[PATCH 4/4] bcachefs: can_use_btree_node()

Make sure btree_node_alloc() respects allocation policy when allocating
from the btree node reserve.

Signed-off-by: Kent Overstreet <[email protected]>
---
 fs/bcachefs/btree_update_interior.c | 41 ++++++++++++++++++++++++++---
 fs/bcachefs/extents.c               | 14 ++++++++++
 fs/bcachefs/extents.h               |  2 ++
 3 files changed, 54 insertions(+), 3 deletions(-)

diff --git a/fs/bcachefs/btree_update_interior.c b/fs/bcachefs/btree_update_interior.c
index 312ef203b27b..e4aa4fa749bc 100644
--- a/fs/bcachefs/btree_update_interior.c
+++ b/fs/bcachefs/btree_update_interior.c
@@ -14,6 +14,7 @@
 #include "btree_locking.h"
 #include "buckets.h"
 #include "clock.h"
+#include "disk_groups.h"
 #include "enumerated_ref.h"
 #include "error.h"
 #include "extents.h"
@@ -277,6 +278,36 @@ static void bch2_btree_node_free_never_used(struct btree_update *as,
 	bch2_trans_node_drop(trans, b);
 }
 
+static bool can_use_btree_node(struct bch_fs *c,
+			       struct disk_reservation *res,
+			       unsigned target,
+			       struct bkey_s_c k)
+{
+	if (!bch2_bkey_devs_rw(c, k))
+		return false;
+
+	if (target && !bch2_bkey_in_target(c, k, target))
+		return false;
+
+	unsigned durability = bch2_bkey_durability(c, k);
+
+	if (durability >= res->nr_replicas)
+		return true;
+
+	struct bch_devs_mask devs = target_rw_devs(c, BCH_DATA_btree, target);
+
+	guard(rcu)();
+
+	unsigned durability_available = 0, i;
+	for_each_set_bit(i, devs.d, BCH_SB_MEMBERS_MAX) {
+		struct bch_dev *ca = bch2_dev_rcu_noerror(c, i);
+		if (ca)
+			durability_available += ca->mi.durability;
+	}
+
+	return durability >= durability_available;
+}
+
 static struct btree *__bch2_btree_node_alloc(struct btree_trans *trans,
 					     struct disk_reservation *res,
 					     struct closure *cl,
@@ -303,10 +334,14 @@ static struct btree *__bch2_btree_node_alloc(struct btree_trans *trans,
 	mutex_lock(&c->btree_reserve_cache_lock);
 	if (c->btree_reserve_cache_nr > nr_reserve) {
 		for (struct btree_alloc *a = c->btree_reserve_cache;
-		     a < c->btree_reserve_cache + c->btree_reserve_cache_nr;
-		     a++) {
-			if (target && !bch2_bkey_in_target(c, bkey_i_to_s_c(&a->k), target))
+		     a < c->btree_reserve_cache + c->btree_reserve_cache_nr;) {
+			/* check if it has sufficient durability */
+
+			if (!can_use_btree_node(c, res, target, bkey_i_to_s_c(&a->k))) {
+				bch2_open_buckets_put(c, &a->ob);
+				*a = c->btree_reserve_cache[--c->btree_reserve_cache_nr];
 				continue;
+			}
 
 			bkey_copy(&b->key, &a->k);
 			b->ob = a->ob;
diff --git a/fs/bcachefs/extents.c b/fs/bcachefs/extents.c
index b36ecfc0ab9d..8152ef1cbbcd 100644
--- a/fs/bcachefs/extents.c
+++ b/fs/bcachefs/extents.c
@@ -1006,6 +1006,20 @@ const struct bch_extent_ptr *bch2_bkey_has_device_c(struct bkey_s_c k, unsigned
 	return NULL;
 }
 
+bool bch2_bkey_devs_rw(struct bch_fs *c, struct bkey_s_c k)
+{
+	struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(k);
+
+	guard(rcu)();
+	bkey_for_each_ptr(ptrs, ptr) {
+		CLASS(bch2_dev_tryget, ca)(c, ptr->dev);
+		if (!ca || ca->mi.state != BCH_MEMBER_STATE_rw)
+			return false;
+	}
+
+	return true;
+}
+
 bool bch2_bkey_has_target(struct bch_fs *c, struct bkey_s_c k, unsigned target)
 {
 	struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(k);
diff --git a/fs/bcachefs/extents.h b/fs/bcachefs/extents.h
index f212f91c278d..35ee03cd5065 100644
--- a/fs/bcachefs/extents.h
+++ b/fs/bcachefs/extents.h
@@ -614,6 +614,8 @@ static inline struct bch_extent_ptr *bch2_bkey_has_device(struct bkey_s k, unsig
 	return (void *) bch2_bkey_has_device_c(k.s_c, dev);
 }
 
+bool bch2_bkey_devs_rw(struct bch_fs *, struct bkey_s_c);
+
 bool bch2_bkey_has_target(struct bch_fs *, struct bkey_s_c, unsigned);
 bool bch2_bkey_in_target(struct bch_fs *, struct bkey_s_c, unsigned);
 
-- 
2.50.0