xref: /illumos-gate/usr/src/uts/common/fs/zfs/dsl_deadlist.c (revision 19b94df933188a15d4f0d6c568f0bab3f127892e)
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 (c) 2010, Oracle and/or its affiliates. All rights reserved.
23  * Copyright (c) 2011 by Delphix. All rights reserved.
24  */
25 
26 #include <sys/dsl_dataset.h>
27 #include <sys/dmu.h>
28 #include <sys/refcount.h>
29 #include <sys/zap.h>
30 #include <sys/zfs_context.h>
31 #include <sys/dsl_pool.h>
32 
33 /*
34  * Deadlist concurrency:
35  *
36  * Deadlists can only be modified from the syncing thread.
37  *
38  * Except for dsl_deadlist_insert(), it can only be modified with the
39  * dp_config_rwlock held with RW_WRITER.
40  *
41  * The accessors (dsl_deadlist_space() and dsl_deadlist_space_range()) can
42  * be called concurrently, from open context, with the dl_config_rwlock held
43  * with RW_READER.
44  *
45  * Therefore, we only need to provide locking between dsl_deadlist_insert() and
46  * the accessors, protecting:
47  *     dl_phys->dl_used,comp,uncomp
48  *     and protecting the dl_tree from being loaded.
49  * The locking is provided by dl_lock.  Note that locking on the bpobj_t
50  * provides its own locking, and dl_oldfmt is immutable.
51  */
52 
53 static int
54 dsl_deadlist_compare(const void *arg1, const void *arg2)
55 {
56 	const dsl_deadlist_entry_t *dle1 = arg1;
57 	const dsl_deadlist_entry_t *dle2 = arg2;
58 
59 	if (dle1->dle_mintxg < dle2->dle_mintxg)
60 		return (-1);
61 	else if (dle1->dle_mintxg > dle2->dle_mintxg)
62 		return (+1);
63 	else
64 		return (0);
65 }
66 
67 static void
68 dsl_deadlist_load_tree(dsl_deadlist_t *dl)
69 {
70 	zap_cursor_t zc;
71 	zap_attribute_t za;
72 
73 	ASSERT(!dl->dl_oldfmt);
74 	if (dl->dl_havetree)
75 		return;
76 
77 	avl_create(&dl->dl_tree, dsl_deadlist_compare,
78 	    sizeof (dsl_deadlist_entry_t),
79 	    offsetof(dsl_deadlist_entry_t, dle_node));
80 	for (zap_cursor_init(&zc, dl->dl_os, dl->dl_object);
81 	    zap_cursor_retrieve(&zc, &za) == 0;
82 	    zap_cursor_advance(&zc)) {
83 		dsl_deadlist_entry_t *dle = kmem_alloc(sizeof (*dle), KM_SLEEP);
84 		dle->dle_mintxg = strtonum(za.za_name, NULL);
85 		VERIFY3U(0, ==, bpobj_open(&dle->dle_bpobj, dl->dl_os,
86 		    za.za_first_integer));
87 		avl_add(&dl->dl_tree, dle);
88 	}
89 	zap_cursor_fini(&zc);
90 	dl->dl_havetree = B_TRUE;
91 }
92 
93 void
94 dsl_deadlist_open(dsl_deadlist_t *dl, objset_t *os, uint64_t object)
95 {
96 	dmu_object_info_t doi;
97 
98 	mutex_init(&dl->dl_lock, NULL, MUTEX_DEFAULT, NULL);
99 	dl->dl_os = os;
100 	dl->dl_object = object;
101 	VERIFY3U(0, ==, dmu_bonus_hold(os, object, dl, &dl->dl_dbuf));
102 	dmu_object_info_from_db(dl->dl_dbuf, &doi);
103 	if (doi.doi_type == DMU_OT_BPOBJ) {
104 		dmu_buf_rele(dl->dl_dbuf, dl);
