1 /*
2  * Copyright (c) 2013-2019 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  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  *
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in
15  *    the documentation and/or other materials provided with the
16  *    distribution.
17  * 3. Neither the name of The DragonFly Project nor the names of its
18  *    contributors may be used to endorse or promote products derived
19  *    from this software without specific, prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  */
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/kernel.h>
37 #include <sys/fcntl.h>
38 #include <sys/buf.h>
39 #include <sys/proc.h>
40 #include <sys/namei.h>
41 #include <sys/mount.h>
42 #include <sys/vnode.h>
43 #include <sys/mountctl.h>
44 #include <vm/vm_kern.h>
45 #include <vm/vm_extern.h>
46 
47 #include "hammer2.h"
48 
49 /*
50  * breadth-first search
51  */
52 typedef struct hammer2_chain_save {
53 	TAILQ_ENTRY(hammer2_chain_save)	entry;
54 	hammer2_chain_t	*chain;
55 	int pri;
56 } hammer2_chain_save_t;
57 
58 TAILQ_HEAD(hammer2_chain_save_list, hammer2_chain_save);
59 typedef struct hammer2_chain_save_list hammer2_chain_save_list_t;
60 
61 typedef struct hammer2_bulkfree_info {
62 	hammer2_dev_t		*hmp;
63 	kmem_anon_desc_t	kp;
64 	hammer2_off_t		sbase;		/* sub-loop iteration */
65 	hammer2_off_t		sstop;
66 	hammer2_bmap_data_t	*bmap;
67 	int			depth;
68 	long			count_10_00;	/* staged->free	     */
69 	long			count_11_10;	/* allocated->staged */
70 	long			count_00_11;	/* (should not happen) */
71 	long			count_01_11;	/* (should not happen) */
72 	long			count_10_11;	/* staged->allocated */
73 	long			count_l0cleans;
74 	long			count_linadjusts;
75 	long			count_inodes_scanned;
76 	long			count_dirents_scanned;
77 	long			count_dedup_factor;
78 	long			count_bytes_scanned;
79 	long			count_chains_scanned;
80 	long			count_chains_reported;
81 	long			bulkfree_calls;
82 	int			bulkfree_ticks;
83 	hammer2_off_t		adj_free;
84 	hammer2_tid_t		mtid;
85 	hammer2_tid_t		saved_mirror_tid;
86 	time_t			save_time;
87 	hammer2_chain_save_list_t list;
88 	hammer2_dedup_t		*dedup;
89 	int			pri;
90 } hammer2_bulkfree_info_t;
91 
92 static int h2_bulkfree_test(hammer2_bulkfree_info_t *info,
93 			hammer2_blockref_t *bref, int pri, int saved_error);
94 
95 /*
96  * General bulk scan function with callback.  Called with a referenced
97  * but UNLOCKED parent.  The parent is returned in the same state.
98  */
99 static
100 int
101 hammer2_bulk_scan(hammer2_chain_t *parent,
102 		  int (*func)(hammer2_bulkfree_info_t *info,
103 			      hammer2_blockref_t *bref),
104 		  hammer2_bulkfree_info_t *info)
105 {
106 	hammer2_blockref_t bref;
107 	hammer2_chain_t *chain;
108 	hammer2_chain_save_t *tail;
109 	hammer2_chain_save_t *save;
110 	int first = 1;
111 	int rup_error;
112 	int error;
113 	int e2;
114 
115 	++info->pri;
116 
117 	chain = NULL;
118 	rup_error = 0;
119 	error = 0;
120 
121 	hammer2_chain_lock(parent, HAMMER2_RESOLVE_ALWAYS |
122 				   HAMMER2_RESOLVE_SHARED);
123 	tail = TAILQ_LAST(&info->list, hammer2_chain_save_list);
124 
125 	/*
126 	 * The parent was previously retrieved NODATA and thus has not
127 	 * tested the CRC.  Now that we have locked it normally, check
128 	 * for a CRC problem and skip it if we found one.  The bulk scan
129 	 * cannot safely traverse invalid block tables (we could end up
130 	 * in an endless loop or cause a panic).
131 	 */
132 	if (parent->error & HAMMER2_ERROR_CHECK) {
133 		error = parent->error;
134 		goto done;
135 	}
136 
137 	/*
138 	 * Report which PFS is being scanned
139 	 */
140 	if (parent->bref.type == HAMMER2_BREF_TYPE_INODE &&
141 	    (parent->bref.flags & HAMMER2_BREF_FLAG_PFSROOT)) {
142 		kprintf("hammer2_bulkfree: Scanning %s\n",
143 			parent->data->ipdata.filename);
144 	}
145 
146 	/*
147 	 * Generally loop on the contents if we have not been flagged
148 	 * for abort.
149 	 *
150 	 * Remember that these chains are completely isolated from
151 	 * the frontend, so we can release locks temporarily without
152 	 * imploding.
153 	 */
154 	for (;;) {
155 		error |= hammer2_chain_scan(parent, &chain, &bref, &first,
156 					    HAMMER2_LOOKUP_NODATA |
157 					    HAMMER2_LOOKUP_SHARED);
158 
159 		/*
160 		 * Handle EOF or other error at current level.  This stops
161 		 * the bulkfree scan.
162 		 */
163 		if (error & ~HAMMER2_ERROR_CHECK)
164 			break;
165 
166 		/*
167 		 * Account for dirents before thre data_off test, since most
168 		 * dirents do not need a data reference.
169 		 */
170 		if (bref.type == HAMMER2_BREF_TYPE_DIRENT)
171 			++info->count_dirents_scanned;
172 
173 		/*
174 		 * Ignore brefs without data (typically dirents)
175 		 */
176 		if ((bref.data_off & ~HAMMER2_OFF_MASK_RADIX) == 0)
177 			continue;
178 
179 		/*
180 		 * Process bref, chain is only non-NULL if the bref
181 		 * might be recursable (its possible that we sometimes get
182 		 * a non-NULL chain where the bref cannot be recursed).
183 		 *
184 		 * If we already ran down this tree we do not have to do it
185 		 * again, but we must still recover any cumulative error
186 		 * recorded from the time we did.
187 		 */
188 		++info->pri;
189 		e2 = h2_bulkfree_test(info, &bref, 1, 0);
190 		if (e2) {
191 			error |= e2 & ~HAMMER2_ERROR_EOF;
192 			continue;
193 		}
194 
195 		if (bref.type == HAMMER2_BREF_TYPE_INODE)
196 			++info->count_inodes_scanned;
197 
198 		error |= func(info, &bref);
199 		if (error & ~HAMMER2_ERROR_CHECK)
200 			break;
201 
202 		/*
203 		 * A non-null chain is always returned if it is
204 		 * recursive, otherwise a non-null chain might be
205 		 * returned but usually is not when not recursive.
