xref: /dragonfly/sys/vfs/hammer2/hammer2_freemap.c (revision 31c7ac8b)
1 /*
2  * Copyright (c) 2011-2014 The DragonFly Project.  All rights reserved.
3  *
4  * This code is derived from software contributed to The DragonFly Project
5  * by Matthew Dillon <dillon@dragonflybsd.org>
6  * by Venkatesh Srinivas <vsrinivas@dragonflybsd.org>
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  *
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in
16  *    the documentation and/or other materials provided with the
17  *    distribution.
18  * 3. Neither the name of The DragonFly Project nor the names of its
19  *    contributors may be used to endorse or promote products derived
20  *    from this software without specific, prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
23  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
24  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
25  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
26  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
27  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
28  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
29  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
30  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
31  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
32  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/kernel.h>
38 #include <sys/fcntl.h>
39 #include <sys/buf.h>
40 #include <sys/proc.h>
41 #include <sys/namei.h>
42 #include <sys/mount.h>
43 #include <sys/vnode.h>
44 #include <sys/mountctl.h>
45 
46 #include "hammer2.h"
47 
48 #define FREEMAP_DEBUG	0
49 
50 struct hammer2_fiterate {
51 	hammer2_off_t	bpref;
52 	hammer2_off_t	bnext;
53 	int		loops;
54 };
55 
56 typedef struct hammer2_fiterate hammer2_fiterate_t;
57 
58 static int hammer2_freemap_try_alloc(hammer2_trans_t *trans,
59 			hammer2_chain_t **parentp, hammer2_blockref_t *bref,
60 			int radix, hammer2_fiterate_t *iter);
61 static void hammer2_freemap_init(hammer2_trans_t *trans, hammer2_mount_t *hmp,
62 			hammer2_key_t key, hammer2_chain_t *chain);
63 static int hammer2_bmap_alloc(hammer2_trans_t *trans, hammer2_mount_t *hmp,
64 			hammer2_bmap_data_t *bmap, uint16_t class,
65 			int n, int radix, hammer2_key_t *basep);
66 static int hammer2_freemap_iterate(hammer2_trans_t *trans,
67 			hammer2_chain_t **parentp, hammer2_chain_t **chainp,
68 			hammer2_fiterate_t *iter);
69 
70 static __inline
71 int
72 hammer2_freemapradix(int radix)
73 {
74 	return(radix);
75 }
76 
77 /*
78  * Calculate the device offset for the specified FREEMAP_NODE or FREEMAP_LEAF
79  * bref.  Return a combined media offset and physical size radix.  Freemap
80  * chains use fixed storage offsets in the 4MB reserved area at the
81  * beginning of each 2GB zone
82  *
83  * Rotate between four possibilities.  Theoretically this means we have three
84  * good freemaps in case of a crash which we can use as a base for the fixup
85  * scan at mount-time.
86  */
87 #define H2FMBASE(key, radix)	((key) & ~(((hammer2_off_t)1 << (radix)) - 1))
88 #define H2FMSHIFT(radix)	((hammer2_off_t)1 << (radix))
89 
90 static
91 int
92 hammer2_freemap_reserve(hammer2_trans_t *trans, hammer2_chain_t *chain,
93 			int radix)
94 {
95 	hammer2_blockref_t *bref = &chain->bref;
96 	hammer2_off_t off;
97 	int index;
98 	size_t bytes;
99 
100 	/*
101 	 * Physical allocation size -> radix.  Typically either 256 for
102 	 * a level 0 freemap leaf or 65536 for a level N freemap node.
103 	 *
104 	 * NOTE: A 256 byte bitmap represents 256 x 8 x 1024 = 2MB of storage.
105 	 *	 Do not use hammer2_allocsize() here as it has a min cap.
106 	 */
107 	bytes = 1 << radix;
108 
109 	/*
110 	 * Calculate block selection index 0..7 of current block.
111 	 */
112 	if ((bref->data_off & ~HAMMER2_OFF_MASK_RADIX) == 0) {
113 		index = 0;
114 	} else {
115 		off = bref->data_off & ~HAMMER2_OFF_MASK_RADIX &
116 		      (((hammer2_off_t)1 << HAMMER2_FREEMAP_LEVEL1_RADIX) - 1);
117 		off = off / HAMMER2_PBUFSIZE;
118 		KKASSERT(off >= HAMMER2_ZONE_FREEMAP_00 &&
119 			 off < HAMMER2_ZONE_FREEMAP_END);
120 		index = (int)(off - HAMMER2_ZONE_FREEMAP_00) / 4;
121 		KKASSERT(index >= 0 && index < HAMMER2_ZONE_FREEMAP_COPIES);
122 	}
123 
124 	/*
125 	 * Calculate new index (our 'allocation').  We have to be careful
126 	 * here as there can be two different transaction ids running
127 	 * concurrently when a flush is in-progress.
128 	 *
129 	 * We also want to make sure, for algorithmic repeatability, that
130 	 * the index sequences are monotonic with transaction ids.  Some
131 	 * skipping is allowed as long as we ensure that all four volume
132 	 * header backups have consistent freemaps.
133 	 *
134 	 * FLUSH  NORMAL FLUSH  NORMAL FLUSH  NORMAL FLUSH  NORMAL
135 	 * N+=1   N+=2
136 	 * (0->1) (1->3) (3->4) (4->6) (6->7) (7->9) (9->10) (10->12)
137 	 *
138 	 * [-concurrent-][-concurrent-][-concurrent-][-concurrent-]
139 	 *
140 	 * (alternative first NORMAL might be 0->2 if flush had not yet
141 	 *  modified the chain, this is the worst case).
142 	 */
143 	if ((trans->flags & HAMMER2_TRANS_ISFLUSH) == 0) {
144 		/*
145 		 * Normal transactions always run with the highest TID.
146 		 * But if a flush is in-progress we want to reserve a slot
147 		 * for the flush with a lower TID running concurrently to
148 		 * do a delete-duplicate.
