On Fri, Jan 3, 2020 at 6:12 AM Vivek Goyal <vgoyal(a)redhat.com> wrote:
On Mon, Aug 26, 2019 at 04:58:29PM -0400, Vivek Goyal wrote:
> On Mon, Aug 26, 2019 at 04:33:26PM -0400, Vivek Goyal wrote:
> > On Mon, Aug 26, 2019 at 04:53:16AM -0700, Christoph Hellwig wrote:
> > > On Wed, Aug 21, 2019 at 01:57:03PM -0400, Vivek Goyal wrote:
> > > > Right now dax_writeback_mapping_range() is passed a bdev and dax_dev
> > > > is searched from that bdev name.
> > > >
> > > > virtio-fs does not have a bdev. So pass in dax_dev also to
> > > > dax_writeback_mapping_range(). If dax_dev is passed in, bdev is not
> > > > used otherwise dax_dev is searched using bdev.
> > >
> > > Please just pass in only the dax_device and get rid of the block device.
> > > The callers should have one at hand easily, e.g. for XFS just call
> > > xfs_find_daxdev_for_inode instead of xfs_find_bdev_for_inode.
> > Sure. Here is the updated patch.
> > This patch can probably go upstream independently. If you are fine with
> > the patch, I can post it separately for inclusion.
> Forgot to update function declaration in case of !CONFIG_FS_DAX. Here is
> the updated patch.
> Subject: dax: Pass dax_dev instead of bdev to dax_writeback_mapping_range()
> As of now dax_writeback_mapping_range() takes "struct block_device" as a
> parameter and dax_dev is searched from bdev name. This also involves taking
> a fresh reference on dax_dev and putting that reference at the end of
> We are developing a new filesystem virtio-fs and using dax to access host
> page cache directly. But there is no block device. IOW, we want to make
> use of dax but want to get rid of this assumption that there is always
> a block device associated with dax_dev.
> So pass in "struct dax_device" as parameter instead of bdev.
> ext2/ext4/xfs are current users and they already have a reference on
> dax_device. So there is no need to take reference and drop reference to
> dax_device on each call of this function.
> Suggested-by: Christoph Hellwig <hch(a)infradead.org>
> Signed-off-by: Vivek Goyal <vgoyal(a)redhat.com>
Ping for this patch. I see christoph and Jan acked it. Can we take it. Not
sure how to get ack from ext4 developers.
Jan counts for ext4, I just missed this. Now merged.