// SPDX-License-Identifier: GPL-2.0
/*
* zfcp device driver
*
* Tracking of manually configured LUNs and helper functions to
* register the LUNs with the SCSI midlayer.
*
* Copyright IBM Corp. 2010
*/
#include "zfcp_def.h"
#include "zfcp_ext.h"
/**
* zfcp_unit_scsi_scan - Register LUN with SCSI midlayer
* @unit: The zfcp LUN/unit to register
*
* When the SCSI midlayer is not allowed to automatically scan and
* attach SCSI devices, zfcp has to register the single devices with
* the SCSI midlayer.
*/
void zfcp_unit_scsi_scan(struct zfcp_unit *unit)
{
struct fc_rport *rport = unit->port->rport;
u64 lun;
lun = scsilun_to_int((struct scsi_lun *) &unit->fcp_lun);
if (rport && rport->port_state == FC_PORTSTATE_ONLINE)
scsi_scan_target(&rport->dev, 0, rport->scsi_target_id, lun,
SCSI_SCAN_MANUAL);
}
static void zfcp_unit_scsi_scan_work(struct work_struct *work)
{
struct zfcp_unit *unit = container_of(work, struct zfcp_unit,
scsi_work);
zfcp_unit_scsi_scan(unit);
put_device(&unit->dev);
}
/**
* zfcp_unit_queue_scsi_scan - Register configured units on port
* @port: The zfcp_port where to register units
*
* After opening a port, all units configured on this port have to be
* registered with the SCSI midlayer. This function should be called
* after calling fc_remote_port_add, so that the fc_rport is already
* ONLINE and the call to scsi_scan_target runs the same way as the
* call in the FC transport class.
*/
void zfcp_unit_queue_scsi_scan(struct zfcp_port *port)
{
struct zfcp_unit *unit;
read_lock_irq(&port->unit_list_lock);
list_for_each_entry(unit, &port->unit_list, list) {
get_device(&unit->dev);
if (scsi_queue_work(port->adapter->scsi_host,
&unit->scsi_work) <= 0)
put_device(&unit->dev);
}
read_unlock_irq(&port->unit_list_lock);
}
static struct zfcp_unit *_zfcp_unit_find(struct zfcp_port *port, u64 fcp_lun)
{
struct zfcp_unit *unit;
list_for_each_entry(unit, &port->unit_list, list)
if (unit->fcp_lun == fcp_lun) {
get_device(&unit->dev);
return unit;
}
return NULL;
}
/**
* zfcp_unit_find - Find and return zfcp_unit with specified FCP LUN
* @port: zfcp_port where to look for the unit
* @fcp_lun: 64 Bit FCP LUN used to identify the zfcp_unit
*
* If zfcp_unit is found, a reference is acquired that has to be
* released later.
*
* Returns: Pointer to the zfcp_unit, or NULL if there is no zfcp_unit
* with the specified FCP LUN.
*/
struct zfcp_unit *zfcp_unit_find(struct zfcp_port *port, u64 fcp_lun)
{
struct zfcp_unit *unit;
read_lock_irq(&port->unit_list_lock);
unit = _zfcp_unit_find(port, fcp_lun);
read_unlock_irq(&port->unit_list_lock);
return unit;
}
/**
* zfcp_unit_release - Drop reference to zfcp_port and free memory of zfcp_unit.
* @dev: pointer to device in zfcp_unit
*/
static void zfcp_unit_release(struct device *dev)
{
struct zfcp_unit *unit = container_of(dev, struct zfcp_unit, dev);
atomic_dec(&unit->port->units);
kfree(unit);
}
/**
* zfcp_unit_add - add unit to unit list of a port.
* @port: pointer to port where unit is added
* @fcp_lun: FCP LUN of unit to be added
* Returns: 0 success
*
* Sets up some unit internal structures and creates sysfs entry.
*/
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 (zfcp_sysfs_port_is_removing(port)) {
/* port is already gone */
retval = -ENODEV;
goto out;
}
unit = zfcp_unit_find(port, fcp_lun);
if (unit) {
put_device(&unit->dev);
retval = -EEXIST;
goto out;
}
unit = kzalloc(sizeof(struct zfcp_unit), GFP_KERNEL);
if (!unit) {
retval = -ENOMEM;
goto out;
}
unit->port = port;
unit->fcp_lun = fcp_lun;
unit->dev.parent = &port->dev;
unit->dev.release = zfcp_unit_release;
unit->dev.groups = zfcp_unit_attr_groups;
INIT_WORK(&unit->scsi_work, zfcp_unit_scsi_scan_work);
if (dev_set_name(&unit->dev, "0x%016llx",
(unsigned long long) fcp_lun)) {
kfree(unit);
retval = -ENOMEM;
goto out;
}
if (device_register(&unit->dev)) {
put_device(&unit->dev);
retval = -ENOMEM;
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);
/*
* lock order: shost->scan_mutex before zfcp_sysfs_port_units_mutex
* due to zfcp_unit_scsi_scan() => zfcp_scsi_slave_alloc()
*/
mutex_unlock(&zfcp_sysfs_port_units_mutex);
zfcp_unit_scsi_scan(unit);
return retval;
out:
mutex_unlock(&zfcp_sysfs_port_units_mutex);
return retval;
}
/**
* zfcp_unit_sdev - Return SCSI device for zfcp_unit
* @unit: The zfcp_unit where to get the SCSI device for
*
* Returns: scsi_device pointer on success, NULL if there is no SCSI
* device for this zfcp_unit
*
* On success, the caller also holds a reference to the SCSI device
* that must be released with scsi_device_put.
*/
struct scsi_device *zfcp_unit_sdev(struct zfcp_unit *unit)
{
struct Scsi_Host *shost;
struct zfcp_port *port;
u64 lun;
lun = scsilun_to_int((struct scsi_lun *) &unit->fcp_lun);
port = unit->port;
shost = port->adapter->scsi_host;
return scsi_device_lookup(shost, 0, port->starget_id, lun);
}
/**
* zfcp_unit_sdev_status - Return zfcp LUN status for SCSI device
* @unit: The unit to lookup the SCSI device for
*
* Returns the zfcp LUN status field of the SCSI device if the SCSI device
* for the zfcp_unit exists, 0 otherwise.
*/
unsigned int zfcp_unit_sdev_status(struct zfcp_unit *unit)
{
unsigned int status = 0;
struct scsi_device *sdev;
struct zfcp_scsi_dev *zfcp_sdev;
sdev = zfcp_unit_sdev(unit);
if (sdev) {
zfcp_sdev = sdev_to_zfcp(sdev);
status = atomic_read(&zfcp_sdev->status);
scsi_device_put(sdev);
}
return status;
}
/**
* zfcp_unit_remove - Remove entry from list of configured units
* @port: The port where to remove the unit from the configuration
* @fcp_lun: The 64 bit LUN of the unit to remove
*
* Returns: -EINVAL if a unit with the specified LUN does not exist,
* 0 on success.
*/
int zfcp_unit_remove(struct zfcp_port *port, u64 fcp_lun)
{
struct zfcp_unit *unit;
struct scsi_device *sdev;
write_lock_irq(&port->unit_list_lock);
unit = _zfcp_unit_find(port, fcp_lun);
if (unit)
list_del(&unit->list);
write_unlock_irq(&port->unit_list_lock);
if (!unit)
return -EINVAL;
sdev = zfcp_unit_sdev(unit);
if (sdev) {
scsi_remove_device(sdev);
scsi_device_put(sdev);
}
device_unregister(&unit->dev);
put_device(&unit->dev); /* undo _zfcp_unit_find() */
return 0;
}
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