Linux 5.20 compat: blk_cleanup_disk()

As of the Linux 5.20 kernel blk_cleanup_disk() has been removed,
all callers should use put_disk().

Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #13728

Author: behlendorf

config/kernel-make-request-fn.m4

@@ -49,6 +49,13 @@ AC_DEFUN([ZFS_AC_KERNEL_SRC_MAKE_REQUEST_FN], [
 		struct gendisk *disk  __attribute__ ((unused));
 		disk = blk_alloc_disk(NUMA_NO_NODE);
 	])
+
+	ZFS_LINUX_TEST_SRC([blk_cleanup_disk], [
+		#include <linux/blkdev.h>
+	],[
+		struct gendisk *disk  __attribute__ ((unused));
+		blk_cleanup_disk(disk);
+	])
 ])
 
 AC_DEFUN([ZFS_AC_KERNEL_MAKE_REQUEST_FN], [
@@ -73,6 +80,19 @@ AC_DEFUN([ZFS_AC_KERNEL_MAKE_REQUEST_FN], [
 		ZFS_LINUX_TEST_RESULT([blk_alloc_disk], [
 			AC_MSG_RESULT(yes)
 			AC_DEFINE([HAVE_BLK_ALLOC_DISK], 1, [blk_alloc_disk() exists])
+
+			dnl #
+			dnl # 5.20 API change,
+			dnl # Removed blk_cleanup_disk(), put_disk() should be used.
+			dnl #
+			AC_MSG_CHECKING([whether blk_cleanup_disk() exists])
+			ZFS_LINUX_TEST_RESULT([blk_cleanup_disk], [
+				AC_MSG_RESULT(yes)
+				AC_DEFINE([HAVE_BLK_CLEANUP_DISK], 1,
+				    [blk_cleanup_disk() exists])
+			], [
+				AC_MSG_RESULT(no)
+			])
 		], [
 			AC_MSG_RESULT(no)
 		])

module/os/linux/zfs/zvol_os.c

@@ -1232,7 +1232,11 @@ zvol_os_free(zvol_state_t *zv)
 	del_gendisk(zv->zv_zso->zvo_disk);
 #if defined(HAVE_SUBMIT_BIO_IN_BLOCK_DEVICE_OPERATIONS) && \
 	defined(HAVE_BLK_ALLOC_DISK)
+#if defined(HAVE_BLK_CLEANUP_DISK)
 	blk_cleanup_disk(zv->zv_zso->zvo_disk);
+#else
+	put_disk(zv->zv_zso->zvo_disk);
+#endif
 #else
 	blk_cleanup_queue(zv->zv_zso->zvo_queue);
 	put_disk(zv->zv_zso->zvo_disk);