3 files changed, 29 insertions, 5 deletions
diff --git a/drivers/md/bcache/journal.c b/drivers/md/bcache/journal.c
index 7c2ca52ca3e4..42407b44a940 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);
diff --git a/drivers/md/bcache/journal.h b/drivers/md/bcache/journal.h
index f2ea34d5f431..cd316b4a1e95 100644
--- a/drivers/md/bcache/journal.h
+++ b/drivers/md/bcache/journal.h
@@ -105,6 +105,7 @@ struct journal {
 	spinlock_t		lock;
 	spinlock_t		flush_write_lock;
 	bool			btree_flushing;
+	bool			do_reserve;
 	/* used when waiting because the journal was full */
 	struct closure_waitlist	wait;
 	struct closure		io;
@@ -182,5 +183,6 @@ int bch_journal_replay(struct cache_set *c, struct list_head *list);
 
 void bch_journal_free(struct cache_set *c);
 int bch_journal_alloc(struct cache_set *c);
+void bch_journal_space_reserve(struct journal *j);
 
 #endif /* _BCACHE_JOURNAL_H */
diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
index 2f49e31142f6..3563d15dbaf2 100644
--- a/drivers/md/bcache/super.c
+++ b/drivers/md/bcache/super.c
@@ -2127,6 +2127,7 @@ static int run_cache_set(struct cache_set *c)
 
 	flash_devs_run(c);
 
+	bch_journal_space_reserve(&c->journal);
 	set_bit(CACHE_SET_RUNNING, &c->flags);
 	return 0;
 err: