* updating the iterator state
*/
-#include <linux/six.h>
-
#include "btree_iter.h"
+#include "six.h"
+
+void bch2_btree_lock_init(struct btree_bkey_cached_common *, enum six_lock_init_flags);
+
+#ifdef CONFIG_LOCKDEP
+void bch2_assert_btree_nodes_not_locked(void);
+#else
+static inline void bch2_assert_btree_nodes_not_locked(void) {}
+#endif
+
+void bch2_trans_unlock_noassert(struct btree_trans *);
+
+static inline bool is_btree_node(struct btree_path *path, unsigned l)
+{
+ return l < BTREE_MAX_DEPTH && !IS_ERR_OR_NULL(path->l[l].b);
+}
+
+static inline struct btree_transaction_stats *btree_trans_stats(struct btree_trans *trans)
+{
+ return trans->fn_idx < ARRAY_SIZE(trans->c->btree_transaction_stats)
+ ? &trans->c->btree_transaction_stats[trans->fn_idx]
+ : NULL;
+}
/* matches six lock types */
enum btree_node_locked_type {
BTREE_NODE_UNLOCKED = -1,
BTREE_NODE_READ_LOCKED = SIX_LOCK_read,
BTREE_NODE_INTENT_LOCKED = SIX_LOCK_intent,
+ BTREE_NODE_WRITE_LOCKED = SIX_LOCK_write,
};
-static inline int btree_node_locked_type(struct btree_iter *iter,
+static inline int btree_node_locked_type(struct btree_path *path,
unsigned level)
{
- /*
- * We're relying on the fact that if nodes_intent_locked is set
- * nodes_locked must be set as well, so that we can compute without
- * branches:
- */
- return BTREE_NODE_UNLOCKED +
- ((iter->nodes_locked >> level) & 1) +
- ((iter->nodes_intent_locked >> level) & 1);
+ return BTREE_NODE_UNLOCKED + ((path->nodes_locked >> (level << 1)) & 3);
}
-static inline bool btree_node_intent_locked(struct btree_iter *iter,
- unsigned level)
+static inline bool btree_node_write_locked(struct btree_path *path, unsigned l)
{
- return btree_node_locked_type(iter, level) == BTREE_NODE_INTENT_LOCKED;
+ return btree_node_locked_type(path, l) == BTREE_NODE_WRITE_LOCKED;
}
-static inline bool btree_node_read_locked(struct btree_iter *iter,
- unsigned level)
+static inline bool btree_node_intent_locked(struct btree_path *path, unsigned l)
{
- return btree_node_locked_type(iter, level) == BTREE_NODE_READ_LOCKED;
+ return btree_node_locked_type(path, l) == BTREE_NODE_INTENT_LOCKED;
}
-static inline bool btree_node_locked(struct btree_iter *iter, unsigned level)
+static inline bool btree_node_read_locked(struct btree_path *path, unsigned l)
{
- return iter->nodes_locked & (1 << level);
+ return btree_node_locked_type(path, l) == BTREE_NODE_READ_LOCKED;
}
-static inline void mark_btree_node_unlocked(struct btree_iter *iter,
- unsigned level)
+static inline bool btree_node_locked(struct btree_path *path, unsigned level)
{
- iter->nodes_locked &= ~(1 << level);
- iter->nodes_intent_locked &= ~(1 << level);
+ return btree_node_locked_type(path, level) != BTREE_NODE_UNLOCKED;
}
-static inline void mark_btree_node_locked(struct btree_iter *iter,
- unsigned level,
- enum six_lock_type type)
+static inline void mark_btree_node_locked_noreset(struct btree_path *path,
+ unsigned level,
+ enum btree_node_locked_type type)
{
/* relying on this to avoid a branch */
BUILD_BUG_ON(SIX_LOCK_read != 0);
BUILD_BUG_ON(SIX_LOCK_intent != 1);
- iter->nodes_locked |= 1 << level;
- iter->nodes_intent_locked |= type << level;
+ path->nodes_locked &= ~(3U << (level << 1));
+ path->nodes_locked |= (type + 1) << (level << 1);
}
-static inline void mark_btree_node_intent_locked(struct btree_iter *iter,
- unsigned level)
+static inline void mark_btree_node_unlocked(struct btree_path *path,
