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' 'cfg80211' 'crypto_hash' 'cryptomgr' 'dm_log' 'dm_mirror' 'dm_mod' 'dm_multipath' 'dm_region_hash' 'ehci_hcd' 'e1000e' 'iptable_filter' 'iptable_nat' 'ip_tables' 'ipt_MASQUERADE' 'ipt_REJECT' 'iTCO_vendor_support' 'iTCO_wdt' 'iwlcore' 'iwl3945' 'iwl3945' 'kvm' 'kvm_intel' 'kvm0' 'llc' 'mac80211' 'microcode' 'mmc_core' 'mmc' 'nf_conntrack' 'nf_conntrack_ipv4' 'nf_defrag_ipv4' 'nf_nat' 'pcompress' 'psmouse' 'rtc_cmos' 'rtc_core' 'rtc_lib' 'scsi_wait_scan' 'sdhci' 'sdhci_pci' 'sdio' 'snd_mixer_oss' 'snd_pcm_oss' 'snd_seq_device' 'snd_seq' 'snd_seq_midi_event' 'snd_seq_oss' 'sr_mod' 'stp' 'x_tables' 'xt_state' 'xt_tcpudp' Zdenek -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
