On Thu, Nov 29, 2012 at 11:26 AM, Linus Torvalds <torva...@linux-foundation.org> wrote: > > (I now realize that Mikulas was talking about this mess, while I > thought he was talking about the AIO code which is largely sane).
Oh wow. The direct-IO code really doesn't seem to care at all. I don't think it needs locking either (it seems to do everything with a private buffer-head), and the problem appears solely to be that it reads i_blksize multiple times, so changing it just happens to confuse the direct-io code. If it were to read it only once, and then use that value, it looks like it should all JustWork(tm). And the right thing to do would seem to just add it to the "dio_submit" structure, that we already have. And it already *has* a blkbits field, but that's the "IO blocksize", not the "getblocks blocksize", if I read that mess correctly. Of course, it then *ALREADY* has that "blkfactor" thing, which is the difference between i_blkbits and blktbits, so it effective *does* have i_blkbits already in the dio_submit structure. But despite it all, it keeps re-reading i_blksize. Christ. That code is a mess. Linus -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/