+ unsigned level)
{
- mark_btree_node_locked(iter, level, SIX_LOCK_intent);
+ EBUG_ON(btree_node_write_locked(path, level));
+ mark_btree_node_locked_noreset(path, level, BTREE_NODE_UNLOCKED);
}
-static inline enum six_lock_type __btree_lock_want(struct btree_iter *iter, int level)
+static inline void mark_btree_node_locked(struct btree_trans *trans,
+ struct btree_path *path,
+ unsigned level,
+ enum btree_node_locked_type type)
{
- return level < iter->locks_want
+ mark_btree_node_locked_noreset(path, level, (enum btree_node_locked_type) type);
+#ifdef CONFIG_BCACHEFS_LOCK_TIME_STATS
+ path->l[level].lock_taken_time = local_clock();
+#endif
+}
+
+static inline enum six_lock_type __btree_lock_want(struct btree_path *path, int level)
+{
+ return level < path->locks_want
? SIX_LOCK_intent
: SIX_LOCK_read;
}
static inline enum btree_node_locked_type
-btree_lock_want(struct btree_iter *iter, int level)
+btree_lock_want(struct btree_path *path, int level)
{
- if (level < iter->level)
+ if (level < path->level)
return BTREE_NODE_UNLOCKED;
- if (level < iter->locks_want)
+ if (level < path->locks_want)
return BTREE_NODE_INTENT_LOCKED;
- if (level == iter->level)
+ if (level == path->level)
return BTREE_NODE_READ_LOCKED;
return BTREE_NODE_UNLOCKED;
}
-static inline void __btree_node_unlock(struct btree_iter *iter, unsigned level)
+static void btree_trans_lock_hold_time_update(struct btree_trans *trans,
+ struct btree_path *path, unsigned level)
+{
+#ifdef CONFIG_BCACHEFS_LOCK_TIME_STATS
+ struct btree_transaction_stats *s = btree_trans_stats(trans);
+
+ if (s)
+ __bch2_time_stats_update(&s->lock_hold_times,
+ path->l[level].lock_taken_time,
+ local_clock());
+#endif
+}
+
+/* unlock: */
+
+static inline void btree_node_unlock(struct btree_trans *trans,
+ struct btree_path *path, unsigned level)
{
- int lock_type = btree_node_locked_type(iter, level);
+ int lock_type = btree_node_locked_type(path, level);
EBUG_ON(level >= BTREE_MAX_DEPTH);
- if (lock_type != BTREE_NODE_UNLOCKED)
- six_unlock_type(&iter->l[level].b->lock, lock_type);
- mark_btree_node_unlocked(iter, level);
+ if (lock_type != BTREE_NODE_UNLOCKED) {
+ six_unlock_type(&path->l[level].b->c.lock, lock_type);
+ btree_trans_lock_hold_time_update(trans, path, level);
+ }
+ mark_btree_node_unlocked(path, level);
}
-static inline void btree_node_unlock(struct btree_iter *iter, unsigned level)
+static inline int btree_path_lowest_level_locked(struct btree_path *path)
{
- EBUG_ON(!level && iter->trans->nounlock);
-
- __btree_node_unlock(iter, level);
+ return __ffs(path->nodes_locked) >> 1;
}
-static inline void __bch2_btree_iter_unlock(struct btree_iter *iter)
+static inline int btree_path_highest_level_locked(struct btree_path *path)
{
- btree_iter_set_dirty(iter, BTREE_ITER_NEED_RELOCK);
-
- while (iter->nodes_locked)
- btree_node_unlock(iter, __ffs(iter->nodes_locked));
+ return __fls(path->nodes_locked) >> 1;
}
-static inline enum bch_time_stats lock_to_time_stat(enum six_lock_type type)
+static inline void __bch2_btree_path_unlock(struct btree_trans *trans,
+ struct btree_path *path)
{
- switch (type) {
- case SIX_LOCK_read:
- return BCH_TIME_btree_lock_contended_read;
- case SIX_LOCK_intent:
- return BCH_TIME_btree_lock_contended_intent;
- case SIX_LOCK_write:
- return BCH_TIME_btree_lock_contended_write;
- default:
- BUG();
- }
+ btree_path_set_dirty(path, BTREE_ITER_NEED_RELOCK);
+
+ while (path->nodes_locked)
