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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Some low level IO code, and hacks for various block layer limitations
4 *
5 * Copyright 2010, 2011 Kent Overstreet <kent.overstreet@gmail.com>
6 * Copyright 2012 Google, Inc.
7 */
8
9#include "bcachefs.h"
10#include "alloc_background.h"
11#include "alloc_foreground.h"
12#include "btree_update.h"
13#include "buckets.h"
14#include "checksum.h"
15#include "clock.h"
16#include "compress.h"
17#include "data_update.h"
18#include "disk_groups.h"
19#include "ec.h"
20#include "error.h"
21#include "io_read.h"
22#include "io_misc.h"
23#include "io_write.h"
24#include "subvolume.h"
25#include "trace.h"
26
27#include <linux/sched/mm.h>
28
29#ifndef CONFIG_BCACHEFS_NO_LATENCY_ACCT
30
31static bool bch2_target_congested(struct bch_fs *c, u16 target)
32{
33 const struct bch_devs_mask *devs;
34 unsigned d, nr = 0, total = 0;
35 u64 now = local_clock(), last;
36 s64 congested;
37 struct bch_dev *ca;
38
39 if (!target)
40 return false;
41
42 rcu_read_lock();
43 devs = bch2_target_to_mask(c, target) ?:
44 &c->rw_devs[BCH_DATA_user];
45
46 for_each_set_bit(d, devs->d, BCH_SB_MEMBERS_MAX) {
47 ca = rcu_dereference(c->devs[d]);
48 if (!ca)
49 continue;
50
51 congested = atomic_read(&ca->congested);
52 last = READ_ONCE(ca->congested_last);
53 if (time_after64(now, last))
54 congested -= (now - last) >> 12;
55
56 total += max(congested, 0LL);
57 nr++;
58 }
59 rcu_read_unlock();
60
61 return bch2_rand_range(nr * CONGESTED_MAX) < total;
62}
63
64#else
65
66static bool bch2_target_congested(struct bch_fs *c, u16 target)
67{
68 return false;
69}
70
71#endif
72
73/* Cache promotion on read */
74
75struct promote_op {
76 struct rcu_head rcu;
77 u64 start_time;
78
79 struct rhash_head hash;
80 struct bpos pos;
81
82 struct data_update write;
83 struct bio_vec bi_inline_vecs[]; /* must be last */
84};
85
86static const struct rhashtable_params bch_promote_params = {
87 .head_offset = offsetof(struct promote_op, hash),
88 .key_offset = offsetof(struct promote_op, pos),
89 .key_len = sizeof(struct bpos),
90};
91
92static inline int should_promote(struct bch_fs *c, struct bkey_s_c k,
93 struct bpos pos,
94 struct bch_io_opts opts,
95 unsigned flags)
96{
97 BUG_ON(!opts.promote_target);
98
99 if (!(flags & BCH_READ_MAY_PROMOTE))
100 return -BCH_ERR_nopromote_may_not;
101
102 if (bch2_bkey_has_target(c, k, opts.promote_target))
103 return -BCH_ERR_nopromote_already_promoted;
104
105 if (bkey_extent_is_unwritten(k))
106 return -BCH_ERR_nopromote_unwritten;
107
108 if (bch2_target_congested(c, opts.promote_target))
109 return -BCH_ERR_nopromote_congested;
110
111 if (rhashtable_lookup_fast(&c->promote_table, &pos,
112 bch_promote_params))
113 return -BCH_ERR_nopromote_in_flight;
114
115 return 0;
116}
117
118static void promote_free(struct bch_fs *c, struct promote_op *op)
119{
120 int ret;
121
122 bch2_data_update_exit(&op->write);
123
124 ret = rhashtable_remove_fast(&c->promote_table, &op->hash,
125 bch_promote_params);
126 BUG_ON(ret);
127 bch2_write_ref_put(c, BCH_WRITE_REF_promote);
128 kfree_rcu(op, rcu);
129}
130
131static void promote_done(struct bch_write_op *wop)
132{
133 struct promote_op *op =
134 container_of(wop, struct promote_op, write.op);
135 struct bch_fs *c = op->write.op.c;
136
137 bch2_time_stats_update(&c->times[BCH_TIME_data_promote],
138 op->start_time);
139 promote_free(c, op);
140}
141
142static void promote_start(struct promote_op *op, struct bch_read_bio *rbio)
143{
144 struct bio *bio = &op->write.op.wbio.bio;
145
146 trace_and_count(op->write.op.c, read_promote, &rbio->bio);
147
148 /* we now own pages: */
149 BUG_ON(!rbio->bounce);
150 BUG_ON(rbio->bio.bi_vcnt > bio->bi_max_vecs);
151
152 memcpy(bio->bi_io_vec, rbio->bio.bi_io_vec,
153 sizeof(struct bio_vec) * rbio->bio.bi_vcnt);
154 swap(bio->bi_vcnt, rbio->bio.bi_vcnt);
155
156 bch2_data_update_read_done(&op->write, rbio->pick.crc);
157}
158
159static struct promote_op *__promote_alloc(struct btree_trans *trans,
160 enum btree_id btree_id,
161 struct bkey_s_c k,
162 struct bpos pos,
163 struct extent_ptr_decoded *pick,
164 struct bch_io_opts opts,
165 unsigned sectors,
166 struct bch_read_bio **rbio)
167{
