// SPDX-License-Identifier: GPL-2.0 #include "bcachefs.h" #include "bkey_methods.h" #include "btree_cache.h" #include "btree_iter.h" #include "btree_locking.h" #include "debug.h" #include "extents.h" #include #include static inline struct bkey_s_c __btree_iter_peek_all(struct btree_iter *, struct btree_iter_level *, struct bkey *); #define BTREE_ITER_NO_NODE_GET_LOCKS ((struct btree *) 1) #define BTREE_ITER_NO_NODE_DROP ((struct btree *) 2) #define BTREE_ITER_NO_NODE_LOCK_ROOT ((struct btree *) 3) #define BTREE_ITER_NO_NODE_UP ((struct btree *) 4) #define BTREE_ITER_NO_NODE_DOWN ((struct btree *) 5) #define BTREE_ITER_NO_NODE_INIT ((struct btree *) 6) #define BTREE_ITER_NO_NODE_ERROR ((struct btree *) 7) static inline bool is_btree_node(struct btree_iter *iter, unsigned l) { return l < BTREE_MAX_DEPTH && (unsigned long) iter->l[l].b >= 128; } /* Returns < 0 if @k is before iter pos, > 0 if @k is after */ static inline int __btree_iter_pos_cmp(struct btree_iter *iter, const struct btree *b, const struct bkey_packed *k, bool interior_node) { int cmp = bkey_cmp_left_packed(b, k, &iter->pos); if (cmp) return cmp; if (bkey_deleted(k)) return -1; /* * Normally, for extents we want the first key strictly greater than * the iterator position - with the exception that for interior nodes, * we don't want to advance past the last key if the iterator position * is POS_MAX: */ if (iter->flags & BTREE_ITER_IS_EXTENTS && (!interior_node || bkey_cmp_left_packed_byval(b, k, POS_MAX))) return -1; return 1; } static inline int btree_iter_pos_cmp(struct btree_iter *iter, const struct btree *b, const struct bkey_packed *k) { return __btree_iter_pos_cmp(iter, b, k, b->level != 0); } /* Btree node locking: */ /* * Updates the saved lock sequence number, so that bch2_btree_node_relock() will * succeed: */ void bch2_btree_node_unlock_write(struct btree *b, struct btree_iter *iter) { struct btree_iter *linked; EBUG_ON(iter->l[b->level].b != b); EBUG_ON(iter->l[b->level].lock_seq + 1 != b->lock.state.seq); trans_for_each_iter_with_node(iter->trans, b, linked) linked->l[b->level].lock_seq += 2; six_unlock_write(&b->lock); } void __bch2_btree_node_lock_write(struct btree *b, struct btree_iter *iter) { struct btree_iter *linked; unsigned readers = 0; EBUG_ON(!btree_node_intent_locked(iter, b->level)); trans_for_each_iter(iter->trans, linked) if (linked->l[b->level].b == b && btree_node_read_locked(linked, b->level)) readers++; /* * Must drop our read locks before calling six_lock_write() - * six_unlock() won't do wakeups until the reader count * goes to 0, and it's safe because we have the node intent * locked: */ atomic64_sub(__SIX_VAL(read_lock, readers), &b->lock.state.counter); btree_node_lock_type(iter->trans->c, b, SIX_LOCK_write); atomic64_add(__SIX_VAL(read_lock, readers), &b->lock.state.counter); } bool __bch2_btree_node_relock(struct btree_iter *iter, unsigned level) { struct btree *b = btree_iter_node(iter, level); int want = __btree_lock_want(iter, level); if (!is_btree_node(iter, level)) return false; if (race_fault()) return false; if (six_relock_type(&b->lock, want, iter->l[level].lock_seq) || (btree_node_lock_seq_matches(iter, b, level) && btree_node_lock_increment(iter, b, level, want))) { mark_btree_node_locked(iter, level, want); return true; } else { return false; } } static bool bch2_btree_node_upgrade(struct btree_iter *iter, unsigned level) { struct btree *b = iter->l[level].b; EBUG_ON(btree_lock_want(iter, level) != BTREE_NODE_INTENT_LOCKED); if (!is_btree_node(iter, level)) return false; if (btree_node_intent_locked(iter, level)) return true; if (race_fault()) return false; if (btree_node_locked(iter, level) ? six_lock_tryupgrade(&b->lock) : six_relock_type(&b->lock, SIX_LOCK_intent, iter->l[level].lock_seq)) goto success; if (btree_node_lock_seq_matches(iter, b, level) && btree_node_lock_increment(iter, b, level, BTREE_NODE_INTENT_LOCKED)) { btree_node_unlock(iter, level); goto success; } return false; success: mark_btree_node_intent_locked(iter, level); return true; } static inline bool btree_iter_get_locks(struct btree_iter *iter, bool upgrade, bool trace) { unsigned l = iter->level; int fail_idx = -1; do { if (!btree_iter_node(iter, l)) break; if (!(upgrade ? bch2_btree_node_upgrade(iter, l) : bch2_btree_node_relock(iter, l))) { if (trace) (upgrade ? trace_node_upgrade_fail : trace_node_relock_fail)(l, iter->l[l].lock_seq, is_btree_node(iter, l) ? 0 : (unsigned long) iter->l[l].b, is_btree_node(iter, l) ? iter->l[l].b->lock.state.seq : 0); fail_idx = l; btree_iter_set_dirty(iter, BTREE_ITER_NEED_TRAVERSE); } l++; } while (l < iter->locks_want); /* * When we fail to get a lock, we have to ensure that any child nodes * can't be relocked so bch2_btree_iter_traverse has to walk back up to * the node that we failed to relock: */ while (fail_idx >= 0) { btree_node_unlock(iter, fail_idx); iter->l[fail_idx].b = BTREE_ITER_NO_NODE_GET_LOCKS; --fail_idx; } if (iter->uptodate == BTREE_ITER_NEED_RELOCK) iter->uptodate = BTREE_ITER_NEED_PEEK; bch2_btree_trans_verify_locks(iter->trans); return iter->uptodate < BTREE_ITER_NEED_RELOCK; } /* Slowpath: */ bool __bch2_btree_node_lock(struct btree *b, struct bpos pos, unsigned level, struct btree_iter *iter, enum six_lock_type type) { struct btree_iter *linked; bool ret = true; /* Check if it's safe to block: */ trans_for_each_iter(iter->trans, linked) { if (!linked->nodes_locked) continue; /* * Must lock btree nodes in key order: */ if (__btree_iter_cmp(iter->btree_id, pos, linked) < 0) ret = false; /* * Can't block taking an intent lock if we have _any_ nodes read * locked: * * - Our read lock blocks another thread with an intent lock on * the same node from getting a write lock, and thus from * dropping its intent lock * * - And the other thread may have multiple nodes intent locked: * both the node we want to intent lock, and the node we * already have read locked - deadlock: */ if (type == SIX_LOCK_intent && linked->nodes_locked != linked->nodes_intent_locked) { if (!