diff options
Diffstat (limited to 'c_src/libbcachefs/io_read.c')
| -rw-r--r-- | c_src/libbcachefs/io_read.c | 1220 |
1 files changed, 1220 insertions, 0 deletions
diff --git a/c_src/libbcachefs/io_read.c b/c_src/libbcachefs/io_read.c new file mode 100644 index 00000000..3c574d88 --- /dev/null +++ b/c_src/libbcachefs/io_read.c @@ -0,0 +1,1220 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Some low level IO code, and hacks for various block layer limitations + * + * Copyright 2010, 2011 Kent Overstreet <kent.overstreet@gmail.com> + * Copyright 2012 Google, Inc. + */ + +#include "bcachefs.h" +#include "alloc_background.h" +#include "alloc_foreground.h" +#include "btree_update.h" +#include "buckets.h" +#include "checksum.h" +#include "clock.h" +#include "compress.h" +#include "data_update.h" +#include "disk_groups.h" +#include "ec.h" +#include "error.h" +#include "io_read.h" +#include "io_misc.h" +#include "io_write.h" +#include "subvolume.h" +#include "trace.h" + +#include <linux/sched/mm.h> + +#ifndef CONFIG_BCACHEFS_NO_LATENCY_ACCT + +static bool bch2_target_congested(struct bch_fs *c, u16 target) +{ + const struct bch_devs_mask *devs; + unsigned d, nr = 0, total = 0; + u64 now = local_clock(), last; + s64 congested; + struct bch_dev *ca; + + if (!target) + return false; + + rcu_read_lock(); + devs = bch2_target_to_mask(c, target) ?: + &c->rw_devs[BCH_DATA_user]; + + for_each_set_bit(d, devs->d, BCH_SB_MEMBERS_MAX) { + ca = rcu_dereference(c->devs[d]); + if (!ca) + continue; + + congested = atomic_read(&ca->congested); + last = READ_ONCE(ca->congested_last); + if (time_after64(now, last)) + congested -= (now - last) >> 12; + + total += max(congested, 0LL); + nr++; + } + rcu_read_unlock(); + + return bch2_rand_range(nr * CONGESTED_MAX) < total; +} + +#else + +static bool bch2_target_congested(struct bch_fs *c, u16 target) +{ + return false; +} + +#endif + +/* Cache promotion on read */ + +struct promote_op { + struct rcu_head rcu; + u64 start_time; + + struct rhash_head hash; + struct bpos pos; + + struct data_update write; + struct bio_vec bi_inline_vecs[]; /* must be last */ +}; + +static const struct rhashtable_params bch_promote_params = { + .head_offset = offsetof(struct promote_op, hash), + .key_offset = offsetof(struct promote_op, pos), + .key_len = sizeof(struct bpos), +}; + +static inline int should_promote(struct bch_fs *c, struct bkey_s_c k, + struct bpos pos, + struct bch_io_opts opts, + unsigned flags) +{ + BUG_ON(!opts.promote_target); + + if (!(flags & BCH_READ_MAY_PROMOTE)) + return -BCH_ERR_nopromote_may_not; + + if (bch2_bkey_has_target(c, k, opts.promote_target)) + return -BCH_ERR_nopromote_already_promoted; + + if (bkey_extent_is_unwritten(k)) + return -BCH_ERR_nopromote_unwritten; + + if (bch2_target_congested(c, opts.promote_target)) + return -BCH_ERR_nopromote_congested; + + if (rhashtable_lookup_fast(&c->promote_table, &pos, + bch_promote_params)) + return -BCH_ERR_nopromote_in_flight; + + return 0; +} + +static void promote_free(struct bch_fs *c, struct promote_op *op) +{ + int ret; + + bch2_data_update_exit(&op->write); + + ret = rhashtable_remove_fast(&c->promote_table, &op->hash, + bch_promote_params); + BUG_ON(ret); + bch2_write_ref_put(c, BCH_WRITE_REF_promote); + kfree_rcu(op, rcu); +} + +static void promote_done(struct bch_write_op *wop) +{ + struct promote_op *op = + container_of(wop, struct promote_op, write.op); + struct bch_fs *c = op->write.op.c; + + bch2_time_stats_update(&c->times[BCH_TIME_data_promote], + op->start_time); + promote_free(c, op); +} + +static void promote_start(struct promote_op *op, struct bch_read_bio *rbio) +{ + struct bio *bio = &op->write.op.wbio.bio; + + trace_and_count(op->write.op.c, read_promote, &rbio->bio); + + /* we now own pages: */ + BUG_ON(!rbio->bounce); + BUG_ON(rbio->bio.bi_vcnt > bio->bi_max_vecs); + + memcpy(bio->bi_io_vec, rbio->bio.bi_io_vec, + sizeof(struct