149 		 */
150 		index = (index + 2) % HAMMER2_ZONE_FREEMAP_COPIES;
151 	} else if (trans->flags & HAMMER2_TRANS_ISALLOCATING) {
152 		/*
153 		 * Flush transaction, hammer2_freemap.c itself is doing a
154 		 * delete-duplicate during an allocation within the freemap.
155 		 */
156 		index = (index + 1) % HAMMER2_ZONE_FREEMAP_COPIES;
157 	} else {
158 		/*
159 		 * Flush transaction, hammer2_flush.c is doing a
160 		 * delete-duplicate on the freemap while flushing
161 		 * hmp->fchain.
162 		 */
163 		index = (index + 1) % HAMMER2_ZONE_FREEMAP_COPIES;
164 	}
165 
166 	/*
167 	 * Calculate the block offset of the reserved block.  This will
168 	 * point into the 4MB reserved area at the base of the appropriate
169 	 * 2GB zone, once added to the FREEMAP_x selection above.
170 	 */
171 	switch(bref->keybits) {
172 	/* case HAMMER2_FREEMAP_LEVEL5_RADIX: not applicable */
173 	case HAMMER2_FREEMAP_LEVEL4_RADIX:	/* 2EB */
174 		KKASSERT(bref->type == HAMMER2_BREF_TYPE_FREEMAP_NODE);
175 		KKASSERT(bytes == HAMMER2_FREEMAP_LEVELN_PSIZE);
176 		off = H2FMBASE(bref->key, HAMMER2_FREEMAP_LEVEL4_RADIX) +
177 		      (index * 4 + HAMMER2_ZONE_FREEMAP_00 +
178 		       HAMMER2_ZONEFM_LEVEL4) * HAMMER2_PBUFSIZE;
179 		break;
180 	case HAMMER2_FREEMAP_LEVEL3_RADIX:	/* 2PB */
181 		KKASSERT(bref->type == HAMMER2_BREF_TYPE_FREEMAP_NODE);
182 		KKASSERT(bytes == HAMMER2_FREEMAP_LEVELN_PSIZE);
183 		off = H2FMBASE(bref->key, HAMMER2_FREEMAP_LEVEL3_RADIX) +
184 		      (index * 4 + HAMMER2_ZONE_FREEMAP_00 +
185 		       HAMMER2_ZONEFM_LEVEL3) * HAMMER2_PBUFSIZE;
186 		break;
187 	case HAMMER2_FREEMAP_LEVEL2_RADIX:	/* 2TB */
188 		KKASSERT(bref->type == HAMMER2_BREF_TYPE_FREEMAP_NODE);
189 		KKASSERT(bytes == HAMMER2_FREEMAP_LEVELN_PSIZE);
190 		off = H2FMBASE(bref->key, HAMMER2_FREEMAP_LEVEL2_RADIX) +
191 		      (index * 4 + HAMMER2_ZONE_FREEMAP_00 +
192 		       HAMMER2_ZONEFM_LEVEL2) * HAMMER2_PBUFSIZE;
193 		break;
194 	case HAMMER2_FREEMAP_LEVEL1_RADIX:	/* 2GB */
195 		KKASSERT(bref->type == HAMMER2_BREF_TYPE_FREEMAP_LEAF);
196 		KKASSERT(bytes == HAMMER2_FREEMAP_LEVELN_PSIZE);
197 		off = H2FMBASE(bref->key, HAMMER2_FREEMAP_LEVEL1_RADIX) +
198 		      (index * 4 + HAMMER2_ZONE_FREEMAP_00 +
199 		       HAMMER2_ZONEFM_LEVEL1) * HAMMER2_PBUFSIZE;
200 		break;
201 	default:
202 		panic("freemap: bad radix(2) %p %d\n", bref, bref->keybits);
203 		/* NOT REACHED */
204 		off = (hammer2_off_t)-1;
205 		break;
206 	}
207 	bref->data_off = off | radix;
208 #if FREEMAP_DEBUG
209 	kprintf("FREEMAP BLOCK TYPE %d %016jx/%d DATA_OFF=%016jx\n",
210 		bref->type, bref->key, bref->keybits, bref->data_off);
211 #endif
212 	return (0);
213 }
214 
215 /*
216  * Normal freemap allocator
217  *
218  * Use available hints to allocate space using the freemap.  Create missing
219  * freemap infrastructure on-the-fly as needed (including marking initial
220  * allocations using the iterator as allocated, instantiating new 2GB zones,
221  * and dealing with the end-of-media edge case).
222  *
223  * ip and bpref are only used as a heuristic to determine locality of
224  * reference.  bref->key may also be used heuristically.
225  *
226  * WARNING! When called from a flush we have to use the 'live' sync_tid
227  *	    and not the flush sync_tid.  The live sync_tid is the flush
228  *	    sync_tid + 1.  That is, freemap allocations which occur during
229  *	    a flush are not part of the flush.  Crash-recovery will restore
230  *	    any lost allocations.
231  */
232 int
233 hammer2_freemap_alloc(hammer2_trans_t *trans, hammer2_chain_t *chain,
234 		      size_t bytes)
235 {
236 	hammer2_mount_t *hmp = chain->hmp;
237 	hammer2_blockref_t *bref = &chain->bref;
238 	hammer2_chain_t *parent;
239 	int radix;
240 	int error;
241 	unsigned int hindex;
242 	hammer2_fiterate_t iter;
243 
244 	/*
245 	 * Validate the allocation size.  It must be a power of 2.
246 	 *
247 	 * For now require that the caller be aware of the minimum
248 	 * allocation (1K).
249 	 */
250 	radix = hammer2_getradix(bytes);
251 	KKASSERT((size_t)1 << radix == bytes);
252 
253 	/*
254 	 * Freemap blocks themselves are simply assigned from the reserve
255 	 * area, not allocated from the freemap.