206 		 */
207 		if (chain == NULL)
208 			continue;
209 
210 		if (chain) {
211 			info->count_bytes_scanned += chain->bytes;
212 			++info->count_chains_scanned;
213 
214 			if (info->count_chains_scanned >=
215 			    info->count_chains_reported + 1000000 ||
216 			    (info->count_chains_scanned < 1000000 &&
217 			     info->count_chains_scanned >=
218 			     info->count_chains_reported + 100000)) {
219 				kprintf(" chains %-7ld inodes %-7ld "
220 					"dirents %-7ld bytes %5ldMB\n",
221 					info->count_chains_scanned,
222 					info->count_inodes_scanned,
223 					info->count_dirents_scanned,
224 					info->count_bytes_scanned / 1000000);
225 				info->count_chains_reported =
226 					info->count_chains_scanned;
227 			}
228 		}
229 
230 		/*
231 		 * Else check type and setup depth-first scan.
232 		 *
233 		 * Account for bytes actually read.
234 		 */
235 		switch(chain->bref.type) {
236 		case HAMMER2_BREF_TYPE_INODE:
237 		case HAMMER2_BREF_TYPE_FREEMAP_NODE:
238 		case HAMMER2_BREF_TYPE_INDIRECT:
239 		case HAMMER2_BREF_TYPE_VOLUME:
240 		case HAMMER2_BREF_TYPE_FREEMAP:
241 			++info->depth;
242 			if (chain->error & HAMMER2_ERROR_CHECK) {
243 				/*
244 				 * Cannot safely recurse chains with crc
245 				 * errors, even in emergency mode.
246 				 */
247 				/* NOP */
248 			} else if (info->depth > 16) {
249 				save = kmalloc(sizeof(*save), M_HAMMER2,
250 					       M_WAITOK | M_ZERO);
251 				save->chain = chain;
252 				hammer2_chain_ref(chain);
253 				TAILQ_INSERT_TAIL(&info->list, save, entry);
254 
255 				/* guess */
256 				info->pri += 10;
257 			} else {
258 				int savepri = info->pri;
259 
260 				hammer2_chain_unlock(chain);
261 				hammer2_chain_unlock(parent);
262 				info->pri = 0;
263 				rup_error |= hammer2_bulk_scan(chain,
264 							       func, info);
265 				info->pri += savepri;
266 				hammer2_chain_lock(parent,
267 						   HAMMER2_RESOLVE_ALWAYS |
268 						   HAMMER2_RESOLVE_SHARED);
269 				hammer2_chain_lock(chain,
270 						   HAMMER2_RESOLVE_ALWAYS |
271 						   HAMMER2_RESOLVE_SHARED);
272 			}
273 			--info->depth;
274 			break;
275 		case HAMMER2_BREF_TYPE_DATA:
276 			break;
277 		default:
278 			/* does not recurse */
279 			break;
280 		}
281 		if (rup_error & HAMMER2_ERROR_ABORTED)
282 			break;
283 	}
284 	if (chain) {
285 		hammer2_chain_unlock(chain);
286 		hammer2_chain_drop(chain);
287 	}
288 
289 	/*
290 	 * If this is a PFSROOT, also re-run any defered elements
291 	 * added during our scan so we can report any cumulative errors
292 	 * for the PFS.
293 	 */
294 	if (parent->bref.type == HAMMER2_BREF_TYPE_INODE &&
295 	    (parent->bref.flags & HAMMER2_BREF_FLAG_PFSROOT)) {
296 		for (;;) {
297 			int opri;
298 
299 			save = tail ? TAILQ_NEXT(tail, entry) :
300 				      TAILQ_FIRST(&info->list);
301 			if (save == NULL)
302 				break;
303 
304 			TAILQ_REMOVE(&info->list, save, entry);
305 			opri = info->pri;
306 			info->pri = 0;
307 			rup_error |= hammer2_bulk_scan(save->chain, func, info);
308 			hammer2_chain_drop(save->chain);
309 			kfree(save, M_HAMMER2);
310 			info->pri = opri;
311 		}
312 	}
313 
314 	error |= rup_error;
315 
316 	/*
317 	 * Report which PFS the errors were encountered in.
318 	 */
319 	if (parent->bref.type == HAMMER2_BREF_TYPE_INODE &&
320 	    (parent->bref.flags & HAMMER2_BREF_FLAG_PFSROOT) &&
321 	    (error & ~HAMMER2_ERROR_EOF)) {
322 		kprintf("hammer2_bulkfree: Encountered errors (%08x) "
323 			"while scanning \"%s\"\n",
324 			error, parent->data->ipdata.filename);
325 	}
326 
327 	/*
328 	 * Save with higher pri now that we know what it is.
329 	 */
330 	h2_bulkfree_test(info, &parent->bref, info->pri + 1,
331 			 (error & ~HAMMER2_ERROR_EOF));
332 
333 done:
334 	hammer2_chain_unlock(parent);
335 
336 	return (error & ~HAMMER2_ERROR_EOF);
337 }
338 
339 /*
340  * Bulkfree algorithm
341  *
342  * Repeat {
343  *	Chain flush (partial synchronization) XXX removed
344  *	Scan the whole topology - build in-memory freemap (mark 11)
345  *	Reconcile the in-memory freemap against the on-disk freemap.
346  *		ondisk xx -> ondisk 11 (if allocated)
347  *		ondisk 11 -> ondisk 10 (if free in-memory)
348  *		ondisk 10 -> ondisk 00 (if free in-memory) - on next pass
349  * }
350  *
351  * The topology scan may have to be performed multiple times to window
352  * freemaps which are too large to fit in kernel memory.
353  *
354  * Races are handled using a double-transition (11->10, 10->00).  The bulkfree
355  * scan snapshots the volume root's blockset and thus can run concurrent with
356  * normal operations, as long as a full flush is made between each pass to
357  * synchronize any modified chains (otherwise their blocks might be improperly
358  * freed).
359  *
360  * Temporary memory in multiples of 64KB is required to reconstruct the leaf
361  * hammer2_bmap_data blocks so they can later be compared against the live
362  * freemap.  Each 64KB block represents 128 x 16KB x 1024 = ~2 GB of storage.
363  * A 32MB save area thus represents around ~1 TB.  The temporary memory
364  * allocated can be specified.  If it is not sufficient multiple topology
365  * passes will be made.
