rcu: treewide: Do not use rcu_read_lock_held when calling rcu_dereference_check
Michal Hocko [Fri, 8 Jul 2011 12:39:41 +0000 (14:39 +0200)]
Since ca5ecddf (rcu: define __rcu address space modifier for sparse)
rcu_dereference_check use rcu_read_lock_held as a part of condition
automatically so callers do not have to do that as well.

Signed-off-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

14 files changed:
include/linux/cgroup.h
include/linux/cred.h
include/linux/fdtable.h
include/linux/rtnetlink.h
include/net/sock.h
kernel/cgroup.c
kernel/exit.c
kernel/pid.c
kernel/rcutorture.c
kernel/sched.c
net/mac80211/sta_info.c
net/netlabel/netlabel_domainhash.c
net/netlabel/netlabel_unlabeled.c
security/keys/keyring.c

index ab4ac0c..da7e4bc 100644 (file)
@@ -539,7 +539,6 @@ static inline struct cgroup_subsys_state *cgroup_subsys_state(
  */
 #define task_subsys_state_check(task, subsys_id, __c)                  \
        rcu_dereference_check(task->cgroups->subsys[subsys_id],         \
-                             rcu_read_lock_held() ||                   \
                              lockdep_is_held(&task->alloc_lock) ||     \
                              cgroup_lock_is_held() || (__c))
 
index 8260799..f240f2f 100644 (file)
@@ -284,7 +284,6 @@ static inline void put_cred(const struct cred *_cred)
        ({                                                              \
                const struct task_struct *__t = (task);                 \
                rcu_dereference_check(__t->real_cred,                   \
-                                     rcu_read_lock_held() ||           \
                                      task_is_dead(__t));               \
        })
 
index 133c0ba..df7e3cf 100644 (file)
@@ -60,7 +60,6 @@ struct files_struct {
 
 #define rcu_dereference_check_fdtable(files, fdtfd) \
        (rcu_dereference_check((fdtfd), \
-                              rcu_read_lock_held() || \
                               lockdep_is_held(&(files)->file_lock) || \
                               atomic_read(&(files)->count) == 1 || \
                               rcu_my_thread_group_empty()))
index bbad657..27576aa 100644 (file)
@@ -758,8 +758,7 @@ extern int lockdep_rtnl_is_held(void);
  * or RTNL. Note : Please prefer rtnl_dereference() or rcu_dereference()
  */
 #define rcu_dereference_rtnl(p)                                        \
-       rcu_dereference_check(p, rcu_read_lock_held() ||        \
-                                lockdep_rtnl_is_held())
+       rcu_dereference_check(p, lockdep_rtnl_is_held())
 
 /**
  * rtnl_dereference - fetch RCU pointer when updates are prevented by RTNL
index c0b938c..d5b65c1 100644 (file)
@@ -1301,8 +1301,7 @@ extern unsigned long sock_i_ino(struct sock *sk);
 static inline struct dst_entry *
 __sk_dst_get(struct sock *sk)
 {
-       return rcu_dereference_check(sk->sk_dst_cache, rcu_read_lock_held() ||
-                                                      sock_owned_by_user(sk) ||
+       return rcu_dereference_check(sk->sk_dst_cache, sock_owned_by_user(sk) ||
                                                       lockdep_is_held(&sk->sk_lock.slock));
 }
 
index 2731d11..5ae71d6 100644 (file)
@@ -1697,7 +1697,6 @@ int cgroup_path(const struct cgroup *cgrp, char *buf, int buflen)
 {
        char *start;
        struct dentry *dentry = rcu_dereference_check(cgrp->dentry,
-                                                     rcu_read_lock_held() ||
                                                      cgroup_lock_is_held());
 
        if (!dentry || cgrp == dummytop) {
@@ -1723,7 +1722,6 @@ int cgroup_path(const struct cgroup *cgrp, char *buf, int buflen)
                        break;
 
                dentry = rcu_dereference_check(cgrp->dentry,
-                                              rcu_read_lock_held() ||
                                               cgroup_lock_is_held());
                if (!cgrp->parent)
                        continue;
@@ -4813,8 +4811,7 @@ unsigned short css_id(struct cgroup_subsys_state *css)
         * on this or this is under rcu_read_lock(). Once css->id is allocated,
         * it's unchanged until freed.
         */
-       cssid = rcu_dereference_check(css->id,
-                       rcu_read_lock_held() || atomic_read(&css->refcnt));
+       cssid = rcu_dereference_check(css->id, atomic_read(&css->refcnt));
 
        if (cssid)
                return cssid->id;
@@ -4826,8 +4823,7 @@ unsigned short css_depth(struct cgroup_subsys_state *css)
 {
        struct css_id *cssid;
 
