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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);
67static int dbBackSplit(dmtree_t * tp, int leafno);
68static int dbJoin(dmtree_t * tp, int leafno, int newval);
69static void dbAdjTree(dmtree_t * tp, int leafno, int newval);
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);
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 */
152int dbMount(struct inode *ipbmap)
153{
154 struct bmap *bmp;
155 struct dbmap_disk *dbmp_le;
156 struct metapage *mp;
157 int i;
158
159 /*
160 * allocate/initialize the in-memory bmap descriptor
161 */
162 /* allocate memory for the in-memory bmap descriptor */
163 bmp = kmalloc(sizeof(struct bmap), GFP_KERNEL);
164 if (bmp == NULL)
165 return -ENOMEM;
166
167 /* read the on-disk bmap descriptor. */
168 mp = read_metapage(ipbmap,
169 BMAPBLKNO << JFS_SBI(ipbmap->i_sb)->l2nbperpage,
170 PSIZE, 0);
171 if (mp == NULL) {
172 kfree(bmp);
173 return -EIO;
174 }
175
176 /* copy the on-disk bmap descriptor to its in-memory version. */
177 dbmp_le = (struct dbmap_disk *) mp->data;
178 bmp->db_mapsize = le64_to_cpu(dbmp_le->dn_mapsize);
179 bmp->db_nfree = le64_to_cpu(dbmp_le->dn_nfree);
180 bmp->db_l2nbperpage = le32_to_cpu(dbmp_le->dn_l2nbperpage);
181 bmp->db_numag = le32_to_cpu(dbmp_le->dn_numag);
182 bmp->db_maxlevel = le32_to_cpu(dbmp_le->dn_maxlevel);
183 bmp->db_maxag = le32_to_cpu(dbmp_le->dn_maxag);
184 bmp->db_agpref = le32_to_cpu(dbmp_le->dn_agpref);
185 bmp->db_aglevel = le32_to_cpu(dbmp_le->dn_aglevel);
186 bmp->db_agheight = le32_to_cpu(dbmp_le->dn_agheight);
187 bmp->db_agwidth = le32_to_cpu(dbmp_le->dn_agwidth);
188 bmp->db_agstart = le32_to_cpu(dbmp_le->dn_agstart);
189 bmp->db_agl2size = le32_to_cpu(dbmp_le->dn_agl2size);
190 for (i = 0; i < MAXAG; i++)
191 bmp->db_agfree[i] = le64_to_cpu(dbmp_le->dn_agfree[i]);
192 bmp->db_agsize = le64_to_cpu(dbmp_le->dn_agsize);
193 bmp->db_maxfreebud = dbmp_le->dn_maxfreebud;
194
195 /* release the buffer. */
196 release_metapage(mp);
197
198 /* bind the bmap inode and the bmap descriptor to each other. */
199 bmp->db_ipbmap = ipbmap;
200 JFS_SBI(ipbmap->i_sb)->bmap = bmp;
201
202 memset(bmp->db_active, 0, sizeof(bmp->db_active));
203
204 /*
205 * allocate/initialize the bmap lock
206 */
207 BMAP_LOCK_INIT(bmp);
208
209 return (0);
210}
211
212
213/*
214 * NAME: dbUnmount()
215 *
216 * FUNCTION: terminate the block allocation map in preparation for
217 * file system unmount.
218 *
219 * the in-core bmap descriptor is written to disk and
220 * the memory for this descriptor is freed.
221 *
222 * PARAMETERS:
223 * ipbmap - pointer to in-core inode for the block map.
224 *
225 * RETURN VALUES:
226 * 0 - success
227 * -EIO - i/o error
228 */
229int dbUnmount(struct inode *ipbmap, int mounterror)
230{
231 struct bmap *bmp = JFS_SBI(ipbmap->i_sb)->bmap;
232
233 if (!(mounterror || isReadOnly(ipbmap)))
234 dbSync(ipbmap);
235
236 /*
237 * Invalidate the page cache buffers
238 */
239 truncate_inode_pages(ipbmap->i_mapping, 0);
240
241 /* free the memory for the in-memory bmap. */
242 kfree(bmp);
243
244 return (0);
245}
246
247/*
248 * dbSync()
249 */
250int dbSync(struct inode *ipbmap)
251{
252 struct dbmap_disk *dbmp_le;
253 struct bmap *bmp = JFS_SBI(ipbmap->i_sb)->bmap;
254 struct metapage *mp;
255 int i;
256
257 /*
258 * write bmap global control page
259 */
260 /* get the buffer for the on-disk bmap descriptor. */
261 mp = read_metapage(ipbmap,
262 BMAPBLKNO << JFS_SBI(ipbmap->i_sb)->l2nbperpage,
263 PSIZE, 0);
264 if (mp == NULL) {
265 jfs_err("dbSync: read_metapage failed!");
266 return -EIO;
267 }
268 /* copy the in-memory version of the bmap to the on-disk version */
269 dbmp_le = (struct dbmap_disk *) mp->data;
270 dbmp_le->dn_mapsize = cpu_to_le64(bmp->db_mapsize);
271 dbmp_le->dn_nfree = cpu_to_le64(bmp->db_nfree);
272 dbmp_le->dn_l2nbperpage = cpu_to_le32(bmp->db_l2nbperpage);
273 dbmp_le->dn_numag = cpu_to_le32(bmp->db_numag);
274 dbmp_le->dn_maxlevel = cpu_to_le32(bmp->db_maxlevel);
275 dbmp_le->dn_maxag = cpu_to_le32(bmp->db_maxag);
276 dbmp_le->dn_agpref = cpu_to_le32(bmp->db_agpref);
277 dbmp_le->dn_aglevel = cpu_to_le32(bmp->db_aglevel);
278 dbmp_le->dn_agheight = cpu_to_le32(bmp->db_agheight);
279 dbmp_le->dn_agwidth = cpu_to_le32(bmp->db_agwidth);
280 dbmp_le->dn_agstart = cpu_to_le32(bmp->db_agstart);
281 dbmp_le->dn_agl2size = cpu_to_le32(bmp->db_agl2size);
282 for (i = 0; i < MAXAG; i++)
283 dbmp_le->dn_agfree[i] = cpu_to_le64(bmp->db_agfree[i]);
284 dbmp_le->dn_agsize = cpu_to_le64(bmp->db_agsize);
285 dbmp_le->dn_maxfreebud = bmp->db_maxfreebud;
286
287 /* write the buffer */
288 write_metapage(mp);
289
290 /*
291 * write out dirty pages of bmap
292 */
293 filemap_write_and_wait(ipbmap->i_mapping);
294
295 diWriteSpecial(ipbmap, 0);
296
297 return (0);
298}
299
300/*
301 * NAME: dbFree()
302 *
303 * FUNCTION: free the specified block range from the working block
304 * allocation map.
305 *
306 * the blocks will be free from the working map one dmap
307 * at a time.
308 *
309 * PARAMETERS:
310 * ip - pointer to in-core inode;
311 * blkno - starting block number to be freed.
312 * nblocks - number of blocks to be freed.
313 *
314 * RETURN VALUES:
315 * 0 - success
316 * -EIO - i/o error
317 */
318int dbFree(struct inode *ip, s64 blkno, s64 nblocks)
319{
320 struct metapage *mp;
321 struct dmap *dp;
322 int nb, rc;
323 s64 lblkno, rem;
324 struct inode *ipbmap = JFS_SBI(ip->i_sb)->ipbmap;
325 struct bmap *bmp = JFS_SBI(ip->i_sb)->bmap;
326 struct super_block *sb = ipbmap->i_sb;
327
328 IREAD_LOCK(ipbmap, RDWRLOCK_DMAP);
329
330 /* block to be freed better be within the mapsize. */
331 if (unlikely((blkno == 0) || (blkno + nblocks > bmp->db_mapsize))) {
332 IREAD_UNLOCK(ipbmap);
333 printk(KERN_ERR "blkno = %Lx, nblocks = %Lx\n",
334 (unsigned long long) blkno,
335 (unsigned long long) nblocks);
336 jfs_error(ip->i_sb, "block to be freed is outside the map\n");
337 return -EIO;
338 }
339
340 /**
341 * TRIM the blocks, when mounted with discard option
342 */
343 if (JFS_SBI(sb)->flag & JFS_DISCARD)
344 if (JFS_SBI(sb)->minblks_trim <= nblocks)
345 jfs_issue_discard(ipbmap, blkno, nblocks);
346
347 /*
348 * free the blocks a dmap at a time.
349 */
350 mp = NULL;
351 for (rem = nblocks; rem > 0; rem -= nb, blkno += nb) {
352 /* release previous dmap if any */
353 if (mp) {
354 write_metapage(mp);
355 }
356
357 /* get the buffer for the current dmap. */
358 lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage);
359 mp = read_metapage(ipbmap, lblkno, PSIZE, 0);
360 if (mp == NULL) {
361 IREAD_UNLOCK(ipbmap);
362 return -EIO;
363 }
364 dp = (struct dmap *) mp->data;
365
366 /* determine the number of blocks to be freed from
367 * this dmap.
368 */
369 nb = min(rem, BPERDMAP - (blkno & (BPERDMAP - 1)));
370
371 /* free the blocks. */
372 if ((rc = dbFreeDmap(bmp, dp, blkno, nb))) {
373 jfs_error(ip->i_sb, "error in block map\n");
374 release_metapage(mp);
375 IREAD_UNLOCK(ipbmap);
376 return (rc);
377 }
378 }
379
380 /* write the last buffer. */
381 write_metapage(mp);
382
383 IREAD_UNLOCK(ipbmap);
384
385 return (0);
386}
387
388
389/*
390 * NAME: dbUpdatePMap()
391 *
392 * FUNCTION: update the allocation state (free or allocate) of the
393 * specified block range in the persistent block allocation map.
394 *
395 * the blocks will be updated in the persistent map one
396 * dmap at a time.
397 *
398 * PARAMETERS:
399 * ipbmap - pointer to in-core inode for the block map.
400 * free - 'true' if block range is to be freed from the persistent
401 * map; 'false' if it is to be allocated.
402 * blkno - starting block number of the range.
403 * nblocks - number of contiguous blocks in the range.
404 * tblk - transaction block;
405 *
406 * RETURN VALUES:
407 * 0 - success
408 * -EIO - i/o error
409 */
410int
411dbUpdatePMap(struct inode *ipbmap,
412 int free, s64 blkno, s64 nblocks, struct tblock * tblk)
413{
414 int nblks, dbitno, wbitno, rbits;
415 int word, nbits, nwords;
416 struct bmap *bmp = JFS_SBI(ipbmap->i_sb)->bmap;
417 s64 lblkno, rem, lastlblkno;
418 u32 mask;
419 struct dmap *dp;
420 struct metapage *mp;
421 struct jfs_log *log;
422 int lsn, difft, diffp;
423 unsigned long flags;
424
425 /* the blocks better be within the mapsize. */
426 if (blkno + nblocks > bmp->db_mapsize) {
427 printk(KERN_ERR "blkno = %Lx, nblocks = %Lx\n",
428 (unsigned long long) blkno,
429 (unsigned long long) nblocks);
430 jfs_error(ipbmap->i_sb, "blocks are outside the map\n");
431 return -EIO;
432 }
433
434 /* compute delta of transaction lsn from log syncpt */
435 lsn = tblk->lsn;
436 log = (struct jfs_log *) JFS_SBI(tblk->sb)->log;
437 logdiff(difft, lsn, log);
438
439 /*
440 * update the block state a dmap at a time.
441 */
442 mp = NULL;
443 lastlblkno = 0;
444 for (rem = nblocks; rem > 0; rem -= nblks, blkno += nblks) {
445 /* get the buffer for the current dmap. */
446 lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage);
447 if (lblkno != lastlblkno) {
448 if (mp) {
449 write_metapage(mp);
450 }
451
452 mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE,
453 0);
454 if (mp == NULL)
455 return -EIO;
456 metapage_wait_for_io(mp);
457 }
458 dp = (struct dmap *) mp->data;
459
460 /* determine the bit number and word within the dmap of
461 * the starting block. also determine how many blocks
462 * are to be updated within this dmap.
463 */
464 dbitno = blkno & (BPERDMAP - 1);
465 word = dbitno >> L2DBWORD;
466 nblks = min(rem, (s64)BPERDMAP - dbitno);
467
468 /* update the bits of the dmap words. the first and last
469 * words may only have a subset of their bits updated. if
470 * this is the case, we'll work against that word (i.e.
471 * partial first and/or last) only in a single pass. a
472 * single pass will also be used to update all words that
473 * are to have all their bits updated.
474 */
475 for (rbits = nblks; rbits > 0;
476 rbits -= nbits, dbitno += nbits) {
477 /* determine the bit number within the word and
478 * the number of bits within the word.
479 */
480 wbitno = dbitno & (DBWORD - 1);
481 nbits = min(rbits, DBWORD - wbitno);
482
483 /* check if only part of the word is to be updated. */
484 if (nbits < DBWORD) {
485 /* update (free or allocate) the bits
486 * in this word.
487 */
488 mask =
489 (ONES << (DBWORD - nbits) >> wbitno);
490 if (free)
491 dp->pmap[word] &=
492 cpu_to_le32(~mask);
493 else
494 dp->pmap[word] |=
495 cpu_to_le32(mask);
496
497 word += 1;
498 } else {
499 /* one or more words are to have all
500 * their bits updated. determine how
501 * many words and how many bits.
502 */
503 nwords = rbits >> L2DBWORD;
504 nbits = nwords << L2DBWORD;
505
506 /* update (free or allocate) the bits
507 * in these words.
508 */
509 if (free)
510 memset(&dp->pmap[word], 0,
511 nwords * 4);
512 else
513 memset(&dp->pmap[word], (int) ONES,
514 nwords * 4);
515
516 word += nwords;
517 }
518 }
519
520 /*
521 * update dmap lsn
522 */
523 if (lblkno == lastlblkno)
524 continue;
525
526 lastlblkno = lblkno;
527
528 LOGSYNC_LOCK(log, flags);
529 if (mp->lsn != 0) {
530 /* inherit older/smaller lsn */
531 logdiff(diffp, mp->lsn, log);
532 if (difft < diffp) {
533 mp->lsn = lsn;
534
535 /* move bp after tblock in logsync list */
536 list_move(&mp->synclist, &tblk->synclist);
537 }
538
539 /* inherit younger/larger clsn */
540 logdiff(difft, tblk->clsn, log);
541 logdiff(diffp, mp->clsn, log);
542 if (difft > diffp)
543 mp->clsn = tblk->clsn;
544 } else {
545 mp->log = log;
546 mp->lsn = lsn;
547
548 /* insert bp after tblock in logsync list */
549 log->count++;
550 list_add(&mp->synclist, &tblk->synclist);
551
552 mp->clsn = tblk->clsn;
553 }
554 LOGSYNC_UNLOCK(log, flags);
555 }
556
557 /* write the last buffer. */
558 if (mp) {
559 write_metapage(mp);
560 }
561
562 return (0);
563}
564
565
566/*
567 * NAME: dbNextAG()
568 *
569 * FUNCTION: find the preferred allocation group for new allocations.
570 *
571 * Within the allocation groups, we maintain a preferred
572 * allocation group which consists of a group with at least
573 * average free space. It is the preferred group that we target
574 * new inode allocation towards. The tie-in between inode
575 * allocation and block allocation occurs as we allocate the
576 * first (data) block of an inode and specify the inode (block)
577 * as the allocation hint for this block.
578 *
579 * We try to avoid having more than one open file growing in
580 * an allocation group, as this will lead to fragmentation.
581 * This differs from the old OS/2 method of trying to keep
582 * empty ags around for large allocations.
583 *
584 * PARAMETERS:
585 * ipbmap - pointer to in-core inode for the block map.
586 *
587 * RETURN VALUES:
588 * the preferred allocation group number.
589 */
590int dbNextAG(struct inode *ipbmap)
591{
592 s64 avgfree;
593 int agpref;
594 s64 hwm = 0;
595 int i;
596 int next_best = -1;
597 struct bmap *bmp = JFS_SBI(ipbmap->i_sb)->bmap;
598
599 BMAP_LOCK(bmp);
600
601 /* determine the average number of free blocks within the ags. */
602 avgfree = (u32)bmp->db_nfree / bmp->db_numag;
603
604 /*
605 * if the current preferred ag does not have an active allocator
606 * and has at least average freespace, return it
607 */
608 agpref = bmp->db_agpref;
609 if ((atomic_read(&bmp->db_active[agpref]) == 0) &&
610 (bmp->db_agfree[agpref] >= avgfree))
611 goto unlock;
612
613 /* From the last preferred ag, find the next one with at least
614 * average free space.
615 */
616 for (i = 0 ; i < bmp->db_numag; i++, agpref++) {
617 if (agpref == bmp->db_numag)
618 agpref = 0;
619
620 if (atomic_read(&bmp->db_active[agpref]))
621 /* open file is currently growing in this ag */
622 continue;
623 if (bmp->db_agfree[agpref] >= avgfree) {
624 /* Return this one */
625 bmp->db_agpref = agpref;
626 goto unlock;
627 } else if (bmp->db_agfree[agpref] > hwm) {
628 /* Less than avg. freespace, but best so far */
629 hwm = bmp->db_agfree[agpref];
630 next_best = agpref;
631 }
632 }
633
634 /*
635 * If no inactive ag was found with average freespace, use the
636 * next best
637 */
638 if (next_best != -1)
639 bmp->db_agpref = next_best;
640 /* else leave db_agpref unchanged */
641unlock:
642 BMAP_UNLOCK(bmp);
643
644 /* return the preferred group.
