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s390/dasd: Fix inconsistent kobject removal

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Our intention was to only remove path kobjects whenever a device is
being set offline. However, one corner case was missing.

If a device is disabled and enabled (using the IOCTLs BIODASDDISABLE and
BIODASDENABLE respectively), the enabling process will call
dasd_eckd_reload_device() which itself calls dasd_eckd_read_conf() in
order to update path information. During that update,
dasd_eckd_clear_conf_data() clears all old data and also removes all
kobjects. This will leave us with an inconsistent state of path kobjects
and a subsequent path verification leads to a failing kobject creation.

Fix this by removing kobjects only in the context of offlining a device
as initially intended.

Fixes: 19508b204740 ("s390/dasd: Display FC Endpoint Security information via sysfs")
Reported-by: Stefan Haberland <sth@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
Reviewed-by: Stefan Haberland <sth@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Jan Höppner 2021-01-18 17:55:18 +01:00 committed by Jens Axboe
parent ef49d40b61
commit ac55ad2b5f
3 changed files with 17 additions and 8 deletions
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20
drivers/s390/block/dasd_devmap.c
View File

@ -1874,18 +1874,26 @@ void dasd_path_create_kobjects(struct dasd_device *device)
}
EXPORT_SYMBOL(dasd_path_create_kobjects);
/*
* As we keep kobjects for the lifetime of a device, this function must not be
* called anywhere but in the context of offlining a device.
*/
void dasd_path_remove_kobj(struct dasd_device *device, int chp)
static void dasd_path_remove_kobj(struct dasd_device *device, int chp)
{
if (device->path[chp].in_sysfs) {
kobject_put(&device->path[chp].kobj);
device->path[chp].in_sysfs = false;
}
}
EXPORT_SYMBOL(dasd_path_remove_kobj);
/*
* As we keep kobjects for the lifetime of a device, this function must not be
* called anywhere but in the context of offlining a device.
*/
void dasd_path_remove_kobjects(struct dasd_device *device)
{
int i;
for (i = 0; i < 8; i++)
dasd_path_remove_kobj(device, i);
}
EXPORT_SYMBOL(dasd_path_remove_kobjects);
int dasd_add_sysfs_files(struct ccw_device *cdev)
{

3
drivers/s390/block/dasd_eckd.c
View File

@ -1036,7 +1036,6 @@ static void dasd_eckd_clear_conf_data(struct dasd_device *device)
device->path[i].ssid = 0;
device->path[i].chpid = 0;
dasd_path_notoper(device, i);
dasd_path_remove_kobj(device, i);
}
}
@ -2173,6 +2172,7 @@ out_err2:
device->block = NULL;
out_err1:
dasd_eckd_clear_conf_data(device);
dasd_path_remove_kobjects(device);
kfree(device->private);
device->private = NULL;
return rc;
@ -2191,6 +2191,7 @@ static void dasd_eckd_uncheck_device(struct dasd_device *device)
private->vdsneq = NULL;
private->gneq = NULL;
dasd_eckd_clear_conf_data(device);
dasd_path_remove_kobjects(device);
}
static struct dasd_ccw_req *

2
drivers/s390/block/dasd_int.h
View File

@ -858,7 +858,7 @@ int dasd_add_sysfs_files(struct ccw_device *);
void dasd_remove_sysfs_files(struct ccw_device *);
void dasd_path_create_kobj(struct dasd_device *, int);
void dasd_path_create_kobjects(struct dasd_device *);
void dasd_path_remove_kobj(struct dasd_device *, int);
void dasd_path_remove_kobjects(struct dasd_device *);
struct dasd_device *dasd_device_from_cdev(struct ccw_device *);
struct dasd_device *dasd_device_from_cdev_locked(struct ccw_device *);