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 */
24
25 #include <sys/zfs_context.h>
26 #include <sys/dmu_objset.h>
27 #include <sys/dmu_traverse.h>
28 #include <sys/dsl_dataset.h>
29 #include <sys/dsl_dir.h>
30 #include <sys/dsl_pool.h>
31 #include <sys/dnode.h>
32 #include <sys/spa.h>
33 #include <sys/zio.h>
34 #include <sys/dmu_impl.h>
35 #include <sys/sa.h>
36 #include <sys/sa_impl.h>
37 #include <sys/callb.h>
38
39 int zfs_pd_blks_max = 100;
40
41 typedef struct prefetch_data {
42 kmutex_t pd_mtx;
43 kcondvar_t pd_cv;
44 int pd_blks_max;
45 int pd_blks_fetched;
46 int pd_flags;
47 boolean_t pd_cancel;
48 boolean_t pd_exited;
49 } prefetch_data_t;
50
51 typedef struct traverse_data {
52 spa_t *td_spa;
53 uint64_t td_objset;
54 blkptr_t *td_rootbp;
55 uint64_t td_min_txg;
56 int td_flags;
57 prefetch_data_t *td_pfd;
58 blkptr_cb_t *td_func;
59 void *td_arg;
60 } traverse_data_t;
61
62 static int traverse_dnode(traverse_data_t *td, const dnode_phys_t *dnp,
63 arc_buf_t *buf, uint64_t objset, uint64_t object);
64
65 static int
66 traverse_zil_block(zilog_t *zilog, blkptr_t *bp, void *arg, uint64_t claim_txg)
67 {
68 traverse_data_t *td = arg;
69 zbookmark_t zb;
70
71 if (bp->blk_birth == 0)
72 return (0);
73
74 if (claim_txg == 0 && bp->blk_birth >= spa_first_txg(td->td_spa))
75 return (0);
76
77 SET_BOOKMARK(&zb, td->td_objset, ZB_ZIL_OBJECT, ZB_ZIL_LEVEL,
78 bp->blk_cksum.zc_word[ZIL_ZC_SEQ]);
79
80 (void) td->td_func(td->td_spa, zilog, bp, NULL, &zb, NULL, td->td_arg);
81
82 return (0);
83 }
84
85 static int
86 traverse_zil_record(zilog_t *zilog, lr_t *lrc, void *arg, uint64_t claim_txg)
87 {
88 traverse_data_t *td = arg;
89
90 if (lrc->lrc_txtype == TX_WRITE) {
91 lr_write_t *lr = (lr_write_t *)lrc;
92 blkptr_t *bp = &lr->lr_blkptr;
93 zbookmark_t zb;
94
95 if (bp->blk_birth == 0)
96 return (0);
97
98 if (claim_txg == 0 || bp->blk_birth < claim_txg)
99 return (0);
100
101 SET_BOOKMARK(&zb, td->td_objset, lr->lr_foid,
102 ZB_ZIL_LEVEL, lr->lr_offset / BP_GET_LSIZE(bp));
103
104 (void) td->td_func(td->td_spa, zilog, bp, NULL, &zb, NULL,
105 td->td_arg);
106 }
107 return (0);
108 }
109
110 static void
111 traverse_zil(traverse_data_t *td, zil_header_t *zh)
112 {
113 uint64_t claim_txg = zh->zh_claim_txg;
114 zilog_t *zilog;
115
116 /*
117 * We only want to visit blocks that have been claimed but not yet
118 * replayed; plus, in read-only mode, blocks that are already stable.
