summaryrefslogtreecommitdiffstats
path: root/fs/bcachefs/journal_reclaim.c
diff options
context:
space:
mode:
Diffstat (limited to 'fs/bcachefs/journal_reclaim.c')
-rw-r--r--fs/bcachefs/journal_reclaim.c867
1 files changed, 867 insertions, 0 deletions
diff --git a/fs/bcachefs/journal_reclaim.c b/fs/bcachefs/journal_reclaim.c
new file mode 100644
index 0000000000..ec712104ad
--- /dev/null
+++ b/fs/bcachefs/journal_reclaim.c
@@ -0,0 +1,867 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include "bcachefs.h"
+#include "btree_key_cache.h"
+#include "btree_update.h"
+#include "buckets.h"
+#include "errcode.h"
+#include "error.h"
+#include "journal.h"
+#include "journal_io.h"
+#include "journal_reclaim.h"
+#include "replicas.h"
+#include "sb-members.h"
+#include "trace.h"
+
+#include <linux/kthread.h>
+#include <linux/sched/mm.h>
+
+/* Free space calculations: */
+
+static unsigned journal_space_from(struct journal_device *ja,
+ enum journal_space_from from)
+{
+ switch (from) {
+ case journal_space_discarded:
+ return ja->discard_idx;
+ case journal_space_clean_ondisk:
+ return ja->dirty_idx_ondisk;
+ case journal_space_clean:
+ return ja->dirty_idx;
+ default:
+ BUG();
+ }
+}
+
+unsigned bch2_journal_dev_buckets_available(struct journal *j,
+ struct journal_device *ja,
+ enum journal_space_from from)
+{
+ unsigned available = (journal_space_from(ja, from) -
+ ja->cur_idx - 1 + ja->nr) % ja->nr;
+
+ /*
+ * Don't use the last bucket unless writing the new last_seq
+ * will make another bucket available:
+ */
+ if (available && ja->dirty_idx_ondisk == ja->dirty_idx)
+ --available;
+
+ return available;
+}
+
+static inline void journal_set_watermark(struct journal *j, bool low_on_space)
+{
+ unsigned watermark = BCH_WATERMARK_stripe;
+
+ if (low_on_space)
+ watermark = max_t(unsigned, watermark, BCH_WATERMARK_reclaim);
+ if (fifo_free(&j->pin) < j->pin.size / 4)
+ watermark = max_t(unsigned, watermark, BCH_WATERMARK_reclaim);
+
+ if (watermark == j->watermark)
+ return;
+
+ swap(watermark, j->watermark);
+ if (watermark > j->watermark)
+ journal_wake(j);
+}
+
+static struct journal_space
+journal_dev_space_available(struct journal *j, struct bch_dev *ca,
+ enum journal_space_from from)
+{
+ struct journal_device *ja = &ca->journal;
+ unsigned sectors, buckets, unwritten;
+ u64 seq;
+
+ if (from == journal_space_total)
+ return (struct journal_space) {
+ .next_entry = ca->mi.bucket_size,
+ .total = ca->mi.bucket_size * ja->nr,
+ };
+
+ buckets = bch2_journal_dev_buckets_available(j, ja, from);
+ sectors = ja->sectors_free;
+
+ /*
+ * We that we don't allocate the space for a journal entry
+ * until we write it out - thus, account for it here:
+ */
+ for (seq = journal_last_unwritten_seq(j);
+ seq <= journal_cur_seq(j);
+ seq++) {
+ unwritten = j->buf[seq & JOURNAL_BUF_MASK].sectors;
+
+ if (!unwritten)
+ continue;
+
+ /* entry won't fit on this device, skip: */
+ if (unwritten > ca->mi.bucket_size)
+ continue;
+
+ if (unwritten >= sectors) {
+ if (!buckets) {
+ sectors = 0;
+ break;
+ }
