1/* $NetBSD: ffs_alloc.c,v 1.14 2004/06/20 22:20:18 jmc Exp $ */
2/* From: NetBSD: ffs_alloc.c,v 1.50 2001/09/06 02:16:01 lukem Exp */
3
4/*
5 * Copyright (c) 2002 Networks Associates Technology, Inc.
6 * All rights reserved.
7 *
8 * This software was developed for the FreeBSD Project by Marshall
9 * Kirk McKusick and Network Associates Laboratories, the Security
10 * Research Division of Network Associates, Inc. under DARPA/SPAWAR
11 * contract N66001-01-C-8035 ("CBOSS"), as part of the DARPA CHATS
12 * research program
13 *
14 * Copyright (c) 1982, 1986, 1989, 1993
15 * The Regents of the University of California. All rights reserved.
16 *
17 * Redistribution and use in source and binary forms, with or without
18 * modification, are permitted provided that the following conditions
19 * are met:
20 * 1. Redistributions of source code must retain the above copyright
21 * notice, this list of conditions and the following disclaimer.
22 * 2. Redistributions in binary form must reproduce the above copyright
23 * notice, this list of conditions and the following disclaimer in the
24 * documentation and/or other materials provided with the distribution.
25 * 3. Neither the name of the University nor the names of its contributors
26 * may be used to endorse or promote products derived from this software
27 * without specific prior written permission.
28 *
29 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
30 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
31 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
32 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
33 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
34 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
35 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
36 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
37 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
38 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
39 * SUCH DAMAGE.
40 *
41 * @(#)ffs_alloc.c 8.19 (Berkeley) 7/13/95
42 */
43
44#include <sys/cdefs.h>
|
45__FBSDID("$FreeBSD: head/usr.sbin/makefs/ffs/ffs_alloc.c 214921 2010-11-07 16:05:04Z cognet $");
|
| 45__FBSDID("$FreeBSD: head/usr.sbin/makefs/ffs/ffs_alloc.c 241015 2012-09-27 23:31:19Z mdf $"); |
46
47#include <sys/param.h>
48#include <sys/time.h>
49
50#include <errno.h>
|
| 51#include <stdint.h> |
52
53#include "makefs.h"
54
55#include <ufs/ufs/dinode.h>
56#include <ufs/ffs/fs.h>
57
58#include "ffs/ufs_bswap.h"
59#include "ffs/buf.h"
60#include "ffs/ufs_inode.h"
61#include "ffs/ffs_extern.h"
62
63static int scanc(u_int, const u_char *, const u_char *, int);
64
65static daddr_t ffs_alloccg(struct inode *, int, daddr_t, int);
66static daddr_t ffs_alloccgblk(struct inode *, struct buf *, daddr_t);
67static daddr_t ffs_hashalloc(struct inode *, int, daddr_t, int,
68 daddr_t (*)(struct inode *, int, daddr_t, int));
69static int32_t ffs_mapsearch(struct fs *, struct cg *, daddr_t, int);
70
71/*
72 * Allocate a block in the file system.
73 *
74 * The size of the requested block is given, which must be some
75 * multiple of fs_fsize and <= fs_bsize.
76 * A preference may be optionally specified. If a preference is given
77 * the following hierarchy is used to allocate a block:
78 * 1) allocate the requested block.
79 * 2) allocate a rotationally optimal block in the same cylinder.
80 * 3) allocate a block in the same cylinder group.
81 * 4) quadradically rehash into other cylinder groups, until an
82 * available block is located.
83 * If no block preference is given the following hierarchy is used
84 * to allocate a block:
85 * 1) allocate a block in the cylinder group that contains the
86 * inode for the file.
87 * 2) quadradically rehash into other cylinder groups, until an
88 * available block is located.