105 		dl->dl_dbuf = NULL;
106 		dl->dl_oldfmt = B_TRUE;
107 		VERIFY3U(0, ==, bpobj_open(&dl->dl_bpobj, os, object));
108 		return;
109 	}
110 
111 	dl->dl_oldfmt = B_FALSE;
112 	dl->dl_phys = dl->dl_dbuf->db_data;
113 	dl->dl_havetree = B_FALSE;
114 }
115 
116 void
117 dsl_deadlist_close(dsl_deadlist_t *dl)
118 {
119 	void *cookie = NULL;
120 	dsl_deadlist_entry_t *dle;
121 
122 	if (dl->dl_oldfmt) {
123 		dl->dl_oldfmt = B_FALSE;
124 		bpobj_close(&dl->dl_bpobj);
125 		return;
126 	}
127 
128 	if (dl->dl_havetree) {
129 		while ((dle = avl_destroy_nodes(&dl->dl_tree, &cookie))
130 		    != NULL) {
131 			bpobj_close(&dle->dle_bpobj);
132 			kmem_free(dle, sizeof (*dle));
133 		}
134 		avl_destroy(&dl->dl_tree);
135 	}
136 	dmu_buf_rele(dl->dl_dbuf, dl);
137 	mutex_destroy(&dl->dl_lock);
138 	dl->dl_dbuf = NULL;
139 	dl->dl_phys = NULL;
140 }
141 
142 uint64_t
143 dsl_deadlist_alloc(objset_t *os, dmu_tx_t *tx)
144 {
145 	if (spa_version(dmu_objset_spa(os)) < SPA_VERSION_DEADLISTS)
146 		return (bpobj_alloc(os, SPA_MAXBLOCKSIZE, tx));
147 	return (zap_create(os, DMU_OT_DEADLIST, DMU_OT_DEADLIST_HDR,
148 	    sizeof (dsl_deadlist_phys_t), tx));
149 }
150 
151 void
152 dsl_deadlist_free(objset_t *os, uint64_t dlobj, dmu_tx_t *tx)
153 {
154 	dmu_object_info_t doi;
155 	zap_cursor_t zc;
156 	zap_attribute_t za;
157 
158 	VERIFY3U(0, ==, dmu_object_info(os, dlobj, &doi));
159 	if (doi.doi_type == DMU_OT_BPOBJ) {
160 		bpobj_free(os, dlobj, tx);
161 		return;
162 	}
163 
164 	for (zap_cursor_init(&zc, os, dlobj);
165 	    zap_cursor_retrieve(&zc, &za) == 0;
166 	    zap_cursor_advance(&zc))
167 		bpobj_free(os, za.za_first_integer, tx);
168 	zap_cursor_fini(&zc);
169 	VERIFY3U(0, ==, dmu_object_free(os, dlobj, tx));
170 }
171 
172 void
173 dsl_deadlist_insert(dsl_deadlist_t *dl, const blkptr_t *bp, dmu_tx_t *tx)
174 {
175 	dsl_deadlist_entry_t dle_tofind;
176 	dsl_deadlist_entry_t *dle;
177 	avl_index_t where;
178 
179 	if (dl->dl_oldfmt) {
180 		bpobj_enqueue(&dl->dl_bpobj, bp, tx);
181 		return;
182 	}
183 
184 	dsl_deadlist_load_tree(dl);
185 
186 	dmu_buf_will_dirty(dl->dl_dbuf, tx);
187 	mutex_enter(&dl->dl_lock);
188 	dl->dl_phys->dl_used +=
189 	    bp_get_dsize_sync(dmu_objset_spa(dl->dl_os), bp);
190 	dl->dl_phys->dl_comp += BP_GET_PSIZE(bp);
191 	dl->dl_phys->dl_uncomp += BP_GET_UCSIZE(bp);
192 	mutex_exit(&dl->dl_lock);
193 
194 	dle_tofind.dle_mintxg = bp->blk_birth;
195 	dle = avl_find(&dl->dl_tree, &dle_tofind, &where);
196 	if (dle == NULL)
197 		dle = avl_nearest(&dl->dl_tree, where, AVL_BEFORE);
198 	else
199 		dle = AVL_PREV(&dl->dl_tree, dle);
200 	bpobj_enqueue(&dle->dle_bpobj, bp, tx);
201 }
202 
203 /*
204  * Insert new key in deadlist, which must be > all current entries.
205  * mintxg is not inclusive.
