From: Brian Norris <computersforpeace@gmail.com>
To: <linux-mtd@lists.infradead.org>
Cc: Richard Weinberger <richard@nod.at>,
Brian Norris <computersforpeace@gmail.com>
Subject: [PATCH 4/4] mtd: warn when registering the same master many times
Date: Mon, 1 Jun 2015 16:17:20 -0700 [thread overview]
Message-ID: <1433200640-17858-4-git-send-email-computersforpeace@gmail.com> (raw)
In-Reply-To: <1433200640-17858-1-git-send-email-computersforpeace@gmail.com>
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>
---
drivers/mtd/mtdcore.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
index 03eec42dc715..f0e157e0be89 100644
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -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(mtd->backing_dev_info, "MTD already registered\n"))
+ return -EEXIST;
+
mtd->backing_dev_info = &mtd_bdi;
BUG_ON(mtd->writesize == 0);
@@ -597,6 +605,7 @@ 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(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);
--
1.9.1
next prev parent reply other threads:[~2015-06-01 23:18 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-06-01 23:17 [PATCH 1/4] mtd: diskonchip: remove two-phase partitioning / registration Brian Norris
2015-06-01 23:17 ` [PATCH 2/4] mtd: propagate error codes from add_mtd_device() Brian Norris
2015-06-02 8:02 ` Richard Weinberger
2015-06-03 0:00 ` Brian Norris
2015-06-01 23:17 ` [PATCH 3/4] mtd: fixup corner case error handling in mtd_device_parse_register() Brian Norris
2015-06-02 8:03 ` Richard Weinberger
2015-10-26 21:34 ` Brian Norris
2015-06-01 23:17 ` Brian Norris [this message]
2015-06-02 8:03 ` [PATCH 4/4] mtd: warn when registering the same master many times Richard Weinberger
2015-10-26 21:35 ` Brian Norris
2015-06-17 1:51 ` [PATCH 1/4] mtd: diskonchip: remove two-phase partitioning / registration Brian Norris
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