(iter->trans->nounlock)) { linked->locks_want = max_t(unsigned, linked->locks_want, __fls(linked->nodes_locked) + 1); btree_iter_get_locks(linked, true, false); } ret = false; } /* * Interior nodes must be locked before their descendants: if * another iterator has possible descendants locked of the node * we're about to lock, it must have the ancestors locked too: */ if (linked->btree_id == iter->btree_id && level > __fls(linked->nodes_locked)) { if (!(iter->trans->nounlock)) { linked->locks_want = max(level + 1, max_t(unsigned, linked->locks_want, iter->locks_want)); btree_iter_get_locks(linked, true, false); } ret = false; } } if (unlikely(!ret)) { trace_trans_restart_would_deadlock(iter->trans->ip); return false; } __btree_node_lock_type(iter->trans->c, b, type); return true; } /* Btree iterator locking: */ #ifdef CONFIG_BCACHEFS_DEBUG void bch2_btree_iter_verify_locks(struct btree_iter *iter) { unsigned l; for (l = 0; btree_iter_node(iter, l); l++) { if (iter->uptodate >= BTREE_ITER_NEED_RELOCK && !btree_node_locked(iter, l)) continue; BUG_ON(btree_lock_want(iter, l) != btree_node_locked_type(iter, l)); } } void bch2_btree_trans_verify_locks(struct btree_trans *trans) { struct btree_iter *iter; trans_for_each_iter(trans, iter) bch2_btree_iter_verify_locks(iter); } #endif __flatten static bool bch2_btree_iter_relock(struct btree_iter *iter, bool trace) { return iter->uptodate >= BTREE_ITER_NEED_RELOCK ? btree_iter_get_locks(iter, false, trace) : true; } bool __bch2_btree_iter_upgrade(struct btree_iter *iter, unsigned new_locks_want) { struct btree_iter *linked; EBUG_ON(iter->locks_want >= new_locks_want); iter->locks_want = new_locks_want; if (btree_iter_get_locks(iter, true, true)) return true; /* * Ancestor nodes must be locked before child nodes, so set locks_want * on iterators that might lock ancestors before us to avoid getting * -EINTR later: */ trans_for_each_iter(iter->trans, linked) if (linked != iter && linked->btree_id == iter->btree_id && linked->locks_want < new_locks_want) { linked->locks_want = new_locks_want; btree_iter_get_locks(linked, true, false); } return false; } bool __bch2_btree_iter_upgrade_nounlock(struct btree_iter *iter, unsigned new_locks_want) { unsigned l = iter->level; EBUG_ON(iter->locks_want >= new_locks_want); iter->locks_want = new_locks_want; do { if (!btree_iter_node(iter, l)) break; if (!bch2_btree_node_upgrade(iter, l)) { iter->locks_want = l; return false; } l++; } while (l < iter->locks_want); return true; } void __bch2_btree_iter_downgrade(struct btree_iter *iter, unsigned downgrade_to) { struct btree_iter *linked; unsigned l; /* * We downgrade linked iterators as well because btree_iter_upgrade * might have had to modify locks_want on linked iterators due to lock * ordering: */ trans_for_each_iter(iter->trans, linked) { unsigned new_locks_want = downgrade_to ?: (linked->flags & BTREE_ITER_INTENT ? 1 : 0); if (linked->locks_want <= new_locks_want) continue; linked->locks_want = new_locks_want; while (linked->nodes_locked && (l = __fls(linked->nodes_locked)) >= linked->locks_want) { if (l > linked->level) { btree_node_unlock(linked, l); } else { if (btree_node_intent_locked(linked, l)) { six_lock_downgrade(&linked->l[l].b->lock); linked->nodes_intent_locked ^= 1 << l; } break; } } } bch2_btree_trans_verify_locks(iter->trans); } /* Btree transaction locking: */ bool bch2_trans_relock(struct btree_trans *trans) { struct btree_iter *iter; bool ret = true; trans_for_each_iter(trans, iter) if (iter->uptodate == BTREE_ITER_NEED_RELOCK) ret &= bch2_btree_iter_relock(iter, true); return ret; } void bch2_trans_unlock(struct btree_trans *trans) { struct btree_iter *iter; trans_for_each_iter(trans, iter) __bch2_btree_iter_unlock(iter); } /* Btree iterator: */ #ifdef CONFIG_BCACHEFS_DEBUG static void __bch2_btree_iter_verify(struct btree_iter *iter, struct btree *b) { struct btree_iter_level *l = &iter->l[b->level]; struct btree_node_iter tmp = l->iter; struct bkey_packed *k; if (!debug_check_iterators(iter->trans->c)) return; if (iter->uptodate > BTREE_ITER_NEED_PEEK) return; bch2_btree_node_iter_verify(&l->iter, b); /* * For interior nodes, the iterator will have skipped past * deleted keys: * * For extents, the iterator may have skipped past deleted keys (but not * whiteouts) */ k = b->level || iter->flags & BTREE_ITER_IS_EXTENTS ? bch2_btree_node_iter_prev_filter(&tmp, b, KEY_TYPE_discard) : bch2_btree_node_iter_prev_all(&tmp, b); if (k && btree_iter_pos_cmp(iter, b, k) > 0) { char buf[100]; struct bkey uk = bkey_unpack_key(b, k); bch2_bkey_to_text(&PBUF(buf), &uk); panic("prev key should be before iter pos:\n%s\n%llu:%llu\n", buf, iter->pos.inode, iter->pos.offset); } k = bch2_btree_node_iter_peek_all(&l->iter, b); if (k && btree_iter_pos_cmp(iter, b, k) < 0) { char buf[100]; struct bkey uk = bkey_unpack_key(b, k); bch2_bkey_to_text(&PBUF(buf), &uk); panic("iter should be after current key:\n" "iter pos %llu:%llu\n" "cur key %s\n", iter->pos.inode, iter->pos.offset, buf); } BUG_ON(iter->uptodate == BTREE_ITER_UPTODATE && (iter->flags & BTREE_ITER_TYPE) == BTREE_ITER_KEYS && !bkey_whiteout(&iter->k) && bch2_btree_node_iter_end(&l->iter)); } void bch2_btree_iter_verify(struct btree_iter *iter, struct btree *b) { struct btree_iter *linked; if (!debug_check_iterators(iter->trans->c)) return; trans_for_each_iter_with_node(iter->trans, b, linked) __bch2_btree_iter_verify(linked, b); } #else static inline void __bch2_btree_iter_verify(struct