645 */
646 return (bmp->db_agpref);
647}
648
649/*
650 * NAME: dbAlloc()
651 *
652 * FUNCTION: attempt to allocate a specified number of contiguous free
653 * blocks from the working allocation block map.
654 *
655 * the block allocation policy uses hints and a multi-step
656 * approach.
657 *
658 * for allocation requests smaller than the number of blocks
659 * per dmap, we first try to allocate the new blocks
660 * immediately following the hint. if these blocks are not
661 * available, we try to allocate blocks near the hint. if
662 * no blocks near the hint are available, we next try to
663 * allocate within the same dmap as contains the hint.
664 *
665 * if no blocks are available in the dmap or the allocation
666 * request is larger than the dmap size, we try to allocate
667 * within the same allocation group as contains the hint. if
668 * this does not succeed, we finally try to allocate anywhere
669 * within the aggregate.
670 *
671 * we also try to allocate anywhere within the aggregate for
672 * for allocation requests larger than the allocation group
673 * size or requests that specify no hint value.
674 *
675 * PARAMETERS:
676 * ip - pointer to in-core inode;
677 * hint - allocation hint.
678 * nblocks - number of contiguous blocks in the range.
679 * results - on successful return, set to the starting block number
680 * of the newly allocated contiguous range.
681 *
682 * RETURN VALUES:
683 * 0 - success
684 * -ENOSPC - insufficient disk resources
685 * -EIO - i/o error
686 */
687int dbAlloc(struct inode *ip, s64 hint, s64 nblocks, s64 * results)
688{
689 int rc, agno;
690 struct inode *ipbmap = JFS_SBI(ip->i_sb)->ipbmap;
691 struct bmap *bmp;
692 struct metapage *mp;
693 s64 lblkno, blkno;
694 struct dmap *dp;
695 int l2nb;
696 s64 mapSize;
697 int writers;
698
699 /* assert that nblocks is valid */
700 assert(nblocks > 0);
701
702 /* get the log2 number of blocks to be allocated.
703 * if the number of blocks is not a log2 multiple,
704 * it will be rounded up to the next log2 multiple.
705 */
706 l2nb = BLKSTOL2(nblocks);
707
708 bmp = JFS_SBI(ip->i_sb)->bmap;
709
710 mapSize = bmp->db_mapsize;
711
712 /* the hint should be within the map */
713 if (hint >= mapSize) {
714 jfs_error(ip->i_sb, "the hint is outside the map\n");
715 return -EIO;
716 }
717
718 /* if the number of blocks to be allocated is greater than the
719 * allocation group size, try to allocate anywhere.
720 */
721 if (l2nb > bmp->db_agl2size) {
722 IWRITE_LOCK(ipbmap, RDWRLOCK_DMAP);
723
724 rc = dbAllocAny(bmp, nblocks, l2nb, results);
725
726 goto write_unlock;
727 }
728
729 /*
730 * If no hint, let dbNextAG recommend an allocation group
731 */
732 if (hint == 0)
733 goto pref_ag;
734
735 /* we would like to allocate close to the hint. adjust the
736 * hint to the block following the hint since the allocators
737 * will start looking for free space starting at this point.
738 */
739 blkno = hint + 1;
740
741 if (blkno >= bmp->db_mapsize)
742 goto pref_ag;
743
744 agno = blkno >> bmp->db_agl2size;
745
746 /* check if blkno crosses over into a new allocation group.
747 * if so, check if we should allow allocations within this
748 * allocation group.
749 */
750 if ((blkno & (bmp->db_agsize - 1)) == 0)
751 /* check if the AG is currently being written to.
752 * if so, call dbNextAG() to find a non-busy
753 * AG with sufficient free space.
754 */
755 if (atomic_read(&bmp->db_active[agno]))
756 goto pref_ag;
757
758 /* check if the allocation request size can be satisfied from a
759 * single dmap. if so, try to allocate from the dmap containing
760 * the hint using a tiered strategy.
761 */
762 if (nblocks <= BPERDMAP) {
763 IREAD_LOCK(ipbmap, RDWRLOCK_DMAP);
764
765 /* get the buffer for the dmap containing the hint.
766 */
767 rc = -EIO;
768 lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage);
769 mp = read_metapage(ipbmap, lblkno, PSIZE, 0);
770 if (mp == NULL)
771 goto read_unlock;
772
773 dp = (struct dmap *) mp->data;
774
775 /* first, try to satisfy the allocation request with the
776 * blocks beginning at the hint.
777 */
778 if ((rc = dbAllocNext(bmp, dp, blkno, (int) nblocks))
779 != -ENOSPC) {
780 if (rc == 0) {
781 *results = blkno;
782 mark_metapage_dirty(mp);
783 }
784
785 release_metapage(mp);
786 goto read_unlock;
787 }
788
789 writers = atomic_read(&bmp->db_active[agno]);
790 if ((writers > 1) ||
791 ((writers == 1) && (JFS_IP(ip)->active_ag != agno))) {
792 /*
793 * Someone else is writing in this allocation
794 * group. To avoid fragmenting, try another ag
795 */
796 release_metapage(mp);
797 IREAD_UNLOCK(ipbmap);
798 goto pref_ag;
799 }
800
801 /* next, try to satisfy the allocation request with blocks
802 * near the hint.
803 */
804 if ((rc =
805 dbAllocNear(bmp, dp, blkno, (int) nblocks, l2nb, results))
806 != -ENOSPC) {
807 if (rc == 0)
808 mark_metapage_dirty(mp);
809
810 release_metapage(mp);
811 goto read_unlock;
812 }
813
814 /* try to satisfy the allocation request with blocks within
815 * the same dmap as the hint.
816 */
817 if ((rc = dbAllocDmapLev(bmp, dp, (int) nblocks, l2nb, results))
818 != -ENOSPC) {
819 if (rc == 0)
820 mark_metapage_dirty(mp);
821
822 release_metapage(mp);
823 goto read_unlock;
824 }
825
826 release_metapage(mp);
827 IREAD_UNLOCK(ipbmap);
828 }
829
830 /* try to satisfy the allocation request with blocks within
831 * the same allocation group as the hint.
832 */
833 IWRITE_LOCK(ipbmap, RDWRLOCK_DMAP);
834 if ((rc = dbAllocAG(bmp, agno, nblocks, l2nb, results)) != -ENOSPC)
835 goto write_unlock;
836
837 IWRITE_UNLOCK(ipbmap);
838
839
840 pref_ag:
841 /*
842 * Let dbNextAG recommend a preferred allocation group
843 */
844 agno = dbNextAG(ipbmap);
845 IWRITE_LOCK(ipbmap, RDWRLOCK_DMAP);
846
847 /* Try to allocate within this allocation group. if that fails, try to
848 * allocate anywhere in the map.
849 */
850 if ((rc = dbAllocAG(bmp, agno, nblocks, l2nb, results)) == -ENOSPC)
851 rc = dbAllocAny(bmp, nblocks, l2nb, results);
852
853 write_unlock:
854 IWRITE_UNLOCK(ipbmap);
855
856 return (rc);
857
858 read_unlock:
859 IREAD_UNLOCK(ipbmap);
860
861 return (rc);
862}
863
864#ifdef _NOTYET
865/*
866 * NAME: dbAllocExact()
867 *
868 * FUNCTION: try to allocate the requested extent;
869 *
870 * PARAMETERS:
871 * ip - pointer to in-core inode;
872 * blkno - extent address;
873 * nblocks - extent length;
874 *
875 * RETURN VALUES:
876 * 0 - success
877 * -ENOSPC - insufficient disk resources
878 * -EIO - i/o error
879 */
880int dbAllocExact(struct inode *ip, s64 blkno, int nblocks)
881{
882 int rc;
883 struct inode *ipbmap = JFS_SBI(ip->i_sb)->ipbmap;
884 struct bmap *bmp = JFS_SBI(ip->i_sb)->bmap;
885 struct dmap *dp;
886 s64 lblkno;
887 struct metapage *mp;
888
889 IREAD_LOCK(ipbmap, RDWRLOCK_DMAP);
890
891 /*
892 * validate extent request:
893 *
894 * note: defragfs policy:
895 * max 64 blocks will be moved.
896 * allocation request size must be satisfied from a single dmap.
897 */
898 if (nblocks <= 0 || nblocks > BPERDMAP || blkno >= bmp->db_mapsize) {
899 IREAD_UNLOCK(ipbmap);
900 return -EINVAL;
901 }
902
903 if (nblocks > ((s64) 1 << bmp->db_maxfreebud)) {
904 /* the free space is no longer available */
905 IREAD_UNLOCK(ipbmap);
906 return -ENOSPC;
907 }
908
909 /* read in the dmap covering the extent */
910 lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage);
911 mp = read_metapage(ipbmap, lblkno, PSIZE, 0);
912 if (mp == NULL) {
913 IREAD_UNLOCK(ipbmap);
914 return -EIO;
915 }
916 dp = (struct dmap *) mp->data;
917
918 /* try to allocate the requested extent */
919 rc = dbAllocNext(bmp, dp, blkno, nblocks);
920
921 IREAD_UNLOCK(ipbmap);
922
923 if (rc == 0)
924 mark_metapage_dirty(mp);
925
926 release_metapage(mp);
927
928 return (rc);
929}
930#endif /* _NOTYET */
931
932/*
933 * NAME: dbReAlloc()
934 *
935 * FUNCTION: attempt to extend a current allocation by a specified
936 * number of blocks.
937 *
938 * this routine attempts to satisfy the allocation request
939 * by first trying to extend the existing allocation in
940 * place by allocating the additional blocks as the blocks
941 * immediately following the current allocation. if these
942 * blocks are not available, this routine will attempt to
943 * allocate a new set of contiguous blocks large enough
944 * to cover the existing allocation plus the additional
945 * number of blocks required.
946 *
947 * PARAMETERS:
948 * ip - pointer to in-core inode requiring allocation.
949 * blkno - starting block of the current allocation.
950 * nblocks - number of contiguous blocks within the current
951 * allocation.
952 * addnblocks - number of blocks to add to the allocation.
953 * results - on successful return, set to the starting block number
954 * of the existing allocation if the existing allocation
955 * was extended in place or to a newly allocated contiguous
956 * range if the existing allocation could not be extended
957 * in place.
958 *
959 * RETURN VALUES:
960 * 0 - success
961 * -ENOSPC - insufficient disk resources
962 * -EIO - i/o error
963 */
964int
965dbReAlloc(struct inode *ip,
966 s64 blkno, s64 nblocks, s64 addnblocks, s64 * results)
967{
968 int rc;
969
970 /* try to extend the allocation in place.
971 */
972 if ((rc = dbExtend(ip, blkno, nblocks, addnblocks)) == 0) {
973 *results = blkno;
974 return (0);
975 } else {
976 if (rc != -ENOSPC)
977 return (rc);
978 }
979
980 /* could not extend the allocation in place, so allocate a
981 * new set of blocks for the entire request (i.e. try to get
982 * a range of contiguous blocks large enough to cover the
983 * existing allocation plus the additional blocks.)
984 */
985 return (dbAlloc
986 (ip, blkno + nblocks - 1, addnblocks + nblocks, results));
987}
988
989
990/*
991 * NAME: dbExtend()
992 *
993 * FUNCTION: attempt to extend a current allocation by a specified
994 * number of blocks.
995 *
996 * this routine attempts to satisfy the allocation request
997 * by first trying to extend the existing allocation in
998 * place by allocating the additional blocks as the blocks
999 * immediately following the current allocation.
1000 *
1001 * PARAMETERS:
1002 * ip - pointer to in-core inode requiring allocation.
1003 * blkno - starting block of the current allocation.
1004 * nblocks - number of contiguous blocks within the current
1005 * allocation.
1006 * addnblocks - number of blocks to add to the allocation.
1007 *
1008 * RETURN VALUES:
1009 * 0 - success
1010 * -ENOSPC - insufficient disk resources
1011 * -EIO - i/o error
1012 */
1013static int dbExtend(struct inode *ip, s64 blkno, s64 nblocks, s64 addnblocks)
1014{
1015 struct jfs_sb_info *sbi = JFS_SBI(ip->i_sb);
1016 s64 lblkno, lastblkno, extblkno;
1017 uint rel_block;
1018 struct metapage *mp;
1019 struct dmap *dp;
1020 int rc;
1021 struct inode *ipbmap = sbi->ipbmap;
1022 struct bmap *bmp;
1023
1024 /*
1025 * We don't want a non-aligned extent to cross a page boundary
1026 */
1027 if (((rel_block = blkno & (sbi->nbperpage - 1))) &&
1028 (rel_block + nblocks + addnblocks > sbi->nbperpage))
1029 return -ENOSPC;
1030
1031 /* get the last block of the current allocation */
1032 lastblkno = blkno + nblocks - 1;
1033
1034 /* determine the block number of the block following
1035 * the existing allocation.
1036 */
1037 extblkno = lastblkno + 1;
1038
1039 IREAD_LOCK(ipbmap, RDWRLOCK_DMAP);
1040
1041 /* better be within the file system */
1042 bmp = sbi->bmap;
1043 if (lastblkno < 0 || lastblkno >= bmp->db_mapsize) {
1044 IREAD_UNLOCK(ipbmap);
1045 jfs_error(ip->i_sb, "the block is outside the filesystem\n");
1046 return -EIO;
1047 }
1048
1049 /* we'll attempt to extend the current allocation in place by
1050 * allocating the additional blocks as the blocks immediately
1051 * following the current allocation. we only try to extend the
1052 * current allocation in place if the number of additional blocks
1053 * can fit into a dmap, the last block of the current allocation
1054 * is not the last block of the file system, and the start of the
1055 * inplace extension is not on an allocation group boundary.
1056 */
1057 if (addnblocks > BPERDMAP || extblkno >= bmp->db_mapsize ||
1058 (extblkno & (bmp->db_agsize - 1)) == 0) {
1059 IREAD_UNLOCK(ipbmap);
1060 return -ENOSPC;
1061 }
1062
1063 /* get the buffer for the dmap containing the first block
1064 * of the extension.
1065 */
1066 lblkno = BLKTODMAP(extblkno, bmp->db_l2nbperpage);
1067 mp = read_metapage(ipbmap, lblkno, PSIZE, 0);
1068 if (mp == NULL) {
1069 IREAD_UNLOCK(ipbmap);
1070 return -EIO;
1071 }
1072
1073 dp = (struct dmap *) mp->data;
1074
1075 /* try to allocate the blocks immediately following the
1076 * current allocation.
1077 */
1078 rc = dbAllocNext(bmp, dp, extblkno, (int) addnblocks);
1079
1080 IREAD_UNLOCK(ipbmap);
1081
1082 /* were we successful ? */
1083 if (rc == 0)
1084 write_metapage(mp);
1085 else
1086 /* we were not successful */
1087 release_metapage(mp);
1088
1089 return (rc);
1090}
1091
1092
1093/*
1094 * NAME: dbAllocNext()
1095 *
1096 * FUNCTION: attempt to allocate the blocks of the specified block
1097 * range within a dmap.
1098 *
1099 * PARAMETERS:
1100 * bmp - pointer to bmap descriptor
1101 * dp - pointer to dmap.
1102 * blkno - starting block number of the range.
1103 * nblocks - number of contiguous free blocks of the range.
1104 *
1105 * RETURN VALUES:
1106 * 0 - success
1107 * -ENOSPC - insufficient disk resources
1108 * -EIO - i/o error
1109 *
1110 * serialization: IREAD_LOCK(ipbmap) held on entry/exit;
1111 */
1112static int dbAllocNext(struct bmap * bmp, struct dmap * dp, s64 blkno,
1113 int nblocks)
1114{
1115 int dbitno, word, rembits, nb, nwords, wbitno, nw;
1116 int l2size;
1117 s8 *leaf;
1118 u32 mask;
1119
1120 if (dp->tree.leafidx != cpu_to_le32(LEAFIND)) {
1121 jfs_error(bmp->db_ipbmap->i_sb, "Corrupt dmap page\n");
1122 return -EIO;
1123 }
1124
1125 /* pick up a pointer to the leaves of the dmap tree.
1126 */
1127 leaf = dp->tree.stree + le32_to_cpu(dp->tree.leafidx);
1128
1129 /* determine the bit number and word within the dmap of the
1130 * starting block.
1131 */
1132 dbitno = blkno & (BPERDMAP - 1);
1133 word = dbitno >> L2DBWORD;
1134
1135 /* check if the specified block range is contained within
1136 * this dmap.
1137 */
1138 if (dbitno + nblocks > BPERDMAP)
1139 return -ENOSPC;
1140
1141 /* check if the starting leaf indicates that anything
1142 * is free.
1143 */
1144 if (leaf[word] == NOFREE)
1145 return -ENOSPC;
1146
1147 /* check the dmaps words corresponding to block range to see
1148 * if the block range is free. not all bits of the first and
1149 * last words may be contained within the block range. if this
1150 * is the case, we'll work against those words (i.e. partial first
1151 * and/or last) on an individual basis (a single pass) and examine
1152 * the actual bits to determine if they are free. a single pass
1153 * will be used for all dmap words fully contained within the
1154 * specified range. within this pass, the leaves of the dmap
1155 * tree will be examined to determine if the blocks are free. a
1156 * single leaf may describe the free space of multiple dmap
1157 * words, so we may visit only a subset of the actual leaves
1158 * corresponding to the dmap words of the block range.
1159 */
1160 for (rembits = nblocks; rembits > 0; rembits -= nb, dbitno += nb) {
1161 /* determine the bit number within the word and
1162 * the number of bits within the word.
