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_bkey_set_needs_rebalance(c, sk.k,
 355                                         op->opts.background_target,
 356                                         op->opts.background_compression) ?:
 357                         bch2_extent_update(trans, inum, &iter, sk.k,
 358                                         &op->res,
 359                                         op->new_i_size, &op->i_sectors_delta,
 360                                         op->flags & BCH_WRITE_CHECK_ENOSPC);
 361                 bch2_trans_iter_exit(trans, &iter);
 362
 363                 if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
 364                         continue;
 365                 if (ret)
 366                         break;
 367
 368                 if (bkey_ge(iter.pos, k->k.p))
 369                         bch2_keylist_pop_front(&op->insert_keys);
 370                 else
 371                         bch2_cut_front(iter.pos, k);
 372         } while (!bch2_keylist_empty(keys));
 373
 374         bch2_trans_put(trans);
 375         bch2_bkey_buf_exit(&sk, c);
 376
 377         return ret;
 378 }
 379
 380 /* Writes */
 381
 382 void bch2_submit_wbio_replicas(struct bch_write_bio *wbio, struct bch_fs *c,
 383                                enum bch_data_type type,
 384                                const struct bkey_i *k,
 385                                bool nocow)
 386 {
 387         struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(bkey_i_to_s_c(k));
 388         const struct bch_extent_ptr *ptr;
 389         struct bch_write_bio *n;
 390         struct bch_dev *ca;
 391
 392         BUG_ON(c->opts.nochanges);
 393
 394         bkey_for_each_ptr(ptrs, ptr) {
 395                 BUG_ON(ptr->dev >= BCH_SB_MEMBERS_MAX ||
 396                        !c->devs[ptr->dev]);
 397
 398                 ca = bch_dev_bkey_exists(c, ptr->dev);
 399
 400                 if (to_entry(ptr + 1) < ptrs.end) {
 401                         n = to_wbio(bio_alloc_clone(NULL, &wbio->bio,
 402                                                 GFP_NOFS, &ca->replica_set));
 403
 404                         n->bio.bi_end_io        = wbio->bio.bi_end_io;
 405                         n->bio.bi_private       = wbio->bio.bi_private;
 406                         n->parent               = wbio;
 407                         n->split                = true;
 408                         n->bounce               = false;
 409                         n->put_bio              = true;
 410                         n->bio.bi_opf           = wbio->bio.bi_opf;
 411                         bio_inc_remaining(&wbio->bio);
 412                 } else {
 413                         n = wbio;
 414                         n->split                = false;
 415                 }
 416
 417                 n->c                    = c;
 418                 n->dev                  = ptr->dev;
 419                 n->have_ioref           = nocow || bch2_dev_get_ioref(ca,
 420                                         type == BCH_DATA_btree ? READ : WRITE);
 421                 n->nocow                = nocow;
 422                 n->submit_time          = local_clock();
 423                 n->inode_offset         = bkey_start_offset(&k->k);
 424                 n->bio.bi_iter.bi_sector = ptr->offset;
 425
 426                 if (likely(n->have_ioref)) {
 427                         this_cpu_add(ca->io_done->sectors[WRITE][type],
 428                                      bio_sectors(&n->bio));
 429
 430                         bio_set_dev(&n->bio, ca->disk_sb.bdev);
 431
 432                         if (type != BCH_DATA_btree && unlikely(c->opts.no_data_io)) {
 433                                 bio_endio(&n->bio);
 434                                 continue;
 435                         }
 436
 437                         submit_bio(&n->bio);
 438                 } else {
 439                         n->bio.bi_status        = BLK_STS_REMOVED;
 440                         bio_endio(&n->bio);
 441                 }
 442         }
 443 }
 444
 445 static void __bch2_write(struct bch_write_op *);
 446
 447 static void bch2_write_done(struct closure *cl)
 448 {
 449         struct bch_write_op *op = container_of(cl, struct bch_write_op, cl);
 450         struct bch_fs *c = op->c;
 451
 452         EBUG_ON(op->open_buckets.nr);
 453
 454         bch2_time_stats_update(&c->times[BCH_TIME_data_write], op->start_time);
 455         bch2_disk_reservation_put(c, &op->res);
 456
 457         if (!(op->flags & BCH_WRITE_MOVE))
 458                 bch2_write_ref_put(c, BCH_WRITE_REF_write);
 459         bch2_keylist_free(&op->insert_keys, op->inline_keys);
 460
 461         EBUG_ON(cl->parent);
 462         closure_debug_destroy(cl);
 463         if (op->end_io)
 464                 op->end_io(op);
 465 }
 466
 467 static noinline int bch2_write_drop_io_error_ptrs(struct bch_write_op *op)
 468 {
 469         struct keylist *keys = &op->insert_keys;
 470         struct bch_extent_ptr *ptr;
 471         struct bkey_i *src, *dst = keys->keys, *n;
 472
 473         for (src = keys->keys; src != keys->top; src = n) {
 474                 n = bkey_next(src);
 475
 476                 if (bkey_extent_is_direct_data(&src->k)) {
 477                         bch2_bkey_drop_ptrs(bkey_i_to_s(src), ptr,
 478                                             test_bit(ptr->dev, op->failed.d));
 479
 480                         if (!bch2_bkey_nr_ptrs(bkey_i_to_s_c(src)))
 481                                 return -EIO;
 482                 }
 483
 484                 if (dst != src)
 485                         memmove_u64s_down(dst, src, src->k.u64s);
 486                 dst = bkey_next(dst);
 487         }
 488
 489         keys->top = dst;
 490         return 0;
 491 }
 492
 493 /**
 494  * __bch2_write_index - after a write, update index to point to new data
 495  * @op:         bch_write_op to process
 496  */
 497 static void __bch2_write_index(struct bch_write_op *op)
 498 {
 499         struct bch_fs *c = op->c;
 500         struct keylist *keys = &op->insert_keys;
 501         unsigned dev;
 502         int ret = 0;
 503
 504         if (unlikely(op->flags & BCH_WRITE_IO_ERROR)) {
 505                 ret = bch2_write_drop_io_error_ptrs(op);
 506                 if (ret)
 507                         goto err;
 508         }
 509
 510         if (!bch2_keylist_empty(keys)) {
 511                 u64 sectors_start = keylist_sectors(keys);
 512
 513                 ret = !(op->flags & BCH_WRITE_MOVE)
 514                         ? bch2_write_index_default(op)
 515                         : bch2_data_update_index_update(op);
 516
 517                 BUG_ON(bch2_err_matches(ret, BCH_ERR_transaction_restart));
 518                 BUG_ON(keylist_sectors(keys) && !ret);
