d2b59bd4b0
Commit0b9902c1fc("s390/qeth: fix deadlock during recovery") removed taking discipline_mutex inside qeth_do_reset(), fixing potential deadlocks. An error path was missed though, that still takes discipline_mutex and thus has the original deadlock potential. Intermittent deadlocks were seen when a qeth channel path is configured offline, causing a race between qeth_do_reset and ccwgroup_remove. Call qeth_set_offline() directly in the qeth_do_reset() error case and then a new variant of ccwgroup_set_offline(), without taking discipline_mutex. Fixes:b41b554c1e("s390/qeth: fix locking for discipline setup / removal") Signed-off-by: Alexandra Winter <wintera@linux.ibm.com> Reviewed-by: Julian Wiedmann <jwi@linux.ibm.com> Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
75 lines
2.2 KiB
C
75 lines
2.2 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
#ifndef S390_CCWGROUP_H
|
|
#define S390_CCWGROUP_H
|
|
|
|
struct ccw_device;
|
|
struct ccw_driver;
|
|
|
|
/**
|
|
* struct ccwgroup_device - ccw group device
|
|
* @state: online/offline state
|
|
* @count: number of attached slave devices
|
|
* @dev: embedded device structure
|
|
* @cdev: variable number of slave devices, allocated as needed
|
|
* @ungroup_work: used to ungroup the ccwgroup device
|
|
*/
|
|
struct ccwgroup_device {
|
|
enum {
|
|
CCWGROUP_OFFLINE,
|
|
CCWGROUP_ONLINE,
|
|
} state;
|
|
/* private: */
|
|
atomic_t onoff;
|
|
struct mutex reg_mutex;
|
|
/* public: */
|
|
unsigned int count;
|
|
struct device dev;
|
|
struct work_struct ungroup_work;
|
|
struct ccw_device *cdev[0];
|
|
};
|
|
|
|
/**
|
|
* struct ccwgroup_driver - driver for ccw group devices
|
|
* @setup: function called during device creation to setup the device
|
|
* @remove: function called on remove
|
|
* @set_online: function called when device is set online
|
|
* @set_offline: function called when device is set offline
|
|
* @shutdown: function called when device is shut down
|
|
* @driver: embedded driver structure
|
|
* @ccw_driver: supported ccw_driver (optional)
|
|
*/
|
|
struct ccwgroup_driver {
|
|
int (*setup) (struct ccwgroup_device *);
|
|
void (*remove) (struct ccwgroup_device *);
|
|
int (*set_online) (struct ccwgroup_device *);
|
|
int (*set_offline) (struct ccwgroup_device *);
|
|
void (*shutdown)(struct ccwgroup_device *);
|
|
|
|
struct device_driver driver;
|
|
struct ccw_driver *ccw_driver;
|
|
};
|
|
|
|
extern int ccwgroup_driver_register (struct ccwgroup_driver *cdriver);
|
|
extern void ccwgroup_driver_unregister (struct ccwgroup_driver *cdriver);
|
|
int ccwgroup_create_dev(struct device *root, struct ccwgroup_driver *gdrv,
|
|
int num_devices, const char *buf);
|
|
|
|
extern int ccwgroup_set_online(struct ccwgroup_device *gdev);
|
|
int ccwgroup_set_offline(struct ccwgroup_device *gdev, bool call_gdrv);
|
|
|
|
extern int ccwgroup_probe_ccwdev(struct ccw_device *cdev);
|
|
extern void ccwgroup_remove_ccwdev(struct ccw_device *cdev);
|
|
|
|
#define to_ccwgroupdev(x) container_of((x), struct ccwgroup_device, dev)
|
|
#define to_ccwgroupdrv(x) container_of((x), struct ccwgroup_driver, driver)
|
|
|
|
#if IS_ENABLED(CONFIG_CCWGROUP)
|
|
bool dev_is_ccwgroup(struct device *dev);
|
|
#else /* CONFIG_CCWGROUP */
|
|
static inline bool dev_is_ccwgroup(struct device *dev)
|
|
{
|
|
return false;
|
|
}
|
|
#endif /* CONFIG_CCWGROUP */
|
|
|
|
#endif
|