1 // SPDX-License-Identifier: CDDL-1.0
2 /*
3 * CDDL HEADER START
4 *
5 * The contents of this file are subject to the terms of the
6 * Common Development and Distribution License (the "License").
7 * You may not use this file except in compliance with the License.
8 *
9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10 * or https://opensource.org/licenses/CDDL-1.0.
11 * See the License for the specific language governing permissions
12 * and limitations under the License.
13 *
14 * When distributing Covered Code, include this CDDL HEADER in each
15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16 * If applicable, add the following below this CDDL HEADER, with the
17 * fields enclosed by brackets "[]" replaced with your own identifying
18 * information: Portions Copyright [yyyy] [name of copyright owner]
19 *
20 * CDDL HEADER END
21 */
22 /*
23 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
24 * Copyright (c) 2012, 2018 by Delphix. All rights reserved.
25 */
26
27 #include <sys/zfs_context.h>
28 #include <sys/dmu_objset.h>
29 #include <sys/dmu_traverse.h>
30 #include <sys/dsl_dataset.h>
31 #include <sys/dsl_dir.h>
32 #include <sys/dsl_pool.h>
33 #include <sys/dnode.h>
34 #include <sys/spa.h>
35 #include <sys/spa_impl.h>
36 #include <sys/zio.h>
37 #include <sys/dmu_impl.h>
38 #include <sys/sa.h>
39 #include <sys/sa_impl.h>
40 #include <sys/callb.h>
41 #include <sys/zfeature.h>
42
43 static int32_t zfs_pd_bytes_max = 50 * 1024 * 1024; /* 50MB */
44 static int32_t send_holes_without_birth_time = 1;
45 static uint_t zfs_traverse_indirect_prefetch_limit = 32;
46
47 typedef struct prefetch_data {
48 kmutex_t pd_mtx;
49 kcondvar_t pd_cv;
50 int32_t pd_bytes_fetched;
51 int pd_flags;
52 boolean_t pd_cancel;
53 boolean_t pd_exited;
54 zbookmark_phys_t pd_resume;
55 } prefetch_data_t;
56
57 typedef struct traverse_data {
58 spa_t *td_spa;
59 uint64_t td_objset;
60 blkptr_t *td_rootbp;
61 uint64_t td_min_txg;
62 zbookmark_phys_t *td_resume;
63 int td_flags;
64 prefetch_data_t *td_pfd;
65 boolean_t td_paused;
66 uint64_t td_hole_birth_enabled_txg;
67 blkptr_cb_t *td_func;
68 void *td_arg;
69 boolean_t td_realloc_possible;
70 } traverse_data_t;
71
72 static int traverse_dnode(traverse_data_t *td, const blkptr_t *bp,
73 const dnode_phys_t *dnp, uint64_t objset, uint64_t object);
74 static void prefetch_dnode_metadata(traverse_data_t *td, const dnode_phys_t *,
75 uint64_t objset, uint64_t object);
76
77 static inline uint64_t
get_birth_time(traverse_data_t * td,const blkptr_t * bp)78 get_birth_time(traverse_data_t *td, const blkptr_t *bp)
79 {
80 if (td->td_flags & TRAVERSE_LOGICAL)
81 return (BP_GET_LOGICAL_BIRTH(bp));
82 else
83 return (BP_GET_BIRTH(bp));
84 }
85
86 static int
traverse_zil_block(zilog_t * zilog,const blkptr_t * bp,void * arg,uint64_t claim_txg)87 traverse_zil_block(zilog_t *zilog, const blkptr_t *bp, void *arg,
88 uint64_t claim_txg)
89 {
90 traverse_data_t *td = arg;
91 zbookmark_phys_t zb;
92
93 if (BP_IS_HOLE(bp))
94 return (0);
95
96 if (claim_txg == 0 &&
97 get_birth_time(td, bp) >= spa_min_claim_txg(td->td_spa))
98 return (-1);
99
100 SET_BOOKMARK(&zb, td->td_objset, ZB_ZIL_OBJECT, ZB_ZIL_LEVEL,
101 bp->blk_cksum.zc_word[ZIL_ZC_SEQ]);
102
103 (void) td->td_func(td->td_spa, zilog, bp, &zb, NULL, td->td_arg);
104
105 return (0);
106 }
107
108 static int
traverse_zil_record(zilog_t * zilog,const lr_t * lrc,void * arg,uint64_t claim_txg)109 traverse_zil_record(zilog_t *zilog, const lr_t *lrc, void *arg,
110 uint64_t claim_txg)
111 {
112 traverse_data_t *td = arg;
113
114 if (lrc->lrc_txtype == TX_WRITE) {
115 lr_write_t *lr = (lr_write_t *)lrc;
116 blkptr_t *bp = &lr->lr_blkptr;
117 zbookmark_phys_t zb;
118
119 if (BP_IS_HOLE(bp))
120 return (0);
121
122 if (claim_txg == 0 || get_birth_time(td, bp) < claim_txg)
123 return (0);
124
125 ASSERT3U(BP_GET_LSIZE(bp), !=, 0);
126 SET_BOOKMARK(&zb, td->td_objset, lr->lr_foid,
127 ZB_ZIL_LEVEL, lr->lr_offset / BP_GET_LSIZE(bp));
128
129 (void) td->td_func(td->td_spa, zilog, bp, &zb, NULL,
130 td->td_arg);
131 }
132 return (0);
133 }
134
135 static void
traverse_zil(traverse_data_t * td,zil_header_t * zh)136 traverse_zil(traverse_data_t *td, zil_header_t *zh)
137 {
138 uint64_t claim_txg = zh->zh_claim_txg;
139
140 /*
141 * We only want to visit blocks that have been claimed but not yet
142 * replayed; plus blocks that are already stable in read-only mode.
