On Fri, Jan 3, 2020 at 6:12 AM Vivek Goyal <vgoyal@xxxxxxxxxx> 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 > > function. > > > > 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@xxxxxxxxxxxxx> > > Signed-off-by: Vivek Goyal <vgoyal@xxxxxxxxxx> > > Hi Dan, > > 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.
