xref: /linux/fs/bcachefs/journal.c (revision c24999e61b2187578fe4256b7bc6190a046c4b93)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * bcachefs journalling code, for btree insertions
4  *
5  * Copyright 2012 Google, Inc.
6  */
7 
8 #include "bcachefs.h"
9 #include "alloc_foreground.h"
10 #include "bkey_methods.h"
11 #include "btree_gc.h"
12 #include "btree_update.h"
13 #include "btree_write_buffer.h"
14 #include "buckets.h"
15 #include "error.h"
16 #include "journal.h"
17 #include "journal_io.h"
18 #include "journal_reclaim.h"
19 #include "journal_sb.h"
20 #include "journal_seq_blacklist.h"
21 #include "trace.h"
22 
23 static const char * const bch2_journal_errors[] = {
24 #define x(n)	#n,
25 	JOURNAL_ERRORS()
26 #undef x
27 	NULL
28 };
29 
30 static inline bool journal_seq_unwritten(struct journal *j, u64 seq)
31 {
32 	return seq > j->seq_ondisk;
33 }
34 
35 static bool __journal_entry_is_open(union journal_res_state state)
36 {
37 	return state.cur_entry_offset < JOURNAL_ENTRY_CLOSED_VAL;
38 }
39 
40 static inline unsigned nr_unwritten_journal_entries(struct journal *j)
41 {
42 	return atomic64_read(&j->seq) - j->seq_ondisk;
43 }
44 
45 static bool journal_entry_is_open(struct journal *j)
46 {
47 	return __journal_entry_is_open(j->reservations);
48 }
49 
50 static void bch2_journal_buf_to_text(struct printbuf *out, struct journal *j, u64 seq)
51 {
52 	union journal_res_state s = READ_ONCE(j->reservations);
53 	unsigned i = seq & JOURNAL_BUF_MASK;
54 	struct journal_buf *buf = j->buf + i;
55 
56 	prt_printf(out, "seq:\t%llu\n", seq);
57 	printbuf_indent_add(out, 2);
58 
59 	prt_printf(out, "refcount:\t%u\n", journal_state_count(s, i));
60 
61 	prt_printf(out, "size:\t");
62 	prt_human_readable_u64(out, vstruct_bytes(buf->data));
63 	prt_newline(out);
64 
65 	prt_printf(out, "expires:\t");
66 	prt_printf(out, "%li jiffies\n", buf->expires - jiffies);
67 
68 	prt_printf(out, "flags:\t");
69 	if (buf->noflush)
70 		prt_str(out, "noflush ");
71 	if (buf->must_flush)
72 		prt_str(out, "must_flush ");
73 	if (buf->separate_flush)
74 		prt_str(out, "separate_flush ");
75 	if (buf->need_flush_to_write_buffer)
76 		prt_str(out, "need_flush_to_write_buffer ");
77 	if (buf->write_started)
78 		prt_str(out, "write_started ");
79 	if (buf->write_allocated)
80 		prt_str(out, "write_allocated ");
81 	if (buf->write_done)
82 		prt_str(out, "write_done");
83 	prt_newline(out);
84 
85 	printbuf_indent_sub(out, 2);
86 }
87 
88 static void bch2_journal_bufs_to_text(struct printbuf *out, struct journal *j)
89 {
90 	if (!out->nr_tabstops)
91 		printbuf_tabstop_push(out, 24);
92 
93 	for (u64 seq = journal_last_unwritten_seq(j);
94 	     seq <= journal_cur_seq(j);
95 	     seq++)
96 		bch2_journal_buf_to_text(out, j, seq);
97 	prt_printf(out, "last buf %s\n", journal_entry_is_open(j) ? "open" : "closed");
98 }
99 
100 static inline struct journal_buf *
101 journal_seq_to_buf(struct journal *j, u64 seq)
102 {
103 	struct journal_buf *buf = NULL;
104 
105 	EBUG_ON(seq > journal_cur_seq(j));
106 
107 	if (journal_seq_unwritten(j, seq)) {
108 		buf = j->buf + (seq & JOURNAL_BUF_MASK);
109 		EBUG_ON(le64_to_cpu(buf->data->seq) != seq);
110 	}
111 	return buf;
112 }
113 
114 static void journal_pin_list_init(struct journal_entry_pin_list *p, int count)
115 {
116 	unsigned i;
117 
118 	for (i = 0; i < ARRAY_SIZE(p->list); i++)
119 		INIT_LIST_HEAD(&p->list[i]);
120 	INIT_LIST_HEAD(&p->flushed);
121 	atomic_set(&p->count, count);
122 	p->devs.nr = 0;
123 }
124 
125 /*
126  * Detect stuck journal conditions and trigger shutdown. Technically the journal
127  * can end up stuck for a variety of reasons, such as a blocked I/O, journal
128  * reservation lockup, etc. Since this is a fatal error with potentially
129  * unpredictable characteristics, we want to be fairly conservative before we
130  * decide to shut things down.
131  *
132  * Consider the journal stuck when it appears full with no ability to commit
133  * btree transactions, to discard journal buckets, nor acquire priority
134  * (reserved watermark) reservation.
135  */
136 static inline bool
137 journal_error_check_stuck(struct journal *j, int error, unsigned flags)
138 {
139 	struct bch_fs *c = container_of(j, struct bch_fs, journal);
140 	bool stuck = false;
141 	struct printbuf buf = PRINTBUF;
142 
143 	if (!(error == JOURNAL_ERR_journal_full ||
144 	      error == JOURNAL_ERR_journal_pin_full) ||
145 	    nr_unwritten_journal_entries(j) ||
146 	    (flags & BCH_WATERMARK_MASK) != BCH_WATERMARK_reclaim)
147 		return stuck;
148 
149 	spin_lock(&j->lock);
150 
151 	if (j->can_discard) {
152 		spin_unlock(&j->lock);
153 		return stuck;
154 	}
155 
156 	stuck = true;
157 
158 	/*
159 	 * The journal shutdown path will set ->err_seq, but do it here first to
160 	 * serialize against concurrent failures and avoid duplicate error
161 	 * reports.
162 	 */
163 	if (j->err_seq) {
164 		spin_unlock(&j->lock);
165 		return stuck;
166 	}
167 	j->err_seq = journal_cur_seq(j);
168 	spin_unlock(&j->lock);
169 
170 	bch_err(c, "Journal stuck! Hava a pre-reservation but journal full (error %s)",
171 		bch2_journal_errors[error]);
172 	bch2_journal_debug_to_text(&buf, j);
173 	bch_err(c, "%s", buf.buf);
174 
175 	printbuf_reset(&buf);
176 	bch2_journal_pins_to_text(&buf, j);
177 	bch_err(c, "Journal pins:\n%s", buf.buf);
178 	printbuf_exit(&buf);
179 
180 	bch2_fatal_error(c);
181 	dump_stack();
182 
183 	return stuck;
184 }
185 
186 void bch2_journal_do_writes(struct journal *j)
187 {
188 	for (u64 seq = journal_last_unwritten_seq(j);
189 	     seq <= journal_cur_seq(j);
190 	     seq++) {
191 		unsigned idx = seq & JOURNAL_BUF_MASK;
192 		struct journal_buf *w = j->buf + idx;
193 
194 		if (w->write_started && !w->write_allocated)
195 			break;
196 		if (w->write_started)
197 			continue;
198 
199 		if (!journal_state_count(j->reservations, idx)) {
200 			w->write_started = true;
201 			closure_call(&w->io, bch2_journal_write, j->wq, NULL);
202 		}
203 
204 		break;
205 	}
206 }
207 
208 /*
209  * Final processing when the last reference of a journal buffer has been
210  * dropped. Drop the pin list reference acquired at journal entry open and write
211  * the buffer, if requested.