143 */
144 if (claim_txg == 0 && spa_writeable(td->td_spa))
145 return;
146
147 zilog_t *zilog = zil_alloc(spa_get_dsl(td->td_spa)->dp_meta_objset, zh);
148 (void) zil_parse(zilog, traverse_zil_block, traverse_zil_record, td,
149 claim_txg, !(td->td_flags & TRAVERSE_NO_DECRYPT));
150 zil_free(zilog);
151 }
152
153 typedef enum resume_skip {
154 RESUME_SKIP_ALL,
155 RESUME_SKIP_NONE,
156 RESUME_SKIP_CHILDREN
157 } resume_skip_t;
158
159 /*
160 * Returns RESUME_SKIP_ALL if td indicates that we are resuming a traversal and
161 * the block indicated by zb does not need to be visited at all. Returns
162 * RESUME_SKIP_CHILDREN if we are resuming a post traversal and we reach the
163 * resume point. This indicates that this block should be visited but not its
164 * children (since they must have been visited in a previous traversal).
165 * Otherwise returns RESUME_SKIP_NONE.
166 */
167 static resume_skip_t
resume_skip_check(const traverse_data_t * td,const dnode_phys_t * dnp,const zbookmark_phys_t * zb)168 resume_skip_check(const traverse_data_t *td, const dnode_phys_t *dnp,
169 const zbookmark_phys_t *zb)
170 {
171 if (td->td_resume != NULL) {
172 /*
173 * If we already visited this bp & everything below,
174 * don't bother doing it again.
175 */
176 if (zbookmark_subtree_completed(dnp, zb, td->td_resume))
177 return (RESUME_SKIP_ALL);
178
179 if (memcmp(zb, td->td_resume, sizeof (*zb)) == 0) {
180 if (td->td_flags & TRAVERSE_POST)
181 return (RESUME_SKIP_CHILDREN);
182 }
183 }
184 return (RESUME_SKIP_NONE);
185 }
186
187 /*
188 * Returns B_TRUE, if prefetch read is issued, otherwise B_FALSE.
189 */
190 static boolean_t
traverse_prefetch_metadata(traverse_data_t * td,const dnode_phys_t * dnp,const blkptr_t * bp,const zbookmark_phys_t * zb)191 traverse_prefetch_metadata(traverse_data_t *td, const dnode_phys_t *dnp,
192 const blkptr_t *bp, const zbookmark_phys_t *zb)
193 {
194 arc_flags_t flags = ARC_FLAG_NOWAIT | ARC_FLAG_PREFETCH |
195 ARC_FLAG_PRESCIENT_PREFETCH;
196 int zio_flags = ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE;
197
198 if (!(td->td_flags & TRAVERSE_PREFETCH_METADATA))
199 return (B_FALSE);
200 /*
201 * If this bp is before the resume point, it may have already been
202 * freed.