168 struct bch_fs *c = trans->c;
169 struct promote_op *op = NULL;
170 struct bio *bio;
171 unsigned pages = DIV_ROUND_UP(sectors, PAGE_SECTORS);
172 int ret;
173
174 if (!bch2_write_ref_tryget(c, BCH_WRITE_REF_promote))
175 return ERR_PTR(-BCH_ERR_nopromote_no_writes);
176
177 op = kzalloc(sizeof(*op) + sizeof(struct bio_vec) * pages, GFP_KERNEL);
178 if (!op) {
179 ret = -BCH_ERR_nopromote_enomem;
180 goto err;
181 }
182
183 op->start_time = local_clock();
184 op->pos = pos;
185
186 /*
187 * We don't use the mempool here because extents that aren't
188 * checksummed or compressed can be too big for the mempool:
189 */
190 *rbio = kzalloc(sizeof(struct bch_read_bio) +
191 sizeof(struct bio_vec) * pages,
192 GFP_KERNEL);
193 if (!*rbio) {
194 ret = -BCH_ERR_nopromote_enomem;
195 goto err;
196 }
197
198 rbio_init(&(*rbio)->bio, opts);
199 bio_init(&(*rbio)->bio, NULL, (*rbio)->bio.bi_inline_vecs, pages, 0);
200
201 if (bch2_bio_alloc_pages(&(*rbio)->bio, sectors << 9, GFP_KERNEL)) {
202 ret = -BCH_ERR_nopromote_enomem;
203 goto err;
204 }
205
206 (*rbio)->bounce = true;
207 (*rbio)->split = true;
208 (*rbio)->kmalloc = true;
209
210 if (rhashtable_lookup_insert_fast(&c->promote_table, &op->hash,
211 bch_promote_params)) {
212 ret = -BCH_ERR_nopromote_in_flight;
213 goto err;
214 }
215
216 bio = &op->write.op.wbio.bio;
217 bio_init(bio, NULL, bio->bi_inline_vecs, pages, 0);
218
219 ret = bch2_data_update_init(trans, NULL, NULL, &op->write,
220 writepoint_hashed((unsigned long) current),
221 opts,
222 (struct data_update_opts) {
223 .target = opts.promote_target,
224 .extra_replicas = 1,
225 .write_flags = BCH_WRITE_ALLOC_NOWAIT|BCH_WRITE_CACHED,
226 },
227 btree_id, k);
228 /*
229 * possible errors: -BCH_ERR_nocow_lock_blocked,
230 * -BCH_ERR_ENOSPC_disk_reservation:
231 */
232 if (ret) {
233 BUG_ON(rhashtable_remove_fast(&c->promote_table, &op->hash,
234 bch_promote_params));
235 goto err;
236 }
237
238 op->write.op.end_io = promote_done;
239
240 return op;
241err:
242 if (*rbio)
243 bio_free_pages(&(*rbio)->bio);
244 kfree(*rbio);
245 *rbio = NULL;
246 kfree(op);
247 bch2_write_ref_put(c, BCH_WRITE_REF_promote);
248 return ERR_PTR(ret);
249}
250
251noinline
252static struct promote_op *promote_alloc(struct btree_trans *trans,
253 struct bvec_iter iter,
254 struct bkey_s_c k,
255 struct extent_ptr_decoded *pick,
256 struct bch_io_opts opts,
257 unsigned flags,
258 struct bch_read_bio **rbio,
259 bool *bounce,
260 bool *read_full)
261{
262 struct bch_fs *c = trans->c;
263 bool promote_full = *read_full || READ_ONCE(c->promote_whole_extents);
264 /* data might have to be decompressed in the write path: */
265 unsigned sectors = promote_full
266 ? max(pick->crc.compressed_size, pick->crc.live_size)
267 : bvec_iter_sectors(iter);
268 struct bpos pos = promote_full
269 ? bkey_start_pos(k.k)
270 : POS(k.k->p.inode, iter.bi_sector);
271 struct promote_op *promote;
272 int ret;
273
274 ret = should_promote(c, k, pos, opts, flags);
275 if (ret)
276 goto nopromote;
277
278 promote = __promote_alloc(trans,
279 k.k->type == KEY_TYPE_reflink_v
280 ? BTREE_ID_reflink
281 : BTREE_ID_extents,
282 k, pos, pick, opts, sectors, rbio);
283 ret = PTR_ERR_OR_ZERO(promote);
284 if (ret)
285 goto nopromote;
286
287 *bounce = true;
288 *read_full = promote_full;
289 return promote;
290nopromote:
291 trace_read_nopromote(c, ret);
292 return NULL;
293}
294
295/* Read */
296
297#define READ_RETRY_AVOID 1
298#define READ_RETRY 2
299#define READ_ERR 3
300
301enum rbio_context {
302 RBIO_CONTEXT_NULL,
303 RBIO_CONTEXT_HIGHPRI,
304 RBIO_CONTEXT_UNBOUND,
305};
306
307static inline struct bch_read_bio *
308bch2_rbio_parent(struct bch_read_bio *rbio)
309{
310 return rbio->split ? rbio->parent : rbio;
311}
312
313__always_inline
314static void bch2_rbio_punt(struct bch_read_bio *rbio, work_func_t fn,
315 enum rbio_context context,
316 struct workqueue_struct *wq)
317{
318 if (context <= rbio->context) {
319 fn(&rbio->work);
320 } else {
321 rbio->work.func = fn;
322 rbio->context = context;
323 queue_work(wq, &rbio->work);
324 }
325}
326
327static inline struct bch_read_bio *bch2_rbio_free(struct bch_read_bio *rbio)
328{
329 BUG_ON(rbio->bounce && !rbio->split);
330
331 if (rbio->promote)
332 promote_free(rbio->c, rbio->promote);