+ btree_node_unlock(trans, path, btree_path_lowest_level_locked(path));
}
/*
- * wrapper around six locks that just traces lock contended time
+ * Updates the saved lock sequence number, so that bch2_btree_node_relock() will
+ * succeed:
*/
-static inline void __btree_node_lock_type(struct bch_fs *c, struct btree *b,
- enum six_lock_type type)
+static inline void
+bch2_btree_node_unlock_write_inlined(struct btree_trans *trans, struct btree_path *path,
+ struct btree *b)
{
- u64 start_time = local_clock();
+ struct btree_path *linked;
+
+ EBUG_ON(path->l[b->c.level].b != b);
+ EBUG_ON(path->l[b->c.level].lock_seq != six_lock_seq(&b->c.lock));
+ EBUG_ON(btree_node_locked_type(path, b->c.level) != SIX_LOCK_write);
+
+ mark_btree_node_locked_noreset(path, b->c.level, BTREE_NODE_INTENT_LOCKED);
+
+ trans_for_each_path_with_node(trans, b, linked)
+ linked->l[b->c.level].lock_seq++;
- six_lock_type(&b->lock, type);
- bch2_time_stats_update(&c->times[lock_to_time_stat(type)], start_time);
+ six_unlock_write(&b->c.lock);
}
-static inline void btree_node_lock_type(struct bch_fs *c, struct btree *b,
- enum six_lock_type type)
+void bch2_btree_node_unlock_write(struct btree_trans *,
+ struct btree_path *, struct btree *);
+
+int bch2_six_check_for_deadlock(struct six_lock *lock, void *p);
+
+/* lock: */
+
+static inline int __btree_node_lock_nopath(struct btree_trans *trans,
+ struct btree_bkey_cached_common *b,
+ enum six_lock_type type,
+ bool lock_may_not_fail,
+ unsigned long ip)
{
- if (!six_trylock_type(&b->lock, type))
- __btree_node_lock_type(c, b, type);
+ int ret;
+
+ trans->lock_may_not_fail = lock_may_not_fail;
+ trans->lock_must_abort = false;
+ trans->locking = b;
+
+ ret = six_lock_ip_waiter(&b->lock, type, &trans->locking_wait,
+ bch2_six_check_for_deadlock, trans, ip);
+ WRITE_ONCE(trans->locking, NULL);
+ WRITE_ONCE(trans->locking_wait.start_time, 0);
+ return ret;
+}
+
+static inline int __must_check
+btree_node_lock_nopath(struct btree_trans *trans,
+ struct btree_bkey_cached_common *b,
+ enum six_lock_type type,
+ unsigned long ip)
+{
+ return __btree_node_lock_nopath(trans, b, type, false, ip);
+}
+
+static inline void btree_node_lock_nopath_nofail(struct btree_trans *trans,
+ struct btree_bkey_cached_common *b,
+ enum six_lock_type type)
+{
+ int ret = __btree_node_lock_nopath(trans, b, type, true, _THIS_IP_);
+
+ BUG_ON(ret);
}
/*
* Lock a btree node if we already have it locked on one of our linked
* iterators:
*/
-static inline bool btree_node_lock_increment(struct btree_iter *iter,
- struct btree *b, unsigned level,
+static inline bool btree_node_lock_increment(struct btree_trans *trans,
+ struct btree_bkey_cached_common *b,
+ unsigned level,
enum btree_node_locked_type want)
{
- struct btree_iter *linked;
+ struct btree_path *path;
- trans_for_each_iter(iter->trans, linked)
- if (linked->l[level].b == b &&
- btree_node_locked_type(linked, level) >= want) {
- six_lock_increment(&b->lock, want);
+ trans_for_each_path(trans, path)
+ if (&path->l[level].b->c == b &&
+ btree_node_locked_type(path, level) >= want) {
+ six_lock_increment(&b->lock, (enum six_lock_type) want);
return true;
}
return false;
}
-bool __bch2_btree_node_lock(struct btree *, struct bpos, unsigned,
- struct btree_iter *, enum six_lock_type);
-
-static inline bool btree_node_lock(struct btree *b, struct bpos pos,
- unsigned level,
- struct btree_iter *iter,
- enum six_lock_type type)