89 */
90int
91ffs_alloc(struct inode *ip, daddr_t lbn __unused, daddr_t bpref, int size,
92 daddr_t *bnp)
93{
94 struct fs *fs = ip->i_fs;
95 daddr_t bno;
96 int cg;
97
98 *bnp = 0;
99 if (size > fs->fs_bsize || fragoff(fs, size) != 0) {
100 errx(1, "ffs_alloc: bad size: bsize %d size %d",
101 fs->fs_bsize, size);
102 }
103 if (size == fs->fs_bsize && fs->fs_cstotal.cs_nbfree == 0)
104 goto nospace;
105 if (bpref >= fs->fs_size)
106 bpref = 0;
107 if (bpref == 0)
108 cg = ino_to_cg(fs, ip->i_number);
109 else
110 cg = dtog(fs, bpref);
111 bno = ffs_hashalloc(ip, cg, bpref, size, ffs_alloccg);
112 if (bno > 0) {
113 if (ip->i_fs->fs_magic == FS_UFS1_MAGIC)
114 ip->i_ffs1_blocks += size / DEV_BSIZE;
115 else
116 ip->i_ffs2_blocks += size / DEV_BSIZE;
117 *bnp = bno;
118 return (0);
119 }
120nospace:
121 return (ENOSPC);
122}
123
124/*
125 * Select the desired position for the next block in a file. The file is
126 * logically divided into sections. The first section is composed of the
127 * direct blocks. Each additional section contains fs_maxbpg blocks.
128 *
129 * If no blocks have been allocated in the first section, the policy is to
130 * request a block in the same cylinder group as the inode that describes
131 * the file. If no blocks have been allocated in any other section, the
132 * policy is to place the section in a cylinder group with a greater than
133 * average number of free blocks. An appropriate cylinder group is found
134 * by using a rotor that sweeps the cylinder groups. When a new group of
135 * blocks is needed, the sweep begins in the cylinder group following the
136 * cylinder group from which the previous allocation was made. The sweep
137 * continues until a cylinder group with greater than the average number
138 * of free blocks is found. If the allocation is for the first block in an
139 * indirect block, the information on the previous allocation is unavailable;
140 * here a best guess is made based upon the logical block number being
141 * allocated.
142 *
143 * If a section is already partially allocated, the policy is to
144 * contiguously allocate fs_maxcontig blocks. The end of one of these
145 * contiguous blocks and the beginning of the next is physically separated
146 * so that the disk head will be in transit between them for at least
147 * fs_rotdelay milliseconds. This is to allow time for the processor to
148 * schedule another I/O transfer.
149 */
150/* XXX ondisk32 */
151daddr_t
152ffs_blkpref_ufs1(struct inode *ip, daddr_t lbn, int indx, int32_t *bap)
153{
154 struct fs *fs;
155 int cg;
156 int avgbfree, startcg;
157
158 fs = ip->i_fs;
159 if (indx % fs->fs_maxbpg == 0 || bap[indx - 1] == 0) {
160 if (lbn < NDADDR + NINDIR(fs)) {
161 cg = ino_to_cg(fs, ip->i_number);
162 return (fs->fs_fpg * cg + fs->fs_frag);
163 }
164 /*
165 * Find a cylinder with greater than average number of
166 * unused data blocks.
167 */
168 if (indx == 0 || bap[indx - 1] == 0)
169 startcg =
170 ino_to_cg(fs, ip->i_number) + lbn / fs->fs_maxbpg;
171 else
172 startcg = dtog(fs,
173 ufs_rw32(bap[indx - 1], UFS_FSNEEDSWAP(fs)) + 1);
174 startcg %= fs->fs_ncg;
175 avgbfree = fs->fs_cstotal.cs_nbfree / fs->fs_ncg;
176 for (cg = startcg; cg < fs->fs_ncg; cg++)
177 if (fs->fs_cs(fs, cg).cs_nbfree >= avgbfree)
178 return (fs->fs_fpg * cg + fs->fs_frag);
179 for (cg = 0; cg <= startcg; cg++)
180 if (fs->fs_cs(fs, cg).cs_nbfree >= avgbfree)
181 return (fs->fs_fpg * cg + fs->fs_frag);
182 return (0);
183 }
184 /*
185 * We just always try to lay things out contiguously.