333 rbio->promote = NULL;
334
335 if (rbio->bounce)
336 bch2_bio_free_pages_pool(rbio->c, &rbio->bio);
337
338 if (rbio->split) {
339 struct bch_read_bio *parent = rbio->parent;
340
341 if (rbio->kmalloc)
342 kfree(rbio);
343 else
344 bio_put(&rbio->bio);
345
346 rbio = parent;
347 }
348
349 return rbio;
350}
351
352/*
353 * Only called on a top level bch_read_bio to complete an entire read request,
354 * not a split:
355 */
356static void bch2_rbio_done(struct bch_read_bio *rbio)
357{
358 if (rbio->start_time)
359 bch2_time_stats_update(&rbio->c->times[BCH_TIME_data_read],
360 rbio->start_time);
361 bio_endio(&rbio->bio);
362}
363
364static void bch2_read_retry_nodecode(struct bch_fs *c, struct bch_read_bio *rbio,
365 struct bvec_iter bvec_iter,
366 struct bch_io_failures *failed,
367 unsigned flags)
368{
369 struct btree_trans *trans = bch2_trans_get(c);
370 struct btree_iter iter;
371 struct bkey_buf sk;
372 struct bkey_s_c k;
373 int ret;
374
375 flags &= ~BCH_READ_LAST_FRAGMENT;
376 flags |= BCH_READ_MUST_CLONE;
377
378 bch2_bkey_buf_init(&sk);
379
380 bch2_trans_iter_init(trans, &iter, rbio->data_btree,
381 rbio->read_pos, BTREE_ITER_SLOTS);
382retry:
383 rbio->bio.bi_status = 0;
384
385 k = bch2_btree_iter_peek_slot(&iter);
386 if (bkey_err(k))
387 goto err;
388
389 bch2_bkey_buf_reassemble(&sk, c, k);
390 k = bkey_i_to_s_c(sk.k);
391 bch2_trans_unlock(trans);
392
393 if (!bch2_bkey_matches_ptr(c, k,
394 rbio->pick.ptr,
395 rbio->data_pos.offset -
396 rbio->pick.crc.offset)) {
397 /* extent we wanted to read no longer exists: */
398 rbio->hole = true;
399 goto out;
400 }
401
402 ret = __bch2_read_extent(trans, rbio, bvec_iter,
403 rbio->read_pos,
404 rbio->data_btree,
405 k, 0, failed, flags);
406 if (ret == READ_RETRY)
407 goto retry;
408 if (ret)
409 goto err;
410out:
411 bch2_rbio_done(rbio);
412 bch2_trans_iter_exit(trans, &iter);
413 bch2_trans_put(trans);
414 bch2_bkey_buf_exit(&sk, c);
415 return;
416err:
417 rbio->bio.bi_status = BLK_STS_IOERR;
418 goto out;
419}
420
421static void bch2_rbio_retry(struct work_struct *work)
422{
423 struct bch_read_bio *rbio =
424 container_of(work, struct bch_read_bio, work);
425 struct bch_fs *c = rbio->c;
426 struct bvec_iter iter = rbio->bvec_iter;
427 unsigned flags = rbio->flags;
428 subvol_inum inum = {
429 .subvol = rbio->subvol,
430 .inum = rbio->read_pos.inode,
431 };
432 struct bch_io_failures failed = { .nr = 0 };
433
434 trace_and_count(c, read_retry, &rbio->bio);
435
436 if (rbio->retry == READ_RETRY_AVOID)
437 bch2_mark_io_failure(&failed, &rbio->pick);
438
439 rbio->bio.bi_status = 0;
440
441 rbio = bch2_rbio_free(rbio);
442
443 flags |= BCH_READ_IN_RETRY;
444 flags &= ~BCH_READ_MAY_PROMOTE;
445
446 if (flags & BCH_READ_NODECODE) {
447 bch2_read_retry_nodecode(c, rbio, iter, &failed, flags);
448 } else {
449 flags &= ~BCH_READ_LAST_FRAGMENT;
450 flags |= BCH_READ_MUST_CLONE;
451
452 __bch2_read(c, rbio, iter, inum, &failed, flags);
453 }
454}
455
456static void bch2_rbio_error(struct bch_read_bio *rbio, int retry,
457 blk_status_t error)
458{
459 rbio->retry = retry;
460
461 if (rbio->flags & BCH_READ_IN_RETRY)
462 return;
463
464 if (retry == READ_ERR) {
465 rbio = bch2_rbio_free(rbio);
466
467 rbio->bio.bi_status = error;
468 bch2_rbio_done(rbio);
469 } else {
470 bch2_rbio_punt(rbio, bch2_rbio_retry,
471 RBIO_CONTEXT_UNBOUND, system_unbound_wq);
472 }
473}
474
475static int __bch2_rbio_narrow_crcs(struct btree_trans *trans,
476 struct bch_read_bio *rbio)
477{
478 struct bch_fs *c = rbio->c;
479 u64 data_offset = rbio->data_pos.offset - rbio->pick.crc.offset;
480 struct bch_extent_crc_unpacked new_crc;
481 struct btree_iter iter;
482 struct bkey_i *new;
483 struct bkey_s_c k;
484 int ret = 0;
485
486 if (crc_is_compressed(rbio->pick.crc))
487 return 0;
488
489 k = bch2_bkey_get_iter(trans, &iter, rbio->data_btree, rbio->data_pos,
490 BTREE_ITER_SLOTS|BTREE_ITER_INTENT);
491 if ((ret = bkey_err(k)))
492 goto out;
493
494 if (bversion_cmp(k.k->version, rbio->version) ||
495 !bch2_bkey_matches_ptr(c, k, rbio->pick.ptr, data_offset))
496 goto out;
497
498 /* Extent was merged? */
499 if (bkey_start_offset(k.k) < data_offset ||
500 k.k->p.offset > data_offset + rbio->pick.crc.uncompressed_size)
