--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+
+#include "bcachefs.h"
+#include "bkey_methods.h"
+#include "bkey_buf.h"
+#include "btree_cache.h"
+#include "btree_iter.h"
+#include "btree_journal_iter.h"
+#include "btree_key_cache.h"
+#include "btree_locking.h"
+#include "btree_update.h"
+#include "debug.h"
+#include "error.h"
+#include "extents.h"
+#include "journal.h"
+#include "journal_io.h"
+#include "replicas.h"
+#include "snapshot.h"
+#include "trace.h"
+
+#include <linux/random.h>
+#include <linux/prefetch.h>
+
+static inline void btree_path_list_remove(struct btree_trans *, struct btree_path *);
+static inline void btree_path_list_add(struct btree_trans *,
+ btree_path_idx_t, btree_path_idx_t);
+
+static inline unsigned long btree_iter_ip_allocated(struct btree_iter *iter)
+{
+#ifdef TRACK_PATH_ALLOCATED
+ return iter->ip_allocated;
+#else
+ return 0;
+#endif
+}
+
+static btree_path_idx_t btree_path_alloc(struct btree_trans *, btree_path_idx_t);
+static void bch2_trans_srcu_lock(struct btree_trans *);
+
+static inline int __btree_path_cmp(const struct btree_path *l,
+ enum btree_id r_btree_id,
+ bool r_cached,
+ struct bpos r_pos,
+ unsigned r_level)
+{
+ /*
+ * Must match lock ordering as defined by __bch2_btree_node_lock:
+ */
+ return cmp_int(l->btree_id, r_btree_id) ?:
+ cmp_int((int) l->cached, (int) r_cached) ?:
+ bpos_cmp(l->pos, r_pos) ?:
+ -cmp_int(l->level, r_level);
+}
+
+static inline int btree_path_cmp(const struct btree_path *l,
+ const struct btree_path *r)
+{
+ return __btree_path_cmp(l, r->btree_id, r->cached, r->pos, r->level);
+}
+
+static inline struct bpos bkey_successor(struct btree_iter *iter, struct bpos p)
+{
+ /* Are we iterating over keys in all snapshots? */
+ if (iter->flags & BTREE_ITER_ALL_SNAPSHOTS) {
+ p = bpos_successor(p);
+ } else {
+ p = bpos_nosnap_successor(p);
+ p.snapshot = iter->snapshot;
+ }
+
+ return p;
+}
+
+static inline struct bpos bkey_predecessor(struct btree_iter *iter, struct bpos p)
+{
+ /* Are we iterating over keys in all snapshots? */
+ if (iter->flags & BTREE_ITER_ALL_SNAPSHOTS) {
+ p = bpos_predecessor(p);
+ } else {
+ p = bpos_nosnap_predecessor(p);
+ p.snapshot = iter->snapshot;
+ }
+
+ return p;
+}
+
+static inline struct bpos btree_iter_search_key(struct btree_iter *iter)
+{
+ struct bpos pos = iter->pos;
+
+ if ((iter->flags & BTREE_ITER_IS_EXTENTS) &&
+ !bkey_eq(pos, POS_MAX))
+ pos = bkey_successor(iter, pos);
+ return pos;
+}
+
+static inline bool btree_path_pos_before_node(struct btree_path *path,
+ struct btree *b)
+{
+ return bpos_lt(path->pos, b->data->min_key);
+}
+
+static inline bool btree_path_pos_after_node(struct btree_path *path,
+ struct btree *b)
+{
+ return bpos_gt(path->pos, b->key.k.p);
+}
+
+static inline bool btree_path_pos_in_node(struct btree_path *path,
+ struct btree *b)
+{
+ return path->btree_id == b->c.btree_id &&
+ !btree_path_pos_before_node(path, b) &&
+ !btree_path_pos_after_node(path, b);
+}
+
+/* Btree iterator: */
+
+#ifdef CONFIG_BCACHEFS_DEBUG
+
+static void bch2_btree_path_verify_cached(struct btree_trans *trans,
+ struct btree_path *path)
+{
+ struct bkey_cached *ck;
+ bool locked = btree_node_locked(path, 0);
+
+ if (!bch2_btree_node_relock(trans, path, 0))
+ return;
+
+ ck = (void *) path->l[0].b;
+ BUG_ON(ck->key.btree_id != path->btree_id ||
+ !bkey_eq(ck->key.pos, path->pos));
+
+ if (!locked)
+ btree_node_unlock(trans, path, 0);
+}
+
+static void bch2_btree_path_verify_level(struct btree_trans *trans,
+ struct btree_path *path, unsigned level)
+{
+ struct btree_path_level *l;
+ struct btree_node_iter tmp;
+ bool locked;
+ struct bkey_packed *p, *k;
+ struct printbuf buf1 = PRINTBUF;
+ struct printbuf buf2 = PRINTBUF;
+ struct printbuf buf3 = PRINTBUF;
+ const char *msg;
+
+ if (!bch2_debug_check_iterators)
+ return;
+
+ l = &path->l[level];
+ tmp = l->iter;
+ locked = btree_node_locked(path, level);
+
+ if (path->cached) {
+ if (!level)
+ bch2_btree_path_verify_cached(trans, path);
+ return;
+ }
+
+ if (!btree_path_node(path, level))
+ return;
+
+ if (!bch2_btree_node_relock_notrace(trans, path, level))
+ return;
+
+ BUG_ON(!btree_path_pos_in_node(path, l->b));
+
+ bch2_btree_node_iter_verify(&l->iter, l->b);
+
+ /*
+ * For interior nodes, the iterator will have skipped past deleted keys:
+ */
+ p = level
+ ? bch2_btree_node_iter_prev(&tmp, l->b)
+ : bch2_btree_node_iter_prev_all(&tmp, l->b);
+ k = bch2_btree_node_iter_peek_all(&l->iter, l->b);
+
+ if (p && bkey_iter_pos_cmp(l->b, p, &path->pos) >= 0) {
+ msg = "before";
+ goto err;
+ }
+
+ if (k && bkey_iter_pos_cmp(l->b, k, &path->pos) < 0) {
+ msg = "after";
+ goto err;
+ }
+
+ if (!locked)
+ btree_node_unlock(trans, path, level);
+ return;
+err:
+ bch2_bpos_to_text(&buf1, path->pos);
+
+ if (p) {
+ struct bkey uk = bkey_unpack_key(l->b, p);
+
+ bch2_bkey_to_text(&buf2, &uk);
+ } else {
+ prt_printf(&buf2, "(none)");
+ }
+
+ if (k) {
+ struct bkey uk = bkey_unpack_key(l->b, k);
+
+ bch2_bkey_to_text(&buf3, &uk);
+ } else {
+ prt_printf(&buf3, "(none)");
+ }
+
+ panic("path should be %s key at level %u:\n"
+ "path pos %s\n"
+ "prev key %s\n"
+ "cur key %s\n",
+ msg, level, buf1.buf, buf2.buf, buf3.buf);
+}
+
+static void bch2_btree_path_verify(struct btree_trans *trans,
+ struct btree_path *path)
+{
+ struct bch_fs *c = trans->c;
+ unsigned i;
+
+ EBUG_ON(path->btree_id >= BTREE_ID_NR);
+
+ for (i = 0; i < (!path->cached ? BTREE_MAX_DEPTH : 1); i++) {
+ if (!path->l[i].b) {
+ BUG_ON(!path->cached &&
+ bch2_btree_id_root(c, path->btree_id)->b->c.level > i);
+ break;
+ }
+
+ bch2_btree_path_verify_level(trans, path, i);
+ }
+
+ bch2_btree_path_verify_locks(path);
+}
+
+void bch2_trans_verify_paths(struct btree_trans *trans)
+{
+ struct btree_path *path;
+ unsigned iter;
+
+ trans_for_each_path(trans, path, iter)
+ bch2_btree_path_verify(trans, path);
+}
+
+static void bch2_btree_iter_verify(struct btree_iter *iter)
+{
+ struct btree_trans *trans = iter->trans;
+
+ BUG_ON(iter->btree_id >= BTREE_ID_NR);
+
+ BUG_ON(!!(iter->flags & BTREE_ITER_CACHED) != btree_iter_path(trans, iter)->cached);
+
+ BUG_ON((iter->flags & BTREE_ITER_IS_EXTENTS) &&
+ (iter->flags & BTREE_ITER_ALL_SNAPSHOTS));
+
+ BUG_ON(!(iter->flags & __BTREE_ITER_ALL_SNAPSHOTS) &&
+ (iter->flags & BTREE_ITER_ALL_SNAPSHOTS) &&
+ !btree_type_has_snapshot_field(iter->btree_id));
+
+ if (iter->update_path)
+ bch2_btree_path_verify(trans, &trans->paths[iter->update_path]);
+ bch2_btree_path_verify(trans, btree_iter_path(trans, iter));
+}
+
+static void bch2_btree_iter_verify_entry_exit(struct btree_iter *iter)
+{
+ BUG_ON((iter->flags & BTREE_ITER_FILTER_SNAPSHOTS) &&
+ !iter->pos.snapshot);
+
+ BUG_ON(!(iter->flags & BTREE_ITER_ALL_SNAPSHOTS) &&
+ iter->pos.snapshot != iter->snapshot);
+
+ BUG_ON(bkey_lt(iter->pos, bkey_start_pos(&iter->k)) ||
+ bkey_gt(iter->pos, iter->k.p));
+}
+
+static int bch2_btree_iter_verify_ret(struct btree_iter *iter, struct bkey_s_c k)
+{
+ struct btree_trans *trans = iter->trans;
+ struct btree_iter copy;
+ struct bkey_s_c prev;
+ int ret = 0;
+
+ if (!bch2_debug_check_iterators)
+ return 0;
+
+ if (!(iter->flags & BTREE_ITER_FILTER_SNAPSHOTS))
+ return 0;
+
+ if (bkey_err(k) || !k.k)
+ return 0;
+
+ BUG_ON(!bch2_snapshot_is_ancestor(trans->c,
+ iter->snapshot,
+ k.k->p.snapshot));
+
+ bch2_trans_iter_init(trans, ©, iter->btree_id, iter->pos,
+ BTREE_ITER_NOPRESERVE|
+ BTREE_ITER_ALL_SNAPSHOTS);
+ prev = bch2_btree_iter_prev(©);
+ if (!prev.k)
+ goto out;
+
+ ret = bkey_err(prev);
+ if (ret)
+ goto out;
+
+ if (bkey_eq(prev.k->p, k.k->p) &&
+ bch2_snapshot_is_ancestor(trans->c, iter->snapshot,
+ prev.k->p.snapshot) > 0) {
+ struct printbuf buf1 = PRINTBUF, buf2 = PRINTBUF;
+
+ bch2_bkey_to_text(&buf1, k.k);
+ bch2_bkey_to_text(&buf2, prev.k);
+
+ panic("iter snap %u\n"
+ "k %s\n"
+ "prev %s\n",
+ iter->snapshot,
+ buf1.buf, buf2.buf);
+ }
+out:
+ bch2_trans_iter_exit(trans, ©);
+ return ret;
+}
+
+void bch2_assert_pos_locked(struct btree_trans *trans, enum btree_id id,
+ struct bpos pos, bool key_cache)
+{
+ struct btree_path *path;
+ struct trans_for_each_path_inorder_iter iter;
+ struct printbuf buf = PRINTBUF;
+
+ btree_trans_sort_paths(trans);
+
+ trans_for_each_path_inorder(trans, path, iter) {
+ int cmp = cmp_int(path->btree_id, id) ?:
+ cmp_int(path->cached, key_cache);
+
+ if (cmp > 0)
+ break;
+ if (cmp < 0)
+ continue;
+
+ if (!btree_node_locked(path, 0) ||
+ !path->should_be_locked)
+ continue;
+
+ if (!key_cache) {
+ if (bkey_ge(pos, path->l[0].b->data->min_key) &&
+ bkey_le(pos, path->l[0].b->key.k.p))
+ return;
+ } else {
+ if (bkey_eq(pos, path->pos))
+ return;
+ }
+ }
+
+ bch2_dump_trans_paths_updates(trans);
+ bch2_bpos_to_text(&buf, pos);
+
+ panic("not locked: %s %s%s\n",
+ bch2_btree_id_str(id), buf.buf,
+ key_cache ? " cached" : "");
+}
+
+#else
+
+static inline void bch2_btree_path_verify_level(struct btree_trans *trans,
+ struct btree_path *path, unsigned l) {}
+static inline void bch2_btree_path_verify(struct btree_trans *trans,
+ struct btree_path *path) {}
+static inline void bch2_btree_iter_verify(struct btree_iter *iter) {}
+static inline void bch2_btree_iter_verify_entry_exit(struct btree_iter *iter) {}
+static inline int bch2_btree_iter_verify_ret(struct btree_iter *iter, struct bkey_s_c k) { return 0; }
+
+#endif
+
+/* Btree path: fixups after btree updates */
+
+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_path_fix_key_modified(struct btree_path *path,
+ struct btree *b,
+ struct bkey_packed *where)
+{
+ struct btree_path_level *l = &path->l[b->c.level];
+
+ if (where != bch2_btree_node_iter_peek_all(&l->iter, l->b))
+ return;
+
+ if (bkey_iter_pos_cmp(l->b, where, &path->pos) < 0)
+ bch2_btree_node_iter_advance(&l->iter, l->b);
+}
+
+void bch2_btree_path_fix_key_modified(struct btree_trans *trans,
+ struct btree *b,
+ struct bkey_packed *where)
+{
+ struct btree_path *path;
+ unsigned i;
+
+ trans_for_each_path_with_node(trans, b, path, i) {
+ __bch2_btree_path_fix_key_modified(path, b, where);
+ bch2_btree_path_verify_level(trans, path, b->c.level);
+ }
+}
+
+static void __bch2_btree_node_iter_fix(struct btree_path *path,
+ 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;
+ unsigned orig_iter_pos = node_iter->data[0].k;
+ bool iter_current_key_modified =
+ orig_iter_pos >= offset &&
+ orig_iter_pos <= offset + clobber_u64s;
+
+ 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 &&
+ bkey_iter_pos_cmp(b, where, &path->pos) >= 0) {
+ bch2_btree_node_iter_push(node_iter, b, where, end);
+ goto fixup_done;
+ } else {
+ /* Iterator is after key that changed */
+ return;
+ }
+found:
+ set->end = t->end_offset;
+
+ /* Iterator hasn't gotten to the key that changed yet: */
+ if (set->k < offset)
+ return;
+
+ if (new_u64s &&
+ bkey_iter_pos_cmp(b, where, &path->pos) >= 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 {
+ /* Iterator is after key that changed */
+ set->k = (int) set->k + shift;
+ return;
+ }
+
+ bch2_btree_node_iter_sort(node_iter, b);
+fixup_done:
+ if (node_iter->data[0].k != orig_iter_pos)
+ iter_current_key_modified = true;
+
+ /*
+ * 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) &&
+ iter_current_key_modified &&
+ b->c.level) {
+ 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);
+ }
+ }
+}
+
+void bch2_btree_node_iter_fix(struct btree_trans *trans,
+ struct btree_path *path,
+ 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_inlined(b, where);
+ struct btree_path *linked;
+ unsigned i;
+
+ if (node_iter != &path->l[b->c.level].iter) {
+ __bch2_btree_node_iter_fix(path, b, node_iter, t,
+ where, clobber_u64s, new_u64s);
+
+ if (bch2_debug_check_iterators)
+ bch2_btree_node_iter_verify(node_iter, b);
+ }
+
+ trans_for_each_path_with_node(trans, b, linked, i) {
+ __bch2_btree_node_iter_fix(linked, b,
+ &linked->l[b->c.level].iter, t,
+ where, clobber_u64s, new_u64s);
+ bch2_btree_path_verify_level(trans, linked, b->c.level);
+ }
+}
+
+/* Btree path level: pointer to a particular btree node and node iter */
+