119 */
120 if (claim_txg == 0 && spa_writeable(td->td_spa))
121 return;
122
123 zilog = zil_alloc(spa_get_dsl(td->td_spa)->dp_meta_objset, zh);
124
125 (void) zil_parse(zilog, traverse_zil_block, traverse_zil_record, td,
126 claim_txg);
127
128 zil_free(zilog);
129 }
130
131 static int
132 traverse_visitbp(traverse_data_t *td, const dnode_phys_t *dnp,
133 arc_buf_t *pbuf, blkptr_t *bp, const zbookmark_t *zb)
134 {
135 zbookmark_t czb;
136 int err = 0, lasterr = 0;
137 arc_buf_t *buf = NULL;
138 prefetch_data_t *pd = td->td_pfd;
139 boolean_t hard = td->td_flags & TRAVERSE_HARD;
140
141 if (bp->blk_birth == 0) {
142 err = td->td_func(td->td_spa, NULL, NULL, pbuf, zb, dnp,
143 td->td_arg);
144 return (err);
145 }
146
147 if (bp->blk_birth <= td->td_min_txg)
148 return (0);
149
150 if (pd && !pd->pd_exited &&
151 ((pd->pd_flags & TRAVERSE_PREFETCH_DATA) ||
152 BP_GET_TYPE(bp) == DMU_OT_DNODE || BP_GET_LEVEL(bp) > 0)) {
153 mutex_enter(&pd->pd_mtx);
154 ASSERT(pd->pd_blks_fetched >= 0);
155 while (pd->pd_blks_fetched == 0 && !pd->pd_exited)
156 cv_wait(&pd->pd_cv, &pd->pd_mtx);
157 pd->pd_blks_fetched--;
158 cv_broadcast(&pd->pd_cv);
159 mutex_exit(&pd->pd_mtx);
160 }
161
162 if (td->td_flags & TRAVERSE_PRE) {
163 err = td->td_func(td->td_spa, NULL, bp, pbuf, zb, dnp,
164 td->td_arg);
165 if (err == TRAVERSE_VISIT_NO_CHILDREN)
166 return (0);
167 if (err)
168 return (err);
169 }
170
171 if (BP_GET_LEVEL(bp) > 0) {
172 uint32_t flags = ARC_WAIT;
173 int i;
174 blkptr_t *cbp;
175 int epb = BP_GET_LSIZE(bp) >> SPA_BLKPTRSHIFT;
176
177 err = dsl_read(NULL, td->td_spa, bp, pbuf,
178 arc_getbuf_func, &buf,
179 ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL, &flags, zb);
180 if (err)
181 return (err);
182
183 /* recursively visitbp() blocks below this */
184 cbp = buf->b_data;
185 for (i = 0; i < epb; i++, cbp++) {
186 SET_BOOKMARK(&czb, zb->zb_objset, zb->zb_object,
187 zb->zb_level - 1,
188 zb->zb_blkid * epb + i);
189 err = traverse_visitbp(td, dnp, buf, cbp, &czb);
190 if (err) {
191 if (!hard)
192 break;
193 lasterr = err;
194 }
195 }
196 } else if (BP_GET_TYPE(bp) == DMU_OT_DNODE) {
197 uint32_t flags = ARC_WAIT;
198 int i;
199 int epb = BP_GET_LSIZE(bp) >> DNODE_SHIFT;
200
201 err = dsl_read(NULL, td->td_spa, bp, pbuf,
202 arc_getbuf_func, &buf,
203 ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL, &flags, zb);
204 if (err)
205 return (err);
206
207 /* recursively visitbp() blocks below this */
208 dnp = buf->b_data;
209 for (i = 0; i < epb; i++, dnp++) {
210 err = traverse_dnode(td, dnp, buf, zb->zb_objset,
211 zb->zb_blkid * epb + i);
212 if (err) {
213 if (!hard)
214 break;
215 lasterr = err;
216 }
217 }
218 } else if (BP_GET_TYPE(bp) == DMU_OT_OBJSET) {
219 uint32_t flags = ARC_WAIT;
220 objset_phys_t *osp;
221 dnode_phys_t *dnp;
222
223 err = dsl_read_nolock(NULL, td->td_spa, bp,
224 arc_getbuf_func, &buf,
225 ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL, &flags, zb);
226 if (err)
227 return (err);
228
229 osp = buf->b_data;
230 dnp = &osp->os_meta_dnode;
231 err = traverse_dnode(td, dnp, buf, zb->zb_objset,
232 DMU_META_DNODE_OBJECT);
233 if (err && hard) {
234 lasterr = err;
235 err = 0;
236 }
237 if (err == 0 && arc_buf_size(buf) >= sizeof (objset_phys_t)) {
