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) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
23 * Copyright (c) 2013, 2017 by Delphix. All rights reserved.
24 * Copyright 2014 HybridCluster. All rights reserved.
25 */
26
27 #include <sys/dbuf.h>
28 #include <sys/dmu.h>
29 #include <sys/dmu_objset.h>
30 #include <sys/dmu_tx.h>
31 #include <sys/dnode.h>
32 #include <sys/zap.h>
33 #include <sys/zfeature.h>
34 #include <sys/dsl_dataset.h>
35
36 /*
37 * Each of the concurrent object allocators will grab
38 * 2^dmu_object_alloc_chunk_shift dnode slots at a time. The default is to
39 * grab 128 slots, which is 4 blocks worth. This was experimentally
40 * determined to be the lowest value that eliminates the measurable effect
41 * of lock contention from this code path.
42 */
43 int dmu_object_alloc_chunk_shift = 7;
44
45 static uint64_t
dmu_object_alloc_impl(objset_t * os,dmu_object_type_t ot,int blocksize,int indirect_blockshift,dmu_object_type_t bonustype,int bonuslen,int dnodesize,dmu_tx_t * tx)46 dmu_object_alloc_impl(objset_t *os, dmu_object_type_t ot, int blocksize,
47 int indirect_blockshift, dmu_object_type_t bonustype, int bonuslen,
48 int dnodesize, dmu_tx_t *tx)
49 {
50 uint64_t object;
51 uint64_t L1_dnode_count = DNODES_PER_BLOCK <<
52 (DMU_META_DNODE(os)->dn_indblkshift - SPA_BLKPTRSHIFT);
53 dnode_t *dn = NULL;
54 int dn_slots = dnodesize >> DNODE_SHIFT;
55 boolean_t restarted = B_FALSE;
56 uint64_t *cpuobj = &os->os_obj_next_percpu[CPU_SEQID %
57 os->os_obj_next_percpu_len];
58 int dnodes_per_chunk = 1 << dmu_object_alloc_chunk_shift;
59 int error;
60
61 if (dn_slots == 0) {
62 dn_slots = DNODE_MIN_SLOTS;
63 } else {
64 ASSERT3S(dn_slots, >=, DNODE_MIN_SLOTS);
65 ASSERT3S(dn_slots, <=, DNODE_MAX_SLOTS);
66 }
67
68 /*
69 * The "chunk" of dnodes that is assigned to a CPU-specific
70 * allocator needs to be at least one block's worth, to avoid
71 * lock contention on the dbuf. It can be at most one L1 block's
72 * worth, so that the "rescan after polishing off a L1's worth"
73 * logic below will be sure to kick in.
74 */
75 if (dnodes_per_chunk < DNODES_PER_BLOCK)
76 dnodes_per_chunk = DNODES_PER_BLOCK;
77 if (dnodes_per_chunk > L1_dnode_count)
78 dnodes_per_chunk = L1_dnode_count;
79
80 object = *cpuobj;
81
82 for (;;) {
83 /*
84 * If we finished a chunk of dnodes, get a new one from
85 * the global allocator.
86 */
87 if ((P2PHASE(object, dnodes_per_chunk) == 0) ||
88 (P2PHASE(object + dn_slots - 1, dnodes_per_chunk) <
89 dn_slots)) {
90 DNODE_STAT_BUMP(dnode_alloc_next_chunk);
91 mutex_enter(&os->os_obj_lock);
92 ASSERT0(P2PHASE(os->os_obj_next_chunk,
93 dnodes_per_chunk));
94 object = os->os_obj_next_chunk;
95
96 /*
97 * Each time we polish off a L1 bp worth of dnodes
98 * (2^12 objects), move to another L1 bp that's
99 * still reasonably sparse (at most 1/4 full). Look
100 * from the beginning at most once per txg. If we
101 * still can't allocate from that L1 block, search
102 * for an empty L0 block, which will quickly skip
103 * to the end of the metadnode if the no nearby L0
104 * blocks are empty. This fallback avoids a
105 * pathology where full dnode blocks containing
106 * large dnodes appear sparse because they have a
107 * low blk_fill, leading to many failed allocation
108 * attempts. In the long term a better mechanism to
109 * search for sparse metadnode regions, such as
110 * spacemaps, could be implemented.