+static inline struct bkey_s_c __btree_iter_unpack(struct bch_fs *c,
+ struct btree_path_level *l,
+ struct bkey *u,
+ struct bkey_packed *k)
+{
+ 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;
+ }
+
+ return bkey_disassemble(l->b, k, u);
+}
+
+static inline struct bkey_s_c btree_path_level_peek_all(struct bch_fs *c,
+ struct btree_path_level *l,
+ struct bkey *u)
+{
+ return __btree_iter_unpack(c, l, u,
+ bch2_btree_node_iter_peek_all(&l->iter, l->b));
+}
+
+static inline struct bkey_s_c btree_path_level_peek(struct btree_trans *trans,
+ struct btree_path *path,
+ struct btree_path_level *l,
+ struct bkey *u)
+{
+ struct bkey_s_c k = __btree_iter_unpack(trans->c, l, u,
+ bch2_btree_node_iter_peek(&l->iter, l->b));
+
+ path->pos = k.k ? k.k->p : l->b->key.k.p;
+ trans->paths_sorted = false;
+ bch2_btree_path_verify_level(trans, path, l - path->l);
+ return k;
+}
+
+static inline struct bkey_s_c btree_path_level_prev(struct btree_trans *trans,
+ struct btree_path *path,
+ struct btree_path_level *l,
+ struct bkey *u)
+{
+ struct bkey_s_c k = __btree_iter_unpack(trans->c, l, u,
+ bch2_btree_node_iter_prev(&l->iter, l->b));
+
+ path->pos = k.k ? k.k->p : l->b->data->min_key;
+ trans->paths_sorted = false;
+ bch2_btree_path_verify_level(trans, path, l - path->l);
+ return k;
+}
+
+static inline bool btree_path_advance_to_pos(struct btree_path *path,
+ struct btree_path_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)) &&
+ bkey_iter_pos_cmp(l->b, k, &path->pos) < 0) {
+ if (max_advance > 0 && nr_advanced >= max_advance)
+ return false;
+
+ bch2_btree_node_iter_advance(&l->iter, l->b);
+ nr_advanced++;
+ }
+
+ return true;
+}
+
+static inline void __btree_path_level_init(struct btree_path *path,
+ unsigned level)
+{
+ struct btree_path_level *l = &path->l[level];
+
+ bch2_btree_node_iter_init(&l->iter, l->b, &path->pos);
+
+ /*
+ * Iterators to interior nodes should always be pointed at the first non
+ * whiteout:
+ */
+ if (level)
+ bch2_btree_node_iter_peek(&l->iter, l->b);
+}
+
+void bch2_btree_path_level_init(struct btree_trans *trans,
+ struct btree_path *path,
+ struct btree *b)
+{
+ BUG_ON(path->cached);
+
+ EBUG_ON(!btree_path_pos_in_node(path, b));
+
+ path->l[b->c.level].lock_seq = six_lock_seq(&b->c.lock);
+ path->l[b->c.level].b = b;
+ __btree_path_level_init(path, b->c.level);
+}
+
+/* Btree path: fixups after btree node updates: */
+
+static void bch2_trans_revalidate_updates_in_node(struct btree_trans *trans, struct btree *b)
+{
+ struct bch_fs *c = trans->c;
+
+ trans_for_each_update(trans, i)
+ if (!i->cached &&
+ i->level == b->c.level &&
+ i->btree_id == b->c.btree_id &&
+ bpos_cmp(i->k->k.p, b->data->min_key) >= 0 &&
+ bpos_cmp(i->k->k.p, b->data->max_key) <= 0) {
+ i->old_v = bch2_btree_path_peek_slot(trans->paths + i->path, &i->old_k).v;
+
+ if (unlikely(trans->journal_replay_not_finished)) {
+ struct bkey_i *j_k =
+ bch2_journal_keys_peek_slot(c, i->btree_id, i->level,
+ i->k->k.p);
+
+ if (j_k) {
+ i->old_k = j_k->k;
+ i->old_v = &j_k->v;
+ }
+ }
+ }
+}
+
+/*
+ * A btree node is being replaced - update the iterator to point to the new
+ * node:
+ */
+void bch2_trans_node_add(struct btree_trans *trans,
+ struct btree_path *path,
+ struct btree *b)
+{
+ struct btree_path *prev;
+
+ BUG_ON(!btree_path_pos_in_node(path, b));
+
+ while ((prev = prev_btree_path(trans, path)) &&
+ btree_path_pos_in_node(prev, b))
+ path = prev;
+
+ for (;
+ path && btree_path_pos_in_node(path, b);
+ path = next_btree_path(trans, path))
+ if (path->uptodate == BTREE_ITER_UPTODATE && !path->cached) {
+ enum btree_node_locked_type t =
+ btree_lock_want(path, b->c.level);
+
+ if (t != BTREE_NODE_UNLOCKED) {
+ btree_node_unlock(trans, path, b->c.level);
+ six_lock_increment(&b->c.lock, (enum six_lock_type) t);
+ mark_btree_node_locked(trans, path, b->c.level, t);
+ }
+
+ bch2_btree_path_level_init(trans, path, b);
+ }
+
+ bch2_trans_revalidate_updates_in_node(trans, b);
+}
+
+/*
+ * A btree node has been modified in such a way as to invalidate iterators - fix
+ * them:
+ */
+void bch2_trans_node_reinit_iter(struct btree_trans *trans, struct btree *b)
+{
+ struct btree_path *path;
+ unsigned i;
+
+ trans_for_each_path_with_node(trans, b, path, i)
+ __btree_path_level_init(path, b->c.level);
+
+ bch2_trans_revalidate_updates_in_node(trans, b);
+}
+
+/* Btree path: traverse, set_pos: */
+
+static inline int btree_path_lock_root(struct btree_trans *trans,
+ struct btree_path *path,
+ unsigned depth_want,
+ unsigned long trace_ip)
+{
+ struct bch_fs *c = trans->c;
+ struct btree *b, **rootp = &bch2_btree_id_root(c, path->btree_id)->b;
+ enum six_lock_type lock_type;
+ unsigned i;
+ int ret;
+
+ EBUG_ON(path->nodes_locked);
+
+ while (1) {
+ b = READ_ONCE(*rootp);
+ path->level = READ_ONCE(b->c.level);
+
+ if (unlikely(path->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
+ */
+ path->level = depth_want;
+ for (i = path->level; i < BTREE_MAX_DEPTH; i++)
+ path->l[i].b = NULL;
+ return 1;
+ }
+
+ lock_type = __btree_lock_want(path, path->level);
+ ret = btree_node_lock(trans, path, &b->c,
+ path->level, lock_type, trace_ip);
+ if (unlikely(ret)) {
+ if (bch2_err_matches(ret, BCH_ERR_lock_fail_root_changed))
+ continue;
+ if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
+ return ret;
+ BUG();
+ }
+
+ if (likely(b == READ_ONCE(*rootp) &&
+ b->c.level == path->level &&
+ !race_fault())) {
+ for (i = 0; i < path->level; i++)
+ path->l[i].b = ERR_PTR(-BCH_ERR_no_btree_node_lock_root);
+ path->l[path->level].b = b;
+ for (i = path->level + 1; i < BTREE_MAX_DEPTH; i++)
+ path->l[i].b = NULL;
+
+ mark_btree_node_locked(trans, path, path->level,
+ (enum btree_node_locked_type) lock_type);
+ bch2_btree_path_level_init(trans, path, b);
+ return 0;
+ }
+
+ six_unlock_type(&b->c.lock, lock_type);
+ }
+}
+
+noinline
+static int btree_path_prefetch(struct btree_trans *trans, struct btree_path *path)
+{
+ struct bch_fs *c = trans->c;
+ struct btree_path_level *l = path_l(path);
+ struct btree_node_iter node_iter = l->iter;
+ struct bkey_packed *k;
+ struct bkey_buf tmp;
+ unsigned nr = test_bit(BCH_FS_started, &c->flags)
+ ? (path->level > 1 ? 0 : 2)
+ : (path->level > 1 ? 1 : 16);
+ bool was_locked = btree_node_locked(path, path->level);
+ int ret = 0;
+
+ bch2_bkey_buf_init(&tmp);
+
+ while (nr-- && !ret) {
+ if (!bch2_btree_node_relock(trans, path, path->level))
+ break;
+
+ bch2_btree_node_iter_advance(&node_iter, l->b);
+ k = bch2_btree_node_iter_peek(&node_iter, l->b);
+ if (!k)
+ break;
+
+ bch2_bkey_buf_unpack(&tmp, c, l->b, k);
+ ret = bch2_btree_node_prefetch(trans, path, tmp.k, path->btree_id,
+ path->level - 1);
+ }
+
+ if (!was_locked)
+ btree_node_unlock(trans, path, path->level);
+
+ bch2_bkey_buf_exit(&tmp, c);
+ return ret;
+}
+
+static int btree_path_prefetch_j(struct btree_trans *trans, struct btree_path *path,
+ struct btree_and_journal_iter *jiter)
+{
+ struct bch_fs *c = trans->c;
+ struct bkey_s_c k;
+ struct bkey_buf tmp;
+ unsigned nr = test_bit(BCH_FS_started, &c->flags)
+ ? (path->level > 1 ? 0 : 2)
+ : (path->level > 1 ? 1 : 16);
+ bool was_locked = btree_node_locked(path, path->level);
+ int ret = 0;
+
+ bch2_bkey_buf_init(&tmp);
+
+ while (nr-- && !ret) {
+ if (!bch2_btree_node_relock(trans, path, path->level))
+ break;
+
+ bch2_btree_and_journal_iter_advance(jiter);
+ k = bch2_btree_and_journal_iter_peek(jiter);
+ if (!k.k)
+ break;
+
+ bch2_bkey_buf_reassemble(&tmp, c, k);
+ ret = bch2_btree_node_prefetch(trans, path, tmp.k, path->btree_id,
+ path->level - 1);
+ }
+
+ if (!was_locked)
+ btree_node_unlock(trans, path, path->level);
+
+ bch2_bkey_buf_exit(&tmp, c);
+ return ret;
+}
+
+static noinline void btree_node_mem_ptr_set(struct btree_trans *trans,
+ struct btree_path *path,
+ unsigned plevel, struct btree *b)
+{
+ struct btree_path_level *l = &path->l[plevel];
+ bool locked = btree_node_locked(path, plevel);
+ struct bkey_packed *k;
+ struct bch_btree_ptr_v2 *bp;
+
+ if (!bch2_btree_node_relock(trans, path, plevel))
+ return;
+
+ k = bch2_btree_node_iter_peek_all(&l->iter, l->b);
+ BUG_ON(k->type != KEY_TYPE_btree_ptr_v2);
+
+ bp = (void *) bkeyp_val(&l->b->format, k);
+ bp->mem_ptr = (unsigned long)b;
+
+ if (!locked)
+ btree_node_unlock(trans, path, plevel);
+}
+
+static noinline int btree_node_iter_and_journal_peek(struct btree_trans *trans,
+ struct btree_path *path,
+ unsigned flags,
+ struct bkey_buf *out)
+{
+ struct bch_fs *c = trans->c;
+ struct btree_path_level *l = path_l(path);
+ struct btree_and_journal_iter jiter;
+ struct bkey_s_c k;
+ int ret = 0;
+
+ __bch2_btree_and_journal_iter_init_node_iter(&jiter, c, l->b, l->iter, path->pos);
+
+ k = bch2_btree_and_journal_iter_peek(&jiter);
+
+ bch2_bkey_buf_reassemble(out, c, k);
+
+ if ((flags & BTREE_ITER_PREFETCH) &&
+ c->opts.btree_node_prefetch)
+ ret = btree_path_prefetch_j(trans, path, &jiter);
+
+ bch2_btree_and_journal_iter_exit(&jiter);
+ return ret;
+}
+
+static __always_inline int btree_path_down(struct btree_trans *trans,
+ struct btree_path *path,
+ unsigned flags,
+ unsigned long trace_ip)
+{
+ struct bch_fs *c = trans->c;
+ struct btree_path_level *l = path_l(path);
+ struct btree *b;
+ unsigned level = path->level - 1;
+ enum six_lock_type lock_type = __btree_lock_want(path, level);
+ struct bkey_buf tmp;
+ int ret;
+
+ EBUG_ON(!btree_node_locked(path, path->level));
+
+ bch2_bkey_buf_init(&tmp);
+
+ if (unlikely(trans->journal_replay_not_finished)) {
+ ret = btree_node_iter_and_journal_peek(trans, path, flags, &tmp);
+ if (ret)
+ goto err;
+ } else {
+ bch2_bkey_buf_unpack(&tmp, c, l->b,
+ bch2_btree_node_iter_peek(&l->iter, l->b));
+
+ if ((flags & BTREE_ITER_PREFETCH) &&
+ c->opts.btree_node_prefetch) {
+ ret = btree_path_prefetch(trans, path);
+ if (ret)
+ goto err;
+ }
+ }
+
+ b = bch2_btree_node_get(trans, path, tmp.k, level, lock_type, trace_ip);
+ ret = PTR_ERR_OR_ZERO(b);
+ if (unlikely(ret))
+ goto err;
+
+ if (likely(!trans->journal_replay_not_finished &&
+ tmp.k->k.type == KEY_TYPE_btree_ptr_v2) &&
+ unlikely(b != btree_node_mem_ptr(tmp.k)))
+ btree_node_mem_ptr_set(trans, path, level + 1, b);
+
+ if (btree_node_read_locked(path, level + 1))
+ btree_node_unlock(trans, path, level + 1);
+
+ mark_btree_node_locked(trans, path, level,
+ (enum btree_node_locked_type) lock_type);
+ path->level = level;
+ bch2_btree_path_level_init(trans, path, b);
+
+ bch2_btree_path_verify_locks(path);
+err:
+ bch2_bkey_buf_exit(&tmp, c);
+ return ret;
+}
+
+
+static int bch2_btree_path_traverse_all(struct btree_trans *trans)
+{
+ struct bch_fs *c = trans->c;
+ struct btree_path *path;
+ unsigned long trace_ip = _RET_IP_;
+ unsigned i;
+ int ret = 0;
+
+ if (trans->in_traverse_all)
+ return -BCH_ERR_transaction_restart_in_traverse_all;
+
+ trans->in_traverse_all = true;
+retry_all:
+ trans->restarted = 0;
+ trans->last_restarted_ip = 0;
+
+ trans_for_each_path(trans, path, i)
+ path->should_be_locked = false;
+
+ btree_trans_sort_paths(trans);
+
+ bch2_trans_unlock(trans);
+ cond_resched();
+
+ if (unlikely(trans->memory_allocation_failure)) {
+ struct closure cl;
+
+ closure_init_stack(&cl);
+
+ do {
+ ret = bch2_btree_cache_cannibalize_lock(trans, &cl);
+ closure_sync(&cl);
+ } while (ret);
+ }
+
+ /* Now, redo traversals in correct order: */
+ i = 0;
+ while (i < trans->nr_sorted) {
+ btree_path_idx_t idx = trans->sorted[i];
+
+ /*
+ * Traversing a path can cause another path to be added at about
+ * the same position:
+ */
+ if (trans->paths[idx].uptodate) {
+ __btree_path_get(&trans->paths[idx], false);
+ ret = bch2_btree_path_traverse_one(trans, idx, 0, _THIS_IP_);
+ __btree_path_put(&trans->paths[idx], false);
+
+ if (bch2_err_matches(ret, BCH_ERR_transaction_restart) ||
+ bch2_err_matches(ret, ENOMEM))
+ goto retry_all;
+ if (ret)
+ goto err;
+ } else {
+ i++;
+ }
+ }
+
+ /*
+ * We used to assert that all paths had been traversed here
+ * (path->uptodate < BTREE_ITER_NEED_TRAVERSE); however, since
+ * path->should_be_locked is not set yet, we might have unlocked and
+ * then failed to relock a path - that's fine.