186 */
187 return ufs_rw32(bap[indx - 1], UFS_FSNEEDSWAP(fs)) + fs->fs_frag;
188}
189
190daddr_t
191ffs_blkpref_ufs2(struct inode *ip, daddr_t lbn, int indx, int64_t *bap)
192{
193 struct fs *fs;
194 int cg;
195 int avgbfree, startcg;
196
197 fs = ip->i_fs;
198 if (indx % fs->fs_maxbpg == 0 || bap[indx - 1] == 0) {
199 if (lbn < NDADDR + NINDIR(fs)) {
200 cg = ino_to_cg(fs, ip->i_number);
201 return (fs->fs_fpg * cg + fs->fs_frag);
202 }
203 /*
204 * Find a cylinder with greater than average number of
205 * unused data blocks.
206 */
207 if (indx == 0 || bap[indx - 1] == 0)
208 startcg =
209 ino_to_cg(fs, ip->i_number) + lbn / fs->fs_maxbpg;
210 else
211 startcg = dtog(fs,
212 ufs_rw64(bap[indx - 1], UFS_FSNEEDSWAP(fs)) + 1);
213 startcg %= fs->fs_ncg;
214 avgbfree = fs->fs_cstotal.cs_nbfree / fs->fs_ncg;
215 for (cg = startcg; cg < fs->fs_ncg; cg++)
216 if (fs->fs_cs(fs, cg).cs_nbfree >= avgbfree) {
217 return (fs->fs_fpg * cg + fs->fs_frag);
218 }
219 for (cg = 0; cg < startcg; cg++)
220 if (fs->fs_cs(fs, cg).cs_nbfree >= avgbfree) {
221 return (fs->fs_fpg * cg + fs->fs_frag);
222 }
223 return (0);
224 }
225 /*
226 * We just always try to lay things out contiguously.
227 */
228 return ufs_rw64(bap[indx - 1], UFS_FSNEEDSWAP(fs)) + fs->fs_frag;
229}
230
231/*
232 * Implement the cylinder overflow algorithm.
233 *
234 * The policy implemented by this algorithm is:
235 * 1) allocate the block in its requested cylinder group.
236 * 2) quadradically rehash on the cylinder group number.
237 * 3) brute force search for a free block.
238 *
239 * `size': size for data blocks, mode for inodes
240 */
241/*VARARGS5*/
242static daddr_t
243ffs_hashalloc(struct inode *ip, int cg, daddr_t pref, int size,
244 daddr_t (*allocator)(struct inode *, int, daddr_t, int))
245{
246 struct fs *fs;
247 daddr_t result;
248 int i, icg = cg;
249
250 fs = ip->i_fs;
251 /*
252 * 1: preferred cylinder group
253 */
254 result = (*allocator)(ip, cg, pref, size);
255 if (result)
256 return (result);
257 /*
258 * 2: quadratic rehash
259 */
260 for (i = 1; i < fs->fs_ncg; i *= 2) {
261 cg += i;
262 if (cg >= fs->fs_ncg)
263 cg -= fs->fs_ncg;
264 result = (*allocator)(ip, cg, 0, size);
265 if (result)
266 return (result);
267 }
268 /*
269 * 3: brute force search
270 * Note that we start at i == 2, since 0 was checked initially,
271 * and 1 is always checked in the quadratic rehash.
272 */
273 cg = (icg + 2) % fs->fs_ncg;
274 for (i = 2; i < fs->fs_ncg; i++) {
275 result = (*allocator)(ip, cg, 0, size);
276 if (result)
277 return (result);
278 cg++;
279 if (cg == fs->fs_ncg)
280 cg = 0;
281 }
282 return (0);
283}
284
285/*
286 * Determine whether a block can be allocated.
287 *
288 * Check to see if a block of the appropriate size is available,
289 * and if it is, allocate it.
