SCSI: zfcp: restore refcount check on port_remove
authorSteffen Maier <maier@linux.vnet.ibm.com>
Tue, 4 Sep 2012 13:23:34 +0000 (15:23 +0200)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Fri, 12 Oct 2012 20:38:47 +0000 (05:38 +0900)
commit960e8a5e0257c26bb5d5b14c8c89919e1293e76c
tree0a9ab1b510569e4c606e6a818220862af0bfbb9d
parentab37eb284ac88f092187f7c4ee4a42c28cdaf3e5
SCSI: zfcp: restore refcount check on port_remove

commit d99b601b63386f3395dc26a699ae703a273d9982 upstream.

Upstream commit f3450c7b917201bb49d67032e9f60d5125675d6a
"[SCSI] zfcp: Replace local reference counting with common kref"
accidentally dropped a reference count check before tearing down
zfcp_ports that are potentially in use by zfcp_units.
Even remote ports in use can be removed causing
unreachable garbage objects zfcp_ports with zfcp_units.
Thus units won't come back even after a manual port_rescan.
The kref of zfcp_port->dev.kobj is already used by the driver core.
We cannot re-use it to track the number of zfcp_units.
Re-introduce our own counter for units per port
and check on port_remove.

Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/s390/scsi/zfcp_aux.c
drivers/s390/scsi/zfcp_def.h
drivers/s390/scsi/zfcp_ext.h
drivers/s390/scsi/zfcp_sysfs.c
drivers/s390/scsi/zfcp_unit.c