bio_vec) * rbio->bio.bi_vcnt); + swap(bio->bi_vcnt, rbio->bio.bi_vcnt); + + bch2_data_update_read_done(&op->write, rbio->pick.crc); +} + +static struct promote_op *__promote_alloc(struct btree_trans *trans, + enum btree_id btree_id, + struct bkey_s_c k, + struct bpos pos, + struct extent_ptr_decoded *pick, + struct bch_io_opts opts, + unsigned sectors, + struct bch_read_bio **rbio) +{ + struct bch_fs *c = trans->c; + struct promote_op *op = NULL; + struct bio *bio; + unsigned pages = DIV_ROUND_UP(sectors, PAGE_SECTORS); + int ret; + + if (!bch2_write_ref_tryget(c, BCH_WRITE_REF_promote)) + return ERR_PTR(-BCH_ERR_nopromote_no_writes); + + op = kzalloc(sizeof(*op) + sizeof(struct bio_vec) * pages, GFP_KERNEL); + if (!op) { + ret = -BCH_ERR_nopromote_enomem; + goto err; + } + + op->start_time = local_clock(); + op->pos = pos; + + /* + * We don't use the mempool here because extents that aren't + * checksummed or compressed can be too big for the mempool: + */ + *rbio = kzalloc(sizeof(struct bch_read_bio) + + sizeof(struct bio_vec) * pages, + GFP_KERNEL); + if (!*rbio) { + ret = -BCH_ERR_nopromote_enomem; + goto err; + } + + rbio_init(&(*rbio)->bio, opts); + bio_init(&(*rbio)->bio, NULL, (*rbio)->bio.bi_inline_vecs, pages, 0); + + if (bch2_bio_alloc_pages(&(*rbio)->bio, sectors << 9, GFP_KERNEL)) { + ret = -BCH_ERR_nopromote_enomem; + goto err; + } + + (*rbio)->bounce = true; + (*rbio)->split = true; + (*rbio)->kmalloc = true; + + if (rhashtable_lookup_insert_fast(&c->promote_table, &op->hash, + bch_promote_params)) { + ret = -BCH_ERR_nopromote_in_flight; + goto err; + } + + bio = &op->write.op.wbio.bio; + bio_init(bio, NULL, bio->bi_inline_vecs, pages, 0); + + ret = bch2_data_update_init(trans, NULL, NULL, &op->write, + writepoint_hashed((unsigned long) current), + opts, + (struct data_update_opts) { + .target = opts.promote_target, + .extra_replicas = 1, + .write_flags = BCH_WRITE_ALLOC_NOWAIT|BCH_WRITE_CACHED, + }, + btree_id, k); + /* + * possible errors: -BCH_ERR_nocow_lock_blocked, + * -BCH_ERR_ENOSPC_disk_reservation: + */ + if (ret) { + BUG_ON(rhashtable_remove_fast(&c->promote_table, &op->hash, + bch_promote_params)); + goto err; + } + + op->write.op.end_io = promote_done; + + return op; +err: + if (*rbio) + bio_free_pages(&(*rbio)->bio); + kfree(*rbio); + *rbio = NULL; + kfree(op); + bch2_write_ref_put(c, BCH_WRITE_REF_promote); + return ERR_PTR(ret); +} + +noinline +static struct promote_op *promote_alloc(struct btree_trans *trans, + struct bvec_iter iter, + struct bkey_s_c k, + struct extent_ptr_decoded *pick, + struct bch_io_opts opts, + unsigned flags, + struct bch_read_bio **rbio, + bool *bounce, + bool *read_full) +{ + struct bch_fs *c = trans->c; + bool promote_full = *read_full || READ_ONCE(c->promote_whole_extents); + /* data might have to be decompressed in the write path: */ + unsigned sectors = promote_full + ? max(pick->crc.compressed_size, pick->crc.live_size) + : bvec_iter_sectors(iter); + struct bpos pos = promote_full + ? bkey_start_pos(k.k) + : POS(k.k->p.inode, iter.bi_sector); + struct promote_op *promote; + int ret; + + ret = should_promote(c, k, pos, opts, flags); + if (ret) + goto nopromote; + + promote = __promote_alloc(trans, + k.k->type == KEY_TYPE_reflink_v + ? BTREE_ID_reflink + : BTREE_ID_extents, + k, pos, pick, opts, sectors, rbio); + ret = PTR_ERR_OR_ZERO(promote); + if (ret) + goto nopromote; + + *bounce = true; + *read_full = promote_full; + return promote; +nopromote: + trace_read_nopromote(c, ret); + return NULL; +} + +/* Read */ + +#define READ_RETRY_AVOID 1 +#define READ_RETRY 2 +#define READ_ERR 3 + +enum rbio_context { + RBIO_CONTEXT_NULL, + RBIO_CONTEXT_HIGHPRI, + RBIO_CONTEXT_UNBOUND, +}; + +static inline struct bch_read_bio * +bch2_rbio_parent(struct bch_read_bio *rbio) +{ + return rbio->split ? rbio->parent : rbio; +} + +__always_inline +static void bch2_rbio_punt(struct bch_read_bio *rbio, work_func_t fn, + enum rbio_context context, + struct workqueue_struct *wq) +{ + if (context <= rbio->context) { + fn(&rbio->work); + } else { + rbio->work.func = fn; + rbio->context = context; + queue_work(wq, &rbio->work); + } +} + +static inline struct bch_read_bio *bch2_rbio_free(struct bch_read_bio *rbio) +{ + BUG_ON(rbio->bounce && !rbio->split); + + if (rbio->promote) + promote_free(rbio->c, rbio->promote); + rbio->promote = NULL; + + if (rbio->bounce) + bch2_bio_free_pages_pool(rbio->c, &rbio->bio); + + if (rbio->split) { + struct bch_read_bio *parent = rbio->parent; + + if (rbio->kmalloc) + kfree(rbio); + else + bio_put(&rbio->bio); + + rbio = parent; + } + + return rbio; +} + +/* + * Only called on a top level bch_read_bio to complete an entire read request, + * not a split: + */ +static void bch2_rbio_done(struct bch_read_bio *rbio) +{ + if (rbio->start_time) + bch2_time_stats_update(&rbio->c->times[BCH_TIME_data_read], + rbio->start_time); + bio_endio(&rbio->bio); +} + +static void bch2_read_retry_nodecode(struct bch_fs *c, struct bch_read_bio *rbio, + struct bvec_iter bvec_iter, + struct bch_io_failures *failed, + unsigned flags) +{ + struct btree_trans *trans = bch2_trans_get(c); + struct btree_iter iter; + struct bkey_buf sk; + struct bkey_s_c k; + int ret; + + flags &= ~BCH_READ_LAST_FRAGMENT; + flags |= BCH_READ_MUST_CLONE; + + bch2_bkey_buf_init(&sk); + + bch2_trans_iter_init(trans, &iter, rbio->data_btree, + rbio->read_pos, BTREE_ITER_SLOTS); +retry: + rbio->bio.bi_status = 0; + + k = bch2_btree_iter_peek_slot(&iter); + if (bkey_err(k)) + goto err; + + bch2_bkey_buf_reassemble(&sk, c, k); + k = bkey_i_to_s_c(sk.k); + bch2_trans_unlock(trans); + + if (!bch2_bkey_matches_ptr(c, k, + rbio->pick.ptr, + rbio->data_pos.offset - + rbio->pick.crc.offset)) { + /* extent we wanted to read no longer exists: */ + rbio->hole = true; + goto out; + } + + ret = __bch2_read_extent(trans, rbio, bvec_iter, + rbio->read_pos, + rbio->data_btree, + k, 0, failed, flags); + if (ret == READ_RETRY) + goto retry; + if (ret) + goto err; +out: + bch2_rbio_done(rbio); + bch2_trans_iter_exit(trans, &iter); + bch2_trans_put(trans); + bch2_bkey_buf_exit(&sk, c); + return; +err: + rbio->bio.bi_status = BLK_STS_IOERR; + goto out; +} + +static void bch2_rbio_retry(struct work_struct *work) +{ + struct bch_read_bio *rbio = + container_of(work, struct bch_read_bio, work); + struct bch_fs *c = rbio->c; + struct bvec_iter iter = rbio->bvec_iter; + unsigned flags = rbio->flags; + subvol_inum inum = { + .subvol = rbio->subvol, + .inum = rbio->read_pos.inode, + }; + struct bch_io_failures failed = { .nr = 0 }; + + trace_and_count(c, read_retry, &rbio->bio); + + if (rbio->retry == READ_RETRY_AVOID) + bch2_mark_io_failure(&failed, &rbio->pick); + + rbio->bio.bi_status = 0; + + rbio = bch2_rbio_free(rbio); + + flags |= BCH_READ_IN_RETRY; + flags &= ~BCH_READ_MAY_PROMOTE; + + if (flags & BCH_READ_NODECODE) { + bch2_read_retry_nodecode(c, rbio, iter, &failed, flags); + } else { + flags &= ~BCH_READ_LAST_FRAGMENT; + flags |= BCH_READ_MUST_CLONE; + + __bch2_read(c, rbio, iter, inum, &failed, flags); + } +} + +static void bch2_rbio_error(struct bch_read_bio *rbio, int retry, + blk_status_t error) +{ + rbio->retry = retry; + + if (rbio->flags & BCH_READ_IN_RETRY) + return; + + if (retry == READ_ERR) { + rbio = bch2_rbio_free(rbio); + + rbio->bio.bi_status = error; + bch2_rbio_done(rbio); + } else { + bch2_rbio_punt(rbio, bch2_rbio_retry, + RBIO_CONTEXT_UNBOUND, system_unbound_wq); + } +} + +static int __bch2_rbio_narrow_crcs(struct btree_trans *trans, + struct bch_read_bio *rbio) +{ + struct bch_fs *c = rbio->c; + u64 data_offset = rbio->data_pos.offset - rbio->pick.crc.offset; + struct bch_extent_crc_unpacked new_crc; + struct btree_iter iter; + struct bkey_i *new; + struct bkey_s_c k; + int ret = 0; + + if (crc_is_compressed(rbio->pick.crc)) + return 0; + + k = bch2_bkey_get_iter(trans, &iter, rbio->data_btree, rbio->data_pos, + BTREE_ITER_SLOTS|BTREE_ITER_INTENT); + if ((ret = bkey_err(k))) + goto out; + + if (bversion_cmp(k.k->version, rbio->version) || + !bch2_bkey_matches_ptr(c, k, rbio->pick.ptr, data_offset)) + goto out; + + /* Extent was merged? */ + if (bkey_start_offset(k.k) < data_offset || + k.k->p.offset > data_offset + rbio->pick.crc.uncompressed_size) + goto out; + + if (bch2_rechecksum_bio(c, &rbio->bio, rbio->version, + rbio->pick.crc, NULL, &new_crc, + bkey_start_offset(k.k) - data_offset, k.k->size, + rbio->pick.crc.csum_type)) { + bch_err(c, "error verifying existing checksum while narrowing checksum (memory corruption?)"); + ret = 0; + goto out; + } + + /* + * going to be temporarily appending another checksum entry: + */ + new = bch2_trans_kmalloc(trans, bkey_bytes(k.k) + + sizeof(struct bch_extent_crc128)); + if ((ret = PTR_ERR_OR_ZERO(new))) + goto out; + + bkey_reassemble(new, k); + + if (!bch2_bkey_narrow_crcs(new, new_crc)) + goto out; + + ret = bch2_trans_update(trans, &iter, new, + BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE); +out: + bch2_trans_iter_exit(trans, &iter); + return ret; +} + +static noinline void bch2_rbio_narrow_crcs(struct bch_read_bio *rbio) +{ + bch2_trans_do(rbio->c, NULL, NULL, BCH_TRANS_COMMIT_no_enospc, + __bch2_rbio_narrow_crcs(trans, rbio)); +} + +/* Inner part that may run in process context */ +static void __bch2_read_endio(struct work_struct *work) +{ + struct bch_read_bio *rbio = + container_of(work, struct bch_read_bio, work); + struct bch_fs *c = rbio->c; + struct bch_dev *ca = bch_dev_bkey_exists(c, rbio->pick.ptr.dev); + struct bio *src = &rbio->bio; + struct bio *dst = &bch2_rbio_parent(rbio)->bio; + struct bvec_iter dst_iter = rbio->bvec_iter; + struct bch_extent_crc_unpacked crc = rbio->pick.crc; + struct nonce nonce = extent_nonce(rbio->version, crc); + unsigned nofs_flags; + struct bch_csum csum; + int ret; + + nofs_flags = memalloc_nofs_save(); + + /* Reset iterator for checksumming and copying bounced data: */ + if (rbio->bounce) { + src->bi_iter.bi_size = crc.compressed_size << 9; + src->bi_iter.bi_idx = 0; + src->bi_iter.bi_bvec_done = 0; + } else { + src->bi_iter = rbio->bvec_iter; + } + + csum = bch2_checksum_bio(c, crc.csum_type, nonce, src); + if (bch2_crc_cmp(csum, rbio->pick.crc.csum) && !c->opts.no_data_io) + goto csum_err; + + /* + * XXX + * We need to rework the narrow_crcs path to deliver the read completion + * first, and then punt to a different workqueue, otherwise we're + * holding up reads while doing btree updates which is bad for memory + * reclaim. + */ + if (unlikely(rbio->narrow_crcs)) + bch2_rbio_narrow_crcs(rbio); + + if (rbio->flags & BCH_READ_NODECODE) + goto nodecode; + + /* Adjust crc to point to subset of data we want: */ + crc.offset += rbio->offset_into_extent; + crc.live_size = bvec_iter_sectors(rbio->bvec_iter); + + if (crc_is_compressed(crc)) { + ret = bch2_encrypt_bio(c, crc.csum_type, nonce, src); + if (ret) + goto decrypt_err; + + if (bch2_bio_uncompress(c, src, dst, dst_iter, crc) && + !c->opts.no_data_io) + goto decompression_err; + } else { + /* don't need to decrypt the entire bio: */ + nonce = nonce_add(nonce, crc.offset << 9); + bio_advance(src, crc.offset << 9); + + BUG_ON(src->bi_iter.bi_size < dst_iter.bi_size); + src->bi_iter.bi_size = dst_iter.bi_size; + + ret = bch2_encrypt_bio(c, crc.csum_type, nonce, src); + if (ret) + goto decrypt_err; + + if (rbio->bounce) { + struct bvec_iter src_iter = src->bi_iter; + + bio_copy_data_iter(dst, &dst_iter, src, &src_iter); + } + } + + if (rbio->promote) { + /* + * Re encrypt data we decrypted, so it's consistent with + * rbio->crc: + */ + ret = bch2_encrypt_bio(c, crc.csum_type, nonce, src); + if (ret) + goto decrypt_err; + + promote_start(rbio->promote, rbio); + rbio->promote = NULL; + } +nodecode: + if (likely(!