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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
commitace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch)
treeb2d64bc10158fdd5497876388cd68142ca374ed3 /drivers/md/bcache/journal.c
parentInitial commit. (diff)
downloadlinux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz
linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/md/bcache/journal.c')
-rw-r--r--drivers/md/bcache/journal.c1000
1 files changed, 1000 insertions, 0 deletions
diff --git a/drivers/md/bcache/journal.c b/drivers/md/bcache/journal.c
new file mode 100644
index 0000000000..c182c21de2
--- /dev/null
+++ b/drivers/md/bcache/journal.c
@@ -0,0 +1,1000 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * bcache journalling code, for btree insertions
+ *
+ * Copyright 2012 Google, Inc.
+ */
+
+#include "bcache.h"
+#include "btree.h"
+#include "debug.h"
+#include "extents.h"
+
+#include <trace/events/bcache.h>
+
+/*
+ * Journal replay/recovery:
+ *
+ * This code is all driven from run_cache_set(); we first read the journal
+ * entries, do some other stuff, then we mark all the keys in the journal
+ * entries (same as garbage collection would), then we replay them - reinserting
+ * them into the cache in precisely the same order as they appear in the
+ * journal.
+ *
+ * We only journal keys that go in leaf nodes, which simplifies things quite a
+ * bit.
+ */
+
+static void journal_read_endio(struct bio *bio)
+{
+ struct closure *cl = bio->bi_private;
+
+ closure_put(cl);
+}
+
+static int journal_read_bucket(struct cache *ca, struct list_head *list,
+ unsigned int bucket_index)
+{
+ struct journal_device *ja = &ca->journal;
+ struct bio *bio = &ja->bio;
+
+ struct journal_replay *i;
+ struct jset *j, *data = ca->set->journal.w[0].data;
+ struct closure cl;
+ unsigned int len, left, offset = 0;
+ int ret = 0;
+ sector_t bucket = bucket_to_sector(ca->set, ca->sb.d[bucket_index]);
+
+ closure_init_stack(&cl);
+
+ pr_debug("reading %u\n", bucket_index);
+
+ while (offset < ca->sb.bucket_size) {
+reread: left = ca->sb.bucket_size - offset;
+ len = min_t(unsigned int, left, PAGE_SECTORS << JSET_BITS);
+
+ bio_reset(bio, ca->bdev, REQ_OP_READ);
+ bio->bi_iter.bi_sector = bucket + offset;
+ bio->bi_iter.bi_size = len << 9;
+
+ bio->bi_end_io = journal_read_endio;
+ bio->bi_private = &cl;
+ bch_bio_map(bio, data);
+
+ closure_bio_submit(ca->set, bio, &cl);
+ closure_sync(&cl);
+
+ /* This function could be simpler now since we no longer write
+ * journal entries that overlap bucket boundaries; this means
+ * the start of a bucket will always have a valid journal entry
+ * if it has any journal entries at all.
+ */
+
+ j = data;
+ while (len) {
+ struct list_head *where;
+ size_t blocks, bytes = set_bytes(j);
+
+ if (j->magic != jset_magic(&ca->sb)) {
+ pr_debug("%u: bad magic\n", bucket_index);
+ return ret;
+ }
+
+ if (bytes > left << 9 ||
+ bytes > PAGE_SIZE << JSET_BITS) {
+ pr_info("%u: too big, %zu bytes, offset %u\n",
+ bucket_index, bytes, offset);
+ return ret;
+ }
+
+ if (bytes > len << 9)
+ goto reread;
+
+ if (j->csum != csum_set(j)) {
+ pr_info("%u: bad csum, %zu bytes, offset %u\n",
+ bucket_index, bytes, offset);
+ return ret;
+ }
+
+ blocks = set_blocks(j, block_bytes(ca));
+
+ /*
+ * Nodes in 'list' are in linear increasing order of
+ * i->j.seq, the node on head has the smallest (oldest)
+ * journal seq, the node on tail has the biggest
+ * (latest) journal seq.
+ */
+
+ /*
+ * Check from the oldest jset for last_seq. If
+ * i->j.seq < j->last_seq, it means the oldest jset
+ * in list is expired and useless, remove it from
+ * this list. Otherwise, j is a candidate jset for
+ * further following checks.
