+// 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_key_cache.h"
#include "btree_locking.h"
+#include "btree_update.h"
#include "debug.h"
+#include "error.h"
#include "extents.h"
+#include "journal.h"
+#include "replicas.h"
#include <linux/prefetch.h>
#include <trace/events/bcachefs.h>
-#define BTREE_ITER_NOT_END ((struct btree *) 1)
+static void btree_iter_set_search_pos(struct btree_iter *, struct bpos);
+static struct btree_iter *btree_iter_child_alloc(struct btree_iter *, unsigned long);
+static struct btree_iter *btree_trans_iter_alloc(struct btree_trans *);
+static void btree_iter_copy(struct btree_iter *, struct btree_iter *);
+
+static inline struct bpos bkey_successor(struct btree_iter *iter, struct bpos p)
+{
+ EBUG_ON(btree_iter_type(iter) == BTREE_ITER_NODES);
+
+ /* 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)
+{
+ EBUG_ON(btree_iter_type(iter) == BTREE_ITER_NODES);
+
+ /* 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 bool is_btree_node(struct btree_iter *iter, unsigned l)
{
- return iter->nodes[l] && iter->nodes[l] != BTREE_ITER_NOT_END;
+ return l < BTREE_MAX_DEPTH &&
+ (unsigned long) iter->l[l].b >= 128;
}
-/* Btree node locking: */
+static inline struct bpos btree_iter_search_key(struct btree_iter *iter)
+{
+ struct bpos pos = iter->pos;
-/*
- * 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)
+ if ((iter->flags & BTREE_ITER_IS_EXTENTS) &&
+ bkey_cmp(pos, POS_MAX))
+ pos = bkey_successor(iter, pos);
+ return pos;
+}
+
+static inline bool btree_iter_pos_before_node(struct btree_iter *iter,
+ struct btree *b)
{
- struct btree_iter *linked;
+ return bpos_cmp(iter->real_pos, b->data->min_key) < 0;
+}
- EBUG_ON(iter->nodes[b->level] != b);
- EBUG_ON(iter->lock_seq[b->level] + 1 != b->lock.state.seq);
+static inline bool btree_iter_pos_after_node(struct btree_iter *iter,
+ struct btree *b)
+{
+ return bpos_cmp(b->key.k.p, iter->real_pos) < 0;
+}
- for_each_linked_btree_node(iter, b, linked)
- linked->lock_seq[b->level] += 2;
+static inline bool btree_iter_pos_in_node(struct btree_iter *iter,
+ struct btree *b)
+{
+ return iter->btree_id == b->c.btree_id &&
+ !btree_iter_pos_before_node(iter, b) &&
+ !btree_iter_pos_after_node(iter, b);
+}
- iter->lock_seq[b->level] += 2;
+/* Btree node locking: */
- six_unlock_write(&b->lock);
+void bch2_btree_node_unlock_write(struct btree *b, struct btree_iter *iter)
+{
+ bch2_btree_node_unlock_write_inlined(b, iter);
}
-void bch2_btree_node_lock_write(struct btree *b, struct btree_iter *iter)
+void __bch2_btree_node_lock_write(struct btree *b, struct btree_iter *iter)
{
struct btree_iter *linked;
unsigned readers = 0;
- EBUG_ON(iter->nodes[b->level] != b);
- EBUG_ON(iter->lock_seq[b->level] != b->lock.state.seq);
+ EBUG_ON(!btree_node_intent_locked(iter, b->c.level));
- if (six_trylock_write(&b->lock))
- return;
-
- for_each_linked_btree_iter(iter, linked)
- if (linked->nodes[b->level] == b &&
- btree_node_read_locked(linked, b->level))
+ trans_for_each_iter(iter->trans, linked)
+ if (linked->l[b->c.level].b == b &&
+ btree_node_read_locked(linked, b->c.level))
readers++;
- if (likely(!readers)) {
- six_lock_write(&b->lock);
+ /*
+ * 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->c.lock.state.counter);
+ btree_node_lock_type(iter->trans->c, b, SIX_LOCK_write);
+ atomic64_add(__SIX_VAL(read_lock, readers),
+ &b->c.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->c.lock, want, iter->l[level].lock_seq) ||
+ (btree_node_lock_seq_matches(iter, b, level) &&
+ btree_node_lock_increment(iter->trans, b, level, want))) {
+ mark_btree_node_locked(iter, level, want);
+ return true;
} else {
- /*
- * 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);
- six_lock_write(&b->lock);
- atomic64_add(__SIX_VAL(read_lock, readers),
- &b->lock.state.counter);
+ return false;
}
}
-bool bch2_btree_node_relock(struct btree_iter *iter, unsigned level)
+static bool bch2_btree_node_upgrade(struct btree_iter *iter, unsigned level)
{
- struct btree_iter *linked;
- struct btree *b = iter->nodes[level];
- enum btree_node_locked_type want = btree_lock_want(iter, level);
- enum btree_node_locked_type have = btree_node_locked_type(iter, level);
+ struct btree *b = iter->l[level].b;
- if (want == have)
- return true;
+ 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 (have != BTREE_NODE_UNLOCKED
- ? six_trylock_convert(&b->lock, have, want)
- : six_relock_type(&b->lock, want, iter->lock_seq[level]))
+ if (btree_node_locked(iter, level)
+ ? six_lock_tryupgrade(&b->c.lock)
+ : six_relock_type(&b->c.lock, SIX_LOCK_intent, iter->l[level].lock_seq))
goto success;
- for_each_linked_btree_iter(iter, linked)
- if (linked->nodes[level] == b &&
- btree_node_locked_type(linked, level) == want &&
- iter->lock_seq[level] == b->lock.state.seq) {
- btree_node_unlock(iter, level);
- six_lock_increment(&b->lock, want);
- goto success;
- }
+ if (btree_node_lock_seq_matches(iter, b, level) &&
+ btree_node_lock_increment(iter->trans, b, level, BTREE_NODE_INTENT_LOCKED)) {
+ btree_node_unlock(iter, level);
+ goto success;
+ }
return false;
success:
- mark_btree_node_unlocked(iter, level);
- mark_btree_node_locked(iter, level, want);
+ mark_btree_node_intent_locked(iter, level);
return true;
}
-/* Slowpath: */
-bool __bch2_btree_node_lock(struct btree *b, struct bpos pos,
- unsigned level,
- struct btree_iter *iter,
- enum six_lock_type type)
+static inline bool btree_iter_get_locks(struct btree_iter *iter, bool upgrade,
+ unsigned long trace_ip)
{
- struct btree_iter *linked;
+ unsigned l = iter->level;
+ int fail_idx = -1;
- /* Can't have children locked before ancestors: */
- EBUG_ON(iter->nodes_locked && level > __ffs(iter->nodes_locked));
-
- /*
- * Can't hold any read locks while we block taking an intent lock - see
- * below for reasoning, and we should have already dropped any read
- * locks in the current iterator
- */
- EBUG_ON(type == SIX_LOCK_intent &&
- iter->nodes_locked != iter->nodes_intent_locked);
+ do {
+ if (!btree_iter_node(iter, l))
+ break;
- for_each_linked_btree_iter(iter, linked)
- if (linked->nodes[level] == b &&
- btree_node_locked_type(linked, level) == type) {
- six_lock_increment(&b->lock, type);
- return true;
+ if (!(upgrade
+ ? bch2_btree_node_upgrade(iter, l)
+ : bch2_btree_node_relock(iter, l))) {
+ (upgrade
+ ? trace_node_upgrade_fail
+ : trace_node_relock_fail)(iter->trans->ip, trace_ip,
+ iter->btree_id, &iter->real_pos,
+ 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->c.lock.state.seq
+ : 0);
+
+ fail_idx = l;
+ btree_iter_set_dirty(iter, BTREE_ITER_NEED_TRAVERSE);
}
+ l++;
+ } while (l < iter->locks_want);
+
/*
- * Must lock btree nodes in key order - this case hapens when locking
- * the prev sibling in btree node merging:
+ * 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:
*/
- if (iter->nodes_locked &&
- __ffs(iter->nodes_locked) == level &&
- __btree_iter_cmp(iter->btree_id, pos, iter))
- return false;
+ 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;
- for_each_linked_btree_iter(iter, linked) {
+ bch2_btree_trans_verify_locks(iter->trans);
+
+ return iter->uptodate < BTREE_ITER_NEED_RELOCK;
+}
+
+static struct bpos btree_node_pos(struct btree_bkey_cached_common *_b,
+ enum btree_iter_type type)
+{
+ return type != BTREE_ITER_CACHED
+ ? container_of(_b, struct btree, c)->key.k.p
+ : container_of(_b, struct bkey_cached, c)->key.pos;
+}
+
+/* Slowpath: */
+bool __bch2_btree_node_lock(struct btree *b, struct bpos pos,
+ unsigned level, struct btree_iter *iter,
+ enum six_lock_type type,
+ six_lock_should_sleep_fn should_sleep_fn, void *p,
+ unsigned long ip)
+{
+ struct btree_trans *trans = iter->trans;
+ struct btree_iter *linked, *deadlock_iter = NULL;
+ u64 start_time = local_clock();
+ unsigned reason = 9;
+ bool ret;
+
+ /* Check if it's safe to block: */
+ trans_for_each_iter(trans, linked) {
if (!linked->nodes_locked)
continue;
*/
if (type == SIX_LOCK_intent &&
linked->nodes_locked != linked->nodes_intent_locked) {
- linked->locks_want = max_t(unsigned,
- linked->locks_want,
- iter->locks_want);
- return false;
+ deadlock_iter = linked;
+ reason = 1;
}
- /* We have to lock btree nodes in key order: */
- if (__btree_iter_cmp(iter->btree_id, pos, linked) < 0)
- return false;
+ if (linked->btree_id != iter->btree_id) {
+ if (linked->btree_id > iter->btree_id) {
+ deadlock_iter = linked;
+ reason = 3;
+ }
+ continue;
+ }
+
+ /*
+ * Within the same btree, cached iterators come before non
+ * cached iterators:
+ */
+ if (btree_iter_is_cached(linked) != btree_iter_is_cached(iter)) {
+ if (btree_iter_is_cached(iter)) {
+ deadlock_iter = linked;
+ reason = 4;
+ }
+ continue;
+ }
/*
* 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)) {
- linked->locks_want = max_t(unsigned,
- linked->locks_want,
- iter->locks_want);
- return false;
+ if (level > __fls(linked->nodes_locked)) {
+ deadlock_iter = linked;
+ reason = 5;
+ }
+
+ /* Must lock btree nodes in key order: */
+ if (btree_node_locked(linked, level) &&
+ bpos_cmp(pos, btree_node_pos((void *) linked->l[level].b,
+ btree_iter_type(linked))) <= 0) {
+ deadlock_iter = linked;
+ reason = 7;
+ BUG_ON(trans->in_traverse_all);
}
}
- six_lock_type(&b->lock, type);
- return true;
+ if (unlikely(deadlock_iter)) {
+ trace_trans_restart_would_deadlock(iter->trans->ip, ip,
+ trans->in_traverse_all, reason,
+ deadlock_iter->btree_id,
+ btree_iter_type(deadlock_iter),
+ &deadlock_iter->real_pos,
+ iter->btree_id,
+ btree_iter_type(iter),
+ &pos);
+ return false;
+ }
+
+ if (six_trylock_type(&b->c.lock, type))
+ return true;
+
+#ifdef CONFIG_BCACHEFS_DEBUG
+ trans->locking_iter_idx = iter->idx;
+ trans->locking_pos = pos;
+ trans->locking_btree_id = iter->btree_id;
+ trans->locking_level = level;
+ trans->locking = b;
+#endif
+
+ ret = six_lock_type(&b->c.lock, type, should_sleep_fn, p) == 0;
+
+#ifdef CONFIG_BCACHEFS_DEBUG
+ trans->locking = NULL;
+#endif
+ if (ret)
+ bch2_time_stats_update(&trans->c->times[lock_to_time_stat(type)],
+ start_time);
+ return ret;
}
/* Btree iterator locking: */
-
-static void btree_iter_drop_extra_locks(struct btree_iter *iter)
+#ifdef CONFIG_BCACHEFS_DEBUG
+static void bch2_btree_iter_verify_locks(struct btree_iter *iter)
{
unsigned l;
- while (iter->nodes_locked &&
- (l = __fls(iter->nodes_locked)) > iter->locks_want) {
- if (!btree_node_locked(iter, l))
- panic("l %u nodes_locked %u\n", l, iter->nodes_locked);
+ if (!(iter->trans->iters_linked & (1ULL << iter->idx))) {
+ BUG_ON(iter->nodes_locked);
+ return;
+ }
- if (l > iter->level) {
- btree_node_unlock(iter, l);
- } else if (btree_node_intent_locked(iter, l)) {
- six_lock_downgrade(&iter->nodes[l]->lock);
- iter->nodes_intent_locked ^= 1 << l;
- }
+ for (l = 0; is_btree_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));
}
}
-bool __bch2_btree_iter_set_locks_want(struct btree_iter *iter,
- unsigned new_locks_want)
+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);
+}
+#else
+static inline void bch2_btree_iter_verify_locks(struct btree_iter *iter) {}
+#endif
+
+__flatten
+static bool bch2_btree_iter_relock(struct btree_iter *iter, unsigned long trace_ip)
+{
+ return btree_iter_get_locks(iter, false, trace_ip);
+}
+
+bool __bch2_btree_iter_upgrade(struct btree_iter *iter,
+ unsigned new_locks_want)
{
struct btree_iter *linked;
- unsigned l;
- /* Drop locks we don't want anymore: */
- if (new_locks_want < iter->locks_want)
- for_each_linked_btree_iter(iter, linked)
- if (linked->locks_want > new_locks_want) {
- linked->locks_want = max_t(unsigned, 1,
- new_locks_want);
- btree_iter_drop_extra_locks(linked);
- }
+ EBUG_ON(iter->locks_want >= new_locks_want);
iter->locks_want = new_locks_want;
- btree_iter_drop_extra_locks(iter);
- for (l = iter->level; l < iter->locks_want && iter->nodes[l]; l++)
- if (!bch2_btree_node_relock(iter, l))
- goto fail;
+ if (btree_iter_get_locks(iter, true, _THIS_IP_))
+ return true;
- return true;
-fail:
/*
- * Just an optimization: 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:
+ * XXX: this is ugly - we'd prefer to not be mucking with other
+ * iterators in the btree_trans here.
