linux-ext4 - Re: [PATCH, RFC] ext4: add EXT4_IOC_ALLOC_DA

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: <20090312052906.GA3033@skywalker>
Date:	Thu, 12 Mar 2009 10:59:06 +0530
From:	"Aneesh Kumar K.V" <aneesh.kumar@...ux.vnet.ibm.com>
To:	Eric Sandeen <sandeen@...hat.com>
Cc:	"Theodore Ts'o" <tytso@....edu>, linux-ext4@...r.kernel.org
Subject: Re: [PATCH, RFC] ext4: add EXT4_IOC_ALLOC_DA_BLKS ioctl

On Wed, Mar 11, 2009 at 05:41:05PM -0500, Eric Sandeen wrote:
> Theodore Ts'o wrote:
> > Add an ioctl which forces all of the delay allocated blocks to be
> > allocated.  This also provides a function ext4_alloc_da_blocks() which
> > will be used by the following commits to force files to be fully
> > allocated to preserve application-expected ext3 behaviour.
> > 
> 
> Is it worth checking whether a) the file has delalloc blocks, and/or b)
> whether the mapping is dirty before we spin off a filemap_flush?
> 
+int ext4_alloc_da_blocks(struct inode *inode)
+{
+       if (!EXT4_I(inode)->i_reserved_data_blocks &&
+           !EXT4_I(inode)->i_reserved_meta_blocks)
+               return 0;

This check test does (a). Since the ioctl is to force allocation of
delayed allocated blocks i guess (a) is enough because we don't want to
cause a filemap_flush when we don't have any delayed allocated blocks
but have dirty pages around.

-aneesh
--
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