1163 */
1164 wbitno = dbitno & (DBWORD - 1);
1165 nb = min(rembits, DBWORD - wbitno);
1166
1167 /* check if only part of the word is to be examined.
1168 */
1169 if (nb < DBWORD) {
1170 /* check if the bits are free.
1171 */
1172 mask = (ONES << (DBWORD - nb) >> wbitno);
1173 if ((mask & ~le32_to_cpu(dp->wmap[word])) != mask)
1174 return -ENOSPC;
1175
1176 word += 1;
1177 } else {
1178 /* one or more dmap words are fully contained
1179 * within the block range. determine how many
1180 * words and how many bits.
1181 */
1182 nwords = rembits >> L2DBWORD;
1183 nb = nwords << L2DBWORD;
1184
1185 /* now examine the appropriate leaves to determine
1186 * if the blocks are free.
1187 */
1188 while (nwords > 0) {
1189 /* does the leaf describe any free space ?
1190 */
1191 if (leaf[word] < BUDMIN)
1192 return -ENOSPC;
1193
1194 /* determine the l2 number of bits provided
1195 * by this leaf.
1196 */
1197 l2size =
1198 min_t(int, leaf[word], NLSTOL2BSZ(nwords));
1199
1200 /* determine how many words were handled.
1201 */
1202 nw = BUDSIZE(l2size, BUDMIN);
1203
1204 nwords -= nw;
1205 word += nw;
1206 }
1207 }
1208 }
1209
1210 /* allocate the blocks.
1211 */
1212 return (dbAllocDmap(bmp, dp, blkno, nblocks));
1213}
1214
1215
1216/*
1217 * NAME: dbAllocNear()
1218 *
1219 * FUNCTION: attempt to allocate a number of contiguous free blocks near
1220 * a specified block (hint) within a dmap.
1221 *
1222 * starting with the dmap leaf that covers the hint, we'll
1223 * check the next four contiguous leaves for sufficient free
1224 * space. if sufficient free space is found, we'll allocate
1225 * the desired free space.
1226 *
1227 * PARAMETERS:
1228 * bmp - pointer to bmap descriptor
1229 * dp - pointer to dmap.
1230 * blkno - block number to allocate near.
1231 * nblocks - actual number of contiguous free blocks desired.
1232 * l2nb - log2 number of contiguous free blocks desired.
1233 * results - on successful return, set to the starting block number
1234 * of the newly allocated range.
1235 *
1236 * RETURN VALUES:
1237 * 0 - success
1238 * -ENOSPC - insufficient disk resources
1239 * -EIO - i/o error
1240 *
1241 * serialization: IREAD_LOCK(ipbmap) held on entry/exit;
1242 */
1243static int
1244dbAllocNear(struct bmap * bmp,
1245 struct dmap * dp, s64 blkno, int nblocks, int l2nb, s64 * results)
1246{
1247 int word, lword, rc;
1248 s8 *leaf;
1249
1250 if (dp->tree.leafidx != cpu_to_le32(LEAFIND)) {
1251 jfs_error(bmp->db_ipbmap->i_sb, "Corrupt dmap page\n");
1252 return -EIO;
1253 }
1254
1255 leaf = dp->tree.stree + le32_to_cpu(dp->tree.leafidx);
1256
1257 /* determine the word within the dmap that holds the hint
1258 * (i.e. blkno). also, determine the last word in the dmap
1259 * that we'll include in our examination.
1260 */
1261 word = (blkno & (BPERDMAP - 1)) >> L2DBWORD;
1262 lword = min(word + 4, LPERDMAP);
1263
1264 /* examine the leaves for sufficient free space.
1265 */
1266 for (; word < lword; word++) {
1267 /* does the leaf describe sufficient free space ?
1268 */
1269 if (leaf[word] < l2nb)
1270 continue;
1271
1272 /* determine the block number within the file system
1273 * of the first block described by this dmap word.
1274 */
1275 blkno = le64_to_cpu(dp->start) + (word << L2DBWORD);
1276
1277 /* if not all bits of the dmap word are free, get the
1278 * starting bit number within the dmap word of the required
1279 * string of free bits and adjust the block number with the
1280 * value.
1281 */
1282 if (leaf[word] < BUDMIN)
1283 blkno +=
1284 dbFindBits(le32_to_cpu(dp->wmap[word]), l2nb);
1285
1286 /* allocate the blocks.
1287 */
1288 if ((rc = dbAllocDmap(bmp, dp, blkno, nblocks)) == 0)
1289 *results = blkno;
1290
1291 return (rc);
1292 }
1293
1294 return -ENOSPC;
1295}
1296
1297
1298/*
1299 * NAME: dbAllocAG()
1300 *
1301 * FUNCTION: attempt to allocate the specified number of contiguous
1302 * free blocks within the specified allocation group.
1303 *
1304 * unless the allocation group size is equal to the number
1305 * of blocks per dmap, the dmap control pages will be used to
1306 * find the required free space, if available. we start the
1307 * search at the highest dmap control page level which
1308 * distinctly describes the allocation group's free space
1309 * (i.e. the highest level at which the allocation group's
1310 * free space is not mixed in with that of any other group).
1311 * in addition, we start the search within this level at a
1312 * height of the dmapctl dmtree at which the nodes distinctly
1313 * describe the allocation group's free space. at this height,
1314 * the allocation group's free space may be represented by 1
1315 * or two sub-trees, depending on the allocation group size.
1316 * we search the top nodes of these subtrees left to right for
1317 * sufficient free space. if sufficient free space is found,
1318 * the subtree is searched to find the leftmost leaf that
1319 * has free space. once we have made it to the leaf, we
1320 * move the search to the next lower level dmap control page
1321 * corresponding to this leaf. we continue down the dmap control
1322 * pages until we find the dmap that contains or starts the
1323 * sufficient free space and we allocate at this dmap.
1324 *
1325 * if the allocation group size is equal to the dmap size,
1326 * we'll start at the dmap corresponding to the allocation
1327 * group and attempt the allocation at this level.
1328 *
1329 * the dmap control page search is also not performed if the
1330 * allocation group is completely free and we go to the first
1331 * dmap of the allocation group to do the allocation. this is
1332 * done because the allocation group may be part (not the first
1333 * part) of a larger binary buddy system, causing the dmap
1334 * control pages to indicate no free space (NOFREE) within
1335 * the allocation group.
1336 *
1337 * PARAMETERS:
1338 * bmp - pointer to bmap descriptor
1339 * agno - allocation group number.
1340 * nblocks - actual number of contiguous free blocks desired.
1341 * l2nb - log2 number of contiguous free blocks desired.
1342 * results - on successful return, set to the starting block number
1343 * of the newly allocated range.
1344 *
1345 * RETURN VALUES:
1346 * 0 - success
1347 * -ENOSPC - insufficient disk resources
1348 * -EIO - i/o error
1349 *
1350 * note: IWRITE_LOCK(ipmap) held on entry/exit;
1351 */
1352static int
1353dbAllocAG(struct bmap * bmp, int agno, s64 nblocks, int l2nb, s64 * results)
1354{
1355 struct metapage *mp;
1356 struct dmapctl *dcp;
1357 int rc, ti, i, k, m, n, agperlev;
1358 s64 blkno, lblkno;
1359 int budmin;
1360
1361 /* allocation request should not be for more than the
1362 * allocation group size.
1363 */
1364 if (l2nb > bmp->db_agl2size) {
1365 jfs_error(bmp->db_ipbmap->i_sb,
1366 "allocation request is larger than the allocation group size\n");
1367 return -EIO;
1368 }
1369
1370 /* determine the starting block number of the allocation
1371 * group.
1372 */
1373 blkno = (s64) agno << bmp->db_agl2size;
1374
1375 /* check if the allocation group size is the minimum allocation
1376 * group size or if the allocation group is completely free. if
1377 * the allocation group size is the minimum size of BPERDMAP (i.e.
1378 * 1 dmap), there is no need to search the dmap control page (below)
1379 * that fully describes the allocation group since the allocation
1380 * group is already fully described by a dmap. in this case, we
1381 * just call dbAllocCtl() to search the dmap tree and allocate the
1382 * required space if available.
1383 *
1384 * if the allocation group is completely free, dbAllocCtl() is
1385 * also called to allocate the required space. this is done for
1386 * two reasons. first, it makes no sense searching the dmap control
1387 * pages for free space when we know that free space exists. second,
1388 * the dmap control pages may indicate that the allocation group
1389 * has no free space if the allocation group is part (not the first
1390 * part) of a larger binary buddy system.
1391 */
1392 if (bmp->db_agsize == BPERDMAP
1393 || bmp->db_agfree[agno] == bmp->db_agsize) {
1394 rc = dbAllocCtl(bmp, nblocks, l2nb, blkno, results);
1395 if ((rc == -ENOSPC) &&
1396 (bmp->db_agfree[agno] == bmp->db_agsize)) {
1397 printk(KERN_ERR "blkno = %Lx, blocks = %Lx\n",
1398 (unsigned long long) blkno,
1399 (unsigned long long) nblocks);
1400 jfs_error(bmp->db_ipbmap->i_sb,
1401 "dbAllocCtl failed in free AG\n");
1402 }
1403 return (rc);
1404 }
1405
1406 /* the buffer for the dmap control page that fully describes the
1407 * allocation group.
1408 */
1409 lblkno = BLKTOCTL(blkno, bmp->db_l2nbperpage, bmp->db_aglevel);
1410 mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0);
1411 if (mp == NULL)
1412 return -EIO;
1413 dcp = (struct dmapctl *) mp->data;
1414 budmin = dcp->budmin;
1415
1416 if (dcp->leafidx != cpu_to_le32(CTLLEAFIND)) {
1417 jfs_error(bmp->db_ipbmap->i_sb, "Corrupt dmapctl page\n");
1418 release_metapage(mp);
1419 return -EIO;
1420 }
1421
1422 /* search the subtree(s) of the dmap control page that describes
1423 * the allocation group, looking for sufficient free space. to begin,
1424 * determine how many allocation groups are represented in a dmap
1425 * control page at the control page level (i.e. L0, L1, L2) that
1426 * fully describes an allocation group. next, determine the starting
1427 * tree index of this allocation group within the control page.
1428 */
1429 agperlev =
1430 (1 << (L2LPERCTL - (bmp->db_agheight << 1))) / bmp->db_agwidth;
1431 ti = bmp->db_agstart + bmp->db_agwidth * (agno & (agperlev - 1));
1432
1433 /* dmap control page trees fan-out by 4 and a single allocation
1434 * group may be described by 1 or 2 subtrees within the ag level
1435 * dmap control page, depending upon the ag size. examine the ag's
1436 * subtrees for sufficient free space, starting with the leftmost
1437 * subtree.
1438 */
1439 for (i = 0; i < bmp->db_agwidth; i++, ti++) {
1440 /* is there sufficient free space ?
1441 */
1442 if (l2nb > dcp->stree[ti])
1443 continue;
1444
1445 /* sufficient free space found in a subtree. now search down
1446 * the subtree to find the leftmost leaf that describes this
1447 * free space.
1448 */
1449 for (k = bmp->db_agheight; k > 0; k--) {
1450 for (n = 0, m = (ti << 2) + 1; n < 4; n++) {
1451 if (l2nb <= dcp->stree[m + n]) {
1452 ti = m + n;
1453 break;
1454 }
1455 }
1456 if (n == 4) {
1457 jfs_error(bmp->db_ipbmap->i_sb,
1458 "failed descending stree\n");
1459 release_metapage(mp);
1460 return -EIO;
1461 }
1462 }
1463
1464 /* determine the block number within the file system
1465 * that corresponds to this leaf.
1466 */
1467 if (bmp->db_aglevel == 2)
1468 blkno = 0;
1469 else if (bmp->db_aglevel == 1)
1470 blkno &= ~(MAXL1SIZE - 1);
1471 else /* bmp->db_aglevel == 0 */
1472 blkno &= ~(MAXL0SIZE - 1);
1473
1474 blkno +=
1475 ((s64) (ti - le32_to_cpu(dcp->leafidx))) << budmin;
1476
1477 /* release the buffer in preparation for going down
1478 * the next level of dmap control pages.
1479 */
1480 release_metapage(mp);
1481
1482 /* check if we need to continue to search down the lower
1483 * level dmap control pages. we need to if the number of
1484 * blocks required is less than maximum number of blocks
1485 * described at the next lower level.
1486 */
1487 if (l2nb < budmin) {
1488
1489 /* search the lower level dmap control pages to get
1490 * the starting block number of the dmap that
1491 * contains or starts off the free space.
1492 */
1493 if ((rc =
1494 dbFindCtl(bmp, l2nb, bmp->db_aglevel - 1,
1495 &blkno))) {
1496 if (rc == -ENOSPC) {
1497 jfs_error(bmp->db_ipbmap->i_sb,
1498 "control page inconsistent\n");
1499 return -EIO;
1500 }
1501 return (rc);
1502 }
1503 }
1504
1505 /* allocate the blocks.
1506 */
1507 rc = dbAllocCtl(bmp, nblocks, l2nb, blkno, results);
1508 if (rc == -ENOSPC) {
1509 jfs_error(bmp->db_ipbmap->i_sb,
1510 "unable to allocate blocks\n");
1511 rc = -EIO;
1512 }
1513 return (rc);
1514 }
1515
1516 /* no space in the allocation group. release the buffer and
1517 * return -ENOSPC.
1518 */
1519 release_metapage(mp);
1520
1521 return -ENOSPC;
1522}
1523
1524
1525/*
1526 * NAME: dbAllocAny()
1527 *
1528 * FUNCTION: attempt to allocate the specified number of contiguous
1529 * free blocks anywhere in the file system.
1530 *
1531 * dbAllocAny() attempts to find the sufficient free space by
1532 * searching down the dmap control pages, starting with the
1533 * highest level (i.e. L0, L1, L2) control page. if free space
1534 * large enough to satisfy the desired free space is found, the
1535 * desired free space is allocated.
1536 *
1537 * PARAMETERS:
1538 * bmp - pointer to bmap descriptor
1539 * nblocks - actual number of contiguous free blocks desired.
1540 * l2nb - log2 number of contiguous free blocks desired.
1541 * results - on successful return, set to the starting block number
1542 * of the newly allocated range.
1543 *
1544 * RETURN VALUES:
1545 * 0 - success
1546 * -ENOSPC - insufficient disk resources
1547 * -EIO - i/o error
1548 *
1549 * serialization: IWRITE_LOCK(ipbmap) held on entry/exit;
1550 */
1551static int dbAllocAny(struct bmap * bmp, s64 nblocks, int l2nb, s64 * results)
1552{
1553 int rc;
1554 s64 blkno = 0;
1555
1556 /* starting with the top level dmap control page, search
1557 * down the dmap control levels for sufficient free space.
1558 * if free space is found, dbFindCtl() returns the starting
1559 * block number of the dmap that contains or starts off the
1560 * range of free space.
1561 */
1562 if ((rc = dbFindCtl(bmp, l2nb, bmp->db_maxlevel, &blkno)))
1563 return (rc);
1564
1565 /* allocate the blocks.
1566 */
1567 rc = dbAllocCtl(bmp, nblocks, l2nb, blkno, results);
1568 if (rc == -ENOSPC) {
1569 jfs_error(bmp->db_ipbmap->i_sb, "unable to allocate blocks\n");
1570 return -EIO;
1571 }
1572 return (rc);
1573}
1574
1575
1576/*
1577 * NAME: dbDiscardAG()
1578 *
1579 * FUNCTION: attempt to discard (TRIM) all free blocks of specific AG
1580 *
1581 * algorithm:
1582 * 1) allocate blocks, as large as possible and save them
1583 * while holding IWRITE_LOCK on ipbmap
1584 * 2) trim all these saved block/length values
1585 * 3) mark the blocks free again
1586 *
1587 * benefit:
1588 * - we work only on one ag at some time, minimizing how long we
1589 * need to lock ipbmap
1590 * - reading / writing the fs is possible most time, even on
1591 * trimming
1592 *
1593 * downside:
1594 * - we write two times to the dmapctl and dmap pages
1595 * - but for me, this seems the best way, better ideas?
