp->db_agpref;
647 if ((atomic_read(&bmp->db_active[agpref]) == 0) &&
648 (bmp->db_agfree[agpref] >= avgfree))
649 goto unlock;
650
651 /* From the last preferred ag, find the next one with at least
652 * average free space.
653 */
654 for (i = 0 ; i < bmp->db_numag; i++, agpref++) {
655 if (agpref >= bmp->db_numag)
656 agpref = 0;
657
658 if (atomic_read(&bmp->db_active[agpref]))
659 /* open file is currently growing in this ag */
660 continue;
661 if (bmp->db_agfree[agpref] >= avgfree) {
662 /* Return this one */
663 bmp->db_agpref = agpref;
664 goto unlock;
665 } else if (bmp->db_agfree[agpref] > hwm) {
666 /* Less than avg. freespace, but best so far */
667 hwm = bmp->db_agfree[agpref];
668 next_best = agpref;
669 }
670 }
671
672 /*
673 * If no inactive ag was found with average freespace, use the
674 * next best
675 */
676 if (next_best != -1)
677 bmp->db_agpref = next_best;
678 /* else leave db_agpref unchanged */
679unlock:
680 BMAP_UNLOCK(bmp);
681
682 /* return the preferred group.
683 */
684 return (bmp->db_agpref);
685}
686
687/*
688 * NAME: dbAlloc()
689 *
690 * FUNCTION: attempt to allocate a specified number of contiguous free
691 * blocks from the working allocation block map.
692 *
693 * the block allocation policy uses hints and a multi-step
694 * approach.
695 *
696 * for allocation requests smaller than the number of blocks
697 * per dmap, we first try to allocate the new blocks
698 * immediately following the hint. if these blocks are not
699 * available, we try to allocate blocks near the hint. if
700 * no blocks near the hint are available, we next try to
701 * allocate within the same dmap as contains the hint.
702 *
703 * if no blocks are available in the dmap or the allocation
704 * request is larger than the dmap size, we try to allocate
705 * within the same allocation group as contains the hint. if
706 * this does not succeed, we finally try to allocate anywhere
707 * within the aggregate.
708 *
709 * we also try to allocate anywhere within the aggregate
710 * for allocation requests larger than the allocation group
711 * size or requests that specify no hint value.
712 *
713 * PARAMETERS:
714 * ip - pointer to in-core inode;
715 * hint - allocation hint.
716 * nblocks - number of contiguous blocks in the range.
717 * results - on successful return, set to the starting block number
718 * of the newly allocated contiguous range.
719 *
720 * RETURN VALUES:
721 * 0 - success
722 * -ENOSPC - insufficient disk resources
723 * -EIO - i/o error
724 */
725int dbAlloc(struct inode *ip, s64 hint, s64 nblocks, s64 * results)
726{
727 int rc, agno;
728 struct inode *ipbmap = JFS_SBI(ip->i_sb)->ipbmap;
729 struct bmap *bmp;
730 struct metapage *mp;
731 s64 lblkno, blkno;
732 struct dmap *dp;
733 int l2nb;
734 s64 mapSize;
735 int writers;
736
737 /* assert that nblocks is valid */
738 assert(nblocks > 0);
739
740 /* get the log2 number of blocks to be allocated.
741 * if the number of blocks is not a log2 multiple,
742 * it will be rounded up to the next log2 multiple.
743 */
744 l2nb = BLKSTOL2(nblocks);
745
746 bmp = JFS_SBI(ip->i_sb)->bmap;
747
748 mapSize = bmp->db_mapsize;
749
750 /* the hint should be within the map */
751 if (hint >= mapSize) {
752 jfs_error(ip->i_sb, "the hint is outside the map\n");
753 return -EIO;
754 }
755
756 /* if the number of blocks to be allocated is greater than the
757 * allocation group size, try to allocate anywhere.
758 */
759 if (l2nb > bmp->db_agl2size) {
760 IWRITE_LOCK(ipbmap, RDWRLOCK_DMAP);
761
762 rc = dbAllocAny(bmp, nblocks, l2nb, results);
763
764 goto write_unlock;
765 }
766
767 /*
768 * If no hint, let dbNextAG recommend an allocation group
769 */
770 if (hint == 0)
771 goto pref_ag;
772
773 /* we would like to allocate close to the hint. adjust the
774 * hint to the block following the hint since the allocators
775 * will start looking for free space starting at this point.
776 */
777 blkno = hint + 1;
778
779 if (blkno >= bmp->db_mapsize)
780 goto pref_ag;
781
782 agno = blkno >> bmp->db_agl2size;
783
784 /* check if blkno crosses over into a new allocation group.
785 * if so, check if we should allow allocations within this
786 * allocation group.
787 */
788 if ((blkno & (bmp->db_agsize - 1)) == 0)
789 /* check if the AG is currently being written to.
790 * if so, call dbNextAG() to find a non-busy
791 * AG with sufficient free space.
792 */
793 if (atomic_read(&bmp->db_active[agno]))
794 goto pref_ag;
795
796 /* check if the allocation request size can be satisfied from a
797 * single dmap. if so, try to allocate from the dmap containing
798 * the hint using a tiered strategy.
799 */
800 if (nblocks <= BPERDMAP) {
801 IREAD_LOCK(ipbmap, RDWRLOCK_DMAP);
802
803 /* get the buffer for the dmap containing the hint.
804 */
805 rc = -EIO;
806 lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage);
807 mp = read_metapage(ipbmap, lblkno, PSIZE, 0);
808 if (mp == NULL)
809 goto read_unlock;
810
811 dp = (struct dmap *) mp->data;
812
813 /* first, try to satisfy the allocation request with the
814 * blocks beginning at the hint.
815 */
816 if ((rc = dbAllocNext(bmp, dp, blkno, (int) nblocks))
817 != -ENOSPC) {
818 if (rc == 0) {
819 *results = blkno;
820 mark_metapage_dirty(mp);
821 }
822
823 release_metapage(mp);
824 goto read_unlock;
825 }
826
827 writers = atomic_read(&bmp->db_active[agno]);
828 if ((writers > 1) ||
829 ((writers == 1) && (JFS_IP(ip)->active_ag != agno))) {
830 /*
831 * Someone else is writing in this allocation
832 * group. To avoid fragmenting, try another ag
833 */
834 release_metapage(mp);
835 IREAD_UNLOCK(ipbmap);
836 goto pref_ag;
837 }
838
839 /* next, try to satisfy the allocation request with blocks
840 * near the hint.
841 */
842 if ((rc =
843 dbAllocNear(bmp, dp, blkno, (int) nblocks, l2nb, results))
844 != -ENOSPC) {
845 if (rc == 0)
846 mark_metapage_dirty(mp);
847
848 release_metapage(mp);
849 goto read_unlock;
850 }
851
852 /* try to satisfy the allocation request with blocks within
853 * the same dmap as the hint.
854 */
855 if ((rc = dbAllocDmapLev(bmp, dp, (int) nblocks, l2nb, results))
856 != -ENOSPC) {
857 if (rc == 0)
858 mark_metapage_dirty(mp);
859
860 release_metapage(mp);
861 goto read_unlock;
862 }
863
864 release_metapage(mp);
865 IREAD_UNLOCK(ipbmap);
866 }
867
868 /* try to satisfy the allocation request with blocks within
869 * the same allocation group as the hint.
870 */
871 IWRITE_LOCK(ipbmap, RDWRLOCK_DMAP);
872 if ((rc = dbAllocAG(bmp, agno, nblocks, l2nb, results)) != -ENOSPC)
873 goto write_unlock;
874
875 IWRITE_UNLOCK(ipbmap);
876
877
878 pref_ag:
879 /*
880 * Let dbNextAG recommend a preferred allocation group
881 */
882 agno = dbNextAG(ipbmap);
883 IWRITE_LOCK(ipbmap, RDWRLOCK_DMAP);
884
885 /* Try to allocate within this allocation group. if that fails, try to
886 * allocate anywhere in the map.
887 */
888 if ((rc = dbAllocAG(bmp, agno, nblocks, l2nb, results)) == -ENOSPC)
889 rc = dbAllocAny(bmp, nblocks, l2nb, results);
890
891 write_unlock:
892 IWRITE_UNLOCK(ipbmap);
893
894 return (rc);
895
896 read_unlock:
897 IREAD_UNLOCK(ipbmap);
898
899 return (rc);
900}
901
902/*
903 * NAME: dbReAlloc()
904 *
905 * FUNCTION: attempt to extend a current allocation by a specified
906 * number of blocks.
907 *
908 * this routine attempts to satisfy the allocation request
909 * by first trying to extend the existing allocation in
910 * place by allocating the additional blocks as the blocks
911 * immediately following the current allocation. if these
912 * blocks are not available, this routine will attempt to
913 * allocate a new set of contiguous blocks large enough
914 * to cover the existing allocation plus the additional
915 * number of blocks required.
916 *
917 * PARAMETERS:
918 * ip - pointer to in-core inode requiring allocation.
919 * blkno - starting block of the current allocation.
920 * nblocks - number of contiguous blocks within the current
921 * allocation.
922 * addnblocks - number of blocks to add to the allocation.
923 * results - on successful return, set to the starting block number
924 * of the existing allocation if the existing allocation
925 * was extended in place or to a newly allocated contiguous
926 * range if the existing allocation could not be extended
927 * in place.
928 *
929 * RETURN VALUES:
930 * 0 - success
931 * -ENOSPC - insufficient disk resources
932 * -EIO - i/o error
933 */
934int
935dbReAlloc(struct inode *ip,
936 s64 blkno, s64 nblocks, s64 addnblocks, s64 * results)
937{
938 int rc;
939
940 /* try to extend the allocation in place.
941 */
942 if ((rc = dbExtend(ip, blkno, nblocks, addnblocks)) == 0) {
943 *results = blkno;
944 return (0);
945 } else {
946 if (rc != -ENOSPC)
947 return (rc);
948 }
949
950 /* could not extend the allocation in place, so allocate a
951 * new set of blocks for the entire request (i.e. try to get
952 * a range of contiguous blocks large enough to cover the
953 * existing allocation plus the additional blocks.)
954 */
955 return (dbAlloc
956 (ip, blkno + nblocks - 1, addnblocks + nblocks, results));
957}
958
959
960/*
961 * NAME: dbExtend()
962 *
963 * FUNCTION: attempt to extend a current allocation by a specified
964 * number of blocks.
965 *
966 * this routine attempts to satisfy the allocation request
967 * by first trying to extend the existing allocation in
968 * place by allocating the additional blocks as the blocks
969 * immediately following the current allocation.
970 *
971 * PARAMETERS:
972 * ip - pointer to in-core inode requiring allocation.
973 * blkno - starting block of the current allocation.
974 * nblocks - number of contiguous blocks within the current
975 * allocation.
976 * addnblocks - number of blocks to add to the allocation.
977 *
978 * RETURN VALUES:
979 * 0 - success
980 * -ENOSPC - insufficient disk resources
981 * -EIO - i/o error
982 */
983static int dbExtend(struct inode *ip, s64 blkno, s64 nblocks, s64 addnblocks)
984{
985 struct jfs_sb_info *sbi = JFS_SBI(ip->i_sb);
986 s64 lblkno, lastblkno, extblkno;
987 uint rel_block;
988 struct metapage *mp;
989 struct dmap *dp;
990 int rc;
991 struct inode *ipbmap = sbi->ipbmap;
992 struct bmap *bmp;
993
994 /*
995 * We don't want a non-aligned extent to cross a page boundary
996 */
997 if (((rel_block = blkno & (sbi->nbperpage - 1))) &&
998 (rel_block + nblocks + addnblocks > sbi->nbperpage))
999 return -ENOSPC;
1000
1001 /* get the last block of the current allocation */
1002 lastblkno = blkno + nblocks - 1;
1003
1004 /* determine the block number of the block following
1005 * the existing allocation.
1006 */
1007 extblkno = lastblkno + 1;
1008
1009 IREAD_LOCK(ipbmap, RDWRLOCK_DMAP);
1010
1011 /* better be within the file system */
1012 bmp = sbi->bmap;
1013 if (lastblkno < 0 || lastblkno >= bmp->db_mapsize) {
1014 IREAD_UNLOCK(ipbmap);
1015 jfs_error(ip->i_sb, "the block is outside the filesystem\n");
1016 return -EIO;
1017 }
1018
1019 /* we'll attempt to extend the current allocation in place by
1020 * allocating the additional blocks as the blocks immediately
1021 * following the current allocation. we only try to extend the
1022 * current allocation in place if the number of additional blocks
1023 * can fit into a dmap, the last block of the current allocation
1024 * is not the last block of the file system, and the start of the
1025 * inplace extension is not on an allocation group boundary.
1026 */
1027 if (addnblocks > BPERDMAP || extblkno >= bmp->db_mapsize ||
1028 (extblkno & (bmp->db_agsize - 1)) == 0) {
1029 IREAD_UNLOCK(ipbmap);
1030 return -ENOSPC;
1031 }
1032
1033 /* get the buffer for the dmap containing the first block
1034 * of the extension.
1035 */
1036 lblkno = BLKTODMAP(extblkno, bmp->db_l2nbperpage);
1037 mp = read_metapage(ipbmap, lblkno, PSIZE, 0);
1038 if (mp == NULL) {
1039 IREAD_UNLOCK(ipbmap);
1040 return -EIO;
1041 }
1042
1043 dp = (struct dmap *) mp->data;
1044
1045 /* try to allocate the blocks immediately following the
1046 * current allocation.
1047 */
1048 rc = dbAllocNext(bmp, dp, extblkno, (int) addnblocks);
1049
1050 IREAD_UNLOCK(ipbmap);
1051
1052 /* were we successful ? */
1053 if (rc == 0)
1054 write_metapage(mp);
1055 else
1056 /* we were not successful */
1057 release_metapage(mp);
1058
1059 return (rc);
1060}
1061
1062
1063/*
1064 * NAME: dbAllocNext()
1065 *
1066 * FUNCTION: attempt to allocate the blocks of the specified block
1067 * range within a dmap.
1068 *
1069 * PARAMETERS:
1070 * bmp - pointer to bmap descriptor
1071 * dp - pointer to dmap.
1072 * blkno - starting block number of the range.
1073 * nblocks - number of contiguous free blocks of the range.
1074 *
1075 * RETURN VALUES:
1076 * 0 - success
1077 * -ENOSPC - insufficient disk resources
1078 * -EIO - i/o error
1079 *
1080 * serialization: IREAD_LOCK(ipbmap) held on entry/exit;
1081 */
1082static int dbAllocNext(struct bmap * bmp, struct dmap * dp, s64 blkno,
1083 int nblocks)
1084{
1085 int dbitno, word, rembits, nb, nwords, wbitno, nw;
1086 int l2size;
1087 s8 *leaf;
1088 u32 mask;
1089
1090 if (dp->tree.leafidx != cpu_to_le32(LEAFIND)) {
1091 jfs_error(bmp->db_ipbmap->i_sb, "Corrupt dmap page\n");
1092 return -EIO;
1093 }
1094
1095 /* pick up a pointer to the leaves of the dmap tree.
1096 */
1097 leaf = dp->tree.stree + le32_to_cpu(dp->tree.leafidx);
1098
1099 /* determine the bit number and word within the dmap of the
1100 * starting block.
1101 */
1102 dbitno = blkno & (BPERDMAP - 1);
1103 word = dbitno >> L2DBWORD;
1104
1105 /* check if the specified block range is contained within
1106 * this dmap.
