Re: [PATCH] 2.6.10 - direct-io async short read bug

From: Daniel McNeil
Date: Tue Mar 08 2005 - 21:26:14 EST


On Tue, 2005-03-08 at 11:18, Badari Pulavarty wrote:
> > Andrew, please don't apply the original patch. We shouldn't even attempt
> > to submit IO beyond the filesize. We should truncate the IO request to
> > filesize. I will send a patch today to fix this.
> >
>
> Well, spoke too soon. This is an ugly corner case :( But I have
> a ugly hack to fix it :)
>
> Let me ask you a basic question: Do we support DIO reads on a file
> which is not blocksize multiple in size ? (say 12K - 10 bytes) ?
>
> What about the ones which are not 4K but 512 byte multiple ? (say 7K) ?
>
> I need answer to those, to figure out how hard I should try to fix this.
>
> Anyway, here is ugly version of the patch - which will limit the IO
> size to filesize and uses lower blocksizes to read the file (since
> the filesize is only 3K, it would go down to 512 byte blocksize).
>

BTW, I got a compile error because the 'iov' parameter is
declared with 'const', so your patch is changing a read-only
value. :(

Daniel

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