256 	 */
257 	if (bref->type == HAMMER2_BREF_TYPE_FREEMAP_NODE ||
258 	    bref->type == HAMMER2_BREF_TYPE_FREEMAP_LEAF) {
259 		return (hammer2_freemap_reserve(trans, chain, radix));
260 	}
261 
262 #if 0
263 	/*
264 	 * (this mechanic is no longer used, DOMAYFREE is used only by
265 	 * the bulk freemap scan now).
266 	 *
267 	 * Mark previously allocated block as possibly freeable.  There might
268 	 * be snapshots and other races so we can't just mark it fully free.
269 	 * (XXX optimize this for the current-transaction create+delete case)
270 	 */
271 	if (bref->data_off & ~HAMMER2_OFF_MASK_RADIX) {
272 		hammer2_freemap_adjust(trans, hmp, bref,
273 				       HAMMER2_FREEMAP_DOMAYFREE);
274 	}
275 #endif
276 
277 	/*
278 	 * Setting ISALLOCATING ensures correct operation even when the
279 	 * flusher itself is making allocations.
280 	 */
281 	KKASSERT(bytes >= HAMMER2_MIN_ALLOC && bytes <= HAMMER2_MAX_ALLOC);
282 	KKASSERT((trans->flags & HAMMER2_TRANS_ISALLOCATING) == 0);
283 	atomic_set_int(&trans->flags, HAMMER2_TRANS_ISALLOCATING);
284 	if (trans->flags & HAMMER2_TRANS_ISFLUSH)
285 		++trans->sync_tid;
286 
287 	/*
288 	 * Calculate the starting point for our allocation search.
289 	 *
290 	 * Each freemap leaf is dedicated to a specific freemap_radix.
291 	 * The freemap_radix can be more fine-grained than the device buffer
292 	 * radix which results in inodes being grouped together in their
293 	 * own segment, terminal-data (16K or less) and initial indirect
294 	 * block being grouped together, and then full-indirect and full-data
295 	 * blocks (64K) being grouped together.
296 	 *
297 	 * The single most important aspect of this is the inode grouping
298 	 * because that is what allows 'find' and 'ls' and other filesystem
299 	 * topology operations to run fast.
300 	 */
301 #if 0
302 	if (bref->data_off & ~HAMMER2_OFF_MASK_RADIX)
303 		bpref = bref->data_off & ~HAMMER2_OFF_MASK_RADIX;
304 	else if (trans->tmp_bpref)
305 		bpref = trans->tmp_bpref;
306 	else if (trans->tmp_ip)
307 		bpref = trans->tmp_ip->chain->bref.data_off;
308 	else
309 #endif
310 	/*
311 	 * Heuristic tracking index.  We would like one for each distinct
312 	 * bref type if possible.  heur_freemap[] has room for two classes
313 	 * for each type.  At a minimum we have to break-up our heuristic
314 	 * by device block sizes.
315 	 */
316 	hindex = hammer2_devblkradix(radix) - HAMMER2_MINIORADIX;
317 	KKASSERT(hindex < HAMMER2_FREEMAP_HEUR_NRADIX);
318 	hindex += bref->type * HAMMER2_FREEMAP_HEUR_NRADIX;
319 	hindex &= HAMMER2_FREEMAP_HEUR_TYPES * HAMMER2_FREEMAP_HEUR_NRADIX - 1;
320 	KKASSERT(hindex < HAMMER2_FREEMAP_HEUR);
321 
322 	iter.bpref = hmp->heur_freemap[hindex];
323 
324 	/*
325 	 * Make sure bpref is in-bounds.  It's ok if bpref covers a zone's
326 	 * reserved area, the try code will iterate past it.
327 	 */
328 	if (iter.bpref > hmp->voldata.volu_size)
329 		iter.bpref = hmp->voldata.volu_size - 1;
330 
331 	/*
332 	 * Iterate the freemap looking for free space before and after.
333 	 */
334 	parent = &hmp->fchain;
335 	hammer2_chain_lock(parent, HAMMER2_RESOLVE_ALWAYS);
336 	error = EAGAIN;
337 	iter.bnext = iter.bpref;
338 	iter.loops = 0;
339 
340 	while (error == EAGAIN) {
341 		error = hammer2_freemap_try_alloc(trans, &parent, bref,
342 						  radix, &iter);
343 	}
344 	hmp->heur_freemap[hindex] = iter.bnext;
345 	hammer2_chain_unlock(parent);
346 
347 	atomic_clear_int(&trans->flags, HAMMER2_TRANS_ISALLOCATING);
348 	if (trans->flags & HAMMER2_TRANS_ISFLUSH)
349 		--trans->sync_tid;
350 
351 	return (error);
352 }
353 
354 static int
355 hammer2_freemap_try_alloc(hammer2_trans_t *trans, hammer2_chain_t **parentp,
356 			  hammer2_blockref_t *bref, int radix,
357 			  hammer2_fiterate_t *iter)
358 {
359 	hammer2_mount_t *hmp = (*parentp)->hmp;
360 	hammer2_off_t l0size;
361 	hammer2_off_t l1size;
362 	hammer2_off_t l1mask;
363 	hammer2_key_t key_dummy;
364 	hammer2_chain_t *chain;
365 	hammer2_off_t key;
366 	size_t bytes;
367 	uint16_t class;
368 	int error = 0;
369 	int cache_index = -1;
370 
371 
372 	/*
373 	 * Calculate the number of bytes being allocated, the number
374 	 * of contiguous bits of bitmap being allocated, and the bitmap
375 	 * mask.
376 	 *
377 	 * WARNING! cpu hardware may mask bits == 64 -> 0 and blow up the
378 	 *	    mask calculation.
379 	 */
380 	bytes = (size_t)1 << radix;
381 	class = (bref->type << 8) | hammer2_devblkradix(radix);
382 
383 	/*
384 	 * Lookup the level1 freemap chain, creating and initializing one
385 	 * if necessary.  Intermediate levels will be created automatically
386 	 * when necessary by hammer2_chain_create().