111 *
112 * os_scan_dnodes is set during txg sync if enough
113 * objects have been freed since the previous
114 * rescan to justify backfilling again.
115 *
116 * Note that dmu_traverse depends on the behavior
117 * that we use multiple blocks of the dnode object
118 * before going back to reuse objects. Any change
119 * to this algorithm should preserve that property
120 * or find another solution to the issues described
121 * in traverse_visitbp.
122 */
123 if (P2PHASE(object, L1_dnode_count) == 0) {
124 uint64_t offset;
125 uint64_t blkfill;
126 int minlvl;
127 if (os->os_rescan_dnodes) {
128 offset = 0;
129 os->os_rescan_dnodes = B_FALSE;
130 } else {
131 offset = object << DNODE_SHIFT;
132 }
133 blkfill = restarted ? 1 : DNODES_PER_BLOCK >> 2;
134 minlvl = restarted ? 1 : 2;
135 restarted = B_TRUE;
136 error = dnode_next_offset(DMU_META_DNODE(os),
137 DNODE_FIND_HOLE, &offset, minlvl,
138 blkfill, 0);
139 if (error == 0) {
140 object = offset >> DNODE_SHIFT;
141 }
142 }
143 /*
144 * Note: if "restarted", we may find a L0 that
145 * is not suitably aligned.
146 */
147 os->os_obj_next_chunk =
148 P2ALIGN(object, dnodes_per_chunk) +
149 dnodes_per_chunk;
150 (void) atomic_swap_64(cpuobj, object);
151 mutex_exit(&os->os_obj_lock);
152 }
153
154 /*
155 * The value of (*cpuobj) before adding dn_slots is the object
156 * ID assigned to us. The value afterwards is the object ID
157 * assigned to whoever wants to do an allocation next.
158 */
159 object = atomic_add_64_nv(cpuobj, dn_slots) - dn_slots;
160
161 /*
162 * XXX We should check for an i/o error here and return
163 * up to our caller. Actually we should pre-read it in
164 * dmu_tx_assign(), but there is currently no mechanism
165 * to do so.
166 */
167 error = dnode_hold_impl(os, object, DNODE_MUST_BE_FREE,
168 dn_slots, FTAG, &dn);
169 if (error == 0) {
170 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
171 /*
172 * Another thread could have allocated it; check
173 * again now that we have the struct lock.
174 */
175 if (dn->dn_type == DMU_OT_NONE) {
176 dnode_allocate(dn, ot, blocksize, 0,
177 bonustype, bonuslen, dn_slots, tx);
178 rw_exit(&dn->dn_struct_rwlock);
179 dmu_tx_add_new_object(tx, dn);
180 dnode_rele(dn, FTAG);
181 return (object);
182 }
183 rw_exit(&dn->dn_struct_rwlock);
184 dnode_rele(dn, FTAG);
185 DNODE_STAT_BUMP(dnode_alloc_race);
186 }
187
188 /*
189 * Skip to next known valid starting point on error. This
190 * is the start of the next block of dnodes.