1107 */
1108 if (dbitno + nblocks > BPERDMAP)
1109 return -ENOSPC;
1110
1111 /* check if the starting leaf indicates that anything
1112 * is free.
1113 */
1114 if (leaf[word] == NOFREE)
1115 return -ENOSPC;
1116
1117 /* check the dmaps words corresponding to block range to see
1118 * if the block range is free. not all bits of the first and
1119 * last words may be contained within the block range. if this
1120 * is the case, we'll work against those words (i.e. partial first
1121 * and/or last) on an individual basis (a single pass) and examine
1122 * the actual bits to determine if they are free. a single pass
1123 * will be used for all dmap words fully contained within the
1124 * specified range. within this pass, the leaves of the dmap
1125 * tree will be examined to determine if the blocks are free. a
1126 * single leaf may describe the free space of multiple dmap
1127 * words, so we may visit only a subset of the actual leaves
1128 * corresponding to the dmap words of the block range.
1129 */
1130 for (rembits = nblocks; rembits > 0; rembits -= nb, dbitno += nb) {
1131 /* determine the bit number within the word and
1132 * the number of bits within the word.
1133 */
1134 wbitno = dbitno & (DBWORD - 1);
1135 nb = min(rembits, DBWORD - wbitno);
1136
1137 /* check if only part of the word is to be examined.
1138 */
1139 if (nb < DBWORD) {
1140 /* check if the bits are free.
1141 */
1142 mask = (ONES << (DBWORD - nb) >> wbitno);
1143 if ((mask & ~le32_to_cpu(dp->wmap[word])) != mask)
1144 return -ENOSPC;
1145
1146 word += 1;
1147 } else {
1148 /* one or more dmap words are fully contained
1149 * within the block range. determine how many
1150 * words and how many bits.
1151 */
1152 nwords = rembits >> L2DBWORD;
1153 nb = nwords << L2DBWORD;
1154
1155 /* now examine the appropriate leaves to determine
1156 * if the blocks are free.
1157 */
1158 while (nwords > 0) {
1159 /* does the leaf describe any free space ?
1160 */
1161 if (leaf[word] < BUDMIN)
1162 return -ENOSPC;
1163
1164 /* determine the l2 number of bits provided
1165 * by this leaf.
1166 */
1167 l2size =
1168 min_t(int, leaf[word], NLSTOL2BSZ(nwords));
1169
1170 /* determine how many words were handled.
1171 */
1172 nw = BUDSIZE(l2size, BUDMIN);
1173
1174 nwords -= nw;
1175 word += nw;
1176 }
1177 }
1178 }
1179
1180 /* allocate the blocks.
1181 */
1182 return (dbAllocDmap(bmp, dp, blkno, nblocks));
1183}
1184
1185
1186/*
1187 * NAME: dbAllocNear()
1188 *
1189 * FUNCTION: attempt to allocate a number of contiguous free blocks near
1190 * a specified block (hint) within a dmap.
1191 *
1192 * starting with the dmap leaf that covers the hint, we'll
1193 * check the next four contiguous leaves for sufficient free
1194 * space. if sufficient free space is found, we'll allocate
1195 * the desired free space.
1196 *
1197 * PARAMETERS:
1198 * bmp - pointer to bmap descriptor
1199 * dp - pointer to dmap.
1200 * blkno - block number to allocate near.
1201 * nblocks - actual number of contiguous free blocks desired.
1202 * l2nb - log2 number of contiguous free blocks desired.
1203 * results - on successful return, set to the starting block number
1204 * of the newly allocated range.
1205 *
1206 * RETURN VALUES:
1207 * 0 - success
1208 * -ENOSPC - insufficient disk resources
1209 * -EIO - i/o error
1210 *
1211 * serialization: IREAD_LOCK(ipbmap) held on entry/exit;
1212 */
1213static int
1214dbAllocNear(struct bmap * bmp,
1215 struct dmap * dp, s64 blkno, int nblocks, int l2nb, s64 * results)
1216{
1217 int word, lword, rc;
1218 s8 *leaf;
1219
1220 if (dp->tree.leafidx != cpu_to_le32(LEAFIND)) {
1221 jfs_error(bmp->db_ipbmap->i_sb, "Corrupt dmap page\n");
1222 return -EIO;
1223 }
1224
1225 leaf = dp->tree.stree + le32_to_cpu(dp->tree.leafidx);
1226
1227 /* determine the word within the dmap that holds the hint
1228 * (i.e. blkno). also, determine the last word in the dmap
1229 * that we'll include in our examination.
1230 */
1231 word = (blkno & (BPERDMAP - 1)) >> L2DBWORD;
1232 lword = min(word + 4, LPERDMAP);
1233
1234 /* examine the leaves for sufficient free space.
1235 */
1236 for (; word < lword; word++) {
1237 /* does the leaf describe sufficient free space ?
1238 */
1239 if (leaf[word] < l2nb)
1240 continue;
1241
1242 /* determine the block number within the file system
1243 * of the first block described by this dmap word.
1244 */
1245 blkno = le64_to_cpu(dp->start) + (word << L2DBWORD);
1246
1247 /* if not all bits of the dmap word are free, get the
1248 * starting bit number within the dmap word of the required
1249 * string of free bits and adjust the block number with the
1250 * value.
1251 */
1252 if (leaf[word] < BUDMIN)
1253 blkno +=
1254 dbFindBits(le32_to_cpu(dp->wmap[word]), l2nb);
1255
1256 /* allocate the blocks.
1257 */
1258 if ((rc = dbAllocDmap(bmp, dp, blkno, nblocks)) == 0)
1259 *results = blkno;
1260
1261 return (rc);
1262 }
1263
1264 return -ENOSPC;
1265}
1266
1267
1268/*
1269 * NAME: dbAllocAG()
1270 *
1271 * FUNCTION: attempt to allocate the specified number of contiguous
1272 * free blocks within the specified allocation group.
1273 *
1274 * unless the allocation group size is equal to the number
1275 * of blocks per dmap, the dmap control pages will be used to
1276 * find the required free space, if available. we start the
1277 * search at the highest dmap control page level which
1278 * distinctly describes the allocation group's free space
1279 * (i.e. the highest level at which the allocation group's
1280 * free space is not mixed in with that of any other group).
1281 * in addition, we start the search within this level at a
1282 * height of the dmapctl dmtree at which the nodes distinctly
1283 * describe the allocation group's free space. at this height,
1284 * the allocation group's free space may be represented by 1
1285 * or two sub-trees, depending on the allocation group size.
1286 * we search the top nodes of these subtrees left to right for
1287 * sufficient free space. if sufficient free space is found,
1288 * the subtree is searched to find the leftmost leaf that
1289 * has free space. once we have made it to the leaf, we
1290 * move the search to the next lower level dmap control page
1291 * corresponding to this leaf. we continue down the dmap control
1292 * pages until we find the dmap that contains or starts the
1293 * sufficient free space and we allocate at this dmap.
1294 *
1295 * if the allocation group size is equal to the dmap size,
1296 * we'll start at the dmap corresponding to the allocation
1297 * group and attempt the allocation at this level.
1298 *
1299 * the dmap control page search is also not performed if the
1300 * allocation group is completely free and we go to the first
1301 * dmap of the allocation group to do the allocation. this is
1302 * done because the allocation group may be part (not the first
1303 * part) of a larger binary buddy system, causing the dmap
1304 * control pages to indicate no free space (NOFREE) within
1305 * the allocation group.
1306 *
1307 * PARAMETERS:
1308 * bmp - pointer to bmap descriptor
1309 * agno - allocation group number.
1310 * nblocks - actual number of contiguous free blocks desired.
1311 * l2nb - log2 number of contiguous free blocks desired.
1312 * results - on successful return, set to the starting block number
1313 * of the newly allocated range.
1314 *
1315 * RETURN VALUES:
1316 * 0 - success
1317 * -ENOSPC - insufficient disk resources
1318 * -EIO - i/o error
1319 *
1320 * note: IWRITE_LOCK(ipmap) held on entry/exit;
1321 */
1322static int
1323dbAllocAG(struct bmap * bmp, int agno, s64 nblocks, int l2nb, s64 * results)
1324{
1325 struct metapage *mp;
1326 struct dmapctl *dcp;
1327 int rc, ti, i, k, m, n, agperlev;
1328 s64 blkno, lblkno;
1329 int budmin;
1330
1331 /* allocation request should not be for more than the
1332 * allocation group size.
1333 */
1334 if (l2nb > bmp->db_agl2size) {
1335 jfs_error(bmp->db_ipbmap->i_sb,
1336 "allocation request is larger than the allocation group size\n");
1337 return -EIO;
1338 }
1339
1340 /* determine the starting block number of the allocation
1341 * group.
1342 */
1343 blkno = (s64) agno << bmp->db_agl2size;
1344
1345 /* check if the allocation group size is the minimum allocation
1346 * group size or if the allocation group is completely free. if
1347 * the allocation group size is the minimum size of BPERDMAP (i.e.
1348 * 1 dmap), there is no need to search the dmap control page (below)
1349 * that fully describes the allocation group since the allocation
1350 * group is already fully described by a dmap. in this case, we
1351 * just call dbAllocCtl() to search the dmap tree and allocate the
1352 * required space if available.
1353 *
1354 * if the allocation group is completely free, dbAllocCtl() is
1355 * also called to allocate the required space. this is done for
1356 * two reasons. first, it makes no sense searching the dmap control
1357 * pages for free space when we know that free space exists. second,
1358 * the dmap control pages may indicate that the allocation group
1359 * has no free space if the allocation group is part (not the first
1360 * part) of a larger binary buddy system.
1361 */
1362 if (bmp->db_agsize == BPERDMAP
1363 || bmp->db_agfree[agno] == bmp->db_agsize) {
1364 rc = dbAllocCtl(bmp, nblocks, l2nb, blkno, results);
1365 if ((rc == -ENOSPC) &&
1366 (bmp->db_agfree[agno] == bmp->db_agsize)) {
1367 printk(KERN_ERR "blkno = %Lx, blocks = %Lx\n",
1368 (unsigned long long) blkno,
1369 (unsigned long long) nblocks);
1370 jfs_error(bmp->db_ipbmap->i_sb,
1371 "dbAllocCtl failed in free AG\n");
1372 }
1373 return (rc);
1374 }
1375
1376 /* the buffer for the dmap control page that fully describes the
1377 * allocation group.
1378 */
1379 lblkno = BLKTOCTL(blkno, bmp->db_l2nbperpage, bmp->db_aglevel);
1380 mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0);
1381 if (mp == NULL)
1382 return -EIO;
1383 dcp = (struct dmapctl *) mp->data;
1384 budmin = dcp->budmin;
1385
1386 if (dcp->leafidx != cpu_to_le32(CTLLEAFIND)) {
1387 jfs_error(bmp->db_ipbmap->i_sb, "Corrupt dmapctl page\n");
1388 release_metapage(mp);
1389 return -EIO;
1390 }
1391
1392 /* search the subtree(s) of the dmap control page that describes
1393 * the allocation group, looking for sufficient free space. to begin,
1394 * determine how many allocation groups are represented in a dmap
1395 * control page at the control page level (i.e. L0, L1, L2) that
1396 * fully describes an allocation group. next, determine the starting
1397 * tree index of this allocation group within the control page.
1398 */
1399 agperlev =
1400 (1 << (L2LPERCTL - (bmp->db_agheight << 1))) / bmp->db_agwidth;
1401 ti = bmp->db_agstart + bmp->db_agwidth * (agno & (agperlev - 1));
1402
1403 /* dmap control page trees fan-out by 4 and a single allocation
1404 * group may be described by 1 or 2 subtrees within the ag level
1405 * dmap control page, depending upon the ag size. examine the ag's
1406 * subtrees for sufficient free space, starting with the leftmost
1407 * subtree.
1408 */
1409 for (i = 0; i < bmp->db_agwidth; i++, ti++) {
1410 /* is there sufficient free space ?
1411 */
1412 if (l2nb > dcp->stree[ti])
1413 continue;
1414
1415 /* sufficient free space found in a subtree. now search down
1416 * the subtree to find the leftmost leaf that describes this
1417 * free space.
1418 */
1419 for (k = bmp->db_agheight; k > 0; k--) {
1420 for (n = 0, m = (ti << 2) + 1; n < 4; n++) {
1421 if (l2nb <= dcp->stree[m + n]) {
1422 ti = m + n;
1423 break;
1424 }
1425 }
1426 if (n == 4) {
1427 jfs_error(bmp->db_ipbmap->i_sb,
1428 "failed descending stree\n");
1429 release_metapage(mp);
1430 return -EIO;
1431 }
1432 }
1433
1434 /* determine the block number within the file system
1435 * that corresponds to this leaf.
1436 */
1437 if (bmp->db_aglevel == 2)
1438 blkno = 0;
1439 else if (bmp->db_aglevel == 1)
1440 blkno &= ~(MAXL1SIZE - 1);
1441 else /* bmp->db_aglevel == 0 */
1442 blkno &= ~(MAXL0SIZE - 1);
1443
1444 blkno +=
1445 ((s64) (ti - le32_to_cpu(dcp->leafidx))) << budmin;
1446
1447 /* release the buffer in preparation for going down
1448 * the next level of dmap control pages.
1449 */
1450 release_metapage(mp);
1451
1452 /* check if we need to continue to search down the lower
1453 * level dmap control pages. we need to if the number of
1454 * blocks required is less than maximum number of blocks
1455 * described at the next lower level.
1456 */
1457 if (l2nb < budmin) {
1458
1459 /* search the lower level dmap control pages to get
1460 * the starting block number of the dmap that
1461 * contains or starts off the free space.
1462 */
1463 if ((rc =
1464 dbFindCtl(bmp, l2nb, bmp->db_aglevel - 1,
1465 &blkno))) {
1466 if (rc == -ENOSPC) {
1467 jfs_error(bmp->db_ipbmap->i_sb,
1468 "control page inconsistent\n");
1469 return -EIO;
1470 }
1471 return (rc);
1472 }
1473 }
1474
1475 /* allocate the blocks.
1476 */
1477 rc = dbAllocCtl(bmp, nblocks, l2nb, blkno, results);
1478 if (rc == -ENOSPC) {
1479 jfs_error(bmp->db_ipbmap->i_sb,
1480 "unable to allocate blocks\n");
1481 rc = -EIO;
1482 }
1483 return (rc);
1484 }
1485
1486 /* no space in the allocation group. release the buffer and
1487 * return -ENOSPC.
1488 */
1489 release_metapage(mp);
1490
1491 return -ENOSPC;
1492}
1493
1494
1495/*
1496 * NAME: dbAllocAny()
1497 *
1498 * FUNCTION: attempt to allocate the specified number of contiguous
1499 * free blocks anywhere in the file system.
1500 *
1501 * dbAllocAny() attempts to find the sufficient free space by
1502 * searching down the dmap control pages, starting with the
1503 * highest level (i.e. L0, L1, L2) control page. if free space
1504 * large enough to satisfy the desired free space is found, the
1505 * desired free space is allocated.
1506 *
1507 * PARAMETERS:
1508 * bmp - pointer to bmap descriptor
1509 * nblocks - actual number of contiguous free blocks desired.
1510 * l2nb - log2 number of contiguous free blocks desired.
1511 * results - on successful return, set to the starting block number
1512 * of the newly allocated range.
1513 *
1514 * RETURN VALUES:
1515 * 0 - success
1516 * -ENOSPC - insufficient disk resources
1517 * -EIO - i/o error
1518 *
1519 * serialization: IWRITE_LOCK(ipbmap) held on entry/exit;
1520 */
1521static int dbAllocAny(struct bmap * bmp, s64 nblocks, int l2nb, s64 * results)
1522{
1523 int rc;
1524 s64 blkno = 0;
1525
1526 /* starting with the top level dmap control page, search
1527 * down the dmap control levels for sufficient free space.
1528 * if free space is found, dbFindCtl() returns the starting
1529 * block number of the dmap that contains or starts off the
1530 * range of free space.
1531 */
1532 if ((rc = dbFindCtl(bmp, l2nb, bmp->db_maxlevel, &blkno)))
1533 return (rc);
1534
1535 /* allocate the blocks.
1536 */
1537 rc = dbAllocCtl(bmp, nblocks, l2nb, blkno, results);
1538 if (rc == -ENOSPC) {
1539 jfs_error(bmp->db_ipbmap->i_sb, "unable to allocate blocks\n");
1540 return -EIO;
1541 }
1542 return (rc);
1543}
1544
1545
1546/*
1547 * NAME: dbDiscardAG()
1548 *
1549 * FUNCTION: attempt to discard (TRIM) all free blocks of specific AG
1550 *
1551 * algorithm:
1552 * 1) allocate blocks, as large as possible and save them
1553 * while holding IWRITE_LOCK on ipbmap
1554 * 2) trim all these saved block/length values
1555 * 3) mark the blocks free again
1556 *
1557 * benefit:
1558 * - we work only on one ag at some time, minimizing how long we
1559 * need to lock ipbmap
1560 * - reading / writing the fs is possible most time, even on
1561 * trimming
1562 *
1563 * downside:
1564 * - we write two times to the dmapctl and dmap pages
1565 * - but for me, this seems the best way, better ideas?
1566 * /TR 2012
1567 *
1568 * PARAMETERS:
1569 * ip - pointer to in-core inode
1570 * agno - ag to trim
1571 * minlen - minimum value of contiguous blocks
1572 *
1573 * RETURN VALUES:
1574 * s64 - actual number of blocks trimmed
1575 */
1576s64 dbDiscardAG(struct inode *ip, int agno, s64 minlen)
1577{
1578 struct inode *ipbmap = JFS_SBI(ip->i_sb)->ipbmap;
1579 struct bmap *bmp = JFS_SBI(ip->i_sb)->bmap;
1580 s64 nblocks, blkno;
1581 u64 trimmed = 0;
1582 int rc, l2nb;
1583 struct super_block *sb = ipbmap->i_sb;
1584
1585 struct range2trim {
1586 u64 blkno;
1587 u64 nblocks;
1588 } *totrim, *tt;
1589
1590 /* max blkno / nblocks pairs to trim */
1591 int count = 0, range_cnt;
1592 u64 max_ranges;
1593
1594 /* prevent others from writing new stuff here, while trimming */
1595 IWRITE_LOCK(ipbmap, RDWRLOCK_DMAP);
1596
1597 nblocks = bmp->db_agfree[agno];
1598 max_ranges = nblocks;
1599 do_div(max_ranges, minlen);
1600 range_cnt = min_t(u64, max_ranges + 1, 32 * 1024);
1601 totrim = kmalloc_array(range_cnt, sizeof(struct range2trim), GFP_NOFS);
1602 if (totrim == NULL) {
1603 jfs_error(bmp->db_ipbmap->i_sb, "no memory for trim array\n");
1604 IWRITE_UNLOCK(ipbmap);
1605 return 0;
1606 }
1607
1608 tt = totrim;
1609 while (nblocks >= minlen) {
1610 l2nb = BLKSTOL2(nblocks);
1611
1612 /* 0 = okay, -EIO = fatal, -ENOSPC -> try smaller block */
1613 rc = dbAllocAG(bmp, agno, nblocks, l2nb, &blkno);
1614 if (rc == 0) {
1615 tt->blkno = blkno;
1616 tt->nblocks = nblocks;
1617 tt++; count++;
1618
1619 /* the whole ag is free, trim now */
1620 if (bmp->db_agfree[agno] == 0)
1621 break;
1622
1623 /* give a hint for the next while */
1624 nblocks = bmp->db_agfree[agno];
1625 continue;
1626 } else if (rc == -ENOSPC) {
1627 /* search for next smaller log2 block */
1628 l2nb = BLKSTOL2(nblocks) - 1;
1629 if (unlikely(l2nb < 0))
1630 break;
1631 nblocks = 1LL << l2nb;
1632 } else {
1633 /* Trim any already allocated blocks */
1634 jfs_error(bmp->db_ipbmap->i_sb, "-EIO\n");
1635 break;
1636 }
1637
1638 /* check, if our trim array is full */
1639 if (unlikely(count >= range_cnt - 1))
1640 break;
1641 }
1642 IWRITE_UNLOCK(ipbmap);
1643
1644 tt->nblocks = 0; /* mark the current end */
1645 for (tt = totrim; tt->nblocks != 0; tt++) {
1646 /* when mounted with online discard, dbFree() will
1647 * call jfs_issue_discard() itself */
1648 if (!(JFS_SBI(sb)->flag & JFS_DISCARD))
1649 jfs_issue_discard(ip, tt->blkno, tt->nblocks);
1650 dbFree(ip, tt->blkno, tt->nblocks);
1651 trimmed += tt->nblocks;
1652 }
1653 kfree(totrim);
1654
1655 return trimmed;
1656}
1657
1658/*
1659 * NAME: dbFindCtl()
1660 *
1661 * FUNCTION: starting at a specified dmap control page level and block
1662 * number, search down the dmap control levels for a range of
1663 * contiguous free blocks large enough to satisfy an allocation
1664 * request for the specified number of free blocks.
1665 *
1666 * if sufficient contiguous free blocks are found, this routine
1667 * returns the starting block number within a dmap page that
1668 * contains or starts a range of contiqious free blocks that
1669 * is sufficient in size.
1670 *
1671 * PARAMETERS:
1672 * bmp - pointer to bmap descriptor
1673 * level - starting dmap control page level.
1674 * l2nb - log2 number of contiguous free blocks desired.
1675 * *blkno - on entry, starting block number for conducting the search.
1676 * on successful return, the first block within a dmap page
1677 * that contains or starts a range of contiguous free blocks.
1678 *
1679 * RETURN VALUES:
1680 * 0 - success
1681 * -ENOSPC - insufficient disk resources
1682 * -EIO - i/o error
1683 *
1684 * serialization: IWRITE_LOCK(ipbmap) held on entry/exit;
1685 */
1686static int dbFindCtl(struct bmap * bmp, int l2nb, int level, s64 * blkno)
1687{
1688 int rc, leafidx, lev;
1689 s64 b, lblkno;
1690 struct dmapctl *dcp;
1691 int budmin;
1692 struct metapage *mp;
1693
1694 /* starting at the specified dmap control page level and block
1695 * number, search down the dmap control levels for the starting
1696 * block number of a dmap page that contains or starts off
1697 * sufficient free blocks.
1698 */
1699 for (lev = level, b = *blkno; lev >= 0; lev--) {
1700 /* get the buffer of the dmap control page for the block
1701 * number and level (i.e. L0, L1, L2).
1702 */
1703 lblkno = BLKTOCTL(b, bmp->db_l2nbperpage, lev);
1704 mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0);
1705 if (mp == NULL)
1706 return -EIO;
1707 dcp = (struct dmapctl *) mp->data;
1708 budmin = dcp->budmin;
1709
1710 if (dcp->leafidx != cpu_to_le32(CTLLEAFIND)) {
1711 jfs_error(bmp->db_ipbmap->i_sb,
1712 "Corrupt dmapctl page\n");
1713 release_metapage(mp);
1714 return -EIO;
1715 }
1716
1717 /* search the tree within the dmap control page for
1718 * sufficient free space. if sufficient free space is found,
1719 * dbFindLeaf() returns the index of the leaf at which
1720 * free space was found.
1721 */
1722 rc = dbFindLeaf((dmtree_t *) dcp, l2nb, &leafidx, true);
1723
1724 /* release the buffer.
1725 */
1726 release_metapage(mp);
1727
1728 /* space found ?
1729 */
1730 if (rc) {
1731 if (lev != level) {
1732 jfs_error(bmp->db_ipbmap->i_sb,
1733 "dmap inconsistent\n");
1734 return -EIO;
1735 }
1736 return -ENOSPC;
1737 }
1738
1739 /* adjust the block number to reflect the location within
1740 * the dmap control page (i.e. the leaf) at which free
1741 * space was found.
1742 */
1743 b += (((s64) leafidx) << budmin);
1744
1745 /* we stop the search at this dmap control page level if
1746 * the number of blocks required is greater than or equal
1747 * to the maximum number of blocks described at the next
1748 * (lower) level.
1749 */
1750 if (l2nb >= budmin)
1751 break;
1752 }
1753
1754 *blkno = b;
1755 return (0);
1756}
1757
1758
1759/*
1760 * NAME: dbAllocCtl()
1761 *
1762 * FUNCTION: attempt to allocate a specified number of contiguous
1763 * blocks starting within a specific dmap.
1764 *
1765 * this routine is called by higher level routines that search
1766 * the dmap control pages above the actual dmaps for contiguous
1767 * free space. the result of successful searches by these
1768 * routines are the starting block numbers within dmaps, with
1769 * the dmaps themselves containing the desired contiguous free
1770 * space or starting a contiguous free space of desired size
1771 * that is made up of the blocks of one or more dmaps. these
1772 * calls should not fail due to insufficent resources.
1773 *
1774 * this routine is called in some cases where it is not known
1775 * whether it will fail due to insufficient resources. more
1776 * specifically, this occurs when allocating from an allocation
1777 * group whose size is equal to the number of blocks per dmap.
1778 * in this case, the dmap control pages are not examined prior
1779 * to calling this routine (to save pathlength) and the call
1780 * might fail.
1781 *
1782 * for a request size that fits within a dmap, this routine relies
1783 * upon the dmap's dmtree to find the requested contiguous free
1784 * space. for request sizes that are larger than a dmap, the
1785 * requested free space will start at the first block of the
1786 * first dmap (i.e. blkno).
1787 *
1788 * PARAMETERS:
1789 * bmp - pointer to bmap descriptor
1790 * nblocks - actual number of contiguous free blocks to allocate.
1791 * l2nb - log2 number of contiguous free blocks to allocate.
1792 * blkno - starting block number of the dmap to start the allocation
1793 * from.
1794 * results - on successful return, set to the starting block number
1795 * of the newly allocated range.
1796 *
1797 * RETURN VALUES:
1798 * 0 - success
1799 * -ENOSPC - insufficient disk resources
1800 * -EIO - i/o error
1801 *
1802 * serialization: IWRITE_LOCK(ipbmap) held on entry/exit;
1803 */
1804static int
1805dbAllocCtl(struct bmap * bmp, s64 nblocks, int l2nb, s64 blkno, s64 * results)
1806{
1807 int rc, nb;
1808 s64 b, lblkno, n;
1809 struct metapage *mp;
1810 struct dmap *dp;
1811
1812 /* check if the allocation request is confined to a single dmap.
1813 */
1814 if (l2nb <= L2BPERDMAP) {
1815 /* get the buffer for the dmap.
1816 */
1817 lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage);
1818 mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0);
1819 if (mp == NULL)
1820 return -EIO;
1821 dp = (struct dmap *) mp->data;
1822
1823 if (dp->tree.budmin < 0)
1824 return -EIO;
1825
1826 /* try to allocate the blocks.
1827 */
1828 rc = dbAllocDmapLev(bmp, dp, (int) nblocks, l2nb, results);
1829 if (rc == 0)
1830 mark_metapage_dirty(mp);
1831
1832 release_metapage(mp);
1833
1834 return (rc);
1835 }
1836
1837 /* allocation request involving multiple dmaps. it must start on
1838 * a dmap boundary.
1839 */
1840 assert((blkno & (BPERDMAP - 1)) == 0);
1841
1842 /* allocate the blocks dmap by dmap.
1843 */
1844 for (n = nblocks, b = blkno; n > 0; n -= nb, b += nb) {
1845 /* get the buffer for the dmap.
1846 */
1847 lblkno = BLKTODMAP(b, bmp->db_l2nbperpage);
1848 mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0);
1849 if (mp == NULL) {
1850 rc = -EIO;
1851 goto backout;
1852 }
1853 dp = (struct dmap *) mp->data;
1854
1855 /* the dmap better be all free.
1856 */
1857 if (dp->tree.stree[ROOT] != L2BPERDMAP) {
1858 release_metapage(mp);
1859 jfs_error(bmp->db_ipbmap->i_sb,
1860 "the dmap is not all free\n");
1861 rc = -EIO;
1862 goto backout;
1863 }
1864
1865 /* determine how many blocks to allocate from this dmap.
1866 */
1867 nb = min_t(s64, n, BPERDMAP);
1868
1869 /* allocate the blocks from the dmap.
1870 */
1871 if ((rc = dbAllocDmap(bmp, dp, b, nb))) {
1872 release_metapage(mp);
1873 goto backout;
1874 }
1875
1876 /* write the buffer.
1877 */
1878 write_metapage(mp);
1879 }
1880
1881 /* set the results (starting block number) and return.
1882 */
1883 *results = blkno;
1884 return (0);
1885
1886 /* something failed in handling an allocation request involving
1887 * multiple dmaps. we'll try to clean up by backing out any
1888 * allocation that has already happened for this request. if
1889 * we fail in backing out the allocation, we'll mark the file
1890 * system to indicate that blocks have been leaked.
1891 */
1892 backout:
1893
1894 /* try to backout the allocations dmap by dmap.
1895 */
1896 for (n = nblocks - n, b = blkno; n > 0;
1897 n -= BPERDMAP, b += BPERDMAP) {
1898 /* get the buffer for this dmap.
1899 */
1900 lblkno = BLKTODMAP(b, bmp->db_l2nbperpage);
1901 mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0);
1902 if (mp == NULL) {
1903 /* could not back out. mark the file system
1904 * to indicate that we have leaked blocks.
1905 */
1906 jfs_error(bmp->db_ipbmap->i_sb,
1907 "I/O Error: Block Leakage\n");
1908 continue;
1909 }
1910 dp = (struct dmap *) mp->data;
1911
1912 /* free the blocks is this dmap.
1913 */
1914 if (dbFreeDmap(bmp, dp, b, BPERDMAP)) {
1915 /* could not back out. mark the file system
1916 * to indicate that we have leaked blocks.
1917 */
1918 release_metapage(mp);
1919 jfs_error(bmp->db_ipbmap->i_sb, "Block Leakage\n");
1920 continue;
1921 }
1922
1923 /* write the buffer.
1924 */
1925 write_metapage(mp);
1926 }
1927
1928 return (rc);
1929}
1930
1931
1932/*
1933 * NAME: dbAllocDmapLev()
1934 *
1935 * FUNCTION: attempt to allocate a specified number of contiguous blocks
1936 * from a specified dmap.
1937 *
1938 * this routine checks if the contiguous blocks are available.
1939 * if so, nblocks of blocks are allocated; otherwise, ENOSPC is
1940 * returned.