 519
 520                 op->written += sectors_start - keylist_sectors(keys);
 521
 522                 if (ret && !bch2_err_matches(ret, EROFS)) {
 523                         struct bkey_i *insert = bch2_keylist_front(&op->insert_keys);
 524
 525                         bch_err_inum_offset_ratelimited(c,
 526                                 insert->k.p.inode, insert->k.p.offset << 9,
 527                                 "write error while doing btree update: %s",
 528                                 bch2_err_str(ret));
 529                 }
 530
 531                 if (ret)
 532                         goto err;
 533         }
 534 out:
 535         /* If some a bucket wasn't written, we can't erasure code it: */
 536         for_each_set_bit(dev, op->failed.d, BCH_SB_MEMBERS_MAX)
 537                 bch2_open_bucket_write_error(c, &op->open_buckets, dev);
 538
 539         bch2_open_buckets_put(c, &op->open_buckets);
 540         return;
 541 err:
 542         keys->top = keys->keys;
 543         op->error = ret;
 544         op->flags |= BCH_WRITE_DONE;
 545         goto out;
 546 }
 547
 548 static inline void __wp_update_state(struct write_point *wp, enum write_point_state state)
 549 {
 550         if (state != wp->state) {
 551                 u64 now = ktime_get_ns();
 552
 553                 if (wp->last_state_change &&
 554                     time_after64(now, wp->last_state_change))
 555                         wp->time[wp->state] += now - wp->last_state_change;
 556                 wp->state = state;
 557                 wp->last_state_change = now;
 558         }
 559 }
 560
 561 static inline void wp_update_state(struct write_point *wp, bool running)
 562 {
 563         enum write_point_state state;
 564
 565         state = running                  ? WRITE_POINT_running :
 566                 !list_empty(&wp->writes) ? WRITE_POINT_waiting_io
 567                                          : WRITE_POINT_stopped;
 568
 569         __wp_update_state(wp, state);
 570 }
 571
 572 static void bch2_write_index(struct closure *cl)
 573 {
 574         struct bch_write_op *op = container_of(cl, struct bch_write_op, cl);
 575         struct write_point *wp = op->wp;
 576         struct workqueue_struct *wq = index_update_wq(op);
 577         unsigned long flags;
 578
 579         if ((op->flags & BCH_WRITE_DONE) &&
 580             (op->flags & BCH_WRITE_MOVE))
 581                 bch2_bio_free_pages_pool(op->c, &op->wbio.bio);
 582
 583         spin_lock_irqsave(&wp->writes_lock, flags);
 584         if (wp->state == WRITE_POINT_waiting_io)
 585                 __wp_update_state(wp, WRITE_POINT_waiting_work);
 586         list_add_tail(&op->wp_list, &wp->writes);
 587         spin_unlock_irqrestore (&wp->writes_lock, flags);
 588
 589         queue_work(wq, &wp->index_update_work);
 590 }
 591
 592 static inline void bch2_write_queue(struct bch_write_op *op, struct write_point *wp)
 593 {
 594         op->wp = wp;
 595
 596         if (wp->state == WRITE_POINT_stopped) {
 597                 spin_lock_irq(&wp->writes_lock);
 598                 __wp_update_state(wp, WRITE_POINT_waiting_io);
 599                 spin_unlock_irq(&wp->writes_lock);
 600         }
 601 }
 602
 603 void bch2_write_point_do_index_updates(struct work_struct *work)
 604 {
 605         struct write_point *wp =
 606                 container_of(work, struct write_point, index_update_work);
 607         struct bch_write_op *op;
 608
 609         while (1) {
 610                 spin_lock_irq(&wp->writes_lock);
 611                 op = list_first_entry_or_null(&wp->writes, struct bch_write_op, wp_list);
 612                 if (op)
 613                         list_del(&op->wp_list);
 614                 wp_update_state(wp, op != NULL);
 615                 spin_unlock_irq(&wp->writes_lock);
 616
 617                 if (!op)
 618                         break;
 619
 620                 op->flags |= BCH_WRITE_IN_WORKER;
 621
 622                 __bch2_write_index(op);
 623
 624                 if (!(op->flags & BCH_WRITE_DONE))
 625                         __bch2_write(op);
 626                 else
 627                         bch2_write_done(&op->cl);
 628         }
 629 }
 630
 631 static void bch2_write_endio(struct bio *bio)
 632 {
 633         struct closure *cl              = bio->bi_private;
 634         struct bch_write_op *op         = container_of(cl, struct bch_write_op, cl);
 635         struct bch_write_bio *wbio      = to_wbio(bio);
 636         struct bch_write_bio *parent    = wbio->split ? wbio->parent : NULL;
 637         struct bch_fs *c                = wbio->c;
 638         struct bch_dev *ca              = bch_dev_bkey_exists(c, wbio->dev);
 639
 640         if (bch2_dev_inum_io_err_on(bio->bi_status, ca,
 641                                     op->pos.inode,
 642                                     wbio->inode_offset << 9,
 643                                     "data write error: %s",
 644                                     bch2_blk_status_to_str(bio->bi_status))) {
 645                 set_bit(wbio->dev, op->failed.d);
 646                 op->flags |= BCH_WRITE_IO_ERROR;
 647         }
 648
 649         if (wbio->nocow)
 650                 set_bit(wbio->dev, op->devs_need_flush->d);
 651
 652         if (wbio->have_ioref) {
 653                 bch2_latency_acct(ca, wbio->submit_time, WRITE);
 654                 percpu_ref_put(&ca->io_ref);
 655         }
 656
 657         if (wbio->bounce)
 658                 bch2_bio_free_pages_pool(c, bio);
 659
 660         if (wbio->put_bio)
 661                 bio_put(bio);
 662
 663         if (parent)
 664                 bio_endio(&parent->bio);
 665         else
 666                 closure_put(cl);
 667 }
 668
 669 static void init_append_extent(struct bch_write_op *op,
 670                                struct write_point *wp,
 671                                struct bversion version,
 672                                struct bch_extent_crc_unpacked crc)
 673 {
 674         struct bkey_i_extent *e;
 675
 676         op->pos.offset += crc.uncompressed_size;
 677
 678         e = bkey_extent_init(op->insert_keys.top);
 679         e->k.p          = op->pos;
 680         e->k.size       = crc.uncompressed_size;
 681         e->k.version    = version;
 682
 683         if (crc.csum_type ||
 684             crc.compression_type ||
 685             crc.nonce)
 686                 bch2_extent_crc_append(&e->k_i, crc);
 687
 688         bch2_alloc_sectors_append_ptrs_inlined(op->c, wp, &e->k_i, crc.compressed_size,
 689                                        op->flags & BCH_WRITE_CACHED);
 690
 691         bch2_keylist_push(&op->insert_keys);
 692 }
 693
 694 static struct bio *bch2_write_bio_alloc(struct bch_fs *c,
 695                                         struct write_point *wp,
