mmc: block: cleanup gendisk creation

Restructure mmc_blk_probe to avoid a failure path with a half created
disk.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Acked-by: NUlf Hansson <ulf.hansson@linaro.org>
Link: https://lore.kernel.org/r/20210809064028.1198327-3-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

drivers/mmc/core/block.c

@@ -2328,7 +2328,8 @@ static struct mmc_blk_data *mmc_blk_alloc_req(struct mmc_card *card,
 					      sector_t size,
 					      bool default_ro,
 					      const char *subname,
-					      int area_type)
+					      int area_type,
+					      unsigned int part_type)
 {
 	struct mmc_blk_data *md;
 	int devidx, ret;
@@ -2375,6 +2376,7 @@ static struct mmc_blk_data *mmc_blk_alloc_req(struct mmc_card *card,
 	kref_init(&md->kref);
 
 	md->queue.blkdata = md;
+	md->part_type = part_type;
 
 	md->disk->major	= MMC_BLOCK_MAJOR;
 	md->disk->minors = perdev_minors;
@@ -2427,6 +2429,10 @@ static struct mmc_blk_data *mmc_blk_alloc_req(struct mmc_card *card,
 		md->disk->disk_name, mmc_card_id(card), mmc_card_name(card),
 		cap_str, md->read_only ? "(ro)" : "");
 
+	/* used in ->open, must be set before add_disk: */
+	if (area_type == MMC_BLK_DATA_AREA_MAIN)
+		dev_set_drvdata(&card->dev, md);
+	device_add_disk(md->parent, md->disk, mmc_disk_attr_groups);
 	return md;
 
  err_kfree:
@@ -2456,7 +2462,7 @@ static struct mmc_blk_data *mmc_blk_alloc(struct mmc_card *card)
 	}
 
 	return mmc_blk_alloc_req(card, &card->dev, size, false, NULL,
-					MMC_BLK_DATA_AREA_MAIN);
+					MMC_BLK_DATA_AREA_MAIN, 0);
 }
 
 static int mmc_blk_alloc_part(struct mmc_card *card,
@@ -2470,10 +2476,9 @@ static int mmc_blk_alloc_part(struct mmc_card *card,
 	struct mmc_blk_data *part_md;
 
 	part_md = mmc_blk_alloc_req(card, disk_to_dev(md->disk), size, default_ro,
-				    subname, area_type);
+				    subname, area_type, part_type);
 	if (IS_ERR(part_md))
 		return PTR_ERR(part_md);
-	part_md->part_type = part_type;
 	list_add(&part_md->part, &md->part);
 
 	return 0;
@@ -2674,20 +2679,13 @@ static int mmc_blk_alloc_parts(struct mmc_card *card, struct mmc_blk_data *md)
 
 static void mmc_blk_remove_req(struct mmc_blk_data *md)
 {
-	struct mmc_card *card;
-
-	if (md) {
-		/*
-		 * Flush remaining requests and free queues. It
-		 * is freeing the queue that stops new requests
-		 * from being accepted.
-		 */
-		card = md->queue.card;
-		if (md->disk->flags & GENHD_FL_UP)
-			del_gendisk(md->disk);
-		mmc_cleanup_queue(&md->queue);
-		mmc_blk_put(md);
-	}
+	/*
+	 * Flush remaining requests and free queues. It is freeing the queue
+	 * that stops new requests from being accepted.
+	 */
+	del_gendisk(md->disk);
+	mmc_cleanup_queue(&md->queue);
+	mmc_blk_put(md);
 }
 
 static void mmc_blk_remove_parts(struct mmc_card *card,
@@ -2876,7 +2874,7 @@ static void mmc_blk_remove_debugfs(struct mmc_card *card,
 
 static int mmc_blk_probe(struct mmc_card *card)
 {
-	struct mmc_blk_data *md, *part_md;
+	struct mmc_blk_data *md;
 	int ret = 0;
 
 	/*
@@ -2904,19 +2902,6 @@ static int mmc_blk_probe(struct mmc_card *card)
 	if (ret)
 		goto out;
 
-	dev_set_drvdata(&card->dev, md);
-
-	device_add_disk(md->parent, md->disk, mmc_disk_attr_groups);
-	if (ret)
-		goto out;
-
-	list_for_each_entry(part_md, &md->part, part) {
-		device_add_disk(part_md->parent, part_md->disk,
-				mmc_disk_attr_groups);
-		if (ret)
-			goto out;
-	}
-
 	/* Add two debugfs entries */
 	mmc_blk_add_debugfs(card, md);