387 	 */
388 	key = H2FMBASE(iter->bnext, HAMMER2_FREEMAP_LEVEL1_RADIX);
389 	l0size = H2FMSHIFT(HAMMER2_FREEMAP_LEVEL0_RADIX);
390 	l1size = H2FMSHIFT(HAMMER2_FREEMAP_LEVEL1_RADIX);
391 	l1mask = l1size - 1;
392 
393 	chain = hammer2_chain_lookup(parentp, &key_dummy, key, key + l1mask,
394 				     &cache_index,
395 				     HAMMER2_LOOKUP_ALWAYS |
396 				     HAMMER2_LOOKUP_MATCHIND);
397 
398 	if (chain == NULL) {
399 		/*
400 		 * Create the missing leaf, be sure to initialize
401 		 * the auxillary freemap tracking information in
402 		 * the bref.check.freemap structure.
403 		 */
404 #if 0
405 		kprintf("freemap create L1 @ %016jx bpref %016jx\n",
406 			key, iter->bpref);
407 #endif
408 		error = hammer2_chain_create(trans, parentp, &chain,
409 				     key, HAMMER2_FREEMAP_LEVEL1_RADIX,
410 				     HAMMER2_BREF_TYPE_FREEMAP_LEAF,
411 				     HAMMER2_FREEMAP_LEVELN_PSIZE);
412 		KKASSERT(error == 0);
413 		if (error == 0) {
414 			hammer2_chain_modify(trans, &chain, 0);
415 			bzero(&chain->data->bmdata[0],
416 			      HAMMER2_FREEMAP_LEVELN_PSIZE);
417 			chain->bref.check.freemap.bigmask = (uint32_t)-1;
418 			chain->bref.check.freemap.avail = l1size;
419 			/* bref.methods should already be inherited */
420 
421 			hammer2_freemap_init(trans, hmp, key, chain);
422 		}
423 	} else if ((chain->bref.check.freemap.bigmask & (1 << radix)) == 0) {
424 		/*
425 		 * Already flagged as not having enough space
426 		 */
427 		error = ENOSPC;
428 	} else {
429 		/*
430 		 * Modify existing chain to setup for adjustment.
431 		 */
432 		hammer2_chain_modify(trans, &chain, 0);
433 	}
434 
435 	/*
436 	 * Scan 2MB entries.
437 	 */
438 	if (error == 0) {
439 		hammer2_bmap_data_t *bmap;
440 		hammer2_key_t base_key;
441 		int count;
442 		int start;
443 		int n;
444 
445 		KKASSERT(chain->bref.type == HAMMER2_BREF_TYPE_FREEMAP_LEAF);
446 		start = (int)((iter->bnext - key) >>
447 			      HAMMER2_FREEMAP_LEVEL0_RADIX);
448 		KKASSERT(start >= 0 && start < HAMMER2_FREEMAP_COUNT);
449 		hammer2_chain_modify(trans, &chain, 0);
450 
451 		error = ENOSPC;
452 		for (count = 0; count < HAMMER2_FREEMAP_COUNT; ++count) {
453 			if (start + count >= HAMMER2_FREEMAP_COUNT &&
454 			    start - count < 0) {
455 				break;
456 			}
457 			n = start + count;
458 			bmap = &chain->data->bmdata[n];
459 			if (n < HAMMER2_FREEMAP_COUNT && bmap->avail &&
460 			    (bmap->class == 0 || bmap->class == class)) {
461 				base_key = key + n * l0size;
462 				error = hammer2_bmap_alloc(trans, hmp, bmap,
463 							   class, n, radix,
464 							   &base_key);
465 				if (error != ENOSPC) {
466 					key = base_key;
467 					break;
468 				}
469 			}
470 			n = start - count;
471 			bmap = &chain->data->bmdata[n];
472 			if (n >= 0 && bmap->avail &&
473 			    (bmap->class == 0 || bmap->class == class)) {
474 				base_key = key + n * l0size;
475 				error = hammer2_bmap_alloc(trans, hmp, bmap,
476 							   class, n, radix,
477 							   &base_key);
478 				if (error != ENOSPC) {
479 					key = base_key;
480 					break;
481 				}
482 			}
483 		}
484 		if (error == ENOSPC)
485 			chain->bref.check.freemap.bigmask &= ~(1 << radix);
486 		/* XXX also scan down from original count */
487 	}
488 
489 	if (error == 0) {
490 		/*
491 		 * Assert validity.  Must be beyond the static allocator used
492 		 * by newfs_hammer2 (and thus also beyond the aux area),
493 		 * not go past the volume size, and must not be in the
494 		 * reserved segment area for a zone.
495 		 */
496 		KKASSERT(key >= hmp->voldata.allocator_beg &&
497 			 key + bytes <= hmp->voldata.volu_size);
498 		KKASSERT((key & HAMMER2_ZONE_MASK64) >= HAMMER2_ZONE_SEG);
499 		bref->data_off = key | radix;
500 
501 #if 0
502 		kprintf("alloc cp=%p %016jx %016jx using %016jx\n",
503 			chain,
504 			bref->key, bref->data_off, chain->bref.data_off);
505 #endif
506 	} else if (error == ENOSPC) {
507 		/*
508 		 * Return EAGAIN with next iteration in iter->bnext, or
509 		 * return ENOSPC if the allocation map has been exhausted.
510 		 */
511 		error = hammer2_freemap_iterate(trans, parentp, &chain, iter);
512 	}
513 
514 	/*
515 	 * Cleanup
516 	 */
517 	if (chain)
518 		hammer2_chain_unlock(chain);
519 	return (error);
520 }
521 
522 /*
523  * Allocate (1<<radix) bytes from the bmap whos base data offset is (*basep).
