Messages in this thread | | | From | "David Cross" <> | Subject | RE: [PATCH] Cachefiles, mpage_cleardirty addtition, west bridge related | Date | Wed, 8 Sep 2010 14:20:06 -0700 |
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-----Original Message----- From: Christoph Hellwig [mailto:hch@infradead.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.
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