block: free the extended dev_t minor later

The dev_t is used as the inode hash, so we should only released it
once then block device inode is gone from the inode cache.  Move it
to bdev_free_inode to ensure that.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210816122614.601358-2-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

block/genhd.c

@@ -1085,8 +1085,6 @@ static void disk_release(struct device *dev)
 	might_sleep();
 
 	bdi_put(disk->bdi);
-	if (MAJOR(dev->devt) == BLOCK_EXT_MAJOR)
-		blk_free_ext_minor(MINOR(dev->devt));
 	disk_release_events(disk);
 	kfree(disk->random);
 	xa_destroy(&disk->part_tbl);

block/partitions/core.c

@@ -259,8 +259,6 @@ static const struct attribute_group *part_attr_groups[] = {
 
 static void part_release(struct device *dev)
 {
-	if (MAJOR(dev->devt) == BLOCK_EXT_MAJOR)
-		blk_free_ext_minor(MINOR(dev->devt));
 	put_disk(dev_to_bdev(dev)->bd_disk);
 	iput(dev_to_bdev(dev)->bd_inode);
 }

fs/block_dev.c

@@ -35,6 +35,7 @@
 #include <linux/uaccess.h>
 #include <linux/suspend.h>
 #include "internal.h"
+#include "../block/blk.h"
 
 struct bdev_inode {
 	struct block_device bdev;
@@ -813,6 +814,10 @@ static void bdev_free_inode(struct inode *inode)
 
 	if (!bdev_is_partition(bdev))
 		kfree(bdev->bd_disk);
+
+	if (MAJOR(bdev->bd_dev) == BLOCK_EXT_MAJOR)
+		blk_free_ext_minor(MINOR(bdev->bd_dev));
+
 	kmem_cache_free(bdev_cachep, BDEV_I(inode));
 }