206  */
207 void
208 dsl_deadlist_add_key(dsl_deadlist_t *dl, uint64_t mintxg, dmu_tx_t *tx)
209 {
210 	uint64_t obj;
211 	dsl_deadlist_entry_t *dle;
212 
213 	if (dl->dl_oldfmt)
214 		return;
215 
216 	dsl_deadlist_load_tree(dl);
217 
218 	dle = kmem_alloc(sizeof (*dle), KM_SLEEP);
219 	dle->dle_mintxg = mintxg;
220 	obj = bpobj_alloc(dl->dl_os, SPA_MAXBLOCKSIZE, tx);
221 	VERIFY3U(0, ==, bpobj_open(&dle->dle_bpobj, dl->dl_os, obj));
222 	avl_add(&dl->dl_tree, dle);
223 
224 	VERIFY3U(0, ==, zap_add_int_key(dl->dl_os, dl->dl_object,
225 	    mintxg, obj, tx));
226 }
227 
228 /*
229  * Remove this key, merging its entries into the previous key.
230  */
231 void
232 dsl_deadlist_remove_key(dsl_deadlist_t *dl, uint64_t mintxg, dmu_tx_t *tx)
233 {
234 	dsl_deadlist_entry_t dle_tofind;
235 	dsl_deadlist_entry_t *dle, *dle_prev;
236 
237 	if (dl->dl_oldfmt)
238 		return;
239 
240 	dsl_deadlist_load_tree(dl);
241 
242 	dle_tofind.dle_mintxg = mintxg;
243 	dle = avl_find(&dl->dl_tree, &dle_tofind, NULL);
244 	dle_prev = AVL_PREV(&dl->dl_tree, dle);
245 
246 	bpobj_enqueue_subobj(&dle_prev->dle_bpobj,
247 	    dle->dle_bpobj.bpo_object, tx);
248 
249 	avl_remove(&dl->dl_tree, dle);
250 	bpobj_close(&dle->dle_bpobj);
251 	kmem_free(dle, sizeof (*dle));
252 
253 	VERIFY3U(0, ==, zap_remove_int(dl->dl_os, dl->dl_object, mintxg, tx));
254 }
255 
256 /*
257  * Walk ds's snapshots to regenerate generate ZAP & AVL.
258  */
259 static void
260 dsl_deadlist_regenerate(objset_t *os, uint64_t dlobj,
261     uint64_t mrs_obj, dmu_tx_t *tx)
262 {
263 	dsl_deadlist_t dl;
264 	dsl_pool_t *dp = dmu_objset_pool(os);
265 
266 	dsl_deadlist_open(&dl, os, dlobj);
267 	if (dl.dl_oldfmt) {
268 		dsl_deadlist_close(&dl);
269 		return;
270 	}
271 
272 	while (mrs_obj != 0) {
273 		dsl_dataset_t *ds;
274 		VERIFY3U(0, ==, dsl_dataset_hold_obj(dp, mrs_obj, FTAG, &ds));
275 		dsl_deadlist_add_key(&dl, ds->ds_phys->ds_prev_snap_txg, tx);
276 		mrs_obj = ds->ds_phys->ds_prev_snap_obj;
277 		dsl_dataset_rele(ds, FTAG);
278 	}
279 	dsl_deadlist_close(&dl);
280 }
281 
282 uint64_t
283 dsl_deadlist_clone(dsl_deadlist_t *dl, uint64_t maxtxg,
284     uint64_t mrs_obj, dmu_tx_t *tx)
285 {
286 	dsl_deadlist_entry_t *dle;
287 	uint64_t newobj;
288 
289 	newobj = dsl_deadlist_alloc(dl->dl_os, tx);
290 
291 	if (dl->dl_oldfmt) {
292 		dsl_deadlist_regenerate(dl->dl_os, newobj, mrs_obj, tx);
293 		return (newobj);
294 	}
295 
296 	dsl_deadlist_load_tree(dl);
297 
298 	for (dle = avl_first(&dl->dl_tree); dle;
299 	    dle = AVL_NEXT(&dl->dl_tree, dle)) {
300 		uint64_t obj;
301 
302 		if (dle->dle_mintxg >= maxtxg)
303 			break;
304 
305 		obj = bpobj_alloc(dl->dl_os, SPA_MAXBLOCKSIZE, tx);
306 		VERIFY3U(0, ==, zap_add_int_key(dl->dl_os, newobj,
307 		    dle->dle_mintxg, obj, tx));
308 	}
309 	return (newobj);
310 }
311 
312 void
313 dsl_deadlist_space(dsl_deadlist_t *dl,
314     uint64_t *usedp, uint64_t *compp, uint64_t *uncompp)
315 {
316 	if (dl->dl_oldfmt) {
317 		VERIFY3U(0, ==, bpobj_space(&dl->dl_bpobj,
318 		    usedp, compp, uncompp));
319 		return;
320 	}
321 
322 	mutex_enter(&dl->dl_lock);
323 	*usedp = dl->dl_phys->dl_used;
324 	*compp = dl->dl_phys->dl_comp;
325 	*uncompp = dl->dl_phys->dl_uncomp;
326 	mutex_exit(&dl->dl_lock);
327 }
328 
329 /*
330  * return space used in the range (mintxg, maxtxg].
