[PATCH v3] erofs-utils: fix thread join loop in erofs_destroy_workqueue

[Nithurshen Karthikeyan]

On Wed, Mar 18, 2026 at 1:47 PM Yifan Zhao <stopire at gmail.com> wrote:
>>
>> On 3/18/2026 2:03 PM, Nithurshen wrote:
>>
>> Currently, `erofs_destroy_workqueue` returns immediately if a single
>> `pthread_join` fails. However, it does not log the failure, making it
>> difficult to debug if a worker thread gets stuck.
>>
>> Add an error log when `pthread_join` fails. Retain the early return
>> behavior to safely abort the teardown process, ensuring we do not
>> free the synchronization primitives and worker array while threads
>> are potentially still alive (avoiding a use after free).
>>
>> Signed-off-by: Nithurshen <nithurshen.dev at gmail.com>
>> ---
>>  lib/workqueue.c | 7 ++++++-
>>  1 file changed, 6 insertions(+), 1 deletion(-)
>>
>> diff --git a/lib/workqueue.c b/lib/workqueue.c
>> index 18ee0f9..4a1a957 100644
>> --- a/lib/workqueue.c
>> +++ b/lib/workqueue.c
>> @@ -1,6 +1,7 @@
>>  // SPDX-License-Identifier: GPL-2.0+ OR Apache-2.0
>>  #include <pthread.h>
>>  #include <stdlib.h>
>> +#include "erofs/print.h"
>>  #include "erofs/workqueue.h"
>>
>>  static void *worker_thread(void *arg)
>> @@ -53,10 +54,14 @@ int erofs_destroy_workqueue(struct erofs_workqueue *wq)
>>   while (wq->nworker) {
>>   int ret = -pthread_join(wq->workers[wq->nworker - 1], NULL);
>>
>> - if (ret)
>> + if (ret) {
>> + erofs_err("failed to join worker thread %u: %d",
>> +  wq->nworker - 1, ret);
>>   return ret;
>> + }
>>   --wq->nworker;
>>   }
>> +
>>   free(wq->workers);
>>   pthread_mutex_destroy(&wq->lock);
>>   pthread_cond_destroy(&wq->cond_empty);
>>
>> Reviewed-by: Yifan Zhao <stopire at gmail.com>

Thanks for the review,
It looks like the CC list was dropped on your last reply,
so I'm adding the mailing list back.