block/bdev: enable large folio support for large logical block sizes

Call mapping_set_folio_min_order() when modifying the logical block
size to ensure folios are allocated with the correct size.

Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20250221223823.1680616-7-mcgrof@kernel.org
Reviewed-by: John Garry <john.g.garry@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christian Brauner <brauner@kernel.org>

block/bdev.c

@@ -148,6 +148,8 @@ static void set_init_blocksize(struct block_device *bdev)
 		bsize <<= 1;
 	}
 	BD_INODE(bdev)->i_blkbits = blksize_bits(bsize);
+	mapping_set_folio_min_order(BD_INODE(bdev)->i_mapping,
+				    get_order(bsize));
 }
 
 int set_blocksize(struct file *file, int size)
@@ -169,6 +171,7 @@ int set_blocksize(struct file *file, int size)
 	if (inode->i_blkbits != blksize_bits(size)) {
 		sync_blockdev(bdev);
 		inode->i_blkbits = blksize_bits(size);
+		mapping_set_folio_min_order(inode->i_mapping, get_order(size));
 		kill_bdev(bdev);
 	}
 	return 0;