1596 * /TR 2012
1597 *
1598 * PARAMETERS:
1599 * ip - pointer to in-core inode
1600 * agno - ag to trim
1601 * minlen - minimum value of contiguous blocks
1602 *
1603 * RETURN VALUES:
1604 * s64 - actual number of blocks trimmed
1605 */
1606s64 dbDiscardAG(struct inode *ip, int agno, s64 minlen)
1607{
1608 struct inode *ipbmap = JFS_SBI(ip->i_sb)->ipbmap;
1609 struct bmap *bmp = JFS_SBI(ip->i_sb)->bmap;
1610 s64 nblocks, blkno;
1611 u64 trimmed = 0;
1612 int rc, l2nb;
1613 struct super_block *sb = ipbmap->i_sb;
1614
1615 struct range2trim {
1616 u64 blkno;
1617 u64 nblocks;
1618 } *totrim, *tt;
1619
1620 /* max blkno / nblocks pairs to trim */
1621 int count = 0, range_cnt;
1622 u64 max_ranges;
1623
1624 /* prevent others from writing new stuff here, while trimming */
1625 IWRITE_LOCK(ipbmap, RDWRLOCK_DMAP);
1626
1627 nblocks = bmp->db_agfree[agno];
1628 max_ranges = nblocks;
1629 do_div(max_ranges, minlen);
1630 range_cnt = min_t(u64, max_ranges + 1, 32 * 1024);
1631 totrim = kmalloc_array(range_cnt, sizeof(struct range2trim), GFP_NOFS);
1632 if (totrim == NULL) {
1633 jfs_error(bmp->db_ipbmap->i_sb, "no memory for trim array\n");
1634 IWRITE_UNLOCK(ipbmap);
1635 return 0;
1636 }
1637
1638 tt = totrim;
1639 while (nblocks >= minlen) {
1640 l2nb = BLKSTOL2(nblocks);
1641
1642 /* 0 = okay, -EIO = fatal, -ENOSPC -> try smaller block */
1643 rc = dbAllocAG(bmp, agno, nblocks, l2nb, &blkno);
1644 if (rc == 0) {
1645 tt->blkno = blkno;
1646 tt->nblocks = nblocks;
1647 tt++; count++;
1648
1649 /* the whole ag is free, trim now */
1650 if (bmp->db_agfree[agno] == 0)
1651 break;
1652
1653 /* give a hint for the next while */
1654 nblocks = bmp->db_agfree[agno];
1655 continue;
1656 } else if (rc == -ENOSPC) {
1657 /* search for next smaller log2 block */
1658 l2nb = BLKSTOL2(nblocks) - 1;
1659 nblocks = 1 << l2nb;
1660 } else {
1661 /* Trim any already allocated blocks */
1662 jfs_error(bmp->db_ipbmap->i_sb, "-EIO\n");
1663 break;
1664 }
1665
1666 /* check, if our trim array is full */
1667 if (unlikely(count >= range_cnt - 1))
1668 break;
1669 }
1670 IWRITE_UNLOCK(ipbmap);
1671
1672 tt->nblocks = 0; /* mark the current end */
1673 for (tt = totrim; tt->nblocks != 0; tt++) {
1674 /* when mounted with online discard, dbFree() will
1675 * call jfs_issue_discard() itself */
1676 if (!(JFS_SBI(sb)->flag & JFS_DISCARD))
1677 jfs_issue_discard(ip, tt->blkno, tt->nblocks);
1678 dbFree(ip, tt->blkno, tt->nblocks);
1679 trimmed += tt->nblocks;
1680 }
1681 kfree(totrim);
1682
1683 return trimmed;
1684}
1685
1686/*
1687 * NAME: dbFindCtl()
1688 *
1689 * FUNCTION: starting at a specified dmap control page level and block
1690 * number, search down the dmap control levels for a range of
1691 * contiguous free blocks large enough to satisfy an allocation
1692 * request for the specified number of free blocks.
1693 *
1694 * if sufficient contiguous free blocks are found, this routine
1695 * returns the starting block number within a dmap page that
1696 * contains or starts a range of contiqious free blocks that
1697 * is sufficient in size.
1698 *
1699 * PARAMETERS:
1700 * bmp - pointer to bmap descriptor
1701 * level - starting dmap control page level.
1702 * l2nb - log2 number of contiguous free blocks desired.
1703 * *blkno - on entry, starting block number for conducting the search.
1704 * on successful return, the first block within a dmap page
1705 * that contains or starts a range of contiguous free blocks.
1706 *
1707 * RETURN VALUES:
1708 * 0 - success
1709 * -ENOSPC - insufficient disk resources
1710 * -EIO - i/o error
1711 *
1712 * serialization: IWRITE_LOCK(ipbmap) held on entry/exit;
1713 */
1714static int dbFindCtl(struct bmap * bmp, int l2nb, int level, s64 * blkno)
1715{
1716 int rc, leafidx, lev;
1717 s64 b, lblkno;
1718 struct dmapctl *dcp;
1719 int budmin;
1720 struct metapage *mp;
1721
1722 /* starting at the specified dmap control page level and block
1723 * number, search down the dmap control levels for the starting
1724 * block number of a dmap page that contains or starts off
1725 * sufficient free blocks.
1726 */
1727 for (lev = level, b = *blkno; lev >= 0; lev--) {
1728 /* get the buffer of the dmap control page for the block
1729 * number and level (i.e. L0, L1, L2).
1730 */
1731 lblkno = BLKTOCTL(b, bmp->db_l2nbperpage, lev);
1732 mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0);
1733 if (mp == NULL)
1734 return -EIO;
1735 dcp = (struct dmapctl *) mp->data;
1736 budmin = dcp->budmin;
1737
1738 if (dcp->leafidx != cpu_to_le32(CTLLEAFIND)) {
1739 jfs_error(bmp->db_ipbmap->i_sb,
1740 "Corrupt dmapctl page\n");
1741 release_metapage(mp);
1742 return -EIO;
1743 }
1744
1745 /* search the tree within the dmap control page for
1746 * sufficient free space. if sufficient free space is found,
1747 * dbFindLeaf() returns the index of the leaf at which
1748 * free space was found.
1749 */
1750 rc = dbFindLeaf((dmtree_t *) dcp, l2nb, &leafidx);
1751
1752 /* release the buffer.
1753 */
1754 release_metapage(mp);
1755
1756 /* space found ?
1757 */
1758 if (rc) {
1759 if (lev != level) {
1760 jfs_error(bmp->db_ipbmap->i_sb,
1761 "dmap inconsistent\n");
1762 return -EIO;
1763 }
1764 return -ENOSPC;
1765 }
1766
1767 /* adjust the block number to reflect the location within
1768 * the dmap control page (i.e. the leaf) at which free
1769 * space was found.
1770 */
1771 b += (((s64) leafidx) << budmin);
1772
1773 /* we stop the search at this dmap control page level if
1774 * the number of blocks required is greater than or equal
1775 * to the maximum number of blocks described at the next
1776 * (lower) level.
1777 */
1778 if (l2nb >= budmin)
1779 break;
1780 }
1781
1782 *blkno = b;
1783 return (0);
1784}
1785
1786
1787/*
1788 * NAME: dbAllocCtl()
1789 *
1790 * FUNCTION: attempt to allocate a specified number of contiguous
1791 * blocks starting within a specific dmap.
1792 *
1793 * this routine is called by higher level routines that search
1794 * the dmap control pages above the actual dmaps for contiguous
1795 * free space. the result of successful searches by these
1796 * routines are the starting block numbers within dmaps, with
1797 * the dmaps themselves containing the desired contiguous free
1798 * space or starting a contiguous free space of desired size
1799 * that is made up of the blocks of one or more dmaps. these
1800 * calls should not fail due to insufficent resources.
1801 *
1802 * this routine is called in some cases where it is not known
1803 * whether it will fail due to insufficient resources. more
1804 * specifically, this occurs when allocating from an allocation
1805 * group whose size is equal to the number of blocks per dmap.
1806 * in this case, the dmap control pages are not examined prior
1807 * to calling this routine (to save pathlength) and the call
1808 * might fail.
1809 *
1810 * for a request size that fits within a dmap, this routine relies
1811 * upon the dmap's dmtree to find the requested contiguous free
1812 * space. for request sizes that are larger than a dmap, the
1813 * requested free space will start at the first block of the
1814 * first dmap (i.e. blkno).
1815 *
1816 * PARAMETERS:
1817 * bmp - pointer to bmap descriptor
1818 * nblocks - actual number of contiguous free blocks to allocate.
1819 * l2nb - log2 number of contiguous free blocks to allocate.
1820 * blkno - starting block number of the dmap to start the allocation
1821 * from.
1822 * results - on successful return, set to the starting block number
1823 * of the newly allocated range.
1824 *
1825 * RETURN VALUES:
1826 * 0 - success
1827 * -ENOSPC - insufficient disk resources
1828 * -EIO - i/o error
1829 *
1830 * serialization: IWRITE_LOCK(ipbmap) held on entry/exit;
1831 */
1832static int
1833dbAllocCtl(struct bmap * bmp, s64 nblocks, int l2nb, s64 blkno, s64 * results)
1834{
1835 int rc, nb;
1836 s64 b, lblkno, n;
1837 struct metapage *mp;
1838 struct dmap *dp;
1839
1840 /* check if the allocation request is confined to a single dmap.
1841 */
1842 if (l2nb <= L2BPERDMAP) {
1843 /* get the buffer for the dmap.
1844 */
1845 lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage);
1846 mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0);
1847 if (mp == NULL)
1848 return -EIO;
1849 dp = (struct dmap *) mp->data;
1850
1851 /* try to allocate the blocks.
1852 */
1853 rc = dbAllocDmapLev(bmp, dp, (int) nblocks, l2nb, results);
1854 if (rc == 0)
1855 mark_metapage_dirty(mp);
1856
1857 release_metapage(mp);
1858
1859 return (rc);
1860 }
1861
1862 /* allocation request involving multiple dmaps. it must start on
1863 * a dmap boundary.
1864 */
1865 assert((blkno & (BPERDMAP - 1)) == 0);
1866
1867 /* allocate the blocks dmap by dmap.
1868 */
1869 for (n = nblocks, b = blkno; n > 0; n -= nb, b += nb) {
1870 /* get the buffer for the dmap.
1871 */
1872 lblkno = BLKTODMAP(b, bmp->db_l2nbperpage);
1873 mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0);
1874 if (mp == NULL) {
1875 rc = -EIO;
1876 goto backout;
1877 }
1878 dp = (struct dmap *) mp->data;
1879
1880 /* the dmap better be all free.
1881 */
1882 if (dp->tree.stree[ROOT] != L2BPERDMAP) {
1883 release_metapage(mp);
1884 jfs_error(bmp->db_ipbmap->i_sb,
1885 "the dmap is not all free\n");
1886 rc = -EIO;
1887 goto backout;
1888 }
1889
1890 /* determine how many blocks to allocate from this dmap.
1891 */
1892 nb = min_t(s64, n, BPERDMAP);
1893
1894 /* allocate the blocks from the dmap.
1895 */
1896 if ((rc = dbAllocDmap(bmp, dp, b, nb))) {
1897 release_metapage(mp);
1898 goto backout;
1899 }
1900
1901 /* write the buffer.
1902 */
1903 write_metapage(mp);
1904 }
1905
1906 /* set the results (starting block number) and return.
1907 */
1908 *results = blkno;
1909 return (0);
1910
1911 /* something failed in handling an allocation request involving
1912 * multiple dmaps. we'll try to clean up by backing out any
1913 * allocation that has already happened for this request. if
1914 * we fail in backing out the allocation, we'll mark the file
1915 * system to indicate that blocks have been leaked.
1916 */
1917 backout:
1918
1919 /* try to backout the allocations dmap by dmap.
1920 */
1921 for (n = nblocks - n, b = blkno; n > 0;
1922 n -= BPERDMAP, b += BPERDMAP) {
1923 /* get the buffer for this dmap.
1924 */
1925 lblkno = BLKTODMAP(b, bmp->db_l2nbperpage);
1926 mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0);
1927 if (mp == NULL) {
1928 /* could not back out. mark the file system
1929 * to indicate that we have leaked blocks.
1930 */
1931 jfs_error(bmp->db_ipbmap->i_sb,
1932 "I/O Error: Block Leakage\n");
1933 continue;
1934 }
1935 dp = (struct dmap *) mp->data;
1936
1937 /* free the blocks is this dmap.
1938 */
1939 if (dbFreeDmap(bmp, dp, b, BPERDMAP)) {
1940 /* could not back out. mark the file system
1941 * to indicate that we have leaked blocks.
1942 */
1943 release_metapage(mp);
1944 jfs_error(bmp->db_ipbmap->i_sb, "Block Leakage\n");
1945 continue;
1946 }
1947
1948 /* write the buffer.
1949 */
1950 write_metapage(mp);
1951 }
1952
1953 return (rc);
1954}
1955
1956
1957/*
1958 * NAME: dbAllocDmapLev()
1959 *
1960 * FUNCTION: attempt to allocate a specified number of contiguous blocks
1961 * from a specified dmap.
1962 *
1963 * this routine checks if the contiguous blocks are available.
1964 * if so, nblocks of blocks are allocated; otherwise, ENOSPC is
1965 * returned.
1966 *
1967 * PARAMETERS:
1968 * mp - pointer to bmap descriptor
1969 * dp - pointer to dmap to attempt to allocate blocks from.
1970 * l2nb - log2 number of contiguous block desired.
1971 * nblocks - actual number of contiguous block desired.
1972 * results - on successful return, set to the starting block number
1973 * of the newly allocated range.
1974 *
1975 * RETURN VALUES:
1976 * 0 - success
1977 * -ENOSPC - insufficient disk resources
1978 * -EIO - i/o error
1979 *
1980 * serialization: IREAD_LOCK(ipbmap), e.g., from dbAlloc(), or
1981 * IWRITE_LOCK(ipbmap), e.g., dbAllocCtl(), held on entry/exit;
1982 */
1983static int
1984dbAllocDmapLev(struct bmap * bmp,
1985 struct dmap * dp, int nblocks, int l2nb, s64 * results)
1986{
1987 s64 blkno;
1988 int leafidx, rc;
1989
1990 /* can't be more than a dmaps worth of blocks */
1991 assert(l2nb <= L2BPERDMAP);
1992
1993 /* search the tree within the dmap page for sufficient
1994 * free space. if sufficient free space is found, dbFindLeaf()
1995 * returns the index of the leaf at which free space was found.
1996 */
1997 if (dbFindLeaf((dmtree_t *) & dp->tree, l2nb, &leafidx))
1998 return -ENOSPC;
1999
2000 /* determine the block number within the file system corresponding
2001 * to the leaf at which free space was found.
2002 */
2003 blkno = le64_to_cpu(dp->start) + (leafidx << L2DBWORD);
2004
2005 /* if not all bits of the dmap word are free, get the starting
2006 * bit number within the dmap word of the required string of free
2007 * bits and adjust the block number with this value.
2008 */
2009 if (dp->tree.stree[leafidx + LEAFIND] < BUDMIN)
2010 blkno += dbFindBits(le32_to_cpu(dp->wmap[leafidx]), l2nb);
2011
2012 /* allocate the blocks */
2013 if ((rc = dbAllocDmap(bmp, dp, blkno, nblocks)) == 0)
2014 *results = blkno;
2015
2016 return (rc);
2017}
2018
2019
2020/*
2021 * NAME: dbAllocDmap()
2022 *
2023 * FUNCTION: adjust the disk allocation map to reflect the allocation
2024 * of a specified block range within a dmap.
2025 *
2026 * this routine allocates the specified blocks from the dmap
2027 * through a call to dbAllocBits(). if the allocation of the
2028 * block range causes the maximum string of free blocks within
2029 * the dmap to change (i.e. the value of the root of the dmap's
2030 * dmtree), this routine will cause this change to be reflected
2031 * up through the appropriate levels of the dmap control pages
2032 * by a call to dbAdjCtl() for the L0 dmap control page that
2033 * covers this dmap.
2034 *
2035 * PARAMETERS:
2036 * bmp - pointer to bmap descriptor
2037 * dp - pointer to dmap to allocate the block range from.
2038 * blkno - starting block number of the block to be allocated.
2039 * nblocks - number of blocks to be allocated.
2040 *
2041 * RETURN VALUES:
2042 * 0 - success
2043 * -EIO - i/o error
2044 *
2045 * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit;
2046 */
2047static int dbAllocDmap(struct bmap * bmp, struct dmap * dp, s64 blkno,
2048 int nblocks)
2049{
2050 s8 oldroot;
2051 int rc;
2052
2053 /* save the current value of the root (i.e. maximum free string)
2054 * of the dmap tree.
2055 */
2056 oldroot = dp->tree.stree[ROOT];
2057
2058 /* allocate the specified (blocks) bits */
2059 dbAllocBits(bmp, dp, blkno, nblocks);
2060
2061 /* if the root has not changed, done. */
2062 if (dp->tree.stree[ROOT] == oldroot)
2063 return (0);
2064
2065 /* root changed. bubble the change up to the dmap control pages.
2066 * if the adjustment of the upper level control pages fails,
2067 * backout the bit allocation (thus making everything consistent).
2068 */
2069 if ((rc = dbAdjCtl(bmp, blkno, dp->tree.stree[ROOT], 1, 0)))
2070 dbFreeBits(bmp, dp, blkno, nblocks);
2071
2072 return (rc);
2073}
2074
2075
2076/*
2077 * NAME: dbFreeDmap()
2078 *
2079 * FUNCTION: adjust the disk allocation map to reflect the allocation
2080 * of a specified block range within a dmap.
2081 *
2082 * this routine frees the specified blocks from the dmap through
2083 * a call to dbFreeBits(). if the deallocation of the block range
2084 * causes the maximum string of free blocks within the dmap to
2085 * change (i.e. the value of the root of the dmap's dmtree), this
2086 * routine will cause this change to be reflected up through the
2087 * appropriate levels of the dmap control pages by a call to
2088 * dbAdjCtl() for the L0 dmap control page that covers this dmap.
2089 *
2090 * PARAMETERS:
2091 * bmp - pointer to bmap descriptor
2092 * dp - pointer to dmap to free the block range from.
2093 * blkno - starting block number of the block to be freed.
2094 * nblocks - number of blocks to be freed.
2095 *
2096 * RETURN VALUES:
2097 * 0 - success
2098 * -EIO - i/o error
2099 *
2100 * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit;
2101 */
2102static int dbFreeDmap(struct bmap * bmp, struct dmap * dp, s64 blkno,
2103 int nblocks)
2104{
2105 s8 oldroot;
2106 int rc = 0, word;
2107
2108 /* save the current value of the root (i.e. maximum free string)
2109 * of the dmap tree.
