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 devided 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. The first patch fix the sas events lost, and the second one introudce wait-complete to fix the hotplug order issues. v1->v2: some code improvements suggested by John Garry Yijing Wang (2): libsas: Don't process sas events in static works libsas: Enhance libsas hotplug drivers/scsi/libsas/sas_discover.c | 58 +++++++++++++++++------- drivers/scsi/libsas/sas_event.c | 90 ++++++++++++++++++++++++++------------ drivers/scsi/libsas/sas_expander.c | 9 +++- drivers/scsi/libsas/sas_init.c | 29 +++++++++--- drivers/scsi/libsas/sas_internal.h | 64 +++++++++++++++++++++++++++ drivers/scsi/libsas/sas_phy.c | 45 ++++--------------- drivers/scsi/libsas/sas_port.c | 22 +++++----- include/scsi/libsas.h | 19 ++++---- 8 files changed, 232 insertions(+), 104 deletions(-) -- 2.5.0