331  * Includes maxtxg, does not include mintxg.
332  * mintxg and maxtxg must both be keys in the deadlist (unless maxtxg is
333  * larger than any bp in the deadlist (eg. UINT64_MAX)).
334  */
335 void
336 dsl_deadlist_space_range(dsl_deadlist_t *dl, uint64_t mintxg, uint64_t maxtxg,
337     uint64_t *usedp, uint64_t *compp, uint64_t *uncompp)
338 {
339 	dsl_deadlist_entry_t *dle;
340 	dsl_deadlist_entry_t dle_tofind;
341 	avl_index_t where;
342 
343 	if (dl->dl_oldfmt) {
344 		VERIFY3U(0, ==, bpobj_space_range(&dl->dl_bpobj,
345 		    mintxg, maxtxg, usedp, compp, uncompp));
346 		return;
347 	}
348 
349 	*usedp = *compp = *uncompp = 0;
350 
351 	mutex_enter(&dl->dl_lock);
352 	dsl_deadlist_load_tree(dl);
353 	dle_tofind.dle_mintxg = mintxg;
354 	dle = avl_find(&dl->dl_tree, &dle_tofind, &where);
355 	/*
356 	 * If we don't find this mintxg, there shouldn't be anything
357 	 * after it either.
358 	 */
359 	ASSERT(dle != NULL ||
360 	    avl_nearest(&dl->dl_tree, where, AVL_AFTER) == NULL);
361 
362 	for (; dle && dle->dle_mintxg < maxtxg;
363 	    dle = AVL_NEXT(&dl->dl_tree, dle)) {
364 		uint64_t used, comp, uncomp;
365 
366 		VERIFY3U(0, ==, bpobj_space(&dle->dle_bpobj,
367 		    &used, &comp, &uncomp));
368 
369 		*usedp += used;
370 		*compp += comp;
371 		*uncompp += uncomp;
372 	}
373 	mutex_exit(&dl->dl_lock);
374 }
375 
376 static void
377 dsl_deadlist_insert_bpobj(dsl_deadlist_t *dl, uint64_t obj, uint64_t birth,
378     dmu_tx_t *tx)
379 {
380 	dsl_deadlist_entry_t dle_tofind;
381 	dsl_deadlist_entry_t *dle;
382 	avl_index_t where;
383 	uint64_t used, comp, uncomp;
384 	bpobj_t bpo;
385 
386 	VERIFY3U(0, ==, bpobj_open(&bpo, dl->dl_os, obj));
387 	VERIFY3U(0, ==, bpobj_space(&bpo, &used, &comp, &uncomp));
388 	bpobj_close(&bpo);
389 
390 	dsl_deadlist_load_tree(dl);
391 
392 	dmu_buf_will_dirty(dl->dl_dbuf, tx);
393 	mutex_enter(&dl->dl_lock);
394 	dl->dl_phys->dl_used += used;
395 	dl->dl_phys->dl_comp += comp;
396 	dl->dl_phys->dl_uncomp += uncomp;
397 	mutex_exit(&dl->dl_lock);
398 
399 	dle_tofind.dle_mintxg = birth;
400 	dle = avl_find(&dl->dl_tree, &dle_tofind, &where);
401 	if (dle == NULL)
402 		dle = avl_nearest(&dl->dl_tree, where, AVL_BEFORE);
403 	bpobj_enqueue_subobj(&dle->dle_bpobj, obj, tx);
404 }
405 
406 static int
407 dsl_deadlist_insert_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx)
408 {
409 	dsl_deadlist_t *dl = arg;
410 	dsl_deadlist_insert(dl, bp, tx);
411 	return (0);
412 }
413 
414 /*
415  * Merge the deadlist pointed to by 'obj' into dl.  obj will be left as
416  * an empty deadlist.