+ */
+err:
+ bch2_btree_cache_cannibalize_unlock(trans);
+
+ trans->in_traverse_all = false;
+
+ trace_and_count(c, trans_traverse_all, trans, trace_ip);
+ return ret;
+}
+
+static inline bool btree_path_check_pos_in_node(struct btree_path *path,
+ unsigned l, int check_pos)
+{
+ if (check_pos < 0 && btree_path_pos_before_node(path, path->l[l].b))
+ return false;
+ if (check_pos > 0 && btree_path_pos_after_node(path, path->l[l].b))
+ return false;
+ return true;
+}
+
+static inline bool btree_path_good_node(struct btree_trans *trans,
+ struct btree_path *path,
+ unsigned l, int check_pos)
+{
+ return is_btree_node(path, l) &&
+ bch2_btree_node_relock(trans, path, l) &&
+ btree_path_check_pos_in_node(path, l, check_pos);
+}
+
+static void btree_path_set_level_down(struct btree_trans *trans,
+ struct btree_path *path,
+ unsigned new_level)
+{
+ unsigned l;
+
+ path->level = new_level;
+
+ for (l = path->level + 1; l < BTREE_MAX_DEPTH; l++)
+ if (btree_lock_want(path, l) == BTREE_NODE_UNLOCKED)
+ btree_node_unlock(trans, path, l);
+
+ btree_path_set_dirty(path, BTREE_ITER_NEED_TRAVERSE);
+ bch2_btree_path_verify(trans, path);
+}
+
+static noinline unsigned __btree_path_up_until_good_node(struct btree_trans *trans,
+ struct btree_path *path,
+ int check_pos)
+{
+ unsigned i, l = path->level;
+again:
+ while (btree_path_node(path, l) &&
+ !btree_path_good_node(trans, path, l, check_pos))
+ __btree_path_set_level_up(trans, path, l++);
+
+ /* If we need intent locks, take them too: */
+ for (i = l + 1;
+ i < path->locks_want && btree_path_node(path, i);
+ i++)
+ if (!bch2_btree_node_relock(trans, path, i)) {
+ while (l <= i)
+ __btree_path_set_level_up(trans, path, l++);
+ goto again;
+ }
+
+ return l;
+}
+
+static inline unsigned btree_path_up_until_good_node(struct btree_trans *trans,
+ struct btree_path *path,
+ int check_pos)
+{
+ return likely(btree_node_locked(path, path->level) &&
+ btree_path_check_pos_in_node(path, path->level, check_pos))
+ ? path->level
+ : __btree_path_up_until_good_node(trans, path, check_pos);
+}
+
+/*
+ * 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 bch2_btree_path_traverse_one(struct btree_trans *trans,
+ btree_path_idx_t path_idx,
+ unsigned flags,
+ unsigned long trace_ip)
+{
+ struct btree_path *path = &trans->paths[path_idx];
+ unsigned depth_want = path->level;
+ int ret = -((int) trans->restarted);
+
+ if (unlikely(ret))
+ goto out;
+
+ if (unlikely(!trans->srcu_held))
+ bch2_trans_srcu_lock(trans);
+
+ /*
+ * Ensure we obey path->should_be_locked: if it's set, we can't unlock
+ * and re-traverse the path without a transaction restart:
+ */
+ if (path->should_be_locked) {
+ ret = bch2_btree_path_relock(trans, path, trace_ip);
+ goto out;
+ }
+
+ if (path->cached) {
+ ret = bch2_btree_path_traverse_cached(trans, path, flags);
+ goto out;
+ }
+
+ path = &trans->paths[path_idx];
+
+ if (unlikely(path->level >= BTREE_MAX_DEPTH))
+ goto out;
+
+ path->level = btree_path_up_until_good_node(trans, path, 0);
+
+ EBUG_ON(btree_path_node(path, path->level) &&
+ !btree_node_locked(path, path->level));
+
+ /*
+ * Note: path->nodes[path->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_path_lock_root() comes next and that it can't fail
+ */
+ while (path->level > depth_want) {
+ ret = btree_path_node(path, path->level)
+ ? btree_path_down(trans, path, flags, trace_ip)
+ : btree_path_lock_root(trans, path, depth_want, trace_ip);
+ if (unlikely(ret)) {
+ if (ret == 1) {
+ /*
+ * No nodes at this level - got to the end of
+ * the btree:
+ */
+ ret = 0;
+ goto out;
+ }
+
+ __bch2_btree_path_unlock(trans, path);
+ path->level = depth_want;
+ path->l[path->level].b = ERR_PTR(ret);
+ goto out;
+ }
+ }
+
+ path->uptodate = BTREE_ITER_UPTODATE;
+out:
+ if (bch2_err_matches(ret, BCH_ERR_transaction_restart) != !!trans->restarted)
+ panic("ret %s (%i) trans->restarted %s (%i)\n",
+ bch2_err_str(ret), ret,
+ bch2_err_str(trans->restarted), trans->restarted);
+ bch2_btree_path_verify(trans, path);
+ return ret;
+}
+
+static inline void btree_path_copy(struct btree_trans *trans, struct btree_path *dst,
+ struct btree_path *src)
+{
+ unsigned i, offset = offsetof(struct btree_path, pos);
+
+ memcpy((void *) dst + offset,
+ (void *) src + offset,
+ sizeof(struct btree_path) - offset);
+
+ for (i = 0; i < BTREE_MAX_DEPTH; i++) {
+ unsigned t = btree_node_locked_type(dst, i);
+
+ if (t != BTREE_NODE_UNLOCKED)
+ six_lock_increment(&dst->l[i].b->c.lock, t);
+ }
+}
+
+static btree_path_idx_t btree_path_clone(struct btree_trans *trans, btree_path_idx_t src,
+ bool intent)
+{
+ btree_path_idx_t new = btree_path_alloc(trans, src);
+ btree_path_copy(trans, trans->paths + new, trans->paths + src);
+ __btree_path_get(trans->paths + new, intent);
+ return new;
+}
+
+__flatten
+btree_path_idx_t __bch2_btree_path_make_mut(struct btree_trans *trans,
+ btree_path_idx_t path, bool intent, unsigned long ip)
+{
+ __btree_path_put(trans->paths + path, intent);
+ path = btree_path_clone(trans, path, intent);
+ trans->paths[path].preserve = false;
+ return path;
+}
+
+btree_path_idx_t __must_check
+__bch2_btree_path_set_pos(struct btree_trans *trans,
+ btree_path_idx_t path_idx, struct bpos new_pos,
+ bool intent, unsigned long ip)
+{
+ int cmp = bpos_cmp(new_pos, trans->paths[path_idx].pos);
+
+ bch2_trans_verify_not_in_restart(trans);
+ EBUG_ON(!trans->paths[path_idx].ref);
+
+ path_idx = bch2_btree_path_make_mut(trans, path_idx, intent, ip);
+
+ struct btree_path *path = trans->paths + path_idx;
+ path->pos = new_pos;
+ trans->paths_sorted = false;
+
+ if (unlikely(path->cached)) {
+ btree_node_unlock(trans, path, 0);
+ path->l[0].b = ERR_PTR(-BCH_ERR_no_btree_node_up);
+ btree_path_set_dirty(path, BTREE_ITER_NEED_TRAVERSE);
+ goto out;
+ }
+
+ unsigned level = btree_path_up_until_good_node(trans, path, cmp);
+
+ if (btree_path_node(path, level)) {
+ struct btree_path_level *l = &path->l[level];
+
+ BUG_ON(!btree_node_locked(path, 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_path_advance_to_pos(path, l, 8))
+ bch2_btree_node_iter_init(&l->iter, l->b, &path->pos);
+
+ /*
+ * Iterators to interior nodes should always be pointed at the first non
+ * whiteout:
+ */
+ if (unlikely(level))
+ bch2_btree_node_iter_peek(&l->iter, l->b);
+ }
+
+ if (unlikely(level != path->level)) {
+ btree_path_set_dirty(path, BTREE_ITER_NEED_TRAVERSE);
+ __bch2_btree_path_unlock(trans, path);
+ }
+out:
+ bch2_btree_path_verify(trans, path);
+ return path_idx;
+}
+
+/* Btree path: main interface: */
+
+static struct btree_path *have_path_at_pos(struct btree_trans *trans, struct btree_path *path)
+{
+ struct btree_path *sib;
+
+ sib = prev_btree_path(trans, path);
+ if (sib && !btree_path_cmp(sib, path))
+ return sib;
+
+ sib = next_btree_path(trans, path);
+ if (sib && !btree_path_cmp(sib, path))
+ return sib;
+
+ return NULL;
+}
+
+static struct btree_path *have_node_at_pos(struct btree_trans *trans, struct btree_path *path)
+{
+ struct btree_path *sib;
+
+ sib = prev_btree_path(trans, path);
+ if (sib && sib->level == path->level && path_l(sib)->b == path_l(path)->b)
+ return sib;
+
+ sib = next_btree_path(trans, path);
+ if (sib && sib->level == path->level && path_l(sib)->b == path_l(path)->b)
+ return sib;
+
+ return NULL;
+}
+
+static inline void __bch2_path_free(struct btree_trans *trans, btree_path_idx_t path)
+{
+ __bch2_btree_path_unlock(trans, trans->paths + path);
+ btree_path_list_remove(trans, trans->paths + path);
+ __clear_bit(path, trans->paths_allocated);
+}
+
+void bch2_path_put(struct btree_trans *trans, btree_path_idx_t path_idx, bool intent)
+{
+ struct btree_path *path = trans->paths + path_idx, *dup;
+
+ if (!__btree_path_put(path, intent))
+ return;
+
+ dup = path->preserve
+ ? have_path_at_pos(trans, path)
+ : have_node_at_pos(trans, path);
+
+ if (!dup && !(!path->preserve && !is_btree_node(path, path->level)))
+ return;
+
+ if (path->should_be_locked &&
+ !trans->restarted &&
+ (!dup || !bch2_btree_path_relock_norestart(trans, dup, _THIS_IP_)))
+ return;
+
+ if (dup) {
+ dup->preserve |= path->preserve;
+ dup->should_be_locked |= path->should_be_locked;
+ }
+
+ __bch2_path_free(trans, path_idx);
+}
+
+static void bch2_path_put_nokeep(struct btree_trans *trans, btree_path_idx_t path,
+ bool intent)
+{
+ if (!__btree_path_put(trans->paths + path, intent))
+ return;
+
+ __bch2_path_free(trans, path);
+}
+
+void __noreturn bch2_trans_restart_error(struct btree_trans *trans, u32 restart_count)
