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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 .automatic_shrinking = true,
91};
92
93static inline int should_promote(struct bch_fs *c, struct bkey_s_c k,
94 struct bpos pos,
95 struct bch_io_opts opts,
96 unsigned flags,
97 struct bch_io_failures *failed)
98{
99 if (!failed) {
100 BUG_ON(!opts.promote_target);
101
102 if (!(flags & BCH_READ_MAY_PROMOTE))
103 return -BCH_ERR_nopromote_may_not;
104
105 if (bch2_bkey_has_target(c, k, opts.promote_target))
106 return -BCH_ERR_nopromote_already_promoted;
107
108 if (bkey_extent_is_unwritten(k))
109 return -BCH_ERR_nopromote_unwritten;
110
111 if (bch2_target_congested(c, opts.promote_target))
112 return -BCH_ERR_nopromote_congested;
113 }
114
115 if (rhashtable_lookup_fast(&c->promote_table, &pos,
116 bch_promote_params))
117 return -BCH_ERR_nopromote_in_flight;
118
119 return 0;
120}
121
122static void promote_free(struct bch_fs *c, struct promote_op *op)
123{
124 int ret;
125
126 bch2_data_update_exit(&op->write);
127
128 ret = rhashtable_remove_fast(&c->promote_table, &op->hash,
129 bch_promote_params);
130 BUG_ON(ret);
131 bch2_write_ref_put(c, BCH_WRITE_REF_promote);
132 kfree_rcu(op, rcu);
133}
134
135static void promote_done(struct bch_write_op *wop)
136{
137 struct promote_op *op =
138 container_of(wop, struct promote_op, write.op);
139 struct bch_fs *c = op->write.op.c;
140
141 bch2_time_stats_update(&c->times[BCH_TIME_data_promote],
142 op->start_time);
143 promote_free(c, op);
144}
145
146static void promote_start(struct promote_op *op, struct bch_read_bio *rbio)
147{
148 struct bio *bio = &op->write.op.wbio.bio;
149
150 trace_and_count(op->write.op.c, read_promote, &rbio->bio);
151
152 /* we now own pages: */
153 BUG_ON(!rbio->bounce);
154 BUG_ON(rbio->bio.bi_vcnt > bio->bi_max_vecs);
155
156 memcpy(bio->bi_io_vec, rbio->bio.bi_io_vec,
157 sizeof(struct bio_vec) * rbio->bio.bi_vcnt);
158 swap(bio->bi_vcnt, rbio->bio.bi_vcnt);
159
160 bch2_data_update_read_done(&op->write, rbio->pick.crc);
161}
162
163static struct promote_op *__promote_alloc(struct btree_trans *trans,
164 enum btree_id btree_id,
165 struct bkey_s_c k,
166 struct bpos pos,
167 struct extent_ptr_decoded *pick,
168 struct bch_io_opts opts,
169 unsigned sectors,
170 struct bch_read_bio **rbio,
171 struct bch_io_failures *failed)
172{
173 struct bch_fs *c = trans->c;
174 struct promote_op *op = NULL;
175 struct bio *bio;
176 unsigned pages = DIV_ROUND_UP(sectors, PAGE_SECTORS);
177 int ret;
178
179 if (!bch2_write_ref_tryget(c, BCH_WRITE_REF_promote))
180 return ERR_PTR(-BCH_ERR_nopromote_no_writes);
181
182 op = kzalloc(struct_size(op, bi_inline_vecs, pages), GFP_KERNEL);
183 if (!op) {
184 ret = -BCH_ERR_nopromote_enomem;
185 goto err;
186 }
187
188 op->start_time = local_clock();
189 op->pos = pos;
190
191 /*
192 * We don't use the mempool here because extents that aren't
193 * checksummed or compressed can be too big for the mempool:
194 */
195 *rbio = kzalloc(sizeof(struct bch_read_bio) +
196 sizeof(struct bio_vec) * pages,
197 GFP_KERNEL);
198 if (!*rbio) {
199 ret = -BCH_ERR_nopromote_enomem;
200 goto err;
201 }
202
203 rbio_init(&(*rbio)->bio, opts);
204 bio_init(&(*rbio)->bio, NULL, (*rbio)->bio.bi_inline_vecs, pages, 0);
205
206 if (bch2_bio_alloc_pages(&(*rbio)->bio, sectors << 9, GFP_KERNEL)) {
207 ret = -BCH_ERR_nopromote_enomem;
208 goto err;
209 }
210
211 (*rbio)->bounce = true;
212 (*rbio)->split = true;
213 (*rbio)->kmalloc = true;
214
215 if (rhashtable_lookup_insert_fast(&c->promote_table, &op->hash,
216 bch_promote_params)) {
217 ret = -BCH_ERR_nopromote_in_flight;
218 goto err;
219 }
220
221 bio = &op->write.op.wbio.bio;
222 bio_init(bio, NULL, bio->bi_inline_vecs, pages, 0);
223
224 struct data_update_opts update_opts = {};
225
226 if (!failed) {
227 update_opts.target = opts.promote_target;
228 update_opts.extra_replicas = 1;
229 update_opts.write_flags = BCH_WRITE_ALLOC_NOWAIT|BCH_WRITE_CACHED;
230 } else {
231 update_opts.target = opts.foreground_target;
232
233 struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(k);
234 unsigned i = 0;
235 bkey_for_each_ptr(ptrs, ptr) {
236 if (bch2_dev_io_failures(failed, ptr->dev))
237 update_opts.rewrite_ptrs |= BIT(i);
238 i++;
239 }
240 }
241
242 ret = bch2_data_update_init(trans, NULL, NULL, &op->write,
243 writepoint_hashed((unsigned long) current),
244 opts,
245 update_opts,
246 btree_id, k);
247 /*
248 * possible errors: -BCH_ERR_nocow_lock_blocked,
249 * -BCH_ERR_ENOSPC_disk_reservation:
250 */
251 if (ret) {
252 BUG_ON(rhashtable_remove_fast(&c->promote_table, &op->hash,
