gfs2: more obvious initializations of mapping->host

what's going on is copying the ->host of bdev's address_space

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Link: https://lore.kernel.org/r/20240411145346.2516848-4-viro@zeniv.linux.org.uk
Signed-off-by: Christian Brauner <brauner@kernel.org>

Author: Al Viro

fs/gfs2/glock.c

@@ -1227,7 +1227,7 @@ int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number,
 	mapping = gfs2_glock2aspace(gl);
 	if (mapping) {
                 mapping->a_ops = &gfs2_meta_aops;
-		mapping->host = s->s_bdev->bd_inode;
+		mapping->host = s->s_bdev->bd_mapping->host;
 		mapping->flags = 0;
 		mapping_set_gfp_mask(mapping, GFP_NOFS);
 		mapping->i_private_data = NULL;

fs/gfs2/ops_fstype.c

@@ -114,7 +114,7 @@ static struct gfs2_sbd *init_sbd(struct super_block *sb)
 
 	address_space_init_once(mapping);
 	mapping->a_ops = &gfs2_rgrp_aops;
-	mapping->host = sb->s_bdev->bd_inode;
+	mapping->host = sb->s_bdev->bd_mapping->host;
 	mapping->flags = 0;
 	mapping_set_gfp_mask(mapping, GFP_NOFS);
 	mapping->i_private_data = NULL;