2110 */
2111 oldroot = dp->tree.stree[ROOT];
2112
2113 /* free the specified (blocks) bits */
2114 rc = dbFreeBits(bmp, dp, blkno, nblocks);
2115
2116 /* if error or the root has not changed, done. */
2117 if (rc || (dp->tree.stree[ROOT] == oldroot))
2118 return (rc);
2119
2120 /* root changed. bubble the change up to the dmap control pages.
2121 * if the adjustment of the upper level control pages fails,
2122 * backout the deallocation.
2123 */
2124 if ((rc = dbAdjCtl(bmp, blkno, dp->tree.stree[ROOT], 0, 0))) {
2125 word = (blkno & (BPERDMAP - 1)) >> L2DBWORD;
2126
2127 /* as part of backing out the deallocation, we will have
2128 * to back split the dmap tree if the deallocation caused
2129 * the freed blocks to become part of a larger binary buddy
2130 * system.
2131 */
2132 if (dp->tree.stree[word] == NOFREE)
2133 dbBackSplit((dmtree_t *) & dp->tree, word);
2134
2135 dbAllocBits(bmp, dp, blkno, nblocks);
2136 }
2137
2138 return (rc);
2139}
2140
2141
2142/*
2143 * NAME: dbAllocBits()
2144 *
2145 * FUNCTION: allocate a specified block range from a dmap.
2146 *
2147 * this routine updates the dmap to reflect the working
2148 * state allocation of the specified block range. it directly
2149 * updates the bits of the working map and causes the adjustment
2150 * of the binary buddy system described by the dmap's dmtree
2151 * leaves to reflect the bits allocated. it also causes the
2152 * dmap's dmtree, as a whole, to reflect the allocated range.
2153 *
2154 * PARAMETERS:
2155 * bmp - pointer to bmap descriptor
2156 * dp - pointer to dmap to allocate bits from.
2157 * blkno - starting block number of the bits to be allocated.
2158 * nblocks - number of bits to be allocated.
2159 *
2160 * RETURN VALUES: none
2161 *
2162 * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit;
2163 */
2164static void dbAllocBits(struct bmap * bmp, struct dmap * dp, s64 blkno,
2165 int nblocks)
2166{
2167 int dbitno, word, rembits, nb, nwords, wbitno, nw, agno;
2168 dmtree_t *tp = (dmtree_t *) & dp->tree;
2169 int size;
2170 s8 *leaf;
2171
2172 /* pick up a pointer to the leaves of the dmap tree */
2173 leaf = dp->tree.stree + LEAFIND;
2174
2175 /* determine the bit number and word within the dmap of the
2176 * starting block.
2177 */
2178 dbitno = blkno & (BPERDMAP - 1);
2179 word = dbitno >> L2DBWORD;
2180
2181 /* block range better be within the dmap */
2182 assert(dbitno + nblocks <= BPERDMAP);
2183
2184 /* allocate the bits of the dmap's words corresponding to the block
2185 * range. not all bits of the first and last words may be contained
2186 * within the block range. if this is the case, we'll work against
2187 * those words (i.e. partial first and/or last) on an individual basis
2188 * (a single pass), allocating the bits of interest by hand and
2189 * updating the leaf corresponding to the dmap word. a single pass
2190 * will be used for all dmap words fully contained within the
2191 * specified range. within this pass, the bits of all fully contained
2192 * dmap words will be marked as free in a single shot and the leaves
2193 * will be updated. a single leaf may describe the free space of
2194 * multiple dmap words, so we may update only a subset of the actual
2195 * leaves corresponding to the dmap words of the block range.
2196 */
2197 for (rembits = nblocks; rembits > 0; rembits -= nb, dbitno += nb) {
2198 /* determine the bit number within the word and
2199 * the number of bits within the word.
2200 */
2201 wbitno = dbitno & (DBWORD - 1);
2202 nb = min(rembits, DBWORD - wbitno);
2203
2204 /* check if only part of a word is to be allocated.
2205 */
2206 if (nb < DBWORD) {
2207 /* allocate (set to 1) the appropriate bits within
2208 * this dmap word.
2209 */
2210 dp->wmap[word] |= cpu_to_le32(ONES << (DBWORD - nb)
2211 >> wbitno);
2212
2213 /* update the leaf for this dmap word. in addition
2214 * to setting the leaf value to the binary buddy max
2215 * of the updated dmap word, dbSplit() will split
2216 * the binary system of the leaves if need be.
2217 */
2218 dbSplit(tp, word, BUDMIN,
2219 dbMaxBud((u8 *) & dp->wmap[word]));
2220
2221 word += 1;
2222 } else {
2223 /* one or more dmap words are fully contained
2224 * within the block range. determine how many
2225 * words and allocate (set to 1) the bits of these
2226 * words.
2227 */
2228 nwords = rembits >> L2DBWORD;
2229 memset(&dp->wmap[word], (int) ONES, nwords * 4);
2230
2231 /* determine how many bits.
2232 */
2233 nb = nwords << L2DBWORD;
2234
2235 /* now update the appropriate leaves to reflect
2236 * the allocated words.
2237 */
2238 for (; nwords > 0; nwords -= nw) {
2239 if (leaf[word] < BUDMIN) {
2240 jfs_error(bmp->db_ipbmap->i_sb,
2241 "leaf page corrupt\n");
2242 break;
2243 }
2244
2245 /* determine what the leaf value should be
2246 * updated to as the minimum of the l2 number
2247 * of bits being allocated and the l2 number
2248 * of bits currently described by this leaf.
2249 */
2250 size = min_t(int, leaf[word],
2251 NLSTOL2BSZ(nwords));
2252
2253 /* update the leaf to reflect the allocation.
2254 * in addition to setting the leaf value to
2255 * NOFREE, dbSplit() will split the binary
2256 * system of the leaves to reflect the current
2257 * allocation (size).
2258 */
2259 dbSplit(tp, word, size, NOFREE);
2260
2261 /* get the number of dmap words handled */
2262 nw = BUDSIZE(size, BUDMIN);
2263 word += nw;
2264 }
2265 }
2266 }
2267
2268 /* update the free count for this dmap */
2269 le32_add_cpu(&dp->nfree, -nblocks);
2270
2271 BMAP_LOCK(bmp);
2272
2273 /* if this allocation group is completely free,
2274 * update the maximum allocation group number if this allocation
2275 * group is the new max.
2276 */
2277 agno = blkno >> bmp->db_agl2size;
2278 if (agno > bmp->db_maxag)
2279 bmp->db_maxag = agno;
2280
2281 /* update the free count for the allocation group and map */
2282 bmp->db_agfree[agno] -= nblocks;
2283 bmp->db_nfree -= nblocks;
2284
2285 BMAP_UNLOCK(bmp);
2286}
2287
2288
2289/*
2290 * NAME: dbFreeBits()
2291 *
2292 * FUNCTION: free a specified block range from a dmap.
2293 *
2294 * this routine updates the dmap to reflect the working
2295 * state allocation of the specified block range. it directly
2296 * updates the bits of the working map and causes the adjustment
2297 * of the binary buddy system described by the dmap's dmtree
2298 * leaves to reflect the bits freed. it also causes the dmap's
2299 * dmtree, as a whole, to reflect the deallocated range.
2300 *
2301 * PARAMETERS:
2302 * bmp - pointer to bmap descriptor
2303 * dp - pointer to dmap to free bits from.
2304 * blkno - starting block number of the bits to be freed.
2305 * nblocks - number of bits to be freed.
2306 *
2307 * RETURN VALUES: 0 for success
2308 *
2309 * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit;
2310 */
2311static int dbFreeBits(struct bmap * bmp, struct dmap * dp, s64 blkno,
2312 int nblocks)
2313{
2314 int dbitno, word, rembits, nb, nwords, wbitno, nw, agno;
2315 dmtree_t *tp = (dmtree_t *) & dp->tree;
2316 int rc = 0;
2317 int size;
2318
2319 /* determine the bit number and word within the dmap of the
2320 * starting block.
2321 */
2322 dbitno = blkno & (BPERDMAP - 1);
2323 word = dbitno >> L2DBWORD;
2324
2325 /* block range better be within the dmap.
2326 */
2327 assert(dbitno + nblocks <= BPERDMAP);
2328
2329 /* free the bits of the dmaps words corresponding to the block range.
2330 * not all bits of the first and last words may be contained within
2331 * the block range. if this is the case, we'll work against those
2332 * words (i.e. partial first and/or last) on an individual basis
2333 * (a single pass), freeing the bits of interest by hand and updating
2334 * the leaf corresponding to the dmap word. a single pass will be used
2335 * for all dmap words fully contained within the specified range.
2336 * within this pass, the bits of all fully contained dmap words will
2337 * be marked as free in a single shot and the leaves will be updated. a
2338 * single leaf may describe the free space of multiple dmap words,
2339 * so we may update only a subset of the actual leaves corresponding
2340 * to the dmap words of the block range.
2341 *
2342 * dbJoin() is used to update leaf values and will join the binary
2343 * buddy system of the leaves if the new leaf values indicate this
2344 * should be done.
2345 */
2346 for (rembits = nblocks; rembits > 0; rembits -= nb, dbitno += nb) {
2347 /* determine the bit number within the word and
2348 * the number of bits within the word.
2349 */
2350 wbitno = dbitno & (DBWORD - 1);
2351 nb = min(rembits, DBWORD - wbitno);
2352
2353 /* check if only part of a word is to be freed.
2354 */
2355 if (nb < DBWORD) {
2356 /* free (zero) the appropriate bits within this
2357 * dmap word.
2358 */
2359 dp->wmap[word] &=
2360 cpu_to_le32(~(ONES << (DBWORD - nb)
2361 >> wbitno));
2362
2363 /* update the leaf for this dmap word.
2364 */
2365 rc = dbJoin(tp, word,
2366 dbMaxBud((u8 *) & dp->wmap[word]));
2367 if (rc)
2368 return rc;
2369
2370 word += 1;
2371 } else {
2372 /* one or more dmap words are fully contained
2373 * within the block range. determine how many
2374 * words and free (zero) the bits of these words.
2375 */
2376 nwords = rembits >> L2DBWORD;
2377 memset(&dp->wmap[word], 0, nwords * 4);
2378
2379 /* determine how many bits.
2380 */
2381 nb = nwords << L2DBWORD;
2382
2383 /* now update the appropriate leaves to reflect
2384 * the freed words.
2385 */
2386 for (; nwords > 0; nwords -= nw) {
2387 /* determine what the leaf value should be
2388 * updated to as the minimum of the l2 number
2389 * of bits being freed and the l2 (max) number
2390 * of bits that can be described by this leaf.
2391 */
2392 size =
2393 min(LITOL2BSZ
2394 (word, L2LPERDMAP, BUDMIN),
2395 NLSTOL2BSZ(nwords));
2396
2397 /* update the leaf.
2398 */
2399 rc = dbJoin(tp, word, size);
2400 if (rc)
2401 return rc;
2402
2403 /* get the number of dmap words handled.
2404 */
2405 nw = BUDSIZE(size, BUDMIN);
2406 word += nw;
2407 }
2408 }
2409 }
2410
2411 /* update the free count for this dmap.
2412 */
2413 le32_add_cpu(&dp->nfree, nblocks);
2414
2415 BMAP_LOCK(bmp);
2416
2417 /* update the free count for the allocation group and
2418 * map.
2419 */
2420 agno = blkno >> bmp->db_agl2size;
2421 bmp->db_nfree += nblocks;
2422 bmp->db_agfree[agno] += nblocks;
2423
2424 /* check if this allocation group is not completely free and
2425 * if it is currently the maximum (rightmost) allocation group.
2426 * if so, establish the new maximum allocation group number by
2427 * searching left for the first allocation group with allocation.
2428 */
2429 if ((bmp->db_agfree[agno] == bmp->db_agsize && agno == bmp->db_maxag) ||
2430 (agno == bmp->db_numag - 1 &&
2431 bmp->db_agfree[agno] == (bmp-> db_mapsize & (BPERDMAP - 1)))) {
2432 while (bmp->db_maxag > 0) {
2433 bmp->db_maxag -= 1;
2434 if (bmp->db_agfree[bmp->db_maxag] !=
2435 bmp->db_agsize)
2436 break;
2437 }
2438
2439 /* re-establish the allocation group preference if the
2440 * current preference is right of the maximum allocation
2441 * group.
2442 */
2443 if (bmp->db_agpref > bmp->db_maxag)
2444 bmp->db_agpref = bmp->db_maxag;
2445 }
2446
2447 BMAP_UNLOCK(bmp);
2448
2449 return 0;
2450}
2451
2452
2453/*
2454 * NAME: dbAdjCtl()
2455 *
2456 * FUNCTION: adjust a dmap control page at a specified level to reflect
2457 * the change in a lower level dmap or dmap control page's
2458 * maximum string of free blocks (i.e. a change in the root
2459 * of the lower level object's dmtree) due to the allocation
2460 * or deallocation of a range of blocks with a single dmap.
2461 *
2462 * on entry, this routine is provided with the new value of
2463 * the lower level dmap or dmap control page root and the
2464 * starting block number of the block range whose allocation
2465 * or deallocation resulted in the root change. this range
2466 * is respresented by a single leaf of the current dmapctl
2467 * and the leaf will be updated with this value, possibly
2468 * causing a binary buddy system within the leaves to be
2469 * split or joined. the update may also cause the dmapctl's
2470 * dmtree to be updated.
2471 *
2472 * if the adjustment of the dmap control page, itself, causes its
2473 * root to change, this change will be bubbled up to the next dmap
2474 * control level by a recursive call to this routine, specifying
2475 * the new root value and the next dmap control page level to
2476 * be adjusted.
2477 * PARAMETERS:
2478 * bmp - pointer to bmap descriptor
2479 * blkno - the first block of a block range within a dmap. it is
2480 * the allocation or deallocation of this block range that
2481 * requires the dmap control page to be adjusted.
2482 * newval - the new value of the lower level dmap or dmap control
2483 * page root.
2484 * alloc - 'true' if adjustment is due to an allocation.
2485 * level - current level of dmap control page (i.e. L0, L1, L2) to
2486 * be adjusted.
2487 *
2488 * RETURN VALUES:
2489 * 0 - success
2490 * -EIO - i/o error
2491 *
2492 * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit;
2493 */
2494static int
2495dbAdjCtl(struct bmap * bmp, s64 blkno, int newval, int alloc, int level)
2496{
2497 struct metapage *mp;
2498 s8 oldroot;
2499 int oldval;
2500 s64 lblkno;
2501 struct dmapctl *dcp;
2502 int rc, leafno, ti;
2503
2504 /* get the buffer for the dmap control page for the specified
2505 * block number and control page level.
2506 */
2507 lblkno = BLKTOCTL(blkno, bmp->db_l2nbperpage, level);
2508 mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0);
2509 if (mp == NULL)
2510 return -EIO;
2511 dcp = (struct dmapctl *) mp->data;
2512
2513 if (dcp->leafidx != cpu_to_le32(CTLLEAFIND)) {
2514 jfs_error(bmp->db_ipbmap->i_sb, "Corrupt dmapctl page\n");
2515 release_metapage(mp);
2516 return -EIO;
2517 }
2518
2519 /* determine the leaf number corresponding to the block and
2520 * the index within the dmap control tree.
2521 */
2522 leafno = BLKTOCTLLEAF(blkno, dcp->budmin);
2523 ti = leafno + le32_to_cpu(dcp->leafidx);
2524
2525 /* save the current leaf value and the current root level (i.e.
2526 * maximum l2 free string described by this dmapctl).
2527 */
2528 oldval = dcp->stree[ti];
2529 oldroot = dcp->stree[ROOT];
2530
2531 /* check if this is a control page update for an allocation.
2532 * if so, update the leaf to reflect the new leaf value using
2533 * dbSplit(); otherwise (deallocation), use dbJoin() to update
2534 * the leaf with the new value. in addition to updating the
2535 * leaf, dbSplit() will also split the binary buddy system of
2536 * the leaves, if required, and bubble new values within the
2537 * dmapctl tree, if required. similarly, dbJoin() will join
2538 * the binary buddy system of leaves and bubble new values up
2539 * the dmapctl tree as required by the new leaf value.
2540 */
2541 if (alloc) {
2542 /* check if we are in the middle of a binary buddy
2543 * system. this happens when we are performing the
2544 * first allocation out of an allocation group that
2545 * is part (not the first part) of a larger binary
2546 * buddy system. if we are in the middle, back split
2547 * the system prior to calling dbSplit() which assumes
2548 * that it is at the front of a binary buddy system.
2549 */
2550 if (oldval == NOFREE) {
2551 rc = dbBackSplit((dmtree_t *) dcp, leafno);
2552 if (rc)
2553 return rc;
2554 oldval = dcp->stree[ti];
2555 }
2556 dbSplit((dmtree_t *) dcp, leafno, dcp->budmin, newval);
2557 } else {
2558 rc = dbJoin((dmtree_t *) dcp, leafno, newval);
2559 if (rc)
2560 return rc;
2561 }
2562
2563 /* check if the root of the current dmap control page changed due
2564 * to the update and if the current dmap control page is not at
2565 * the current top level (i.e. L0, L1, L2) of the map. if so (i.e.
2566 * root changed and this is not the top level), call this routine
2567 * again (recursion) for the next higher level of the mapping to
2568 * reflect the change in root for the current dmap control page.
2569 */
2570 if (dcp->stree[ROOT] != oldroot) {
2571 /* are we below the top level of the map. if so,
2572 * bubble the root up to the next higher level.
2573 */
2574 if (level < bmp->db_maxlevel) {
2575 /* bubble up the new root of this dmap control page to
2576 * the next level.