366  */
367 
368 /*
369  * Bulkfree callback info
370  */
371 static void hammer2_bulkfree_thread(void *arg __unused);
372 static void cbinfo_bmap_init(hammer2_bulkfree_info_t *cbinfo, size_t size);
373 static int h2_bulkfree_callback(hammer2_bulkfree_info_t *cbinfo,
374 			hammer2_blockref_t *bref);
375 static int h2_bulkfree_sync(hammer2_bulkfree_info_t *cbinfo);
376 static void h2_bulkfree_sync_adjust(hammer2_bulkfree_info_t *cbinfo,
377 			hammer2_off_t data_off, hammer2_bmap_data_t *live,
378 			hammer2_bmap_data_t *bmap, hammer2_key_t alloc_base);
379 
380 void
381 hammer2_bulkfree_init(hammer2_dev_t *hmp)
382 {
383 	hammer2_thr_create(&hmp->bfthr, NULL, hmp,
384 			   hmp->devrepname, -1, -1,
385 			   hammer2_bulkfree_thread);
386 }
387 
388 void
389 hammer2_bulkfree_uninit(hammer2_dev_t *hmp)
390 {
391 	hammer2_thr_delete(&hmp->bfthr);
392 }
393 
394 static void
395 hammer2_bulkfree_thread(void *arg)
396 {
397 	hammer2_thread_t *thr = arg;
398 	hammer2_ioc_bulkfree_t bfi;
399 	uint32_t flags;
400 
401 	for (;;) {
402 		hammer2_thr_wait_any(thr,
403 				     HAMMER2_THREAD_STOP |
404 				     HAMMER2_THREAD_FREEZE |
405 				     HAMMER2_THREAD_UNFREEZE |
406 				     HAMMER2_THREAD_REMASTER,
407 				     hz * 60);
408 
409 		flags = thr->flags;
410 		cpu_ccfence();
411 		if (flags & HAMMER2_THREAD_STOP)
412 			break;
413 		if (flags & HAMMER2_THREAD_FREEZE) {
414 			hammer2_thr_signal2(thr, HAMMER2_THREAD_FROZEN,
415 						 HAMMER2_THREAD_FREEZE);
416 			continue;
417 		}
418 		if (flags & HAMMER2_THREAD_UNFREEZE) {
419 			hammer2_thr_signal2(thr, 0,
420 						 HAMMER2_THREAD_FROZEN |
421 						 HAMMER2_THREAD_UNFREEZE);
422 			continue;
423 		}
424 		if (flags & HAMMER2_THREAD_FROZEN)
425 			continue;
426 		if (flags & HAMMER2_THREAD_REMASTER) {
427 			hammer2_thr_signal2(thr, 0, HAMMER2_THREAD_REMASTER);
428 			bzero(&bfi, sizeof(bfi));
429 			bfi.size = 8192 * 1024;
430 			/* hammer2_bulkfree_pass(thr->hmp, &bfi); */
431 		}
432 	}
433 	thr->td = NULL;
434 	hammer2_thr_signal(thr, HAMMER2_THREAD_STOPPED);
435 	/* structure can go invalid at this point */
436 }
437 
438 int
439 hammer2_bulkfree_pass(hammer2_dev_t *hmp, hammer2_chain_t *vchain,
440 		      hammer2_ioc_bulkfree_t *bfi)
441 {
442 	hammer2_bulkfree_info_t cbinfo;
443 	hammer2_chain_save_t *save;
444 	hammer2_off_t incr;
445 	size_t size;
446 	int error;
447 
448 	/*
449 	 * We have to clear the live dedup cache as it might have entries
450 	 * that are freeable as of now.  Any new entries in the dedup cache
451 	 * made after this point, even if they become freeable, will have
452 	 * previously been fully allocated and will be protected by the
453 	 * 2-stage bulkfree.
454 	 */
455 	hammer2_dedup_clear(hmp);
456 
457 	/*
458 	 * Setup for free pass using the buffer size specified by the
459 	 * hammer2 utility, 32K-aligned.
460 	 */
461 	bzero(&cbinfo, sizeof(cbinfo));
462 	size = (bfi->size + HAMMER2_FREEMAP_LEVELN_PSIZE - 1) &
463 	       ~(size_t)(HAMMER2_FREEMAP_LEVELN_PSIZE - 1);
464 
465 	/*
466 	 * Cap at 1/4 physical memory (hammer2 utility will not normally
467 	 * ever specify a buffer this big, but leave the option available).
468 	 */
469 	if (size > kmem_lim_size() * 1024 * 1024 / 4) {
470 		size = kmem_lim_size() * 1024 * 1024 / 4;
471 		kprintf("hammer2: Warning: capping bulkfree buffer at %jdM\n",
472 			(intmax_t)size / (1024 * 1024));
473 	}
474 
475 #define HAMMER2_FREEMAP_SIZEDIV	\
476 	(HAMMER2_FREEMAP_LEVEL1_SIZE / HAMMER2_FREEMAP_LEVELN_PSIZE)
477 #define HAMMER2_FREEMAP_SIZEMASK	(HAMMER2_FREEMAP_SIZEDIV - 1)
478 
479 	/*
480 	 * Cap at the size needed to cover the whole volume to avoid
481 	 * making an unnecessarily large allocation.
482 	 */
483 	if (size > hmp->voldata.volu_size / HAMMER2_FREEMAP_SIZEDIV) {
484 		size = (hmp->voldata.volu_size + HAMMER2_FREEMAP_SIZEMASK) /
485 			HAMMER2_FREEMAP_SIZEDIV;
486 	}
487 
488 	/*
489 	 * Minimum bitmap buffer size, then align to a LEVELN_PSIZE (32K)
490 	 * boundary.
491 	 */
492 	if (size < 1024 * 1024)
493 		size = 1024 * 1024;
494 	size = (size + HAMMER2_FREEMAP_LEVELN_PSIZE - 1) &
495 	       ~(size_t)(HAMMER2_FREEMAP_LEVELN_PSIZE - 1);
496 
497 	cbinfo.hmp = hmp;
498 	cbinfo.bmap = kmem_alloc_swapbacked(&cbinfo.kp, size, VM_SUBSYS_HAMMER);
499 	cbinfo.saved_mirror_tid = hmp->voldata.mirror_tid;
500 
501 	cbinfo.dedup = kmalloc(sizeof(*cbinfo.dedup) * HAMMER2_DEDUP_HEUR_SIZE,
502 			       M_HAMMER2, M_WAITOK | M_ZERO);
503 
504 	kprintf("hammer2: bulkfree buf=%jdM\n",
505 		(intmax_t)size / (1024 * 1024));
506 
507 	/*
508 	 * Normalize start point to a 2GB boundary.  We operate on a
509 	 * 64KB leaf bitmap boundary which represents 2GB of storage.
510 	 */
511 	cbinfo.sbase = bfi->sbase;
512 	if (cbinfo.sbase > hmp->voldata.volu_size)
513 		cbinfo.sbase = hmp->voldata.volu_size;
514 	cbinfo.sbase &= ~HAMMER2_FREEMAP_LEVEL1_MASK;
515 	TAILQ_INIT(&cbinfo.list);
516 
517 	cbinfo.bulkfree_ticks = ticks;
518 
519 	/*
520 	 * Loop on a full meta-data scan as many times as required to
521 	 * get through all available storage.
