diff --git a/net/rds/info.c b/net/rds/info.c index 21b32eb16559..31e7ad108459 100644 --- a/net/rds/info.c +++ b/net/rds/info.c @@ -32,6 +32,7 @@ */ #include #include +#include #include #include #include @@ -68,6 +69,7 @@ struct rds_info_iterator { unsigned long offset; }; +DEFINE_STATIC_SRCU(rds_info_srcu); static DEFINE_SPINLOCK(rds_info_lock); static rds_info_func rds_info_funcs[RDS_INFO_LAST - RDS_INFO_FIRST + 1]; @@ -78,8 +80,11 @@ void rds_info_register_func(int optname, rds_info_func func) BUG_ON(optname < RDS_INFO_FIRST || optname > RDS_INFO_LAST); spin_lock(&rds_info_lock); - BUG_ON(rds_info_funcs[offset]); - rds_info_funcs[offset] = func; + if (WARN_ON_ONCE(rds_info_funcs[offset])) { + spin_unlock(&rds_info_lock); + return; + } + WRITE_ONCE(rds_info_funcs[offset], func); spin_unlock(&rds_info_lock); } EXPORT_SYMBOL_GPL(rds_info_register_func); @@ -91,9 +96,13 @@ void rds_info_deregister_func(int optname, rds_info_func func) BUG_ON(optname < RDS_INFO_FIRST || optname > RDS_INFO_LAST); spin_lock(&rds_info_lock); - BUG_ON(rds_info_funcs[offset] != func); - rds_info_funcs[offset] = NULL; + if (WARN_ON_ONCE(rds_info_funcs[offset] != func)) { + spin_unlock(&rds_info_lock); + return; + } + WRITE_ONCE(rds_info_funcs[offset], NULL); spin_unlock(&rds_info_lock); + synchronize_srcu(&rds_info_srcu); } EXPORT_SYMBOL_GPL(rds_info_deregister_func); @@ -162,6 +171,7 @@ int rds_info_getsockopt(struct socket *sock, int optname, sockopt_t *opt) rds_info_func func; struct page **pages = NULL; size_t offset0 = 0; + int srcu_idx; int npages = 0; int ret; int len; @@ -214,8 +224,10 @@ int rds_info_getsockopt(struct socket *sock, int optname, sockopt_t *opt) rdsdebug("len %d nr_pages %lu\n", len, nr_pages); call_func: - func = rds_info_funcs[optname - RDS_INFO_FIRST]; + srcu_idx = srcu_read_lock(&rds_info_srcu); + func = READ_ONCE(rds_info_funcs[optname - RDS_INFO_FIRST]); if (!func) { + srcu_read_unlock(&rds_info_srcu, srcu_idx); ret = -ENOPROTOOPT; goto out; } @@ -225,6 +237,7 @@ int rds_info_getsockopt(struct socket *sock, int optname, sockopt_t *opt) iter.offset = offset0; func(sock, len, &iter, &lens); + srcu_read_unlock(&rds_info_srcu, srcu_idx); BUG_ON(lens.each == 0); total = lens.nr * lens.each;