2577 */
2578 if ((rc =
2579 dbAdjCtl(bmp, blkno, dcp->stree[ROOT], alloc,
2580 level + 1))) {
2581 /* something went wrong in bubbling up the new
2582 * root value, so backout the changes to the
2583 * current dmap control page.
2584 */
2585 if (alloc) {
2586 dbJoin((dmtree_t *) dcp, leafno,
2587 oldval);
2588 } else {
2589 /* the dbJoin() above might have
2590 * caused a larger binary buddy system
2591 * to form and we may now be in the
2592 * middle of it. if this is the case,
2593 * back split the buddies.
2594 */
2595 if (dcp->stree[ti] == NOFREE)
2596 dbBackSplit((dmtree_t *)
2597 dcp, leafno);
2598 dbSplit((dmtree_t *) dcp, leafno,
2599 dcp->budmin, oldval);
2600 }
2601
2602 /* release the buffer and return the error.
2603 */
2604 release_metapage(mp);
2605 return (rc);
2606 }
2607 } else {
2608 /* we're at the top level of the map. update
2609 * the bmap control page to reflect the size
2610 * of the maximum free buddy system.
2611 */
2612 assert(level == bmp->db_maxlevel);
2613 if (bmp->db_maxfreebud != oldroot) {
2614 jfs_error(bmp->db_ipbmap->i_sb,
2615 "the maximum free buddy is not the old root\n");
2616 }
2617 bmp->db_maxfreebud = dcp->stree[ROOT];
2618 }
2619 }
2620
2621 /* write the buffer.
2622 */
2623 write_metapage(mp);
2624
2625 return (0);
2626}
2627
2628
2629/*
2630 * NAME: dbSplit()
2631 *
2632 * FUNCTION: update the leaf of a dmtree with a new value, splitting
2633 * the leaf from the binary buddy system of the dmtree's
2634 * leaves, as required.
2635 *
2636 * PARAMETERS:
2637 * tp - pointer to the tree containing the leaf.
2638 * leafno - the number of the leaf to be updated.
2639 * splitsz - the size the binary buddy system starting at the leaf
2640 * must be split to, specified as the log2 number of blocks.
2641 * newval - the new value for the leaf.
2642 *
2643 * RETURN VALUES: none
2644 *
2645 * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit;
2646 */
2647static void dbSplit(dmtree_t * tp, int leafno, int splitsz, int newval)
2648{
2649 int budsz;
2650 int cursz;
2651 s8 *leaf = tp->dmt_stree + le32_to_cpu(tp->dmt_leafidx);
2652
2653 /* check if the leaf needs to be split.
2654 */
2655 if (leaf[leafno] > tp->dmt_budmin) {
2656 /* the split occurs by cutting the buddy system in half
2657 * at the specified leaf until we reach the specified
2658 * size. pick up the starting split size (current size
2659 * - 1 in l2) and the corresponding buddy size.
2660 */
2661 cursz = leaf[leafno] - 1;
2662 budsz = BUDSIZE(cursz, tp->dmt_budmin);
2663
2664 /* split until we reach the specified size.
2665 */
2666 while (cursz >= splitsz) {
2667 /* update the buddy's leaf with its new value.
2668 */
2669 dbAdjTree(tp, leafno ^ budsz, cursz);
2670
2671 /* on to the next size and buddy.
2672 */
2673 cursz -= 1;
2674 budsz >>= 1;
2675 }
2676 }
2677
2678 /* adjust the dmap tree to reflect the specified leaf's new
2679 * value.
2680 */
2681 dbAdjTree(tp, leafno, newval);
2682}
2683
2684
2685/*
2686 * NAME: dbBackSplit()
2687 *
2688 * FUNCTION: back split the binary buddy system of dmtree leaves
2689 * that hold a specified leaf until the specified leaf
2690 * starts its own binary buddy system.
2691 *
2692 * the allocators typically perform allocations at the start
2693 * of binary buddy systems and dbSplit() is used to accomplish
2694 * any required splits. in some cases, however, allocation
2695 * may occur in the middle of a binary system and requires a
2696 * back split, with the split proceeding out from the middle of
2697 * the system (less efficient) rather than the start of the
2698 * system (more efficient). the cases in which a back split
2699 * is required are rare and are limited to the first allocation
2700 * within an allocation group which is a part (not first part)
2701 * of a larger binary buddy system and a few exception cases
2702 * in which a previous join operation must be backed out.
2703 *
2704 * PARAMETERS:
2705 * tp - pointer to the tree containing the leaf.
2706 * leafno - the number of the leaf to be updated.
2707 *
2708 * RETURN VALUES: none
2709 *
2710 * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit;
2711 */
2712static int dbBackSplit(dmtree_t * tp, int leafno)
2713{
2714 int budsz, bud, w, bsz, size;
2715 int cursz;
2716 s8 *leaf = tp->dmt_stree + le32_to_cpu(tp->dmt_leafidx);
2717
2718 /* leaf should be part (not first part) of a binary
2719 * buddy system.
2720 */
2721 assert(leaf[leafno] == NOFREE);
2722
2723 /* the back split is accomplished by iteratively finding the leaf
2724 * that starts the buddy system that contains the specified leaf and
2725 * splitting that system in two. this iteration continues until
2726 * the specified leaf becomes the start of a buddy system.
2727 *
2728 * determine maximum possible l2 size for the specified leaf.
2729 */
2730 size =
2731 LITOL2BSZ(leafno, le32_to_cpu(tp->dmt_l2nleafs),
2732 tp->dmt_budmin);
2733
2734 /* determine the number of leaves covered by this size. this
2735 * is the buddy size that we will start with as we search for
2736 * the buddy system that contains the specified leaf.
2737 */
2738 budsz = BUDSIZE(size, tp->dmt_budmin);
2739
2740 /* back split.
2741 */
2742 while (leaf[leafno] == NOFREE) {
2743 /* find the leftmost buddy leaf.
2744 */
2745 for (w = leafno, bsz = budsz;; bsz <<= 1,
2746 w = (w < bud) ? w : bud) {
2747 if (bsz >= le32_to_cpu(tp->dmt_nleafs)) {
2748 jfs_err("JFS: block map error in dbBackSplit");
2749 return -EIO;
2750 }
2751
2752 /* determine the buddy.
2753 */
2754 bud = w ^ bsz;
2755
2756 /* check if this buddy is the start of the system.
2757 */
2758 if (leaf[bud] != NOFREE) {
2759 /* split the leaf at the start of the
2760 * system in two.
2761 */
2762 cursz = leaf[bud] - 1;
2763 dbSplit(tp, bud, cursz, cursz);
2764 break;
2765 }
2766 }
2767 }
2768
2769 if (leaf[leafno] != size) {
2770 jfs_err("JFS: wrong leaf value in dbBackSplit");
2771 return -EIO;
2772 }
2773 return 0;
2774}
2775
2776
2777/*
2778 * NAME: dbJoin()
2779 *
2780 * FUNCTION: update the leaf of a dmtree with a new value, joining
2781 * the leaf with other leaves of the dmtree into a multi-leaf
2782 * binary buddy system, as required.
2783 *
2784 * PARAMETERS:
2785 * tp - pointer to the tree containing the leaf.
2786 * leafno - the number of the leaf to be updated.
2787 * newval - the new value for the leaf.
2788 *
2789 * RETURN VALUES: none
2790 */
2791static int dbJoin(dmtree_t * tp, int leafno, int newval)
2792{
2793 int budsz, buddy;
2794 s8 *leaf;
2795
2796 /* can the new leaf value require a join with other leaves ?
2797 */
2798 if (newval >= tp->dmt_budmin) {
2799 /* pickup a pointer to the leaves of the tree.
2800 */
2801 leaf = tp->dmt_stree + le32_to_cpu(tp->dmt_leafidx);
2802
2803 /* try to join the specified leaf into a large binary
2804 * buddy system. the join proceeds by attempting to join
2805 * the specified leafno with its buddy (leaf) at new value.
2806 * if the join occurs, we attempt to join the left leaf
2807 * of the joined buddies with its buddy at new value + 1.
2808 * we continue to join until we find a buddy that cannot be
2809 * joined (does not have a value equal to the size of the
2810 * last join) or until all leaves have been joined into a
2811 * single system.
2812 *
2813 * get the buddy size (number of words covered) of
2814 * the new value.
2815 */
2816 budsz = BUDSIZE(newval, tp->dmt_budmin);
2817
2818 /* try to join.
2819 */
2820 while (budsz < le32_to_cpu(tp->dmt_nleafs)) {
2821 /* get the buddy leaf.
2822 */
2823 buddy = leafno ^ budsz;
2824
2825 /* if the leaf's new value is greater than its
2826 * buddy's value, we join no more.
2827 */
2828 if (newval > leaf[buddy])
2829 break;
2830
2831 /* It shouldn't be less */
2832 if (newval < leaf[buddy])
2833 return -EIO;
2834
2835 /* check which (leafno or buddy) is the left buddy.
2836 * the left buddy gets to claim the blocks resulting
2837 * from the join while the right gets to claim none.
2838 * the left buddy is also eligible to participate in
2839 * a join at the next higher level while the right
2840 * is not.
2841 *
2842 */
2843 if (leafno < buddy) {
2844 /* leafno is the left buddy.
2845 */
2846 dbAdjTree(tp, buddy, NOFREE);
2847 } else {
2848 /* buddy is the left buddy and becomes
2849 * leafno.
2850 */
2851 dbAdjTree(tp, leafno, NOFREE);
2852 leafno = buddy;
2853 }
2854
2855 /* on to try the next join.
2856 */
2857 newval += 1;
2858 budsz <<= 1;
2859 }
2860 }
2861
2862 /* update the leaf value.
2863 */
2864 dbAdjTree(tp, leafno, newval);
2865
2866 return 0;
2867}
2868
2869
2870/*
2871 * NAME: dbAdjTree()
2872 *
2873 * FUNCTION: update a leaf of a dmtree with a new value, adjusting
2874 * the dmtree, as required, to reflect the new leaf value.
2875 * the combination of any buddies must already be done before
2876 * this is called.
2877 *
2878 * PARAMETERS:
2879 * tp - pointer to the tree to be adjusted.
2880 * leafno - the number of the leaf to be updated.
2881 * newval - the new value for the leaf.
2882 *
2883 * RETURN VALUES: none
2884 */
2885static void dbAdjTree(dmtree_t * tp, int leafno, int newval)
2886{
2887 int lp, pp, k;
2888 int max;
2889
2890 /* pick up the index of the leaf for this leafno.
2891 */
2892 lp = leafno + le32_to_cpu(tp->dmt_leafidx);
2893
2894 /* is the current value the same as the old value ? if so,
2895 * there is nothing to do.
2896 */
2897 if (tp->dmt_stree[lp] == newval)
2898 return;
2899
2900 /* set the new value.
2901 */
2902 tp->dmt_stree[lp] = newval;
2903
2904 /* bubble the new value up the tree as required.
2905 */
2906 for (k = 0; k < le32_to_cpu(tp->dmt_height); k++) {
2907 /* get the index of the first leaf of the 4 leaf
2908 * group containing the specified leaf (leafno).
2909 */
2910 lp = ((lp - 1) & ~0x03) + 1;
2911
2912 /* get the index of the parent of this 4 leaf group.
2913 */
2914 pp = (lp - 1) >> 2;
2915
2916 /* determine the maximum of the 4 leaves.
2917 */
2918 max = TREEMAX(&tp->dmt_stree[lp]);
2919
2920 /* if the maximum of the 4 is the same as the
2921 * parent's value, we're done.
2922 */
2923 if (tp->dmt_stree[pp] == max)
2924 break;
2925
2926 /* parent gets new value.
2927 */
2928 tp->dmt_stree[pp] = max;
2929
2930 /* parent becomes leaf for next go-round.
2931 */
2932 lp = pp;
2933 }
2934}
2935
2936
2937/*
2938 * NAME: dbFindLeaf()
2939 *
2940 * FUNCTION: search a dmtree_t for sufficient free blocks, returning
2941 * the index of a leaf describing the free blocks if
2942 * sufficient free blocks are found.
2943 *
2944 * the search starts at the top of the dmtree_t tree and
2945 * proceeds down the tree to the leftmost leaf with sufficient
2946 * free space.
2947 *
2948 * PARAMETERS:
2949 * tp - pointer to the tree to be searched.
2950 * l2nb - log2 number of free blocks to search for.
2951 * leafidx - return pointer to be set to the index of the leaf
2952 * describing at least l2nb free blocks if sufficient
2953 * free blocks are found.
2954 *
2955 * RETURN VALUES:
2956 * 0 - success
2957 * -ENOSPC - insufficient free blocks.
2958 */
2959static int dbFindLeaf(dmtree_t * tp, int l2nb, int *leafidx)
2960{
2961 int ti, n = 0, k, x = 0;
2962
2963 /* first check the root of the tree to see if there is
2964 * sufficient free space.
2965 */
2966 if (l2nb > tp->dmt_stree[ROOT])
2967 return -ENOSPC;
2968
2969 /* sufficient free space available. now search down the tree
2970 * starting at the next level for the leftmost leaf that
2971 * describes sufficient free space.
2972 */
2973 for (k = le32_to_cpu(tp->dmt_height), ti = 1;
2974 k > 0; k--, ti = ((ti + n) << 2) + 1) {
2975 /* search the four nodes at this level, starting from
2976 * the left.
2977 */
2978 for (x = ti, n = 0; n < 4; n++) {
2979 /* sufficient free space found. move to the next
2980 * level (or quit if this is the last level).
2981 */
2982 if (l2nb <= tp->dmt_stree[x + n])
2983 break;
2984 }
2985
2986 /* better have found something since the higher
2987 * levels of the tree said it was here.
2988 */
2989 assert(n < 4);
2990 }
2991
2992 /* set the return to the leftmost leaf describing sufficient
2993 * free space.
2994 */
2995 *leafidx = x + n - le32_to_cpu(tp->dmt_leafidx);
2996
2997 return (0);
2998}
2999
3000
3001/*
3002 * NAME: dbFindBits()
3003 *
3004 * FUNCTION: find a specified number of binary buddy free bits within a
3005 * dmap bitmap word value.
3006 *
3007 * this routine searches the bitmap value for (1 << l2nb) free
3008 * bits at (1 << l2nb) alignments within the value.
3009 *
3010 * PARAMETERS:
3011 * word - dmap bitmap word value.
3012 * l2nb - number of free bits specified as a log2 number.
3013 *
3014 * RETURN VALUES:
3015 * starting bit number of free bits.
3016 */
3017static int dbFindBits(u32 word, int l2nb)
3018{
3019 int bitno, nb;
3020 u32 mask;
3021
3022 /* get the number of bits.
3023 */
3024 nb = 1 << l2nb;
3025 assert(nb <= DBWORD);
3026
3027 /* complement the word so we can use a mask (i.e. 0s represent
3028 * free bits) and compute the mask.
3029 */
3030 word = ~word;
3031 mask = ONES << (DBWORD - nb);
3032
3033 /* scan the word for nb free bits at nb alignments.
3034 */
3035 for (bitno = 0; mask != 0; bitno += nb, mask >>= nb) {
3036 if ((mask & word) == mask)
3037 break;
3038 }
3039
3040 ASSERT(bitno < 32);
3041
3042 /* return the bit number.
3043 */
3044 return (bitno);
3045}
3046
3047
3048/*
3049 * NAME: dbMaxBud(u8 *cp)
3050 *
3051 * FUNCTION: determine the largest binary buddy string of free
3052 * bits within 32-bits of the map.
3053 *
3054 * PARAMETERS:
3055 * cp - pointer to the 32-bit value.
3056 *
3057 * RETURN VALUES:
3058 * largest binary buddy of free bits within a dmap word.
3059 */
3060static int dbMaxBud(u8 * cp)
3061{
3062 signed char tmp1, tmp2;
3063
3064 /* check if the wmap word is all free. if so, the
3065 * free buddy size is BUDMIN.
3066 */
3067 if (*((uint *) cp) == 0)
3068 return (BUDMIN);
3069
3070 /* check if the wmap word is half free. if so, the
3071 * free buddy size is BUDMIN-1.
3072 */
3073 if (*((u16 *) cp) == 0 || *((u16 *) cp + 1) == 0)
3074 return (BUDMIN - 1);
3075
3076 /* not all free or half free. determine the free buddy
3077 * size thru table lookup using quarters of the wmap word.
3078 */
3079 tmp1 = max(budtab[cp[2]], budtab[cp[3]]);
3080 tmp2 = max(budtab[cp[0]], budtab[cp[1]]);
3081 return (max(tmp1, tmp2));
3082}
3083
3084
3085/*
3086 * NAME: cnttz(uint word)
3087 *
3088 * FUNCTION: determine the number of trailing zeros within a 32-bit
3089 * value.
3090 *
3091 * PARAMETERS:
3092 * value - 32-bit value to be examined.
3093 *
3094 * RETURN VALUES:
3095 * count of trailing zeros
3096 */
3097static int cnttz(u32 word)
3098{
3099 int n;
3100
3101 for (n = 0; n < 32; n++, word >>= 1) {
3102 if (word & 0x01)
3103 break;
3104 }
3105
3106 return (n);
3107}
3108
3109
3110/*
3111 * NAME: cntlz(u32 value)
3112 *
3113 * FUNCTION: determine the number of leading zeros within a 32-bit
3114 * value.
3115 *
3116 * PARAMETERS:
3117 * value - 32-bit value to be examined.
