1 files changed, 245 insertions, 151 deletions

diff --git a/fs/bcachefs/journal_reclaim.c b/fs/bcachefs/journal_reclaim.c
index 98345dcd1e67..3b5b646859cb 100644
--- a/fs/bcachefs/journal_reclaim.c
+++ b/fs/bcachefs/journal_reclaim.c
@@ -2,15 +2,213 @@
 
 #include "bcachefs.h"
 #include "journal.h"
+#include "journal_io.h"
 #include "journal_reclaim.h"
 #include "replicas.h"
 #include "super.h"
 
+/* Free space calculations: */
+
+unsigned bch2_journal_dev_buckets_available(struct journal *j,
+					    struct journal_device *ja)
+{
+	struct bch_fs *c = container_of(j, struct bch_fs, journal);
+	unsigned next = (ja->cur_idx + 1) % ja->nr;
+	unsigned available = (ja->last_idx + ja->nr - next) % ja->nr;
+
+	/*
+	 * Allocator startup needs some journal space before we can do journal
+	 * replay:
+	 */
+	if (available &&
+	    test_bit(BCH_FS_ALLOCATOR_STARTED, &c->flags))
+		available--;
+
+	/*
+	 * Don't use the last bucket unless writing the new last_seq
+	 * will make another bucket available:
+	 */
+	if (available &&
+	    journal_last_seq(j) <= ja->bucket_seq[ja->last_idx])
+		--available;
+
+	return available;
+}
+
+void bch2_journal_space_available(struct journal *j)
+{
+	struct bch_fs *c = container_of(j, struct bch_fs, journal);
+	struct bch_dev *ca;
+	unsigned sectors_next_entry	= UINT_MAX;
+	unsigned sectors_total		= UINT_MAX;
+	unsigned max_entry_size		= min(j->buf[0].buf_size >> 9,
+					      j->buf[1].buf_size >> 9);
+	unsigned i, nr_online = 0, nr_devs = 0;
+	unsigned unwritten_sectors = j->reservations.prev_buf_unwritten
+		? journal_prev_buf(j)->sectors
+		: 0;
+	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;
+		unsigned buckets_this_device, sectors_this_device;
+
+		if (!ja->nr)
+			continue;
+
+		nr_online++;
+
+		buckets_this_device = bch2_journal_dev_buckets_available(j, ja);
+		sectors_this_device = 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:
+		 */
+		if (unwritten_sectors >= sectors_this_device) {
+			if (!buckets_this_device)
+				continue;
+
+			buckets_this_device--;
+			sectors_this_device = ca->mi.bucket_size;
+		}
+
+		sectors_this_device -= unwritten_sectors;
+
+		if (sectors_this_device < ca->mi.bucket_size &&
+		    buckets_this_device) {
+			buckets_this_device--;
+			sectors_this_device = ca->mi.bucket_size;
+		}
+
+		if (!sectors_this_device)
+			continue;
+
+		sectors_next_entry = min(sectors_next_entry,
+					 sectors_this_device);
+
+		sectors_total = min(sectors_total,
+			buckets_this_device * ca->mi.bucket_size +
+			sectors_this_device);
+
+		max_entry_size = min_t(unsigned, max_entry_size,
+				       ca->mi.bucket_size);
+
+		nr_devs++;
+	}
+	rcu_read_unlock();
+
+	if (nr_online < c->opts.metadata_replicas_required) {
+		ret = -EROFS;
+		sectors_next_entry = 0;
+	} else if (!sectors_next_entry ||
+		   nr_devs < min_t(unsigned, nr_online,
+				   c->opts.metadata_replicas)) {
+		ret = -ENOSPC;
+		sectors_next_entry = 0;
+	} else if (!fifo_free(&j->pin)) {
+		ret = -ENOSPC;
+		sectors_next_entry = 0;
+	}
+
+	j->cur_entry_sectors	= sectors_next_entry;
+	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->nr &&
+		ja->last_idx != ja->cur_idx &&
+		ja->bucket_seq[ja->last_idx] < j->last_seq_ondisk;
+	spin_unlock(&j->lock);
+
+	return ret;
+}
+
+/*
+ * Advance ja->last_idx as long as it points to buckets that are no longer
+ * dirty, issuing discards if necessary:
+ */
+static void 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->reclaim_lock);
+
+	for_each_rw_member(ca, c, iter) {
+		struct journal_device *ja = &ca->journal;
+
+		while (should_discard_bucket(j, ja)) {
+			if (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->last_idx]),
+					ca->mi.bucket_size, GFP_NOIO);
+
+			spin_lock(&j->lock);
+			ja->last_idx = (ja->last_idx + 1) % ja->nr;
+
+			bch2_journal_space_available(j);
+			spin_unlock(&j->lock);
+		}
+	}
+
+	mutex_unlock(&j->reclaim_lock);
+}
+
 /*
  * Journal entry pinning - machinery for holding a reference on a given journal
  * entry, holding it open to ensure it gets replayed during recovery:
  */
 