253 bch_promote_params));
254 goto err;
255 }
256
257 op->write.op.end_io = promote_done;
258
259 return op;
260err:
261 if (*rbio)
262 bio_free_pages(&(*rbio)->bio);
263 kfree(*rbio);
264 *rbio = NULL;
265 /* We may have added to the rhashtable and thus need rcu freeing: */
266 kfree_rcu(op, rcu);
267 bch2_write_ref_put(c, BCH_WRITE_REF_promote);
268 return ERR_PTR(ret);
269}
270
271noinline
272static struct promote_op *promote_alloc(struct btree_trans *trans,
273 struct bvec_iter iter,
274 struct bkey_s_c k,
275 struct extent_ptr_decoded *pick,
276 struct bch_io_opts opts,
277 unsigned flags,
278 struct bch_read_bio **rbio,
279 bool *bounce,
280 bool *read_full,
281 struct bch_io_failures *failed)
282{
283 struct bch_fs *c = trans->c;
284 /*
285 * if failed != NULL we're not actually doing a promote, we're
286 * recovering from an io/checksum error
287 */
288 bool promote_full = (failed ||
289 *read_full ||
290 READ_ONCE(c->opts.promote_whole_extents));
291 /* data might have to be decompressed in the write path: */
292 unsigned sectors = promote_full
293 ? max(pick->crc.compressed_size, pick->crc.live_size)
294 : bvec_iter_sectors(iter);
295 struct bpos pos = promote_full
296 ? bkey_start_pos(k.k)
297 : POS(k.k->p.inode, iter.bi_sector);
298 struct promote_op *promote;
299 int ret;
300
301 ret = should_promote(c, k, pos, opts, flags, failed);
302 if (ret)
303 goto nopromote;
304
305 promote = __promote_alloc(trans,
306 k.k->type == KEY_TYPE_reflink_v
307 ? BTREE_ID_reflink
308 : BTREE_ID_extents,
309 k, pos, pick, opts, sectors, rbio, failed);
310 ret = PTR_ERR_OR_ZERO(promote);
311 if (ret)
312 goto nopromote;
313
314 *bounce = true;
315 *read_full = promote_full;
316 return promote;
317nopromote:
318 trace_read_nopromote(c, ret);
319 return NULL;
320}
321
322/* Read */
323
324#define READ_RETRY_AVOID 1
325#define READ_RETRY 2
326#define READ_ERR 3
327
328enum rbio_context {
329 RBIO_CONTEXT_NULL,
330 RBIO_CONTEXT_HIGHPRI,
331 RBIO_CONTEXT_UNBOUND,
332};
333
334static inline struct bch_read_bio *
335bch2_rbio_parent(struct bch_read_bio *rbio)
336{
337 return rbio->split ? rbio->parent : rbio;
338}
339
340__always_inline
341static void bch2_rbio_punt(struct bch_read_bio *rbio, work_func_t fn,
342 enum rbio_context context,
343 struct workqueue_struct *wq)
344{
345 if (context <= rbio->context) {
346 fn(&rbio->work);
347 } else {
348 rbio->work.func = fn;
349 rbio->context = context;
350 queue_work(wq, &rbio->work);
351 }
352}
353
354static inline struct bch_read_bio *bch2_rbio_free(struct bch_read_bio *rbio)
355{
356 BUG_ON(rbio->bounce && !rbio->split);
357
358 if (rbio->promote)
359 promote_free(rbio->c, rbio->promote);
360 rbio->promote = NULL;
361
362 if (rbio->bounce)
363 bch2_bio_free_pages_pool(rbio->c, &rbio->bio);
364
365 if (rbio->split) {
366 struct bch_read_bio *parent = rbio->parent;
367
368 if (rbio->kmalloc)
369 kfree(rbio);
370 else
371 bio_put(&rbio->bio);
372
373 rbio = parent;
374 }
375
376 return rbio;
377}
378
379/*
380 * Only called on a top level bch_read_bio to complete an entire read request,
381 * not a split:
382 */
383static void bch2_rbio_done(struct bch_read_bio *rbio)
384{
385 if (rbio->start_time)
386 bch2_time_stats_update(&rbio->c->times[BCH_TIME_data_read],
387 rbio->start_time);
388 bio_endio(&rbio->bio);
389}
390
391static void bch2_read_retry_nodecode(struct bch_fs *c, struct bch_read_bio *rbio,
392 struct bvec_iter bvec_iter,
393 struct bch_io_failures *failed,
394 unsigned flags)
395{
396 struct btree_trans *trans = bch2_trans_get(c);
397 struct btree_iter iter;
398 struct bkey_buf sk;
399 struct bkey_s_c k;
400 int ret;
401
402 flags &= ~BCH_READ_LAST_FRAGMENT;
403 flags |= BCH_READ_MUST_CLONE;
404
405 bch2_bkey_buf_init(&sk);
406
407 bch2_trans_iter_init(trans, &iter, rbio->data_btree,
408 rbio->read_pos, BTREE_ITER_slots);
409retry:
410 bch2_trans_begin(trans);
411 rbio->bio.bi_status = 0;
412
413 ret = lockrestart_do(trans, bkey_err(k = bch2_btree_iter_peek_slot(&iter)));
414 if (ret)
415 goto err;
416
417 bch2_bkey_buf_reassemble(&sk, c, k);
418 k = bkey_i_to_s_c(sk.k);
419
420 if (!bch2_bkey_matches_ptr(c, k,
421 rbio->pick.ptr,
422 rbio->data_pos.offset -
423 rbio->pick.crc.offset)) {
424 /* extent we wanted to read no longer exists: */
425 rbio->hole = true;
426 goto out;
427 }
428
429 ret = __bch2_read_extent(trans, rbio, bvec_iter,
430 rbio->read_pos,
431 rbio->data_btree,
432 k, 0, failed, flags);
433 if (ret == READ_RETRY)
434 goto retry;
435 if (ret)
436 goto err;
437out:
438 bch2_rbio_done(rbio);
439 bch2_trans_iter_exit(trans, &iter);
440 bch2_trans_put(trans);