+
+ buckets--;
+ sectors = ca->mi.bucket_size;
+ }
+
+ sectors -= unwritten;
+ }
+
+ if (sectors < ca->mi.bucket_size && buckets) {
+ buckets--;
+ sectors = ca->mi.bucket_size;
+ }
+
+ return (struct journal_space) {
+ .next_entry = sectors,
+ .total = sectors + buckets * ca->mi.bucket_size,
+ };
+}
+
+static struct journal_space __journal_space_available(struct journal *j, unsigned nr_devs_want,
+ enum journal_space_from from)
+{
+ struct bch_fs *c = container_of(j, struct bch_fs, journal);
+ struct bch_dev *ca;
+ unsigned i, pos, nr_devs = 0;
+ struct journal_space space, dev_space[BCH_SB_MEMBERS_MAX];
+
+ BUG_ON(nr_devs_want > ARRAY_SIZE(dev_space));
+
+ rcu_read_lock();
+ for_each_member_device_rcu(ca, c, i,
+ &c->rw_devs[BCH_DATA_journal]) {
+ if (!ca->journal.nr)
+ continue;
+
+ space = journal_dev_space_available(j, ca, from);
+ if (!space.next_entry)
+ continue;
+
+ for (pos = 0; pos < nr_devs; pos++)
+ if (space.total > dev_space[pos].total)
+ break;
+
+ array_insert_item(dev_space, nr_devs, pos, space);
+ }
+ rcu_read_unlock();
+
+ if (nr_devs < nr_devs_want)
+ return (struct journal_space) { 0, 0 };
+
+ /*
+ * We sorted largest to smallest, and we want the smallest out of the
+ * @nr_devs_want largest devices:
+ */
+ return dev_space[nr_devs_want - 1];
+}
+
+void bch2_journal_space_available(struct journal *j)
+{
+ struct bch_fs *c = container_of(j, struct bch_fs, journal);
+ struct bch_dev *ca;
+ unsigned clean, clean_ondisk, total;
+ unsigned max_entry_size = min(j->buf[0].buf_size >> 9,
+ j->buf[1].buf_size >> 9);
+ unsigned i, nr_online = 0, nr_devs_want;
+ bool can_discard = false;
+ int ret = 0;
+
+ lockdep_assert_held(&j->lock);
+
+ rcu_read_lock();
+ for_each_member_device_rcu(ca, c, i,
+ &c->rw_devs[BCH_DATA_journal]) {
+ struct journal_device *ja = &ca->journal;
+
+ if (!ja->nr)
+ continue;
+
+ while (ja->dirty_idx != ja->cur_idx &&
+ ja->bucket_seq[ja->dirty_idx] < journal_last_seq(j))
+ ja->dirty_idx = (ja->dirty_idx + 1) % ja->nr;
+
+ while (ja->dirty_idx_ondisk != ja->dirty_idx &&
+ ja->bucket_seq[ja->dirty_idx_ondisk] < j->last_seq_ondisk)
+ ja->dirty_idx_ondisk = (ja->dirty_idx_ondisk + 1) % ja->nr;
+
+ if (ja->discard_idx != ja->dirty_idx_ondisk)
+ can_discard = true;
+
+ max_entry_size = min_t(unsigned, max_entry_size, ca->mi.bucket_size);
+ nr_online++;
+ }
+ rcu_read_unlock();
+
+ j->can_discard = can_discard;
+
+ if (nr_online < c->opts.metadata_replicas_required) {
+ ret = JOURNAL_ERR_insufficient_devices;
+ goto out;
+ }
+
+ nr_devs_want = min_t(unsigned, nr_online, c->opts.metadata_replicas);
+
+ for (i = 0; i < journal_space_nr; i++)
+ j->space[i] = __journal_space_available(j, nr_devs_want, i);
+
+ clean_ondisk = j->space[journal_space_clean_ondisk].total;
+ clean = j->space[journal_space_clean].total;
+ total = j->space[journal_space_total].total;
+
+ if (!j->space[journal_space_discarded].next_entry)
+ ret = JOURNAL_ERR_journal_full;
+
+ if ((j->space[journal_space_clean_ondisk].next_entry <
+ j->space[journal_space_clean_ondisk].total) &&