212  */
213 void bch2_journal_buf_put_final(struct journal *j, u64 seq)
214 {
215 	lockdep_assert_held(&j->lock);
216 
217 	if (__bch2_journal_pin_put(j, seq))
218 		bch2_journal_reclaim_fast(j);
219 	bch2_journal_do_writes(j);
220 }
221 
222 /*
223  * Returns true if journal entry is now closed:
224  *
225  * We don't close a journal_buf until the next journal_buf is finished writing,
226  * and can be opened again - this also initializes the next journal_buf:
227  */
228 static void __journal_entry_close(struct journal *j, unsigned closed_val, bool trace)
229 {
230 	struct bch_fs *c = container_of(j, struct bch_fs, journal);
231 	struct journal_buf *buf = journal_cur_buf(j);
232 	union journal_res_state old, new;
233 	unsigned sectors;
234 
235 	BUG_ON(closed_val != JOURNAL_ENTRY_CLOSED_VAL &&
236 	       closed_val != JOURNAL_ENTRY_ERROR_VAL);
237 
238 	lockdep_assert_held(&j->lock);
239 
240 	old.v = atomic64_read(&j->reservations.counter);
241 	do {
242 		new.v = old.v;
243 		new.cur_entry_offset = closed_val;
244 
245 		if (old.cur_entry_offset == JOURNAL_ENTRY_ERROR_VAL ||
246 		    old.cur_entry_offset == new.cur_entry_offset)
247 			return;
248 	} while (!atomic64_try_cmpxchg(&j->reservations.counter,
249 				       &old.v, new.v));
250 
251 	if (!__journal_entry_is_open(old))
252 		return;
253 
254 	/* Close out old buffer: */
255 	buf->data->u64s		= cpu_to_le32(old.cur_entry_offset);
256 
257 	if (trace_journal_entry_close_enabled() && trace) {
258 		struct printbuf pbuf = PRINTBUF;
259 		pbuf.atomic++;
260 
261 		prt_str(&pbuf, "entry size: ");
262 		prt_human_readable_u64(&pbuf, vstruct_bytes(buf->data));
263 		prt_newline(&pbuf);
264 		bch2_prt_task_backtrace(&pbuf, current, 1, GFP_NOWAIT);
265 		trace_journal_entry_close(c, pbuf.buf);
266 		printbuf_exit(&pbuf);
267 	}
268 
269 	sectors = vstruct_blocks_plus(buf->data, c->block_bits,
270 				      buf->u64s_reserved) << c->block_bits;
271 	BUG_ON(sectors > buf->sectors);
272 	buf->sectors = sectors;
273 
274 	/*
275 	 * We have to set last_seq here, _before_ opening a new journal entry:
276 	 *
277 	 * A threads may replace an old pin with a new pin on their current
278 	 * journal reservation - the expectation being that the journal will
279 	 * contain either what the old pin protected or what the new pin
280 	 * protects.
281 	 *
282 	 * After the old pin is dropped journal_last_seq() won't include the old
283 	 * pin, so we can only write the updated last_seq on the entry that
284 	 * contains whatever the new pin protects.
285 	 *
286 	 * Restated, we can _not_ update last_seq for a given entry if there
287 	 * could be a newer entry open with reservations/pins that have been
288 	 * taken against it.
289 	 *
290 	 * Hence, we want update/set last_seq on the current journal entry right
291 	 * before we open a new one:
292 	 */
293 	buf->last_seq		= journal_last_seq(j);
294 	buf->data->last_seq	= cpu_to_le64(buf->last_seq);
295 	BUG_ON(buf->last_seq > le64_to_cpu(buf->data->seq));
296 
297 	cancel_delayed_work(&j->write_work);
298 
299 	bch2_journal_space_available(j);
300 
301 	__bch2_journal_buf_put(j, old.idx, le64_to_cpu(buf->data->seq));
302 }
303 
304 void bch2_journal_halt(struct journal *j)
305 {
306 	spin_lock(&j->lock);
307 	__journal_entry_close(j, JOURNAL_ENTRY_ERROR_VAL, true);
308 	if (!j->err_seq)
309 		j->err_seq = journal_cur_seq(j);
310 	journal_wake(j);
311 	spin_unlock(&j->lock);
312 }
313 
314 static bool journal_entry_want_write(struct journal *j)
315 {
316 	bool ret = !journal_entry_is_open(j) ||
317 		journal_cur_seq(j) == journal_last_unwritten_seq(j);
318 
319 	/* Don't close it yet if we already have a write in flight: */
320 	if (ret)
321 		__journal_entry_close(j, JOURNAL_ENTRY_CLOSED_VAL, true);
322 	else if (nr_unwritten_journal_entries(j)) {
323 		struct journal_buf *buf = journal_cur_buf(j);
324 
325 		if (!buf->flush_time) {
326 			buf->flush_time	= local_clock() ?: 1;
327 			buf->expires = jiffies;
328 		}
329 	}
330 
331 	return ret;
332 }
333 
334 bool bch2_journal_entry_close(struct journal *j)
335 {
336 	bool ret;
337 
338 	spin_lock(&j->lock);
339 	ret = journal_entry_want_write(j);
340 	spin_unlock(&j->lock);
341 
342 	return ret;
343 }
344 
345 /*
346  * should _only_ called from journal_res_get() - when we actually want a
347  * journal reservation - journal entry is open means journal is dirty:
348  */
349 static int journal_entry_open(struct journal *j)
350 {
351 	struct bch_fs *c = container_of(j, struct bch_fs, journal);
352 	struct journal_buf *buf = j->buf +
353 		((journal_cur_seq(j) + 1) & JOURNAL_BUF_MASK);
354 	union journal_res_state old, new;
355 	int u64s;
356 
357 	lockdep_assert_held(&j->lock);
358 	BUG_ON(journal_entry_is_open(j));
359 	BUG_ON(BCH_SB_CLEAN(c->disk_sb.sb));
360 
361 	if (j->blocked)
362 		return JOURNAL_ERR_blocked;
363 
364 	if (j->cur_entry_error)
365 		return j->cur_entry_error;
366 
367 	if (bch2_journal_error(j))
368 		return JOURNAL_ERR_insufficient_devices; /* -EROFS */
369 
370 	if (!fifo_free(&j->pin))
371 		return JOURNAL_ERR_journal_pin_full;
372 
373 	if (nr_unwritten_journal_entries(j) == ARRAY_SIZE(j->buf))
374 		return JOURNAL_ERR_max_in_flight;
375 
376 	BUG_ON(!j->cur_entry_sectors);
377 
378 	buf->expires		=
379 		(journal_cur_seq(j) == j->flushed_seq_ondisk
380 		 ? jiffies
381 		 : j->last_flush_write) +
382 		msecs_to_jiffies(c->opts.journal_flush_delay);
383 
384 	buf->u64s_reserved	= j->entry_u64s_reserved;
385 	buf->disk_sectors	= j->cur_entry_sectors;
386 	buf->sectors		= min(buf->disk_sectors, buf->buf_size >> 9);
387 
388 	u64s = (int) (buf->sectors << 9) / sizeof(u64) -
389 		journal_entry_overhead(j);
390 	u64s = clamp_t(int, u64s, 0, JOURNAL_ENTRY_CLOSED_VAL - 1);
391 
392 	if (u64s <= (ssize_t) j->early_journal_entries.nr)
393 		return JOURNAL_ERR_journal_full;
394 
395 	if (fifo_empty(&j->pin) && j->reclaim_thread)
396 		wake_up_process(j->reclaim_thread);
397 
398 	/*
399 	 * The fifo_push() needs to happen at the same time as j->seq is
400 	 * incremented for journal_last_seq() to be calculated correctly
