linux-kernel - Re: [2.6.39-rc2][bisected] Constant DISK_MEDIA_CHANGE

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Date:	Sat, 16 Apr 2011 20:25:25 +0200
From:	Jens Axboe <jaxboe@...ionio.com>
To:	"maciej.rutecki@...il.com" <maciej.rutecki@...il.com>
CC:	Shaun Ruffell <sruffell@...ium.com>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	Tejun Heo <tj@...nel.org>
Subject: Re: [2.6.39-rc2][bisected] Constant DISK_MEDIA_CHANGE_EVENTS from
  CDROM drive.

On 2011-04-15 19:13, Maciej Rutecki wrote:
> I created a Bugzilla entry at 
> https://bugzilla.kernel.org/show_bug.cgi?id=33342
> for your bug report, please add your address to the CC list in there, thanks!
> 
> On piątek, 8 kwietnia 2011 o 22:15:13 Shaun Ruffell wrote:
>> Running with 2.6.39-rc2 on a CentOS 5.5 installation with a "IDE interface:
>> Intel Corporation 82801CA Ultra ATA Storage Controller (rev 02)"
>> (8086:248b), I've noticed constant DISK_MEDIA_CHANGE uevents.  In my
>> kernel log:
>>
>> [ 1107.530699] kobject: 'hda' (f5372610): fill_kobj_path: path =
>> '/block/hda' [ 1109.580559] kobject: 'hda' (f5372610): kobject_uevent_env
>> [ 1109.580594] kobject: 'hda' (f5372610): fill_kobj_path: path =
>> '/block/hda' [ 1111.630560] kobject: 'hda' (f5372610): kobject_uevent_env
>> [ 1111.630595] kobject: 'hda' (f5372610): fill_kobj_path: path =
>> '/block/hda' [ 1113.680560] kobject: 'hda' (f5372610): kobject_uevent_env
>>
>> And from udevmonitor --env:
>>
>> UEVENT[1302291995.789487] change@...ock/hda
>> ACTION=change
>> DEVPATH=/block/hda
>> SUBSYSTEM=block
>> DISK_MEDIA_CHANGE=1
>> MAJOR=3
>> MINOR=0
>> DEVNAME=hda
>> DEVTYPE=disk
>> SEQNUM=1318
>>
>> I bisected it down to 929e27252e8ca69363f81f26af5eaba62cb4c572 'ide:
>> ide_requeue_and_plug() reinstate "always plug" behaviour'
>>
>> I haven't yet looked into how that change would result in the change in
>> behavior I'm seeing but I thought I would let you know sooner rather than
>> leter in case this is something that is already known.

Tejun, why would something like that trigger and endless stream of media
change events? I bet this is what is cauing ide-cd to hang the system as
well now. What I know:

- It only triggers on UP
- And then it only triggers when PREEMPT is completely turned off

-- 
Jens Axboe

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/