Messages in this thread | | | Subject | Re: [PATCH v4 00/11] Enhance libsas hotplug feature | From | John Garry <> | Date | Wed, 6 Sep 2017 14:07:57 +0100 |
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On 06/09/2017 10:15, Jason Yan wrote: > Hello all, Yijing Wang handed over this topic to me. We are working > on it the last two months. We have tested the patchset for a long > time. Here is the new version. > > Now the libsas hotplug has some issues, Dan Williams report > a similar bug here before > https://www.mail-archive.com/linux-scsi@vger.kernel.org/msg39187.html > > The issues we have found > 1. if LLDD burst reports lots of phy-up/phy-down sas events, some events > may lost because a same sas events is pending now, finally libsas topo > may different the hardware. > 2. receive a phy down sas event, libsas call sas_deform_port to remove > devices, it would first delete the sas port, then put a destruction > discovery event in a new work, and queue it at the tail of workqueue, > once the sas port be deleted, its children device will be deleted too, > when the destruction work start, it will found the target device has > been removed, and report a sysfs warnning. > 3. since a hotplug process will be divided into several works, if a phy up > sas event insert into phydown works, like > destruction work ---> PORTE_BYTES_DMAED (sas_form_port) ---->PHYE_LOSS_OF_SIGNAL > the hot remove flow would broken by PORTE_BYTES_DMAED event, it's not > we expected, and issues would occur. > > v3->v4: -get rid of unused ha event and do some cleanup > -use dynamic alloced work and support shutting down the phy if active event reached the threshold > -use flush_workqueue instead of wait-completion to process discover events synchronously > -direct call probe and destruct function > -other small code improvements > v2->v3: some code improvements suggested by Johannes and John, > split v2 patch 2 into several small patches. > v1->v2: some code improvements suggested by John Garry > > Jason Yan (10): > libsas: kill useless ha_event and do some cleanup > libsas: remove the numbering for each event enum > libsas: remove unused port_gone_completion and DISCE_PORT_GONE > libsas: rename notify_port_event() for consistency > libsas: Use dynamic alloced work to avoid sas event lost > libsas: shut down the PHY if events reached the threshold > libsas: make the event threshold configurable > libsas: Use new workqueue to run sas event and disco event > libsas: libsas: use flush_workqueue to process disco events > synchronously > libsas: direct call probe and destruct > > chenxiang (1): > libsas: add event to defer list tail instead of head when draining >
Regardless of the fate of the rest of the patches in this series, I think patches 1,2,3,4,11/11 can be taken in isolation (subject to review, of course). It would save maintaining them out-of-tree.
John
> drivers/scsi/aic94xx/aic94xx_hwi.c | 3 - > drivers/scsi/hisi_sas/hisi_sas_main.c | 7 ++- > drivers/scsi/libsas/sas_ata.c | 1 - > drivers/scsi/libsas/sas_discover.c | 36 +++++++----- > drivers/scsi/libsas/sas_dump.c | 10 ---- > drivers/scsi/libsas/sas_dump.h | 1 - > drivers/scsi/libsas/sas_event.c | 97 +++++++++++++++++++------------- > drivers/scsi/libsas/sas_expander.c | 2 +- > drivers/scsi/libsas/sas_init.c | 101 +++++++++++++++++++++++++++++----- > drivers/scsi/libsas/sas_internal.h | 7 +++ > drivers/scsi/libsas/sas_phy.c | 73 ++++++++++++------------ > drivers/scsi/libsas/sas_port.c | 25 +++++---- > include/scsi/libsas.h | 81 ++++++++++++--------------- > include/scsi/scsi_transport_sas.h | 1 + > 14 files changed, 270 insertions(+), 175 deletions(-) >
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