+ */
+ while (!list_empty(list)) {
+ i = list_first_entry(list,
+ struct journal_replay, list);
+ if (i->j.seq >= j->last_seq)
+ break;
+ list_del(&i->list);
+ kfree(i);
+ }
+
+ /* iterate list in reverse order (from latest jset) */
+ list_for_each_entry_reverse(i, list, list) {
+ if (j->seq == i->j.seq)
+ goto next_set;
+
+ /*
+ * if j->seq is less than any i->j.last_seq
+ * in list, j is an expired and useless jset.
+ */
+ if (j->seq < i->j.last_seq)
+ goto next_set;
+
+ /*
+ * 'where' points to first jset in list which
+ * is elder then j.
+ */
+ if (j->seq > i->j.seq) {
+ where = &i->list;
+ goto add;
+ }
+ }
+
+ where = list;
+add:
+ i = kmalloc(offsetof(struct journal_replay, j) +
+ bytes, GFP_KERNEL);
+ if (!i)
+ return -ENOMEM;
+ unsafe_memcpy(&i->j, j, bytes,
+ /* "bytes" was calculated by set_bytes() above */);
+ /* Add to the location after 'where' points to */
+ list_add(&i->list, where);
+ ret = 1;
+
+ if (j->seq > ja->seq[bucket_index])
+ ja->seq[bucket_index] = j->seq;
+next_set:
+ offset += blocks * ca->sb.block_size;
+ len -= blocks * ca->sb.block_size;
+ j = ((void *) j) + blocks * block_bytes(ca);
+ }
+ }
+
+ return ret;
+}
+
+int bch_journal_read(struct cache_set *c, struct list_head *list)
+{
+#define read_bucket(b) \
+ ({ \
+ ret = journal_read_bucket(ca, list, b); \
+ __set_bit(b, bitmap); \
+ if (ret < 0) \
+ return ret; \
+ ret; \
+ })
+
+ struct cache *ca = c->cache;
+ int ret = 0;
+ struct journal_device *ja = &ca->journal;
+ DECLARE_BITMAP(bitmap, SB_JOURNAL_BUCKETS);
+ unsigned int i, l, r, m;
+ uint64_t seq;
+
+ bitmap_zero(bitmap, SB_JOURNAL_BUCKETS);
+ pr_debug("%u journal buckets\n", ca->sb.njournal_buckets);
+
+ /*
+ * Read journal buckets ordered by golden ratio hash to quickly
+ * find a sequence of buckets with valid journal entries
+ */
+ for (i = 0; i < ca->sb.njournal_buckets; i++) {
+ /*
+ * We must try the index l with ZERO first for
+ * correctness due to the scenario that the journal
+ * bucket is circular buffer which might have wrapped
+ */
+ l = (i * 2654435769U) % ca->sb.njournal_buckets;
+
+ if (test_bit(l, bitmap))
+ break;
+
+ if (read_bucket(l))
+ goto bsearch;
+ }
+
+ /*
+ * If that fails, check all the buckets we haven't checked
+ * already
+ */
+ pr_debug("falling back to linear search\n");
+
+ for_each_clear_bit(l, bitmap, ca->sb.njournal_buckets)
+ if (read_bucket(l))
+ goto bsearch;
+
+ /* no journal entries on this device? */
+ if (l == ca->sb.njournal_buckets)
+ goto out;
+bsearch:
+ BUG_ON(list_empty(list));
+
+ /* Binary search */
+ m = l;
+ r = find_next_bit(bitmap, ca->sb.njournal_buckets, l + 1);
+ pr_debug("starting binary search, l %u r %u\n", l, r);
+
+ while (l + 1 < r) {
+ seq = list_entry(list->prev, struct journal_replay,
+ list)->j.seq;
+
+ m = (l + r) >> 1;
+ read_bucket(m);
+
+ if (seq != list_entry(list->prev, struct journal_replay,
+ list)->j.seq)
+ l = m;
+ else
+ r = m;
+ }
+
+ /*
+ * Read buckets in reverse order until we stop finding more
+ * journal entries
+ */
