The recent change in sysfs, bcdde7e221
"sysfs: make __sysfs_remove_dir() recursive" revealed an asymmetric
rphy device creation/deletion sequence in scsi_transport_sas:
modprobe mpt2sas
sas_rphy_add
device_add A rphy->dev
device_add B sas_device transport class
device_add C sas_end_device transport class
device_add D bsg class
rmmod mpt2sas
sas_rphy_delete
sas_rphy_remove
device_del B
device_del C
device_del A
sysfs_remove_group recursive sysfs dir removal
sas_rphy_free
device_del D warning
where device A is the parent of B, C, and D.
When sas_rphy_free tries to unregister the bsg request queue (device D
above), the ensuing sysfs cleanup discovers that its sysfs group has
already been removed and emits a warning, "sysfs group... not found for
kobject 'end_device-X:0'".
Since bsg creation is a side effect of sas_rphy_add, move its
complementary removal call into sas_rphy_remove. This imposes the
following tear-down order for the devices above: D, B, C, A.
Note the sas_device and sas_end_device transport class devices (B and C
above) are created and destroyed both via the list match traversal in
attribute_container_device_trigger, so the order in which they are
handled is fixed. This is fine as long as they are deleted before their
parent device.
Signed-off-by: Joe Lawrence <joe.lawrence@stratus.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
6aa6caff30