524  *
525  * If the linear iterator is mid-block we use it directly (the bitmap should
526  * already be marked allocated), otherwise we search for a block in the bitmap
527  * that fits the allocation request.
528  *
529  * A partial bitmap allocation sets the minimum bitmap granularity (16KB)
530  * to fully allocated and adjusts the linear allocator to allow the
531  * remaining space to be allocated.
532  */
533 static
534 int
535 hammer2_bmap_alloc(hammer2_trans_t *trans, hammer2_mount_t *hmp,
536 		   hammer2_bmap_data_t *bmap,
537 		   uint16_t class, int n, int radix, hammer2_key_t *basep)
538 {
539 	hammer2_io_t *dio;
540 	size_t size;
541 	size_t bsize;
542 	int bmradix;
543 	uint32_t bmmask;
544 	int offset;
545 	int error;
546 	int i;
547 	int j;
548 
549 	/*
550 	 * Take into account 2-bits per block when calculating bmradix.
551 	 */
552 	size = (size_t)1 << radix;
553 
554 	if (radix <= HAMMER2_FREEMAP_BLOCK_RADIX) {
555 		bmradix = 2;
556 		bsize = HAMMER2_FREEMAP_BLOCK_SIZE;
557 		/* (16K) 2 bits per allocation block */
558 	} else {
559 		bmradix = 2 << (radix - HAMMER2_FREEMAP_BLOCK_RADIX);
560 		bsize = size;
561 		/* (32K-256K) 4, 8, 16, 32 bits per allocation block */
562 	}
563 
564 	/*
565 	 * Use the linear iterator to pack small allocations, otherwise
566 	 * fall-back to finding a free 16KB chunk.  The linear iterator
567 	 * is only valid when *NOT* on a freemap chunking boundary (16KB).
568 	 * If it is the bitmap must be scanned.  It can become invalid
569 	 * once we pack to the boundary.  We adjust it after a bitmap
570 	 * allocation only for sub-16KB allocations (so the perfectly good
571 	 * previous value can still be used for fragments when 16KB+
572 	 * allocations are made).
573 	 *
574 	 * Beware of hardware artifacts when bmradix == 32 (intermediate
575 	 * result can wind up being '1' instead of '0' if hardware masks
576 	 * bit-count & 31).
577 	 *
578 	 * NOTE: j needs to be even in the j= calculation.  As an artifact
579 	 *	 of the /2 division, our bitmask has to clear bit 0.
580 	 *
581 	 * NOTE: TODO this can leave little unallocatable fragments lying
582 	 *	 around.
583 	 */
584 	if (((uint32_t)bmap->linear & HAMMER2_FREEMAP_BLOCK_MASK) + size <=
585 	    HAMMER2_FREEMAP_BLOCK_SIZE &&
586 	    (bmap->linear & HAMMER2_FREEMAP_BLOCK_MASK) &&
587 	    bmap->linear < HAMMER2_SEGSIZE) {
588 		KKASSERT(bmap->linear >= 0 &&
589 			 bmap->linear + size <= HAMMER2_SEGSIZE &&
590 			 (bmap->linear & (HAMMER2_MIN_ALLOC - 1)) == 0);
591 		offset = bmap->linear;
592 		i = offset / (HAMMER2_SEGSIZE / 8);
593 		j = (offset / (HAMMER2_FREEMAP_BLOCK_SIZE / 2)) & 30;
594 		bmmask = (bmradix == 32) ?
595 			 0xFFFFFFFFU : (1 << bmradix) - 1;
596 		bmmask <<= j;
597 		bmap->linear = offset + size;
598 	} else {
599 		for (i = 0; i < 8; ++i) {
600 			bmmask = (bmradix == 32) ?
601 				 0xFFFFFFFFU : (1 << bmradix) - 1;
602 			for (j = 0; j < 32; j += bmradix) {
603 				if ((bmap->bitmap[i] & bmmask) == 0)
604 					goto success;
605 				bmmask <<= bmradix;
606 			}
607 		}
608 		/*fragments might remain*/
609 		/*KKASSERT(bmap->avail == 0);*/
610 		return (ENOSPC);
611 success:
612 		offset = i * (HAMMER2_SEGSIZE / 8) +
613 			 (j * (HAMMER2_FREEMAP_BLOCK_SIZE / 2));
614 		if (size & HAMMER2_FREEMAP_BLOCK_MASK)
615 			bmap->linear = offset + size;
616 	}
617 
618 	KKASSERT(i >= 0 && i < 8);	/* 8 x 16 -> 128 x 16K -> 2MB */
619 
620 	/*
621 	 * Optimize the buffer cache to avoid unnecessary read-before-write
622 	 * operations.
623 	 *
624 	 * The device block size could be larger than the allocation size
625 	 * so the actual bitmap test is somewhat more involved.  We have
626 	 * to use a compatible buffer size for this operation.
627 	 */
628 	if ((bmap->bitmap[i] & bmmask) == 0 &&
629 	    hammer2_devblksize(size) != size) {
630 		size_t psize = hammer2_devblksize(size);
631 		hammer2_off_t pmask = (hammer2_off_t)psize - 1;
632 		int pbmradix = 2 << (hammer2_devblkradix(radix) -
633 				     HAMMER2_FREEMAP_BLOCK_RADIX);
634 		uint32_t pbmmask;
635 		int pradix = hammer2_getradix(psize);
636 
637 		pbmmask = (pbmradix == 32) ? 0xFFFFFFFFU : (1 << pbmradix) - 1;
638 		while ((pbmmask & bmmask) == 0)
639 			pbmmask <<= pbmradix;
640 
641 #if 0
642 		kprintf("%016jx mask %08x %08x %08x (%zd/%zd)\n",
643 			*basep + offset, bmap->bitmap[i],
644 			pbmmask, bmmask, size, psize);
645 #endif
646 
647 		if ((bmap->bitmap[i] & pbmmask) == 0) {
648 			error = hammer2_io_newq(hmp,
649 						(*basep + (offset & ~pmask)) |
650 						 pradix,
651 						psize, &dio);
652 			hammer2_io_bqrelse(&dio);
653 		}
654 	}
655 
656 #if 0
657 	/*
658 	 * When initializing a new inode segment also attempt to initialize
659 	 * an adjacent segment.  Be careful not to index beyond the array
660 	 * bounds.
