1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21 /*
22 * Copyright 2008 Sun Microsystems, Inc. All rights reserved.
23 * Use is subject to license terms.
24 */
25
26 #pragma ident "%Z%%M% %I% %E% SMI"
27
28 #include <sys/zfs_context.h>
29 #include <sys/spa.h>
30 #include <sys/dmu.h>
31 #include <sys/zio.h>
32 #include <sys/space_map.h>
33
34 /*
35 * Space map routines.
36 * NOTE: caller is responsible for all locking.
37 */
38 static int
39 space_map_seg_compare(const void *x1, const void *x2)
40 {
41 const space_seg_t *s1 = x1;
42 const space_seg_t *s2 = x2;
43
44 if (s1->ss_start < s2->ss_start) {
45 if (s1->ss_end > s2->ss_start)
46 return (0);
47 return (-1);
48 }
49 if (s1->ss_start > s2->ss_start) {
50 if (s1->ss_start < s2->ss_end)
51 return (0);
52 return (1);
53 }
54 return (0);
55 }
56
57 void
58 space_map_create(space_map_t *sm, uint64_t start, uint64_t size, uint8_t shift,
59 kmutex_t *lp)
60 {
61 bzero(sm, sizeof (*sm));
62
63 avl_create(&sm->sm_root, space_map_seg_compare,
64 sizeof (space_seg_t), offsetof(struct space_seg, ss_node));
65
66 sm->sm_start = start;
67 sm->sm_size = size;
68 sm->sm_shift = shift;
69 sm->sm_lock = lp;
70 }
71
72 void
73 space_map_destroy(space_map_t *sm)
74 {
75 ASSERT(!sm->sm_loaded && !sm->sm_loading);
76 VERIFY3U(sm->sm_space, ==, 0);
77 avl_destroy(&sm->sm_root);
78 }
79
80 void
81 space_map_add(space_map_t *sm, uint64_t start, uint64_t size)
82 {
83 avl_index_t where;
84 space_seg_t ssearch, *ss_before, *ss_after, *ss;
85 uint64_t end = start + size;
86 int merge_before, merge_after;
87
88 ASSERT(MUTEX_HELD(sm->sm_lock));
89 VERIFY(size != 0);
90 VERIFY3U(start, >=, sm->sm_start);
91 VERIFY3U(end, <=, sm->sm_start + sm->sm_size);
92 VERIFY(sm->sm_space + size <= sm->sm_size);
93 VERIFY(P2PHASE(start, 1ULL << sm->sm_shift) == 0);
94 VERIFY(P2PHASE(size, 1ULL << sm->sm_shift) == 0);
95
96 ssearch.ss_start = start;
97 ssearch.ss_end = end;
98 ss = avl_find(&sm->sm_root, &ssearch, &where);
99
100 if (ss != NULL && ss->ss_start <= start && ss->ss_end >= end) {
101 zfs_panic_recover("zfs: allocating allocated segment"
102 "(offset=%llu size=%llu)\n",
103 (longlong_t)start, (longlong_t)size);
104 return;
105 }
106
107 /* Make sure we don't overlap with either of our neighbors */
108 VERIFY(ss == NULL);
109
110 ss_before = avl_nearest(&sm->sm_root, where, AVL_BEFORE);
111 ss_after = avl_nearest(&sm->sm_root, where, AVL_AFTER);
112
113 merge_before = (ss_before != NULL && ss_before->ss_end == start);
114 merge_after = (ss_after != NULL && ss_after->ss_start == end);
115
116 if (merge_before && merge_after) {
117 avl_remove(&sm->sm_root, ss_before);
118 ss_after->ss_start = ss_before->ss_start;
119 kmem_free(ss_before, sizeof (*ss_before));
120 } else if (merge_before) {
121 ss_before->ss_end = end;
122 } else if (merge_after) {
123 ss_after->ss_start = start;
124 } else {
125 ss = kmem_alloc(sizeof (*ss), KM_SLEEP);
126 ss->ss_start = start;
127 ss->ss_end = end;
128 avl_insert(&sm->sm_root, ss, where);
129 }
130
131 sm->sm_space += size;
132 }
133
134 void
135 space_map_remove(space_map_t *sm, uint64_t start, uint64_t size)
136 {
137 avl_index_t where;
138 space_seg_t ssearch, *ss, *newseg;
139 uint64_t end = start + size;
140 int left_over, right_over;
141
142 ASSERT(MUTEX_HELD(sm->sm_lock));
143 VERIFY(size != 0);
144 VERIFY(P2PHASE(start, 1ULL << sm->sm_shift) == 0);
145 VERIFY(P2PHASE(size, 1ULL << sm->sm_shift) == 0);