441 bch2_bkey_buf_exit(&sk, c);
442 return;
443err:
444 rbio->bio.bi_status = BLK_STS_IOERR;
445 goto out;
446}
447
448static void bch2_rbio_retry(struct work_struct *work)
449{
450 struct bch_read_bio *rbio =
451 container_of(work, struct bch_read_bio, work);
452 struct bch_fs *c = rbio->c;
453 struct bvec_iter iter = rbio->bvec_iter;
454 unsigned flags = rbio->flags;
455 subvol_inum inum = {
456 .subvol = rbio->subvol,
457 .inum = rbio->read_pos.inode,
458 };
459 struct bch_io_failures failed = { .nr = 0 };
460
461 trace_and_count(c, read_retry, &rbio->bio);
462
463 if (rbio->retry == READ_RETRY_AVOID)
464 bch2_mark_io_failure(&failed, &rbio->pick);
465
466 rbio->bio.bi_status = 0;
467
468 rbio = bch2_rbio_free(rbio);
469
470 flags |= BCH_READ_IN_RETRY;
471 flags &= ~BCH_READ_MAY_PROMOTE;
472
473 if (flags & BCH_READ_NODECODE) {
474 bch2_read_retry_nodecode(c, rbio, iter, &failed, flags);
475 } else {
476 flags &= ~BCH_READ_LAST_FRAGMENT;
477 flags |= BCH_READ_MUST_CLONE;
478
479 __bch2_read(c, rbio, iter, inum, &failed, flags);
480 }
481}
482
483static void bch2_rbio_error(struct bch_read_bio *rbio, int retry,
484 blk_status_t error)
485{
486 rbio->retry = retry;
487
488 if (rbio->flags & BCH_READ_IN_RETRY)
489 return;
490
491 if (retry == READ_ERR) {
492 rbio = bch2_rbio_free(rbio);
493
494 rbio->bio.bi_status = error;
495 bch2_rbio_done(rbio);
496 } else {
497 bch2_rbio_punt(rbio, bch2_rbio_retry,
498 RBIO_CONTEXT_UNBOUND, system_unbound_wq);
499 }
500}
501
502static int __bch2_rbio_narrow_crcs(struct btree_trans *trans,
503 struct bch_read_bio *rbio)
504{
505 struct bch_fs *c = rbio->c;
506 u64 data_offset = rbio->data_pos.offset - rbio->pick.crc.offset;
507 struct bch_extent_crc_unpacked new_crc;
508 struct btree_iter iter;
509 struct bkey_i *new;
510 struct bkey_s_c k;
511 int ret = 0;
512
513 if (crc_is_compressed(rbio->pick.crc))
514 return 0;
515
516 k = bch2_bkey_get_iter(trans, &iter, rbio->data_btree, rbio->data_pos,
517 BTREE_ITER_slots|BTREE_ITER_intent);
518 if ((ret = bkey_err(k)))
519 goto out;
520
521 if (bversion_cmp(k.k->bversion, rbio->version) ||
522 !bch2_bkey_matches_ptr(c, k, rbio->pick.ptr, data_offset))
523 goto out;
524
525 /* Extent was merged? */
526 if (bkey_start_offset(k.k) < data_offset ||
527 k.k->p.offset > data_offset + rbio->pick.crc.uncompressed_size)
528 goto out;
529
530 if (bch2_rechecksum_bio(c, &rbio->bio, rbio->version,
531 rbio->pick.crc, NULL, &new_crc,
532 bkey_start_offset(k.k) - data_offset, k.k->size,
533 rbio->pick.crc.csum_type)) {
534 bch_err(c, "error verifying existing checksum while narrowing checksum (memory corruption?)");
535 ret = 0;
536 goto out;
537 }
538
539 /*
540 * going to be temporarily appending another checksum entry:
541 */
542 new = bch2_trans_kmalloc(trans, bkey_bytes(k.k) +
543 sizeof(struct bch_extent_crc128));
544 if ((ret = PTR_ERR_OR_ZERO(new)))
545 goto out;
546
547 bkey_reassemble(new, k);
548
549 if (!bch2_bkey_narrow_crcs(new, new_crc))
550 goto out;
551
552 ret = bch2_trans_update(trans, &iter, new,
553 BTREE_UPDATE_internal_snapshot_node);
554out:
555 bch2_trans_iter_exit(trans, &iter);
556 return ret;
557}
558
559static noinline void bch2_rbio_narrow_crcs(struct bch_read_bio *rbio)
560{
561 bch2_trans_commit_do(rbio->c, NULL, NULL, BCH_TRANS_COMMIT_no_enospc,
562 __bch2_rbio_narrow_crcs(trans, rbio));
563}
564
565/* Inner part that may run in process context */
566static void __bch2_read_endio(struct work_struct *work)
567{
568 struct bch_read_bio *rbio =
569 container_of(work, struct bch_read_bio, work);
570 struct bch_fs *c = rbio->c;
571 struct bio *src = &rbio->bio;
572 struct bio *dst = &bch2_rbio_parent(rbio)->bio;
573 struct bvec_iter dst_iter = rbio->bvec_iter;
574 struct bch_extent_crc_unpacked crc = rbio->pick.crc;
575 struct nonce nonce = extent_nonce(rbio->version, crc);
576 unsigned nofs_flags;
577 struct bch_csum csum;
578 int ret;
579
580 nofs_flags = memalloc_nofs_save();
581
582 /* Reset iterator for checksumming and copying bounced data: */
583 if (rbio->bounce) {
584 src->bi_iter.bi_size = crc.compressed_size << 9;
585 src->bi_iter.bi_idx = 0;
586 src->bi_iter.bi_bvec_done = 0;
587 } else {
588 src->bi_iter = rbio->bvec_iter;
589 }
590
591 csum = bch2_checksum_bio(c, crc.csum_type, nonce, src);
592 if (bch2_crc_cmp(csum, rbio->pick.crc.csum) && !c->opts.no_data_io)
593 goto csum_err;
594
595 /*
596 * XXX
597 * We need to rework the narrow_crcs path to deliver the read completion
598 * first, and then punt to a different workqueue, otherwise we're
599 * holding up reads while doing btree updates which is bad for memory
600 * reclaim.