290 */
291static daddr_t
292ffs_alloccg(struct inode *ip, int cg, daddr_t bpref, int size)
293{
294 struct cg *cgp;
295 struct buf *bp;
296 daddr_t bno, blkno;
297 int error, frags, allocsiz, i;
298 struct fs *fs = ip->i_fs;
299 const int needswap = UFS_FSNEEDSWAP(fs);
300
301 if (fs->fs_cs(fs, cg).cs_nbfree == 0 && size == fs->fs_bsize)
302 return (0);
303 error = bread(ip->i_fd, ip->i_fs, fsbtodb(fs, cgtod(fs, cg)),
304 (int)fs->fs_cgsize, &bp);
305 if (error) {
306 brelse(bp);
307 return (0);
308 }
309 cgp = (struct cg *)bp->b_data;
310 if (!cg_chkmagic_swap(cgp, needswap) ||
311 (cgp->cg_cs.cs_nbfree == 0 && size == fs->fs_bsize)) {
312 brelse(bp);
313 return (0);
314 }
315 if (size == fs->fs_bsize) {
316 bno = ffs_alloccgblk(ip, bp, bpref);
317 bdwrite(bp);
318 return (bno);
319 }
320 /*
321 * check to see if any fragments are already available
322 * allocsiz is the size which will be allocated, hacking
323 * it down to a smaller size if necessary
324 */
325 frags = numfrags(fs, size);
326 for (allocsiz = frags; allocsiz < fs->fs_frag; allocsiz++)
327 if (cgp->cg_frsum[allocsiz] != 0)
328 break;
329 if (allocsiz == fs->fs_frag) {
330 /*
331 * no fragments were available, so a block will be
332 * allocated, and hacked up
333 */
334 if (cgp->cg_cs.cs_nbfree == 0) {
335 brelse(bp);
336 return (0);
337 }
338 bno = ffs_alloccgblk(ip, bp, bpref);
339 bpref = dtogd(fs, bno);
340 for (i = frags; i < fs->fs_frag; i++)
341 setbit(cg_blksfree_swap(cgp, needswap), bpref + i);
342 i = fs->fs_frag - frags;
343 ufs_add32(cgp->cg_cs.cs_nffree, i, needswap);
344 fs->fs_cstotal.cs_nffree += i;
345 fs->fs_cs(fs, cg).cs_nffree += i;
346 fs->fs_fmod = 1;
347 ufs_add32(cgp->cg_frsum[i], 1, needswap);
348 bdwrite(bp);
349 return (bno);
350 }
351 bno = ffs_mapsearch(fs, cgp, bpref, allocsiz);
352 for (i = 0; i < frags; i++)
353 clrbit(cg_blksfree_swap(cgp, needswap), bno + i);
354 ufs_add32(cgp->cg_cs.cs_nffree, -frags, needswap);
355 fs->fs_cstotal.cs_nffree -= frags;
356 fs->fs_cs(fs, cg).cs_nffree -= frags;
357 fs->fs_fmod = 1;
358 ufs_add32(cgp->cg_frsum[allocsiz], -1, needswap);
359 if (frags != allocsiz)
360 ufs_add32(cgp->cg_frsum[allocsiz - frags], 1, needswap);
361 blkno = cg * fs->fs_fpg + bno;
362 bdwrite(bp);
363 return blkno;
364}
365
366/*
367 * Allocate a block in a cylinder group.
368 *
369 * This algorithm implements the following policy:
370 * 1) allocate the requested block.
371 * 2) allocate a rotationally optimal block in the same cylinder.
372 * 3) allocate the next available block on the block rotor for the
373 * specified cylinder group.
374 * Note that this routine only allocates fs_bsize blocks; these
375 * blocks may be fragmented by the routine that allocates them.
