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34dc7c2f BB |
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 | /* | |
428870ff | 22 | * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. |
29809a6c | 23 | * Portions Copyright 2011 Martin Matuska |
93e28d66 | 24 | * Copyright (c) 2012, 2019 by Delphix. All rights reserved. |
34dc7c2f BB |
25 | */ |
26 | ||
34dc7c2f BB |
27 | #include <sys/zfs_context.h> |
28 | #include <sys/txg_impl.h> | |
29 | #include <sys/dmu_impl.h> | |
0b1401ee | 30 | #include <sys/spa_impl.h> |
428870ff | 31 | #include <sys/dmu_tx.h> |
34dc7c2f | 32 | #include <sys/dsl_pool.h> |
428870ff | 33 | #include <sys/dsl_scan.h> |
4747a7d3 | 34 | #include <sys/zil.h> |
34dc7c2f | 35 | #include <sys/callb.h> |
e5d1c27e | 36 | #include <sys/trace_zfs.h> |
34dc7c2f BB |
37 | |
38 | /* | |
89103a26 AL |
39 | * ZFS Transaction Groups |
40 | * ---------------------- | |
41 | * | |
42 | * ZFS transaction groups are, as the name implies, groups of transactions | |
43 | * that act on persistent state. ZFS asserts consistency at the granularity of | |
44 | * these transaction groups. Each successive transaction group (txg) is | |
45 | * assigned a 64-bit consecutive identifier. There are three active | |
46 | * transaction group states: open, quiescing, or syncing. At any given time, | |
47 | * there may be an active txg associated with each state; each active txg may | |
48 | * either be processing, or blocked waiting to enter the next state. There may | |
49 | * be up to three active txgs, and there is always a txg in the open state | |
50 | * (though it may be blocked waiting to enter the quiescing state). In broad | |
e8b96c60 | 51 | * strokes, transactions -- operations that change in-memory structures -- are |
89103a26 AL |
52 | * accepted into the txg in the open state, and are completed while the txg is |
53 | * in the open or quiescing states. The accumulated changes are written to | |
54 | * disk in the syncing state. | |
55 | * | |
56 | * Open | |
57 | * | |
58 | * When a new txg becomes active, it first enters the open state. New | |
e8b96c60 | 59 | * transactions -- updates to in-memory structures -- are assigned to the |
89103a26 AL |
60 | * currently open txg. There is always a txg in the open state so that ZFS can |
61 | * accept new changes (though the txg may refuse new changes if it has hit | |
62 | * some limit). ZFS advances the open txg to the next state for a variety of | |
63 | * reasons such as it hitting a time or size threshold, or the execution of an | |
64 | * administrative action that must be completed in the syncing state. | |
65 | * | |
66 | * Quiescing | |
67 | * | |
68 | * After a txg exits the open state, it enters the quiescing state. The | |
69 | * quiescing state is intended to provide a buffer between accepting new | |
70 | * transactions in the open state and writing them out to stable storage in | |
71 | * the syncing state. While quiescing, transactions can continue their | |
72 | * operation without delaying either of the other states. Typically, a txg is | |
73 | * in the quiescing state very briefly since the operations are bounded by | |
74 | * software latencies rather than, say, slower I/O latencies. After all | |
75 | * transactions complete, the txg is ready to enter the next state. | |
76 | * | |
77 | * Syncing | |
78 | * | |
79 | * In the syncing state, the in-memory state built up during the open and (to | |
80 | * a lesser degree) the quiescing states is written to stable storage. The | |
81 | * process of writing out modified data can, in turn modify more data. For | |
82 | * example when we write new blocks, we need to allocate space for them; those | |
83 | * allocations modify metadata (space maps)... which themselves must be | |
84 | * written to stable storage. During the sync state, ZFS iterates, writing out | |
85 | * data until it converges and all in-memory changes have been written out. | |
86 | * The first such pass is the largest as it encompasses all the modified user | |
87 | * data (as opposed to filesystem metadata). Subsequent passes typically have | |
88 | * far less data to write as they consist exclusively of filesystem metadata. | |
89 | * | |
90 | * To ensure convergence, after a certain number of passes ZFS begins | |
91 | * overwriting locations on stable storage that had been allocated earlier in | |
92 | * the syncing state (and subsequently freed). ZFS usually allocates new | |
93 | * blocks to optimize for large, continuous, writes. For the syncing state to | |
94 | * converge however it must complete a pass where no new blocks are allocated | |
95 | * since each allocation requires a modification of persistent metadata. | |
96 | * Further, to hasten convergence, after a prescribed number of passes, ZFS | |
97 | * also defers frees, and stops compressing. | |
98 | * | |
99 | * In addition to writing out user data, we must also execute synctasks during | |
100 | * the syncing context. A synctask is the mechanism by which some | |
101 | * administrative activities work such as creating and destroying snapshots or | |
