2009-08-04 22:56:19

by Jan Kara

[permalink] [raw]
Subject: Re: EXT3/NFS inodes corruption


On Tue 04-08-09 13:15:05, Sylvain Rochet wrote:
> On Tue, Aug 04, 2009 at 12:29:01AM +0200, Jan Kara wrote:
> >
> > OK, I've found some time and written the debugging patch. Hopefully it
> > will tell us more. It should output messages to the kernel log if it
> > finds something suspicious - like:
> > No dentry for unlinked inode...
> > Dentry ... for unlinked inode ... has no parent
> > Found directory entry ... for unlinked inode
> >
> > When you see such messages in the log, send them to me please. Also
> > attach the System.map file so that I can translate the address where
> > i_nlink was dropped - for that ext3 should be compiled into the kernel
> > (should not be a module). Thanks a lot for testing.
> Patch applied.
> And there is already a lot of output.
> http://edony.tuxfamily.org/~grad/bazooka/System.map-
> http://edony.tuxfamily.org/~grad/bazooka/config-
> http://edony.tuxfamily.org/~grad/bazooka/kern.log
Thanks for testing. So you seem to be really stressting the path where
creation of new files / directories fails (probably due to group quota). I
have one idea what could cause your filesystem corruption, although it's a
wild guess... Please try attached oneliner.
Also your corruption reminded me that Al Viro has been fixing problems
where we could cache one inode twice when a filesystem was mounted over NFS
and that could also lead to a filesystem corruption. So I'm adding him to
CC just in case he has some idea. BTW Al, what do you think about the
problem I describe in the attached patch? I'm not sure if it can cause some
real problems but in theory it could...

Jan Kara <[email protected]>

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0001-fs-Make-sure-data-stored-into-inode-is-properly-see.patch (1.00 kB)
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