"Wilcox, Matthew R" <matthew.r.wil...@intel.com> writes:
> So ... what you're doing here is if somebody requests the last 512
> bytes, you're asking for the last page. That's going to work as long
> as the partition is a multiple of PAGE_SIZE, but not if the partition
> happens to be misaligned. It's an improvement, although I'd be
> tempted to do this as:
>
> if (pos == max) {
> unsigned blkbits = inode->i_blkbits;
> - sector_t block = pos >> blkbits;
> + long page = pos >> PAGE_SHIFT;
> + sector_t block = page << (PAGE_SHIFT - blkbits);
> unsigned first = pos - (block << blkbits);
> long size;
Yeah, that's easier to read.
> We need to cope with the case where the end of a partition isn't on a
> page boundary though.
Well, that's usually done by falling back to buffered I/O. I gave that
a try and panicked the box. :) I'll keep looking into it, but probably
won't have another patch until next week.
Cheers,
Jeff
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