git.sesse.net Git - bcachefs-tools-debian/blob - libbcachefs/io_write.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright 2010, 2011 Kent Overstreet <kent.overstreet@gmail.com>
   4  * Copyright 2012 Google, Inc.
   5  */
   6
   7 #include "bcachefs.h"
   8 #include "alloc_foreground.h"
   9 #include "bkey_buf.h"
  10 #include "bset.h"
  11 #include "btree_update.h"
  12 #include "buckets.h"
  13 #include "checksum.h"
  14 #include "clock.h"
  15 #include "compress.h"
  16 #include "debug.h"
  17 #include "ec.h"
  18 #include "error.h"
  19 #include "extent_update.h"
  20 #include "inode.h"
  21 #include "io_write.h"
  22 #include "journal.h"
  23 #include "keylist.h"
  24 #include "move.h"
  25 #include "nocow_locking.h"
  26 #include "rebalance.h"
  27 #include "subvolume.h"
  28 #include "super.h"
  29 #include "super-io.h"
  30 #include "trace.h"
  31
  32 #include <linux/blkdev.h>
  33 #include <linux/prefetch.h>
  34 #include <linux/random.h>
  35 #include <linux/sched/mm.h>
  36
  37 #ifndef CONFIG_BCACHEFS_NO_LATENCY_ACCT
  38
  39 static inline void bch2_congested_acct(struct bch_dev *ca, u64 io_latency,
  40                                        u64 now, int rw)
  41 {
  42         u64 latency_capable =
  43                 ca->io_latency[rw].quantiles.entries[QUANTILE_IDX(1)].m;
  44         /* ideally we'd be taking into account the device's variance here: */
  45         u64 latency_threshold = latency_capable << (rw == READ ? 2 : 3);
  46         s64 latency_over = io_latency - latency_threshold;
  47
  48         if (latency_threshold && latency_over > 0) {
  49                 /*
  50                  * bump up congested by approximately latency_over * 4 /
  51                  * latency_threshold - we don't need much accuracy here so don't
  52                  * bother with the divide:
  53                  */
  54                 if (atomic_read(&ca->congested) < CONGESTED_MAX)
  55                         atomic_add(latency_over >>
  56                                    max_t(int, ilog2(latency_threshold) - 2, 0),
  57                                    &ca->congested);
  58
  59                 ca->congested_last = now;
  60         } else if (atomic_read(&ca->congested) > 0) {
  61                 atomic_dec(&ca->congested);
  62         }
  63 }
  64
  65 void bch2_latency_acct(struct bch_dev *ca, u64 submit_time, int rw)
  66 {
  67         atomic64_t *latency = &ca->cur_latency[rw];
  68         u64 now = local_clock();
  69         u64 io_latency = time_after64(now, submit_time)
  70                 ? now - submit_time
  71                 : 0;
  72         u64 old, new, v = atomic64_read(latency);
  73
  74         do {
  75                 old = v;
  76
  77                 /*
  78                  * If the io latency was reasonably close to the current
  79                  * latency, skip doing the update and atomic operation - most of
  80                  * the time:
  81                  */
  82                 if (abs((int) (old - io_latency)) < (old >> 1) &&
  83                     now & ~(~0U << 5))
  84                         break;
  85
  86                 new = ewma_add(old, io_latency, 5);
  87         } while ((v = atomic64_cmpxchg(latency, old, new)) != old);
  88
  89         bch2_congested_acct(ca, io_latency, now, rw);
  90
  91         __bch2_time_stats_update(&ca->io_latency[rw], submit_time, now);
  92 }
  93
  94 #endif
  95
  96 /* Allocate, free from mempool: */
  97
  98 void bch2_bio_free_pages_pool(struct bch_fs *c, struct bio *bio)
  99 {
 100         struct bvec_iter_all iter;
 101         struct bio_vec *bv;
 102
 103         bio_for_each_segment_all(bv, bio, iter)
 104                 if (bv->bv_page != ZERO_PAGE(0))
 105                         mempool_free(bv->bv_page, &c->bio_bounce_pages);
 106         bio->bi_vcnt = 0;
 107 }
 108
 109 static struct page *__bio_alloc_page_pool(struct bch_fs *c, bool *using_mempool)
 110 {
 111         struct page *page;
 112
 113         if (likely(!*using_mempool)) {
 114                 page = alloc_page(GFP_NOFS);
 115                 if (unlikely(!page)) {
 116                         mutex_lock(&c->bio_bounce_pages_lock);
 117                         *using_mempool = true;
 118                         goto pool_alloc;
 119
 120                 }
 121         } else {
 122 pool_alloc:
 123                 page = mempool_alloc(&c->bio_bounce_pages, GFP_NOFS);
 124         }
 125
 126         return page;
 127 }
 128
 129 void bch2_bio_alloc_pages_pool(struct bch_fs *c, struct bio *bio,
 130                                size_t size)
 131 {
 132         bool using_mempool = false;
 133
 134         while (size) {
 135                 struct page *page = __bio_alloc_page_pool(c, &using_mempool);
 136                 unsigned len = min_t(size_t, PAGE_SIZE, size);
 137
 138                 BUG_ON(!bio_add_page(bio, page, len, 0));
 139                 size -= len;
 140         }
 141
 142         if (using_mempool)
 143                 mutex_unlock(&c->bio_bounce_pages_lock);
 144 }
 145
 146 /* Extent update path: */
 147
 148 int bch2_sum_sector_overwrites(struct btree_trans *trans,
 149                                struct btree_iter *extent_iter,
 150                                struct bkey_i *new,
 151                                bool *usage_increasing,
 152                                s64 *i_sectors_delta,
 153                                s64 *disk_sectors_delta)
 154 {
 155         struct bch_fs *c = trans->c;
 156         struct btree_iter iter;
 157         struct bkey_s_c old;
 158         unsigned new_replicas = bch2_bkey_replicas(c, bkey_i_to_s_c(new));
 159         bool new_compressed = bch2_bkey_sectors_compressed(bkey_i_to_s_c(new));
 160         int ret = 0;
 161
 162         *usage_increasing       = false;
 163         *i_sectors_delta        = 0;
 164         *disk_sectors_delta     = 0;
 165
 166         bch2_trans_copy_iter(&iter, extent_iter);
 167
 168         for_each_btree_key_upto_continue_norestart(iter,
 169                                 new->k.p, BTREE_ITER_SLOTS, old, ret) {
 170                 s64 sectors = min(new->k.p.offset, old.k->p.offset) -
 171                         max(bkey_start_offset(&new->k),
 172                             bkey_start_offset(old.k));
 173
 174                 *i_sectors_delta += sectors *
 175                         (bkey_extent_is_allocation(&new->k) -
 176                          bkey_extent_is_allocation(old.k));
 177
 178                 *disk_sectors_delta += sectors * bch2_bkey_nr_ptrs_allocated(bkey_i_to_s_c(new));
 179                 *disk_sectors_delta -= new->k.p.snapshot == old.k->p.snapshot
 180                         ? sectors * bch2_bkey_nr_ptrs_fully_allocated(old)
 181                         : 0;
 182
 183                 if (!*usage_increasing &&
 184                     (new->k.p.snapshot != old.k->p.snapshot ||
 185                      new_replicas > bch2_bkey_replicas(c, old) ||
 186                      (!new_compressed && bch2_bkey_sectors_compressed(old))))
 187                         *usage_increasing = true;
 188
 189                 if (bkey_ge(old.k->p, new->k.p))
 190                         break;
 191         }
 192
 193         bch2_trans_iter_exit(trans, &iter);
 194         return ret;
 195 }
 196
 197 static inline int bch2_extent_update_i_size_sectors(struct btree_trans *trans,
 198                                                     struct btree_iter *extent_iter,
 199                                                     u64 new_i_size,
 200                                                     s64 i_sectors_delta)
 201 {
 202         struct btree_iter iter;
 203         struct bkey_i *k;
 204         struct bkey_i_inode_v3 *inode;
 205         unsigned inode_update_flags = BTREE_UPDATE_NOJOURNAL;
 206         int ret;
 207
 208         k = bch2_bkey_get_mut_noupdate(trans, &iter, BTREE_ID_inodes,
 209                               SPOS(0,
 210                                    extent_iter->pos.inode,
 211                                    extent_iter->snapshot),
 212                               BTREE_ITER_CACHED);
 213         ret = PTR_ERR_OR_ZERO(k);
 214         if (unlikely(ret))