522 	 */
523 	error = 0;
524 	while (cbinfo.sbase < hmp->voldata.volu_size) {
525 		/*
526 		 * We have enough ram to represent (incr) bytes of storage.
527 		 * Each 64KB of ram represents 2GB of storage.
528 		 *
529 		 * We must also clean out our de-duplication heuristic for
530 		 * each (incr) bytes of storage, otherwise we wind up not
531 		 * scanning meta-data for later areas of storage because
532 		 * they had already been scanned in earlier areas of storage.
533 		 * Since the ranging is different, we have to restart
534 		 * the dedup heuristic too.
535 		 */
536 		int allmedia;
537 
538 		cbinfo_bmap_init(&cbinfo, size);
539 		bzero(cbinfo.dedup, sizeof(*cbinfo.dedup) *
540 				    HAMMER2_DEDUP_HEUR_SIZE);
541 		cbinfo.count_inodes_scanned = 0;
542 		cbinfo.count_dirents_scanned = 0;
543 		cbinfo.count_bytes_scanned = 0;
544 		cbinfo.count_chains_scanned = 0;
545 		cbinfo.count_chains_reported = 0;
546 
547 		incr = size / HAMMER2_FREEMAP_LEVELN_PSIZE *
548 		       HAMMER2_FREEMAP_LEVEL1_SIZE;
549 		if (hmp->voldata.volu_size - cbinfo.sbase <= incr) {
550 			cbinfo.sstop = hmp->voldata.volu_size;
551 			allmedia = 1;
552 		} else {
553 			cbinfo.sstop = cbinfo.sbase + incr;
554 			allmedia = 0;
555 		}
556 		kprintf("hammer2: pass %016jx-%016jx ",
557 			(intmax_t)cbinfo.sbase,
558 			(intmax_t)cbinfo.sstop);
559 		if (allmedia && cbinfo.sbase == 0)
560 			kprintf("(all media)\n");
561 		else if (allmedia)
562 			kprintf("(remaining media)\n");
563 		else
564 			kprintf("(%jdGB of media)\n",
565 				(intmax_t)incr / (1024L*1024*1024));
566 
567 		/*
568 		 * Scan topology for stuff inside this range.
569 		 *
570 		 * NOTE - By not using a transaction the operation can
571 		 *	  run concurrent with the frontend as well as
572 		 *	  with flushes.
573 		 *
574 		 *	  We cannot safely set a mtid without a transaction,
575 		 *	  and in fact we don't want to set one anyway.  We
576 		 *	  want the bulkfree to be passive and no interfere
577 		 *	  with crash recovery.
578 		 */
579 #undef HAMMER2_BULKFREE_TRANS	/* undef - don't use transaction */
580 #ifdef HAMMER2_BULKFREE_TRANS
581 		hammer2_trans_init(hmp->spmp, 0);
582 		cbinfo.mtid = hammer2_trans_sub(hmp->spmp);
583 #else
584 		cbinfo.mtid = 0;
585 #endif
586 		cbinfo.pri = 0;
587 		error |= hammer2_bulk_scan(vchain,
588 					   h2_bulkfree_callback, &cbinfo);
589 
590 		while ((save = TAILQ_FIRST(&cbinfo.list)) != NULL &&
591 		       (error & ~HAMMER2_ERROR_CHECK) == 0) {
592 			TAILQ_REMOVE(&cbinfo.list, save, entry);
593 			cbinfo.pri = 0;
594 			error |= hammer2_bulk_scan(save->chain,
595 						   h2_bulkfree_callback,
596 						   &cbinfo);
597 			hammer2_chain_drop(save->chain);
598 			kfree(save, M_HAMMER2);
599 		}
600 		while (save) {
601 			TAILQ_REMOVE(&cbinfo.list, save, entry);
602 			hammer2_chain_drop(save->chain);
603 			kfree(save, M_HAMMER2);
604 			save = TAILQ_FIRST(&cbinfo.list);
605 		}
606 
607 		/*
608 		 * If the complete scan succeeded we can synchronize our
609 		 * in-memory freemap against live storage.  If an abort
610 		 * occured we cannot safely synchronize our partially
611 		 * filled-out in-memory freemap.
612 		 *
613 		 * We still synchronize on CHECK failures.  That is, we still
614 		 * want bulkfree to operate even if the filesystem has defects.
615 		 */
616 		if (error & ~HAMMER2_ERROR_CHECK) {
617 			kprintf("bulkfree lastdrop %d %d error=0x%04x\n",
618 				vchain->refs, vchain->core.chain_count, error);
619 		} else {
620 			if (error & HAMMER2_ERROR_CHECK) {
621 				kprintf("bulkfree lastdrop %d %d "
622 					"(with check errors)\n",
623 					vchain->refs, vchain->core.chain_count);
624 			} else {
625 				kprintf("bulkfree lastdrop %d %d\n",
626 					vchain->refs, vchain->core.chain_count);
627 			}
628 
629 			error = h2_bulkfree_sync(&cbinfo);
630 
631 			hammer2_voldata_lock(hmp);
632 			hammer2_voldata_modify(hmp);
633 			hmp->voldata.allocator_free += cbinfo.adj_free;
634 			hammer2_voldata_unlock(hmp);
635 		}
636 
637 		/*
638 		 * Cleanup for next loop.