102 | * datasets. Note that when a synctask is initiated it enters the open txg, | |
103 | * and ZFS then pushes that txg as quickly as possible to completion of the | |
104 | * syncing state in order to reduce the latency of the administrative | |
105 | * activity. To complete the syncing state, ZFS writes out a new uberblock, | |
106 | * the root of the tree of blocks that comprise all state stored on the ZFS | |
107 | * pool. Finally, if there is a quiesced txg waiting, we signal that it can | |
108 | * now transition to the syncing state. | |
34dc7c2f BB |
109 | */ |
110 | ||
460748d4 BB |
111 | static __attribute__((noreturn)) void txg_sync_thread(void *arg); |
112 | static __attribute__((noreturn)) void txg_quiesce_thread(void *arg); | |
34dc7c2f | 113 | |
572e2857 | 114 | int zfs_txg_timeout = 5; /* max seconds worth of delta per txg */ |
34dc7c2f BB |
115 | |
116 | /* | |
117 | * Prepare the txg subsystem. | |
118 | */ | |
119 | void | |
120 | txg_init(dsl_pool_t *dp, uint64_t txg) | |
121 | { | |
122 | tx_state_t *tx = &dp->dp_tx; | |
123 | int c; | |
861166b0 | 124 | memset(tx, 0, sizeof (tx_state_t)); |
34dc7c2f | 125 | |
00b46022 | 126 | tx->tx_cpu = vmem_zalloc(max_ncpus * sizeof (tx_cpu_t), KM_SLEEP); |
34dc7c2f BB |
127 | |
128 | for (c = 0; c < max_ncpus; c++) { | |
129 | int i; | |
130 | ||
131 | mutex_init(&tx->tx_cpu[c].tc_lock, NULL, MUTEX_DEFAULT, NULL); | |
448d7aaa | 132 | mutex_init(&tx->tx_cpu[c].tc_open_lock, NULL, MUTEX_NOLOCKDEP, |
2696dfaf | 133 | NULL); |
34dc7c2f BB |
134 | for (i = 0; i < TXG_SIZE; i++) { |
135 | cv_init(&tx->tx_cpu[c].tc_cv[i], NULL, CV_DEFAULT, | |
136 | NULL); | |
428870ff BB |
137 | list_create(&tx->tx_cpu[c].tc_callbacks[i], |
138 | sizeof (dmu_tx_callback_t), | |
139 | offsetof(dmu_tx_callback_t, dcb_node)); | |
34dc7c2f BB |
140 | } |
141 | } | |
142 | ||
34dc7c2f BB |
143 | mutex_init(&tx->tx_sync_lock, NULL, MUTEX_DEFAULT, NULL); |
144 | ||
fb5f0bc8 BB |
145 | cv_init(&tx->tx_sync_more_cv, NULL, CV_DEFAULT, NULL); |
146 | cv_init(&tx->tx_sync_done_cv, NULL, CV_DEFAULT, NULL); | |
147 | cv_init(&tx->tx_quiesce_more_cv, NULL, CV_DEFAULT, NULL); | |
148 | cv_init(&tx->tx_quiesce_done_cv, NULL, CV_DEFAULT, NULL); | |
149 | cv_init(&tx->tx_exit_cv, NULL, CV_DEFAULT, NULL); | |
150 | ||
34dc7c2f BB |
151 | tx->tx_open_txg = txg; |
152 | } | |
153 | ||
154 | /* | |
155 | * Close down the txg subsystem. | |
156 | */ | |
157 | void | |
158 | txg_fini(dsl_pool_t *dp) | |
159 | { | |
160 | tx_state_t *tx = &dp->dp_tx; | |
161 | int c; | |
162 | ||
1ce23dca | 163 | ASSERT0(tx->tx_threads); |
34dc7c2f | 164 | |
34dc7c2f BB |
165 | mutex_destroy(&tx->tx_sync_lock); |
166 | ||
fb5f0bc8 BB |
167 | cv_destroy(&tx->tx_sync_more_cv); |
168 | cv_destroy(&tx->tx_sync_done_cv); | |
169 | cv_destroy(&tx->tx_quiesce_more_cv); | |
170 | cv_destroy(&tx->tx_quiesce_done_cv); | |
171 | cv_destroy(&tx->tx_exit_cv); | |
172 | ||
34dc7c2f BB |
173 | for (c = 0; c < max_ncpus; c++) { |
174 | int i; | |
175 | ||
2696dfaf | 176 | mutex_destroy(&tx->tx_cpu[c].tc_open_lock); |
34dc7c2f | 177 | mutex_destroy(&tx->tx_cpu[c].tc_lock); |
428870ff | 178 | for (i = 0; i < TXG_SIZE; i++) { |
34dc7c2f | 179 | cv_destroy(&tx->tx_cpu[c].tc_cv[i]); |
428870ff BB |
180 | list_destroy(&tx->tx_cpu[c].tc_callbacks[i]); |
181 | } | |
34dc7c2f BB |
182 | } |
183 | ||
428870ff BB |
184 | if (tx->tx_commit_cb_taskq != NULL) |
185 | taskq_destroy(tx->tx_commit_cb_taskq); | |
186 | ||
00b46022 | 187 | vmem_free(tx->tx_cpu, max_ncpus * sizeof (tx_cpu_t)); |
34dc7c2f | 188 | |
861166b0 | 189 | memset(tx, 0, sizeof (tx_state_t)); |
34dc7c2f BB |
190 | } |
191 | ||
192 | /* | |
193 | * Start syncing transaction groups. | |
194 | */ | |
195 | void | |
196 | txg_sync_start(dsl_pool_t *dp) | |
197 | { | |
198 | tx_state_t *tx = &dp->dp_tx; | |
199 | ||
200 | mutex_enter(&tx->tx_sync_lock); | |
201 | ||
202 | dprintf("pool %p\n", dp); | |
203 | ||
1ce23dca | 204 | ASSERT0(tx->tx_threads); |
34dc7c2f BB |
205 | |
206 | tx->tx_threads = 2; | |
207 | ||
208 | tx->tx_quiesce_thread = thread_create(NULL, 0, txg_quiesce_thread, | |
1229323d | 209 | dp, 0, &p0, TS_RUN, defclsyspri); |
34dc7c2f | 210 | |
b128c09f BB |
211 | /* |
212 | * The sync thread can need a larger-than-default stack size on | |
213 | * 32-bit x86. This is due in part to nested pools and | |
214 | * scrub_visitbp() recursion. | |
215 | */ | |
89666a8e | 216 | tx->tx_sync_thread = thread_create(NULL, 0, txg_sync_thread, |
1229323d | 217 | dp, 0, &p0, TS_RUN, defclsyspri); |
34dc7c2f BB |
218 | |
219 | mutex_exit(&tx->tx_sync_lock); | |
220 | } | |
221 | ||
222 | static void | |
223 | txg_thread_enter(tx_state_t *tx, callb_cpr_t *cpr) | |
224 | { | |
225 | CALLB_CPR_INIT(cpr, &tx->tx_sync_lock, callb_generic_cpr, FTAG); | |
226 | mutex_enter(&tx->tx_sync_lock); | |
227 | } | |
228 | ||
229 | static void | |
230 | txg_thread_exit(tx_state_t *tx, callb_cpr_t *cpr, kthread_t **tpp) | |
231 | { | |
232 | ASSERT(*tpp != NULL); | |
233 | *tpp = NULL; | |
234 | tx->tx_threads--; | |
235 | cv_broadcast(&tx->tx_exit_cv); | |
