xref: /linux/fs/bcachefs/data_update.c (revision 90d32e92011eaae8e70a9169b4e7acf4ca8f9d3a)
1 // SPDX-License-Identifier: GPL-2.0
2 
3 #include "bcachefs.h"
4 #include "alloc_foreground.h"
5 #include "bkey_buf.h"
6 #include "btree_update.h"
7 #include "buckets.h"
8 #include "data_update.h"
9 #include "ec.h"
10 #include "error.h"
11 #include "extents.h"
12 #include "io_write.h"
13 #include "keylist.h"
14 #include "move.h"
15 #include "nocow_locking.h"
16 #include "rebalance.h"
17 #include "snapshot.h"
18 #include "subvolume.h"
19 #include "trace.h"
20 
21 static void trace_move_extent_finish2(struct bch_fs *c, struct bkey_s_c k)
22 {
23 	if (trace_move_extent_finish_enabled()) {
24 		struct printbuf buf = PRINTBUF;
25 
26 		bch2_bkey_val_to_text(&buf, c, k);
27 		trace_move_extent_finish(c, buf.buf);
28 		printbuf_exit(&buf);
29 	}
30 }
31 
32 static void trace_move_extent_fail2(struct data_update *m,
33 			 struct bkey_s_c new,
34 			 struct bkey_s_c wrote,
35 			 struct bkey_i *insert,
36 			 const char *msg)
37 {
38 	struct bch_fs *c = m->op.c;
39 	struct bkey_s_c old = bkey_i_to_s_c(m->k.k);
40 	const union bch_extent_entry *entry;
41 	struct bch_extent_ptr *ptr;
42 	struct extent_ptr_decoded p;
43 	struct printbuf buf = PRINTBUF;
44 	unsigned i, rewrites_found = 0;
45 
46 	if (!trace_move_extent_fail_enabled())
47 		return;
48 
49 	prt_str(&buf, msg);
50 
51 	if (insert) {
52 		i = 0;
53 		bkey_for_each_ptr_decode(old.k, bch2_bkey_ptrs_c(old), p, entry) {
54 			if (((1U << i) & m->data_opts.rewrite_ptrs) &&
55 			    (ptr = bch2_extent_has_ptr(old, p, bkey_i_to_s(insert))) &&
56 			    !ptr->cached)
57 				rewrites_found |= 1U << i;
58 			i++;
59 		}
60 	}
61 
62 	prt_printf(&buf, "\nrewrite ptrs:   %u%u%u%u",
63 		   (m->data_opts.rewrite_ptrs & (1 << 0)) != 0,
64 		   (m->data_opts.rewrite_ptrs & (1 << 1)) != 0,
65 		   (m->data_opts.rewrite_ptrs & (1 << 2)) != 0,
66 		   (m->data_opts.rewrite_ptrs & (1 << 3)) != 0);
67 
68 	prt_printf(&buf, "\nrewrites found: %u%u%u%u",
69 		   (rewrites_found & (1 << 0)) != 0,
70 		   (rewrites_found & (1 << 1)) != 0,
71 		   (rewrites_found & (1 << 2)) != 0,
72 		   (rewrites_found & (1 << 3)) != 0);
73 
74 	prt_str(&buf, "\nold:    ");
75 	bch2_bkey_val_to_text(&buf, c, old);
76 
77 	prt_str(&buf, "\nnew:    ");
78 	bch2_bkey_val_to_text(&buf, c, new);
79 
80 	prt_str(&buf, "\nwrote:  ");
81 	bch2_bkey_val_to_text(&buf, c, wrote);
82 
83 	if (insert) {
84 		prt_str(&buf, "\ninsert: ");
85 		bch2_bkey_val_to_text(&buf, c, bkey_i_to_s_c(insert));
86 	}
87 
88 	trace_move_extent_fail(c, buf.buf);
89 	printbuf_exit(&buf);
90 }
91 
92 static int __bch2_data_update_index_update(struct btree_trans *trans,
93 					   struct bch_write_op *op)
94 {
95 	struct bch_fs *c = op->c;
96 	struct btree_iter iter;
97 	struct data_update *m =
98 		container_of(op, struct data_update, op);
99 	struct keylist *keys = &op->insert_keys;
100 	struct bkey_buf _new, _insert;
101 	int ret = 0;
102 
103 	bch2_bkey_buf_init(&_new);
104 	bch2_bkey_buf_init(&_insert);
105 	bch2_bkey_buf_realloc(&_insert, c, U8_MAX);
106 
107 	bch2_trans_iter_init(trans, &iter, m->btree_id,
108 			     bkey_start_pos(&bch2_keylist_front(keys)->k),
109 			     BTREE_ITER_slots|BTREE_ITER_intent);
110 
111 	while (1) {
112 		struct bkey_s_c k;
113 		struct bkey_s_c old = bkey_i_to_s_c(m->k.k);
