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    SubjectRe: [Ecryptfs-devel] [PATCH 3/11] eCryptfs: read_write.c routines
    On Fri, 21 Sep 2007 16:51:25 -0500
    Michael Halcrow <> wrote:

    > On Wed, Sep 19, 2007 at 10:38:50PM -0700, Andrew Morton wrote:
    > > > + virt = kmap(page_for_lower);
    > > > + rc = ecryptfs_write_lower(ecryptfs_inode, virt, offset, size);
    > > > + kunmap(page_for_lower);
    > > > + return rc;
    > > > +}
    > >
    > > argh, kmap.
    > Here is a patch that moves to kmap_atomic(), adding an intermediate
    > copy. Although I would really like to find a way to avoid having to do
    > this extra copy.

    We might as well stick with kmap. I was just having a whine - I don't know
    what to do about this really, apart from perhaps giving in to reality and
    making kmap work better.

    btw, I'm not really a great admirer of the whole patchset: it does some
    pretty nasty-looking things: allocating dynamic memory, grabbing the
    underlying pageframes with virt_to_page(), passing them back into kernel
    APIs which are supposed to be called from userspace, etc. It's all rather
    ugly and abusive-looking.

    But given that you're trying to do things which the kernel just isn't set
    up to do, it isn't immediately obvious what can be done to fix it.

    Perhaps there are problems whcih I didn't have time to spot, and perhaps
    there are things which could be done to improve it. But I don't have time
    to sit down and absorb it all to a sufficient level of detail to be able to
    suggest anything, and nobody else seems to be interested in reading the
    patches so whoop, in it all goes.

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      Last update: 2007-09-22 00:09    [W:0.035 / U:4.848 seconds]
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