md: introduce struct md_submodule_head and APIs

Prepare to unify registration and unregistration of md personalities
and md-cluster, also prepare for add kconfig for md-bitmap.

Link: https://lore.kernel.org/linux-raid/20250215092225.2427977-4-yukuai1@huaweicloud.com
Signed-off-by: Yu Kuai <yukuai3@huawei.com>

diff --git a/drivers/md/md-cluster.h b/drivers/md/md-cluster.h
index 6c7aad00f5da7caaf807ea8b547284eb8aa7d4cf..4e842af11fb463b9f1426882632f701a3b873ee2 100644 (file)
--- a/drivers/md/md-cluster.h
+++ b/drivers/md/md-cluster.h
@@ -10,6 +10,8 @@ struct mddev;
 struct md_rdev;
 
 struct md_cluster_operations {
+       struct md_submodule_head head;
+
        int (*join)(struct mddev *mddev, int nodes);
        int (*leave)(struct mddev *mddev);
        int (*slot_number)(struct mddev *mddev);

diff --git a/drivers/md/md.c b/drivers/md/md.c
index afd626a4f1973b3a5b162984a57b509749514890..638929889289f99f1dd11e2dcb1896d3353ddb2e 100644 (file)
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -79,6 +79,8 @@ static const char *action_name[NR_SYNC_ACTIONS] = {
        [ACTION_IDLE]           = "idle",
 };
 
+static DEFINE_XARRAY(md_submodule);
+
 /* pers_list is a list of registered personalities protected by pers_lock. */
 static LIST_HEAD(pers_list);
 static DEFINE_SPINLOCK(pers_lock);
@@ -8522,6 +8524,18 @@ static const struct proc_ops mdstat_proc_ops = {
        .proc_poll      = mdstat_poll,
 };
 
+int register_md_submodule(struct md_submodule_head *msh)
+{
+       return xa_insert(&md_submodule, msh->id, msh, GFP_KERNEL);
+}
+EXPORT_SYMBOL_GPL(register_md_submodule);
+
+void unregister_md_submodule(struct md_submodule_head *msh)
+{
+       xa_erase(&md_submodule, msh->id);
+}
+EXPORT_SYMBOL_GPL(unregister_md_submodule);
+
 int register_md_personality(struct md_personality *p)
 {
        pr_debug("md: %s personality registered for level %d\n",

diff --git a/drivers/md/md.h b/drivers/md/md.h
index c9bc70e6d5b495cdb38496715067f1b630355d89..4807fa0d0362f2fe996870aef8022c8a2d15ac0d 100644 (file)
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -18,10 +18,37 @@
 #include <linux/timer.h>
 #include <linux/wait.h>
 #include <linux/workqueue.h>
+#include <linux/raid/md_u.h>
 #include <trace/events/block.h>
 
 #define MaxSector (~(sector_t)0)
 
+enum md_submodule_type {
+       MD_PERSONALITY = 0,
+       MD_CLUSTER,
+       MD_BITMAP, /* TODO */
+};
+
+enum md_submodule_id {
+       ID_LINEAR       = LEVEL_LINEAR,
+       ID_RAID0        = 0,
+       ID_RAID1        = 1,
+       ID_RAID4        = 4,
+       ID_RAID5        = 5,
+       ID_RAID6        = 6,
+       ID_RAID10       = 10,
+       ID_CLUSTER,
+       ID_BITMAP,      /* TODO */
+       ID_LLBITMAP,    /* TODO */
+};
+
+struct md_submodule_head {
+       enum md_submodule_type  type;
+       enum md_submodule_id    id;
+       const char              *name;
+       struct module           *owner;
+};
+
 /*
  * These flags should really be called "NO_RETRY" rather than
  * "FAILFAST" because they don't make any promise about time lapse,
@@ -698,6 +725,7 @@ static inline void md_sync_acct_bio(struct bio *bio, unsigned long nr_sectors)
 
 struct md_personality
 {
+       struct md_submodule_head head;
        char *name;
        int level;
        struct list_head list;
@@ -842,6 +870,9 @@ static inline void safe_put_page(struct page *p)
        if (p) put_page(p);
 }
 
+int register_md_submodule(struct md_submodule_head *msh);
+void unregister_md_submodule(struct md_submodule_head *msh);
+
 extern int register_md_personality(struct md_personality *p);
 extern int unregister_md_personality(struct md_personality *p);
 extern struct md_thread *md_register_thread(