401 	 */
402 	atomic64_inc(&j->seq);
403 	journal_pin_list_init(fifo_push_ref(&j->pin), 1);
404 
405 	BUG_ON(j->pin.back - 1 != atomic64_read(&j->seq));
406 
407 	BUG_ON(j->buf + (journal_cur_seq(j) & JOURNAL_BUF_MASK) != buf);
408 
409 	bkey_extent_init(&buf->key);
410 	buf->noflush		= false;
411 	buf->must_flush		= false;
412 	buf->separate_flush	= false;
413 	buf->flush_time		= 0;
414 	buf->need_flush_to_write_buffer = true;
415 	buf->write_started	= false;
416 	buf->write_allocated	= false;
417 	buf->write_done		= false;
418 
419 	memset(buf->data, 0, sizeof(*buf->data));
420 	buf->data->seq	= cpu_to_le64(journal_cur_seq(j));
421 	buf->data->u64s	= 0;
422 
423 	if (j->early_journal_entries.nr) {
424 		memcpy(buf->data->_data, j->early_journal_entries.data,
425 		       j->early_journal_entries.nr * sizeof(u64));
426 		le32_add_cpu(&buf->data->u64s, j->early_journal_entries.nr);
427 	}
428 
429 	/*
430 	 * Must be set before marking the journal entry as open:
431 	 */
432 	j->cur_entry_u64s = u64s;
433 
434 	old.v = atomic64_read(&j->reservations.counter);
435 	do {
436 		new.v = old.v;
437 
438 		BUG_ON(old.cur_entry_offset == JOURNAL_ENTRY_ERROR_VAL);
439 
440 		new.idx++;
441 		BUG_ON(journal_state_count(new, new.idx));
442 		BUG_ON(new.idx != (journal_cur_seq(j) & JOURNAL_BUF_MASK));
443 
444 		journal_state_inc(&new);
445 
446 		/* Handle any already added entries */
447 		new.cur_entry_offset = le32_to_cpu(buf->data->u64s);
448 	} while (!atomic64_try_cmpxchg(&j->reservations.counter,
449 				       &old.v, new.v));
450 
451 	if (nr_unwritten_journal_entries(j) == 1)
452 		mod_delayed_work(j->wq,
453 				 &j->write_work,
454 				 msecs_to_jiffies(c->opts.journal_flush_delay));
455 	journal_wake(j);
456 
457 	if (j->early_journal_entries.nr)
458 		darray_exit(&j->early_journal_entries);
459 	return 0;
460 }
461 
462 static bool journal_quiesced(struct journal *j)
463 {
464 	bool ret = atomic64_read(&j->seq) == j->seq_ondisk;
465 
466 	if (!ret)
467 		bch2_journal_entry_close(j);
468 	return ret;
469 }
470 
471 static void journal_quiesce(struct journal *j)
472 {
473 	wait_event(j->wait, journal_quiesced(j));
474 }
475 
476 static void journal_write_work(struct work_struct *work)
477 {
478 	struct journal *j = container_of(work, struct journal, write_work.work);
479 
480 	spin_lock(&j->lock);
481 	if (__journal_entry_is_open(j->reservations)) {
482 		long delta = journal_cur_buf(j)->expires - jiffies;
483 
484 		if (delta > 0)
485 			mod_delayed_work(j->wq, &j->write_work, delta);
486 		else
487 			__journal_entry_close(j, JOURNAL_ENTRY_CLOSED_VAL, true);
488 	}
489 	spin_unlock(&j->lock);
490 }
491 
492 static int __journal_res_get(struct journal *j, struct journal_res *res,
493 			     unsigned flags)
494 {
495 	struct bch_fs *c = container_of(j, struct bch_fs, journal);
496 	struct journal_buf *buf;
497 	bool can_discard;
498 	int ret;
499 retry:
500 	if (journal_res_get_fast(j, res, flags))
501 		return 0;
502 
503 	if (bch2_journal_error(j))
504 		return -BCH_ERR_erofs_journal_err;
505 
506 	if (j->blocked)
507 		return -BCH_ERR_journal_res_get_blocked;
508 
509 	if ((flags & BCH_WATERMARK_MASK) < j->watermark) {
510 		ret = JOURNAL_ERR_journal_full;
511 		can_discard = j->can_discard;
512 		goto out;
513 	}
514 
515 	if (nr_unwritten_journal_entries(j) == ARRAY_SIZE(j->buf) && !journal_entry_is_open(j)) {
516 		ret = JOURNAL_ERR_max_in_flight;
517 		goto out;
518 	}
519 
520 	spin_lock(&j->lock);
521 
522 	/*
523 	 * Recheck after taking the lock, so we don't race with another thread
524 	 * that just did journal_entry_open() and call bch2_journal_entry_close()
525 	 * unnecessarily
526 	 */
527 	if (journal_res_get_fast(j, res, flags)) {
528 		ret = 0;
529 		goto unlock;
530 	}
531 
532 	/*
533 	 * If we couldn't get a reservation because the current buf filled up,
534 	 * and we had room for a bigger entry on disk, signal that we want to
535 	 * realloc the journal bufs:
536 	 */
537 	buf = journal_cur_buf(j);
538 	if (journal_entry_is_open(j) &&
539 	    buf->buf_size >> 9 < buf->disk_sectors &&
540 	    buf->buf_size < JOURNAL_ENTRY_SIZE_MAX)
541 		j->buf_size_want = max(j->buf_size_want, buf->buf_size << 1);
542 
543 	__journal_entry_close(j, JOURNAL_ENTRY_CLOSED_VAL, false);
544 	ret = journal_entry_open(j) ?: JOURNAL_ERR_retry;
545 unlock:
546 	can_discard = j->can_discard;
547 	spin_unlock(&j->lock);
548 out:
549 	if (ret == JOURNAL_ERR_retry)
550 		goto retry;
551 	if (!ret)
552 		return 0;
553 
554 	if (journal_error_check_stuck(j, ret, flags))
555 		ret = -BCH_ERR_journal_res_get_blocked;
556 
557 	if (ret == JOURNAL_ERR_max_in_flight &&
558 	    track_event_change(&c->times[BCH_TIME_blocked_journal_max_in_flight], true)) {
559 
560 		struct printbuf buf = PRINTBUF;
561 		prt_printf(&buf, "seq %llu\n", journal_cur_seq(j));
562 		bch2_journal_bufs_to_text(&buf, j);
563 		trace_journal_entry_full(c, buf.buf);
564 		printbuf_exit(&buf);
565 		count_event(c, journal_entry_full);
566 	}
567 
568 	/*
569 	 * Journal is full - can't rely on reclaim from work item due to
570 	 * freezing:
571 	 */
572 	if ((ret == JOURNAL_ERR_journal_full ||
573 	     ret == JOURNAL_ERR_journal_pin_full) &&
574 	    !(flags & JOURNAL_RES_GET_NONBLOCK)) {
575 		if (can_discard) {
576 			bch2_journal_do_discards(j);
577 			goto retry;
578 		}
579 
580 		if (mutex_trylock(&j->reclaim_lock)) {
581 			bch2_journal_reclaim(j);
582 			mutex_unlock(&j->reclaim_lock);
583 		}
584 	}
585 
586 	return ret == JOURNAL_ERR_insufficient_devices
587 		? -BCH_ERR_erofs_journal_err
588 		: -BCH_ERR_journal_res_get_blocked;
589 }
590 
591 /*
592  * Essentially the entry function to the journaling code. When bcachefs is doing
593  * a btree insert, it calls this function to get the current journal write.
594  * Journal write is the structure used set up journal writes. The calling
595  * function will then add its keys to the structure, queuing them for the next
596  * write.
597  *
598  * To ensure forward progress, the current task must not be holding any
599  * btree node write locks.
