--- /dev/null
+// 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;
+}
projects / bcachefs-tools-debian / blobdiff