+static void bch2_journal_reclaim_fast(struct journal *j)
+{
+	struct journal_entry_pin_list temp;
+	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)) {
+		BUG_ON(!list_empty(&fifo_peek_front(&j->pin).list));
+		BUG_ON(!fifo_pop(&j->pin, temp));
+		popped = true;
+	}
+
+	if (popped)
+		bch2_journal_space_available(j);
+}
+
+void bch2_journal_pin_put(struct journal *j, u64 seq)
+{
+	struct journal_entry_pin_list *pin_list = journal_seq_pin(j, seq);
+
+	if (atomic_dec_and_test(&pin_list->count)) {
+		spin_lock(&j->lock);
+		bch2_journal_reclaim_fast(j);
+		spin_unlock(&j->lock);
+	}
+}
+
 static inline void __journal_pin_add(struct journal *j,
 				     u64 seq,
 				     struct journal_entry_pin *pin,
@@ -25,10 +223,7 @@ static inline void __journal_pin_add(struct journal *j,
 	pin->seq	= seq;
 	pin->flush	= flush_fn;
 
-	if (flush_fn)
-		list_add(&pin->list, &pin_list->list);
-	else
-		INIT_LIST_HEAD(&pin->list);
+	list_add(&pin->list, flush_fn ? &pin_list->list : &pin_list->flushed);
 
 	/*
 	 * If the journal is currently full,  we might want to call flush_fn
@@ -130,86 +325,53 @@ void bch2_journal_pin_flush(struct journal *j, struct journal_entry_pin *pin)
  * data off of a specific device:
  */
 
-/**
- * bch2_journal_reclaim_fast - do the fast part of journal reclaim
- *
- * Called from IO submission context, does not block. Cleans up after btree
- * write completions by advancing the journal pin and each cache's last_idx,
- * kicking off discards and background reclaim as necessary.
- */
-void bch2_journal_reclaim_fast(struct journal *j)
-{
-	struct journal_entry_pin_list temp;
-	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)) {
-		BUG_ON(!list_empty(&fifo_peek_front(&j->pin).list));
-		BUG_ON(!fifo_pop(&j->pin, temp));
-		popped = true;
-	}
-
-	if (popped)
-		journal_wake(j);
-}
-
-static void journal_pin_mark_flushing(struct journal *j,
-				      struct journal_entry_pin *pin,
-				      u64 seq)
-{
-	lockdep_assert_held(&j->reclaim_lock);
-
-	list_move(&pin->list, &journal_seq_pin(j, seq)->flushed);
-	BUG_ON(j->flush_in_progress);
-	j->flush_in_progress = pin;
-}
-
-static void journal_pin_flush(struct journal *j,
-			      struct journal_entry_pin *pin,
-			      u64 seq)
-{
-	pin->flush(j, pin, seq);
-
-	BUG_ON(j->flush_in_progress != pin);
-	j->flush_in_progress = NULL;
-	wake_up(&j->pin_flush_wait);
-}
-
 static struct journal_entry_pin *
-journal_get_next_pin(struct journal *j, u64 seq_to_flush, u64 *seq)
+journal_get_next_pin(struct journal *j, u64 max_seq, u64 *seq)
 {
 	struct journal_entry_pin_list *pin_list;
 	struct journal_entry_pin *ret = NULL;
 