639 		 */
640 #ifdef HAMMER2_BULKFREE_TRANS
641 		hammer2_trans_done(hmp->spmp, 0);
642 #endif
643 		if (error & ~HAMMER2_ERROR_CHECK)
644 			break;
645 		cbinfo.sbase = cbinfo.sstop;
646 		cbinfo.adj_free = 0;
647 	}
648 	kmem_free_swapbacked(&cbinfo.kp);
649 	kfree(cbinfo.dedup, M_HAMMER2);
650 	cbinfo.dedup = NULL;
651 
652 	bfi->sstop = cbinfo.sbase;
653 
654 	incr = bfi->sstop / (hmp->voldata.volu_size / 10000);
655 	if (incr > 10000)
656 		incr = 10000;
657 
658 	kprintf("bulkfree pass statistics (%d.%02d%% storage processed):\n",
659 		(int)incr / 100,
660 		(int)incr % 100);
661 
662 	if (error & ~HAMMER2_ERROR_CHECK) {
663 		kprintf("    bulkfree was aborted\n");
664 	} else {
665 		if (error & HAMMER2_ERROR_CHECK) {
666 			kprintf("    WARNING: bulkfree "
667 				"encountered CRC errors\n");
668 		}
669 		kprintf("    transition->free   %ld\n", cbinfo.count_10_00);
670 		kprintf("    transition->staged %ld\n", cbinfo.count_11_10);
671 		kprintf("    ERR(00)->allocated %ld\n", cbinfo.count_00_11);
672 		kprintf("    ERR(01)->allocated %ld\n", cbinfo.count_01_11);
673 		kprintf("    staged->allocated  %ld\n", cbinfo.count_10_11);
674 		kprintf("    ~2MB segs cleaned  %ld\n", cbinfo.count_l0cleans);
675 		kprintf("    linear adjusts     %ld\n",
676 			cbinfo.count_linadjusts);
677 		kprintf("    dedup factor       %ld\n",
678 			cbinfo.count_dedup_factor);
679 	}
680 
681 	return error;
682 }
683 
684 static void
685 cbinfo_bmap_init(hammer2_bulkfree_info_t *cbinfo, size_t size)
686 {
687 	hammer2_bmap_data_t *bmap = cbinfo->bmap;
688 	hammer2_key_t key = cbinfo->sbase;
689 	hammer2_key_t lokey;
690 	hammer2_key_t hikey;
691 
692 	lokey = (cbinfo->hmp->voldata.allocator_beg + HAMMER2_SEGMASK64) &
693 		~HAMMER2_SEGMASK64;
694 	hikey = cbinfo->hmp->voldata.volu_size & ~HAMMER2_SEGMASK64;
695 
696 	bzero(bmap, size);
697 	while (size) {
698 		bzero(bmap, sizeof(*bmap));
699 		if (lokey < H2FMBASE(key, HAMMER2_FREEMAP_LEVEL1_RADIX))
700 			lokey = H2FMBASE(key, HAMMER2_FREEMAP_LEVEL1_RADIX);
701 		if (lokey < H2FMZONEBASE(key) + HAMMER2_ZONE_SEG64)
702 			lokey = H2FMZONEBASE(key) + HAMMER2_ZONE_SEG64;
703 		if (key < lokey || key >= hikey) {
704 			memset(bmap->bitmapq, -1,
705 			       sizeof(bmap->bitmapq));
706 			bmap->avail = 0;
707 			bmap->linear = HAMMER2_SEGSIZE;
708 		} else {
709 			bmap->avail = HAMMER2_FREEMAP_LEVEL0_SIZE;
710 		}
711 		size -= sizeof(*bmap);
712 		key += HAMMER2_FREEMAP_LEVEL0_SIZE;
713 		++bmap;
714 	}
715 }
716 
717 static int
718 h2_bulkfree_callback(hammer2_bulkfree_info_t *cbinfo, hammer2_blockref_t *bref)
719 {
720 	hammer2_bmap_data_t *bmap;
721 	hammer2_off_t data_off;
722 	uint16_t class;
723 	size_t bytes;
724 	int radix;
725 
726 	/*
727 	 * Check for signal and allow yield to userland during scan.
728 	 */
729 	if (hammer2_signal_check(&cbinfo->save_time))
730 		return HAMMER2_ERROR_ABORTED;
731 
732 	/*
733 	 * Deal with kernel thread cpu or I/O hogging by limiting the
734 	 * number of chains scanned per second to hammer2_bulkfree_tps.
735 	 * Ignore leaf records (DIRENT and DATA), no per-record I/O is
736 	 * involved for those since we don't load their data.
737 	 */
738 	if (bref->type != HAMMER2_BREF_TYPE_DATA &&
739 	    bref->type != HAMMER2_BREF_TYPE_DIRENT) {
740 		++cbinfo->bulkfree_calls;
741 		if (cbinfo->bulkfree_calls > hammer2_bulkfree_tps) {
742 			int dticks = ticks - cbinfo->bulkfree_ticks;
743 			if (dticks < 0)
744 				dticks = 0;
745 			if (dticks < hz) {
746 				tsleep(&cbinfo->bulkfree_ticks, 0,
747 				       "h2bw", hz - dticks);
748 			}
749 			cbinfo->bulkfree_calls = 0;
750 			cbinfo->bulkfree_ticks = ticks;
751 		}
752 	}
753 
754 	/*
755 	 * Calculate the data offset and determine if it is within
756 	 * the current freemap range being gathered.
757 	 */
758 	data_off = bref->data_off & ~HAMMER2_OFF_MASK_RADIX;
759 	if (data_off < cbinfo->sbase || data_off >= cbinfo->sstop)
760 		return 0;
761 	if (data_off < cbinfo->hmp->voldata.allocator_beg)
762 		return 0;
763 	if (data_off >= cbinfo->hmp->voldata.volu_size)
764 		return 0;
765 
766 	/*
767 	 * Calculate the information needed to generate the in-memory
768 	 * freemap record.
769 	 *
770 	 * Hammer2 does not allow allocations to cross the L1 (2GB) boundary,
771 	 * it's a problem if it does.  (Or L0 (2MB) for that matter).
772 	 */
773 	radix = (int)(bref->data_off & HAMMER2_OFF_MASK_RADIX);
774 	KKASSERT(radix != 0);
775 	bytes = (size_t)1 << radix;
776 	class = (bref->type << 8) | hammer2_devblkradix(radix);
777 
778 	if (data_off + bytes > cbinfo->sstop) {
779 		kprintf("hammer2_bulkfree_scan: illegal 2GB boundary "
780 			"%016jx %016jx/%d\n",
781 			(intmax_t)bref->data_off,
782 			(intmax_t)bref->key,
783 			bref->keybits);
784 		bytes = cbinfo->sstop - data_off;	/* XXX */
785 	}
786 
787 	/*
788 	 * Convert to a storage offset relative to the beginning of the
789 	 * storage range we are collecting.  Then lookup the level0 bmap entry.
790 	 */
791 	data_off -= cbinfo->sbase;
792 	bmap = cbinfo->bmap + (data_off >> HAMMER2_FREEMAP_LEVEL0_RADIX);
793 
794 	/*
795 	 * Convert data_off to a bmap-relative value (~4MB storage range).
796 	 * Adjust linear, class, and avail.
797 	 *
798 	 * Hammer2 does not allow allocations to cross the L0 (4MB) boundary,
799 	 */
800 	data_off &= HAMMER2_FREEMAP_LEVEL0_MASK;
801 	if (data_off + bytes > HAMMER2_FREEMAP_LEVEL0_SIZE) {
802 		kprintf("hammer2_bulkfree_scan: illegal 4MB boundary "
803 			"%016jx %016jx/%d\n",
804 			(intmax_t)bref->data_off,
805 			(intmax_t)bref->key,
806 			bref->keybits);
807 		bytes = HAMMER2_FREEMAP_LEVEL0_SIZE - data_off;
808 	}
809 
810 	if (bmap->class == 0) {
811 		bmap->class = class;
812 		bmap->avail = HAMMER2_FREEMAP_LEVEL0_SIZE;
813 	}
814 
815 	/*
816 	 * NOTE: bmap->class does not have to match class.  Classification
817 	 *	 is relaxed when free space is low, so some mixing can occur.