+{
+ panic("trans->restart_count %u, should be %u, last restarted by %pS\n",
+ trans->restart_count, restart_count,
+ (void *) trans->last_begin_ip);
+}
+
+void __noreturn bch2_trans_in_restart_error(struct btree_trans *trans)
+{
+ panic("in transaction restart: %s, last restarted by %pS\n",
+ bch2_err_str(trans->restarted),
+ (void *) trans->last_restarted_ip);
+}
+
+noinline __cold
+void bch2_trans_updates_to_text(struct printbuf *buf, struct btree_trans *trans)
+{
+ prt_printf(buf, "transaction updates for %s journal seq %llu",
+ trans->fn, trans->journal_res.seq);
+ prt_newline(buf);
+ printbuf_indent_add(buf, 2);
+
+ trans_for_each_update(trans, i) {
+ struct bkey_s_c old = { &i->old_k, i->old_v };
+
+ prt_printf(buf, "update: btree=%s cached=%u %pS",
+ bch2_btree_id_str(i->btree_id),
+ i->cached,
+ (void *) i->ip_allocated);
+ prt_newline(buf);
+
+ prt_printf(buf, " old ");
+ bch2_bkey_val_to_text(buf, trans->c, old);
+ prt_newline(buf);
+
+ prt_printf(buf, " new ");
+ bch2_bkey_val_to_text(buf, trans->c, bkey_i_to_s_c(i->k));
+ prt_newline(buf);
+ }
+
+ for (struct jset_entry *e = trans->journal_entries;
+ e != btree_trans_journal_entries_top(trans);
+ e = vstruct_next(e))
+ bch2_journal_entry_to_text(buf, trans->c, e);
+
+ printbuf_indent_sub(buf, 2);
+}
+
+noinline __cold
+void bch2_dump_trans_updates(struct btree_trans *trans)
+{
+ struct printbuf buf = PRINTBUF;
+
+ bch2_trans_updates_to_text(&buf, trans);
+ bch2_print_string_as_lines(KERN_ERR, buf.buf);
+ printbuf_exit(&buf);
+}
+
+static void bch2_btree_path_to_text(struct printbuf *out, struct btree_trans *trans, btree_path_idx_t path_idx)
+{
+ struct btree_path *path = trans->paths + path_idx;
+
+ prt_printf(out, "path: idx %2u ref %u:%u %c %c btree=%s l=%u pos ",
+ path_idx, path->ref, path->intent_ref,
+ path->preserve ? 'P' : ' ',
+ path->should_be_locked ? 'S' : ' ',
+ bch2_btree_id_str(path->btree_id),
+ path->level);
+ bch2_bpos_to_text(out, path->pos);
+
+ prt_printf(out, " locks %u", path->nodes_locked);
+#ifdef TRACK_PATH_ALLOCATED
+ prt_printf(out, " %pS", (void *) path->ip_allocated);
+#endif
+ prt_newline(out);
+}
+
+static noinline __cold
+void __bch2_trans_paths_to_text(struct printbuf *out, struct btree_trans *trans,
+ bool nosort)
+{
+ struct trans_for_each_path_inorder_iter iter;
+
+ if (!nosort)
+ btree_trans_sort_paths(trans);
+
+ trans_for_each_path_idx_inorder(trans, iter)
+ bch2_btree_path_to_text(out, trans, iter.path_idx);
+}
+
+noinline __cold
+void bch2_trans_paths_to_text(struct printbuf *out, struct btree_trans *trans)
+{
+ __bch2_trans_paths_to_text(out, trans, false);
+}
+
+static noinline __cold
+void __bch2_dump_trans_paths_updates(struct btree_trans *trans, bool nosort)
+{
+ struct printbuf buf = PRINTBUF;
+
+ __bch2_trans_paths_to_text(&buf, trans, nosort);
+ bch2_trans_updates_to_text(&buf, trans);
+
+ bch2_print_string_as_lines(KERN_ERR, buf.buf);
+ printbuf_exit(&buf);
+}
+
+noinline __cold
+void bch2_dump_trans_paths_updates(struct btree_trans *trans)
+{
+ __bch2_dump_trans_paths_updates(trans, false);
+}
+
+noinline __cold
+static void bch2_trans_update_max_paths(struct btree_trans *trans)
+{
+ struct btree_transaction_stats *s = btree_trans_stats(trans);
+ struct printbuf buf = PRINTBUF;
+ size_t nr = bitmap_weight(trans->paths_allocated, trans->nr_paths);
+
+ bch2_trans_paths_to_text(&buf, trans);
+
+ if (!buf.allocation_failure) {
+ mutex_lock(&s->lock);
+ if (nr > s->nr_max_paths) {
+ s->nr_max_paths = nr;
+ swap(s->max_paths_text, buf.buf);
+ }
+ mutex_unlock(&s->lock);
+ }
+
+ printbuf_exit(&buf);
+
+ trans->nr_paths_max = nr;
+}
+
+noinline __cold
+int __bch2_btree_trans_too_many_iters(struct btree_trans *trans)
+{
+ if (trace_trans_restart_too_many_iters_enabled()) {
+ struct printbuf buf = PRINTBUF;
+
+ bch2_trans_paths_to_text(&buf, trans);
+ trace_trans_restart_too_many_iters(trans, _THIS_IP_, buf.buf);
+ printbuf_exit(&buf);
+ }
+
+ count_event(trans->c, trans_restart_too_many_iters);
+
+ return btree_trans_restart(trans, BCH_ERR_transaction_restart_too_many_iters);
+}
+
+static noinline void btree_path_overflow(struct btree_trans *trans)
+{
+ bch2_dump_trans_paths_updates(trans);
+ bch_err(trans->c, "trans path overflow");
+}
+
+static noinline void btree_paths_realloc(struct btree_trans *trans)
+{
+ unsigned nr = trans->nr_paths * 2;
+
+ void *p = kzalloc(BITS_TO_LONGS(nr) * sizeof(unsigned long) +
+ sizeof(struct btree_trans_paths) +
+ nr * sizeof(struct btree_path) +
+ nr * sizeof(btree_path_idx_t) + 8 +
+ nr * sizeof(struct btree_insert_entry), GFP_KERNEL|__GFP_NOFAIL);
+
+ unsigned long *paths_allocated = p;
+ memcpy(paths_allocated, trans->paths_allocated, BITS_TO_LONGS(trans->nr_paths) * sizeof(unsigned long));
+ p += BITS_TO_LONGS(nr) * sizeof(unsigned long);
+
+ p += sizeof(struct btree_trans_paths);
+ struct btree_path *paths = p;
+ *trans_paths_nr(paths) = nr;
+ memcpy(paths, trans->paths, trans->nr_paths * sizeof(struct btree_path));
+ p += nr * sizeof(struct btree_path);
+
+ btree_path_idx_t *sorted = p;
+ memcpy(sorted, trans->sorted, trans->nr_sorted * sizeof(btree_path_idx_t));
+ p += nr * sizeof(btree_path_idx_t) + 8;
+
+ struct btree_insert_entry *updates = p;
+ memcpy(updates, trans->updates, trans->nr_paths * sizeof(struct btree_insert_entry));
+
+ unsigned long *old = trans->paths_allocated;
+
+ rcu_assign_pointer(trans->paths_allocated, paths_allocated);
+ rcu_assign_pointer(trans->paths, paths);
+ rcu_assign_pointer(trans->sorted, sorted);
+ rcu_assign_pointer(trans->updates, updates);
+
+ trans->nr_paths = nr;
+
+ if (old != trans->_paths_allocated)
+ kfree_rcu_mightsleep(old);
+}
+
+static inline btree_path_idx_t btree_path_alloc(struct btree_trans *trans,
+ btree_path_idx_t pos)
+{
+ btree_path_idx_t idx = find_first_zero_bit(trans->paths_allocated, trans->nr_paths);
+
+ if (unlikely(idx == trans->nr_paths)) {
+ if (trans->nr_paths == BTREE_ITER_MAX) {
+ btree_path_overflow(trans);
+ return 0;
+ }
+
+ btree_paths_realloc(trans);
+ }
+
+ /*
+ * Do this before marking the new path as allocated, since it won't be
+ * initialized yet:
+ */
+ if (unlikely(idx > trans->nr_paths_max))
+ bch2_trans_update_max_paths(trans);
+
+ __set_bit(idx, trans->paths_allocated);
+
+ struct btree_path *path = &trans->paths[idx];
+ path->ref = 0;
+ path->intent_ref = 0;
+ path->nodes_locked = 0;
+
+ btree_path_list_add(trans, pos, idx);
+ trans->paths_sorted = false;
+ return idx;
+}
+
+btree_path_idx_t bch2_path_get(struct btree_trans *trans,
+ enum btree_id btree_id, struct bpos pos,
+ unsigned locks_want, unsigned level,
+ unsigned flags, unsigned long ip)
+{
+ struct btree_path *path;
+ bool cached = flags & BTREE_ITER_CACHED;
+ bool intent = flags & BTREE_ITER_INTENT;
+ struct trans_for_each_path_inorder_iter iter;
+ btree_path_idx_t path_pos = 0, path_idx;
+
+ bch2_trans_verify_not_in_restart(trans);
+ bch2_trans_verify_locks(trans);
+
+ btree_trans_sort_paths(trans);
+
+ trans_for_each_path_inorder(trans, path, iter) {
+ if (__btree_path_cmp(path,
+ btree_id,
+ cached,
+ pos,
+ level) > 0)
+ break;
+
+ path_pos = iter.path_idx;
+ }
+
+ if (path_pos &&
+ trans->paths[path_pos].cached == cached &&
+ trans->paths[path_pos].btree_id == btree_id &&
+ trans->paths[path_pos].level == level) {
+ __btree_path_get(trans->paths + path_pos, intent);
+ path_idx = bch2_btree_path_set_pos(trans, path_pos, pos, intent, ip);
+ path = trans->paths + path_idx;
+ } else {
+ path_idx = btree_path_alloc(trans, path_pos);
+ path = trans->paths + path_idx;
+
+ __btree_path_get(path, intent);
+ path->pos = pos;
+ path->btree_id = btree_id;
+ path->cached = cached;
+ path->uptodate = BTREE_ITER_NEED_TRAVERSE;
+ path->should_be_locked = false;
+ path->level = level;
+ path->locks_want = locks_want;
+ path->nodes_locked = 0;
+ for (unsigned i = 0; i < ARRAY_SIZE(path->l); i++)
+ path->l[i].b = ERR_PTR(-BCH_ERR_no_btree_node_init);
+#ifdef TRACK_PATH_ALLOCATED
+ path->ip_allocated = ip;
+#endif
+ trans->paths_sorted = false;
+ }
+
+ if (!(flags & BTREE_ITER_NOPRESERVE))
+ path->preserve = true;
+
+ if (path->intent_ref)
+ locks_want = max(locks_want, level + 1);
+
+ /*
+ * If the path has locks_want greater than requested, we don't downgrade
+ * it here - on transaction restart because btree node split needs to
+ * upgrade locks, we might be putting/getting the iterator again.
+ * Downgrading iterators only happens via bch2_trans_downgrade(), after
+ * a successful transaction commit.