601 */
602 if (unlikely(rbio->narrow_crcs))
603 bch2_rbio_narrow_crcs(rbio);
604
605 if (rbio->flags & BCH_READ_NODECODE)
606 goto nodecode;
607
608 /* Adjust crc to point to subset of data we want: */
609 crc.offset += rbio->offset_into_extent;
610 crc.live_size = bvec_iter_sectors(rbio->bvec_iter);
611
612 if (crc_is_compressed(crc)) {
613 ret = bch2_encrypt_bio(c, crc.csum_type, nonce, src);
614 if (ret)
615 goto decrypt_err;
616
617 if (bch2_bio_uncompress(c, src, dst, dst_iter, crc) &&
618 !c->opts.no_data_io)
619 goto decompression_err;
620 } else {
621 /* don't need to decrypt the entire bio: */
622 nonce = nonce_add(nonce, crc.offset << 9);
623 bio_advance(src, crc.offset << 9);
624
625 BUG_ON(src->bi_iter.bi_size < dst_iter.bi_size);
626 src->bi_iter.bi_size = dst_iter.bi_size;
627
628 ret = bch2_encrypt_bio(c, crc.csum_type, nonce, src);
629 if (ret)
630 goto decrypt_err;
631
632 if (rbio->bounce) {
633 struct bvec_iter src_iter = src->bi_iter;
634
635 bio_copy_data_iter(dst, &dst_iter, src, &src_iter);
636 }
637 }
638
639 if (rbio->promote) {
640 /*
641 * Re encrypt data we decrypted, so it's consistent with
642 * rbio->crc:
643 */
644 ret = bch2_encrypt_bio(c, crc.csum_type, nonce, src);
645 if (ret)
646 goto decrypt_err;
647
648 promote_start(rbio->promote, rbio);
649 rbio->promote = NULL;
650 }
651nodecode:
652 if (likely(!(rbio->flags & BCH_READ_IN_RETRY))) {
653 rbio = bch2_rbio_free(rbio);
654 bch2_rbio_done(rbio);
655 }
656out:
657 memalloc_nofs_restore(nofs_flags);
658 return;
659csum_err:
660 /*
661 * Checksum error: if the bio wasn't bounced, we may have been
662 * reading into buffers owned by userspace (that userspace can
663 * scribble over) - retry the read, bouncing it this time:
664 */
665 if (!rbio->bounce && (rbio->flags & BCH_READ_USER_MAPPED)) {
666 rbio->flags |= BCH_READ_MUST_BOUNCE;
667 bch2_rbio_error(rbio, READ_RETRY, BLK_STS_IOERR);
668 goto out;
669 }
670
671 struct printbuf buf = PRINTBUF;
672 buf.atomic++;
673 prt_str(&buf, "data ");
674 bch2_csum_err_msg(&buf, crc.csum_type, rbio->pick.crc.csum, csum);
675
676 struct bch_dev *ca = rbio->have_ioref ? bch2_dev_have_ref(c, rbio->pick.ptr.dev) : NULL;
677 if (ca) {
678 bch_err_inum_offset_ratelimited(ca,
679 rbio->read_pos.inode,
680 rbio->read_pos.offset << 9,
681 "data %s", buf.buf);
682 bch2_io_error(ca, BCH_MEMBER_ERROR_checksum);
683 }
684 printbuf_exit(&buf);
685 bch2_rbio_error(rbio, READ_RETRY_AVOID, BLK_STS_IOERR);
686 goto out;
687decompression_err:
688 bch_err_inum_offset_ratelimited(c, rbio->read_pos.inode,
689 rbio->read_pos.offset << 9,
690 "decompression error");
691 bch2_rbio_error(rbio, READ_ERR, BLK_STS_IOERR);
692 goto out;
693decrypt_err:
694 bch_err_inum_offset_ratelimited(c, rbio->read_pos.inode,
695 rbio->read_pos.offset << 9,
696 "decrypt error");
697 bch2_rbio_error(rbio, READ_ERR, BLK_STS_IOERR);
698 goto out;
699}
700
701static void bch2_read_endio(struct bio *bio)
702{
703 struct bch_read_bio *rbio =
704 container_of(bio, struct bch_read_bio, bio);
705 struct bch_fs *c = rbio->c;
706 struct bch_dev *ca = rbio->have_ioref ? bch2_dev_have_ref(c, rbio->pick.ptr.dev) : NULL;
707 struct workqueue_struct *wq = NULL;
708 enum rbio_context context = RBIO_CONTEXT_NULL;
709
710 if (rbio->have_ioref) {
711 bch2_latency_acct(ca, rbio->submit_time, READ);
712 percpu_ref_put(&ca->io_ref);
713 }
714
715 if (!rbio->split)
716 rbio->bio.bi_end_io = rbio->end_io;
717
718 if (bio->bi_status) {
719 if (ca) {
720 bch_err_inum_offset_ratelimited(ca,
721 rbio->read_pos.inode,
722 rbio->read_pos.offset,
723 "data read error: %s",
724 bch2_blk_status_to_str(bio->bi_status));
725 bch2_io_error(ca, BCH_MEMBER_ERROR_read);
726 }
727 bch2_rbio_error(rbio, READ_RETRY_AVOID, bio->bi_status);
728 return;
729 }
730
731 if (((rbio->flags & BCH_READ_RETRY_IF_STALE) && race_fault()) ||
732 (ca && dev_ptr_stale(ca, &rbio->pick.ptr))) {
