diff options
Diffstat (limited to 'fs/bcachefs/btree_locking.c')
-rw-r--r-- | fs/bcachefs/btree_locking.c | 286 |
1 files changed, 147 insertions, 139 deletions
diff --git a/fs/bcachefs/btree_locking.c b/fs/bcachefs/btree_locking.c index 3f20fbcb8389..535232a240dc 100644 --- a/fs/bcachefs/btree_locking.c +++ b/fs/bcachefs/btree_locking.c @@ -8,10 +8,12 @@ struct lock_class_key bch2_btree_node_lock_key; /* Btree node locking: */ -void bch2_btree_node_unlock_write(struct btree_trans *trans, - struct btree_path *path, struct btree *b) +static inline void six_lock_readers_add(struct six_lock *lock, int nr) { - bch2_btree_node_unlock_write_inlined(trans, path, b); + if (!lock->readers) + atomic64_add(__SIX_VAL(read_lock, nr), &lock->state.counter); + else + this_cpu_add(*lock->readers, nr); } struct six_lock_count bch2_btree_node_lock_counts(struct btree_trans *trans, @@ -34,14 +36,16 @@ struct six_lock_count bch2_btree_node_lock_counts(struct btree_trans *trans, return ret; } -static inline void six_lock_readers_add(struct six_lock *lock, int nr) +/* unlock */ + +void bch2_btree_node_unlock_write(struct btree_trans *trans, + struct btree_path *path, struct btree *b) { - if (!lock->readers) - atomic64_add(__SIX_VAL(read_lock, nr), &lock->state.counter); - else - this_cpu_add(*lock->readers, nr); + bch2_btree_node_unlock_write_inlined(trans, path, b); } +/* lock */ + void __bch2_btree_node_lock_write(struct btree_trans *trans, struct btree *b) { int readers = bch2_btree_node_lock_counts(trans, NULL, b, b->c.level).read; @@ -57,118 +61,6 @@ void __bch2_btree_node_lock_write(struct btree_trans *trans, struct btree *b) six_lock_readers_add(&b->c.lock, readers); } -bool __bch2_btree_node_relock(struct btree_trans *trans, - struct btree_path *path, unsigned level) -{ - struct btree *b = btree_path_node(path, level); - int want = __btree_lock_want(path, level); - - if (!is_btree_node(path, level)) - goto fail; - - if (race_fault()) - goto fail; - - if (six_relock_type(&b->c.lock, want, path->l[level].lock_seq) || - (btree_node_lock_seq_matches(path, b, level) && - btree_node_lock_increment(trans, b, level, want))) { - mark_btree_node_locked(trans, path, level, want); - return true; - } -fail: - if (b != ERR_PTR(-BCH_ERR_no_btree_node_cached) && - b != ERR_PTR(-BCH_ERR_no_btree_node_init)) - trace_btree_node_relock_fail(trans, _RET_IP_, path, level); - return false; -} - -bool bch2_btree_node_upgrade(struct btree_trans *trans, - struct btree_path *path, unsigned level) -{ - struct btree *b = path->l[level].b; - - if (!is_btree_node(path, level)) - return false; - - switch (btree_lock_want(path, level)) { - case BTREE_NODE_UNLOCKED: - BUG_ON(btree_node_locked(path, level)); - return true; - case BTREE_NODE_READ_LOCKED: - BUG_ON(btree_node_intent_locked(path, level)); - return bch2_btree_node_relock(trans, path, level); - case BTREE_NODE_INTENT_LOCKED: - break; - } - - if (btree_node_intent_locked(path, level)) - return true; - - if (race_fault()) - return false; - - if (btree_node_locked(path, level) - ? six_lock_tryupgrade(&b->c.lock) - : six_relock_type(&b->c.lock, SIX_LOCK_intent, path->l[level].lock_seq)) - goto success; - - if (btree_node_lock_seq_matches(path, b, level) && - btree_node_lock_increment(trans, b, level, BTREE_NODE_INTENT_LOCKED)) { - btree_node_unlock(trans, path, level); - goto success; - } - - trace_btree_node_upgrade_fail(trans, _RET_IP_, path, level); - return false; -success: - mark_btree_node_intent_locked(trans, path, level); - return true; -} - -static inline bool btree_path_get_locks(struct btree_trans *trans, - struct btree_path *path, - bool upgrade) -{ - unsigned l = path->level; - int fail_idx = -1; - - do { - if (!btree_path_node(path, l)) - break; - - if (!(upgrade - ? bch2_btree_node_upgrade(trans, path, l) - : bch2_btree_node_relock(trans, path, l))) - fail_idx = l; - - l++; - } while (l < path->locks_want); - - /* - * When we fail to get a lock, we have to ensure that any child nodes - * can't be relocked so bch2_btree_path_traverse has to walk back up to - * the node that we failed to relock: - */ - if (fail_idx >= 0) { - __bch2_btree_path_unlock(trans, path); - btree_path_set_dirty(path, BTREE_ITER_NEED_TRAVERSE); - - do { - path->l[fail_idx].b = upgrade - ? ERR_PTR(-BCH_ERR_no_btree_node_upgrade) - : ERR_PTR(-BCH_ERR_no_btree_node_relock); - --fail_idx; - } while (fail_idx >= 0); - } - - if (path->uptodate == BTREE_ITER_NEED_RELOCK) - path->uptodate = BTREE_ITER_UPTODATE; - - bch2_trans_verify_locks(trans); - - return path->uptodate < BTREE_ITER_NEED_RELOCK; -} - /* Slowpath: */ int __bch2_btree_node_lock(struct btree_trans *trans, struct btree_path *path, @@ -250,34 +142,121 @@ deadlock: return btree_trans_restart(trans, BCH_ERR_transaction_restart_would_deadlock); } -/* Btree iterator locking: */ - -#ifdef CONFIG_BCACHEFS_DEBUG +/* relock */ -void bch2_btree_path_verify_locks(struct btree_path *path) +static inline bool btree_path_get_locks(struct btree_trans *trans, + struct btree_path *path, + bool upgrade) { - unsigned l; + unsigned l = path->level; + int fail_idx = -1; - if (!path->nodes_locked) { - BUG_ON(path->uptodate == BTREE_ITER_UPTODATE && - btree_path_node(path, path->level)); - return; + do { + if (!btree_path_node(path, l)) + break; + + if (!