+ *
+ * On failure to upgrade the iterator, setting iter->locks_want and
+ * calling get_locks() is sufficient to make bch2_btree_iter_traverse()
+ * get the locks we want on transaction restart.
+ *
+ * But if this iterator was a clone, on transaction restart what we did
+ * to this iterator isn't going to be preserved.
+ *
+ * Possibly we could add an iterator field for the parent iterator when
+ * an iterator is a copy - for now, we'll just upgrade any other
+ * iterators with the same btree id.
+ *
+ * The code below used to be needed to ensure ancestor nodes get locked
+ * before interior nodes - now that's handled by
+ * bch2_btree_iter_traverse_all().
*/
- for_each_linked_btree_iter(iter, linked)
- if (linked->btree_id == iter->btree_id &&
- btree_iter_cmp(linked, iter) <= 0)
- linked->locks_want = max_t(unsigned, linked->locks_want,
- new_locks_want);
+ trans_for_each_iter(iter->trans, linked)
+ if (linked != iter &&
+ btree_iter_type(linked) == btree_iter_type(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, _THIS_IP_);
+ }
+
return false;
}
-static void __bch2_btree_iter_unlock(struct btree_iter *iter)
+void __bch2_btree_iter_downgrade(struct btree_iter *iter,
+ unsigned new_locks_want)
+{
+ unsigned l;
+
+ EBUG_ON(iter->locks_want < new_locks_want);
+
+ iter->locks_want = new_locks_want;
+
+ while (iter->nodes_locked &&
+ (l = __fls(iter->nodes_locked)) >= iter->locks_want) {
+ if (l > iter->level) {
+ btree_node_unlock(iter, l);
+ } else {
+ if (btree_node_intent_locked(iter, l)) {
+ six_lock_downgrade(&iter->l[l].b->c.lock);
+ iter->nodes_intent_locked ^= 1 << l;
+ }
+ break;
+ }
+ }
+
+ bch2_btree_trans_verify_locks(iter->trans);
+}
+
+void bch2_trans_downgrade(struct btree_trans *trans)
{
- iter->flags &= ~BTREE_ITER_UPTODATE;
+ struct btree_iter *iter;
- while (iter->nodes_locked)
- btree_node_unlock(iter, __ffs(iter->nodes_locked));
+ trans_for_each_iter(trans, iter)
+ bch2_btree_iter_downgrade(iter);
}
-int bch2_btree_iter_unlock(struct btree_iter *iter)
+/* Btree transaction locking: */
+
+static inline bool btree_iter_should_be_locked(struct btree_trans *trans,
+ struct btree_iter *iter)
{
- struct btree_iter *linked;
+ return (iter->flags & BTREE_ITER_KEEP_UNTIL_COMMIT) ||
+ iter->should_be_locked;
+}
+
+bool bch2_trans_relock(struct btree_trans *trans)
+{
+ struct btree_iter *iter;
+
+ trans_for_each_iter(trans, iter)
+ if (!bch2_btree_iter_relock(iter, _RET_IP_) &&
+ btree_iter_should_be_locked(trans, iter)) {
+ trace_trans_restart_relock(trans->ip, _RET_IP_,
+ iter->btree_id, &iter->real_pos);
+ return false;
+ }
+ return true;
+}
- for_each_linked_btree_iter(iter, linked)
- __bch2_btree_iter_unlock(linked);
- __bch2_btree_iter_unlock(iter);
+void bch2_trans_unlock(struct btree_trans *trans)
+{
+ struct btree_iter *iter;
- return iter->flags & BTREE_ITER_ERROR ? -EIO : 0;
+ 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)
+static void bch2_btree_iter_verify_cached(struct btree_iter *iter)
{
- struct btree_node_iter *node_iter = &iter->node_iters[b->level];
- struct btree_node_iter tmp = *node_iter;
- struct bkey_packed *k;
+ struct bkey_cached *ck;
+ bool locked = btree_node_locked(iter, 0);
+
+ if (!bch2_btree_node_relock(iter, 0))
+ return;
+
+ ck = (void *) iter->l[0].b;
+ BUG_ON(ck->key.btree_id != iter->btree_id ||
+ bkey_cmp(ck->key.pos, iter->pos));
+
+ if (!locked)
+ btree_node_unlock(iter, 0);
+}
+
+static void bch2_btree_iter_verify_level(struct btree_iter *iter,
+ unsigned level)
+{
+ struct btree_iter_level *l;
+ struct btree_node_iter tmp;
+ bool locked;
+ struct bkey_packed *p, *k;
+ char buf1[100], buf2[100], buf3[100];
+ const char *msg;
+
+ if (!bch2_debug_check_iterators)
+ return;
+
+ l = &iter->l[level];
+ tmp = l->iter;
+ locked = btree_node_locked(iter, level);
+
+ if (btree_iter_type(iter) == BTREE_ITER_CACHED) {
+ if (!level)
+ bch2_btree_iter_verify_cached(iter);
+ return;
+ }
+
+ BUG_ON(iter->level < iter->min_depth);
+
+ if (!btree_iter_node(iter, level))
+ return;
+
+ if (!bch2_btree_node_relock(iter, level))
+ return;
+
+ BUG_ON(!btree_iter_pos_in_node(iter, l->b));
- bch2_btree_node_iter_verify(node_iter, b);
+ /*
+ * node iterators don't use leaf node iterator:
+ */
+ if (btree_iter_type(iter) == BTREE_ITER_NODES &&
+ level <= iter->min_depth)
+ goto unlock;
+
+ bch2_btree_node_iter_verify(&l->iter, l->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
- ? bch2_btree_node_iter_prev(&tmp, b)
- : bch2_btree_node_iter_prev_all(&tmp, b);
- if (k && btree_iter_pos_cmp_packed(b, &iter->pos, k,
- iter->flags & BTREE_ITER_IS_EXTENTS)) {
- char buf[100];
- struct bkey uk = bkey_unpack_key(b, k);
+ p = level || btree_node_type_is_extents(iter->btree_id)
+ ? 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, &iter->real_pos) >= 0) {
+ msg = "before";
+ goto err;
+ }
- bch2_bkey_to_text(buf, sizeof(buf), &uk);
- panic("prev key should be before after pos:\n%s\n%llu:%llu\n",
- buf, iter->pos.inode, iter->pos.offset);
+ if (k && bkey_iter_pos_cmp(l->b, k, &iter->real_pos) < 0) {
+ msg = "after";
+ goto err;
}
+unlock:
+ if (!locked)
+ btree_node_unlock(iter, level);
+ return;
+err:
+ strcpy(buf2, "(none)");
+ strcpy(buf3, "(none)");
- k = bch2_btree_node_iter_peek_all(node_iter, b);
- if (k && !btree_iter_pos_cmp_packed(b, &iter->pos, k,
- iter->flags & BTREE_ITER_IS_EXTENTS)) {
- char buf[100];
- struct bkey uk = bkey_unpack_key(b, k);
+ bch2_bpos_to_text(&PBUF(buf1), iter->real_pos);
+
+ if (p) {
+ struct bkey uk = bkey_unpack_key(l->b, p);
+ bch2_bkey_to_text(&PBUF(buf2), &uk);
+ }
- bch2_bkey_to_text(buf, sizeof(buf), &uk);
- panic("next key should be before iter pos:\n%llu:%llu\n%s\n",
- iter->pos.inode, iter->pos.offset, buf);
+ if (k) {
+ struct bkey uk = bkey_unpack_key(l->b, k);
+ bch2_bkey_to_text(&PBUF(buf3), &uk);
}
+
+ panic("iterator should be %s key at level %u:\n"
+ "iter pos %s\n"
+ "prev key %s\n"
+ "cur key %s\n",
+ msg, level, buf1, buf2, buf3);
}
-void bch2_btree_iter_verify(struct btree_iter *iter, struct btree *b)
+static void bch2_btree_iter_verify(struct btree_iter *iter)
{
- struct btree_iter *linked;
+ enum btree_iter_type type = btree_iter_type(iter);
+ unsigned i;
+
+ EBUG_ON(iter->btree_id >= BTREE_ID_NR);
+
+ BUG_ON(!(iter->flags & BTREE_ITER_ALL_SNAPSHOTS) &&
+ iter->pos.snapshot != iter->snapshot);
+
+ BUG_ON((iter->flags & BTREE_ITER_IS_EXTENTS) &&
+ (iter->flags & BTREE_ITER_ALL_SNAPSHOTS));
+
+ BUG_ON(type == BTREE_ITER_NODES &&
+ !(iter->flags & BTREE_ITER_ALL_SNAPSHOTS));
+
+ BUG_ON(type != BTREE_ITER_NODES &&
+ (iter->flags & BTREE_ITER_ALL_SNAPSHOTS) &&
+ !btree_type_has_snapshots(iter->btree_id));
+
+ bch2_btree_iter_verify_locks(iter);
+
+ for (i = 0; i < BTREE_MAX_DEPTH; i++)
+ bch2_btree_iter_verify_level(iter, i);
+}
+
+static void bch2_btree_iter_verify_entry_exit(struct btree_iter *iter)
+{
+ enum btree_iter_type type = btree_iter_type(iter);
- if (iter->nodes[b->level] == b)
- __bch2_btree_iter_verify(iter, b);
+ BUG_ON(!(iter->flags & BTREE_ITER_ALL_SNAPSHOTS) &&
+ iter->pos.snapshot != iter->snapshot);
- for_each_linked_btree_node(iter, b, linked)
- __bch2_btree_iter_verify(iter, b);
+ BUG_ON((type == BTREE_ITER_KEYS ||
+ type == BTREE_ITER_CACHED) &&
+ (bkey_cmp(iter->pos, bkey_start_pos(&iter->k)) < 0 ||
+ bkey_cmp(iter->pos, iter->k.p) > 0));
}
+void bch2_btree_trans_verify_iters(struct btree_trans *trans, struct btree *b)
+{
+ struct btree_iter *iter;
+
+ if (!bch2_debug_check_iterators)
+ return;
+
+ trans_for_each_iter_with_node(trans, b, iter)
+ bch2_btree_iter_verify_level(iter, b->c.level);
+}
+
+#else
+
+static inline void bch2_btree_iter_verify_level(struct btree_iter *iter, unsigned l) {}
+static inline void bch2_btree_iter_verify(struct btree_iter *iter) {}
+static inline void bch2_btree_iter_verify_entry_exit(struct btree_iter *iter) {}
+
#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_iter_fix_key_modified(struct btree_iter *iter,
+ struct btree *b,
+ struct bkey_packed *where)
+{
+ struct btree_iter_level *l = &iter->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, &iter->real_pos) < 0)
+ bch2_btree_node_iter_advance(&l->iter, l->b);
+
+ btree_iter_set_dirty(iter, BTREE_ITER_NEED_PEEK);
+}
+
+void bch2_btree_iter_fix_key_modified(struct btree_iter *iter,
+ struct btree *b,
+ struct bkey_packed *where)
+{
+ struct btree_iter *linked;
+
+ trans_for_each_iter_with_node(iter->trans, b, linked) {
+ __bch2_btree_iter_fix_key_modified(linked, b, where);
+ bch2_btree_iter_verify_level(linked, b->c.level);
+ }
+}
+
static void __bch2_btree_node_iter_fix(struct btree_iter *iter,
struct btree *b,
struct btree_node_iter *node_iter,
struct btree_node_iter_set *set;
unsigned offset = __btree_node_key_to_offset(b, where);
int shift = new_u64s - clobber_u64s;
- unsigned old_end = (int) __btree_node_key_to_offset(b, end) - shift;
+ 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)
/* didn't find the bset in the iterator - might have to readd it: */
if (new_u64s &&
- btree_iter_pos_cmp_packed(b, &iter->pos, where,
- iter->flags & BTREE_ITER_IS_EXTENTS))
+ bkey_iter_pos_cmp(b, where, &iter->real_pos) >= 0) {
bch2_btree_node_iter_push(node_iter, b, where, end);
- return;
+ goto fixup_done;
+ } else {
+ /* Iterator is after key that changed */
+ return;
+ }
found:
- set->end = (int) set->end + shift;
+ 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_packed(b, &iter->pos, where,
- iter->flags & BTREE_ITER_IS_EXTENTS)) {
+ bkey_iter_pos_cmp(b, where, &iter->real_pos) >= 0) {
set->k = offset;
- bch2_btree_node_iter_sort(node_iter, b);
} else if (set->k < offset + clobber_u64s) {
set->k = offset + new_u64s;
if (set->k == set->end)
- *set = node_iter->data[--node_iter->used];
- bch2_btree_node_iter_sort(node_iter, b);
+ 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;
+
/*
- * Interior nodes are special because iterators for interior nodes don't
- * obey the usual invariants regarding the iterator position:
- *
- * We may have whiteouts that compare greater than the iterator
- * position, and logically should be in the iterator, but that we
- * skipped past to find the first live key greater than the iterator
- * position. This becomes an issue when we insert a new key that is
- * greater than the current iterator position, but smaller than the
- * whiteouts we've already skipped past - this happens in the course of
- * a btree split.