+static inline int btree_node_lock(struct btree_trans *trans,
+ struct btree_path *path,
+ struct btree_bkey_cached_common *b,
+ unsigned level,
+ enum six_lock_type type,
+ unsigned long ip)
{
+ int ret = 0;
+
EBUG_ON(level >= BTREE_MAX_DEPTH);
+ EBUG_ON(!test_bit(path->idx, trans->paths_allocated));
+
+ if (likely(six_trylock_type(&b->lock, type)) ||
+ btree_node_lock_increment(trans, b, level, (enum btree_node_locked_type) type) ||
+ !(ret = btree_node_lock_nopath(trans, b, type, btree_path_ip_allocated(path)))) {
+#ifdef CONFIG_BCACHEFS_LOCK_TIME_STATS
+ path->l[b->level].lock_taken_time = local_clock();
+#endif
+ }
- return likely(six_trylock_type(&b->lock, type)) ||
- btree_node_lock_increment(iter, b, level, type) ||
- __bch2_btree_node_lock(b, pos, level, iter, type);
+ return ret;
}
-bool __bch2_btree_node_relock(struct btree_iter *, unsigned);
+int __bch2_btree_node_lock_write(struct btree_trans *, struct btree_path *,
+ struct btree_bkey_cached_common *b, bool);
-static inline bool bch2_btree_node_relock(struct btree_iter *iter,
- unsigned level)
+static inline int __btree_node_lock_write(struct btree_trans *trans,
+ struct btree_path *path,
+ struct btree_bkey_cached_common *b,
+ bool lock_may_not_fail)
{
- EBUG_ON(btree_node_locked(iter, level) &&
- btree_node_locked_type(iter, level) !=
- __btree_lock_want(iter, level));
+ EBUG_ON(&path->l[b->level].b->c != b);
+ EBUG_ON(path->l[b->level].lock_seq != six_lock_seq(&b->lock));
+ EBUG_ON(!btree_node_intent_locked(path, b->level));
+
+ /*
+ * six locks are unfair, and read locks block while a thread wants a
+ * write lock: thus, we need to tell the cycle detector we have a write
+ * lock _before_ taking the lock:
+ */
+ mark_btree_node_locked_noreset(path, b->level, BTREE_NODE_WRITE_LOCKED);
- return likely(btree_node_locked(iter, level)) ||
- __bch2_btree_node_relock(iter, level);
+ return likely(six_trylock_write(&b->lock))
+ ? 0
+ : __bch2_btree_node_lock_write(trans, path, b, lock_may_not_fail);
}
-/*
- * Updates the saved lock sequence number, so that bch2_btree_node_relock() will
- * succeed:
- */
-static inline void
-bch2_btree_node_unlock_write_inlined(struct btree *b, struct btree_iter *iter)
+static inline int __must_check
+bch2_btree_node_lock_write(struct btree_trans *trans,
+ struct btree_path *path,
+ struct btree_bkey_cached_common *b)
{
- struct btree_iter *linked;
+ return __btree_node_lock_write(trans, path, b, false);
+}
+
+void bch2_btree_node_lock_write_nofail(struct btree_trans *,
+ struct btree_path *,
+ struct btree_bkey_cached_common *);
- EBUG_ON(iter->l[b->level].b != b);
- EBUG_ON(iter->l[b->level].lock_seq + 1 != b->lock.state.seq);
+/* relock: */
- trans_for_each_iter_with_node(iter->trans, b, linked)
- linked->l[b->level].lock_seq += 2;
+bool bch2_btree_path_relock_norestart(struct btree_trans *,
+ struct btree_path *, unsigned long);
+int __bch2_btree_path_relock(struct btree_trans *,
+ struct btree_path *, unsigned long);
- six_unlock_write(&b->lock);
+static inline int bch2_btree_path_relock(struct btree_trans *trans,
+ struct btree_path *path, unsigned long trace_ip)
+{
+ return btree_node_locked(path, path->level)
+ ? 0
+ : __bch2_btree_path_relock(trans, path, trace_ip);
}
-void bch2_btree_node_unlock_write(struct btree *, struct btree_iter *);
+bool __bch2_btree_node_relock(struct btree_trans *, struct btree_path *, unsigned, bool trace);