114 		struct bkey_i *insert = NULL;
115 		struct bkey_i_extent *new;
116 		const union bch_extent_entry *entry_c;
117 		union bch_extent_entry *entry;
118 		struct extent_ptr_decoded p;
119 		struct bch_extent_ptr *ptr;
120 		const struct bch_extent_ptr *ptr_c;
121 		struct bpos next_pos;
122 		bool should_check_enospc;
123 		s64 i_sectors_delta = 0, disk_sectors_delta = 0;
124 		unsigned rewrites_found = 0, durability, i;
125 
126 		bch2_trans_begin(trans);
127 
128 		k = bch2_btree_iter_peek_slot(&iter);
129 		ret = bkey_err(k);
130 		if (ret)
131 			goto err;
132 
133 		new = bkey_i_to_extent(bch2_keylist_front(keys));
134 
135 		if (!bch2_extents_match(k, old)) {
136 			trace_move_extent_fail2(m, k, bkey_i_to_s_c(&new->k_i),
137 						NULL, "no match:");
138 			goto nowork;
139 		}
140 
141 		bkey_reassemble(_insert.k, k);
142 		insert = _insert.k;
143 
144 		bch2_bkey_buf_copy(&_new, c, bch2_keylist_front(keys));
145 		new = bkey_i_to_extent(_new.k);
146 		bch2_cut_front(iter.pos, &new->k_i);
147 
148 		bch2_cut_front(iter.pos,	insert);
149 		bch2_cut_back(new->k.p,		insert);
150 		bch2_cut_back(insert->k.p,	&new->k_i);
151 
152 		/*
153 		 * @old: extent that we read from
154 		 * @insert: key that we're going to update, initialized from
155 		 * extent currently in btree - same as @old unless we raced with
156 		 * other updates
157 		 * @new: extent with new pointers that we'll be adding to @insert
158 		 *
159 		 * Fist, drop rewrite_ptrs from @new:
160 		 */
161 		i = 0;
162 		bkey_for_each_ptr_decode(old.k, bch2_bkey_ptrs_c(old), p, entry_c) {
163 			if (((1U << i) & m->data_opts.rewrite_ptrs) &&
164 			    (ptr = bch2_extent_has_ptr(old, p, bkey_i_to_s(insert))) &&
165 			    !ptr->cached) {
166 				bch2_extent_ptr_set_cached(bkey_i_to_s(insert), ptr);
167 				rewrites_found |= 1U << i;
168 			}
169 			i++;
170 		}
171 
172 		if (m->data_opts.rewrite_ptrs &&
173 		    !rewrites_found &&
174 		    bch2_bkey_durability(c, k) >= m->op.opts.data_replicas) {
175 			trace_move_extent_fail2(m, k, bkey_i_to_s_c(&new->k_i), insert, "no rewrites found:");
176 			goto nowork;
177 		}
178 
179 		/*
180 		 * A replica that we just wrote might conflict with a replica
181 		 * that we want to keep, due to racing with another move:
182 		 */
183 restart_drop_conflicting_replicas:
184 		extent_for_each_ptr(extent_i_to_s(new), ptr)
185 			if ((ptr_c = bch2_bkey_has_device_c(bkey_i_to_s_c(insert), ptr->dev)) &&
186 			    !ptr_c->cached) {
187 				bch2_bkey_drop_ptr_noerror(bkey_i_to_s(&new->k_i), ptr);
188 				goto restart_drop_conflicting_replicas;
189 			}
190 
191 		if (!bkey_val_u64s(&new->k)) {
192 			trace_move_extent_fail2(m, k, bkey_i_to_s_c(&new->k_i), insert, "new replicas conflicted:");
193 			goto nowork;
194 		}
195 
196 		/* Now, drop pointers that conflict with what we just wrote: */
197 		extent_for_each_ptr_decode(extent_i_to_s(new), p, entry)
198 			if ((ptr = bch2_bkey_has_device(bkey_i_to_s(insert), p.ptr.dev)))
199 				bch2_bkey_drop_ptr_noerror(bkey_i_to_s(insert), ptr);
200 
201 		durability = bch2_bkey_durability(c, bkey_i_to_s_c(insert)) +
202 			bch2_bkey_durability(c, bkey_i_to_s_c(&new->k_i));
203 
204 		/* Now, drop excess replicas: */
205 restart_drop_extra_replicas:
206 
207 		rcu_read_lock();