+ pr_debug("finishing up: m %u njournal_buckets %u\n",
+ m, ca->sb.njournal_buckets);
+ l = m;
+
+ while (1) {
+ if (!l--)
+ l = ca->sb.njournal_buckets - 1;
+
+ if (l == m)
+ break;
+
+ if (test_bit(l, bitmap))
+ continue;
+
+ if (!read_bucket(l))
+ break;
+ }
+
+ seq = 0;
+
+ for (i = 0; i < ca->sb.njournal_buckets; i++)
+ if (ja->seq[i] > seq) {
+ seq = ja->seq[i];
+ /*
+ * When journal_reclaim() goes to allocate for
+ * the first time, it'll use the bucket after
+ * ja->cur_idx
+ */
+ ja->cur_idx = i;
+ ja->last_idx = ja->discard_idx = (i + 1) %
+ ca->sb.njournal_buckets;
+
+ }
+
+out:
+ if (!list_empty(list))
+ c->journal.seq = list_entry(list->prev,
+ struct journal_replay,
+ list)->j.seq;
+
+ return 0;
+#undef read_bucket
+}
+
+void bch_journal_mark(struct cache_set *c, struct list_head *list)
+{
+ atomic_t p = { 0 };
+ struct bkey *k;
+ struct journal_replay *i;
+ struct journal *j = &c->journal;
+ uint64_t last = j->seq;
+
+ /*
+ * journal.pin should never fill up - we never write a journal
+ * entry when it would fill up. But if for some reason it does, we
+ * iterate over the list in reverse order so that we can just skip that
+ * refcount instead of bugging.
+ */
+
+ list_for_each_entry_reverse(i, list, list) {
+ BUG_ON(last < i->j.seq);
+ i->pin = NULL;
+
+ while (last-- != i->j.seq)
+ if (fifo_free(&j->pin) > 1) {
+ fifo_push_front(&j->pin, p);
+ atomic_set(&fifo_front(&j->pin), 0);
+ }
+
+ if (fifo_free(&j->pin) > 1) {
+ fifo_push_front(&j->pin, p);
+ i->pin = &fifo_front(&j->pin);
+ atomic_set(i->pin, 1);
+ }
+
+ for (k = i->j.start;
+ k < bset_bkey_last(&i->j);
+ k = bkey_next(k))
+ if (!__bch_extent_invalid(c, k)) {
+ unsigned int j;
+
+ for (j = 0; j < KEY_PTRS(k); j++)
+ if (ptr_available(c, k, j))
+ atomic_inc(&PTR_BUCKET(c, k, j)->pin);
+
+ bch_initial_mark_key(c, 0, k);
+ }
+ }
+}
+
+static bool is_discard_enabled(struct cache_set *s)
+{
+ struct cache *ca = s->cache;
+
+ if (ca->discard)
+ return true;
+
+ return false;
+}
+
+int bch_journal_replay(struct cache_set *s, struct list_head *list)
+{
+ int ret = 0, keys = 0, entries = 0;
+ struct bkey *k;
+ struct journal_replay *i =
+ list_entry(list->prev, struct journal_replay, list);
+
+ uint64_t start = i->j.last_seq, end = i->j.seq, n = start;
+ struct keylist keylist;
+
+ list_for_each_entry(i, list, list) {
+ BUG_ON(i->pin && atomic_read(i->pin) != 1);
+
+ if (n != i->j.seq) {
+ if (n == start && is_discard_enabled(s))
+ pr_info("journal entries %llu-%llu may be discarded! (replaying %llu-%llu)\n",
+ n, i->j.seq - 1, start, end);
+ else {
+ pr_err("journal entries %llu-%llu missing! (replaying %llu-%llu)\n",
+ n, i->j.seq - 1, start, end);
+ ret = -EIO;
+ goto err;
+ }
+ }
+
+ for (k = i->j.start;
+ k < bset_bkey_last(&i->j);
+ k = bkey_next(k)) {
+ trace_bcache_journal_replay_key(k);
+
+ bch_keylist_init_single(&keylist, k);
+
+ ret = bch_btree_insert(s, &keylist, i->pin, NULL);
+ if (ret)
+ goto err;
+
+ BUG_ON(!bch_keylist_empty(&keylist));
+ keys++;
+
+ cond_resched();
+ }
+