+ (clean - clean_ondisk <= total / 8) &&
+ (clean_ondisk * 2 > clean))
+ set_bit(JOURNAL_MAY_SKIP_FLUSH, &j->flags);
+ else
+ clear_bit(JOURNAL_MAY_SKIP_FLUSH, &j->flags);
+
+ journal_set_watermark(j, clean * 4 <= total);
+out:
+ j->cur_entry_sectors = !ret ? j->space[journal_space_discarded].next_entry : 0;
+ j->cur_entry_error = ret;
+
+ if (!ret)
+ journal_wake(j);
+}
+
+/* Discards - last part of journal reclaim: */
+
+static bool should_discard_bucket(struct journal *j, struct journal_device *ja)
+{
+ bool ret;
+
+ spin_lock(&j->lock);
+ ret = ja->discard_idx != ja->dirty_idx_ondisk;
+ spin_unlock(&j->lock);
+
+ return ret;
+}
+
+/*
+ * Advance ja->discard_idx as long as it points to buckets that are no longer
+ * dirty, issuing discards if necessary:
+ */
+void bch2_journal_do_discards(struct journal *j)
+{
+ struct bch_fs *c = container_of(j, struct bch_fs, journal);
+ struct bch_dev *ca;
+ unsigned iter;
+
+ mutex_lock(&j->discard_lock);
+
+ for_each_rw_member(ca, c, iter) {
+ struct journal_device *ja = &ca->journal;
+
+ while (should_discard_bucket(j, ja)) {
+ if (!c->opts.nochanges &&
+ ca->mi.discard &&
+ bdev_max_discard_sectors(ca->disk_sb.bdev))
+ blkdev_issue_discard(ca->disk_sb.bdev,
+ bucket_to_sector(ca,
+ ja->buckets[ja->discard_idx]),
+ ca->mi.bucket_size, GFP_NOFS);
+
+ spin_lock(&j->lock);
+ ja->discard_idx = (ja->discard_idx + 1) % ja->nr;
+
+ bch2_journal_space_available(j);
+ spin_unlock(&j->lock);
+ }
+ }
+
+ mutex_unlock(&j->discard_lock);
+}
+
+/*
+ * Journal entry pinning - machinery for holding a reference on a given journal
+ * entry, holding it open to ensure it gets replayed during recovery:
+ */
+
+void bch2_journal_reclaim_fast(struct journal *j)
+{
+ bool popped = false;
+
+ lockdep_assert_held(&j->lock);
+
+ /*
+ * Unpin journal entries whose reference counts reached zero, meaning
+ * all btree nodes got written out
+ */
+ while (!fifo_empty(&j->pin) &&
+ !atomic_read(&fifo_peek_front(&j->pin).count)) {
+ j->pin.front++;
+ popped = true;
+ }
+
+ if (popped)
+ bch2_journal_space_available(j);
+}
+
+bool __bch2_journal_pin_put(struct journal *j, u64 seq)
+{
+ struct journal_entry_pin_list *pin_list = journal_seq_pin(j, seq);
+
+ return atomic_dec_and_test(&pin_list->count);
+}
+
+void bch2_journal_pin_put(struct journal *j, u64 seq)
+{
+ if (__bch2_journal_pin_put(j, seq)) {
+ spin_lock(&j->lock);
+ bch2_journal_reclaim_fast(j);
+ spin_unlock(&j->lock);
+ }
+}
+
+static inline bool __journal_pin_drop(struct journal *j,
+ struct journal_entry_pin *pin)
+{
+ struct journal_entry_pin_list *pin_list;
+
+ if (!journal_pin_active(pin))
+ return false;
+
+ if (j->flush_in_progress == pin)
+ j->flush_in_progress_dropped = true;
+
+ pin_list = journal_seq_pin(j, pin->seq);
+ pin->seq = 0;
+ list_del_init(&pin->list);
+
+ /*
+ * Unpinning a journal entry may make journal_next_bucket() succeed, if
+ * writing a new last_seq will now make another bucket available:
+ */
+ return atomic_dec_and_test(&pin_list->count) &&
+ pin_list == &fifo_peek_front(&j->pin);
+}
