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         /*
 206          * Crazy performance optimization:
 207          * Every extent update needs to also update the inode: the inode trigger
 208          * will set bi->journal_seq to the journal sequence number of this
 209          * transaction - for fsync.
 210          *
 211          * But if that's the only reason we're updating the inode (we're not
 212          * updating bi_size or bi_sectors), then we don't need the inode update
 213          * to be journalled - if we crash, the bi_journal_seq update will be
 214          * lost, but that's fine.
 215          */
 216         unsigned inode_update_flags = BTREE_UPDATE_NOJOURNAL;
 217         int ret;
 218
 219         k = bch2_bkey_get_mut_noupdate(trans, &iter, BTREE_ID_inodes,
 220                               SPOS(0,
 221                                    extent_iter->pos.inode,
 222                                    extent_iter->snapshot),
 223                               BTREE_ITER_CACHED);
 224         ret = PTR_ERR_OR_ZERO(k);
 225         if (unlikely(ret))
 226                 return ret;
 227
 228         if (unlikely(k->k.type != KEY_TYPE_inode_v3)) {
 229                 k = bch2_inode_to_v3(trans, k);
 230                 ret = PTR_ERR_OR_ZERO(k);
 231                 if (unlikely(ret))
 232                         goto err;
 233         }
 234
 235         inode = bkey_i_to_inode_v3(k);
 236
 237         if (!(le64_to_cpu(inode->v.bi_flags) & BCH_INODE_i_size_dirty) &&
 238             new_i_size > le64_to_cpu(inode->v.bi_size)) {
 239                 inode->v.bi_size = cpu_to_le64(new_i_size);
 240                 inode_update_flags = 0;
 241         }
 242
 243         if (i_sectors_delta) {
 244                 le64_add_cpu(&inode->v.bi_sectors, i_sectors_delta);
 245                 inode_update_flags = 0;
 246         }
 247
 248         if (inode->k.p.snapshot != iter.snapshot) {
 249                 inode->k.p.snapshot = iter.snapshot;
 250                 inode_update_flags = 0;
 251         }
 252
 253         ret = bch2_trans_update(trans, &iter, &inode->k_i,
 254                                 BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE|
 255                                 inode_update_flags);
 256 err:
 257         bch2_trans_iter_exit(trans, &iter);
 258         return ret;
 259 }
 260
 261 int bch2_extent_update(struct btree_trans *trans,
 262                        subvol_inum inum,
 263                        struct btree_iter *iter,
 264                        struct bkey_i *k,
 265                        struct disk_reservation *disk_res,
 266                        u64 new_i_size,
 267                        s64 *i_sectors_delta_total,
 268                        bool check_enospc)
 269 {
 270         struct bpos next_pos;
 271         bool usage_increasing;
 272         s64 i_sectors_delta = 0, disk_sectors_delta = 0;
 273         int ret;
 274
 275         /*
 276          * This traverses us the iterator without changing iter->path->pos to
 277          * search_key() (which is pos + 1 for extents): we want there to be a
 278          * path already traversed at iter->pos because
 279          * bch2_trans_extent_update() will use it to attempt extent merging
 280          */
 281         ret = __bch2_btree_iter_traverse(iter);
 282         if (ret)
 283                 return ret;
 284
 285         ret = bch2_extent_trim_atomic(trans, iter, k);
 286         if (ret)
 287                 return ret;
 288
 289         next_pos = k->k.p;
 290
 291         ret = bch2_sum_sector_overwrites(trans, iter, k,
 292                         &usage_increasing,
 293                         &i_sectors_delta,
 294                         &disk_sectors_delta);
 295         if (ret)
 296                 return ret;
 297
 298         if (disk_res &&
 299             disk_sectors_delta > (s64) disk_res->sectors) {
 300                 ret = bch2_disk_reservation_add(trans->c, disk_res,
 301                                         disk_sectors_delta - disk_res->sectors,
 302                                         !check_enospc || !usage_increasing
 303                                         ? BCH_DISK_RESERVATION_NOFAIL : 0);
 304                 if (ret)
 305                         return ret;
 306         }
 307
 308         /*
 309          * Note:
 310          * We always have to do an inode update - even when i_size/i_sectors
 311          * aren't changing - for fsync to work properly; fsync relies on
 312          * inode->bi_journal_seq which is updated by the trigger code:
 313          */
 314         ret =   bch2_extent_update_i_size_sectors(trans, iter,
 315                                                   min(k->k.p.offset << 9, new_i_size),
 316                                                   i_sectors_delta) ?:
 317                 bch2_trans_update(trans, iter, k, 0) ?:
 318                 bch2_trans_commit(trans, disk_res, NULL,
 319                                 BCH_TRANS_COMMIT_no_check_rw|
 320                                 BCH_TRANS_COMMIT_no_enospc);
 321         if (unlikely(ret))
 322                 return ret;
 323
 324         if (i_sectors_delta_total)
 325                 *i_sectors_delta_total += i_sectors_delta;
 326         bch2_btree_iter_set_pos(iter, next_pos);
 327         return 0;
 328 }
 329
 330 static int bch2_write_index_default(struct bch_write_op *op)
 331 {
 332         struct bch_fs *c = op->c;
 333         struct bkey_buf sk;
 334         struct keylist *keys = &op->insert_keys;
 335         struct bkey_i *k = bch2_keylist_front(keys);
 336         struct btree_trans *trans = bch2_trans_get(c);
 337         struct btree_iter iter;
 338         subvol_inum inum = {
 339                 .subvol = op->subvol,
 340                 .inum   = k->k.p.inode,
 341         };
 342         int ret;
 343
 344         BUG_ON(!inum.subvol);
 345
 346         bch2_bkey_buf_init(&sk);
 347
 348         do {
 349                 bch2_trans_begin(trans);
 350
 351                 k = bch2_keylist_front(keys);
 352                 bch2_bkey_buf_copy(&sk, c, k);
 353
 354                 ret = bch2_subvolume_get_snapshot(trans, inum.subvol,
 355                                                   &sk.k->k.p.snapshot);
 356                 if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
 357                         continue;
 358                 if (ret)
 359                         break;
 360
 361                 bch2_trans_iter_init(trans, &iter, BTREE_ID_extents,
 362                                      bkey_start_pos(&sk.k->k),
 363                                      BTREE_ITER_SLOTS|BTREE_ITER_INTENT);
 364
 365                 ret =   bch2_bkey_set_needs_rebalance(c, sk.k,
 366                                         op->opts.background_target,
 367                                         op->opts.background_compression) ?:
 368                         bch2_extent_update(trans, inum, &iter, sk.k,
 369                                         &op->res,
 370                                         op->new_i_size, &op->i_sectors_delta,
 371                                         op->flags & BCH_WRITE_CHECK_ENOSPC);
 372                 bch2_trans_iter_exit(trans, &iter);
 373
 374                 if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
 375                         continue;
 376                 if (ret)
 377                         break;
 378
 379                 if (bkey_ge(iter.pos, k->k.p))
 380                         bch2_keylist_pop_front(&op->insert_keys);
 381                 else
 382                         bch2_cut_front(iter.pos, k);