(rbio->flags & BCH_READ_IN_RETRY))) { + rbio = bch2_rbio_free(rbio); + bch2_rbio_done(rbio); + } +out: + memalloc_nofs_restore(nofs_flags); + return; +csum_err: + /* + * Checksum error: if the bio wasn't bounced, we may have been + * reading into buffers owned by userspace (that userspace can + * scribble over) - retry the read, bouncing it this time: + */ + if (!rbio->bounce && (rbio->flags & BCH_READ_USER_MAPPED)) { + rbio->flags |= BCH_READ_MUST_BOUNCE; + bch2_rbio_error(rbio, READ_RETRY, BLK_STS_IOERR); + goto out; + } + + struct printbuf buf = PRINTBUF; + buf.atomic++; + prt_str(&buf, "data "); + bch2_csum_err_msg(&buf, crc.csum_type, rbio->pick.crc.csum, csum); + + bch_err_inum_offset_ratelimited(ca, + rbio->read_pos.inode, + rbio->read_pos.offset << 9, + "data %s", buf.buf); + printbuf_exit(&buf); + + bch2_io_error(ca, BCH_MEMBER_ERROR_checksum); + bch2_rbio_error(rbio, READ_RETRY_AVOID, BLK_STS_IOERR); + goto out; +decompression_err: + bch_err_inum_offset_ratelimited(c, rbio->read_pos.inode, + rbio->read_pos.offset << 9, + "decompression error"); + bch2_rbio_error(rbio, READ_ERR, BLK_STS_IOERR); + goto out; +decrypt_err: + bch_err_inum_offset_ratelimited(c, rbio->read_pos.inode, + rbio->read_pos.offset << 9, + "decrypt error"); + bch2_rbio_error(rbio, READ_ERR, BLK_STS_IOERR); + goto out; +} + +static void bch2_read_endio(struct bio *bio) +{ + struct bch_read_bio *rbio = + container_of(bio, struct bch_read_bio, bio); + struct bch_fs *c = rbio->c; + struct bch_dev *ca = bch_dev_bkey_exists(c, rbio->pick.ptr.dev); + struct workqueue_struct *wq = NULL; + enum rbio_context context = RBIO_CONTEXT_NULL; + + if (rbio->have_ioref) { + bch2_latency_acct(ca, rbio->submit_time, READ); + percpu_ref_put(&ca->io_ref); + } + + if (!rbio->split) + rbio->bio.bi_end_io = rbio->end_io; + + if (bch2_dev_inum_io_err_on(bio->bi_status, ca, BCH_MEMBER_ERROR_read, + rbio->read_pos.inode, + rbio->read_pos.offset, + "data read error: %s", + bch2_blk_status_to_str(bio->bi_status))) { + bch2_rbio_error(rbio, READ_RETRY_AVOID, bio->bi_status); + return; + } + + if (((rbio->flags & BCH_READ_RETRY_IF_STALE) && race_fault()) || + ptr_stale(ca, &rbio->pick.ptr)) { + trace_and_count(c, read_reuse_race, &rbio->bio); + + if (rbio->flags & BCH_READ_RETRY_IF_STALE) + bch2_rbio_error(rbio, READ_RETRY, BLK_STS_AGAIN); + else + bch2_rbio_error(rbio, READ_ERR, BLK_STS_AGAIN); + return; + } + + if (rbio->narrow_crcs || + rbio->promote || + crc_is_compressed(rbio->pick.crc) || + bch2_csum_type_is_encryption(rbio->pick.crc.csum_type)) + context = RBIO_CONTEXT_UNBOUND, wq = system_unbound_wq; + else if (rbio->pick.crc.csum_type) + context = RBIO_CONTEXT_HIGHPRI, wq = system_highpri_wq; + + bch2_rbio_punt(rbio, __bch2_read_endio, context, wq); +} + +int __bch2_read_indirect_extent(struct btree_trans *trans, + unsigned *offset_into_extent, + struct bkey_buf *orig_k) +{ + struct btree_iter iter; + struct bkey_s_c k; + u64 reflink_offset; + int ret; + + reflink_offset = le64_to_cpu(bkey_i_to_reflink_p(orig_k->k)->v.idx) + + *offset_into_extent; + + k = bch2_bkey_get_iter(trans, &iter, BTREE_ID_reflink, + POS(0, reflink_offset), 0); + ret = bkey_err(k); + if (ret) + goto err; + + if (k.k->type != KEY_TYPE_reflink_v && + k.k->type != KEY_TYPE_indirect_inline_data) { + bch_err_inum_offset_ratelimited(trans->c, + orig_k->k->k.p.inode, + orig_k->k->k.p.offset << 9, + "%llu len %u points to nonexistent indirect extent %llu", + orig_k->k->k.p.offset, + orig_k->k->k.size, + reflink_offset); + bch2_inconsistent_error(trans->c); + ret = -EIO; + goto err; + } + + *offset_into_extent = iter.pos.offset - bkey_start_offset(k.k); + bch2_bkey_buf_reassemble(orig_k, trans->c, k); +err: + bch2_trans_iter_exit(trans, &iter); + return ret; +} + +static noinline void read_from_stale_dirty_pointer(struct btree_trans *trans, + struct bkey_s_c k, + struct bch_extent_ptr ptr) +{ + struct bch_fs *c = trans->c; + struct bch_dev *ca = bch_dev_bkey_exists(c, ptr.dev); + struct btree_iter iter; + struct printbuf buf = PRINTBUF; + int ret; + + bch2_trans_iter_init(trans, &iter, BTREE_ID_alloc, + PTR_BUCKET_POS(c, &ptr), + BTREE_ITER_CACHED); + + prt_printf(&buf, "Attempting to read