Hi,

Please refer to the code below:

Custom field in warehouse:

from odoo import models, fields

class StockWarehouse(models.Model):
    _inherit = "stock.warehouse"

    is_blocked = fields.Boolean(
        string="Block Operations",
        help="If enabled, all stock movements (inbound, outbound, internal) "
             "for this warehouse will be restricted."
    )

Warning :

from odoo.exceptions import UserError

class StockPicking(models.Model):
    _inherit = "stock.picking"

    def action_confirm(self):
        for picking in self:
            if picking.location_id.warehouse_id.is_blocked or picking.location_dest_id.warehouse_id.is_blocked:
                raise UserError("This warehouse is locked for stocktaking. No transfers allowed.")
        return super().action_confirm()

    def button_validate(self):
        for picking in self:
            if picking.location_id.warehouse_id.is_blocked or picking.location_dest_id.warehouse_id.is_blocked:
                raise UserError("This warehouse is locked for stocktaking. No transfers allowed.")
        return super().button_validate()

Hope it helps.