Re: busy inodes -> ext3 umount crash

[Jiri Slaby <jirislaby@gmail.com>]

On 04/20/2010 05:28 PM, Jan Kara wrote:
> On Tue 20-04-10 16:12:03, Jiri Slaby wrote:
>> On 04/19/2010 04:33 PM, Jiri Slaby wrote:
>>> The trigger for busy inodes is as simple as (I=initialization done only
>>> once):
>>> I> # dd if=/dev/zero of=/dev/shm/ext3 bs=1024 count=1 seek=$((100*1024))
>>> I> # mkfs.ext3 -m 0 /dev/shm/ext3
>>> # mount -oloop /dev/shm/ext3 /mnt/c
>>> # umount /mnt/c
>>> # dmesg|tail
>>> VFS: Busy inodes after unmount of loop0. Self-destruct in 5 seconds.
>>> Have a nice day...
>>>
>>> (The printk time varies -- this sequence really suffices.)
>>
>> Well, this happens only after gnome-session is started and it's fuzzy --
>> sometimes it happens, sometimes not. I didn't find 100% trigger yet.
>   Hmph - maybe something in inotify? Dunno...

fsnotify...

>>>> So if you can easily reproduce
>>>> the "busy inodes" message then I'd start with debugging that one. Do you
>>>> see it also with vanilla kernels?
>>
>> Vanilla seems not to be affected. It's in next/master already though
>> (2603ecd9). I'll investigate it further later.
>   Do you mean it's in today's linux-next but not in Linus' tree?

Yes, exactly.

And the winner is (seemingly):
commit 69c1182c4e5d8b7da772ddad512c6f6b67ec1bb8
Author: Eric Paris <eparis@redhat.com>
Date:   Thu Dec 17 21:24:27 2009 -0500

    fsnotify: vfsmount marks generic functions

    Much like inode-mark.c has all of the code dealing with marks on inodes
    this patch adds a vfsmount-mark.c which has similar code but is intended
    for marks on vfsmounts.

    Signed-off-by: Eric Paris <eparis@redhat.com>


I can't verify it by reverting on the top of -mm as it doesn't revert
cleanly. Do you see any bug in there?

thanks,
-- 
js