From 40d62789c14a6c2df0c0ba89fb053e1f9f00ffc2 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Thu, 13 Aug 2015 12:32:55 +1000 Subject: [PATCH] md: extend spinlock protection in register_md_cluster_operations This code looks racy. The only possible race is if two modules try to register at the same time and that won't happen. But make the code look safe anyway. Signed-off-by: NeilBrown --- drivers/md/md.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) diff --git a/drivers/md/md.c b/drivers/md/md.c index c0637603a3918..7d5a6cede9b07 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -7427,15 +7427,19 @@ int unregister_md_personality(struct md_personality *p) } EXPORT_SYMBOL(unregister_md_personality); -int register_md_cluster_operations(struct md_cluster_operations *ops, struct module *module) +int register_md_cluster_operations(struct md_cluster_operations *ops, + struct module *module) { - if (md_cluster_ops != NULL) - return -EALREADY; + int ret = 0; spin_lock(&pers_lock); - md_cluster_ops = ops; - md_cluster_mod = module; + if (md_cluster_ops != NULL) + ret = -EALREADY; + else { + md_cluster_ops = ops; + md_cluster_mod = module; + } spin_unlock(&pers_lock); - return 0; + return ret; } EXPORT_SYMBOL(register_md_cluster_operations); -- 2.39.5