Disallow writes to filesystems mounted read-only via NULLFS. In this case
[dragonfly.git] / sys / kern / subr_blist.c
CommitLineData
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1/*
2 * BLIST.C - Bitmap allocator/deallocator, using a radix tree with hinting
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3 *
4 * Copyright (c) 1998,2004 The DragonFly Project. All rights reserved.
5 *
6 * This code is derived from software contributed to The DragonFly Project
7 * by Matthew Dillon <dillon@backplane.com>
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 *
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in
17 * the documentation and/or other materials provided with the
18 * distribution.
19 * 3. Neither the name of The DragonFly Project nor the names of its
20 * contributors may be used to endorse or promote products derived
21 * from this software without specific, prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
24 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
25 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
26 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
27 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
28 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
29 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
30 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
31 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
32 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
33 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 *
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36 *
37 * This module implements a general bitmap allocator/deallocator. The
38 * allocator eats around 2 bits per 'block'. The module does not
39 * try to interpret the meaning of a 'block' other then to return
40 * SWAPBLK_NONE on an allocation failure.
41 *
42 * A radix tree is used to maintain the bitmap. Two radix constants are
43 * involved: One for the bitmaps contained in the leaf nodes (typically
44 * 32), and one for the meta nodes (typically 16). Both meta and leaf
45 * nodes have a hint field. This field gives us a hint as to the largest
46 * free contiguous range of blocks under the node. It may contain a
47 * value that is too high, but will never contain a value that is too
48 * low. When the radix tree is searched, allocation failures in subtrees
49 * update the hint.
50 *
51 * The radix tree also implements two collapsed states for meta nodes:
52 * the ALL-ALLOCATED state and the ALL-FREE state. If a meta node is
53 * in either of these two states, all information contained underneath
54 * the node is considered stale. These states are used to optimize
55 * allocation and freeing operations.
56 *
57 * The hinting greatly increases code efficiency for allocations while
58 * the general radix structure optimizes both allocations and frees. The
59 * radix tree should be able to operate well no matter how much
60 * fragmentation there is and no matter how large a bitmap is used.
61 *
62 * Unlike the rlist code, the blist code wires all necessary memory at
63 * creation time. Neither allocations nor frees require interaction with
64 * the memory subsystem. In contrast, the rlist code may allocate memory
65 * on an rlist_free() call. The non-blocking features of the blist code
66 * are used to great advantage in the swap code (vm/nswap_pager.c). The
67 * rlist code uses a little less overall memory then the blist code (but
68 * due to swap interleaving not all that much less), but the blist code
69 * scales much, much better.
70 *
71 * LAYOUT: The radix tree is layed out recursively using a
72 * linear array. Each meta node is immediately followed (layed out
73 * sequentially in memory) by BLIST_META_RADIX lower level nodes. This
74 * is a recursive structure but one that can be easily scanned through
75 * a very simple 'skip' calculation. In order to support large radixes,
76 * portions of the tree may reside outside our memory allocation. We
77 * handle this with an early-termination optimization (when bighint is
78 * set to -1) on the scan. The memory allocation is only large enough
79 * to cover the number of blocks requested at creation time even if it
80 * must be encompassed in larger root-node radix.
81 *
82 * NOTE: the allocator cannot currently allocate more then
83 * BLIST_BMAP_RADIX blocks per call. It will panic with 'allocation too
84 * large' if you try. This is an area that could use improvement. The
85 * radix is large enough that this restriction does not effect the swap
86 * system, though. Currently only the allocation code is effected by
87 * this algorithmic unfeature. The freeing code can handle arbitrary
88 * ranges.
89 *
90 * This code can be compiled stand-alone for debugging.
