md: merge common code into find_pers()

- pers_lock() are held and released from caller
- try_module_get() is called from caller
- error message from caller

Merge above code into find_pers(), and rename it to get_pers(), also
add a wrapper to module_put() as put_pers().

Link: https://lore.kernel.org/linux-raid/20250215092225.2427977-2-yukuai1@huaweicloud.com
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Su Yue <glass.su@suse.com>

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 827646b..afd626a 100644 (file)
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -888,16 +888,37 @@ struct md_rdev *md_find_rdev_rcu(struct mddev *mddev, dev_t dev)
 }
 EXPORT_SYMBOL_GPL(md_find_rdev_rcu);
 
-static struct md_personality *find_pers(int level, char *clevel)
+static struct md_personality *get_pers(int level, char *clevel)
 {
+       struct md_personality *ret = NULL;
        struct md_personality *pers;
+
+       spin_lock(&pers_lock);
        list_for_each_entry(pers, &pers_list, list) {
-               if (level != LEVEL_NONE && pers->level == level)
-                       return pers;
-               if (strcmp(pers->name, clevel)==0)
-                       return pers;
+               if ((level != LEVEL_NONE && pers->level == level) ||
+                   !strcmp(pers->name, clevel)) {
+                       if (try_module_get(pers->owner))
+                               ret = pers;
+                       break;
+               }
        }
-       return NULL;
+       spin_unlock(&pers_lock);
+
+       if (!ret) {
+               if (level != LEVEL_NONE)
+                       pr_warn("md: personality for level %d is not loaded!\n",
+                               level);
+               else
+                       pr_warn("md: personality for level %s is not loaded!\n",
+                               clevel);
+       }
+
+       return ret;
+}
+
+static void put_pers(struct md_personality *pers)
+{
+       module_put(pers->owner);
 }
 
 /* return the offset of the super block in 512byte sectors */
@@ -3931,24 +3952,20 @@ level_store(struct mddev *mddev, const char *buf, size_t len)
 
        if (request_module("md-%s", clevel) != 0)
                request_module("md-level-%s", clevel);
-       spin_lock(&pers_lock);
-       pers = find_pers(level, clevel);
-       if (!pers || !try_module_get(pers->owner)) {
-               spin_unlock(&pers_lock);
-               pr_warn("md: personality %s not loaded\n", clevel);
+       pers = get_pers(level, clevel);
+       if (!pers) {
                rv = -EINVAL;
                goto out_unlock;
        }
-       spin_unlock(&pers_lock);
 
        if (pers == mddev->pers) {
                /* Nothing to do! */
-               module_put(pers->owner);
+               put_pers(pers);
                rv = len;
                goto out_unlock;
        }
        if (!pers->takeover) {
-               module_put(pers->owner);
+               put_pers(pers);
                pr_warn("md: %s: %s does not support personality takeover\n",
                        mdname(mddev), clevel);
                rv = -EINVAL;
@@ -3969,7 +3986,7 @@ level_store(struct mddev *mddev, const char *buf, size_t len)
                mddev->raid_disks -= mddev->delta_disks;
                mddev->delta_disks = 0;
                mddev->reshape_backwards = 0;
-               module_put(pers->owner);
+               put_pers(pers);
                pr_warn("md: %s: %s would not accept array\n",
                        mdname(mddev), clevel);
                rv = PTR_ERR(priv);
@@ -4026,7 +4043,7 @@ level_store(struct mddev *mddev, const char *buf, size_t len)
                        mddev->to_remove = &md_redundancy_group;
        }
 
-       module_put(oldpers->owner);
+       put_pers(oldpers);
 
        rdev_for_each(rdev, mddev) {
                if (rdev->raid_disk < 0)
@@ -6096,20 +6113,11 @@ int md_run(struct mddev *mddev)
                        goto exit_sync_set;
        }
 
-       spin_lock(&pers_lock);
-       pers = find_pers(mddev->level, mddev->clevel);
-       if (!pers || !try_module_get(pers->owner)) {
-               spin_unlock(&pers_lock);
-               if (mddev->level != LEVEL_NONE)
-                       pr_warn("md: personality for level %d is not loaded!\n",
-                               mddev->level);
-               else
-                       pr_warn("md: personality for level %s is not loaded!\n",
-                               mddev->clevel);
+       pers = get_pers(mddev->level, mddev->clevel);
+       if (!pers) {
                err = -EINVAL;
                goto abort;
        }
-       spin_unlock(&pers_lock);
        if (mddev->level != pers->level) {
                mddev->level = pers->level;
                mddev->new_level = pers->level;
@@ -6119,7 +6127,7 @@ int md_run(struct mddev *mddev)
        if (mddev->reshape_position != MaxSector &&
            pers->start_reshape == NULL) {
                /* This personality cannot handle reshaping... */
-               module_put(pers->owner);
+               put_pers(pers);
                err = -EINVAL;
                goto abort;
        }
@@ -6246,7 +6254,7 @@ bitmap_abort:
        if (mddev->private)
                pers->free(mddev, mddev->private);
        mddev->private = NULL;
-       module_put(pers->owner);
+       put_pers(pers);
        mddev->bitmap_ops->destroy(mddev);
 abort:
        bioset_exit(&mddev->io_clone_set);
@@ -6467,7 +6475,7 @@ static void __md_stop(struct mddev *mddev)
        mddev->private = NULL;
        if (pers->sync_request && mddev->to_remove == NULL)
                mddev->to_remove = &md_redundancy_group;
-       module_put(pers->owner);
+       put_pers(pers);
        clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
 
        bioset_exit(&mddev->bio_set);