 383         } while (!bch2_keylist_empty(keys));
 384
 385         bch2_trans_put(trans);
 386         bch2_bkey_buf_exit(&sk, c);
 387
 388         return ret;
 389 }
 390
 391 /* Writes */
 392
 393 void bch2_submit_wbio_replicas(struct bch_write_bio *wbio, struct bch_fs *c,
 394                                enum bch_data_type type,
 395                                const struct bkey_i *k,
 396                                bool nocow)
 397 {
 398         struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(bkey_i_to_s_c(k));
 399         struct bch_write_bio *n;
 400
 401         BUG_ON(c->opts.nochanges);
 402
 403         bkey_for_each_ptr(ptrs, ptr) {
 404                 BUG_ON(!bch2_dev_exists2(c, ptr->dev));
 405
 406                 struct bch_dev *ca = bch_dev_bkey_exists(c, ptr->dev);
 407
 408                 if (to_entry(ptr + 1) < ptrs.end) {
 409                         n = to_wbio(bio_alloc_clone(NULL, &wbio->bio,
 410                                                 GFP_NOFS, &ca->replica_set));
 411
 412                         n->bio.bi_end_io        = wbio->bio.bi_end_io;
 413                         n->bio.bi_private       = wbio->bio.bi_private;
 414                         n->parent               = wbio;
 415                         n->split                = true;
 416                         n->bounce               = false;
 417                         n->put_bio              = true;
 418                         n->bio.bi_opf           = wbio->bio.bi_opf;
 419                         bio_inc_remaining(&wbio->bio);
 420                 } else {
 421                         n = wbio;
 422                         n->split                = false;
 423                 }
 424
 425                 n->c                    = c;
 426                 n->dev                  = ptr->dev;
 427                 n->have_ioref           = nocow || bch2_dev_get_ioref(ca,
 428                                         type == BCH_DATA_btree ? READ : WRITE);
 429                 n->nocow                = nocow;
 430                 n->submit_time          = local_clock();
 431                 n->inode_offset         = bkey_start_offset(&k->k);
 432                 n->bio.bi_iter.bi_sector = ptr->offset;
 433
 434                 if (likely(n->have_ioref)) {
 435                         this_cpu_add(ca->io_done->sectors[WRITE][type],
 436                                      bio_sectors(&n->bio));
 437
 438                         bio_set_dev(&n->bio, ca->disk_sb.bdev);
 439
 440                         if (type != BCH_DATA_btree && unlikely(c->opts.no_data_io)) {
 441                                 bio_endio(&n->bio);
 442                                 continue;
 443                         }
 444
 445                         submit_bio(&n->bio);
 446                 } else {
 447                         n->bio.bi_status        = BLK_STS_REMOVED;
 448                         bio_endio(&n->bio);
 449                 }
 450         }
 451 }
 452
 453 static void __bch2_write(struct bch_write_op *);
 454
 455 static void bch2_write_done(struct closure *cl)
 456 {
 457         struct bch_write_op *op = container_of(cl, struct bch_write_op, cl);
 458         struct bch_fs *c = op->c;
 459
 460         EBUG_ON(op->open_buckets.nr);
 461
 462         bch2_time_stats_update(&c->times[BCH_TIME_data_write], op->start_time);
 463         bch2_disk_reservation_put(c, &op->res);
 464
 465         if (!(op->flags & BCH_WRITE_MOVE))
 466                 bch2_write_ref_put(c, BCH_WRITE_REF_write);
 467         bch2_keylist_free(&op->insert_keys, op->inline_keys);
 468
 469         EBUG_ON(cl->parent);
 470         closure_debug_destroy(cl);
 471         if (op->end_io)
 472                 op->end_io(op);
 473 }
 474
 475 static noinline int bch2_write_drop_io_error_ptrs(struct bch_write_op *op)
 476 {
 477         struct keylist *keys = &op->insert_keys;
 478         struct bch_extent_ptr *ptr;
 479         struct bkey_i *src, *dst = keys->keys, *n;
 480
 481         for (src = keys->keys; src != keys->top; src = n) {
 482                 n = bkey_next(src);
 483
 484                 if (bkey_extent_is_direct_data(&src->k)) {
 485                         bch2_bkey_drop_ptrs(bkey_i_to_s(src), ptr,
 486                                             test_bit(ptr->dev, op->failed.d));
 487
 488                         if (!bch2_bkey_nr_ptrs(bkey_i_to_s_c(src)))
 489                                 return -EIO;
 490                 }
 491
 492                 if (dst != src)
 493                         memmove_u64s_down(dst, src, src->k.u64s);
 494                 dst = bkey_next(dst);
 495         }
 496
 497         keys->top = dst;
 498         return 0;
 499 }
 500
 501 /**
 502  * __bch2_write_index - after a write, update index to point to new data
 503  * @op:         bch_write_op to process
 504  */
 505 static void __bch2_write_index(struct bch_write_op *op)
 506 {
 507         struct bch_fs *c = op->c;
 508         struct keylist *keys = &op->insert_keys;
 509         unsigned dev;
 510         int ret = 0;
 511
 512         if (unlikely(op->flags & BCH_WRITE_IO_ERROR)) {
 513                 ret = bch2_write_drop_io_error_ptrs(op);
 514                 if (ret)
 515                         goto err;
 516         }
 517
 518         if (!bch2_keylist_empty(keys)) {
 519                 u64 sectors_start = keylist_sectors(keys);
 520
 521                 ret = !(op->flags & BCH_WRITE_MOVE)
 522                         ? bch2_write_index_default(op)
 523                         : bch2_data_update_index_update(op);
 524
 525                 BUG_ON(bch2_err_matches(ret, BCH_ERR_transaction_restart));
 526                 BUG_ON(keylist_sectors(keys) && !ret);
 527
 528                 op->written += sectors_start - keylist_sectors(keys);
 529
 530                 if (ret && !bch2_err_matches(ret, EROFS)) {
 531                         struct bkey_i *insert = bch2_keylist_front(&op->insert_keys);
 532
 533                         bch_err_inum_offset_ratelimited(c,
 534                                 insert->k.p.inode, insert->k.p.offset << 9,
 535                                 "write error while doing btree update: %s",
 536                                 bch2_err_str(ret));
 537                 }
 538
 539                 if (ret)
 540                         goto err;
 541         }
 542 out:
 543         /* If some a bucket wasn't written, we can't erasure code it: */
 544         for_each_set_bit(dev, op->failed.d, BCH_SB_MEMBERS_MAX)
 545                 bch2_open_bucket_write_error(c, &op->open_buckets, dev);
 546
 547         bch2_open_buckets_put(c, &op->open_buckets);
 548         return;
 549 err:
 550         keys->top = keys->keys;
 551         op->error = ret;
 552         op->flags |= BCH_WRITE_DONE;
 553         goto out;
 554 }
 555
 556 static inline void __wp_update_state(struct write_point *wp, enum write_point_state state)
 557 {
 558         if (state != wp->state) {
 559                 u64 now = ktime_get_ns();
 560
 561                 if (wp->last_state_change &&
 562                     time_after64(now, wp->last_state_change))
 563                         wp->time[wp->state] += now - wp->last_state_change;
 564                 wp->state = state;
 565                 wp->last_state_change = now;
 566         }
 567 }
 568
 569 static inline void wp_update_state(struct write_point *wp, bool running)
 570 {
 571         enum write_point_state state;
 572
 573         state = running                  ? WRITE_POINT_running :
 574                 !list_empty(&wp->writes) ? WRITE_POINT_waiting_io