(upgrade + ? bch2_btree_node_upgrade(trans, path, l) + : bch2_btree_node_relock(trans, path, l))) + fail_idx = l; + + l++; + } while (l < path->locks_want); + + /* + * When we fail to get a lock, we have to ensure that any child nodes + * can't be relocked so bch2_btree_path_traverse has to walk back up to + * the node that we failed to relock: + */ + if (fail_idx >= 0) { + __bch2_btree_path_unlock(trans, path); + btree_path_set_dirty(path, BTREE_ITER_NEED_TRAVERSE); + + do { + path->l[fail_idx].b = upgrade + ? ERR_PTR(-BCH_ERR_no_btree_node_upgrade) + : ERR_PTR(-BCH_ERR_no_btree_node_relock); + --fail_idx; + } while (fail_idx >= 0); } - for (l = 0; btree_path_node(path, l); l++) - BUG_ON(btree_lock_want(path, l) != - btree_node_locked_type(path, l)); + if (path->uptodate == BTREE_ITER_NEED_RELOCK) + path->uptodate = BTREE_ITER_UPTODATE; + + bch2_trans_verify_locks(trans); + + return path->uptodate < BTREE_ITER_NEED_RELOCK; } -void bch2_trans_verify_locks(struct btree_trans *trans) +bool __bch2_btree_node_relock(struct btree_trans *trans, + struct btree_path *path, unsigned level) { - struct btree_path *path; + struct btree *b = btree_path_node(path, level); + int want = __btree_lock_want(path, level); - trans_for_each_path(trans, path) - bch2_btree_path_verify_locks(path); + if (!is_btree_node(path, level)) + goto fail; + + if (race_fault()) + goto fail; + + if (six_relock_type(&b->c.lock, want, path->l[level].lock_seq) || + (btree_node_lock_seq_matches(path, b, level) && + btree_node_lock_increment(trans, b, level, want))) { + mark_btree_node_locked(trans, path, level, want); + return true; + } +fail: + if (b != ERR_PTR(-BCH_ERR_no_btree_node_cached) && + b != ERR_PTR(-BCH_ERR_no_btree_node_init)) + trace_btree_node_relock_fail(trans, _RET_IP_, path, level); + return false; } -#endif +/* upgrade */ + +bool bch2_btree_node_upgrade(struct btree_trans *trans, + struct btree_path *path, unsigned level) +{ + struct btree *b = path->l[level].b; + + if (!is_btree_node(path, level)) + return false; + + switch (btree_lock_want(path, level)) { + case BTREE_NODE_UNLOCKED: + BUG_ON(btree_node_locked(path, level)); + return true; + case BTREE_NODE_READ_LOCKED: + BUG_ON(btree_node_intent_locked(path, level)); + return bch2_btree_node_relock(trans, path, level); + case BTREE_NODE_INTENT_LOCKED: + break; + } + + if (btree_node_intent_locked(path, level)) + return true; + + if (race_fault()) + return false; + + if (btree_node_locked(path, level) + ? six_lock_tryupgrade(&b->c.lock) + : six_relock_type(&b->c.lock, SIX_LOCK_intent, path->l[level].lock_seq)) + goto success; + + if (btree_node_lock_seq_matches(path, b, level) && + btree_node_lock_increment(trans, b, level, BTREE_NODE_INTENT_LOCKED)) { + btree_node_unlock(trans, path, level); + goto success; + } + + trace_btree_node_upgrade_fail(trans, _RET_IP_, path, level); + return false; +success: + mark_btree_node_intent_locked(trans, path, level); + return true; +} /* Btree path locking: */ @@ -406,6 +385,8 @@ void __bch2_btree_path_downgrade(struct btree_trans *trans, bch2_btree_path_verify_locks(path); } +/* Btree transaction locking: */ + void bch2_trans_downgrade(struct btree_trans *trans) { struct btree_path *path; @@ -414,8 +395,6 @@ void bch2_trans_downgrade(struct btree_trans *trans) bch2_btree_path_downgrade(trans, path); } -/* Btree transaction locking: */ - int bch2_trans_relock(struct btree_trans *trans) { struct btree_path *path; @@ -440,3 +419,32 @@ void bch2_trans_unlock(struct btree_trans *trans) trans_for_each_path(trans, path) __bch2_btree_path_unlock(trans, path); } + +/* Debug */ + +#ifdef CONFIG_BCACHEFS_DEBUG + +void bch2_btree_path_verify_locks(struct btree_path *path) +{ + unsigned l; + + if (!path->nodes_locked) { + BUG_ON(path->uptodate == BTREE_ITER_UPTODATE && + btree_path_node(path, path->level)); + return; + } + + for (l = 0; btree_path_node(path, l); l++) + BUG_ON(btree_lock_want(path, l) != + btree_node_locked_type(path, l)); +} + +void bch2_trans_verify_locks(struct btree_trans *trans) +{ + struct btree_path *path; + + trans_for_each_path(trans, path) + bch2_btree_path_verify_locks(path); +} + +#endif |