661 	 *
662 	 * We do this to try to localize inode accesses to improve
663 	 * directory scan rates.  XXX doesn't improve scan rates.
664 	 */
665 	if (size == HAMMER2_INODE_BYTES) {
666 		if (n & 1) {
667 			if (bmap[-1].radix == 0 && bmap[-1].avail)
668 				bmap[-1].radix = radix;
669 		} else {
670 			if (bmap[1].radix == 0 && bmap[1].avail)
671 				bmap[1].radix = radix;
672 		}
673 	}
674 #endif
675 
676 	/*
677 	 * Adjust the linear iterator, set the radix if necessary (might as
678 	 * well just set it unconditionally), adjust *basep to return the
679 	 * allocated data offset.
680 	 */
681 	bmap->bitmap[i] |= bmmask;
682 	bmap->class = class;
683 	bmap->avail -= size;
684 	*basep += offset;
685 
686 	hammer2_voldata_lock(hmp);
687 	hmp->voldata.allocator_free -= size;  /* XXX */
688 	hammer2_voldata_unlock(hmp, 1);
689 
690 	return(0);
691 }
692 
693 static
694 void
695 hammer2_freemap_init(hammer2_trans_t *trans, hammer2_mount_t *hmp,
696 		     hammer2_key_t key, hammer2_chain_t *chain)
697 {
698 	hammer2_off_t l1size;
699 	hammer2_off_t lokey;
700 	hammer2_off_t hikey;
701 	hammer2_bmap_data_t *bmap;
702 	int count;
703 
704 	l1size = H2FMSHIFT(HAMMER2_FREEMAP_LEVEL1_RADIX);
705 
706 	/*
707 	 * Calculate the portion of the 2GB map that should be initialized
708 	 * as free.  Portions below or after will be initialized as allocated.
709 	 * SEGMASK-align the areas so we don't have to worry about sub-scans
710 	 * or endianess when using memset.
711 	 *
712 	 * (1) Ensure that all statically allocated space from newfs_hammer2
713 	 *     is marked allocated.
714 	 *
715 	 * (2) Ensure that the reserved area is marked allocated (typically
716 	 *     the first 4MB of the 2GB area being represented).
717 	 *
718 	 * (3) Ensure that any trailing space at the end-of-volume is marked
719 	 *     allocated.
720 	 *
721 	 * WARNING! It is possible for lokey to be larger than hikey if the
722 	 *	    entire 2GB segment is within the static allocation.
723 	 */
724 	lokey = (hmp->voldata.allocator_beg + HAMMER2_SEGMASK64) &
725 		~HAMMER2_SEGMASK64;
726 
727 	if (lokey < H2FMBASE(key, HAMMER2_FREEMAP_LEVEL1_RADIX) +
728 		  HAMMER2_ZONE_SEG64) {
729 		lokey = H2FMBASE(key, HAMMER2_FREEMAP_LEVEL1_RADIX) +
730 			HAMMER2_ZONE_SEG64;
731 	}
732 
733 	hikey = key + H2FMSHIFT(HAMMER2_FREEMAP_LEVEL1_RADIX);
734 	if (hikey > hmp->voldata.volu_size) {
735 		hikey = hmp->voldata.volu_size & ~HAMMER2_SEGMASK64;
736 	}
737 
738 	chain->bref.check.freemap.avail =
739 		H2FMSHIFT(HAMMER2_FREEMAP_LEVEL1_RADIX);
740 	bmap = &chain->data->bmdata[0];
741 
742 	for (count = 0; count < HAMMER2_FREEMAP_COUNT; ++count) {
743 		if (key < lokey || key >= hikey) {
744 			memset(bmap->bitmap, -1,
745 			       sizeof(bmap->bitmap));
746 			bmap->avail = 0;
747 			bmap->linear = HAMMER2_SEGSIZE;
748 			chain->bref.check.freemap.avail -=
749 				H2FMSHIFT(HAMMER2_FREEMAP_LEVEL0_RADIX);
750 		} else {
751 			bmap->avail = H2FMSHIFT(HAMMER2_FREEMAP_LEVEL0_RADIX);
752 		}
753 		key += H2FMSHIFT(HAMMER2_FREEMAP_LEVEL0_RADIX);
754 		++bmap;
755 	}
756 }
757 
758 /*
759  * The current Level 1 freemap has been exhausted, iterate to the next
760  * one, return ENOSPC if no freemaps remain.
761  *
762  * XXX this should rotate back to the beginning to handle freed-up space
763  * XXX or use intermediate entries to locate free space. TODO
764  */
765 static int
766 hammer2_freemap_iterate(hammer2_trans_t *trans, hammer2_chain_t **parentp,
767 			hammer2_chain_t **chainp, hammer2_fiterate_t *iter)
768 {
769 	hammer2_mount_t *hmp = (*parentp)->hmp;
770 
771 	iter->bnext &= ~(H2FMSHIFT(HAMMER2_FREEMAP_LEVEL1_RADIX) - 1);
772 	iter->bnext += H2FMSHIFT(HAMMER2_FREEMAP_LEVEL1_RADIX);
773 	if (iter->bnext >= hmp->voldata.volu_size) {
774 		iter->bnext = 0;
775 		if (++iter->loops == 2)
776 			return (ENOSPC);
777 	}
778 	return(EAGAIN);
779 }
780 
781 /*
782  * Adjust the bit-pattern for data in the freemap bitmap according to
783  * (how).  This code is called from on-mount recovery to fixup (mark
784  * as allocated) blocks whos freemap upates might not have been committed
785  * in the last crash and is used by the bulk freemap scan to stage frees.
