On Thu, Apr 7, 2022 at 11:05 PM Shiyang Ruan <ruansy.fnst@xxxxxxxxxxx> wrote:
>
>
>
> 在 2022/3/30 14:00, Christoph Hellwig 写道:
> >> @@ -1892,6 +1893,8 @@ xfs_free_buftarg(
> >> list_lru_destroy(&btp->bt_lru);
> >>
> >> blkdev_issue_flush(btp->bt_bdev);
> >> + if (btp->bt_daxdev)
> >> + dax_unregister_holder(btp->bt_daxdev, btp->bt_mount);
> >> fs_put_dax(btp->bt_daxdev);
> >>
> >> kmem_free(btp);
> >> @@ -1939,6 +1942,7 @@ xfs_alloc_buftarg(
> >> struct block_device *bdev)
> >> {
> >> xfs_buftarg_t *btp;
> >> + int error;
> >>
> >> btp = kmem_zalloc(sizeof(*btp), KM_NOFS);
> >>
> >> @@ -1946,6 +1950,14 @@ xfs_alloc_buftarg(
> >> btp->bt_dev = bdev->bd_dev;
> >> btp->bt_bdev = bdev;
> >> btp->bt_daxdev = fs_dax_get_by_bdev(bdev, &btp->bt_dax_part_off);
> >> + if (btp->bt_daxdev) {
> >> + error = dax_register_holder(btp->bt_daxdev, mp,
> >> + &xfs_dax_holder_operations);
> >> + if (error) {
> >> + xfs_err(mp, "DAX device already in use?!");
> >> + goto error_free;
> >> + }
> >> + }
> >
> > It seems to me that just passing the holder and holder ops to
> > fs_dax_get_by_bdev and the holder to dax_unregister_holder would
> > significantly simply the interface here.
> >
> > Dan, what do you think?
>
> Hi Dan,
>
> Could you give some advise on this API? Is it needed to move
> dax_register_holder's job into fs_dax_get_by_bdev()?
Yes, works for me to just add them as optional arguments.