203 */
204 if (resume_skip_check(td, dnp, zb) != RESUME_SKIP_NONE)
205 return (B_FALSE);
206 if (BP_IS_HOLE(bp) || get_birth_time(td, bp) <= td->td_min_txg)
207 return (B_FALSE);
208 if (BP_GET_LEVEL(bp) == 0 && BP_GET_TYPE(bp) != DMU_OT_DNODE)
209 return (B_FALSE);
210 ASSERT(!BP_IS_REDACTED(bp));
211
212 if ((td->td_flags & TRAVERSE_NO_DECRYPT) && BP_IS_PROTECTED(bp))
213 zio_flags |= ZIO_FLAG_RAW;
214
215 (void) arc_read(NULL, td->td_spa, bp, NULL, NULL,
216 ZIO_PRIORITY_ASYNC_READ, zio_flags, &flags, zb);
217 return (B_TRUE);
218 }
219
220 static boolean_t
prefetch_needed(prefetch_data_t * pfd,const blkptr_t * bp)221 prefetch_needed(prefetch_data_t *pfd, const blkptr_t *bp)
222 {
223 ASSERT(pfd->pd_flags & TRAVERSE_PREFETCH_DATA);
224 if (BP_IS_HOLE(bp) || BP_IS_EMBEDDED(bp) ||
225 BP_GET_TYPE(bp) == DMU_OT_INTENT_LOG || BP_IS_REDACTED(bp))
226 return (B_FALSE);
227 return (B_TRUE);
228 }
229
230 static int
traverse_visitbp(traverse_data_t * td,const dnode_phys_t * dnp,const blkptr_t * bp,const zbookmark_phys_t * zb)231 traverse_visitbp(traverse_data_t *td, const dnode_phys_t *dnp,
232 const blkptr_t *bp, const zbookmark_phys_t *zb)
233 {
234 int err = 0;
235 arc_buf_t *buf = NULL;
236 prefetch_data_t *pd = td->td_pfd;
237
238 switch (resume_skip_check(td, dnp, zb)) {
239 case RESUME_SKIP_ALL:
240 return (0);
241 case RESUME_SKIP_CHILDREN:
242 goto post;
243 case RESUME_SKIP_NONE:
244 break;
245 default:
246 ASSERT(0);
247 }
248
249 if (BP_GET_LOGICAL_BIRTH(bp) == 0) {
250 /*
251 * Since this block has a birth time of 0 it must be one of
252 * two things: a hole created before the
253 * SPA_FEATURE_HOLE_BIRTH feature was enabled, or a hole
254 * which has always been a hole in an object.
255 *
256 * If a file is written sparsely, then the unwritten parts of
257 * the file were "always holes" -- that is, they have been
258 * holes since this object was allocated. However, we (and
259 * our callers) can not necessarily tell when an object was
260 * allocated. Therefore, if it's possible that this object
261 * was freed and then its object number reused, we need to
262 * visit all the holes with birth==0.
263 *
264 * If it isn't possible that the object number was reused,
265 * then if SPA_FEATURE_HOLE_BIRTH was enabled before we wrote
266 * all the blocks we will visit as part of this traversal,
267 * then this hole must have always existed, so we can skip
268 * it. We visit blocks born after (exclusive) td_min_txg.
269 *
270 * Note that the meta-dnode cannot be reallocated.
271 */
272 if (!send_holes_without_birth_time &&
273 (!td->td_realloc_possible ||
274 zb->zb_object == DMU_META_DNODE_OBJECT) &&
275 td->td_hole_birth_enabled_txg <= td->td_min_txg)
276 return (0);
277 } else if (get_birth_time(td, bp) <= td->td_min_txg) {
278 return (0);
279 }
280
281 if (pd != NULL && !pd->pd_exited && prefetch_needed(pd, bp)) {
282 uint64_t size = BP_GET_LSIZE(bp);
283 mutex_enter(&pd->pd_mtx);
284 ASSERT(pd->pd_bytes_fetched >= 0);
285 while (pd->pd_bytes_fetched < size && !pd->pd_exited)
286 cv_wait_sig(&pd->pd_cv, &pd->pd_mtx);
287 pd->pd_bytes_fetched -= size;
288 cv_broadcast(&pd->pd_cv);
289 mutex_exit(&pd->pd_mtx);
290 }
291
292 if (BP_IS_HOLE(bp) || BP_IS_REDACTED(bp)) {
293 err = td->td_func(td->td_spa, NULL, bp, zb, dnp, td->td_arg);
294 if (err != 0)
295 goto post;
296 return (0);
297 }
298
299 if (td->td_flags & TRAVERSE_PRE) {
300 err = td->td_func(td->td_spa, NULL, bp, zb, dnp,
301 td->td_arg);
302 if (err == TRAVERSE_VISIT_NO_CHILDREN)
303 return (0);
304 if (err != 0)
305 goto post;
306 }
307
308 if (BP_GET_LEVEL(bp) > 0) {
309 arc_flags_t flags = ARC_FLAG_WAIT;
310 int32_t i, ptidx, pidx;
311 uint32_t prefetchlimit;
312 int32_t epb = BP_GET_LSIZE(bp) >> SPA_BLKPTRSHIFT;
313 zbookmark_phys_t *czb;
314
315 ASSERT(!BP_IS_PROTECTED(bp));
316
317 err = arc_read(NULL, td->td_spa, bp, arc_getbuf_func, &buf,
318 ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL, &flags, zb);
319 if (err != 0)
320 goto post;
321
322 czb = kmem_alloc(sizeof (zbookmark_phys_t), KM_SLEEP);
323
324 /*
325 * When performing a traversal it is beneficial to
326 * asynchronously read-ahead the upcoming indirect
327 * blocks since they will be needed shortly. However,
328 * since a 128k indirect (non-L0) block may contain up
329 * to 1024 128-byte block pointers, its preferable to not
330 * prefetch them all at once. Issuing a large number of
331 * async reads may effect performance, and the earlier
332 * the indirect blocks are prefetched the less likely
333 * they are to still be resident in the ARC when needed.