501 goto out;
502
503 if (bch2_rechecksum_bio(c, &rbio->bio, rbio->version,
504 rbio->pick.crc, NULL, &new_crc,
505 bkey_start_offset(k.k) - data_offset, k.k->size,
506 rbio->pick.crc.csum_type)) {
507 bch_err(c, "error verifying existing checksum while narrowing checksum (memory corruption?)");
508 ret = 0;
509 goto out;
510 }
511
512 /*
513 * going to be temporarily appending another checksum entry:
514 */
515 new = bch2_trans_kmalloc(trans, bkey_bytes(k.k) +
516 sizeof(struct bch_extent_crc128));
517 if ((ret = PTR_ERR_OR_ZERO(new)))
518 goto out;
519
520 bkey_reassemble(new, k);
521
522 if (!bch2_bkey_narrow_crcs(new, new_crc))
523 goto out;
524
525 ret = bch2_trans_update(trans, &iter, new,
526 BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE);
527out:
528 bch2_trans_iter_exit(trans, &iter);
529 return ret;
530}
531
532static noinline void bch2_rbio_narrow_crcs(struct bch_read_bio *rbio)
533{
534 bch2_trans_do(rbio->c, NULL, NULL, BCH_TRANS_COMMIT_no_enospc,
535 __bch2_rbio_narrow_crcs(trans, rbio));
536}
537
538/* Inner part that may run in process context */
539static void __bch2_read_endio(struct work_struct *work)
540{
541 struct bch_read_bio *rbio =
542 container_of(work, struct bch_read_bio, work);
543 struct bch_fs *c = rbio->c;
544 struct bch_dev *ca = bch_dev_bkey_exists(c, rbio->pick.ptr.dev);
545 struct bio *src = &rbio->bio;
546 struct bio *dst = &bch2_rbio_parent(rbio)->bio;
547 struct bvec_iter dst_iter = rbio->bvec_iter;
548 struct bch_extent_crc_unpacked crc = rbio->pick.crc;
549 struct nonce nonce = extent_nonce(rbio->version, crc);
550 unsigned nofs_flags;
551 struct bch_csum csum;
552 int ret;
553
554 nofs_flags = memalloc_nofs_save();
555
556 /* Reset iterator for checksumming and copying bounced data: */
557 if (rbio->bounce) {
558 src->bi_iter.bi_size = crc.compressed_size << 9;
559 src->bi_iter.bi_idx = 0;
560 src->bi_iter.bi_bvec_done = 0;
561 } else {
562 src->bi_iter = rbio->bvec_iter;
563 }
564
565 csum = bch2_checksum_bio(c, crc.csum_type, nonce, src);
566 if (bch2_crc_cmp(csum, rbio->pick.crc.csum) && !c->opts.no_data_io)
567 goto csum_err;
568
569 /*
570 * XXX
571 * We need to rework the narrow_crcs path to deliver the read completion
572 * first, and then punt to a different workqueue, otherwise we're
573 * holding up reads while doing btree updates which is bad for memory
574 * reclaim.
575 */
576 if (unlikely(rbio->narrow_crcs))
577 bch2_rbio_narrow_crcs(rbio);
578
579 if (rbio->flags & BCH_READ_NODECODE)
580 goto nodecode;
581
582 /* Adjust crc to point to subset of data we want: */
583 crc.offset += rbio->offset_into_extent;
584 crc.live_size = bvec_iter_sectors(rbio->bvec_iter);
585
586 if (crc_is_compressed(crc)) {
587 ret = bch2_encrypt_bio(c, crc.csum_type, nonce, src);
588 if (ret)
589 goto decrypt_err;
590
591 if (bch2_bio_uncompress(c, src, dst, dst_iter, crc) &&
592 !c->opts.no_data_io)
593 goto decompression_err;
594 } else {
595 /* don't need to decrypt the entire bio: */
596 nonce = nonce_add(nonce, crc.offset << 9);
597 bio_advance(src, crc.offset << 9);
598
599 BUG_ON(src->bi_iter.bi_size < dst_iter.bi_size);
600 src->bi_iter.bi_size = dst_iter.bi_size;
601
602 ret = bch2_encrypt_bio(c, crc.csum_type, nonce, src);
603 if (ret)
604 goto decrypt_err;
605
606 if (rbio->bounce) {
607 struct bvec_iter src_iter = src->bi_iter;
608
609 bio_copy_data_iter(dst, &dst_iter, src, &src_iter);
610 }
611 }
612
613 if (rbio->promote) {
614 /*
615 * Re encrypt data we decrypted, so it's consistent with
616 * rbio->crc:
617 */
618 ret = bch2_encrypt_bio(c, crc.csum_type, nonce, src);
619 if (ret)
620 goto decrypt_err;
621
622 promote_start(rbio->promote, rbio);
623 rbio->promote = NULL;
624 }
625nodecode:
626 if (likely(!(rbio->flags & BCH_READ_IN_RETRY))) {
627 rbio = bch2_rbio_free(rbio);
628 bch2_rbio_done(rbio);
629 }
630out:
631 memalloc_nofs_restore(nofs_flags);
632 return;
633csum_err:
634 /*
635 * Checksum error: if the bio wasn't bounced, we may have been
636 * reading into buffers owned by userspace (that userspace can
637 * scribble over) - retry the read, bouncing it this time:
638 */
639 if (!rbio->bounce && (rbio->flags & BCH_READ_USER_MAPPED)) {
640 rbio->flags |= BCH_READ_MUST_BOUNCE;