 215                 return ret;
 216
 217         if (unlikely(k->k.type != KEY_TYPE_inode_v3)) {
 218                 k = bch2_inode_to_v3(trans, k);
 219                 ret = PTR_ERR_OR_ZERO(k);
 220                 if (unlikely(ret))
 221                         goto err;
 222         }
 223
 224         inode = bkey_i_to_inode_v3(k);
 225
 226         if (!(le64_to_cpu(inode->v.bi_flags) & BCH_INODE_I_SIZE_DIRTY) &&
 227             new_i_size > le64_to_cpu(inode->v.bi_size)) {
 228                 inode->v.bi_size = cpu_to_le64(new_i_size);
 229                 inode_update_flags = 0;
 230         }
 231
 232         if (i_sectors_delta) {
 233                 le64_add_cpu(&inode->v.bi_sectors, i_sectors_delta);
 234                 inode_update_flags = 0;
 235         }
 236
 237         if (inode->k.p.snapshot != iter.snapshot) {
 238                 inode->k.p.snapshot = iter.snapshot;
 239                 inode_update_flags = 0;
 240         }
 241
 242         ret = bch2_trans_update(trans, &iter, &inode->k_i,
 243                                 BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE|
 244                                 inode_update_flags);
 245 err:
 246         bch2_trans_iter_exit(trans, &iter);
 247         return ret;
 248 }
 249
 250 int bch2_extent_update(struct btree_trans *trans,
 251                        subvol_inum inum,
 252                        struct btree_iter *iter,
 253                        struct bkey_i *k,
 254                        struct disk_reservation *disk_res,
 255                        u64 new_i_size,
 256                        s64 *i_sectors_delta_total,
 257                        bool check_enospc)
 258 {
 259         struct bpos next_pos;
 260         bool usage_increasing;
 261         s64 i_sectors_delta = 0, disk_sectors_delta = 0;
 262         int ret;
 263
 264         /*
 265          * This traverses us the iterator without changing iter->path->pos to
 266          * search_key() (which is pos + 1 for extents): we want there to be a
 267          * path already traversed at iter->pos because
 268          * bch2_trans_extent_update() will use it to attempt extent merging
 269          */
 270         ret = __bch2_btree_iter_traverse(iter);
 271         if (ret)
 272                 return ret;
 273
 274         ret = bch2_extent_trim_atomic(trans, iter, k);
 275         if (ret)
 276                 return ret;
 277
 278         next_pos = k->k.p;
 279
 280         ret = bch2_sum_sector_overwrites(trans, iter, k,
 281                         &usage_increasing,
 282                         &i_sectors_delta,
 283                         &disk_sectors_delta);
 284         if (ret)
 285                 return ret;
 286
 287         if (disk_res &&
 288             disk_sectors_delta > (s64) disk_res->sectors) {
 289                 ret = bch2_disk_reservation_add(trans->c, disk_res,
 290                                         disk_sectors_delta - disk_res->sectors,
 291                                         !check_enospc || !usage_increasing
 292                                         ? BCH_DISK_RESERVATION_NOFAIL : 0);
 293                 if (ret)
 294                         return ret;
 295         }
 296
 297         /*
 298          * Note:
 299          * We always have to do an inode update - even when i_size/i_sectors
 300          * aren't changing - for fsync to work properly; fsync relies on
 301          * inode->bi_journal_seq which is updated by the trigger code:
 302          */
 303         ret =   bch2_extent_update_i_size_sectors(trans, iter,
 304                                                   min(k->k.p.offset << 9, new_i_size),
 305                                                   i_sectors_delta) ?:
 306                 bch2_trans_update(trans, iter, k, 0) ?:
 307                 bch2_trans_commit(trans, disk_res, NULL,
 308                                 BTREE_INSERT_NOCHECK_RW|
 309                                 BTREE_INSERT_NOFAIL);
 310         if (unlikely(ret))
 311                 return ret;
 312
 313         if (i_sectors_delta_total)
 314                 *i_sectors_delta_total += i_sectors_delta;
 315         bch2_btree_iter_set_pos(iter, next_pos);
 316         return 0;
 317 }
 318
 319 static int bch2_write_index_default(struct bch_write_op *op)
 320 {
 321         struct bch_fs *c = op->c;
 322         struct bkey_buf sk;
 323         struct keylist *keys = &op->insert_keys;
 324         struct bkey_i *k = bch2_keylist_front(keys);
 325         struct btree_trans *trans = bch2_trans_get(c);
 326         struct btree_iter iter;
 327         subvol_inum inum = {
 328                 .subvol = op->subvol,
 329                 .inum   = k->k.p.inode,
 330         };
 331         int ret;
 332
 333         BUG_ON(!inum.subvol);
 334
 335         bch2_bkey_buf_init(&sk);
 336
 337         do {
 338                 bch2_trans_begin(trans);
 339
 340                 k = bch2_keylist_front(keys);
 341                 bch2_bkey_buf_copy(&sk, c, k);
 342
 343                 ret = bch2_subvolume_get_snapshot(trans, inum.subvol,
 344                                                   &sk.k->k.p.snapshot);
 345                 if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
 346                         continue;
 347                 if (ret)
 348                         break;
 349
 350                 bch2_trans_iter_init(trans, &iter, BTREE_ID_extents,
 351                                      bkey_start_pos(&sk.k->k),
 352                                      BTREE_ITER_SLOTS|BTREE_ITER_INTENT);
 353
 354                 ret = bch2_extent_update(trans, inum, &iter, sk.k,
 355                                          &op->res,
 356                                          op->new_i_size, &op->i_sectors_delta,
 357                                          op->flags & BCH_WRITE_CHECK_ENOSPC);
 358                 bch2_trans_iter_exit(trans, &iter);
 359
 360                 if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
 361                         continue;
 362                 if (ret)
 363                         break;
 364
 365                 if (bkey_ge(iter.pos, k->k.p))
 366                         bch2_keylist_pop_front(&op->insert_keys);
 367                 else
 368                         bch2_cut_front(iter.pos, k);
 369         } while (!bch2_keylist_empty(keys));
 370
 371         bch2_trans_put(trans);
 372         bch2_bkey_buf_exit(&sk, c);
 373
 374         return ret;
 375 }
 376
 377 /* Writes */
 378
 379 void bch2_submit_wbio_replicas(struct bch_write_bio *wbio, struct bch_fs *c,
 380                                enum bch_data_type type,
 381                                const struct bkey_i *k,
 382                                bool nocow)
 383 {
 384         struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(bkey_i_to_s_c(k));
 385         const struct bch_extent_ptr *ptr;
 386         struct bch_write_bio *n;
 387         struct bch_dev *ca;
 388
 389         BUG_ON(c->opts.nochanges);
 390
 391         bkey_for_each_ptr(ptrs, ptr) {
 392                 BUG_ON(ptr->dev >= BCH_SB_MEMBERS_MAX ||
 393                        !c->devs[ptr->dev]);
 394
 395                 ca = bch_dev_bkey_exists(c, ptr->dev);
 396
 397                 if (to_entry(ptr + 1) < ptrs.end) {
 398                         n = to_wbio(bio_alloc_clone(NULL, &wbio->bio,
 399                                                 GFP_NOFS, &ca->replica_set));
 400
 401                         n->bio.bi_end_io        = wbio->bio.bi_end_io;
 402                         n->bio.bi_private       = wbio->bio.bi_private;
 403                         n->parent               = wbio;
 404                         n->split                = true;
 405                         n->bounce               = false;
 406                         n->put_bio              = true;
 407                         n->bio.bi_opf           = wbio->bio.bi_opf;
 408                         bio_inc_remaining(&wbio->bio);
 409                 } else {
 410                         n = wbio;
 411                         n->split                = false;
 412                 }
 413
 414                 n->c                    = c;