208 		bkey_for_each_ptr_decode(old.k, bch2_bkey_ptrs(bkey_i_to_s(insert)), p, entry) {
209 			unsigned ptr_durability = bch2_extent_ptr_durability(c, &p);
210 
211 			if (!p.ptr.cached &&
212 			    durability - ptr_durability >= m->op.opts.data_replicas) {
213 				durability -= ptr_durability;
214 
215 				bch2_extent_ptr_set_cached(bkey_i_to_s(insert), &entry->ptr);
216 				goto restart_drop_extra_replicas;
217 			}
218 		}
219 		rcu_read_unlock();
220 
221 		/* Finally, add the pointers we just wrote: */
222 		extent_for_each_ptr_decode(extent_i_to_s(new), p, entry)
223 			bch2_extent_ptr_decoded_append(insert, &p);
224 
225 		bch2_bkey_narrow_crcs(insert, (struct bch_extent_crc_unpacked) { 0 });
226 		bch2_extent_normalize(c, bkey_i_to_s(insert));
227 
228 		ret = bch2_sum_sector_overwrites(trans, &iter, insert,
229 						 &should_check_enospc,
230 						 &i_sectors_delta,
231 						 &disk_sectors_delta);
232 		if (ret)
233 			goto err;
234 
235 		if (disk_sectors_delta > (s64) op->res.sectors) {
236 			ret = bch2_disk_reservation_add(c, &op->res,
237 						disk_sectors_delta - op->res.sectors,
238 						!should_check_enospc
239 						? BCH_DISK_RESERVATION_NOFAIL : 0);
240 			if (ret)
241 				goto out;
242 		}
243 
244 		next_pos = insert->k.p;
245 
246 		/*
247 		 * Check for nonce offset inconsistency:
248 		 * This is debug code - we've been seeing this bug rarely, and
249 		 * it's been hard to reproduce, so this should give us some more
250 		 * information when it does occur:
251 		 */
252 		struct printbuf err = PRINTBUF;
253 		int invalid = bch2_bkey_invalid(c, bkey_i_to_s_c(insert), __btree_node_type(0, m->btree_id), 0, &err);
254 		printbuf_exit(&err);
255 
256 		if (invalid) {
257 			struct printbuf buf = PRINTBUF;
258 
259 			prt_str(&buf, "about to insert invalid key in data update path");
260 			prt_str(&buf, "\nold: ");
261 			bch2_bkey_val_to_text(&buf, c, old);
262 			prt_str(&buf, "\nk:   ");
263 			bch2_bkey_val_to_text(&buf, c, k);
264 			prt_str(&buf, "\nnew: ");
265 			bch2_bkey_val_to_text(&buf, c, bkey_i_to_s_c(insert));
266 
267 			bch2_print_string_as_lines(KERN_ERR, buf.buf);
268 			printbuf_exit(&buf);
269 
270 			bch2_fatal_error(c);
271 			goto out;
272 		}
273 
274 		if (trace_data_update_enabled()) {
275 			struct printbuf buf = PRINTBUF;
276 
277 			prt_str(&buf, "\nold: ");
278 			bch2_bkey_val_to_text(&buf, c, old);
279 			prt_str(&buf, "\nk:   ");
280 			bch2_bkey_val_to_text(&buf, c, k);
281 			prt_str(&buf, "\nnew: ");
282 			bch2_bkey_val_to_text(&buf, c, bkey_i_to_s_c(insert));
283 
284 			trace_data_update(c, buf.buf);
285 			printbuf_exit(&buf);
286 		}
287 
288 		ret =   bch2_insert_snapshot_whiteouts(trans, m->btree_id,
289 						k.k->p, bkey_start_pos(&insert->k)) ?:
290 			bch2_insert_snapshot_whiteouts(trans, m->btree_id,
291 						k.k->p, insert->k.p) ?:
292 			bch2_bkey_set_needs_rebalance(c, insert, &op->opts) ?:
293 			bch2_trans_update(trans, &iter, insert,
294 				BTREE_UPDATE_internal_snapshot_node) ?:
295 			bch2_trans_commit(trans, &op->res,
296 				NULL,
297 				BCH_TRANS_COMMIT_no_check_rw|
298 				BCH_TRANS_COMMIT_no_enospc|
299 				m->data_opts.btree_insert_flags);
300 		if (!ret) {
301 			bch2_btree_iter_set_pos(&iter, next_pos);
302 
303 			this_cpu_add(c->counters[BCH_COUNTER_move_extent_finish], new->k.size);