btree_iter *iter, struct btree *b) {} #endif static void btree_node_iter_set_set_pos(struct btree_node_iter *iter, struct btree *b, struct bset_tree *t, struct bkey_packed *k) { struct btree_node_iter_set *set; btree_node_iter_for_each(iter, set) if (set->end == t->end_offset) { set->k = __btree_node_key_to_offset(b, k); bch2_btree_node_iter_sort(iter, b); return; } bch2_btree_node_iter_push(iter, b, k, btree_bkey_last(b, t)); } static void __bch2_btree_node_iter_fix(struct btree_iter *iter, struct btree *b, struct btree_node_iter *node_iter, struct bset_tree *t, struct bkey_packed *where, unsigned clobber_u64s, unsigned new_u64s) { const struct bkey_packed *end = btree_bkey_last(b, t); struct btree_node_iter_set *set; unsigned offset = __btree_node_key_to_offset(b, where); int shift = new_u64s - clobber_u64s; unsigned old_end = t->end_offset - shift; btree_node_iter_for_each(node_iter, set) if (set->end == old_end) goto found; /* didn't find the bset in the iterator - might have to readd it: */ if (new_u64s && btree_iter_pos_cmp(iter, b, where) > 0) { btree_iter_set_dirty(iter, BTREE_ITER_NEED_PEEK); bch2_btree_node_iter_push(node_iter, b, where, end); if (!b->level && node_iter == &iter->l[0].iter) bkey_disassemble(b, bch2_btree_node_iter_peek_all(node_iter, b), &iter->k); } goto iter_current_key_not_modified; found: set->end = t->end_offset; /* Iterator hasn't gotten to the key that changed yet: */ if (set->k < offset) return; if (new_u64s && btree_iter_pos_cmp(iter, b, where) > 0) { set->k = offset; } else if (set->k < offset + clobber_u64s) { set->k = offset + new_u64s; if (set->k == set->end) bch2_btree_node_iter_set_drop(node_iter, set); } else { set->k = (int) set->k + shift; goto iter_current_key_not_modified; } btree_iter_set_dirty(iter, BTREE_ITER_NEED_PEEK); bch2_btree_node_iter_sort(node_iter, b); if (!b->level && node_iter == &iter->l[0].iter) { /* * not legal to call bkey_debugcheck() here, because we're * called midway through the update path after update has been * marked but before deletes have actually happened: */ #if 0 __btree_iter_peek_all(iter, &iter->l[0], &iter->k); #endif struct btree_iter_level *l = &iter->l[0]; struct bkey_packed *k = bch2_btree_node_iter_peek_all(&l->iter, l->b); if (unlikely(!k)) iter->k.type = KEY_TYPE_deleted; else bkey_disassemble(l->b, k, &iter->k); } iter_current_key_not_modified: /* * When a new key is added, and the node iterator now points to that * key, the iterator might have skipped past deleted keys that should * come after the key the iterator now points to. We have to rewind to * before those deleted keys - otherwise bch2_btree_node_iter_prev_all() * breaks: */ if (!bch2_btree_node_iter_end(node_iter) && (b->level || (iter->flags & BTREE_ITER_IS_EXTENTS))) { struct bset_tree *t; struct bkey_packed *k, *k2, *p; k = bch2_btree_node_iter_peek_all(node_iter, b); for_each_bset(b, t) { bool set_pos = false; if (node_iter->data[0].end == t->end_offset) continue; k2 = bch2_btree_node_iter_bset_pos(node_iter, b, t); while ((p = bch2_bkey_prev_all(b, t, k2)) && bkey_iter_cmp(b, k, p) < 0) { k2 = p; set_pos = true; } if (set_pos) btree_node_iter_set_set_pos(node_iter, b, t, k2); } } bch2_btree_node_iter_verify(node_iter, b); } void bch2_btree_node_iter_fix(struct btree_iter *iter, struct btree *b, struct btree_node_iter *node_iter, struct bkey_packed *where, unsigned clobber_u64s, unsigned new_u64s) { struct bset_tree *t = bch2_bkey_to_bset(b, where); struct btree_iter *linked; if (node_iter != &iter->l[b->level].iter) __bch2_btree_node_iter_fix(iter, b, node_iter, t, where, clobber_u64s, new_u64s); trans_for_each_iter_with_node(iter->trans, b, linked) __bch2_btree_node_iter_fix(linked, b, &linked->l[b->level].iter, t, where, clobber_u64s, new_u64s); } static inline struct bkey_s_c __btree_iter_unpack(struct btree_iter *iter, struct btree_iter_level *l, struct bkey *u, struct bkey_packed *k) { struct bkey_s_c ret; if (unlikely(!k)) { /* * signal to bch2_btree_iter_peek_slot() that we're currently at * a hole */ u->type = KEY_TYPE_deleted; return bkey_s_c_null; } ret = bkey_disassemble(l->b, k, u); if (debug_check_bkeys(iter->trans->c)) bch2_bkey_debugcheck(iter->trans->c, l->b, ret); return ret; } /* peek_all() doesn't skip deleted keys */ static inline struct bkey_s_c __btree_iter_peek_all(struct btree_iter *iter, struct btree_iter_level *l, struct bkey *u) { return __btree_iter_unpack(iter, l, u, bch2_btree_node_iter_peek_all(&l->iter, l->b)); } static inline struct bkey_s_c __btree_iter_peek(struct btree_iter *iter, struct btree_iter_level *l) { return __btree_iter_unpack(iter, l, &iter->k, bch2_btree_node_iter_peek(&l->iter, l->b)); } static inline bool btree_iter_advance_to_pos(struct btree_iter *iter, struct btree_iter_level *l, int max_advance) { struct bkey_packed *k; int nr_advanced = 0; while ((k = bch2_btree_node_iter_peek_all(&l->iter, l->b)) && btree_iter_pos_cmp(iter, l->b, k) < 0) { if (max_advance > 0 && nr_advanced >= max_advance) return false; bch2_btree_node_iter_advance(&l->iter, l->b); nr_advanced++; } return true; } /* * Verify that iterator for parent node points to child node: */ static void btree_iter_verify_new_node(struct btree_iter *iter, struct btree *b) { struct btree_iter_level *l; unsigned plevel; bool parent_locked; struct bkey_packed *k; if (!IS_ENABLED(CONFIG_BCACHEFS_DEBUG)) return; plevel = b->level + 1; if (!btree_iter_node(iter, plevel)) return; parent_locked = btree_node_locked(iter, plevel); if (!bch2_btree_node_relock(iter, plevel)) return; l = &iter->l[plevel]; k = bch2_btree_node_iter_peek_all(&l->iter, l->b); if (!k || bkey_deleted(k) || bkey_cmp_left_packed(l->b, k, &b->key.k.p)) { char buf[100]; struct bkey uk = bkey_unpack_key(b, k); bch2_bkey_to_text(&PBUF(buf), &uk); panic("parent iter doesn't point to new node:\n%s\n%llu:%llu\n", buf, b->key.k.p.inode, b->key.k.p.offset); } if (!parent_locked) btree_node_unlock(iter, b->level + 1); } static inline bool btree_iter_pos_after_node(struct btree_iter *iter, struct btree *b) { return __btree_iter_pos_cmp(iter, NULL, bkey_to_packed(&b->key), true) < 0; } static inline bool btree_iter_pos_in_node(struct btree_iter *iter, struct btree *b) { return iter->btree_id == b->btree_id && bkey_cmp(iter->pos, b->data->min_key) >= 0 && !btree_iter_pos_after_node(iter, b); } static inline void __btree_iter_init(struct btree_iter *iter, unsigned level) { struct btree_iter_level *l = &iter->l[level]; bch2_btree_node_iter_init(&l->iter, l->b, &iter->pos); if (iter->flags & BTREE_ITER_IS_EXTENTS) btree_iter_advance_to_pos(iter, l, -1); /* Skip to first non whiteout: */ if (level) bch2_btree_node_iter_peek(&l->iter, l->b); btree_iter_set_dirty(iter, BTREE_ITER_NEED_PEEK); } static inline void btree_iter_node_set(struct btree_iter *iter, struct btree *b) { btree_iter_verify_new_node(iter, b); EBUG_ON(!btree_iter_pos_in_node(iter, b)); EBUG_ON(b->lock.state.seq & 1); iter->l[b->level].lock_seq = b->lock.state.seq; iter->l[b->level].b = b; __btree_iter_init(iter, b->level); } /* * A btree node is being replaced - update the iterator to point to the new * node: */ void bch2_btree_iter_node_replace(struct btree_iter *iter, struct btree *b) { enum btree_node_locked_type t; struct btree_iter *linked; trans_for_each_iter(iter->trans, linked) if (btree_iter_pos_in_node(linked, b)) { /* * bch2_btree_iter_node_drop() has already been called - * the old node we're replacing has already been * unlocked and the pointer invalidated */ BUG_ON(btree_node_locked(linked, b->level)); t = btree_lock_want(linked, b->level); if (t != BTREE_NODE_UNLOCKED) { six_lock_increment(&b->lock, t); mark_btree_node_locked(linked, b->level, t); } btree_iter_node_set(linked, b); } six_unlock_intent(&b->lock); } void bch2_btree_iter_node_drop(struct btree_iter *iter, struct btree *b) { struct btree_iter *linked; unsigned level = b->level; trans_for_each_iter(iter->trans, linked) if (linked->l[level].b == b) { __btree_node_unlock(linked, level); linked->l[level].b = BTREE_ITER_NO_NODE_DROP; } } /* * A btree node has been modified in such a way as to invalidate iterators - fix * them: */ void bch2_btree_iter_reinit_node(struct btree_iter *iter, struct btree *b) { struct btree_iter *linked; trans_for_each_iter_with_node(iter->trans, b, linked) __btree_iter_init(linked, b->level); } static inline int btree_iter_lock_root(struct btree_iter *iter, unsigned depth_want) { struct bch_fs *c = iter->trans->c; struct btree *b; enum six_lock_type lock_type; unsigned i; EBUG_ON(iter->nodes_locked); while (1) { b = READ_ONCE(c->btree_roots[iter->btree_id].b); iter->level = READ_ONCE(b->level); if (unlikely(iter->level < depth_want)) { /* * the root is at a lower depth than the depth we want: * got to the end of the btree, or we're walking nodes * greater than some depth and there are no nodes >= * that depth */ iter->level = depth_want; for (i = iter->level; i < BTREE_MAX_DEPTH; i++) iter->l[i].b = NULL; return 1; } lock_type = __btree_lock_want(iter, iter->level); if (unlikely(!btree_node_lock(b, POS_MAX, iter->level, iter, lock_type))) return -EINTR; if (likely(b == c->btree_roots[iter->btree_id].b && b->level == iter->level && !race_fault())) { for (i = 0; i < iter->level; i++) iter->l[i].b = BTREE_ITER_NO_NODE_LOCK_ROOT; iter->l[iter->level].b = b; for (i = iter->level + 1; i < BTREE_MAX_DEPTH; i++) iter->l[i].b = NULL; mark_btree_node_locked(iter, iter->level, lock_type); btree_iter_node_set(iter, b); return 0; } six_unlock_type(&b->lock, lock_type); } } noinline static void btree_iter_prefetch(struct btree_iter *iter) { struct bch_fs *c = iter->trans->c; struct btree_iter_level *l = &iter->l[iter->level]; struct btree_node_iter node_iter = l->iter; struct bkey_packed *k; BKEY_PADDED(k) tmp; unsigned nr = test_bit(BCH_FS_STARTED, &c->flags) ? (iter->level > 1 ? 0 : 2) : (iter->level > 1 ? 1 : 16); bool was_locked = btree_node_locked(iter, iter->level); while (nr) { if (!bch2_btree_node_relock(iter, iter->level)) return; bch2_btree_node_iter_advance(&node_iter, l->b); k = bch2_btree_node_iter_peek(&node_iter, l->b); if (!k) break; bch2_bkey_unpack(l->b, &tmp.k, k); bch2_btree_node_prefetch(c, iter, &tmp.k, iter->level - 1); } if (!was_locked) btree_node_unlock(iter, iter->level); } static inline int btree_iter_down(struct btree_iter *iter) { struct bch_fs *c = iter->trans->c; struct btree_iter_level *l = &iter->l[iter->level]; struct btree *b; unsigned level = iter->level - 1; enum six_lock_type lock_type = __btree_lock_want(iter, level); BKEY_PADDED(k) tmp; BUG_ON(!btree_node_locked(iter, iter->level)); bch2_bkey_unpack(l->b, &tmp.k, bch2_btree_node_iter_peek(&l->iter, l->b)); b = bch2_btree_node_get(c, iter, &tmp.k, level, lock_type); if (unlikely(IS_ERR(b))) return PTR_ERR(b); mark_btree_node_locked(iter, level, lock_type); btree_iter_node_set(iter, b); if (iter->flags & BTREE_ITER_PREFETCH) btree_iter_prefetch(iter); iter->level = level; return 0; } static void btree_iter_up(struct btree_iter *iter) { btree_node_unlock(iter, iter->level++); } int __must_check __bch2_btree_iter_traverse(struct btree_iter *); static int __btree_iter_traverse_all(struct btree_trans *trans, struct btree_iter *orig_iter, int ret) { struct bch_fs *c = trans->c; struct btree_iter *iter; u8 sorted[BTREE_ITER_MAX]; unsigned i, nr_sorted = 0; trans_for_each_iter(trans, iter) sorted[nr_sorted++] = iter - trans->iters; #define btree_iter_cmp_by_idx(_l, _r) \ btree_iter_cmp(&trans->iters[_l], &trans->iters[_r]) bubble_sort(sorted, nr_sorted, btree_iter_cmp_by_idx); #undef