 415                 n->dev                  = ptr->dev;
 416                 n->have_ioref           = nocow || bch2_dev_get_ioref(ca,
 417                                         type == BCH_DATA_btree ? READ : WRITE);
 418                 n->nocow                = nocow;
 419                 n->submit_time          = local_clock();
 420                 n->inode_offset         = bkey_start_offset(&k->k);
 421                 n->bio.bi_iter.bi_sector = ptr->offset;
 422
 423                 if (likely(n->have_ioref)) {
 424                         this_cpu_add(ca->io_done->sectors[WRITE][type],
 425                                      bio_sectors(&n->bio));
 426
 427                         bio_set_dev(&n->bio, ca->disk_sb.bdev);
 428
 429                         if (type != BCH_DATA_btree && unlikely(c->opts.no_data_io)) {
 430                                 bio_endio(&n->bio);
 431                                 continue;
 432                         }
 433
 434                         submit_bio(&n->bio);
 435                 } else {
 436                         n->bio.bi_status        = BLK_STS_REMOVED;
 437                         bio_endio(&n->bio);
 438                 }
 439         }
 440 }
 441
 442 static void __bch2_write(struct bch_write_op *);
 443
 444 static void bch2_write_done(struct closure *cl)
 445 {
 446         struct bch_write_op *op = container_of(cl, struct bch_write_op, cl);
 447         struct bch_fs *c = op->c;
 448
 449         EBUG_ON(op->open_buckets.nr);
 450
 451         bch2_time_stats_update(&c->times[BCH_TIME_data_write], op->start_time);
 452         bch2_disk_reservation_put(c, &op->res);
 453
 454         if (!(op->flags & BCH_WRITE_MOVE))
 455                 bch2_write_ref_put(c, BCH_WRITE_REF_write);
 456         bch2_keylist_free(&op->insert_keys, op->inline_keys);
 457
 458         EBUG_ON(cl->parent);
 459         closure_debug_destroy(cl);
 460         if (op->end_io)
 461                 op->end_io(op);
 462 }
 463
 464 static noinline int bch2_write_drop_io_error_ptrs(struct bch_write_op *op)
 465 {
 466         struct keylist *keys = &op->insert_keys;
 467         struct bch_extent_ptr *ptr;
 468         struct bkey_i *src, *dst = keys->keys, *n;
 469
 470         for (src = keys->keys; src != keys->top; src = n) {
 471                 n = bkey_next(src);
 472
 473                 if (bkey_extent_is_direct_data(&src->k)) {
 474                         bch2_bkey_drop_ptrs(bkey_i_to_s(src), ptr,
 475                                             test_bit(ptr->dev, op->failed.d));
 476
 477                         if (!bch2_bkey_nr_ptrs(bkey_i_to_s_c(src)))
 478                                 return -EIO;
 479                 }
 480
 481                 if (dst != src)
 482                         memmove_u64s_down(dst, src, src->k.u64s);
 483                 dst = bkey_next(dst);
 484         }
 485
 486         keys->top = dst;
 487         return 0;
 488 }
 489
 490 /**
 491  * __bch2_write_index - after a write, update index to point to new data
 492  * @op:         bch_write_op to process
 493  */
 494 static void __bch2_write_index(struct bch_write_op *op)
 495 {
 496         struct bch_fs *c = op->c;
 497         struct keylist *keys = &op->insert_keys;
 498         struct bkey_i *k;
 499         unsigned dev;
 500         int ret = 0;
 501
 502         if (unlikely(op->flags & BCH_WRITE_IO_ERROR)) {
 503                 ret = bch2_write_drop_io_error_ptrs(op);
 504                 if (ret)
 505                         goto err;
 506         }
 507
 508         /*
 509          * probably not the ideal place to hook this in, but I don't
 510          * particularly want to plumb io_opts all the way through the btree
 511          * update stack right now
 512          */
 513         for_each_keylist_key(keys, k)
 514                 bch2_rebalance_add_key(c, bkey_i_to_s_c(k), &op->opts);
 515
 516         if (!bch2_keylist_empty(keys)) {
 517                 u64 sectors_start = keylist_sectors(keys);
 518
 519                 ret = !(op->flags & BCH_WRITE_MOVE)
 520                         ? bch2_write_index_default(op)
 521                         : bch2_data_update_index_update(op);
 522
 523                 BUG_ON(bch2_err_matches(ret, BCH_ERR_transaction_restart));
 524                 BUG_ON(keylist_sectors(keys) && !ret);
 525
 526                 op->written += sectors_start - keylist_sectors(keys);
 527
 528                 if (ret && !bch2_err_matches(ret, EROFS)) {
 529                         struct bkey_i *insert = bch2_keylist_front(&op->insert_keys);
 530
 531                         bch_err_inum_offset_ratelimited(c,
 532                                 insert->k.p.inode, insert->k.p.offset << 9,
 533                                 "write error while doing btree update: %s",
 534                                 bch2_err_str(ret));
 535                 }
 536
 537                 if (ret)
 538                         goto err;
 539         }
 540 out:
 541         /* If some a bucket wasn't written, we can't erasure code it: */
 542         for_each_set_bit(dev, op->failed.d, BCH_SB_MEMBERS_MAX)
 543                 bch2_open_bucket_write_error(c, &op->open_buckets, dev);
 544
 545         bch2_open_buckets_put(c, &op->open_buckets);
 546         return;
 547 err:
 548         keys->top = keys->keys;
 549         op->error = ret;
 550         op->flags |= BCH_WRITE_DONE;
 551         goto out;
 552 }
 553
 554 static inline void __wp_update_state(struct write_point *wp, enum write_point_state state)
 555 {
 556         if (state != wp->state) {
 557                 u64 now = ktime_get_ns();
 558
 559                 if (wp->last_state_change &&
 560                     time_after64(now, wp->last_state_change))
 561                         wp->time[wp->state] += now - wp->last_state_change;
 562                 wp->state = state;
 563                 wp->last_state_change = now;
 564         }
 565 }
 566
 567 static inline void wp_update_state(struct write_point *wp, bool running)
 568 {
 569         enum write_point_state state;
 570
 571         state = running                  ? WRITE_POINT_running :
 572                 !list_empty(&wp->writes) ? WRITE_POINT_waiting_io
 573                                          : WRITE_POINT_stopped;
 574
 575         __wp_update_state(wp, state);
 576 }
 577
 578 static void bch2_write_index(struct closure *cl)
 579 {
 580         struct bch_write_op *op = container_of(cl, struct bch_write_op, cl);
 581         struct write_point *wp = op->wp;
 582         struct workqueue_struct *wq = index_update_wq(op);
 583         unsigned long flags;
 584
 585         if ((op->flags & BCH_WRITE_DONE) &&
 586             (op->flags & BCH_WRITE_MOVE))
 587                 bch2_bio_free_pages_pool(op->c, &op->wbio.bio);
 588
 589         spin_lock_irqsave(&wp->writes_lock, flags);
 590         if (wp->state == WRITE_POINT_waiting_io)
 591                 __wp_update_state(wp, WRITE_POINT_waiting_work);
 592         list_add_tail(&op->wp_list, &wp->writes);
 593         spin_unlock_irqrestore (&wp->writes_lock, flags);
 594
 595         queue_work(wq, &wp->index_update_work);
 596 }
 597
 598 static inline void bch2_write_queue(struct bch_write_op *op, struct write_point *wp)
 599 {
 600         op->wp = wp;
 601
 602         if (wp->state == WRITE_POINT_stopped) {
 603                 spin_lock_irq(&wp->writes_lock);
 604                 __wp_update_state(wp, WRITE_POINT_waiting_io);
 605                 spin_unlock_irq(&wp->writes_lock);
 606         }
 607 }
 608
 609 void bch2_write_point_do_index_updates(struct work_struct *work)
 610 {
 611         struct write_point *wp =
 612                 container_of(work, struct write_point, index_update_work);
 613         struct bch_write_op *op;
 614
 615         while (1) {
 616                 spin_lock_irq(&wp->writes_lock);
 617                 op = list_first_entry_or_null(&wp->writes, struct bch_write_op, wp_list);
 618                 if (op)
 619                         list_del(&op->wp_list);
 620                 wp_update_state(wp, op != NULL);
 621                 spin_unlock_irq(&wp->writes_lock);
 622
 623                 if (!op)
 624                         break;
 625