+ if (i->pin)
+ atomic_dec(i->pin);
+ n = i->j.seq + 1;
+ entries++;
+ }
+
+ pr_info("journal replay done, %i keys in %i entries, seq %llu\n",
+ keys, entries, end);
+err:
+ while (!list_empty(list)) {
+ i = list_first_entry(list, struct journal_replay, list);
+ list_del(&i->list);
+ kfree(i);
+ }
+
+ return ret;
+}
+
+void bch_journal_space_reserve(struct journal *j)
+{
+ j->do_reserve = true;
+}
+
+/* Journalling */
+
+static void btree_flush_write(struct cache_set *c)
+{
+ struct btree *b, *t, *btree_nodes[BTREE_FLUSH_NR];
+ unsigned int i, nr;
+ int ref_nr;
+ atomic_t *fifo_front_p, *now_fifo_front_p;
+ size_t mask;
+
+ if (c->journal.btree_flushing)
+ return;
+
+ spin_lock(&c->journal.flush_write_lock);
+ if (c->journal.btree_flushing) {
+ spin_unlock(&c->journal.flush_write_lock);
+ return;
+ }
+ c->journal.btree_flushing = true;
+ spin_unlock(&c->journal.flush_write_lock);
+
+ /* get the oldest journal entry and check its refcount */
+ spin_lock(&c->journal.lock);
+ fifo_front_p = &fifo_front(&c->journal.pin);
+ ref_nr = atomic_read(fifo_front_p);
+ if (ref_nr <= 0) {
+ /*
+ * do nothing if no btree node references
+ * the oldest journal entry
+ */
+ spin_unlock(&c->journal.lock);
+ goto out;
+ }
+ spin_unlock(&c->journal.lock);
+
+ mask = c->journal.pin.mask;
+ nr = 0;
+ atomic_long_inc(&c->flush_write);
+ memset(btree_nodes, 0, sizeof(btree_nodes));
+
+ mutex_lock(&c->bucket_lock);
+ list_for_each_entry_safe_reverse(b, t, &c->btree_cache, list) {
+ /*
+ * It is safe to get now_fifo_front_p without holding
+ * c->journal.lock here, because we don't need to know
+ * the exactly accurate value, just check whether the
+ * front pointer of c->journal.pin is changed.
+ */
+ now_fifo_front_p = &fifo_front(&c->journal.pin);
+ /*
+ * If the oldest journal entry is reclaimed and front
+ * pointer of c->journal.pin changes, it is unnecessary
+ * to scan c->btree_cache anymore, just quit the loop and
+ * flush out what we have already.
+ */
+ if (now_fifo_front_p != fifo_front_p)
+ break;
+ /*
+ * quit this loop if all matching btree nodes are
+ * scanned and record in btree_nodes[] already.
+ */
+ ref_nr = atomic_read(fifo_front_p);
+ if (nr >= ref_nr)
+ break;
+
+ if (btree_node_journal_flush(b))
+ pr_err("BUG: flush_write bit should not be set here!\n");
+
+ mutex_lock(&b->write_lock);
+
+ if (!btree_node_dirty(b)) {
+ mutex_unlock(&b->write_lock);
+ continue;
+ }
+
+ if (!btree_current_write(b)->journal) {
+ mutex_unlock(&b->write_lock);
+ continue;
+ }
+
+ /*
+ * Only select the btree node which exactly references
+ * the oldest journal entry.
+ *
+ * If the journal entry pointed by fifo_front_p is
+ * reclaimed in parallel, don't worry:
+ * - the list_for_each_xxx loop will quit when checking
+ * next now_fifo_front_p.
+ * - If there are matched nodes recorded in btree_nodes[],
+ * they are clean now (this is why and how the oldest
+ * journal entry can be reclaimed). These selected nodes
+ * will be ignored and skipped in the following for-loop.
