linux/drivers/s390/char/tape_class.c
Michael Holzheu 92bf435f38 [S390] tape: duplicate sysfs filename when setting tape device online
When a tape device is set online, offline and online again, the following
error message is printed on the console: "sysfs: duplicate filename
'non-rewinding' can not be created". The reason is that when setting a
device online, the tape driver creates a sysfs symlink from the tape device
to the tape class device. Unfortunately the symlink is not removed
correctly, when the device is set offline. Instead of passing the
tape device object to sysfs_remove_link, the class device object is used.
This patch fixes this problem and uses the correct tape device object now.

Signed-off-by: Michael Holzheu <holzheu@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2008-04-17 07:46:59 +02:00

128 lines
2.8 KiB
C

/*
* (C) Copyright IBM Corp. 2004
* tape_class.c
*
* Tape class device support
*
* Author: Stefan Bader <shbader@de.ibm.com>
* Based on simple class device code by Greg K-H
*/
#include "tape_class.h"
MODULE_AUTHOR("Stefan Bader <shbader@de.ibm.com>");
MODULE_DESCRIPTION(
"(C) Copyright IBM Corp. 2004 All Rights Reserved.\n"
"tape_class.c"
);
MODULE_LICENSE("GPL");
static struct class *tape_class;
/*
* Register a tape device and return a pointer to the cdev structure.
*
* device
* The pointer to the struct device of the physical (base) device.
* drivername
* The pointer to the drivers name for it's character devices.
* dev
* The intended major/minor number. The major number may be 0 to
* get a dynamic major number.
* fops
* The pointer to the drivers file operations for the tape device.
* devname
* The pointer to the name of the character device.
*/
struct tape_class_device *register_tape_dev(
struct device * device,
dev_t dev,
const struct file_operations *fops,
char * device_name,
char * mode_name)
{
struct tape_class_device * tcd;
int rc;
char * s;
tcd = kzalloc(sizeof(struct tape_class_device), GFP_KERNEL);
if (!tcd)
return ERR_PTR(-ENOMEM);
strncpy(tcd->device_name, device_name, TAPECLASS_NAME_LEN);
for (s = strchr(tcd->device_name, '/'); s; s = strchr(s, '/'))
*s = '!';
strncpy(tcd->mode_name, mode_name, TAPECLASS_NAME_LEN);
for (s = strchr(tcd->mode_name, '/'); s; s = strchr(s, '/'))
*s = '!';
tcd->char_device = cdev_alloc();
if (!tcd->char_device) {
rc = -ENOMEM;
goto fail_with_tcd;
}
tcd->char_device->owner = fops->owner;
tcd->char_device->ops = fops;
tcd->char_device->dev = dev;
rc = cdev_add(tcd->char_device, tcd->char_device->dev, 1);
if (rc)
goto fail_with_cdev;
tcd->class_device = device_create(tape_class, device,
tcd->char_device->dev,
"%s", tcd->device_name
);
rc = IS_ERR(tcd->class_device) ? PTR_ERR(tcd->class_device) : 0;
if (rc)
goto fail_with_cdev;
rc = sysfs_create_link(
&device->kobj,
&tcd->class_device->kobj,
tcd->mode_name
);
if (rc)
goto fail_with_class_device;
return tcd;
fail_with_class_device:
device_destroy(tape_class, tcd->char_device->dev);
fail_with_cdev:
cdev_del(tcd->char_device);
fail_with_tcd:
kfree(tcd);
return ERR_PTR(rc);
}
EXPORT_SYMBOL(register_tape_dev);
void unregister_tape_dev(struct device *device, struct tape_class_device *tcd)
{
if (tcd != NULL && !IS_ERR(tcd)) {
sysfs_remove_link(&device->kobj, tcd->mode_name);
device_destroy(tape_class, tcd->char_device->dev);
cdev_del(tcd->char_device);
kfree(tcd);
}
}
EXPORT_SYMBOL(unregister_tape_dev);
static int __init tape_init(void)
{
tape_class = class_create(THIS_MODULE, "tape390");
return 0;
}
static void __exit tape_exit(void)
{
class_destroy(tape_class);
tape_class = NULL;
}
postcore_initcall(tape_init);
module_exit(tape_exit);