btree_iter_cmp_by_idx retry_all: bch2_trans_unlock(trans); if (unlikely(ret == -ENOMEM)) { struct closure cl; closure_init_stack(&cl); do { ret = bch2_btree_cache_cannibalize_lock(c, &cl); closure_sync(&cl); } while (ret); } if (unlikely(ret == -EIO)) { trans->error = true; orig_iter->flags |= BTREE_ITER_ERROR; orig_iter->l[orig_iter->level].b = BTREE_ITER_NO_NODE_ERROR; goto out; } BUG_ON(ret && ret != -EINTR); /* Now, redo traversals in correct order: */ for (i = 0; i < nr_sorted; i++) { iter = &trans->iters[sorted[i]]; do { ret = __bch2_btree_iter_traverse(iter); } while (ret == -EINTR); if (ret) goto retry_all; } ret = hweight64(trans->iters_live) > 1 ? -EINTR : 0; out: bch2_btree_cache_cannibalize_unlock(c); return ret; } int bch2_btree_iter_traverse_all(struct btree_trans *trans) { return __btree_iter_traverse_all(trans, NULL, 0); } static unsigned btree_iter_up_until_locked(struct btree_iter *iter, bool check_pos) { unsigned l = iter->level; while (btree_iter_node(iter, l) && (!is_btree_node(iter, l) || !bch2_btree_node_relock(iter, l) || (check_pos && !btree_iter_pos_in_node(iter, iter->l[l].b)))) { btree_node_unlock(iter, l); iter->l[l].b = BTREE_ITER_NO_NODE_UP; l++; } return l; } /* * This is the main state machine for walking down the btree - walks down to a * specified depth * * Returns 0 on success, -EIO on error (error reading in a btree node). * * On error, caller (peek_node()/peek_key()) must return NULL; the error is * stashed in the iterator and returned from bch2_trans_exit(). */ int __must_check __bch2_btree_iter_traverse(struct btree_iter *iter) { unsigned depth_want = iter->level; if (unlikely(iter->level >= BTREE_MAX_DEPTH)) return 0; if (bch2_btree_iter_relock(iter, false)) return 0; /* * XXX: correctly using BTREE_ITER_UPTODATE should make using check_pos * here unnecessary */ iter->level = btree_iter_up_until_locked(iter, true); /* * If we've got a btree node locked (i.e. we aren't about to relock the * root) - advance its node iterator if necessary: * * XXX correctly using BTREE_ITER_UPTODATE should make this unnecessary */ if (btree_iter_node(iter, iter->level)) btree_iter_advance_to_pos(iter, &iter->l[iter->level], -1); /* * Note: iter->nodes[iter->level] may be temporarily NULL here - that * would indicate to other code that we got to the end of the btree, * here it indicates that relocking the root failed - it's critical that * btree_iter_lock_root() comes next and that it can't fail */ while (iter->level > depth_want) { int ret = btree_iter_node(iter, iter->level) ? btree_iter_down(iter) : btree_iter_lock_root(iter, depth_want); if (unlikely(ret)) { if (ret == 1) return 0; iter->level = depth_want; iter->l[iter->level].b = BTREE_ITER_NO_NODE_DOWN; return ret; } } iter->uptodate = BTREE_ITER_NEED_PEEK; bch2_btree_trans_verify_locks(iter->trans); __bch2_btree_iter_verify(iter, iter->l[iter->level].b); return 0; } int __must_check bch2_btree_iter_traverse(struct btree_iter *iter) { int ret; ret = bch2_trans_cond_resched(iter->trans) ?: __bch2_btree_iter_traverse(iter); if (unlikely(ret)) ret = __btree_iter_traverse_all(iter->trans, iter, ret); return ret; } static inline void bch2_btree_iter_checks(struct btree_iter *iter, enum btree_iter_type type) { EBUG_ON(iter->btree_id >= BTREE_ID_NR); EBUG_ON(!!(iter->flags & BTREE_ITER_IS_EXTENTS) != (btree_node_type_is_extents(iter->btree_id) && type != BTREE_ITER_NODES)); bch2_btree_trans_verify_locks(iter->trans); } /* Iterate across nodes (leaf and interior nodes) */ struct btree *bch2_btree_iter_peek_node(struct btree_iter *iter) { struct btree *b; int ret; bch2_btree_iter_checks(iter, BTREE_ITER_NODES); if (iter->uptodate == BTREE_ITER_UPTODATE) return iter->l[iter->level].b; ret = bch2_btree_iter_traverse(iter); if (ret) return NULL; b = btree_iter_node(iter, iter->level); if (!b) return NULL; BUG_ON(bkey_cmp(b->key.k.p, iter->pos) < 0); iter->pos = b->key.k.p; iter->uptodate = BTREE_ITER_UPTODATE; return b; } struct btree *bch2_btree_iter_next_node(struct btree_iter *iter, unsigned depth) { struct btree *b; int ret; bch2_btree_iter_checks(iter, BTREE_ITER_NODES); /* already got to end? */ if (!btree_iter_node(iter, iter->level)) return NULL; bch2_trans_cond_resched(iter->trans); btree_iter_up(iter); if (!bch2_btree_node_relock(iter, iter->level)) btree_iter_set_dirty(iter, BTREE_ITER_NEED_RELOCK); ret = bch2_btree_iter_traverse(iter); if (ret) return NULL; /* got to end? */ b = btree_iter_node(iter, iter->level); if (!b) return NULL; if (bkey_cmp(iter->pos, b->key.k.p) < 0) { /* * Haven't gotten to the end of the parent node: go back down to * the next child node */ /* * We don't really want to be unlocking here except we can't * directly tell btree_iter_traverse() "traverse to this level" * except by setting iter->level, so we have to unlock so we * don't screw up our lock invariants: */ if (btree_node_read_locked(iter, iter->level)) btree_node_unlock(iter, iter->level); /* ick: */ iter->pos = iter->btree_id == BTREE_ID_INODES ? btree_type_successor(iter->btree_id, iter->pos) : bkey_successor(iter->pos); iter->level = depth; btree_iter_set_dirty(iter, BTREE_ITER_NEED_TRAVERSE); ret = bch2_btree_iter_traverse(iter); if (ret) return NULL; b = iter->l[iter->level].b; } iter->pos = b->key.k.p; iter->uptodate = BTREE_ITER_UPTODATE; return b; } /* Iterate across keys (in leaf nodes only) */ void bch2_btree_iter_set_pos_same_leaf(struct btree_iter *iter, struct bpos new_pos) { struct btree_iter_level *l = &iter->l[0]; EBUG_ON(iter->level != 0); EBUG_ON(bkey_cmp(new_pos, iter->pos) < 0); EBUG_ON(!btree_node_locked(iter, 0)); EBUG_ON(bkey_cmp(new_pos, l->b->key.k.p) > 0); iter->pos = new_pos; btree_iter_set_dirty(iter, BTREE_ITER_NEED_PEEK); btree_iter_advance_to_pos(iter, l, -1); if (bch2_btree_node_iter_end(&l->iter) && btree_iter_pos_after_node(iter, l->b)) btree_iter_set_dirty(iter, BTREE_ITER_NEED_TRAVERSE); } void bch2_btree_iter_set_pos(struct btree_iter *iter, struct bpos new_pos) { int cmp = bkey_cmp(new_pos, iter->pos); unsigned level; if (!cmp) return; iter->pos = new_pos; level = btree_iter_up_until_locked(iter, true); if (btree_iter_node(iter, level)) { /* * We might have to skip over many keys, or just a few: try * advancing the node iterator, and if we have to skip over too * many keys just reinit it (or if we're rewinding, since that * is expensive). */ if (cmp < 0 || !btree_iter_advance_to_pos(iter, &iter->l[level], 8)) __btree_iter_init(iter, level); /* Don't leave it locked if we're not supposed to: */ if (btree_lock_want(iter, level) == BTREE_NODE_UNLOCKED) btree_node_unlock(iter, level); } if (level != iter->level) btree_iter_set_dirty(iter, BTREE_ITER_NEED_TRAVERSE); else btree_iter_set_dirty(iter, BTREE_ITER_NEED_PEEK); } static inline struct bkey_s_c btree_iter_peek_uptodate(struct btree_iter *iter) { struct btree_iter_level *l = &iter->l[0]; struct bkey_s_c ret = { .k = &iter->k }; if (!bkey_deleted(&iter->k)) { EBUG_ON(bch2_btree_node_iter_end(&l->iter)); ret.v = bkeyp_val(&l->b->format, __bch2_btree_node_iter_peek_all(&l->iter, l->b)); } if (debug_check_bkeys(iter->trans->c) && !bkey_deleted(ret.k)) bch2_bkey_debugcheck(iter->trans->c, l->b, ret); return ret; } struct bkey_s_c bch2_btree_iter_peek(struct btree_iter *iter) { struct btree_iter_level *l = &iter->l[0]; struct bkey_s_c k; int ret; bch2_btree_iter_checks(iter, BTREE_ITER_KEYS); if (iter->uptodate == BTREE_ITER_UPTODATE) return btree_iter_peek_uptodate(iter); while (1) { if (iter->uptodate >= BTREE_ITER_NEED_RELOCK) { ret = bch2_btree_iter_traverse(iter); if (unlikely(ret)) return bkey_s_c_err(ret); } k = __btree_iter_peek(iter, l); if (likely(k.k)) break; /* got to the end of the leaf, iterator needs to be traversed: */ iter->pos = l->b->key.k.p; iter->uptodate = BTREE_ITER_NEED_TRAVERSE; if (!bkey_cmp(iter->pos, POS_MAX)) return bkey_s_c_null; iter->pos = btree_type_successor(iter->btree_id, iter->pos); } /* * iter->pos should always be equal to the key we just * returned - except extents can straddle iter->pos: */ if (!(iter->flags & BTREE_ITER_IS_EXTENTS) || bkey_cmp(bkey_start_pos(k.k), iter->pos) > 0) iter->pos = bkey_start_pos(k.k); iter->uptodate = BTREE_ITER_UPTODATE; return k; } static noinline struct bkey_s_c bch2_btree_iter_peek_next_leaf(struct btree_iter *iter) { struct btree_iter_level *l = &iter->l[0]; iter->pos = l->b->key.k.p; iter->uptodate = BTREE_ITER_NEED_TRAVERSE; if (!bkey_cmp(iter->pos, POS_MAX)) return bkey_s_c_null; iter->pos = btree_type_successor(iter->btree_id, iter->pos); return bch2_btree_iter_peek(iter); } struct bkey_s_c bch2_btree_iter_next(struct btree_iter *iter) { struct btree_iter_level *l = &iter->l[0]; struct bkey_packed *p; struct bkey_s_c k; bch2_btree_iter_checks(iter, BTREE_ITER_KEYS); iter->pos = btree_type_successor(iter->btree_id, iter->k.p); if (unlikely(iter->uptodate != BTREE_ITER_UPTODATE)) { /* * XXX: when we just need to relock we should be able to avoid * calling traverse, but we need to kill BTREE_ITER_NEED_PEEK * for that to work */ btree_iter_set_dirty(iter, BTREE_ITER_NEED_TRAVERSE); return bch2_btree_iter_peek(iter); } do { bch2_btree_node_iter_advance(&l->iter, l->b); p = bch2_btree_node_iter_peek_all(&l->iter, l->b); if (unlikely(!p)) return bch2_btree_iter_peek_next_leaf(iter); } while (bkey_whiteout(p)); k = __btree_iter_unpack(iter, l, &iter->k, p); EBUG_ON(bkey_cmp(bkey_start_pos(k.k), iter->pos) < 0); iter->pos = bkey_start_pos(k.k); return k; } struct bkey_s_c bch2_btree_iter_prev(struct btree_iter *iter) { struct btree_iter_level *l = &iter->l[0]; struct bkey_packed *p; struct bkey_s_c k; int ret; bch2_btree_iter_checks(iter, BTREE_ITER_KEYS); if (unlikely(iter->uptodate != BTREE_ITER_UPTODATE)) { k = bch2_btree_iter_peek(iter); if (IS_ERR(k.k)) return k; } while (1) { p = bch2_btree_node_iter_prev(&l->iter, l->b); if (likely(p)) break; iter->pos = l->b->data->min_key; if (!bkey_cmp(iter->pos, POS_MIN)) return bkey_s_c_null; bch2_btree_iter_set_pos(iter, btree_type_predecessor(iter->btree_id, iter->pos)); ret = bch2_btree_iter_traverse(iter); if (unlikely(ret)) return bkey_s_c_err(ret); p = bch2_btree_node_iter_peek(&l->iter, l->b); if (p) break; } k = __btree_iter_unpack(iter, l, &iter->k, p); EBUG_ON(bkey_cmp(bkey_start_pos(k.k), iter->pos) > 0); iter->pos = bkey_start_pos(k.k); iter->uptodate = BTREE_ITER_UPTODATE; return k; } static inline struct bkey_s_c __bch2_btree_iter_peek_slot_extents(struct btree_iter *iter) { struct btree_iter_level *l = &iter->l[0]; struct btree_node_iter node_iter; struct bkey_s_c k; struct bkey n; int ret; recheck: while ((k = __btree_iter_peek_all(iter, l, &iter->k)).k && bkey_cmp(k.k->p, iter->pos) <= 0) bch2_btree_node_iter_advance(&l->iter, l->b); /* * iterator is now at the correct position for inserting at iter->pos, * but we need to keep iterating until we find the first non whiteout so * we know how big a hole we have, if any: */ node_iter = l->iter; if (k.k && bkey_whiteout(k.k)) k = __btree_iter_unpack(iter, l, &iter->k, bch2_btree_node_iter_peek(&node_iter, l->b)); /* * If we got to the end of the node, check if we need to traverse to the * next node: */ if (unlikely(!k.k && btree_iter_pos_after_node(iter, l->b))) { btree_iter_set_dirty(iter, BTREE_ITER_NEED_TRAVERSE); ret = bch2_btree_iter_traverse(iter); if (unlikely(ret)) return bkey_s_c_err(ret); goto recheck; } if (k.k && !bkey_whiteout(k.k) && bkey_cmp(bkey_start_pos(k.k), iter->pos) <= 0) { /* * if we