238 dnp = &osp->os_userused_dnode;
239 err = traverse_dnode(td, dnp, buf, zb->zb_objset,
240 DMU_USERUSED_OBJECT);
241 }
242 if (err && hard) {
243 lasterr = err;
244 err = 0;
245 }
246 if (err == 0 && arc_buf_size(buf) >= sizeof (objset_phys_t)) {
247 dnp = &osp->os_groupused_dnode;
248 err = traverse_dnode(td, dnp, buf, zb->zb_objset,
249 DMU_GROUPUSED_OBJECT);
250 }
251 }
252
253 if (buf)
254 (void) arc_buf_remove_ref(buf, &buf);
255
256 if (err == 0 && lasterr == 0 && (td->td_flags & TRAVERSE_POST)) {
257 err = td->td_func(td->td_spa, NULL, bp, pbuf, zb, dnp,
258 td->td_arg);
259 }
260
261 return (err != 0 ? err : lasterr);
262 }
263
264 static int
265 traverse_dnode(traverse_data_t *td, const dnode_phys_t *dnp,
266 arc_buf_t *buf, uint64_t objset, uint64_t object)
267 {
268 int j, err = 0, lasterr = 0;
269 zbookmark_t czb;
270 boolean_t hard = (td->td_flags & TRAVERSE_HARD);
271
272 for (j = 0; j < dnp->dn_nblkptr; j++) {
273 SET_BOOKMARK(&czb, objset, object, dnp->dn_nlevels - 1, j);
274 err = traverse_visitbp(td, dnp, buf,
275 (blkptr_t *)&dnp->dn_blkptr[j], &czb);
276 if (err) {
277 if (!hard)
278 break;
279 lasterr = err;
280 }
281 }
282
283 if (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) {
284 SET_BOOKMARK(&czb, objset,
285 object, 0, DMU_SPILL_BLKID);
286 err = traverse_visitbp(td, dnp, buf,
287 (blkptr_t *)&dnp->dn_spill, &czb);
288 if (err) {
289 if (!hard)
290 return (err);
291 lasterr = err;
292 }
293 }
294 return (err != 0 ? err : lasterr);
295 }
296
297 /* ARGSUSED */
298 static int
299 traverse_prefetcher(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
300 arc_buf_t *pbuf, const zbookmark_t *zb, const dnode_phys_t *dnp,
301 void *arg)
302 {
303 prefetch_data_t *pfd = arg;
304 uint32_t aflags = ARC_NOWAIT | ARC_PREFETCH;
305
306 ASSERT(pfd->pd_blks_fetched >= 0);
307 if (pfd->pd_cancel)
308 return (EINTR);
309
310 if (bp == NULL || !((pfd->pd_flags & TRAVERSE_PREFETCH_DATA) ||
311 BP_GET_TYPE(bp) == DMU_OT_DNODE || BP_GET_LEVEL(bp) > 0) ||
312 BP_GET_TYPE(bp) == DMU_OT_INTENT_LOG)
313 return (0);
314
315 mutex_enter(&pfd->pd_mtx);
316 while (!pfd->pd_cancel && pfd->pd_blks_fetched >= pfd->pd_blks_max)
317 cv_wait(&pfd->pd_cv, &pfd->pd_mtx);
318 pfd->pd_blks_fetched++;
319 cv_broadcast(&pfd->pd_cv);
320 mutex_exit(&pfd->pd_mtx);
321
322 (void) dsl_read(NULL, spa, bp, pbuf, NULL, NULL,
323 ZIO_PRIORITY_ASYNC_READ,
324 ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE,
325 &aflags, zb);
326
327 return (0);
328 }
329
330 static void
331 traverse_prefetch_thread(void *arg)
332 {
333 traverse_data_t *td_main = arg;
334 traverse_data_t td = *td_main;
335 zbookmark_t czb;
336
337 td.td_func = traverse_prefetcher;
338 td.td_arg = td_main->td_pfd;
339 td.td_pfd = NULL;
340
341 SET_BOOKMARK(&czb, td.td_objset,
342 ZB_ROOT_OBJECT, ZB_ROOT_LEVEL, ZB_ROOT_BLKID);
343 (void) traverse_visitbp(&td, NULL, NULL, td.td_rootbp, &czb);
344
345 mutex_enter(&td_main->td_pfd->pd_mtx);
346 td_main->td_pfd->pd_exited = B_TRUE;
347 cv_broadcast(&td_main->td_pfd->pd_cv);
348 mutex_exit(&td_main->td_pfd->pd_mtx);
349 }
350
351 /*
352 * NB: dataset must not be changing on-disk (eg, is a snapshot or we are
353 * in syncing context).