818 	 */
819 #if 0
820 	/*
821 	 * XXX removed
822 	 */
823 	if (bmap->class != class) {
824 		kprintf("hammer2_bulkfree_scan: illegal mixed class "
825 			"%016jx %016jx/%d (%04x vs %04x)\n",
826 			(intmax_t)bref->data_off,
827 			(intmax_t)bref->key,
828 			bref->keybits,
829 			class, bmap->class);
830 	}
831 #endif
832 
833 	/*
834 	 * Just record the highest byte-granular offset for now.  Do not
835 	 * match against allocations which are in multiples of whole blocks.
836 	 *
837 	 * Make sure that any in-block linear offset at least covers the
838 	 * data range.  This can cause bmap->linear to become block-aligned.
839 	 */
840 	if (bytes & HAMMER2_FREEMAP_BLOCK_MASK) {
841 		if (bmap->linear < (int32_t)data_off + (int32_t)bytes)
842 			bmap->linear = (int32_t)data_off + (int32_t)bytes;
843 	} else if (bmap->linear >= (int32_t)data_off &&
844 		   bmap->linear < (int32_t)data_off + (int32_t)bytes) {
845 		bmap->linear = (int32_t)data_off + (int32_t)bytes;
846 	}
847 
848 	/*
849 	 * Adjust the hammer2_bitmap_t bitmap[HAMMER2_BMAP_ELEMENTS].
850 	 * 64-bit entries, 2 bits per entry, to code 11.
851 	 *
852 	 * NOTE: data_off mask to 524288, shift right by 14 (radix for 16384),
853 	 *	 and multiply shift amount by 2 for sets of 2 bits.
854 	 *
855 	 * NOTE: The allocation can be smaller than HAMMER2_FREEMAP_BLOCK_SIZE.
856 	 *	 also, data_off may not be FREEMAP_BLOCK_SIZE aligned.
857 	 */
858 	while (bytes > 0) {
859 		hammer2_bitmap_t bmask;
860 		int bindex;
861 
862 		bindex = (int)data_off >> (HAMMER2_FREEMAP_BLOCK_RADIX +
863 					   HAMMER2_BMAP_INDEX_RADIX);
864 		bmask = (hammer2_bitmap_t)3 <<
865 			((((int)data_off & HAMMER2_BMAP_INDEX_MASK) >>
866 			 HAMMER2_FREEMAP_BLOCK_RADIX) << 1);
867 
868 		/*
869 		 * NOTE! The (avail) calculation is bitmap-granular.  Multiple
870 		 *	 sub-granular records can wind up at the same bitmap
871 		 *	 position.
872 		 */
873 		if ((bmap->bitmapq[bindex] & bmask) == 0) {
874 			if (bytes < HAMMER2_FREEMAP_BLOCK_SIZE) {
875 				bmap->avail -= HAMMER2_FREEMAP_BLOCK_SIZE;
876 			} else {
877 				bmap->avail -= bytes;
878 			}
879 			bmap->bitmapq[bindex] |= bmask;
880 		}
881 		data_off += HAMMER2_FREEMAP_BLOCK_SIZE;
882 		if (bytes < HAMMER2_FREEMAP_BLOCK_SIZE)
883 			bytes = 0;
884 		else
885 			bytes -= HAMMER2_FREEMAP_BLOCK_SIZE;
886 	}
887 	return 0;
888 }
889 
890 /*
891  * Synchronize the in-memory bitmap with the live freemap.  This is not a
892  * direct copy.  Instead the bitmaps must be compared:
893  *
894  *	In-memory	Live-freemap
895  *	   00		  11 -> 10	(do nothing if live modified)
896  *			  10 -> 00	(do nothing if live modified)
897  *	   11		  10 -> 11	handles race against live
898  *			  ** -> 11	nominally warn of corruption
899  *
900  * We must also fixup the hints in HAMMER2_BREF_TYPE_FREEMAP_LEAF.
901  */
902 static int
903 h2_bulkfree_sync(hammer2_bulkfree_info_t *cbinfo)
904 {
905 	hammer2_off_t data_off;
906 	hammer2_key_t key;
907 	hammer2_key_t key_dummy;
908 	hammer2_bmap_data_t *bmap;
909 	hammer2_bmap_data_t *live;
910 	hammer2_chain_t *live_parent;
911 	hammer2_chain_t *live_chain;
912 	int bmapindex;
913 	int error;
914 
915 	kprintf("hammer2_bulkfree - range ");
916 
917 	if (cbinfo->sbase < cbinfo->hmp->voldata.allocator_beg)
918 		kprintf("%016jx-",
919 			(intmax_t)cbinfo->hmp->voldata.allocator_beg);
920 	else
921 		kprintf("%016jx-",
922 			(intmax_t)cbinfo->sbase);
923 
924 	if (cbinfo->sstop > cbinfo->hmp->voldata.volu_size)
925 		kprintf("%016jx\n",
926 			(intmax_t)cbinfo->hmp->voldata.volu_size);
927 	else
928 		kprintf("%016jx\n",
929 			(intmax_t)cbinfo->sstop);
930 
931 	data_off = cbinfo->sbase;
932 	bmap = cbinfo->bmap;
933 
934 	live_parent = &cbinfo->hmp->fchain;
935 	hammer2_chain_ref(live_parent);
936 	hammer2_chain_lock(live_parent, HAMMER2_RESOLVE_ALWAYS);
937 	live_chain = NULL;
938 	error = 0;
939 
940 	/*
941 	 * Iterate each hammer2_bmap_data_t line (128 bytes) managing
942 	 * 4MB of storage.
943 	 */
944 	while (data_off < cbinfo->sstop) {
945 		/*
946 		 * The freemap is not used below allocator_beg or beyond
947 		 * volu_size.
948 		 */
949 
950 		if (data_off < cbinfo->hmp->voldata.allocator_beg)
951 			goto next;
952 		if (data_off >= cbinfo->hmp->voldata.volu_size)
953 			goto next;
954 
955 		/*
956 		 * Locate the freemap leaf on the live filesystem
957 		 */
958 		key = (data_off & ~HAMMER2_FREEMAP_LEVEL1_MASK);
959 
960 		if (live_chain == NULL || live_chain->bref.key != key) {
961 			if (live_chain) {
962 				hammer2_chain_unlock(live_chain);
963 				hammer2_chain_drop(live_chain);
964 			}
965 			live_chain = hammer2_chain_lookup(
966 					    &live_parent,
967 					    &key_dummy,
968 					    key,
969 					    key + HAMMER2_FREEMAP_LEVEL1_MASK,
970 					    &error,
971 					    HAMMER2_LOOKUP_ALWAYS);
972 			if (error) {
973 				kprintf("hammer2_bulkfree: freemap lookup "
974 					"error near %016jx, error %s\n",
975 					(intmax_t)data_off,
976 					hammer2_error_str(live_chain->error));
977 				break;
978 			}
979 		}
980 		if (live_chain == NULL) {
981 			/*
982 			 * XXX if we implement a full recovery mode we need
983 			 * to create/recreate missing freemap chains if our
984 			 * bmap has any allocated blocks.