 575                                          : WRITE_POINT_stopped;
 576
 577         __wp_update_state(wp, state);
 578 }
 579
 580 static CLOSURE_CALLBACK(bch2_write_index)
 581 {
 582         closure_type(op, struct bch_write_op, cl);
 583         struct write_point *wp = op->wp;
 584         struct workqueue_struct *wq = index_update_wq(op);
 585         unsigned long flags;
 586
 587         if ((op->flags & BCH_WRITE_DONE) &&
 588             (op->flags & BCH_WRITE_MOVE))
 589                 bch2_bio_free_pages_pool(op->c, &op->wbio.bio);
 590
 591         spin_lock_irqsave(&wp->writes_lock, flags);
 592         if (wp->state == WRITE_POINT_waiting_io)
 593                 __wp_update_state(wp, WRITE_POINT_waiting_work);
 594         list_add_tail(&op->wp_list, &wp->writes);
 595         spin_unlock_irqrestore (&wp->writes_lock, flags);
 596
 597         queue_work(wq, &wp->index_update_work);
 598 }
 599
 600 static inline void bch2_write_queue(struct bch_write_op *op, struct write_point *wp)
 601 {
 602         op->wp = wp;
 603
 604         if (wp->state == WRITE_POINT_stopped) {
 605                 spin_lock_irq(&wp->writes_lock);
 606                 __wp_update_state(wp, WRITE_POINT_waiting_io);
 607                 spin_unlock_irq(&wp->writes_lock);
 608         }
 609 }
 610
 611 void bch2_write_point_do_index_updates(struct work_struct *work)
 612 {
 613         struct write_point *wp =
 614                 container_of(work, struct write_point, index_update_work);
 615         struct bch_write_op *op;
 616
 617         while (1) {
 618                 spin_lock_irq(&wp->writes_lock);
 619                 op = list_first_entry_or_null(&wp->writes, struct bch_write_op, wp_list);
 620                 if (op)
 621                         list_del(&op->wp_list);
 622                 wp_update_state(wp, op != NULL);
 623                 spin_unlock_irq(&wp->writes_lock);
 624
 625                 if (!op)
 626                         break;
 627
 628                 op->flags |= BCH_WRITE_IN_WORKER;
 629
 630                 __bch2_write_index(op);
 631
 632                 if (!(op->flags & BCH_WRITE_DONE))
 633                         __bch2_write(op);
 634                 else
 635                         bch2_write_done(&op->cl);
 636         }
 637 }
 638
 639 static void bch2_write_endio(struct bio *bio)
 640 {
 641         struct closure *cl              = bio->bi_private;
 642         struct bch_write_op *op         = container_of(cl, struct bch_write_op, cl);
 643         struct bch_write_bio *wbio      = to_wbio(bio);
 644         struct bch_write_bio *parent    = wbio->split ? wbio->parent : NULL;
 645         struct bch_fs *c                = wbio->c;
 646         struct bch_dev *ca              = bch_dev_bkey_exists(c, wbio->dev);
 647
 648         if (bch2_dev_inum_io_err_on(bio->bi_status, ca, BCH_MEMBER_ERROR_write,
 649                                     op->pos.inode,
 650                                     wbio->inode_offset << 9,
 651                                     "data write error: %s",
 652                                     bch2_blk_status_to_str(bio->bi_status))) {
 653                 set_bit(wbio->dev, op->failed.d);
 654                 op->flags |= BCH_WRITE_IO_ERROR;
 655         }
 656
 657         if (wbio->nocow)
 658                 set_bit(wbio->dev, op->devs_need_flush->d);
 659
 660         if (wbio->have_ioref) {
 661                 bch2_latency_acct(ca, wbio->submit_time, WRITE);
 662                 percpu_ref_put(&ca->io_ref);
 663         }
 664
 665         if (wbio->bounce)
 666                 bch2_bio_free_pages_pool(c, bio);
 667
 668         if (wbio->put_bio)
 669                 bio_put(bio);
 670
 671         if (parent)
 672                 bio_endio(&parent->bio);
 673         else
 674                 closure_put(cl);
 675 }
 676
 677 static void init_append_extent(struct bch_write_op *op,
 678                                struct write_point *wp,
 679                                struct bversion version,
 680                                struct bch_extent_crc_unpacked crc)
 681 {
 682         struct bkey_i_extent *e;
 683
 684         op->pos.offset += crc.uncompressed_size;
 685
 686         e = bkey_extent_init(op->insert_keys.top);
 687         e->k.p          = op->pos;
 688         e->k.size       = crc.uncompressed_size;
 689         e->k.version    = version;
 690
 691         if (crc.csum_type ||
 692             crc.compression_type ||
 693             crc.nonce)
 694                 bch2_extent_crc_append(&e->k_i, crc);
 695
 696         bch2_alloc_sectors_append_ptrs_inlined(op->c, wp, &e->k_i, crc.compressed_size,
 697                                        op->flags & BCH_WRITE_CACHED);
 698
 699         bch2_keylist_push(&op->insert_keys);
 700 }
 701
 702 static struct bio *bch2_write_bio_alloc(struct bch_fs *c,
 703                                         struct write_point *wp,
 704                                         struct bio *src,
 705                                         bool *page_alloc_failed,
 706                                         void *buf)
 707 {
 708         struct bch_write_bio *wbio;
 709         struct bio *bio;
 710         unsigned output_available =
 711                 min(wp->sectors_free << 9, src->bi_iter.bi_size);
 712         unsigned pages = DIV_ROUND_UP(output_available +
 713                                       (buf
 714                                        ? ((unsigned long) buf & (PAGE_SIZE - 1))
 715                                        : 0), PAGE_SIZE);
 716
 717         pages = min(pages, BIO_MAX_VECS);
 718
 719         bio = bio_alloc_bioset(NULL, pages, 0,
 720                                GFP_NOFS, &c->bio_write);
 721         wbio                    = wbio_init(bio);
 722         wbio->put_bio           = true;
 723         /* copy WRITE_SYNC flag */
 724         wbio->bio.bi_opf        = src->bi_opf;
 725
 726         if (buf) {
 727                 bch2_bio_map(bio, buf, output_available);
 728                 return bio;
 729         }
 730
 731         wbio->bounce            = true;
 732
 733         /*
 734          * We can't use mempool for more than c->sb.encoded_extent_max
 735          * worth of pages, but we'd like to allocate more if we can:
 736          */
 737         bch2_bio_alloc_pages_pool(c, bio,
 738                                   min_t(unsigned, output_available,
 739                                         c->opts.encoded_extent_max));
 740
 741         if (bio->bi_iter.bi_size < output_available)
 742                 *page_alloc_failed =
 743                         bch2_bio_alloc_pages(bio,
 744                                              output_available -
 745                                              bio->bi_iter.bi_size,
 746                                              GFP_NOFS) != 0;
 747
 748         return bio;
 749 }
 750
 751 static int bch2_write_rechecksum(struct bch_fs *c,
 752                                  struct bch_write_op *op,
 753                                  unsigned new_csum_type)
 754 {
 755         struct bio *bio = &op->wbio.bio;
 756         struct bch_extent_crc_unpacked new_crc;
 757         int ret;
 758
 759         /* bch2_rechecksum_bio() can't encrypt or decrypt data: */
 760
 761         if (bch2_csum_type_is_encryption(op->crc.csum_type) !=
 762             bch2_csum_type_is_encryption(new_csum_type))
 763                 new_csum_type = op->crc.csum_type;
 764
 765         ret = bch2_rechecksum_bio(c, bio, op->version, op->crc,
 766                                   NULL, &new_crc,
 767                                   op->crc.offset, op->crc.live_size,