+
+void bch2_journal_pin_drop(struct journal *j,
+ struct journal_entry_pin *pin)
+{
+ spin_lock(&j->lock);
+ if (__journal_pin_drop(j, pin))
+ bch2_journal_reclaim_fast(j);
+ spin_unlock(&j->lock);
+}
+
+static enum journal_pin_type journal_pin_type(journal_pin_flush_fn fn)
+{
+ if (fn == bch2_btree_node_flush0 ||
+ fn == bch2_btree_node_flush1)
+ return JOURNAL_PIN_btree;
+ else if (fn == bch2_btree_key_cache_journal_flush)
+ return JOURNAL_PIN_key_cache;
+ else
+ return JOURNAL_PIN_other;
+}
+
+void bch2_journal_pin_set(struct journal *j, u64 seq,
+ struct journal_entry_pin *pin,
+ journal_pin_flush_fn flush_fn)
+{
+ struct journal_entry_pin_list *pin_list;
+ bool reclaim;
+
+ spin_lock(&j->lock);
+
+ if (seq < journal_last_seq(j)) {
+ /*
+ * bch2_journal_pin_copy() raced with bch2_journal_pin_drop() on
+ * the src pin - with the pin dropped, the entry to pin might no
+ * longer to exist, but that means there's no longer anything to
+ * copy and we can bail out here:
+ */
+ spin_unlock(&j->lock);
+ return;
+ }
+
+ pin_list = journal_seq_pin(j, seq);
+
+ reclaim = __journal_pin_drop(j, pin);
+
+ atomic_inc(&pin_list->count);
+ pin->seq = seq;
+ pin->flush = flush_fn;
+
+ if (flush_fn)
+ list_add(&pin->list, &pin_list->list[journal_pin_type(flush_fn)]);
+ else
+ list_add(&pin->list, &pin_list->flushed);
+
+ if (reclaim)
+ bch2_journal_reclaim_fast(j);
+ spin_unlock(&j->lock);
+
+ /*
+ * If the journal is currently full, we might want to call flush_fn
+ * immediately:
+ */
+ journal_wake(j);
+}
+
+/**
+ * bch2_journal_pin_flush: ensure journal pin callback is no longer running
+ * @j: journal object
+ * @pin: pin to flush
+ */
+void bch2_journal_pin_flush(struct journal *j, struct journal_entry_pin *pin)
+{
+ BUG_ON(journal_pin_active(pin));
+
+ wait_event(j->pin_flush_wait, j->flush_in_progress != pin);
+}
+
+/*
+ * Journal reclaim: flush references to open journal entries to reclaim space in
+ * the journal
+ *
+ * May be done by the journal code in the background as needed to free up space
+ * for more journal entries, or as part of doing a clean shutdown, or to migrate
+ * data off of a specific device:
+ */
+
+static struct journal_entry_pin *
+journal_get_next_pin(struct journal *j,
+ u64 seq_to_flush,
+ unsigned allowed_below_seq,
+ unsigned allowed_above_seq,
+ u64 *seq)
+{
+ struct journal_entry_pin_list *pin_list;
+ struct journal_entry_pin *ret = NULL;
+ unsigned i;
+
+ fifo_for_each_entry_ptr(pin_list, &j->pin, *seq) {
+ if (*seq > seq_to_flush && !allowed_above_seq)
+ break;
+
+ for (i = 0; i < JOURNAL_PIN_NR; i++)
+ if ((((1U << i) & allowed_below_seq) && *seq <= seq_to_flush) ||
+ ((1U << i) & allowed_above_seq)) {
+ ret = list_first_entry_or_null(&pin_list->list[i],
+ struct journal_entry_pin, list);
+ if (ret)
+ return ret;
+ }
+ }
+
+ return NULL;
+}
+
+/* returns true if we did work */
+static size_t journal_flush_pins(struct journal *j,
+ u64 seq_to_flush,
+ unsigned allowed_below_seq,
+ unsigned allowed_above_seq,
+ unsigned min_any,
+ unsigned min_key_cache)
+{