from stale dirty pointer:"); + printbuf_indent_add(&buf, 2); + prt_newline(&buf); + + bch2_bkey_val_to_text(&buf, c, k); + prt_newline(&buf); + + prt_printf(&buf, "memory gen: %u", *bucket_gen(ca, iter.pos.offset)); + + ret = lockrestart_do(trans, bkey_err(k = bch2_btree_iter_peek_slot(&iter))); + if (!ret) { + prt_newline(&buf); + bch2_bkey_val_to_text(&buf, c, k); + } + + bch2_fs_inconsistent(c, "%s", buf.buf); + + bch2_trans_iter_exit(trans, &iter); + printbuf_exit(&buf); +} + +int __bch2_read_extent(struct btree_trans *trans, struct bch_read_bio *orig, + struct bvec_iter iter, struct bpos read_pos, + enum btree_id data_btree, struct bkey_s_c k, + unsigned offset_into_extent, + struct bch_io_failures *failed, unsigned flags) +{ + struct bch_fs *c = trans->c; + struct extent_ptr_decoded pick; + struct bch_read_bio *rbio = NULL; + struct bch_dev *ca = NULL; + struct promote_op *promote = NULL; + bool bounce = false, read_full = false, narrow_crcs = false; + struct bpos data_pos = bkey_start_pos(k.k); + int pick_ret; + + if (bkey_extent_is_inline_data(k.k)) { + unsigned bytes = min_t(unsigned, iter.bi_size, + bkey_inline_data_bytes(k.k)); + + swap(iter.bi_size, bytes); + memcpy_to_bio(&orig->bio, iter, bkey_inline_data_p(k)); + swap(iter.bi_size, bytes); + bio_advance_iter(&orig->bio, &iter, bytes); + zero_fill_bio_iter(&orig->bio, iter); + goto out_read_done; + } +retry_pick: + pick_ret = bch2_bkey_pick_read_device(c, k, failed, &pick); + + /* hole or reservation - just zero fill: */ + if (!pick_ret) + goto hole; + + if (pick_ret < 0) { + bch_err_inum_offset_ratelimited(c, + read_pos.inode, read_pos.offset << 9, + "no device to read from"); + goto err; + } + + ca = bch_dev_bkey_exists(c, pick.ptr.dev); + + /* + * Stale dirty pointers are treated as IO errors, but @failed isn't + * allocated unless we're in the retry path - so if we're not in the + * retry path, don't check here, it'll be caught in bch2_read_endio() + * and we'll end up in the retry path: + */ + if ((flags & BCH_READ_IN_RETRY) && + !pick.ptr.cached && + unlikely(ptr_stale(ca, &pick.ptr))) { + read_from_stale_dirty_pointer(trans, k, pick.ptr); + bch2_mark_io_failure(failed, &pick); + goto retry_pick; + } + + /* + * Unlock the iterator while the btree node's lock is still in + * cache, before doing the IO: + */ + bch2_trans_unlock(trans); + + if (flags & BCH_READ_NODECODE) { + /* + * can happen if we retry, and the extent we were going to read + * has been merged in the meantime: + */ + if (pick.crc.compressed_size > orig->bio.bi_vcnt * PAGE_SECTORS) + goto hole; + + iter.bi_size = pick.crc.compressed_size << 9; + goto get_bio; + } + + if (!(flags & BCH_READ_LAST_FRAGMENT) || + bio_flagged(&orig->bio, BIO_CHAIN)) + flags |= BCH_READ_MUST_CLONE; + + narrow_crcs = !(flags & BCH_READ_IN_RETRY) && + bch2_can_narrow_extent_crcs(k, pick.crc); + + if (narrow_crcs && (flags & BCH_READ_USER_MAPPED)) + flags |= BCH_READ_MUST_BOUNCE; + + EBUG_ON(offset_into_extent + bvec_iter_sectors(iter) > k.k->size); + + if (crc_is_compressed(pick.crc) || + (pick.crc.csum_type != BCH_CSUM_none && + (bvec_iter_sectors(iter) != pick.crc.uncompressed_size || + (bch2_csum_type_is_encryption(pick.crc.csum_type) && + (flags & BCH_READ_USER_MAPPED)) || + (flags & BCH_READ_MUST_BOUNCE)))) { + read_full = true; + bounce = true; + } + + if (orig->opts.promote_target) + promote = promote_alloc(trans, iter, k, &pick, orig->opts, flags, + &rbio, &bounce, &read_full); + + if (!read_full) { + EBUG_ON(crc_is_compressed(pick.crc)); + EBUG_ON(pick.crc.csum_type && + (bvec_iter_sectors(iter) != pick.crc.uncompressed_size || + bvec_iter_sectors(iter) != pick.crc.live_size || + pick.crc.offset || + offset_into_extent)); + + data_pos.offset += offset_into_extent; + pick.ptr.offset += pick.crc.offset + + offset_into_extent; + offset_into_extent = 0; + pick.crc.compressed_size = bvec_iter_sectors(iter); + pick.crc.uncompressed_size = bvec_iter_sectors(iter); + pick.crc.offset = 0; + pick.crc.live_size = bvec_iter_sectors(iter); + } +get_bio: + if (rbio) { + /* + * promote already allocated bounce rbio: + * promote needs to allocate a bio big enough for uncompressing + * data in the write path, but we're not going to use it all + * here: + */ + EBUG_ON(rbio->bio.bi_iter.bi_size < + pick.crc.compressed_size << 9); + rbio->bio.bi_iter.bi_size = + pick.crc.compressed_size << 9; + } else if (bounce) { + unsigned sectors = pick.crc.compressed_size; + + rbio = rbio_init(bio_alloc_bioset(NULL, + DIV_ROUND_UP(sectors, PAGE_SECTORS), + 0, + GFP_NOFS, + &c->bio_read_split), + orig->opts); + + bch2_bio_alloc_pages_pool(c, &rbio->bio, sectors << 9); + rbio->bounce = true; + rbio->split = true; + } else if (flags & BCH_READ_MUST_CLONE) { + /* + * Have to clone if there were any splits, due to error + * reporting issues (if a split errored, and retrying didn't + * work, when it reports the error to its parent (us) we don't + * know if the error was from our bio, and we should retry, or + * from the whole bio, in which case we don't want to retry and + * lose the error) + */ + rbio = rbio_init(bio_alloc_clone(NULL, &orig->bio, GFP_NOFS, + &c->bio_read_split), + orig->opts); + rbio->bio.bi_iter = iter; + rbio->split = true; + } else { + rbio = orig; + rbio->bio.bi_iter = iter; + EBUG_ON(bio_flagged(&rbio->bio, BIO_CHAIN)); + } + + EBUG_ON(bio_sectors(&rbio->bio) != pick.crc.compressed_size); + + rbio->c = c; + rbio->submit_time = local_clock(); + if (rbio->split) + rbio->parent = orig; + else + rbio->end_io = orig->bio.bi_end_io; + rbio->bvec_iter = iter; + rbio->offset_into_extent= offset_into_extent; + rbio->flags = flags; + rbio->have_ioref = pick_ret > 0 && bch2_dev_get_ioref(ca, READ); + rbio->narrow_crcs = narrow_crcs; + rbio->hole = 0; + rbio->retry = 0; + rbio->context = 0; + /* XXX: only initialize this if needed */ + rbio->devs_have = bch2_bkey_devs(k); + rbio->pick = pick; + rbio->subvol = orig->subvol; + rbio->read_pos = read_pos; + rbio->data_btree = data_btree; + rbio->data_pos = data_pos; + rbio->version = k.k->version; + rbio->promote = promote; + INIT_WORK(&rbio->work, NULL); + + rbio->bio.bi_opf = orig->bio.bi_opf; + rbio->bio.bi_iter.bi_sector = pick.ptr.offset; + rbio->bio.bi_end_io = bch2_read_endio; + + if (rbio->bounce) + trace_and_count(c, read_bounce, &rbio->bio); + + this_cpu_add(c->counters[BCH_COUNTER_io_read], bio_sectors(&rbio->bio)); + bch2_increment_clock(c, bio_sectors(&rbio->bio), READ); + + /* + * If it's being moved internally, we don't want to flag it as a cache + * hit: + */ + if (pick.ptr.cached && !(flags & BCH_READ_NODECODE)) + bch2_bucket_io_time_reset(trans, pick.ptr.dev, + PTR_BUCKET_NR(ca, &pick.ptr), READ); + + if (!(flags & (BCH_READ_IN_RETRY|BCH_READ_LAST_FRAGMENT))) { + bio_inc_remaining(&orig->bio); + trace_and_count(c, read_split, &orig->bio); + } + + if (!rbio->pick.idx) { + if (!rbio->have_ioref) { + bch_err_inum_offset_ratelimited(c, + read_pos.inode, + read_pos.offset << 9, + "no device to read from"); + bch2_rbio_error(rbio, READ_RETRY_AVOID, BLK_STS_IOERR); + goto out; + } + + this_cpu_add(ca->io_done->sectors[READ][BCH_DATA_user], + bio_sectors(&rbio->bio)); + bio_set_dev(&rbio->bio, ca->disk_sb.bdev); + + if (unlikely(c->opts.no_data_io)) { + if (likely(!(flags & BCH_READ_IN_RETRY))) + bio_endio(&rbio->bio); + } else { + if (likely(!(flags & BCH_READ_IN_RETRY))) + submit_bio(&rbio->bio); + else + submit_bio_wait(&rbio->bio); + } + + /* + * We just submitted IO which may block, we expect relock fail + * events and shouldn't count them: + */ + trans->notrace_relock_fail = true; + } else { + /* Attempting reconstruct read: */ + if (bch2_ec_read_extent(trans, rbio)) { + bch2_rbio_error(rbio, READ_RETRY_AVOID, BLK_STS_IOERR); + goto out; + } + + if (likely(!(flags & BCH_READ_IN_RETRY))) + bio_endio(&rbio->bio); + } +out: + if (likely(!