334 * Therefore, prefetching indirect blocks is limited to
335 * zfs_traverse_indirect_prefetch_limit=32 blocks by
336 * default.
337 *
338 * pidx: Index for which next prefetch to be issued.
339 * ptidx: Index at which next prefetch to be triggered.
340 */
341 ptidx = 0;
342 pidx = 1;
343 prefetchlimit = zfs_traverse_indirect_prefetch_limit;
344 for (i = 0; i < epb; i++) {
345 if (prefetchlimit && i == ptidx) {
346 ASSERT3S(ptidx, <=, pidx);
347 for (uint32_t prefetched = 0; pidx < epb &&
348 prefetched < prefetchlimit; pidx++) {
349 SET_BOOKMARK(czb, zb->zb_objset,
350 zb->zb_object, zb->zb_level - 1,
351 zb->zb_blkid * epb + pidx);
352 if (traverse_prefetch_metadata(td, dnp,
353 &((blkptr_t *)buf->b_data)[pidx],
354 czb) == B_TRUE) {
355 prefetched++;
356 if (prefetched ==
357 MAX(prefetchlimit / 2, 1))
358 ptidx = pidx;
359 }
360 }
361 }
362
363 /* recursively visitbp() blocks below this */
364 SET_BOOKMARK(czb, zb->zb_objset, zb->zb_object,
365 zb->zb_level - 1,
366 zb->zb_blkid * epb + i);
367 err = traverse_visitbp(td, dnp,
368 &((blkptr_t *)buf->b_data)[i], czb);
369 if (err != 0)
370 break;
371 }
372
373 kmem_free(czb, sizeof (zbookmark_phys_t));
374
375 } else if (BP_GET_TYPE(bp) == DMU_OT_DNODE) {
376 arc_flags_t flags = ARC_FLAG_WAIT;
377 zio_flag_t zio_flags = ZIO_FLAG_CANFAIL;
378 int32_t i;
379 int32_t epb = BP_GET_LSIZE(bp) >> DNODE_SHIFT;
380 dnode_phys_t *child_dnp;
381
382 /*
383 * dnode blocks might have their bonus buffers encrypted, so
384 * we must be careful to honor TRAVERSE_NO_DECRYPT
385 */
386 if ((td->td_flags & TRAVERSE_NO_DECRYPT) && BP_IS_PROTECTED(bp))
387 zio_flags |= ZIO_FLAG_RAW;
388
389 err = arc_read(NULL, td->td_spa, bp, arc_getbuf_func, &buf,
390 ZIO_PRIORITY_ASYNC_READ, zio_flags, &flags, zb);
391 if (err != 0)
392 goto post;
393
394 child_dnp = buf->b_data;
395
396 for (i = 0; i < epb; i += child_dnp[i].dn_extra_slots + 1) {
397 prefetch_dnode_metadata(td, &child_dnp[i],
398 zb->zb_objset, zb->zb_blkid * epb + i);
399 }
400
401 /* recursively visitbp() blocks below this */
402 for (i = 0; i < epb; i += child_dnp[i].dn_extra_slots + 1) {
403 err = traverse_dnode(td, bp, &child_dnp[i],
404 zb->zb_objset, zb->zb_blkid * epb + i);
405 if (err != 0)
406 break;
407 }
408 } else if (BP_GET_TYPE(bp) == DMU_OT_OBJSET) {
409 zio_flag_t zio_flags = ZIO_FLAG_CANFAIL;
410 arc_flags_t flags = ARC_FLAG_WAIT;
411 objset_phys_t *osp;
412
413 if ((td->td_flags & TRAVERSE_NO_DECRYPT) && BP_IS_PROTECTED(bp))
414 zio_flags |= ZIO_FLAG_RAW;
415
416 err = arc_read(NULL, td->td_spa, bp, arc_getbuf_func, &buf,
417 ZIO_PRIORITY_ASYNC_READ, zio_flags, &flags, zb);
418 if (err != 0)
419 goto post;
420
421 osp = buf->b_data;
422 prefetch_dnode_metadata(td, &osp->os_meta_dnode, zb->zb_objset,
423 DMU_META_DNODE_OBJECT);
424 /*
425 * See the block comment above for the goal of this variable.
