Re: BUG: reiserfs+acl+quota deadlock

[Tarmo Tänav <tarmo@itech.ee>]

Tried the attached patch but it changed nothing, I trying to create
a new file as a user whose quota grace time has ran out will still
cause everything accessing the users homedir (the one with the quota)
to hang in D state.

Also note that the bug I reported only exists when acl is also
enabled (does not have to be used). And although my kernel is not
built with debug (or reiserfs debug) support, I don't get any
oopses or reiserfs errors.. it just hangs.


On K, 2005-08-10 at 15:00 +0200, Jan Kara wrote:
>   Hello,
> 
> > I've already reported a similiar bug to the one I found now
> > and that was fixed by:
> > "[PATCH] reiserfs: fix deadlock in inode creation failure path w/
> > default ACL"
> > 
> > This bug is similiar in effect but has some differences in how
> > to trigger it. The end effect will be just like with the other
> > bug that the affected directory will be unaccessible to any user
> > or process.
> > 
> > So here's the way to reproduce it, as minimal as I could get it:
> > 
> > You need reiserfs, quota and acl support in kernel.
> > you also need quota tools (edquota, quotaon, quotacheck), I used
> > linuxquota 3.12.
> > 
> > # cd /mnt
> > # dd if=/dev/zero of=test bs=1M count=50
> > 50+0 records in
> > 50+0 records out
> > # mkreiserfs -f test >/dev/null
> > mkreiserfs 3.6.19 (2003 www.namesys.com)
> > 
> > test is not a block special device
> > Continue (y/n):y
> > # mkdir mpoint
> > # mount test mpoint -o loop,acl,usrquota
> > # mkdir mpoint/user1
> > # useradd -d /mnt/mpoint/user1 user1     # may also use existing user
> > # chown user1 mpoint/user1
> > # quotacheck -v mpoint                   # initializes quota file
> > # edquota user1
> > ---- set soft block limit to 1000, hard limit to 4000 ----
> > # edquota -t
> > ---- set the grace periods to something small: 1minutes ---
> > # quotaon mpoint
> > # ## at this point "repquota -a" should show the quota for user1
> > # su user1
> > # cd
> > # ## now we are in user1 home dir as user1
> > # cat /dev/zero > file1
> > loop2: warning, user block quota exceeded.
> > loop2: write failed, user block limit reached.
> > cat: write error: No space left on device
> > --- now we wait till the grace period expires (repquota -a) ----
> > # cat "" > otherfile
> > loop2: write failed, user block quota exceeded too long.
> > ---- and it will hang forever ----
> > # ## /mnt/mpoint can still be accessed, but /mnt/mpoint/user1 can't
> > 
> > 
> > I tested this on an -mm patchset kernel (2.6.13-rc5-mm1), but I
> > discovered the bug in my server which runs plain 2.6.12 with the
> > patch from Jeff Mahoney for the first reiserfs+acl bug.
> > 
> > The main difference between the two bugs is that the first one requires
> > the existance of a default acl, this one does not, but it does require
> > acl to be enabled.
>   This seems to be the same problem as bug #4771 that I've just fix. Can
> you try attached patch please?
>   Andrew, can you include the patch into -mm if ReiserFS guys won't object?

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