236 | CALLB_CPR_EXIT(cpr); /* drops &tx->tx_sync_lock */ | |
237 | thread_exit(); | |
238 | } | |
239 | ||
240 | static void | |
63fd3c6c | 241 | txg_thread_wait(tx_state_t *tx, callb_cpr_t *cpr, kcondvar_t *cv, clock_t time) |
34dc7c2f BB |
242 | { |
243 | CALLB_CPR_SAFE_BEGIN(cpr); | |
244 | ||
f4e35b16 | 245 | if (time) { |
ac6e5fb2 | 246 | (void) cv_timedwait_idle(cv, &tx->tx_sync_lock, |
428870ff | 247 | ddi_get_lbolt() + time); |
f4e35b16 | 248 | } else { |
ac6e5fb2 | 249 | cv_wait_idle(cv, &tx->tx_sync_lock); |
f4e35b16 | 250 | } |
34dc7c2f BB |
251 | |
252 | CALLB_CPR_SAFE_END(cpr, &tx->tx_sync_lock); | |
253 | } | |
254 | ||
255 | /* | |
256 | * Stop syncing transaction groups. | |
257 | */ | |
258 | void | |
259 | txg_sync_stop(dsl_pool_t *dp) | |
260 | { | |
261 | tx_state_t *tx = &dp->dp_tx; | |
262 | ||
263 | dprintf("pool %p\n", dp); | |
264 | /* | |
265 | * Finish off any work in progress. | |
266 | */ | |
1ce23dca | 267 | ASSERT3U(tx->tx_threads, ==, 2); |
428870ff BB |
268 | |
269 | /* | |
93e28d66 | 270 | * We need to ensure that we've vacated the deferred metaslab trees. |
428870ff BB |
271 | */ |
272 | txg_wait_synced(dp, tx->tx_open_txg + TXG_DEFER_SIZE); | |
34dc7c2f BB |
273 | |
274 | /* | |
275 | * Wake all sync threads and wait for them to die. | |
276 | */ | |
277 | mutex_enter(&tx->tx_sync_lock); | |
278 | ||
1ce23dca | 279 | ASSERT3U(tx->tx_threads, ==, 2); |
34dc7c2f BB |
280 | |
281 | tx->tx_exiting = 1; | |
282 | ||
283 | cv_broadcast(&tx->tx_quiesce_more_cv); | |
284 | cv_broadcast(&tx->tx_quiesce_done_cv); | |
285 | cv_broadcast(&tx->tx_sync_more_cv); | |
286 | ||
287 | while (tx->tx_threads != 0) | |
288 | cv_wait(&tx->tx_exit_cv, &tx->tx_sync_lock); | |
289 | ||
290 | tx->tx_exiting = 0; | |
291 | ||
292 | mutex_exit(&tx->tx_sync_lock); | |
293 | } | |
294 | ||
84268b09 CS |
295 | /* |
296 | * Get a handle on the currently open txg and keep it open. | |
297 | * | |
298 | * The txg is guaranteed to stay open until txg_rele_to_quiesce() is called for | |
299 | * the handle. Once txg_rele_to_quiesce() has been called, the txg stays | |
300 | * in quiescing state until txg_rele_to_sync() is called for the handle. | |
301 | * | |
302 | * It is guaranteed that subsequent calls return monotonically increasing | |
303 | * txgs for the same dsl_pool_t. Of course this is not strong monotonicity, | |
304 | * because the same txg can be returned multiple times in a row. This | |
305 | * guarantee holds both for subsequent calls from one thread and for multiple | |
306 | * threads. For example, it is impossible to observe the following sequence | |
307 | * of events: | |
308 | * | |
309 | * Thread 1 Thread 2 | |
310 | * | |
311 | * 1 <- txg_hold_open(P, ...) | |
312 | * 2 <- txg_hold_open(P, ...) | |
313 | * 1 <- txg_hold_open(P, ...) | |
314 | * | |
315 | */ | |
34dc7c2f BB |
316 | uint64_t |
317 | txg_hold_open(dsl_pool_t *dp, txg_handle_t *th) | |
318 | { | |
319 | tx_state_t *tx = &dp->dp_tx; | |
15a9e033 | 320 | tx_cpu_t *tc; |
34dc7c2f BB |
321 | uint64_t txg; |
322 | ||
15a9e033 PS |
323 | /* |
324 | * It appears the processor id is simply used as a "random" | |
325 | * number to index into the array, and there isn't any other | |
326 | * significance to the chosen tx_cpu. Because.. Why not use | |
327 | * the current cpu to index into the array? | |
328 | */ | |
09eb36ce | 329 | tc = &tx->tx_cpu[CPU_SEQID_UNSTABLE]; |
15a9e033 | 330 | |
2696dfaf | 331 | mutex_enter(&tc->tc_open_lock); |
34dc7c2f | 332 | txg = tx->tx_open_txg; |
2696dfaf GW |
333 | |
334 | mutex_enter(&tc->tc_lock); | |
34dc7c2f | 335 | tc->tc_count[txg & TXG_MASK]++; |
2696dfaf | 336 | mutex_exit(&tc->tc_lock); |
34dc7c2f BB |
337 | |
338 | th->th_cpu = tc; | |
339 | th->th_txg = txg; | |
340 | ||
341 | return (txg); | |
342 | } | |
343 | ||
344 | void | |
345 | txg_rele_to_quiesce(txg_handle_t *th) | |
346 | { | |
347 | tx_cpu_t *tc = th->th_cpu; | |
348 | ||
2696dfaf GW |
349 | ASSERT(!MUTEX_HELD(&tc->tc_lock)); |
350 | mutex_exit(&tc->tc_open_lock); | |
34dc7c2f BB |
351 | } |
352 | ||
428870ff BB |
353 | void |
354 | txg_register_callbacks(txg_handle_t *th, list_t *tx_callbacks) | |
355 | { | |
356 | tx_cpu_t *tc = th->th_cpu; | |
357 | int g = th->th_txg & TXG_MASK; | |
358 | ||
359 | mutex_enter(&tc->tc_lock); | |
360 | list_move_tail(&tc->tc_callbacks[g], tx_callbacks); | |
361 | mutex_exit(&tc->tc_lock); | |
362 | } | |
363 | ||
34dc7c2f BB |
364 | void |
365 | txg_rele_to_sync(txg_handle_t *th) | |
366 | { | |
367 | tx_cpu_t *tc = th->th_cpu; | |
368 | int g = th->th_txg & TXG_MASK; | |
369 | ||
370 | mutex_enter(&tc->tc_lock); | |
371 | ASSERT(tc->tc_count[g] != 0); | |
372 | if (--tc->tc_count[g] == 0) | |
373 | cv_broadcast(&tc->tc_cv[g]); | |
374 | mutex_exit(&tc->tc_lock); | |
375 | ||
376 | th->th_cpu = NULL; /* defensive */ | |
377 | } | |
378 | ||
e49f1e20 WA |
379 | /* |
380 | * Blocks until all transactions in the group are committed. | |
381 | * | |
382 | * On return, the transaction group has reached a stable state in which it can | |
383 | * then be passed off to the syncing context. | |
384 | */ | |
34dc7c2f BB |