304 			trace_move_extent_finish2(c, bkey_i_to_s_c(&new->k_i));
305 		}
306 err:
307 		if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
308 			ret = 0;
309 		if (ret)
310 			break;
311 next:
312 		while (bkey_ge(iter.pos, bch2_keylist_front(keys)->k.p)) {
313 			bch2_keylist_pop_front(keys);
314 			if (bch2_keylist_empty(keys))
315 				goto out;
316 		}
317 		continue;
318 nowork:
319 		if (m->stats) {
320 			BUG_ON(k.k->p.offset <= iter.pos.offset);
321 			atomic64_inc(&m->stats->keys_raced);
322 			atomic64_add(k.k->p.offset - iter.pos.offset,
323 				     &m->stats->sectors_raced);
324 		}
325 
326 		count_event(c, move_extent_fail);
327 
328 		bch2_btree_iter_advance(&iter);
329 		goto next;
330 	}
331 out:
332 	bch2_trans_iter_exit(trans, &iter);
333 	bch2_bkey_buf_exit(&_insert, c);
334 	bch2_bkey_buf_exit(&_new, c);
335 	BUG_ON(bch2_err_matches(ret, BCH_ERR_transaction_restart));
336 	return ret;
337 }
338 
339 int bch2_data_update_index_update(struct bch_write_op *op)
340 {
341 	return bch2_trans_run(op->c, __bch2_data_update_index_update(trans, op));
342 }
343 
344 void bch2_data_update_read_done(struct data_update *m,
345 				struct bch_extent_crc_unpacked crc)
346 {
347 	/* write bio must own pages: */
348 	BUG_ON(!m->op.wbio.bio.bi_vcnt);
349 
350 	m->op.crc = crc;
351 	m->op.wbio.bio.bi_iter.bi_size = crc.compressed_size << 9;
352 
353 	closure_call(&m->op.cl, bch2_write, NULL, NULL);
354 }
355 
356 void bch2_data_update_exit(struct data_update *update)
357 {
358 	struct bch_fs *c = update->op.c;
359 	struct bkey_ptrs_c ptrs =
360 		bch2_bkey_ptrs_c(bkey_i_to_s_c(update->k.k));
361 
362 	bkey_for_each_ptr(ptrs, ptr) {
363 		struct bch_dev *ca = bch2_dev_have_ref(c, ptr->dev);
364 		if (c->opts.nocow_enabled)
365 			bch2_bucket_nocow_unlock(&c->nocow_locks,
366 						 PTR_BUCKET_POS(ca, ptr), 0);
367 		bch2_dev_put(ca);
368 	}
369 
370 	bch2_bkey_buf_exit(&update->k, c);
371 	bch2_disk_reservation_put(c, &update->op.res);
372 	bch2_bio_free_pages_pool(c, &update->op.wbio.bio);
373 }
374 
375 static void bch2_update_unwritten_extent(struct btree_trans *trans,
376 				  struct data_update *update)
377 {
378 	struct bch_fs *c = update->op.c;
379 	struct bio *bio = &update->op.wbio.bio;
380 	struct bkey_i_extent *e;
381 	struct write_point *wp;
382 	struct closure cl;
383 	struct btree_iter iter;
384 	struct bkey_s_c k;
385 	int ret;
386 
387 	closure_init_stack(&cl);
388 	bch2_keylist_init(&update->op.insert_keys, update->op.inline_keys);
389 
390 	while (bio_sectors(bio)) {
391 		unsigned sectors = bio_sectors(bio);
392 
393 		bch2_trans_begin(trans);
394 
395 		bch2_trans_iter_init(trans, &iter, update->btree_id, update->op.pos,
396 				     BTREE_ITER_slots);
397 		ret = lockrestart_do(trans, ({
398 			k = bch2_btree_iter_peek_slot(&iter);
399 			bkey_err(k);
400 		}));
401 		bch2_trans_iter_exit(trans, &iter);
402 
403 		if (ret || !bch2_extents_match(k, bkey_i_to_s_c(update->k.k)))
404 			break;
405 
406 		e = bkey_extent_init(update->op.insert_keys.top);
407 		e->k.p = update->op.pos;
408 
409 		ret = bch2_alloc_sectors_start_trans(trans,
410 				update->op.target,
411 				false,
412 				update->op.write_point,
413 				&update->op.devs_have,
414 				update->op.nr_replicas,
415 				update->op.nr_replicas,
416 				update->op.watermark,
