md-bitmap: suspend array earlier in location_store()

Now that mddev_suspend() doean't rely on 'mddev->pers' to be set, it's
safe to call mddev_suspend() earlier.

This will also be helper to refactor mddev_suspend() later.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20230825030956.1527023-6-yukuai1@huaweicloud.com

drivers/md/md-bitmap.c

@@ -2351,6 +2351,8 @@ location_store(struct mddev *mddev, const char *buf, size_t len)
 	rv = mddev_lock(mddev);
 	if (rv)
 		return rv;
+
+	mddev_suspend(mddev);
 	if (mddev->pers) {
 		if (mddev->recovery || mddev->sync_thread) {
 			rv = -EBUSY;
@@ -2365,11 +2367,8 @@ location_store(struct mddev *mddev, const char *buf, size_t len)
 			rv = -EBUSY;
 			goto out;
 		}
-		if (mddev->pers) {
-			mddev_suspend(mddev);
-			md_bitmap_destroy(mddev);
-			mddev_resume(mddev);
-		}
+
+		md_bitmap_destroy(mddev);
 		mddev->bitmap_info.offset = 0;
 		if (mddev->bitmap_info.file) {
 			struct file *f = mddev->bitmap_info.file;
@@ -2379,6 +2378,8 @@ location_store(struct mddev *mddev, const char *buf, size_t len)
 	} else {
 		/* No bitmap, OK to set a location */
 		long long offset;
+		struct bitmap *bitmap;
+
 		if (strncmp(buf, "none", 4) == 0)
 			/* nothing to be done */;
 		else if (strncmp(buf, "file:", 5) == 0) {
@@ -2402,25 +2403,20 @@ location_store(struct mddev *mddev, const char *buf, size_t len)
 				rv = -EINVAL;
 				goto out;
 			}
+
 			mddev->bitmap_info.offset = offset;
-			if (mddev->pers) {
-				struct bitmap *bitmap;
-				bitmap = md_bitmap_create(mddev, -1);
-				mddev_suspend(mddev);
-				if (IS_ERR(bitmap))
-					rv = PTR_ERR(bitmap);
-				else {
-					mddev->bitmap = bitmap;
-					rv = md_bitmap_load(mddev);
-					if (rv)
-						mddev->bitmap_info.offset = 0;
-				}
-				if (rv) {
-					md_bitmap_destroy(mddev);
-					mddev_resume(mddev);
-					goto out;
-				}
-				mddev_resume(mddev);
+			bitmap = md_bitmap_create(mddev, -1);
+			if (IS_ERR(bitmap)) {
+				rv = PTR_ERR(bitmap);
+				goto out;
+			}
+
+			mddev->bitmap = bitmap;
+			rv = md_bitmap_load(mddev);
+			if (rv) {
+				mddev->bitmap_info.offset = 0;
+				md_bitmap_destroy(mddev);
+				goto out;
 			}
 		}
 	}
@@ -2433,6 +2429,7 @@ location_store(struct mddev *mddev, const char *buf, size_t len)
 	}
 	rv = 0;
 out:
+	mddev_resume(mddev);
 	mddev_unlock(mddev);
 	if (rv)
 		return rv;