3118 *
3119 * RETURN VALUES:
3120 * count of leading zeros
3121 */
3122static int cntlz(u32 value)
3123{
3124 int n;
3125
3126 for (n = 0; n < 32; n++, value <<= 1) {
3127 if (value & HIGHORDER)
3128 break;
3129 }
3130 return (n);
3131}
3132
3133
3134/*
3135 * NAME: blkstol2(s64 nb)
3136 *
3137 * FUNCTION: convert a block count to its log2 value. if the block
3138 * count is not a l2 multiple, it is rounded up to the next
3139 * larger l2 multiple.
3140 *
3141 * PARAMETERS:
3142 * nb - number of blocks
3143 *
3144 * RETURN VALUES:
3145 * log2 number of blocks
3146 */
3147static int blkstol2(s64 nb)
3148{
3149 int l2nb;
3150 s64 mask; /* meant to be signed */
3151
3152 mask = (s64) 1 << (64 - 1);
3153
3154 /* count the leading bits.
3155 */
3156 for (l2nb = 0; l2nb < 64; l2nb++, mask >>= 1) {
3157 /* leading bit found.
3158 */
3159 if (nb & mask) {
3160 /* determine the l2 value.
3161 */
3162 l2nb = (64 - 1) - l2nb;
3163
3164 /* check if we need to round up.
3165 */
3166 if (~mask & nb)
3167 l2nb++;
3168
3169 return (l2nb);
3170 }
3171 }
3172 assert(0);
3173 return 0; /* fix compiler warning */
3174}
3175
3176
3177/*
3178 * NAME: dbAllocBottomUp()
3179 *
3180 * FUNCTION: alloc the specified block range from the working block
3181 * allocation map.
3182 *
3183 * the blocks will be alloc from the working map one dmap
3184 * at a time.
3185 *
3186 * PARAMETERS:
3187 * ip - pointer to in-core inode;
3188 * blkno - starting block number to be freed.
3189 * nblocks - number of blocks to be freed.
3190 *
3191 * RETURN VALUES:
3192 * 0 - success
3193 * -EIO - i/o error
3194 */
3195int dbAllocBottomUp(struct inode *ip, s64 blkno, s64 nblocks)
3196{
3197 struct metapage *mp;
3198 struct dmap *dp;
3199 int nb, rc;
3200 s64 lblkno, rem;
3201 struct inode *ipbmap = JFS_SBI(ip->i_sb)->ipbmap;
3202 struct bmap *bmp = JFS_SBI(ip->i_sb)->bmap;
3203
3204 IREAD_LOCK(ipbmap, RDWRLOCK_DMAP);
3205
3206 /* block to be allocated better be within the mapsize. */
3207 ASSERT(nblocks <= bmp->db_mapsize - blkno);
3208
3209 /*
3210 * allocate the blocks a dmap at a time.
3211 */
3212 mp = NULL;
3213 for (rem = nblocks; rem > 0; rem -= nb, blkno += nb) {
3214 /* release previous dmap if any */
3215 if (mp) {
3216 write_metapage(mp);
3217 }
3218
3219 /* get the buffer for the current dmap. */
3220 lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage);
3221 mp = read_metapage(ipbmap, lblkno, PSIZE, 0);
3222 if (mp == NULL) {
3223 IREAD_UNLOCK(ipbmap);
3224 return -EIO;
3225 }
3226 dp = (struct dmap *) mp->data;
3227
3228 /* determine the number of blocks to be allocated from
3229 * this dmap.
3230 */
3231 nb = min(rem, BPERDMAP - (blkno & (BPERDMAP - 1)));
3232
3233 /* allocate the blocks. */
3234 if ((rc = dbAllocDmapBU(bmp, dp, blkno, nb))) {
3235 release_metapage(mp);
3236 IREAD_UNLOCK(ipbmap);
3237 return (rc);
3238 }
3239 }
3240
3241 /* write the last buffer. */
3242 write_metapage(mp);
3243
3244 IREAD_UNLOCK(ipbmap);
3245
3246 return (0);
3247}
3248
3249
3250static int dbAllocDmapBU(struct bmap * bmp, struct dmap * dp, s64 blkno,
3251 int nblocks)
3252{
3253 int rc;
3254 int dbitno, word, rembits, nb, nwords, wbitno, agno;
3255 s8 oldroot;
3256 struct dmaptree *tp = (struct dmaptree *) & dp->tree;
3257
3258 /* save the current value of the root (i.e. maximum free string)
3259 * of the dmap tree.
3260 */
3261 oldroot = tp->stree[ROOT];
3262
3263 /* determine the bit number and word within the dmap of the
3264 * starting block.
3265 */
3266 dbitno = blkno & (BPERDMAP - 1);
3267 word = dbitno >> L2DBWORD;
3268
3269 /* block range better be within the dmap */
3270 assert(dbitno + nblocks <= BPERDMAP);
3271
3272 /* allocate the bits of the dmap's words corresponding to the block
3273 * range. not all bits of the first and last words may be contained
3274 * within the block range. if this is the case, we'll work against
3275 * those words (i.e. partial first and/or last) on an individual basis
3276 * (a single pass), allocating the bits of interest by hand and
3277 * updating the leaf corresponding to the dmap word. a single pass
3278 * will be used for all dmap words fully contained within the
3279 * specified range. within this pass, the bits of all fully contained
3280 * dmap words will be marked as free in a single shot and the leaves
3281 * will be updated. a single leaf may describe the free space of
3282 * multiple dmap words, so we may update only a subset of the actual
3283 * leaves corresponding to the dmap words of the block range.
3284 */
3285 for (rembits = nblocks; rembits > 0; rembits -= nb, dbitno += nb) {
3286 /* determine the bit number within the word and
3287 * the number of bits within the word.
3288 */
3289 wbitno = dbitno & (DBWORD - 1);
3290 nb = min(rembits, DBWORD - wbitno);
3291
3292 /* check if only part of a word is to be allocated.
3293 */
3294 if (nb < DBWORD) {
3295 /* allocate (set to 1) the appropriate bits within
3296 * this dmap word.
3297 */
3298 dp->wmap[word] |= cpu_to_le32(ONES << (DBWORD - nb)
3299 >> wbitno);
3300
3301 word++;
3302 } else {
3303 /* one or more dmap words are fully contained
3304 * within the block range. determine how many
3305 * words and allocate (set to 1) the bits of these
3306 * words.
3307 */
3308 nwords = rembits >> L2DBWORD;
3309 memset(&dp->wmap[word], (int) ONES, nwords * 4);
3310
3311 /* determine how many bits */
3312 nb = nwords << L2DBWORD;
3313 word += nwords;
3314 }
3315 }
3316
3317 /* update the free count for this dmap */
3318 le32_add_cpu(&dp->nfree, -nblocks);
3319
3320 /* reconstruct summary tree */
3321 dbInitDmapTree(dp);
3322
3323 BMAP_LOCK(bmp);
3324
3325 /* if this allocation group is completely free,
3326 * update the highest active allocation group number
3327 * if this allocation group is the new max.
3328 */
3329 agno = blkno >> bmp->db_agl2size;
3330 if (agno > bmp->db_maxag)
3331 bmp->db_maxag = agno;
3332
3333 /* update the free count for the allocation group and map */
3334 bmp->db_agfree[agno] -= nblocks;
3335 bmp->db_nfree -= nblocks;
3336
3337 BMAP_UNLOCK(bmp);
3338
3339 /* if the root has not changed, done. */
3340 if (tp->stree[ROOT] == oldroot)
3341 return (0);
3342
3343 /* root changed. bubble the change up to the dmap control pages.
3344 * if the adjustment of the upper level control pages fails,
3345 * backout the bit allocation (thus making everything consistent).
3346 */
3347 if ((rc = dbAdjCtl(bmp, blkno, tp->stree[ROOT], 1, 0)))
3348 dbFreeBits(bmp, dp, blkno, nblocks);
3349
3350 return (rc);
3351}
3352
3353
3354/*
3355 * NAME: dbExtendFS()
3356 *
3357 * FUNCTION: extend bmap from blkno for nblocks;
3358 * dbExtendFS() updates bmap ready for dbAllocBottomUp();
3359 *
3360 * L2
3361 * |
3362 * L1---------------------------------L1
3363 * | |
3364 * L0---------L0---------L0 L0---------L0---------L0
3365 * | | | | | |
3366 * d0,...,dn d0,...,dn d0,...,dn d0,...,dn d0,...,dn d0,.,dm;
3367 * L2L1L0d0,...,dnL0d0,...,dnL0d0,...,dnL1L0d0,...,dnL0d0,...,dnL0d0,..dm
3368 *
3369 * <---old---><----------------------------extend----------------------->
3370 */
3371int dbExtendFS(struct inode *ipbmap, s64 blkno, s64 nblocks)
3372{
3373 struct jfs_sb_info *sbi = JFS_SBI(ipbmap->i_sb);
3374 int nbperpage = sbi->nbperpage;
3375 int i, i0 = true, j, j0 = true, k, n;
3376 s64 newsize;
3377 s64 p;
3378 struct metapage *mp, *l2mp, *l1mp = NULL, *l0mp = NULL;
3379 struct dmapctl *l2dcp, *l1dcp, *l0dcp;
3380 struct dmap *dp;
3381 s8 *l0leaf, *l1leaf, *l2leaf;
3382 struct bmap *bmp = sbi->bmap;
3383 int agno, l2agsize, oldl2agsize;
3384 s64 ag_rem;
3385
3386 newsize = blkno + nblocks;
3387
3388 jfs_info("dbExtendFS: blkno:%Ld nblocks:%Ld newsize:%Ld",
3389 (long long) blkno, (long long) nblocks, (long long) newsize);
3390
3391 /*
3392 * initialize bmap control page.
3393 *
3394 * all the data in bmap control page should exclude
3395 * the mkfs hidden dmap page.
3396 */
3397
3398 /* update mapsize */
3399 bmp->db_mapsize = newsize;
3400 bmp->db_maxlevel = BMAPSZTOLEV(bmp->db_mapsize);
3401
3402 /* compute new AG size */
3403 l2agsize = dbGetL2AGSize(newsize);
3404 oldl2agsize = bmp->db_agl2size;
3405
3406 bmp->db_agl2size = l2agsize;
3407 bmp->db_agsize = 1 << l2agsize;
3408
3409 /* compute new number of AG */
3410 agno = bmp->db_numag;
3411 bmp->db_numag = newsize >> l2agsize;
3412 bmp->db_numag += ((u32) newsize % (u32) bmp->db_agsize) ? 1 : 0;
3413
3414 /*
3415 * reconfigure db_agfree[]
3416 * from old AG configuration to new AG configuration;
3417 *
3418 * coalesce contiguous k (newAGSize/oldAGSize) AGs;
3419 * i.e., (AGi, ..., AGj) where i = k*n and j = k*(n+1) - 1 to AGn;
3420 * note: new AG size = old AG size * (2**x).
3421 */
3422 if (l2agsize == oldl2agsize)
3423 goto extend;
3424 k = 1 << (l2agsize - oldl2agsize);
3425 ag_rem = bmp->db_agfree[0]; /* save agfree[0] */
3426 for (i = 0, n = 0; i < agno; n++) {
3427 bmp->db_agfree[n] = 0; /* init collection point */
3428
3429 /* coalesce contiguous k AGs; */
3430 for (j = 0; j < k && i < agno; j++, i++) {
3431 /* merge AGi to AGn */
3432 bmp->db_agfree[n] += bmp->db_agfree[i];
3433 }
3434 }
3435 bmp->db_agfree[0] += ag_rem; /* restore agfree[0] */
3436
3437 for (; n < MAXAG; n++)
3438 bmp->db_agfree[n] = 0;
3439
3440 /*
3441 * update highest active ag number
3442 */
3443
3444 bmp->db_maxag = bmp->db_maxag / k;
3445
3446 /*
3447 * extend bmap
3448 *
3449 * update bit maps and corresponding level control pages;
3450 * global control page db_nfree, db_agfree[agno], db_maxfreebud;
3451 */
3452 extend:
3453 /* get L2 page */
3454 p = BMAPBLKNO + nbperpage; /* L2 page */
3455 l2mp = read_metapage(ipbmap, p, PSIZE, 0);
3456 if (!l2mp) {
3457 jfs_error(ipbmap->i_sb, "L2 page could not be read\n");
3458 return -EIO;
3459 }
3460 l2dcp = (struct dmapctl *) l2mp->data;
3461
3462 /* compute start L1 */
3463 k = blkno >> L2MAXL1SIZE;
3464 l2leaf = l2dcp->stree + CTLLEAFIND + k;
3465 p = BLKTOL1(blkno, sbi->l2nbperpage); /* L1 page */
3466
3467 /*
3468 * extend each L1 in L2
3469 */
3470 for (; k < LPERCTL; k++, p += nbperpage) {
3471 /* get L1 page */
3472 if (j0) {
3473 /* read in L1 page: (blkno & (MAXL1SIZE - 1)) */
3474 l1mp = read_metapage(ipbmap, p, PSIZE, 0);
3475 if (l1mp == NULL)
3476 goto errout;
3477 l1dcp = (struct dmapctl *) l1mp->data;
3478
3479 /* compute start L0 */
3480 j = (blkno & (MAXL1SIZE - 1)) >> L2MAXL0SIZE;
3481 l1leaf = l1dcp->stree + CTLLEAFIND + j;
3482 p = BLKTOL0(blkno, sbi->l2nbperpage);
3483 j0 = false;
3484 } else {
3485 /* assign/init L1 page */
3486 l1mp = get_metapage(ipbmap, p, PSIZE, 0);
3487 if (l1mp == NULL)
3488 goto errout;
3489
3490 l1dcp = (struct dmapctl *) l1mp->data;
3491
3492 /* compute start L0 */
3493 j = 0;
3494 l1leaf = l1dcp->stree + CTLLEAFIND;
3495 p += nbperpage; /* 1st L0 of L1.k */
3496 }
3497
3498 /*
3499 * extend each L0 in L1
3500 */
3501 for (; j < LPERCTL; j++) {
3502 /* get L0 page */
3503 if (i0) {
3504 /* read in L0 page: (blkno & (MAXL0SIZE - 1)) */
3505
3506 l0mp = read_metapage(ipbmap, p, PSIZE, 0);
3507 if (l0mp == NULL)
3508 goto errout;
3509 l0dcp = (struct dmapctl *) l0mp->data;
3510
3511 /* compute start dmap */
3512 i = (blkno & (MAXL0SIZE - 1)) >>
3513 L2BPERDMAP;
3514 l0leaf = l0dcp->stree + CTLLEAFIND + i;
3515 p = BLKTODMAP(blkno,
3516 sbi->l2nbperpage);
3517 i0 = false;
3518 } else {
3519 /* assign/init L0 page */
3520 l0mp = get_metapage(ipbmap, p, PSIZE, 0);
3521 if (l0mp == NULL)
3522 goto errout;
3523
3524 l0dcp = (struct dmapctl *) l0mp->data;
3525
3526 /* compute start dmap */
3527 i = 0;
3528 l0leaf = l0dcp->stree + CTLLEAFIND;
3529 p += nbperpage; /* 1st dmap of L0.j */
3530 }
3531
3532 /*
3533 * extend each dmap in L0
3534 */
3535 for (; i < LPERCTL; i++) {
3536 /*
3537 * reconstruct the dmap page, and
3538 * initialize corresponding parent L0 leaf
3539 */
3540 if ((n = blkno & (BPERDMAP - 1))) {
3541 /* read in dmap page: */
3542 mp = read_metapage(ipbmap, p,
3543 PSIZE, 0);
3544 if (mp == NULL)
3545 goto errout;
3546 n = min(nblocks, (s64)BPERDMAP - n);
3547 } else {
3548 /* assign/init dmap page */
3549 mp = read_metapage(ipbmap, p,
3550 PSIZE, 0);
3551 if (mp == NULL)
3552 goto errout;
3553
3554 n = min_t(s64, nblocks, BPERDMAP);
3555 }
3556
3557 dp = (struct dmap *) mp->data;
3558 *l0leaf = dbInitDmap(dp, blkno, n);
3559
3560 bmp->db_nfree += n;
3561 agno = le64_to_cpu(dp->start) >> l2agsize;
3562 bmp->db_agfree[agno] += n;
3563
3564 write_metapage(mp);
3565
3566 l0leaf++;
3567 p += nbperpage;
3568
3569 blkno += n;
3570 nblocks -= n;
3571 if (nblocks == 0)
3572 break;
3573 } /* for each dmap in a L0 */
3574
3575 /*
3576 * build current L0 page from its leaves, and
3577 * initialize corresponding parent L1 leaf
3578 */
3579 *l1leaf = dbInitDmapCtl(l0dcp, 0, ++i);
3580 write_metapage(l0mp);
3581 l0mp = NULL;
3582
3583 if (nblocks)
3584 l1leaf++; /* continue for next L0 */
3585 else {
3586 /* more than 1 L0 ? */
3587 if (j > 0)
3588 break; /* build L1 page */
3589 else {
3590 /* summarize in global bmap page */
3591 bmp->db_maxfreebud = *l1leaf;
3592 release_metapage(l1mp);
3593 release_metapage(l2mp);
3594 goto finalize;
3595 }
3596 }
3597 } /* for each L0 in a L1 */
3598
3599 /*
3600 * build current L1 page from its leaves, and
3601 * initialize corresponding parent L2 leaf
3602 */
3603 *l2leaf = dbInitDmapCtl(l1dcp, 1, ++j);
3604 write_metapage(l1mp);
3605 l1mp = NULL;
3606
3607 if (nblocks)
3608 l2leaf++; /* continue for next L1 */
3609 else {
3610 /* more than 1 L1 ? */
3611 if (k > 0)
3612 break; /* build L2 page */
3613 else {
3614 /* summarize in global bmap page */
3615 bmp->db_maxfreebud = *l2leaf;
3616 release_metapage(l2mp);
3617 goto finalize;
3618 }
3619 }
3620 } /* for each L1 in a L2 */
3621
3622 jfs_error(ipbmap->i_sb, "function has not returned as expected\n");
3623errout:
3624 if (l0mp)
3625 release_metapage(l0mp);
3626 if (l1mp)
3627 release_metapage(l1mp);
3628 release_metapage(l2mp);
3629 return -EIO;
3630
3631 /*
3632 * finalize bmap control page
3633 */
3634finalize:
3635
3636 return 0;
3637}
3638
3639
3640/*
3641 * dbFinalizeBmap()
3642 */
3643void dbFinalizeBmap(struct inode *ipbmap)
3644{
3645 struct bmap *bmp = JFS_SBI(ipbmap->i_sb)->bmap;
3646 int actags, inactags, l2nl;
3647 s64 ag_rem, actfree, inactfree, avgfree;
3648 int i, n;
3649
3650 /*
3651 * finalize bmap control page
3652 */
3653//finalize:
3654 /*
3655 * compute db_agpref: preferred ag to allocate from
3656 * (the leftmost ag with average free space in it);
3657 */
3658//agpref:
3659 /* get the number of active ags and inacitve ags */
3660 actags = bmp->db_maxag + 1;
3661 inactags = bmp->db_numag - actags;
3662 ag_rem = bmp->db_mapsize & (bmp->db_agsize - 1); /* ??? */
3663
3664 /* determine how many blocks are in the inactive allocation
3665 * groups. in doing this, we must account for the fact that
3666 * the rightmost group might be a partial group (i.e. file
3667 * system size is not a multiple of the group size).
