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	<20160208193012.GG17411@fieldses.org>
Date: Mon, 8 Feb 2016 14:45:54 -0500
Message-ID: <CAHQdGtRN16=oYbsgtf_XEpxyWpz-H8+u6j2ekckqumiHh5Yv7g@mail.gmail.com>
Subject: Re: silent truncation for large file offsets
From: Trond Myklebust <trond.myklebust@primarydata.com>
To: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Christoph Hellwig <hch@infradead.org>,
        Linux NFS Mailing List <linux-nfs@vger.kernel.org>
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Sender: linux-nfs-owner@vger.kernel.org

On Mon, Feb 8, 2016 at 2:30 PM, J. Bruce Fields <bfields@fieldses.org> wrote:
> On Mon, Feb 08, 2016 at 10:33:28AM -0800, Christoph Hellwig wrote:
>> >From a Linux client to a Linux server (in fact the same system in this
>> example), NFSv4.1, XFS file system:
>>
>> root@vm:~/xfstests# truncate --size 9223372036854775807 /mnt/nfs1/test
>> root@vm:~/xfstests# ls -l /mnt/nfs1/test
>> -rw-r--r-- 1 root root 9223372036854775806 Feb  8 18:30 /mnt/nfs1/test
>> root@vm:~/xfstests# ls -l /mnt/test/test
>> -rw-r--r-- 1 root root 9223372036854775807 Feb  8 18:30 /mnt/test/test
>>
>> so the file gets created with the correct size on the server, but
>> the clients shows the size truncated.
>>
>> This is extraced from xfstests generic/911 which tests clone
>> functionality and fails because of this issue.
>
> Took a quick look at wireshark, and GETATTR is returning the correct
> (larger) size.
>
> Also FSINFO (this is v3) returns 9223372036854775807 as the maximum file
> size.
>

I'll bet it's this:

static inline loff_t nfs_size_to_loff_t(__u64 size)
{
        if (size > (__u64) OFFSET_MAX - 1)
                return OFFSET_MAX - 1;
        return (loff_t) size;
}

Should be "return OFFSET_MAX", no?