 768                                   new_csum_type);
 769         if (ret)
 770                 return ret;
 771
 772         bio_advance(bio, op->crc.offset << 9);
 773         bio->bi_iter.bi_size = op->crc.live_size << 9;
 774         op->crc = new_crc;
 775         return 0;
 776 }
 777
 778 static int bch2_write_decrypt(struct bch_write_op *op)
 779 {
 780         struct bch_fs *c = op->c;
 781         struct nonce nonce = extent_nonce(op->version, op->crc);
 782         struct bch_csum csum;
 783         int ret;
 784
 785         if (!bch2_csum_type_is_encryption(op->crc.csum_type))
 786                 return 0;
 787
 788         /*
 789          * If we need to decrypt data in the write path, we'll no longer be able
 790          * to verify the existing checksum (poly1305 mac, in this case) after
 791          * it's decrypted - this is the last point we'll be able to reverify the
 792          * checksum:
 793          */
 794         csum = bch2_checksum_bio(c, op->crc.csum_type, nonce, &op->wbio.bio);
 795         if (bch2_crc_cmp(op->crc.csum, csum) && !c->opts.no_data_io)
 796                 return -EIO;
 797
 798         ret = bch2_encrypt_bio(c, op->crc.csum_type, nonce, &op->wbio.bio);
 799         op->crc.csum_type = 0;
 800         op->crc.csum = (struct bch_csum) { 0, 0 };
 801         return ret;
 802 }
 803
 804 static enum prep_encoded_ret {
 805         PREP_ENCODED_OK,
 806         PREP_ENCODED_ERR,
 807         PREP_ENCODED_CHECKSUM_ERR,
 808         PREP_ENCODED_DO_WRITE,
 809 } bch2_write_prep_encoded_data(struct bch_write_op *op, struct write_point *wp)
 810 {
 811         struct bch_fs *c = op->c;
 812         struct bio *bio = &op->wbio.bio;
 813
 814         if (!(op->flags & BCH_WRITE_DATA_ENCODED))
 815                 return PREP_ENCODED_OK;
 816
 817         BUG_ON(bio_sectors(bio) != op->crc.compressed_size);
 818
 819         /* Can we just write the entire extent as is? */
 820         if (op->crc.uncompressed_size == op->crc.live_size &&
 821             op->crc.uncompressed_size <= c->opts.encoded_extent_max >> 9 &&
 822             op->crc.compressed_size <= wp->sectors_free &&
 823             (op->crc.compression_type == bch2_compression_opt_to_type(op->compression_opt) ||
 824              op->incompressible)) {
 825                 if (!crc_is_compressed(op->crc) &&
 826                     op->csum_type != op->crc.csum_type &&
 827                     bch2_write_rechecksum(c, op, op->csum_type) &&
 828                     !c->opts.no_data_io)
 829                         return PREP_ENCODED_CHECKSUM_ERR;
 830
 831                 return PREP_ENCODED_DO_WRITE;
 832         }
 833
 834         /*
 835          * If the data is compressed and we couldn't write the entire extent as
 836          * is, we have to decompress it:
 837          */
 838         if (crc_is_compressed(op->crc)) {
 839                 struct bch_csum csum;
 840
 841                 if (bch2_write_decrypt(op))
 842                         return PREP_ENCODED_CHECKSUM_ERR;
 843
 844                 /* Last point we can still verify checksum: */
 845                 csum = bch2_checksum_bio(c, op->crc.csum_type,
 846                                          extent_nonce(op->version, op->crc),
 847                                          bio);
 848                 if (bch2_crc_cmp(op->crc.csum, csum) && !c->opts.no_data_io)
 849                         return PREP_ENCODED_CHECKSUM_ERR;
 850
 851                 if (bch2_bio_uncompress_inplace(c, bio, &op->crc))
 852                         return PREP_ENCODED_ERR;
 853         }
 854
 855         /*
 856          * No longer have compressed data after this point - data might be
 857          * encrypted:
 858          */
 859
 860         /*
 861          * If the data is checksummed and we're only writing a subset,
 862          * rechecksum and adjust bio to point to currently live data:
 863          */
 864         if ((op->crc.live_size != op->crc.uncompressed_size ||
 865              op->crc.csum_type != op->csum_type) &&
 866             bch2_write_rechecksum(c, op, op->csum_type) &&
 867             !c->opts.no_data_io)
 868                 return PREP_ENCODED_CHECKSUM_ERR;
 869
 870         /*
 871          * If we want to compress the data, it has to be decrypted:
 872          */
 873         if ((op->compression_opt ||
 874              bch2_csum_type_is_encryption(op->crc.csum_type) !=
 875              bch2_csum_type_is_encryption(op->csum_type)) &&
 876             bch2_write_decrypt(op))
 877                 return PREP_ENCODED_CHECKSUM_ERR;
 878
 879         return PREP_ENCODED_OK;
 880 }
 881
 882 static int bch2_write_extent(struct bch_write_op *op, struct write_point *wp,
 883                              struct bio **_dst)
 884 {
 885         struct bch_fs *c = op->c;
 886         struct bio *src = &op->wbio.bio, *dst = src;
 887         struct bvec_iter saved_iter;
 888         void *ec_buf;
 889         unsigned total_output = 0, total_input = 0;
 890         bool bounce = false;
 891         bool page_alloc_failed = false;
 892         int ret, more = 0;
 893
 894         BUG_ON(!bio_sectors(src));
 895
 896         ec_buf = bch2_writepoint_ec_buf(c, wp);
 897
 898         switch (bch2_write_prep_encoded_data(op, wp)) {
 899         case PREP_ENCODED_OK:
 900                 break;
 901         case PREP_ENCODED_ERR:
 902                 ret = -EIO;
 903                 goto err;
 904         case PREP_ENCODED_CHECKSUM_ERR:
 905                 goto csum_err;
 906         case PREP_ENCODED_DO_WRITE:
 907                 /* XXX look for bug here */
 908                 if (ec_buf) {
 909                         dst = bch2_write_bio_alloc(c, wp, src,
 910                                                    &page_alloc_failed,
 911                                                    ec_buf);
 912                         bio_copy_data(dst, src);
 913                         bounce = true;
 914                 }
 915                 init_append_extent(op, wp, op->version, op->crc);
 916                 goto do_write;
 917         }
 918
 919         if (ec_buf ||
 920             op->compression_opt ||
 921             (op->csum_type &&
 922              !(op->flags & BCH_WRITE_PAGES_STABLE)) ||
 923             (bch2_csum_type_is_encryption(op->csum_type) &&
 924              !(op->flags & BCH_WRITE_PAGES_OWNED))) {
 925                 dst = bch2_write_bio_alloc(c, wp, src,
 926                                            &page_alloc_failed,
 927                                            ec_buf);
 928                 bounce = true;
 929         }
 930
 931         saved_iter = dst->bi_iter;
 932
 933         do {
 934                 struct bch_extent_crc_unpacked crc = { 0 };
 935                 struct bversion version = op->version;
 936                 size_t dst_len = 0, src_len = 0;
 937
 938                 if (page_alloc_failed &&
 939                     dst->bi_iter.bi_size  < (wp->sectors_free << 9) &&
 940                     dst->bi_iter.bi_size < c->opts.encoded_extent_max)
 941                         break;
 942
 943                 BUG_ON(op->compression_opt &&
 944                        (op->flags & BCH_WRITE_DATA_ENCODED) &&
 945                        bch2_csum_type_is_encryption(op->crc.csum_type));
 946                 BUG_ON(op->compression_opt && !bounce);
 947
 948                 crc.compression_type = op->incompressible
 949                         ? BCH_COMPRESSION_TYPE_incompressible
 950                         : op->compression_opt
 951                         ? bch2_bio_compress(c, dst, &dst_len, src, &src_len,
