diff options
| -rw-r--r-- | drivers/s390/block/dasd.c | 4 | ||||
| -rw-r--r-- | drivers/s390/block/dasd_devmap.c | 74 | ||||
| -rw-r--r-- | drivers/s390/block/dasd_int.h | 1 |
3 files changed, 51 insertions, 28 deletions
diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c index 25c1ef6dfd44..3cd87f85f702 100644 --- a/drivers/s390/block/dasd.c +++ b/drivers/s390/block/dasd.c @@ -893,7 +893,7 @@ dasd_handle_killed_request(struct ccw_device *cdev, unsigned long intparm) device = (struct dasd_device *) cqr->device; if (device == NULL || - device != dasd_device_from_cdev(cdev) || + device != dasd_device_from_cdev_locked(cdev) || strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) { MESSAGE(KERN_DEBUG, "invalid device in request: bus_id %s", cdev->dev.bus_id); @@ -970,7 +970,7 @@ dasd_int_handler(struct ccw_device *cdev, unsigned long intparm, /* first of all check for state change pending interrupt */ mask = DEV_STAT_ATTENTION | DEV_STAT_DEV_END | DEV_STAT_UNIT_EXCEP; if ((irb->scsw.dstat & mask) == mask) { - device = dasd_device_from_cdev(cdev); + device = dasd_device_from_cdev_locked(cdev); if (!IS_ERR(device)) { dasd_handle_state_change_pending(device); dasd_put_device(device); diff --git a/drivers/s390/block/dasd_devmap.c b/drivers/s390/block/dasd_devmap.c index 9af02c79ce8a..80cf0999465a 100644 --- a/drivers/s390/block/dasd_devmap.c +++ b/drivers/s390/block/dasd_devmap.c @@ -523,17 +523,17 @@ dasd_create_device(struct ccw_device *cdev) { struct dasd_devmap *devmap; struct dasd_device *device; + unsigned long flags; int rc; devmap = dasd_devmap_from_cdev(cdev); if (IS_ERR(devmap)) return (void *) devmap; - cdev->dev.driver_data = devmap; device = dasd_alloc_device(); if (IS_ERR(device)) return device; - atomic_set(&device->ref_count, 2); + atomic_set(&device->ref_count, 3); spin_lock(&dasd_devmap_lock); if (!devmap->device) { @@ -552,6 +552,11 @@ dasd_create_device(struct ccw_device *cdev) dasd_free_device(device); return ERR_PTR(rc); } + + spin_lock_irqsave(get_ccwdev_lock(cdev), flags); + cdev->dev.driver_data = device; + spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags); + return device; } @@ -569,6 +574,7 @@ dasd_delete_device(struct dasd_device *device) { struct ccw_device *cdev; struct dasd_devmap *devmap; + unsigned long flags; /* First remove device pointer from devmap. */ devmap = dasd_find_busid(device->cdev->dev.bus_id); @@ -582,9 +588,16 @@ dasd_delete_device(struct dasd_device *device) devmap->device = NULL; spin_unlock(&dasd_devmap_lock); - /* Drop ref_count by 2, one for the devmap reference and - * one for the passed reference. */ - atomic_sub(2, &device->ref_count); + /* Disconnect dasd_device structure from ccw_device structure. */ + spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags); + device->cdev->dev.driver_data = NULL; + spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags); + + /* + * Drop ref_count by 3, one for the devmap reference, one for + * the cdev reference and one for the passed reference. + */ + atomic_sub(3, &device->ref_count); /* Wait for reference counter to drop to zero. */ wait_event(dasd_delete_wq, atomic_read(&device->ref_count) == 0); @@ -593,9 +606,6 @@ dasd_delete_device(struct dasd_device *device) cdev = device->cdev; device->cdev = NULL; - /* Disconnect dasd_devmap structure from ccw_device structure. */ - cdev->dev.driver_data = NULL; - /* Put ccw_device structure. */ put_device(&cdev->dev); @@ -615,21 +625,32 @@ dasd_put_device_wake(struct dasd_device *device) /* * Return dasd_device structure associated with cdev. + * This function needs to be called with the ccw device + * lock held. It can be used from interrupt context. + */ +struct dasd_device * +dasd_device_from_cdev_locked(struct ccw_device *cdev) +{ + struct dasd_device *device = cdev->dev.driver_data; + + if (!device) + return ERR_PTR(-ENODEV); + dasd_get_device(device); + return device; +} + +/* + * Return dasd_device structure associated with cdev. */ struct dasd_device * dasd_device_from_cdev(struct ccw_device *cdev) { - struct dasd_devmap *devmap; struct dasd_device *device; + unsigned long flags; - device = ERR_PTR(-ENODEV); - spin_lock(&dasd_devmap_lock); - devmap = cdev->dev.driver_data; - if (devmap && devmap->device) { - device = devmap->device; - dasd_get_device(device); - } - spin_unlock(&dasd_devmap_lock); + spin_lock_irqsave(get_ccwdev_lock(cdev), flags); + device = dasd_device_from_cdev_locked(cdev); + spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags); return device; } @@ -730,16 +751,17 @@ static ssize_t dasd_discipline_show(struct device *dev, struct device_attribute *attr, char *buf) { - struct dasd_devmap *devmap; - char *dname; + struct dasd_device *device; + ssize_t len; - spin_lock(&dasd_devmap_lock); - dname = "none"; - devmap = dev->driver_data; - if (devmap && devmap->device && devmap->device->discipline) - dname = devmap->device->discipline->name; - spin_unlock(&dasd_devmap_lock); - return snprintf(buf, PAGE_SIZE, "%s\n", dname); + device = dasd_device_from_cdev(to_ccwdev(dev)); + if (!IS_ERR(device) && device->discipline) { + len = snprintf(buf, PAGE_SIZE, "%s\n", + device->discipline->name); + dasd_put_device(device); + } else + len = snprintf(buf, PAGE_SIZE, "none\n"); + return len; } static DEVICE_ATTR(discipline, 0444, dasd_discipline_show, NULL); diff --git a/drivers/s390/block/dasd_int.h b/drivers/s390/block/dasd_int.h index 3ccf06d28ba1..9f52004f6fc2 100644 --- a/drivers/s390/block/dasd_int.h +++ b/drivers/s390/block/dasd_int.h @@ -534,6 +534,7 @@ int dasd_add_sysfs_files(struct ccw_device *); void dasd_remove_sysfs_files(struct ccw_device *); struct dasd_device *dasd_device_from_cdev(struct ccw_device *); +struct dasd_device *dasd_device_from_cdev_locked(struct ccw_device *); struct dasd_device *dasd_device_from_devindex(int); int dasd_parse(void); |