 626                 op->flags |= BCH_WRITE_IN_WORKER;
 627
 628                 __bch2_write_index(op);
 629
 630                 if (!(op->flags & BCH_WRITE_DONE))
 631                         __bch2_write(op);
 632                 else
 633                         bch2_write_done(&op->cl);
 634         }
 635 }
 636
 637 static void bch2_write_endio(struct bio *bio)
 638 {
 639         struct closure *cl              = bio->bi_private;
 640         struct bch_write_op *op         = container_of(cl, struct bch_write_op, cl);
 641         struct bch_write_bio *wbio      = to_wbio(bio);
 642         struct bch_write_bio *parent    = wbio->split ? wbio->parent : NULL;
 643         struct bch_fs *c                = wbio->c;
 644         struct bch_dev *ca              = bch_dev_bkey_exists(c, wbio->dev);
 645
 646         if (bch2_dev_inum_io_err_on(bio->bi_status, ca,
 647                                     op->pos.inode,
 648                                     wbio->inode_offset << 9,
 649                                     "data write error: %s",
 650                                     bch2_blk_status_to_str(bio->bi_status))) {
 651                 set_bit(wbio->dev, op->failed.d);
 652                 op->flags |= BCH_WRITE_IO_ERROR;
 653         }
 654
 655         if (wbio->nocow)
 656                 set_bit(wbio->dev, op->devs_need_flush->d);
 657
 658         if (wbio->have_ioref) {
 659                 bch2_latency_acct(ca, wbio->submit_time, WRITE);
 660                 percpu_ref_put(&ca->io_ref);
 661         }
 662
 663         if (wbio->bounce)
 664                 bch2_bio_free_pages_pool(c, bio);
 665
 666         if (wbio->put_bio)
 667                 bio_put(bio);
 668
 669         if (parent)
 670                 bio_endio(&parent->bio);
 671         else
 672                 closure_put(cl);
 673 }
 674
 675 static void init_append_extent(struct bch_write_op *op,
 676                                struct write_point *wp,
 677                                struct bversion version,
 678                                struct bch_extent_crc_unpacked crc)
 679 {
 680         struct bkey_i_extent *e;
 681
 682         op->pos.offset += crc.uncompressed_size;
 683
 684         e = bkey_extent_init(op->insert_keys.top);
 685         e->k.p          = op->pos;
 686         e->k.size       = crc.uncompressed_size;
 687         e->k.version    = version;
 688
 689         if (crc.csum_type ||
 690             crc.compression_type ||
 691             crc.nonce)
 692                 bch2_extent_crc_append(&e->k_i, crc);
 693
 694         bch2_alloc_sectors_append_ptrs_inlined(op->c, wp, &e->k_i, crc.compressed_size,
 695                                        op->flags & BCH_WRITE_CACHED);
 696
 697         bch2_keylist_push(&op->insert_keys);
 698 }
 699
 700 static struct bio *bch2_write_bio_alloc(struct bch_fs *c,
 701                                         struct write_point *wp,
 702                                         struct bio *src,
 703                                         bool *page_alloc_failed,
 704                                         void *buf)
 705 {
 706         struct bch_write_bio *wbio;
 707         struct bio *bio;
 708         unsigned output_available =
 709                 min(wp->sectors_free << 9, src->bi_iter.bi_size);
 710         unsigned pages = DIV_ROUND_UP(output_available +
 711                                       (buf
 712                                        ? ((unsigned long) buf & (PAGE_SIZE - 1))
 713                                        : 0), PAGE_SIZE);
 714
 715         pages = min(pages, BIO_MAX_VECS);
 716
 717         bio = bio_alloc_bioset(NULL, pages, 0,
 718                                GFP_NOFS, &c->bio_write);
 719         wbio                    = wbio_init(bio);
 720         wbio->put_bio           = true;
 721         /* copy WRITE_SYNC flag */
 722         wbio->bio.bi_opf        = src->bi_opf;
 723
 724         if (buf) {
 725                 bch2_bio_map(bio, buf, output_available);
 726                 return bio;
 727         }
 728
 729         wbio->bounce            = true;
 730
 731         /*
 732          * We can't use mempool for more than c->sb.encoded_extent_max
 733          * worth of pages, but we'd like to allocate more if we can:
 734          */
 735         bch2_bio_alloc_pages_pool(c, bio,
 736                                   min_t(unsigned, output_available,
 737                                         c->opts.encoded_extent_max));
 738
 739         if (bio->bi_iter.bi_size < output_available)
 740                 *page_alloc_failed =
 741                         bch2_bio_alloc_pages(bio,
 742                                              output_available -
 743                                              bio->bi_iter.bi_size,
 744                                              GFP_NOFS) != 0;
 745
 746         return bio;
 747 }
 748
 749 static int bch2_write_rechecksum(struct bch_fs *c,
 750                                  struct bch_write_op *op,
 751                                  unsigned new_csum_type)
 752 {
 753         struct bio *bio = &op->wbio.bio;
 754         struct bch_extent_crc_unpacked new_crc;
 755         int ret;
 756
 757         /* bch2_rechecksum_bio() can't encrypt or decrypt data: */
 758
 759         if (bch2_csum_type_is_encryption(op->crc.csum_type) !=
 760             bch2_csum_type_is_encryption(new_csum_type))
 761                 new_csum_type = op->crc.csum_type;
 762
 763         ret = bch2_rechecksum_bio(c, bio, op->version, op->crc,
 764                                   NULL, &new_crc,
 765                                   op->crc.offset, op->crc.live_size,
 766                                   new_csum_type);
 767         if (ret)
 768                 return ret;
 769
 770         bio_advance(bio, op->crc.offset << 9);
 771         bio->bi_iter.bi_size = op->crc.live_size << 9;
 772         op->crc = new_crc;
 773         return 0;
 774 }
 775
 776 static int bch2_write_decrypt(struct bch_write_op *op)
 777 {
 778         struct bch_fs *c = op->c;
 779         struct nonce nonce = extent_nonce(op->version, op->crc);
 780         struct bch_csum csum;
 781         int ret;
 782
 783         if (!bch2_csum_type_is_encryption(op->crc.csum_type))
 784                 return 0;
 785
 786         /*
 787          * If we need to decrypt data in the write path, we'll no longer be able
 788          * to verify the existing checksum (poly1305 mac, in this case) after
 789          * it's decrypted - this is the last point we'll be able to reverify the
 790          * checksum:
 791          */
 792         csum = bch2_checksum_bio(c, op->crc.csum_type, nonce, &op->wbio.bio);
 793         if (bch2_crc_cmp(op->crc.csum, csum))
 794                 return -EIO;
 795
 796         ret = bch2_encrypt_bio(c, op->crc.csum_type, nonce, &op->wbio.bio);
 797         op->crc.csum_type = 0;
 798         op->crc.csum = (struct bch_csum) { 0, 0 };
 799         return ret;
 800 }
 801
 802 static enum prep_encoded_ret {
 803         PREP_ENCODED_OK,
 804         PREP_ENCODED_ERR,
 805         PREP_ENCODED_CHECKSUM_ERR,
 806         PREP_ENCODED_DO_WRITE,
 807 } bch2_write_prep_encoded_data(struct bch_write_op *op, struct write_point *wp)
 808 {
 809         struct bch_fs *c = op->c;
 810         struct bio *bio = &op->wbio.bio;
 811
 812         if (!(op->flags & BCH_WRITE_DATA_ENCODED))
 813                 return PREP_ENCODED_OK;
 814
 815         BUG_ON(bio_sectors(bio) != op->crc.compressed_size);
 816
 817         /* Can we just write the entire extent as is? */
 818         if (op->crc.uncompressed_size == op->crc.live_size &&
 819             op->crc.compressed_size <= wp->sectors_free &&
 820             (op->crc.compression_type == bch2_compression_opt_to_type(op->compression_opt) ||
 821              op->incompressible)) {
 822                 if (!crc_is_compressed(op->crc) &&
 823                     op->csum_type != op->crc.csum_type &&
 824                     bch2_write_rechecksum(c, op, op->csum_type) &&
 825                     !c->opts.no_data_io)
 826                         return PREP_ENCODED_CHECKSUM_ERR;
 827
 828                 return PREP_ENCODED_DO_WRITE;
 829         }
