--- /dev/null
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _BCACHEFS_BTREE_UPDATE_INTERIOR_H
+#define _BCACHEFS_BTREE_UPDATE_INTERIOR_H
+
+#include "btree_cache.h"
+#include "btree_locking.h"
+#include "btree_update.h"
+
+#define BTREE_UPDATE_NODES_MAX ((BTREE_MAX_DEPTH - 2) * 2 + GC_MERGE_NODES)
+
+#define BTREE_UPDATE_JOURNAL_RES (BTREE_UPDATE_NODES_MAX * (BKEY_BTREE_PTR_U64s_MAX + 1))
+
+/*
+ * Tracks an in progress split/rewrite of a btree node and the update to the
+ * parent node:
+ *
+ * When we split/rewrite a node, we do all the updates in memory without
+ * waiting for any writes to complete - we allocate the new node(s) and update
+ * the parent node, possibly recursively up to the root.
+ *
+ * The end result is that we have one or more new nodes being written -
+ * possibly several, if there were multiple splits - and then a write (updating
+ * an interior node) which will make all these new nodes visible.
+ *
+ * Additionally, as we split/rewrite nodes we free the old nodes - but the old
+ * nodes can't be freed (their space on disk can't be reclaimed) until the
+ * update to the interior node that makes the new node visible completes -
+ * until then, the old nodes are still reachable on disk.
+ *
+ */
+struct btree_update {
+ struct closure cl;
+ struct bch_fs *c;
+ u64 start_time;
+
+ struct list_head list;
+ struct list_head unwritten_list;
+
+ /* What kind of update are we doing? */
+ enum {
+ BTREE_INTERIOR_NO_UPDATE,
+ BTREE_INTERIOR_UPDATING_NODE,
+ BTREE_INTERIOR_UPDATING_ROOT,
+ BTREE_INTERIOR_UPDATING_AS,
+ } mode;
+
+ unsigned nodes_written:1;
+ unsigned took_gc_lock:1;
+
+ enum btree_id btree_id;
+ unsigned update_level;
+
+ struct disk_reservation disk_res;
+
+ /*
+ * BTREE_INTERIOR_UPDATING_NODE:
+ * The update that made the new nodes visible was a regular update to an
+ * existing interior node - @b. We can't write out the update to @b
+ * until the new nodes we created are finished writing, so we block @b
+ * from writing by putting this btree_interior update on the
+ * @b->write_blocked list with @write_blocked_list:
+ */
+ struct btree *b;
+ struct list_head write_blocked_list;
+
+ /*
+ * We may be freeing nodes that were dirty, and thus had journal entries
+ * pinned: we need to transfer the oldest of those pins to the
+ * btree_update operation, and release it when the new node(s)
+ * are all persistent and reachable:
+ */
+ struct journal_entry_pin journal;
+
+ /* Preallocated nodes we reserve when we start the update: */
+ struct prealloc_nodes {
+ struct btree *b[BTREE_UPDATE_NODES_MAX];
+ unsigned nr;
+ } prealloc_nodes[2];
+
+ /* Nodes being freed: */
+ struct keylist old_keys;
+ u64 _old_keys[BTREE_UPDATE_NODES_MAX *
+ BKEY_BTREE_PTR_U64s_MAX];
+
+ /* Nodes being added: */
+ struct keylist new_keys;
+ u64 _new_keys[BTREE_UPDATE_NODES_MAX *
+ BKEY_BTREE_PTR_U64s_MAX];
+
+ /* New nodes, that will be made reachable by this update: */
+ struct btree *new_nodes[BTREE_UPDATE_NODES_MAX];
+ unsigned nr_new_nodes;
+
+ struct btree *old_nodes[BTREE_UPDATE_NODES_MAX];
+ __le64 old_nodes_seq[BTREE_UPDATE_NODES_MAX];
+ unsigned nr_old_nodes;
+
+ open_bucket_idx_t open_buckets[BTREE_UPDATE_NODES_MAX *
+ BCH_REPLICAS_MAX];
+ open_bucket_idx_t nr_open_buckets;
+
+ unsigned journal_u64s;