- *
- * We have to rewind the iterator past to before those whiteouts here,
- * else bkey_node_iter_prev() is not going to work and who knows what
- * else would happen. And we have to do it manually, because here we've
- * already done the insert and the iterator is currently inconsistent:
- *
- * We've got multiple competing invariants, here - we have to be careful
- * about rewinding iterators for interior nodes, because they should
- * always point to the key for the child node the btree iterator points
- * to.
+ * 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 (b->level && new_u64s && !bkey_deleted(where) &&
- btree_iter_pos_cmp_packed(b, &iter->pos, where,
- iter->flags & BTREE_ITER_IS_EXTENTS)) {
+ if (!bch2_btree_node_iter_end(node_iter) &&
+ iter_current_key_modified &&
+ (b->c.level ||
+ btree_node_type_is_extents(iter->btree_id))) {
struct bset_tree *t;
- struct bkey_packed *k;
+ struct bkey_packed *k, *k2, *p;
+
+ k = bch2_btree_node_iter_peek_all(node_iter, b);
for_each_bset(b, t) {
- if (bch2_bkey_to_bset(b, where) == t)
+ bool set_pos = false;
+
+ if (node_iter->data[0].end == t->end_offset)
continue;
- k = bch2_bkey_prev_all(b, t,
- bch2_btree_node_iter_bset_pos(node_iter, b, t));
- if (k &&
- __btree_node_iter_cmp(node_iter, b,
- k, where) > 0) {
- struct btree_node_iter_set *set;
- unsigned offset =
- __btree_node_key_to_offset(b, bkey_next(k));
-
- btree_node_iter_for_each(node_iter, set)
- if (set->k == offset) {
- set->k = __btree_node_key_to_offset(b, k);
- bch2_btree_node_iter_sort(node_iter, b);
- goto next_bset;
- }
-
- bch2_btree_node_iter_push(node_iter, b, k,
- btree_bkey_last(b, t));
+ 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;
}
-next_bset:
- t = t;
+
+ if (set_pos)
+ btree_node_iter_set_set_pos(node_iter,
+ b, t, k2);
}
}
+
+ if (!b->c.level &&
+ node_iter == &iter->l[0].iter &&
+ iter_current_key_modified)
+ btree_iter_set_dirty(iter, BTREE_ITER_NEED_PEEK);
}
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)
+ 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->node_iters[b->level])
+ if (node_iter != &iter->l[b->c.level].iter) {
__bch2_btree_node_iter_fix(iter, b, node_iter, t,
- where, clobber_u64s, new_u64s);
+ where, clobber_u64s, new_u64s);
- if (iter->nodes[b->level] == b)
- __bch2_btree_node_iter_fix(iter, b,
- &iter->node_iters[b->level], t,
- where, clobber_u64s, new_u64s);
+ if (bch2_debug_check_iterators)
+ bch2_btree_node_iter_verify(node_iter, b);
+ }
- for_each_linked_btree_node(iter, b, linked)
+ trans_for_each_iter_with_node(iter->trans, b, linked) {
__bch2_btree_node_iter_fix(linked, b,
- &linked->node_iters[b->level], t,
- where, clobber_u64s, new_u64s);
-
- /* interior node iterators are... special... */
- if (!b->level)
- bch2_btree_iter_verify(iter, b);
+ &linked->l[b->c.level].iter, t,
+ where, clobber_u64s, new_u64s);
+ bch2_btree_iter_verify_level(linked, b->c.level);
+ }
}
-/* peek_all() doesn't skip deleted keys */
-static inline struct bkey_s_c __btree_iter_peek_all(struct btree_iter *iter)
+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 btree *b = iter->nodes[iter->level];
- struct bkey_packed *k =
- bch2_btree_node_iter_peek_all(&iter->node_iters[iter->level], b);
struct bkey_s_c ret;
- EBUG_ON(!btree_node_locked(iter, iter->level));
-
- if (!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;
+ }
- ret = bkey_disassemble(b, k, &iter->k);
+ ret = bkey_disassemble(l->b, k, u);
- if (debug_check_bkeys(iter->c))
- bch2_bkey_debugcheck(iter->c, b, ret);
+ /*
+ * XXX: bch2_btree_bset_insert_key() generates invalid keys when we
+ * overwrite extents - it sets k->type = KEY_TYPE_deleted on the key
+ * being overwritten but doesn't change k->size. But this is ok, because
+ * those keys are never written out, we just have to avoid a spurious
+ * assertion here:
+ */
+ if (bch2_debug_check_bkeys && !bkey_deleted(ret.k))
+ bch2_bkey_debugcheck(iter->trans->c, l->b, ret);
return ret;
}
-static inline struct bkey_s_c __btree_iter_peek(struct btree_iter *iter)
+/* peek_all() doesn't skip deleted keys */
+static inline struct bkey_s_c btree_iter_level_peek_all(struct btree_iter *iter,
+ struct btree_iter_level *l)
{
- struct btree *b = iter->nodes[iter->level];
- struct bkey_packed *k =
- bch2_btree_node_iter_peek(&iter->node_iters[iter->level], b);
- struct bkey_s_c ret;
-
- EBUG_ON(!btree_node_locked(iter, iter->level));
+ return __btree_iter_unpack(iter, l, &iter->k,
+ bch2_btree_node_iter_peek_all(&l->iter, l->b));
+}
- if (!k)
- return bkey_s_c_null;
+static inline struct bkey_s_c btree_iter_level_peek(struct btree_iter *iter,
+ struct btree_iter_level *l)
+{
+ struct bkey_s_c k = __btree_iter_unpack(iter, l, &iter->k,
+ bch2_btree_node_iter_peek(&l->iter, l->b));
- ret = bkey_disassemble(b, k, &iter->k);
+ iter->real_pos = k.k ? k.k->p : l->b->key.k.p;
+ return k;
+}
- if (debug_check_bkeys(iter->c))
- bch2_bkey_debugcheck(iter->c, b, ret);
+static inline struct bkey_s_c btree_iter_level_prev(struct btree_iter *iter,
+ struct btree_iter_level *l)
+{
+ struct bkey_s_c k = __btree_iter_unpack(iter, l, &iter->k,
+ bch2_btree_node_iter_prev(&l->iter, l->b));
- return ret;
+ iter->real_pos = k.k ? k.k->p : l->b->data->min_key;
+ return k;
}
-static inline void __btree_iter_advance(struct btree_iter *iter)
+static inline bool btree_iter_advance_to_pos(struct btree_iter *iter,
+ struct btree_iter_level *l,
+ int max_advance)
{
- bch2_btree_node_iter_advance(&iter->node_iters[iter->level],
- iter->nodes[iter->level]);
+ 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, &iter->real_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 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) ||
- !iter->nodes[b->level + 1])
+ if (!IS_ENABLED(CONFIG_BCACHEFS_DEBUG))
return;
- parent_locked = btree_node_locked(iter, b->level + 1);
+ plevel = b->c.level + 1;
+ if (!btree_iter_node(iter, plevel))
+ return;
+
+ parent_locked = btree_node_locked(iter, plevel);
- if (!bch2_btree_node_relock(iter, b->level + 1))
+ if (!bch2_btree_node_relock(iter, plevel))
return;
- k = bch2_btree_node_iter_peek_all(&iter->node_iters[b->level + 1],
- iter->nodes[b->level + 1]);
+ l = &iter->l[plevel];
+ k = bch2_btree_node_iter_peek_all(&l->iter, l->b);
if (!k ||
bkey_deleted(k) ||
- bkey_cmp_left_packed(iter->nodes[b->level + 1],
- k, &b->key.k.p)) {
- char buf[100];
+ bkey_cmp_left_packed(l->b, k, &b->key.k.p)) {
+ char buf1[100];
+ char buf2[100];
+ char buf3[100];
+ char buf4[100];
struct bkey uk = bkey_unpack_key(b, k);
- bch2_bkey_to_text(buf, sizeof(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);
+ bch2_dump_btree_node(iter->trans->c, l->b);
+ bch2_bpos_to_text(&PBUF(buf1), iter->real_pos);
+ bch2_bkey_to_text(&PBUF(buf2), &uk);
+ bch2_bpos_to_text(&PBUF(buf3), b->data->min_key);
+ bch2_bpos_to_text(&PBUF(buf3), b->data->max_key);
+ panic("parent iter doesn't point to new node:\n"
+ "iter pos %s %s\n"
+ "iter key %s\n"
+ "new node %s-%s\n",
+ bch2_btree_ids[iter->btree_id], buf1,
+ buf2, buf3, buf4);
}
if (!parent_locked)
- btree_node_unlock(iter, b->level + 1);
+ btree_node_unlock(iter, b->c.level + 1);
}
static inline void __btree_iter_init(struct btree_iter *iter,
- struct btree *b)
+ unsigned level)
{
- bch2_btree_node_iter_init(&iter->node_iters[b->level], b, iter->pos,
- iter->flags & BTREE_ITER_IS_EXTENTS,
- btree_node_is_extents(b));
+ struct btree_iter_level *l = &iter->l[level];
- /* Skip to first non whiteout: */
- if (b->level)
- bch2_btree_node_iter_peek(&iter->node_iters[b->level], b);
-}
+ bch2_btree_node_iter_init(&l->iter, l->b, &iter->real_pos);
-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_cmp(iter->pos, &b->key.k,
- iter->flags & BTREE_ITER_IS_EXTENTS);
+ /*
+ * Iterators to interior nodes should always be pointed at the 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)
{
+ BUG_ON(btree_iter_type(iter) == BTREE_ITER_CACHED);
+
btree_iter_verify_new_node(iter, b);
EBUG_ON(!btree_iter_pos_in_node(iter, b));
- EBUG_ON(b->lock.state.seq & 1);
+ EBUG_ON(b->c.lock.state.seq & 1);
- iter->lock_seq[b->level] = b->lock.state.seq;
- iter->nodes[b->level] = b;
- __btree_iter_init(iter, b);
+ iter->l[b->c.level].lock_seq = b->c.lock.state.seq;
+ iter->l[b->c.level].b = b;
+ __btree_iter_init(iter, b->c.level);
}
/*
* A btree node is being replaced - update the iterator to point to the new
* node:
*/
-bool bch2_btree_iter_node_replace(struct btree_iter *iter, struct btree *b)
+void bch2_btree_iter_node_replace(struct btree_iter *iter, struct btree *b)
{
+ enum btree_node_locked_type t;
struct btree_iter *linked;
- for_each_linked_btree_iter(iter, linked)
- if (btree_iter_pos_in_node(linked, b)) {
+ trans_for_each_iter(iter->trans, linked)
+ if (btree_iter_type(linked) != BTREE_ITER_CACHED &&
+ 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));
-
- /*
- * If @linked wants this node read locked, we don't want
- * to actually take the read lock now because it's not
- * legal to hold read locks on other nodes while we take
- * write locks, so the journal can make forward
- * progress...
