Dne 16.12.2009 18:46, Greg KH napsal(a): > On Wed, Dec 16, 2009 at 05:32:21PM +0100, Zdenek Kabelac wrote: >> Dne 16.12.2009 14:45, Greg KH napsal(a): >>> On Wed, Dec 16, 2009 at 10:44:41AM +0100, Milan Broz wrote: >>>> On 12/16/2009 01:47 AM, Greg KH wrote: >>>>> On Tue, Dec 15, 2009 at 05:35:08PM +0000, James Bottomley wrote: >>>>>> commit: d2bb7df8cac647b92f51fb84ae735771e7adbfa7 >>>>>> From: Milan Broz <mbroz@xxxxxxxxxx> >>>>>> Date: Thu, 10 Dec 2009 23:51:53 +0000 >>>>>> Subject: [PATCH] dm: sysfs add empty release function to avoid debug warning >>>>>> >>>>>> This patch just removes an unnecessary warning: >>>>>> kobject: 'dm': does not have a release() function, >>>>>> it is broken and must be fixed. >>>>>> >>>>>> The kobject is embedded in mapped device struct, so >>>>>> code does not need to release memory explicitly here. >>>>> >>>> >>>>> Please, this is totally and completly wrong. And if you feel that it is >>>>> needed, then your design is wrong and it needs to be fixed. >>>> >>>> There are several places in kernel, where kobject have not defined release >>>> method. Yes, something is wrong here. >>> >>> Where are those instances, becides the use of static kobjects, which is >>> being worked on? >>> >>> That still does not make this change acceptable, it is incorrect. >>> >>>> So quietly ignoring warning is ok? Why is not there BUG_ON(!release) then? >>> >>> I was trying to be nice and not crash your machine and give you the >>> opportunity to fix it easily. >>> >>>> The sysfs attributes here just represents attributes of block device object, >>>> this device is always removed before release here is called. >>> >>> Then why use a kobject at all? Your reference counting will be all >>> wrong if you use it incorrectly like this. >>> >>>> So if there is preferred to do another alloc/free, no problem. >>> >>> Please do. >>> >>> Also, with the addition of this patch, your comments for the kobject are >>> now incorrect as well. >>> >> >> Here is list of just some errors I get on my 2.6.32 linux kernel. >> (error message itself is removed) >> Messages are printed during module removal/reboot. >> >> 'aead' (ffffffffa017c050): does not have a release() function, it is broken >> and must be fixed. >> 'bridge' >> 'cdrom' > > <snip> > > You will find that all of these are modules, right? That's being worked > on still. > Yes - true in most cases - here are exceptions: fill_kobj_path: path = '/devices/system/kvm/kvm0' fill_kobj_path: path = '/devices/system/kvm' fill_kobj_path: path = '/bus/sdio' fill_kobj_path: path = '/bus/mmc' Please note, these are only modules in use on my system in use - so there is probably more of them... Zdenek -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