 830
 831         /*
 832          * If the data is compressed and we couldn't write the entire extent as
 833          * is, we have to decompress it:
 834          */
 835         if (crc_is_compressed(op->crc)) {
 836                 struct bch_csum csum;
 837
 838                 if (bch2_write_decrypt(op))
 839                         return PREP_ENCODED_CHECKSUM_ERR;
 840
 841                 /* Last point we can still verify checksum: */
 842                 csum = bch2_checksum_bio(c, op->crc.csum_type,
 843                                          extent_nonce(op->version, op->crc),
 844                                          bio);
 845                 if (bch2_crc_cmp(op->crc.csum, csum) && !c->opts.no_data_io)
 846                         return PREP_ENCODED_CHECKSUM_ERR;
 847
 848                 if (bch2_bio_uncompress_inplace(c, bio, &op->crc))
 849                         return PREP_ENCODED_ERR;
 850         }
 851
 852         /*
 853          * No longer have compressed data after this point - data might be
 854          * encrypted:
 855          */
 856
 857         /*
 858          * If the data is checksummed and we're only writing a subset,
 859          * rechecksum and adjust bio to point to currently live data:
 860          */
 861         if ((op->crc.live_size != op->crc.uncompressed_size ||
 862              op->crc.csum_type != op->csum_type) &&
 863             bch2_write_rechecksum(c, op, op->csum_type) &&
 864             !c->opts.no_data_io)
 865                 return PREP_ENCODED_CHECKSUM_ERR;
 866
 867         /*
 868          * If we want to compress the data, it has to be decrypted:
 869          */
 870         if ((op->compression_opt ||
 871              bch2_csum_type_is_encryption(op->crc.csum_type) !=
 872              bch2_csum_type_is_encryption(op->csum_type)) &&
 873             bch2_write_decrypt(op))
 874                 return PREP_ENCODED_CHECKSUM_ERR;
 875
 876         return PREP_ENCODED_OK;
 877 }
 878
 879 static int bch2_write_extent(struct bch_write_op *op, struct write_point *wp,
 880                              struct bio **_dst)
 881 {
 882         struct bch_fs *c = op->c;
 883         struct bio *src = &op->wbio.bio, *dst = src;
 884         struct bvec_iter saved_iter;
 885         void *ec_buf;
 886         unsigned total_output = 0, total_input = 0;
 887         bool bounce = false;
 888         bool page_alloc_failed = false;
 889         int ret, more = 0;
 890
 891         BUG_ON(!bio_sectors(src));
 892
 893         ec_buf = bch2_writepoint_ec_buf(c, wp);
 894
 895         switch (bch2_write_prep_encoded_data(op, wp)) {
 896         case PREP_ENCODED_OK:
 897                 break;
 898         case PREP_ENCODED_ERR:
 899                 ret = -EIO;
 900                 goto err;
 901         case PREP_ENCODED_CHECKSUM_ERR:
 902                 goto csum_err;
 903         case PREP_ENCODED_DO_WRITE:
 904                 /* XXX look for bug here */
 905                 if (ec_buf) {
 906                         dst = bch2_write_bio_alloc(c, wp, src,
 907                                                    &page_alloc_failed,
 908                                                    ec_buf);
 909                         bio_copy_data(dst, src);
 910                         bounce = true;
 911                 }
 912                 init_append_extent(op, wp, op->version, op->crc);
 913                 goto do_write;
 914         }
 915
 916         if (ec_buf ||
 917             op->compression_opt ||
 918             (op->csum_type &&
 919              !(op->flags & BCH_WRITE_PAGES_STABLE)) ||
 920             (bch2_csum_type_is_encryption(op->csum_type) &&
 921              !(op->flags & BCH_WRITE_PAGES_OWNED))) {
 922                 dst = bch2_write_bio_alloc(c, wp, src,
 923                                            &page_alloc_failed,
 924                                            ec_buf);
 925                 bounce = true;
 926         }
 927
 928         saved_iter = dst->bi_iter;
 929
 930         do {
 931                 struct bch_extent_crc_unpacked crc = { 0 };
 932                 struct bversion version = op->version;
 933                 size_t dst_len = 0, src_len = 0;
 934
 935                 if (page_alloc_failed &&
 936                     dst->bi_iter.bi_size  < (wp->sectors_free << 9) &&
 937                     dst->bi_iter.bi_size < c->opts.encoded_extent_max)
 938                         break;
 939
 940                 BUG_ON(op->compression_opt &&
 941                        (op->flags & BCH_WRITE_DATA_ENCODED) &&
 942                        bch2_csum_type_is_encryption(op->crc.csum_type));
 943                 BUG_ON(op->compression_opt && !bounce);
 944
 945                 crc.compression_type = op->incompressible
 946                         ? BCH_COMPRESSION_TYPE_incompressible
 947                         : op->compression_opt
 948                         ? bch2_bio_compress(c, dst, &dst_len, src, &src_len,
 949                                             op->compression_opt)
 950                         : 0;
 951                 if (!crc_is_compressed(crc)) {
 952                         dst_len = min(dst->bi_iter.bi_size, src->bi_iter.bi_size);
 953                         dst_len = min_t(unsigned, dst_len, wp->sectors_free << 9);
 954
 955                         if (op->csum_type)
 956                                 dst_len = min_t(unsigned, dst_len,
 957                                                 c->opts.encoded_extent_max);
 958
 959                         if (bounce) {
 960                                 swap(dst->bi_iter.bi_size, dst_len);
 961                                 bio_copy_data(dst, src);
 962                                 swap(dst->bi_iter.bi_size, dst_len);
 963                         }
 964
 965                         src_len = dst_len;
 966                 }
 967
 968                 BUG_ON(!src_len || !dst_len);
 969
 970                 if (bch2_csum_type_is_encryption(op->csum_type)) {
 971                         if (bversion_zero(version)) {
 972                                 version.lo = atomic64_inc_return(&c->key_version);
 973                         } else {
 974                                 crc.nonce = op->nonce;
 975                                 op->nonce += src_len >> 9;
 976                         }
 977                 }
 978
 979                 if ((op->flags & BCH_WRITE_DATA_ENCODED) &&
 980                     !crc_is_compressed(crc) &&
 981                     bch2_csum_type_is_encryption(op->crc.csum_type) ==
 982                     bch2_csum_type_is_encryption(op->csum_type)) {
 983                         u8 compression_type = crc.compression_type;
 984                         u16 nonce = crc.nonce;
 985                         /*
 986                          * Note: when we're using rechecksum(), we need to be
 987                          * checksumming @src because it has all the data our
 988                          * existing checksum covers - if we bounced (because we
 989                          * were trying to compress), @dst will only have the
 990                          * part of the data the new checksum will cover.
 991                          *
 992                          * But normally we want to be checksumming post bounce,
 993                          * because part of the reason for bouncing is so the
 994                          * data can't be modified (by userspace) while it's in
 995                          * flight.
 996                          */
 997                         if (bch2_rechecksum_bio(c, src, version, op->crc,
 998                                         &crc, &op->crc,
 999                                         src_len >> 9,
1000                                         bio_sectors(src) - (src_len >> 9),
1001                                         op->csum_type))
1002                                 goto csum_err;
1003                         /*
1004                          * rchecksum_bio sets compression_type on crc from op->crc,
1005                          * this isn't always correct as sometimes we're changing
1006                          * an extent from uncompressed to incompressible.