385 | static void |
386 | txg_quiesce(dsl_pool_t *dp, uint64_t txg) | |
387 | { | |
388 | tx_state_t *tx = &dp->dp_tx; | |
f26b4b3c | 389 | uint64_t tx_open_time; |
34dc7c2f BB |
390 | int g = txg & TXG_MASK; |
391 | int c; | |
392 | ||
393 | /* | |
2696dfaf | 394 | * Grab all tc_open_locks so nobody else can get into this txg. |
34dc7c2f BB |
395 | */ |
396 | for (c = 0; c < max_ncpus; c++) | |
2696dfaf | 397 | mutex_enter(&tx->tx_cpu[c].tc_open_lock); |
34dc7c2f BB |
398 | |
399 | ASSERT(txg == tx->tx_open_txg); | |
400 | tx->tx_open_txg++; | |
f26b4b3c | 401 | tx->tx_open_time = tx_open_time = gethrtime(); |
0b1401ee | 402 | |
63fd3c6c AL |
403 | DTRACE_PROBE2(txg__quiescing, dsl_pool_t *, dp, uint64_t, txg); |
404 | DTRACE_PROBE2(txg__opened, dsl_pool_t *, dp, uint64_t, tx->tx_open_txg); | |
405 | ||
57f5a200 BB |
406 | /* |
407 | * Now that we've incremented tx_open_txg, we can let threads | |
408 | * enter the next transaction group. | |
409 | */ | |
410 | for (c = 0; c < max_ncpus; c++) | |
2696dfaf | 411 | mutex_exit(&tx->tx_cpu[c].tc_open_lock); |
57f5a200 | 412 | |
f26b4b3c RY |
413 | spa_txg_history_set(dp->dp_spa, txg, TXG_STATE_OPEN, tx_open_time); |
414 | spa_txg_history_add(dp->dp_spa, txg + 1, tx_open_time); | |
415 | ||
34dc7c2f | 416 | /* |
84268b09 CS |
417 | * Quiesce the transaction group by waiting for everyone to |
418 | * call txg_rele_to_sync() for their open transaction handles. | |
34dc7c2f BB |
419 | */ |
420 | for (c = 0; c < max_ncpus; c++) { | |
421 | tx_cpu_t *tc = &tx->tx_cpu[c]; | |
422 | mutex_enter(&tc->tc_lock); | |
423 | while (tc->tc_count[g] != 0) | |
424 | cv_wait(&tc->tc_cv[g], &tc->tc_lock); | |
425 | mutex_exit(&tc->tc_lock); | |
426 | } | |
0b1401ee BB |
427 | |
428 | spa_txg_history_set(dp->dp_spa, txg, TXG_STATE_QUIESCED, gethrtime()); | |
34dc7c2f BB |
429 | } |
430 | ||
428870ff BB |
431 | static void |
432 | txg_do_callbacks(list_t *cb_list) | |
433 | { | |
434 | dmu_tx_do_callbacks(cb_list, 0); | |
435 | ||
436 | list_destroy(cb_list); | |
437 | ||
438 | kmem_free(cb_list, sizeof (list_t)); | |
439 | } | |
440 | ||
441 | /* | |
442 | * Dispatch the commit callbacks registered on this txg to worker threads. | |
e49f1e20 WA |
443 | * |
444 | * If no callbacks are registered for a given TXG, nothing happens. | |
445 | * This function creates a taskq for the associated pool, if needed. | |
428870ff BB |
446 | */ |
447 | static void | |
448 | txg_dispatch_callbacks(dsl_pool_t *dp, uint64_t txg) | |
449 | { | |
450 | int c; | |
451 | tx_state_t *tx = &dp->dp_tx; | |
452 | list_t *cb_list; | |
453 | ||
454 | for (c = 0; c < max_ncpus; c++) { | |
455 | tx_cpu_t *tc = &tx->tx_cpu[c]; | |
e49f1e20 WA |
456 | /* |
457 | * No need to lock tx_cpu_t at this point, since this can | |
458 | * only be called once a txg has been synced. | |
459 | */ | |
428870ff BB |
460 | |
461 | int g = txg & TXG_MASK; | |
462 | ||
463 | if (list_is_empty(&tc->tc_callbacks[g])) | |
464 | continue; | |
465 | ||
466 | if (tx->tx_commit_cb_taskq == NULL) { | |
467 | /* | |
468 | * Commit callback taskq hasn't been created yet. | |
469 | */ | |
470 | tx->tx_commit_cb_taskq = taskq_create("tx_commit_cb", | |
60a4c7d2 PD |
471 | 100, defclsyspri, boot_ncpus, boot_ncpus * 2, |
472 | TASKQ_PREPOPULATE | TASKQ_DYNAMIC | | |
473 | TASKQ_THREADS_CPU_PCT); | |
428870ff BB |
474 | } |
475 | ||
79c76d5b | 476 | cb_list = kmem_alloc(sizeof (list_t), KM_SLEEP); |
428870ff BB |
477 | list_create(cb_list, sizeof (dmu_tx_callback_t), |
478 | offsetof(dmu_tx_callback_t, dcb_node)); | |
479 | ||
090ff092 | 480 | list_move_tail(cb_list, &tc->tc_callbacks[g]); |
428870ff BB |
481 | |
482 | (void) taskq_dispatch(tx->tx_commit_cb_taskq, (task_func_t *) | |
483 | txg_do_callbacks, cb_list, TQ_SLEEP); | |
484 | } | |
485 | } | |
486 | ||
54a179e7 RC |
487 | /* |
488 | * Wait for pending commit callbacks of already-synced transactions to finish | |
489 | * processing. | |
490 | * Calling this function from within a commit callback will deadlock. | |
491 | */ | |
492 | void | |
493 | txg_wait_callbacks(dsl_pool_t *dp) | |
494 | { | |
495 | tx_state_t *tx = &dp->dp_tx; | |
496 | ||
497 | if (tx->tx_commit_cb_taskq != NULL) | |
c5528b9b | 498 | taskq_wait_outstanding(tx->tx_commit_cb_taskq, 0); |
54a179e7 RC |
499 | } |
500 | ||
e48afbc4 SD |
501 | static boolean_t |
502 | txg_is_quiescing(dsl_pool_t *dp) | |
503 | { | |
504 | tx_state_t *tx = &dp->dp_tx; | |
505 | ASSERT(MUTEX_HELD(&tx->tx_sync_lock)); | |
506 | return (tx->tx_quiescing_txg != 0); | |
507 | } | |
508 | ||
509 | static boolean_t | |
510 | txg_has_quiesced_to_sync(dsl_pool_t *dp) | |
511 | { | |
512 | tx_state_t *tx = &dp->dp_tx; | |
513 | ASSERT(MUTEX_HELD(&tx->tx_sync_lock)); | |
514 | return (tx->tx_quiesced_txg != 0); | |
515 | } | |
516 | ||
460748d4 | 517 | static __attribute__((noreturn)) void |
c25b8f99 | 518 | txg_sync_thread(void *arg) |
34dc7c2f | 519 | { |
867959b5 | 520 | dsl_pool_t *dp = arg; |
428870ff | 521 | spa_t *spa = dp->dp_spa; |
34dc7c2f BB |
522 | tx_state_t *tx = &dp->dp_tx; |
523 | callb_cpr_t cpr; | |