 696                                         struct bio *src,
 697                                         bool *page_alloc_failed,
 698                                         void *buf)
 699 {
 700         struct bch_write_bio *wbio;
 701         struct bio *bio;
 702         unsigned output_available =
 703                 min(wp->sectors_free << 9, src->bi_iter.bi_size);
 704         unsigned pages = DIV_ROUND_UP(output_available +
 705                                       (buf
 706                                        ? ((unsigned long) buf & (PAGE_SIZE - 1))
 707                                        : 0), PAGE_SIZE);
 708
 709         pages = min(pages, BIO_MAX_VECS);
 710
 711         bio = bio_alloc_bioset(NULL, pages, 0,
 712                                GFP_NOFS, &c->bio_write);
 713         wbio                    = wbio_init(bio);
 714         wbio->put_bio           = true;
 715         /* copy WRITE_SYNC flag */
 716         wbio->bio.bi_opf        = src->bi_opf;
 717
 718         if (buf) {
 719                 bch2_bio_map(bio, buf, output_available);
 720                 return bio;
 721         }
 722
 723         wbio->bounce            = true;
 724
 725         /*
 726          * We can't use mempool for more than c->sb.encoded_extent_max
 727          * worth of pages, but we'd like to allocate more if we can:
 728          */
 729         bch2_bio_alloc_pages_pool(c, bio,
 730                                   min_t(unsigned, output_available,
 731                                         c->opts.encoded_extent_max));
 732
 733         if (bio->bi_iter.bi_size < output_available)
 734                 *page_alloc_failed =
 735                         bch2_bio_alloc_pages(bio,
 736                                              output_available -
 737                                              bio->bi_iter.bi_size,
 738                                              GFP_NOFS) != 0;
 739
 740         return bio;
 741 }
 742
 743 static int bch2_write_rechecksum(struct bch_fs *c,
 744                                  struct bch_write_op *op,
 745                                  unsigned new_csum_type)
 746 {
 747         struct bio *bio = &op->wbio.bio;
 748         struct bch_extent_crc_unpacked new_crc;
 749         int ret;
 750
 751         /* bch2_rechecksum_bio() can't encrypt or decrypt data: */
 752
 753         if (bch2_csum_type_is_encryption(op->crc.csum_type) !=
 754             bch2_csum_type_is_encryption(new_csum_type))
 755                 new_csum_type = op->crc.csum_type;
 756
 757         ret = bch2_rechecksum_bio(c, bio, op->version, op->crc,
 758                                   NULL, &new_crc,
 759                                   op->crc.offset, op->crc.live_size,
 760                                   new_csum_type);
 761         if (ret)
 762                 return ret;
 763
 764         bio_advance(bio, op->crc.offset << 9);
 765         bio->bi_iter.bi_size = op->crc.live_size << 9;
 766         op->crc = new_crc;
 767         return 0;
 768 }
 769
 770 static int bch2_write_decrypt(struct bch_write_op *op)
 771 {
 772         struct bch_fs *c = op->c;
 773         struct nonce nonce = extent_nonce(op->version, op->crc);
 774         struct bch_csum csum;
 775         int ret;
 776
 777         if (!bch2_csum_type_is_encryption(op->crc.csum_type))
 778                 return 0;
 779
 780         /*
 781          * If we need to decrypt data in the write path, we'll no longer be able
 782          * to verify the existing checksum (poly1305 mac, in this case) after
 783          * it's decrypted - this is the last point we'll be able to reverify the
 784          * checksum:
 785          */
 786         csum = bch2_checksum_bio(c, op->crc.csum_type, nonce, &op->wbio.bio);
 787         if (bch2_crc_cmp(op->crc.csum, csum))
 788                 return -EIO;
 789
 790         ret = bch2_encrypt_bio(c, op->crc.csum_type, nonce, &op->wbio.bio);
 791         op->crc.csum_type = 0;
 792         op->crc.csum = (struct bch_csum) { 0, 0 };
 793         return ret;
 794 }
 795
 796 static enum prep_encoded_ret {
 797         PREP_ENCODED_OK,
 798         PREP_ENCODED_ERR,
 799         PREP_ENCODED_CHECKSUM_ERR,
 800         PREP_ENCODED_DO_WRITE,
 801 } bch2_write_prep_encoded_data(struct bch_write_op *op, struct write_point *wp)
 802 {
 803         struct bch_fs *c = op->c;
 804         struct bio *bio = &op->wbio.bio;
 805
 806         if (!(op->flags & BCH_WRITE_DATA_ENCODED))
 807                 return PREP_ENCODED_OK;
 808
 809         BUG_ON(bio_sectors(bio) != op->crc.compressed_size);
 810
 811         /* Can we just write the entire extent as is? */
 812         if (op->crc.uncompressed_size == op->crc.live_size &&
 813             op->crc.uncompressed_size <= c->opts.encoded_extent_max >> 9 &&
 814             op->crc.compressed_size <= wp->sectors_free &&
 815             (op->crc.compression_type == bch2_compression_opt_to_type(op->compression_opt) ||
 816              op->incompressible)) {
 817                 if (!crc_is_compressed(op->crc) &&
 818                     op->csum_type != op->crc.csum_type &&
 819                     bch2_write_rechecksum(c, op, op->csum_type) &&
 820                     !c->opts.no_data_io)
 821                         return PREP_ENCODED_CHECKSUM_ERR;
 822
 823                 return PREP_ENCODED_DO_WRITE;
 824         }
 825
 826         /*
 827          * If the data is compressed and we couldn't write the entire extent as
 828          * is, we have to decompress it:
 829          */
 830         if (crc_is_compressed(op->crc)) {
 831                 struct bch_csum csum;
 832
 833                 if (bch2_write_decrypt(op))
 834                         return PREP_ENCODED_CHECKSUM_ERR;
 835
 836                 /* Last point we can still verify checksum: */
 837                 csum = bch2_checksum_bio(c, op->crc.csum_type,
 838                                          extent_nonce(op->version, op->crc),
 839                                          bio);
 840                 if (bch2_crc_cmp(op->crc.csum, csum) && !c->opts.no_data_io)
 841                         return PREP_ENCODED_CHECKSUM_ERR;
 842
 843                 if (bch2_bio_uncompress_inplace(c, bio, &op->crc))
 844                         return PREP_ENCODED_ERR;
 845         }
 846
 847         /*
 848          * No longer have compressed data after this point - data might be
 849          * encrypted:
 850          */
 851
 852         /*
 853          * If the data is checksummed and we're only writing a subset,
 854          * rechecksum and adjust bio to point to currently live data:
 855          */
 856         if ((op->crc.live_size != op->crc.uncompressed_size ||
 857              op->crc.csum_type != op->csum_type) &&
