On Sun, Jul 25 2021 at 1:54P -0400,
Christoph Hellwig <hch@xxxxxx> wrote:
> device mapper is currently the only outlier that tries to call
> register_disk after add_disk, leading to fairly inconsistent state
> of these block layer data structures. Instead change device-mapper
> to just register the gendisk later now that the holder mechanism
> can cope with that.
>
> Note that this introduces a user visible change: the dm kobject is
> now only visible after the initial table has been loaded.
>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: Mike Snitzer <snitzer@xxxxxxxxxx>
Jens, feel free to pick this series up once you're comfortable with it.
Thanks,
Mike
> ---
> drivers/md/dm-rq.c | 1 -
> drivers/md/dm.c | 23 +++++++++++------------
> 2 files changed, 11 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/md/dm-rq.c b/drivers/md/dm-rq.c
> index 0dbd48cbdff9..5b95eea517d1 100644
> --- a/drivers/md/dm-rq.c
> +++ b/drivers/md/dm-rq.c
> @@ -559,7 +559,6 @@ int dm_mq_init_request_queue(struct mapped_device *md, struct dm_table *t)
> err = blk_mq_init_allocated_queue(md->tag_set, md->queue);
> if (err)
> goto out_tag_set;
> - elevator_init_mq(md->queue);
> return 0;
>
> out_tag_set:
> diff --git a/drivers/md/dm.c b/drivers/md/dm.c
> index f003bd5b93ce..7981b7287628 100644
> --- a/drivers/md/dm.c
> +++ b/drivers/md/dm.c
> @@ -1693,7 +1693,10 @@ static void cleanup_mapped_device(struct mapped_device *md)
> spin_lock(&_minor_lock);
> md->disk->private_data = NULL;
> spin_unlock(&_minor_lock);
> - del_gendisk(md->disk);
> + if (dm_get_md_type(md) != DM_TYPE_NONE) {
> + dm_sysfs_exit(md);
> + del_gendisk(md->disk);
> + }
> dm_queue_destroy_keyslot_manager(md->queue);
> blk_cleanup_disk(md->disk);
> }
> @@ -1788,7 +1791,6 @@ static struct mapped_device *alloc_dev(int minor)
> goto bad;
> }
>
> - add_disk_no_queue_reg(md->disk);
> format_dev_t(md->name, MKDEV(_major, minor));
>
> md->wq = alloc_workqueue("kdmflush", WQ_MEM_RECLAIM, 0);
> @@ -1989,19 +1991,12 @@ static struct dm_table *__unbind(struct mapped_device *md)
> */
> int dm_create(int minor, struct mapped_device **result)
> {
> - int r;
> struct mapped_device *md;
>
> md = alloc_dev(minor);
> if (!md)
> return -ENXIO;
>
> - r = dm_sysfs_init(md);
> - if (r) {
> - free_dev(md);
> - return r;
> - }
> -
> *result = md;
> return 0;
> }
> @@ -2081,10 +2076,15 @@ int dm_setup_md_queue(struct mapped_device *md, struct dm_table *t)
> r = dm_table_set_restrictions(t, md->queue, &limits);
> if (r)
> return r;
> - md->type = type;
>
> - blk_register_queue(md->disk);
> + add_disk(md->disk);
>
> + r = dm_sysfs_init(md);
> + if (r) {
> + del_gendisk(md->disk);
> + return r;
> + }
> + md->type = type;
> return 0;
> }
>
> @@ -2190,7 +2190,6 @@ static void __dm_destroy(struct mapped_device *md, bool wait)
> DMWARN("%s: Forcibly removing mapped_device still in use! (%d users)",
> dm_device_name(md), atomic_read(&md->holders));
>
> - dm_sysfs_exit(md);
> dm_table_destroy(__unbind(md));
> free_dev(md);
> }
> --
> 2.30.2
>
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