417 				0, &cl, &wp);
418 		if (bch2_err_matches(ret, BCH_ERR_operation_blocked)) {
419 			bch2_trans_unlock(trans);
420 			closure_sync(&cl);
421 			continue;
422 		}
423 
424 		bch_err_fn_ratelimited(c, ret);
425 
426 		if (ret)
427 			return;
428 
429 		sectors = min(sectors, wp->sectors_free);
430 
431 		bch2_key_resize(&e->k, sectors);
432 
433 		bch2_open_bucket_get(c, wp, &update->op.open_buckets);
434 		bch2_alloc_sectors_append_ptrs(c, wp, &e->k_i, sectors, false);
435 		bch2_alloc_sectors_done(c, wp);
436 
437 		bio_advance(bio, sectors << 9);
438 		update->op.pos.offset += sectors;
439 
440 		extent_for_each_ptr(extent_i_to_s(e), ptr)
441 			ptr->unwritten = true;
442 		bch2_keylist_push(&update->op.insert_keys);
443 
444 		ret = __bch2_data_update_index_update(trans, &update->op);
445 
446 		bch2_open_buckets_put(c, &update->op.open_buckets);
447 
448 		if (ret)
449 			break;
450 	}
451 
452 	if (closure_nr_remaining(&cl) != 1) {
453 		bch2_trans_unlock(trans);
454 		closure_sync(&cl);
455 	}
456 }
457 
458 int bch2_extent_drop_ptrs(struct btree_trans *trans,
459 			  struct btree_iter *iter,
460 			  struct bkey_s_c k,
461 			  struct data_update_opts data_opts)
462 {
463 	struct bch_fs *c = trans->c;
464 	struct bkey_i *n;
465 	int ret;
466 
467 	n = bch2_bkey_make_mut_noupdate(trans, k);
468 	ret = PTR_ERR_OR_ZERO(n);
469 	if (ret)
470 		return ret;
471 
472 	while (data_opts.kill_ptrs) {
473 		unsigned i = 0, drop = __fls(data_opts.kill_ptrs);
474 
475 		bch2_bkey_drop_ptrs(bkey_i_to_s(n), ptr, i++ == drop);
476 		data_opts.kill_ptrs ^= 1U << drop;
477 	}
478 
479 	/*
480 	 * If the new extent no longer has any pointers, bch2_extent_normalize()
481 	 * will do the appropriate thing with it (turning it into a
482 	 * KEY_TYPE_error key, or just a discard if it was a cached extent)
483 	 */
484 	bch2_extent_normalize(c, bkey_i_to_s(n));
485 
486 	/*
487 	 * Since we're not inserting through an extent iterator
488 	 * (BTREE_ITER_all_snapshots iterators aren't extent iterators),
489 	 * we aren't using the extent overwrite path to delete, we're
490 	 * just using the normal key deletion path:
491 	 */
492 	if (bkey_deleted(&n->k) && !(iter->flags & BTREE_ITER_is_extents))
493 		n->k.size = 0;
494 
495 	return bch2_trans_relock(trans) ?:
496 		bch2_trans_update(trans, iter, n, BTREE_UPDATE_internal_snapshot_node) ?:
497 		bch2_trans_commit(trans, NULL, NULL, BCH_TRANS_COMMIT_no_enospc);
498 }
499 
500 int bch2_data_update_init(struct btree_trans *trans,
501 			  struct btree_iter *iter,
502 			  struct moving_context *ctxt,
503 			  struct data_update *m,
504 			  struct write_point_specifier wp,
505 			  struct bch_io_opts io_opts,
506 			  struct data_update_opts data_opts,
507 			  enum btree_id btree_id,
508 			  struct bkey_s_c k)
509 {
510 	struct bch_fs *c = trans->c;
511 	struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(k);
512 	const union bch_extent_entry *entry;
513 	struct extent_ptr_decoded p;
514 	unsigned i, reserve_sectors = k.k->size * data_opts.extra_replicas;
515 	unsigned ptrs_locked = 0;
516 	int ret = 0;
517 
518 	/*
519 	 * fs is corrupt  we have a key for a snapshot node that doesn't exist,
520 	 * and we have to check for this because we go rw before repairing the
521 	 * snapshots table - just skip it, we can move it later.