91 *
92 * $FreeBSD: src/sys/kern/subr_blist.c,v 1.5.2.2 2003/01/12 09:23:12 dillon Exp $
efda3bd0 93 * $DragonFly: src/sys/kern/subr_blist.c,v 1.6 2006/09/05 00:55:45 dillon Exp $
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94 */
95
96#ifdef _KERNEL
97
98#include <sys/param.h>
99#include <sys/systm.h>
100#include <sys/lock.h>
101#include <sys/kernel.h>
102#include <sys/blist.h>
103#include <sys/malloc.h>
104#include <vm/vm.h>
105#include <vm/vm_object.h>
106#include <vm/vm_kern.h>
107#include <vm/vm_extern.h>
108#include <vm/vm_page.h>
109
110#else
111
112#ifndef BLIST_NO_DEBUG
113#define BLIST_DEBUG
114#endif
115
116#define SWAPBLK_NONE ((daddr_t)-1)
117
118#include <sys/types.h>
119#include <stdio.h>
120#include <string.h>
121#include <stdlib.h>
122#include <stdarg.h>
123
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124#define kmalloc(a,b,c) malloc(a)
125#define kfree(a,b) free(a)
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126
127typedef unsigned int u_daddr_t;
128
129#include <sys/blist.h>
130
131void panic(const char *ctl, ...);
132
133#endif
134
135/*
136 * static support functions
137 */
138
139static daddr_t blst_leaf_alloc(blmeta_t *scan, daddr_t blk, int count);
140static daddr_t blst_meta_alloc(blmeta_t *scan, daddr_t blk,
141 daddr_t count, daddr_t radix, int skip);
142static void blst_leaf_free(blmeta_t *scan, daddr_t relblk, int count);
143static void blst_meta_free(blmeta_t *scan, daddr_t freeBlk, daddr_t count,
144 daddr_t radix, int skip, daddr_t blk);
145static void blst_copy(blmeta_t *scan, daddr_t blk, daddr_t radix,
146 daddr_t skip, blist_t dest, daddr_t count);
147static daddr_t blst_radix_init(blmeta_t *scan, daddr_t radix,
148 int skip, daddr_t count);
149#ifndef _KERNEL
150static void blst_radix_print(blmeta_t *scan, daddr_t blk,
151 daddr_t radix, int skip, int tab);
152#endif
153
154#ifdef _KERNEL
155static MALLOC_DEFINE(M_SWAP, "SWAP", "Swap space");
156#endif
157
158/*
159 * blist_create() - create a blist capable of handling up to the specified
160 * number of blocks
161 *
162 * blocks must be greater then 0
163 *
164 * The smallest blist consists of a single leaf node capable of
165 * managing BLIST_BMAP_RADIX blocks.
166 */
167
168blist_t
169blist_create(daddr_t blocks)
170{
171 blist_t bl;
172 int radix;
173 int skip = 0;
174
175 /*
176 * Calculate radix and skip field used for scanning.
177 */
178 radix = BLIST_BMAP_RADIX;
179
180 while (radix < blocks) {
181 radix *= BLIST_META_RADIX;
182 skip = (skip + 1) * BLIST_META_RADIX;
183 }
184
efda3bd0 185 bl = kmalloc(sizeof(struct blist), M_SWAP, M_WAITOK);
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186
187 bzero(bl, sizeof(*bl));
188
189 bl->bl_blocks = blocks;
190 bl->bl_radix = radix;
191 bl->bl_skip = skip;
192 bl->bl_rootblks = 1 +
193 blst_radix_init(NULL, bl->bl_radix, bl->bl_skip, blocks);
efda3bd0 194 bl->bl_root = kmalloc(sizeof(blmeta_t) * bl->bl_rootblks, M_SWAP, M_WAITOK);
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195
196#if defined(BLIST_DEBUG)
197 printf(
198 "BLIST representing %d blocks (%d MB of swap)"
199 ", requiring %dK of ram\n",
200 bl->bl_blocks,
201 bl->bl_blocks * 4 / 1024,
202 (bl->bl_rootblks * sizeof(blmeta_t) + 1023) / 1024
203 );
204 printf("BLIST raw radix tree contains %d records\n", bl->bl_rootblks);
205#endif
206 blst_radix_init(bl->bl_root, bl->bl_radix, bl->bl_skip, blocks);
207
208 return(bl);
209}
210
211void
212blist_destroy(blist_t bl)
213{
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214 kfree(bl->bl_root, M_SWAP);
215 kfree(bl, M_SWAP);
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216}
217
218/*
219 * blist_alloc() - reserve space in the block bitmap. Return the base
220 * of a contiguous region or SWAPBLK_NONE if space could
221 * not be allocated.
