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Diffstat (limited to 'libbcachefs/btree_locking.c')
-rw-r--r--libbcachefs/btree_locking.c73
1 files changed, 50 insertions, 23 deletions
diff --git a/libbcachefs/btree_locking.c b/libbcachefs/btree_locking.c
index 1eca320e..1ed8327a 100644
--- a/libbcachefs/btree_locking.c
+++ b/libbcachefs/btree_locking.c
@@ -32,13 +32,14 @@ struct six_lock_count bch2_btree_node_lock_counts(struct btree_trans *trans,
{
struct btree_path *path;
struct six_lock_count ret;
+ unsigned i;
memset(&ret, 0, sizeof(ret));
if (IS_ERR_OR_NULL(b))
return ret;
- trans_for_each_path(trans, path)
+ trans_for_each_path(trans, path, i)
if (path != skip && &path->l[level].b->c == b) {
int t = btree_node_locked_type(path, level);
@@ -94,9 +95,10 @@ static noinline void print_chain(struct printbuf *out, struct lock_graph *g)
struct trans_waiting_for_lock *i;
for (i = g->g; i != g->g + g->nr; i++) {
+ struct task_struct *task = i->trans->locking_wait.task;
if (i != g->g)
prt_str(out, "<- ");
- prt_printf(out, "%u ", i->trans->locking_wait.task->pid);
+ prt_printf(out, "%u ", task ?task->pid : 0);
}
prt_newline(out);
}
@@ -280,9 +282,8 @@ int bch2_check_for_deadlock(struct btree_trans *trans, struct printbuf *cycle)
struct lock_graph g;
struct trans_waiting_for_lock *top;
struct btree_bkey_cached_common *b;
- struct btree_path *path;
- unsigned path_idx;
- int ret;
+ btree_path_idx_t path_idx;
+ int ret = 0;
g.nr = 0;
@@ -295,13 +296,26 @@ int bch2_check_for_deadlock(struct btree_trans *trans, struct printbuf *cycle)
}
lock_graph_down(&g, trans);
+
+ /* trans->paths is rcu protected vs. freeing */
+ rcu_read_lock();
+ if (cycle)
+ cycle->atomic++;
next:
if (!g.nr)
- return 0;
+ goto out;
top = &g.g[g.nr - 1];
- trans_for_each_path_safe_from(top->trans, path, path_idx, top->path_idx) {
+ struct btree_path *paths = rcu_dereference(top->trans->paths);
+ if (!paths)
+ goto up;
+
+ unsigned long *paths_allocated = trans_paths_allocated(paths);
+
+ trans_for_each_path_idx_from(paths_allocated, *trans_paths_nr(paths),
+ path_idx, top->path_idx) {
+ struct btree_path *path = paths + path_idx;
if (!path->nodes_locked)
continue;
@@ -367,18 +381,23 @@ next:
ret = lock_graph_descend(&g, trans, cycle);
if (ret)
- return ret;
+ goto out;
goto next;
}
raw_spin_unlock(&b->lock.wait_lock);
}
}
-
+up:
if (g.nr > 1 && cycle)
print_chain(cycle, &g);
lock_graph_up(&g);
goto next;
+out:
+ if (cycle)
+ --cycle->atomic;
+ rcu_read_unlock();
+ return ret;
}
int bch2_six_check_for_deadlock(struct six_lock *lock, void *p)
@@ -417,7 +436,7 @@ void bch2_btree_node_lock_write_nofail(struct btree_trans *trans,
struct btree_bkey_cached_common *b)
{
struct btree_path *linked;
- unsigned i;
+ unsigned i, iter;
int ret;
/*
@@ -431,7 +450,7 @@ void bch2_btree_node_lock_write_nofail(struct btree_trans *trans,
* already taken are no longer needed:
*/
- trans_for_each_path(trans, linked) {
+ trans_for_each_path(trans, linked, iter) {
if (!linked->nodes_locked)
continue;
@@ -643,8 +662,6 @@ bool __bch2_btree_path_upgrade(struct btree_trans *trans,
unsigned new_locks_want,
struct get_locks_fail *f)
{
- struct btree_path *linked;
-
if (bch2_btree_path_upgrade_noupgrade_sibs(trans, path, new_locks_want, f))
return true;
@@ -667,8 +684,11 @@ bool __bch2_btree_path_upgrade(struct btree_trans *trans,
* before interior nodes - now that's handled by
* bch2_btree_path_traverse_all().
