mtd: warn when registering the same master many times (be0dbff8) · Commits · 戴 / test

When CONFIG_MTD_PARTITIONED_MASTER=y, it is fatal to call mtd_device_parse_register() twice on the same MTD, as we try to register the same device/kobject multipile times. When CONFIG_MTD_PARTITIONED_MASTER=n, calling mtd_device_parse_register() is more of just a nuisance, as we can mostly navigate around any conflicting actions. But anyway, doing so is a Bad Thing (TM), and we should complain loudly for any drivers that try to do this. Signed-off-by:

Brian Norris <computersforpeace@gmail.com> Reviewed-by:

Richard Weinberger <richard@nod.at>

drivers/mtd/mtdcore.c

+9 −0

Original line number	Diff line number	Diff line
		@@ -387,6 +387,14 @@ int add_mtd_device(struct mtd_info *mtd)
		struct mtd_notifier *not;
		int i, error;

		/*
		* May occur, for instance, on buggy drivers which call
		* mtd_device_parse_register() multiple times on the same master MTD,
		* especially with CONFIG_MTD_PARTITIONED_MASTER=y.
		*/
		if (WARN_ONCE(mtd->backing_dev_info, "MTD already registered\n"))
		return -EEXIST;

		mtd->backing_dev_info = &mtd_bdi;

		BUG_ON(mtd->writesize == 0);
		@@ -606,6 +614,7 @@ int mtd_device_parse_register(struct mtd_info mtd, const char const *types,
		* does cause problems with parse_mtd_partitions() above (e.g.,
		* cmdlineparts will register partitions more than once).
		*/
		WARN_ONCE(mtd->reboot_notifier.notifier_call, "MTD already registered\n");
		if (mtd->_reboot && !mtd->reboot_notifier.notifier_call) {
		mtd->reboot_notifier.notifier_call = mtd_reboot_notifier;
		register_reboot_notifier(&mtd->reboot_notifier);

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