+ struct journal_entry_pin *pin;
+ size_t nr_flushed = 0;
+ journal_pin_flush_fn flush_fn;
+ u64 seq;
+ int err;
+
+ lockdep_assert_held(&j->reclaim_lock);
+
+ while (1) {
+ unsigned allowed_above = allowed_above_seq;
+ unsigned allowed_below = allowed_below_seq;
+
+ if (min_any) {
+ allowed_above |= ~0;
+ allowed_below |= ~0;
+ }
+
+ if (min_key_cache) {
+ allowed_above |= 1U << JOURNAL_PIN_key_cache;
+ allowed_below |= 1U << JOURNAL_PIN_key_cache;
+ }
+
+ cond_resched();
+
+ j->last_flushed = jiffies;
+
+ spin_lock(&j->lock);
+ pin = journal_get_next_pin(j, seq_to_flush, allowed_below, allowed_above, &seq);
+ if (pin) {
+ BUG_ON(j->flush_in_progress);
+ j->flush_in_progress = pin;
+ j->flush_in_progress_dropped = false;
+ flush_fn = pin->flush;
+ }
+ spin_unlock(&j->lock);
+
+ if (!pin)
+ break;
+
+ if (min_key_cache && pin->flush == bch2_btree_key_cache_journal_flush)
+ min_key_cache--;
+
+ if (min_any)
+ min_any--;
+
+ err = flush_fn(j, pin, seq);
+
+ spin_lock(&j->lock);
+ /* Pin might have been dropped or rearmed: */
+ if (likely(!err && !j->flush_in_progress_dropped))
+ list_move(&pin->list, &journal_seq_pin(j, seq)->flushed);
+ j->flush_in_progress = NULL;
+ j->flush_in_progress_dropped = false;
+ spin_unlock(&j->lock);
+
+ wake_up(&j->pin_flush_wait);
+
+ if (err)
+ break;
+
+ nr_flushed++;
+ }
+
+ return nr_flushed;
+}
+
+static u64 journal_seq_to_flush(struct journal *j)
+{
+ struct bch_fs *c = container_of(j, struct bch_fs, journal);
+ struct bch_dev *ca;
+ u64 seq_to_flush = 0;
+ unsigned iter;
+
+ spin_lock(&j->lock);
+
+ for_each_rw_member(ca, c, iter) {
+ struct journal_device *ja = &ca->journal;
+ unsigned nr_buckets, bucket_to_flush;
+
+ if (!ja->nr)
+ continue;
+
+ /* Try to keep the journal at most half full: */
+ nr_buckets = ja->nr / 2;
+
+ nr_buckets = min(nr_buckets, ja->nr);
+
+ bucket_to_flush = (ja->cur_idx + nr_buckets) % ja->nr;
+ seq_to_flush = max(seq_to_flush,
+ ja->bucket_seq[bucket_to_flush]);
+ }
+
+ /* Also flush if the pin fifo is more than half full */
+ seq_to_flush = max_t(s64, seq_to_flush,
+ (s64) journal_cur_seq(j) -
+ (j->pin.size >> 1));
+ spin_unlock(&j->lock);
+
+ return seq_to_flush;
+}
+
+/**
+ * __bch2_journal_reclaim - free up journal buckets
+ * @j: journal object
+ * @direct: direct or background reclaim?
+ * @kicked: requested to run since we last ran?
+ * Returns: 0 on success, or -EIO if the journal has been shutdown
+ *
+ * Background journal reclaim writes out btree nodes. It should be run
+ * early enough so that we never completely run out of journal buckets.
+ *
+ * High watermarks for triggering background reclaim:
+ * - FIFO has fewer than 512 entries left
+ * - fewer than 25% journal buckets free
+ *
+ * Background reclaim runs until low watermarks are reached:
+ * - FIFO has more than 1024 entries left
+ * - more than 50% journal buckets free
+ *
+ * As long as a reclaim can complete in the time it takes to fill up
+ * 512 journal entries or 25% of all journal buckets, then
+ * journal_next_bucket() should not stall.