-void __bch2_btree_node_lock_write(struct btree *, struct btree_iter *);
+static inline bool bch2_btree_node_relock(struct btree_trans *trans,
+ struct btree_path *path, unsigned level)
+{
+ EBUG_ON(btree_node_locked(path, level) &&
+ !btree_node_write_locked(path, level) &&
+ btree_node_locked_type(path, level) != __btree_lock_want(path, level));
+
+ return likely(btree_node_locked(path, level)) ||
+ (!IS_ERR_OR_NULL(path->l[level].b) &&
+ __bch2_btree_node_relock(trans, path, level, true));
+}
-static inline void bch2_btree_node_lock_write(struct btree *b, struct btree_iter *iter)
+static inline bool bch2_btree_node_relock_notrace(struct btree_trans *trans,
+ struct btree_path *path, unsigned level)
{
- EBUG_ON(iter->l[b->level].b != b);
- EBUG_ON(iter->l[b->level].lock_seq != b->lock.state.seq);
+ EBUG_ON(btree_node_locked(path, level) &&
+ !btree_node_write_locked(path, level) &&
+ btree_node_locked_type(path, level) != __btree_lock_want(path, level));
- if (unlikely(!six_trylock_write(&b->lock)))
- __bch2_btree_node_lock_write(b, iter);
+ return likely(btree_node_locked(path, level)) ||
+ (!IS_ERR_OR_NULL(path->l[level].b) &&
+ __bch2_btree_node_relock(trans, path, level, false));
}
-#endif /* _BCACHEFS_BTREE_LOCKING_H */
+/* upgrade */
+
+
+struct get_locks_fail {
+ unsigned l;
+ struct btree *b;
+};
+
+bool bch2_btree_path_upgrade_noupgrade_sibs(struct btree_trans *,
+ struct btree_path *, unsigned,
+ struct get_locks_fail *);
+bool __bch2_btree_path_upgrade(struct btree_trans *,
+ struct btree_path *, unsigned,
+ struct get_locks_fail *);
+static inline int bch2_btree_path_upgrade(struct btree_trans *trans,
+ struct btree_path *path,
+ unsigned new_locks_want)
+{
+ struct get_locks_fail f;
+ unsigned old_locks_want = path->locks_want;
+
+ new_locks_want = min(new_locks_want, BTREE_MAX_DEPTH);
+
+ if (path->locks_want < new_locks_want
+ ? __bch2_btree_path_upgrade(trans, path, new_locks_want, &f)
+ : path->uptodate == BTREE_ITER_UPTODATE)
+ return 0;
+
+ trace_and_count(trans->c, trans_restart_upgrade, trans, _THIS_IP_, path,
+ old_locks_want, new_locks_want, &f);
+ return btree_trans_restart(trans, BCH_ERR_transaction_restart_upgrade);
+}
+
+/* misc: */
+
+static inline void btree_path_set_should_be_locked(struct btree_path *path)
+{
+ EBUG_ON(!btree_node_locked(path, path->level));
+ EBUG_ON(path->uptodate);
+
+ path->should_be_locked = true;
+}
+
+static inline void __btree_path_set_level_up(struct btree_trans *trans,
+ struct btree_path *path,
+ unsigned l)
+{
+ btree_node_unlock(trans, path, l);
+ path->l[l].b = ERR_PTR(-BCH_ERR_no_btree_node_up);
+}
+
+static inline void btree_path_set_level_up(struct btree_trans *trans,
+ struct btree_path *path)
+{
+ __btree_path_set_level_up(trans, path, path->level++);
+ btree_path_set_dirty(path, BTREE_ITER_NEED_TRAVERSE);
+}
+
+/* debug */
+
+struct six_lock_count bch2_btree_node_lock_counts(struct btree_trans *,
+ struct btree_path *,
+ struct btree_bkey_cached_common *b,
+ unsigned);
+
+int bch2_check_for_deadlock(struct btree_trans *, struct printbuf *);
+
+#ifdef CONFIG_BCACHEFS_DEBUG
+void bch2_btree_path_verify_locks(struct btree_path *);
+void bch2_trans_verify_locks(struct btree_trans *);
+#else
+static inline void bch2_btree_path_verify_locks(struct btree_path *path) {}
+static inline void bch2_trans_verify_locks(struct btree_trans *trans) {}
+#endif
+
+#endif /* _BCACHEFS_BTREE_LOCKING_H */
projects / bcachefs-tools-debian / blobdiff