733 trace_and_count(c, read_reuse_race, &rbio->bio);
734
735 if (rbio->flags & BCH_READ_RETRY_IF_STALE)
736 bch2_rbio_error(rbio, READ_RETRY, BLK_STS_AGAIN);
737 else
738 bch2_rbio_error(rbio, READ_ERR, BLK_STS_AGAIN);
739 return;
740 }
741
742 if (rbio->narrow_crcs ||
743 rbio->promote ||
744 crc_is_compressed(rbio->pick.crc) ||
745 bch2_csum_type_is_encryption(rbio->pick.crc.csum_type))
746 context = RBIO_CONTEXT_UNBOUND, wq = system_unbound_wq;
747 else if (rbio->pick.crc.csum_type)
748 context = RBIO_CONTEXT_HIGHPRI, wq = system_highpri_wq;
749
750 bch2_rbio_punt(rbio, __bch2_read_endio, context, wq);
751}
752
753int __bch2_read_indirect_extent(struct btree_trans *trans,
754 unsigned *offset_into_extent,
755 struct bkey_buf *orig_k)
756{
757 struct btree_iter iter;
758 struct bkey_s_c k;
759 u64 reflink_offset;
760 int ret;
761
762 reflink_offset = le64_to_cpu(bkey_i_to_reflink_p(orig_k->k)->v.idx) +
763 *offset_into_extent;
764
765 k = bch2_bkey_get_iter(trans, &iter, BTREE_ID_reflink,
766 POS(0, reflink_offset), 0);
767 ret = bkey_err(k);
768 if (ret)
769 goto err;
770
771 if (k.k->type != KEY_TYPE_reflink_v &&
772 k.k->type != KEY_TYPE_indirect_inline_data) {
773 bch_err_inum_offset_ratelimited(trans->c,
774 orig_k->k->k.p.inode,
775 orig_k->k->k.p.offset << 9,
776 "%llu len %u points to nonexistent indirect extent %llu",
777 orig_k->k->k.p.offset,
778 orig_k->k->k.size,
779 reflink_offset);
780 bch2_inconsistent_error(trans->c);
781 ret = -BCH_ERR_missing_indirect_extent;
782 goto err;
783 }
784
785 *offset_into_extent = iter.pos.offset - bkey_start_offset(k.k);
786 bch2_bkey_buf_reassemble(orig_k, trans->c, k);
787err:
788 bch2_trans_iter_exit(trans, &iter);
789 return ret;
790}
791
792static noinline void read_from_stale_dirty_pointer(struct btree_trans *trans,
793 struct bch_dev *ca,
794 struct bkey_s_c k,
795 struct bch_extent_ptr ptr)
796{
797 struct bch_fs *c = trans->c;
798 struct btree_iter iter;
799 struct printbuf buf = PRINTBUF;
800 int ret;
801
802 bch2_trans_iter_init(trans, &iter, BTREE_ID_alloc,
803 PTR_BUCKET_POS(ca, &ptr),
804 BTREE_ITER_cached);
805
806 int gen = bucket_gen_get(ca, iter.pos.offset);
807 if (gen >= 0) {
808 prt_printf(&buf, "Attempting to read from stale dirty pointer:\n");
809 printbuf_indent_add(&buf, 2);
810
811 bch2_bkey_val_to_text(&buf, c, k);
812 prt_newline(&buf);
813
814 prt_printf(&buf, "memory gen: %u", gen);
815
816 ret = lockrestart_do(trans, bkey_err(k = bch2_btree_iter_peek_slot(&iter)));
817 if (!ret) {
818 prt_newline(&buf);
819 bch2_bkey_val_to_text(&buf, c, k);
820 }
821 } else {
822 prt_printf(&buf, "Attempting to read from invalid bucket %llu:%llu:\n",
823 iter.pos.inode, iter.pos.offset);
824 printbuf_indent_add(&buf, 2);
825
826 prt_printf(&buf, "first bucket %u nbuckets %llu\n",
827 ca->mi.first_bucket, ca->mi.nbuckets);
828
829 bch2_bkey_val_to_text(&buf, c, k);
830 prt_newline(&buf);
831 }
832
833 bch2_fs_inconsistent(c, "%s", buf.buf);
834
835 bch2_trans_iter_exit(trans, &iter);
836 printbuf_exit(&buf);
837}
838
839int __bch2_read_extent(struct btree_trans *trans, struct bch_read_bio *orig,
840 struct bvec_iter iter, struct bpos read_pos,
841 enum btree_id data_btree, struct bkey_s_c k,
842 unsigned offset_into_extent,
843 struct bch_io_failures *failed, unsigned flags)
844{
845 struct bch_fs *c = trans->c;
846 struct extent_ptr_decoded pick;
847 struct bch_read_bio *rbio = NULL;
848 struct promote_op *promote = NULL;
849 bool bounce = false, read_full = false, narrow_crcs = false;
850 struct bpos data_pos = bkey_start_pos(k.k);
851 int pick_ret;
852
853 if (bkey_extent_is_inline_data(k.k)) {
854 unsigned bytes = min_t(unsigned, iter.bi_size,
855 bkey_inline_data_bytes(k.k));
856
857 swap(iter.bi_size, bytes);
858 memcpy_to_bio(&orig->bio, iter, bkey_inline_data_p(k));
859 swap(iter.bi_size, bytes);
860 bio_advance_iter(&orig->bio, &iter, bytes);