426 * If the maxblkid of the meta-dnode is 0, then we know that
427 * we've never had more than DNODES_PER_BLOCK objects in the
428 * dataset, which means we can't have reused any object ids.
429 */
430 if (osp->os_meta_dnode.dn_maxblkid == 0)
431 td->td_realloc_possible = B_FALSE;
432
433 if (OBJSET_BUF_HAS_USERUSED(buf)) {
434 if (OBJSET_BUF_HAS_PROJECTUSED(buf))
435 prefetch_dnode_metadata(td,
436 &osp->os_projectused_dnode,
437 zb->zb_objset, DMU_PROJECTUSED_OBJECT);
438 prefetch_dnode_metadata(td, &osp->os_groupused_dnode,
439 zb->zb_objset, DMU_GROUPUSED_OBJECT);
440 prefetch_dnode_metadata(td, &osp->os_userused_dnode,
441 zb->zb_objset, DMU_USERUSED_OBJECT);
442 }
443
444 err = traverse_dnode(td, bp, &osp->os_meta_dnode, zb->zb_objset,
445 DMU_META_DNODE_OBJECT);
446 if (err == 0 && OBJSET_BUF_HAS_USERUSED(buf)) {
447 if (OBJSET_BUF_HAS_PROJECTUSED(buf))
448 err = traverse_dnode(td, bp,
449 &osp->os_projectused_dnode, zb->zb_objset,
450 DMU_PROJECTUSED_OBJECT);
451 if (err == 0)
452 err = traverse_dnode(td, bp,
453 &osp->os_groupused_dnode, zb->zb_objset,
454 DMU_GROUPUSED_OBJECT);
455 if (err == 0)
456 err = traverse_dnode(td, bp,
457 &osp->os_userused_dnode, zb->zb_objset,
458 DMU_USERUSED_OBJECT);
459 }
460 }
461
462 if (buf)
463 arc_buf_destroy(buf, &buf);
464
465 post:
466 if (err == 0 && (td->td_flags & TRAVERSE_POST))
467 err = td->td_func(td->td_spa, NULL, bp, zb, dnp, td->td_arg);
468
469 if ((td->td_flags & TRAVERSE_HARD) && (err == EIO || err == ECKSUM)) {
470 /*
471 * Ignore this disk error as requested by the HARD flag,
472 * and continue traversal.
473 */
474 err = 0;
475 }
476
477 /*
478 * If we are stopping here, set td_resume.
479 */
480 if (td->td_resume != NULL && err != 0 && !td->td_paused) {
481 td->td_resume->zb_objset = zb->zb_objset;
482 td->td_resume->zb_object = zb->zb_object;
483 td->td_resume->zb_level = 0;
484 /*
485 * If we have stopped on an indirect block (e.g. due to
486 * i/o error), we have not visited anything below it.
487 * Set the bookmark to the first level-0 block that we need
488 * to visit. This way, the resuming code does not need to
489 * deal with resuming from indirect blocks.
490 *
491 * Note, if zb_level <= 0, dnp may be NULL, so we don't want
492 * to dereference it.
493 */
494 td->td_resume->zb_blkid = zb->zb_blkid;
495 if (zb->zb_level > 0) {
496 td->td_resume->zb_blkid <<= zb->zb_level *
497 (dnp->dn_indblkshift - SPA_BLKPTRSHIFT);
498 }
499 td->td_paused = B_TRUE;
500 }
501
502 return (err);
503 }
504
505 static void
prefetch_dnode_metadata(traverse_data_t * td,const dnode_phys_t * dnp,uint64_t objset,uint64_t object)506 prefetch_dnode_metadata(traverse_data_t *td, const dnode_phys_t *dnp,
507 uint64_t objset, uint64_t object)
508 {
509 int j;
510 zbookmark_phys_t czb;
511
512 for (j = 0; j < dnp->dn_nblkptr; j++) {
513 SET_BOOKMARK(&czb, objset, object, dnp->dn_nlevels - 1, j);
514 traverse_prefetch_metadata(td, dnp, &dnp->dn_blkptr[j], &czb);
515 }
516
517 if (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) {
518 SET_BOOKMARK(&czb, objset, object, 0, DMU_SPILL_BLKID);
519 traverse_prefetch_metadata(td, dnp, DN_SPILL_BLKPTR(dnp), &czb);
520 }
521 }
522
523 static int
traverse_dnode(traverse_data_t * td,const blkptr_t * bp,const dnode_phys_t * dnp,uint64_t objset,uint64_t object)524 traverse_dnode(traverse_data_t *td, const blkptr_t *bp, const dnode_phys_t *dnp,