+ */
+ if (((btree_current_write(b)->journal - fifo_front_p) &
+ mask) != 0) {
+ mutex_unlock(&b->write_lock);
+ continue;
+ }
+
+ set_btree_node_journal_flush(b);
+
+ mutex_unlock(&b->write_lock);
+
+ btree_nodes[nr++] = b;
+ /*
+ * To avoid holding c->bucket_lock too long time,
+ * only scan for BTREE_FLUSH_NR matched btree nodes
+ * at most. If there are more btree nodes reference
+ * the oldest journal entry, try to flush them next
+ * time when btree_flush_write() is called.
+ */
+ if (nr == BTREE_FLUSH_NR)
+ break;
+ }
+ mutex_unlock(&c->bucket_lock);
+
+ for (i = 0; i < nr; i++) {
+ b = btree_nodes[i];
+ if (!b) {
+ pr_err("BUG: btree_nodes[%d] is NULL\n", i);
+ continue;
+ }
+
+ /* safe to check without holding b->write_lock */
+ if (!btree_node_journal_flush(b)) {
+ pr_err("BUG: bnode %p: journal_flush bit cleaned\n", b);
+ continue;
+ }
+
+ mutex_lock(&b->write_lock);
+ if (!btree_current_write(b)->journal) {
+ clear_bit(BTREE_NODE_journal_flush, &b->flags);
+ mutex_unlock(&b->write_lock);
+ pr_debug("bnode %p: written by others\n", b);
+ continue;
+ }
+
+ if (!btree_node_dirty(b)) {
+ clear_bit(BTREE_NODE_journal_flush, &b->flags);
+ mutex_unlock(&b->write_lock);
+ pr_debug("bnode %p: dirty bit cleaned by others\n", b);
+ continue;
+ }
+
+ __bch_btree_node_write(b, NULL);
+ clear_bit(BTREE_NODE_journal_flush, &b->flags);
+ mutex_unlock(&b->write_lock);
+ }
+
+out:
+ spin_lock(&c->journal.flush_write_lock);
+ c->journal.btree_flushing = false;
+ spin_unlock(&c->journal.flush_write_lock);
+}
+
+#define last_seq(j) ((j)->seq - fifo_used(&(j)->pin) + 1)
+
+static void journal_discard_endio(struct bio *bio)
+{
+ struct journal_device *ja =
+ container_of(bio, struct journal_device, discard_bio);
+ struct cache *ca = container_of(ja, struct cache, journal);
+
+ atomic_set(&ja->discard_in_flight, DISCARD_DONE);
+
+ closure_wake_up(&ca->set->journal.wait);
+ closure_put(&ca->set->cl);
+}
+
+static void journal_discard_work(struct work_struct *work)
+{
+ struct journal_device *ja =
+ container_of(work, struct journal_device, discard_work);
+
+ submit_bio(&ja->discard_bio);
+}
+
+static void do_journal_discard(struct cache *ca)
+{
+ struct journal_device *ja = &ca->journal;
+ struct bio *bio = &ja->discard_bio;
+
+ if (!ca->discard) {
+ ja->discard_idx = ja->last_idx;
+ return;
+ }
+
+ switch (atomic_read(&ja->discard_in_flight)) {
+ case DISCARD_IN_FLIGHT:
+ return;
+
+ case DISCARD_DONE:
+ ja->discard_idx = (ja->discard_idx + 1) %
+ ca->sb.njournal_buckets;
+
+ atomic_set(&ja->discard_in_flight, DISCARD_READY);
+ fallthrough;
+
+ case DISCARD_READY:
+ if (ja->discard_idx == ja->last_idx)
+ return;
+
+ atomic_set(&ja->discard_in_flight, DISCARD_IN_FLIGHT);
+
+ bio_init(bio, ca->bdev, bio->bi_inline_vecs, 1, REQ_OP_DISCARD);
+ bio->bi_iter.bi_sector = bucket_to_sector(ca->set,
+ ca->sb.d[ja->discard_idx]);
+ bio->bi_iter.bi_size = bucket_bytes(ca);
+ bio->bi_end_io = journal_discard_endio;
+
+ closure_get(&ca->set->cl);
+ INIT_WORK(&ja->discard_work, journal_discard_work);
+ queue_work(bch_journal_wq, &ja->discard_work);
+ }
+}
+
+static unsigned int free_journal_buckets(struct cache_set *c)
+{
+ struct journal *j = &c->journal;
