linux-ext4 - Re: [PATCH] ext4: fix interaction between i_size, fallocate, and delalloc after a crash

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20171007183213.jfezqvcbjslzwm7e@thunk.org>
Date:   Sat, 7 Oct 2017 14:32:13 -0400
From:   Theodore Ts'o <tytso@....edu>
To:     Amir Goldstein <amir73il@...il.com>
Cc:     Ashlie Martinez <ashmrtn@...xas.edu>,
        Xiao Yang <yangx.jy@...fujitsu.com>,
        Eryu Guan <eguan@...hat.com>, Josef Bacik <jbacik@...com>,
        fstests <fstests@...r.kernel.org>,
        Ext4 <linux-ext4@...r.kernel.org>,
        Vijay Chidambaram <vvijay03@...il.com>
Subject: Re: [PATCH] ext4: fix interaction between i_size, fallocate, and
 delalloc after a crash

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