- *
- * Instead, btree_iter_node_set() sets things up so
- * bch2_btree_node_relock() will succeed:
- */
+ BUG_ON(btree_node_locked(linked, b->c.level));
- if (btree_want_intent(linked, b->level)) {
- six_lock_increment(&b->lock, SIX_LOCK_intent);
- mark_btree_node_intent_locked(linked, b->level);
+ t = btree_lock_want(linked, b->c.level);
+ if (t != BTREE_NODE_UNLOCKED) {
+ six_lock_increment(&b->c.lock, t);
+ mark_btree_node_locked(linked, b->c.level, t);
}
btree_iter_node_set(linked, b);
}
-
- if (!btree_iter_pos_in_node(iter, b)) {
- six_unlock_intent(&b->lock);
- return false;
- }
-
- mark_btree_node_intent_locked(iter, b->level);
- btree_iter_node_set(iter, b);
- return true;
-}
-
-void bch2_btree_iter_node_drop_linked(struct btree_iter *iter, struct btree *b)
-{
- struct btree_iter *linked;
-
- for_each_linked_btree_iter(iter, linked)
- bch2_btree_iter_node_drop(linked, b);
}
void bch2_btree_iter_node_drop(struct btree_iter *iter, struct btree *b)
{
- unsigned level = b->level;
+ struct btree_iter *linked;
+ unsigned level = b->c.level;
- if (iter->nodes[level] == b) {
- iter->flags &= ~BTREE_ITER_UPTODATE;
- btree_node_unlock(iter, level);
- iter->nodes[level] = BTREE_ITER_NOT_END;
- }
+ 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;
+ }
}
/*
{
struct btree_iter *linked;
- for_each_linked_btree_node(iter, b, linked)
- __btree_iter_init(linked, b);
- __btree_iter_init(iter, b);
+ trans_for_each_iter_with_node(iter->trans, b, linked)
+ __btree_iter_init(linked, b->c.level);
+}
+
+static int lock_root_check_fn(struct six_lock *lock, void *p)
+{
+ struct btree *b = container_of(lock, struct btree, c.lock);
+ struct btree **rootp = p;
+
+ return b == *rootp ? 0 : -1;
}
static inline int btree_iter_lock_root(struct btree_iter *iter,
- unsigned depth_want)
+ unsigned depth_want,
+ unsigned long trace_ip)
{
- struct bch_fs *c = iter->c;
- struct btree *b;
+ struct bch_fs *c = iter->trans->c;
+ struct btree *b, **rootp = &c->btree_roots[iter->btree_id].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);
+ b = READ_ONCE(*rootp);
+ iter->level = READ_ONCE(b->c.level);
if (unlikely(iter->level < depth_want)) {
/*
* that depth
*/
iter->level = depth_want;
- iter->nodes[iter->level] = NULL;
- return 0;
+ for (i = iter->level; i < BTREE_MAX_DEPTH; i++)
+ iter->l[i].b = NULL;
+ return 1;
}
- lock_type = btree_lock_want(iter, iter->level);
+ lock_type = __btree_lock_want(iter, iter->level);
if (unlikely(!btree_node_lock(b, POS_MAX, iter->level,
- iter, lock_type)))
+ iter, lock_type,
+ lock_root_check_fn, rootp,
+ trace_ip)))
return -EINTR;
- if (likely(b == c->btree_roots[iter->btree_id].b &&
- b->level == iter->level &&
+ if (likely(b == READ_ONCE(*rootp) &&
+ b->c.level == iter->level &&
!race_fault())) {
for (i = 0; i < iter->level; i++)
- iter->nodes[i] = BTREE_ITER_NOT_END;
- iter->nodes[iter->level] = b;
+ 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);
+ six_unlock_type(&b->c.lock, lock_type);
}
}
noinline
static void btree_iter_prefetch(struct btree_iter *iter)
{
- struct btree *b = iter->nodes[iter->level + 1];
- struct btree_node_iter node_iter = iter->node_iters[iter->level + 1];
+ 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 = iter->level ? 1 : 8;
- bool was_locked = btree_node_locked(iter, iter->level + 1);
+ struct bkey_buf 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);
+
+ bch2_bkey_buf_init(&tmp);
while (nr) {
- if (!bch2_btree_node_relock(iter, iter->level + 1))
- return;
+ if (!bch2_btree_node_relock(iter, iter->level))
+ break;
- bch2_btree_node_iter_advance(&node_iter, b);
- k = bch2_btree_node_iter_peek(&node_iter, b);
+ 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(b, &tmp.k, k);
- bch2_btree_node_prefetch(iter->c, &tmp.k,
- iter->level, iter->btree_id);
+ bch2_bkey_buf_unpack(&tmp, c, l->b, k);
+ bch2_btree_node_prefetch(c, iter, tmp.k, iter->btree_id,
+ iter->level - 1);
}
if (!was_locked)
- btree_node_unlock(iter, iter->level + 1);
+ btree_node_unlock(iter, iter->level);
+
+ bch2_bkey_buf_exit(&tmp, c);
}
-static inline int btree_iter_down(struct btree_iter *iter)
+static noinline void btree_node_mem_ptr_set(struct btree_iter *iter,
+ unsigned plevel, struct btree *b)
{
+ struct btree_iter_level *l = &iter->l[plevel];
+ bool locked = btree_node_locked(iter, plevel);
+ struct bkey_packed *k;
+ struct bch_btree_ptr_v2 *bp;
+
+ if (!bch2_btree_node_relock(iter, 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(iter, plevel);
+}
+
+static __always_inline int btree_iter_down(struct btree_iter *iter,
+ unsigned long trace_ip)
+{
+ struct bch_fs *c = iter->trans->c;
+ struct btree_iter_level *l = &iter->l[iter->level];
struct btree *b;
- struct bkey_s_c k = __btree_iter_peek(iter);
unsigned level = iter->level - 1;
- enum six_lock_type lock_type = btree_lock_want(iter, level);
- BKEY_PADDED(k) tmp;
+ enum six_lock_type lock_type = __btree_lock_want(iter, level);
+ struct bkey_buf tmp;
+ int ret;
- bkey_reassemble(&tmp.k, k);
+ EBUG_ON(!btree_node_locked(iter, iter->level));
- b = bch2_btree_node_get(iter->c, iter, &tmp.k, level, lock_type);
- if (unlikely(IS_ERR(b)))
- return PTR_ERR(b);
+ bch2_bkey_buf_init(&tmp);
+ bch2_bkey_buf_unpack(&tmp, c, l->b,
+ bch2_btree_node_iter_peek(&l->iter, l->b));
+
+ b = bch2_btree_node_get(c, iter, tmp.k, level, lock_type, trace_ip);
+ ret = PTR_ERR_OR_ZERO(b);
+ if (unlikely(ret))
+ goto err;
- iter->level = level;
mark_btree_node_locked(iter, level, lock_type);
btree_iter_node_set(iter, b);
+ if (tmp.k->k.type == KEY_TYPE_btree_ptr_v2 &&
+ unlikely(b != btree_node_mem_ptr(tmp.k)))
+ btree_node_mem_ptr_set(iter, level + 1, b);
+
if (iter->flags & BTREE_ITER_PREFETCH)
btree_iter_prefetch(iter);
- return 0;
-}
+ if (btree_node_read_locked(iter, level + 1))
+ btree_node_unlock(iter, level + 1);
+ iter->level = level;
-static void btree_iter_up(struct btree_iter *iter)
-{
- btree_node_unlock(iter, iter->level++);
+ bch2_btree_iter_verify_locks(iter);
+err:
+ bch2_bkey_buf_exit(&tmp, c);
+ return ret;
}
-int __must_check __bch2_btree_iter_traverse(struct btree_iter *);
+static int btree_iter_traverse_one(struct btree_iter *, unsigned long);
-static int btree_iter_traverse_error(struct btree_iter *iter, int ret)
+static int __btree_iter_traverse_all(struct btree_trans *trans, int ret,
+ unsigned long trace_ip)
{
- struct bch_fs *c = iter->c;
- struct btree_iter *linked, *sorted_iters, **i;
+ struct bch_fs *c = trans->c;
+ struct btree_iter *iter;
+ u8 sorted[BTREE_ITER_MAX];
+ int i, nr_sorted = 0;
+ bool relock_fail;
+
+ if (trans->in_traverse_all)
+ return -EINTR;
+
+ trans->in_traverse_all = true;
retry_all:
- bch2_btree_iter_unlock(iter);
+ nr_sorted = 0;
+ relock_fail = false;
+
+ trans_for_each_iter(trans, iter) {
+ if (!bch2_btree_iter_relock(iter, _THIS_IP_))
+ relock_fail = true;
+ sorted[nr_sorted++] = iter->idx;
+ }
+
+ if (!relock_fail) {
+ trans->in_traverse_all = false;
+ return 0;
+ }
+
+#define btree_iter_cmp_by_idx(_l, _r) \
+ btree_iter_lock_cmp(&trans->iters[_l], &trans->iters[_r])
+
+ bubble_sort(sorted, nr_sorted, btree_iter_cmp_by_idx);
+#undef btree_iter_cmp_by_idx
+
+ for (i = nr_sorted - 2; i >= 0; --i) {
+ struct btree_iter *iter1 = trans->iters + sorted[i];
+ struct btree_iter *iter2 = trans->iters + sorted[i + 1];
+
+ if (iter1->btree_id == iter2->btree_id &&
+ iter1->locks_want < iter2->locks_want)
+ __bch2_btree_iter_upgrade(iter1, iter2->locks_want);
+ else if (!iter1->locks_want && iter2->locks_want)
+ __bch2_btree_iter_upgrade(iter1, 1);
+ }
- if (ret != -ENOMEM && ret != -EINTR)
- goto io_error;
+ bch2_trans_unlock(trans);
+ cond_resched();
- if (ret == -ENOMEM) {
+ if (unlikely(ret == -ENOMEM)) {
struct closure cl;
closure_init_stack(&cl);
} while (ret);
}
- /*
- * Linked iters are normally a circular singly linked list - break cycle
- * while we sort them:
- */
- linked = iter->next;
- iter->next = NULL;
- sorted_iters = NULL;
-
- while (linked) {
- iter = linked;
- linked = linked->next;
-
- i = &sorted_iters;
- while (*i && btree_iter_cmp(iter, *i) > 0)
- i = &(*i)->next;
-
- iter->next = *i;
- *i = iter;
+ if (unlikely(ret == -EIO)) {
+ trans->error = true;
+ goto out;
}
- /* Make list circular again: */
- iter = sorted_iters;
- while (iter->next)
- iter = iter->next;
- iter->next = sorted_iters;
+ BUG_ON(ret && ret != -EINTR);
/* Now, redo traversals in correct order: */
+ for (i = 0; i < nr_sorted; i++) {
+ unsigned idx = sorted[i];
- iter = sorted_iters;
- do {
-retry:
- ret = __bch2_btree_iter_traverse(iter);
- if (unlikely(ret)) {
- if (ret == -EINTR)
- goto retry;
- goto retry_all;
- }
+ /*
+ * sucessfully traversing one iterator can cause another to be
+ * unlinked, in btree_key_cache_fill()
+ */
+ if (!(trans->iters_linked & (1ULL << idx)))
+ continue;
- iter = iter->next;
- } while (iter != sorted_iters);
+ ret = btree_iter_traverse_one(&trans->iters[idx], _THIS_IP_);
+ if (ret)
+ goto retry_all;
+ }
- ret = btree_iter_linked(iter) ? -EINTR : 0;
+ if (hweight64(trans->iters_live) > 1)
+ ret = -EINTR;
+ else
+ trans_for_each_iter(trans, iter)
+ if (iter->flags & BTREE_ITER_KEEP_UNTIL_COMMIT) {
+ ret = -EINTR;
+ break;
+ }
out:
bch2_btree_cache_cannibalize_unlock(c);
+
+ trans->in_traverse_all = false;
+
+ trace_trans_traverse_all(trans->ip, trace_ip);
return ret;
-io_error:
- BUG_ON(ret != -EIO);
+}
- iter->flags |= BTREE_ITER_ERROR;
- iter->nodes[iter->level] = NULL;
- goto out;
+int bch2_btree_iter_traverse_all(struct btree_trans *trans)
+{
+ return __btree_iter_traverse_all(trans, 0, _RET_IP_);
+}
+
+static inline bool btree_iter_good_node(struct btree_iter *iter,
+ unsigned l, int check_pos)
+{
+ if (!is_btree_node(iter, l) ||
+ !bch2_btree_node_relock(iter, l))
+ return false;
+
+ if (check_pos < 0 && btree_iter_pos_before_node(iter, iter->l[l].b))
+ return false;
+ if (check_pos > 0 && btree_iter_pos_after_node(iter, iter->l[l].b))
+ return false;
+ return true;
+}
+
+static inline unsigned btree_iter_up_until_good_node(struct btree_iter *iter,
+ int check_pos)
+{
+ unsigned l = iter->level;
+
+ while (btree_iter_node(iter, l) &&
+ !btree_iter_good_node(iter, l, check_pos)) {
+ btree_node_unlock(iter, l);
+ iter->l[l].b = BTREE_ITER_NO_NODE_UP;
+ l++;
+ }
+
+ return l;
}
/*
* 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_btree_iter_unlock().
