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Similar to 189574, properly handle subclasses of bus drivers when deleting

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a driver during kldunload.  Specifically, recursively walk the tree of
subclasses of a given driver attachment's bus device class detaching all
instances of that driver for each class and its subclasses.

Reported by:	bschmidt
Reviewed by:	imp
MFC after:	1 week
This commit is contained in:
John Baldwin 2011-03-01 14:43:37 +00:00
parent 74b5505e5d
commit 88690d6a73
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=219135
1 changed files with 89 additions and 38 deletions
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127
sys/kern/subr_bus.c
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@ -987,10 +987,12 @@ devclass_find(const char *classname)
* is called by devclass_add_driver to accomplish the recursive
* notification of all the children classes of dc, as well as dc.
* Each layer will have BUS_DRIVER_ADDED() called for all instances of
* the devclass. We do a full search here of the devclass list at
* each iteration level to save storing children-lists in the devclass
* structure. If we ever move beyond a few dozen devices doing this,
* we may need to reevaluate...
* the devclass.
*
* We do a full search here of the devclass list at each iteration
* level to save storing children-lists in the devclass structure. If
* we ever move beyond a few dozen devices doing this, we may need to
* reevaluate...
*
* @param dc the devclass to edit
* @param driver the driver that was just added
@ -1085,46 +1087,30 @@ devclass_add_driver(devclass_t dc, driver_t *driver, int pass, devclass_t *dcp)
}
/**
* @brief Delete a device driver from a device class
* @brief Register that a device driver has been deleted from a devclass
*
* Delete a device driver from a devclass. This is normally called
* automatically by DRIVER_MODULE().
* Register that a device driver has been removed from a devclass.
* This is called by devclass_delete_driver to accomplish the
* recursive notification of all the children classes of busclass, as
* well as busclass. Each layer will attempt to detach the driver
* from any devices that are children of the bus's devclass. The function
* will return an error if a device fails to detach.
*
* We do a full search here of the devclass list at each iteration
* level to save storing children-lists in the devclass structure. If
* we ever move beyond a few dozen devices doing this, we may need to
* reevaluate...
*
* If the driver is currently attached to any devices,
* devclass_delete_driver() will first attempt to detach from each
* device. If one of the detach calls fails, the driver will not be
* deleted.
*
* @param dc the devclass to edit
* @param driver the driver to unregister
* @param busclass the devclass of the parent bus
* @param dc the devclass of the driver being deleted
* @param driver the driver being deleted
*/
static int
devclass_delete_driver(devclass_t busclass, driver_t *driver)
devclass_driver_deleted(devclass_t busclass, devclass_t dc, driver_t *driver)
{
devclass_t dc = devclass_find(driver->name);
driverlink_t dl;
devclass_t parent;
device_t dev;
int i;
int error;
PDEBUG(("%s from devclass %s", driver->name, DEVCLANAME(busclass)));
if (!dc)
return (0);
/*
* Find the link structure in the bus' list of drivers.
*/
TAILQ_FOREACH(dl, &busclass->drivers, link) {
if (dl->driver == driver)
break;
}
if (!dl) {
PDEBUG(("%s not found in %s list", driver->name,
busclass->name));
return (ENOENT);
}
int error, i;
/*
* Disassociate from any devices. We iterate through all the
@ -1151,6 +1137,71 @@ devclass_delete_driver(devclass_t busclass, driver_t *driver)
}
}
/*
* Walk through the children classes. Since we only keep a
* single parent pointer around, we walk the entire list of
* devclasses looking for children. We set the
* DC_HAS_CHILDREN flag when a child devclass is created on
* the parent, so we only walk the list for those devclasses
* that have children.
*/
if (!(busclass->flags & DC_HAS_CHILDREN))
return (0);
parent = busclass;
TAILQ_FOREACH(busclass, &devclasses, link) {
if (busclass->parent == parent) {
error = devclass_driver_deleted(busclass, dc, driver);
if (error)
return (error);
}
}
return (0);
}
/**
* @brief Delete a device driver from a device class
*
* Delete a device driver from a devclass. This is normally called
* automatically by DRIVER_MODULE().
*
* If the driver is currently attached to any devices,
* devclass_delete_driver() will first attempt to detach from each
* device. If one of the detach calls fails, the driver will not be
* deleted.
*
* @param dc the devclass to edit
* @param driver the driver to unregister
*/
static int
devclass_delete_driver(devclass_t busclass, driver_t *driver)
{
devclass_t dc = devclass_find(driver->name);
driverlink_t dl;
int error;
PDEBUG(("%s from devclass %s", driver->name, DEVCLANAME(busclass)));
if (!dc)
return (0);
/*
* Find the link structure in the bus' list of drivers.
*/
TAILQ_FOREACH(dl, &busclass->drivers, link) {
if (dl->driver == driver)
break;
}
if (!dl) {
PDEBUG(("%s not found in %s list", driver->name,
busclass->name));
return (ENOENT);
}
error = devclass_driver_deleted(busclass, dc, driver);
if (error != 0)
return (error);
TAILQ_REMOVE(&busclass->drivers, dl, link);
free(dl, M_BUS);