for usbip_host event_handler() handles following events. defined in "usbip_common.h" 1. SDEV_EVENT_REMOVED (USBIP_EH_SHUTDOWN | USBIP_EH_RESET | USBIP_EH_BYE) 2. SDEV_EVENT_DOWN (USBIP_EH_SHUTDOWN | USBIP_EH_RESET) 3. SDEV_EVENT_ERROR_TCP (USBIP_EH_SHUTDOWN | USBIP_EH_RESET) 4. SDEV_EVENT_ERROR_SUBMIT (USBIP_EH_SHUTDOWN | USBIP_EH_RESET) 5. VDEV_EVENT_ERROR_MALLOC (USBIP_EH_SHUTDOWN | USBIP_EH_UNUSABLE) In case of events(1,2,3,4), stub_shoutdown_connection() gets executed first and than stub_device_reset() . In case of event 5, stub_shoutdown_connection() kills kernel threads and stub_device_unusable() changes devices status to "SDEV_ST_ERROR"(fatal error). thus stub_device_reset() can't be called without stub_shutdown_connection(), so there is no problem of resource leak . you are also right, i could have set pointers to NULL in stub_shutdown_connection() but i used stub_device_reset() which is intended to reset usbip_device stuct member variables. i'll resend patches, if maintainer ask for that. thanks --navin-patidar On Tue, Sep 18, 2012 at 3:06 PM, Dan Carpenter <dan.carpenter@xxxxxxxxxx> wrote: > On Tue, Sep 18, 2012 at 03:02:15PM +0530, navin patidar wrote: >> On Tue, Sep 18, 2012 at 1:10 PM, Dan Carpenter <dan.carpenter@xxxxxxxxxx> wrote: >> > On Tue, Sep 18, 2012 at 09:30:06AM +0530, navin patidar wrote: >> >> stub_device_reset should set kernel thread pointers to NULL. >> >> so that at the time of usbip_host removal stub_shoutdown_connection >> >> doesn't try to kill kernel threads which are already killed. >> >> >> > >> > If you have the Oops output, that's always nice to put in the commit >> > message. >> >> i'll surely keep this in mind before submitting further patches. >> >> > Why don't you set the pointers to NULL in stub_shutdown_connection() >> > since that's where you actually kill the threads. Setting them to >> > NULL in stub_device_reset() will (sometimes) solve the problem but >> > it gives you a new problem of a resource leak. >> >> stub_device_reset() always gets executed after >> stub_shutdown_connection() , never before. >> > > No it isn't. Read event_handler() more carefully. They can be > executed independently. > > In other words, stub_shutdown_connection() can be called without > calling stub_device_reset() and stub_device_reset() can be called > without stub_shutdown_connection(). If either of those happen then > it causes a problem with the patch you have just sent. > > regards, > dan carpenter > _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/devel