376 */
377static daddr_t
378ffs_alloccgblk(struct inode *ip, struct buf *bp, daddr_t bpref)
379{
380 struct cg *cgp;
381 daddr_t blkno;
382 int32_t bno;
383 struct fs *fs = ip->i_fs;
384 const int needswap = UFS_FSNEEDSWAP(fs);
385 u_int8_t *blksfree_swap;
386
387 cgp = (struct cg *)bp->b_data;
388 blksfree_swap = cg_blksfree_swap(cgp, needswap);
389 if (bpref == 0 || (uint32_t)dtog(fs, bpref) != ufs_rw32(cgp->cg_cgx, needswap)) {
390 bpref = ufs_rw32(cgp->cg_rotor, needswap);
391 } else {
392 bpref = blknum(fs, bpref);
393 bno = dtogd(fs, bpref);
394 /*
395 * if the requested block is available, use it
396 */
397 if (ffs_isblock(fs, blksfree_swap, fragstoblks(fs, bno)))
398 goto gotit;
399 }
400 /*
401 * Take the next available one in this cylinder group.
402 */
403 bno = ffs_mapsearch(fs, cgp, bpref, (int)fs->fs_frag);
404 if (bno < 0)
405 return (0);
406 cgp->cg_rotor = ufs_rw32(bno, needswap);
407gotit:
408 blkno = fragstoblks(fs, bno);
409 ffs_clrblock(fs, blksfree_swap, (long)blkno);
410 ffs_clusteracct(fs, cgp, blkno, -1);
411 ufs_add32(cgp->cg_cs.cs_nbfree, -1, needswap);
412 fs->fs_cstotal.cs_nbfree--;
413 fs->fs_cs(fs, ufs_rw32(cgp->cg_cgx, needswap)).cs_nbfree--;
414 fs->fs_fmod = 1;
415 blkno = ufs_rw32(cgp->cg_cgx, needswap) * fs->fs_fpg + bno;
416 return (blkno);
417}
418
419/*
420 * Free a block or fragment.
421 *
422 * The specified block or fragment is placed back in the
423 * free map. If a fragment is deallocated, a possible
424 * block reassembly is checked.
425 */
426void
427ffs_blkfree(struct inode *ip, daddr_t bno, long size)
428{
429 struct cg *cgp;
430 struct buf *bp;
431 int32_t fragno, cgbno;
432 int i, error, cg, blk, frags, bbase;
433 struct fs *fs = ip->i_fs;
434 const int needswap = UFS_FSNEEDSWAP(fs);
435
436 if (size > fs->fs_bsize || fragoff(fs, size) != 0 ||
437 fragnum(fs, bno) + numfrags(fs, size) > fs->fs_frag) {
438 errx(1, "blkfree: bad size: bno %lld bsize %d size %ld",
439 (long long)bno, fs->fs_bsize, size);
440 }
441 cg = dtog(fs, bno);
442 if (bno >= fs->fs_size) {
|
442 warnx("bad block %lld, ino %llu", (long long)bno,
443 (unsigned long long)ip->i_number);
|
443 warnx("bad block %lld, ino %ju", (long long)bno,
444 (uintmax_t)ip->i_number); |
445 return;
446 }
447 error = bread(ip->i_fd, ip->i_fs, fsbtodb(fs, cgtod(fs, cg)),
448 (int)fs->fs_cgsize, &bp);
449 if (error) {
450 brelse(bp);
451 return;
452 }
453 cgp = (struct cg *)bp->b_data;
454 if (!cg_chkmagic_swap(cgp, needswap)) {
455 brelse(bp);
456 return;
457 }
458 cgbno = dtogd(fs, bno);
459 if (size == fs->fs_bsize) {
460 fragno = fragstoblks(fs, cgbno);
461 if (!ffs_isfreeblock(fs, cg_blksfree_swap(cgp, needswap), fragno)) {
462 errx(1, "blkfree: freeing free block %lld",
463 (long long)bno);
464 }
465 ffs_setblock(fs, cg_blksfree_swap(cgp, needswap), fragno);
466 ffs_clusteracct(fs, cgp, fragno, 1);
467 ufs_add32(cgp->cg_cs.cs_nbfree, 1, needswap);
468 fs->fs_cstotal.cs_nbfree++;
469 fs->fs_cs(fs, cg).cs_nbfree++;
470 } else {
471 bbase = cgbno - fragnum(fs, cgbno);
472 /*
473 * decrement the counts associated with the old frags
474 */
475 blk = blkmap(fs, cg_blksfree_swap(cgp, needswap), bbase);
476 ffs_fragacct_swap(fs, blk, cgp->cg_frsum, -1, needswap);
477 /*
478 * deallocate the fragment
479 */
480 frags = numfrags(fs, size);
481 for (i = 0; i < frags; i++) {
482 if (isset(cg_blksfree_swap(cgp, needswap), cgbno + i)) {