+ struct cache *ca = c->cache;
+ struct journal_device *ja = &c->cache->journal;
+ unsigned int n;
+
+ /* In case njournal_buckets is not power of 2 */
+ if (ja->cur_idx >= ja->discard_idx)
+ n = ca->sb.njournal_buckets + ja->discard_idx - ja->cur_idx;
+ else
+ n = ja->discard_idx - ja->cur_idx;
+
+ if (n > (1 + j->do_reserve))
+ return n - (1 + j->do_reserve);
+
+ return 0;
+}
+
+static void journal_reclaim(struct cache_set *c)
+{
+ struct bkey *k = &c->journal.key;
+ struct cache *ca = c->cache;
+ uint64_t last_seq;
+ struct journal_device *ja = &ca->journal;
+ atomic_t p __maybe_unused;
+
+ atomic_long_inc(&c->reclaim);
+
+ while (!atomic_read(&fifo_front(&c->journal.pin)))
+ fifo_pop(&c->journal.pin, p);
+
+ last_seq = last_seq(&c->journal);
+
+ /* Update last_idx */
+
+ while (ja->last_idx != ja->cur_idx &&
+ ja->seq[ja->last_idx] < last_seq)
+ ja->last_idx = (ja->last_idx + 1) %
+ ca->sb.njournal_buckets;
+
+ do_journal_discard(ca);
+
+ if (c->journal.blocks_free)
+ goto out;
+
+ if (!free_journal_buckets(c))
+ goto out;
+
+ ja->cur_idx = (ja->cur_idx + 1) % ca->sb.njournal_buckets;
+ k->ptr[0] = MAKE_PTR(0,
+ bucket_to_sector(c, ca->sb.d[ja->cur_idx]),
+ ca->sb.nr_this_dev);
+ atomic_long_inc(&c->reclaimed_journal_buckets);
+
+ bkey_init(k);
+ SET_KEY_PTRS(k, 1);
+ c->journal.blocks_free = ca->sb.bucket_size >> c->block_bits;
+
+out:
+ if (!journal_full(&c->journal))
+ __closure_wake_up(&c->journal.wait);
+}
+
+void bch_journal_next(struct journal *j)
+{
+ atomic_t p = { 1 };
+
+ j->cur = (j->cur == j->w)
+ ? &j->w[1]
+ : &j->w[0];
+
+ /*
+ * The fifo_push() needs to happen at the same time as j->seq is
+ * incremented for last_seq() to be calculated correctly
+ */
+ BUG_ON(!fifo_push(&j->pin, p));
+ atomic_set(&fifo_back(&j->pin), 1);
+
+ j->cur->data->seq = ++j->seq;
+ j->cur->dirty = false;
+ j->cur->need_write = false;
+ j->cur->data->keys = 0;
+
+ if (fifo_full(&j->pin))
+ pr_debug("journal_pin full (%zu)\n", fifo_used(&j->pin));
+}
+
+static void journal_write_endio(struct bio *bio)
+{
+ struct journal_write *w = bio->bi_private;
+
+ cache_set_err_on(bio->bi_status, w->c, "journal io error");
+ closure_put(&w->c->journal.io);
+}
+
+static void journal_write(struct closure *cl);
+
+static void journal_write_done(struct closure *cl)
+{
+ struct journal *j = container_of(cl, struct journal, io);
+ struct journal_write *w = (j->cur == j->w)
+ ? &j->w[1]
+ : &j->w[0];
+
+ __closure_wake_up(&w->wait);
+ continue_at_nobarrier(cl, journal_write, bch_journal_wq);
+}
+
+static void journal_write_unlock(struct closure *cl)
+ __releases(&c->journal.lock)
+{
+ struct cache_set *c = container_of(cl, struct cache_set, journal.io);
+
+ c->journal.io_in_flight = 0;
+ spin_unlock(&c->journal.lock);
+}
+
+static void journal_write_unlocked(struct closure *cl)
+ __releases(c->journal.lock)
+{
+ struct cache_set *c = container_of(cl, struct cache_set, journal.io);
+ struct cache *ca = c->cache;
+ struct journal_write *w = c->journal.cur;
+ struct bkey *k = &c->journal.key;
+ unsigned int i, sectors = set_blocks(w->data, block_bytes(ca)) *
+ ca->sb.block_size;
+
+ struct bio *bio;
+ struct bio_list list;
+