641 bch2_rbio_error(rbio, READ_RETRY, BLK_STS_IOERR);
642 goto out;
643 }
644
645 struct printbuf buf = PRINTBUF;
646 buf.atomic++;
647 prt_str(&buf, "data ");
648 bch2_csum_err_msg(&buf, crc.csum_type, rbio->pick.crc.csum, csum);
649
650 bch_err_inum_offset_ratelimited(ca,
651 rbio->read_pos.inode,
652 rbio->read_pos.offset << 9,
653 "data %s", buf.buf);
654 printbuf_exit(&buf);
655
656 bch2_io_error(ca, BCH_MEMBER_ERROR_checksum);
657 bch2_rbio_error(rbio, READ_RETRY_AVOID, BLK_STS_IOERR);
658 goto out;
659decompression_err:
660 bch_err_inum_offset_ratelimited(c, rbio->read_pos.inode,
661 rbio->read_pos.offset << 9,
662 "decompression error");
663 bch2_rbio_error(rbio, READ_ERR, BLK_STS_IOERR);
664 goto out;
665decrypt_err:
666 bch_err_inum_offset_ratelimited(c, rbio->read_pos.inode,
667 rbio->read_pos.offset << 9,
668 "decrypt error");
669 bch2_rbio_error(rbio, READ_ERR, BLK_STS_IOERR);
670 goto out;
671}
672
673static void bch2_read_endio(struct bio *bio)
674{
675 struct bch_read_bio *rbio =
676 container_of(bio, struct bch_read_bio, bio);
677 struct bch_fs *c = rbio->c;
678 struct bch_dev *ca = bch_dev_bkey_exists(c, rbio->pick.ptr.dev);
679 struct workqueue_struct *wq = NULL;
680 enum rbio_context context = RBIO_CONTEXT_NULL;
681
682 if (rbio->have_ioref) {
683 bch2_latency_acct(ca, rbio->submit_time, READ);
684 percpu_ref_put(&ca->io_ref);
685 }
686
687 if (!rbio->split)
688 rbio->bio.bi_end_io = rbio->end_io;
689
690 if (bch2_dev_inum_io_err_on(bio->bi_status, ca, BCH_MEMBER_ERROR_read,
691 rbio->read_pos.inode,
692 rbio->read_pos.offset,
693 "data read error: %s",
694 bch2_blk_status_to_str(bio->bi_status))) {
695 bch2_rbio_error(rbio, READ_RETRY_AVOID, bio->bi_status);
696 return;
697 }
698
699 if (((rbio->flags & BCH_READ_RETRY_IF_STALE) && race_fault()) ||
700 ptr_stale(ca, &rbio->pick.ptr)) {
701 trace_and_count(c, read_reuse_race, &rbio->bio);
702
703 if (rbio->flags & BCH_READ_RETRY_IF_STALE)
704 bch2_rbio_error(rbio, READ_RETRY, BLK_STS_AGAIN);
705 else
706 bch2_rbio_error(rbio, READ_ERR, BLK_STS_AGAIN);
707 return;
708 }
709
710 if (rbio->narrow_crcs ||
711 rbio->promote ||
712 crc_is_compressed(rbio->pick.crc) ||
713 bch2_csum_type_is_encryption(rbio->pick.crc.csum_type))
714 context = RBIO_CONTEXT_UNBOUND, wq = system_unbound_wq;
715 else if (rbio->pick.crc.csum_type)
716 context = RBIO_CONTEXT_HIGHPRI, wq = system_highpri_wq;
717
718 bch2_rbio_punt(rbio, __bch2_read_endio, context, wq);
719}
720
721int __bch2_read_indirect_extent(struct btree_trans *trans,
722 unsigned *offset_into_extent,
723 struct bkey_buf *orig_k)
724{
725 struct btree_iter iter;
726 struct bkey_s_c k;
727 u64 reflink_offset;
728 int ret;
729
730 reflink_offset = le64_to_cpu(bkey_i_to_reflink_p(orig_k->k)->v.idx) +
731 *offset_into_extent;
732
733 k = bch2_bkey_get_iter(trans, &iter, BTREE_ID_reflink,
734 POS(0, reflink_offset), 0);
735 ret = bkey_err(k);
736 if (ret)
737 goto err;
738
739 if (k.k->type != KEY_TYPE_reflink_v &&
740 k.k->type != KEY_TYPE_indirect_inline_data) {
741 bch_err_inum_offset_ratelimited(trans->c,
742 orig_k->k->k.p.inode,
743 orig_k->k->k.p.offset << 9,
744 "%llu len %u points to nonexistent indirect extent %llu",
745 orig_k->k->k.p.offset,
746 orig_k->k->k.size,
747 reflink_offset);
748 bch2_inconsistent_error(trans->c);
749 ret = -EIO;
750 goto err;
751 }
752
753 *offset_into_extent = iter.pos.offset - bkey_start_offset(k.k);
754 bch2_bkey_buf_reassemble(orig_k, trans->c, k);
755err:
756 bch2_trans_iter_exit(trans, &iter);
757 return ret;
758}
759
760static noinline void read_from_stale_dirty_pointer(struct btree_trans *trans,
761 struct bkey_s_c k,
762 struct bch_extent_ptr ptr)
763{
764 struct bch_fs *c = trans->c;
765 struct bch_dev *ca = bch_dev_bkey_exists(c, ptr.dev);
766 struct btree_iter iter;
767 struct printbuf buf = PRINTBUF;
768 int ret;
769
770 bch2_trans_iter_init(trans, &iter, BTREE_ID_alloc,
771 PTR_BUCKET_POS(c, &ptr),
772 BTREE_ITER_CACHED);
773
774 prt_printf(&buf, "Attempting to read from stale dirty pointer:");
775 printbuf_indent_add(&buf, 2);
776 prt_newline(&buf);
777
778 bch2_bkey_val_to_text(&buf, c, k);
779 prt_newline(&buf);
780
781 prt_printf(&buf, "memory gen: %u", *bucket_gen(ca, iter.pos.offset));
782