1941 *
1942 * PARAMETERS:
1943 * mp - pointer to bmap descriptor
1944 * dp - pointer to dmap to attempt to allocate blocks from.
1945 * l2nb - log2 number of contiguous block desired.
1946 * nblocks - actual number of contiguous block desired.
1947 * results - on successful return, set to the starting block number
1948 * of the newly allocated range.
1949 *
1950 * RETURN VALUES:
1951 * 0 - success
1952 * -ENOSPC - insufficient disk resources
1953 * -EIO - i/o error
1954 *
1955 * serialization: IREAD_LOCK(ipbmap), e.g., from dbAlloc(), or
1956 * IWRITE_LOCK(ipbmap), e.g., dbAllocCtl(), held on entry/exit;
1957 */
1958static int
1959dbAllocDmapLev(struct bmap * bmp,
1960 struct dmap * dp, int nblocks, int l2nb, s64 * results)
1961{
1962 s64 blkno;
1963 int leafidx, rc;
1964
1965 /* can't be more than a dmaps worth of blocks */
1966 assert(l2nb <= L2BPERDMAP);
1967
1968 /* search the tree within the dmap page for sufficient
1969 * free space. if sufficient free space is found, dbFindLeaf()
1970 * returns the index of the leaf at which free space was found.
1971 */
1972 if (dbFindLeaf((dmtree_t *) &dp->tree, l2nb, &leafidx, false))
1973 return -ENOSPC;
1974
1975 if (leafidx < 0)
1976 return -EIO;
1977
1978 /* determine the block number within the file system corresponding
1979 * to the leaf at which free space was found.
1980 */
1981 blkno = le64_to_cpu(dp->start) + (leafidx << L2DBWORD);
1982
1983 /* if not all bits of the dmap word are free, get the starting
1984 * bit number within the dmap word of the required string of free
1985 * bits and adjust the block number with this value.
1986 */
1987 if (dp->tree.stree[leafidx + LEAFIND] < BUDMIN)
1988 blkno += dbFindBits(le32_to_cpu(dp->wmap[leafidx]), l2nb);
1989
1990 /* allocate the blocks */
1991 if ((rc = dbAllocDmap(bmp, dp, blkno, nblocks)) == 0)
1992 *results = blkno;
1993
1994 return (rc);
1995}
1996
1997
1998/*
1999 * NAME: dbAllocDmap()
2000 *
2001 * FUNCTION: adjust the disk allocation map to reflect the allocation
2002 * of a specified block range within a dmap.
2003 *
2004 * this routine allocates the specified blocks from the dmap
2005 * through a call to dbAllocBits(). if the allocation of the
2006 * block range causes the maximum string of free blocks within
2007 * the dmap to change (i.e. the value of the root of the dmap's
2008 * dmtree), this routine will cause this change to be reflected
2009 * up through the appropriate levels of the dmap control pages
2010 * by a call to dbAdjCtl() for the L0 dmap control page that
2011 * covers this dmap.
2012 *
2013 * PARAMETERS:
2014 * bmp - pointer to bmap descriptor
2015 * dp - pointer to dmap to allocate the block range from.
2016 * blkno - starting block number of the block to be allocated.
2017 * nblocks - number of blocks to be allocated.
2018 *
2019 * RETURN VALUES:
2020 * 0 - success
2021 * -EIO - i/o error
2022 *
2023 * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit;
2024 */
2025static int dbAllocDmap(struct bmap * bmp, struct dmap * dp, s64 blkno,
2026 int nblocks)
2027{
2028 s8 oldroot;
2029 int rc;
2030
2031 /* save the current value of the root (i.e. maximum free string)
2032 * of the dmap tree.
2033 */
2034 oldroot = dp->tree.stree[ROOT];
2035
2036 /* allocate the specified (blocks) bits */
2037 dbAllocBits(bmp, dp, blkno, nblocks);
2038
2039 /* if the root has not changed, done. */
2040 if (dp->tree.stree[ROOT] == oldroot)
2041 return (0);
2042
2043 /* root changed. bubble the change up to the dmap control pages.
2044 * if the adjustment of the upper level control pages fails,
2045 * backout the bit allocation (thus making everything consistent).
2046 */
2047 if ((rc = dbAdjCtl(bmp, blkno, dp->tree.stree[ROOT], 1, 0)))
2048 dbFreeBits(bmp, dp, blkno, nblocks);
2049
2050 return (rc);
2051}
2052
2053
2054/*
2055 * NAME: dbFreeDmap()
2056 *
2057 * FUNCTION: adjust the disk allocation map to reflect the allocation
2058 * of a specified block range within a dmap.
2059 *
2060 * this routine frees the specified blocks from the dmap through
2061 * a call to dbFreeBits(). if the deallocation of the block range
2062 * causes the maximum string of free blocks within the dmap to
2063 * change (i.e. the value of the root of the dmap's dmtree), this
2064 * routine will cause this change to be reflected up through the
2065 * appropriate levels of the dmap control pages by a call to
2066 * dbAdjCtl() for the L0 dmap control page that covers this dmap.
2067 *
2068 * PARAMETERS:
2069 * bmp - pointer to bmap descriptor
2070 * dp - pointer to dmap to free the block range from.
2071 * blkno - starting block number of the block to be freed.
2072 * nblocks - number of blocks to be freed.
2073 *
2074 * RETURN VALUES:
2075 * 0 - success
2076 * -EIO - i/o error
2077 *
2078 * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit;
2079 */
2080static int dbFreeDmap(struct bmap * bmp, struct dmap * dp, s64 blkno,
2081 int nblocks)
2082{
2083 s8 oldroot;
2084 int rc = 0, word;
2085
2086 /* save the current value of the root (i.e. maximum free string)
2087 * of the dmap tree.
2088 */
2089 oldroot = dp->tree.stree[ROOT];
2090
2091 /* free the specified (blocks) bits */
2092 rc = dbFreeBits(bmp, dp, blkno, nblocks);
2093
2094 /* if error or the root has not changed, done. */
2095 if (rc || (dp->tree.stree[ROOT] == oldroot))
2096 return (rc);
2097
2098 /* root changed. bubble the change up to the dmap control pages.
2099 * if the adjustment of the upper level control pages fails,
2100 * backout the deallocation.
2101 */
2102 if ((rc = dbAdjCtl(bmp, blkno, dp->tree.stree[ROOT], 0, 0))) {
2103 word = (blkno & (BPERDMAP - 1)) >> L2DBWORD;
2104
2105 /* as part of backing out the deallocation, we will have
2106 * to back split the dmap tree if the deallocation caused
2107 * the freed blocks to become part of a larger binary buddy
2108 * system.
2109 */
2110 if (dp->tree.stree[word] == NOFREE)
2111 dbBackSplit((dmtree_t *)&dp->tree, word, false);
2112
2113 dbAllocBits(bmp, dp, blkno, nblocks);
2114 }
2115
2116 return (rc);
2117}
2118
2119
2120/*
2121 * NAME: dbAllocBits()
2122 *
2123 * FUNCTION: allocate a specified block range from a dmap.
2124 *
2125 * this routine updates the dmap to reflect the working
2126 * state allocation of the specified block range. it directly
2127 * updates the bits of the working map and causes the adjustment
2128 * of the binary buddy system described by the dmap's dmtree
2129 * leaves to reflect the bits allocated. it also causes the
2130 * dmap's dmtree, as a whole, to reflect the allocated range.
2131 *
2132 * PARAMETERS:
2133 * bmp - pointer to bmap descriptor
2134 * dp - pointer to dmap to allocate bits from.
2135 * blkno - starting block number of the bits to be allocated.
2136 * nblocks - number of bits to be allocated.
2137 *
2138 * RETURN VALUES: none
2139 *
2140 * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit;
2141 */
2142static void dbAllocBits(struct bmap * bmp, struct dmap * dp, s64 blkno,
2143 int nblocks)
2144{
2145 int dbitno, word, rembits, nb, nwords, wbitno, nw, agno;
2146 dmtree_t *tp = (dmtree_t *) & dp->tree;
2147 int size;
2148 s8 *leaf;
2149
2150 /* pick up a pointer to the leaves of the dmap tree */
2151 leaf = dp->tree.stree + LEAFIND;
2152
2153 /* determine the bit number and word within the dmap of the
2154 * starting block.
2155 */
2156 dbitno = blkno & (BPERDMAP - 1);
2157 word = dbitno >> L2DBWORD;
2158
2159 /* block range better be within the dmap */
2160 assert(dbitno + nblocks <= BPERDMAP);
2161
2162 /* allocate the bits of the dmap's words corresponding to the block
2163 * range. not all bits of the first and last words may be contained
2164 * within the block range. if this is the case, we'll work against
2165 * those words (i.e. partial first and/or last) on an individual basis
2166 * (a single pass), allocating the bits of interest by hand and
2167 * updating the leaf corresponding to the dmap word. a single pass
2168 * will be used for all dmap words fully contained within the
2169 * specified range. within this pass, the bits of all fully contained
2170 * dmap words will be marked as free in a single shot and the leaves
2171 * will be updated. a single leaf may describe the free space of
2172 * multiple dmap words, so we may update only a subset of the actual
2173 * leaves corresponding to the dmap words of the block range.
2174 */
2175 for (rembits = nblocks; rembits > 0; rembits -= nb, dbitno += nb) {
2176 /* determine the bit number within the word and
2177 * the number of bits within the word.
2178 */
2179 wbitno = dbitno & (DBWORD - 1);
2180 nb = min(rembits, DBWORD - wbitno);
2181
2182 /* check if only part of a word is to be allocated.
2183 */
2184 if (nb < DBWORD) {
2185 /* allocate (set to 1) the appropriate bits within
2186 * this dmap word.
2187 */
2188 dp->wmap[word] |= cpu_to_le32(ONES << (DBWORD - nb)
2189 >> wbitno);
2190
2191 /* update the leaf for this dmap word. in addition
2192 * to setting the leaf value to the binary buddy max
2193 * of the updated dmap word, dbSplit() will split
2194 * the binary system of the leaves if need be.
2195 */
2196 dbSplit(tp, word, BUDMIN,
2197 dbMaxBud((u8 *)&dp->wmap[word]), false);
2198
2199 word += 1;
2200 } else {
2201 /* one or more dmap words are fully contained
2202 * within the block range. determine how many
2203 * words and allocate (set to 1) the bits of these
2204 * words.
2205 */
2206 nwords = rembits >> L2DBWORD;
2207 memset(&dp->wmap[word], (int) ONES, nwords * 4);
2208
2209 /* determine how many bits.
2210 */
2211 nb = nwords << L2DBWORD;
2212
2213 /* now update the appropriate leaves to reflect
2214 * the allocated words.
2215 */
2216 for (; nwords > 0; nwords -= nw) {
2217 if (leaf[word] < BUDMIN) {
2218 jfs_error(bmp->db_ipbmap->i_sb,
2219 "leaf page corrupt\n");
2220 break;
2221 }
2222
2223 /* determine what the leaf value should be
2224 * updated to as the minimum of the l2 number
2225 * of bits being allocated and the l2 number
2226 * of bits currently described by this leaf.
2227 */
2228 size = min_t(int, leaf[word],
2229 NLSTOL2BSZ(nwords));
2230
2231 /* update the leaf to reflect the allocation.
2232 * in addition to setting the leaf value to
2233 * NOFREE, dbSplit() will split the binary
2234 * system of the leaves to reflect the current
2235 * allocation (size).
2236 */
2237 dbSplit(tp, word, size, NOFREE, false);
2238
2239 /* get the number of dmap words handled */
2240 nw = BUDSIZE(size, BUDMIN);
2241 word += nw;
2242 }
2243 }
2244 }
2245
2246 /* update the free count for this dmap */
2247 le32_add_cpu(&dp->nfree, -nblocks);
2248
2249 BMAP_LOCK(bmp);
2250
2251 /* if this allocation group is completely free,
2252 * update the maximum allocation group number if this allocation
2253 * group is the new max.
2254 */
2255 agno = blkno >> bmp->db_agl2size;
2256 if (agno > bmp->db_maxag)
2257 bmp->db_maxag = agno;
2258
2259 /* update the free count for the allocation group and map */
2260 bmp->db_agfree[agno] -= nblocks;
2261 bmp->db_nfree -= nblocks;
2262
2263 BMAP_UNLOCK(bmp);
2264}
2265
2266
2267/*
2268 * NAME: dbFreeBits()
2269 *
2270 * FUNCTION: free a specified block range from a dmap.
2271 *
2272 * this routine updates the dmap to reflect the working
2273 * state allocation of the specified block range. it directly
2274 * updates the bits of the working map and causes the adjustment
2275 * of the binary buddy system described by the dmap's dmtree
2276 * leaves to reflect the bits freed. it also causes the dmap's
2277 * dmtree, as a whole, to reflect the deallocated range.
2278 *
2279 * PARAMETERS:
2280 * bmp - pointer to bmap descriptor
2281 * dp - pointer to dmap to free bits from.
2282 * blkno - starting block number of the bits to be freed.
2283 * nblocks - number of bits to be freed.
2284 *
2285 * RETURN VALUES: 0 for success
2286 *
2287 * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit;
2288 */
2289static int dbFreeBits(struct bmap * bmp, struct dmap * dp, s64 blkno,
2290 int nblocks)
2291{
2292 int dbitno, word, rembits, nb, nwords, wbitno, nw, agno;
2293 dmtree_t *tp = (dmtree_t *) & dp->tree;
2294 int rc = 0;
2295 int size;
2296
2297 /* determine the bit number and word within the dmap of the
2298 * starting block.
2299 */
2300 dbitno = blkno & (BPERDMAP - 1);
2301 word = dbitno >> L2DBWORD;
2302
2303 /* block range better be within the dmap.
2304 */
2305 assert(dbitno + nblocks <= BPERDMAP);
2306
2307 /* free the bits of the dmaps words corresponding to the block range.
2308 * not all bits of the first and last words may be contained within
2309 * the block range. if this is the case, we'll work against those
2310 * words (i.e. partial first and/or last) on an individual basis
2311 * (a single pass), freeing the bits of interest by hand and updating
2312 * the leaf corresponding to the dmap word. a single pass will be used
2313 * for all dmap words fully contained within the specified range.
2314 * within this pass, the bits of all fully contained dmap words will
2315 * be marked as free in a single shot and the leaves will be updated. a
2316 * single leaf may describe the free space of multiple dmap words,
2317 * so we may update only a subset of the actual leaves corresponding
2318 * to the dmap words of the block range.
2319 *
2320 * dbJoin() is used to update leaf values and will join the binary
2321 * buddy system of the leaves if the new leaf values indicate this
2322 * should be done.
2323 */
2324 for (rembits = nblocks; rembits > 0; rembits -= nb, dbitno += nb) {
2325 /* determine the bit number within the word and
2326 * the number of bits within the word.
2327 */
2328 wbitno = dbitno & (DBWORD - 1);
2329 nb = min(rembits, DBWORD - wbitno);
2330
2331 /* check if only part of a word is to be freed.
2332 */
2333 if (nb < DBWORD) {
2334 /* free (zero) the appropriate bits within this
2335 * dmap word.
2336 */
2337 dp->wmap[word] &=
2338 cpu_to_le32(~(ONES << (DBWORD - nb)
2339 >> wbitno));
2340
2341 /* update the leaf for this dmap word.