861 zero_fill_bio_iter(&orig->bio, iter);
862 goto out_read_done;
863 }
864retry_pick:
865 pick_ret = bch2_bkey_pick_read_device(c, k, failed, &pick);
866
867 /* hole or reservation - just zero fill: */
868 if (!pick_ret)
869 goto hole;
870
871 if (pick_ret < 0) {
872 struct printbuf buf = PRINTBUF;
873 bch2_bkey_val_to_text(&buf, c, k);
874
875 bch_err_inum_offset_ratelimited(c,
876 read_pos.inode, read_pos.offset << 9,
877 "no device to read from: %s\n %s",
878 bch2_err_str(pick_ret),
879 buf.buf);
880 printbuf_exit(&buf);
881 goto err;
882 }
883
884 struct bch_dev *ca = bch2_dev_get_ioref(c, pick.ptr.dev, READ);
885
886 /*
887 * Stale dirty pointers are treated as IO errors, but @failed isn't
888 * allocated unless we're in the retry path - so if we're not in the
889 * retry path, don't check here, it'll be caught in bch2_read_endio()
890 * and we'll end up in the retry path:
891 */
892 if ((flags & BCH_READ_IN_RETRY) &&
893 !pick.ptr.cached &&
894 ca &&
895 unlikely(dev_ptr_stale(ca, &pick.ptr))) {
896 read_from_stale_dirty_pointer(trans, ca, k, pick.ptr);
897 bch2_mark_io_failure(failed, &pick);
898 percpu_ref_put(&ca->io_ref);
899 goto retry_pick;
900 }
901
902 /*
903 * Unlock the iterator while the btree node's lock is still in
904 * cache, before doing the IO:
905 */
906 bch2_trans_unlock(trans);
907
908 if (flags & BCH_READ_NODECODE) {
909 /*
910 * can happen if we retry, and the extent we were going to read
911 * has been merged in the meantime:
912 */
913 if (pick.crc.compressed_size > orig->bio.bi_vcnt * PAGE_SECTORS) {
914 if (ca)
915 percpu_ref_put(&ca->io_ref);
916 goto hole;
917 }
918
919 iter.bi_size = pick.crc.compressed_size << 9;
920 goto get_bio;
921 }
922
923 if (!(flags & BCH_READ_LAST_FRAGMENT) ||
924 bio_flagged(&orig->bio, BIO_CHAIN))
925 flags |= BCH_READ_MUST_CLONE;
926
927 narrow_crcs = !(flags & BCH_READ_IN_RETRY) &&
928 bch2_can_narrow_extent_crcs(k, pick.crc);
929
930 if (narrow_crcs && (flags & BCH_READ_USER_MAPPED))
931 flags |= BCH_READ_MUST_BOUNCE;
932
933 EBUG_ON(offset_into_extent + bvec_iter_sectors(iter) > k.k->size);
934
935 if (crc_is_compressed(pick.crc) ||
936 (pick.crc.csum_type != BCH_CSUM_none &&
937 (bvec_iter_sectors(iter) != pick.crc.uncompressed_size ||
938 (bch2_csum_type_is_encryption(pick.crc.csum_type) &&
939 (flags & BCH_READ_USER_MAPPED)) ||
940 (flags & BCH_READ_MUST_BOUNCE)))) {
941 read_full = true;
942 bounce = true;
943 }
944
945 if (orig->opts.promote_target)// || failed)
946 promote = promote_alloc(trans, iter, k, &pick, orig->opts, flags,
947 &rbio, &bounce, &read_full, failed);
948
949 if (!read_full) {
950 EBUG_ON(crc_is_compressed(pick.crc));
951 EBUG_ON(pick.crc.csum_type &&
952 (bvec_iter_sectors(iter) != pick.crc.uncompressed_size ||
953 bvec_iter_sectors(iter) != pick.crc.live_size ||
954 pick.crc.offset ||
955 offset_into_extent));
956
957 data_pos.offset += offset_into_extent;
958 pick.ptr.offset += pick.crc.offset +
959 offset_into_extent;
960 offset_into_extent = 0;
961 pick.crc.compressed_size = bvec_iter_sectors(iter);
962 pick.crc.uncompressed_size = bvec_iter_sectors(iter);
963 pick.crc.offset = 0;
964 pick.crc.live_size = bvec_iter_sectors(iter);
965 }
966get_bio:
967 if (rbio) {
968 /*
969 * promote already allocated bounce rbio:
970 * promote needs to allocate a bio big enough for uncompressing
971 * data in the write path, but we're not going to use it all
972 * here:
973 */
974 EBUG_ON(rbio->bio.bi_iter.bi_size <
975 pick.crc.compressed_size << 9);
976 rbio->bio.bi_iter.bi_size =
977 pick.crc.compressed_size << 9;
978 } else if (bounce) {
979 unsigned sectors = pick.crc.compressed_size;
980
981 rbio = rbio_init(bio_alloc_bioset(NULL,
982 DIV_ROUND_UP(sectors, PAGE_SECTORS),
983 0,
984 GFP_NOFS,
985 &c->bio_read_split),
986 orig->opts);
987
988 bch2_bio_alloc_pages_pool(c, &rbio->bio, sectors << 9);
989 rbio->bounce = true;
990 rbio->split = true;