191 */
192 if (dmu_object_next(os, &object, B_TRUE, 0) != 0) {
193 object = P2ROUNDUP(object + 1, DNODES_PER_BLOCK);
194 DNODE_STAT_BUMP(dnode_alloc_next_block);
195 }
196 (void) atomic_swap_64(cpuobj, object);
197 }
198 }
199
200 uint64_t
dmu_object_alloc(objset_t * os,dmu_object_type_t ot,int blocksize,dmu_object_type_t bonustype,int bonuslen,dmu_tx_t * tx)201 dmu_object_alloc(objset_t *os, dmu_object_type_t ot, int blocksize,
202 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx)
203 {
204 return (dmu_object_alloc_impl(os, ot, blocksize, 0, bonustype,
205 bonuslen, 0, tx));
206 }
207
208 uint64_t
dmu_object_alloc_ibs(objset_t * os,dmu_object_type_t ot,int blocksize,int indirect_blockshift,dmu_object_type_t bonustype,int bonuslen,dmu_tx_t * tx)209 dmu_object_alloc_ibs(objset_t *os, dmu_object_type_t ot, int blocksize,
210 int indirect_blockshift, dmu_object_type_t bonustype, int bonuslen,
211 dmu_tx_t *tx)
212 {
213 return (dmu_object_alloc_impl(os, ot, blocksize, indirect_blockshift,
214 bonustype, bonuslen, 0, tx));
215 }
216
217 uint64_t
dmu_object_alloc_dnsize(objset_t * os,dmu_object_type_t ot,int blocksize,dmu_object_type_t bonustype,int bonuslen,int dnodesize,dmu_tx_t * tx)218 dmu_object_alloc_dnsize(objset_t *os, dmu_object_type_t ot, int blocksize,
219 dmu_object_type_t bonustype, int bonuslen, int dnodesize, dmu_tx_t *tx)
220 {
221 return (dmu_object_alloc_impl(os, ot, blocksize, 0, bonustype,
222 bonuslen, dnodesize, tx));
223 }
224
225 int
dmu_object_claim(objset_t * os,uint64_t object,dmu_object_type_t ot,int blocksize,dmu_object_type_t bonustype,int bonuslen,dmu_tx_t * tx)226 dmu_object_claim(objset_t *os, uint64_t object, dmu_object_type_t ot,
227 int blocksize, dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx)
228 {
229 return (dmu_object_claim_dnsize(os, object, ot, blocksize, bonustype,
230 bonuslen, 0, tx));
231 }
232
233 int
dmu_object_claim_dnsize(objset_t * os,uint64_t object,dmu_object_type_t ot,int blocksize,dmu_object_type_t bonustype,int bonuslen,int dnodesize,dmu_tx_t * tx)234 dmu_object_claim_dnsize(objset_t *os, uint64_t object, dmu_object_type_t ot,
235 int blocksize, dmu_object_type_t bonustype, int bonuslen,
236 int dnodesize, dmu_tx_t *tx)
237 {
238 dnode_t *dn;
239 int dn_slots = dnodesize >> DNODE_SHIFT;
240 int err;
241
242 if (dn_slots == 0)
243 dn_slots = DNODE_MIN_SLOTS;
244 ASSERT3S(dn_slots, >=, DNODE_MIN_SLOTS);
245 ASSERT3S(dn_slots, <=, DNODE_MAX_SLOTS);
246
247 if (object == DMU_META_DNODE_OBJECT && !dmu_tx_private_ok(tx))
248 return (SET_ERROR(EBADF));
249
250 err = dnode_hold_impl(os, object, DNODE_MUST_BE_FREE, dn_slots,
251 FTAG, &dn);
252 if (err)
253 return (err);
254 dnode_allocate(dn, ot, blocksize, 0, bonustype, bonuslen, dn_slots, tx);
255 dmu_tx_add_new_object(tx, dn);
256
257 dnode_rele(dn, FTAG);
258
259 return (0);
260 }
261
262 int
dmu_object_reclaim(objset_t * os,uint64_t object,dmu_object_type_t ot,int blocksize,dmu_object_type_t bonustype,int bonuslen,dmu_tx_t * tx)263 dmu_object_reclaim(objset_t *os, uint64_t object, dmu_object_type_t ot,
264 int blocksize, dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx)
265 {
266 return (dmu_object_reclaim_dnsize(os, object, ot, blocksize, bonustype,