+ */
+static int __bch2_journal_reclaim(struct journal *j, bool direct, bool kicked)
+{
+ struct bch_fs *c = container_of(j, struct bch_fs, journal);
+ bool kthread = (current->flags & PF_KTHREAD) != 0;
+ u64 seq_to_flush;
+ size_t min_nr, min_key_cache, nr_flushed;
+ unsigned flags;
+ int ret = 0;
+
+ /*
+ * We can't invoke memory reclaim while holding the reclaim_lock -
+ * journal reclaim is required to make progress for memory reclaim
+ * (cleaning the caches), so we can't get stuck in memory reclaim while
+ * we're holding the reclaim lock:
+ */
+ lockdep_assert_held(&j->reclaim_lock);
+ flags = memalloc_noreclaim_save();
+
+ do {
+ if (kthread && kthread_should_stop())
+ break;
+
+ if (bch2_journal_error(j)) {
+ ret = -EIO;
+ break;
+ }
+
+ bch2_journal_do_discards(j);
+
+ seq_to_flush = journal_seq_to_flush(j);
+ min_nr = 0;
+
+ /*
+ * If it's been longer than j->reclaim_delay_ms since we last flushed,
+ * make sure to flush at least one journal pin:
+ */
+ if (time_after(jiffies, j->last_flushed +
+ msecs_to_jiffies(c->opts.journal_reclaim_delay)))
+ min_nr = 1;
+
+ if (j->watermark != BCH_WATERMARK_stripe)
+ min_nr = 1;
+
+ if (atomic_read(&c->btree_cache.dirty) * 2 > c->btree_cache.used)
+ min_nr = 1;
+
+ min_key_cache = min(bch2_nr_btree_keys_need_flush(c), (size_t) 128);
+
+ trace_and_count(c, journal_reclaim_start, c,
+ direct, kicked,
+ min_nr, min_key_cache,
+ atomic_read(&c->btree_cache.dirty),
+ c->btree_cache.used,
+ atomic_long_read(&c->btree_key_cache.nr_dirty),
+ atomic_long_read(&c->btree_key_cache.nr_keys));
+
+ nr_flushed = journal_flush_pins(j, seq_to_flush,
+ ~0, 0,
+ min_nr, min_key_cache);
+
+ if (direct)
+ j->nr_direct_reclaim += nr_flushed;
+ else
+ j->nr_background_reclaim += nr_flushed;
+ trace_and_count(c, journal_reclaim_finish, c, nr_flushed);
+
+ if (nr_flushed)
+ wake_up(&j->reclaim_wait);
+ } while ((min_nr || min_key_cache) && nr_flushed && !direct);
+
+ memalloc_noreclaim_restore(flags);
+
+ return ret;
+}
+
+int bch2_journal_reclaim(struct journal *j)
+{
+ return __bch2_journal_reclaim(j, true, true);
+}
+
+static int bch2_journal_reclaim_thread(void *arg)
+{
+ struct journal *j = arg;
+ struct bch_fs *c = container_of(j, struct bch_fs, journal);
+ unsigned long delay, now;
+ bool journal_empty;
+ int ret = 0;
+
+ set_freezable();
+
+ j->last_flushed = jiffies;
+
+ while (!ret && !kthread_should_stop()) {
+ bool kicked = j->reclaim_kicked;
+
+ j->reclaim_kicked = false;
+
+ mutex_lock(&j->reclaim_lock);
+ ret = __bch2_journal_reclaim(j, false, kicked);
+ mutex_unlock(&j->reclaim_lock);
+
+ now = jiffies;
+ delay = msecs_to_jiffies(c->opts.journal_reclaim_delay);
+ j->next_reclaim = j->last_flushed + delay;
+
+ if (!time_in_range(j->next_reclaim, now, now + delay))
+ j->next_reclaim = now + delay;
+
+ while (1) {
+ set_current_state(TASK_INTERRUPTIBLE|TASK_FREEZABLE);
+ if (kthread_should_stop())
+ break;
+ if (j->reclaim_kicked)
+ break;
+
+ spin_lock(&j->lock);
+ journal_empty = fifo_empty(&j->pin);
+ spin_unlock(&j->lock);
+
+ if (journal_empty)
+ schedule();
+ else if (time_after(j->next_reclaim, jiffies))
+ schedule_timeout(j->next_reclaim - jiffies);
+ else
+ break;
+ }
+ __set_current_state(TASK_RUNNING);
+ }
+
+ return 0;
+}
+
+void bch2_journal_reclaim_stop(struct journal *j)