+ bio_list_init(&list);
+
+ if (!w->need_write) {
+ closure_return_with_destructor(cl, journal_write_unlock);
+ return;
+ } else if (journal_full(&c->journal)) {
+ journal_reclaim(c);
+ spin_unlock(&c->journal.lock);
+
+ btree_flush_write(c);
+ continue_at(cl, journal_write, bch_journal_wq);
+ return;
+ }
+
+ c->journal.blocks_free -= set_blocks(w->data, block_bytes(ca));
+
+ w->data->btree_level = c->root->level;
+
+ bkey_copy(&w->data->btree_root, &c->root->key);
+ bkey_copy(&w->data->uuid_bucket, &c->uuid_bucket);
+
+ w->data->prio_bucket[ca->sb.nr_this_dev] = ca->prio_buckets[0];
+ w->data->magic = jset_magic(&ca->sb);
+ w->data->version = BCACHE_JSET_VERSION;
+ w->data->last_seq = last_seq(&c->journal);
+ w->data->csum = csum_set(w->data);
+
+ for (i = 0; i < KEY_PTRS(k); i++) {
+ ca = c->cache;
+ bio = &ca->journal.bio;
+
+ atomic_long_add(sectors, &ca->meta_sectors_written);
+
+ bio_reset(bio, ca->bdev, REQ_OP_WRITE |
+ REQ_SYNC | REQ_META | REQ_PREFLUSH | REQ_FUA);
+ bio->bi_iter.bi_sector = PTR_OFFSET(k, i);
+ bio->bi_iter.bi_size = sectors << 9;
+
+ bio->bi_end_io = journal_write_endio;
+ bio->bi_private = w;
+ bch_bio_map(bio, w->data);
+
+ trace_bcache_journal_write(bio, w->data->keys);
+ bio_list_add(&list, bio);
+
+ SET_PTR_OFFSET(k, i, PTR_OFFSET(k, i) + sectors);
+
+ ca->journal.seq[ca->journal.cur_idx] = w->data->seq;
+ }
+
+ /* If KEY_PTRS(k) == 0, this jset gets lost in air */
+ BUG_ON(i == 0);
+
+ atomic_dec_bug(&fifo_back(&c->journal.pin));
+ bch_journal_next(&c->journal);
+ journal_reclaim(c);
+
+ spin_unlock(&c->journal.lock);
+
+ while ((bio = bio_list_pop(&list)))
+ closure_bio_submit(c, bio, cl);
+
+ continue_at(cl, journal_write_done, NULL);
+}
+
+static void journal_write(struct closure *cl)
+{
+ struct cache_set *c = container_of(cl, struct cache_set, journal.io);
+
+ spin_lock(&c->journal.lock);
+ journal_write_unlocked(cl);
+}
+
+static void journal_try_write(struct cache_set *c)
+ __releases(c->journal.lock)
+{
+ struct closure *cl = &c->journal.io;
+ struct journal_write *w = c->journal.cur;
+
+ w->need_write = true;
+
+ if (!c->journal.io_in_flight) {
+ c->journal.io_in_flight = 1;
+ closure_call(cl, journal_write_unlocked, NULL, &c->cl);
+ } else {
+ spin_unlock(&c->journal.lock);
+ }
+}
+
+static struct journal_write *journal_wait_for_write(struct cache_set *c,
+ unsigned int nkeys)
+ __acquires(&c->journal.lock)
+{
+ size_t sectors;
+ struct closure cl;
+ bool wait = false;
+ struct cache *ca = c->cache;
+
+ closure_init_stack(&cl);
+
+ spin_lock(&c->journal.lock);
+
+ while (1) {
+ struct journal_write *w = c->journal.cur;
+
+ sectors = __set_blocks(w->data, w->data->keys + nkeys,
+ block_bytes(ca)) * ca->sb.block_size;
+
+ if (sectors <= min_t(size_t,
+ c->journal.blocks_free * ca->sb.block_size,
+ PAGE_SECTORS << JSET_BITS))
+ return w;
+
+ if (wait)
+ closure_wait(&c->journal.wait, &cl);
+
+ if (!journal_full(&c->journal)) {
+ if (wait)
+ trace_bcache_journal_entry_full(c);
+
+ /*
+ * XXX: If we were inserting so many keys that they
+ * won't fit in an _empty_ journal write, we'll
+ * deadlock. For now, handle this in
+ * bch_keylist_realloc() - but something to think about.
