Merge tag 'mmc-v5.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc

Pull MMC fixes from Ulf Hansson:

 - Use kref to fix KASAN splats triggered during card removal

 - Don't allocate IDA for OF aliases

* tag 'mmc-v5.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc:
  mmc: core: Don't allocate IDA for OF aliases
  mmc: core: Use kref in place of struct mmc_blk_data::usage

Author: torvalds

drivers/mmc/core/block.c

@@ -28,6 +28,7 @@
 #include <linux/errno.h>
 #include <linux/hdreg.h>
 #include <linux/kdev_t.h>
+#include <linux/kref.h>
 #include <linux/blkdev.h>
 #include <linux/cdev.h>
 #include <linux/mutex.h>
@@ -111,7 +112,7 @@ struct mmc_blk_data {
 #define MMC_BLK_CMD23	(1 << 0)	/* Can do SET_BLOCK_COUNT for multiblock */
 #define MMC_BLK_REL_WR	(1 << 1)	/* MMC Reliable write support */
 
-	unsigned int	usage;
+	struct kref	kref;
 	unsigned int	read_only;
 	unsigned int	part_type;
 	unsigned int	reset_done;
@@ -181,10 +182,8 @@ static struct mmc_blk_data *mmc_blk_get(struct gendisk *disk)
 
 	mutex_lock(&open_lock);
 	md = disk->private_data;
-	if (md && md->usage == 0)
+	if (md && !kref_get_unless_zero(&md->kref))
 		md = NULL;
-	if (md)
-		md->usage++;
 	mutex_unlock(&open_lock);
 
 	return md;
@@ -196,18 +195,25 @@ static inline int mmc_get_devidx(struct gendisk *disk)
 	return devidx;
 }
 
-static void mmc_blk_put(struct mmc_blk_data *md)
+static void mmc_blk_kref_release(struct kref *ref)
 {
-	mutex_lock(&open_lock);
-	md->usage--;
-	if (md->usage == 0) {
-		int devidx = mmc_get_devidx(md->disk);
+	struct mmc_blk_data *md = container_of(ref, struct mmc_blk_data, kref);
+	int devidx;
 
-		ida_simple_remove(&mmc_blk_ida, devidx);
-		put_disk(md->disk);
-		kfree(md);
-	}
+	devidx = mmc_get_devidx(md->disk);
+	ida_simple_remove(&mmc_blk_ida, devidx);
+
+	mutex_lock(&open_lock);
+	md->disk->private_data = NULL;
 	mutex_unlock(&open_lock);
+
+	put_disk(md->disk);
+	kfree(md);
+}
+
+static void mmc_blk_put(struct mmc_blk_data *md)
+{
+	kref_put(&md->kref, mmc_blk_kref_release);
 }
 
 static ssize_t power_ro_lock_show(struct device *dev,
@@ -2327,7 +2333,8 @@ static struct mmc_blk_data *mmc_blk_alloc_req(struct mmc_card *card,
 
 	INIT_LIST_HEAD(&md->part);
 	INIT_LIST_HEAD(&md->rpmbs);
-	md->usage = 1;
+	kref_init(&md->kref);
+
 	md->queue.blkdata = md;
 
 	md->disk->major	= MMC_BLOCK_MAJOR;

drivers/mmc/core/host.c

@@ -75,7 +75,8 @@ static void mmc_host_classdev_release(struct device *dev)
 {
 	struct mmc_host *host = cls_dev_to_mmc_host(dev);
 	wakeup_source_unregister(host->ws);
-	ida_simple_remove(&mmc_host_ida, host->index);
+	if (of_alias_get_id(host->parent->of_node, "mmc") < 0)
+		ida_simple_remove(&mmc_host_ida, host->index);
 	kfree(host);
 }
 
@@ -502,7 +503,7 @@ static int mmc_first_nonreserved_index(void)
  */
 struct mmc_host *mmc_alloc_host(int extra, struct device *dev)
 {
-	int err;
+	int index;
 	struct mmc_host *host;
 	int alias_id, min_idx, max_idx;
 
@@ -515,20 +516,19 @@ struct mmc_host *mmc_alloc_host(int extra, struct device *dev)
 
 	alias_id = of_alias_get_id(dev->of_node, "mmc");
 	if (alias_id >= 0) {
-		min_idx = alias_id;
-		max_idx = alias_id + 1;
+		index = alias_id;
 	} else {
 		min_idx = mmc_first_nonreserved_index();
 		max_idx = 0;
-	}
 
-	err = ida_simple_get(&mmc_host_ida, min_idx, max_idx, GFP_KERNEL);
-	if (err < 0) {
-		kfree(host);
-		return NULL;
+		index = ida_simple_get(&mmc_host_ida, min_idx, max_idx, GFP_KERNEL);
+		if (index < 0) {
+			kfree(host);
+			return NULL;
+		}
 	}
 
-	host->index = err;
+	host->index = index;
 
 	dev_set_name(&host->class_dev, "mmc%d", host->index);
 	host->ws = wakeup_source_register(NULL, dev_name(&host->class_dev));