 858             bch2_write_rechecksum(c, op, op->csum_type) &&
 859             !c->opts.no_data_io)
 860                 return PREP_ENCODED_CHECKSUM_ERR;
 861
 862         /*
 863          * If we want to compress the data, it has to be decrypted:
 864          */
 865         if ((op->compression_opt ||
 866              bch2_csum_type_is_encryption(op->crc.csum_type) !=
 867              bch2_csum_type_is_encryption(op->csum_type)) &&
 868             bch2_write_decrypt(op))
 869                 return PREP_ENCODED_CHECKSUM_ERR;
 870
 871         return PREP_ENCODED_OK;
 872 }
 873
 874 static int bch2_write_extent(struct bch_write_op *op, struct write_point *wp,
 875                              struct bio **_dst)
 876 {
 877         struct bch_fs *c = op->c;
 878         struct bio *src = &op->wbio.bio, *dst = src;
 879         struct bvec_iter saved_iter;
 880         void *ec_buf;
 881         unsigned total_output = 0, total_input = 0;
 882         bool bounce = false;
 883         bool page_alloc_failed = false;
 884         int ret, more = 0;
 885
 886         BUG_ON(!bio_sectors(src));
 887
 888         ec_buf = bch2_writepoint_ec_buf(c, wp);
 889
 890         switch (bch2_write_prep_encoded_data(op, wp)) {
 891         case PREP_ENCODED_OK:
 892                 break;
 893         case PREP_ENCODED_ERR:
 894                 ret = -EIO;
 895                 goto err;
 896         case PREP_ENCODED_CHECKSUM_ERR:
 897                 goto csum_err;
 898         case PREP_ENCODED_DO_WRITE:
 899                 /* XXX look for bug here */
 900                 if (ec_buf) {
 901                         dst = bch2_write_bio_alloc(c, wp, src,
 902                                                    &page_alloc_failed,
 903                                                    ec_buf);
 904                         bio_copy_data(dst, src);
 905                         bounce = true;
 906                 }
 907                 init_append_extent(op, wp, op->version, op->crc);
 908                 goto do_write;
 909         }
 910
 911         if (ec_buf ||
 912             op->compression_opt ||
 913             (op->csum_type &&
 914              !(op->flags & BCH_WRITE_PAGES_STABLE)) ||
 915             (bch2_csum_type_is_encryption(op->csum_type) &&
 916              !(op->flags & BCH_WRITE_PAGES_OWNED))) {
 917                 dst = bch2_write_bio_alloc(c, wp, src,
 918                                            &page_alloc_failed,
 919                                            ec_buf);
 920                 bounce = true;
 921         }
 922
 923         saved_iter = dst->bi_iter;
 924
 925         do {
 926                 struct bch_extent_crc_unpacked crc = { 0 };
 927                 struct bversion version = op->version;
 928                 size_t dst_len = 0, src_len = 0;
 929
 930                 if (page_alloc_failed &&
 931                     dst->bi_iter.bi_size  < (wp->sectors_free << 9) &&
 932                     dst->bi_iter.bi_size < c->opts.encoded_extent_max)
 933                         break;
 934
 935                 BUG_ON(op->compression_opt &&
 936                        (op->flags & BCH_WRITE_DATA_ENCODED) &&
 937                        bch2_csum_type_is_encryption(op->crc.csum_type));
 938                 BUG_ON(op->compression_opt && !bounce);
 939
 940                 crc.compression_type = op->incompressible
 941                         ? BCH_COMPRESSION_TYPE_incompressible
 942                         : op->compression_opt
 943                         ? bch2_bio_compress(c, dst, &dst_len, src, &src_len,
 944                                             op->compression_opt)
 945                         : 0;
 946                 if (!crc_is_compressed(crc)) {
 947                         dst_len = min(dst->bi_iter.bi_size, src->bi_iter.bi_size);
 948                         dst_len = min_t(unsigned, dst_len, wp->sectors_free << 9);
 949
 950                         if (op->csum_type)
 951                                 dst_len = min_t(unsigned, dst_len,
 952                                                 c->opts.encoded_extent_max);
 953
 954                         if (bounce) {
 955                                 swap(dst->bi_iter.bi_size, dst_len);
 956                                 bio_copy_data(dst, src);
 957                                 swap(dst->bi_iter.bi_size, dst_len);
 958                         }
 959
 960                         src_len = dst_len;
 961                 }
 962
 963                 BUG_ON(!src_len || !dst_len);
 964
 965                 if (bch2_csum_type_is_encryption(op->csum_type)) {
 966                         if (bversion_zero(version)) {
 967                                 version.lo = atomic64_inc_return(&c->key_version);
 968                         } else {
 969                                 crc.nonce = op->nonce;
 970                                 op->nonce += src_len >> 9;
 971                         }
 972                 }
 973
 974                 if ((op->flags & BCH_WRITE_DATA_ENCODED) &&
 975                     !crc_is_compressed(crc) &&
 976                     bch2_csum_type_is_encryption(op->crc.csum_type) ==
 977                     bch2_csum_type_is_encryption(op->csum_type)) {
 978                         u8 compression_type = crc.compression_type;
 979                         u16 nonce = crc.nonce;
 980                         /*
 981                          * Note: when we're using rechecksum(), we need to be
 982                          * checksumming @src because it has all the data our
 983                          * existing checksum covers - if we bounced (because we
 984                          * were trying to compress), @dst will only have the
 985                          * part of the data the new checksum will cover.
 986                          *
 987                          * But normally we want to be checksumming post bounce,
 988                          * because part of the reason for bouncing is so the
 989                          * data can't be modified (by userspace) while it's in
 990                          * flight.
 991                          */
 992                         if (bch2_rechecksum_bio(c, src, version, op->crc,
 993                                         &crc, &op->crc,
 994                                         src_len >> 9,
 995                                         bio_sectors(src) - (src_len >> 9),
 996                                         op->csum_type))
 997                                 goto csum_err;
 998                         /*
 999                          * rchecksum_bio sets compression_type on crc from op->crc,
1000                          * this isn't always correct as sometimes we're changing
1001                          * an extent from uncompressed to incompressible.