0b75bdb3 | 524 | clock_t start, delta; |
34dc7c2f | 525 | |
92119cc2 | 526 | (void) spl_fstrans_mark(); |
34dc7c2f BB |
527 | txg_thread_enter(tx, &cpr); |
528 | ||
529 | start = delta = 0; | |
34dc7c2f | 530 | for (;;) { |
baf67d15 BB |
531 | clock_t timeout = zfs_txg_timeout * hz; |
532 | clock_t timer; | |
b128c09f | 533 | uint64_t txg; |
87d98efe | 534 | |
34dc7c2f | 535 | /* |
428870ff | 536 | * We sync when we're scanning, there's someone waiting |
b128c09f BB |
537 | * on us, or the quiesce thread has handed off a txg to |
538 | * us, or we have reached our timeout. | |
34dc7c2f BB |
539 | */ |
540 | timer = (delta >= timeout ? 0 : timeout - delta); | |
428870ff | 541 | while (!dsl_scan_active(dp->dp_scan) && |
b128c09f | 542 | !tx->tx_exiting && timer > 0 && |
34dc7c2f | 543 | tx->tx_synced_txg >= tx->tx_sync_txg_waiting && |
50e09edd | 544 | !txg_has_quiesced_to_sync(dp)) { |
34dc7c2f | 545 | dprintf("waiting; tx_synced=%llu waiting=%llu dp=%p\n", |
8e739b2c RE |
546 | (u_longlong_t)tx->tx_synced_txg, |
547 | (u_longlong_t)tx->tx_sync_txg_waiting, dp); | |
34dc7c2f | 548 | txg_thread_wait(tx, &cpr, &tx->tx_sync_more_cv, timer); |
428870ff | 549 | delta = ddi_get_lbolt() - start; |
34dc7c2f BB |
550 | timer = (delta > timeout ? 0 : timeout - delta); |
551 | } | |
552 | ||
553 | /* | |
554 | * Wait until the quiesce thread hands off a txg to us, | |
555 | * prompting it to do so if necessary. | |
556 | */ | |
e48afbc4 | 557 | while (!tx->tx_exiting && !txg_has_quiesced_to_sync(dp)) { |
50e09edd KJ |
558 | if (txg_is_quiescing(dp)) { |
559 | txg_thread_wait(tx, &cpr, | |
560 | &tx->tx_quiesce_done_cv, 0); | |
561 | continue; | |
562 | } | |
34dc7c2f BB |
563 | if (tx->tx_quiesce_txg_waiting < tx->tx_open_txg+1) |
564 | tx->tx_quiesce_txg_waiting = tx->tx_open_txg+1; | |
565 | cv_broadcast(&tx->tx_quiesce_more_cv); | |
566 | txg_thread_wait(tx, &cpr, &tx->tx_quiesce_done_cv, 0); | |
567 | } | |
568 | ||
baf67d15 | 569 | if (tx->tx_exiting) |
34dc7c2f BB |
570 | txg_thread_exit(tx, &cpr, &tx->tx_sync_thread); |
571 | ||
34dc7c2f BB |
572 | /* |
573 | * Consume the quiesced txg which has been handed off to | |
574 | * us. This may cause the quiescing thread to now be | |
575 | * able to quiesce another txg, so we must signal it. | |
576 | */ | |
e48afbc4 | 577 | ASSERT(tx->tx_quiesced_txg != 0); |
34dc7c2f BB |
578 | txg = tx->tx_quiesced_txg; |
579 | tx->tx_quiesced_txg = 0; | |
580 | tx->tx_syncing_txg = txg; | |
63fd3c6c | 581 | DTRACE_PROBE2(txg__syncing, dsl_pool_t *, dp, uint64_t, txg); |
34dc7c2f | 582 | cv_broadcast(&tx->tx_quiesce_more_cv); |
34dc7c2f BB |
583 | |
584 | dprintf("txg=%llu quiesce_txg=%llu sync_txg=%llu\n", | |
8e739b2c RE |
585 | (u_longlong_t)txg, (u_longlong_t)tx->tx_quiesce_txg_waiting, |
586 | (u_longlong_t)tx->tx_sync_txg_waiting); | |
34dc7c2f | 587 | mutex_exit(&tx->tx_sync_lock); |
b128c09f | 588 | |
a783dd96 | 589 | txg_stat_t *ts = spa_txg_history_init_io(spa, txg, dp); |
428870ff BB |
590 | start = ddi_get_lbolt(); |
591 | spa_sync(spa, txg); | |
592 | delta = ddi_get_lbolt() - start; | |
a783dd96 | 593 | spa_txg_history_fini_io(spa, ts); |
34dc7c2f | 594 | |
34dc7c2f | 595 | mutex_enter(&tx->tx_sync_lock); |
34dc7c2f BB |
596 | tx->tx_synced_txg = txg; |
597 | tx->tx_syncing_txg = 0; | |
63fd3c6c | 598 | DTRACE_PROBE2(txg__synced, dsl_pool_t *, dp, uint64_t, txg); |
34dc7c2f | 599 | cv_broadcast(&tx->tx_sync_done_cv); |
428870ff BB |
600 | |
601 | /* | |
602 | * Dispatch commit callbacks to worker threads. | |
603 | */ | |
604 | txg_dispatch_callbacks(dp, txg); | |
34dc7c2f BB |
605 | } |
606 | } | |
607 | ||
460748d4 | 608 | static __attribute__((noreturn)) void |
c25b8f99 | 609 | txg_quiesce_thread(void *arg) |
34dc7c2f | 610 | { |
867959b5 | 611 | dsl_pool_t *dp = arg; |
34dc7c2f BB |
612 | tx_state_t *tx = &dp->dp_tx; |
613 | callb_cpr_t cpr; | |
614 | ||
615 | txg_thread_enter(tx, &cpr); | |
616 | ||
617 | for (;;) { | |
618 | uint64_t txg; | |
619 | ||
620 | /* | |
621 | * We quiesce when there's someone waiting on us. | |
622 | * However, we can only have one txg in "quiescing" or | |
623 | * "quiesced, waiting to sync" state. So we wait until | |
624 | * the "quiesced, waiting to sync" txg has been consumed | |
625 | * by the sync thread. | |
626 | */ | |
627 | while (!tx->tx_exiting && | |
628 | (tx->tx_open_txg >= tx->tx_quiesce_txg_waiting || | |
e48afbc4 | 629 | txg_has_quiesced_to_sync(dp))) |
34dc7c2f BB |
630 | txg_thread_wait(tx, &cpr, &tx->tx_quiesce_more_cv, 0); |
631 | ||
632 | if (tx->tx_exiting) | |
633 | txg_thread_exit(tx, &cpr, &tx->tx_quiesce_thread); | |
634 | ||
635 | txg = tx->tx_open_txg; | |
636 | dprintf("txg=%llu quiesce_txg=%llu sync_txg=%llu\n", | |
8e739b2c RE |
637 | (u_longlong_t)txg, |
638 | (u_longlong_t)tx->tx_quiesce_txg_waiting, | |
639 | (u_longlong_t)tx->tx_sync_txg_waiting); | |
e48afbc4 SD |
640 | tx->tx_quiescing_txg = txg; |
641 | ||
34dc7c2f BB |
642 | mutex_exit(&tx->tx_sync_lock); |
643 | txg_quiesce(dp, txg); | |
644 | mutex_enter(&tx->tx_sync_lock); | |
645 | ||
646 | /* | |
647 | * Hand this txg off to the sync thread. | |
648 | */ | |