783 ret = lockrestart_do(trans, bkey_err(k = bch2_btree_iter_peek_slot(&iter)));
784 if (!ret) {
785 prt_newline(&buf);
786 bch2_bkey_val_to_text(&buf, c, k);
787 }
788
789 bch2_fs_inconsistent(c, "%s", buf.buf);
790
791 bch2_trans_iter_exit(trans, &iter);
792 printbuf_exit(&buf);
793}
794
795int __bch2_read_extent(struct btree_trans *trans, struct bch_read_bio *orig,
796 struct bvec_iter iter, struct bpos read_pos,
797 enum btree_id data_btree, struct bkey_s_c k,
798 unsigned offset_into_extent,
799 struct bch_io_failures *failed, unsigned flags)
800{
801 struct bch_fs *c = trans->c;
802 struct extent_ptr_decoded pick;
803 struct bch_read_bio *rbio = NULL;
804 struct bch_dev *ca = NULL;
805 struct promote_op *promote = NULL;
806 bool bounce = false, read_full = false, narrow_crcs = false;
807 struct bpos data_pos = bkey_start_pos(k.k);
808 int pick_ret;
809
810 if (bkey_extent_is_inline_data(k.k)) {
811 unsigned bytes = min_t(unsigned, iter.bi_size,
812 bkey_inline_data_bytes(k.k));
813
814 swap(iter.bi_size, bytes);
815 memcpy_to_bio(&orig->bio, iter, bkey_inline_data_p(k));
816 swap(iter.bi_size, bytes);
817 bio_advance_iter(&orig->bio, &iter, bytes);
818 zero_fill_bio_iter(&orig->bio, iter);
819 goto out_read_done;
820 }
821retry_pick:
822 pick_ret = bch2_bkey_pick_read_device(c, k, failed, &pick);
823
824 /* hole or reservation - just zero fill: */
825 if (!pick_ret)
826 goto hole;
827
828 if (pick_ret < 0) {
829 bch_err_inum_offset_ratelimited(c,
830 read_pos.inode, read_pos.offset << 9,
831 "no device to read from");
832 goto err;
833 }
834
835 ca = bch_dev_bkey_exists(c, pick.ptr.dev);
836
837 /*
838 * Stale dirty pointers are treated as IO errors, but @failed isn't
839 * allocated unless we're in the retry path - so if we're not in the
840 * retry path, don't check here, it'll be caught in bch2_read_endio()
841 * and we'll end up in the retry path:
842 */
843 if ((flags & BCH_READ_IN_RETRY) &&
844 !pick.ptr.cached &&
845 unlikely(ptr_stale(ca, &pick.ptr))) {
846 read_from_stale_dirty_pointer(trans, k, pick.ptr);
847 bch2_mark_io_failure(failed, &pick);
848 goto retry_pick;
849 }
850
851 /*
852 * Unlock the iterator while the btree node's lock is still in
853 * cache, before doing the IO:
854 */
855 bch2_trans_unlock(trans);
856
857 if (flags & BCH_READ_NODECODE) {
858 /*
859 * can happen if we retry, and the extent we were going to read
860 * has been merged in the meantime:
861 */
862 if (pick.crc.compressed_size > orig->bio.bi_vcnt * PAGE_SECTORS)
863 goto hole;
864
865 iter.bi_size = pick.crc.compressed_size << 9;
866 goto get_bio;
867 }
868
869 if (!(flags & BCH_READ_LAST_FRAGMENT) ||
870 bio_flagged(&orig->bio, BIO_CHAIN))
871 flags |= BCH_READ_MUST_CLONE;
872
873 narrow_crcs = !(flags & BCH_READ_IN_RETRY) &&
874 bch2_can_narrow_extent_crcs(k, pick.crc);
875
876 if (narrow_crcs && (flags & BCH_READ_USER_MAPPED))
877 flags |= BCH_READ_MUST_BOUNCE;
878
879 EBUG_ON(offset_into_extent + bvec_iter_sectors(iter) > k.k->size);
880
881 if (crc_is_compressed(pick.crc) ||
882 (pick.crc.csum_type != BCH_CSUM_none &&
883 (bvec_iter_sectors(iter) != pick.crc.uncompressed_size ||
884 (bch2_csum_type_is_encryption(pick.crc.csum_type) &&
885 (flags & BCH_READ_USER_MAPPED)) ||
886 (flags & BCH_READ_MUST_BOUNCE)))) {
887 read_full = true;
888 bounce = true;
889 }
890
891 if (orig->opts.promote_target)
892 promote = promote_alloc(trans, iter, k, &pick, orig->opts, flags,
893 &rbio, &bounce, &read_full);
894
895 if (!read_full) {
896 EBUG_ON(crc_is_compressed(pick.crc));
897 EBUG_ON(pick.crc.csum_type &&
898 (bvec_iter_sectors(iter) != pick.crc.uncompressed_size ||
899 bvec_iter_sectors(iter) != pick.crc.live_size ||
900 pick.crc.offset ||
901 offset_into_extent));
902
903 data_pos.offset += offset_into_extent;
904 pick.ptr.offset += pick.crc.offset +
905 offset_into_extent;
906 offset_into_extent = 0;
907 pick.crc.compressed_size = bvec_iter_sectors(iter);
908 pick.crc.uncompressed_size = bvec_iter_sectors(iter);
909 pick.crc.offset = 0;
910 pick.crc.live_size = bvec_iter_sectors(iter);
911 }
912get_bio:
913 if (rbio) {
914 /*
915 * promote already allocated bounce rbio:
916 * promote needs to allocate a bio big enough for uncompressing
917 * data in the write path, but we're not going to use it all