-	/* no need to iterate over empty fifo entries: */
-	bch2_journal_reclaim_fast(j);
+	spin_lock(&j->lock);
+
+	BUG_ON(!atomic_read(&fifo_peek_front(&j->pin).count));
 
 	fifo_for_each_entry_ptr(pin_list, &j->pin, *seq)
-		if (*seq > seq_to_flush ||
+		if (*seq > max_seq ||
 		    (ret = list_first_entry_or_null(&pin_list->list,
 				struct journal_entry_pin, list)))
 			break;
 
+	if (ret) {
+		list_move(&ret->list, &pin_list->flushed);
+		BUG_ON(j->flush_in_progress);
+		j->flush_in_progress = ret;
+		j->last_flushed = jiffies;
+	}
+
+	spin_unlock(&j->lock);
+
 	return ret;
 }
 
-static bool should_discard_bucket(struct journal *j, struct journal_device *ja)
+static void journal_flush_pins(struct journal *j, u64 seq_to_flush,
+			       unsigned min_nr)
 {
-	bool ret;
+	struct journal_entry_pin *pin;
+	u64 seq;
 
-	spin_lock(&j->lock);
-	ret = ja->nr &&
-		(ja->last_idx != ja->cur_idx &&
-		 ja->bucket_seq[ja->last_idx] < j->last_seq_ondisk);
-	spin_unlock(&j->lock);
+	lockdep_assert_held(&j->reclaim_lock);
 
-	return ret;
+	while ((pin = journal_get_next_pin(j, min_nr
+				? U64_MAX : seq_to_flush, &seq))) {
+		if (min_nr)
+			min_nr--;
+
+		pin->flush(j, pin, seq);
+
+		BUG_ON(j->flush_in_progress != pin);
+		j->flush_in_progress = NULL;
+		wake_up(&j->pin_flush_wait);
+	}
 }
 
 /**
@@ -236,104 +398,44 @@ void bch2_journal_reclaim_work(struct work_struct *work)
 				struct bch_fs, journal.reclaim_work);
 	struct journal *j = &c->journal;
 	struct bch_dev *ca;
-	struct journal_entry_pin *pin;
-	u64 seq, seq_to_flush = 0;
-	unsigned iter, bucket_to_flush;
-	unsigned long next_flush;
-	bool reclaim_lock_held = false, need_flush;
+	unsigned iter, bucket_to_flush, min_nr = 0;
+	u64 seq_to_flush = 0;
+
+	journal_do_discards(j);
+
+	mutex_lock(&j->reclaim_lock);
+	spin_lock(&j->lock);
 
-	/*
-	 * Advance last_idx to point to the oldest journal entry containing
-	 * btree node updates that have not yet been written out
-	 */
 	for_each_rw_member(ca, c, iter) {
 		struct journal_device *ja = &ca->journal;
 
 		if (!ja->nr)
 			continue;
 
-		while (should_discard_bucket(j, ja)) {
-			if (!reclaim_lock_held) {
-				/*
-				 * ugh:
-				 * might be called from __journal_res_get()
-				 * under wait_event() - have to go back to
-				 * TASK_RUNNING before doing something that
-				 * would block, but only if we're doing work:
-				 */
-				__set_current_state(TASK_RUNNING);
-
-				mutex_lock(&j->reclaim_lock);
-				reclaim_lock_held = true;
-				/* recheck under reclaim_lock: */
-				continue;
-			}
 