522 	 */
523 	if (unlikely(k.k->p.snapshot && !bch2_snapshot_equiv(c, k.k->p.snapshot)))
524 		return -BCH_ERR_data_update_done;
525 
526 	bch2_bkey_buf_init(&m->k);
527 	bch2_bkey_buf_reassemble(&m->k, c, k);
528 	m->btree_id	= btree_id;
529 	m->data_opts	= data_opts;
530 	m->ctxt		= ctxt;
531 	m->stats	= ctxt ? ctxt->stats : NULL;
532 
533 	bch2_write_op_init(&m->op, c, io_opts);
534 	m->op.pos	= bkey_start_pos(k.k);
535 	m->op.version	= k.k->version;
536 	m->op.target	= data_opts.target;
537 	m->op.write_point = wp;
538 	m->op.nr_replicas = 0;
539 	m->op.flags	|= BCH_WRITE_PAGES_STABLE|
540 		BCH_WRITE_PAGES_OWNED|
541 		BCH_WRITE_DATA_ENCODED|
542 		BCH_WRITE_MOVE|
543 		m->data_opts.write_flags;
544 	m->op.compression_opt	= background_compression(io_opts);
545 	m->op.watermark		= m->data_opts.btree_insert_flags & BCH_WATERMARK_MASK;
546 
547 	bkey_for_each_ptr(ptrs, ptr) {
548 		if (!bch2_dev_tryget(c, ptr->dev)) {
549 			bkey_for_each_ptr(ptrs, ptr2) {
550 				if (ptr2 == ptr)
551 					break;
552 				bch2_dev_put(bch2_dev_have_ref(c, ptr2->dev));
553 			}
554 			return -BCH_ERR_data_update_done;
555 		}
556 	}
557 
558 	unsigned durability_have = 0, durability_removing = 0;
559 
560 	i = 0;
561 	bkey_for_each_ptr_decode(k.k, ptrs, p, entry) {
562 		struct bch_dev *ca = bch2_dev_have_ref(c, p.ptr.dev);
563 		struct bpos bucket = PTR_BUCKET_POS(ca, &p.ptr);
564 		bool locked;
565 
566 		rcu_read_lock();
567 		if (((1U << i) & m->data_opts.rewrite_ptrs)) {
568 			BUG_ON(p.ptr.cached);
569 
570 			if (crc_is_compressed(p.crc))
571 				reserve_sectors += k.k->size;
572 
573 			m->op.nr_replicas += bch2_extent_ptr_desired_durability(c, &p);
574 			durability_removing += bch2_extent_ptr_desired_durability(c, &p);
575 		} else if (!p.ptr.cached &&
576 			   !((1U << i) & m->data_opts.kill_ptrs)) {
577 			bch2_dev_list_add_dev(&m->op.devs_have, p.ptr.dev);
578 			durability_have += bch2_extent_ptr_durability(c, &p);
579 		}
580 		rcu_read_unlock();
581 
582 		/*
583 		 * op->csum_type is normally initialized from the fs/file's
584 		 * current options - but if an extent is encrypted, we require
585 		 * that it stays encrypted:
586 		 */
587 		if (bch2_csum_type_is_encryption(p.crc.csum_type)) {
588 			m->op.nonce	= p.crc.nonce + p.crc.offset;
589 			m->op.csum_type = p.crc.csum_type;
590 		}
591 
592 		if (p.crc.compression_type == BCH_COMPRESSION_TYPE_incompressible)
593 			m->op.incompressible = true;
594 
595 		if (c->opts.nocow_enabled) {
596 			if (ctxt) {
597 				move_ctxt_wait_event(ctxt,
598 						(locked = bch2_bucket_nocow_trylock(&c->nocow_locks,
599 									  bucket, 0)) ||
600 						list_empty(&ctxt->ios));
601 
602 				if (!locked)
603 					bch2_bucket_nocow_lock(&c->nocow_locks, bucket, 0);
604 			} else {
605 				if (!bch2_bucket_nocow_trylock(&c->nocow_locks, bucket, 0)) {