146
147 ssearch.ss_start = start;
148 ssearch.ss_end = end;
149 ss = avl_find(&sm->sm_root, &ssearch, &where);
150
151 /* Make sure we completely overlap with someone */
152 if (ss == NULL) {
153 zfs_panic_recover("zfs: freeing free segment "
154 "(offset=%llu size=%llu)",
155 (longlong_t)start, (longlong_t)size);
156 return;
157 }
158 VERIFY3U(ss->ss_start, <=, start);
159 VERIFY3U(ss->ss_end, >=, end);
160 VERIFY(sm->sm_space - size <= sm->sm_size);
161
162 left_over = (ss->ss_start != start);
163 right_over = (ss->ss_end != end);
164
165 if (left_over && right_over) {
166 newseg = kmem_alloc(sizeof (*newseg), KM_SLEEP);
167 newseg->ss_start = end;
168 newseg->ss_end = ss->ss_end;
169 ss->ss_end = start;
170 avl_insert_here(&sm->sm_root, newseg, ss, AVL_AFTER);
171 } else if (left_over) {
172 ss->ss_end = start;
173 } else if (right_over) {
174 ss->ss_start = end;
175 } else {
176 avl_remove(&sm->sm_root, ss);
177 kmem_free(ss, sizeof (*ss));
178 }
179
180 sm->sm_space -= size;
181 }
182
183
184
185 int
186 space_map_fold(space_map_t *sm, uint8_t oldwidth, uint8_t newwidth)
187 {
188 space_seg_t *ss;
189 uint64_t d, r;
190
191 ASSERT(MUTEX_HELD(sm->sm_lock));
192
193 for (ss = avl_first(&sm->sm_root); ss != NULL;
194 ss = AVL_NEXT(&sm->sm_root, ss)) {
195 d = ss->ss_start / oldwidth;
196 r = ss->ss_start % oldwidth;
197 ss->ss_start = d * newwidth + r;
198
199 d = ss->ss_end / oldwidth;
200 r = ss->ss_end % oldwidth;
201 ss->ss_end = d * newwidth + r;
202 }
203 }
204
205 int
206 space_map_contains(space_map_t *sm, uint64_t start, uint64_t size)
207 {
208 avl_index_t where;
209 space_seg_t ssearch, *ss;
210 uint64_t end = start + size;
211
212 ASSERT(MUTEX_HELD(sm->sm_lock));
213 VERIFY(size != 0);
214 VERIFY(P2PHASE(start, 1ULL << sm->sm_shift) == 0);
215 VERIFY(P2PHASE(size, 1ULL << sm->sm_shift) == 0);
216
217 ssearch.ss_start = start;
218 ssearch.ss_end = end;
219 ss = avl_find(&sm->sm_root, &ssearch, &where);
220
221 return (ss != NULL && ss->ss_start <= start && ss->ss_end >= end);
222 }
223
224 void
225 space_map_vacate(space_map_t *sm, space_map_func_t *func, space_map_t *mdest)
226 {
227 space_seg_t *ss;
228 void *cookie = NULL;
229
230 ASSERT(MUTEX_HELD(sm->sm_lock));
231
232 while ((ss = avl_destroy_nodes(&sm->sm_root, &cookie)) != NULL) {
233 if (func != NULL)
234 func(mdest, ss->ss_start, ss->ss_end - ss->ss_start);
235 kmem_free(ss, sizeof (*ss));
236 }
237 sm->sm_space = 0;
238 }
239
240 void
241 space_map_walk(space_map_t *sm, space_map_func_t *func, space_map_t *mdest)
242 {
243 space_seg_t *ss;
244
245 for (ss = avl_first(&sm->sm_root); ss; ss = AVL_NEXT(&sm->sm_root, ss))
246 func(mdest, ss->ss_start, ss->ss_end - ss->ss_start);
247 }
248
249 void
250 space_map_excise(space_map_t *sm, uint64_t start, uint64_t size)
251 {
252 avl_tree_t *t = &sm->sm_root;
253 avl_index_t where;
254 space_seg_t *ss, search;
255 uint64_t end = start + size;
256 uint64_t rm_start, rm_end;
257
258 ASSERT(MUTEX_HELD(sm->sm_lock));
259
260 search.ss_start = start;
261 search.ss_end = start;
262
263 for (;;) {
264 ss = avl_find(t, &search, &where);
265
266 if (ss == NULL)
267 ss = avl_nearest(t, where, AVL_AFTER);
268
269 if (ss == NULL || ss->ss_start >= end)
270 break;
271
272 rm_start = MAX(ss->ss_start, start);
273 rm_end = MIN(ss->ss_end, end);
274
275 space_map_remove(sm, rm_start, rm_end - rm_start);
276 }
277 }
278
279 /*
280 * Replace smd with the union of smd and sms.