+ */
+
+ locks_want = min(locks_want, BTREE_MAX_DEPTH);
+ if (locks_want > path->locks_want)
+ bch2_btree_path_upgrade_noupgrade_sibs(trans, path, locks_want, NULL);
+
+ return path_idx;
+}
+
+struct bkey_s_c bch2_btree_path_peek_slot(struct btree_path *path, struct bkey *u)
+{
+
+ struct btree_path_level *l = path_l(path);
+ struct bkey_packed *_k;
+ struct bkey_s_c k;
+
+ if (unlikely(!l->b))
+ return bkey_s_c_null;
+
+ EBUG_ON(path->uptodate != BTREE_ITER_UPTODATE);
+ EBUG_ON(!btree_node_locked(path, path->level));
+
+ if (!path->cached) {
+ _k = bch2_btree_node_iter_peek_all(&l->iter, l->b);
+ k = _k ? bkey_disassemble(l->b, _k, u) : bkey_s_c_null;
+
+ EBUG_ON(k.k && bkey_deleted(k.k) && bpos_eq(k.k->p, path->pos));
+
+ if (!k.k || !bpos_eq(path->pos, k.k->p))
+ goto hole;
+ } else {
+ struct bkey_cached *ck = (void *) path->l[0].b;
+
+ EBUG_ON(ck &&
+ (path->btree_id != ck->key.btree_id ||
+ !bkey_eq(path->pos, ck->key.pos)));
+ if (!ck || !ck->valid)
+ return bkey_s_c_null;
+
+ *u = ck->k->k;
+ k = bkey_i_to_s_c(ck->k);
+ }
+
+ return k;
+hole:
+ bkey_init(u);
+ u->p = path->pos;
+ return (struct bkey_s_c) { u, NULL };
+}
+
+/* Btree iterators: */
+
+int __must_check
+__bch2_btree_iter_traverse(struct btree_iter *iter)
+{
+ return bch2_btree_path_traverse(iter->trans, iter->path, iter->flags);
+}
+
+int __must_check
+bch2_btree_iter_traverse(struct btree_iter *iter)
+{
+ struct btree_trans *trans = iter->trans;
+ int ret;
+
+ iter->path = bch2_btree_path_set_pos(trans, iter->path,
+ btree_iter_search_key(iter),
+ iter->flags & BTREE_ITER_INTENT,
+ btree_iter_ip_allocated(iter));
+
+ ret = bch2_btree_path_traverse(iter->trans, iter->path, iter->flags);
+ if (ret)
+ return ret;
+
+ btree_path_set_should_be_locked(trans->paths + iter->path);
+ return 0;
+}
+
+/* Iterate across nodes (leaf and interior nodes) */
+
+struct btree *bch2_btree_iter_peek_node(struct btree_iter *iter)
+{
+ struct btree_trans *trans = iter->trans;
+ struct btree *b = NULL;
+ int ret;
+
+ EBUG_ON(trans->paths[iter->path].cached);
+ bch2_btree_iter_verify(iter);
+
+ ret = bch2_btree_path_traverse(trans, iter->path, iter->flags);
+ if (ret)
+ goto err;
+
+ struct btree_path *path = btree_iter_path(trans, iter);
+ b = btree_path_node(path, path->level);
+ if (!b)
+ goto out;
+
+ BUG_ON(bpos_lt(b->key.k.p, iter->pos));
+
+ bkey_init(&iter->k);
+ iter->k.p = iter->pos = b->key.k.p;
+
+ iter->path = bch2_btree_path_set_pos(trans, iter->path, b->key.k.p,
+ iter->flags & BTREE_ITER_INTENT,
+ btree_iter_ip_allocated(iter));
+ btree_path_set_should_be_locked(btree_iter_path(trans, iter));
+out:
+ bch2_btree_iter_verify_entry_exit(iter);
+ bch2_btree_iter_verify(iter);
+
+ return b;
+err:
+ b = ERR_PTR(ret);
+ goto out;
+}
+
+struct btree *bch2_btree_iter_peek_node_and_restart(struct btree_iter *iter)
+{
+ struct btree *b;
+
+ while (b = bch2_btree_iter_peek_node(iter),
+ bch2_err_matches(PTR_ERR_OR_ZERO(b), BCH_ERR_transaction_restart))
+ bch2_trans_begin(iter->trans);
+
+ return b;
+}
+
+struct btree *bch2_btree_iter_next_node(struct btree_iter *iter)
+{
+ struct btree_trans *trans = iter->trans;
+ struct btree *b = NULL;
+ int ret;
+
+ EBUG_ON(trans->paths[iter->path].cached);
+ bch2_trans_verify_not_in_restart(trans);
+ bch2_btree_iter_verify(iter);
+
+ struct btree_path *path = btree_iter_path(trans, iter);
+
+ /* already at end? */
+ if (!btree_path_node(path, path->level))
+ return NULL;
+
+ /* got to end? */
+ if (!btree_path_node(path, path->level + 1)) {
+ btree_path_set_level_up(trans, path);
+ return NULL;
+ }
+
+ if (!bch2_btree_node_relock(trans, path, path->level + 1)) {
+ __bch2_btree_path_unlock(trans, path);
+ path->l[path->level].b = ERR_PTR(-BCH_ERR_no_btree_node_relock);
+ path->l[path->level + 1].b = ERR_PTR(-BCH_ERR_no_btree_node_relock);
+ btree_path_set_dirty(path, BTREE_ITER_NEED_TRAVERSE);
+ trace_and_count(trans->c, trans_restart_relock_next_node, trans, _THIS_IP_, path);
+ ret = btree_trans_restart(trans, BCH_ERR_transaction_restart_relock);
+ goto err;
+ }
+
+ b = btree_path_node(path, path->level + 1);
+
+ if (bpos_eq(iter->pos, b->key.k.p)) {
+ __btree_path_set_level_up(trans, path, path->level++);
+ } else {
+ /*
+ * Haven't gotten to the end of the parent node: go back down to
+ * the next child node
+ */
+ iter->path = bch2_btree_path_set_pos(trans, iter->path,
+ bpos_successor(iter->pos),
+ iter->flags & BTREE_ITER_INTENT,
+ btree_iter_ip_allocated(iter));
+
+ path = btree_iter_path(trans, iter);
+ btree_path_set_level_down(trans, path, iter->min_depth);
+
+ ret = bch2_btree_path_traverse(trans, iter->path, iter->flags);
+ if (ret)
+ goto err;
+
+ path = btree_iter_path(trans, iter);
+ b = path->l[path->level].b;
+ }
+
+ bkey_init(&iter->k);
+ iter->k.p = iter->pos = b->key.k.p;
+
+ iter->path = bch2_btree_path_set_pos(trans, iter->path, b->key.k.p,
+ iter->flags & BTREE_ITER_INTENT,
+ btree_iter_ip_allocated(iter));
+ btree_path_set_should_be_locked(btree_iter_path(trans, iter));
+ EBUG_ON(btree_iter_path(trans, iter)->uptodate);
+out:
+ bch2_btree_iter_verify_entry_exit(iter);
+ bch2_btree_iter_verify(iter);
+
+ return b;
+err:
+ b = ERR_PTR(ret);
+ goto out;
+}
+
+/* Iterate across keys (in leaf nodes only) */
+
+inline bool bch2_btree_iter_advance(struct btree_iter *iter)
+{
+ struct bpos pos = iter->k.p;
+ bool ret = !(iter->flags & BTREE_ITER_ALL_SNAPSHOTS
+ ? bpos_eq(pos, SPOS_MAX)
+ : bkey_eq(pos, SPOS_MAX));
+
+ if (ret && !(iter->flags & BTREE_ITER_IS_EXTENTS))
+ pos = bkey_successor(iter, pos);
+ bch2_btree_iter_set_pos(iter, pos);
+ return ret;
+}
+
+inline bool bch2_btree_iter_rewind(struct btree_iter *iter)
+{
+ struct bpos pos = bkey_start_pos(&iter->k);
+ bool ret = !(iter->flags & BTREE_ITER_ALL_SNAPSHOTS
+ ? bpos_eq(pos, POS_MIN)
+ : bkey_eq(pos, POS_MIN));
+
+ if (ret && !(iter->flags & BTREE_ITER_IS_EXTENTS))
+ pos = bkey_predecessor(iter, pos);
+ bch2_btree_iter_set_pos(iter, pos);
+ return ret;
+}
+
+static noinline
+void bch2_btree_trans_peek_prev_updates(struct btree_trans *trans, struct btree_iter *iter,
+ struct bkey_s_c *k)
+{
+ struct bpos end = path_l(btree_iter_path(trans, iter))->b->data->min_key;
+
+ trans_for_each_update(trans, i)
+ if (!i->key_cache_already_flushed &&
+ i->btree_id == iter->btree_id &&
+ bpos_le(i->k->k.p, iter->pos) &&
+ bpos_ge(i->k->k.p, k->k ? k->k->p : end)) {
+ iter->k = i->k->k;
+ *k = bkey_i_to_s_c(i->k);
+ }
+}
+
+static noinline
+void bch2_btree_trans_peek_updates(struct btree_trans *trans, struct btree_iter *iter,
+ struct bkey_s_c *k)
+{
+ struct btree_path *path = btree_iter_path(trans, iter);
+ struct bpos end = path_l(path)->b->key.k.p;
+
+ trans_for_each_update(trans, i)
+ if (!i->key_cache_already_flushed &&
+ i->btree_id == iter->btree_id &&
+ bpos_ge(i->k->k.p, path->pos) &&
+ bpos_le(i->k->k.p, k->k ? k->k->p : end)) {
+ iter->k = i->k->k;
+ *k = bkey_i_to_s_c(i->k);
+ }
+}
+
+static noinline
+void bch2_btree_trans_peek_slot_updates(struct btree_trans *trans, struct btree_iter *iter,
+ struct bkey_s_c *k)
+{
+ trans_for_each_update(trans, i)
+ if (!i->key_cache_already_flushed &&
+ i->btree_id == iter->btree_id &&
+ bpos_eq(i->k->k.p, iter->pos)) {
+ iter->k = i->k->k;
+ *k = bkey_i_to_s_c(i->k);
+ }
+}
+
+static struct bkey_i *bch2_btree_journal_peek(struct btree_trans *trans,
+ struct btree_iter *iter,
+ struct bpos end_pos)
+{
+ struct btree_path *path = btree_iter_path(trans, iter);
+
+ return bch2_journal_keys_peek_upto(trans->c, iter->btree_id,
+ path->level,
+ path->pos,
+ end_pos,
+ &iter->journal_idx);
+}
+
+static noinline
+struct bkey_s_c btree_trans_peek_slot_journal(struct btree_trans *trans,
+ struct btree_iter *iter)
+{
+ struct btree_path *path = btree_iter_path(trans, iter);
+ struct bkey_i *k = bch2_btree_journal_peek(trans, iter, path->pos);
+
+ if (k) {
+ iter->k = k->k;
+ return bkey_i_to_s_c(k);
+ } else {
+ return bkey_s_c_null;
+ }
+}
+
+static noinline
+struct bkey_s_c btree_trans_peek_journal(struct btree_trans *trans,
+ struct btree_iter *iter,
+ struct bkey_s_c k)
+{
+ struct btree_path *path = btree_iter_path(trans, iter);
+ struct bkey_i *next_journal =
+ bch2_btree_journal_peek(trans, iter,
+ k.k ? k.k->p : path_l(path)->b->key.k.p);
+
+ if (next_journal) {
+ iter->k = next_journal->k;
+ k = bkey_i_to_s_c(next_journal);
+ }
+
+ return k;
+}
+
+/*
+ * Checks btree key cache for key at iter->pos and returns it if present, or
+ * bkey_s_c_null:
+ */
+static noinline
+struct bkey_s_c btree_trans_peek_key_cache(struct btree_iter *iter, struct bpos pos)
+{
+ struct btree_trans *trans = iter->trans;
+ struct bch_fs *c = trans->c;
+ struct bkey u;
+ struct bkey_s_c k;
+ int ret;
+
+ if ((iter->flags & BTREE_ITER_KEY_CACHE_FILL) &&
+ bpos_eq(iter->pos, pos))
+ return bkey_s_c_null;
+
+ if (!bch2_btree_key_cache_find(c, iter->btree_id, pos))
+ return bkey_s_c_null;
+
+ if (!iter->key_cache_path)
+ iter->key_cache_path = bch2_path_get(trans, iter->btree_id, pos,
+ iter->flags & BTREE_ITER_INTENT, 0,
+ iter->flags|BTREE_ITER_CACHED|
+ BTREE_ITER_CACHED_NOFILL,
+ _THIS_IP_);
+
+ iter->key_cache_path = bch2_btree_path_set_pos(trans, iter->key_cache_path, pos,
+ iter->flags & BTREE_ITER_INTENT,
+ btree_iter_ip_allocated(iter));
+
+ ret = bch2_btree_path_traverse(trans, iter->key_cache_path,
+ iter->flags|BTREE_ITER_CACHED) ?:
+ bch2_btree_path_relock(trans, btree_iter_path(trans, iter), _THIS_IP_);
+ if (unlikely(ret))
+ return bkey_s_c_err(ret);
+
+ btree_path_set_should_be_locked(trans->paths + iter->key_cache_path);
+
+ k = bch2_btree_path_peek_slot(trans->paths + iter->key_cache_path, &u);
+ if (k.k && !bkey_err(k)) {
+ iter->k = u;
+ k.k = &iter->k;
+ }
+ return k;
+}
+
+static struct bkey_s_c __bch2_btree_iter_peek(struct btree_iter *iter, struct bpos search_key)
+{
+ struct btree_trans *trans = iter->trans;
+ struct bkey_s_c k, k2;
+ int ret;
+
+ EBUG_ON(btree_iter_path(trans, iter)->cached);
+ bch2_btree_iter_verify(iter);
+
+ while (1) {
+ struct btree_path_level *l;
+
+ iter->path = bch2_btree_path_set_pos(trans, iter->path, search_key,
+ iter->flags & BTREE_ITER_INTENT,
+ btree_iter_ip_allocated(iter));
+
+ ret = bch2_btree_path_traverse(trans, iter->path, iter->flags);
+ if (unlikely(ret)) {
+ /* ensure that iter->k is consistent with iter->pos: */
+ bch2_btree_iter_set_pos(iter, iter->pos);
+ k = bkey_s_c_err(ret);
+ goto out;
+ }
+
+ struct btree_path *path = btree_iter_path(trans, iter);
+ l = path_l(path);
+
+ if (unlikely(!l->b)) {
+ /* No btree nodes at requested level: */
+ bch2_btree_iter_set_pos(iter, SPOS_MAX);
+ k = bkey_s_c_null;
+ goto out;
+ }
+
+ btree_path_set_should_be_locked(path);
+
+ k = btree_path_level_peek_all(trans->c, l, &iter->k);
+
+ if (unlikely(iter->flags & BTREE_ITER_WITH_KEY_CACHE) &&
+ k.k &&
+ (k2 = btree_trans_peek_key_cache(iter, k.k->p)).k) {
+ k = k2;
+ ret = bkey_err(k);
+ if (ret) {
+ bch2_btree_iter_set_pos(iter, iter->pos);
+ goto out;
+ }
+ }
+
+ if (unlikely(iter->flags & BTREE_ITER_WITH_JOURNAL))
+ k = btree_trans_peek_journal(trans, iter, k);
+
+ if (unlikely((iter->flags & BTREE_ITER_WITH_UPDATES) &&
+ trans->nr_updates))
+ bch2_btree_trans_peek_updates(trans, iter, &k);
+
+ if (k.k && bkey_deleted(k.k)) {
+ /*
+ * If we've got a whiteout, and it's after the search
+ * key, advance the search key to the whiteout instead
+ * of just after the whiteout - it might be a btree
+ * whiteout, with a real key at the same position, since
+ * in the btree deleted keys sort before non deleted.
+ */
+ search_key = !bpos_eq(search_key, k.k->p)
+ ? k.k->p
+ : bpos_successor(k.k->p);
+ continue;
+ }
+
+ if (likely(k.k)) {
+ break;
+ } else if (likely(!bpos_eq(l->b->key.k.p, SPOS_MAX))) {
+ /* Advance to next leaf node: */
+ search_key = bpos_successor(l->b->key.k.p);
+ } else {
+ /* End of btree: */
+ bch2_btree_iter_set_pos(iter, SPOS_MAX);
+ k = bkey_s_c_null;
+ goto out;
+ }
+ }
+out:
+ bch2_btree_iter_verify(iter);
+
+ return k;
+}
+
+/**
+ * bch2_btree_iter_peek_upto() - returns first key greater than or equal to
+ * iterator's current position
+ * @iter: iterator to peek from
+ * @end: search limit: returns keys less than or equal to @end
+ *
+ * Returns: key if found, or an error extractable with bkey_err().
