On Fri, 2018-08-10 at 15:27 +-0000, Bart Van Assche wrote: +AD4- On Fri, 2018-08-10 at 10:39 +-0800, jianchao.wang wrote: +AD4- +AD4- On 08/10/2018 03:41 AM, Bart Van Assche wrote: +AD4- +AD4- +AD4- +-void blk+AF8-pm+AF8-runtime+AF8-exit(struct request+AF8-queue +ACo-q) +AD4- +AD4- +AD4- +-+AHs- +AD4- +AD4- +AD4- +- if (+ACE-q-+AD4-dev) +AD4- +AD4- +AD4- +- return+ADs- +AD4- +AD4- +AD4- +- +AD4- +AD4- +AD4- +- pm+AF8-runtime+AF8-get+AF8-sync(q-+AD4-dev)+ADs- +AD4- +AD4- +AD4- +- q-+AD4-dev +AD0- NULL+ADs- +AD4- +AD4- +AD4- +-+AH0- +AD4- +AD4- +AD4- +-EXPORT+AF8-SYMBOL(blk+AF8-pm+AF8-runtime+AF8-exit)+ADs- +AD4- +AD4- +AD4- +- +AD4- +AD4- +AD4- /+ACoAKg- +AD4- +AD4- +AD4- +ACo- blk+AF8-pre+AF8-runtime+AF8-suspend - Pre runtime suspend check +AD4- +AD4- +AD4- +ACo- +AEA-q: the queue of the device +AD4- +AD4- +AD4- diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c +AD4- +AD4- +AD4- index 69ab459abb98..5537762dfcfd 100644 +AD4- +AD4- +AD4- --- a/drivers/scsi/sd.c +AD4- +AD4- +AD4- +-+-+- b/drivers/scsi/sd.c +AD4- +AD4- +AD4- +AEAAQA- -3420,12 +-3420,11 +AEAAQA- static int sd+AF8-probe(struct device +ACo-dev) +AD4- +AD4- +AD4- +ACoAKg-/ +AD4- +AD4- +AD4- static int sd+AF8-remove(struct device +ACo-dev) +AD4- +AD4- +AD4- +AHs- +AD4- +AD4- +AD4- - struct scsi+AF8-disk +ACo-sdkp+ADs- +AD4- +AD4- +AD4- - dev+AF8-t devt+ADs- +AD4- +AD4- +AD4- +- struct scsi+AF8-disk +ACo-sdkp +AD0- dev+AF8-get+AF8-drvdata(dev)+ADs- +AD4- +AD4- +AD4- +- struct scsi+AF8-device +ACo-sdp +AD0- sdkp-+AD4-device+ADs- +AD4- +AD4- +AD4- +- dev+AF8-t devt +AD0- disk+AF8-devt(sdkp-+AD4-disk)+ADs- +AD4- +AD4- +AD4- +AD4- +AD4- +AD4- - sdkp +AD0- dev+AF8-get+AF8-drvdata(dev)+ADs- +AD4- +AD4- +AD4- - devt +AD0- disk+AF8-devt(sdkp-+AD4-disk)+ADs- +AD4- +AD4- +AD4- - scsi+AF8-autopm+AF8-get+AF8-device(sdkp-+AD4-device)+ADs- +AD4- +AD4- +AD4- +- blk+AF8-pm+AF8-runtime+AF8-exit(sdp-+AD4-request+AF8-queue) +AD4- +AD4- +AD4- +AD4- +AD4- +AD4- Based on +AF8AXw-scsi+AF8-device+AF8-remove, sd+AF8-remove will be invoked before blk+AF8-cleanup+AF8-queue. +AD4- +AD4- So it should be not safe that we set the q-+AD4-dev to NULL here. +AD4- +AD4- +AD4- +AD4- We have following operations in followed patch: +AD4- +AD4- +-static inline void blk+AF8-pm+AF8-mark+AF8-last+AF8-busy(struct request +ACo-rq) +AD4- +AD4- +-+AHs- +AD4- +AD4- +- if (rq-+AD4-q-+AD4-dev +ACYAJg- +ACE-(rq-+AD4-rq+AF8-flags +ACY- RQF+AF8-PM)) +AD4- +AD4- +- pm+AF8-runtime+AF8-mark+AF8-last+AF8-busy(rq-+AD4-q-+AD4-dev)+ADs- +AD4- +AD4- +-+AH0- +AD4- +AD4- How about moving the blk+AF8-pm+AF8-runtime+AF8-exit() call into blk+AF8-cleanup+AF8-queue() at +AD4- a point where it is sure that there are no requests in progress? That should +AD4- avoid that blk+AF8-pm+AF8-mark+AF8-last+AF8-busy() races against blk+AF8-pm+AF8-runtime+AF8-exit(). That wouldn't work because unbinding the SCSI ULD doesn't remove the request queue. How about changing blk+AF8-pm+AF8-runtime+AF8-exit() into something like the following? void blk+AF8-pm+AF8-runtime+AF8-exit(struct request+AF8-queue +ACo-q) +AHs- if (+ACE-q-+AD4-dev) return+ADs- pm+AF8-runtime+AF8-get+AF8-sync(q-+AD4-dev)+ADs- blk+AF8-freeze+AF8-queue(q)+ADs- q-+AD4-dev +AD0- NULL+ADs- blk+AF8-unfreeze+AF8-queue(q)+ADs- +AH0- Bart.