281 */
282 void
283 space_map_union(space_map_t *smd, space_map_t *sms)
284 {
285 avl_tree_t *t = &sms->sm_root;
286 space_seg_t *ss;
287
288 ASSERT(MUTEX_HELD(smd->sm_lock));
289
290 /*
291 * For each source segment, remove any intersections with the
292 * destination, then add the source segment to the destination.
293 */
294 for (ss = avl_first(t); ss != NULL; ss = AVL_NEXT(t, ss)) {
295 space_map_excise(smd, ss->ss_start, ss->ss_end - ss->ss_start);
296 space_map_add(smd, ss->ss_start, ss->ss_end - ss->ss_start);
297 }
298 }
299
300 /*
301 * Wait for any in-progress space_map_load() to complete.
302 */
303 void
304 space_map_load_wait(space_map_t *sm)
305 {
306 ASSERT(MUTEX_HELD(sm->sm_lock));
307
308 while (sm->sm_loading)
309 cv_wait(&sm->sm_load_cv, sm->sm_lock);
310 }
311
312 /*
313 * Note: space_map_load() will drop sm_lock across dmu_read() calls.
314 * The caller must be OK with this.
315 */
316 int
317 space_map_load(space_map_t *sm, space_map_ops_t *ops, uint8_t maptype,
318 space_map_obj_t *smo, objset_t *os)
319 {
320 uint64_t *entry, *entry_map, *entry_map_end;
321 uint64_t bufsize, size, offset, end, space;
322 uint64_t mapstart = sm->sm_start;
323 int error = 0;
324
325 ASSERT(MUTEX_HELD(sm->sm_lock));
326
327 space_map_load_wait(sm);
328
329 if (sm->sm_loaded)
330 return (0);
331
332 sm->sm_loading = B_TRUE;
333 end = smo->smo_objsize;
334 space = smo->smo_alloc;
335
336 ASSERT(sm->sm_ops == NULL);
337 VERIFY3U(sm->sm_space, ==, 0);
338
339 if (maptype == SM_FREE) {
340 space_map_add(sm, sm->sm_start, sm->sm_size);
341 space = sm->sm_size - space;
342 }
343
344 bufsize = 1ULL << SPACE_MAP_BLOCKSHIFT;
345 entry_map = zio_buf_alloc(bufsize);
346
347 mutex_exit(sm->sm_lock);
348 if (end > bufsize)
349 dmu_prefetch(os, smo->smo_object, bufsize, end - bufsize);
350 mutex_enter(sm->sm_lock);
351
352 for (offset = 0; offset < end; offset += bufsize) {
353 size = MIN(end - offset, bufsize);
354 VERIFY(P2PHASE(size, sizeof (uint64_t)) == 0);
355 VERIFY(size != 0);
356
357 dprintf("object=%llu offset=%llx size=%llx\n",
358 smo->smo_object, offset, size);
359
360 mutex_exit(sm->sm_lock);
361 error = dmu_read(os, smo->smo_object, offset, size, entry_map);
362 mutex_enter(sm->sm_lock);
363 if (error != 0)
364 break;
365
366 entry_map_end = entry_map + (size / sizeof (uint64_t));
367 for (entry = entry_map; entry < entry_map_end; entry++) {
368 uint64_t e = *entry;
369
370 if (SM_IS_DEBUG(e)) /* Skip debug entries */
371 continue;
372
373 if (SM_IS_SPECIAL(e)) {
374 uint8_t oldwidth, newwidth;
375 ASSERT(SM_SPECIAL_ACTION_DECODE(e) == SM_FOLD);
376 oldwidth = BF64_ENCODE(e, 0, 8);
377 newwidth = BF64_ENCODE(e, 8, 8);
378 space_map_fold(sm, oldwidth, newwidth);
379 continue;
380 }
381
382 (SM_TYPE_DECODE(e) == maptype ?