483 errx(1, "blkfree: freeing free frag: block %lld",
484 (long long)(cgbno + i));
485 }
486 setbit(cg_blksfree_swap(cgp, needswap), cgbno + i);
487 }
488 ufs_add32(cgp->cg_cs.cs_nffree, i, needswap);
489 fs->fs_cstotal.cs_nffree += i;
490 fs->fs_cs(fs, cg).cs_nffree += i;
491 /*
492 * add back in counts associated with the new frags
493 */
494 blk = blkmap(fs, cg_blksfree_swap(cgp, needswap), bbase);
495 ffs_fragacct_swap(fs, blk, cgp->cg_frsum, 1, needswap);
496 /*
497 * if a complete block has been reassembled, account for it
498 */
499 fragno = fragstoblks(fs, bbase);
500 if (ffs_isblock(fs, cg_blksfree_swap(cgp, needswap), fragno)) {
501 ufs_add32(cgp->cg_cs.cs_nffree, -fs->fs_frag, needswap);
502 fs->fs_cstotal.cs_nffree -= fs->fs_frag;
503 fs->fs_cs(fs, cg).cs_nffree -= fs->fs_frag;
504 ffs_clusteracct(fs, cgp, fragno, 1);
505 ufs_add32(cgp->cg_cs.cs_nbfree, 1, needswap);
506 fs->fs_cstotal.cs_nbfree++;
507 fs->fs_cs(fs, cg).cs_nbfree++;
508 }
509 }
510 fs->fs_fmod = 1;
511 bdwrite(bp);
512}
513
514
515static int
516scanc(u_int size, const u_char *cp, const u_char table[], int mask)
517{
518 const u_char *end = &cp[size];
519
520 while (cp < end && (table[*cp] & mask) == 0)
521 cp++;
522 return (end - cp);
523}
524
525/*
526 * Find a block of the specified size in the specified cylinder group.
527 *
528 * It is a panic if a request is made to find a block if none are
529 * available.
530 */
531static int32_t
532ffs_mapsearch(struct fs *fs, struct cg *cgp, daddr_t bpref, int allocsiz)
533{
534 int32_t bno;
535 int start, len, loc, i;
536 int blk, field, subfield, pos;
537 int ostart, olen;
538 const int needswap = UFS_FSNEEDSWAP(fs);
539
540 /*
541 * find the fragment by searching through the free block
542 * map for an appropriate bit pattern
543 */
544 if (bpref)
545 start = dtogd(fs, bpref) / NBBY;
546 else
547 start = ufs_rw32(cgp->cg_frotor, needswap) / NBBY;
548 len = howmany(fs->fs_fpg, NBBY) - start;
549 ostart = start;
550 olen = len;
551 loc = scanc((u_int)len,
552 (const u_char *)&cg_blksfree_swap(cgp, needswap)[start],
553 (const u_char *)fragtbl[fs->fs_frag],
554 (1 << (allocsiz - 1 + (fs->fs_frag % NBBY))));
555 if (loc == 0) {
556 len = start + 1;
557 start = 0;
558 loc = scanc((u_int)len,
559 (const u_char *)&cg_blksfree_swap(cgp, needswap)[0],
560 (const u_char *)fragtbl[fs->fs_frag],
561 (1 << (allocsiz - 1 + (fs->fs_frag % NBBY))));
562 if (loc == 0) {
563 errx(1,
564 "ffs_alloccg: map corrupted: start %d len %d offset %d %ld",
565 ostart, olen,
566 ufs_rw32(cgp->cg_freeoff, needswap),
567 (long)cg_blksfree_swap(cgp, needswap) - (long)cgp);
568 /* NOTREACHED */
569 }
570 }
571 bno = (start + len - loc) * NBBY;
572 cgp->cg_frotor = ufs_rw32(bno, needswap);
573 /*
574 * found the byte in the map
575 * sift through the bits to find the selected frag
576 */
577 for (i = bno + NBBY; bno < i; bno += fs->fs_frag) {
578 blk = blkmap(fs, cg_blksfree_swap(cgp, needswap), bno);
579 blk <<= 1;
580 field = around[allocsiz];
581 subfield = inside[allocsiz];
582 for (pos = 0; pos <= fs->fs_frag - allocsiz; pos++) {
583 if ((blk & field) == subfield)
584 return (bno + pos);
585 field <<= 1;
586 subfield <<= 1;
587 }
588 }
589 errx(1, "ffs_alloccg: block not in map: bno %lld", (long long)bno);
590 return (-1);
591}
592
593/*
594 * Update the cluster map because of an allocation or free.