+{
+ struct task_struct *p = j->reclaim_thread;
+
+ j->reclaim_thread = NULL;
+
+ if (p) {
+ kthread_stop(p);
+ put_task_struct(p);
+ }
+}
+
+int bch2_journal_reclaim_start(struct journal *j)
+{
+ struct bch_fs *c = container_of(j, struct bch_fs, journal);
+ struct task_struct *p;
+ int ret;
+
+ if (j->reclaim_thread)
+ return 0;
+
+ p = kthread_create(bch2_journal_reclaim_thread, j,
+ "bch-reclaim/%s", c->name);
+ ret = PTR_ERR_OR_ZERO(p);
+ if (ret) {
+ bch_err_msg(c, ret, "creating journal reclaim thread");
+ return ret;
+ }
+
+ get_task_struct(p);
+ j->reclaim_thread = p;
+ wake_up_process(p);
+ return 0;
+}
+
+static int journal_flush_done(struct journal *j, u64 seq_to_flush,
+ bool *did_work)
+{
+ int ret;
+
+ ret = bch2_journal_error(j);
+ if (ret)
+ return ret;
+
+ mutex_lock(&j->reclaim_lock);
+
+ if (journal_flush_pins(j, seq_to_flush,
+ (1U << JOURNAL_PIN_key_cache)|
+ (1U << JOURNAL_PIN_other), 0, 0, 0) ||
+ journal_flush_pins(j, seq_to_flush,
+ (1U << JOURNAL_PIN_btree), 0, 0, 0))
+ *did_work = true;
+
+ if (seq_to_flush > journal_cur_seq(j))
+ bch2_journal_entry_close(j);
+
+ spin_lock(&j->lock);
+ /*
+ * If journal replay hasn't completed, the unreplayed journal entries
+ * hold refs on their corresponding sequence numbers
+ */
+ ret = !test_bit(JOURNAL_REPLAY_DONE, &j->flags) ||
+ journal_last_seq(j) > seq_to_flush ||
+ !fifo_used(&j->pin);
+
+ spin_unlock(&j->lock);
+ mutex_unlock(&j->reclaim_lock);
+
+ return ret;
+}
+
+bool bch2_journal_flush_pins(struct journal *j, u64 seq_to_flush)
+{
+ bool did_work = false;
+
+ if (!test_bit(JOURNAL_STARTED, &j->flags))
+ return false;
+
+ closure_wait_event(&j->async_wait,
+ journal_flush_done(j, seq_to_flush, &did_work));
+
+ return did_work;
+}
+
+int bch2_journal_flush_device_pins(struct journal *j, int dev_idx)
+{
+ struct bch_fs *c = container_of(j, struct bch_fs, journal);
+ struct journal_entry_pin_list *p;
+ u64 iter, seq = 0;
+ int ret = 0;
+
+ spin_lock(&j->lock);
+ fifo_for_each_entry_ptr(p, &j->pin, iter)
+ if (dev_idx >= 0
+ ? bch2_dev_list_has_dev(p->devs, dev_idx)
+ : p->devs.nr < c->opts.metadata_replicas)
+ seq = iter;
+ spin_unlock(&j->lock);
+
+ bch2_journal_flush_pins(j, seq);
+
+ ret = bch2_journal_error(j);
+ if (ret)
+ return ret;
+
+ mutex_lock(&c->replicas_gc_lock);
+ bch2_replicas_gc_start(c, 1 << BCH_DATA_journal);
+
+ /*
+ * Now that we've populated replicas_gc, write to the journal to mark
+ * active journal devices. This handles the case where the journal might
+ * be empty. Otherwise we could clear all journal replicas and
+ * temporarily put the fs into an unrecoverable state. Journal recovery
+ * expects to find devices marked for journal data on unclean mount.
+ */
+ ret = bch2_journal_meta(&c->journal);
+ if (ret)
+ goto err;
+
+ seq = 0;
+ spin_lock(&j->lock);
+ while (!ret) {
+ struct bch_replicas_padded replicas;
+
+ seq = max(seq, journal_last_seq(j));
+ if (seq >= j->pin.back)
+ break;
+ bch2_devlist_to_replicas(&replicas.e, BCH_DATA_journal,
+ journal_seq_pin(j, seq)->devs);
+ seq++;
+
+ spin_unlock(&j->lock);
+ ret = bch2_mark_replicas(c, &replicas.e);
+ spin_lock(&j->lock);
+ }
+ spin_unlock(&j->lock);
+err:
+ ret = bch2_replicas_gc_end(c, ret);
+ mutex_unlock(&c->replicas_gc_lock);
+
+ return ret;
+}