qla2xxx: fix session free stall by using scst_unregister_session wait=0#347
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lnocturno merged 1 commit intoSCST-project:masterfrom Mar 2, 2026
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Calling scst_unregister_session(wait=1) from qlt_free_session_done blocks the qla2xxx_wq worker until session teardown completes, but teardown requires the TM thread to process SCST_UNREG_SESS_TM while the TM thread is blocked on scst_mutex held by concurrent session teardown in the global management thread. Under load this stall exceeds the hung-task timeout. Switch to wait=0 and wait on fcport->unreg_done instead, matching the pattern in iscsi-scst.
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Hi Brian, Thank you for the patch! Gleb |
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Calling
scst_unregister_session(wait=1)fromqlt_free_session_doneblocks theqla2xxx_wqworker until session teardown completes, but teardown requires the TM thread to processSCST_UNREG_SESS_TMwhile the TM thread is blocked onscst_mutexheld by concurrent session teardown (scst_sess_free_tgt_devs -> synchronize_rcu()) in the global management thread.Under load this stall exceeds the hung-task timeout. Switch to
wait=0and wait onfcport->unreg_doneinstead, matching the pattern in iscsi-scst.sqa_free_session_done()is called fromscst_free_session()between its twoscst_mutexwindows, so the completion is signalled without holding the lock.(IMO, the declaration of the completion and setting of
fcport->unreg_donehints that this was always the intent.)