267 bonuslen, DNODE_MIN_SIZE, B_FALSE, tx));
268 }
269
270 int
dmu_object_reclaim_dnsize(objset_t * os,uint64_t object,dmu_object_type_t ot,int blocksize,dmu_object_type_t bonustype,int bonuslen,int dnodesize,boolean_t keep_spill,dmu_tx_t * tx)271 dmu_object_reclaim_dnsize(objset_t *os, uint64_t object, dmu_object_type_t ot,
272 int blocksize, dmu_object_type_t bonustype, int bonuslen, int dnodesize,
273 boolean_t keep_spill, dmu_tx_t *tx)
274 {
275 dnode_t *dn;
276 int dn_slots = dnodesize >> DNODE_SHIFT;
277 int err;
278
279 if (dn_slots == 0)
280 dn_slots = DNODE_MIN_SLOTS;
281
282 if (object == DMU_META_DNODE_OBJECT)
283 return (SET_ERROR(EBADF));
284
285 err = dnode_hold_impl(os, object, DNODE_MUST_BE_ALLOCATED, 0,
286 FTAG, &dn);
287 if (err)
288 return (err);
289
290 dnode_reallocate(dn, ot, blocksize, bonustype, bonuslen, dn_slots,
291 keep_spill, tx);
292
293 dnode_rele(dn, FTAG);
294 return (err);
295 }
296
297 int
dmu_object_rm_spill(objset_t * os,uint64_t object,dmu_tx_t * tx)298 dmu_object_rm_spill(objset_t *os, uint64_t object, dmu_tx_t *tx)
299 {
300 dnode_t *dn;
301 int err;
302
303 err = dnode_hold_impl(os, object, DNODE_MUST_BE_ALLOCATED, 0,
304 FTAG, &dn);
305 if (err)
306 return (err);
307
308 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
309 if (dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR) {
310 dbuf_rm_spill(dn, tx);
311 dnode_rm_spill(dn, tx);
312 }
313 rw_exit(&dn->dn_struct_rwlock);
314
315 dnode_rele(dn, FTAG);
316 return (err);
317 }
318
319 int
dmu_object_free(objset_t * os,uint64_t object,dmu_tx_t * tx)320 dmu_object_free(objset_t *os, uint64_t object, dmu_tx_t *tx)
321 {
322 dnode_t *dn;
323 int err;
324
325 ASSERT(object != DMU_META_DNODE_OBJECT || dmu_tx_private_ok(tx));
326
327 err = dnode_hold_impl(os, object, DNODE_MUST_BE_ALLOCATED, 0,
328 FTAG, &dn);
329 if (err)
330 return (err);
331
332 ASSERT(dn->dn_type != DMU_OT_NONE);
333 /*
334 * If we don't create this free range, we'll leak indirect blocks when
335 * we get to freeing the dnode in syncing context.
336 */
337 dnode_free_range(dn, 0, DMU_OBJECT_END, tx);
338 dnode_free(dn, tx);
339 dnode_rele(dn, FTAG);
340
341 return (0);
342 }
343
344 /*
345 * Return (in *objectp) the next object which is allocated (or a hole)
346 * after *object, taking into account only objects that may have been modified
347 * after the specified txg.
348 */
349 int
dmu_object_next(objset_t * os,uint64_t * objectp,boolean_t hole,uint64_t txg)350 dmu_object_next(objset_t *os, uint64_t *objectp, boolean_t hole, uint64_t txg)
351 {
352 uint64_t offset;
353 uint64_t start_obj;
354 struct dsl_dataset *ds = os->os_dsl_dataset;
355 int error;
356
357 if (*objectp == 0) {
358 start_obj = 1;
359 } else if (ds && ds->ds_feature_inuse[SPA_FEATURE_LARGE_DNODE]) {
360 uint64_t i = *objectp + 1;
361 uint64_t last_obj = *objectp | (DNODES_PER_BLOCK - 1);
362 dmu_object_info_t doi;
363
364 /*
365 * Scan through the remaining meta dnode block. The contents
366 * of each slot in the block are known so it can be quickly
367 * checked. If the block is exhausted without a match then
368 * hand off to dnode_next_offset() for further scanning.