skipped forward to find the first non whiteout and * there _wasn't_ actually a hole, we want the iterator to be * pointed at the key we found: */ l->iter = node_iter; EBUG_ON(bkey_cmp(k.k->p, iter->pos) < 0); EBUG_ON(bkey_deleted(k.k)); iter->uptodate = BTREE_ITER_UPTODATE; __bch2_btree_iter_verify(iter, l->b); return k; } /* hole */ /* holes can't span inode numbers: */ if (iter->pos.offset == KEY_OFFSET_MAX) { if (iter->pos.inode == KEY_INODE_MAX) return bkey_s_c_null; iter->pos = bkey_successor(iter->pos); goto recheck; } if (!k.k) k.k = &l->b->key.k; bkey_init(&n); n.p = iter->pos; bch2_key_resize(&n, min_t(u64, KEY_SIZE_MAX, (k.k->p.inode == n.p.inode ? bkey_start_offset(k.k) : KEY_OFFSET_MAX) - n.p.offset)); EBUG_ON(!n.size); iter->k = n; iter->uptodate = BTREE_ITER_UPTODATE; __bch2_btree_iter_verify(iter, l->b); return (struct bkey_s_c) { &iter->k, NULL }; } static inline struct bkey_s_c __bch2_btree_iter_peek_slot(struct btree_iter *iter) { struct btree_iter_level *l = &iter->l[0]; struct bkey_s_c k; int ret; if (iter->flags & BTREE_ITER_IS_EXTENTS) return __bch2_btree_iter_peek_slot_extents(iter); recheck: while ((k = __btree_iter_peek_all(iter, l, &iter->k)).k && bkey_deleted(k.k) && bkey_cmp(k.k->p, iter->pos) == 0) bch2_btree_node_iter_advance(&l->iter, l->b); /* * If we got to the end of the node, check if we need to traverse to the * next node: */ if (unlikely(!k.k && btree_iter_pos_after_node(iter, l->b))) { btree_iter_set_dirty(iter, BTREE_ITER_NEED_TRAVERSE); ret = bch2_btree_iter_traverse(iter); if (unlikely(ret)) return bkey_s_c_err(ret); goto recheck; } if (!k.k || bkey_deleted(k.k) || bkey_cmp(iter->pos, k.k->p)) { /* hole */ bkey_init(&iter->k); iter->k.p = iter->pos; k = (struct bkey_s_c) { &iter->k, NULL }; } iter->uptodate = BTREE_ITER_UPTODATE; __bch2_btree_iter_verify(iter, l->b); return k; } struct bkey_s_c bch2_btree_iter_peek_slot(struct btree_iter *iter) { int ret; bch2_btree_iter_checks(iter, BTREE_ITER_SLOTS); if (iter->uptodate == BTREE_ITER_UPTODATE) return btree_iter_peek_uptodate(iter); if (iter->uptodate >= BTREE_ITER_NEED_RELOCK) { ret = bch2_btree_iter_traverse(iter); if (unlikely(ret)) return bkey_s_c_err(ret); } return __bch2_btree_iter_peek_slot(iter); } struct bkey_s_c bch2_btree_iter_next_slot(struct btree_iter *iter) { bch2_btree_iter_checks(iter, BTREE_ITER_SLOTS); iter->pos = btree_type_successor(iter->btree_id, iter->k.p); if (unlikely(iter->uptodate != BTREE_ITER_UPTODATE)) { /* * XXX: when we just need to relock we should be able to avoid * calling traverse, but we need to kill BTREE_ITER_NEED_PEEK * for that to work */ btree_iter_set_dirty(iter, BTREE_ITER_NEED_TRAVERSE); return bch2_btree_iter_peek_slot(iter); } if (!bkey_deleted(&iter->k)) bch2_btree_node_iter_advance(&iter->l[0].iter, iter->l[0].b); btree_iter_set_dirty(iter, BTREE_ITER_NEED_PEEK); return __bch2_btree_iter_peek_slot(iter); } static inline void bch2_btree_iter_init(struct btree_trans *trans, struct btree_iter *iter, enum btree_id btree_id, struct bpos pos, unsigned flags) { struct bch_fs *c = trans->c; unsigned i; if (btree_node_type_is_extents(btree_id) && !(flags & BTREE_ITER_NODES)) flags |= BTREE_ITER_IS_EXTENTS; iter->trans = trans; iter->pos = pos; bkey_init(&iter->k); iter->k.p = pos; iter->flags = flags; iter->uptodate = BTREE_ITER_NEED_TRAVERSE; iter->btree_id = btree_id; iter->level = 0; iter->locks_want = flags & BTREE_ITER_INTENT ? 1 : 0; iter->nodes_locked = 0; iter->nodes_intent_locked = 0; for (i = 0; i < ARRAY_SIZE(iter->l); i++) iter->l[i].b = NULL; iter->l[iter->level].b = BTREE_ITER_NO_NODE_INIT; prefetch(c->btree_roots[btree_id].b); } /* new transactional stuff: */ int bch2_trans_iter_put(struct btree_trans *trans, struct btree_iter *iter) { int ret = btree_iter_err(iter); trans->iters_live &= ~(1ULL << iter->idx); return ret; } static inline void __bch2_trans_iter_free(struct btree_trans *trans, unsigned idx) { __bch2_btree_iter_unlock(&trans->iters[idx]); trans->iters_linked &= ~(1ULL << idx); trans->iters_live &= ~(1ULL << idx); trans->iters_touched &= ~(1ULL << idx); trans->iters_unlink_on_restart &= ~(1ULL << idx); trans->iters_unlink_on_commit &= ~(1ULL << idx); } int bch2_trans_iter_free(struct btree_trans *trans, struct btree_iter *iter) { int ret = btree_iter_err(iter); __bch2_trans_iter_free(trans, iter->idx); return ret; } int bch2_trans_iter_free_on_commit(struct btree_trans *trans, struct btree_iter *iter) { int ret = btree_iter_err(iter); trans->iters_unlink_on_commit |= 1ULL << iter->idx; return ret; } static int bch2_trans_realloc_iters(struct btree_trans *trans, unsigned new_size) { void *new_iters, *new_updates; new_size = roundup_pow_of_two(new_size); BUG_ON(new_size > BTREE_ITER_MAX); if (new_size <= trans->size) return 0; BUG_ON(trans->used_mempool); bch2_trans_unlock(trans); new_iters = kmalloc(sizeof(struct btree_iter) * new_size + sizeof(struct btree_insert_entry) * (new_size + 4), GFP_NOFS); if (new_iters) goto success; new_iters = mempool_alloc(&trans->c->btree_iters_pool, GFP_NOFS); new_size = BTREE_ITER_MAX; trans->used_mempool = true; success: new_updates = new_iters + sizeof(struct btree_iter) * new_size; memcpy(new_iters, trans->iters, sizeof(struct btree_iter) * trans->nr_iters); memcpy(new_updates, trans->updates, sizeof(struct btree_insert_entry) * trans->nr_updates); if (IS_ENABLED(CONFIG_BCACHEFS_DEBUG)) memset(trans->iters, POISON_FREE, sizeof(struct btree_iter) * trans->nr_iters + sizeof(struct btree_insert_entry) * trans->nr_iters); if (trans->iters != trans->iters_onstack) kfree(trans->iters); trans->iters = new_iters; trans->updates = new_updates; trans->size = new_size; if (trans->iters_live) { trace_trans_restart_iters_realloced(trans->ip, trans->size); return -EINTR; } return 0; } static int btree_trans_iter_alloc(struct btree_trans *trans) { unsigned idx = __ffs64(~trans->iters_linked); if (idx < trans->nr_iters) goto got_slot; if (trans->nr_iters == trans->size) { int ret = bch2_trans_realloc_iters(trans, trans->size * 2); if (ret) return ret; } idx = trans->nr_iters++; BUG_ON(trans->nr_iters > trans->size); trans->iters[idx].idx = idx; got_slot: BUG_ON(trans->iters_linked & (1ULL << idx)); trans->iters_linked |= 1ULL << idx; return idx; } static struct btree_iter *__btree_trans_get_iter(struct btree_trans *trans, unsigned btree_id, struct bpos pos, unsigned flags, u64 iter_id) { struct btree_iter *iter; int idx; BUG_ON(trans->nr_iters > BTREE_ITER_MAX); for (idx = 0; idx < trans->nr_iters; idx++) { if (!