From: Theodore Ts'o <tytso@mit.edu>
Subject: Re: resizing file system fails when file system block size is
 smaller than page size
Date: Tue, 25 Oct 2016 13:19:36 -0400
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To: Jerry Lee <jerrylee@qnap.com>
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On Fri, Sep 09, 2016 at 07:36:06PM +0800, Jerry Lee wrote:
> 
> I have a file system with 4K block size on a 32K page size platform, and
> something strange happened when expanding the file system from size 17TB to
> 20TB.  It seems that the new file system size is not calculated correctly.
> 
> $ resize2fs /dev/mapper/dev
> resize2fs 1.43.3 (04-Sep-2016)
> Filesystem at /dev/mapper/dev is mounted on /share/DATA; on-line
> resizing required
> resize2fs: On-line shrinking not supported
> 
> After digging into the issue, I find that the following operation makes the
> high 32bit of the new_size variable be wiped out and results in a smaller
> size compared to the currently used block counts.

Thanks for the report; I've applied your suggested fix.

       	       	       	    	    - Ted