Hi, James, On 2016/6/1 22:06, James Bottomley wrote: > On Tue, 2016-05-31 at 16:38 +0800, Wei Fang wrote: >> sas_ata_strategy_handler() adds the works of the ata error handler >> to system_unbound_wq. This workqueue asynchronously runs work items, >> so the ata error handler will be performed concurrently on different >> CPUs. In this case, ->host_failed will be decreased simultaneously in >> scsi_eh_finish_cmd() on different CPUs, and become abnormal. >> >> It will lead to permanently inequal between ->host_failed and >> ->host_busy, and scsi error handler thread won't become running. >> IO errors after that won't be handled forever. >> >> Use atomic type for ->host_failed to fix this race. > > As I said previously, you don't need atomics to do this, could you just > remove the decrement in scsi_eh_finish_command() and zero the counter > after the strategy handler completes. > OK, I'll send v3 later. Thanks, Wei -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