222 */
223
224daddr_t
225blist_alloc(blist_t bl, daddr_t count)
226{
227 daddr_t blk = SWAPBLK_NONE;
228
229 if (bl) {
230 if (bl->bl_radix == BLIST_BMAP_RADIX)
231 blk = blst_leaf_alloc(bl->bl_root, 0, count);
232 else
233 blk = blst_meta_alloc(bl->bl_root, 0, count, bl->bl_radix, bl->bl_skip);
234 if (blk != SWAPBLK_NONE)
235 bl->bl_free -= count;
236 }
237 return(blk);
238}
239
240/*
241 * blist_free() - free up space in the block bitmap. Return the base
242 * of a contiguous region. Panic if an inconsistancy is
243 * found.
244 */
245
246void
247blist_free(blist_t bl, daddr_t blkno, daddr_t count)
248{
249 if (bl) {
250 if (bl->bl_radix == BLIST_BMAP_RADIX)
251 blst_leaf_free(bl->bl_root, blkno, count);
252 else
253 blst_meta_free(bl->bl_root, blkno, count, bl->bl_radix, bl->bl_skip, 0);
254 bl->bl_free += count;
255 }
256}
257
258/*
259 * blist_resize() - resize an existing radix tree to handle the
260 * specified number of blocks. This will reallocate
261 * the tree and transfer the previous bitmap to the new
262 * one. When extending the tree you can specify whether
263 * the new blocks are to left allocated or freed.
264 */
265
266void
267blist_resize(blist_t *pbl, daddr_t count, int freenew)
268{
269 blist_t newbl = blist_create(count);
270 blist_t save = *pbl;
271
272 *pbl = newbl;
273 if (count > save->bl_blocks)
274 count = save->bl_blocks;
275 blst_copy(save->bl_root, 0, save->bl_radix, save->bl_skip, newbl, count);
276
277 /*
278 * If resizing upwards, should we free the new space or not?
279 */
280 if (freenew && count < newbl->bl_blocks) {
281 blist_free(newbl, count, newbl->bl_blocks - count);
282 }
283 blist_destroy(save);
284}
285
286#ifdef BLIST_DEBUG
287
288/*
289 * blist_print() - dump radix tree
290 */
291
292void
293blist_print(blist_t bl)
294{
295 printf("BLIST {\n");
296 blst_radix_print(bl->bl_root, 0, bl->bl_radix, bl->bl_skip, 4);
297 printf("}\n");
298}
299
300#endif
301
302/************************************************************************
303 * ALLOCATION SUPPORT FUNCTIONS *
304 ************************************************************************
305 *
306 * These support functions do all the actual work. They may seem
307 * rather longish, but that's because I've commented them up. The
308 * actual code is straight forward.
309 *
310 */
311
312/*
313 * blist_leaf_alloc() - allocate at a leaf in the radix tree (a bitmap).
314 *
315 * This is the core of the allocator and is optimized for the 1 block
316 * and the BLIST_BMAP_RADIX block allocation cases. Other cases are
317 * somewhat slower. The 1 block allocation case is log2 and extremely
318 * quick.
319 */
320
321static daddr_t
322blst_leaf_alloc(
323 blmeta_t *scan,
324 daddr_t blk,
325 int count
326) {
327 u_daddr_t orig = scan->u.bmu_bitmap;
328
329 if (orig == 0) {
330 /*
331 * Optimize bitmap all-allocated case. Also, count = 1
332 * case assumes at least 1 bit is free in the bitmap, so
333 * we have to take care of this case here.
334 */
335 scan->bm_bighint = 0;
336 return(SWAPBLK_NONE);
337 }
338 if (count == 1) {
339 /*
340 * Optimized code to allocate one bit out of the bitmap
341 */
342 u_daddr_t mask;
343 int j = BLIST_BMAP_RADIX/2;
344 int r = 0;
345
346 mask = (u_daddr_t)-1 >> (BLIST_BMAP_RADIX/2);
347
348 while (j) {
349 if ((orig & mask) == 0) {
350 r += j;
351 orig >>= j;
352 }
353 j >>= 1;
354 mask >>= j;
355 }
356 scan->u.bmu_bitmap &= ~(1 << r);
357 return(blk + r);
358 }
359 if (count <= BLIST_BMAP_RADIX) {
360 /*
361 * non-optimized code to allocate N bits out of the bitmap.