 952                                             op->compression_opt)
 953                         : 0;
 954                 if (!crc_is_compressed(crc)) {
 955                         dst_len = min(dst->bi_iter.bi_size, src->bi_iter.bi_size);
 956                         dst_len = min_t(unsigned, dst_len, wp->sectors_free << 9);
 957
 958                         if (op->csum_type)
 959                                 dst_len = min_t(unsigned, dst_len,
 960                                                 c->opts.encoded_extent_max);
 961
 962                         if (bounce) {
 963                                 swap(dst->bi_iter.bi_size, dst_len);
 964                                 bio_copy_data(dst, src);
 965                                 swap(dst->bi_iter.bi_size, dst_len);
 966                         }
 967
 968                         src_len = dst_len;
 969                 }
 970
 971                 BUG_ON(!src_len || !dst_len);
 972
 973                 if (bch2_csum_type_is_encryption(op->csum_type)) {
 974                         if (bversion_zero(version)) {
 975                                 version.lo = atomic64_inc_return(&c->key_version);
 976                         } else {
 977                                 crc.nonce = op->nonce;
 978                                 op->nonce += src_len >> 9;
 979                         }
 980                 }
 981
 982                 if ((op->flags & BCH_WRITE_DATA_ENCODED) &&
 983                     !crc_is_compressed(crc) &&
 984                     bch2_csum_type_is_encryption(op->crc.csum_type) ==
 985                     bch2_csum_type_is_encryption(op->csum_type)) {
 986                         u8 compression_type = crc.compression_type;
 987                         u16 nonce = crc.nonce;
 988                         /*
 989                          * Note: when we're using rechecksum(), we need to be
 990                          * checksumming @src because it has all the data our
 991                          * existing checksum covers - if we bounced (because we
 992                          * were trying to compress), @dst will only have the
 993                          * part of the data the new checksum will cover.
 994                          *
 995                          * But normally we want to be checksumming post bounce,
 996                          * because part of the reason for bouncing is so the
 997                          * data can't be modified (by userspace) while it's in
 998                          * flight.
 999                          */
1000                         if (bch2_rechecksum_bio(c, src, version, op->crc,
1001                                         &crc, &op->crc,
1002                                         src_len >> 9,
1003                                         bio_sectors(src) - (src_len >> 9),
1004                                         op->csum_type))
1005                                 goto csum_err;
1006                         /*
1007                          * rchecksum_bio sets compression_type on crc from op->crc,
1008                          * this isn't always correct as sometimes we're changing
1009                          * an extent from uncompressed to incompressible.
1010                          */
1011                         crc.compression_type = compression_type;
1012                         crc.nonce = nonce;
1013                 } else {
1014                         if ((op->flags & BCH_WRITE_DATA_ENCODED) &&
1015                             bch2_rechecksum_bio(c, src, version, op->crc,
1016                                         NULL, &op->crc,
1017                                         src_len >> 9,
1018                                         bio_sectors(src) - (src_len >> 9),
1019                                         op->crc.csum_type))
1020                                 goto csum_err;
1021
1022                         crc.compressed_size     = dst_len >> 9;
1023                         crc.uncompressed_size   = src_len >> 9;
1024                         crc.live_size           = src_len >> 9;
1025
1026                         swap(dst->bi_iter.bi_size, dst_len);
1027                         ret = bch2_encrypt_bio(c, op->csum_type,
1028                                                extent_nonce(version, crc), dst);
1029                         if (ret)
1030                                 goto err;
1031
1032                         crc.csum = bch2_checksum_bio(c, op->csum_type,
1033                                          extent_nonce(version, crc), dst);
1034                         crc.csum_type = op->csum_type;
1035                         swap(dst->bi_iter.bi_size, dst_len);
1036                 }
1037
1038                 init_append_extent(op, wp, version, crc);
1039
1040                 if (dst != src)
1041                         bio_advance(dst, dst_len);
1042                 bio_advance(src, src_len);
1043                 total_output    += dst_len;
1044                 total_input     += src_len;
1045         } while (dst->bi_iter.bi_size &&
1046                  src->bi_iter.bi_size &&
1047                  wp->sectors_free &&
1048                  !bch2_keylist_realloc(&op->insert_keys,
1049                                       op->inline_keys,
1050                                       ARRAY_SIZE(op->inline_keys),
1051                                       BKEY_EXTENT_U64s_MAX));
1052
1053         more = src->bi_iter.bi_size != 0;
1054
1055         dst->bi_iter = saved_iter;
1056
1057         if (dst == src && more) {
1058                 BUG_ON(total_output != total_input);
1059
1060                 dst = bio_split(src, total_input >> 9,
1061                                 GFP_NOFS, &c->bio_write);
1062                 wbio_init(dst)->put_bio = true;
1063                 /* copy WRITE_SYNC flag */
1064                 dst->bi_opf             = src->bi_opf;
1065         }
1066
1067         dst->bi_iter.bi_size = total_output;
1068 do_write:
1069         *_dst = dst;
1070         return more;
1071 csum_err:
1072         bch_err(c, "error verifying existing checksum while rewriting existing data (memory corruption?)");
1073         ret = -EIO;
1074 err:
1075         if (to_wbio(dst)->bounce)
1076                 bch2_bio_free_pages_pool(c, dst);
1077         if (to_wbio(dst)->put_bio)
1078                 bio_put(dst);
1079
1080         return ret;
1081 }
1082
1083 static bool bch2_extent_is_writeable(struct bch_write_op *op,
1084                                      struct bkey_s_c k)
1085 {
1086         struct bch_fs *c = op->c;
1087         struct bkey_s_c_extent e;
1088         struct extent_ptr_decoded p;
1089         const union bch_extent_entry *entry;
1090         unsigned replicas = 0;
1091
1092         if (k.k->type != KEY_TYPE_extent)
1093                 return false;
1094
1095         e = bkey_s_c_to_extent(k);
1096         extent_for_each_ptr_decode(e, p, entry) {
1097                 if (crc_is_encoded(p.crc) || p.has_ec)
1098                         return false;
1099
1100                 replicas += bch2_extent_ptr_durability(c, &p);
1101         }
1102
1103         return replicas >= op->opts.data_replicas;
1104 }
1105
1106 static inline void bch2_nocow_write_unlock(struct bch_write_op *op)
1107 {
1108         struct bch_fs *c = op->c;
1109
1110         for_each_keylist_key(&op->insert_keys, k) {
1111                 struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(bkey_i_to_s_c(k));
1112
1113                 bkey_for_each_ptr(ptrs, ptr)
1114                         bch2_bucket_nocow_unlock(&c->nocow_locks,
1115                                                  PTR_BUCKET_POS(c, ptr),