600  */
601 int bch2_journal_res_get_slowpath(struct journal *j, struct journal_res *res,
602 				  unsigned flags)
603 {
604 	int ret;
605 
606 	closure_wait_event(&j->async_wait,
607 		   (ret = __journal_res_get(j, res, flags)) != -BCH_ERR_journal_res_get_blocked ||
608 		   (flags & JOURNAL_RES_GET_NONBLOCK));
609 	return ret;
610 }
611 
612 /* journal_entry_res: */
613 
614 void bch2_journal_entry_res_resize(struct journal *j,
615 				   struct journal_entry_res *res,
616 				   unsigned new_u64s)
617 {
618 	union journal_res_state state;
619 	int d = new_u64s - res->u64s;
620 
621 	spin_lock(&j->lock);
622 
623 	j->entry_u64s_reserved += d;
624 	if (d <= 0)
625 		goto out;
626 
627 	j->cur_entry_u64s = max_t(int, 0, j->cur_entry_u64s - d);
628 	smp_mb();
629 	state = READ_ONCE(j->reservations);
630 
631 	if (state.cur_entry_offset < JOURNAL_ENTRY_CLOSED_VAL &&
632 	    state.cur_entry_offset > j->cur_entry_u64s) {
633 		j->cur_entry_u64s += d;
634 		/*
635 		 * Not enough room in current journal entry, have to flush it:
636 		 */
637 		__journal_entry_close(j, JOURNAL_ENTRY_CLOSED_VAL, true);
638 	} else {
639 		journal_cur_buf(j)->u64s_reserved += d;
640 	}
641 out:
642 	spin_unlock(&j->lock);
643 	res->u64s += d;
644 }
645 
646 /* journal flushing: */
647 
648 /**
649  * bch2_journal_flush_seq_async - wait for a journal entry to be written
650  * @j:		journal object
651  * @seq:	seq to flush
652  * @parent:	closure object to wait with
653  * Returns:	1 if @seq has already been flushed, 0 if @seq is being flushed,
654  *		-EIO if @seq will never be flushed
655  *
656  * Like bch2_journal_wait_on_seq, except that it triggers a write immediately if
657  * necessary
658  */
659 int bch2_journal_flush_seq_async(struct journal *j, u64 seq,
660 				 struct closure *parent)
661 {
662 	struct journal_buf *buf;
663 	int ret = 0;
664 
665 	if (seq <= j->flushed_seq_ondisk)
666 		return 1;
667 
668 	spin_lock(&j->lock);
669 
670 	if (WARN_ONCE(seq > journal_cur_seq(j),
671 		      "requested to flush journal seq %llu, but currently at %llu",
672 		      seq, journal_cur_seq(j)))
673 		goto out;
674 
675 	/* Recheck under lock: */
676 	if (j->err_seq && seq >= j->err_seq) {
677 		ret = -EIO;
678 		goto out;
679 	}
680 
681 	if (seq <= j->flushed_seq_ondisk) {
682 		ret = 1;
683 		goto out;
684 	}
685 
686 	/* if seq was written, but not flushed - flush a newer one instead */
687 	seq = max(seq, journal_last_unwritten_seq(j));
688 
689 recheck_need_open:
690 	if (seq > journal_cur_seq(j)) {
691 		struct journal_res res = { 0 };
692 
693 		if (journal_entry_is_open(j))
694 			__journal_entry_close(j, JOURNAL_ENTRY_CLOSED_VAL, true);
695 
696 		spin_unlock(&j->lock);
697 
698 		/*
699 		 * We're called from bch2_journal_flush_seq() -> wait_event();
700 		 * but this might block. We won't usually block, so we won't
701 		 * livelock:
702 		 */
703 		sched_annotate_sleep();
704 		ret = bch2_journal_res_get(j, &res, jset_u64s(0), 0);
705 		if (ret)
706 			return ret;
707 
708 		seq = res.seq;
709 		buf = journal_seq_to_buf(j, seq);
710 		buf->must_flush = true;
711 
712 		if (!buf->flush_time) {
713 			buf->flush_time	= local_clock() ?: 1;
714 			buf->expires = jiffies;
715 		}
716 
717 		if (parent && !closure_wait(&buf->wait, parent))
718 			BUG();
719 
720 		bch2_journal_res_put(j, &res);
721 
722 		spin_lock(&j->lock);
723 		goto want_write;
724 	}
725 
726 	/*
727 	 * if write was kicked off without a flush, or if we promised it
728 	 * wouldn't be a flush, flush the next sequence number instead
729 	 */
730 	buf = journal_seq_to_buf(j, seq);
731 	if (buf->noflush) {
732 		seq++;
733 		goto recheck_need_open;
734 	}
735 
736 	buf->must_flush = true;
737 
738 	if (parent && !closure_wait(&buf->wait, parent))
739 		BUG();
740 want_write:
741 	if (seq == journal_cur_seq(j))
742 		journal_entry_want_write(j);
743 out:
744 	spin_unlock(&j->lock);
745 	return ret;
746 }
747 
748 int bch2_journal_flush_seq(struct journal *j, u64 seq)
749 {
750 	u64 start_time = local_clock();
751 	int ret, ret2;
752 
753 	/*
754 	 * Don't update time_stats when @seq is already flushed:
755 	 */
756 	if (seq <= j->flushed_seq_ondisk)
757 		return 0;
758 
759 	ret = wait_event_interruptible(j->wait, (ret2 = bch2_journal_flush_seq_async(j, seq, NULL)));
760 
761 	if (!ret)
762 		bch2_time_stats_update(j->flush_seq_time, start_time);
763 
764 	return ret ?: ret2 < 0 ? ret2 : 0;
765 }
766 
767 /*
768  * bch2_journal_flush_async - if there is an open journal entry, or a journal
769  * still being written, write it and wait for the write to complete
770  */
771 void bch2_journal_flush_async(struct journal *j, struct closure *parent)
772 {
773 	bch2_journal_flush_seq_async(j, atomic64_read(&j->seq), parent);
774 }
775 
776 int bch2_journal_flush(struct journal *j)
777 {
778 	return bch2_journal_flush_seq(j, atomic64_read(&j->seq));
779 }
780 
781 /*
782  * bch2_journal_noflush_seq - tell the journal not to issue any flushes before
783  * @seq
784  */
785 bool bch2_journal_noflush_seq(struct journal *j, u64 seq)
786 {
787 	struct bch_fs *c = container_of(j, struct bch_fs, journal);
788 	u64 unwritten_seq;
789 	bool ret = false;
790 
791 	if (!(c->sb.features & (1ULL << BCH_FEATURE_journal_no_flush)))
792 		return false;
793 
794 	if (seq <= c->journal.flushed_seq_ondisk)
795 		return false;
796 
797 	spin_lock(&j->lock);
798 	if (seq <= c->journal.flushed_seq_ondisk)
799 		goto out;
800 
801 	for (unwritten_seq = journal_last_unwritten_seq(j);
802 	     unwritten_seq < seq;
803 	     unwritten_seq++) {
804 		struct journal_buf *buf = journal_seq_to_buf(j, unwritten_seq);
805 
806 		/* journal flush already in flight, or flush requseted */
807 		if (buf->must_flush)
808 			goto out;
809 