1002                          */
1003                         crc.compression_type = compression_type;
1004                         crc.nonce = nonce;
1005                 } else {
1006                         if ((op->flags & BCH_WRITE_DATA_ENCODED) &&
1007                             bch2_rechecksum_bio(c, src, version, op->crc,
1008                                         NULL, &op->crc,
1009                                         src_len >> 9,
1010                                         bio_sectors(src) - (src_len >> 9),
1011                                         op->crc.csum_type))
1012                                 goto csum_err;
1013
1014                         crc.compressed_size     = dst_len >> 9;
1015                         crc.uncompressed_size   = src_len >> 9;
1016                         crc.live_size           = src_len >> 9;
1017
1018                         swap(dst->bi_iter.bi_size, dst_len);
1019                         ret = bch2_encrypt_bio(c, op->csum_type,
1020                                                extent_nonce(version, crc), dst);
1021                         if (ret)
1022                                 goto err;
1023
1024                         crc.csum = bch2_checksum_bio(c, op->csum_type,
1025                                          extent_nonce(version, crc), dst);
1026                         crc.csum_type = op->csum_type;
1027                         swap(dst->bi_iter.bi_size, dst_len);
1028                 }
1029
1030                 init_append_extent(op, wp, version, crc);
1031
1032                 if (dst != src)
1033                         bio_advance(dst, dst_len);
1034                 bio_advance(src, src_len);
1035                 total_output    += dst_len;
1036                 total_input     += src_len;
1037         } while (dst->bi_iter.bi_size &&
1038                  src->bi_iter.bi_size &&
1039                  wp->sectors_free &&
1040                  !bch2_keylist_realloc(&op->insert_keys,
1041                                       op->inline_keys,
1042                                       ARRAY_SIZE(op->inline_keys),
1043                                       BKEY_EXTENT_U64s_MAX));
1044
1045         more = src->bi_iter.bi_size != 0;
1046
1047         dst->bi_iter = saved_iter;
1048
1049         if (dst == src && more) {
1050                 BUG_ON(total_output != total_input);
1051
1052                 dst = bio_split(src, total_input >> 9,
1053                                 GFP_NOFS, &c->bio_write);
1054                 wbio_init(dst)->put_bio = true;
1055                 /* copy WRITE_SYNC flag */
1056                 dst->bi_opf             = src->bi_opf;
1057         }
1058
1059         dst->bi_iter.bi_size = total_output;
1060 do_write:
1061         *_dst = dst;
1062         return more;
1063 csum_err:
1064         bch_err(c, "error verifying existing checksum while rewriting existing data (memory corruption?)");
1065         ret = -EIO;
1066 err:
1067         if (to_wbio(dst)->bounce)
1068                 bch2_bio_free_pages_pool(c, dst);
1069         if (to_wbio(dst)->put_bio)
1070                 bio_put(dst);
1071
1072         return ret;
1073 }
1074
1075 static bool bch2_extent_is_writeable(struct bch_write_op *op,
1076                                      struct bkey_s_c k)
1077 {
1078         struct bch_fs *c = op->c;
1079         struct bkey_s_c_extent e;
1080         struct extent_ptr_decoded p;
1081         const union bch_extent_entry *entry;
1082         unsigned replicas = 0;
1083
1084         if (k.k->type != KEY_TYPE_extent)
1085                 return false;
1086
1087         e = bkey_s_c_to_extent(k);
1088         extent_for_each_ptr_decode(e, p, entry) {
1089                 if (crc_is_encoded(p.crc) || p.has_ec)
1090                         return false;
1091
1092                 replicas += bch2_extent_ptr_durability(c, &p);
1093         }
1094
1095         return replicas >= op->opts.data_replicas;
1096 }
1097
1098 static inline void bch2_nocow_write_unlock(struct bch_write_op *op)
1099 {
1100         struct bch_fs *c = op->c;
1101         const struct bch_extent_ptr *ptr;
1102         struct bkey_i *k;
1103
1104         for_each_keylist_key(&op->insert_keys, k) {
1105                 struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(bkey_i_to_s_c(k));
1106
1107                 bkey_for_each_ptr(ptrs, ptr)
1108                         bch2_bucket_nocow_unlock(&c->nocow_locks,
1109                                                PTR_BUCKET_POS(c, ptr),
1110                                                BUCKET_NOCOW_LOCK_UPDATE);
1111         }
1112 }
1113
1114 static int bch2_nocow_write_convert_one_unwritten(struct btree_trans *trans,
1115                                                   struct btree_iter *iter,
1116                                                   struct bkey_i *orig,
1117                                                   struct bkey_s_c k,
1118                                                   u64 new_i_size)
1119 {
1120         struct bkey_i *new;
1121         struct bkey_ptrs ptrs;
1122         struct bch_extent_ptr *ptr;
1123         int ret;
1124
1125         if (!bch2_extents_match(bkey_i_to_s_c(orig), k)) {
1126                 /* trace this */
1127                 return 0;
1128         }
1129
1130         new = bch2_bkey_make_mut_noupdate(trans, k);
1131         ret = PTR_ERR_OR_ZERO(new);
1132         if (ret)
1133                 return ret;
1134
1135         bch2_cut_front(bkey_start_pos(&orig->k), new);
1136         bch2_cut_back(orig->k.p, new);
1137
1138         ptrs = bch2_bkey_ptrs(bkey_i_to_s(new));
1139         bkey_for_each_ptr(ptrs, ptr)
1140                 ptr->unwritten = 0;
1141
1142         /*
1143          * Note that we're not calling bch2_subvol_get_snapshot() in this path -
1144          * that was done when we kicked off the write, and here it's important
1145          * that we update the extent that we wrote to - even if a snapshot has
1146          * since been created. The write is still outstanding, so we're ok
1147          * w.r.t. snapshot atomicity:
1148          */
1149         return  bch2_extent_update_i_size_sectors(trans, iter,
1150                                         min(new->k.p.offset << 9, new_i_size), 0) ?:
1151                 bch2_trans_update(trans, iter, new,
1152                                   BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE);
1153 }
1154
1155 static void bch2_nocow_write_convert_unwritten(struct bch_write_op *op)
1156 {
1157         struct bch_fs *c = op->c;
1158         struct btree_trans *trans = bch2_trans_get(c);
1159         struct btree_iter iter;
1160         struct bkey_i *orig;