2342 */
2343 rc = dbJoin(tp, word,
2344 dbMaxBud((u8 *)&dp->wmap[word]), false);
2345 if (rc)
2346 return rc;
2347
2348 word += 1;
2349 } else {
2350 /* one or more dmap words are fully contained
2351 * within the block range. determine how many
2352 * words and free (zero) the bits of these words.
2353 */
2354 nwords = rembits >> L2DBWORD;
2355 memset(&dp->wmap[word], 0, nwords * 4);
2356
2357 /* determine how many bits.
2358 */
2359 nb = nwords << L2DBWORD;
2360
2361 /* now update the appropriate leaves to reflect
2362 * the freed words.
2363 */
2364 for (; nwords > 0; nwords -= nw) {
2365 /* determine what the leaf value should be
2366 * updated to as the minimum of the l2 number
2367 * of bits being freed and the l2 (max) number
2368 * of bits that can be described by this leaf.
2369 */
2370 size =
2371 min(LITOL2BSZ
2372 (word, L2LPERDMAP, BUDMIN),
2373 NLSTOL2BSZ(nwords));
2374
2375 /* update the leaf.
2376 */
2377 rc = dbJoin(tp, word, size, false);
2378 if (rc)
2379 return rc;
2380
2381 /* get the number of dmap words handled.
2382 */
2383 nw = BUDSIZE(size, BUDMIN);
2384 word += nw;
2385 }
2386 }
2387 }
2388
2389 /* update the free count for this dmap.
2390 */
2391 le32_add_cpu(&dp->nfree, nblocks);
2392
2393 BMAP_LOCK(bmp);
2394
2395 /* update the free count for the allocation group and
2396 * map.
2397 */
2398 agno = blkno >> bmp->db_agl2size;
2399 bmp->db_nfree += nblocks;
2400 bmp->db_agfree[agno] += nblocks;
2401
2402 /* check if this allocation group is not completely free and
2403 * if it is currently the maximum (rightmost) allocation group.
2404 * if so, establish the new maximum allocation group number by
2405 * searching left for the first allocation group with allocation.
2406 */
2407 if ((bmp->db_agfree[agno] == bmp->db_agsize && agno == bmp->db_maxag) ||
2408 (agno == bmp->db_numag - 1 &&
2409 bmp->db_agfree[agno] == (bmp-> db_mapsize & (BPERDMAP - 1)))) {
2410 while (bmp->db_maxag > 0) {
2411 bmp->db_maxag -= 1;
2412 if (bmp->db_agfree[bmp->db_maxag] !=
2413 bmp->db_agsize)
2414 break;
2415 }
2416
2417 /* re-establish the allocation group preference if the
2418 * current preference is right of the maximum allocation
2419 * group.
2420 */
2421 if (bmp->db_agpref > bmp->db_maxag)
2422 bmp->db_agpref = bmp->db_maxag;
2423 }
2424
2425 BMAP_UNLOCK(bmp);
2426
2427 return 0;
2428}
2429
2430
2431/*
2432 * NAME: dbAdjCtl()
2433 *
2434 * FUNCTION: adjust a dmap control page at a specified level to reflect
2435 * the change in a lower level dmap or dmap control page's
2436 * maximum string of free blocks (i.e. a change in the root
2437 * of the lower level object's dmtree) due to the allocation
2438 * or deallocation of a range of blocks with a single dmap.
2439 *
2440 * on entry, this routine is provided with the new value of
2441 * the lower level dmap or dmap control page root and the
2442 * starting block number of the block range whose allocation
2443 * or deallocation resulted in the root change. this range
2444 * is respresented by a single leaf of the current dmapctl
2445 * and the leaf will be updated with this value, possibly
2446 * causing a binary buddy system within the leaves to be
2447 * split or joined. the update may also cause the dmapctl's
2448 * dmtree to be updated.
2449 *
2450 * if the adjustment of the dmap control page, itself, causes its
2451 * root to change, this change will be bubbled up to the next dmap
2452 * control level by a recursive call to this routine, specifying
2453 * the new root value and the next dmap control page level to
2454 * be adjusted.
2455 * PARAMETERS:
2456 * bmp - pointer to bmap descriptor
2457 * blkno - the first block of a block range within a dmap. it is
2458 * the allocation or deallocation of this block range that
2459 * requires the dmap control page to be adjusted.
2460 * newval - the new value of the lower level dmap or dmap control
2461 * page root.
2462 * alloc - 'true' if adjustment is due to an allocation.
2463 * level - current level of dmap control page (i.e. L0, L1, L2) to
2464 * be adjusted.
2465 *
2466 * RETURN VALUES:
2467 * 0 - success
2468 * -EIO - i/o error
2469 *
2470 * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit;
2471 */
2472static int
2473dbAdjCtl(struct bmap * bmp, s64 blkno, int newval, int alloc, int level)
2474{
2475 struct metapage *mp;
2476 s8 oldroot;
2477 int oldval;
2478 s64 lblkno;
2479 struct dmapctl *dcp;
2480 int rc, leafno, ti;
2481
2482 /* get the buffer for the dmap control page for the specified
2483 * block number and control page level.
2484 */
2485 lblkno = BLKTOCTL(blkno, bmp->db_l2nbperpage, level);
2486 mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0);
2487 if (mp == NULL)
2488 return -EIO;
2489 dcp = (struct dmapctl *) mp->data;
2490
2491 if (dcp->leafidx != cpu_to_le32(CTLLEAFIND)) {
2492 jfs_error(bmp->db_ipbmap->i_sb, "Corrupt dmapctl page\n");
2493 release_metapage(mp);
2494 return -EIO;
2495 }
2496
2497 /* determine the leaf number corresponding to the block and
2498 * the index within the dmap control tree.
2499 */
2500 leafno = BLKTOCTLLEAF(blkno, dcp->budmin);
2501 ti = leafno + le32_to_cpu(dcp->leafidx);
2502
2503 /* save the current leaf value and the current root level (i.e.
2504 * maximum l2 free string described by this dmapctl).
2505 */
2506 oldval = dcp->stree[ti];
2507 oldroot = dcp->stree[ROOT];
2508
2509 /* check if this is a control page update for an allocation.
2510 * if so, update the leaf to reflect the new leaf value using
2511 * dbSplit(); otherwise (deallocation), use dbJoin() to update
2512 * the leaf with the new value. in addition to updating the
2513 * leaf, dbSplit() will also split the binary buddy system of
2514 * the leaves, if required, and bubble new values within the
2515 * dmapctl tree, if required. similarly, dbJoin() will join
2516 * the binary buddy system of leaves and bubble new values up
2517 * the dmapctl tree as required by the new leaf value.
2518 */
2519 if (alloc) {
2520 /* check if we are in the middle of a binary buddy
2521 * system. this happens when we are performing the
2522 * first allocation out of an allocation group that
2523 * is part (not the first part) of a larger binary
2524 * buddy system. if we are in the middle, back split
2525 * the system prior to calling dbSplit() which assumes
2526 * that it is at the front of a binary buddy system.
2527 */
2528 if (oldval == NOFREE) {
2529 rc = dbBackSplit((dmtree_t *)dcp, leafno, true);
2530 if (rc) {
2531 release_metapage(mp);
2532 return rc;
2533 }
2534 oldval = dcp->stree[ti];
2535 }
2536 dbSplit((dmtree_t *) dcp, leafno, dcp->budmin, newval, true);
2537 } else {
2538 rc = dbJoin((dmtree_t *) dcp, leafno, newval, true);
2539 if (rc) {
2540 release_metapage(mp);
2541 return rc;
2542 }
2543 }
2544
2545 /* check if the root of the current dmap control page changed due
2546 * to the update and if the current dmap control page is not at
2547 * the current top level (i.e. L0, L1, L2) of the map. if so (i.e.
2548 * root changed and this is not the top level), call this routine
2549 * again (recursion) for the next higher level of the mapping to
2550 * reflect the change in root for the current dmap control page.
2551 */
2552 if (dcp->stree[ROOT] != oldroot) {
2553 /* are we below the top level of the map. if so,
2554 * bubble the root up to the next higher level.
2555 */
2556 if (level < bmp->db_maxlevel) {
2557 /* bubble up the new root of this dmap control page to
2558 * the next level.
2559 */
2560 if ((rc =
2561 dbAdjCtl(bmp, blkno, dcp->stree[ROOT], alloc,
2562 level + 1))) {
2563 /* something went wrong in bubbling up the new
2564 * root value, so backout the changes to the
2565 * current dmap control page.
2566 */
2567 if (alloc) {
2568 dbJoin((dmtree_t *) dcp, leafno,
2569 oldval, true);
2570 } else {
2571 /* the dbJoin() above might have
2572 * caused a larger binary buddy system
2573 * to form and we may now be in the
2574 * middle of it. if this is the case,
2575 * back split the buddies.
2576 */
2577 if (dcp->stree[ti] == NOFREE)
2578 dbBackSplit((dmtree_t *)
2579 dcp, leafno, true);
2580 dbSplit((dmtree_t *) dcp, leafno,
2581 dcp->budmin, oldval, true);
2582 }
2583
2584 /* release the buffer and return the error.
2585 */
2586 release_metapage(mp);
2587 return (rc);
2588 }
2589 } else {
2590 /* we're at the top level of the map. update
2591 * the bmap control page to reflect the size
2592 * of the maximum free buddy system.
2593 */
2594 assert(level == bmp->db_maxlevel);
2595 if (bmp->db_maxfreebud != oldroot) {
2596 jfs_error(bmp->db_ipbmap->i_sb,
2597 "the maximum free buddy is not the old root\n");
2598 }
2599 bmp->db_maxfreebud = dcp->stree[ROOT];
2600 }
2601 }
2602
2603 /* write the buffer.
2604 */
2605 write_metapage(mp);
2606
2607 return (0);
2608}
2609
2610
2611/*
2612 * NAME: dbSplit()
2613 *
2614 * FUNCTION: update the leaf of a dmtree with a new value, splitting
2615 * the leaf from the binary buddy system of the dmtree's
2616 * leaves, as required.
2617 *
2618 * PARAMETERS:
2619 * tp - pointer to the tree containing the leaf.
2620 * leafno - the number of the leaf to be updated.
2621 * splitsz - the size the binary buddy system starting at the leaf
2622 * must be split to, specified as the log2 number of blocks.
2623 * newval - the new value for the leaf.
2624 *
2625 * RETURN VALUES: none
2626 *
2627 * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit;
2628 */
2629static void dbSplit(dmtree_t *tp, int leafno, int splitsz, int newval, bool is_ctl)
2630{
2631 int budsz;
2632 int cursz;
2633 s8 *leaf = tp->dmt_stree + le32_to_cpu(tp->dmt_leafidx);
2634
2635 /* check if the leaf needs to be split.
2636 */
2637 if (leaf[leafno] > tp->dmt_budmin) {
2638 /* the split occurs by cutting the buddy system in half
2639 * at the specified leaf until we reach the specified
2640 * size. pick up the starting split size (current size
2641 * - 1 in l2) and the corresponding buddy size.
2642 */
2643 cursz = leaf[leafno] - 1;
2644 budsz = BUDSIZE(cursz, tp->dmt_budmin);
2645
2646 /* split until we reach the specified size.
2647 */
2648 while (cursz >= splitsz) {
2649 /* update the buddy's leaf with its new value.
2650 */
2651 dbAdjTree(tp, leafno ^ budsz, cursz, is_ctl);
2652
2653 /* on to the next size and buddy.
2654 */
2655 cursz -= 1;
2656 budsz >>= 1;
2657 }
2658 }
2659
2660 /* adjust the dmap tree to reflect the specified leaf's new
2661 * value.
2662 */
2663 dbAdjTree(tp, leafno, newval, is_ctl);
2664}
2665
2666
2667/*
2668 * NAME: dbBackSplit()
2669 *
2670 * FUNCTION: back split the binary buddy system of dmtree leaves
2671 * that hold a specified leaf until the specified leaf
2672 * starts its own binary buddy system.
2673 *
2674 * the allocators typically perform allocations at the start
2675 * of binary buddy systems and dbSplit() is used to accomplish
2676 * any required splits. in some cases, however, allocation
2677 * may occur in the middle of a binary system and requires a
2678 * back split, with the split proceeding out from the middle of
2679 * the system (less efficient) rather than the start of the
2680 * system (more efficient). the cases in which a back split
2681 * is required are rare and are limited to the first allocation
2682 * within an allocation group which is a part (not first part)
2683 * of a larger binary buddy system and a few exception cases
2684 * in which a previous join operation must be backed out.
2685 *
2686 * PARAMETERS:
2687 * tp - pointer to the tree containing the leaf.
2688 * leafno - the number of the leaf to be updated.
2689 *
2690 * RETURN VALUES: none
2691 *
2692 * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit;
2693 */
2694static int dbBackSplit(dmtree_t *tp, int leafno, bool is_ctl)
2695{
2696 int budsz, bud, w, bsz, size;
2697 int cursz;
2698 s8 *leaf = tp->dmt_stree + le32_to_cpu(tp->dmt_leafidx);
2699
2700 /* leaf should be part (not first part) of a binary
2701 * buddy system.
2702 */
2703 assert(leaf[leafno] == NOFREE);
2704
2705 /* the back split is accomplished by iteratively finding the leaf
2706 * that starts the buddy system that contains the specified leaf and
2707 * splitting that system in two. this iteration continues until
2708 * the specified leaf becomes the start of a buddy system.
2709 *
2710 * determine maximum possible l2 size for the specified leaf.
2711 */
2712 size =
2713 LITOL2BSZ(leafno, le32_to_cpu(tp->dmt_l2nleafs),
2714 tp->dmt_budmin);
2715
2716 /* determine the number of leaves covered by this size. this
2717 * is the buddy size that we will start with as we search for
2718 * the buddy system that contains the specified leaf.
2719 */
2720 budsz = BUDSIZE(size, tp->dmt_budmin);
2721
2722 /* back split.
2723 */
2724 while (leaf[leafno] == NOFREE) {
2725 /* find the leftmost buddy leaf.
2726 */
2727 for (w = leafno, bsz = budsz;; bsz <<= 1,
2728 w = (w < bud) ? w : bud) {
2729 if (bsz >= le32_to_cpu(tp->dmt_nleafs)) {
2730 jfs_err("JFS: block map error in dbBackSplit");
2731 return -EIO;
2732 }
2733
2734 /* determine the buddy.
2735 */
2736 bud = w ^ bsz;
2737
2738 /* check if this buddy is the start of the system.
2739 */
2740 if (leaf[bud] != NOFREE) {
2741 /* split the leaf at the start of the
2742 * system in two.
2743 */
2744 cursz = leaf[bud] - 1;
2745 dbSplit(tp, bud, cursz, cursz, is_ctl);
2746 break;
2747 }
2748 }
2749 }
2750
2751 if (leaf[leafno] != size) {
2752 jfs_err("JFS: wrong leaf value in dbBackSplit");
2753 return -EIO;
2754 }
2755 return 0;
2756}
2757
2758
2759/*
2760 * NAME: dbJoin()
2761 *
2762 * FUNCTION: update the leaf of a dmtree with a new value, joining
2763 * the leaf with other leaves of the dmtree into a multi-leaf
2764 * binary buddy system, as required.
2765 *
2766 * PARAMETERS:
2767 * tp - pointer to the tree containing the leaf.
2768 * leafno - the number of the leaf to be updated.
2769 * newval - the new value for the leaf.