362 * The more bits, the faster the code runs. It will run
363 * the slowest allocating 2 bits, but since there aren't any
364 * memory ops in the core loop (or shouldn't be, anyway),
365 * you probably won't notice the difference.
366 */
367 int j;
368 int n = BLIST_BMAP_RADIX - count;
369 u_daddr_t mask;
370
371 mask = (u_daddr_t)-1 >> n;
372
373 for (j = 0; j <= n; ++j) {
374 if ((orig & mask) == mask) {
375 scan->u.bmu_bitmap &= ~mask;
376 return(blk + j);
377 }
378 mask = (mask << 1);
379 }
380 }
381 /*
382 * We couldn't allocate count in this subtree, update bighint.
383 */
384 scan->bm_bighint = count - 1;
385 return(SWAPBLK_NONE);
386}
387
388/*
389 * blist_meta_alloc() - allocate at a meta in the radix tree.
390 *
391 * Attempt to allocate at a meta node. If we can't, we update
392 * bighint and return a failure. Updating bighint optimize future
393 * calls that hit this node. We have to check for our collapse cases
394 * and we have a few optimizations strewn in as well.
395 */
396
397static daddr_t
398blst_meta_alloc(
399 blmeta_t *scan,
400 daddr_t blk,
401 daddr_t count,
402 daddr_t radix,
403 int skip
404) {
405 int i;
406 int next_skip = ((u_int)skip / BLIST_META_RADIX);
407
408 if (scan->u.bmu_avail == 0) {
409 /*
410 * ALL-ALLOCATED special case
411 */
412 scan->bm_bighint = count;
413 return(SWAPBLK_NONE);
414 }
415
416 if (scan->u.bmu_avail == radix) {
417 radix /= BLIST_META_RADIX;
418
419 /*
420 * ALL-FREE special case, initialize uninitialize
421 * sublevel.
422 */
423 for (i = 1; i <= skip; i += next_skip) {
424 if (scan[i].bm_bighint == (daddr_t)-1)
425 break;
426 if (next_skip == 1) {
427 scan[i].u.bmu_bitmap = (u_daddr_t)-1;
428 scan[i].bm_bighint = BLIST_BMAP_RADIX;
429 } else {
430 scan[i].bm_bighint = radix;
431 scan[i].u.bmu_avail = radix;
432 }
433 }
434 } else {
435 radix /= BLIST_META_RADIX;
436 }
437
438 for (i = 1; i <= skip; i += next_skip) {
439 if (count <= scan[i].bm_bighint) {
440 /*
441 * count fits in object
442 */
443 daddr_t r;
444 if (next_skip == 1) {
445 r = blst_leaf_alloc(&scan[i], blk, count);
446 } else {
447 r = blst_meta_alloc(&scan[i], blk, count, radix, next_skip - 1);
448 }
449 if (r != SWAPBLK_NONE) {
450 scan->u.bmu_avail -= count;
451 if (scan->bm_bighint > scan->u.bmu_avail)
452 scan->bm_bighint = scan->u.bmu_avail;
453 return(r);
454 }
455 } else if (scan[i].bm_bighint == (daddr_t)-1) {
456 /*
457 * Terminator
458 */
459 break;
460 } else if (count > radix) {
461 /*
462 * count does not fit in object even if it were
463 * complete free.
464 */
465 panic("blist_meta_alloc: allocation too large");
466 }
467 blk += radix;
468 }
469
470 /*
471 * We couldn't allocate count in this subtree, update bighint.
472 */
473 if (scan->bm_bighint >= count)
474 scan->bm_bighint = count - 1;
475 return(SWAPBLK_NONE);
476}
477
478/*
479 * BLST_LEAF_FREE() - free allocated block from leaf bitmap
480 *
481 */
482
483static void
484blst_leaf_free(
485 blmeta_t *scan,
486 daddr_t blk,
487 int count
488) {
489 /*
490 * free some data in this bitmap
491 *
492 * e.g.