+ * stashed in the iterator and returned from bch2_trans_exit().
*/
-int __must_check __bch2_btree_iter_traverse(struct btree_iter *iter)
+static int btree_iter_traverse_one(struct btree_iter *iter,
+ unsigned long trace_ip)
{
unsigned depth_want = iter->level;
+ int ret = 0;
- if (unlikely(!iter->nodes[iter->level]))
- return 0;
-
- iter->flags &= ~(BTREE_ITER_UPTODATE|BTREE_ITER_AT_END_OF_LEAF);
-
- /* make sure we have all the intent locks we need - ugh */
- if (unlikely(iter->nodes[iter->level] &&
- iter->level + 1 < iter->locks_want)) {
- unsigned i;
+ /*
+ * if we need interior nodes locked, call btree_iter_relock() to make
+ * sure we walk back up enough that we lock them:
+ */
+ if (iter->uptodate == BTREE_ITER_NEED_RELOCK ||
+ iter->locks_want > 1)
+ bch2_btree_iter_relock(iter, _THIS_IP_);
- for (i = iter->level + 1;
- i < iter->locks_want && iter->nodes[i];
- i++)
- if (!bch2_btree_node_relock(iter, i)) {
- while (iter->nodes[iter->level] &&
- iter->level + 1 < iter->locks_want)
- btree_iter_up(iter);
- break;
- }
+ if (btree_iter_type(iter) == BTREE_ITER_CACHED) {
+ ret = bch2_btree_iter_traverse_cached(iter);
+ goto out;
}
- /*
- * If the current node isn't locked, go up until we have a locked node
- * or run out of nodes:
- */
- while (iter->nodes[iter->level] &&
- !(is_btree_node(iter, iter->level) &&
- bch2_btree_node_relock(iter, iter->level) &&
- btree_iter_pos_cmp(iter->pos,
- &iter->nodes[iter->level]->key.k,
- iter->flags & BTREE_ITER_IS_EXTENTS)))
- btree_iter_up(iter);
+ if (iter->uptodate < BTREE_ITER_NEED_RELOCK)
+ goto out;
- /*
- * If we've got a btree node locked (i.e. we aren't about to relock the
- * root) - advance its node iterator if necessary:
- */
- if (iter->nodes[iter->level]) {
- struct bkey_s_c k;
+ if (unlikely(iter->level >= BTREE_MAX_DEPTH))
+ goto out;
- while ((k = __btree_iter_peek_all(iter)).k &&
- !btree_iter_pos_cmp(iter->pos, k.k,
- iter->flags & BTREE_ITER_IS_EXTENTS))
- __btree_iter_advance(iter);
- }
+ iter->level = btree_iter_up_until_good_node(iter, 0);
/*
* Note: iter->nodes[iter->level] may be temporarily NULL here - that
* btree_iter_lock_root() comes next and that it can't fail
*/
while (iter->level > depth_want) {
- int ret = iter->nodes[iter->level]
- ? btree_iter_down(iter)
- : btree_iter_lock_root(iter, depth_want);
+ ret = btree_iter_node(iter, iter->level)
+ ? btree_iter_down(iter, trace_ip)
+ : btree_iter_lock_root(iter, depth_want, trace_ip);
if (unlikely(ret)) {
+ if (ret == 1) {
+ /*
+ * Got to the end of the btree (in
+ * BTREE_ITER_NODES mode)
+ */
+ ret = 0;
+ goto out;
+ }
+
iter->level = depth_want;
- iter->nodes[iter->level] = BTREE_ITER_NOT_END;
- return ret;
+
+ if (ret == -EIO) {
+ iter->flags |= BTREE_ITER_ERROR;
+ iter->l[iter->level].b =
+ BTREE_ITER_NO_NODE_ERROR;
+ } else {
+ iter->l[iter->level].b =
+ BTREE_ITER_NO_NODE_DOWN;
+ }
+ goto out;
}
}
- return 0;
+ iter->uptodate = BTREE_ITER_NEED_PEEK;
+out:
+ trace_iter_traverse(iter->trans->ip, trace_ip,
+ iter->btree_id, &iter->real_pos, ret);
+ bch2_btree_iter_verify(iter);
+ return ret;
}
-int __must_check bch2_btree_iter_traverse(struct btree_iter *iter)
+static int __must_check __bch2_btree_iter_traverse(struct btree_iter *iter)
{
+ struct btree_trans *trans = iter->trans;
int ret;
- ret = __bch2_btree_iter_traverse(iter);
+ ret = bch2_trans_cond_resched(trans) ?:
+ btree_iter_traverse_one(iter, _RET_IP_);
if (unlikely(ret))
- ret = btree_iter_traverse_error(iter, ret);
+ ret = __btree_iter_traverse_all(trans, ret, _RET_IP_);
return ret;
}
+/*
+ * Note:
+ * bch2_btree_iter_traverse() is for external users, btree_iter_traverse() is
+ * for internal btree iterator users
+ *
+ * bch2_btree_iter_traverse sets iter->real_pos to iter->pos,
+ * btree_iter_traverse() does not:
+ */
+static inline int __must_check
+btree_iter_traverse(struct btree_iter *iter)
+{
+ return iter->uptodate >= BTREE_ITER_NEED_RELOCK
+ ? __bch2_btree_iter_traverse(iter)
+ : 0;
+}
+
+int __must_check
+bch2_btree_iter_traverse(struct btree_iter *iter)
+{
+ int ret;
+
+ btree_iter_set_search_pos(iter, btree_iter_search_key(iter));
+
+ ret = btree_iter_traverse(iter);
+ if (ret)
+ return ret;
+
+ iter->should_be_locked = true;
+ return 0;
+}
+
/* Iterate across nodes (leaf and interior nodes) */
struct btree *bch2_btree_iter_peek_node(struct btree_iter *iter)
struct btree *b;
int ret;
- EBUG_ON(iter->flags & BTREE_ITER_IS_EXTENTS);
+ EBUG_ON(btree_iter_type(iter) != BTREE_ITER_NODES);
+ bch2_btree_iter_verify(iter);
- ret = bch2_btree_iter_traverse(iter);
+ ret = btree_iter_traverse(iter);
if (ret)
- return ERR_PTR(ret);
+ return NULL;
- b = iter->nodes[iter->level];
+ b = btree_iter_node(iter, iter->level);
+ if (!b)
+ return NULL;
- if (b) {
- EBUG_ON(bkey_cmp(b->key.k.p, iter->pos) < 0);
- iter->pos = b->key.k.p;
- }
+ BUG_ON(bpos_cmp(b->key.k.p, iter->pos) < 0);
+
+ iter->pos = iter->real_pos = b->key.k.p;
+
+ bch2_btree_iter_verify(iter);
+ iter->should_be_locked = true;
return b;
}
-struct btree *bch2_btree_iter_next_node(struct btree_iter *iter, unsigned depth)
+struct btree *bch2_btree_iter_next_node(struct btree_iter *iter)
{
struct btree *b;
int ret;
- EBUG_ON(iter->flags & BTREE_ITER_IS_EXTENTS);
+ EBUG_ON(btree_iter_type(iter) != BTREE_ITER_NODES);
+ bch2_btree_iter_verify(iter);
- btree_iter_up(iter);
-
- if (!iter->nodes[iter->level])
+ /* already got to end? */
+ if (!btree_iter_node(iter, iter->level))
return NULL;
- /* parent node usually won't be locked: redo traversal if necessary */
- ret = bch2_btree_iter_traverse(iter);
+ bch2_trans_cond_resched(iter->trans);
+
+ btree_node_unlock(iter, iter->level);
+ iter->l[iter->level].b = BTREE_ITER_NO_NODE_UP;
+ iter->level++;
+
+ btree_iter_set_dirty(iter, BTREE_ITER_NEED_TRAVERSE);
+ ret = btree_iter_traverse(iter);
if (ret)
return NULL;
- b = iter->nodes[iter->level];
+ /* got to end? */
+ b = btree_iter_node(iter, iter->level);
if (!b)
- return b;
+ return NULL;
+
+ if (bpos_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
+ */
+ btree_iter_set_search_pos(iter, bpos_successor(iter->pos));
- if (bkey_cmp(iter->pos, b->key.k.p) < 0) {
- /* Haven't gotten to the end of the parent node: */
+ /* Unlock to avoid screwing up our lock invariants: */
+ 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;
+ iter->level = iter->min_depth;
+ btree_iter_set_dirty(iter, BTREE_ITER_NEED_TRAVERSE);
+ bch2_btree_iter_verify(iter);
- ret = bch2_btree_iter_traverse(iter);
+ ret = btree_iter_traverse(iter);
if (ret)
return NULL;
- b = iter->nodes[iter->level];
+ b = iter->l[iter->level].b;
}
- iter->pos = b->key.k.p;
+ iter->pos = iter->real_pos = b->key.k.p;
+
+ bch2_btree_iter_verify(iter);
+ iter->should_be_locked = true;
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)
+static void btree_iter_set_search_pos(struct btree_iter *iter, struct bpos new_pos)
{
- struct btree *b = iter->nodes[0];
- struct btree_node_iter *node_iter = &iter->node_iters[0];
- struct bkey_packed *k;
+#ifdef CONFIG_BCACHEFS_DEBUG
+ struct bpos old_pos = iter->real_pos;
+#endif
+ int cmp = bpos_cmp(new_pos, iter->real_pos);
+ unsigned l = iter->level;
+
+ if (!cmp)
+ goto out;
- 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, b->key.k.p) > 0);
+ iter->real_pos = new_pos;
+ iter->should_be_locked = false;
- while ((k = bch2_btree_node_iter_peek_all(node_iter, b)) &&
- !btree_iter_pos_cmp_packed(b, &new_pos, k,
- iter->flags & BTREE_ITER_IS_EXTENTS))
- bch2_btree_node_iter_advance(node_iter, b);
+ if (unlikely(btree_iter_type(iter) == BTREE_ITER_CACHED)) {
+ btree_node_unlock(iter, 0);
+ iter->l[0].b = BTREE_ITER_NO_NODE_CACHED;
+ btree_iter_set_dirty(iter, BTREE_ITER_NEED_TRAVERSE);
+ return;
+ }
- if (!k &&
- !btree_iter_pos_cmp(new_pos, &b->key.k,
- iter->flags & BTREE_ITER_IS_EXTENTS))
- iter->flags |= BTREE_ITER_AT_END_OF_LEAF;
+ l = btree_iter_up_until_good_node(iter, cmp);
+
+ if (btree_iter_node(iter, l)) {
+ /*
+ * 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[l], 8))
+ __btree_iter_init(iter, l);
- iter->pos = new_pos;
- iter->flags &= ~BTREE_ITER_UPTODATE;
+ /* Don't leave it locked if we're not supposed to: */
+ if (btree_lock_want(iter, l) == BTREE_NODE_UNLOCKED)
+ btree_node_unlock(iter, l);
+ }
+out:
+ if (l != iter->level)
+ btree_iter_set_dirty(iter, BTREE_ITER_NEED_TRAVERSE);
+ else
+ btree_iter_set_dirty(iter, BTREE_ITER_NEED_PEEK);
+
+ bch2_btree_iter_verify(iter);
+#ifdef CONFIG_BCACHEFS_DEBUG
+ trace_iter_set_search_pos(iter->trans->ip, _RET_IP_,
+ iter->btree_id,
+ &old_pos, &new_pos, l);
+#endif
}
-void bch2_btree_iter_set_pos(struct btree_iter *iter, struct bpos new_pos)
+inline bool bch2_btree_iter_advance(struct btree_iter *iter)
{
- EBUG_ON(bkey_cmp(new_pos, iter->pos) < 0); /* XXX handle this */
- iter->pos = new_pos;
- iter->flags &= ~BTREE_ITER_UPTODATE;
+ struct bpos pos = iter->k.p;
+ bool ret = bpos_cmp(pos, POS_MAX) != 0;
+
+ if (ret && !(iter->flags & BTREE_ITER_IS_EXTENTS))
+ pos = bkey_successor(iter, pos);
+ bch2_btree_iter_set_pos(iter, pos);
+ return ret;
}
-void bch2_btree_iter_advance_pos(struct btree_iter *iter)
+inline bool bch2_btree_iter_rewind(struct btree_iter *iter)
{
- if (iter->flags & BTREE_ITER_UPTODATE &&
- !(iter->flags & BTREE_ITER_WITH_HOLES)) {
- struct bkey_s_c k;
+ struct bpos pos = bkey_start_pos(&iter->k);
+ bool ret = bpos_cmp(pos, POS_MIN) != 0;
- __btree_iter_advance(iter);
- k = __btree_iter_peek(iter);
- if (likely(k.k)) {
- iter->pos = bkey_start_pos(k.k);
- return;
- }
- }
+ if (ret && !(iter->flags & BTREE_ITER_IS_EXTENTS))
+ pos = bkey_predecessor(iter, pos);
+ bch2_btree_iter_set_pos(iter, pos);
+ return ret;
+}
+
+static inline bool btree_iter_set_pos_to_next_leaf(struct btree_iter *iter)
+{
+ struct bpos next_pos = iter->l[0].b->key.k.p;
+ bool ret = bpos_cmp(next_pos, POS_MAX) != 0;
/*
- * We use iter->k instead of iter->pos for extents: iter->pos will be
- * equal to the start of the extent we returned, but we need to advance
- * to the end of the extent we returned.