1116                                                  BUCKET_NOCOW_LOCK_UPDATE);
1117         }
1118 }
1119
1120 static int bch2_nocow_write_convert_one_unwritten(struct btree_trans *trans,
1121                                                   struct btree_iter *iter,
1122                                                   struct bkey_i *orig,
1123                                                   struct bkey_s_c k,
1124                                                   u64 new_i_size)
1125 {
1126         if (!bch2_extents_match(bkey_i_to_s_c(orig), k)) {
1127                 /* trace this */
1128                 return 0;
1129         }
1130
1131         struct bkey_i *new = bch2_bkey_make_mut_noupdate(trans, k);
1132         int ret = PTR_ERR_OR_ZERO(new);
1133         if (ret)
1134                 return ret;
1135
1136         bch2_cut_front(bkey_start_pos(&orig->k), new);
1137         bch2_cut_back(orig->k.p, new);
1138
1139         struct bkey_ptrs ptrs = bch2_bkey_ptrs(bkey_i_to_s(new));
1140         bkey_for_each_ptr(ptrs, ptr)
1141                 ptr->unwritten = 0;
1142
1143         /*
1144          * Note that we're not calling bch2_subvol_get_snapshot() in this path -
1145          * that was done when we kicked off the write, and here it's important
1146          * that we update the extent that we wrote to - even if a snapshot has
1147          * since been created. The write is still outstanding, so we're ok
1148          * w.r.t. snapshot atomicity:
1149          */
1150         return  bch2_extent_update_i_size_sectors(trans, iter,
1151                                         min(new->k.p.offset << 9, new_i_size), 0) ?:
1152                 bch2_trans_update(trans, iter, new,
1153                                   BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE);
1154 }
1155
1156 static void bch2_nocow_write_convert_unwritten(struct bch_write_op *op)
1157 {
1158         struct bch_fs *c = op->c;
1159         struct btree_trans *trans = bch2_trans_get(c);
1160
1161         for_each_keylist_key(&op->insert_keys, orig) {
1162                 int ret = for_each_btree_key_upto_commit(trans, iter, BTREE_ID_extents,
1163                                      bkey_start_pos(&orig->k), orig->k.p,
1164                                      BTREE_ITER_INTENT, k,
1165                                      NULL, NULL, BCH_TRANS_COMMIT_no_enospc, ({
1166                         bch2_nocow_write_convert_one_unwritten(trans, &iter, orig, k, op->new_i_size);
1167                 }));
1168
1169                 if (ret && !bch2_err_matches(ret, EROFS)) {
1170                         struct bkey_i *insert = bch2_keylist_front(&op->insert_keys);
1171
1172                         bch_err_inum_offset_ratelimited(c,
1173                                 insert->k.p.inode, insert->k.p.offset << 9,
1174                                 "write error while doing btree update: %s",
1175                                 bch2_err_str(ret));
1176                 }
1177
1178                 if (ret) {
1179                         op->error = ret;
1180                         break;
1181                 }
1182         }
1183
1184         bch2_trans_put(trans);
1185 }
1186
1187 static void __bch2_nocow_write_done(struct bch_write_op *op)
1188 {
1189         bch2_nocow_write_unlock(op);
1190
1191         if (unlikely(op->flags & BCH_WRITE_IO_ERROR)) {
1192                 op->error = -EIO;
1193         } else if (unlikely(op->flags & BCH_WRITE_CONVERT_UNWRITTEN))
1194                 bch2_nocow_write_convert_unwritten(op);
1195 }
1196
1197 static CLOSURE_CALLBACK(bch2_nocow_write_done)
1198 {
1199         closure_type(op, struct bch_write_op, cl);
1200
1201         __bch2_nocow_write_done(op);
1202         bch2_write_done(cl);
1203 }
1204
1205 struct bucket_to_lock {
1206         struct bpos             b;
1207         unsigned                gen;
1208         struct nocow_lock_bucket *l;
1209 };
1210
1211 static void bch2_nocow_write(struct bch_write_op *op)
1212 {
1213         struct bch_fs *c = op->c;
1214         struct btree_trans *trans;
1215         struct btree_iter iter;
1216         struct bkey_s_c k;
1217         DARRAY_PREALLOCATED(struct bucket_to_lock, 3) buckets;
1218         u32 snapshot;
1219         struct bucket_to_lock *stale_at;
1220         int ret;
1221
1222         if (op->flags & BCH_WRITE_MOVE)
1223                 return;
1224
1225         darray_init(&buckets);
1226         trans = bch2_trans_get(c);
1227 retry:
1228         bch2_trans_begin(trans);
1229
1230         ret = bch2_subvolume_get_snapshot(trans, op->subvol, &snapshot);
1231         if (unlikely(ret))
1232                 goto err;
1233
1234         bch2_trans_iter_init(trans, &iter, BTREE_ID_extents,
1235                              SPOS(op->pos.inode, op->pos.offset, snapshot),
1236                              BTREE_ITER_SLOTS);
1237         while (1) {
1238                 struct bio *bio = &op->wbio.bio;
1239
1240                 buckets.nr = 0;
1241
1242                 k = bch2_btree_iter_peek_slot(&iter);
1243                 ret = bkey_err(k);
1244                 if (ret)
1245                         break;
1246
1247                 /* fall back to normal cow write path? */
1248                 if (unlikely(k.k->p.snapshot != snapshot ||
1249                              !bch2_extent_is_writeable(op, k)))
1250                         break;
1251
1252                 if (bch2_keylist_realloc(&op->insert_keys,
1253                                          op->inline_keys,
1254                                          ARRAY_SIZE(op->inline_keys),
1255                                          k.k->u64s))
1256                         break;
1257
1258                 /* Get iorefs before dropping btree locks: */
1259                 struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(k);
1260                 bkey_for_each_ptr(ptrs, ptr) {
1261                         struct bpos b = PTR_BUCKET_POS(c, ptr);
1262                         struct nocow_lock_bucket *l =
1263                                 bucket_nocow_lock(&c->nocow_locks, bucket_to_u64(b));
1264                         prefetch(l);
1265
1266                         if (unlikely(!bch2_dev_get_ioref(bch_dev_bkey_exists(c, ptr->dev), WRITE)))
1267                                 goto err_get_ioref;
1268
1269                         /* XXX allocating memory with btree locks held - rare */
1270                         darray_push_gfp(&buckets, ((struct bucket_to_lock) {
1271                                                    .b = b, .gen = ptr->gen, .l = l,
1272                                                    }), GFP_KERNEL|__GFP_NOFAIL);
1273
1274                         if (ptr->unwritten)
1275                                 op->flags |= BCH_WRITE_CONVERT_UNWRITTEN;
1276                 }
1277
1278                 /* Unlock before taking nocow locks, doing IO: */
1279                 bkey_reassemble(op->insert_keys.top, k);
1280                 bch2_trans_unlock(trans);
1281
1282                 bch2_cut_front(op->pos, op->insert_keys.top);
1283                 if (op->flags & BCH_WRITE_CONVERT_UNWRITTEN)
1284                         bch2_cut_back(POS(op->pos.inode, op->pos.offset + bio_sectors(bio)), op->insert_keys.top);
1285
1286                 darray_for_each(buckets, i) {
1287                         struct bch_dev *ca = bch_dev_bkey_exists(c, i->b.inode);
1288
1289                         __bch2_bucket_nocow_lock(&c->nocow_locks, i->l,
1290                                                  bucket_to_u64(i->b),
1291                                                  BUCKET_NOCOW_LOCK_UPDATE);
