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@xxxxxxxxxxxxxxx/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(-)
