bcachefs: bch2_bkey_get_empty_slot()
Add a new helper for allocating a new slot in a btree.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
diff --git a/fs/bcachefs/btree_update.h b/fs/bcachefs/btree_update.h
index 34ca2c43..1ac3a81 100644
--- a/fs/bcachefs/btree_update.h
+++ b/fs/bcachefs/btree_update.h
@@ -86,6 +86,9 @@ int bch2_btree_node_update_key_get_iter(struct btree_trans *,
int bch2_trans_update_extent(struct btree_trans *, struct btree_iter *,
struct bkey_i *, enum btree_update_flags);
+int bch2_bkey_get_empty_slot(struct btree_trans *, struct btree_iter *,
+ enum btree_id, struct bpos);
+
int __must_check bch2_trans_update(struct btree_trans *, struct btree_iter *,
struct bkey_i *, enum btree_update_flags);
int __must_check bch2_trans_update_buffered(struct btree_trans *,
diff --git a/fs/bcachefs/btree_update_leaf.c b/fs/bcachefs/btree_update_leaf.c
index 0952885f..3369346 100644
--- a/fs/bcachefs/btree_update_leaf.c
+++ b/fs/bcachefs/btree_update_leaf.c
@@ -1735,6 +1735,37 @@ int __must_check bch2_trans_update_buffered(struct btree_trans *trans,
return 0;
}
+int bch2_bkey_get_empty_slot(struct btree_trans *trans, struct btree_iter *iter,
+ enum btree_id btree, struct bpos end)
+{
+ struct bkey_s_c k;
+ int ret = 0;
+
+ bch2_trans_iter_init(trans, iter, btree, POS_MAX, BTREE_ITER_INTENT);
+ k = bch2_btree_iter_prev(iter);
+ ret = bkey_err(k);
+ if (ret)
+ goto err;
+
+ bch2_btree_iter_advance(iter);
+ k = bch2_btree_iter_peek_slot(iter);
+ ret = bkey_err(k);
+ if (ret)
+ goto err;
+
+ BUG_ON(k.k->type != KEY_TYPE_deleted);
+
+ if (bkey_gt(k.k->p, end)) {
+ ret = -BCH_ERR_ENOSPC_btree_slot;
+ goto err;
+ }
+
+ return 0;
+err:
+ bch2_trans_iter_exit(trans, iter);
+ return ret;
+}
+
void bch2_trans_commit_hook(struct btree_trans *trans,
struct btree_trans_commit_hook *h)
{
diff --git a/fs/bcachefs/errcode.h b/fs/bcachefs/errcode.h
index 4304e25..c73a5e7 100644
--- a/fs/bcachefs/errcode.h
+++ b/fs/bcachefs/errcode.h
@@ -92,6 +92,7 @@
x(ENOSPC, ENOSPC_sb_replicas) \
x(ENOSPC, ENOSPC_sb_members) \
x(ENOSPC, ENOSPC_sb_crypt) \
+ x(ENOSPC, ENOSPC_btree_slot) \
x(0, open_buckets_empty) \
x(0, freelist_empty) \
x(BCH_ERR_freelist_empty, no_buckets_found) \
diff --git a/fs/bcachefs/subvolume.c b/fs/bcachefs/subvolume.c
index cac295a..8d87f90 100644
--- a/fs/bcachefs/subvolume.c
+++ b/fs/bcachefs/subvolume.c
@@ -909,32 +909,19 @@ int bch2_subvolume_create(struct btree_trans *trans, u64 inode,
u32 *new_snapshotid,
bool ro)
{
- struct bch_fs *c = trans->c;
struct btree_iter dst_iter, src_iter = (struct btree_iter) { NULL };
struct bkey_i_subvolume *new_subvol = NULL;
struct bkey_i_subvolume *src_subvol = NULL;
- struct bkey_s_c k;
u32 parent = 0, new_nodes[2], snapshot_subvols[2];
int ret = 0;
- for_each_btree_key(trans, dst_iter, BTREE_ID_subvolumes, SUBVOL_POS_MIN,
- BTREE_ITER_SLOTS|BTREE_ITER_INTENT, k, ret) {
- if (bkey_gt(k.k->p, SUBVOL_POS_MAX))
- break;
-
- /*
- * bch2_subvolume_delete() doesn't flush the btree key cache -
- * ideally it would but that's tricky
- */
- if (bkey_deleted(k.k) &&
- !bch2_btree_key_cache_find(c, BTREE_ID_subvolumes, dst_iter.pos))
- goto found_slot;
- }
-
- if (!ret)
+ ret = bch2_bkey_get_empty_slot(trans, &dst_iter,
+ BTREE_ID_subvolumes, POS(0, U32_MAX));
+ if (ret == -BCH_ERR_ENOSPC_btree_slot)
ret = -BCH_ERR_ENOSPC_subvolume_create;
- goto err;
-found_slot:
+ if (ret)
+ return ret;
+
snapshot_subvols[0] = dst_iter.pos.offset;
snapshot_subvols[1] = src_subvolid;