493 * 0000111111111110000
494 * \_________/\__/
495 * v n
496 */
497 int n = blk & (BLIST_BMAP_RADIX - 1);
498 u_daddr_t mask;
499
500 mask = ((u_daddr_t)-1 << n) &
501 ((u_daddr_t)-1 >> (BLIST_BMAP_RADIX - count - n));
502
503 if (scan->u.bmu_bitmap & mask)
504 panic("blst_radix_free: freeing free block");
505 scan->u.bmu_bitmap |= mask;
506
507 /*
508 * We could probably do a better job here. We are required to make
509 * bighint at least as large as the biggest contiguous block of
510 * data. If we just shoehorn it, a little extra overhead will
511 * be incured on the next allocation (but only that one typically).
512 */
513 scan->bm_bighint = BLIST_BMAP_RADIX;
514}
515
516/*
517 * BLST_META_FREE() - free allocated blocks from radix tree meta info
518 *
519 * This support routine frees a range of blocks from the bitmap.
520 * The range must be entirely enclosed by this radix node. If a
521 * meta node, we break the range down recursively to free blocks
522 * in subnodes (which means that this code can free an arbitrary
523 * range whereas the allocation code cannot allocate an arbitrary
524 * range).
525 */
526
527static void
528blst_meta_free(
529 blmeta_t *scan,
530 daddr_t freeBlk,
531 daddr_t count,
532 daddr_t radix,
533 int skip,
534 daddr_t blk
535) {
536 int i;
537 int next_skip = ((u_int)skip / BLIST_META_RADIX);
538
539#if 0
540 printf("FREE (%x,%d) FROM (%x,%d)\n",
541 freeBlk, count,
542 blk, radix
543 );
544#endif
545
546 if (scan->u.bmu_avail == 0) {
547 /*
548 * ALL-ALLOCATED special case, with possible
549 * shortcut to ALL-FREE special case.
550 */
551 scan->u.bmu_avail = count;
552 scan->bm_bighint = count;
553
554 if (count != radix) {
555 for (i = 1; i <= skip; i += next_skip) {
556 if (scan[i].bm_bighint == (daddr_t)-1)
557 break;
558 scan[i].bm_bighint = 0;
559 if (next_skip == 1) {
560 scan[i].u.bmu_bitmap = 0;
561 } else {
562 scan[i].u.bmu_avail = 0;
563 }
564 }
565 /* fall through */
566 }
567 } else {
568 scan->u.bmu_avail += count;
569 /* scan->bm_bighint = radix; */
570 }
571
572 /*
573 * ALL-FREE special case.
574 */
575
576 if (scan->u.bmu_avail == radix)
577 return;
578 if (scan->u.bmu_avail > radix)
579 panic("blst_meta_free: freeing already free blocks (%d) %d/%d", count, scan->u.bmu_avail, radix);
580
581 /*
582 * Break the free down into its components
583 */
584
585 radix /= BLIST_META_RADIX;
586
587 i = (freeBlk - blk) / radix;
588 blk += i * radix;
589 i = i * next_skip + 1;
590
591 while (i <= skip && blk < freeBlk + count) {
592 daddr_t v;
593
594 v = blk + radix - freeBlk;
595 if (v > count)
596 v = count;
597
598 if (scan->bm_bighint == (daddr_t)-1)
599 panic("blst_meta_free: freeing unexpected range");
600
601 if (next_skip == 1) {
602 blst_leaf_free(&scan[i], freeBlk, v);
603 } else {
604 blst_meta_free(&scan[i], freeBlk, v, radix, next_skip - 1, blk);
605 }
606 if (scan->bm_bighint < scan[i].bm_bighint)
607 scan->bm_bighint = scan[i].bm_bighint;
608 count -= v;
609 freeBlk += v;
610 blk += radix;
611 i += next_skip;
612 }
613}
614
615/*
616 * BLIST_RADIX_COPY() - copy one radix tree to another
617 *
618 * Locates free space in the source tree and frees it in the destination
619 * tree. The space may not already be free in the destination.
