The recent change in sysfs, bcdde7e221a8750f9b62b6d0bd31b72ea4ad9309
"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@xxxxxxxxxxx>
Cc: "James E.J. Bottomley" <JBottomley@xxxxxxxxxxxxx>
---
drivers/scsi/scsi_transport_sas.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/scsi/scsi_transport_sas.c b/drivers/scsi/scsi_transport_sas.c
index 1b681427dde0..c341f855fadc 100644
--- a/drivers/scsi/scsi_transport_sas.c
+++ b/drivers/scsi/scsi_transport_sas.c
@@ -1621,8 +1621,6 @@ void sas_rphy_free(struct sas_rphy *rphy)
list_del(&rphy->list);
mutex_unlock(&sas_host->lock);
- sas_bsg_remove(shost, rphy);
-
transport_destroy_device(dev);
put_device(dev);
@@ -1681,6 +1679,7 @@ sas_rphy_remove(struct sas_rphy *rphy)
}
sas_rphy_unlink(rphy);
+ sas_bsg_remove(NULL, rphy);
transport_remove_device(dev);
device_del(dev);
}
--
1.8.3.1
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