3668 */
3669 inactfree = (inactags && ag_rem) ?
3670 ((inactags - 1) << bmp->db_agl2size) + ag_rem
3671 : inactags << bmp->db_agl2size;
3672
3673 /* determine how many free blocks are in the active
3674 * allocation groups plus the average number of free blocks
3675 * within the active ags.
3676 */
3677 actfree = bmp->db_nfree - inactfree;
3678 avgfree = (u32) actfree / (u32) actags;
3679
3680 /* if the preferred allocation group has not average free space.
3681 * re-establish the preferred group as the leftmost
3682 * group with average free space.
3683 */
3684 if (bmp->db_agfree[bmp->db_agpref] < avgfree) {
3685 for (bmp->db_agpref = 0; bmp->db_agpref < actags;
3686 bmp->db_agpref++) {
3687 if (bmp->db_agfree[bmp->db_agpref] >= avgfree)
3688 break;
3689 }
3690 if (bmp->db_agpref >= bmp->db_numag) {
3691 jfs_error(ipbmap->i_sb,
3692 "cannot find ag with average freespace\n");
3693 }
3694 }
3695
3696 /*
3697 * compute db_aglevel, db_agheight, db_width, db_agstart:
3698 * an ag is covered in aglevel dmapctl summary tree,
3699 * at agheight level height (from leaf) with agwidth number of nodes
3700 * each, which starts at agstart index node of the smmary tree node
3701 * array;
3702 */
3703 bmp->db_aglevel = BMAPSZTOLEV(bmp->db_agsize);
3704 l2nl =
3705 bmp->db_agl2size - (L2BPERDMAP + bmp->db_aglevel * L2LPERCTL);
3706 bmp->db_agheight = l2nl >> 1;
3707 bmp->db_agwidth = 1 << (l2nl - (bmp->db_agheight << 1));
3708 for (i = 5 - bmp->db_agheight, bmp->db_agstart = 0, n = 1; i > 0;
3709 i--) {
3710 bmp->db_agstart += n;
3711 n <<= 2;
3712 }
3713
3714}
3715
3716
3717/*
3718 * NAME: dbInitDmap()/ujfs_idmap_page()
3719 *
3720 * FUNCTION: initialize working/persistent bitmap of the dmap page
3721 * for the specified number of blocks:
3722 *
3723 * at entry, the bitmaps had been initialized as free (ZEROS);
3724 * The number of blocks will only account for the actually
3725 * existing blocks. Blocks which don't actually exist in
3726 * the aggregate will be marked as allocated (ONES);
3727 *
3728 * PARAMETERS:
3729 * dp - pointer to page of map
3730 * nblocks - number of blocks this page
3731 *
3732 * RETURNS: NONE
3733 */
3734static int dbInitDmap(struct dmap * dp, s64 Blkno, int nblocks)
3735{
3736 int blkno, w, b, r, nw, nb, i;
3737
3738 /* starting block number within the dmap */
3739 blkno = Blkno & (BPERDMAP - 1);
3740
3741 if (blkno == 0) {
3742 dp->nblocks = dp->nfree = cpu_to_le32(nblocks);
3743 dp->start = cpu_to_le64(Blkno);
3744
3745 if (nblocks == BPERDMAP) {
3746 memset(&dp->wmap[0], 0, LPERDMAP * 4);
3747 memset(&dp->pmap[0], 0, LPERDMAP * 4);
3748 goto initTree;
3749 }
3750 } else {
3751 le32_add_cpu(&dp->nblocks, nblocks);
3752 le32_add_cpu(&dp->nfree, nblocks);
3753 }
3754
3755 /* word number containing start block number */
3756 w = blkno >> L2DBWORD;
3757
3758 /*
3759 * free the bits corresponding to the block range (ZEROS):
3760 * note: not all bits of the first and last words may be contained
3761 * within the block range.
3762 */
3763 for (r = nblocks; r > 0; r -= nb, blkno += nb) {
3764 /* number of bits preceding range to be freed in the word */
3765 b = blkno & (DBWORD - 1);
3766 /* number of bits to free in the word */
3767 nb = min(r, DBWORD - b);
3768
3769 /* is partial word to be freed ? */
3770 if (nb < DBWORD) {
3771 /* free (set to 0) from the bitmap word */
3772 dp->wmap[w] &= cpu_to_le32(~(ONES << (DBWORD - nb)
3773 >> b));
3774 dp->pmap[w] &= cpu_to_le32(~(ONES << (DBWORD - nb)
3775 >> b));
3776
3777 /* skip the word freed */
3778 w++;
3779 } else {
3780 /* free (set to 0) contiguous bitmap words */
3781 nw = r >> L2DBWORD;
3782 memset(&dp->wmap[w], 0, nw * 4);
3783 memset(&dp->pmap[w], 0, nw * 4);
3784
3785 /* skip the words freed */
3786 nb = nw << L2DBWORD;
3787 w += nw;
3788 }
3789 }
3790
3791 /*
3792 * mark bits following the range to be freed (non-existing
3793 * blocks) as allocated (ONES)
3794 */
3795
3796 if (blkno == BPERDMAP)
3797 goto initTree;
3798
3799 /* the first word beyond the end of existing blocks */
3800 w = blkno >> L2DBWORD;
3801
3802 /* does nblocks fall on a 32-bit boundary ? */
3803 b = blkno & (DBWORD - 1);
3804 if (b) {
3805 /* mark a partial word allocated */
3806 dp->wmap[w] = dp->pmap[w] = cpu_to_le32(ONES >> b);
3807 w++;
3808 }
3809
3810 /* set the rest of the words in the page to allocated (ONES) */
3811 for (i = w; i < LPERDMAP; i++)
3812 dp->pmap[i] = dp->wmap[i] = cpu_to_le32(ONES);
3813
3814 /*
3815 * init tree
3816 */
3817 initTree:
3818 return (dbInitDmapTree(dp));
3819}
3820
3821
3822/*
3823 * NAME: dbInitDmapTree()/ujfs_complete_dmap()
3824 *
3825 * FUNCTION: initialize summary tree of the specified dmap:
3826 *
3827 * at entry, bitmap of the dmap has been initialized;
3828 *
3829 * PARAMETERS:
3830 * dp - dmap to complete
3831 * blkno - starting block number for this dmap
3832 * treemax - will be filled in with max free for this dmap
3833 *
3834 * RETURNS: max free string at the root of the tree
3835 */
3836static int dbInitDmapTree(struct dmap * dp)
3837{
3838 struct dmaptree *tp;
3839 s8 *cp;
3840 int i;
3841
3842 /* init fixed info of tree */
3843 tp = &dp->tree;
3844 tp->nleafs = cpu_to_le32(LPERDMAP);
3845 tp->l2nleafs = cpu_to_le32(L2LPERDMAP);
3846 tp->leafidx = cpu_to_le32(LEAFIND);
3847 tp->height = cpu_to_le32(4);
3848 tp->budmin = BUDMIN;
3849
3850 /* init each leaf from corresponding wmap word:
3851 * note: leaf is set to NOFREE(-1) if all blocks of corresponding
3852 * bitmap word are allocated.
3853 */
3854 cp = tp->stree + le32_to_cpu(tp->leafidx);
3855 for (i = 0; i < LPERDMAP; i++)
3856 *cp++ = dbMaxBud((u8 *) & dp->wmap[i]);
3857
3858 /* build the dmap's binary buddy summary tree */
3859 return (dbInitTree(tp));
3860}
3861
3862
3863/*
3864 * NAME: dbInitTree()/ujfs_adjtree()
3865 *
3866 * FUNCTION: initialize binary buddy summary tree of a dmap or dmapctl.
3867 *
3868 * at entry, the leaves of the tree has been initialized
3869 * from corresponding bitmap word or root of summary tree
3870 * of the child control page;
3871 * configure binary buddy system at the leaf level, then
3872 * bubble up the values of the leaf nodes up the tree.
3873 *
3874 * PARAMETERS:
3875 * cp - Pointer to the root of the tree
3876 * l2leaves- Number of leaf nodes as a power of 2
3877 * l2min - Number of blocks that can be covered by a leaf
3878 * as a power of 2
3879 *
3880 * RETURNS: max free string at the root of the tree
3881 */
3882static int dbInitTree(struct dmaptree * dtp)
3883{
3884 int l2max, l2free, bsize, nextb, i;
3885 int child, parent, nparent;
3886 s8 *tp, *cp, *cp1;
3887
3888 tp = dtp->stree;
3889
3890 /* Determine the maximum free string possible for the leaves */
3891 l2max = le32_to_cpu(dtp->l2nleafs) + dtp->budmin;
3892
3893 /*
3894 * configure the leaf levevl into binary buddy system
3895 *
3896 * Try to combine buddies starting with a buddy size of 1
3897 * (i.e. two leaves). At a buddy size of 1 two buddy leaves
3898 * can be combined if both buddies have a maximum free of l2min;
3899 * the combination will result in the left-most buddy leaf having
3900 * a maximum free of l2min+1.
3901 * After processing all buddies for a given size, process buddies
3902 * at the next higher buddy size (i.e. current size * 2) and
3903 * the next maximum free (current free + 1).
3904 * This continues until the maximum possible buddy combination
3905 * yields maximum free.
3906 */
3907 for (l2free = dtp->budmin, bsize = 1; l2free < l2max;
3908 l2free++, bsize = nextb) {
3909 /* get next buddy size == current buddy pair size */
3910 nextb = bsize << 1;
3911
3912 /* scan each adjacent buddy pair at current buddy size */
3913 for (i = 0, cp = tp + le32_to_cpu(dtp->leafidx);
3914 i < le32_to_cpu(dtp->nleafs);
3915 i += nextb, cp += nextb) {
3916 /* coalesce if both adjacent buddies are max free */
3917 if (*cp == l2free && *(cp + bsize) == l2free) {
3918 *cp = l2free + 1; /* left take right */
3919 *(cp + bsize) = -1; /* right give left */
3920 }
3921 }
3922 }
3923
3924 /*
3925 * bubble summary information of leaves up the tree.
3926 *
3927 * Starting at the leaf node level, the four nodes described by
3928 * the higher level parent node are compared for a maximum free and
3929 * this maximum becomes the value of the parent node.
3930 * when all lower level nodes are processed in this fashion then
3931 * move up to the next level (parent becomes a lower level node) and
3932 * continue the process for that level.
3933 */
3934 for (child = le32_to_cpu(dtp->leafidx),
3935 nparent = le32_to_cpu(dtp->nleafs) >> 2;
3936 nparent > 0; nparent >>= 2, child = parent) {
3937 /* get index of 1st node of parent level */
3938 parent = (child - 1) >> 2;
3939
3940 /* set the value of the parent node as the maximum
3941 * of the four nodes of the current level.
3942 */
3943 for (i = 0, cp = tp + child, cp1 = tp + parent;
3944 i < nparent; i++, cp += 4, cp1++)
3945 *cp1 = TREEMAX(cp);
3946 }
3947
3948 return (*tp);
3949}
3950
3951
3952/*
3953 * dbInitDmapCtl()
3954 *
3955 * function: initialize dmapctl page
3956 */
3957static int dbInitDmapCtl(struct dmapctl * dcp, int level, int i)
3958{ /* start leaf index not covered by range */
3959 s8 *cp;
3960
3961 dcp->nleafs = cpu_to_le32(LPERCTL);
3962 dcp->l2nleafs = cpu_to_le32(L2LPERCTL);
3963 dcp->leafidx = cpu_to_le32(CTLLEAFIND);
3964 dcp->height = cpu_to_le32(5);
3965 dcp->budmin = L2BPERDMAP + L2LPERCTL * level;
3966
3967 /*
3968 * initialize the leaves of current level that were not covered
3969 * by the specified input block range (i.e. the leaves have no
3970 * low level dmapctl or dmap).
3971 */
3972 cp = &dcp->stree[CTLLEAFIND + i];
3973 for (; i < LPERCTL; i++)
3974 *cp++ = NOFREE;
3975
3976 /* build the dmap's binary buddy summary tree */
3977 return (dbInitTree((struct dmaptree *) dcp));
3978}
3979
3980
3981/*
3982 * NAME: dbGetL2AGSize()/ujfs_getagl2size()
3983 *
3984 * FUNCTION: Determine log2(allocation group size) from aggregate size
3985 *
3986 * PARAMETERS:
3987 * nblocks - Number of blocks in aggregate
3988 *
3989 * RETURNS: log2(allocation group size) in aggregate blocks
3990 */
3991static int dbGetL2AGSize(s64 nblocks)
3992{
3993 s64 sz;
3994 s64 m;
3995 int l2sz;
3996
3997 if (nblocks < BPERDMAP * MAXAG)
3998 return (L2BPERDMAP);
3999
4000 /* round up aggregate size to power of 2 */
4001 m = ((u64) 1 << (64 - 1));
4002 for (l2sz = 64; l2sz >= 0; l2sz--, m >>= 1) {
4003 if (m & nblocks)
4004 break;
4005 }
4006
4007 sz = (s64) 1 << l2sz;
4008 if (sz < nblocks)
4009 l2sz += 1;
4010
4011 /* agsize = roundupSize/max_number_of_ag */
4012 return (l2sz - L2MAXAG);
4013}
4014
4015
4016/*
4017 * NAME: dbMapFileSizeToMapSize()
4018 *
4019 * FUNCTION: compute number of blocks the block allocation map file
4020 * can cover from the map file size;
4021 *
4022 * RETURNS: Number of blocks which can be covered by this block map file;
4023 */
4024
4025/*
4026 * maximum number of map pages at each level including control pages
4027 */
4028#define MAXL0PAGES (1 + LPERCTL)
4029#define MAXL1PAGES (1 + LPERCTL * MAXL0PAGES)
4030#define MAXL2PAGES (1 + LPERCTL * MAXL1PAGES)
4031
4032/*
4033 * convert number of map pages to the zero origin top dmapctl level
4034 */
4035#define BMAPPGTOLEV(npages) \
4036 (((npages) <= 3 + MAXL0PAGES) ? 0 : \
4037 ((npages) <= 2 + MAXL1PAGES) ? 1 : 2)
4038
4039s64 dbMapFileSizeToMapSize(struct inode * ipbmap)
4040{
4041 struct super_block *sb = ipbmap->i_sb;
4042 s64 nblocks;
4043 s64 npages, ndmaps;
4044 int level, i;
4045 int complete, factor;
4046
4047 nblocks = ipbmap->i_size >> JFS_SBI(sb)->l2bsize;
4048 npages = nblocks >> JFS_SBI(sb)->l2nbperpage;
4049 level = BMAPPGTOLEV(npages);
4050
4051 /* At each level, accumulate the number of dmap pages covered by
4052 * the number of full child levels below it;
4053 * repeat for the last incomplete child level.
4054 */
4055 ndmaps = 0;
4056 npages--; /* skip the first global control page */
4057 /* skip higher level control pages above top level covered by map */
4058 npages -= (2 - level);
4059 npages--; /* skip top level's control page */
4060 for (i = level; i >= 0; i--) {
4061 factor =
4062 (i == 2) ? MAXL1PAGES : ((i == 1) ? MAXL0PAGES : 1);
4063 complete = (u32) npages / factor;
4064 ndmaps += complete * ((i == 2) ? LPERCTL * LPERCTL :
4065 ((i == 1) ? LPERCTL : 1));
4066
4067 /* pages in last/incomplete child */
4068 npages = (u32) npages % factor;
4069 /* skip incomplete child's level control page */
4070 npages--;
4071 }
4072
4073 /* convert the number of dmaps into the number of blocks
4074 * which can be covered by the dmaps;
4075 */
4076 nblocks = ndmaps << L2BPERDMAP;
4077
4078 return (nblocks);
4079}
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}