+ * Typically, we don't want to modify iter->pos here, since that
+ * indicates where we searched from - unless we got to the end of the
+ * btree, in that case we want iter->pos to reflect that:
*/
- bch2_btree_iter_set_pos(iter,
- btree_type_successor(iter->btree_id, iter->k.p));
+ if (ret)
+ btree_iter_set_search_pos(iter, bpos_successor(next_pos));
+ else
+ bch2_btree_iter_set_pos(iter, POS_MAX);
+
+ return ret;
}
-/* XXX: expensive */
-void bch2_btree_iter_rewind(struct btree_iter *iter, struct bpos pos)
+static inline bool btree_iter_set_pos_to_prev_leaf(struct btree_iter *iter)
{
- /* incapable of rewinding across nodes: */
- BUG_ON(bkey_cmp(pos, iter->nodes[iter->level]->data->min_key) < 0);
+ struct bpos next_pos = iter->l[0].b->data->min_key;
+ bool ret = bpos_cmp(next_pos, POS_MIN) != 0;
+
+ if (ret)
+ btree_iter_set_search_pos(iter, bpos_predecessor(next_pos));
+ else
+ bch2_btree_iter_set_pos(iter, POS_MIN);
+
+ return ret;
+}
+
+static inline struct bkey_i *btree_trans_peek_updates(struct btree_iter *iter,
+ struct bpos pos)
+{
+ struct btree_insert_entry *i;
+
+ if (!(iter->flags & BTREE_ITER_WITH_UPDATES))
+ return NULL;
+
+ trans_for_each_update(iter->trans, i)
+ if ((cmp_int(iter->btree_id, i->iter->btree_id) ?:
+ bkey_cmp(pos, i->k->k.p)) <= 0) {
+ if (iter->btree_id == i->iter->btree_id)
+ return i->k;
+ break;
+ }
- iter->pos = pos;
- iter->flags &= ~BTREE_ITER_UPTODATE;
- __btree_iter_init(iter, iter->nodes[iter->level]);
+ return NULL;
}
+/**
+ * bch2_btree_iter_peek: returns first key greater than or equal to iterator's
+ * current position
+ */
struct bkey_s_c bch2_btree_iter_peek(struct btree_iter *iter)
{
+ struct bpos search_key = btree_iter_search_key(iter);
+ struct bkey_i *next_update;
struct bkey_s_c k;
int ret;
- EBUG_ON(!!(iter->flags & BTREE_ITER_IS_EXTENTS) !=
- (iter->btree_id == BTREE_ID_EXTENTS));
+ EBUG_ON(btree_iter_type(iter) != BTREE_ITER_KEYS);
+ bch2_btree_iter_verify(iter);
+ bch2_btree_iter_verify_entry_exit(iter);
+start:
+ next_update = btree_trans_peek_updates(iter, search_key);
+ btree_iter_set_search_pos(iter, search_key);
- if (iter->flags & BTREE_ITER_UPTODATE) {
- struct btree *b = iter->nodes[0];
- struct bkey_packed *k =
- __bch2_btree_node_iter_peek_all(&iter->node_iters[0], b);
- struct bkey_s_c ret = {
- .k = &iter->k,
- .v = bkeyp_val(&b->format, k)
- };
+ while (1) {
+ ret = btree_iter_traverse(iter);
+ if (unlikely(ret))
+ return bkey_s_c_err(ret);
- EBUG_ON(!btree_node_locked(iter, 0));
+ k = btree_iter_level_peek(iter, &iter->l[0]);
- if (debug_check_bkeys(iter->c))
- bch2_bkey_debugcheck(iter->c, b, ret);
- return ret;
+ if (next_update &&
+ bpos_cmp(next_update->k.p, iter->real_pos) <= 0) {
+ iter->k = next_update->k;
+ k = bkey_i_to_s_c(next_update);
+ }
+
+ if (likely(k.k)) {
+ if (bkey_deleted(k.k)) {
+ search_key = bkey_successor(iter, k.k->p);
+ goto start;
+ }
+
+ break;
+ }
+
+ if (!btree_iter_set_pos_to_next_leaf(iter))
+ return bkey_s_c_null;
}
+ /*
+ * 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 if (bkey_cmp(bkey_start_pos(k.k), iter->pos) > 0)
+ iter->pos = bkey_start_pos(k.k);
+
+ bch2_btree_iter_verify_entry_exit(iter);
+ bch2_btree_iter_verify(iter);
+ iter->should_be_locked = true;
+ return k;
+}
+
+/**
+ * bch2_btree_iter_next: returns first key greater than iterator's current
+ * position
+ */
+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
+ */
+struct bkey_s_c bch2_btree_iter_peek_prev(struct btree_iter *iter)
+{
+ struct btree_iter_level *l = &iter->l[0];
+ struct bkey_s_c k;
+ int ret;
+
+ EBUG_ON(btree_iter_type(iter) != BTREE_ITER_KEYS);
+ EBUG_ON(iter->flags & BTREE_ITER_WITH_UPDATES);
+ bch2_btree_iter_verify(iter);
+ bch2_btree_iter_verify_entry_exit(iter);
+
+ btree_iter_set_search_pos(iter, iter->pos);
+
while (1) {
- ret = bch2_btree_iter_traverse(iter);
+ ret = btree_iter_traverse(iter);
if (unlikely(ret)) {
- iter->k = KEY(iter->pos.inode, iter->pos.offset, 0);
- return bkey_s_c_err(ret);
+ k = bkey_s_c_err(ret);
+ goto no_key;
}
- k = __btree_iter_peek(iter);
- if (likely(k.k)) {
- /*
- * 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);
+ k = btree_iter_level_peek(iter, l);
+ if (!k.k ||
+ ((iter->flags & BTREE_ITER_IS_EXTENTS)
+ ? bkey_cmp(bkey_start_pos(k.k), iter->pos) >= 0
+ : bkey_cmp(k.k->p, iter->pos) > 0))
+ k = btree_iter_level_prev(iter, l);
- iter->flags |= BTREE_ITER_UPTODATE;
- return k;
+ if (likely(k.k))
+ break;
+
+ if (!btree_iter_set_pos_to_prev_leaf(iter)) {
+ k = bkey_s_c_null;
+ goto no_key;
}
+ }
- iter->pos = iter->nodes[0]->key.k.p;
+ EBUG_ON(bkey_cmp(bkey_start_pos(k.k), iter->pos) > 0);
- if (!bkey_cmp(iter->pos, POS_MAX)) {
- iter->k = KEY(iter->pos.inode, iter->pos.offset, 0);
- bch2_btree_iter_unlock(iter);
- return bkey_s_c_null;
- }
+ /* Extents can straddle iter->pos: */
+ if (bkey_cmp(k.k->p, iter->pos) < 0)
+ iter->pos = k.k->p;
+out:
+ bch2_btree_iter_verify_entry_exit(iter);
+ bch2_btree_iter_verify(iter);
+ iter->should_be_locked = true;
+ return k;
+no_key:
+ /*
+ * btree_iter_level_peek() may have set iter->k to a key we didn't want, and
+ * then we errored going to the previous leaf - make sure it's
+ * consistent with iter->pos:
+ */
+ bkey_init(&iter->k);
+ iter->k.p = iter->pos;
+ goto out;
+}
- iter->pos = btree_type_successor(iter->btree_id, iter->pos);
- }
+/**
+ * bch2_btree_iter_prev: returns first key less than iterator's current
+ * position
+ */
+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_with_holes(struct btree_iter *iter)
+struct bkey_s_c bch2_btree_iter_peek_slot(struct btree_iter *iter)
{
+ struct bpos search_key;
struct bkey_s_c k;
- struct bkey n;
int ret;
- EBUG_ON(!!(iter->flags & BTREE_ITER_IS_EXTENTS) !=
- (iter->btree_id == BTREE_ID_EXTENTS));
+ EBUG_ON(btree_iter_type(iter) != BTREE_ITER_KEYS &&
+ btree_iter_type(iter) != BTREE_ITER_CACHED);
+ bch2_btree_iter_verify(iter);
+ bch2_btree_iter_verify_entry_exit(iter);
- iter->flags &= ~BTREE_ITER_UPTODATE;
+ /* 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;
- while (1) {
- ret = bch2_btree_iter_traverse(iter);
- if (unlikely(ret)) {
- iter->k = KEY(iter->pos.inode, iter->pos.offset, 0);
- return bkey_s_c_err(ret);
+ bch2_btree_iter_set_pos(iter, bpos_nosnap_successor(iter->pos));
+ }
+
+ search_key = btree_iter_search_key(iter);
+ btree_iter_set_search_pos(iter, search_key);
+
+ ret = btree_iter_traverse(iter);
+ if (unlikely(ret))
+ return bkey_s_c_err(ret);
+
+ if (btree_iter_type(iter) == BTREE_ITER_CACHED ||
+ !(iter->flags & BTREE_ITER_IS_EXTENTS)) {
+ struct bkey_i *next_update;
+ struct bkey_cached *ck;
+
+ switch (btree_iter_type(iter)) {
+ case BTREE_ITER_KEYS:
+ k = btree_iter_level_peek_all(iter, &iter->l[0]);
+ EBUG_ON(k.k && bkey_deleted(k.k) && bkey_cmp(k.k->p, iter->pos) == 0);
+ break;
+ case BTREE_ITER_CACHED:
+ ck = (void *) iter->l[0].b;
+ EBUG_ON(iter->btree_id != ck->key.btree_id ||
+ bkey_cmp(iter->pos, ck->key.pos));
+ BUG_ON(!ck->valid);
+
+ k = bkey_i_to_s_c(ck->k);
+ break;
+ case BTREE_ITER_NODES:
+ BUG();
}
- k = __btree_iter_peek_all(iter);
-recheck:
- if (!k.k || bkey_cmp(bkey_start_pos(k.k), iter->pos) > 0) {
- /* hole */
- bkey_init(&n);
- n.p = iter->pos;
-
- if (iter->flags & BTREE_ITER_IS_EXTENTS) {
- if (n.p.offset == KEY_OFFSET_MAX) {
- iter->pos = bkey_successor(iter->pos);
- goto recheck;
- }
+ next_update = btree_trans_peek_updates(iter, search_key);
+ if (next_update &&
+ (!k.k || bpos_cmp(next_update->k.p, k.k->p) <= 0)) {
+ iter->k = next_update->k;
+ k = bkey_i_to_s_c(next_update);
+ }
+ } else {
+ if ((iter->flags & BTREE_ITER_INTENT)) {
+ struct btree_iter *child =
+ btree_iter_child_alloc(iter, _THIS_IP_);
- if (!k.k)
- k.k = &iter->nodes[0]->key.k;
+ btree_iter_copy(child, iter);
+ k = bch2_btree_iter_peek(child);
- 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));
+ if (k.k && !bkey_err(k))
+ iter->k = child->k;
+ } else {
+ struct bpos pos = iter->pos;
- EBUG_ON(!n.size);
- }
+ k = bch2_btree_iter_peek(iter);
+ iter->pos = pos;
+ }
- iter->k = n;
- return (struct bkey_s_c) { &iter->k, NULL };
- } else if (!bkey_deleted(k.k)) {
+ if (unlikely(bkey_err(k)))
return k;
- } else {