991 } else if (flags & BCH_READ_MUST_CLONE) {
992 /*
993 * Have to clone if there were any splits, due to error
994 * reporting issues (if a split errored, and retrying didn't
995 * work, when it reports the error to its parent (us) we don't
996 * know if the error was from our bio, and we should retry, or
997 * from the whole bio, in which case we don't want to retry and
998 * lose the error)
999 */
1000 rbio = rbio_init(bio_alloc_clone(NULL, &orig->bio, GFP_NOFS,
1001 &c->bio_read_split),
1002 orig->opts);
1003 rbio->bio.bi_iter = iter;
1004 rbio->split = true;
1005 } else {
1006 rbio = orig;
1007 rbio->bio.bi_iter = iter;
1008 EBUG_ON(bio_flagged(&rbio->bio, BIO_CHAIN));
1009 }
1010
1011 EBUG_ON(bio_sectors(&rbio->bio) != pick.crc.compressed_size);
1012
1013 rbio->c = c;
1014 rbio->submit_time = local_clock();
1015 if (rbio->split)
1016 rbio->parent = orig;
1017 else
1018 rbio->end_io = orig->bio.bi_end_io;
1019 rbio->bvec_iter = iter;
1020 rbio->offset_into_extent= offset_into_extent;
1021 rbio->flags = flags;
1022 rbio->have_ioref = ca != NULL;
1023 rbio->narrow_crcs = narrow_crcs;
1024 rbio->hole = 0;
1025 rbio->retry = 0;
1026 rbio->context = 0;
1027 /* XXX: only initialize this if needed */
1028 rbio->devs_have = bch2_bkey_devs(k);
1029 rbio->pick = pick;
1030 rbio->subvol = orig->subvol;
1031 rbio->read_pos = read_pos;
1032 rbio->data_btree = data_btree;
1033 rbio->data_pos = data_pos;
1034 rbio->version = k.k->bversion;
1035 rbio->promote = promote;
1036 INIT_WORK(&rbio->work, NULL);
1037
1038 if (flags & BCH_READ_NODECODE)
1039 orig->pick = pick;
1040
1041 rbio->bio.bi_opf = orig->bio.bi_opf;
1042 rbio->bio.bi_iter.bi_sector = pick.ptr.offset;
1043 rbio->bio.bi_end_io = bch2_read_endio;
1044
1045 if (rbio->bounce)
1046 trace_and_count(c, read_bounce, &rbio->bio);
1047
1048 this_cpu_add(c->counters[BCH_COUNTER_io_read], bio_sectors(&rbio->bio));
1049 bch2_increment_clock(c, bio_sectors(&rbio->bio), READ);
1050
1051 /*
1052 * If it's being moved internally, we don't want to flag it as a cache
1053 * hit:
1054 */
1055 if (ca && pick.ptr.cached && !(flags & BCH_READ_NODECODE))
1056 bch2_bucket_io_time_reset(trans, pick.ptr.dev,
1057 PTR_BUCKET_NR(ca, &pick.ptr), READ);
1058
1059 if (!(flags & (BCH_READ_IN_RETRY|BCH_READ_LAST_FRAGMENT))) {
1060 bio_inc_remaining(&orig->bio);
1061 trace_and_count(c, read_split, &orig->bio);
1062 }
1063
1064 if (!rbio->pick.idx) {
1065 if (!rbio->have_ioref) {
1066 bch_err_inum_offset_ratelimited(c,
1067 read_pos.inode,
1068 read_pos.offset << 9,
1069 "no device to read from");
1070 bch2_rbio_error(rbio, READ_RETRY_AVOID, BLK_STS_IOERR);
1071 goto out;
1072 }
1073
1074 this_cpu_add(ca->io_done->sectors[READ][BCH_DATA_user],
1075 bio_sectors(&rbio->bio));
1076 bio_set_dev(&rbio->bio, ca->disk_sb.bdev);
1077
1078 if (unlikely(c->opts.no_data_io)) {
1079 if (likely(!(flags & BCH_READ_IN_RETRY)))
1080 bio_endio(&rbio->bio);
1081 } else {
1082 if (likely(!(flags & BCH_READ_IN_RETRY)))
1083 submit_bio(&rbio->bio);
1084 else
1085 submit_bio_wait(&rbio->bio);
1086 }
1087
1088 /*
1089 * We just submitted IO which may block, we expect relock fail
1090 * events and shouldn't count them:
1091 */
1092 trans->notrace_relock_fail = true;
1093 } else {
1094 /* Attempting reconstruct read: */
1095 if (bch2_ec_read_extent(trans, rbio, k)) {
1096 bch2_rbio_error(rbio, READ_RETRY_AVOID, BLK_STS_IOERR);
1097 goto out;
1098 }
1099
1100 if (likely(!(flags & BCH_READ_IN_RETRY)))
1101 bio_endio(&rbio->bio);
1102 }
1103out:
1104 if (likely(!(flags & BCH_READ_IN_RETRY))) {
1105 return 0;
1106 } else {
1107 int ret;
1108
1109 rbio->context = RBIO_CONTEXT_UNBOUND;
1110 bch2_read_endio(&rbio->bio);
1111
1112 ret = rbio->retry;
1113 rbio = bch2_rbio_free(rbio);
1114
1115 if (ret == READ_RETRY_AVOID) {
1116 bch2_mark_io_failure(failed, &pick);
1117 ret = READ_RETRY;
1118 }
1119
1120 if (!ret)
1121 goto out_read_done;
1122