918 * here:
919 */
920 EBUG_ON(rbio->bio.bi_iter.bi_size <
921 pick.crc.compressed_size << 9);
922 rbio->bio.bi_iter.bi_size =
923 pick.crc.compressed_size << 9;
924 } else if (bounce) {
925 unsigned sectors = pick.crc.compressed_size;
926
927 rbio = rbio_init(bio_alloc_bioset(NULL,
928 DIV_ROUND_UP(sectors, PAGE_SECTORS),
929 0,
930 GFP_NOFS,
931 &c->bio_read_split),
932 orig->opts);
933
934 bch2_bio_alloc_pages_pool(c, &rbio->bio, sectors << 9);
935 rbio->bounce = true;
936 rbio->split = true;
937 } else if (flags & BCH_READ_MUST_CLONE) {
938 /*
939 * Have to clone if there were any splits, due to error
940 * reporting issues (if a split errored, and retrying didn't
941 * work, when it reports the error to its parent (us) we don't
942 * know if the error was from our bio, and we should retry, or
943 * from the whole bio, in which case we don't want to retry and
944 * lose the error)
945 */
946 rbio = rbio_init(bio_alloc_clone(NULL, &orig->bio, GFP_NOFS,
947 &c->bio_read_split),
948 orig->opts);
949 rbio->bio.bi_iter = iter;
950 rbio->split = true;
951 } else {
952 rbio = orig;
953 rbio->bio.bi_iter = iter;
954 EBUG_ON(bio_flagged(&rbio->bio, BIO_CHAIN));
955 }
956
957 EBUG_ON(bio_sectors(&rbio->bio) != pick.crc.compressed_size);
958
959 rbio->c = c;
960 rbio->submit_time = local_clock();
961 if (rbio->split)
962 rbio->parent = orig;
963 else
964 rbio->end_io = orig->bio.bi_end_io;
965 rbio->bvec_iter = iter;
966 rbio->offset_into_extent= offset_into_extent;
967 rbio->flags = flags;
968 rbio->have_ioref = pick_ret > 0 && bch2_dev_get_ioref(ca, READ);
969 rbio->narrow_crcs = narrow_crcs;
970 rbio->hole = 0;
971 rbio->retry = 0;
972 rbio->context = 0;
973 /* XXX: only initialize this if needed */
974 rbio->devs_have = bch2_bkey_devs(k);
975 rbio->pick = pick;
976 rbio->subvol = orig->subvol;
977 rbio->read_pos = read_pos;
978 rbio->data_btree = data_btree;
979 rbio->data_pos = data_pos;
980 rbio->version = k.k->version;
981 rbio->promote = promote;
982 INIT_WORK(&rbio->work, NULL);
983
984 rbio->bio.bi_opf = orig->bio.bi_opf;
985 rbio->bio.bi_iter.bi_sector = pick.ptr.offset;
986 rbio->bio.bi_end_io = bch2_read_endio;
987
988 if (rbio->bounce)
989 trace_and_count(c, read_bounce, &rbio->bio);
990
991 this_cpu_add(c->counters[BCH_COUNTER_io_read], bio_sectors(&rbio->bio));
992 bch2_increment_clock(c, bio_sectors(&rbio->bio), READ);
993
994 /*
995 * If it's being moved internally, we don't want to flag it as a cache
996 * hit:
997 */
998 if (pick.ptr.cached && !(flags & BCH_READ_NODECODE))
999 bch2_bucket_io_time_reset(trans, pick.ptr.dev,
1000 PTR_BUCKET_NR(ca, &pick.ptr), READ);
1001
1002 if (!(flags & (BCH_READ_IN_RETRY|BCH_READ_LAST_FRAGMENT))) {
1003 bio_inc_remaining(&orig->bio);
1004 trace_and_count(c, read_split, &orig->bio);
1005 }
1006
1007 if (!rbio->pick.idx) {
1008 if (!rbio->have_ioref) {
1009 bch_err_inum_offset_ratelimited(c,
1010 read_pos.inode,
1011 read_pos.offset << 9,
1012 "no device to read from");
1013 bch2_rbio_error(rbio, READ_RETRY_AVOID, BLK_STS_IOERR);
1014 goto out;
1015 }
1016
1017 this_cpu_add(ca->io_done->sectors[READ][BCH_DATA_user],
1018 bio_sectors(&rbio->bio));
1019 bio_set_dev(&rbio->bio, ca->disk_sb.bdev);
1020
1021 if (unlikely(c->opts.no_data_io)) {
1022 if (likely(!(flags & BCH_READ_IN_RETRY)))
1023 bio_endio(&rbio->bio);
1024 } else {
1025 if (likely(!(flags & BCH_READ_IN_RETRY)))
1026 submit_bio(&rbio->bio);
1027 else
1028 submit_bio_wait(&rbio->bio);
1029 }
1030
1031 /*
1032 * We just submitted IO which may block, we expect relock fail
1033 * events and shouldn't count them:
1034 */
1035 trans->notrace_relock_fail = true;
1036 } else {
1037 /* Attempting reconstruct read: */
1038 if (bch2_ec_read_extent(trans, rbio)) {
1039 bch2_rbio_error(rbio, READ_RETRY_AVOID, BLK_STS_IOERR);
1040 goto out;
1041 }
1042
1043 if (likely(!(flags & BCH_READ_IN_RETRY)))
1044 bio_endio(&rbio->bio);
1045 }
1046out:
1047 if (likely(!(flags & BCH_READ_IN_RETRY))) {
1048 return 0;
1049 } else {
1050 int ret;
1051
1052 rbio->context = RBIO_CONTEXT_UNBOUND;
1053 bch2_read_endio(&rbio->bio);
1054
1055 ret = rbio->retry;
1056 rbio = bch2_rbio_free(rbio);
1057
1058 if (ret == READ_RETRY_AVOID) {
1059 bch2_mark_io_failure(failed, &pick);
1060 ret = READ_RETRY;