8e739b2c RE |
649 | dprintf("quiesce done, handing off txg %llu\n", |
650 | (u_longlong_t)txg); | |
e48afbc4 | 651 | tx->tx_quiescing_txg = 0; |
34dc7c2f | 652 | tx->tx_quiesced_txg = txg; |
63fd3c6c | 653 | DTRACE_PROBE2(txg__quiesced, dsl_pool_t *, dp, uint64_t, txg); |
34dc7c2f BB |
654 | cv_broadcast(&tx->tx_sync_more_cv); |
655 | cv_broadcast(&tx->tx_quiesce_done_cv); | |
656 | } | |
657 | } | |
658 | ||
659 | /* | |
63fd3c6c | 660 | * Delay this thread by delay nanoseconds if we are still in the open |
e1cfd73f AG |
661 | * transaction group and there is already a waiting txg quiescing or quiesced. |
662 | * Abort the delay if this txg stalls or enters the quiescing state. | |
34dc7c2f BB |
663 | */ |
664 | void | |
63fd3c6c | 665 | txg_delay(dsl_pool_t *dp, uint64_t txg, hrtime_t delay, hrtime_t resolution) |
34dc7c2f BB |
666 | { |
667 | tx_state_t *tx = &dp->dp_tx; | |
63fd3c6c | 668 | hrtime_t start = gethrtime(); |
34dc7c2f | 669 | |
d3cc8b15 | 670 | /* don't delay if this txg could transition to quiescing immediately */ |
34dc7c2f BB |
671 | if (tx->tx_open_txg > txg || |
672 | tx->tx_syncing_txg == txg-1 || tx->tx_synced_txg == txg-1) | |
673 | return; | |
674 | ||
675 | mutex_enter(&tx->tx_sync_lock); | |
676 | if (tx->tx_open_txg > txg || tx->tx_synced_txg == txg-1) { | |
677 | mutex_exit(&tx->tx_sync_lock); | |
678 | return; | |
679 | } | |
680 | ||
63fd3c6c AL |
681 | while (gethrtime() - start < delay && |
682 | tx->tx_syncing_txg < txg-1 && !txg_stalled(dp)) { | |
683 | (void) cv_timedwait_hires(&tx->tx_quiesce_more_cv, | |
684 | &tx->tx_sync_lock, delay, resolution, 0); | |
685 | } | |
34dc7c2f | 686 | |
570827e1 BB |
687 | DMU_TX_STAT_BUMP(dmu_tx_delay); |
688 | ||
34dc7c2f BB |
689 | mutex_exit(&tx->tx_sync_lock); |
690 | } | |
691 | ||
186898bb DB |
692 | static boolean_t |
693 | txg_wait_synced_impl(dsl_pool_t *dp, uint64_t txg, boolean_t wait_sig) | |
34dc7c2f BB |
694 | { |
695 | tx_state_t *tx = &dp->dp_tx; | |
696 | ||
13fe0198 MA |
697 | ASSERT(!dsl_pool_config_held(dp)); |
698 | ||
34dc7c2f | 699 | mutex_enter(&tx->tx_sync_lock); |
1ce23dca | 700 | ASSERT3U(tx->tx_threads, ==, 2); |
34dc7c2f | 701 | if (txg == 0) |
428870ff | 702 | txg = tx->tx_open_txg + TXG_DEFER_SIZE; |
34dc7c2f BB |
703 | if (tx->tx_sync_txg_waiting < txg) |
704 | tx->tx_sync_txg_waiting = txg; | |
705 | dprintf("txg=%llu quiesce_txg=%llu sync_txg=%llu\n", | |
8e739b2c RE |
706 | (u_longlong_t)txg, (u_longlong_t)tx->tx_quiesce_txg_waiting, |
707 | (u_longlong_t)tx->tx_sync_txg_waiting); | |
34dc7c2f BB |
708 | while (tx->tx_synced_txg < txg) { |
709 | dprintf("broadcasting sync more " | |
30af21b0 | 710 | "tx_synced=%llu waiting=%llu dp=%px\n", |
8e739b2c RE |
711 | (u_longlong_t)tx->tx_synced_txg, |
712 | (u_longlong_t)tx->tx_sync_txg_waiting, dp); | |
34dc7c2f | 713 | cv_broadcast(&tx->tx_sync_more_cv); |
186898bb DB |
714 | if (wait_sig) { |
715 | /* | |
716 | * Condition wait here but stop if the thread receives a | |
717 | * signal. The caller may call txg_wait_synced*() again | |
718 | * to resume waiting for this txg. | |
719 | */ | |
720 | if (cv_wait_io_sig(&tx->tx_sync_done_cv, | |
721 | &tx->tx_sync_lock) == 0) { | |
722 | mutex_exit(&tx->tx_sync_lock); | |
723 | return (B_TRUE); | |
724 | } | |
725 | } else { | |
726 | cv_wait_io(&tx->tx_sync_done_cv, &tx->tx_sync_lock); | |
727 | } | |
34dc7c2f BB |
728 | } |
729 | mutex_exit(&tx->tx_sync_lock); | |
186898bb DB |
730 | return (B_FALSE); |
731 | } | |
732 | ||
733 | void | |
734 | txg_wait_synced(dsl_pool_t *dp, uint64_t txg) | |
735 | { | |
736 | VERIFY0(txg_wait_synced_impl(dp, txg, B_FALSE)); | |
737 | } | |
738 | ||
739 | /* | |
740 | * Similar to a txg_wait_synced but it can be interrupted from a signal. | |
741 | * Returns B_TRUE if the thread was signaled while waiting. | |
742 | */ | |
743 | boolean_t | |
744 | txg_wait_synced_sig(dsl_pool_t *dp, uint64_t txg) | |
745 | { | |
746 | return (txg_wait_synced_impl(dp, txg, B_TRUE)); | |
34dc7c2f BB |
747 | } |
748 | ||
1b939560 BB |
749 | /* |
750 | * Wait for the specified open transaction group. Set should_quiesce | |
751 | * when the current open txg should be quiesced immediately. | |
752 | */ | |
34dc7c2f | 753 | void |
1b939560 | 754 | txg_wait_open(dsl_pool_t *dp, uint64_t txg, boolean_t should_quiesce) |
34dc7c2f BB |
755 | { |
756 | tx_state_t *tx = &dp->dp_tx; | |
757 | ||
13fe0198 MA |
758 | ASSERT(!dsl_pool_config_held(dp)); |
759 | ||
34dc7c2f | 760 | mutex_enter(&tx->tx_sync_lock); |
1ce23dca | 761 | ASSERT3U(tx->tx_threads, ==, 2); |
34dc7c2f BB |
762 | if (txg == 0) |
763 | txg = tx->tx_open_txg + 1; | |
1b939560 | 764 | if (tx->tx_quiesce_txg_waiting < txg && should_quiesce) |
34dc7c2f BB |
765 | tx->tx_quiesce_txg_waiting = txg; |
766 | dprintf("txg=%llu quiesce_txg=%llu sync_txg=%llu\n", | |
8e739b2c RE |
767 | (u_longlong_t)txg, (u_longlong_t)tx->tx_quiesce_txg_waiting, |
768 | (u_longlong_t)tx->tx_sync_txg_waiting); | |
34dc7c2f BB |
769 | while (tx->tx_open_txg < txg) { |
770 | cv_broadcast(&tx->tx_quiesce_more_cv); | |
f4e35b16 BB |
771 | /* |
