Guenter Roeck reports a lockdep splat and DEBUG_OBJECTS_WORK related warning when bch2_copygc_thread() initializes its rhashtable. The lockdep splat relates to a warning print caused by the fact that the rhashtable exists on the stack but is not annotated as so. This is something that could be addressed by INIT_WORK_ONSTACK(), but rhashtable doesn't expose that control and probably isnt worth the churn for just one user. Instead, dynamically allocate the buckets_in_flight structure and avoid the splat that way.
Reported-by: Guenter Roeck <[email protected]> Tested-by: Guenter Roeck <[email protected]> Signed-off-by: Brian Foster <[email protected]> --- fs/bcachefs/movinggc.c | 24 ++++++++++++++---------- 1 file changed, 14 insertions(+), 10 deletions(-) diff --git a/fs/bcachefs/movinggc.c b/fs/bcachefs/movinggc.c index 6f9882f6622b..0158c7aae6b0 100644 --- a/fs/bcachefs/movinggc.c +++ b/fs/bcachefs/movinggc.c @@ -305,14 +305,16 @@ static int bch2_copygc_thread(void *arg) struct moving_context ctxt; struct bch_move_stats move_stats; struct io_clock *clock = &c->io_clock[WRITE]; - struct buckets_in_flight buckets; + struct buckets_in_flight *buckets; u64 last, wait; int ret = 0; - memset(&buckets, 0, sizeof(buckets)); - - ret = rhashtable_init(&buckets.table, &bch_move_bucket_params); + buckets = kzalloc(sizeof(struct buckets_in_flight), GFP_KERNEL); + if (!buckets) + return -ENOMEM; + ret = rhashtable_init(&buckets->table, &bch_move_bucket_params); if (ret) { + kfree(buckets); bch_err_msg(c, ret, "allocating copygc buckets in flight"); return ret; } @@ -331,12 +333,12 @@ static int bch2_copygc_thread(void *arg) cond_resched(); if (!c->copy_gc_enabled) { - move_buckets_wait(&ctxt, &buckets, true); + move_buckets_wait(&ctxt, buckets, true); kthread_wait_freezable(c->copy_gc_enabled); } if (unlikely(freezing(current))) { - move_buckets_wait(&ctxt, &buckets, true); + move_buckets_wait(&ctxt, buckets, true); __refrigerator(false); continue; } @@ -347,7 +349,7 @@ static int bch2_copygc_thread(void *arg) if (wait > clock->max_slop) { c->copygc_wait_at = last; c->copygc_wait = last + wait; - move_buckets_wait(&ctxt, &buckets, true); + move_buckets_wait(&ctxt, buckets, true); trace_and_count(c, copygc_wait, c, wait, last + wait); bch2_kthread_io_clock_wait(clock, last + wait, MAX_SCHEDULE_TIMEOUT); @@ -357,7 +359,7 @@ static int bch2_copygc_thread(void *arg) c->copygc_wait = 0; c->copygc_running = true; - ret = bch2_copygc(&ctxt, &buckets, &did_work); + ret = bch2_copygc(&ctxt, buckets, &did_work); c->copygc_running = false; wake_up(&c->copygc_running_wq); @@ -373,8 +375,10 @@ static int bch2_copygc_thread(void *arg) } } - move_buckets_wait(&ctxt, &buckets, true); - rhashtable_destroy(&buckets.table); + move_buckets_wait(&ctxt, buckets, true); + + rhashtable_destroy(&buckets->table); + kfree(buckets); bch2_moving_ctxt_exit(&ctxt); bch2_move_stats_exit(&move_stats, c); -- 2.41.0