+ u64 journal_entries[BTREE_UPDATE_JOURNAL_RES];
+
+ /* Only here to reduce stack usage on recursive splits: */
+ struct keylist parent_keys;
+ /*
+ * Enough room for btree_split's keys without realloc - btree node
+ * pointers never have crc/compression info, so we only need to acount
+ * for the pointers for three keys
+ */
+ u64 inline_keys[BKEY_BTREE_PTR_U64s_MAX * 3];
+};
+
+struct btree *__bch2_btree_node_alloc_replacement(struct btree_update *,
+ struct btree_trans *,
+ struct btree *,
+ struct bkey_format);
+
+int bch2_btree_split_leaf(struct btree_trans *, btree_path_idx_t, unsigned);
+
+int __bch2_foreground_maybe_merge(struct btree_trans *, btree_path_idx_t,
+ unsigned, unsigned, enum btree_node_sibling);
+
+static inline int bch2_foreground_maybe_merge_sibling(struct btree_trans *trans,
+ btree_path_idx_t path_idx,
+ unsigned level, unsigned flags,
+ enum btree_node_sibling sib)
+{
+ struct btree_path *path = trans->paths + path_idx;
+ struct btree *b;
+
+ EBUG_ON(!btree_node_locked(path, level));
+
+ b = path->l[level].b;
+ if (b->sib_u64s[sib] > trans->c->btree_foreground_merge_threshold)
+ return 0;
+
+ return __bch2_foreground_maybe_merge(trans, path_idx, level, flags, sib);
+}
+
+static inline int bch2_foreground_maybe_merge(struct btree_trans *trans,
+ btree_path_idx_t path,
+ unsigned level,
+ unsigned flags)
+{
+ return bch2_foreground_maybe_merge_sibling(trans, path, level, flags,
+ btree_prev_sib) ?:
+ bch2_foreground_maybe_merge_sibling(trans, path, level, flags,
+ btree_next_sib);
+}
+
+int bch2_btree_node_rewrite(struct btree_trans *, struct btree_iter *,
+ struct btree *, unsigned);
+void bch2_btree_node_rewrite_async(struct bch_fs *, struct btree *);
+int bch2_btree_node_update_key(struct btree_trans *, struct btree_iter *,
+ struct btree *, struct bkey_i *,
+ unsigned, bool);
+int bch2_btree_node_update_key_get_iter(struct btree_trans *, struct btree *,
+ struct bkey_i *, unsigned, bool);
+
+void bch2_btree_set_root_for_read(struct bch_fs *, struct btree *);
+void bch2_btree_root_alloc(struct bch_fs *, enum btree_id);
+
+static inline unsigned btree_update_reserve_required(struct bch_fs *c,
+ struct btree *b)
+{
+ unsigned depth = btree_node_root(c, b)->c.level + 1;
+
+ /*
+ * Number of nodes we might have to allocate in a worst case btree
+ * split operation - we split all the way up to the root, then allocate
+ * a new root, unless we're already at max depth:
+ */
+ if (depth < BTREE_MAX_DEPTH)
+ return (depth - b->c.level) * 2 + 1;
+ else
+ return (depth - b->c.level) * 2 - 1;
+}
+
+static inline void btree_node_reset_sib_u64s(struct btree *b)
+{
+ b->sib_u64s[0] = b->nr.live_u64s;
+ b->sib_u64s[1] = b->nr.live_u64s;
+}
+
+static inline void *btree_data_end(struct bch_fs *c, struct btree *b)
+{
+ return (void *) b->data + btree_bytes(c);
+}
+
+static inline struct bkey_packed *unwritten_whiteouts_start(struct bch_fs *c,
+ struct btree *b)
+{
+ return (void *) ((u64 *) btree_data_end(c, b) - b->whiteout_u64s);
+}
+
+static inline struct bkey_packed *unwritten_whiteouts_end(struct bch_fs *c,
+ struct btree *b)
+{
+ return btree_data_end(c, b);
+}
+
+static inline void *write_block(struct btree *b)
+{
+ return (void *) b->data + (b->written << 9);
+}
+
+static inline bool __btree_addr_written(struct btree *b, void *p)
+{
