linux-ext4 - Re: [RFC][Patch 1/2] Persistent preallocation in ext4

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: <1167778052.4197.3.camel@dyn9047017103.beaverton.ibm.com>
Date:	Tue, 02 Jan 2007 14:47:32 -0800
From:	Mingming Cao <cmm@...ibm.com>
To:	"Amit K. Arora" <aarora@...ux.vnet.ibm.com>
Cc:	linux-ext4@...r.kernel.org, suparna@...ibm.com, suzuki@...ibm.com,
	alex@...sterfs.com
Subject: Re: [RFC][Patch 1/2] Persistent preallocation in ext4

On Tue, 2007-01-02 at 16:34 +0530, Amit K. Arora wrote:
> Hi Mingming,
> > And, Looking at other places calling ext4_*_get_blocks() in the kernel,
> > it seems not all of them protected by i_mutex lock. I think it probably
> > okay to not holding i_mutex during calling ext4_ext4_get_blocks().
> 
> We are not holding i_mutex lock during ext4_ext_get_blocks() call.
> Above, this lock is being held inorder to avoid race while updating the
> filesize in inode (reference your comment in a previous mail "I think we
> should update i_size and i_disksize after preallocation. Oh,
> to protect parallel updating i_size, we have to take i_mutex down.").
> Perhaps, truncate_mutex lock should be used here, and not i_mutex.
> 

truncate_mutex is hold at the entry of ext4_**_get_blocks() to protect
parallel block allocation. Here I was worried about concurrent modifying
i_size and i_disksize which were protected by the i_mutex lock. Sorry
for any confusion.

-
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html