1161         struct bkey_s_c k;
1162         int ret;
1163
1164         for_each_keylist_key(&op->insert_keys, orig) {
1165                 ret = for_each_btree_key_upto_commit(trans, iter, BTREE_ID_extents,
1166                                      bkey_start_pos(&orig->k), orig->k.p,
1167                                      BTREE_ITER_INTENT, k,
1168                                      NULL, NULL, BTREE_INSERT_NOFAIL, ({
1169                         bch2_nocow_write_convert_one_unwritten(trans, &iter, orig, k, op->new_i_size);
1170                 }));
1171
1172                 if (ret && !bch2_err_matches(ret, EROFS)) {
1173                         struct bkey_i *insert = bch2_keylist_front(&op->insert_keys);
1174
1175                         bch_err_inum_offset_ratelimited(c,
1176                                 insert->k.p.inode, insert->k.p.offset << 9,
1177                                 "write error while doing btree update: %s",
1178                                 bch2_err_str(ret));
1179                 }
1180
1181                 if (ret) {
1182                         op->error = ret;
1183                         break;
1184                 }
1185         }
1186
1187         bch2_trans_put(trans);
1188 }
1189
1190 static void __bch2_nocow_write_done(struct bch_write_op *op)
1191 {
1192         bch2_nocow_write_unlock(op);
1193
1194         if (unlikely(op->flags & BCH_WRITE_IO_ERROR)) {
1195                 op->error = -EIO;
1196         } else if (unlikely(op->flags & BCH_WRITE_CONVERT_UNWRITTEN))
1197                 bch2_nocow_write_convert_unwritten(op);
1198 }
1199
1200 static void bch2_nocow_write_done(struct closure *cl)
1201 {
1202         struct bch_write_op *op = container_of(cl, struct bch_write_op, cl);
1203
1204         __bch2_nocow_write_done(op);
1205         bch2_write_done(cl);
1206 }
1207
1208 static void bch2_nocow_write(struct bch_write_op *op)
1209 {
1210         struct bch_fs *c = op->c;
1211         struct btree_trans *trans;
1212         struct btree_iter iter;
1213         struct bkey_s_c k;
1214         struct bkey_ptrs_c ptrs;
1215         const struct bch_extent_ptr *ptr;
1216         struct {
1217                 struct bpos     b;
1218                 unsigned        gen;
1219                 struct nocow_lock_bucket *l;
1220         } buckets[BCH_REPLICAS_MAX];
1221         unsigned nr_buckets = 0;
1222         u32 snapshot;
1223         int ret, i;
1224
1225         if (op->flags & BCH_WRITE_MOVE)
1226                 return;
1227
1228         trans = bch2_trans_get(c);
1229 retry:
1230         bch2_trans_begin(trans);
1231
1232         ret = bch2_subvolume_get_snapshot(trans, op->subvol, &snapshot);
1233         if (unlikely(ret))
1234                 goto err;
1235
1236         bch2_trans_iter_init(trans, &iter, BTREE_ID_extents,
1237                              SPOS(op->pos.inode, op->pos.offset, snapshot),
1238                              BTREE_ITER_SLOTS);
1239         while (1) {
1240                 struct bio *bio = &op->wbio.bio;
1241
1242                 nr_buckets = 0;
1243
1244                 k = bch2_btree_iter_peek_slot(&iter);
1245                 ret = bkey_err(k);
1246                 if (ret)
1247                         break;
1248
1249                 /* fall back to normal cow write path? */
1250                 if (unlikely(k.k->p.snapshot != snapshot ||
1251                              !bch2_extent_is_writeable(op, k)))
1252                         break;
1253
1254                 if (bch2_keylist_realloc(&op->insert_keys,
1255                                         op->inline_keys,
1256                                         ARRAY_SIZE(op->inline_keys),
1257                                         k.k->u64s))
1258                         break;
1259
1260                 /* Get iorefs before dropping btree locks: */
1261                 ptrs = bch2_bkey_ptrs_c(k);
1262                 bkey_for_each_ptr(ptrs, ptr) {
1263                         buckets[nr_buckets].b = PTR_BUCKET_POS(c, ptr);
1264                         buckets[nr_buckets].gen = ptr->gen;
1265                         buckets[nr_buckets].l =
1266                                 bucket_nocow_lock(&c->nocow_locks,
1267                                                   bucket_to_u64(buckets[nr_buckets].b));
1268
1269                         prefetch(buckets[nr_buckets].l);
1270
1271                         if (unlikely(!bch2_dev_get_ioref(bch_dev_bkey_exists(c, ptr->dev), WRITE)))
1272                                 goto err_get_ioref;
1273
1274                         nr_buckets++;
1275
1276                         if (ptr->unwritten)
1277                                 op->flags |= BCH_WRITE_CONVERT_UNWRITTEN;
1278                 }
1279
1280                 /* Unlock before taking nocow locks, doing IO: */
1281                 bkey_reassemble(op->insert_keys.top, k);
1282                 bch2_trans_unlock(trans);
1283
1284                 bch2_cut_front(op->pos, op->insert_keys.top);
1285                 if (op->flags & BCH_WRITE_CONVERT_UNWRITTEN)
1286                         bch2_cut_back(POS(op->pos.inode, op->pos.offset + bio_sectors(bio)), op->insert_keys.top);
1287
1288                 for (i = 0; i < nr_buckets; i++) {
1289                         struct bch_dev *ca = bch_dev_bkey_exists(c, buckets[i].b.inode);
1290                         struct nocow_lock_bucket *l = buckets[i].l;
1291                         bool stale;
1292
1293                         __bch2_bucket_nocow_lock(&c->nocow_locks, l,
1294                                                  bucket_to_u64(buckets[i].b),
1295                                                  BUCKET_NOCOW_LOCK_UPDATE);
1296
1297                         rcu_read_lock();
1298                         stale = gen_after(*bucket_gen(ca, buckets[i].b.offset), buckets[i].gen);
1299                         rcu_read_unlock();
1300
1301                         if (unlikely(stale))
1302                                 goto err_bucket_stale;
1303                 }
1304
1305                 bio = &op->wbio.bio;
1306                 if (k.k->p.offset < op->pos.offset + bio_sectors(bio)) {
1307                         bio = bio_split(bio, k.k->p.offset - op->pos.offset,
1308                                         GFP_KERNEL, &c->bio_write);
1309                         wbio_init(bio)->put_bio = true;
1310                         bio->bi_opf = op->wbio.bio.bi_opf;
1311                 } else {
1312                         op->flags |= BCH_WRITE_DONE;
1313                 }
1314
1315                 op->pos.offset += bio_sectors(bio);
1316                 op->written += bio_sectors(bio);
1317
1318                 bio->bi_end_io  = bch2_write_endio;