+ */
+struct bkey_s_c bch2_btree_iter_peek_upto(struct btree_iter *iter, struct bpos end)
+{
+ struct btree_trans *trans = iter->trans;
+ struct bpos search_key = btree_iter_search_key(iter);
+ struct bkey_s_c k;
+ struct bpos iter_pos;
+ int ret;
+
+ EBUG_ON((iter->flags & BTREE_ITER_FILTER_SNAPSHOTS) && bkey_eq(end, POS_MAX));
+
+ if (iter->update_path) {
+ bch2_path_put_nokeep(trans, iter->update_path,
+ iter->flags & BTREE_ITER_INTENT);
+ iter->update_path = 0;
+ }
+
+ bch2_btree_iter_verify_entry_exit(iter);
+
+ while (1) {
+ k = __bch2_btree_iter_peek(iter, search_key);
+ if (unlikely(!k.k))
+ goto end;
+ if (unlikely(bkey_err(k)))
+ goto out_no_locked;
+
+ /*
+ * We need to check against @end before FILTER_SNAPSHOTS because
+ * if we get to a different inode that requested we might be
+ * seeing keys for a different snapshot tree that will all be
+ * filtered out.
+ *
+ * But we can't do the full check here, because bkey_start_pos()
+ * isn't monotonically increasing before FILTER_SNAPSHOTS, and
+ * that's what we check against in extents mode:
+ */
+ if (k.k->p.inode > end.inode)
+ goto end;
+
+ if (iter->update_path &&
+ !bkey_eq(trans->paths[iter->update_path].pos, k.k->p)) {
+ bch2_path_put_nokeep(trans, iter->update_path,
+ iter->flags & BTREE_ITER_INTENT);
+ iter->update_path = 0;
+ }
+
+ if ((iter->flags & BTREE_ITER_FILTER_SNAPSHOTS) &&
+ (iter->flags & BTREE_ITER_INTENT) &&
+ !(iter->flags & BTREE_ITER_IS_EXTENTS) &&
+ !iter->update_path) {
+ struct bpos pos = k.k->p;
+
+ if (pos.snapshot < iter->snapshot) {
+ search_key = bpos_successor(k.k->p);
+ continue;
+ }
+
+ pos.snapshot = iter->snapshot;
+
+ /*
+ * advance, same as on exit for iter->path, but only up
+ * to snapshot
+ */
+ __btree_path_get(trans->paths + iter->path, iter->flags & BTREE_ITER_INTENT);
+ iter->update_path = iter->path;
+
+ iter->update_path = bch2_btree_path_set_pos(trans,
+ iter->update_path, pos,
+ iter->flags & BTREE_ITER_INTENT,
+ _THIS_IP_);
+ ret = bch2_btree_path_traverse(trans, iter->update_path, iter->flags);
+ if (unlikely(ret)) {
+ k = bkey_s_c_err(ret);
+ goto out_no_locked;
+ }
+ }
+
+ /*
+ * We can never have a key in a leaf node at POS_MAX, so
+ * we don't have to check these successor() calls:
+ */
+ if ((iter->flags & BTREE_ITER_FILTER_SNAPSHOTS) &&
+ !bch2_snapshot_is_ancestor(trans->c,
+ iter->snapshot,
+ k.k->p.snapshot)) {
+ search_key = bpos_successor(k.k->p);
+ continue;
+ }
+
+ if (bkey_whiteout(k.k) &&
+ !(iter->flags & BTREE_ITER_ALL_SNAPSHOTS)) {
+ search_key = bkey_successor(iter, k.k->p);
+ continue;
+ }
+
+ /*
+ * iter->pos should be mononotically increasing, and always be
+ * equal to the key we just returned - except extents can
+ * straddle iter->pos:
+ */
+ if (!(iter->flags & BTREE_ITER_IS_EXTENTS))
+ iter_pos = k.k->p;
+ else
+ iter_pos = bkey_max(iter->pos, bkey_start_pos(k.k));
+
+ if (unlikely(!(iter->flags & BTREE_ITER_IS_EXTENTS)
+ ? bkey_gt(iter_pos, end)
+ : bkey_ge(iter_pos, end)))
+ goto end;
+
+ break;
+ }
+
+ iter->pos = iter_pos;
+
+ iter->path = bch2_btree_path_set_pos(trans, iter->path, k.k->p,
+ iter->flags & BTREE_ITER_INTENT,
+ btree_iter_ip_allocated(iter));
+
+ btree_path_set_should_be_locked(btree_iter_path(trans, iter));
+out_no_locked:
+ if (iter->update_path) {
+ ret = bch2_btree_path_relock(trans, trans->paths + iter->update_path, _THIS_IP_);
+ if (unlikely(ret))
+ k = bkey_s_c_err(ret);
+ else
+ btree_path_set_should_be_locked(trans->paths + iter->update_path);
+ }
+
+ if (!(iter->flags & BTREE_ITER_ALL_SNAPSHOTS))
+ iter->pos.snapshot = iter->snapshot;
+
+ ret = bch2_btree_iter_verify_ret(iter, k);
+ if (unlikely(ret)) {
+ bch2_btree_iter_set_pos(iter, iter->pos);
+ k = bkey_s_c_err(ret);
+ }
+
+ bch2_btree_iter_verify_entry_exit(iter);
+
+ return k;
+end:
+ bch2_btree_iter_set_pos(iter, end);
+ k = bkey_s_c_null;
+ goto out_no_locked;
+}
+
+/**
+ * bch2_btree_iter_next() - returns first key greater than iterator's current
+ * position
+ * @iter: iterator to peek from
+ *
+ * Returns: key if found, or an error extractable with bkey_err().
+ */
+struct bkey_s_c bch2_btree_iter_next(struct btree_iter *iter)
+{
+ if (!bch2_btree_iter_advance(iter))
+ return bkey_s_c_null;
+
+ return bch2_btree_iter_peek(iter);
+}
+
+/**
+ * bch2_btree_iter_peek_prev() - returns first key less than or equal to
+ * iterator's current position
+ * @iter: iterator to peek from
+ *
+ * Returns: key if found, or an error extractable with bkey_err().
+ */
+struct bkey_s_c bch2_btree_iter_peek_prev(struct btree_iter *iter)
+{
+ struct btree_trans *trans = iter->trans;
+ struct bpos search_key = iter->pos;
+ struct bkey_s_c k;
+ struct bkey saved_k;
+ const struct bch_val *saved_v;
+ btree_path_idx_t saved_path = 0;
+ int ret;
+
+ EBUG_ON(btree_iter_path(trans, iter)->cached ||
+ btree_iter_path(trans, iter)->level);
+
+ if (iter->flags & BTREE_ITER_WITH_JOURNAL)
+ return bkey_s_c_err(-EIO);
+
+ bch2_btree_iter_verify(iter);
+ bch2_btree_iter_verify_entry_exit(iter);
+
+ if (iter->flags & BTREE_ITER_FILTER_SNAPSHOTS)
+ search_key.snapshot = U32_MAX;
+
+ while (1) {
+ iter->path = bch2_btree_path_set_pos(trans, iter->path, search_key,
+ iter->flags & BTREE_ITER_INTENT,
+ btree_iter_ip_allocated(iter));
+
+ ret = bch2_btree_path_traverse(trans, iter->path, iter->flags);
+ if (unlikely(ret)) {
+ /* ensure that iter->k is consistent with iter->pos: */
+ bch2_btree_iter_set_pos(iter, iter->pos);
+ k = bkey_s_c_err(ret);
+ goto out_no_locked;
+ }
+
+ struct btree_path *path = btree_iter_path(trans, iter);
+
+ k = btree_path_level_peek(trans, path, &path->l[0], &iter->k);
+ if (!k.k ||
+ ((iter->flags & BTREE_ITER_IS_EXTENTS)
+ ? bpos_ge(bkey_start_pos(k.k), search_key)
+ : bpos_gt(k.k->p, search_key)))
+ k = btree_path_level_prev(trans, path, &path->l[0], &iter->k);
+
+ if (unlikely((iter->flags & BTREE_ITER_WITH_UPDATES) &&
+ trans->nr_updates))
+ bch2_btree_trans_peek_prev_updates(trans, iter, &k);
+
+ if (likely(k.k)) {
+ if (iter->flags & BTREE_ITER_FILTER_SNAPSHOTS) {
+ if (k.k->p.snapshot == iter->snapshot)
+ goto got_key;
+
+ /*
+ * If we have a saved candidate, and we're no
+ * longer at the same _key_ (not pos), return
+ * that candidate
+ */
+ if (saved_path && !bkey_eq(k.k->p, saved_k.p)) {
+ bch2_path_put_nokeep(trans, iter->path,
+ iter->flags & BTREE_ITER_INTENT);
+ iter->path = saved_path;
+ saved_path = 0;
+ iter->k = saved_k;
+ k.v = saved_v;
+ goto got_key;
+ }
+
+ if (bch2_snapshot_is_ancestor(trans->c,
+ iter->snapshot,
+ k.k->p.snapshot)) {
+ if (saved_path)
+ bch2_path_put_nokeep(trans, saved_path,
+ iter->flags & BTREE_ITER_INTENT);
+ saved_path = btree_path_clone(trans, iter->path,
+ iter->flags & BTREE_ITER_INTENT);
+ path = btree_iter_path(trans, iter);
+ saved_k = *k.k;
+ saved_v = k.v;
+ }
+
+ search_key = bpos_predecessor(k.k->p);
+ continue;
+ }
+got_key:
+ if (bkey_whiteout(k.k) &&
+ !(iter->flags & BTREE_ITER_ALL_SNAPSHOTS)) {
+ search_key = bkey_predecessor(iter, k.k->p);
+ if (iter->flags & BTREE_ITER_FILTER_SNAPSHOTS)
+ search_key.snapshot = U32_MAX;
+ continue;
+ }
+
+ btree_path_set_should_be_locked(path);
+ break;
+ } else if (likely(!bpos_eq(path->l[0].b->data->min_key, POS_MIN))) {
+ /* Advance to previous leaf node: */
+ search_key = bpos_predecessor(path->l[0].b->data->min_key);
+ } else {
+ /* Start of btree: */
+ bch2_btree_iter_set_pos(iter, POS_MIN);
+ k = bkey_s_c_null;
+ goto out_no_locked;
+ }
+ }
+
+ EBUG_ON(bkey_gt(bkey_start_pos(k.k), iter->pos));
+
+ /* Extents can straddle iter->pos: */
+ if (bkey_lt(k.k->p, iter->pos))
+ iter->pos = k.k->p;
+
+ if (iter->flags & BTREE_ITER_FILTER_SNAPSHOTS)
+ iter->pos.snapshot = iter->snapshot;
+out_no_locked:
+ if (saved_path)
+ bch2_path_put_nokeep(trans, saved_path, iter->flags & BTREE_ITER_INTENT);
+
+ bch2_btree_iter_verify_entry_exit(iter);
+ bch2_btree_iter_verify(iter);
+
+ return k;
+}
+
+/**
+ * bch2_btree_iter_prev() - returns first key less than iterator's current
+ * position
+ * @iter: iterator to peek from
+ *
+ * Returns: key if found, or an error extractable with bkey_err().