1007                          */
1008                         crc.compression_type = compression_type;
1009                         crc.nonce = nonce;
1010                 } else {
1011                         if ((op->flags & BCH_WRITE_DATA_ENCODED) &&
1012                             bch2_rechecksum_bio(c, src, version, op->crc,
1013                                         NULL, &op->crc,
1014                                         src_len >> 9,
1015                                         bio_sectors(src) - (src_len >> 9),
1016                                         op->crc.csum_type))
1017                                 goto csum_err;
1018
1019                         crc.compressed_size     = dst_len >> 9;
1020                         crc.uncompressed_size   = src_len >> 9;
1021                         crc.live_size           = src_len >> 9;
1022
1023                         swap(dst->bi_iter.bi_size, dst_len);
1024                         ret = bch2_encrypt_bio(c, op->csum_type,
1025                                                extent_nonce(version, crc), dst);
1026                         if (ret)
1027                                 goto err;
1028
1029                         crc.csum = bch2_checksum_bio(c, op->csum_type,
1030                                          extent_nonce(version, crc), dst);
1031                         crc.csum_type = op->csum_type;
1032                         swap(dst->bi_iter.bi_size, dst_len);
1033                 }
1034
1035                 init_append_extent(op, wp, version, crc);
1036
1037                 if (dst != src)
1038                         bio_advance(dst, dst_len);
1039                 bio_advance(src, src_len);
1040                 total_output    += dst_len;
1041                 total_input     += src_len;
1042         } while (dst->bi_iter.bi_size &&
1043                  src->bi_iter.bi_size &&
1044                  wp->sectors_free &&
1045                  !bch2_keylist_realloc(&op->insert_keys,
1046                                       op->inline_keys,
1047                                       ARRAY_SIZE(op->inline_keys),
1048                                       BKEY_EXTENT_U64s_MAX));
1049
1050         more = src->bi_iter.bi_size != 0;
1051
1052         dst->bi_iter = saved_iter;
1053
1054         if (dst == src && more) {
1055                 BUG_ON(total_output != total_input);
1056
1057                 dst = bio_split(src, total_input >> 9,
1058                                 GFP_NOFS, &c->bio_write);
1059                 wbio_init(dst)->put_bio = true;
1060                 /* copy WRITE_SYNC flag */
1061                 dst->bi_opf             = src->bi_opf;
1062         }
1063
1064         dst->bi_iter.bi_size = total_output;
1065 do_write:
1066         *_dst = dst;
1067         return more;
1068 csum_err:
1069         bch_err(c, "error verifying existing checksum while rewriting existing data (memory corruption?)");
1070         ret = -EIO;
1071 err:
1072         if (to_wbio(dst)->bounce)
1073                 bch2_bio_free_pages_pool(c, dst);
1074         if (to_wbio(dst)->put_bio)
1075                 bio_put(dst);
1076
1077         return ret;
1078 }
1079
1080 static bool bch2_extent_is_writeable(struct bch_write_op *op,
1081                                      struct bkey_s_c k)
1082 {
1083         struct bch_fs *c = op->c;
1084         struct bkey_s_c_extent e;
1085         struct extent_ptr_decoded p;
1086         const union bch_extent_entry *entry;
1087         unsigned replicas = 0;
1088
1089         if (k.k->type != KEY_TYPE_extent)
1090                 return false;
1091
1092         e = bkey_s_c_to_extent(k);
1093         extent_for_each_ptr_decode(e, p, entry) {
1094                 if (p.crc.csum_type ||
1095                     crc_is_compressed(p.crc) ||
1096                     p.has_ec)
1097                         return false;
1098
1099                 replicas += bch2_extent_ptr_durability(c, &p);
1100         }
1101
1102         return replicas >= op->opts.data_replicas;
1103 }
1104
1105 static inline void bch2_nocow_write_unlock(struct bch_write_op *op)
1106 {
1107         struct bch_fs *c = op->c;
1108         const struct bch_extent_ptr *ptr;
1109         struct bkey_i *k;
1110
1111         for_each_keylist_key(&op->insert_keys, k) {
1112                 struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(bkey_i_to_s_c(k));
1113
1114                 bkey_for_each_ptr(ptrs, ptr)
1115                         bch2_bucket_nocow_unlock(&c->nocow_locks,
1116                                                PTR_BUCKET_POS(c, ptr),
1117                                                BUCKET_NOCOW_LOCK_UPDATE);
1118         }
1119 }
1120
1121 static int bch2_nocow_write_convert_one_unwritten(struct btree_trans *trans,
1122                                                   struct btree_iter *iter,
1123                                                   struct bkey_i *orig,
1124                                                   struct bkey_s_c k,
1125                                                   u64 new_i_size)
1126 {
1127         struct bkey_i *new;
1128         struct bkey_ptrs ptrs;
1129         struct bch_extent_ptr *ptr;
1130         int ret;
1131
1132         if (!bch2_extents_match(bkey_i_to_s_c(orig), k)) {
1133                 /* trace this */
1134                 return 0;
1135         }
1136
1137         new = bch2_bkey_make_mut_noupdate(trans, k);
1138         ret = PTR_ERR_OR_ZERO(new);
1139         if (ret)
1140                 return ret;
1141
1142         bch2_cut_front(bkey_start_pos(&orig->k), new);
1143         bch2_cut_back(orig->k.p, new);
1144
1145         ptrs = bch2_bkey_ptrs(bkey_i_to_s(new));
1146         bkey_for_each_ptr(ptrs, ptr)
1147                 ptr->unwritten = 0;
1148
1149         /*
1150          * Note that we're not calling bch2_subvol_get_snapshot() in this path -
1151          * that was done when we kicked off the write, and here it's important
1152          * that we update the extent that we wrote to - even if a snapshot has
1153          * since been created. The write is still outstanding, so we're ok
1154          * w.r.t. snapshot atomicity:
1155          */
1156         return  bch2_extent_update_i_size_sectors(trans, iter,
1157                                         min(new->k.p.offset << 9, new_i_size), 0) ?:
1158                 bch2_trans_update(trans, iter, new,
1159                                   BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE);
1160 }
1161
1162 static void bch2_nocow_write_convert_unwritten(struct bch_write_op *op)
1163 {
1164         struct bch_fs *c = op->c;
1165         struct btree_trans *trans = bch2_trans_get(c);
1166         struct btree_iter iter;
1167         struct bkey_i *orig;
1168         struct bkey_s_c k;
1169         int ret;
1170
1171         for_each_keylist_key(&op->insert_keys, orig) {
1172                 ret = for_each_btree_key_upto_commit(trans, iter, BTREE_ID_extents,
1173                                      bkey_start_pos(&orig->k), orig->k.p,
1174                                      BTREE_ITER_INTENT, k,
1175                                      NULL, NULL, BTREE_INSERT_NOFAIL, ({
1176                         bch2_nocow_write_convert_one_unwritten(trans, &iter, orig, k, op->new_i_size);
1177                 }));
1178
1179                 if (ret && !bch2_err_matches(ret, EROFS)) {
1180                         struct bkey_i *insert = bch2_keylist_front(&op->insert_keys);
1181
1182                         bch_err_inum_offset_ratelimited(c,
1183                                 insert->k.p.inode, insert->k.p.offset << 9,
1184                                 "write error while doing btree update: %s",
1185                                 bch2_err_str(ret));
1186                 }
1187
1188                 if (ret) {
1189                         op->error = ret;
1190                         break;
1191                 }
1192         }
1193
1194         bch2_trans_put(trans);
1195 }
1196
1197 static void __bch2_nocow_write_done(struct bch_write_op *op)
1198 {
1199         bch2_nocow_write_unlock(op);
1200
1201         if (unlikely(op->flags & BCH_WRITE_IO_ERROR)) {
1202                 op->error = -EIO;
1203         } else if (unlikely(op->flags & BCH_WRITE_CONVERT_UNWRITTEN))
1204                 bch2_nocow_write_convert_unwritten(op);
1205 }
1206
1207 static void bch2_nocow_write_done(struct closure *cl)
1208 {
1209         struct bch_write_op *op = container_of(cl, struct bch_write_op, cl);
1210
1211         __bch2_nocow_write_done(op);
1212         bch2_write_done(cl);
1213 }
1214
1215 static void bch2_nocow_write(struct bch_write_op *op)
1216 {
1217         struct bch_fs *c = op->c;
1218         struct btree_trans *trans;
1219         struct btree_iter iter;
1220         struct bkey_s_c k;
1221         struct bkey_ptrs_c ptrs;
1222         const struct bch_extent_ptr *ptr;
1223         struct {
1224                 struct bpos     b;
1225                 unsigned        gen;
1226                 struct nocow_lock_bucket *l;
1227         } buckets[BCH_REPLICAS_MAX];
1228         unsigned nr_buckets = 0;
1229         u32 snapshot;
1230         int ret, i;
1231
1232         if (op->flags & BCH_WRITE_MOVE)
1233                 return;
1234
1235         trans = bch2_trans_get(c);
1236 retry:
1237         bch2_trans_begin(trans);
1238
1239         ret = bch2_subvolume_get_snapshot(trans, op->subvol, &snapshot);
1240         if (unlikely(ret))
1241                 goto err;
1242
1243         bch2_trans_iter_init(trans, &iter, BTREE_ID_extents,
1244                              SPOS(op->pos.inode, op->pos.offset, snapshot),
1245                              BTREE_ITER_SLOTS);
1246         while (1) {
1247                 struct bio *bio = &op->wbio.bio;
1248
1249                 nr_buckets = 0;
1250
1251                 k = bch2_btree_iter_peek_slot(&iter);
1252                 ret = bkey_err(k);
1253                 if (ret)