383 space_map_add : space_map_remove)(sm,
384 (SM_OFFSET_DECODE(e) << sm->sm_shift) + mapstart,
385 SM_RUN_DECODE(e) << sm->sm_shift);
386 }
387 }
388
389 if (error == 0) {
390 VERIFY3U(sm->sm_space, ==, space);
391
392 sm->sm_loaded = B_TRUE;
393 sm->sm_ops = ops;
394 if (ops != NULL)
395 ops->smop_load(sm);
396 } else {
397 space_map_vacate(sm, NULL, NULL);
398 }
399
400 zio_buf_free(entry_map, bufsize);
401
402 sm->sm_loading = B_FALSE;
403
404 cv_broadcast(&sm->sm_load_cv);
405
406 return (error);
407 }
408
409 void
410 space_map_unload(space_map_t *sm)
411 {
412 ASSERT(MUTEX_HELD(sm->sm_lock));
413
414 if (sm->sm_loaded && sm->sm_ops != NULL)
415 sm->sm_ops->smop_unload(sm);
416
417 sm->sm_loaded = B_FALSE;
418 sm->sm_ops = NULL;
419
420 space_map_vacate(sm, NULL, NULL);
421 }
422
423 uint64_t
424 space_map_alloc(space_map_t *sm, uint64_t size)
425 {
426 uint64_t start;
427
428 start = sm->sm_ops->smop_alloc(sm, size);
429 if (start != -1ULL)
430 space_map_remove(sm, start, size);
431 return (start);
432 }
433
434 void
435 space_map_claim(space_map_t *sm, uint64_t start, uint64_t size)
436 {
437 sm->sm_ops->smop_claim(sm, start, size);
438 space_map_remove(sm, start, size);
439 }
440
441 void
442 space_map_free(space_map_t *sm, uint64_t start, uint64_t size)
443 {
444 space_map_add(sm, start, size);
445 sm->sm_ops->smop_free(sm, start, size);
446 }
447
448 /*
449 * Note: space_map_sync() will drop sm_lock across dmu_write() calls.
450 */
451 void
452 space_map_sync(space_map_t *sm, uint8_t maptype,
453 space_map_obj_t *smo, objset_t *os, dmu_tx_t *tx)
454 {
455 spa_t *spa = dmu_objset_spa(os);
456 void *cookie = NULL;
457 space_seg_t *ss;
458 uint64_t bufsize, start, size, run_len;
459 uint64_t *entry, *entry_map, *entry_map_end;
460
461 ASSERT(MUTEX_HELD(sm->sm_lock));
462
463 if (sm->sm_space == 0)
464 return;
465
466 dprintf("object %4llu, txg %llu, pass %d, %c, count %lu, space %llx\n",
467 smo->smo_object, dmu_tx_get_txg(tx), spa_sync_pass(spa),
468 maptype == SM_ALLOC ? 'A' : 'F', avl_numnodes(&sm->sm_root),
469 sm->sm_space);
470
471 if (maptype == SM_ALLOC)
472 smo->smo_alloc += sm->sm_space;
473 else
474 smo->smo_alloc -= sm->sm_space;
475
476 bufsize = (8 + avl_numnodes(&sm->sm_root)) * sizeof (uint64_t);
477 bufsize = MIN(bufsize, 1ULL << SPACE_MAP_BLOCKSHIFT);
478 entry_map = zio_buf_alloc(bufsize);
479 entry_map_end = entry_map + (bufsize / sizeof (uint64_t));
480 entry = entry_map;
481
482 *entry++ = SM_DEBUG_ENCODE(1) |
483 SM_DEBUG_ACTION_ENCODE(maptype) |
484 SM_DEBUG_SYNCPASS_ENCODE(spa_sync_pass(spa)) |
485 SM_DEBUG_TXG_ENCODE(dmu_tx_get_txg(tx));
486
487 while ((ss = avl_destroy_nodes(&sm->sm_root, &cookie)) != NULL) {
488 size = ss->ss_end - ss->ss_start;
489 start = (ss->ss_start - sm->sm_start) >> sm->sm_shift;
490
491 sm->sm_space -= size;
492 size >>= sm->sm_shift;
493
494 while (size) {
495 run_len = MIN(size, SM_RUN_MAX);
496
497 if (entry == entry_map_end) {
498 mutex_exit(sm->sm_lock);
499 dmu_write(os, smo->smo_object, smo->smo_objsize,
500 bufsize, entry_map, tx);
501 mutex_enter(sm->sm_lock);
502 smo->smo_objsize += bufsize;
503 entry = entry_map;
504 }
505
506 *entry++ = SM_OFFSET_ENCODE(start) |
507 SM_TYPE_ENCODE(maptype) |
508 SM_RUN_ENCODE(run_len);
509
510 start += run_len;
511 size -= run_len;
512 }
513 kmem_free(ss, sizeof (*ss));
514 }
515
516 if (entry != entry_map) {
517 size = (entry - entry_map) * sizeof (uint64_t);
518 mutex_exit(sm->sm_lock);
519 dmu_write(os, smo->smo_object, smo->smo_objsize,
520 size, entry_map, tx);
521 mutex_enter(sm->sm_lock);
522 smo->smo_objsize += size;
523 }
524
525 zio_buf_free(entry_map, bufsize);
526
527 VERIFY3U(sm->sm_space, ==, 0);
528 }
529
530 void
531 space_map_truncate(space_map_obj_t *smo, objset_t *os, dmu_tx_t *tx)
532 {
533 VERIFY(dmu_free_range(os, smo->smo_object, 0, -1ULL, tx) == 0);
534
535 smo->smo_objsize = 0;
536 smo->smo_alloc = 0;
537 }