+ */
+struct bkey_s_c bch2_btree_iter_prev(struct btree_iter *iter)
+{
+ if (!bch2_btree_iter_rewind(iter))
+ return bkey_s_c_null;
+
+ return bch2_btree_iter_peek_prev(iter);
+}
+
+struct bkey_s_c bch2_btree_iter_peek_slot(struct btree_iter *iter)
+{
+ struct btree_trans *trans = iter->trans;
+ struct bpos search_key;
+ struct bkey_s_c k;
+ int ret;
+
+ bch2_btree_iter_verify(iter);
+ bch2_btree_iter_verify_entry_exit(iter);
+ EBUG_ON(btree_iter_path(trans, iter)->level && (iter->flags & BTREE_ITER_WITH_KEY_CACHE));
+
+ /* extents can't span inode numbers: */
+ if ((iter->flags & BTREE_ITER_IS_EXTENTS) &&
+ unlikely(iter->pos.offset == KEY_OFFSET_MAX)) {
+ if (iter->pos.inode == KEY_INODE_MAX)
+ return bkey_s_c_null;
+
+ bch2_btree_iter_set_pos(iter, bpos_nosnap_successor(iter->pos));
+ }
+
+ search_key = btree_iter_search_key(iter);
+ iter->path = bch2_btree_path_set_pos(trans, iter->path, search_key,
+ iter->flags & BTREE_ITER_INTENT,
+ btree_iter_ip_allocated(iter));
+
+ ret = bch2_btree_path_traverse(trans, iter->path, iter->flags);
+ if (unlikely(ret)) {
+ k = bkey_s_c_err(ret);
+ goto out_no_locked;
+ }
+
+ if ((iter->flags & BTREE_ITER_CACHED) ||
+ !(iter->flags & (BTREE_ITER_IS_EXTENTS|BTREE_ITER_FILTER_SNAPSHOTS))) {
+ k = bkey_s_c_null;
+
+ if (unlikely((iter->flags & BTREE_ITER_WITH_UPDATES) &&
+ trans->nr_updates)) {
+ bch2_btree_trans_peek_slot_updates(trans, iter, &k);
+ if (k.k)
+ goto out;
+ }
+
+ if (unlikely(iter->flags & BTREE_ITER_WITH_JOURNAL) &&
+ (k = btree_trans_peek_slot_journal(trans, iter)).k)
+ goto out;
+
+ if (unlikely(iter->flags & BTREE_ITER_WITH_KEY_CACHE) &&
+ (k = btree_trans_peek_key_cache(iter, iter->pos)).k) {
+ if (!bkey_err(k))
+ iter->k = *k.k;
+ /* We're not returning a key from iter->path: */
+ goto out_no_locked;
+ }
+
+ k = bch2_btree_path_peek_slot(trans->paths + iter->path, &iter->k);
+ if (unlikely(!k.k))
+ goto out_no_locked;
+ } else {
+ struct bpos next;
+ struct bpos end = iter->pos;
+
+ if (iter->flags & BTREE_ITER_IS_EXTENTS)
+ end.offset = U64_MAX;
+
+ EBUG_ON(btree_iter_path(trans, iter)->level);
+
+ if (iter->flags & BTREE_ITER_INTENT) {
+ struct btree_iter iter2;
+
+ bch2_trans_copy_iter(&iter2, iter);
+ k = bch2_btree_iter_peek_upto(&iter2, end);
+
+ if (k.k && !bkey_err(k)) {
+ iter->k = iter2.k;
+ k.k = &iter->k;
+ }
+ bch2_trans_iter_exit(trans, &iter2);
+ } else {
+ struct bpos pos = iter->pos;
+
+ k = bch2_btree_iter_peek_upto(iter, end);
+ if (unlikely(bkey_err(k)))
+ bch2_btree_iter_set_pos(iter, pos);
+ else
+ iter->pos = pos;
+ }
+
+ if (unlikely(bkey_err(k)))
+ goto out_no_locked;
+
+ next = k.k ? bkey_start_pos(k.k) : POS_MAX;
+
+ if (bkey_lt(iter->pos, next)) {
+ bkey_init(&iter->k);
+ iter->k.p = iter->pos;
+
+ if (iter->flags & BTREE_ITER_IS_EXTENTS) {
+ bch2_key_resize(&iter->k,
+ min_t(u64, KEY_SIZE_MAX,
+ (next.inode == iter->pos.inode
+ ? next.offset
+ : KEY_OFFSET_MAX) -
+ iter->pos.offset));
+ EBUG_ON(!iter->k.size);
+ }
+
+ k = (struct bkey_s_c) { &iter->k, NULL };
+ }
+ }
+out:
+ btree_path_set_should_be_locked(btree_iter_path(trans, iter));
+out_no_locked:
+ bch2_btree_iter_verify_entry_exit(iter);
+ bch2_btree_iter_verify(iter);
+ ret = bch2_btree_iter_verify_ret(iter, k);
+ if (unlikely(ret))
+ return bkey_s_c_err(ret);
+
+ return k;
+}
+
+struct bkey_s_c bch2_btree_iter_next_slot(struct btree_iter *iter)
+{
+ if (!bch2_btree_iter_advance(iter))
+ return bkey_s_c_null;
+
+ return bch2_btree_iter_peek_slot(iter);
+}
+
+struct bkey_s_c bch2_btree_iter_prev_slot(struct btree_iter *iter)
+{
+ if (!bch2_btree_iter_rewind(iter))
+ return bkey_s_c_null;
+
+ return bch2_btree_iter_peek_slot(iter);
+}
+
+struct bkey_s_c bch2_btree_iter_peek_and_restart_outlined(struct btree_iter *iter)
+{
+ struct bkey_s_c k;
+
+ while (btree_trans_too_many_iters(iter->trans) ||
+ (k = bch2_btree_iter_peek_type(iter, iter->flags),
+ bch2_err_matches(bkey_err(k), BCH_ERR_transaction_restart)))
+ bch2_trans_begin(iter->trans);
+
+ return k;
+}
+
+/* new transactional stuff: */
+
+#ifdef CONFIG_BCACHEFS_DEBUG
+static void btree_trans_verify_sorted_refs(struct btree_trans *trans)
+{
+ struct btree_path *path;
+ unsigned i;
+
+ BUG_ON(trans->nr_sorted != bitmap_weight(trans->paths_allocated, trans->nr_paths) - 1);
+
+ trans_for_each_path(trans, path, i) {
+ BUG_ON(path->sorted_idx >= trans->nr_sorted);
+ BUG_ON(trans->sorted[path->sorted_idx] != i);
+ }
+
+ for (i = 0; i < trans->nr_sorted; i++) {
+ unsigned idx = trans->sorted[i];
+
+ BUG_ON(!test_bit(idx, trans->paths_allocated));
+ BUG_ON(trans->paths[idx].sorted_idx != i);
+ }
+}
+
+static void btree_trans_verify_sorted(struct btree_trans *trans)
+{
+ struct btree_path *path, *prev = NULL;
+ struct trans_for_each_path_inorder_iter iter;
+
+ if (!bch2_debug_check_iterators)
+ return;
+
+ trans_for_each_path_inorder(trans, path, iter) {
+ if (prev && btree_path_cmp(prev, path) > 0) {
+ __bch2_dump_trans_paths_updates(trans, true);
+ panic("trans paths out of order!\n");
+ }
+ prev = path;
+ }
+}
+#else
+static inline void btree_trans_verify_sorted_refs(struct btree_trans *trans) {}
+static inline void btree_trans_verify_sorted(struct btree_trans *trans) {}
+#endif
+
+void __bch2_btree_trans_sort_paths(struct btree_trans *trans)
+{
+ int i, l = 0, r = trans->nr_sorted, inc = 1;
+ bool swapped;
+
+ btree_trans_verify_sorted_refs(trans);
+
+ if (trans->paths_sorted)
+ goto out;
+
+ /*
+ * Cocktail shaker sort: this is efficient because iterators will be
+ * mostly sorted.
+ */
+ do {
+ swapped = false;
+
+ for (i = inc > 0 ? l : r - 2;
+ i + 1 < r && i >= l;
+ i += inc) {
+ if (btree_path_cmp(trans->paths + trans->sorted[i],
+ trans->paths + trans->sorted[i + 1]) > 0) {
+ swap(trans->sorted[i], trans->sorted[i + 1]);
+ trans->paths[trans->sorted[i]].sorted_idx = i;
+ trans->paths[trans->sorted[i + 1]].sorted_idx = i + 1;
+ swapped = true;
+ }
+ }
+
+ if (inc > 0)
+ --r;
+ else
+ l++;
+ inc = -inc;
+ } while (swapped);
+
+ trans->paths_sorted = true;
+out:
+ btree_trans_verify_sorted(trans);
+}
+
+static inline void btree_path_list_remove(struct btree_trans *trans,
+ struct btree_path *path)
+{
+ EBUG_ON(path->sorted_idx >= trans->nr_sorted);
+#ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
+ trans->nr_sorted--;
+ memmove_u64s_down_small(trans->sorted + path->sorted_idx,
+ trans->sorted + path->sorted_idx + 1,
+ DIV_ROUND_UP(trans->nr_sorted - path->sorted_idx,
+ sizeof(u64) / sizeof(btree_path_idx_t)));
+#else
+ array_remove_item(trans->sorted, trans->nr_sorted, path->sorted_idx);
+#endif
+ for (unsigned i = path->sorted_idx; i < trans->nr_sorted; i++)
+ trans->paths[trans->sorted[i]].sorted_idx = i;
+}
+
+static inline void btree_path_list_add(struct btree_trans *trans,
+ btree_path_idx_t pos,
+ btree_path_idx_t path_idx)
+{
+ struct btree_path *path = trans->paths + path_idx;
+
+ path->sorted_idx = pos ? trans->paths[pos].sorted_idx + 1 : trans->nr_sorted;
+
+#ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
+ memmove_u64s_up_small(trans->sorted + path->sorted_idx + 1,
+ trans->sorted + path->sorted_idx,
+ DIV_ROUND_UP(trans->nr_sorted - path->sorted_idx,
+ sizeof(u64) / sizeof(btree_path_idx_t)));
+ trans->nr_sorted++;
+ trans->sorted[path->sorted_idx] = path_idx;
+#else
+ array_insert_item(trans->sorted, trans->nr_sorted, path->sorted_idx, path_idx);
+#endif
+
+ for (unsigned i = path->sorted_idx; i < trans->nr_sorted; i++)
+ trans->paths[trans->sorted[i]].sorted_idx = i;
+
+ btree_trans_verify_sorted_refs(trans);
+}
+
+void bch2_trans_iter_exit(struct btree_trans *trans, struct btree_iter *iter)
+{
+ if (iter->update_path)
+ bch2_path_put_nokeep(trans, iter->update_path,
+ iter->flags & BTREE_ITER_INTENT);
+ if (iter->path)
+ bch2_path_put(trans, iter->path,
+ iter->flags & BTREE_ITER_INTENT);
+ if (iter->key_cache_path)
+ bch2_path_put(trans, iter->key_cache_path,
+ iter->flags & BTREE_ITER_INTENT);
+ iter->path = 0;
+ iter->update_path = 0;
+ iter->key_cache_path = 0;
+ iter->trans = NULL;
+}
+
+void bch2_trans_iter_init_outlined(struct btree_trans *trans,
+ struct btree_iter *iter,
+ enum btree_id btree_id, struct bpos pos,
+ unsigned flags)
+{
+ bch2_trans_iter_init_common(trans, iter, btree_id, pos, 0, 0,
+ bch2_btree_iter_flags(trans, btree_id, flags),
+ _RET_IP_);
+}
+
+void bch2_trans_node_iter_init(struct btree_trans *trans,
+ struct btree_iter *iter,
+ enum btree_id btree_id,
+ struct bpos pos,
+ unsigned locks_want,
+ unsigned depth,
+ unsigned flags)
+{
+ flags |= BTREE_ITER_NOT_EXTENTS;
+ flags |= __BTREE_ITER_ALL_SNAPSHOTS;
+ flags |= BTREE_ITER_ALL_SNAPSHOTS;
+
+ bch2_trans_iter_init_common(trans, iter, btree_id, pos, locks_want, depth,
+ __bch2_btree_iter_flags(trans, btree_id, flags),
+ _RET_IP_);
+
+ iter->min_depth = depth;
+
+ struct btree_path *path = btree_iter_path(trans, iter);
+ BUG_ON(path->locks_want < min(locks_want, BTREE_MAX_DEPTH));
+ BUG_ON(path->level != depth);
+ BUG_ON(iter->min_depth != depth);
+}
+
+void bch2_trans_copy_iter(struct btree_iter *dst, struct btree_iter *src)
+{
+ struct btree_trans *trans = src->trans;
+
+ *dst = *src;
+ if (src->path)
+ __btree_path_get(trans->paths + src->path, src->flags & BTREE_ITER_INTENT);
+ if (src->update_path)
+ __btree_path_get(trans->paths + src->update_path, src->flags & BTREE_ITER_INTENT);
+ dst->key_cache_path = 0;
+}
+
+void *__bch2_trans_kmalloc(struct btree_trans *trans, size_t size)
+{
+ struct bch_fs *c = trans->c;
+ unsigned new_top = trans->mem_top + size;
+ unsigned old_bytes = trans->mem_bytes;
+ unsigned new_bytes = roundup_pow_of_two(new_top);
+ int ret;
+ void *new_mem;
+ void *p;
+
+ WARN_ON_ONCE(new_bytes > BTREE_TRANS_MEM_MAX);
+
+ struct btree_transaction_stats *s = btree_trans_stats(trans);
+ s->max_mem = max(s->max_mem, new_bytes);
+
+ new_mem = krealloc(trans->mem, new_bytes, GFP_NOWAIT|__GFP_NOWARN);
+ if (unlikely(!new_mem)) {
+ bch2_trans_unlock(trans);
+
+ new_mem = krealloc(trans->mem, new_bytes, GFP_KERNEL);
+ if (!new_mem && new_bytes <= BTREE_TRANS_MEM_MAX) {
+ new_mem = mempool_alloc(&c->btree_trans_mem_pool, GFP_KERNEL);
+ new_bytes = BTREE_TRANS_MEM_MAX;
+ kfree(trans->mem);
+ }
+
+ if (!new_mem)
+ return ERR_PTR(-BCH_ERR_ENOMEM_trans_kmalloc);
+
+ trans->mem = new_mem;
+ trans->mem_bytes = new_bytes;
+
+ ret = bch2_trans_relock(trans);
+ if (ret)
+ return ERR_PTR(ret);
+ }
+
+ trans->mem = new_mem;
+ trans->mem_bytes = new_bytes;
+
+ if (old_bytes) {
+ trace_and_count(c, trans_restart_mem_realloced, trans, _RET_IP_, new_bytes);
+ return ERR_PTR(btree_trans_restart(trans, BCH_ERR_transaction_restart_mem_realloced));
+ }
+
+ p = trans->mem + trans->mem_top;
+ trans->mem_top += size;
+ memset(p, 0, size);
+ return p;
+}
+
+static inline void check_srcu_held_too_long(struct btree_trans *trans)
+{
+ WARN(trans->srcu_held && time_after(jiffies, trans->srcu_lock_time + HZ * 10),
+ "btree trans held srcu lock (delaying memory reclaim) for %lu seconds",
+ (jiffies - trans->srcu_lock_time) / HZ);
+}
+
+void bch2_trans_srcu_unlock(struct btree_trans *trans)
+{
+ if (trans->srcu_held) {
+ struct bch_fs *c = trans->c;
+ struct btree_path *path;
+ unsigned i;
+
+ trans_for_each_path(trans, path, i)
+ if (path->cached && !btree_node_locked(path, 0))
+ path->l[0].b = ERR_PTR(-BCH_ERR_no_btree_node_srcu_reset);
+
+ check_srcu_held_too_long(trans);
+ srcu_read_unlock(&c->btree_trans_barrier, trans->srcu_idx);
+ trans->srcu_held = false;
+ }
+}
+
+static void bch2_trans_srcu_lock(struct btree_trans *trans)
+{
+ if (!trans->srcu_held) {
+ trans->srcu_idx = srcu_read_lock(&trans->c->btree_trans_barrier);
+ trans->srcu_lock_time = jiffies;
+ trans->srcu_held = true;
+ }
+}
+
+/**
+ * bch2_trans_begin() - reset a transaction after a interrupted attempt
+ * @trans: transaction to reset
+ *
+ * Returns: current restart counter, to be used with trans_was_restarted()
+ *
+ * While iterating over nodes or updating nodes a attempt to lock a btree node
+ * may return BCH_ERR_transaction_restart when the trylock fails. When this
+ * occurs bch2_trans_begin() should be called and the transaction retried.