417  */
418 void
419 dsl_deadlist_merge(dsl_deadlist_t *dl, uint64_t obj, dmu_tx_t *tx)
420 {
421 	zap_cursor_t zc;
422 	zap_attribute_t za;
423 	dmu_buf_t *bonus;
424 	dsl_deadlist_phys_t *dlp;
425 	dmu_object_info_t doi;
426 
427 	VERIFY3U(0, ==, dmu_object_info(dl->dl_os, obj, &doi));
428 	if (doi.doi_type == DMU_OT_BPOBJ) {
429 		bpobj_t bpo;
430 		VERIFY3U(0, ==, bpobj_open(&bpo, dl->dl_os, obj));
431 		VERIFY3U(0, ==, bpobj_iterate(&bpo,
432 		    dsl_deadlist_insert_cb, dl, tx));
433 		bpobj_close(&bpo);
434 		return;
435 	}
436 
437 	for (zap_cursor_init(&zc, dl->dl_os, obj);
438 	    zap_cursor_retrieve(&zc, &za) == 0;
439 	    zap_cursor_advance(&zc)) {
440 		uint64_t mintxg = strtonum(za.za_name, NULL);
441 		dsl_deadlist_insert_bpobj(dl, za.za_first_integer, mintxg, tx);
442 		VERIFY3U(0, ==, zap_remove_int(dl->dl_os, obj, mintxg, tx));
443 	}
444 	zap_cursor_fini(&zc);
445 
446 	VERIFY3U(0, ==, dmu_bonus_hold(dl->dl_os, obj, FTAG, &bonus));
447 	dlp = bonus->db_data;
448 	dmu_buf_will_dirty(bonus, tx);
449 	bzero(dlp, sizeof (*dlp));
450 	dmu_buf_rele(bonus, FTAG);
451 }
452 
453 /*
454  * Remove entries on dl that are >= mintxg, and put them on the bpobj.
455  */
456 void
457 dsl_deadlist_move_bpobj(dsl_deadlist_t *dl, bpobj_t *bpo, uint64_t mintxg,
458     dmu_tx_t *tx)
459 {
460 	dsl_deadlist_entry_t dle_tofind;
461 	dsl_deadlist_entry_t *dle;
462 	avl_index_t where;
463 
464 	ASSERT(!dl->dl_oldfmt);
465 	dmu_buf_will_dirty(dl->dl_dbuf, tx);
466 	dsl_deadlist_load_tree(dl);
467 
468 	dle_tofind.dle_mintxg = mintxg;
469 	dle = avl_find(&dl->dl_tree, &dle_tofind, &where);
470 	if (dle == NULL)
471 		dle = avl_nearest(&dl->dl_tree, where, AVL_AFTER);
472 	while (dle) {
473 		uint64_t used, comp, uncomp;
474 		dsl_deadlist_entry_t *dle_next;
475 
476 		bpobj_enqueue_subobj(bpo, dle->dle_bpobj.bpo_object, tx);
477 
478 		VERIFY3U(0, ==, bpobj_space(&dle->dle_bpobj,
479 		    &used, &comp, &uncomp));
480 		mutex_enter(&dl->dl_lock);
481 		ASSERT3U(dl->dl_phys->dl_used, >=, used);
482 		ASSERT3U(dl->dl_phys->dl_comp, >=, comp);
483 		ASSERT3U(dl->dl_phys->dl_uncomp, >=, uncomp);
484 		dl->dl_phys->dl_used -= used;
485 		dl->dl_phys->dl_comp -= comp;
486 		dl->dl_phys->dl_uncomp -= uncomp;
487 		mutex_exit(&dl->dl_lock);
488 
489 		VERIFY3U(0, ==, zap_remove_int(dl->dl_os, dl->dl_object,
490 		    dle->dle_mintxg, tx));
491 
492 		dle_next = AVL_NEXT(&dl->dl_tree, dle);
493 		avl_remove(&dl->dl_tree, dle);
494 		bpobj_close(&dle->dle_bpobj);
495 		kmem_free(dle, sizeof (*dle));
496 		dle = dle_next;
497 	}
498 }
499