985 			 */
986 			if (bmap->class &&
987 			    bmap->avail != HAMMER2_FREEMAP_LEVEL0_SIZE) {
988 				kprintf("hammer2_bulkfree: cannot locate "
989 					"live leaf for allocated data "
990 					"near %016jx\n",
991 					(intmax_t)data_off);
992 			}
993 			goto next;
994 		}
995 		if (live_chain->error) {
996 			kprintf("hammer2_bulkfree: unable to access freemap "
997 				"near %016jx, error %s\n",
998 				(intmax_t)data_off,
999 				hammer2_error_str(live_chain->error));
1000 			hammer2_chain_unlock(live_chain);
1001 			hammer2_chain_drop(live_chain);
1002 			live_chain = NULL;
1003 			goto next;
1004 		}
1005 
1006 		bmapindex = (data_off & HAMMER2_FREEMAP_LEVEL1_MASK) >>
1007 			    HAMMER2_FREEMAP_LEVEL0_RADIX;
1008 		live = &live_chain->data->bmdata[bmapindex];
1009 
1010 		/*
1011 		 * Shortcut if the bitmaps match and the live linear
1012 		 * indicator is sane.  We can't do a perfect check of
1013 		 * live->linear because the only real requirement is that
1014 		 * if it is not block-aligned, that it not cover the space
1015 		 * within its current block which overlaps one of the data
1016 		 * ranges we scan.  We don't retain enough fine-grained
1017 		 * data in our scan to be able to set it exactly.
1018 		 *
1019 		 * TODO - we could shortcut this by testing that both
1020 		 * live->class and bmap->class are 0, and both avails are
1021 		 * set to HAMMER2_FREEMAP_LEVEL0_SIZE (4MB).
1022 		 */
1023 		if (bcmp(live->bitmapq, bmap->bitmapq,
1024 			 sizeof(bmap->bitmapq)) == 0 &&
1025 		    live->linear >= bmap->linear) {
1026 			goto next;
1027 		}
1028 		if (hammer2_debug & 1) {
1029 			kprintf("live %016jx %04d.%04x (avail=%d)\n",
1030 				data_off, bmapindex, live->class, live->avail);
1031 		}
1032 
1033 		hammer2_chain_modify(live_chain, cbinfo->mtid, 0, 0);
1034 		live_chain->bref.check.freemap.bigmask = -1;
1035 		cbinfo->hmp->freemap_relaxed = 0;	/* reset heuristic */
1036 		live = &live_chain->data->bmdata[bmapindex];
1037 
1038 		h2_bulkfree_sync_adjust(cbinfo, data_off, live, bmap,
1039 					live_chain->bref.key +
1040 					bmapindex *
1041 					HAMMER2_FREEMAP_LEVEL0_SIZE);
1042 next:
1043 		data_off += HAMMER2_FREEMAP_LEVEL0_SIZE;
1044 		++bmap;
1045 	}
1046 	if (live_chain) {
1047 		hammer2_chain_unlock(live_chain);
1048 		hammer2_chain_drop(live_chain);
1049 	}
1050 	if (live_parent) {
1051 		hammer2_chain_unlock(live_parent);
1052 		hammer2_chain_drop(live_parent);
1053 	}
1054 	return error;
1055 }
1056 
1057 /*
1058  * Merge the bulkfree bitmap against the existing bitmap.
1059  */
1060 static
1061 void
1062 h2_bulkfree_sync_adjust(hammer2_bulkfree_info_t *cbinfo,
1063 			hammer2_off_t data_off, hammer2_bmap_data_t *live,
1064 			hammer2_bmap_data_t *bmap, hammer2_key_t alloc_base)
1065 {
1066 	int bindex;
1067 	int scount;
1068 	hammer2_off_t tmp_off;
1069 	hammer2_bitmap_t lmask;
1070 	hammer2_bitmap_t mmask;
1071 
1072 	tmp_off = data_off;
1073 
1074 	for (bindex = 0; bindex < HAMMER2_BMAP_ELEMENTS; ++bindex) {
1075 		lmask = live->bitmapq[bindex];	/* live */
1076 		mmask = bmap->bitmapq[bindex];	/* snapshotted bulkfree */
1077 		if (lmask == mmask) {
1078 			tmp_off += HAMMER2_BMAP_INDEX_SIZE;
1079 			continue;
1080 		}
1081 
1082 		for (scount = 0;
1083 		     scount < HAMMER2_BMAP_BITS_PER_ELEMENT;
1084 		     scount += 2) {
1085 			if ((mmask & 3) == 0) {
1086 				/*
1087 				 * in-memory 00		live 11 -> 10
1088 				 *			live 10 -> 00
1089 				 *
1090 				 * Storage might be marked allocated or
1091 				 * staged and must be remarked staged or
1092 				 * free.
1093 				 */
1094 				switch (lmask & 3) {
1095 				case 0:	/* 00 */
1096 					break;
1097 				case 1:	/* 01 */
1098 					kprintf("hammer2_bulkfree: cannot "
1099 						"transition m=00/l=01\n");
1100 					break;
1101 				case 2:	/* 10 -> 00 */
1102 					live->bitmapq[bindex] &=
1103 					    ~((hammer2_bitmap_t)2 << scount);
1104 					live->avail +=
1105 						HAMMER2_FREEMAP_BLOCK_SIZE;
1106 					if (live->avail >
1107 					    HAMMER2_FREEMAP_LEVEL0_SIZE) {
1108 						live->avail =
1109 						    HAMMER2_FREEMAP_LEVEL0_SIZE;
1110 					}
1111 					cbinfo->adj_free +=
1112 						HAMMER2_FREEMAP_BLOCK_SIZE;
1113 					++cbinfo->count_10_00;
1114 					hammer2_io_dedup_assert(
1115 						cbinfo->hmp,
1116 						tmp_off |
1117 						HAMMER2_FREEMAP_BLOCK_RADIX,
1118 						HAMMER2_FREEMAP_BLOCK_SIZE);
1119 					break;
1120 				case 3:	/* 11 -> 10 */
1121 					live->bitmapq[bindex] &=
1122 					    ~((hammer2_bitmap_t)1 << scount);
1123 					++cbinfo->count_11_10;
1124 					hammer2_io_dedup_delete(
1125 						cbinfo->hmp,
1126 						HAMMER2_BREF_TYPE_DATA,
1127 						tmp_off |
1128 						HAMMER2_FREEMAP_BLOCK_RADIX,
1129 						HAMMER2_FREEMAP_BLOCK_SIZE);
1130 					break;
1131 				}
1132 			} else if ((mmask & 3) == 3) {
1133 				/*
1134 				 * in-memory 11		live 10 -> 11
1135 				 *			live ** -> 11
1136 				 *
1137 				 * Storage might be incorrectly marked free
1138 				 * or staged and must be remarked fully
1139 				 * allocated.
