1 files changed, 26 insertions, 5 deletions

diff --git a/drivers/md/bcache/journal.c b/drivers/md/bcache/journal.c
index df5347ea450b..e5da469a4235 100644
--- a/drivers/md/bcache/journal.c
+++ b/drivers/md/bcache/journal.c
@@ -405,6 +405,11 @@ err:
 	return ret;
 }
 
+void bch_journal_space_reserve(struct journal *j)
+{
+	j->do_reserve = true;
+}
+
 /* Journalling */
 
 static void btree_flush_write(struct cache_set *c)
@@ -621,12 +626,30 @@ static void do_journal_discard(struct cache *ca)
 	}
 }
 
+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;
-	unsigned int next;
 	struct journal_device *ja = &ca->journal;
 	atomic_t p __maybe_unused;
 
@@ -649,12 +672,10 @@ static void journal_reclaim(struct cache_set *c)
 	if (c->journal.blocks_free)
 		goto out;
 
-	next = (ja->cur_idx + 1) % ca->sb.njournal_buckets;
-	/* No space available on this device */
-	if (next == ja->discard_idx)
+	if (!free_journal_buckets(c))
 		goto out;
 
-	ja->cur_idx = next;
+	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);