Update bcachefs sources to 7958ebe324 bcachefs: Fix alloc_v4_backpointers()

1 files changed, 109 insertions, 5 deletions

diff --git a/libbcachefs/nocow_locking.c b/libbcachefs/nocow_locking.c
index b325fb10..bff62671 100644
--- a/libbcachefs/nocow_locking.c
+++ b/libbcachefs/nocow_locking.c
@@ -4,12 +4,116 @@
 #include "nocow_locking.h"
 #include "util.h"
 
+#include <linux/closure.h>
+
+bool bch2_bucket_nocow_is_locked(struct bucket_nocow_lock_table *t, struct bpos bucket)
+{
+	u64 dev_bucket = bucket_to_u64(bucket);
+	struct nocow_lock_bucket *l = bucket_nocow_lock(t, dev_bucket);
+	unsigned i;
+
+	for (i = 0; i < ARRAY_SIZE(l->b); i++)
+		if (l->b[i] == dev_bucket && atomic_read(&l->l[i]))
+			return true;
+	return false;
+}
+
+void bch2_bucket_nocow_unlock(struct bucket_nocow_lock_table *t, struct bpos bucket, int flags)
+{
+	u64 dev_bucket = bucket_to_u64(bucket);
+	struct nocow_lock_bucket *l = bucket_nocow_lock(t, dev_bucket);
+	int lock_val = flags ? 1 : -1;
+	unsigned i;
+
+	for (i = 0; i < ARRAY_SIZE(l->b); i++)
+		if (l->b[i] == dev_bucket) {
+			if (!atomic_sub_return(lock_val, &l->l[i]))
+				closure_wake_up(&l->wait);
+			return;
+		}
+
+	BUG();
+}
+
+static bool bch2_bucket_nocow_trylock(struct nocow_lock_bucket *l,
+				      u64 dev_bucket, int flags)
+{
+	int v, lock_val = flags ? 1 : -1;
+	unsigned i;
+
+	spin_lock(&l->lock);
+
+	for (i = 0; i < ARRAY_SIZE(l->b); i++)
+		if (l->b[i] == dev_bucket)
+			goto got_entry;
+
+	for (i = 0; i < ARRAY_SIZE(l->b); i++)
+		if (!atomic_read(&l->l[i])) {
+			l->b[i] = dev_bucket;
+			goto take_lock;
+		}
+fail:
+	spin_unlock(&l->lock);
+	return false;
+got_entry:
+	v = atomic_read(&l->l[i]);
+	if (lock_val > 0 ? v < 0 : v > 0)
+		goto fail;
+take_lock:
+	atomic_add(lock_val, &l->l[i]);
+	spin_unlock(&l->lock);
+	return true;
+}
+
 void __bch2_bucket_nocow_lock(struct bucket_nocow_lock_table *t,
-			      two_state_lock_t *l, int flags)
+			      struct nocow_lock_bucket *l,
+			      u64 dev_bucket, int flags)
+{
+	if (!bch2_bucket_nocow_trylock(l, dev_bucket, flags)) {
+		struct bch_fs *c = container_of(t, struct bch_fs, nocow_locks);
+		u64 start_time = local_clock();
+
+		__closure_wait_event(&l->wait, bch2_bucket_nocow_trylock(l, dev_bucket, flags));
+		bch2_time_stats_update(&c->times[BCH_TIME_nocow_lock_contended], start_time);
+	}
+}
+
+void bch2_nocow_locks_to_text(struct printbuf *out, struct bucket_nocow_lock_table *t)
 {
-	struct bch_fs *c = container_of(t, struct bch_fs, nocow_locks);
-	u64 start_time = local_clock();
+	unsigned i, nr_zero = 0;
+	struct nocow_lock_bucket *l;
+
+	for (l = t->l; l < t->l + ARRAY_SIZE(t->l); l++) {
+		unsigned v = 0;
+
+		for (i = 0; i < ARRAY_SIZE(l->l); i++)
+			v |= atomic_read(&l->l[i]);
+
+		if (!v) {
+			nr_zero++;
+			continue;
+		}
+
+		if (nr_zero)
+			prt_printf(out, "(%u empty entries)\n", nr_zero);
+		nr_zero = 0;
+
+		for (i = 0; i < ARRAY_SIZE(l->l); i++)
+			if (atomic_read(&l->l[i]))
+				prt_printf(out, "%llu: %i ", l->b[i], atomic_read(&l->l[i]));
+		prt_newline(out);
+	}
+
+	if (nr_zero)
+		prt_printf(out, "(%u empty entries)\n", nr_zero);
+}
+
+int bch2_fs_nocow_locking_init(struct bch_fs *c)
+{
+	unsigned i;
+
+	for (i = 0; i < ARRAY_SIZE(c->nocow_locks.l); i++)
+		spin_lock_init(&c->nocow_locks.l[i].lock);
 
-	__bch2_two_state_lock(l, flags & BUCKET_NOCOW_LOCK_UPDATE);
-	bch2_time_stats_update(&c->times[BCH_TIME_nocow_lock_contended], start_time);
+	return 0;
 }