810 		buf->noflush = true;
811 	}
812 
813 	ret = true;
814 out:
815 	spin_unlock(&j->lock);
816 	return ret;
817 }
818 
819 int bch2_journal_meta(struct journal *j)
820 {
821 	struct journal_buf *buf;
822 	struct journal_res res;
823 	int ret;
824 
825 	memset(&res, 0, sizeof(res));
826 
827 	ret = bch2_journal_res_get(j, &res, jset_u64s(0), 0);
828 	if (ret)
829 		return ret;
830 
831 	buf = j->buf + (res.seq & JOURNAL_BUF_MASK);
832 	buf->must_flush = true;
833 
834 	if (!buf->flush_time) {
835 		buf->flush_time	= local_clock() ?: 1;
836 		buf->expires = jiffies;
837 	}
838 
839 	bch2_journal_res_put(j, &res);
840 
841 	return bch2_journal_flush_seq(j, res.seq);
842 }
843 
844 /* block/unlock the journal: */
845 
846 void bch2_journal_unblock(struct journal *j)
847 {
848 	spin_lock(&j->lock);
849 	j->blocked--;
850 	spin_unlock(&j->lock);
851 
852 	journal_wake(j);
853 }
854 
855 void bch2_journal_block(struct journal *j)
856 {
857 	spin_lock(&j->lock);
858 	j->blocked++;
859 	spin_unlock(&j->lock);
860 
861 	journal_quiesce(j);
862 }
863 
864 static struct journal_buf *__bch2_next_write_buffer_flush_journal_buf(struct journal *j, u64 max_seq)
865 {
866 	struct journal_buf *ret = NULL;
867 
868 	/* We're inside wait_event(), but using mutex_lock(: */
869 	sched_annotate_sleep();
870 	mutex_lock(&j->buf_lock);
871 	spin_lock(&j->lock);
872 	max_seq = min(max_seq, journal_cur_seq(j));
873 
874 	for (u64 seq = journal_last_unwritten_seq(j);
875 	     seq <= max_seq;
876 	     seq++) {
877 		unsigned idx = seq & JOURNAL_BUF_MASK;
878 		struct journal_buf *buf = j->buf + idx;
879 
880 		if (buf->need_flush_to_write_buffer) {
881 			if (seq == journal_cur_seq(j))
882 				__journal_entry_close(j, JOURNAL_ENTRY_CLOSED_VAL, true);
883 
884 			union journal_res_state s;
885 			s.v = atomic64_read_acquire(&j->reservations.counter);
886 
887 			ret = journal_state_count(s, idx)
888 				? ERR_PTR(-EAGAIN)
889 				: buf;
890 			break;
891 		}
892 	}
893 
894 	spin_unlock(&j->lock);
895 	if (IS_ERR_OR_NULL(ret))
896 		mutex_unlock(&j->buf_lock);
897 	return ret;
898 }
899 
900 struct journal_buf *bch2_next_write_buffer_flush_journal_buf(struct journal *j, u64 max_seq)
901 {
902 	struct journal_buf *ret;
903 
904 	wait_event(j->wait, (ret = __bch2_next_write_buffer_flush_journal_buf(j, max_seq)) != ERR_PTR(-EAGAIN));
905 	return ret;
906 }
907 
908 /* allocate journal on a device: */
909 
910 static int __bch2_set_nr_journal_buckets(struct bch_dev *ca, unsigned nr,
911 					 bool new_fs, struct closure *cl)
912 {
913 	struct bch_fs *c = ca->fs;
914 	struct journal_device *ja = &ca->journal;
915 	u64 *new_bucket_seq = NULL, *new_buckets = NULL;
916 	struct open_bucket **ob = NULL;
917 	long *bu = NULL;
918 	unsigned i, pos, nr_got = 0, nr_want = nr - ja->nr;
919 	int ret = 0;
920 
921 	BUG_ON(nr <= ja->nr);
922 
923 	bu		= kcalloc(nr_want, sizeof(*bu), GFP_KERNEL);
924 	ob		= kcalloc(nr_want, sizeof(*ob), GFP_KERNEL);
925 	new_buckets	= kcalloc(nr, sizeof(u64), GFP_KERNEL);
926 	new_bucket_seq	= kcalloc(nr, sizeof(u64), GFP_KERNEL);
927 	if (!bu || !ob || !new_buckets || !new_bucket_seq) {
928 		ret = -BCH_ERR_ENOMEM_set_nr_journal_buckets;
929 		goto err_free;
930 	}
931 
932 	for (nr_got = 0; nr_got < nr_want; nr_got++) {
933 		if (new_fs) {
934 			bu[nr_got] = bch2_bucket_alloc_new_fs(ca);
935 			if (bu[nr_got] < 0) {
936 				ret = -BCH_ERR_ENOSPC_bucket_alloc;
937 				break;
938 			}
939 		} else {
940 			ob[nr_got] = bch2_bucket_alloc(c, ca, BCH_WATERMARK_normal,
941 						       BCH_DATA_journal, cl);
942 			ret = PTR_ERR_OR_ZERO(ob[nr_got]);
943 			if (ret)
944 				break;
945 
946 			ret = bch2_trans_run(c,
947 				bch2_trans_mark_metadata_bucket(trans, ca,
948 						ob[nr_got]->bucket, BCH_DATA_journal,
949 						ca->mi.bucket_size, BTREE_TRIGGER_transactional));
950 			if (ret) {
951 				bch2_open_bucket_put(c, ob[nr_got]);
952 				bch_err_msg(c, ret, "marking new journal buckets");
953 				break;
954 			}
955 
956 			bu[nr_got] = ob[nr_got]->bucket;
957 		}
958 	}
959 
960 	if (!nr_got)
961 		goto err_free;
962 
963 	/* Don't return an error if we successfully allocated some buckets: */
964 	ret = 0;
965 
966 	if (c) {
967 		bch2_journal_flush_all_pins(&c->journal);
968 		bch2_journal_block(&c->journal);
969 		mutex_lock(&c->sb_lock);
970 	}
971 
972 	memcpy(new_buckets,	ja->buckets,	ja->nr * sizeof(u64));
973 	memcpy(new_bucket_seq,	ja->bucket_seq,	ja->nr * sizeof(u64));
974 
975 	BUG_ON(ja->discard_idx > ja->nr);
976 
977 	pos = ja->discard_idx ?: ja->nr;
978 
979 	memmove(new_buckets + pos + nr_got,
980 		new_buckets + pos,
981 		sizeof(new_buckets[0]) * (ja->nr - pos));
982 	memmove(new_bucket_seq + pos + nr_got,
983 		new_bucket_seq + pos,
984 		sizeof(new_bucket_seq[0]) * (ja->nr - pos));
985 
986 	for (i = 0; i < nr_got; i++) {
987 		new_buckets[pos + i] = bu[i];
988 		new_bucket_seq[pos + i] = 0;
989 	}
990 
991 	nr = ja->nr + nr_got;
992 
993 	ret = bch2_journal_buckets_to_sb(c, ca, new_buckets, nr);
994 	if (ret)
995 		goto err_unblock;
996 
997 	if (!new_fs)
998 		bch2_write_super(c);
999 
1000 	/* Commit: */
1001 	if (c)
1002 		spin_lock(&c->journal.lock);
1003 
1004 	swap(new_buckets,	ja->buckets);
1005 	swap(new_bucket_seq,	ja->bucket_seq);
1006 	ja->nr = nr;
1007 
1008 	if (pos <= ja->discard_idx)
1009 		ja->discard_idx = (ja->discard_idx + nr_got) % ja->nr;
1010 	if (pos <= ja->dirty_idx_ondisk)
1011 		ja->dirty_idx_ondisk = (ja->dirty_idx_ondisk + nr_got) % ja->nr;
1012 	if (pos <= ja->dirty_idx)
1013 		ja->dirty_idx = (ja->dirty_idx + nr_got) % ja->nr;
1014 	if (pos <= ja->cur_idx)
1015 		ja->cur_idx = (ja->cur_idx + nr_got) % ja->nr;
1016 
1017 	if (c)
1018 		spin_unlock(&c->journal.lock);
1019 err_unblock:
1020 	if (c) {
1021 		bch2_journal_unblock(&c->journal);
1022 		mutex_unlock(&c->sb_lock);
1023 	}
1024 
1025 	if (ret && !new_fs)
1026 		for (i = 0; i < nr_got; i++)
1027 			bch2_trans_run(c,
1028 				bch2_trans_mark_metadata_bucket(trans, ca,
1029 						bu[i], BCH_DATA_free, 0,
1030 						BTREE_TRIGGER_transactional));
1031 err_free:
1032 	if (!new_fs)
1033 		for (i = 0; i < nr_got; i++)
1034 			bch2_open_bucket_put(c, ob[i]);
1035 
1036 	kfree(new_bucket_seq);
1037 	kfree(new_buckets);
1038 	kfree(ob);
1039 	kfree(bu);
1040 	return ret;
1041 }
1042 
1043 /*
1044  * Allocate more journal space at runtime - not currently making use if it, but
1045  * the code works:
1046  */
1047 int bch2_set_nr_journal_buckets(struct bch_fs *c, struct bch_dev *ca,
1048 				unsigned nr)
1049 {
1050 	struct journal_device *ja = &ca->journal;
1051 	struct closure cl;
1052 	int ret = 0;
1053 
1054 	closure_init_stack(&cl);
1055 
1056 	down_write(&c->state_lock);
1057 
1058 	/* don't handle reducing nr of buckets yet: */
1059 	if (nr < ja->nr)
1060 		goto unlock;
1061 
1062 	while (ja->nr < nr) {
1063 		struct disk_reservation disk_res = { 0, 0, 0 };
1064 
1065 		/*
1066 		 * note: journal buckets aren't really counted as _sectors_ used yet, so
1067 		 * we don't need the disk reservation to avoid the BUG_ON() in buckets.c
1068 		 * when space used goes up without a reservation - but we do need the
1069 		 * reservation to ensure we'll actually be able to allocate:
1070 		 *
1071 		 * XXX: that's not right, disk reservations only ensure a
1072 		 * filesystem-wide allocation will succeed, this is a device
1073 		 * specific allocation - we can hang here:
1074 		 */
1075 
1076 		ret = bch2_disk_reservation_get(c, &disk_res,
1077 						bucket_to_sector(ca, nr - ja->nr), 1, 0);
1078 		if (ret)
1079 			break;
1080 
1081 		ret = __bch2_set_nr_journal_buckets(ca, nr, false, &cl);
1082 
1083 		bch2_disk_reservation_put(c, &disk_res);
1084 
1085 		closure_sync(&cl);
1086 
1087 		if (ret && ret != -BCH_ERR_bucket_alloc_blocked)
1088 			break;
1089 	}
1090 
1091 	bch_err_fn(c, ret);
1092 unlock:
1093 	up_write(&c->state_lock);
1094 	return ret;
1095 }
1096 
1097 int bch2_dev_journal_alloc(struct bch_dev *ca, bool new_fs)
1098 {
1099 	unsigned nr;
1100 	int ret;
1101 
1102 	if (dynamic_fault("bcachefs:add:journal_alloc")) {
1103 		ret = -BCH_ERR_ENOMEM_set_nr_journal_buckets;
1104 		goto err;
1105 	}
1106 
1107 	/* 1/128th of the device by default: */
1108 	nr = ca->mi.nbuckets >> 7;
1109 
1110 	/*
1111 	 * clamp journal size to 8192 buckets or 8GB (in sectors), whichever
1112 	 * is smaller:
1113 	 */
1114 	nr = clamp_t(unsigned, nr,
1115 		     BCH_JOURNAL_BUCKETS_MIN,
1116 		     min(1 << 13,
1117 			 (1 << 24) / ca->mi.bucket_size));
1118 
1119 	ret = __bch2_set_nr_journal_buckets(ca, nr, new_fs, NULL);
1120 err:
1121 	bch_err_fn(ca, ret);
1122 	return ret;
1123 }
1124 
1125 int bch2_fs_journal_alloc(struct bch_fs *c)
1126 {
1127 	for_each_online_member(c, ca) {
1128 		if (ca->journal.nr)
1129 			continue;
1130 
1131 		int ret = bch2_dev_journal_alloc(ca, true);
1132 		if (ret) {
1133 			percpu_ref_put(&ca->io_ref);
1134 			return ret;
1135 		}
1136 	}
1137 
1138 	return 0;
1139 }
1140 
1141 /* startup/shutdown: */
1142 
1143 static bool bch2_journal_writing_to_device(struct journal *j, unsigned dev_idx)
1144 {
1145 	bool ret = false;
1146 	u64 seq;
1147 
1148 	spin_lock(&j->lock);
1149 	for (seq = journal_last_unwritten_seq(j);
1150 	     seq <= journal_cur_seq(j) && !ret;
1151 	     seq++) {
1152 		struct journal_buf *buf = journal_seq_to_buf(j, seq);
1153 
1154 		if (bch2_bkey_has_device_c(bkey_i_to_s_c(&buf->key), dev_idx))
1155 			ret = true;
1156 	}
1157 	spin_unlock(&j->lock);
1158 
1159 	return ret;
1160 }
1161 
1162 void bch2_dev_journal_stop(struct journal *j, struct bch_dev *ca)
1163 {
1164 	wait_event(j->wait, !bch2_journal_writing_to_device(j, ca->dev_idx));
1165 }
1166 
1167 void bch2_fs_journal_stop(struct journal *j)
1168 {
1169 	if (!test_bit(JOURNAL_running, &j->flags))
1170 		return;
1171 
1172 	bch2_journal_reclaim_stop(j);
1173 	bch2_journal_flush_all_pins(j);
1174 
1175 	wait_event(j->wait, bch2_journal_entry_close(j));
1176 
1177 	/*
1178 	 * Always write a new journal entry, to make sure the clock hands are up
1179 	 * to date (and match the superblock)
1180 	 */
1181 	bch2_journal_meta(j);
1182 
1183 	journal_quiesce(j);
1184 	cancel_delayed_work_sync(&j->write_work);
1185 
1186 	WARN(!bch2_journal_error(j) &&
1187 	     test_bit(JOURNAL_replay_done, &j->flags) &&
1188 	     j->last_empty_seq != journal_cur_seq(j),
1189 	     "journal shutdown error: cur seq %llu but last empty seq %llu",
1190 	     journal_cur_seq(j), j->last_empty_seq);
1191 
1192 	if (!bch2_journal_error(j))
1193 		clear_bit(JOURNAL_running, &j->flags);
1194 }
1195 
1196 int bch2_fs_journal_start(struct journal *j, u64 cur_seq)
1197 {
1198 	struct bch_fs *c = container_of(j, struct bch_fs, journal);
1199 	struct journal_entry_pin_list *p;
1200 	struct journal_replay *i, **_i;
1201 	struct genradix_iter iter;
1202 	bool had_entries = false;
1203 	u64 last_seq = cur_seq, nr, seq;
1204 
1205 	genradix_for_each_reverse(&c->journal_entries, iter, _i) {
1206 		i = *_i;
1207 
1208 		if (journal_replay_ignore(i))
1209 			continue;
1210 
1211 		last_seq = le64_to_cpu(i->j.last_seq);
1212 		break;
1213 	}
1214 
1215 	nr = cur_seq - last_seq;
1216 
1217 	if (nr + 1 > j->pin.size) {
1218 		free_fifo(&j->pin);
1219 		init_fifo(&j->pin, roundup_pow_of_two(nr + 1), GFP_KERNEL);
1220 		if (!j->pin.data) {
1221 			bch_err(c, "error reallocating journal fifo (%llu open entries)", nr);
1222 			return -BCH_ERR_ENOMEM_journal_pin_fifo;
1223 		}
1224 	}
1225 
1226 	j->replay_journal_seq	= last_seq;
1227 	j->replay_journal_seq_end = cur_seq;