-       cssid = rcu_dereference_check(css->id,
-                       rcu_read_lock_held() || atomic_read(&css->refcnt));
+       cssid = rcu_dereference_check(css->id, atomic_read(&css->refcnt));
 
        if (cssid)
                return cssid->depth;
index 20a4064..07dc154 100644 (file)
@@ -85,7 +85,6 @@ static void __exit_signal(struct task_struct *tsk)
        struct tty_struct *uninitialized_var(tty);
 
        sighand = rcu_dereference_check(tsk->sighand,
-                                       rcu_read_lock_held() ||
                                        lockdep_tasklist_lock_is_held());
        spin_lock(&sighand->siglock);
 
index 57a8346..e432057 100644 (file)
@@ -405,7 +405,6 @@ struct task_struct *pid_task(struct pid *pid, enum pid_type type)
        if (pid) {
                struct hlist_node *first;
                first = rcu_dereference_check(hlist_first_rcu(&pid->tasks[type]),
-                                             rcu_read_lock_held() ||
                                              lockdep_tasklist_lock_is_held());
                if (first)
                        result = hlist_entry(first, struct task_struct, pids[(type)].node);
index 2e138db..ced7210 100644 (file)
@@ -941,7 +941,6 @@ static void rcu_torture_timer(unsigned long unused)
        idx = cur_ops->readlock();
        completed = cur_ops->completed();
        p = rcu_dereference_check(rcu_torture_current,
-                                 rcu_read_lock_held() ||
                                  rcu_read_lock_bh_held() ||
                                  rcu_read_lock_sched_held() ||
                                  srcu_read_lock_held(&srcu_ctl));
@@ -1002,7 +1001,6 @@ rcu_torture_reader(void *arg)
                idx = cur_ops->readlock();
                completed = cur_ops->completed();
                p = rcu_dereference_check(rcu_torture_current,
-                                         rcu_read_lock_held() ||
                                          rcu_read_lock_bh_held() ||
                                          rcu_read_lock_sched_held() ||
                                          srcu_read_lock_held(&srcu_ctl));
index 3f2e502..71e5a25 100644 (file)
@@ -581,7 +581,6 @@ static inline int cpu_of(struct rq *rq)
 
 #define rcu_dereference_check_sched_domain(p) \
        rcu_dereference_check((p), \
-                             rcu_read_lock_held() || \
                              lockdep_is_held(&sched_domains_mutex))
 
 /*
index b83870b..3db78b6 100644 (file)
@@ -97,7 +97,6 @@ struct sta_info *sta_info_get(struct ieee80211_sub_if_data *sdata,
        struct sta_info *sta;
 
        sta = rcu_dereference_check(local->sta_hash[STA_HASH(addr)],
-                                   rcu_read_lock_held() ||
                                    lockdep_is_held(&local->sta_lock) ||
                                    lockdep_is_held(&local->sta_mtx));
        while (sta) {
@@ -105,7 +104,6 @@ struct sta_info *sta_info_get(struct ieee80211_sub_if_data *sdata,
                    memcmp(sta->sta.addr, addr, ETH_ALEN) == 0)
                        break;
                sta = rcu_dereference_check(sta->hnext,
-                                           rcu_read_lock_held() ||
                                            lockdep_is_held(&local->sta_lock) ||
                                            lockdep_is_held(&local->sta_mtx));
        }
@@ -123,7 +121,6 @@ struct sta_info *sta_info_get_bss(struct ieee80211_sub_if_data *sdata,
        struct sta_info *sta;
 
        sta = rcu_dereference_check(local->sta_hash[STA_HASH(addr)],
-                                   rcu_read_lock_held() ||
                                    lockdep_is_held(&local->sta_lock) ||
                                    lockdep_is_held(&local->sta_mtx));
        while (sta) {
@@ -132,7 +129,6 @@ struct sta_info *sta_info_get_bss(struct ieee80211_sub_if_data *sdata,
                    memcmp(sta->sta.addr, addr, ETH_ALEN) == 0)
                        break;
                sta = rcu_dereference_check(sta->hnext,
-                                           rcu_read_lock_held() ||
                                            lockdep_is_held(&local->sta_lock) ||
                                            lockdep_is_held(&local->sta_mtx));
        }
index de0d8e4..2aa975e 100644 (file)
@@ -55,8 +55,7 @@ struct netlbl_domhsh_tbl {
  * should be okay */
 static DEFINE_SPINLOCK(netlbl_domhsh_lock);
 #define netlbl_domhsh_rcu_deref(p) \
-       rcu_dereference_check(p, rcu_read_lock_held() || \
-                                lockdep_is_held(&netlbl_domhsh_lock))
+       rcu_dereference_check(p, lockdep_is_held(&netlbl_domhsh_lock))
 static struct netlbl_domhsh_tbl *netlbl_domhsh = NULL;
 static struct netlbl_dom_map *netlbl_domhsh_def = NULL;
 
index 9c38658..3de3768 100644 (file)
@@ -116,8 +116,7 @@ struct netlbl_unlhsh_walk_arg {
  * hash table should be okay */
 static DEFINE_SPINLOCK(netlbl_unlhsh_lock);
 #define netlbl_unlhsh_rcu_deref(p) \
-       rcu_dereference_check(p, rcu_read_lock_held() || \
-                                lockdep_is_held(&netlbl_unlhsh_lock))
+       rcu_dereference_check(p, lockdep_is_held(&netlbl_unlhsh_lock))
 static struct netlbl_unlhsh_tbl *netlbl_unlhsh = NULL;
 static struct netlbl_unlhsh_iface *netlbl_unlhsh_def = NULL;
 
index a06ffab..30e242f 100644 (file)
@@ -155,7 +155,6 @@ static void keyring_destroy(struct key *keyring)
        }
 
        klist = rcu_dereference_check(keyring->payload.subscriptions,
-                                     rcu_read_lock_held() ||
                                      atomic_read(&keyring->usage) == 0);
        if (klist) {
                for (loop = klist->nkeys - 1; loop >= 0; loop--)