+ */
+u32 bch2_trans_begin(struct btree_trans *trans)
+{
+ struct btree_path *path;
+ unsigned i;
+ u64 now;
+
+ bch2_trans_reset_updates(trans);
+
+ trans->restart_count++;
+ trans->mem_top = 0;
+ trans->journal_entries = NULL;
+
+ trans_for_each_path(trans, path, i) {
+ path->should_be_locked = false;
+
+ /*
+ * If the transaction wasn't restarted, we're presuming to be
+ * doing something new: dont keep iterators excpt the ones that
+ * are in use - except for the subvolumes btree:
+ */
+ if (!trans->restarted && path->btree_id != BTREE_ID_subvolumes)
+ path->preserve = false;
+
+ /*
+ * XXX: we probably shouldn't be doing this if the transaction
+ * was restarted, but currently we still overflow transaction
+ * iterators if we do that
+ */
+ if (!path->ref && !path->preserve)
+ __bch2_path_free(trans, i);
+ else
+ path->preserve = false;
+ }
+
+ now = local_clock();
+
+ if (!IS_ENABLED(CONFIG_BCACHEFS_NO_LATENCY_ACCT) &&
+ time_after64(now, trans->last_begin_time + 10))
+ __bch2_time_stats_update(&btree_trans_stats(trans)->duration,
+ trans->last_begin_time, now);
+
+ if (!trans->restarted &&
+ (need_resched() ||
+ time_after64(now, trans->last_begin_time + BTREE_TRANS_MAX_LOCK_HOLD_TIME_NS))) {
+ drop_locks_do(trans, (cond_resched(), 0));
+ now = local_clock();
+ }
+ trans->last_begin_time = now;
+
+ if (unlikely(trans->srcu_held &&
+ time_after(jiffies, trans->srcu_lock_time + msecs_to_jiffies(10))))
+ bch2_trans_srcu_unlock(trans);
+
+ trans->last_begin_ip = _RET_IP_;
+ if (trans->restarted) {
+ bch2_btree_path_traverse_all(trans);
+ trans->notrace_relock_fail = false;
+ }
+
+ return trans->restart_count;
+}
+
+const char *bch2_btree_transaction_fns[BCH_TRANSACTIONS_NR] = { "(unknown)" };
+
+unsigned bch2_trans_get_fn_idx(const char *fn)
+{
+ for (unsigned i = 0; i < ARRAY_SIZE(bch2_btree_transaction_fns); i++)
+ if (!bch2_btree_transaction_fns[i] ||
+ bch2_btree_transaction_fns[i] == fn) {
+ bch2_btree_transaction_fns[i] = fn;
+ return i;
+ }
+
+ pr_warn_once("BCH_TRANSACTIONS_NR not big enough!");
+ return 0;
+}
+
+struct btree_trans *__bch2_trans_get(struct bch_fs *c, unsigned fn_idx)
+ __acquires(&c->btree_trans_barrier)
+{
+ struct btree_trans *trans;
+
+ if (IS_ENABLED(__KERNEL__)) {
+ trans = this_cpu_xchg(c->btree_trans_bufs->trans, NULL);
+ if (trans) {
+ memset(trans, 0, offsetof(struct btree_trans, list));
+ goto got_trans;
+ }
+ }
+
+ trans = mempool_alloc(&c->btree_trans_pool, GFP_NOFS);
+ memset(trans, 0, sizeof(*trans));
+ closure_init_stack(&trans->ref);
+
+ seqmutex_lock(&c->btree_trans_lock);
+ if (IS_ENABLED(CONFIG_BCACHEFS_DEBUG)) {
+ struct btree_trans *pos;
+ pid_t pid = current->pid;
+
+ trans->locking_wait.task = current;
+
+ list_for_each_entry(pos, &c->btree_trans_list, list) {
+ struct task_struct *pos_task = READ_ONCE(pos->locking_wait.task);
+ /*
+ * We'd much prefer to be stricter here and completely
+ * disallow multiple btree_trans in the same thread -
+ * but the data move path calls bch2_write when we
+ * already have a btree_trans initialized.
+ */
+ BUG_ON(pos_task &&
+ pid == pos_task->pid &&
+ bch2_trans_locked(pos));
+
+ if (pos_task && pid < pos_task->pid) {
+ list_add_tail(&trans->list, &pos->list);
+ goto list_add_done;
+ }
+ }
+ }
+ list_add_tail(&trans->list, &c->btree_trans_list);
+list_add_done:
+ seqmutex_unlock(&c->btree_trans_lock);
+got_trans:
+ trans->c = c;
+ trans->last_begin_time = local_clock();
+ trans->fn_idx = fn_idx;
+ trans->locking_wait.task = current;
+ trans->journal_replay_not_finished =
+ unlikely(!test_bit(JOURNAL_REPLAY_DONE, &c->journal.flags)) &&
+ atomic_inc_not_zero(&c->journal_keys.ref);
+ trans->nr_paths = ARRAY_SIZE(trans->_paths);
+ trans->paths_allocated = trans->_paths_allocated;
+ trans->sorted = trans->_sorted;
+ trans->paths = trans->_paths;
+ trans->updates = trans->_updates;
+
+ *trans_paths_nr(trans->paths) = BTREE_ITER_INITIAL;
+
+ trans->paths_allocated[0] = 1;
+
+ if (fn_idx < BCH_TRANSACTIONS_NR) {
+ trans->fn = bch2_btree_transaction_fns[fn_idx];
+
+ struct btree_transaction_stats *s = &c->btree_transaction_stats[fn_idx];
+
+ if (s->max_mem) {
+ unsigned expected_mem_bytes = roundup_pow_of_two(s->max_mem);
+
+ trans->mem = kmalloc(expected_mem_bytes, GFP_KERNEL);
+ if (likely(trans->mem))
+ trans->mem_bytes = expected_mem_bytes;
+ }
+
+ trans->nr_paths_max = s->nr_max_paths;
+ trans->journal_entries_size = s->journal_entries_size;
+ }
+
+ trans->srcu_idx = srcu_read_lock(&c->btree_trans_barrier);
+ trans->srcu_lock_time = jiffies;
+ trans->srcu_held = true;
+ return trans;
+}
+
+static void check_btree_paths_leaked(struct btree_trans *trans)
+{
+#ifdef CONFIG_BCACHEFS_DEBUG
+ struct bch_fs *c = trans->c;
+ struct btree_path *path;
+ unsigned i;
+
+ trans_for_each_path(trans, path, i)
+ if (path->ref)
+ goto leaked;
+ return;
+leaked:
+ bch_err(c, "btree paths leaked from %s!", trans->fn);
+ trans_for_each_path(trans, path, i)
+ if (path->ref)
+ printk(KERN_ERR " btree %s %pS\n",
+ bch2_btree_id_str(path->btree_id),
+ (void *) path->ip_allocated);
+ /* Be noisy about this: */
+ bch2_fatal_error(c);
+#endif
+}
+
+void bch2_trans_put(struct btree_trans *trans)
+ __releases(&c->btree_trans_barrier)
+{
+ struct bch_fs *c = trans->c;
+
+ bch2_trans_unlock(trans);
+
+ trans_for_each_update(trans, i)
+ __btree_path_put(trans->paths + i->path, true);
+ trans->nr_updates = 0;
+ trans->locking_wait.task = NULL;
+
+ check_btree_paths_leaked(trans);
+
+ if (trans->srcu_held) {
+ check_srcu_held_too_long(trans);
+ srcu_read_unlock(&c->btree_trans_barrier, trans->srcu_idx);
+ }
+
+ if (trans->fs_usage_deltas) {
+ if (trans->fs_usage_deltas->size + sizeof(trans->fs_usage_deltas) ==
+ REPLICAS_DELTA_LIST_MAX)
+ mempool_free(trans->fs_usage_deltas,
+ &c->replicas_delta_pool);
+ else
+ kfree(trans->fs_usage_deltas);
+ }
+
+ if (unlikely(trans->journal_replay_not_finished))
+ bch2_journal_keys_put(c);
+
+ unsigned long *paths_allocated = trans->paths_allocated;
+ trans->paths_allocated = NULL;
+ trans->paths = NULL;
+
+ if (paths_allocated != trans->_paths_allocated)
+ kfree_rcu_mightsleep(paths_allocated);
+
+ if (trans->mem_bytes == BTREE_TRANS_MEM_MAX)
+ mempool_free(trans->mem, &c->btree_trans_mem_pool);
+ else
+ kfree(trans->mem);
+
+ /* Userspace doesn't have a real percpu implementation: */
+ if (IS_ENABLED(__KERNEL__))
+ trans = this_cpu_xchg(c->btree_trans_bufs->trans, trans);
+
+ if (trans) {
+ closure_sync(&trans->ref);
+
+ seqmutex_lock(&c->btree_trans_lock);
+ list_del(&trans->list);
+ seqmutex_unlock(&c->btree_trans_lock);
+
+ mempool_free(trans, &c->btree_trans_pool);
+ }
+}
+
+static void __maybe_unused
+bch2_btree_bkey_cached_common_to_text(struct printbuf *out,
+ struct btree_bkey_cached_common *b)
+{
+ struct six_lock_count c = six_lock_counts(&b->lock);
+ struct task_struct *owner;
+ pid_t pid;
+
+ rcu_read_lock();
+ owner = READ_ONCE(b->lock.owner);
+ pid = owner ? owner->pid : 0;
+ rcu_read_unlock();
+
+ prt_tab(out);
+ prt_printf(out, "%px %c l=%u %s:", b, b->cached ? 'c' : 'b',
+ b->level, bch2_btree_id_str(b->btree_id));
+ bch2_bpos_to_text(out, btree_node_pos(b));
+
+ prt_tab(out);
+ prt_printf(out, " locks %u:%u:%u held by pid %u",
+ c.n[0], c.n[1], c.n[2], pid);
+}
+
+void bch2_btree_trans_to_text(struct printbuf *out, struct btree_trans *trans)
+{
+ struct btree_bkey_cached_common *b;
+ static char lock_types[] = { 'r', 'i', 'w' };
+ struct task_struct *task = READ_ONCE(trans->locking_wait.task);
+ unsigned l, idx;
+
+ /* before rcu_read_lock(): */
+ bch2_printbuf_make_room(out, 4096);
+
+ if (!out->nr_tabstops) {
+ printbuf_tabstop_push(out, 16);
+ printbuf_tabstop_push(out, 32);
+ }
+
+ prt_printf(out, "%i %s\n", task ? task->pid : 0, trans->fn);
+
+ /* trans->paths is rcu protected vs. freeing */
+ rcu_read_lock();
+ out->atomic++;
+
+ struct btree_path *paths = rcu_dereference(trans->paths);
+ if (!paths)
+ goto out;
+
+ unsigned long *paths_allocated = trans_paths_allocated(paths);
+
+ trans_for_each_path_idx_from(paths_allocated, *trans_paths_nr(paths), idx, 1) {
+ struct btree_path *path = paths + idx;
+ if (!path->nodes_locked)
+ continue;
+
+ prt_printf(out, " path %u %c l=%u %s:",
+ idx,
+ path->cached ? 'c' : 'b',
+ path->level,
+ bch2_btree_id_str(path->btree_id));
+ bch2_bpos_to_text(out, path->pos);
+ prt_newline(out);
+
+ for (l = 0; l < BTREE_MAX_DEPTH; l++) {
+ if (btree_node_locked(path, l) &&
+ !IS_ERR_OR_NULL(b = (void *) READ_ONCE(path->l[l].b))) {
+ prt_printf(out, " %c l=%u ",
+ lock_types[btree_node_locked_type(path, l)], l);
+ bch2_btree_bkey_cached_common_to_text(out, b);
+ prt_newline(out);
+ }
+ }
+ }
+
+ b = READ_ONCE(trans->locking);
+ if (b) {
+ prt_printf(out, " blocked for %lluus on",
+ div_u64(local_clock() - trans->locking_wait.start_time,
+ 1000));
+ prt_newline(out);
+ prt_printf(out, " %c", lock_types[trans->locking_wait.lock_want]);
+ bch2_btree_bkey_cached_common_to_text(out, b);
+ prt_newline(out);
+ }
+out:
+ --out->atomic;
+ rcu_read_unlock();
+}
+
+void bch2_fs_btree_iter_exit(struct bch_fs *c)
+{
+ struct btree_transaction_stats *s;
+ struct btree_trans *trans;
+ int cpu;
+
+ if (c->btree_trans_bufs)
+ for_each_possible_cpu(cpu) {
+ struct btree_trans *trans =
+ per_cpu_ptr(c->btree_trans_bufs, cpu)->trans;
+
+ if (trans) {
+ closure_sync(&trans->ref);
+
+ seqmutex_lock(&c->btree_trans_lock);
+ list_del(&trans->list);
+ seqmutex_unlock(&c->btree_trans_lock);
+ }
+ kfree(trans);
+ }
+ free_percpu(c->btree_trans_bufs);
+
+ trans = list_first_entry_or_null(&c->btree_trans_list, struct btree_trans, list);
+ if (trans)
+ panic("%s leaked btree_trans\n", trans->fn);
+
+ for (s = c->btree_transaction_stats;
+ s < c->btree_transaction_stats + ARRAY_SIZE(c->btree_transaction_stats);
+ s++) {
+ kfree(s->max_paths_text);
+ bch2_time_stats_exit(&s->lock_hold_times);
+ }
+
+ if (c->btree_trans_barrier_initialized)
+ cleanup_srcu_struct(&c->btree_trans_barrier);
+ mempool_exit(&c->btree_trans_mem_pool);
+ mempool_exit(&c->btree_trans_pool);
+}
+
+void bch2_fs_btree_iter_init_early(struct bch_fs *c)
+{
+ struct btree_transaction_stats *s;
+
+ for (s = c->btree_transaction_stats;
+ s < c->btree_transaction_stats + ARRAY_SIZE(c->btree_transaction_stats);
+ s++) {
+ bch2_time_stats_init(&s->duration);
+ bch2_time_stats_init(&s->lock_hold_times);
+ mutex_init(&s->lock);
+ }
+
+ INIT_LIST_HEAD(&c->btree_trans_list);
+ seqmutex_init(&c->btree_trans_lock);
+}
+
+int bch2_fs_btree_iter_init(struct bch_fs *c)
+{
+ int ret;
+
+ c->btree_trans_bufs = alloc_percpu(struct btree_trans_buf);
+ if (!c->btree_trans_bufs)
+ return -ENOMEM;
+
+ ret = mempool_init_kmalloc_pool(&c->btree_trans_pool, 1,
+ sizeof(struct btree_trans)) ?:
+ mempool_init_kmalloc_pool(&c->btree_trans_mem_pool, 1,
+ BTREE_TRANS_MEM_MAX) ?:
+ init_srcu_struct(&c->btree_trans_barrier);
+ if (!ret)
+ c->btree_trans_barrier_initialized = true;
+ return ret;
+}
projects / bcachefs-tools-debian / blobdiff