606 					ret = -BCH_ERR_nocow_lock_blocked;
607 					goto err;
608 				}
609 			}
610 			ptrs_locked |= (1U << i);
611 		}
612 
613 		i++;
614 	}
615 
616 	unsigned durability_required = max(0, (int) (io_opts.data_replicas - durability_have));
617 
618 	/*
619 	 * If current extent durability is less than io_opts.data_replicas,
620 	 * we're not trying to rereplicate the extent up to data_replicas here -
621 	 * unless extra_replicas was specified
622 	 *
623 	 * Increasing replication is an explicit operation triggered by
624 	 * rereplicate, currently, so that users don't get an unexpected -ENOSPC
625 	 */
626 	if (!(m->data_opts.write_flags & BCH_WRITE_CACHED) &&
627 	    !durability_required) {
628 		m->data_opts.kill_ptrs |= m->data_opts.rewrite_ptrs;
629 		m->data_opts.rewrite_ptrs = 0;
630 		/* if iter == NULL, it's just a promote */
631 		if (iter)
632 			ret = bch2_extent_drop_ptrs(trans, iter, k, m->data_opts);
633 		goto done;
634 	}
635 
636 	m->op.nr_replicas = min(durability_removing, durability_required) +
637 		m->data_opts.extra_replicas;
638 
639 	/*
640 	 * If device(s) were set to durability=0 after data was written to them
641 	 * we can end up with a duribilty=0 extent, and the normal algorithm
642 	 * that tries not to increase durability doesn't work:
643 	 */
644 	if (!(durability_have + durability_removing))
645 		m->op.nr_replicas = max((unsigned) m->op.nr_replicas, 1);
646 
647 	m->op.nr_replicas_required = m->op.nr_replicas;
648 
649 	if (reserve_sectors) {
650 		ret = bch2_disk_reservation_add(c, &m->op.res, reserve_sectors,
651 				m->data_opts.extra_replicas
652 				? 0
653 				: BCH_DISK_RESERVATION_NOFAIL);
654 		if (ret)
655 			goto err;
656 	}
657 
658 	if (bkey_extent_is_unwritten(k)) {
659 		bch2_update_unwritten_extent(trans, m);
660 		goto done;
661 	}
662 
663 	return 0;
664 err:
665 	i = 0;
666 	bkey_for_each_ptr_decode(k.k, ptrs, p, entry) {
667 		struct bch_dev *ca = bch2_dev_have_ref(c, p.ptr.dev);
668 		struct bpos bucket = PTR_BUCKET_POS(ca, &p.ptr);
669 		if ((1U << i) & ptrs_locked)
670 			bch2_bucket_nocow_unlock(&c->nocow_locks, bucket, 0);
671 		bch2_dev_put(ca);
672 		i++;
673 	}
674 
675 	bch2_bkey_buf_exit(&m->k, c);
676 	bch2_bio_free_pages_pool(c, &m->op.wbio.bio);
677 	return ret;
678 done:
679 	bch2_data_update_exit(m);
680 	return ret ?: -BCH_ERR_data_update_done;
681 }
682 
683 void bch2_data_update_opts_normalize(struct bkey_s_c k, struct data_update_opts *opts)
684 {
685 	struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(k);
686 	unsigned i = 0;
687 
688 	bkey_for_each_ptr(ptrs, ptr) {
689 		if ((opts->rewrite_ptrs & (1U << i)) && ptr->cached) {
690 			opts->kill_ptrs |= 1U << i;
691 			opts->rewrite_ptrs ^= 1U << i;
692 		}
693 
694 		i++;
695 	}
696 }
697