1254                         break;
1255
1256                 /* fall back to normal cow write path? */
1257                 if (unlikely(k.k->p.snapshot != snapshot ||
1258                              !bch2_extent_is_writeable(op, k)))
1259                         break;
1260
1261                 if (bch2_keylist_realloc(&op->insert_keys,
1262                                         op->inline_keys,
1263                                         ARRAY_SIZE(op->inline_keys),
1264                                         k.k->u64s))
1265                         break;
1266
1267                 /* Get iorefs before dropping btree locks: */
1268                 ptrs = bch2_bkey_ptrs_c(k);
1269                 bkey_for_each_ptr(ptrs, ptr) {
1270                         buckets[nr_buckets].b = PTR_BUCKET_POS(c, ptr);
1271                         buckets[nr_buckets].gen = ptr->gen;
1272                         buckets[nr_buckets].l =
1273                                 bucket_nocow_lock(&c->nocow_locks,
1274                                                   bucket_to_u64(buckets[nr_buckets].b));
1275
1276                         prefetch(buckets[nr_buckets].l);
1277
1278                         if (unlikely(!bch2_dev_get_ioref(bch_dev_bkey_exists(c, ptr->dev), WRITE)))
1279                                 goto err_get_ioref;
1280
1281                         nr_buckets++;
1282
1283                         if (ptr->unwritten)
1284                                 op->flags |= BCH_WRITE_CONVERT_UNWRITTEN;
1285                 }
1286
1287                 /* Unlock before taking nocow locks, doing IO: */
1288                 bkey_reassemble(op->insert_keys.top, k);
1289                 bch2_trans_unlock(trans);
1290
1291                 bch2_cut_front(op->pos, op->insert_keys.top);
1292                 if (op->flags & BCH_WRITE_CONVERT_UNWRITTEN)
1293                         bch2_cut_back(POS(op->pos.inode, op->pos.offset + bio_sectors(bio)), op->insert_keys.top);
1294
1295                 for (i = 0; i < nr_buckets; i++) {
1296                         struct bch_dev *ca = bch_dev_bkey_exists(c, buckets[i].b.inode);
1297                         struct nocow_lock_bucket *l = buckets[i].l;
1298                         bool stale;
1299
1300                         __bch2_bucket_nocow_lock(&c->nocow_locks, l,
1301                                                  bucket_to_u64(buckets[i].b),
1302                                                  BUCKET_NOCOW_LOCK_UPDATE);
1303
1304                         rcu_read_lock();
1305                         stale = gen_after(*bucket_gen(ca, buckets[i].b.offset), buckets[i].gen);
1306                         rcu_read_unlock();
1307
1308                         if (unlikely(stale))
1309                                 goto err_bucket_stale;
1310                 }
1311
1312                 bio = &op->wbio.bio;
1313                 if (k.k->p.offset < op->pos.offset + bio_sectors(bio)) {
1314                         bio = bio_split(bio, k.k->p.offset - op->pos.offset,
1315                                         GFP_KERNEL, &c->bio_write);
1316                         wbio_init(bio)->put_bio = true;
1317                         bio->bi_opf = op->wbio.bio.bi_opf;
1318                 } else {
1319                         op->flags |= BCH_WRITE_DONE;
1320                 }
1321
1322                 op->pos.offset += bio_sectors(bio);
1323                 op->written += bio_sectors(bio);
1324
1325                 bio->bi_end_io  = bch2_write_endio;
1326                 bio->bi_private = &op->cl;
1327                 bio->bi_opf |= REQ_OP_WRITE;
1328                 closure_get(&op->cl);
1329                 bch2_submit_wbio_replicas(to_wbio(bio), c, BCH_DATA_user,
1330                                           op->insert_keys.top, true);
1331
1332                 bch2_keylist_push(&op->insert_keys);
1333                 if (op->flags & BCH_WRITE_DONE)
1334                         break;
1335                 bch2_btree_iter_advance(&iter);
1336         }
1337 out:
1338         bch2_trans_iter_exit(trans, &iter);
1339 err:
1340         if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
1341                 goto retry;
1342
1343         if (ret) {
1344                 bch_err_inum_offset_ratelimited(c,
1345                                 op->pos.inode,
1346                                 op->pos.offset << 9,
1347                                 "%s: btree lookup error %s",
1348                                 __func__, bch2_err_str(ret));
1349                 op->error = ret;
1350                 op->flags |= BCH_WRITE_DONE;
1351         }
1352
1353         bch2_trans_put(trans);
1354
1355         /* fallback to cow write path? */
1356         if (!(op->flags & BCH_WRITE_DONE)) {
1357                 closure_sync(&op->cl);
1358                 __bch2_nocow_write_done(op);
1359                 op->insert_keys.top = op->insert_keys.keys;
1360         } else if (op->flags & BCH_WRITE_SYNC) {
1361                 closure_sync(&op->cl);
1362                 bch2_nocow_write_done(&op->cl);
1363         } else {
1364                 /*
1365                  * XXX
1366                  * needs to run out of process context because ei_quota_lock is
1367                  * a mutex
1368                  */
1369                 continue_at(&op->cl, bch2_nocow_write_done, index_update_wq(op));
1370         }
1371         return;
1372 err_get_ioref:
1373         for (i = 0; i < nr_buckets; i++)
1374                 percpu_ref_put(&bch_dev_bkey_exists(c, buckets[i].b.inode)->io_ref);
1375
1376         /* Fall back to COW path: */
1377         goto out;
1378 err_bucket_stale:
1379         while (i >= 0) {
1380                 bch2_bucket_nocow_unlock(&c->nocow_locks,
1381                                          buckets[i].b,
1382                                          BUCKET_NOCOW_LOCK_UPDATE);
1383                 --i;
1384         }
1385         for (i = 0; i < nr_buckets; i++)
1386                 percpu_ref_put(&bch_dev_bkey_exists(c, buckets[i].b.inode)->io_ref);
1387
1388         /* We can retry this: */
1389         ret = -BCH_ERR_transaction_restart;
1390         goto out;
1391 }
1392
1393 static void __bch2_write(struct bch_write_op *op)
1394 {
1395         struct bch_fs *c = op->c;
1396         struct write_point *wp = NULL;
1397         struct bio *bio = NULL;
1398         unsigned nofs_flags;
1399         int ret;
1400
1401         nofs_flags = memalloc_nofs_save();
1402
1403         if (unlikely(op->opts.nocow && c->opts.nocow_enabled)) {
1404                 bch2_nocow_write(op);
1405                 if (op->flags & BCH_WRITE_DONE)
1406                         goto out_nofs_restore;
1407         }
1408 again:
1409         memset(&op->failed, 0, sizeof(op->failed));
1410
1411         do {
1412                 struct bkey_i *key_to_write;
1413                 unsigned key_to_write_offset = op->insert_keys.top_p -
1414                         op->insert_keys.keys_p;
1415
1416                 /* +1 for possible cache device: */
1417                 if (op->open_buckets.nr + op->nr_replicas + 1 >
1418                     ARRAY_SIZE(op->open_buckets.v))
1419                         break;
1420
1421                 if (bch2_keylist_realloc(&op->insert_keys,
1422                                         op->inline_keys,
1423                                         ARRAY_SIZE(op->inline_keys),
1424                                         BKEY_EXTENT_U64s_MAX))
1425                         break;
1426
1427                 /*
1428                  * The copygc thread is now global, which means it's no longer
1429                  * freeing up space on specific disks, which means that
1430                  * allocations for specific disks may hang arbitrarily long:
1431                  */
1432                 ret = bch2_trans_do(c, NULL, NULL, 0,
1433                         bch2_alloc_sectors_start_trans(trans,
1434                                 op->target,
1435                                 op->opts.erasure_code && !(op->flags & BCH_WRITE_CACHED),
1436                                 op->write_point,
1437                                 &op->devs_have,
1438                                 op->nr_replicas,
1439                                 op->nr_replicas_required,
1440                                 op->watermark,
1441                                 op->flags,
1442                                 (op->flags & (BCH_WRITE_ALLOC_NOWAIT|
1443                                               BCH_WRITE_ONLY_SPECIFIED_DEVS))
1444                                 ? NULL : &op->cl, &wp));
1445                 if (unlikely(ret)) {
1446                         if (bch2_err_matches(ret, BCH_ERR_operation_blocked))
1447                                 break;
1448
1449                         goto err;
1450                 }
1451
1452                 EBUG_ON(!wp);
1453
1454                 bch2_open_bucket_get(c, wp, &op->open_buckets);
1455                 ret = bch2_write_extent(op, wp, &bio);
1456
1457                 bch2_alloc_sectors_done_inlined(c, wp);
1458 err:
1459                 if (ret <= 0) {
1460                         op->flags |= BCH_WRITE_DONE;
1461
1462                         if (ret < 0) {
1463                                 op->error = ret;
1464                                 break;
1465                         }
1466                 }
1467
1468                 bio->bi_end_io  = bch2_write_endio;
1469                 bio->bi_private = &op->cl;
1470                 bio->bi_opf |= REQ_OP_WRITE;
1471
1472                 closure_get(bio->bi_private);
1473
1474                 key_to_write = (void *) (op->insert_keys.keys_p +
1475                                          key_to_write_offset);
1476
1477                 bch2_submit_wbio_replicas(to_wbio(bio), c, BCH_DATA_user,
1478                                           key_to_write, false);
1479         } while (ret);
1480
1481         /*
1482          * Sync or no?
