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dahdi_dynamic: Remove calls to __module_get().

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The board drivers are the ones calling the unregister function, and
therefore we do not need to worry about them unloading while calling the
destroy callback.

When destroying spans with the ioctl, replace __module_get() with
try_module_get. This avoids hitting a BUG in module_get on kernel versions <
2.6.29.

ALSO move the call to try_module_get out of the dahdi_dynamic_release function
and into destroy. This way if the destroy callback isn't called because the
dynamic driver is unloading the dynamic device can be left on the list to be
cleaned up by the dahdi_dynamic_unregister_driver function().

Signed-off-by: Shaun Ruffell <sruffell@digium.com>

git-svn-id: http://svn.asterisk.org/svn/dahdi/linux/trunk@10624 a0bf4364-ded3-4de4-8d8a-66a801d63aff
This commit is contained in:
Shaun Ruffell 2012-04-03 19:44:33 +00:00
parent 4ee22f19d1
commit d46ad9bca1
1 changed files with 21 additions and 15 deletions
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36
drivers/dahdi/dahdi_dynamic.c
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@ -385,16 +385,6 @@ static void dahdi_dynamic_release(struct kref *kref)
WARN_ON(test_bit(DAHDI_FLAGBIT_REGISTERED, &d->span.flags));
if (d->pvt) {
if (d->driver && d->driver->destroy) {
__module_get(d->driver->owner);
d->driver->destroy(d);
module_put(d->driver->owner);
} else {
WARN_ON(1);
}
}
kfree(d->msgbuf);
for (x = 0; x < d->span.channels; x++)
@ -465,6 +455,24 @@ static int _destroy_dynamic(struct dahdi_dynamic_span *dds)
return -EBUSY;
}
if (d->pvt) {
if (d->driver && d->driver->destroy) {
if (!try_module_get(d->driver->owner)) {
/* The driver for this device is in the
* process of unloading. Leave this dynamic on
* the list so it's cleaned up when the driver
* unregisters. */
dynamic_put(d);
return -ENXIO;
}
d->driver->destroy(d);
module_put(d->driver->owner);
} else {
WARN_ON(1);
}
d->pvt = NULL;
}
dahdi_unregister_device(d->ddev);
spin_lock_irqsave(&dspan_lock, flags);
@ -762,19 +770,17 @@ void dahdi_dynamic_unregister_driver(struct dahdi_dynamic_driver *dri)
list_for_each_entry_safe(d, n, &dspan_list, list) {
if (d->driver == dri) {
if (d->pvt) {
if (d->driver && d->driver->destroy) {
__module_get(d->driver->owner);
if (d->driver && d->driver->destroy)
d->driver->destroy(d);
module_put(d->driver->owner);
} else {
else
WARN_ON(1);
}
}
dahdi_unregister_device(d->ddev);
spin_lock_irqsave(&dspan_lock, flags);
list_del_rcu(&d->list);
spin_unlock_irqrestore(&dspan_lock, flags);
synchronize_rcu();
d->driver = NULL;
dynamic_put(d);
}
}