*/
- if (!path->cached && !trans->in_traverse_all)
- trans_for_each_path(trans, linked)
+ if (!path->cached && !trans->in_traverse_all) {
+ struct btree_path *linked;
+ unsigned i;
+
+ trans_for_each_path(trans, linked, i)
if (linked != path &&
linked->cached == path->cached &&
linked->btree_id == path->btree_id &&
@@ -676,6 +696,7 @@ bool __bch2_btree_path_upgrade(struct btree_trans *trans,
linked->locks_want = new_locks_want;
btree_path_get_locks(trans, linked, true, NULL);
}
+ }
return false;
}
@@ -708,7 +729,6 @@ void __bch2_btree_path_downgrade(struct btree_trans *trans,
bch2_btree_path_verify_locks(path);
- path->downgrade_seq++;
trace_path_downgrade(trans, _RET_IP_, path, old_locks_want);
}
@@ -717,22 +737,24 @@ void __bch2_btree_path_downgrade(struct btree_trans *trans,
void bch2_trans_downgrade(struct btree_trans *trans)
{
struct btree_path *path;
+ unsigned i;
if (trans->restarted)
return;
- trans_for_each_path(trans, path)
+ trans_for_each_path(trans, path, i)
bch2_btree_path_downgrade(trans, path);
}
int bch2_trans_relock(struct btree_trans *trans)
{
struct btree_path *path;
+ unsigned i;
if (unlikely(trans->restarted))
return -((int) trans->restarted);
- trans_for_each_path(trans, path)
+ trans_for_each_path(trans, path, i)
if (path->should_be_locked &&
!bch2_btree_path_relock_norestart(trans, path, _RET_IP_)) {
trace_and_count(trans->c, trans_restart_relock, trans, _RET_IP_, path);
@@ -744,11 +766,12 @@ int bch2_trans_relock(struct btree_trans *trans)
int bch2_trans_relock_notrace(struct btree_trans *trans)
{
struct btree_path *path;
+ unsigned i;
if (unlikely(trans->restarted))
return -((int) trans->restarted);
- trans_for_each_path(trans, path)
+ trans_for_each_path(trans, path, i)
if (path->should_be_locked &&
!bch2_btree_path_relock_norestart(trans, path, _RET_IP_)) {
return btree_trans_restart(trans, BCH_ERR_transaction_restart_relock);
@@ -759,16 +782,18 @@ int bch2_trans_relock_notrace(struct btree_trans *trans)
void bch2_trans_unlock_noassert(struct btree_trans *trans)
{
struct btree_path *path;
+ unsigned i;
- trans_for_each_path(trans, path)
+ trans_for_each_path(trans, path, i)
__bch2_btree_path_unlock(trans, path);
}
void bch2_trans_unlock(struct btree_trans *trans)
{
struct btree_path *path;
+ unsigned i;
- trans_for_each_path(trans, path)
+ trans_for_each_path(trans, path, i)
__bch2_btree_path_unlock(trans, path);
}
@@ -781,8 +806,9 @@ void bch2_trans_unlock_long(struct btree_trans *trans)
bool bch2_trans_locked(struct btree_trans *trans)
{
struct btree_path *path;
+ unsigned i;
- trans_for_each_path(trans, path)
+ trans_for_each_path(trans, path, i)
if (path->nodes_locked)
return true;
return false;
@@ -828,8 +854,9 @@ void bch2_btree_path_verify_locks(struct btree_path *path)
void bch2_trans_verify_locks(struct btree_trans *trans)
{
struct btree_path *path;
+ unsigned i;
- trans_for_each_path(trans, path)
+ trans_for_each_path(trans, path, i)
bch2_btree_path_verify_locks(path);
}
generated by cgit v1.2.3 (git 2.46.0) at 2025-08-01 19:32:18 +0000