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authorBrian Norris <computersforpeace@gmail.com>2015-06-01 16:17:20 -0700
committerBrian Norris <computersforpeace@gmail.com>2015-10-26 14:34:07 -0700
commitbe0dbff8b46d69bd738f63b4fe0cf64417f776b0 (patch)
tree044a2240eba4a10e2a8d920ecd2119e19d84b3de /drivers/mtd
parent3e00ed0e984bbec47f5e531bad3cf36885aa5d83 (diff)
downloadblackbird-op-linux-be0dbff8b46d69bd738f63b4fe0cf64417f776b0.tar.gz
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mtd: warn when registering the same master many times
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>
Diffstat (limited to 'drivers/mtd')
-rw-r--r--drivers/mtd/mtdcore.c9
1 files changed, 9 insertions, 0 deletions
diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
index a2e76ac9f1dc..41dc501cb49a 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_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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