+ return p < write_block(b);
+}
+
+static inline bool bset_written(struct btree *b, struct bset *i)
+{
+ return __btree_addr_written(b, i);
+}
+
+static inline bool bkey_written(struct btree *b, struct bkey_packed *k)
+{
+ return __btree_addr_written(b, k);
+}
+
+static inline ssize_t __bch_btree_u64s_remaining(struct bch_fs *c,
+ struct btree *b,
+ void *end)
+{
+ ssize_t used = bset_byte_offset(b, end) / sizeof(u64) +
+ b->whiteout_u64s;
+ ssize_t total = c->opts.btree_node_size >> 3;
+
+ /* Always leave one extra u64 for bch2_varint_decode: */
+ used++;
+
+ return total - used;
+}
+
+static inline size_t bch_btree_keys_u64s_remaining(struct bch_fs *c,
+ struct btree *b)
+{
+ ssize_t remaining = __bch_btree_u64s_remaining(c, b,
+ btree_bkey_last(b, bset_tree_last(b)));
+
+ BUG_ON(remaining < 0);
+
+ if (bset_written(b, btree_bset_last(b)))
+ return 0;
+
+ return remaining;
+}
+
+#define BTREE_WRITE_SET_U64s_BITS 9
+
+static inline unsigned btree_write_set_buffer(struct btree *b)
+{
+ /*
+ * Could buffer up larger amounts of keys for btrees with larger keys,
+ * pending benchmarking:
+ */
+ return 8 << BTREE_WRITE_SET_U64s_BITS;
+}
+
+static inline struct btree_node_entry *want_new_bset(struct bch_fs *c,
+ struct btree *b)
+{
+ struct bset_tree *t = bset_tree_last(b);
+ struct btree_node_entry *bne = max(write_block(b),
+ (void *) btree_bkey_last(b, bset_tree_last(b)));
+ ssize_t remaining_space =
+ __bch_btree_u64s_remaining(c, b, bne->keys.start);
+
+ if (unlikely(bset_written(b, bset(b, t)))) {
+ if (remaining_space > (ssize_t) (block_bytes(c) >> 3))
+ return bne;
+ } else {
+ if (unlikely(bset_u64s(t) * sizeof(u64) > btree_write_set_buffer(b)) &&
+ remaining_space > (ssize_t) (btree_write_set_buffer(b) >> 3))
+ return bne;
+ }
+
+ return NULL;
+}
+
+static inline void push_whiteout(struct bch_fs *c, struct btree *b,
+ struct bpos pos)
+{
+ struct bkey_packed k;
+
+ BUG_ON(bch_btree_keys_u64s_remaining(c, b) < BKEY_U64s);
+ EBUG_ON(btree_node_just_written(b));
+
+ if (!bkey_pack_pos(&k, pos, b)) {
+ struct bkey *u = (void *) &k;
+
+ bkey_init(u);
+ u->p = pos;
+ }
+
+ k.needs_whiteout = true;
+
+ b->whiteout_u64s += k.u64s;
+ bkey_p_copy(unwritten_whiteouts_start(c, b), &k);
+}
+
+/*
+ * write lock must be held on @b (else the dirty bset that we were going to
+ * insert into could be written out from under us)
+ */
+static inline bool bch2_btree_node_insert_fits(struct bch_fs *c,
+ struct btree *b, unsigned u64s)
+{
+ if (unlikely(btree_node_need_rewrite(b)))
+ return false;
+
+ return u64s <= bch_btree_keys_u64s_remaining(c, b);
+}
+
+void bch2_btree_updates_to_text(struct printbuf *, struct bch_fs *);
+
+bool bch2_btree_interior_updates_flush(struct bch_fs *);
+
+void bch2_journal_entry_to_btree_root(struct bch_fs *, struct jset_entry *);
+struct jset_entry *bch2_btree_roots_to_journal_entries(struct bch_fs *,
+ struct jset_entry *, unsigned long);
+
+void bch2_do_pending_node_rewrites(struct bch_fs *);
+void bch2_free_pending_node_rewrites(struct bch_fs *);
+
+void bch2_fs_btree_interior_update_exit(struct bch_fs *);
+void bch2_fs_btree_interior_update_init_early(struct bch_fs *);
+int bch2_fs_btree_interior_update_init(struct bch_fs *);
+
+#endif /* _BCACHEFS_BTREE_UPDATE_INTERIOR_H */
projects / bcachefs-tools-debian / blobdiff