525 uint64_t objset, uint64_t object)
526 {
527 int j, err = 0;
528 zbookmark_phys_t czb;
529
530 if (object != DMU_META_DNODE_OBJECT && td->td_resume != NULL &&
531 object < td->td_resume->zb_object)
532 return (0);
533
534 if (td->td_flags & TRAVERSE_PRE) {
535 SET_BOOKMARK(&czb, objset, object, ZB_DNODE_LEVEL,
536 ZB_DNODE_BLKID);
537 err = td->td_func(td->td_spa, NULL, bp, &czb, dnp,
538 td->td_arg);
539 if (err == TRAVERSE_VISIT_NO_CHILDREN)
540 return (0);
541 if (err != 0)
542 return (err);
543 }
544
545 for (j = 0; j < dnp->dn_nblkptr; j++) {
546 SET_BOOKMARK(&czb, objset, object, dnp->dn_nlevels - 1, j);
547 err = traverse_visitbp(td, dnp, &dnp->dn_blkptr[j], &czb);
548 if (err != 0)
549 break;
550 }
551
552 if (err == 0 && (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR)) {
553 SET_BOOKMARK(&czb, objset, object, 0, DMU_SPILL_BLKID);
554 err = traverse_visitbp(td, dnp, DN_SPILL_BLKPTR(dnp), &czb);
555 }
556
557 if (err == 0 && (td->td_flags & TRAVERSE_POST)) {
558 SET_BOOKMARK(&czb, objset, object, ZB_DNODE_LEVEL,
559 ZB_DNODE_BLKID);
560 err = td->td_func(td->td_spa, NULL, bp, &czb, dnp,
561 td->td_arg);
562 if (err == TRAVERSE_VISIT_NO_CHILDREN)
563 return (0);
564 if (err != 0)
565 return (err);
566 }
567 return (err);
568 }
569
570 static int
traverse_prefetcher(spa_t * spa,zilog_t * zilog,const blkptr_t * bp,const zbookmark_phys_t * zb,const dnode_phys_t * dnp,void * arg)571 traverse_prefetcher(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
572 const zbookmark_phys_t *zb, const dnode_phys_t *dnp, void *arg)
573 {
574 (void) zilog, (void) dnp;
575 prefetch_data_t *pfd = arg;
576 int zio_flags = ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE;
577 arc_flags_t aflags = ARC_FLAG_NOWAIT | ARC_FLAG_PREFETCH |
578 ARC_FLAG_PRESCIENT_PREFETCH;
579
580 ASSERT(pfd->pd_bytes_fetched >= 0);
581 if (zb->zb_level == ZB_DNODE_LEVEL)
582 return (0);
583 if (pfd->pd_cancel)
584 return (SET_ERROR(EINTR));
585
586 if (!prefetch_needed(pfd, bp))
587 return (0);
588
589 mutex_enter(&pfd->pd_mtx);
590 while (!pfd->pd_cancel && pfd->pd_bytes_fetched >= zfs_pd_bytes_max)
591 cv_wait_sig(&pfd->pd_cv, &pfd->pd_mtx);
592 pfd->pd_bytes_fetched += BP_GET_LSIZE(bp);
593 cv_broadcast(&pfd->pd_cv);
594 mutex_exit(&pfd->pd_mtx);
595
596 if ((pfd->pd_flags & TRAVERSE_NO_DECRYPT) && BP_IS_PROTECTED(bp))
597 zio_flags |= ZIO_FLAG_RAW;
598
599 (void) arc_read(NULL, spa, bp, NULL, NULL, ZIO_PRIORITY_ASYNC_READ,
600 zio_flags, &aflags, zb);
601
602 return (0);
603 }
604
605 static void
traverse_prefetch_thread(void * arg)606 traverse_prefetch_thread(void *arg)
607 {
608 traverse_data_t *td_main = arg;
609 traverse_data_t td = *td_main;
610 zbookmark_phys_t czb;
611 fstrans_cookie_t cookie = spl_fstrans_mark();
612
613 td.td_func = traverse_prefetcher;
614 td.td_arg = td_main->td_pfd;
615 td.td_pfd = NULL;
616 td.td_resume = &td_main->td_pfd->pd_resume;
617
618 SET_BOOKMARK(&czb, td.td_objset,
619 ZB_ROOT_OBJECT, ZB_ROOT_LEVEL, ZB_ROOT_BLKID);
620 (void) traverse_visitbp(&td, NULL, td.td_rootbp, &czb);
621
622 mutex_enter(&td_main->td_pfd->pd_mtx);
623 td_main->td_pfd->pd_exited = B_TRUE;
624 cv_broadcast(&td_main->td_pfd->pd_cv);
625 mutex_exit(&td_main->td_pfd->pd_mtx);
626 spl_fstrans_unmark(cookie);
627 }
628
629 /*
630 * NB: dataset must not be changing on-disk (eg, is a snapshot or we are
631 * in syncing context).
632 */
633 static int
traverse_impl(spa_t * spa,dsl_dataset_t * ds,uint64_t objset,blkptr_t * rootbp,uint64_t txg_start,zbookmark_phys_t * resume,int flags,blkptr_cb_t func,void * arg)634 traverse_impl(spa_t *spa, dsl_dataset_t *ds, uint64_t objset, blkptr_t *rootbp,
635 uint64_t txg_start, zbookmark_phys_t *resume, int flags,
636 blkptr_cb_t func, void *arg)
637 {
638 traverse_data_t *td;
639 prefetch_data_t *pd;
640 zbookmark_phys_t *czb;
641 int err;
642
643 ASSERT(ds == NULL || objset == ds->ds_object);
644 ASSERT(!(flags & TRAVERSE_PRE) || !(flags & TRAVERSE_POST));
645
646 td = kmem_alloc(sizeof (traverse_data_t), KM_SLEEP);
647 pd = kmem_zalloc(sizeof (prefetch_data_t), KM_SLEEP);
648 czb = kmem_alloc(sizeof (zbookmark_phys_t), KM_SLEEP);
649
650 td->td_spa = spa;
651 td->td_objset = objset;
652 td->td_rootbp = rootbp;
653 td->td_min_txg = txg_start;
654 td->td_resume = resume;
655 td->td_func = func;
656 td->td_arg = arg;
657 td->td_pfd = pd;
658 td->td_flags = flags;
659 td->td_paused = B_FALSE;
660 td->td_realloc_possible = (txg_start == 0 ? B_FALSE : B_TRUE);
661
662 if (spa_feature_is_active(spa, SPA_FEATURE_HOLE_BIRTH)) {
663 VERIFY(spa_feature_enabled_txg(spa,
664 SPA_FEATURE_HOLE_BIRTH, &td->td_hole_birth_enabled_txg));
665 } else {
666 td->td_hole_birth_enabled_txg = UINT64_MAX;
667 }
668
669 pd->pd_flags = flags;
670 if (resume != NULL)
671 pd->pd_resume = *resume;
672 mutex_init(&pd->pd_mtx, NULL, MUTEX_DEFAULT, NULL);
673 cv_init(&pd->pd_cv, NULL, CV_DEFAULT, NULL);
674
675 SET_BOOKMARK(czb, td->td_objset,
676 ZB_ROOT_OBJECT, ZB_ROOT_LEVEL, ZB_ROOT_BLKID);
677
678 /* See comment on ZIL traversal in dsl_scan_visitds. */
679 if (ds != NULL && !ds->ds_is_snapshot && !BP_IS_HOLE(rootbp)) {
680 zio_flag_t zio_flags = ZIO_FLAG_CANFAIL;
681 arc_flags_t flags = ARC_FLAG_WAIT;
682 objset_phys_t *osp;
683 arc_buf_t *buf;
684 ASSERT(!BP_IS_REDACTED(rootbp));
685
686 if ((td->td_flags & TRAVERSE_NO_DECRYPT) &&
687 BP_IS_PROTECTED(rootbp))
688 zio_flags |= ZIO_FLAG_RAW;
689
690 err = arc_read(NULL, td->td_spa, rootbp, arc_getbuf_func,
691 &buf, ZIO_PRIORITY_ASYNC_READ, zio_flags, &flags, czb);
692 if (err != 0) {
693 /*
694 * If both TRAVERSE_HARD and TRAVERSE_PRE are set,
695 * continue to visitbp so that td_func can be called
696 * in pre stage, and err will reset to zero.
697 */
698 if (!(td->td_flags & TRAVERSE_HARD) ||
699 !(td->td_flags & TRAVERSE_PRE))
700 goto out;
701 } else {
702 osp = buf->b_data;
703 traverse_zil(td, &osp->os_zil_header);
704 arc_buf_destroy(buf, &buf);
705 }
706 }
707
708 if (!(flags & TRAVERSE_PREFETCH_DATA) ||
709 taskq_dispatch(spa->spa_prefetch_taskq, traverse_prefetch_thread,
710 td, TQ_NOQUEUE) == TASKQID_INVALID)
711 pd->pd_exited = B_TRUE;
712
713 err = traverse_visitbp(td, NULL, rootbp, czb);
714
715 mutex_enter(&pd->pd_mtx);
716 pd->pd_cancel = B_TRUE;
717 cv_broadcast(&pd->pd_cv);
718 while (!pd->pd_exited)
719 cv_wait_sig(&pd->pd_cv, &pd->pd_mtx);
720 mutex_exit(&pd->pd_mtx);
721 out:
722 mutex_destroy(&pd->pd_mtx);
723 cv_destroy(&pd->pd_cv);
724
725 kmem_free(czb, sizeof (zbookmark_phys_t));
726 kmem_free(pd, sizeof (struct prefetch_data));
727 kmem_free(td, sizeof (struct traverse_data));
728
729 return (err);
730 }
731
732 /*
733 * NB: dataset must not be changing on-disk (eg, is a snapshot or we are
734 * in syncing context).