- __btree_iter_advance(iter);
+ }
+
+ if (!(iter->flags & BTREE_ITER_IS_EXTENTS)) {
+ if (!k.k ||
+ ((iter->flags & BTREE_ITER_ALL_SNAPSHOTS)
+ ? bpos_cmp(iter->pos, k.k->p)
+ : bkey_cmp(iter->pos, k.k->p))) {
+ bkey_init(&iter->k);
+ iter->k.p = iter->pos;
+ k = (struct bkey_s_c) { &iter->k, NULL };
+ }
+ } else {
+ struct bpos next = k.k ? bkey_start_pos(k.k) : POS_MAX;
+
+ if (bkey_cmp(iter->pos, next) < 0) {
+ bkey_init(&iter->k);
+ iter->k.p = iter->pos;
+ bch2_key_resize(&iter->k,
+ min_t(u64, KEY_SIZE_MAX,
+ (next.inode == iter->pos.inode
+ ? next.offset
+ : KEY_OFFSET_MAX) -
+ iter->pos.offset));
+
+ k = (struct bkey_s_c) { &iter->k, NULL };
+ EBUG_ON(!k.k->size);
}
}
+
+ bch2_btree_iter_verify_entry_exit(iter);
+ bch2_btree_iter_verify(iter);
+ iter->should_be_locked = true;
+
+ return k;
}
-void __bch2_btree_iter_init(struct btree_iter *iter, struct bch_fs *c,
- enum btree_id btree_id, struct bpos pos,
- unsigned locks_want, unsigned depth,
- unsigned flags)
+struct bkey_s_c bch2_btree_iter_next_slot(struct btree_iter *iter)
{
- EBUG_ON(depth >= BTREE_MAX_DEPTH);
- EBUG_ON(locks_want > BTREE_MAX_DEPTH);
+ if (!bch2_btree_iter_advance(iter))
+ return bkey_s_c_null;
+
+ return bch2_btree_iter_peek_slot(iter);
+}
- iter->c = c;
- iter->pos = pos;
- iter->flags = flags;
+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);
+}
+
+static inline void bch2_btree_iter_init(struct btree_trans *trans,
+ struct btree_iter *iter, enum btree_id btree_id)
+{
+ struct bch_fs *c = trans->c;
+ unsigned i;
+
+ iter->trans = trans;
+ iter->uptodate = BTREE_ITER_NEED_TRAVERSE;
iter->btree_id = btree_id;
- iter->level = depth;
- iter->locks_want = locks_want;
+ iter->real_pos = POS_MIN;
+ iter->level = 0;
+ iter->min_depth = 0;
+ iter->locks_want = 0;
iter->nodes_locked = 0;
iter->nodes_intent_locked = 0;
- memset(iter->nodes, 0, sizeof(iter->nodes));
- iter->nodes[iter->level] = BTREE_ITER_NOT_END;
- iter->next = iter;
+ for (i = 0; i < ARRAY_SIZE(iter->l); i++)
+ iter->l[i].b = BTREE_ITER_NO_NODE_INIT;
prefetch(c->btree_roots[btree_id].b);
}
-void bch2_btree_iter_unlink(struct btree_iter *iter)
+/* new transactional stuff: */
+
+static void btree_iter_child_free(struct btree_iter *iter)
{
- struct btree_iter *linked;
+ struct btree_iter *child = btree_iter_child(iter);
- __bch2_btree_iter_unlock(iter);
+ if (child) {
+ bch2_trans_iter_free(iter->trans, child);
+ iter->child_idx = U8_MAX;
+ }
+}
- if (!btree_iter_linked(iter))
- return;
+static struct btree_iter *btree_iter_child_alloc(struct btree_iter *iter,
+ unsigned long ip)
+{
+ struct btree_trans *trans = iter->trans;
+ struct btree_iter *child = btree_iter_child(iter);
- for_each_linked_btree_iter(iter, linked) {
+ if (!child) {
+ child = btree_trans_iter_alloc(trans);
+ child->ip_allocated = ip;
+ iter->child_idx = child->idx;
- if (linked->next == iter) {
- linked->next = iter->next;
- return;
- }
+ trans->iters_live |= 1ULL << child->idx;
+ trans->iters_touched |= 1ULL << child->idx;
}
- BUG();
+ return child;
+}
+
+static inline void __bch2_trans_iter_free(struct btree_trans *trans,
+ unsigned idx)
+{
+ btree_iter_child_free(&trans->iters[idx]);
+
+ __bch2_btree_iter_unlock(&trans->iters[idx]);
+ trans->iters_linked &= ~(1ULL << idx);
+ trans->iters_live &= ~(1ULL << idx);
+ trans->iters_touched &= ~(1ULL << idx);
+}
+
+int bch2_trans_iter_put(struct btree_trans *trans,
+ struct btree_iter *iter)
+{
+ int ret;
+
+ if (IS_ERR_OR_NULL(iter))
+ return 0;
+
+ BUG_ON(trans->iters + iter->idx != iter);
+ BUG_ON(!btree_iter_live(trans, iter));
+
+ ret = btree_iter_err(iter);
+
+ if (!(trans->iters_touched & (1ULL << iter->idx)) &&
+ !(iter->flags & BTREE_ITER_KEEP_UNTIL_COMMIT))
+ __bch2_trans_iter_free(trans, iter->idx);
+
+ trans->iters_live &= ~(1ULL << iter->idx);
+ return ret;
}
-void bch2_btree_iter_link(struct btree_iter *iter, struct btree_iter *new)
+int bch2_trans_iter_free(struct btree_trans *trans,
+ struct btree_iter *iter)
{
- BUG_ON(btree_iter_linked(new));
+ if (IS_ERR_OR_NULL(iter))
+ return 0;
- new->next = iter->next;
- iter->next = new;
+ set_btree_iter_dontneed(trans, iter);
- if (IS_ENABLED(CONFIG_BCACHEFS_DEBUG)) {
- unsigned nr_iters = 1;
+ return bch2_trans_iter_put(trans, iter);
+}
- for_each_linked_btree_iter(iter, new)
- nr_iters++;
+noinline __cold
+static void btree_trans_iter_alloc_fail(struct btree_trans *trans)
+{
- BUG_ON(nr_iters > SIX_LOCK_MAX_RECURSE);
+ struct btree_iter *iter;
+ struct btree_insert_entry *i;
+ char buf[100];
+
+ trans_for_each_iter(trans, iter)
+ printk(KERN_ERR "iter: btree %s pos %s%s%s%s %pS\n",
+ bch2_btree_ids[iter->btree_id],
+ (bch2_bpos_to_text(&PBUF(buf), iter->pos), buf),
+ btree_iter_live(trans, iter) ? " live" : "",
+ (trans->iters_touched & (1ULL << iter->idx)) ? " touched" : "",
+ iter->flags & BTREE_ITER_KEEP_UNTIL_COMMIT ? " keep" : "",
+ (void *) iter->ip_allocated);
+
+ trans_for_each_update(trans, i) {
+ char buf[300];
+
+ bch2_bkey_val_to_text(&PBUF(buf), trans->c, bkey_i_to_s_c(i->k));
+ printk(KERN_ERR "update: btree %s %s\n",
+ bch2_btree_ids[i->iter->btree_id], buf);
}
+ panic("trans iter oveflow\n");
+}
+
+static struct btree_iter *btree_trans_iter_alloc(struct btree_trans *trans)
+{
+ struct btree_iter *iter;
+ unsigned idx;
+
+ if (unlikely(trans->iters_linked ==
+ ~((~0ULL << 1) << (BTREE_ITER_MAX - 1))))
+ btree_trans_iter_alloc_fail(trans);
+
+ idx = __ffs64(~trans->iters_linked);
+ iter = &trans->iters[idx];
+
+ iter->trans = trans;
+ iter->idx = idx;
+ iter->child_idx = U8_MAX;
+ iter->flags = 0;
+ iter->nodes_locked = 0;
+ iter->nodes_intent_locked = 0;
+ trans->iters_linked |= 1ULL << idx;
+ return iter;
}
-void bch2_btree_iter_copy(struct btree_iter *dst, struct btree_iter *src)
+static void btree_iter_copy(struct btree_iter *dst, struct btree_iter *src)
{
+ unsigned i;
+
__bch2_btree_iter_unlock(dst);
- memcpy(dst, src, offsetof(struct btree_iter, next));
- dst->nodes_locked = dst->nodes_intent_locked = 0;
+ btree_iter_child_free(dst);
+
+ memcpy(&dst->flags, &src->flags,
+ sizeof(struct btree_iter) - offsetof(struct btree_iter, flags));
+
+ for (i = 0; i < BTREE_MAX_DEPTH; i++)
+ if (btree_node_locked(dst, i))
+ six_lock_increment(&dst->l[i].b->c.lock,
+ __btree_lock_want(dst, i));
+
+ dst->flags &= ~BTREE_ITER_KEEP_UNTIL_COMMIT;
+ dst->flags &= ~BTREE_ITER_SET_POS_AFTER_COMMIT;
+}
+
+struct btree_iter *__bch2_trans_get_iter(struct btree_trans *trans,
+ unsigned btree_id, struct bpos pos,
+ unsigned locks_want,
+ unsigned depth,
+ unsigned flags)
+{
+ struct btree_iter *iter, *best = NULL;
+ struct bpos real_pos, pos_min = POS_MIN;
+
+ if ((flags & BTREE_ITER_TYPE) != BTREE_ITER_NODES &&
+ btree_node_type_is_extents(btree_id) &&
+ !(flags & BTREE_ITER_NOT_EXTENTS) &&
+ !(flags & BTREE_ITER_ALL_SNAPSHOTS))
+ flags |= BTREE_ITER_IS_EXTENTS;
+
+ if ((flags & BTREE_ITER_TYPE) != BTREE_ITER_NODES &&
+ !btree_type_has_snapshots(btree_id))
+ flags &= ~BTREE_ITER_ALL_SNAPSHOTS;
+
+ if (!(flags & BTREE_ITER_ALL_SNAPSHOTS))
+ pos.snapshot = btree_type_has_snapshots(btree_id)
+ ? U32_MAX : 0;
+
+ real_pos = pos;
+
+ if ((flags & BTREE_ITER_IS_EXTENTS) &&
+ bkey_cmp(pos, POS_MAX))
+ real_pos = bpos_nosnap_successor(pos);
+
+ trans_for_each_iter(trans, iter) {
+ if (btree_iter_type(iter) != (flags & BTREE_ITER_TYPE))
+ continue;
+
+ if (iter->btree_id != btree_id)
+ continue;
+
+ if (best) {
+ int cmp = bkey_cmp(bpos_diff(best->real_pos, real_pos),
+ bpos_diff(iter->real_pos, real_pos));
+
+ if (cmp < 0 ||
+ ((cmp == 0 && btree_iter_keep(trans, iter))))
+ continue;
+ }
+
+ best = iter;
+ }
+
+ if (!best) {
+ iter = btree_trans_iter_alloc(trans);
+ bch2_btree_iter_init(trans, iter, btree_id);
+ } else if (btree_iter_keep(trans, best)) {
+ iter = btree_trans_iter_alloc(trans);
+ btree_iter_copy(iter, best);
+ } else {
+ iter = best;
+ }
+
+ trans->iters_live |= 1ULL << iter->idx;
+ trans->iters_touched |= 1ULL << iter->idx;
+
+ iter->flags = flags;
+
+ iter->snapshot = pos.snapshot;
+
+ /*
+ * If the iterator has locks_want greater than requested, we explicitly
+ * do not 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 an explicit
+ * bch2_trans_downgrade().