2770 *
2771 * RETURN VALUES: none
2772 */
2773static int dbJoin(dmtree_t *tp, int leafno, int newval, bool is_ctl)
2774{
2775 int budsz, buddy;
2776 s8 *leaf;
2777
2778 /* can the new leaf value require a join with other leaves ?
2779 */
2780 if (newval >= tp->dmt_budmin) {
2781 /* pickup a pointer to the leaves of the tree.
2782 */
2783 leaf = tp->dmt_stree + le32_to_cpu(tp->dmt_leafidx);
2784
2785 /* try to join the specified leaf into a large binary
2786 * buddy system. the join proceeds by attempting to join
2787 * the specified leafno with its buddy (leaf) at new value.
2788 * if the join occurs, we attempt to join the left leaf
2789 * of the joined buddies with its buddy at new value + 1.
2790 * we continue to join until we find a buddy that cannot be
2791 * joined (does not have a value equal to the size of the
2792 * last join) or until all leaves have been joined into a
2793 * single system.
2794 *
2795 * get the buddy size (number of words covered) of
2796 * the new value.
2797 */
2798 budsz = BUDSIZE(newval, tp->dmt_budmin);
2799
2800 /* try to join.
2801 */
2802 while (budsz < le32_to_cpu(tp->dmt_nleafs)) {
2803 /* get the buddy leaf.
2804 */
2805 buddy = leafno ^ budsz;
2806
2807 /* if the leaf's new value is greater than its
2808 * buddy's value, we join no more.
2809 */
2810 if (newval > leaf[buddy])
2811 break;
2812
2813 /* It shouldn't be less */
2814 if (newval < leaf[buddy])
2815 return -EIO;
2816
2817 /* check which (leafno or buddy) is the left buddy.
2818 * the left buddy gets to claim the blocks resulting
2819 * from the join while the right gets to claim none.
2820 * the left buddy is also eligible to participate in
2821 * a join at the next higher level while the right
2822 * is not.
2823 *
2824 */
2825 if (leafno < buddy) {
2826 /* leafno is the left buddy.
2827 */
2828 dbAdjTree(tp, buddy, NOFREE, is_ctl);
2829 } else {
2830 /* buddy is the left buddy and becomes
2831 * leafno.
2832 */
2833 dbAdjTree(tp, leafno, NOFREE, is_ctl);
2834 leafno = buddy;
2835 }
2836
2837 /* on to try the next join.
2838 */
2839 newval += 1;
2840 budsz <<= 1;
2841 }
2842 }
2843
2844 /* update the leaf value.
2845 */
2846 dbAdjTree(tp, leafno, newval, is_ctl);
2847
2848 return 0;
2849}
2850
2851
2852/*
2853 * NAME: dbAdjTree()
2854 *
2855 * FUNCTION: update a leaf of a dmtree with a new value, adjusting
2856 * the dmtree, as required, to reflect the new leaf value.
2857 * the combination of any buddies must already be done before
2858 * this is called.
2859 *
2860 * PARAMETERS:
2861 * tp - pointer to the tree to be adjusted.
2862 * leafno - the number of the leaf to be updated.
2863 * newval - the new value for the leaf.
2864 *
2865 * RETURN VALUES: none
2866 */
2867static void dbAdjTree(dmtree_t *tp, int leafno, int newval, bool is_ctl)
2868{
2869 int lp, pp, k;
2870 int max, size;
2871
2872 size = is_ctl ? CTLTREESIZE : TREESIZE;
2873
2874 /* pick up the index of the leaf for this leafno.
2875 */
2876 lp = leafno + le32_to_cpu(tp->dmt_leafidx);
2877
2878 if (WARN_ON_ONCE(lp >= size || lp < 0))
2879 return;
2880
2881 /* is the current value the same as the old value ? if so,
2882 * there is nothing to do.
2883 */
2884 if (tp->dmt_stree[lp] == newval)
2885 return;
2886
2887 /* set the new value.
2888 */
2889 tp->dmt_stree[lp] = newval;
2890
2891 /* bubble the new value up the tree as required.
2892 */
2893 for (k = 0; k < le32_to_cpu(tp->dmt_height); k++) {
2894 if (lp == 0)
2895 break;
2896
2897 /* get the index of the first leaf of the 4 leaf
2898 * group containing the specified leaf (leafno).
2899 */
2900 lp = ((lp - 1) & ~0x03) + 1;
2901
2902 /* get the index of the parent of this 4 leaf group.
2903 */
2904 pp = (lp - 1) >> 2;
2905
2906 /* determine the maximum of the 4 leaves.
2907 */
2908 max = TREEMAX(&tp->dmt_stree[lp]);
2909
2910 /* if the maximum of the 4 is the same as the
2911 * parent's value, we're done.
2912 */
2913 if (tp->dmt_stree[pp] == max)
2914 break;
2915
2916 /* parent gets new value.
2917 */
2918 tp->dmt_stree[pp] = max;
2919
2920 /* parent becomes leaf for next go-round.
2921 */
2922 lp = pp;
2923 }
2924}
2925
2926
2927/*
2928 * NAME: dbFindLeaf()
2929 *
2930 * FUNCTION: search a dmtree_t for sufficient free blocks, returning
2931 * the index of a leaf describing the free blocks if
2932 * sufficient free blocks are found.
2933 *
2934 * the search starts at the top of the dmtree_t tree and
2935 * proceeds down the tree to the leftmost leaf with sufficient
2936 * free space.
2937 *
2938 * PARAMETERS:
2939 * tp - pointer to the tree to be searched.
2940 * l2nb - log2 number of free blocks to search for.
2941 * leafidx - return pointer to be set to the index of the leaf
2942 * describing at least l2nb free blocks if sufficient
2943 * free blocks are found.
2944 * is_ctl - determines if the tree is of type ctl
2945 *
2946 * RETURN VALUES:
2947 * 0 - success
2948 * -ENOSPC - insufficient free blocks.
2949 */
2950static int dbFindLeaf(dmtree_t *tp, int l2nb, int *leafidx, bool is_ctl)
2951{
2952 int ti, n = 0, k, x = 0;
2953 int max_size, max_idx;
2954
2955 max_size = is_ctl ? CTLTREESIZE : TREESIZE;
2956 max_idx = is_ctl ? LPERCTL : LPERDMAP;
2957
2958 /* first check the root of the tree to see if there is
2959 * sufficient free space.
2960 */
2961 if (l2nb > tp->dmt_stree[ROOT])
2962 return -ENOSPC;
2963
2964 /* sufficient free space available. now search down the tree
2965 * starting at the next level for the leftmost leaf that
2966 * describes sufficient free space.
2967 */
2968 for (k = le32_to_cpu(tp->dmt_height), ti = 1;
2969 k > 0; k--, ti = ((ti + n) << 2) + 1) {
2970 /* search the four nodes at this level, starting from
2971 * the left.
2972 */
2973 for (x = ti, n = 0; n < 4; n++) {
2974 /* sufficient free space found. move to the next
2975 * level (or quit if this is the last level).
2976 */
2977 if (x + n > max_size)
2978 return -ENOSPC;
2979 if (l2nb <= tp->dmt_stree[x + n])
2980 break;
2981 }
2982
2983 /* better have found something since the higher
2984 * levels of the tree said it was here.
2985 */
2986 assert(n < 4);
2987 }
2988 if (le32_to_cpu(tp->dmt_leafidx) >= max_idx)
2989 return -ENOSPC;
2990
2991 /* set the return to the leftmost leaf describing sufficient
2992 * free space.
2993 */
2994 *leafidx = x + n - le32_to_cpu(tp->dmt_leafidx);
2995
2996 return (0);
2997}
2998
2999
3000/*
3001 * NAME: dbFindBits()
3002 *
3003 * FUNCTION: find a specified number of binary buddy free bits within a
3004 * dmap bitmap word value.
3005 *
3006 * this routine searches the bitmap value for (1 << l2nb) free
3007 * bits at (1 << l2nb) alignments within the value.
3008 *
3009 * PARAMETERS:
3010 * word - dmap bitmap word value.
3011 * l2nb - number of free bits specified as a log2 number.
3012 *
3013 * RETURN VALUES:
3014 * starting bit number of free bits.
3015 */
3016static int dbFindBits(u32 word, int l2nb)
3017{
3018 int bitno, nb;
3019 u32 mask;
3020
3021 /* get the number of bits.
3022 */
3023 nb = 1 << l2nb;
3024 assert(nb <= DBWORD);
3025
3026 /* complement the word so we can use a mask (i.e. 0s represent
3027 * free bits) and compute the mask.
3028 */
3029 word = ~word;
3030 mask = ONES << (DBWORD - nb);
3031
3032 /* scan the word for nb free bits at nb alignments.
3033 */
3034 for (bitno = 0; mask != 0; bitno += nb, mask = (mask >> nb)) {
3035 if ((mask & word) == mask)
3036 break;
3037 }
3038
3039 ASSERT(bitno < 32);
3040
3041 /* return the bit number.
3042 */
3043 return (bitno);
3044}
3045
3046
3047/*
3048 * NAME: dbMaxBud(u8 *cp)
3049 *
3050 * FUNCTION: determine the largest binary buddy string of free
3051 * bits within 32-bits of the map.
3052 *
3053 * PARAMETERS:
3054 * cp - pointer to the 32-bit value.
3055 *
3056 * RETURN VALUES:
3057 * largest binary buddy of free bits within a dmap word.
3058 */
3059static int dbMaxBud(u8 * cp)
3060{
3061 signed char tmp1, tmp2;
3062
3063 /* check if the wmap word is all free. if so, the
3064 * free buddy size is BUDMIN.
3065 */
3066 if (*((uint *) cp) == 0)
3067 return (BUDMIN);
3068
3069 /* check if the wmap word is half free. if so, the
3070 * free buddy size is BUDMIN-1.
3071 */
3072 if (*((u16 *) cp) == 0 || *((u16 *) cp + 1) == 0)
3073 return (BUDMIN - 1);
3074
3075 /* not all free or half free. determine the free buddy
3076 * size thru table lookup using quarters of the wmap word.
3077 */
3078 tmp1 = max(budtab[cp[2]], budtab[cp[3]]);
3079 tmp2 = max(budtab[cp[0]], budtab[cp[1]]);
3080 return (max(tmp1, tmp2));
3081}
3082
3083
3084/*
3085 * NAME: cnttz(uint word)
3086 *
3087 * FUNCTION: determine the number of trailing zeros within a 32-bit
3088 * value.
3089 *
3090 * PARAMETERS:
3091 * value - 32-bit value to be examined.
3092 *
3093 * RETURN VALUES:
3094 * count of trailing zeros
3095 */
3096static int cnttz(u32 word)
3097{
3098 int n;
3099
3100 for (n = 0; n < 32; n++, word >>= 1) {
3101 if (word & 0x01)
3102 break;
3103 }
3104
3105 return (n);
3106}
3107
3108
3109/*
3110 * NAME: cntlz(u32 value)
3111 *
3112 * FUNCTION: determine the number of leading zeros within a 32-bit
3113 * value.
3114 *
3115 * PARAMETERS:
3116 * value - 32-bit value to be examined.
3117 *
3118 * RETURN VALUES:
3119 * count of leading zeros
3120 */
3121static int cntlz(u32 value)
3122{
3123 int n;
3124
3125 for (n = 0; n < 32; n++, value <<= 1) {
3126 if (value & HIGHORDER)
3127 break;
3128 }
3129 return (n);
3130}
3131
3132
3133/*
3134 * NAME: blkstol2(s64 nb)
3135 *
3136 * FUNCTION: convert a block count to its log2 value. if the block
3137 * count is not a l2 multiple, it is rounded up to the next
3138 * larger l2 multiple.
3139 *
3140 * PARAMETERS:
3141 * nb - number of blocks
3142 *
3143 * RETURN VALUES:
3144 * log2 number of blocks
3145 */
3146static int blkstol2(s64 nb)
3147{
3148 int l2nb;
3149 s64 mask; /* meant to be signed */
3150
3151 mask = (s64) 1 << (64 - 1);
3152
3153 /* count the leading bits.
3154 */
3155 for (l2nb = 0; l2nb < 64; l2nb++, mask >>= 1) {
3156 /* leading bit found.
3157 */
3158 if (nb & mask) {
3159 /* determine the l2 value.
3160 */
3161 l2nb = (64 - 1) - l2nb;
3162
3163 /* check if we need to round up.
3164 */
3165 if (~mask & nb)
3166 l2nb++;
3167
3168 return (l2nb);
3169 }
3170 }
3171 assert(0);
3172 return 0; /* fix compiler warning */
3173}
3174
3175
3176/*
3177 * NAME: dbAllocBottomUp()
3178 *
3179 * FUNCTION: alloc the specified block range from the working block
3180 * allocation map.
3181 *
3182 * the blocks will be alloc from the working map one dmap
3183 * at a time.
3184 *
3185 * PARAMETERS:
3186 * ip - pointer to in-core inode;
3187 * blkno - starting block number to be freed.
3188 * nblocks - number of blocks to be freed.
3189 *
3190 * RETURN VALUES:
3191 * 0 - success
3192 * -EIO - i/o error
3193 */
3194int dbAllocBottomUp(struct inode *ip, s64 blkno, s64 nblocks)
3195{
3196 struct metapage *mp;
3197 struct dmap *dp;
3198 int nb, rc;
3199 s64 lblkno, rem;
3200 struct inode *ipbmap = JFS_SBI(ip->i_sb)->ipbmap;
3201 struct bmap *bmp = JFS_SBI(ip->i_sb)->bmap;
3202
3203 IREAD_LOCK(ipbmap, RDWRLOCK_DMAP);
3204
3205 /* block to be allocated better be within the mapsize. */
3206 ASSERT(nblocks <= bmp->db_mapsize - blkno);
3207
3208 /*
3209 * allocate the blocks a dmap at a time.
3210 */
3211 mp = NULL;
3212 for (rem = nblocks; rem > 0; rem -= nb, blkno += nb) {
3213 /* release previous dmap if any */
3214 if (mp) {
3215 write_metapage(mp);
3216 }
3217
3218 /* get the buffer for the current dmap. */
3219 lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage);
3220 mp = read_metapage(ipbmap, lblkno, PSIZE, 0);
3221 if (mp == NULL) {
3222 IREAD_UNLOCK(ipbmap);
3223 return -EIO;
3224 }
3225 dp = (struct dmap *) mp->data;
3226
3227 /* determine the number of blocks to be allocated from
3228 * this dmap.
3229 */
3230 nb = min(rem, BPERDMAP - (blkno & (BPERDMAP - 1)));
3231
3232 /* allocate the blocks. */
3233 if ((rc = dbAllocDmapBU(bmp, dp, blkno, nb))) {
3234 release_metapage(mp);
3235 IREAD_UNLOCK(ipbmap);
3236 return (rc);
3237 }
3238 }
3239
3240 /* write the last buffer. */
3241 write_metapage(mp);
3242
3243 IREAD_UNLOCK(ipbmap);
3244
3245 return (0);
3246}
3247
3248
3249static int dbAllocDmapBU(struct bmap * bmp, struct dmap * dp, s64 blkno,
3250 int nblocks)
3251{
3252 int rc;
3253 int dbitno, word, rembits, nb, nwords, wbitno, agno;
3254 s8 oldroot;
3255 struct dmaptree *tp = (struct dmaptree *) & dp->tree;
3256
3257 /* save the current value of the root (i.e. maximum free string)
3258 * of the dmap tree.