786  *
787  * XXX currently disabled when how == 0 (the normal real-time case).  At
788  * the moment we depend on the bulk freescan to actually free blocks.  It
789  * will still call this routine with a non-zero how to stage possible frees
790  * and to do the actual free.
791  *
792  * WARNING! When called from a flush we have to use the 'live' sync_tid
793  *	    and not the flush sync_tid.  The live sync_tid is the flush
794  *	    sync_tid + 1.  That is, freemap allocations which occur during
795  *	    a flush are not part of the flush.  Crash-recovery will restore
796  *	    any lost allocations.
797  */
798 void
799 hammer2_freemap_adjust(hammer2_trans_t *trans, hammer2_mount_t *hmp,
800 		       hammer2_blockref_t *bref, int how)
801 {
802 	hammer2_off_t data_off = bref->data_off;
803 	hammer2_chain_t *chain;
804 	hammer2_chain_t *parent;
805 	hammer2_bmap_data_t *bmap;
806 	hammer2_key_t key;
807 	hammer2_key_t key_dummy;
808 	hammer2_off_t l0size;
809 	hammer2_off_t l1size;
810 	hammer2_off_t l1mask;
811 	uint32_t *bitmap;
812 	const uint32_t bmmask00 = 0;
813 	uint32_t bmmask01;
814 	uint32_t bmmask10;
815 	uint32_t bmmask11;
816 	size_t bytes;
817 	uint16_t class;
818 	int radix;
819 	int start;
820 	int count;
821 	int modified = 0;
822 	int cache_index = -1;
823 	int error;
824 
825 	radix = (int)data_off & HAMMER2_OFF_MASK_RADIX;
826 	data_off &= ~HAMMER2_OFF_MASK_RADIX;
827 	KKASSERT(radix <= HAMMER2_MAX_RADIX);
828 
829 	bytes = (size_t)1 << radix;
830 	class = (bref->type << 8) | hammer2_devblkradix(radix);
831 
832 	/*
833 	 * We can't adjust thre freemap for data allocations made by
834 	 * newfs_hammer2.
835 	 */
836 	if (data_off < hmp->voldata.allocator_beg)
837 		return;
838 
839 	KKASSERT((data_off & HAMMER2_ZONE_MASK64) >= HAMMER2_ZONE_SEG);
840 	KKASSERT((trans->flags & HAMMER2_TRANS_ISALLOCATING) == 0);
841 	atomic_set_int(&trans->flags, HAMMER2_TRANS_ISALLOCATING);
842 	if (trans->flags & HAMMER2_TRANS_ISFLUSH)
843 		++trans->sync_tid;
844 
845 	/*
846 	 * Lookup the level1 freemap chain.  The chain must exist.
847 	 */
848 	key = H2FMBASE(data_off, HAMMER2_FREEMAP_LEVEL1_RADIX);
849 	l0size = H2FMSHIFT(HAMMER2_FREEMAP_LEVEL0_RADIX);
850 	l1size = H2FMSHIFT(HAMMER2_FREEMAP_LEVEL1_RADIX);
851 	l1mask = l1size - 1;
852 
853 	parent = &hmp->fchain;
854 	hammer2_chain_lock(parent, HAMMER2_RESOLVE_ALWAYS);
855 
856 	chain = hammer2_chain_lookup(&parent, &key_dummy, key, key + l1mask,
857 				     &cache_index,
858 				     HAMMER2_LOOKUP_ALWAYS |
859 				     HAMMER2_LOOKUP_MATCHIND);
860 
861 	/*
862 	 * Stop early if we are trying to free something but no leaf exists.
863 	 */
864 	if (chain == NULL && how != HAMMER2_FREEMAP_DORECOVER) {
865 		kprintf("hammer2_freemap_adjust: %016jx: no chain\n",
866 			(intmax_t)bref->data_off);
867 		goto done;
868 	}
869 
870 	/*
871 	 * Create any missing leaf(s) if we are doing a recovery (marking
872 	 * the block(s) as being allocated instead of being freed).  Be sure
873 	 * to initialize the auxillary freemap tracking info in the
874 	 * bref.check.freemap structure.
875 	 */
876 	if (chain == NULL && how == HAMMER2_FREEMAP_DORECOVER) {
877 		error = hammer2_chain_create(trans, &parent, &chain,
878 				     key, HAMMER2_FREEMAP_LEVEL1_RADIX,
879 				     HAMMER2_BREF_TYPE_FREEMAP_LEAF,
880 				     HAMMER2_FREEMAP_LEVELN_PSIZE);
881 
882 		if (hammer2_debug & 0x0040) {
883 			kprintf("fixup create chain %p %016jx:%d\n",
884 				chain, chain->bref.key, chain->bref.keybits);
885 		}
886 
887 		if (error == 0) {
888 			hammer2_chain_modify(trans, &chain, 0);
889 			bzero(&chain->data->bmdata[0],
890 			      HAMMER2_FREEMAP_LEVELN_PSIZE);
891 			chain->bref.check.freemap.bigmask = (uint32_t)-1;
892 			chain->bref.check.freemap.avail = l1size;
893 			/* bref.methods should already be inherited */
894 
895 			hammer2_freemap_init(trans, hmp, key, chain);
896 		}
897 		/* XXX handle error */
898 	}
899 
900 #if FREEMAP_DEBUG
901 	kprintf("FREEMAP ADJUST TYPE %d %016jx/%d DATA_OFF=%016jx\n",
902 		chain->bref.type, chain->bref.key,
903 		chain->bref.keybits, chain->bref.data_off);
904 #endif
905 
906 	/*
907 	 * Calculate the bitmask (runs in 2-bit pairs).