(flags & BCH_READ_IN_RETRY))) { + return 0; + } else { + int ret; + + rbio->context = RBIO_CONTEXT_UNBOUND; + bch2_read_endio(&rbio->bio); + + ret = rbio->retry; + rbio = bch2_rbio_free(rbio); + + if (ret == READ_RETRY_AVOID) { + bch2_mark_io_failure(failed, &pick); + ret = READ_RETRY; + } + + if (!ret) + goto out_read_done; + + return ret; + } + +err: + if (flags & BCH_READ_IN_RETRY) + return READ_ERR; + + orig->bio.bi_status = BLK_STS_IOERR; + goto out_read_done; + +hole: + /* + * won't normally happen in the BCH_READ_NODECODE + * (bch2_move_extent()) path, but if we retry and the extent we wanted + * to read no longer exists we have to signal that: + */ + if (flags & BCH_READ_NODECODE) + orig->hole = true; + + zero_fill_bio_iter(&orig->bio, iter); +out_read_done: + if (flags & BCH_READ_LAST_FRAGMENT) + bch2_rbio_done(orig); + return 0; +} + +void __bch2_read(struct bch_fs *c, struct bch_read_bio *rbio, + struct bvec_iter bvec_iter, subvol_inum inum, + struct bch_io_failures *failed, unsigned flags) +{ + struct btree_trans *trans = bch2_trans_get(c); + struct btree_iter iter; + struct bkey_buf sk; + struct bkey_s_c k; + u32 snapshot; + int ret; + + BUG_ON(flags & BCH_READ_NODECODE); + + bch2_bkey_buf_init(&sk); +retry: + bch2_trans_begin(trans); + iter = (struct btree_iter) { NULL }; + + ret = bch2_subvolume_get_snapshot(trans, inum.subvol, &snapshot); + if (ret) + goto err; + + bch2_trans_iter_init(trans, &iter, BTREE_ID_extents, + SPOS(inum.inum, bvec_iter.bi_sector, snapshot), + BTREE_ITER_SLOTS); + while (1) { + unsigned bytes, sectors, offset_into_extent; + enum btree_id data_btree = BTREE_ID_extents; + + /* + * read_extent -> io_time_reset may cause a transaction restart + * without returning an error, we need to check for that here: + */ + ret = bch2_trans_relock(trans); + if (ret) + break; + + bch2_btree_iter_set_pos(&iter, + POS(inum.inum, bvec_iter.bi_sector)); + + k = bch2_btree_iter_peek_slot(&iter); + ret = bkey_err(k); + if (ret) + break; + + offset_into_extent = iter.pos.offset - + bkey_start_offset(k.k); + sectors = k.k->size - offset_into_extent; + + bch2_bkey_buf_reassemble(&sk, c, k); + + ret = bch2_read_indirect_extent(trans, &data_btree, + &offset_into_extent, &sk); + if (ret) + break; + + k = bkey_i_to_s_c(sk.k); + + /* + * With indirect extents, the amount of data to read is the min + * of the original extent and the indirect extent: + */ + sectors = min(sectors, k.k->size - offset_into_extent); + + bytes = min(sectors, bvec_iter_sectors(bvec_iter)) << 9; + swap(bvec_iter.bi_size, bytes); + + if (bvec_iter.bi_size == bytes) + flags |= BCH_READ_LAST_FRAGMENT; + + ret = __bch2_read_extent(trans, rbio, bvec_iter, iter.pos, + data_btree, k, + offset_into_extent, failed, flags); + if (ret) + break; + + if (flags & BCH_READ_LAST_FRAGMENT) + break; + + swap(bvec_iter.bi_size, bytes); + bio_advance_iter(&rbio->bio, &bvec_iter, bytes); + + ret = btree_trans_too_many_iters(trans); + if (ret) + break; + } +err: + bch2_trans_iter_exit(trans, &iter); + + if (bch2_err_matches(ret, BCH_ERR_transaction_restart) || + ret == READ_RETRY || + ret == READ_RETRY_AVOID) + goto retry; + + bch2_trans_put(trans); + bch2_bkey_buf_exit(&sk, c); + + if (ret) { + bch_err_inum_offset_ratelimited(c, inum.inum, + bvec_iter.bi_sector << 9, + "read error %i from btree lookup", ret); + rbio->bio.bi_status = BLK_STS_IOERR; + bch2_rbio_done(rbio); + } +} + +void bch2_fs_io_read_exit(struct bch_fs *c) +{ + if (c->promote_table.tbl) + rhashtable_destroy(&c->promote_table); + bioset_exit(&c->bio_read_split); + bioset_exit(&c->bio_read); +} + +int bch2_fs_io_read_init(struct bch_fs *c) +{ + if (bioset_init(&c->bio_read, 1, offsetof(struct bch_read_bio, bio), + BIOSET_NEED_BVECS)) + return -BCH_ERR_ENOMEM_bio_read_init; + + if (bioset_init(&c->bio_read_split, 1, offsetof(struct bch_read_bio, bio), + BIOSET_NEED_BVECS)) + return -BCH_ERR_ENOMEM_bio_read_split_init; + + if (rhashtable_init(&c->promote_table, &bch_promote_params)) + return -BCH_ERR_ENOMEM_promote_table_init; + + return 0; +} |