1123 return ret;
1124 }
1125
1126err:
1127 if (flags & BCH_READ_IN_RETRY)
1128 return READ_ERR;
1129
1130 orig->bio.bi_status = BLK_STS_IOERR;
1131 goto out_read_done;
1132
1133hole:
1134 /*
1135 * won't normally happen in the BCH_READ_NODECODE
1136 * (bch2_move_extent()) path, but if we retry and the extent we wanted
1137 * to read no longer exists we have to signal that:
1138 */
1139 if (flags & BCH_READ_NODECODE)
1140 orig->hole = true;
1141
1142 zero_fill_bio_iter(&orig->bio, iter);
1143out_read_done:
1144 if (flags & BCH_READ_LAST_FRAGMENT)
1145 bch2_rbio_done(orig);
1146 return 0;
1147}
1148
1149void __bch2_read(struct bch_fs *c, struct bch_read_bio *rbio,
1150 struct bvec_iter bvec_iter, subvol_inum inum,
1151 struct bch_io_failures *failed, unsigned flags)
1152{
1153 struct btree_trans *trans = bch2_trans_get(c);
1154 struct btree_iter iter;
1155 struct bkey_buf sk;
1156 struct bkey_s_c k;
1157 int ret;
1158
1159 BUG_ON(flags & BCH_READ_NODECODE);
1160
1161 bch2_bkey_buf_init(&sk);
1162 bch2_trans_iter_init(trans, &iter, BTREE_ID_extents,
1163 POS(inum.inum, bvec_iter.bi_sector),
1164 BTREE_ITER_slots);
1165
1166 while (1) {
1167 unsigned bytes, sectors, offset_into_extent;
1168 enum btree_id data_btree = BTREE_ID_extents;
1169
1170 bch2_trans_begin(trans);
1171
1172 u32 snapshot;
1173 ret = bch2_subvolume_get_snapshot(trans, inum.subvol, &snapshot);
1174 if (ret)
1175 goto err;
1176
1177 bch2_btree_iter_set_snapshot(&iter, snapshot);
1178
1179 bch2_btree_iter_set_pos(&iter,
1180 POS(inum.inum, bvec_iter.bi_sector));
1181
1182 k = bch2_btree_iter_peek_slot(&iter);
1183 ret = bkey_err(k);
1184 if (ret)
1185 goto err;
1186
1187 offset_into_extent = iter.pos.offset -
1188 bkey_start_offset(k.k);
1189 sectors = k.k->size - offset_into_extent;
1190
1191 bch2_bkey_buf_reassemble(&sk, c, k);
1192
1193 ret = bch2_read_indirect_extent(trans, &data_btree,
1194 &offset_into_extent, &sk);
1195 if (ret)
1196 goto err;
1197
1198 k = bkey_i_to_s_c(sk.k);
1199
1200 /*
1201 * With indirect extents, the amount of data to read is the min
1202 * of the original extent and the indirect extent:
1203 */
1204 sectors = min(sectors, k.k->size - offset_into_extent);
1205
1206 bytes = min(sectors, bvec_iter_sectors(bvec_iter)) << 9;
1207 swap(bvec_iter.bi_size, bytes);
1208
1209 if (bvec_iter.bi_size == bytes)
1210 flags |= BCH_READ_LAST_FRAGMENT;
1211
1212 ret = __bch2_read_extent(trans, rbio, bvec_iter, iter.pos,
1213 data_btree, k,
1214 offset_into_extent, failed, flags);
1215 if (ret)
1216 goto err;
1217
1218 if (flags & BCH_READ_LAST_FRAGMENT)
1219 break;
1220
1221 swap(bvec_iter.bi_size, bytes);
1222 bio_advance_iter(&rbio->bio, &bvec_iter, bytes);
1223err:
1224 if (ret &&
1225 !bch2_err_matches(ret, BCH_ERR_transaction_restart) &&
1226 ret != READ_RETRY &&
1227 ret != READ_RETRY_AVOID)
1228 break;
1229 }
1230
1231 bch2_trans_iter_exit(trans, &iter);
1232 bch2_trans_put(trans);
1233 bch2_bkey_buf_exit(&sk, c);
1234
1235 if (ret) {
1236 bch_err_inum_offset_ratelimited(c, inum.inum,
1237 bvec_iter.bi_sector << 9,
1238 "read error %i from btree lookup", ret);
1239 rbio->bio.bi_status = BLK_STS_IOERR;
1240 bch2_rbio_done(rbio);
1241 }
1242}
1243
1244void bch2_fs_io_read_exit(struct bch_fs *c)
1245{
1246 if (c->promote_table.tbl)
1247 rhashtable_destroy(&c->promote_table);
1248 bioset_exit(&c->bio_read_split);
1249 bioset_exit(&c->bio_read);
1250}
1251
1252int bch2_fs_io_read_init(struct bch_fs *c)
1253{
1254 if (bioset_init(&c->bio_read, 1, offsetof(struct bch_read_bio, bio),
1255 BIOSET_NEED_BVECS))
1256 return -BCH_ERR_ENOMEM_bio_read_init;
1257
1258 if (bioset_init(&c->bio_read_split, 1, offsetof(struct bch_read_bio, bio),
1259 BIOSET_NEED_BVECS))
1260 return -BCH_ERR_ENOMEM_bio_read_split_init;
1261
1262 if (rhashtable_init(&c->promote_table, &bch_promote_params))
1263 return -BCH_ERR_ENOMEM_promote_table_init;
1264
1265 return 0;
1266}