1319                 bio->bi_private = &op->cl;
1320                 bio->bi_opf |= REQ_OP_WRITE;
1321                 closure_get(&op->cl);
1322                 bch2_submit_wbio_replicas(to_wbio(bio), c, BCH_DATA_user,
1323                                           op->insert_keys.top, true);
1324
1325                 bch2_keylist_push(&op->insert_keys);
1326                 if (op->flags & BCH_WRITE_DONE)
1327                         break;
1328                 bch2_btree_iter_advance(&iter);
1329         }
1330 out:
1331         bch2_trans_iter_exit(trans, &iter);
1332 err:
1333         if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
1334                 goto retry;
1335
1336         if (ret) {
1337                 bch_err_inum_offset_ratelimited(c,
1338                                 op->pos.inode,
1339                                 op->pos.offset << 9,
1340                                 "%s: btree lookup error %s",
1341                                 __func__, bch2_err_str(ret));
1342                 op->error = ret;
1343                 op->flags |= BCH_WRITE_DONE;
1344         }
1345
1346         bch2_trans_put(trans);
1347
1348         /* fallback to cow write path? */
1349         if (!(op->flags & BCH_WRITE_DONE)) {
1350                 closure_sync(&op->cl);
1351                 __bch2_nocow_write_done(op);
1352                 op->insert_keys.top = op->insert_keys.keys;
1353         } else if (op->flags & BCH_WRITE_SYNC) {
1354                 closure_sync(&op->cl);
1355                 bch2_nocow_write_done(&op->cl);
1356         } else {
1357                 /*
1358                  * XXX
1359                  * needs to run out of process context because ei_quota_lock is
1360                  * a mutex
1361                  */
1362                 continue_at(&op->cl, bch2_nocow_write_done, index_update_wq(op));
1363         }
1364         return;
1365 err_get_ioref:
1366         for (i = 0; i < nr_buckets; i++)
1367                 percpu_ref_put(&bch_dev_bkey_exists(c, buckets[i].b.inode)->io_ref);
1368
1369         /* Fall back to COW path: */
1370         goto out;
1371 err_bucket_stale:
1372         while (i >= 0) {
1373                 bch2_bucket_nocow_unlock(&c->nocow_locks,
1374                                          buckets[i].b,
1375                                          BUCKET_NOCOW_LOCK_UPDATE);
1376                 --i;
1377         }
1378         for (i = 0; i < nr_buckets; i++)
1379                 percpu_ref_put(&bch_dev_bkey_exists(c, buckets[i].b.inode)->io_ref);
1380
1381         /* We can retry this: */
1382         ret = -BCH_ERR_transaction_restart;
1383         goto out;
1384 }
1385
1386 static void __bch2_write(struct bch_write_op *op)
1387 {
1388         struct bch_fs *c = op->c;
1389         struct write_point *wp = NULL;
1390         struct bio *bio = NULL;
1391         unsigned nofs_flags;
1392         int ret;
1393
1394         nofs_flags = memalloc_nofs_save();
1395
1396         if (unlikely(op->opts.nocow && c->opts.nocow_enabled)) {
1397                 bch2_nocow_write(op);
1398                 if (op->flags & BCH_WRITE_DONE)
1399                         goto out_nofs_restore;
1400         }
1401 again:
1402         memset(&op->failed, 0, sizeof(op->failed));
1403
1404         do {
1405                 struct bkey_i *key_to_write;
1406                 unsigned key_to_write_offset = op->insert_keys.top_p -
1407                         op->insert_keys.keys_p;
1408
1409                 /* +1 for possible cache device: */
1410                 if (op->open_buckets.nr + op->nr_replicas + 1 >
1411                     ARRAY_SIZE(op->open_buckets.v))
1412                         break;
1413
1414                 if (bch2_keylist_realloc(&op->insert_keys,
1415                                         op->inline_keys,
1416                                         ARRAY_SIZE(op->inline_keys),
1417                                         BKEY_EXTENT_U64s_MAX))
1418                         break;
1419
1420                 /*
1421                  * The copygc thread is now global, which means it's no longer
1422                  * freeing up space on specific disks, which means that
1423                  * allocations for specific disks may hang arbitrarily long:
1424                  */
1425                 ret = bch2_trans_do(c, NULL, NULL, 0,
1426                         bch2_alloc_sectors_start_trans(trans,
1427                                 op->target,
1428                                 op->opts.erasure_code && !(op->flags & BCH_WRITE_CACHED),
1429                                 op->write_point,
1430                                 &op->devs_have,
1431                                 op->nr_replicas,
1432                                 op->nr_replicas_required,
1433                                 op->watermark,
1434                                 op->flags,
1435                                 (op->flags & (BCH_WRITE_ALLOC_NOWAIT|
1436                                               BCH_WRITE_ONLY_SPECIFIED_DEVS))
1437                                 ? NULL : &op->cl, &wp));
1438                 if (unlikely(ret)) {
1439                         if (bch2_err_matches(ret, BCH_ERR_operation_blocked))
1440                                 break;
1441
1442                         goto err;
1443                 }
1444
1445                 EBUG_ON(!wp);
1446
1447                 bch2_open_bucket_get(c, wp, &op->open_buckets);
1448                 ret = bch2_write_extent(op, wp, &bio);
1449
1450                 bch2_alloc_sectors_done_inlined(c, wp);
1451 err:
1452                 if (ret <= 0) {
1453                         op->flags |= BCH_WRITE_DONE;
1454
1455                         if (ret < 0) {
1456                                 op->error = ret;
1457                                 break;
1458                         }
1459                 }
1460
1461                 bio->bi_end_io  = bch2_write_endio;
1462                 bio->bi_private = &op->cl;
1463                 bio->bi_opf |= REQ_OP_WRITE;
1464
1465                 closure_get(bio->bi_private);
1466
1467                 key_to_write = (void *) (op->insert_keys.keys_p +
1468                                          key_to_write_offset);
1469
1470                 bch2_submit_wbio_replicas(to_wbio(bio), c, BCH_DATA_user,
1471                                           key_to_write, false);
1472         } while (ret);
1473
1474         /*
1475          * Sync or no?
1476          *
1477          * If we're running asynchronously, wne may still want to block
1478          * synchronously here if we weren't able to submit all of the IO at
1479          * once, as that signals backpressure to the caller.
