[Drbd-dev] [PATCH 4/5] block: make blkdev_get/put() handle exclusive access
snitzer at redhat.com
Thu Nov 4 16:04:00 CET 2010
On Wed, Nov 03 2010 at 12:10pm -0400,
Christoph Hellwig <hch at infradead.org> wrote:
> On Mon, Nov 01, 2010 at 05:15:28PM +0100, Tejun Heo wrote:
> > * blkdev_get() is extended to include exclusive access management.
> > @holder argument is added and, if is @FMODE_EXCL specified, it will
> > gain exclusive access atomically w.r.t. other exclusive accesses.
> > * blkdev_put() is similarly extended. It now takes @mode argument and
> > if @FMODE_EXCL is set, it releases an exclusive access. Also, when
> > the last exclusive claim is released, the holder/slave symlinks are
> > removed automatically.
> Could we get rid of FMODE_EXCL and just make a non-NULL holder field
> mean to open it exlusively (and pass a holder to the blkdev_put to
> release it)?
I agree that the need for a FMODE_EXCL flag is awkward. Christoph's
proposed change should clean things up nicely.
Other than that, for the DM bits:
Acked-by: Mike Snitzer <snitzer at redhat.com>
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