+ */
+
+ locks_want = min(locks_want, BTREE_MAX_DEPTH);
+ if (locks_want > iter->locks_want) {
+ iter->locks_want = locks_want;
+ btree_iter_get_locks(iter, true, _THIS_IP_);
+ }
+
+ while (iter->level != depth) {
+ btree_node_unlock(iter, iter->level);
+ iter->l[iter->level].b = BTREE_ITER_NO_NODE_INIT;
+ iter->uptodate = BTREE_ITER_NEED_TRAVERSE;
+ if (iter->level < depth)
+ iter->level++;
+ else
+ iter->level--;
+ }
+
+ iter->min_depth = depth;
+
+ bch2_btree_iter_set_pos(iter, pos);
+ btree_iter_set_search_pos(iter, real_pos);
+
+ trace_trans_get_iter(_RET_IP_, trans->ip,
+ btree_id,
+ &real_pos, locks_want, iter->uptodate,
+ best ? &best->real_pos : &pos_min,
+ best ? best->locks_want : U8_MAX,
+ best ? best->uptodate : U8_MAX);
+
+ 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 =
+ __bch2_trans_get_iter(trans, btree_id, pos,
+ locks_want, depth,
+ BTREE_ITER_NODES|
+ BTREE_ITER_NOT_EXTENTS|
+ BTREE_ITER_ALL_SNAPSHOTS|
+ flags);
+
+ BUG_ON(bkey_cmp(iter->pos, pos));
+ BUG_ON(iter->locks_want != min(locks_want, BTREE_MAX_DEPTH));
+ BUG_ON(iter->level != depth);
+ BUG_ON(iter->min_depth != depth);
+ iter->ip_allocated = _RET_IP_;
+
+ return iter;
+}
+
+struct btree_iter *__bch2_trans_copy_iter(struct btree_trans *trans,
+ struct btree_iter *src)
+{
+ struct btree_iter *iter;
+
+ iter = btree_trans_iter_alloc(trans);
+ btree_iter_copy(iter, src);
+
+ trans->iters_live |= 1ULL << iter->idx;
+ /*
+ * We don't need to preserve this iter since it's cheap to copy it
+ * again - this will cause trans_iter_put() to free it right away:
+ */
+ set_btree_iter_dontneed(trans, iter);
+
+ return iter;
+}
+
+void *bch2_trans_kmalloc(struct btree_trans *trans, size_t size)
+{
+ size_t new_top = trans->mem_top + size;
+ void *p;
+
+ if (new_top > trans->mem_bytes) {
+ size_t old_bytes = trans->mem_bytes;
+ size_t new_bytes = roundup_pow_of_two(new_top);
+ void *new_mem;
+
+ WARN_ON_ONCE(new_bytes > BTREE_TRANS_MEM_MAX);
+
+ new_mem = krealloc(trans->mem, new_bytes, GFP_NOFS);
+ if (!new_mem && new_bytes <= BTREE_TRANS_MEM_MAX) {
+ new_mem = mempool_alloc(&trans->c->btree_trans_mem_pool, GFP_KERNEL);
+ new_bytes = BTREE_TRANS_MEM_MAX;
+ kfree(trans->mem);
+ }
+
+ if (!new_mem)
+ return ERR_PTR(-ENOMEM);
+
+ trans->mem = new_mem;
+ trans->mem_bytes = new_bytes;
+
+ if (old_bytes) {
+ trace_trans_restart_mem_realloced(trans->ip, _RET_IP_, new_bytes);
+ return ERR_PTR(-EINTR);
+ }
+ }
+
+ p = trans->mem + trans->mem_top;
+ trans->mem_top += size;
+ memset(p, 0, size);
+ return p;
+}
+
+inline void bch2_trans_unlink_iters(struct btree_trans *trans)
+{
+ u64 iters = trans->iters_linked &
+ ~trans->iters_touched &
+ ~trans->iters_live;
+
+ while (iters) {
+ unsigned idx = __ffs64(iters);
+
+ iters &= ~(1ULL << idx);
+ __bch2_trans_iter_free(trans, idx);
+ }
+}
+
+void bch2_trans_reset(struct btree_trans *trans, unsigned flags)
+{
+ struct btree_iter *iter;
+
+ trans_for_each_iter(trans, iter) {
+ iter->flags &= ~(BTREE_ITER_KEEP_UNTIL_COMMIT|
+ BTREE_ITER_SET_POS_AFTER_COMMIT);
+ iter->should_be_locked = false;
+ }
+
+ bch2_trans_unlink_iters(trans);
+
+ trans->iters_touched &= trans->iters_live;
+
+ trans->extra_journal_res = 0;
+ trans->nr_updates = 0;
+ trans->mem_top = 0;
+
+ trans->hooks = NULL;
+ trans->extra_journal_entries = NULL;
+ trans->extra_journal_entry_u64s = 0;
+
+ if (trans->fs_usage_deltas) {
+ trans->fs_usage_deltas->used = 0;
+ memset(&trans->fs_usage_deltas->memset_start, 0,
+ (void *) &trans->fs_usage_deltas->memset_end -
+ (void *) &trans->fs_usage_deltas->memset_start);
+ }
+
+ if (!(flags & TRANS_RESET_NOUNLOCK))
+ bch2_trans_cond_resched(trans);
+
+ if (!(flags & TRANS_RESET_NOTRAVERSE) &&
+ trans->iters_linked)
+ bch2_btree_iter_traverse_all(trans);
+}
+
+static void bch2_trans_alloc_iters(struct btree_trans *trans, struct bch_fs *c)
+{
+ size_t iters_bytes = sizeof(struct btree_iter) * BTREE_ITER_MAX;
+ size_t updates_bytes = sizeof(struct btree_insert_entry) * BTREE_ITER_MAX;
+ void *p = NULL;
+
+ BUG_ON(trans->used_mempool);
+
+#ifdef __KERNEL__
+ p = this_cpu_xchg(c->btree_iters_bufs->iter, NULL);
+#endif
+ if (!p)
+ p = mempool_alloc(&trans->c->btree_iters_pool, GFP_NOFS);
+
+ trans->iters = p; p += iters_bytes;
+ trans->updates = p; p += updates_bytes;
+}
+
+void bch2_trans_init(struct btree_trans *trans, struct bch_fs *c,
+ unsigned expected_nr_iters,
+ size_t expected_mem_bytes)
+ __acquires(&c->btree_trans_barrier)
+{
+ memset(trans, 0, sizeof(*trans));
+ trans->c = c;
+ trans->ip = _RET_IP_;
+
+ /*
+ * reallocating iterators currently completely breaks
+ * bch2_trans_iter_put(), we always allocate the max:
+ */
+ bch2_trans_alloc_iters(trans, c);
+
+ if (expected_mem_bytes) {
+ trans->mem_bytes = roundup_pow_of_two(expected_mem_bytes);
+ trans->mem = kmalloc(trans->mem_bytes, GFP_KERNEL|__GFP_NOFAIL);
+
+ if (!unlikely(trans->mem)) {
+ trans->mem = mempool_alloc(&c->btree_trans_mem_pool, GFP_KERNEL);
+ trans->mem_bytes = BTREE_TRANS_MEM_MAX;
+ }
+ }
+
+ trans->srcu_idx = srcu_read_lock(&c->btree_trans_barrier);
+
+#ifdef CONFIG_BCACHEFS_DEBUG
+ trans->pid = current->pid;
+ mutex_lock(&c->btree_trans_lock);
+ list_add(&trans->list, &c->btree_trans_list);
+ mutex_unlock(&c->btree_trans_lock);
+#endif
+}
+
+int bch2_trans_exit(struct btree_trans *trans)
+ __releases(&c->btree_trans_barrier)
+{
+ struct bch_fs *c = trans->c;
+
+ bch2_trans_unlock(trans);
+
+#ifdef CONFIG_BCACHEFS_DEBUG
+ if (trans->iters_live) {
+ struct btree_iter *iter;
+
+ trans_for_each_iter(trans, iter)
+ btree_iter_child_free(iter);
+ }
+
+ if (trans->iters_live) {
+ struct btree_iter *iter;
+
+ bch_err(c, "btree iterators leaked!");
+ trans_for_each_iter(trans, iter)
+ if (btree_iter_live(trans, iter))
+ printk(KERN_ERR " btree %s allocated at %pS\n",
+ bch2_btree_ids[iter->btree_id],
+ (void *) iter->ip_allocated);
+ /* Be noisy about this: */
+ bch2_fatal_error(c);
+ }
+
+ mutex_lock(&trans->c->btree_trans_lock);
+ list_del(&trans->list);
+ mutex_unlock(&trans->c->btree_trans_lock);
+#endif
+
+ srcu_read_unlock(&c->btree_trans_barrier, trans->srcu_idx);
+
+ bch2_journal_preres_put(&trans->c->journal, &trans->journal_preres);
+
+ 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,
+ &trans->c->replicas_delta_pool);
+ else
+ kfree(trans->fs_usage_deltas);
+ }
+
+ if (trans->mem_bytes == BTREE_TRANS_MEM_MAX)
+ mempool_free(trans->mem, &trans->c->btree_trans_mem_pool);
+ else
+ kfree(trans->mem);
+
+#ifdef __KERNEL__
+ /*
+ * Userspace doesn't have a real percpu implementation:
+ */
+ trans->iters = this_cpu_xchg(c->btree_iters_bufs->iter, trans->iters);
+#endif
+
+ if (trans->iters)
+ mempool_free(trans->iters, &trans->c->btree_iters_pool);
+
+ trans->mem = (void *) 0x1;
+ trans->iters = (void *) 0x1;
+
+ return trans->error ? -EIO : 0;
+}
+
+static void __maybe_unused
+bch2_btree_iter_node_to_text(struct printbuf *out,
+ struct btree_bkey_cached_common *_b,
+ enum btree_iter_type type)
+{
+ pr_buf(out, " l=%u %s:",
+ _b->level, bch2_btree_ids[_b->btree_id]);
+ bch2_bpos_to_text(out, btree_node_pos(_b, type));
+}
+
+#ifdef CONFIG_BCACHEFS_DEBUG
+static bool trans_has_btree_nodes_locked(struct btree_trans *trans)
+{
+ struct btree_iter *iter;
+
+ trans_for_each_iter(trans, iter)
+ if (btree_iter_type(iter) != BTREE_ITER_CACHED &&
+ iter->nodes_locked)
+ return true;
+ return false;
+}
+#endif
+
+void bch2_btree_trans_to_text(struct printbuf *out, struct bch_fs *c)
+{
+#ifdef CONFIG_BCACHEFS_DEBUG
+ struct btree_trans *trans;
+ struct btree_iter *iter;
+ struct btree *b;
+ unsigned l;
+
+ mutex_lock(&c->btree_trans_lock);
+ list_for_each_entry(trans, &c->btree_trans_list, list) {
+ if (!trans_has_btree_nodes_locked(trans))
+ continue;
+
+ pr_buf(out, "%i %ps\n", trans->pid, (void *) trans->ip);
+
+ trans_for_each_iter(trans, iter) {
+ if (!iter->nodes_locked)
+ continue;
+
+ pr_buf(out, " iter %u %c %s:",
+ iter->idx,
+ btree_iter_type(iter) == BTREE_ITER_CACHED ? 'c' : 'b',
+ bch2_btree_ids[iter->btree_id]);
+ bch2_bpos_to_text(out, iter->pos);
+ pr_buf(out, "\n");
+
+ for (l = 0; l < BTREE_MAX_DEPTH; l++) {
+ if (btree_node_locked(iter, l)) {
+ pr_buf(out, " %s l=%u ",
+ btree_node_intent_locked(iter, l) ? "i" : "r", l);
+ bch2_btree_iter_node_to_text(out,
+ (void *) iter->l[l].b,
+ btree_iter_type(iter));
+ pr_buf(out, "\n");
+ }
+ }
+ }
+
+ b = READ_ONCE(trans->locking);
+ if (b) {
+ iter = &trans->iters[trans->locking_iter_idx];
+ pr_buf(out, " locking iter %u %c l=%u %s:",
+ trans->locking_iter_idx,
+ btree_iter_type(iter) == BTREE_ITER_CACHED ? 'c' : 'b',
+ trans->locking_level,
+ bch2_btree_ids[trans->locking_btree_id]);
+ bch2_bpos_to_text(out, trans->locking_pos);
+
+ pr_buf(out, " node ");
+ bch2_btree_iter_node_to_text(out,
+ (void *) b,
+ btree_iter_type(iter));
+ pr_buf(out, "\n");
+ }
+ }
+ mutex_unlock(&c->btree_trans_lock);
+#endif
+}
+
+void bch2_fs_btree_iter_exit(struct bch_fs *c)
+{
+ mempool_exit(&c->btree_trans_mem_pool);
+ mempool_exit(&c->btree_iters_pool);
+ cleanup_srcu_struct(&c->btree_trans_barrier);
+}
+
+int bch2_fs_btree_iter_init(struct bch_fs *c)
+{
+ unsigned nr = BTREE_ITER_MAX;
+
+ INIT_LIST_HEAD(&c->btree_trans_list);
+ mutex_init(&c->btree_trans_lock);
+
+ return init_srcu_struct(&c->btree_trans_barrier) ?:
+ mempool_init_kmalloc_pool(&c->btree_iters_pool, 1,
+ sizeof(struct btree_iter) * nr +
+ sizeof(struct btree_insert_entry) * nr) ?:
+ mempool_init_kmalloc_pool(&c->btree_trans_mem_pool, 1,
+ BTREE_TRANS_MEM_MAX);
}
projects / bcachefs-tools-debian / blobdiff