1480          */
1481         if ((op->flags & BCH_WRITE_SYNC) ||
1482             (!(op->flags & BCH_WRITE_DONE) &&
1483              !(op->flags & BCH_WRITE_IN_WORKER))) {
1484                 closure_sync(&op->cl);
1485                 __bch2_write_index(op);
1486
1487                 if (!(op->flags & BCH_WRITE_DONE))
1488                         goto again;
1489                 bch2_write_done(&op->cl);
1490         } else {
1491                 bch2_write_queue(op, wp);
1492                 continue_at(&op->cl, bch2_write_index, NULL);
1493         }
1494 out_nofs_restore:
1495         memalloc_nofs_restore(nofs_flags);
1496 }
1497
1498 static void bch2_write_data_inline(struct bch_write_op *op, unsigned data_len)
1499 {
1500         struct bio *bio = &op->wbio.bio;
1501         struct bvec_iter iter;
1502         struct bkey_i_inline_data *id;
1503         unsigned sectors;
1504         int ret;
1505
1506         op->flags |= BCH_WRITE_WROTE_DATA_INLINE;
1507         op->flags |= BCH_WRITE_DONE;
1508
1509         bch2_check_set_feature(op->c, BCH_FEATURE_inline_data);
1510
1511         ret = bch2_keylist_realloc(&op->insert_keys, op->inline_keys,
1512                                    ARRAY_SIZE(op->inline_keys),
1513                                    BKEY_U64s + DIV_ROUND_UP(data_len, 8));
1514         if (ret) {
1515                 op->error = ret;
1516                 goto err;
1517         }
1518
1519         sectors = bio_sectors(bio);
1520         op->pos.offset += sectors;
1521
1522         id = bkey_inline_data_init(op->insert_keys.top);
1523         id->k.p         = op->pos;
1524         id->k.version   = op->version;
1525         id->k.size      = sectors;
1526
1527         iter = bio->bi_iter;
1528         iter.bi_size = data_len;
1529         memcpy_from_bio(id->v.data, bio, iter);
1530
1531         while (data_len & 7)
1532                 id->v.data[data_len++] = '\0';
1533         set_bkey_val_bytes(&id->k, data_len);
1534         bch2_keylist_push(&op->insert_keys);
1535
1536         __bch2_write_index(op);
1537 err:
1538         bch2_write_done(&op->cl);
1539 }
1540
1541 /**
1542  * bch2_write() - handle a write to a cache device or flash only volume
1543  * @cl:         &bch_write_op->cl
1544  *
1545  * This is the starting point for any data to end up in a cache device; it could
1546  * be from a normal write, or a writeback write, or a write to a flash only
1547  * volume - it's also used by the moving garbage collector to compact data in
1548  * mostly empty buckets.
1549  *
1550  * It first writes the data to the cache, creating a list of keys to be inserted
1551  * (if the data won't fit in a single open bucket, there will be multiple keys);
1552  * after the data is written it calls bch_journal, and after the keys have been
1553  * added to the next journal write they're inserted into the btree.
1554  *
1555  * If op->discard is true, instead of inserting the data it invalidates the
1556  * region of the cache represented by op->bio and op->inode.
1557  */
1558 void bch2_write(struct closure *cl)
1559 {
1560         struct bch_write_op *op = container_of(cl, struct bch_write_op, cl);
1561         struct bio *bio = &op->wbio.bio;
1562         struct bch_fs *c = op->c;
1563         unsigned data_len;
1564
1565         EBUG_ON(op->cl.parent);
1566         BUG_ON(!op->nr_replicas);
1567         BUG_ON(!op->write_point.v);
1568         BUG_ON(bkey_eq(op->pos, POS_MAX));
1569
1570         op->start_time = local_clock();
1571         bch2_keylist_init(&op->insert_keys, op->inline_keys);
1572         wbio_init(bio)->put_bio = false;
1573
1574         if (bio->bi_iter.bi_size & (c->opts.block_size - 1)) {
1575                 bch_err_inum_offset_ratelimited(c,
1576                         op->pos.inode,
1577                         op->pos.offset << 9,
1578                         "misaligned write");
1579                 op->error = -EIO;
1580                 goto err;
1581         }
1582
1583         if (c->opts.nochanges) {
1584                 op->error = -BCH_ERR_erofs_no_writes;
1585                 goto err;
1586         }
1587
1588         if (!(op->flags & BCH_WRITE_MOVE) &&
1589             !bch2_write_ref_tryget(c, BCH_WRITE_REF_write)) {
1590                 op->error = -BCH_ERR_erofs_no_writes;
1591                 goto err;
1592         }
1593
1594         this_cpu_add(c->counters[BCH_COUNTER_io_write], bio_sectors(bio));
1595         bch2_increment_clock(c, bio_sectors(bio), WRITE);
1596
1597         data_len = min_t(u64, bio->bi_iter.bi_size,
1598                          op->new_i_size - (op->pos.offset << 9));
1599
1600         if (c->opts.inline_data &&
1601             data_len <= min(block_bytes(c) / 2, 1024U)) {
1602                 bch2_write_data_inline(op, data_len);
1603                 return;
1604         }
1605
1606         __bch2_write(op);
1607         return;
1608 err:
1609         bch2_disk_reservation_put(c, &op->res);
1610
1611         closure_debug_destroy(&op->cl);
1612         if (op->end_io)
1613                 op->end_io(op);
1614 }
1615
1616 static const char * const bch2_write_flags[] = {
1617 #define x(f)    #f,
1618         BCH_WRITE_FLAGS()
1619 #undef x
1620         NULL
1621 };
1622
1623 void bch2_write_op_to_text(struct printbuf *out, struct bch_write_op *op)
1624 {
1625         prt_str(out, "pos: ");
1626         bch2_bpos_to_text(out, op->pos);
1627         prt_newline(out);
1628         printbuf_indent_add(out, 2);
1629
1630         prt_str(out, "started: ");
1631         bch2_pr_time_units(out, local_clock() - op->start_time);
1632         prt_newline(out);
1633
1634         prt_str(out, "flags: ");
1635         prt_bitflags(out, bch2_write_flags, op->flags);
1636         prt_newline(out);
1637
1638         prt_printf(out, "ref: %u", closure_nr_remaining(&op->cl));
1639         prt_newline(out);
1640
1641         printbuf_indent_sub(out, 2);
1642 }
1643
1644 void bch2_fs_io_write_exit(struct bch_fs *c)
1645 {
1646         mempool_exit(&c->bio_bounce_pages);
1647         bioset_exit(&c->bio_write);
1648 }
1649
1650 int bch2_fs_io_write_init(struct bch_fs *c)
1651 {
1652         if (bioset_init(&c->bio_write, 1, offsetof(struct bch_write_bio, bio),
1653                         BIOSET_NEED_BVECS))
1654                 return -BCH_ERR_ENOMEM_bio_write_init;
1655
1656         if (mempool_init_page_pool(&c->bio_bounce_pages,
1657                                    max_t(unsigned,
1658                                          c->opts.btree_node_size,
1659                                          c->opts.encoded_extent_max) /
1660                                    PAGE_SIZE, 0))
1661                 return -BCH_ERR_ENOMEM_bio_bounce_pages_init;
1662
1663         return 0;
1664 }