+ */
+ BUG_ON(!w->data->keys);
+
+ journal_try_write(c); /* unlocks */
+ } else {
+ if (wait)
+ trace_bcache_journal_full(c);
+
+ journal_reclaim(c);
+ spin_unlock(&c->journal.lock);
+
+ btree_flush_write(c);
+ }
+
+ closure_sync(&cl);
+ spin_lock(&c->journal.lock);
+ wait = true;
+ }
+}
+
+static void journal_write_work(struct work_struct *work)
+{
+ struct cache_set *c = container_of(to_delayed_work(work),
+ struct cache_set,
+ journal.work);
+ spin_lock(&c->journal.lock);
+ if (c->journal.cur->dirty)
+ journal_try_write(c);
+ else
+ spin_unlock(&c->journal.lock);
+}
+
+/*
+ * Entry point to the journalling code - bio_insert() and btree_invalidate()
+ * pass bch_journal() a list of keys to be journalled, and then
+ * bch_journal() hands those same keys off to btree_insert_async()
+ */
+
+atomic_t *bch_journal(struct cache_set *c,
+ struct keylist *keys,
+ struct closure *parent)
+{
+ struct journal_write *w;
+ atomic_t *ret;
+
+ /* No journaling if CACHE_SET_IO_DISABLE set already */
+ if (unlikely(test_bit(CACHE_SET_IO_DISABLE, &c->flags)))
+ return NULL;
+
+ if (!CACHE_SYNC(&c->cache->sb))
+ return NULL;
+
+ w = journal_wait_for_write(c, bch_keylist_nkeys(keys));
+
+ memcpy(bset_bkey_last(w->data), keys->keys, bch_keylist_bytes(keys));
+ w->data->keys += bch_keylist_nkeys(keys);
+
+ ret = &fifo_back(&c->journal.pin);
+ atomic_inc(ret);
+
+ if (parent) {
+ closure_wait(&w->wait, parent);
+ journal_try_write(c);
+ } else if (!w->dirty) {
+ w->dirty = true;
+ queue_delayed_work(bch_flush_wq, &c->journal.work,
+ msecs_to_jiffies(c->journal_delay_ms));
+ spin_unlock(&c->journal.lock);
+ } else {
+ spin_unlock(&c->journal.lock);
+ }
+
+
+ return ret;
+}
+
+void bch_journal_meta(struct cache_set *c, struct closure *cl)
+{
+ struct keylist keys;
+ atomic_t *ref;
+
+ bch_keylist_init(&keys);
+
+ ref = bch_journal(c, &keys, cl);
+ if (ref)
+ atomic_dec_bug(ref);
+}
+
+void bch_journal_free(struct cache_set *c)
+{
+ free_pages((unsigned long) c->journal.w[1].data, JSET_BITS);
+ free_pages((unsigned long) c->journal.w[0].data, JSET_BITS);
+ free_fifo(&c->journal.pin);
+}
+
+int bch_journal_alloc(struct cache_set *c)
+{
+ struct journal *j = &c->journal;
+
+ spin_lock_init(&j->lock);
+ spin_lock_init(&j->flush_write_lock);
+ INIT_DELAYED_WORK(&j->work, journal_write_work);
+
+ c->journal_delay_ms = 100;
+
+ j->w[0].c = c;
+ j->w[1].c = c;
+
+ if (!(init_fifo(&j->pin, JOURNAL_PIN, GFP_KERNEL)) ||
+ !(j->w[0].data = (void *) __get_free_pages(GFP_KERNEL|__GFP_COMP, JSET_BITS)) ||
+ !(j->w[1].data = (void *) __get_free_pages(GFP_KERNEL|__GFP_COMP, JSET_BITS)))
+ return -ENOMEM;
+
+ return 0;
+}