1483          *
1484          * If we're running asynchronously, wne may still want to block
1485          * synchronously here if we weren't able to submit all of the IO at
1486          * once, as that signals backpressure to the caller.
1487          */
1488         if ((op->flags & BCH_WRITE_SYNC) ||
1489             (!(op->flags & BCH_WRITE_DONE) &&
1490              !(op->flags & BCH_WRITE_IN_WORKER))) {
1491                 closure_sync(&op->cl);
1492                 __bch2_write_index(op);
1493
1494                 if (!(op->flags & BCH_WRITE_DONE))
1495                         goto again;
1496                 bch2_write_done(&op->cl);
1497         } else {
1498                 bch2_write_queue(op, wp);
1499                 continue_at(&op->cl, bch2_write_index, NULL);
1500         }
1501 out_nofs_restore:
1502         memalloc_nofs_restore(nofs_flags);
1503 }
1504
1505 static void bch2_write_data_inline(struct bch_write_op *op, unsigned data_len)
1506 {
1507         struct bio *bio = &op->wbio.bio;
1508         struct bvec_iter iter;
1509         struct bkey_i_inline_data *id;
1510         unsigned sectors;
1511         int ret;
1512
1513         op->flags |= BCH_WRITE_WROTE_DATA_INLINE;
1514         op->flags |= BCH_WRITE_DONE;
1515
1516         bch2_check_set_feature(op->c, BCH_FEATURE_inline_data);
1517
1518         ret = bch2_keylist_realloc(&op->insert_keys, op->inline_keys,
1519                                    ARRAY_SIZE(op->inline_keys),
1520                                    BKEY_U64s + DIV_ROUND_UP(data_len, 8));
1521         if (ret) {
1522                 op->error = ret;
1523                 goto err;
1524         }
1525
1526         sectors = bio_sectors(bio);
1527         op->pos.offset += sectors;
1528
1529         id = bkey_inline_data_init(op->insert_keys.top);
1530         id->k.p         = op->pos;
1531         id->k.version   = op->version;
1532         id->k.size      = sectors;
1533
1534         iter = bio->bi_iter;
1535         iter.bi_size = data_len;
1536         memcpy_from_bio(id->v.data, bio, iter);
1537
1538         while (data_len & 7)
1539                 id->v.data[data_len++] = '\0';
1540         set_bkey_val_bytes(&id->k, data_len);
1541         bch2_keylist_push(&op->insert_keys);
1542
1543         __bch2_write_index(op);
1544 err:
1545         bch2_write_done(&op->cl);
1546 }
1547
1548 /**
1549  * bch2_write() - handle a write to a cache device or flash only volume
1550  * @cl:         &bch_write_op->cl
1551  *
1552  * This is the starting point for any data to end up in a cache device; it could
1553  * be from a normal write, or a writeback write, or a write to a flash only
1554  * volume - it's also used by the moving garbage collector to compact data in
1555  * mostly empty buckets.
1556  *
1557  * It first writes the data to the cache, creating a list of keys to be inserted
1558  * (if the data won't fit in a single open bucket, there will be multiple keys);
1559  * after the data is written it calls bch_journal, and after the keys have been
1560  * added to the next journal write they're inserted into the btree.
1561  *
1562  * If op->discard is true, instead of inserting the data it invalidates the
1563  * region of the cache represented by op->bio and op->inode.
1564  */
1565 void bch2_write(struct closure *cl)
1566 {
1567         struct bch_write_op *op = container_of(cl, struct bch_write_op, cl);
1568         struct bio *bio = &op->wbio.bio;
1569         struct bch_fs *c = op->c;
1570         unsigned data_len;
1571
1572         EBUG_ON(op->cl.parent);
1573         BUG_ON(!op->nr_replicas);
1574         BUG_ON(!op->write_point.v);
1575         BUG_ON(bkey_eq(op->pos, POS_MAX));
1576
1577         op->start_time = local_clock();
1578         bch2_keylist_init(&op->insert_keys, op->inline_keys);
1579         wbio_init(bio)->put_bio = false;
1580
1581         if (bio->bi_iter.bi_size & (c->opts.block_size - 1)) {
1582                 bch_err_inum_offset_ratelimited(c,
1583                         op->pos.inode,
1584                         op->pos.offset << 9,
1585                         "misaligned write");
1586                 op->error = -EIO;
1587                 goto err;
1588         }
1589
1590         if (c->opts.nochanges) {
1591                 op->error = -BCH_ERR_erofs_no_writes;
1592                 goto err;
1593         }
1594
1595         if (!(op->flags & BCH_WRITE_MOVE) &&
1596             !bch2_write_ref_tryget(c, BCH_WRITE_REF_write)) {
1597                 op->error = -BCH_ERR_erofs_no_writes;
1598                 goto err;
1599         }
1600
1601         this_cpu_add(c->counters[BCH_COUNTER_io_write], bio_sectors(bio));
1602         bch2_increment_clock(c, bio_sectors(bio), WRITE);
1603
1604         data_len = min_t(u64, bio->bi_iter.bi_size,
1605                          op->new_i_size - (op->pos.offset << 9));
1606
1607         if (c->opts.inline_data &&
1608             data_len <= min(block_bytes(c) / 2, 1024U)) {
1609                 bch2_write_data_inline(op, data_len);
1610                 return;
1611         }
1612
1613         __bch2_write(op);
1614         return;
1615 err:
1616         bch2_disk_reservation_put(c, &op->res);
1617
1618         closure_debug_destroy(&op->cl);
1619         if (op->end_io)
1620                 op->end_io(op);
1621 }
1622
1623 static const char * const bch2_write_flags[] = {
1624 #define x(f)    #f,
1625         BCH_WRITE_FLAGS()
1626 #undef x
1627         NULL
1628 };
1629
1630 void bch2_write_op_to_text(struct printbuf *out, struct bch_write_op *op)
1631 {
1632         prt_str(out, "pos: ");
1633         bch2_bpos_to_text(out, op->pos);
1634         prt_newline(out);
1635         printbuf_indent_add(out, 2);
1636
1637         prt_str(out, "started: ");
1638         bch2_pr_time_units(out, local_clock() - op->start_time);
1639         prt_newline(out);
1640
1641         prt_str(out, "flags: ");
1642         prt_bitflags(out, bch2_write_flags, op->flags);
1643         prt_newline(out);
1644
1645         prt_printf(out, "ref: %u", closure_nr_remaining(&op->cl));
1646         prt_newline(out);
1647
1648         printbuf_indent_sub(out, 2);
1649 }
1650
1651 void bch2_fs_io_write_exit(struct bch_fs *c)
1652 {
1653         mempool_exit(&c->bio_bounce_pages);
1654         bioset_exit(&c->bio_write);
1655 }
1656
1657 int bch2_fs_io_write_init(struct bch_fs *c)
1658 {
1659         if (bioset_init(&c->bio_write, 1, offsetof(struct bch_write_bio, bio),
1660                         BIOSET_NEED_BVECS))
1661                 return -BCH_ERR_ENOMEM_bio_write_init;
1662
1663         if (mempool_init_page_pool(&c->bio_bounce_pages,
1664                                    max_t(unsigned,
1665                                          c->opts.btree_node_size,
1666                                          c->opts.encoded_extent_max) /
1667                                    PAGE_SIZE, 0))
1668                 return -BCH_ERR_ENOMEM_bio_bounce_pages_init;
1669
1670         return 0;
1671 }