-			if (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->last_idx]),
-					ca->mi.bucket_size, GFP_NOIO);
-
-			spin_lock(&j->lock);
-			ja->last_idx = (ja->last_idx + 1) % ja->nr;
-			spin_unlock(&j->lock);
-
-			journal_wake(j);
-		}
-
-		/*
-		 * Write out enough btree nodes to free up 50% journal
-		 * buckets
-		 */
-		spin_lock(&j->lock);
+		/* Try to keep the journal at most half full: */
 		bucket_to_flush = (ja->cur_idx + (ja->nr >> 1)) % ja->nr;
 		seq_to_flush = max_t(u64, seq_to_flush,
 				     ja->bucket_seq[bucket_to_flush]);
-		spin_unlock(&j->lock);
 	}
 
 	/* Also flush if the pin fifo is more than half full */
-	spin_lock(&j->lock);
 	seq_to_flush = max_t(s64, seq_to_flush,
 			     (s64) journal_cur_seq(j) -
 			     (j->pin.size >> 1));
+	spin_unlock(&j->lock);
 
 	/*
 	 * If it's been longer than j->reclaim_delay_ms since we last flushed,
 	 * make sure to flush at least one journal pin:
 	 */
-	next_flush = j->last_flushed + msecs_to_jiffies(j->reclaim_delay_ms);
-	need_flush = time_after(jiffies, next_flush);
-
-	while ((pin = journal_get_next_pin(j, need_flush
-					   ? U64_MAX
-					   : seq_to_flush, &seq))) {
-		if (!reclaim_lock_held) {
-			spin_unlock(&j->lock);
-			__set_current_state(TASK_RUNNING);
-			mutex_lock(&j->reclaim_lock);
-			reclaim_lock_held = true;
-			spin_lock(&j->lock);
-			continue;
-		}
+	if (time_after(jiffies, j->last_flushed +
+		       msecs_to_jiffies(j->reclaim_delay_ms)))
+		min_nr = 1;
 
-		journal_pin_mark_flushing(j, pin, seq);
-		spin_unlock(&j->lock);
-
-		journal_pin_flush(j, pin, seq);
-
-		need_flush = false;
-		j->last_flushed = jiffies;
+	journal_flush_pins(j, seq_to_flush, min_nr);
 
-		spin_lock(&j->lock);
-	}
-
-	spin_unlock(&j->lock);
-
-	if (reclaim_lock_held)
-		mutex_unlock(&j->reclaim_lock);
+	mutex_unlock(&j->reclaim_lock);
 
 	if (!test_bit(BCH_FS_RO, &c->flags))
 		queue_delayed_work(c->journal_reclaim_wq, &j->reclaim_work,
@@ -342,8 +444,6 @@ void bch2_journal_reclaim_work(struct work_struct *work)
 
 static int journal_flush_done(struct journal *j, u64 seq_to_flush)
 {
-	struct journal_entry_pin *pin;
-	u64 pin_seq;
 	int ret;
 
 	ret = bch2_journal_error(j);
@@ -351,16 +451,10 @@ static int journal_flush_done(struct journal *j, u64 seq_to_flush)
 		return ret;
 
 	mutex_lock(&j->reclaim_lock);
-	spin_lock(&j->lock);
-
-	while ((pin = journal_get_next_pin(j, seq_to_flush, &pin_seq))) {
-		journal_pin_mark_flushing(j, pin, pin_seq);
-		spin_unlock(&j->lock);
 
-		journal_pin_flush(j, pin, pin_seq);
+	journal_flush_pins(j, seq_to_flush, 0);
 
-		spin_lock(&j->lock);
-	}
+	spin_lock(&j->lock);
 	/*
 	 * If journal replay hasn't completed, the unreplayed journal entries
 	 * hold refs on their corresponding sequence numbers