595 *
596 * Cnt == 1 means free; cnt == -1 means allocating.
597 */
598void
599ffs_clusteracct(struct fs *fs, struct cg *cgp, int32_t blkno, int cnt)
600{
601 int32_t *sump;
602 int32_t *lp;
603 u_char *freemapp, *mapp;
604 int i, start, end, forw, back, map, bit;
605 const int needswap = UFS_FSNEEDSWAP(fs);
606
607 if (fs->fs_contigsumsize <= 0)
608 return;
609 freemapp = cg_clustersfree_swap(cgp, needswap);
610 sump = cg_clustersum_swap(cgp, needswap);
611 /*
612 * Allocate or clear the actual block.
613 */
614 if (cnt > 0)
615 setbit(freemapp, blkno);
616 else
617 clrbit(freemapp, blkno);
618 /*
619 * Find the size of the cluster going forward.
620 */
621 start = blkno + 1;
622 end = start + fs->fs_contigsumsize;
623 if ((unsigned)end >= ufs_rw32(cgp->cg_nclusterblks, needswap))
624 end = ufs_rw32(cgp->cg_nclusterblks, needswap);
625 mapp = &freemapp[start / NBBY];
626 map = *mapp++;
627 bit = 1 << (start % NBBY);
628 for (i = start; i < end; i++) {
629 if ((map & bit) == 0)
630 break;
631 if ((i & (NBBY - 1)) != (NBBY - 1)) {
632 bit <<= 1;
633 } else {
634 map = *mapp++;
635 bit = 1;
636 }
637 }
638 forw = i - start;
639 /*
640 * Find the size of the cluster going backward.
641 */
642 start = blkno - 1;
643 end = start - fs->fs_contigsumsize;
644 if (end < 0)
645 end = -1;
646 mapp = &freemapp[start / NBBY];
647 map = *mapp--;
648 bit = 1 << (start % NBBY);
649 for (i = start; i > end; i--) {
650 if ((map & bit) == 0)
651 break;
652 if ((i & (NBBY - 1)) != 0) {
653 bit >>= 1;
654 } else {
655 map = *mapp--;
656 bit = 1 << (NBBY - 1);
657 }
658 }
659 back = start - i;
660 /*
661 * Account for old cluster and the possibly new forward and
662 * back clusters.
663 */
664 i = back + forw + 1;
665 if (i > fs->fs_contigsumsize)
666 i = fs->fs_contigsumsize;
667 ufs_add32(sump[i], cnt, needswap);
668 if (back > 0)
669 ufs_add32(sump[back], -cnt, needswap);
670 if (forw > 0)
671 ufs_add32(sump[forw], -cnt, needswap);
672
673 /*
674 * Update cluster summary information.
675 */
676 lp = &sump[fs->fs_contigsumsize];
677 for (i = fs->fs_contigsumsize; i > 0; i--)
678 if (ufs_rw32(*lp--, needswap) > 0)
679 break;
680 fs->fs_maxcluster[ufs_rw32(cgp->cg_cgx, needswap)] = i;
681}
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