3259 */
3260 oldroot = tp->stree[ROOT];
3261
3262 /* determine the bit number and word within the dmap of the
3263 * starting block.
3264 */
3265 dbitno = blkno & (BPERDMAP - 1);
3266 word = dbitno >> L2DBWORD;
3267
3268 /* block range better be within the dmap */
3269 assert(dbitno + nblocks <= BPERDMAP);
3270
3271 /* allocate the bits of the dmap's words corresponding to the block
3272 * range. not all bits of the first and last words may be contained
3273 * within the block range. if this is the case, we'll work against
3274 * those words (i.e. partial first and/or last) on an individual basis
3275 * (a single pass), allocating the bits of interest by hand and
3276 * updating the leaf corresponding to the dmap word. a single pass
3277 * will be used for all dmap words fully contained within the
3278 * specified range. within this pass, the bits of all fully contained
3279 * dmap words will be marked as free in a single shot and the leaves
3280 * will be updated. a single leaf may describe the free space of
3281 * multiple dmap words, so we may update only a subset of the actual
3282 * leaves corresponding to the dmap words of the block range.
3283 */
3284 for (rembits = nblocks; rembits > 0; rembits -= nb, dbitno += nb) {
3285 /* determine the bit number within the word and
3286 * the number of bits within the word.
3287 */
3288 wbitno = dbitno & (DBWORD - 1);
3289 nb = min(rembits, DBWORD - wbitno);
3290
3291 /* check if only part of a word is to be allocated.
3292 */
3293 if (nb < DBWORD) {
3294 /* allocate (set to 1) the appropriate bits within
3295 * this dmap word.
3296 */
3297 dp->wmap[word] |= cpu_to_le32(ONES << (DBWORD - nb)
3298 >> wbitno);
3299
3300 word++;
3301 } else {
3302 /* one or more dmap words are fully contained
3303 * within the block range. determine how many
3304 * words and allocate (set to 1) the bits of these
3305 * words.
3306 */
3307 nwords = rembits >> L2DBWORD;
3308 memset(&dp->wmap[word], (int) ONES, nwords * 4);
3309
3310 /* determine how many bits */
3311 nb = nwords << L2DBWORD;
3312 word += nwords;
3313 }
3314 }
3315
3316 /* update the free count for this dmap */
3317 le32_add_cpu(&dp->nfree, -nblocks);
3318
3319 /* reconstruct summary tree */
3320 dbInitDmapTree(dp);
3321
3322 BMAP_LOCK(bmp);
3323
3324 /* if this allocation group is completely free,
3325 * update the highest active allocation group number
3326 * if this allocation group is the new max.
3327 */
3328 agno = blkno >> bmp->db_agl2size;
3329 if (agno > bmp->db_maxag)
3330 bmp->db_maxag = agno;
3331
3332 /* update the free count for the allocation group and map */
3333 bmp->db_agfree[agno] -= nblocks;
3334 bmp->db_nfree -= nblocks;
3335
3336 BMAP_UNLOCK(bmp);
3337
3338 /* if the root has not changed, done. */
3339 if (tp->stree[ROOT] == oldroot)
3340 return (0);
3341
3342 /* root changed. bubble the change up to the dmap control pages.
3343 * if the adjustment of the upper level control pages fails,
3344 * backout the bit allocation (thus making everything consistent).
3345 */
3346 if ((rc = dbAdjCtl(bmp, blkno, tp->stree[ROOT], 1, 0)))
3347 dbFreeBits(bmp, dp, blkno, nblocks);
3348
3349 return (rc);
3350}
3351
3352
3353/*
3354 * NAME: dbExtendFS()
3355 *
3356 * FUNCTION: extend bmap from blkno for nblocks;
3357 * dbExtendFS() updates bmap ready for dbAllocBottomUp();
3358 *
3359 * L2
3360 * |
3361 * L1---------------------------------L1
3362 * | |
3363 * L0---------L0---------L0 L0---------L0---------L0
3364 * | | | | | |
3365 * d0,...,dn d0,...,dn d0,...,dn d0,...,dn d0,...,dn d0,.,dm;
3366 * L2L1L0d0,...,dnL0d0,...,dnL0d0,...,dnL1L0d0,...,dnL0d0,...,dnL0d0,..dm
3367 *
3368 * <---old---><----------------------------extend----------------------->
3369 */
3370int dbExtendFS(struct inode *ipbmap, s64 blkno, s64 nblocks)
3371{
3372 struct jfs_sb_info *sbi = JFS_SBI(ipbmap->i_sb);
3373 int nbperpage = sbi->nbperpage;
3374 int i, i0 = true, j, j0 = true, k, n;
3375 s64 newsize;
3376 s64 p;
3377 struct metapage *mp, *l2mp, *l1mp = NULL, *l0mp = NULL;
3378 struct dmapctl *l2dcp, *l1dcp, *l0dcp;
3379 struct dmap *dp;
3380 s8 *l0leaf, *l1leaf, *l2leaf;
3381 struct bmap *bmp = sbi->bmap;
3382 int agno, l2agsize, oldl2agsize;
3383 s64 ag_rem;
3384
3385 newsize = blkno + nblocks;
3386
3387 jfs_info("dbExtendFS: blkno:%Ld nblocks:%Ld newsize:%Ld",
3388 (long long) blkno, (long long) nblocks, (long long) newsize);
3389
3390 /*
3391 * initialize bmap control page.
3392 *
3393 * all the data in bmap control page should exclude
3394 * the mkfs hidden dmap page.
3395 */
3396
3397 /* update mapsize */
3398 bmp->db_mapsize = newsize;
3399 bmp->db_maxlevel = BMAPSZTOLEV(bmp->db_mapsize);
3400
3401 /* compute new AG size */
3402 l2agsize = dbGetL2AGSize(newsize);
3403 oldl2agsize = bmp->db_agl2size;
3404
3405 bmp->db_agl2size = l2agsize;
3406 bmp->db_agsize = 1 << l2agsize;
3407
3408 /* compute new number of AG */
3409 agno = bmp->db_numag;
3410 bmp->db_numag = newsize >> l2agsize;
3411 bmp->db_numag += ((u32) newsize % (u32) bmp->db_agsize) ? 1 : 0;
3412
3413 /*
3414 * reconfigure db_agfree[]
3415 * from old AG configuration to new AG configuration;
3416 *
3417 * coalesce contiguous k (newAGSize/oldAGSize) AGs;
3418 * i.e., (AGi, ..., AGj) where i = k*n and j = k*(n+1) - 1 to AGn;
3419 * note: new AG size = old AG size * (2**x).
3420 */
3421 if (l2agsize == oldl2agsize)
3422 goto extend;
3423 k = 1 << (l2agsize - oldl2agsize);
3424 ag_rem = bmp->db_agfree[0]; /* save agfree[0] */
3425 for (i = 0, n = 0; i < agno; n++) {
3426 bmp->db_agfree[n] = 0; /* init collection point */
3427
3428 /* coalesce contiguous k AGs; */
3429 for (j = 0; j < k && i < agno; j++, i++) {
3430 /* merge AGi to AGn */
3431 bmp->db_agfree[n] += bmp->db_agfree[i];
3432 }
3433 }
3434 bmp->db_agfree[0] += ag_rem; /* restore agfree[0] */
3435
3436 for (; n < MAXAG; n++)
3437 bmp->db_agfree[n] = 0;
3438
3439 /*
3440 * update highest active ag number
3441 */
3442
3443 bmp->db_maxag = bmp->db_maxag / k;
3444
3445 /*
3446 * extend bmap
3447 *
3448 * update bit maps and corresponding level control pages;
3449 * global control page db_nfree, db_agfree[agno], db_maxfreebud;
3450 */
3451 extend:
3452 /* get L2 page */
3453 p = BMAPBLKNO + nbperpage; /* L2 page */
3454 l2mp = read_metapage(ipbmap, p, PSIZE, 0);
3455 if (!l2mp) {
3456 jfs_error(ipbmap->i_sb, "L2 page could not be read\n");
3457 return -EIO;
3458 }
3459 l2dcp = (struct dmapctl *) l2mp->data;
3460
3461 /* compute start L1 */
3462 k = blkno >> L2MAXL1SIZE;
3463 l2leaf = l2dcp->stree + CTLLEAFIND + k;
3464 p = BLKTOL1(blkno, sbi->l2nbperpage); /* L1 page */
3465
3466 /*
3467 * extend each L1 in L2
3468 */
3469 for (; k < LPERCTL; k++, p += nbperpage) {
3470 /* get L1 page */
3471 if (j0) {
3472 /* read in L1 page: (blkno & (MAXL1SIZE - 1)) */
3473 l1mp = read_metapage(ipbmap, p, PSIZE, 0);
3474 if (l1mp == NULL)
3475 goto errout;
3476 l1dcp = (struct dmapctl *) l1mp->data;
3477
3478 /* compute start L0 */
3479 j = (blkno & (MAXL1SIZE - 1)) >> L2MAXL0SIZE;
3480 l1leaf = l1dcp->stree + CTLLEAFIND + j;
3481 p = BLKTOL0(blkno, sbi->l2nbperpage);
3482 j0 = false;
3483 } else {
3484 /* assign/init L1 page */
3485 l1mp = get_metapage(ipbmap, p, PSIZE, 0);
3486 if (l1mp == NULL)
3487 goto errout;
3488
3489 l1dcp = (struct dmapctl *) l1mp->data;
3490
3491 /* compute start L0 */
3492 j = 0;
3493 l1leaf = l1dcp->stree + CTLLEAFIND;
3494 p += nbperpage; /* 1st L0 of L1.k */
3495 }
3496
3497 /*
3498 * extend each L0 in L1
3499 */
3500 for (; j < LPERCTL; j++) {
3501 /* get L0 page */
3502 if (i0) {
3503 /* read in L0 page: (blkno & (MAXL0SIZE - 1)) */
3504
3505 l0mp = read_metapage(ipbmap, p, PSIZE, 0);
3506 if (l0mp == NULL)
3507 goto errout;
3508 l0dcp = (struct dmapctl *) l0mp->data;
3509
3510 /* compute start dmap */
3511 i = (blkno & (MAXL0SIZE - 1)) >>
3512 L2BPERDMAP;
3513 l0leaf = l0dcp->stree + CTLLEAFIND + i;
3514 p = BLKTODMAP(blkno,
3515 sbi->l2nbperpage);
3516 i0 = false;
3517 } else {
3518 /* assign/init L0 page */
3519 l0mp = get_metapage(ipbmap, p, PSIZE, 0);
3520 if (l0mp == NULL)
3521 goto errout;
3522
3523 l0dcp = (struct dmapctl *) l0mp->data;
3524
3525 /* compute start dmap */
3526 i = 0;
3527 l0leaf = l0dcp->stree + CTLLEAFIND;
3528 p += nbperpage; /* 1st dmap of L0.j */
3529 }
3530
3531 /*
3532 * extend each dmap in L0
3533 */
3534 for (; i < LPERCTL; i++) {
3535 /*
3536 * reconstruct the dmap page, and
3537 * initialize corresponding parent L0 leaf
3538 */
3539 if ((n = blkno & (BPERDMAP - 1))) {
3540 /* read in dmap page: */
3541 mp = read_metapage(ipbmap, p,
3542 PSIZE, 0);
3543 if (mp == NULL)
3544 goto errout;
3545 n = min(nblocks, (s64)BPERDMAP - n);
3546 } else {
3547 /* assign/init dmap page */
3548 mp = read_metapage(ipbmap, p,
3549 PSIZE, 0);
3550 if (mp == NULL)
3551 goto errout;
3552
3553 n = min_t(s64, nblocks, BPERDMAP);
3554 }
3555
3556 dp = (struct dmap *) mp->data;
3557 *l0leaf = dbInitDmap(dp, blkno, n);
3558
3559 bmp->db_nfree += n;
3560 agno = le64_to_cpu(dp->start) >> l2agsize;
3561 bmp->db_agfree[agno] += n;
3562
3563 write_metapage(mp);
3564
3565 l0leaf++;
3566 p += nbperpage;
3567
3568 blkno += n;
3569 nblocks -= n;
3570 if (nblocks == 0)
3571 break;
3572 } /* for each dmap in a L0 */
3573
3574 /*
3575 * build current L0 page from its leaves, and
3576 * initialize corresponding parent L1 leaf
3577 */
3578 *l1leaf = dbInitDmapCtl(l0dcp, 0, ++i);
3579 write_metapage(l0mp);
3580 l0mp = NULL;
3581
3582 if (nblocks)
3583 l1leaf++; /* continue for next L0 */
3584 else {
3585 /* more than 1 L0 ? */
3586 if (j > 0)
3587 break; /* build L1 page */
3588 else {
3589 /* summarize in global bmap page */
3590 bmp->db_maxfreebud = *l1leaf;
3591 release_metapage(l1mp);
3592 release_metapage(l2mp);
3593 goto finalize;
3594 }
3595 }
3596 } /* for each L0 in a L1 */
3597
3598 /*
3599 * build current L1 page from its leaves, and
3600 * initialize corresponding parent L2 leaf
3601 */
3602 *l2leaf = dbInitDmapCtl(l1dcp, 1, ++j);
3603 write_metapage(l1mp);
3604 l1mp = NULL;
3605
3606 if (nblocks)
3607 l2leaf++; /* continue for next L1 */
3608 else {
3609 /* more than 1 L1 ? */
3610 if (k > 0)
3611 break; /* build L2 page */
3612 else {
3613 /* summarize in global bmap page */
3614 bmp->db_maxfreebud = *l2leaf;
3615 release_metapage(l2mp);
3616 goto finalize;
3617 }
3618 }
3619 } /* for each L1 in a L2 */
3620
3621 jfs_error(ipbmap->i_sb, "function has not returned as expected\n");
3622errout:
3623 if (l0mp)
3624 release_metapage(l0mp);
3625 if (l1mp)
3626 release_metapage(l1mp);
3627 release_metapage(l2mp);
3628 return -EIO;
3629
3630 /*
3631 * finalize bmap control page
3632 */
3633finalize:
3634
3635 return 0;
3636}
3637
3638
3639/*
3640 * dbFinalizeBmap()
3641 */
3642void dbFinalizeBmap(struct inode *ipbmap)
3643{
3644 struct bmap *bmp = JFS_SBI(ipbmap->i_sb)->bmap;
3645 int actags, inactags, l2nl;
3646 s64 ag_rem, actfree, inactfree, avgfree;
3647 int i, n;
3648
3649 /*
3650 * finalize bmap control page
3651 */
3652//finalize:
3653 /*
3654 * compute db_agpref: preferred ag to allocate from
3655 * (the leftmost ag with average free space in it);
3656 */
3657//agpref:
3658 /* get the number of active ags and inactive ags */
3659 actags = bmp->db_maxag + 1;
3660 inactags = bmp->db_numag - actags;
3661 ag_rem = bmp->db_mapsize & (bmp->db_agsize - 1); /* ??? */
3662
3663 /* determine how many blocks are in the inactive allocation
3664 * groups. in doing this, we must account for the fact that
3665 * the rightmost group might be a partial group (i.e. file
3666 * system size is not a multiple of the group size).
3667 */
3668 inactfree = (inactags && ag_rem) ?
3669 ((inactags - 1) << bmp->db_agl2size) + ag_rem
3670 : inactags << bmp->db_agl2size;
3671
3672 /* determine how many free blocks are in the active
3673 * allocation groups plus the average number of free blocks
3674 * within the active ags.