1140 				 */
1141 				switch (lmask & 3) {
1142 				case 0:	/* 00 */
1143 					++cbinfo->count_00_11;
1144 					cbinfo->adj_free -=
1145 						HAMMER2_FREEMAP_BLOCK_SIZE;
1146 					live->avail -=
1147 						HAMMER2_FREEMAP_BLOCK_SIZE;
1148 					if ((int32_t)live->avail < 0)
1149 						live->avail = 0;
1150 					break;
1151 				case 1:	/* 01 */
1152 					++cbinfo->count_01_11;
1153 					break;
1154 				case 2:	/* 10 -> 11 */
1155 					++cbinfo->count_10_11;
1156 					break;
1157 				case 3:	/* 11 */
1158 					break;
1159 				}
1160 				live->bitmapq[bindex] |=
1161 					((hammer2_bitmap_t)3 << scount);
1162 			}
1163 			mmask >>= 2;
1164 			lmask >>= 2;
1165 			tmp_off += HAMMER2_FREEMAP_BLOCK_SIZE;
1166 		}
1167 	}
1168 
1169 	/*
1170 	 * Determine if the live bitmap is completely free and reset its
1171 	 * fields if so.  Otherwise check to see if we can reduce the linear
1172 	 * offset.
1173 	 */
1174 	for (bindex = HAMMER2_BMAP_ELEMENTS - 1; bindex >= 0; --bindex) {
1175 		if (live->bitmapq[bindex] != 0)
1176 			break;
1177 	}
1178 	if (bindex < 0) {
1179 		/*
1180 		 * Completely empty, reset entire segment
1181 		 */
1182 #if 0
1183 		kprintf("hammer2: cleanseg %016jx.%04x (%d)\n",
1184 			alloc_base, live->class, live->avail);
1185 #endif
1186 		live->avail = HAMMER2_FREEMAP_LEVEL0_SIZE;
1187 		live->class = 0;
1188 		live->linear = 0;
1189 		++cbinfo->count_l0cleans;
1190 	} else if (bindex < 7) {
1191 		/*
1192 		 * Partially full, bitmapq[bindex] != 0.  Our bulkfree pass
1193 		 * does not record enough information to set live->linear
1194 		 * exactly.
1195 		 *
1196 		 * NOTE: Setting live->linear to a sub-block (16K) boundary
1197 		 *	 forces the live code to iterate to the next fully
1198 		 *	 free block.  It does NOT mean that all blocks above
1199 		 *	 live->linear are available.
1200 		 *
1201 		 *	 Setting live->linear to a fragmentary (less than
1202 		 *	 16K) boundary allows allocations to iterate within
1203 		 *	 that sub-block.
1204 		 */
1205 		if (live->linear < bmap->linear &&
1206 		    ((live->linear ^ bmap->linear) &
1207 		     ~HAMMER2_FREEMAP_BLOCK_MASK) == 0) {
1208 			/*
1209 			 * If greater than but still within the same
1210 			 * sub-block as live we can adjust linear upward.
1211 			 */
1212 			live->linear = bmap->linear;
1213 			++cbinfo->count_linadjusts;
1214 		} else {
1215 			/*
1216 			 * Otherwise adjust to the nearest higher or same
1217 			 * sub-block boundary.  The live system may have
1218 			 * bounced live->linear around so we cannot make any
1219 			 * assumptions with regards to available fragmentary
1220 			 * allocations.
1221 			 */
1222 			live->linear =
1223 				(bmap->linear + HAMMER2_FREEMAP_BLOCK_MASK) &
1224 				~HAMMER2_FREEMAP_BLOCK_MASK;
1225 			++cbinfo->count_linadjusts;
1226 		}
1227 	} else {
1228 		/*
1229 		 * Completely full, effectively disable the linear iterator
1230 		 */
1231 		live->linear = HAMMER2_SEGSIZE;
1232 	}
1233 
1234 #if 0
1235 	if (bmap->class) {
1236 		kprintf("%016jx %04d.%04x (avail=%7d) "
1237 			"%08x %08x %08x %08x %08x %08x %08x %08x\n",
1238 			(intmax_t)data_off,
1239 			(int)((data_off &
1240 			       HAMMER2_FREEMAP_LEVEL1_MASK) >>
1241 			      HAMMER2_FREEMAP_LEVEL0_RADIX),
1242 			bmap->class,
1243 			bmap->avail,
1244 			bmap->bitmap[0], bmap->bitmap[1],
1245 			bmap->bitmap[2], bmap->bitmap[3],
1246 			bmap->bitmap[4], bmap->bitmap[5],
1247 			bmap->bitmap[6], bmap->bitmap[7]);
1248 	}
1249 #endif
1250 }
1251 
1252 /*
1253  * BULKFREE DEDUP HEURISTIC
1254  *
1255  * WARNING! This code is SMP safe but the heuristic allows SMP collisions.
1256  *	    All fields must be loaded into locals and validated.
1257  */
1258 static
1259 int
1260 h2_bulkfree_test(hammer2_bulkfree_info_t *cbinfo, hammer2_blockref_t *bref,
1261 		 int pri, int saved_error)
1262 {
1263 	hammer2_dedup_t *dedup;
1264 	int best;
1265 	int n;
1266 	int i;
1267 
1268 	n = hammer2_icrc32(&bref->data_off, sizeof(bref->data_off));
1269 	dedup = cbinfo->dedup + (n & (HAMMER2_DEDUP_HEUR_MASK & ~7));
1270 
1271 	for (i = best = 0; i < 8; ++i) {
1272 		if (dedup[i].data_off == bref->data_off) {
1273 			if (dedup[i].ticks < pri)
1274 				dedup[i].ticks = pri;
1275 			if (pri == 1)
1276 				cbinfo->count_dedup_factor += dedup[i].ticks;
1277 			return (dedup[i].saved_error | HAMMER2_ERROR_EOF);
1278 		}
1279 		if (dedup[i].ticks < dedup[best].ticks)
1280 			best = i;
1281 	}
1282 	dedup[best].data_off = bref->data_off;
1283 	dedup[best].ticks = pri;
1284 	dedup[best].saved_error = saved_error;
1285 
1286 	return 0;
1287 }
1288