1228 	j->last_seq_ondisk	= last_seq;
1229 	j->flushed_seq_ondisk	= cur_seq - 1;
1230 	j->seq_ondisk		= cur_seq - 1;
1231 	j->pin.front		= last_seq;
1232 	j->pin.back		= cur_seq;
1233 	atomic64_set(&j->seq, cur_seq - 1);
1234 
1235 	fifo_for_each_entry_ptr(p, &j->pin, seq)
1236 		journal_pin_list_init(p, 1);
1237 
1238 	genradix_for_each(&c->journal_entries, iter, _i) {
1239 		i = *_i;
1240 
1241 		if (journal_replay_ignore(i))
1242 			continue;
1243 
1244 		seq = le64_to_cpu(i->j.seq);
1245 		BUG_ON(seq >= cur_seq);
1246 
1247 		if (seq < last_seq)
1248 			continue;
1249 
1250 		if (journal_entry_empty(&i->j))
1251 			j->last_empty_seq = le64_to_cpu(i->j.seq);
1252 
1253 		p = journal_seq_pin(j, seq);
1254 
1255 		p->devs.nr = 0;
1256 		darray_for_each(i->ptrs, ptr)
1257 			bch2_dev_list_add_dev(&p->devs, ptr->dev);
1258 
1259 		had_entries = true;
1260 	}
1261 
1262 	if (!had_entries)
1263 		j->last_empty_seq = cur_seq - 1; /* to match j->seq */
1264 
1265 	spin_lock(&j->lock);
1266 
1267 	set_bit(JOURNAL_running, &j->flags);
1268 	j->last_flush_write = jiffies;
1269 
1270 	j->reservations.idx = j->reservations.unwritten_idx = journal_cur_seq(j);
1271 	j->reservations.unwritten_idx++;
1272 
1273 	c->last_bucket_seq_cleanup = journal_cur_seq(j);
1274 
1275 	bch2_journal_space_available(j);
1276 	spin_unlock(&j->lock);
1277 
1278 	return bch2_journal_reclaim_start(j);
1279 }
1280 
1281 /* init/exit: */
1282 
1283 void bch2_dev_journal_exit(struct bch_dev *ca)
1284 {
1285 	struct journal_device *ja = &ca->journal;
1286 
1287 	for (unsigned i = 0; i < ARRAY_SIZE(ja->bio); i++) {
1288 		kfree(ja->bio[i]);
1289 		ja->bio[i] = NULL;
1290 	}
1291 
1292 	kfree(ja->buckets);
1293 	kfree(ja->bucket_seq);
1294 	ja->buckets	= NULL;
1295 	ja->bucket_seq	= NULL;
1296 }
1297 
1298 int bch2_dev_journal_init(struct bch_dev *ca, struct bch_sb *sb)
1299 {
1300 	struct journal_device *ja = &ca->journal;
1301 	struct bch_sb_field_journal *journal_buckets =
1302 		bch2_sb_field_get(sb, journal);
1303 	struct bch_sb_field_journal_v2 *journal_buckets_v2 =
1304 		bch2_sb_field_get(sb, journal_v2);
1305 
1306 	ja->nr = 0;
1307 
1308 	if (journal_buckets_v2) {
1309 		unsigned nr = bch2_sb_field_journal_v2_nr_entries(journal_buckets_v2);
1310 
1311 		for (unsigned i = 0; i < nr; i++)
1312 			ja->nr += le64_to_cpu(journal_buckets_v2->d[i].nr);
1313 	} else if (journal_buckets) {
1314 		ja->nr = bch2_nr_journal_buckets(journal_buckets);
1315 	}
1316 
1317 	ja->bucket_seq = kcalloc(ja->nr, sizeof(u64), GFP_KERNEL);
1318 	if (!ja->bucket_seq)
1319 		return -BCH_ERR_ENOMEM_dev_journal_init;
1320 
1321 	unsigned nr_bvecs = DIV_ROUND_UP(JOURNAL_ENTRY_SIZE_MAX, PAGE_SIZE);
1322 
1323 	for (unsigned i = 0; i < ARRAY_SIZE(ja->bio); i++) {
1324 		ja->bio[i] = kmalloc(struct_size(ja->bio[i], bio.bi_inline_vecs,
1325 				     nr_bvecs), GFP_KERNEL);
1326 		if (!ja->bio[i])
1327 			return -BCH_ERR_ENOMEM_dev_journal_init;
1328 
1329 		ja->bio[i]->ca = ca;
1330 		ja->bio[i]->buf_idx = i;
1331 		bio_init(&ja->bio[i]->bio, NULL, ja->bio[i]->bio.bi_inline_vecs, nr_bvecs, 0);
1332 	}
1333 
1334 	ja->buckets = kcalloc(ja->nr, sizeof(u64), GFP_KERNEL);
1335 	if (!ja->buckets)
1336 		return -BCH_ERR_ENOMEM_dev_journal_init;
1337 
1338 	if (journal_buckets_v2) {
1339 		unsigned nr = bch2_sb_field_journal_v2_nr_entries(journal_buckets_v2);
1340 		unsigned dst = 0;
1341 
1342 		for (unsigned i = 0; i < nr; i++)
1343 			for (unsigned j = 0; j < le64_to_cpu(journal_buckets_v2->d[i].nr); j++)
1344 				ja->buckets[dst++] =
1345 					le64_to_cpu(journal_buckets_v2->d[i].start) + j;
1346 	} else if (journal_buckets) {
1347 		for (unsigned i = 0; i < ja->nr; i++)
1348 			ja->buckets[i] = le64_to_cpu(journal_buckets->buckets[i]);
1349 	}
1350 
1351 	return 0;
1352 }
1353 
1354 void bch2_fs_journal_exit(struct journal *j)
1355 {
1356 	if (j->wq)
1357 		destroy_workqueue(j->wq);
1358 
1359 	darray_exit(&j->early_journal_entries);
1360 
1361 	for (unsigned i = 0; i < ARRAY_SIZE(j->buf); i++)
1362 		kvfree(j->buf[i].data);
1363 	free_fifo(&j->pin);
1364 }
1365 
1366 int bch2_fs_journal_init(struct journal *j)
1367 {
1368 	static struct lock_class_key res_key;
1369 
1370 	mutex_init(&j->buf_lock);
1371 	spin_lock_init(&j->lock);
1372 	spin_lock_init(&j->err_lock);
1373 	init_waitqueue_head(&j->wait);
1374 	INIT_DELAYED_WORK(&j->write_work, journal_write_work);
1375 	init_waitqueue_head(&j->reclaim_wait);
1376 	init_waitqueue_head(&j->pin_flush_wait);
1377 	mutex_init(&j->reclaim_lock);
1378 	mutex_init(&j->discard_lock);
1379 
1380 	lockdep_init_map(&j->res_map, "journal res", &res_key, 0);
1381 
1382 	atomic64_set(&j->reservations.counter,
1383 		((union journal_res_state)
1384 		 { .cur_entry_offset = JOURNAL_ENTRY_CLOSED_VAL }).v);
1385 
1386 	if (!(init_fifo(&j->pin, JOURNAL_PIN, GFP_KERNEL)))
1387 		return -BCH_ERR_ENOMEM_journal_pin_fifo;
1388 
1389 	for (unsigned i = 0; i < ARRAY_SIZE(j->buf); i++) {
1390 		j->buf[i].buf_size = JOURNAL_ENTRY_SIZE_MIN;
1391 		j->buf[i].data = kvmalloc(j->buf[i].buf_size, GFP_KERNEL);
1392 		if (!j->buf[i].data)
1393 			return -BCH_ERR_ENOMEM_journal_buf;
1394 		j->buf[i].idx = i;
1395 	}
1396 
1397 	j->pin.front = j->pin.back = 1;
1398 
1399 	j->wq = alloc_workqueue("bcachefs_journal",
1400 				WQ_HIGHPRI|WQ_FREEZABLE|WQ_UNBOUND|WQ_MEM_RECLAIM, 512);
1401 	if (!j->wq)
1402 		return -BCH_ERR_ENOMEM_fs_other_alloc;
1403 	return 0;
1404 }
1405 
1406 /* debug: */
1407 
1408 static const char * const bch2_journal_flags_strs[] = {
1409 #define x(n)	#n,
1410 	JOURNAL_FLAGS()
1411 #undef x
1412 	NULL
1413 };
1414 
1415 void __bch2_journal_debug_to_text(struct printbuf *out, struct journal *j)
1416 {
1417 	struct bch_fs *c = container_of(j, struct bch_fs, journal);
1418 	union journal_res_state s;
