[LU-19860] Missing mutex_unlock in chlg_obd_get() error path causes deadlock

• Type: Bug
• Resolution: Fixed
• Priority: Medium
• Severity: 3
• Assignee: Sohei Koyama
• Reporter: Sohei Koyama

Description

chlg_obd_get() in lustre/mdc/mdc_changelog.c acquires chlg_registered_dev_lock but fails to release it when ced_obds list is empty, causing a deadlock for any subsequent caller that tries to acquire the same mutex.

 

static inline struct obd_device* chlg_obd_get(struct chlg_registered_dev *dev)
{
      struct obd_device *obd;
      mutex_lock(&chlg_registered_dev_lock);
      if (list_empty(&dev->ced_obds))
          return NULL;              // <-- mutex not released
      ...
      mutex_unlock(&chlg_registered_dev_lock);
      return obd;
}

Issue Links

• duplicates: LU-18999 chlg_obd_get() does not unlock semaphore on error path