3675 */
3676 actfree = bmp->db_nfree - inactfree;
3677 avgfree = (u32) actfree / (u32) actags;
3678
3679 /* if the preferred allocation group has not average free space.
3680 * re-establish the preferred group as the leftmost
3681 * group with average free space.
3682 */
3683 if (bmp->db_agfree[bmp->db_agpref] < avgfree) {
3684 for (bmp->db_agpref = 0; bmp->db_agpref < actags;
3685 bmp->db_agpref++) {
3686 if (bmp->db_agfree[bmp->db_agpref] >= avgfree)
3687 break;
3688 }
3689 if (bmp->db_agpref >= bmp->db_numag) {
3690 jfs_error(ipbmap->i_sb,
3691 "cannot find ag with average freespace\n");
3692 }
3693 }
3694
3695 /*
3696 * compute db_aglevel, db_agheight, db_width, db_agstart:
3697 * an ag is covered in aglevel dmapctl summary tree,
3698 * at agheight level height (from leaf) with agwidth number of nodes
3699 * each, which starts at agstart index node of the smmary tree node
3700 * array;
3701 */
3702 bmp->db_aglevel = BMAPSZTOLEV(bmp->db_agsize);
3703 l2nl =
3704 bmp->db_agl2size - (L2BPERDMAP + bmp->db_aglevel * L2LPERCTL);
3705 bmp->db_agheight = l2nl >> 1;
3706 bmp->db_agwidth = 1 << (l2nl - (bmp->db_agheight << 1));
3707 for (i = 5 - bmp->db_agheight, bmp->db_agstart = 0, n = 1; i > 0;
3708 i--) {
3709 bmp->db_agstart += n;
3710 n <<= 2;
3711 }
3712
3713}
3714
3715
3716/*
3717 * NAME: dbInitDmap()/ujfs_idmap_page()
3718 *
3719 * FUNCTION: initialize working/persistent bitmap of the dmap page
3720 * for the specified number of blocks:
3721 *
3722 * at entry, the bitmaps had been initialized as free (ZEROS);
3723 * The number of blocks will only account for the actually
3724 * existing blocks. Blocks which don't actually exist in
3725 * the aggregate will be marked as allocated (ONES);
3726 *
3727 * PARAMETERS:
3728 * dp - pointer to page of map
3729 * nblocks - number of blocks this page
3730 *
3731 * RETURNS: NONE
3732 */
3733static int dbInitDmap(struct dmap * dp, s64 Blkno, int nblocks)
3734{
3735 int blkno, w, b, r, nw, nb, i;
3736
3737 /* starting block number within the dmap */
3738 blkno = Blkno & (BPERDMAP - 1);
3739
3740 if (blkno == 0) {
3741 dp->nblocks = dp->nfree = cpu_to_le32(nblocks);
3742 dp->start = cpu_to_le64(Blkno);
3743
3744 if (nblocks == BPERDMAP) {
3745 memset(&dp->wmap[0], 0, LPERDMAP * 4);
3746 memset(&dp->pmap[0], 0, LPERDMAP * 4);
3747 goto initTree;
3748 }
3749 } else {
3750 le32_add_cpu(&dp->nblocks, nblocks);
3751 le32_add_cpu(&dp->nfree, nblocks);
3752 }
3753
3754 /* word number containing start block number */
3755 w = blkno >> L2DBWORD;
3756
3757 /*
3758 * free the bits corresponding to the block range (ZEROS):
3759 * note: not all bits of the first and last words may be contained
3760 * within the block range.
3761 */
3762 for (r = nblocks; r > 0; r -= nb, blkno += nb) {
3763 /* number of bits preceding range to be freed in the word */
3764 b = blkno & (DBWORD - 1);
3765 /* number of bits to free in the word */
3766 nb = min(r, DBWORD - b);
3767
3768 /* is partial word to be freed ? */
3769 if (nb < DBWORD) {
3770 /* free (set to 0) from the bitmap word */
3771 dp->wmap[w] &= cpu_to_le32(~(ONES << (DBWORD - nb)
3772 >> b));
3773 dp->pmap[w] &= cpu_to_le32(~(ONES << (DBWORD - nb)
3774 >> b));
3775
3776 /* skip the word freed */
3777 w++;
3778 } else {
3779 /* free (set to 0) contiguous bitmap words */
3780 nw = r >> L2DBWORD;
3781 memset(&dp->wmap[w], 0, nw * 4);
3782 memset(&dp->pmap[w], 0, nw * 4);
3783
3784 /* skip the words freed */
3785 nb = nw << L2DBWORD;
3786 w += nw;
3787 }
3788 }
3789
3790 /*
3791 * mark bits following the range to be freed (non-existing
3792 * blocks) as allocated (ONES)
3793 */
3794
3795 if (blkno == BPERDMAP)
3796 goto initTree;
3797
3798 /* the first word beyond the end of existing blocks */
3799 w = blkno >> L2DBWORD;
3800
3801 /* does nblocks fall on a 32-bit boundary ? */
3802 b = blkno & (DBWORD - 1);
3803 if (b) {
3804 /* mark a partial word allocated */
3805 dp->wmap[w] = dp->pmap[w] = cpu_to_le32(ONES >> b);
3806 w++;
3807 }
3808
3809 /* set the rest of the words in the page to allocated (ONES) */
3810 for (i = w; i < LPERDMAP; i++)
3811 dp->pmap[i] = dp->wmap[i] = cpu_to_le32(ONES);
3812
3813 /*
3814 * init tree
3815 */
3816 initTree:
3817 return (dbInitDmapTree(dp));
3818}
3819
3820
3821/*
3822 * NAME: dbInitDmapTree()/ujfs_complete_dmap()
3823 *
3824 * FUNCTION: initialize summary tree of the specified dmap:
3825 *
3826 * at entry, bitmap of the dmap has been initialized;
3827 *
3828 * PARAMETERS:
3829 * dp - dmap to complete
3830 * blkno - starting block number for this dmap
3831 * treemax - will be filled in with max free for this dmap
3832 *
3833 * RETURNS: max free string at the root of the tree
3834 */
3835static int dbInitDmapTree(struct dmap * dp)
3836{
3837 struct dmaptree *tp;
3838 s8 *cp;
3839 int i;
3840
3841 /* init fixed info of tree */
3842 tp = &dp->tree;
3843 tp->nleafs = cpu_to_le32(LPERDMAP);
3844 tp->l2nleafs = cpu_to_le32(L2LPERDMAP);
3845 tp->leafidx = cpu_to_le32(LEAFIND);
3846 tp->height = cpu_to_le32(4);
3847 tp->budmin = BUDMIN;
3848
3849 /* init each leaf from corresponding wmap word:
3850 * note: leaf is set to NOFREE(-1) if all blocks of corresponding
3851 * bitmap word are allocated.
3852 */
3853 cp = tp->stree + le32_to_cpu(tp->leafidx);
3854 for (i = 0; i < LPERDMAP; i++)
3855 *cp++ = dbMaxBud((u8 *) & dp->wmap[i]);
3856
3857 /* build the dmap's binary buddy summary tree */
3858 return (dbInitTree(tp));
3859}
3860
3861
3862/*
3863 * NAME: dbInitTree()/ujfs_adjtree()
3864 *
3865 * FUNCTION: initialize binary buddy summary tree of a dmap or dmapctl.
3866 *
3867 * at entry, the leaves of the tree has been initialized
3868 * from corresponding bitmap word or root of summary tree
3869 * of the child control page;
3870 * configure binary buddy system at the leaf level, then
3871 * bubble up the values of the leaf nodes up the tree.
3872 *
3873 * PARAMETERS:
3874 * cp - Pointer to the root of the tree
3875 * l2leaves- Number of leaf nodes as a power of 2
3876 * l2min - Number of blocks that can be covered by a leaf
3877 * as a power of 2
3878 *
3879 * RETURNS: max free string at the root of the tree
3880 */
3881static int dbInitTree(struct dmaptree * dtp)
3882{
3883 int l2max, l2free, bsize, nextb, i;
3884 int child, parent, nparent;
3885 s8 *tp, *cp, *cp1;
3886
3887 tp = dtp->stree;
3888
3889 /* Determine the maximum free string possible for the leaves */
3890 l2max = le32_to_cpu(dtp->l2nleafs) + dtp->budmin;
3891
3892 /*
3893 * configure the leaf level into binary buddy system
3894 *
3895 * Try to combine buddies starting with a buddy size of 1
3896 * (i.e. two leaves). At a buddy size of 1 two buddy leaves
3897 * can be combined if both buddies have a maximum free of l2min;
3898 * the combination will result in the left-most buddy leaf having
3899 * a maximum free of l2min+1.
3900 * After processing all buddies for a given size, process buddies
3901 * at the next higher buddy size (i.e. current size * 2) and
3902 * the next maximum free (current free + 1).
3903 * This continues until the maximum possible buddy combination
3904 * yields maximum free.
3905 */
3906 for (l2free = dtp->budmin, bsize = 1; l2free < l2max;
3907 l2free++, bsize = nextb) {
3908 /* get next buddy size == current buddy pair size */
3909 nextb = bsize << 1;
3910
3911 /* scan each adjacent buddy pair at current buddy size */
3912 for (i = 0, cp = tp + le32_to_cpu(dtp->leafidx);
3913 i < le32_to_cpu(dtp->nleafs);
3914 i += nextb, cp += nextb) {
3915 /* coalesce if both adjacent buddies are max free */
3916 if (*cp == l2free && *(cp + bsize) == l2free) {
3917 *cp = l2free + 1; /* left take right */
3918 *(cp + bsize) = -1; /* right give left */
3919 }
3920 }
3921 }
3922
3923 /*
3924 * bubble summary information of leaves up the tree.
3925 *
3926 * Starting at the leaf node level, the four nodes described by
3927 * the higher level parent node are compared for a maximum free and
3928 * this maximum becomes the value of the parent node.
3929 * when all lower level nodes are processed in this fashion then
3930 * move up to the next level (parent becomes a lower level node) and
3931 * continue the process for that level.
3932 */
3933 for (child = le32_to_cpu(dtp->leafidx),
3934 nparent = le32_to_cpu(dtp->nleafs) >> 2;
3935 nparent > 0; nparent >>= 2, child = parent) {
3936 /* get index of 1st node of parent level */
3937 parent = (child - 1) >> 2;
3938
3939 /* set the value of the parent node as the maximum
3940 * of the four nodes of the current level.
3941 */
3942 for (i = 0, cp = tp + child, cp1 = tp + parent;
3943 i < nparent; i++, cp += 4, cp1++)
3944 *cp1 = TREEMAX(cp);
3945 }
3946
3947 return (*tp);
3948}
3949
3950
3951/*
3952 * dbInitDmapCtl()
3953 *
3954 * function: initialize dmapctl page
3955 */
3956static int dbInitDmapCtl(struct dmapctl * dcp, int level, int i)
3957{ /* start leaf index not covered by range */
3958 s8 *cp;
3959
3960 dcp->nleafs = cpu_to_le32(LPERCTL);
3961 dcp->l2nleafs = cpu_to_le32(L2LPERCTL);
3962 dcp->leafidx = cpu_to_le32(CTLLEAFIND);
3963 dcp->height = cpu_to_le32(5);
3964 dcp->budmin = L2BPERDMAP + L2LPERCTL * level;
3965
3966 /*
3967 * initialize the leaves of current level that were not covered
3968 * by the specified input block range (i.e. the leaves have no
3969 * low level dmapctl or dmap).
3970 */
3971 cp = &dcp->stree[CTLLEAFIND + i];
3972 for (; i < LPERCTL; i++)
3973 *cp++ = NOFREE;
3974
3975 /* build the dmap's binary buddy summary tree */
3976 return (dbInitTree((struct dmaptree *) dcp));
3977}
3978
3979
3980/*
3981 * NAME: dbGetL2AGSize()/ujfs_getagl2size()
3982 *
3983 * FUNCTION: Determine log2(allocation group size) from aggregate size
3984 *
3985 * PARAMETERS:
3986 * nblocks - Number of blocks in aggregate
3987 *
3988 * RETURNS: log2(allocation group size) in aggregate blocks
3989 */
3990static int dbGetL2AGSize(s64 nblocks)
3991{
3992 s64 sz;
3993 s64 m;
3994 int l2sz;
3995
3996 if (nblocks < BPERDMAP * MAXAG)
3997 return (L2BPERDMAP);
3998
3999 /* round up aggregate size to power of 2 */
4000 m = ((u64) 1 << (64 - 1));
4001 for (l2sz = 64; l2sz >= 0; l2sz--, m >>= 1) {
4002 if (m & nblocks)
4003 break;
4004 }
4005
4006 sz = (s64) 1 << l2sz;
4007 if (sz < nblocks)
4008 l2sz += 1;
4009
4010 /* agsize = roundupSize/max_number_of_ag */
4011 return (l2sz - L2MAXAG);
4012}
4013
4014
4015/*
4016 * NAME: dbMapFileSizeToMapSize()
4017 *
4018 * FUNCTION: compute number of blocks the block allocation map file
4019 * can cover from the map file size;
4020 *
4021 * RETURNS: Number of blocks which can be covered by this block map file;
4022 */
4023
4024/*
4025 * maximum number of map pages at each level including control pages
4026 */
4027#define MAXL0PAGES (1 + LPERCTL)
4028#define MAXL1PAGES (1 + LPERCTL * MAXL0PAGES)
4029
4030/*
4031 * convert number of map pages to the zero origin top dmapctl level
4032 */
4033#define BMAPPGTOLEV(npages) \
4034 (((npages) <= 3 + MAXL0PAGES) ? 0 : \
4035 ((npages) <= 2 + MAXL1PAGES) ? 1 : 2)
4036
4037s64 dbMapFileSizeToMapSize(struct inode * ipbmap)
4038{
4039 struct super_block *sb = ipbmap->i_sb;
4040 s64 nblocks;
4041 s64 npages, ndmaps;
4042 int level, i;
4043 int complete, factor;
4044
4045 nblocks = ipbmap->i_size >> JFS_SBI(sb)->l2bsize;
4046 npages = nblocks >> JFS_SBI(sb)->l2nbperpage;
4047 level = BMAPPGTOLEV(npages);
4048
4049 /* At each level, accumulate the number of dmap pages covered by
4050 * the number of full child levels below it;
4051 * repeat for the last incomplete child level.
4052 */
4053 ndmaps = 0;
4054 npages--; /* skip the first global control page */
4055 /* skip higher level control pages above top level covered by map */
4056 npages -= (2 - level);
4057 npages--; /* skip top level's control page */
4058 for (i = level; i >= 0; i--) {
4059 factor =
4060 (i == 2) ? MAXL1PAGES : ((i == 1) ? MAXL0PAGES : 1);
4061 complete = (u32) npages / factor;
4062 ndmaps += complete * ((i == 2) ? LPERCTL * LPERCTL :
4063 ((i == 1) ? LPERCTL : 1));
4064
4065 /* pages in last/incomplete child */
4066 npages = (u32) npages % factor;
4067 /* skip incomplete child's level control page */
4068 npages--;
4069 }
4070
4071 /* convert the number of dmaps into the number of blocks
4072 * which can be covered by the dmaps;
4073 */
4074 nblocks = ndmaps << L2BPERDMAP;
4075
4076 return (nblocks);
4077}