1419 	unsigned long now = jiffies;
1420 	u64 nr_writes = j->nr_flush_writes + j->nr_noflush_writes;
1421 
1422 	printbuf_tabstops_reset(out);
1423 	printbuf_tabstop_push(out, 28);
1424 	out->atomic++;
1425 
1426 	rcu_read_lock();
1427 	s = READ_ONCE(j->reservations);
1428 
1429 	prt_printf(out, "flags:\t");
1430 	prt_bitflags(out, bch2_journal_flags_strs, j->flags);
1431 	prt_newline(out);
1432 	prt_printf(out, "dirty journal entries:\t%llu/%llu\n",	fifo_used(&j->pin), j->pin.size);
1433 	prt_printf(out, "seq:\t%llu\n",				journal_cur_seq(j));
1434 	prt_printf(out, "seq_ondisk:\t%llu\n",			j->seq_ondisk);
1435 	prt_printf(out, "last_seq:\t%llu\n",			journal_last_seq(j));
1436 	prt_printf(out, "last_seq_ondisk:\t%llu\n",		j->last_seq_ondisk);
1437 	prt_printf(out, "flushed_seq_ondisk:\t%llu\n",		j->flushed_seq_ondisk);
1438 	prt_printf(out, "watermark:\t%s\n",			bch2_watermarks[j->watermark]);
1439 	prt_printf(out, "each entry reserved:\t%u\n",		j->entry_u64s_reserved);
1440 	prt_printf(out, "nr flush writes:\t%llu\n",		j->nr_flush_writes);
1441 	prt_printf(out, "nr noflush writes:\t%llu\n",		j->nr_noflush_writes);
1442 	prt_printf(out, "average write size:\t");
1443 	prt_human_readable_u64(out, nr_writes ? div64_u64(j->entry_bytes_written, nr_writes) : 0);
1444 	prt_newline(out);
1445 	prt_printf(out, "nr direct reclaim:\t%llu\n",		j->nr_direct_reclaim);
1446 	prt_printf(out, "nr background reclaim:\t%llu\n",	j->nr_background_reclaim);
1447 	prt_printf(out, "reclaim kicked:\t%u\n",		j->reclaim_kicked);
1448 	prt_printf(out, "reclaim runs in:\t%u ms\n",		time_after(j->next_reclaim, now)
1449 	       ? jiffies_to_msecs(j->next_reclaim - jiffies) : 0);
1450 	prt_printf(out, "blocked:\t%u\n",			j->blocked);
1451 	prt_printf(out, "current entry sectors:\t%u\n",		j->cur_entry_sectors);
1452 	prt_printf(out, "current entry error:\t%s\n",		bch2_journal_errors[j->cur_entry_error]);
1453 	prt_printf(out, "current entry:\t");
1454 
1455 	switch (s.cur_entry_offset) {
1456 	case JOURNAL_ENTRY_ERROR_VAL:
1457 		prt_printf(out, "error\n");
1458 		break;
1459 	case JOURNAL_ENTRY_CLOSED_VAL:
1460 		prt_printf(out, "closed\n");
1461 		break;
1462 	default:
1463 		prt_printf(out, "%u/%u\n", s.cur_entry_offset, j->cur_entry_u64s);
1464 		break;
1465 	}
1466 
1467 	prt_printf(out, "unwritten entries:\n");
1468 	bch2_journal_bufs_to_text(out, j);
1469 
1470 	prt_printf(out, "space:\n");
1471 	printbuf_indent_add(out, 2);
1472 	prt_printf(out, "discarded\t%u:%u\n",
1473 	       j->space[journal_space_discarded].next_entry,
1474 	       j->space[journal_space_discarded].total);
1475 	prt_printf(out, "clean ondisk\t%u:%u\n",
1476 	       j->space[journal_space_clean_ondisk].next_entry,
1477 	       j->space[journal_space_clean_ondisk].total);
1478 	prt_printf(out, "clean\t%u:%u\n",
1479 	       j->space[journal_space_clean].next_entry,
1480 	       j->space[journal_space_clean].total);
1481 	prt_printf(out, "total\t%u:%u\n",
1482 	       j->space[journal_space_total].next_entry,
1483 	       j->space[journal_space_total].total);
1484 	printbuf_indent_sub(out, 2);
1485 
1486 	for_each_member_device_rcu(c, ca, &c->rw_devs[BCH_DATA_journal]) {
1487 		struct journal_device *ja = &ca->journal;
1488 
1489 		if (!test_bit(ca->dev_idx, c->rw_devs[BCH_DATA_journal].d))
1490 			continue;
1491 
1492 		if (!ja->nr)
1493 			continue;
1494 
1495 		prt_printf(out, "dev %u:\n",			ca->dev_idx);
1496 		printbuf_indent_add(out, 2);
1497 		prt_printf(out, "nr\t%u\n",			ja->nr);
1498 		prt_printf(out, "bucket size\t%u\n",		ca->mi.bucket_size);
1499 		prt_printf(out, "available\t%u:%u\n",		bch2_journal_dev_buckets_available(j, ja, journal_space_discarded), ja->sectors_free);
1500 		prt_printf(out, "discard_idx\t%u\n",		ja->discard_idx);
1501 		prt_printf(out, "dirty_ondisk\t%u (seq %llu)\n",ja->dirty_idx_ondisk,	ja->bucket_seq[ja->dirty_idx_ondisk]);
1502 		prt_printf(out, "dirty_idx\t%u (seq %llu)\n",	ja->dirty_idx,		ja->bucket_seq[ja->dirty_idx]);
1503 		prt_printf(out, "cur_idx\t%u (seq %llu)\n",	ja->cur_idx,		ja->bucket_seq[ja->cur_idx]);
1504 		printbuf_indent_sub(out, 2);
1505 	}
1506 
1507 	rcu_read_unlock();
1508 
1509 	--out->atomic;
1510 }
1511 
1512 void bch2_journal_debug_to_text(struct printbuf *out, struct journal *j)
1513 {
1514 	spin_lock(&j->lock);
1515 	__bch2_journal_debug_to_text(out, j);
1516 	spin_unlock(&j->lock);
1517 }
1518 
1519 bool bch2_journal_seq_pins_to_text(struct printbuf *out, struct journal *j, u64 *seq)
1520 {
1521 	struct journal_entry_pin_list *pin_list;
1522 	struct journal_entry_pin *pin;
1523 
1524 	spin_lock(&j->lock);
1525 	if (!test_bit(JOURNAL_running, &j->flags)) {
1526 		spin_unlock(&j->lock);
1527 		return true;
1528 	}
1529 
1530 	*seq = max(*seq, j->pin.front);
1531 
1532 	if (*seq >= j->pin.back) {
1533 		spin_unlock(&j->lock);
1534 		return true;
1535 	}
1536 
1537 	out->atomic++;
1538 
1539 	pin_list = journal_seq_pin(j, *seq);
1540 
1541 	prt_printf(out, "%llu: count %u\n", *seq, atomic_read(&pin_list->count));
1542 	printbuf_indent_add(out, 2);
1543 
1544 	for (unsigned i = 0; i < ARRAY_SIZE(pin_list->list); i++)
1545 		list_for_each_entry(pin, &pin_list->list[i], list)
1546 			prt_printf(out, "\t%px %ps\n", pin, pin->flush);
1547 
1548 	if (!list_empty(&pin_list->flushed))
1549 		prt_printf(out, "flushed:\n");
1550 
1551 	list_for_each_entry(pin, &pin_list->flushed, list)
1552 		prt_printf(out, "\t%px %ps\n", pin, pin->flush);
1553 
1554 	printbuf_indent_sub(out, 2);
1555 
1556 	--out->atomic;
1557 	spin_unlock(&j->lock);
1558 
1559 	return false;
1560 }
1561 
1562 void bch2_journal_pins_to_text(struct printbuf *out, struct journal *j)
1563 {
1564 	u64 seq = 0;
1565 
1566 	while (!bch2_journal_seq_pins_to_text(out, j, &seq))
1567 		seq++;
1568 }
1569