369 */
370 while (i <= last_obj) {
371 error = dmu_object_info(os, i, &doi);
372 if (error == ENOENT) {
373 if (hole) {
374 *objectp = i;
375 return (0);
376 } else {
377 i++;
378 }
379 } else if (error == EEXIST) {
380 i++;
381 } else if (error == 0) {
382 if (hole) {
383 i += doi.doi_dnodesize >> DNODE_SHIFT;
384 } else {
385 *objectp = i;
386 return (0);
387 }
388 } else {
389 return (error);
390 }
391 }
392
393 start_obj = i;
394 } else {
395 start_obj = *objectp + 1;
396 }
397
398 offset = start_obj << DNODE_SHIFT;
399
400 error = dnode_next_offset(DMU_META_DNODE(os),
401 (hole ? DNODE_FIND_HOLE : 0), &offset, 0, DNODES_PER_BLOCK, txg);
402
403 *objectp = offset >> DNODE_SHIFT;
404
405 return (error);
406 }
407
408 /*
409 * Turn this object from old_type into DMU_OTN_ZAP_METADATA, and bump the
410 * refcount on SPA_FEATURE_EXTENSIBLE_DATASET.
411 *
412 * Only for use from syncing context, on MOS objects.
413 */
414 void
dmu_object_zapify(objset_t * mos,uint64_t object,dmu_object_type_t old_type,dmu_tx_t * tx)415 dmu_object_zapify(objset_t *mos, uint64_t object, dmu_object_type_t old_type,
416 dmu_tx_t *tx)
417 {
418 dnode_t *dn;
419
420 ASSERT(dmu_tx_is_syncing(tx));
421
422 VERIFY0(dnode_hold(mos, object, FTAG, &dn));
423 if (dn->dn_type == DMU_OTN_ZAP_METADATA) {
424 dnode_rele(dn, FTAG);
425 return;
426 }
427 ASSERT3U(dn->dn_type, ==, old_type);
428 ASSERT0(dn->dn_maxblkid);
429
430 /*
431 * We must initialize the ZAP data before changing the type,
432 * so that concurrent calls to *_is_zapified() can determine if
433 * the object has been completely zapified by checking the type.
434 */
435 mzap_create_impl(mos, object, 0, 0, tx);
436
437 dn->dn_next_type[tx->tx_txg & TXG_MASK] = dn->dn_type =
438 DMU_OTN_ZAP_METADATA;
439 dnode_setdirty(dn, tx);
440 dnode_rele(dn, FTAG);
441
442 spa_feature_incr(dmu_objset_spa(mos),
443 SPA_FEATURE_EXTENSIBLE_DATASET, tx);
444 }
445
446 void
dmu_object_free_zapified(objset_t * mos,uint64_t object,dmu_tx_t * tx)447 dmu_object_free_zapified(objset_t *mos, uint64_t object, dmu_tx_t *tx)
448 {
449 dnode_t *dn;
450 dmu_object_type_t t;
451
452 ASSERT(dmu_tx_is_syncing(tx));
453
454 VERIFY0(dnode_hold(mos, object, FTAG, &dn));
455 t = dn->dn_type;
456 dnode_rele(dn, FTAG);
457
458 if (t == DMU_OTN_ZAP_METADATA) {
459 spa_feature_decr(dmu_objset_spa(mos),
460 SPA_FEATURE_EXTENSIBLE_DATASET, tx);
461 }
462 VERIFY0(dmu_object_free(mos, object, tx));
463 }
464