linux-kernel - RE: [PATCH] Cachefiles, mpage_cleardirty addtition, west bridge related

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] [day] [month] [year] [list]

Message-ID: <AE20F72077384EF281F87A1E094BED26@stanford.edu>
Date:	Wed, 8 Sep 2010 14:20:06 -0700
From:	"David Cross" <david.cross@...ress.com>
To:	"'Christoph Hellwig'" <hch@...radead.org>
Cc:	<dhowells@...hat.com>, <linux-cachefs@...hat.com>,
	<greg@...ah.com>, <linux-kernel@...r.kernel.org>
Subject: RE: [PATCH] Cachefiles, mpage_cleardirty addtition, west bridge related



-----Original Message-----
From: Christoph Hellwig [mailto:hch@...radead.org] 

On Wed, Sep 08, 2010 at 09:51:22AM -0700, David Cross wrote:
> > This is used by the current west bridge driver in the linux-next tree,
> > marked as BROKEN at the moment. It is used in order to clear dirty pages
> > from the page cache for a specific file after it has been allocated.
This
> > allows west bridge to transfer data from USB to storage directly without
> > requiring that the file data path go through the CPU. The easiest way to
> > think of this is that it allows for direct file based DMA. Please let me
> > know if you have any additional questions or concerns on this.

> It's sad enough that it was taken into any tree at all, but we're not
> going to add incorrect crap into the kernel kernel for it.

Can you elaborate on what you mean by "incorrect crap" in a constructive way
if at all possible please?

> mpage_* are pagecache manpipulation routines, and are only for use by
> filesystems for inodes they manage.  A driver may never access this
> directly.

Then what about a user space call such as falloc()? Is your objection to the
existence of the code or the place where it is called from?

> Is this the same piece of junk you wanted fat_get_block
> exported for?

It is the same driver code, but I removed the fat_get_block call in a patch
that I submitted previously based on past inputs, instead adding a few lines
to this function.





---------------------------------------------------------------
This message and any attachments may contain Cypress (or its
subsidiaries) confidential information. If it has been received
in error, please advise the sender and immediately delete this
message.
---------------------------------------------------------------

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