620 */
621
622static void blst_copy(
623 blmeta_t *scan,
624 daddr_t blk,
625 daddr_t radix,
626 daddr_t skip,
627 blist_t dest,
628 daddr_t count
629) {
630 int next_skip;
631 int i;
632
633 /*
634 * Leaf node
635 */
636
637 if (radix == BLIST_BMAP_RADIX) {
638 u_daddr_t v = scan->u.bmu_bitmap;
639
640 if (v == (u_daddr_t)-1) {
641 blist_free(dest, blk, count);
642 } else if (v != 0) {
643 int i;
644
645 for (i = 0; i < BLIST_BMAP_RADIX && i < count; ++i) {
646 if (v & (1 << i))
647 blist_free(dest, blk + i, 1);
648 }
649 }
650 return;
651 }
652
653 /*
654 * Meta node
655 */
656
657 if (scan->u.bmu_avail == 0) {
658 /*
659 * Source all allocated, leave dest allocated
660 */
661 return;
662 }
663 if (scan->u.bmu_avail == radix) {
664 /*
665 * Source all free, free entire dest
666 */
667 if (count < radix)
668 blist_free(dest, blk, count);
669 else
670 blist_free(dest, blk, radix);
671 return;
672 }
673
674
675 radix /= BLIST_META_RADIX;
676 next_skip = ((u_int)skip / BLIST_META_RADIX);
677
678 for (i = 1; count && i <= skip; i += next_skip) {
679 if (scan[i].bm_bighint == (daddr_t)-1)
680 break;
681
682 if (count >= radix) {
683 blst_copy(
684 &scan[i],
685 blk,
686 radix,
687 next_skip - 1,
688 dest,
689 radix
690 );
691 count -= radix;
692 } else {
693 if (count) {
694 blst_copy(
695 &scan[i],
696 blk,
697 radix,
698 next_skip - 1,
699 dest,
700 count
701 );
702 }
703 count = 0;
704 }
705 blk += radix;
706 }
707}
708
709/*
710 * BLST_RADIX_INIT() - initialize radix tree
711 *
712 * Initialize our meta structures and bitmaps and calculate the exact
713 * amount of space required to manage 'count' blocks - this space may
714 * be considerably less then the calculated radix due to the large
715 * RADIX values we use.
716 */
717
718static daddr_t
719blst_radix_init(blmeta_t *scan, daddr_t radix, int skip, daddr_t count)
720{
721 int i;
722 int next_skip;
723 daddr_t memindex = 0;
724
725 /*
726 * Leaf node
727 */
728
729 if (radix == BLIST_BMAP_RADIX) {
730 if (scan) {
731 scan->bm_bighint = 0;
732 scan->u.bmu_bitmap = 0;
733 }
734 return(memindex);
735 }
736
737 /*
738 * Meta node. If allocating the entire object we can special
739 * case it. However, we need to figure out how much memory
740 * is required to manage 'count' blocks, so we continue on anyway.
741 */
742
743 if (scan) {
744 scan->bm_bighint = 0;
745 scan->u.bmu_avail = 0;
746 }
747
748 radix /= BLIST_META_RADIX;
749 next_skip = ((u_int)skip / BLIST_META_RADIX);
750
751 for (i = 1; i <= skip; i += next_skip) {
752 if (count >= radix) {
753 /*
754 * Allocate the entire object
755 */
756 memindex = i + blst_radix_init(
757 ((scan) ? &scan[i] : NULL),
758 radix,
759 next_skip - 1,
760 radix
761 );
762 count -= radix;
763 } else if (count > 0) {
764 /*
765 * Allocate a partial object
766 */
767 memindex = i + blst_radix_init(
768 ((scan) ? &scan[i] : NULL),
769 radix,
770 next_skip - 1,
771 count
772 );
773 count = 0;
774 } else {
775 /*
776 * Add terminator and break out
777 */
778 if (scan)
779 scan[i].bm_bighint = (daddr_t)-1;
780 break;
781 }
782 }
