From 6022e75bf0686799a6ecca3c33a669e6c70e9d26 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 c0637603a391..7d5a6cede9b0 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); -- 2.30.2