1061 }
1062
1063 if (!ret)
1064 goto out_read_done;
1065
1066 return ret;
1067 }
1068
1069err:
1070 if (flags & BCH_READ_IN_RETRY)
1071 return READ_ERR;
1072
1073 orig->bio.bi_status = BLK_STS_IOERR;
1074 goto out_read_done;
1075
1076hole:
1077 /*
1078 * won't normally happen in the BCH_READ_NODECODE
1079 * (bch2_move_extent()) path, but if we retry and the extent we wanted
1080 * to read no longer exists we have to signal that:
1081 */
1082 if (flags & BCH_READ_NODECODE)
1083 orig->hole = true;
1084
1085 zero_fill_bio_iter(&orig->bio, iter);
1086out_read_done:
1087 if (flags & BCH_READ_LAST_FRAGMENT)
1088 bch2_rbio_done(orig);
1089 return 0;
1090}
1091
1092void __bch2_read(struct bch_fs *c, struct bch_read_bio *rbio,
1093 struct bvec_iter bvec_iter, subvol_inum inum,
1094 struct bch_io_failures *failed, unsigned flags)
1095{
1096 struct btree_trans *trans = bch2_trans_get(c);
1097 struct btree_iter iter;
1098 struct bkey_buf sk;
1099 struct bkey_s_c k;
1100 u32 snapshot;
1101 int ret;
1102
1103 BUG_ON(flags & BCH_READ_NODECODE);
1104
1105 bch2_bkey_buf_init(&sk);
1106retry:
1107 bch2_trans_begin(trans);
1108 iter = (struct btree_iter) { NULL };
1109
1110 ret = bch2_subvolume_get_snapshot(trans, inum.subvol, &snapshot);
1111 if (ret)
1112 goto err;
1113
1114 bch2_trans_iter_init(trans, &iter, BTREE_ID_extents,
1115 SPOS(inum.inum, bvec_iter.bi_sector, snapshot),
1116 BTREE_ITER_SLOTS);
1117 while (1) {
1118 unsigned bytes, sectors, offset_into_extent;
1119 enum btree_id data_btree = BTREE_ID_extents;
1120
1121 /*
1122 * read_extent -> io_time_reset may cause a transaction restart
1123 * without returning an error, we need to check for that here:
1124 */
1125 ret = bch2_trans_relock(trans);
1126 if (ret)
1127 break;
1128
1129 bch2_btree_iter_set_pos(&iter,
1130 POS(inum.inum, bvec_iter.bi_sector));
1131
1132 k = bch2_btree_iter_peek_slot(&iter);
1133 ret = bkey_err(k);
1134 if (ret)
1135 break;
1136
1137 offset_into_extent = iter.pos.offset -
1138 bkey_start_offset(k.k);
1139 sectors = k.k->size - offset_into_extent;
1140
1141 bch2_bkey_buf_reassemble(&sk, c, k);
1142
1143 ret = bch2_read_indirect_extent(trans, &data_btree,
1144 &offset_into_extent, &sk);
1145 if (ret)
1146 break;
1147
1148 k = bkey_i_to_s_c(sk.k);
1149
1150 /*
1151 * With indirect extents, the amount of data to read is the min
1152 * of the original extent and the indirect extent:
1153 */
1154 sectors = min(sectors, k.k->size - offset_into_extent);
1155
1156 bytes = min(sectors, bvec_iter_sectors(bvec_iter)) << 9;
1157 swap(bvec_iter.bi_size, bytes);
1158
1159 if (bvec_iter.bi_size == bytes)
1160 flags |= BCH_READ_LAST_FRAGMENT;
1161
1162 ret = __bch2_read_extent(trans, rbio, bvec_iter, iter.pos,
1163 data_btree, k,
1164 offset_into_extent, failed, flags);
1165 if (ret)
1166 break;
1167
1168 if (flags & BCH_READ_LAST_FRAGMENT)
1169 break;
1170
1171 swap(bvec_iter.bi_size, bytes);
1172 bio_advance_iter(&rbio->bio, &bvec_iter, bytes);
1173
1174 ret = btree_trans_too_many_iters(trans);
1175 if (ret)
1176 break;
1177 }
1178err:
1179 bch2_trans_iter_exit(trans, &iter);
1180
1181 if (bch2_err_matches(ret, BCH_ERR_transaction_restart) ||
1182 ret == READ_RETRY ||
1183 ret == READ_RETRY_AVOID)
1184 goto retry;
1185
1186 bch2_trans_put(trans);
1187 bch2_bkey_buf_exit(&sk, c);
1188
1189 if (ret) {
1190 bch_err_inum_offset_ratelimited(c, inum.inum,
1191 bvec_iter.bi_sector << 9,
1192 "read error %i from btree lookup", ret);
1193 rbio->bio.bi_status = BLK_STS_IOERR;
1194 bch2_rbio_done(rbio);
1195 }
1196}
1197
1198void bch2_fs_io_read_exit(struct bch_fs *c)
1199{
1200 if (c->promote_table.tbl)
1201 rhashtable_destroy(&c->promote_table);
1202 bioset_exit(&c->bio_read_split);
1203 bioset_exit(&c->bio_read);
1204}
1205
1206int bch2_fs_io_read_init(struct bch_fs *c)
1207{
1208 if (bioset_init(&c->bio_read, 1, offsetof(struct bch_read_bio, bio),
1209 BIOSET_NEED_BVECS))
1210 return -BCH_ERR_ENOMEM_bio_read_init;
1211
1212 if (bioset_init(&c->bio_read_split, 1, offsetof(struct bch_read_bio, bio),
1213 BIOSET_NEED_BVECS))
1214 return -BCH_ERR_ENOMEM_bio_read_split_init;
1215
1216 if (rhashtable_init(&c->promote_table, &bch_promote_params))
1217 return -BCH_ERR_ENOMEM_promote_table_init;
1218
1219 return 0;
1220}