908 	 */
909 	start = ((int)(data_off >> HAMMER2_FREEMAP_BLOCK_RADIX) & 15) * 2;
910 	bmmask01 = 1 << start;
911 	bmmask10 = 2 << start;
912 	bmmask11 = 3 << start;
913 
914 	/*
915 	 * Fixup the bitmap.  Partial blocks cannot be fully freed unless
916 	 * a bulk scan is able to roll them up.
917 	 */
918 	if (radix < HAMMER2_FREEMAP_BLOCK_RADIX) {
919 		count = 1;
920 		if (how == HAMMER2_FREEMAP_DOREALFREE)
921 			how = HAMMER2_FREEMAP_DOMAYFREE;
922 	} else {
923 		count = 1 << (radix - HAMMER2_FREEMAP_BLOCK_RADIX);
924 	}
925 
926 	/*
927 	 * [re]load the bmap and bitmap pointers.  Each bmap entry covers
928 	 * a 2MB swath.  The bmap itself (LEVEL1) covers 2GB.
929 	 *
930 	 * Be sure to reset the linear iterator to ensure that the adjustment
931 	 * is not ignored.
932 	 */
933 again:
934 	bmap = &chain->data->bmdata[(int)(data_off >> HAMMER2_SEGRADIX) &
935 				    (HAMMER2_FREEMAP_COUNT - 1)];
936 	bitmap = &bmap->bitmap[(int)(data_off >> (HAMMER2_SEGRADIX - 3)) & 7];
937 	bmap->linear = 0;
938 
939 	while (count) {
940 		KKASSERT(bmmask11);
941 		if (how == HAMMER2_FREEMAP_DORECOVER) {
942 			/*
943 			 * Recovery request, mark as allocated.
944 			 */
945 			if ((*bitmap & bmmask11) != bmmask11) {
946 				if (modified == 0) {
947 					hammer2_chain_modify(trans, &chain, 0);
948 					modified = 1;
949 					goto again;
950 				}
951 				if ((*bitmap & bmmask11) == bmmask00)
952 					bmap->avail -= 1 << radix;
953 				if (bmap->class == 0)
954 					bmap->class = class;
955 				*bitmap |= bmmask11;
956 				if (hammer2_debug & 0x0040) {
957 					kprintf("hammer2_freemap_recover: "
958 						"fixup type=%02x "
959 						"block=%016jx/%zd\n",
960 						bref->type, data_off, bytes);
961 				}
962 			} else {
963 				/*
964 				kprintf("hammer2_freemap_recover:  good "
965 					"type=%02x block=%016jx/%zd\n",
966 					bref->type, data_off, bytes);
967 				*/
968 			}
969 		} else if ((*bitmap & bmmask11) == bmmask11) {
970 			/*
971 			 * Mayfree/Realfree request and bitmap is currently
972 			 * marked as being fully allocated.
973 			 */
974 			if (!modified) {
975 				hammer2_chain_modify(trans, &chain, 0);
976 				modified = 1;
977 				goto again;
978 			}
979 			if (how == HAMMER2_FREEMAP_DOREALFREE)
980 				*bitmap &= ~bmmask11;
981 			else
982 				*bitmap = (*bitmap & ~bmmask11) | bmmask10;
983 		} else if ((*bitmap & bmmask11) == bmmask10) {
984 			/*
985 			 * Mayfree/Realfree request and bitmap is currently
986 			 * marked as being possibly freeable.
987 			 */
988 			if (how == HAMMER2_FREEMAP_DOREALFREE) {
989 				if (!modified) {
990 					hammer2_chain_modify(trans, &chain, 0);
991 					modified = 1;
992 					goto again;
993 				}
994 				*bitmap &= ~bmmask11;
995 			}
996 		} else {
997 			/*
998 			 * 01 - Not implemented, currently illegal state
999 			 * 00 - Not allocated at all, illegal free.
1000 			 */
1001 			panic("hammer2_freemap_adjust: "
1002 			      "Illegal state %08x(%08x)",
1003 			      *bitmap, *bitmap & bmmask11);
1004 		}
1005 		--count;
1006 		bmmask01 <<= 2;
1007 		bmmask10 <<= 2;
1008 		bmmask11 <<= 2;
1009 	}
1010 	if (how == HAMMER2_FREEMAP_DOREALFREE && modified) {
1011 		bmap->avail += 1 << radix;
1012 		KKASSERT(bmap->avail <= HAMMER2_SEGSIZE);
1013 		if (bmap->avail == HAMMER2_SEGSIZE &&
1014 		    bmap->bitmap[0] == 0 &&
1015 		    bmap->bitmap[1] == 0 &&
1016 		    bmap->bitmap[2] == 0 &&
1017 		    bmap->bitmap[3] == 0 &&
1018 		    bmap->bitmap[4] == 0 &&
1019 		    bmap->bitmap[5] == 0 &&
1020 		    bmap->bitmap[6] == 0 &&
1021 		    bmap->bitmap[7] == 0) {
1022 			key = H2FMBASE(data_off, HAMMER2_FREEMAP_LEVEL0_RADIX);
1023 			kprintf("Freeseg %016jx\n", (intmax_t)key);
1024 			bmap->class = 0;
1025 		}
1026 	}
1027 
1028 	/*
1029 	 * chain->bref.check.freemap.bigmask (XXX)
1030 	 *
1031 	 * Setting bigmask is a hint to the allocation code that there might
1032 	 * be something allocatable.  We also set this in recovery... it
1033 	 * doesn't hurt and we might want to use the hint for other validation
1034 	 * operations later on.
1035 	 */
1036 	if (modified)
1037 		chain->bref.check.freemap.bigmask |= 1 << radix;
1038 
1039 	hammer2_chain_unlock(chain);
1040 done:
1041 	hammer2_chain_unlock(parent);
1042 	atomic_clear_int(&trans->flags, HAMMER2_TRANS_ISALLOCATING);
1043 	if (trans->flags & HAMMER2_TRANS_ISFLUSH)
1044 		--trans->sync_tid;
1045 }
1046