Linux 6.5 compat: blkdev changes

Multiple changes to the blkdev API were introduced in Linux 6.5. This
includes passing (void* holder) to blkdev_put, adding a new
blk_holder_ops* arg to blkdev_get_by_path, adding a new blk_mode_t type
that replaces uses of fmode_t, and removing an argument from the release
handler on block_device_operations that we weren't using. The open
function definition has also changed to take gendisk* and blk_mode_t, so
update it accordingly, too.

Implement local wrappers for blkdev_get_by_path() and
vdev_blkdev_put() so that the in-line calls are cleaner, and place the
conditionally-compiled implementation details inside of both of these
local wrappers. Both calls are exclusively used within vdev_disk.c, at
this time.

Add blk_mode_is_open_write() to test FMODE_WRITE / BLK_OPEN_WRITE
The wrapper function is now used for testing using the appropriate
method for the kernel, whether the open mode is writable or not.

Emphasize fmode_t arg in zvol_release is not used

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Coleman Kane <ckane@colemankane.org>
Closes #15099

include/os/linux/kernel/linux/blkdev_compat.h

@@ -398,6 +398,12 @@ vdev_lookup_bdev(const char *path, dev_t *dev)
 #endif
 }
 
+#if defined(HAVE_BLK_MODE_T)
+#define	blk_mode_is_open_write(flag)	((flag) & BLK_OPEN_WRITE)
+#else
+#define	blk_mode_is_open_write(flag)	((flag) & FMODE_WRITE)
+#endif
+
 /*
  * Kernels without bio_set_op_attrs use bi_rw for the bio flags.
  */