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

[bcachefs-tools-debian] / libbcachefs / nocow_locking.c

diff --git a/libbcachefs/nocow_locking.c b/libbcachefs/nocow_locking.c
index b325fb105322a8393587813d9852bcbd652ebb4f..bff6267158cc3f6d30bbb3b1ac141d28b8379294 100644 (file)
--- 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;
 }