354 */
355 static int
356 traverse_impl(spa_t *spa, dsl_dataset_t *ds, blkptr_t *rootbp,
357 uint64_t txg_start, int flags, blkptr_cb_t func, void *arg)
358 {
359 traverse_data_t td;
360 prefetch_data_t pd = { 0 };
361 zbookmark_t czb;
362 int err;
363
364 td.td_spa = spa;
365 td.td_objset = ds ? ds->ds_object : 0;
366 td.td_rootbp = rootbp;
367 td.td_min_txg = txg_start;
368 td.td_func = func;
369 td.td_arg = arg;
370 td.td_pfd = &pd;
371 td.td_flags = flags;
372
373 pd.pd_blks_max = zfs_pd_blks_max;
374 pd.pd_flags = flags;
375 mutex_init(&pd.pd_mtx, NULL, MUTEX_DEFAULT, NULL);
376 cv_init(&pd.pd_cv, NULL, CV_DEFAULT, NULL);
377
378 /* See comment on ZIL traversal in dsl_scan_visitds. */
379 if (ds != NULL && !dsl_dataset_is_snapshot(ds)) {
380 objset_t *os;
381
382 err = dmu_objset_from_ds(ds, &os);
383 if (err)
384 return (err);
385
386 traverse_zil(&td, &os->os_zil_header);
387 }
388
389 if (!(flags & TRAVERSE_PREFETCH) ||
390 0 == taskq_dispatch(system_taskq, traverse_prefetch_thread,
391 &td, TQ_NOQUEUE))
392 pd.pd_exited = B_TRUE;
393
394 SET_BOOKMARK(&czb, td.td_objset,
395 ZB_ROOT_OBJECT, ZB_ROOT_LEVEL, ZB_ROOT_BLKID);
396 err = traverse_visitbp(&td, NULL, NULL, rootbp, &czb);
397
398 mutex_enter(&pd.pd_mtx);
399 pd.pd_cancel = B_TRUE;
400 cv_broadcast(&pd.pd_cv);
401 while (!pd.pd_exited)
402 cv_wait(&pd.pd_cv, &pd.pd_mtx);
403 mutex_exit(&pd.pd_mtx);
404
405 mutex_destroy(&pd.pd_mtx);
406 cv_destroy(&pd.pd_cv);
407
408 return (err);
409 }
410
411 /*
412 * NB: dataset must not be changing on-disk (eg, is a snapshot or we are
413 * in syncing context).
414 */
415 int
416 traverse_dataset(dsl_dataset_t *ds, uint64_t txg_start, int flags,
417 blkptr_cb_t func, void *arg)
418 {
419 return (traverse_impl(ds->ds_dir->dd_pool->dp_spa, ds,
420 &ds->ds_phys->ds_bp, txg_start, flags, func, arg));
421 }
422
423 /*
424 * NB: pool must not be changing on-disk (eg, from zdb or sync context).
425 */
426 int
427 traverse_pool(spa_t *spa, uint64_t txg_start, int flags,
428 blkptr_cb_t func, void *arg)
429 {
430 int err, lasterr = 0;
431 uint64_t obj;
432 dsl_pool_t *dp = spa_get_dsl(spa);
433 objset_t *mos = dp->dp_meta_objset;
434 boolean_t hard = (flags & TRAVERSE_HARD);
435
436 /* visit the MOS */
437 err = traverse_impl(spa, NULL, spa_get_rootblkptr(spa),
438 txg_start, flags, func, arg);
439 if (err)
440 return (err);
441
442 /* visit each dataset */
443 for (obj = 1; err == 0 || (err != ESRCH && hard);
444 err = dmu_object_next(mos, &obj, FALSE, txg_start)) {
445 dmu_object_info_t doi;
446
447 err = dmu_object_info(mos, obj, &doi);
448 if (err) {
449 if (!hard)
450 return (err);
451 lasterr = err;
452 continue;
453 }
454
455 if (doi.doi_type == DMU_OT_DSL_DATASET) {
456 dsl_dataset_t *ds;
457 uint64_t txg = txg_start;
458
459 rw_enter(&dp->dp_config_rwlock, RW_READER);
460 err = dsl_dataset_hold_obj(dp, obj, FTAG, &ds);
461 rw_exit(&dp->dp_config_rwlock);
462 if (err) {
463 if (!hard)
464 return (err);
465 lasterr = err;
466 continue;
467 }
468 if (ds->ds_phys->ds_prev_snap_txg > txg)
469 txg = ds->ds_phys->ds_prev_snap_txg;
470 err = traverse_dataset(ds, txg, flags, func, arg);
471 dsl_dataset_rele(ds, FTAG);
472 if (err) {
473 if (!hard)
474 return (err);
475 lasterr = err;
476 }
477 }
478 }
479 if (err == ESRCH)
480 err = 0;
481 return (err != 0 ? err : lasterr);
482 }