1292
1293                         rcu_read_lock();
1294                         bool stale = gen_after(*bucket_gen(ca, i->b.offset), i->gen);
1295                         rcu_read_unlock();
1296
1297                         if (unlikely(stale)) {
1298                                 stale_at = i;
1299                                 goto err_bucket_stale;
1300                         }
1301                 }
1302
1303                 bio = &op->wbio.bio;
1304                 if (k.k->p.offset < op->pos.offset + bio_sectors(bio)) {
1305                         bio = bio_split(bio, k.k->p.offset - op->pos.offset,
1306                                         GFP_KERNEL, &c->bio_write);
1307                         wbio_init(bio)->put_bio = true;
1308                         bio->bi_opf = op->wbio.bio.bi_opf;
1309                 } else {
1310                         op->flags |= BCH_WRITE_DONE;
1311                 }
1312
1313                 op->pos.offset += bio_sectors(bio);
1314                 op->written += bio_sectors(bio);
1315
1316                 bio->bi_end_io  = bch2_write_endio;
1317                 bio->bi_private = &op->cl;
1318                 bio->bi_opf |= REQ_OP_WRITE;
1319                 closure_get(&op->cl);
1320                 bch2_submit_wbio_replicas(to_wbio(bio), c, BCH_DATA_user,
1321                                           op->insert_keys.top, true);
1322
1323                 bch2_keylist_push(&op->insert_keys);
1324                 if (op->flags & BCH_WRITE_DONE)
1325                         break;
1326                 bch2_btree_iter_advance(&iter);
1327         }
1328 out:
1329         bch2_trans_iter_exit(trans, &iter);
1330 err:
1331         if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
1332                 goto retry;
1333
1334         if (ret) {
1335                 bch_err_inum_offset_ratelimited(c,
1336                         op->pos.inode, op->pos.offset << 9,
1337                         "%s: btree lookup error %s", __func__, bch2_err_str(ret));
1338                 op->error = ret;
1339                 op->flags |= BCH_WRITE_DONE;
1340         }
1341
1342         bch2_trans_put(trans);
1343         darray_exit(&buckets);
1344
1345         /* fallback to cow write path? */
1346         if (!(op->flags & BCH_WRITE_DONE)) {
1347                 closure_sync(&op->cl);
1348                 __bch2_nocow_write_done(op);
1349                 op->insert_keys.top = op->insert_keys.keys;
1350         } else if (op->flags & BCH_WRITE_SYNC) {
1351                 closure_sync(&op->cl);
1352                 bch2_nocow_write_done(&op->cl.work);
1353         } else {
1354                 /*
1355                  * XXX
1356                  * needs to run out of process context because ei_quota_lock is
1357                  * a mutex
1358                  */
1359                 continue_at(&op->cl, bch2_nocow_write_done, index_update_wq(op));
1360         }
1361         return;
1362 err_get_ioref:
1363         darray_for_each(buckets, i)
1364                 percpu_ref_put(&bch_dev_bkey_exists(c, i->b.inode)->io_ref);
1365
1366         /* Fall back to COW path: */
1367         goto out;
1368 err_bucket_stale:
1369         darray_for_each(buckets, i) {
1370                 bch2_bucket_nocow_unlock(&c->nocow_locks, i->b, BUCKET_NOCOW_LOCK_UPDATE);
1371                 if (i == stale_at)
1372                         break;
1373         }
1374
1375         /* We can retry this: */
1376         ret = -BCH_ERR_transaction_restart;
1377         goto err_get_ioref;
1378 }
1379
1380 static void __bch2_write(struct bch_write_op *op)
1381 {
1382         struct bch_fs *c = op->c;
1383         struct write_point *wp = NULL;
1384         struct bio *bio = NULL;
1385         unsigned nofs_flags;
1386         int ret;
1387
1388         nofs_flags = memalloc_nofs_save();
1389
1390         if (unlikely(op->opts.nocow && c->opts.nocow_enabled)) {
1391                 bch2_nocow_write(op);
1392                 if (op->flags & BCH_WRITE_DONE)
1393                         goto out_nofs_restore;
1394         }
1395 again:
1396         memset(&op->failed, 0, sizeof(op->failed));
1397
1398         do {
1399                 struct bkey_i *key_to_write;
1400                 unsigned key_to_write_offset = op->insert_keys.top_p -
1401                         op->insert_keys.keys_p;
1402
1403                 /* +1 for possible cache device: */
1404                 if (op->open_buckets.nr + op->nr_replicas + 1 >
1405                     ARRAY_SIZE(op->open_buckets.v))
1406                         break;
1407
1408                 if (bch2_keylist_realloc(&op->insert_keys,
1409                                         op->inline_keys,
1410                                         ARRAY_SIZE(op->inline_keys),
1411                                         BKEY_EXTENT_U64s_MAX))
1412                         break;
1413
1414                 /*
1415                  * The copygc thread is now global, which means it's no longer
1416                  * freeing up space on specific disks, which means that
1417                  * allocations for specific disks may hang arbitrarily long:
1418                  */
1419                 ret = bch2_trans_do(c, NULL, NULL, 0,
1420                         bch2_alloc_sectors_start_trans(trans,
1421                                 op->target,
1422                                 op->opts.erasure_code && !(op->flags & BCH_WRITE_CACHED),
1423                                 op->write_point,
1424                                 &op->devs_have,
1425                                 op->nr_replicas,
1426                                 op->nr_replicas_required,
1427                                 op->watermark,
1428                                 op->flags,
1429                                 (op->flags & (BCH_WRITE_ALLOC_NOWAIT|
1430                                               BCH_WRITE_ONLY_SPECIFIED_DEVS))
1431                                 ? NULL : &op->cl, &wp));
1432                 if (unlikely(ret)) {
1433                         if (bch2_err_matches(ret, BCH_ERR_operation_blocked))
1434                                 break;
1435
1436                         goto err;
1437                 }
1438
1439                 EBUG_ON(!wp);
1440
1441                 bch2_open_bucket_get(c, wp, &op->open_buckets);
1442                 ret = bch2_write_extent(op, wp, &bio);
1443
1444                 bch2_alloc_sectors_done_inlined(c, wp);
1445 err:
1446                 if (ret <= 0) {
1447                         op->flags |= BCH_WRITE_DONE;
1448
1449                         if (ret < 0) {
1450                                 bch_err_inum_offset_ratelimited(c,
1451                                         op->pos.inode,
1452                                         op->pos.offset << 9,
1453                                         "%s(): error: %s", __func__, bch2_err_str(ret));
1454                                 op->error = ret;
1455                                 break;
1456                         }
1457                 }
1458
1459                 bio->bi_end_io  = bch2_write_endio;
1460                 bio->bi_private = &op->cl;
1461                 bio->bi_opf |= REQ_OP_WRITE;
1462
1463                 closure_get(bio->bi_private);
1464
1465                 key_to_write = (void *) (op->insert_keys.keys_p +
1466                                          key_to_write_offset);
1467
1468                 bch2_submit_wbio_replicas(to_wbio(bio), c, BCH_DATA_user,
1469                                           key_to_write, false);
1470         } while (ret);
1471
1472         /*
1473          * Sync or no?
