[patch] sysfs device support for ide-tape

From: Will Dyson
Date: Fri Sep 16 2005 - 01:56:21 EST


Greetings,

I was recently given an old Travan tape drive and asked to do
something useful with it. The ide-scsi + st (+serverworks ide
controller) combo results in a hard lockup of the machine which I have
not had the energy to debug, so I turned to ide-tape (which seems to
work). The system in question debian stable, using udev to manage
/dev.

The following patch to ide-tape.c allows udev to create the cdev nodes
for my drive.


diff -r 3df8dce293b2 drivers/ide/ide-tape.c
--- a/drivers/ide/ide-tape.c Wed Sep 14 22:56:27 2005
+++ b/drivers/ide/ide-tape.c Fri Sep 16 02:32:02 2005
@@ -1013,6 +1013,8 @@

static DECLARE_MUTEX(idetape_ref_sem);

+static struct class *idetape_sysfs_class;
+
#define to_ide_tape(obj) container_of(obj, struct ide_tape_obj, kref)

#define ide_tape_g(disk) \
@@ -4704,6 +4706,10 @@

drive->dsc_overlap = 0;
drive->driver_data = NULL;
+ class_device_destroy(idetape_sysfs_class,
+ MKDEV(IDETAPE_MAJOR, tape->minor));
+ class_device_destroy(idetape_sysfs_class,
+ MKDEV(IDETAPE_MAJOR, tape->minor + 128));
devfs_remove("%s/mt", drive->devfs_name);
devfs_remove("%s/mtn", drive->devfs_name);
devfs_unregister_tape(g->number);
@@ -4878,6 +4884,11 @@

idetape_setup(drive, tape, minor);

+ class_device_create(idetape_sysfs_class,
+ MKDEV(IDETAPE_MAJOR, minor), dev, "%s", tape->name);
+ class_device_create(idetape_sysfs_class,
+ MKDEV(IDETAPE_MAJOR, minor + 128), dev, "n%s", tape->name);
+
devfs_mk_cdev(MKDEV(HWIF(drive)->major, minor),
S_IFCHR | S_IRUGO | S_IWUGO,
"%s/mt", drive->devfs_name);
@@ -4903,6 +4914,7 @@
static void __exit idetape_exit (void)
{
driver_unregister(&idetape_driver.gen_driver);
+ class_destroy(idetape_sysfs_class);
unregister_chrdev(IDETAPE_MAJOR, "ht");
}

@@ -4911,11 +4923,33 @@
*/
static int idetape_init (void)
{
+ int error = 1;
+ idetape_sysfs_class = class_create(THIS_MODULE, "ide_tape");
+ if (IS_ERR(idetape_sysfs_class)) {
+ idetape_sysfs_class = NULL;
+ printk(KERN_ERR "Unable to create sysfs class for ide tapes\n");
+ error = -EBUSY;
+ goto out;
+ }
+
if (register_chrdev(IDETAPE_MAJOR, "ht", &idetape_fops)) {
printk(KERN_ERR "ide-tape: Failed to register character device interface\n");
- return -EBUSY;
- }
- return driver_register(&idetape_driver.gen_driver);
+ error = -EBUSY;
+ goto out_free_class;
+ }
+
+ error = driver_register(&idetape_driver.gen_driver);
+ if (error)
+ goto out_free_driver;
+
+ return 0;
+
+out_free_driver:
+ driver_unregister(&idetape_driver.gen_driver);
+out_free_class:
+ class_destroy(idetape_sysfs_class);
+out:
+ return error;
}

module_init(idetape_init);

--
Will Dyson
-
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