Re: [PATCH md-6.15 7/7] md: switch md-cluster to use md_submodle_head

Su Yue
2025-02-18T03:42:52Z

On Sat 15 Feb 2025 at 17:22, Yu Kuai <yukuai1@huaweicloud.com>
wrote:

> From: Yu Kuai <yukuai3@huawei.com>
>
> To make code cleaner, and prepare to add kconfig for bitmap.
>
> Also remove the unsed global variables pers_lock, md_cluster_ops
> and
> md_cluster_mod, and exported symbols
> register_md_cluster_operations(),
> unregister_md_cluster_operations() and md_cluster_ops.
>
> Signed-off-by: Yu Kuai <yukuai3@huawei.com>
>
Reviewed-by: Su Yue <glass.su@suse.com>

> ---
> drivers/md/md-cluster.c | 14 ++++++++++----
> drivers/md/md-cluster.h | 3 ---
> drivers/md/md.c | 41
> ++++++-----------------------------------
> drivers/md/md.h | 2 +-
> 4 files changed, 17 insertions(+), 43 deletions(-)
>
> diff --git a/drivers/md/md-cluster.c b/drivers/md/md-cluster.c
> index 6fd436a1d373..94221d964d4f 100644
> --- a/drivers/md/md-cluster.c
> +++ b/drivers/md/md-cluster.c
> @@ -1612,7 +1612,14 @@ static int gather_bitmaps(struct md_rdev
> *rdev)
> return err;
> }
>
> -static const struct md_cluster_operations cluster_ops = {
> +static struct md_cluster_operations cluster_ops = {
> + .head = {
> + .type = MD_CLUSTER,
> + .id = ID_CLUSTER,
> + .name = "cluster",
> + .owner = THIS_MODULE,
> + },
> +
> .join = join,
> .leave = leave,
> .slot_number = slot_number,
> @@ -1642,13 +1649,12 @@ static int __init cluster_init(void)
> {
> pr_warn("md-cluster: support raid1 and raid10 (limited
> support)\n");
> pr_info("Registering Cluster MD functions\n");
> - register_md_cluster_operations(&cluster_ops, THIS_MODULE);
> - return 0;
> + return register_md_submodule(&cluster_ops.head);
> }
>
> static void cluster_exit(void)
> {
> - unregister_md_cluster_operations();
> + unregister_md_submodule(&cluster_ops.head);
> }
>
> module_init(cluster_init);
> diff --git a/drivers/md/md-cluster.h b/drivers/md/md-cluster.h
> index 4e842af11fb4..8fb06d853173 100644
> --- a/drivers/md/md-cluster.h
> +++ b/drivers/md/md-cluster.h
> @@ -37,9 +37,6 @@ struct md_cluster_operations {
> void (*update_size)(struct mddev *mddev, sector_t
> old_dev_sectors);
> };
>
> -extern int register_md_cluster_operations(const struct
> md_cluster_operations *ops,
> - struct module *module);
> -extern int unregister_md_cluster_operations(void);
> extern int md_setup_cluster(struct mddev *mddev, int nodes);
> extern void md_cluster_stop(struct mddev *mddev);
> extern void md_reload_sb(struct mddev *mddev, int raid_disk);
> diff --git a/drivers/md/md.c b/drivers/md/md.c
> index d94c9aa8c3aa..4d93cc1aaabc 100644
> --- a/drivers/md/md.c
> +++ b/drivers/md/md.c
> @@ -81,13 +81,8 @@ static const char
> *action_name[NR_SYNC_ACTIONS] = {
>
> static DEFINE_XARRAY(md_submodule);
>
> -static DEFINE_SPINLOCK(pers_lock);
> -
> static const struct kobj_type md_ktype;
>
> -static const struct md_cluster_operations *md_cluster_ops;
> -static struct module *md_cluster_mod;
> -
> static DECLARE_WAIT_QUEUE_HEAD(resync_wait);
> static struct workqueue_struct *md_wq;
>
> @@ -7452,11 +7447,12 @@ static int update_raid_disks(struct
> mddev *mddev, int raid_disks)
>
> static int get_cluster_ops(struct mddev *mddev)
> {
> - spin_lock(&pers_lock);
> - mddev->cluster_ops = md_cluster_ops;
> - if (mddev->cluster_ops && !try_module_get(md_cluster_mod))
> + xa_lock(&md_submodule);
> + mddev->cluster_ops = xa_load(&md_submodule, ID_CLUSTER);
> + if (mddev->cluster_ops &&
> + !try_module_get(mddev->cluster_ops->head.owner))
> mddev->cluster_ops = NULL;
> - spin_unlock(&pers_lock);
> + xa_unlock(&md_submodule);
>
> return mddev->cluster_ops == NULL ? -ENOENT : 0;
> }
> @@ -7467,7 +7463,7 @@ static void put_cluster_ops(struct mddev
> *mddev)
> return;
>
> mddev->cluster_ops->leave(mddev);
> - module_put(md_cluster_mod);
> + module_put(mddev->cluster_ops->head.owner);
> mddev->cluster_ops = NULL;
> }
>
> @@ -8559,31 +8555,6 @@ void unregister_md_submodule(struct
> md_submodule_head *msh)
> }
> EXPORT_SYMBOL_GPL(unregister_md_submodule);
>
> -int register_md_cluster_operations(const struct
> md_cluster_operations *ops,
> - struct module *module)
> -{
> - int ret = 0;
> - spin_lock(&pers_lock);
> - if (md_cluster_ops != NULL)
> - ret = -EALREADY;
> - else {
> - md_cluster_ops = ops;
> - md_cluster_mod = module;
> - }
> - spin_unlock(&pers_lock);
> - return ret;
> -}
> -EXPORT_SYMBOL(register_md_cluster_operations);
> -
> -int unregister_md_cluster_operations(void)
> -{
> - spin_lock(&pers_lock);
> - md_cluster_ops = NULL;
> - spin_unlock(&pers_lock);
> - return 0;
> -}
> -EXPORT_SYMBOL(unregister_md_cluster_operations);
> -
> int md_setup_cluster(struct mddev *mddev, int nodes)
> {
> int ret = get_cluster_ops(mddev);
> diff --git a/drivers/md/md.h b/drivers/md/md.h
> index 873f33e2a1f6..dd6a28f5d8e6 100644
> --- a/drivers/md/md.h
> +++ b/drivers/md/md.h
> @@ -603,7 +603,7 @@ struct mddev {
> mempool_t *serial_info_pool;
> void (*sync_super)(struct mddev *mddev, struct md_rdev *rdev);
> struct md_cluster_info *cluster_info;
> - const struct md_cluster_operations *cluster_ops;
> + struct md_cluster_operations *cluster_ops;
> unsigned int good_device_nr; /* good device num
> within cluster raid */
> unsigned int noio_flag; /* for memalloc scope API
> */