772 | * Callers setting should_quiesce will use cv_wait_io() and | |
773 | * be accounted for as iowait time. Otherwise, the caller is | |
774 | * understood to be idle and cv_wait_sig() is used to prevent | |
775 | * incorrectly inflating the system load average. | |
776 | */ | |
777 | if (should_quiesce == B_TRUE) { | |
778 | cv_wait_io(&tx->tx_quiesce_done_cv, &tx->tx_sync_lock); | |
779 | } else { | |
ac6e5fb2 MM |
780 | cv_wait_idle(&tx->tx_quiesce_done_cv, |
781 | &tx->tx_sync_lock); | |
f4e35b16 | 782 | } |
34dc7c2f BB |
783 | } |
784 | mutex_exit(&tx->tx_sync_lock); | |
785 | } | |
786 | ||
e8b96c60 | 787 | /* |
50e09edd | 788 | * Pass in the txg number that should be synced. |
e8b96c60 MA |
789 | */ |
790 | void | |
50e09edd | 791 | txg_kick(dsl_pool_t *dp, uint64_t txg) |
e8b96c60 MA |
792 | { |
793 | tx_state_t *tx = &dp->dp_tx; | |
794 | ||
795 | ASSERT(!dsl_pool_config_held(dp)); | |
796 | ||
50e09edd KJ |
797 | if (tx->tx_sync_txg_waiting >= txg) |
798 | return; | |
799 | ||
e8b96c60 | 800 | mutex_enter(&tx->tx_sync_lock); |
50e09edd KJ |
801 | if (tx->tx_sync_txg_waiting < txg) { |
802 | tx->tx_sync_txg_waiting = txg; | |
803 | cv_broadcast(&tx->tx_sync_more_cv); | |
e8b96c60 MA |
804 | } |
805 | mutex_exit(&tx->tx_sync_lock); | |
806 | } | |
807 | ||
b128c09f | 808 | boolean_t |
34dc7c2f BB |
809 | txg_stalled(dsl_pool_t *dp) |
810 | { | |
811 | tx_state_t *tx = &dp->dp_tx; | |
812 | return (tx->tx_quiesce_txg_waiting > tx->tx_open_txg); | |
813 | } | |
814 | ||
b128c09f BB |
815 | boolean_t |
816 | txg_sync_waiting(dsl_pool_t *dp) | |
817 | { | |
818 | tx_state_t *tx = &dp->dp_tx; | |
819 | ||
820 | return (tx->tx_syncing_txg <= tx->tx_sync_txg_waiting || | |
821 | tx->tx_quiesced_txg != 0); | |
822 | } | |
823 | ||
4747a7d3 MA |
824 | /* |
825 | * Verify that this txg is active (open, quiescing, syncing). Non-active | |
826 | * txg's should not be manipulated. | |
827 | */ | |
8c4fb36a | 828 | #ifdef ZFS_DEBUG |
4747a7d3 MA |
829 | void |
830 | txg_verify(spa_t *spa, uint64_t txg) | |
831 | { | |
2a8ba608 | 832 | dsl_pool_t *dp __maybe_unused = spa_get_dsl(spa); |
4747a7d3 MA |
833 | if (txg <= TXG_INITIAL || txg == ZILTEST_TXG) |
834 | return; | |
835 | ASSERT3U(txg, <=, dp->dp_tx.tx_open_txg); | |
836 | ASSERT3U(txg, >=, dp->dp_tx.tx_synced_txg); | |
837 | ASSERT3U(txg, >=, dp->dp_tx.tx_open_txg - TXG_CONCURRENT_STATES); | |
838 | } | |
8c4fb36a | 839 | #endif |
4747a7d3 | 840 | |
34dc7c2f BB |
841 | /* |
842 | * Per-txg object lists. | |
843 | */ | |
844 | void | |
4747a7d3 | 845 | txg_list_create(txg_list_t *tl, spa_t *spa, size_t offset) |
34dc7c2f BB |
846 | { |
847 | int t; | |
848 | ||
849 | mutex_init(&tl->tl_lock, NULL, MUTEX_DEFAULT, NULL); | |
850 | ||
851 | tl->tl_offset = offset; | |
4747a7d3 | 852 | tl->tl_spa = spa; |
34dc7c2f BB |
853 | |
854 | for (t = 0; t < TXG_SIZE; t++) | |
855 | tl->tl_head[t] = NULL; | |
856 | } | |
857 | ||
8c4fb36a TC |
858 | static boolean_t |
859 | txg_list_empty_impl(txg_list_t *tl, uint64_t txg) | |
860 | { | |
861 | ASSERT(MUTEX_HELD(&tl->tl_lock)); | |
862 | TXG_VERIFY(tl->tl_spa, txg); | |
863 | return (tl->tl_head[txg & TXG_MASK] == NULL); | |
864 | } | |
865 | ||
866 | boolean_t | |
867 | txg_list_empty(txg_list_t *tl, uint64_t txg) | |
868 | { | |
869 | mutex_enter(&tl->tl_lock); | |
870 | boolean_t ret = txg_list_empty_impl(tl, txg); | |
871 | mutex_exit(&tl->tl_lock); | |
872 | ||
873 | return (ret); | |
874 | } | |
875 | ||
34dc7c2f BB |
876 | void |
877 | txg_list_destroy(txg_list_t *tl) | |
878 | { | |
879 | int t; | |
880 | ||
8c4fb36a | 881 | mutex_enter(&tl->tl_lock); |
34dc7c2f | 882 | for (t = 0; t < TXG_SIZE; t++) |
8c4fb36a TC |
883 | ASSERT(txg_list_empty_impl(tl, t)); |
884 | mutex_exit(&tl->tl_lock); | |
34dc7c2f BB |
885 | |
886 | mutex_destroy(&tl->tl_lock); | |
887 | } | |
888 | ||
acbad6ff AR |
889 | /* |
890 | * Returns true if all txg lists are empty. | |
891 | * | |
892 | * Warning: this is inherently racy (an item could be added immediately | |
8c4fb36a | 893 | * after this function returns). |
acbad6ff AR |
894 | */ |
895 | boolean_t | |
896 | txg_all_lists_empty(txg_list_t *tl) | |
897 | { | |
8c4fb36a | 898 | mutex_enter(&tl->tl_lock); |
1c27024e | 899 | for (int i = 0; i < TXG_SIZE; i++) { |
8c4fb36a TC |
900 | if (!txg_list_empty_impl(tl, i)) { |
901 | mutex_exit(&tl->tl_lock); | |
acbad6ff AR |
902 | return (B_FALSE); |
903 | } | |
904 | } | |
8c4fb36a | 905 | mutex_exit(&tl->tl_lock); |
acbad6ff AR |
906 | return (B_TRUE); |
907 | } | |
908 | ||
34dc7c2f | 909 | /* |
13fe0198 MA |
910 | * Add an entry to the list (unless it's already on the list). |
911 | * Returns B_TRUE if it was actually added. | |
34dc7c2f | 912 | */ |
13fe0198 | 913 | boolean_t |
34dc7c2f BB |
914 | txg_list_add(txg_list_t *tl, void *p, uint64_t txg) |
915 | { | |
916 | int t = txg & TXG_MASK; | |
917 | txg_node_t *tn = (txg_node_t *)((char *)p + tl->tl_offset); | |
13fe0198 | 918 | boolean_t add; |
34dc7c2f | 919 | |
8c4fb36a | 920 | TXG_VERIFY(tl->tl_spa, txg); |
34dc7c2f | 921 | mutex_enter(&tl->tl_lock); |
13fe0198 MA |
922 | add = (tn->tn_member[t] == 0); |
