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Re: [Gluster-devel] regressions due to 64-bit ext4 directory cookies
From: |
J. Bruce Fields |
Subject: |
Re: [Gluster-devel] regressions due to 64-bit ext4 directory cookies |
Date: |
Wed, 13 Feb 2013 08:40:33 -0500 |
User-agent: |
Mutt/1.5.21 (2010-09-15) |
On Tue, Feb 12, 2013 at 10:56:36PM -0800, Andreas Dilger wrote:
> On 2013-02-12, at 12:28 PM, J. Bruce Fields wrote:
> > 06effdbb49af5f6c "nfsd: vfs_llseek() with 32 or 64 bit offsets (hashes)"
> > and previous patches solved problems with hash collisions in large
> > directories by using 64- instead of 32- bit directory hashes in some
> > cases. But it caused problems for users who assume directory offsets
> > are "small". Two cases we've run across:
> >
> > - older NFS clients: 64-bit cookies cause applications on
> > many older clients to fail.
> > - gluster: gluster assumed that it could take the top bits of
> > the offset for its own use.
> >
> > In both cases we could argue we're in the right: the nfs protocol
> > defines cookies to be 64 bits, so clients should be prepared to handle them
> > (remapping to smaller integers if necessary to placate
> > applications using older system interfaces).
>
> There appears to already be support for handling this for NFSv2
> clients, so it should be possible to have an NFS server mount
> option to set this for all clients:
>
> /* NFSv2 only supports 32 bit cookies */
> if (rqstp->rq_vers > 2)
> may_flags |= NFSD_MAY_64BIT_COOKIE;
>
> Alternately, this might be detected on a per-client basis by
> whitelist or blacklist if there is some way for the server to
> identify the client?
No, there isn't.
--b.
- Re: [Gluster-devel] regressions due to 64-bit ext4 directory cookies, (continued)
- Re: [Gluster-devel] regressions due to 64-bit ext4 directory cookies, J. Bruce Fields, 2013/02/14
- Re: [Gluster-devel] regressions due to 64-bit ext4 directory cookies, Dave Chinner, 2013/02/14
- Re: [Gluster-devel] regressions due to 64-bit ext4 directory cookies, J. Bruce Fields, 2013/02/14
- Re: [Gluster-devel] regressions due to 64-bit ext4 directory cookies, Dave Chinner, 2013/02/14
- [Gluster-devel] Language Bindings and Data Serialization in Gluster, Brad Childs, 2013/02/15
- Re: [Gluster-devel] Language Bindings and Data Serialization in Gluster, Jay Vyas, 2013/02/15
Message not available
- Re: [Gluster-devel] regressions due to 64-bit ext4 directory cookies,
J. Bruce Fields <=
Re: [Gluster-devel] regressions due to 64-bit ext4 directory cookies, John Mark Walker, 2013/02/13