783 if (memindex < i)
784 memindex = i;
785 return(memindex);
786}
787
788#ifdef BLIST_DEBUG
789
790static void
791blst_radix_print(blmeta_t *scan, daddr_t blk, daddr_t radix, int skip, int tab)
792{
793 int i;
794 int next_skip;
795 int lastState = 0;
796
797 if (radix == BLIST_BMAP_RADIX) {
798 printf(
799 "%*.*s(%04x,%d): bitmap %08x big=%d\n",
800 tab, tab, "",
801 blk, radix,
802 scan->u.bmu_bitmap,
803 scan->bm_bighint
804 );
805 return;
806 }
807
808 if (scan->u.bmu_avail == 0) {
809 printf(
810 "%*.*s(%04x,%d) ALL ALLOCATED\n",
811 tab, tab, "",
812 blk,
813 radix
814 );
815 return;
816 }
817 if (scan->u.bmu_avail == radix) {
818 printf(
819 "%*.*s(%04x,%d) ALL FREE\n",
820 tab, tab, "",
821 blk,
822 radix
823 );
824 return;
825 }
826
827 printf(
828 "%*.*s(%04x,%d): subtree (%d/%d) big=%d {\n",
829 tab, tab, "",
830 blk, radix,
831 scan->u.bmu_avail,
832 radix,
833 scan->bm_bighint
834 );
835
836 radix /= BLIST_META_RADIX;
837 next_skip = ((u_int)skip / BLIST_META_RADIX);
838 tab += 4;
839
840 for (i = 1; i <= skip; i += next_skip) {
841 if (scan[i].bm_bighint == (daddr_t)-1) {
842 printf(
843 "%*.*s(%04x,%d): Terminator\n",
844 tab, tab, "",
845 blk, radix
846 );
847 lastState = 0;
848 break;
849 }
850 blst_radix_print(
851 &scan[i],
852 blk,
853 radix,
854 next_skip - 1,
855 tab
856 );
857 blk += radix;
858 }
859 tab -= 4;
860
861 printf(
862 "%*.*s}\n",
863 tab, tab, ""
864 );
865}
866
867#endif
868
869#ifdef BLIST_DEBUG
870
871int
872main(int ac, char **av)
873{
874 int size = 1024;
875 int i;
876 blist_t bl;
877
878 for (i = 1; i < ac; ++i) {
879 const char *ptr = av[i];
880 if (*ptr != '-') {
881 size = strtol(ptr, NULL, 0);
882 continue;
883 }
884 ptr += 2;
885 fprintf(stderr, "Bad option: %s\n", ptr - 2);
886 exit(1);
887 }
888 bl = blist_create(size);
889 blist_free(bl, 0, size);
890
891 for (;;) {
892 char buf[1024];
893 daddr_t da = 0;
894 daddr_t count = 0;
895
896
897 printf("%d/%d/%d> ", bl->bl_free, size, bl->bl_radix);
898 fflush(stdout);
899 if (fgets(buf, sizeof(buf), stdin) == NULL)
900 break;
901 switch(buf[0]) {
902 case 'r':
903 if (sscanf(buf + 1, "%d", &count) == 1) {
904 blist_resize(&bl, count, 1);
905 } else {
906 printf("?\n");
907 }
908 case 'p':
909 blist_print(bl);
910 break;
911 case 'a':
912 if (sscanf(buf + 1, "%d", &count) == 1) {
913 daddr_t blk = blist_alloc(bl, count);
914 printf(" R=%04x\n", blk);
915 } else {
916 printf("?\n");
917 }
918 break;
919 case 'f':
920 if (sscanf(buf + 1, "%x %d", &da, &count) == 2) {
921 blist_free(bl, da, count);
922 } else {
923 printf("?\n");
924 }
925 break;
926 case '?':
927 case 'h':
928 puts(
929 "p -print\n"
930 "a %d -allocate\n"
931 "f %x %d -free\n"
932 "r %d -resize\n"
933 "h/? -help"
934 );
935 break;
936 default:
937 printf("?\n");
938 break;
939 }
940 }
941 return(0);
942}
943
944void
945panic(const char *ctl, ...)
946{
e2565a42 947 __va_list va;
984263bc 948
e2565a42 949 __va_start(va, ctl);
984263bc
MD
950 vfprintf(stderr, ctl, va);
951 fprintf(stderr, "\n");
e2565a42 952 __va_end(va);
984263bc
MD
953 exit(1);
954}
955
956#endif
957