735 */
736 int
traverse_dataset_resume(dsl_dataset_t * ds,uint64_t txg_start,zbookmark_phys_t * resume,int flags,blkptr_cb_t func,void * arg)737 traverse_dataset_resume(dsl_dataset_t *ds, uint64_t txg_start,
738 zbookmark_phys_t *resume,
739 int flags, blkptr_cb_t func, void *arg)
740 {
741 return (traverse_impl(ds->ds_dir->dd_pool->dp_spa, ds, ds->ds_object,
742 &dsl_dataset_phys(ds)->ds_bp, txg_start, resume, flags, func, arg));
743 }
744
745 int
traverse_dataset(dsl_dataset_t * ds,uint64_t txg_start,int flags,blkptr_cb_t func,void * arg)746 traverse_dataset(dsl_dataset_t *ds, uint64_t txg_start,
747 int flags, blkptr_cb_t func, void *arg)
748 {
749 return (traverse_dataset_resume(ds, txg_start, NULL, flags, func, arg));
750 }
751
752 int
traverse_dataset_destroyed(spa_t * spa,blkptr_t * blkptr,uint64_t txg_start,zbookmark_phys_t * resume,int flags,blkptr_cb_t func,void * arg)753 traverse_dataset_destroyed(spa_t *spa, blkptr_t *blkptr,
754 uint64_t txg_start, zbookmark_phys_t *resume, int flags,
755 blkptr_cb_t func, void *arg)
756 {
757 return (traverse_impl(spa, NULL, ZB_DESTROYED_OBJSET,
758 blkptr, txg_start, resume, flags, func, arg));
759 }
760
761 /*
762 * NB: pool must not be changing on-disk (eg, from zdb or sync context).
763 */
764 int
traverse_pool(spa_t * spa,uint64_t txg_start,int flags,blkptr_cb_t func,void * arg)765 traverse_pool(spa_t *spa, uint64_t txg_start, int flags,
766 blkptr_cb_t func, void *arg)
767 {
768 int err;
769 dsl_pool_t *dp = spa_get_dsl(spa);
770 objset_t *mos = dp->dp_meta_objset;
771 boolean_t hard = (flags & TRAVERSE_HARD);
772
773 /* visit the MOS */
774 err = traverse_impl(spa, NULL, 0, spa_get_rootblkptr(spa),
775 txg_start, NULL, flags, func, arg);
776 if (err != 0)
777 return (err);
778
779 /* visit each dataset */
780 for (uint64_t obj = 1; err == 0;
781 err = dmu_object_next(mos, &obj, B_FALSE, txg_start)) {
782 dmu_object_info_t doi;
783
784 err = dmu_object_info(mos, obj, &doi);
785 if (err != 0) {
786 if (hard)
787 continue;
788 break;
789 }
790
791 if (doi.doi_bonus_type == DMU_OT_DSL_DATASET) {
792 dsl_dataset_t *ds;
793 uint64_t txg = txg_start;
794
795 dsl_pool_config_enter(dp, FTAG);
796 err = dsl_dataset_hold_obj(dp, obj, FTAG, &ds);
797 dsl_pool_config_exit(dp, FTAG);
798 if (err != 0) {
799 if (hard)
800 continue;
801 break;
802 }
803 if (dsl_dataset_phys(ds)->ds_prev_snap_txg > txg)
804 txg = dsl_dataset_phys(ds)->ds_prev_snap_txg;
805 err = traverse_dataset(ds, txg, flags, func, arg);
806 dsl_dataset_rele(ds, FTAG);
807 if (err != 0)
808 break;
809 }
810 }
811 if (err == ESRCH)
812 err = 0;
813 return (err);
814 }
815
816 EXPORT_SYMBOL(traverse_dataset);
817 EXPORT_SYMBOL(traverse_pool);
818
819 ZFS_MODULE_PARAM(zfs, zfs_, pd_bytes_max, INT, ZMOD_RW,
820 "Max number of bytes to prefetch");
821
822 ZFS_MODULE_PARAM(zfs, zfs_, traverse_indirect_prefetch_limit, UINT, ZMOD_RW,
823 "Traverse prefetch number of blocks pointed by indirect block");
824
825 ZFS_MODULE_PARAM(zfs, , send_holes_without_birth_time, INT, ZMOD_RW,
826 "Ignore hole_birth txg for zfs send");
827