From d99b601b63386f3395dc26a699ae703a273d9982 Mon Sep 17 00:00:00 2001 From: Steffen Maier Date: Tue, 4 Sep 2012 15:23:34 +0200 Subject: [SCSI] zfcp: restore refcount check on port_remove 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 Reviewed-by: Heiko Carstens Cc: #2.6.33+ Signed-off-by: James Bottomley --- drivers/s390/scsi/zfcp_unit.c | 36 ++++++++++++++++++++++++++---------- 1 file changed, 26 insertions(+), 10 deletions(-) (limited to 'drivers/s390/scsi/zfcp_unit.c') diff --git a/drivers/s390/scsi/zfcp_unit.c b/drivers/s390/scsi/zfcp_unit.c index 3f2bff0..1cd2b99 100644 --- a/drivers/s390/scsi/zfcp_unit.c +++ b/drivers/s390/scsi/zfcp_unit.c @@ -104,7 +104,7 @@ static void zfcp_unit_release(struct device *dev) { struct zfcp_unit *unit = container_of(dev, struct zfcp_unit, dev); - put_device(&unit->port->dev); + atomic_dec(&unit->port->units); kfree(unit); } @@ -119,16 +119,27 @@ static void zfcp_unit_release(struct device *dev) int zfcp_unit_add(struct zfcp_port *port, u64 fcp_lun) { struct zfcp_unit *unit; + int retval = 0; + + mutex_lock(&zfcp_sysfs_port_units_mutex); + if (atomic_read(&port->units) == -1) { + /* port is already gone */ + retval = -ENODEV; + goto out; + } unit = zfcp_unit_find(port, fcp_lun); if (unit) { put_device(&unit->dev); - return -EEXIST; + retval = -EEXIST; + goto out; } unit = kzalloc(sizeof(struct zfcp_unit), GFP_KERNEL); - if (!unit) - return -ENOMEM; + if (!unit) { + retval = -ENOMEM; + goto out; + } unit->port = port; unit->fcp_lun = fcp_lun; @@ -139,28 +150,33 @@ int zfcp_unit_add(struct zfcp_port *port, u64 fcp_lun) if (dev_set_name(&unit->dev, "0x%016llx", (unsigned long long) fcp_lun)) { kfree(unit); - return -ENOMEM; + retval = -ENOMEM; + goto out; } - get_device(&port->dev); - if (device_register(&unit->dev)) { put_device(&unit->dev); - return -ENOMEM; + retval = -ENOMEM; + goto out; } if (sysfs_create_group(&unit->dev.kobj, &zfcp_sysfs_unit_attrs)) { device_unregister(&unit->dev); - return -EINVAL; + retval = -EINVAL; + goto out; } + atomic_inc(&port->units); /* under zfcp_sysfs_port_units_mutex ! */ + write_lock_irq(&port->unit_list_lock); list_add_tail(&unit->list, &port->unit_list); write_unlock_irq(&port->unit_list_lock); zfcp_unit_scsi_scan(unit); - return 0; +out: + mutex_unlock(&zfcp_sysfs_port_units_mutex); + return retval; } /** -- cgit v1.1