1474          *
1475          * If we're running asynchronously, wne may still want to block
1476          * synchronously here if we weren't able to submit all of the IO at
1477          * once, as that signals backpressure to the caller.
1478          */
1479         if ((op->flags & BCH_WRITE_SYNC) ||
1480             (!(op->flags & BCH_WRITE_DONE) &&
1481              !(op->flags & BCH_WRITE_IN_WORKER))) {
1482                 closure_sync(&op->cl);
1483                 __bch2_write_index(op);
1484
1485                 if (!(op->flags & BCH_WRITE_DONE))
1486                         goto again;
1487                 bch2_write_done(&op->cl);
1488         } else {
1489                 bch2_write_queue(op, wp);
1490                 continue_at(&op->cl, bch2_write_index, NULL);
1491         }
1492 out_nofs_restore:
1493         memalloc_nofs_restore(nofs_flags);
1494 }
1495
1496 static void bch2_write_data_inline(struct bch_write_op *op, unsigned data_len)
1497 {
1498         struct bio *bio = &op->wbio.bio;
1499         struct bvec_iter iter;
1500         struct bkey_i_inline_data *id;
1501         unsigned sectors;
1502         int ret;
1503
1504         op->flags |= BCH_WRITE_WROTE_DATA_INLINE;
1505         op->flags |= BCH_WRITE_DONE;
1506
1507         bch2_check_set_feature(op->c, BCH_FEATURE_inline_data);
1508
1509         ret = bch2_keylist_realloc(&op->insert_keys, op->inline_keys,
1510                                    ARRAY_SIZE(op->inline_keys),
1511                                    BKEY_U64s + DIV_ROUND_UP(data_len, 8));
1512         if (ret) {
1513                 op->error = ret;
1514                 goto err;
1515         }
1516
1517         sectors = bio_sectors(bio);
1518         op->pos.offset += sectors;
1519
1520         id = bkey_inline_data_init(op->insert_keys.top);
1521         id->k.p         = op->pos;
1522         id->k.version   = op->version;
1523         id->k.size      = sectors;
1524
1525         iter = bio->bi_iter;
1526         iter.bi_size = data_len;
1527         memcpy_from_bio(id->v.data, bio, iter);
1528
1529         while (data_len & 7)
1530                 id->v.data[data_len++] = '\0';
1531         set_bkey_val_bytes(&id->k, data_len);
1532         bch2_keylist_push(&op->insert_keys);
1533
1534         __bch2_write_index(op);
1535 err:
1536         bch2_write_done(&op->cl);
1537 }
1538
1539 /**
1540  * bch2_write() - handle a write to a cache device or flash only volume
1541  * @cl:         &bch_write_op->cl
1542  *
1543  * This is the starting point for any data to end up in a cache device; it could
1544  * be from a normal write, or a writeback write, or a write to a flash only
1545  * volume - it's also used by the moving garbage collector to compact data in
1546  * mostly empty buckets.
1547  *
1548  * It first writes the data to the cache, creating a list of keys to be inserted
1549  * (if the data won't fit in a single open bucket, there will be multiple keys);
1550  * after the data is written it calls bch_journal, and after the keys have been
1551  * added to the next journal write they're inserted into the btree.
1552  *
1553  * If op->discard is true, instead of inserting the data it invalidates the
1554  * region of the cache represented by op->bio and op->inode.
1555  */
1556 CLOSURE_CALLBACK(bch2_write)
1557 {
1558         closure_type(op, struct bch_write_op, cl);
1559         struct bio *bio = &op->wbio.bio;
1560         struct bch_fs *c = op->c;
1561         unsigned data_len;
1562
1563         EBUG_ON(op->cl.parent);
1564         BUG_ON(!op->nr_replicas);
1565         BUG_ON(!op->write_point.v);
1566         BUG_ON(bkey_eq(op->pos, POS_MAX));
1567
1568         op->start_time = local_clock();
1569         bch2_keylist_init(&op->insert_keys, op->inline_keys);
1570         wbio_init(bio)->put_bio = false;
1571
1572         if (bio->bi_iter.bi_size & (c->opts.block_size - 1)) {
1573                 bch_err_inum_offset_ratelimited(c,
1574                         op->pos.inode,
1575                         op->pos.offset << 9,
1576                         "misaligned write");
1577                 op->error = -EIO;
1578                 goto err;
1579         }
1580
1581         if (c->opts.nochanges) {
1582                 op->error = -BCH_ERR_erofs_no_writes;
1583                 goto err;
1584         }
1585
1586         if (!(op->flags & BCH_WRITE_MOVE) &&
1587             !bch2_write_ref_tryget(c, BCH_WRITE_REF_write)) {
1588                 op->error = -BCH_ERR_erofs_no_writes;
1589                 goto err;
1590         }
1591
1592         this_cpu_add(c->counters[BCH_COUNTER_io_write], bio_sectors(bio));
1593         bch2_increment_clock(c, bio_sectors(bio), WRITE);
1594
1595         data_len = min_t(u64, bio->bi_iter.bi_size,
1596                          op->new_i_size - (op->pos.offset << 9));
1597
1598         if (c->opts.inline_data &&
1599             data_len <= min(block_bytes(c) / 2, 1024U)) {
1600                 bch2_write_data_inline(op, data_len);
1601                 return;
1602         }
1603
1604         __bch2_write(op);
1605         return;
1606 err:
1607         bch2_disk_reservation_put(c, &op->res);
1608
1609         closure_debug_destroy(&op->cl);
1610         if (op->end_io)
1611                 op->end_io(op);
1612 }
1613
1614 static const char * const bch2_write_flags[] = {
1615 #define x(f)    #f,
1616         BCH_WRITE_FLAGS()
1617 #undef x
1618         NULL
1619 };
1620
1621 void bch2_write_op_to_text(struct printbuf *out, struct bch_write_op *op)
1622 {
1623         prt_str(out, "pos: ");
1624         bch2_bpos_to_text(out, op->pos);
1625         prt_newline(out);
1626         printbuf_indent_add(out, 2);
1627
1628         prt_str(out, "started: ");
1629         bch2_pr_time_units(out, local_clock() - op->start_time);
1630         prt_newline(out);
1631
1632         prt_str(out, "flags: ");
1633         prt_bitflags(out, bch2_write_flags, op->flags);
1634         prt_newline(out);
1635
1636         prt_printf(out, "ref: %u", closure_nr_remaining(&op->cl));
1637         prt_newline(out);
1638
1639         printbuf_indent_sub(out, 2);
1640 }
1641
1642 void bch2_fs_io_write_exit(struct bch_fs *c)
1643 {
1644         mempool_exit(&c->bio_bounce_pages);
1645         bioset_exit(&c->bio_write);
1646 }
1647
1648 int bch2_fs_io_write_init(struct bch_fs *c)
1649 {
1650         if (bioset_init(&c->bio_write, 1, offsetof(struct bch_write_bio, bio),
1651                         BIOSET_NEED_BVECS))
1652                 return -BCH_ERR_ENOMEM_bio_write_init;
1653
1654         if (mempool_init_page_pool(&c->bio_bounce_pages,
1655                                    max_t(unsigned,
1656                                          c->opts.btree_node_size,
1657                                          c->opts.encoded_extent_max) /
1658                                    PAGE_SIZE, 0))
1659                 return -BCH_ERR_ENOMEM_bio_bounce_pages_init;
1660
1661         return 0;
1662 }