923 | if (add) { | |
34dc7c2f BB |
924 | tn->tn_member[t] = 1; |
925 | tn->tn_next[t] = tl->tl_head[t]; | |
926 | tl->tl_head[t] = tn; | |
927 | } | |
928 | mutex_exit(&tl->tl_lock); | |
929 | ||
13fe0198 | 930 | return (add); |
34dc7c2f BB |
931 | } |
932 | ||
428870ff | 933 | /* |
13fe0198 MA |
934 | * Add an entry to the end of the list, unless it's already on the list. |
935 | * (walks list to find end) | |
936 | * Returns B_TRUE if it was actually added. | |
428870ff | 937 | */ |
13fe0198 | 938 | boolean_t |
428870ff BB |
939 | txg_list_add_tail(txg_list_t *tl, void *p, uint64_t txg) |
940 | { | |
941 | int t = txg & TXG_MASK; | |
942 | txg_node_t *tn = (txg_node_t *)((char *)p + tl->tl_offset); | |
13fe0198 | 943 | boolean_t add; |
428870ff | 944 | |
8c4fb36a | 945 | TXG_VERIFY(tl->tl_spa, txg); |
428870ff | 946 | mutex_enter(&tl->tl_lock); |
13fe0198 MA |
947 | add = (tn->tn_member[t] == 0); |
948 | if (add) { | |
428870ff BB |
949 | txg_node_t **tp; |
950 | ||
951 | for (tp = &tl->tl_head[t]; *tp != NULL; tp = &(*tp)->tn_next[t]) | |
952 | continue; | |
953 | ||
954 | tn->tn_member[t] = 1; | |
955 | tn->tn_next[t] = NULL; | |
956 | *tp = tn; | |
957 | } | |
958 | mutex_exit(&tl->tl_lock); | |
959 | ||
13fe0198 | 960 | return (add); |
428870ff BB |
961 | } |
962 | ||
34dc7c2f BB |
963 | /* |
964 | * Remove the head of the list and return it. | |
965 | */ | |
966 | void * | |
967 | txg_list_remove(txg_list_t *tl, uint64_t txg) | |
968 | { | |
969 | int t = txg & TXG_MASK; | |
970 | txg_node_t *tn; | |
971 | void *p = NULL; | |
972 | ||
8c4fb36a | 973 | TXG_VERIFY(tl->tl_spa, txg); |
34dc7c2f BB |
974 | mutex_enter(&tl->tl_lock); |
975 | if ((tn = tl->tl_head[t]) != NULL) { | |
a1d477c2 MA |
976 | ASSERT(tn->tn_member[t]); |
977 | ASSERT(tn->tn_next[t] == NULL || tn->tn_next[t]->tn_member[t]); | |
34dc7c2f BB |
978 | p = (char *)tn - tl->tl_offset; |
979 | tl->tl_head[t] = tn->tn_next[t]; | |
980 | tn->tn_next[t] = NULL; | |
981 | tn->tn_member[t] = 0; | |
982 | } | |
983 | mutex_exit(&tl->tl_lock); | |
984 | ||
985 | return (p); | |
986 | } | |
987 | ||
988 | /* | |
989 | * Remove a specific item from the list and return it. | |
990 | */ | |
991 | void * | |
992 | txg_list_remove_this(txg_list_t *tl, void *p, uint64_t txg) | |
993 | { | |
994 | int t = txg & TXG_MASK; | |
995 | txg_node_t *tn, **tp; | |
996 | ||
8c4fb36a | 997 | TXG_VERIFY(tl->tl_spa, txg); |
34dc7c2f BB |
998 | mutex_enter(&tl->tl_lock); |
999 | ||
1000 | for (tp = &tl->tl_head[t]; (tn = *tp) != NULL; tp = &tn->tn_next[t]) { | |
1001 | if ((char *)tn - tl->tl_offset == p) { | |
1002 | *tp = tn->tn_next[t]; | |
1003 | tn->tn_next[t] = NULL; | |
1004 | tn->tn_member[t] = 0; | |
1005 | mutex_exit(&tl->tl_lock); | |
1006 | return (p); | |
1007 | } | |
1008 | } | |
1009 | ||
1010 | mutex_exit(&tl->tl_lock); | |
1011 | ||
1012 | return (NULL); | |
1013 | } | |
1014 | ||
13fe0198 | 1015 | boolean_t |
34dc7c2f BB |
1016 | txg_list_member(txg_list_t *tl, void *p, uint64_t txg) |
1017 | { | |
1018 | int t = txg & TXG_MASK; | |
1019 | txg_node_t *tn = (txg_node_t *)((char *)p + tl->tl_offset); | |
1020 | ||
8c4fb36a | 1021 | TXG_VERIFY(tl->tl_spa, txg); |
13fe0198 | 1022 | return (tn->tn_member[t] != 0); |
34dc7c2f BB |
1023 | } |
1024 | ||
1025 | /* | |
8c4fb36a | 1026 | * Walk a txg list |
34dc7c2f BB |
1027 | */ |
1028 | void * | |
1029 | txg_list_head(txg_list_t *tl, uint64_t txg) | |
1030 | { | |
1031 | int t = txg & TXG_MASK; | |
8c4fb36a TC |
1032 | txg_node_t *tn; |
1033 | ||
1034 | mutex_enter(&tl->tl_lock); | |
1035 | tn = tl->tl_head[t]; | |
1036 | mutex_exit(&tl->tl_lock); | |
34dc7c2f | 1037 | |
8c4fb36a | 1038 | TXG_VERIFY(tl->tl_spa, txg); |
34dc7c2f BB |
1039 | return (tn == NULL ? NULL : (char *)tn - tl->tl_offset); |
1040 | } | |
1041 | ||
1042 | void * | |
1043 | txg_list_next(txg_list_t *tl, void *p, uint64_t txg) | |
1044 | { | |
1045 | int t = txg & TXG_MASK; | |
1046 | txg_node_t *tn = (txg_node_t *)((char *)p + tl->tl_offset); | |
1047 | ||
8c4fb36a TC |
1048 | TXG_VERIFY(tl->tl_spa, txg); |
1049 | ||
1050 | mutex_enter(&tl->tl_lock); | |
34dc7c2f | 1051 | tn = tn->tn_next[t]; |
8c4fb36a | 1052 | mutex_exit(&tl->tl_lock); |
34dc7c2f BB |
1053 | |
1054 | return (tn == NULL ? NULL : (char *)tn - tl->tl_offset); | |
1055 | } | |
c28b2279 | 1056 | |
c28b2279 BB |
1057 | EXPORT_SYMBOL(txg_init); |
1058 | EXPORT_SYMBOL(txg_fini); | |
1059 | EXPORT_SYMBOL(txg_sync_start); | |
1060 | EXPORT_SYMBOL(txg_sync_stop); | |
1061 | EXPORT_SYMBOL(txg_hold_open); | |
1062 | EXPORT_SYMBOL(txg_rele_to_quiesce); | |
1063 | EXPORT_SYMBOL(txg_rele_to_sync); | |
1064 | EXPORT_SYMBOL(txg_register_callbacks); | |
1065 | EXPORT_SYMBOL(txg_delay); | |
1066 | EXPORT_SYMBOL(txg_wait_synced); | |
1067 | EXPORT_SYMBOL(txg_wait_open); | |
54a179e7 | 1068 | EXPORT_SYMBOL(txg_wait_callbacks); |
c28b2279 BB |
1069 | EXPORT_SYMBOL(txg_stalled); |
1070 | EXPORT_SYMBOL(txg_sync_waiting); | |
87d98efe | 1071 | |
a7929f31 | 1072 | ZFS_MODULE_PARAM(zfs_txg, zfs_txg_, timeout, INT, ZMOD_RW, |
03fdcb9a | 1073 | "Max seconds worth of delta per txg"); |