(trans->iters_linked & (1ULL << idx))) continue; iter = &trans->iters[idx]; if (iter_id ? iter->id == iter_id : (iter->btree_id == btree_id && !bkey_cmp(iter->pos, pos))) goto found; } idx = -1; found: if (idx < 0) { idx = btree_trans_iter_alloc(trans); if (idx < 0) return ERR_PTR(idx); iter = &trans->iters[idx]; iter->id = iter_id; bch2_btree_iter_init(trans, iter, btree_id, pos, flags); } else { iter = &trans->iters[idx]; iter->flags &= ~(BTREE_ITER_INTENT|BTREE_ITER_PREFETCH); iter->flags |= flags & (BTREE_ITER_INTENT|BTREE_ITER_PREFETCH); if ((iter->flags & BTREE_ITER_INTENT) && !bch2_btree_iter_upgrade(iter, 1)) { trace_trans_restart_upgrade(trans->ip); return ERR_PTR(-EINTR); } } BUG_ON(iter->btree_id != btree_id); BUG_ON(trans->iters_live & (1ULL << idx)); trans->iters_live |= 1ULL << idx; trans->iters_touched |= 1ULL << idx; BUG_ON(iter->btree_id != btree_id); BUG_ON((iter->flags ^ flags) & BTREE_ITER_TYPE); return iter; } struct btree_iter *__bch2_trans_get_iter(struct btree_trans *trans, enum btree_id btree_id, struct bpos pos, unsigned flags, u64 iter_id) { struct btree_iter *iter = __btree_trans_get_iter(trans, btree_id, pos, flags, iter_id); if (!IS_ERR(iter)) bch2_btree_iter_set_pos(iter, pos); return iter; } struct btree_iter *bch2_trans_get_node_iter(struct btree_trans *trans, enum btree_id btree_id, struct bpos pos, unsigned locks_want, unsigned depth, unsigned flags) { struct btree_iter *iter = __btree_trans_get_iter(trans, btree_id, pos, flags|BTREE_ITER_NODES, 0); unsigned i; BUG_ON(IS_ERR(iter)); BUG_ON(bkey_cmp(iter->pos, pos)); iter->locks_want = locks_want; iter->level = depth; for (i = 0; i < ARRAY_SIZE(iter->l); i++) iter->l[i].b = NULL; iter->l[iter->level].b = BTREE_ITER_NO_NODE_INIT; return iter; } struct btree_iter *bch2_trans_copy_iter(struct btree_trans *trans, struct btree_iter *src) { struct btree_iter *iter; int i, idx; idx = btree_trans_iter_alloc(trans); if (idx < 0) return ERR_PTR(idx); trans->iters_live |= 1ULL << idx; trans->iters_touched |= 1ULL << idx; trans->iters_unlink_on_restart |= 1ULL << idx; iter = &trans->iters[idx]; memcpy(&iter->trans, &src->trans, (void *) &iter[1] - (void *) &iter->trans); for (i = 0; i < BTREE_MAX_DEPTH; i++) if (btree_node_locked(iter, i)) six_lock_increment(&iter->l[i].b->lock, __btree_lock_want(iter, i)); return &trans->iters[idx]; } static int bch2_trans_preload_mem(struct btree_trans *trans, size_t size) { if (size > trans->mem_bytes) { size_t old_bytes = trans->mem_bytes; size_t new_bytes = roundup_pow_of_two(size); void *new_mem = krealloc(trans->mem, new_bytes, GFP_NOFS); if (!new_mem) return -ENOMEM; trans->mem = new_mem; trans->mem_bytes = new_bytes; if (old_bytes) { trace_trans_restart_mem_realloced(trans->ip, new_bytes); return -EINTR; } } return 0; } void *bch2_trans_kmalloc(struct btree_trans *trans, size_t size) { void *p; int ret; ret = bch2_trans_preload_mem(trans, trans->mem_top + size); if (ret) return ERR_PTR(ret); p = trans->mem + trans->mem_top; trans->mem_top += size; return p; } inline void bch2_trans_unlink_iters(struct btree_trans *trans, u64 iters) { iters &= trans->iters_linked; iters &= ~trans->iters_live; while (iters) { unsigned idx = __ffs64(iters); iters &= ~(1ULL << idx); __bch2_trans_iter_free(trans, idx); } } void bch2_trans_begin(struct btree_trans *trans) { u64 iters_to_unlink; /* * On transaction restart, the transaction isn't required to allocate * all the same iterators it on the last iteration: * * Unlink any iterators it didn't use this iteration, assuming it got * further (allocated an iter with a higher idx) than where the iter * was originally allocated: */ iters_to_unlink = ~trans->iters_live & ((1ULL << fls64(trans->iters_live)) - 1); iters_to_unlink |= trans->iters_unlink_on_restart; iters_to_unlink |= trans->iters_unlink_on_commit; trans->iters_live = 0; bch2_trans_unlink_iters(trans, iters_to_unlink); trans->iters_touched = 0; trans->iters_unlink_on_restart = 0; trans->iters_unlink_on_commit = 0; trans->nr_updates = 0; trans->mem_top = 0; bch2_btree_iter_traverse_all(trans); } void bch2_trans_init(struct btree_trans *trans, struct bch_fs *c, unsigned expected_nr_iters, size_t expected_mem_bytes) { memset(trans, 0, offsetof(struct btree_trans, iters_onstack)); trans->c = c; trans->ip = _RET_IP_; trans->size = ARRAY_SIZE(trans->iters_onstack); trans->iters = trans->iters_onstack; trans->updates = trans->updates_onstack; trans->fs_usage_deltas = NULL; if (expected_nr_iters > trans->size) bch2_trans_realloc_iters(trans, expected_nr_iters); if (expected_mem_bytes) bch2_trans_preload_mem(trans, expected_mem_bytes); } int bch2_trans_exit(struct btree_trans *trans) { bch2_trans_unlock(trans); kfree(trans->fs_usage_deltas); kfree(trans->mem); if (trans->used_mempool) mempool_free(trans->iters, &trans->c->btree_iters_pool); else if (trans->iters != trans->iters_onstack) kfree(trans->iters); trans->mem = (void *) 0x1; trans->iters = (void *) 0x1; return trans->error ? -EIO : 0; }