From: Theodore Ts'o <tytso@mit.edu>
Subject: Re: [PATCH] ext4: fix interaction between i_size, fallocate, and
 delalloc after a crash
Date: Sat, 7 Oct 2017 14:32:13 -0400
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Cc: Ashlie Martinez <ashmrtn@utexas.edu>,
        Xiao Yang <yangx.jy@cn.fujitsu.com>,
        Eryu Guan <eguan@redhat.com>, Josef Bacik <jbacik@fb.com>,
        fstests <fstests@vger.kernel.org>,
        Ext4 <linux-ext4@vger.kernel.org>,
        Vijay Chidambaram <vvijay03@gmail.com>
To: Amir Goldstein <amir73il@gmail.com>
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On Sat, Oct 07, 2017 at 08:54:06AM +0300, Amir Goldstein wrote:
> >     If fallocate(2) is called with the FALLOC_FL_KEEP_SIZE flag, either
> 
> According to patch without keep size flag?

Oops, thanks for catching that.  I'll fix the commit description.

> BTW looking at the patch, does truncate racing with fallocate that
> would increase size beyond truncated size works correctly?

Yes, because we the inode is locked via i_mutex (well, now an write
lock on i_rwsem) during both truncate and fallocate operations.

     		 	     	      	  - Ted