ocfs2: use list_for_each_entry() instead of list_for_each()

[dan.carpenter@oracle.com: fix up some NULL dereference bugs]
Signed-off-by: Dong Fang <yp.fangdong@gmail.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Jeff Liu <jeff.liu@oracle.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 files changed, 40 insertions, 90 deletions

diff --git a/fs/ocfs2/dlm/dlmast.c b/fs/ocfs2/dlm/dlmast.c
index fbec0be62326..b46278f9ae44 100644
--- a/fs/ocfs2/dlm/dlmast.c
+++ b/fs/ocfs2/dlm/dlmast.c
@@ -292,7 +292,7 @@ int dlm_proxy_ast_handler(struct o2net_msg *msg, u32 len, void *data,
         struct dlm_lock *lock = NULL;
         struct dlm_proxy_ast *past = (struct dlm_proxy_ast *) msg->buf;
         char *name;
-        struct list_head *iter, *head=NULL;
+        struct list_head *head = NULL;
         __be64 cookie;
         u32 flags;
         u8 node;
@@ -373,8 +373,7 @@ int dlm_proxy_ast_handler(struct o2net_msg *msg, u32 len, void *data,
         /* try convert queue for both ast/bast */
         head = &res->converting;
         lock = NULL;
-        list_for_each(iter, head) {
-                lock = list_entry (iter, struct dlm_lock, list);
+        list_for_each_entry(lock, head, list) {
                 if (lock->ml.cookie == cookie)
                         goto do_ast;
         }
@@ -385,8 +384,7 @@ int dlm_proxy_ast_handler(struct o2net_msg *msg, u32 len, void *data,
         else
                 head = &res->granted;
 
-        list_for_each(iter, head) {
-                lock = list_entry (iter, struct dlm_lock, list);
+        list_for_each_entry(lock, head, list) {
                 if (lock->ml.cookie == cookie)
                         goto do_ast;
         }
diff --git a/fs/ocfs2/dlm/dlmcommon.h b/fs/ocfs2/dlm/dlmcommon.h
index de854cca12a2..e0517762fcc0 100644
--- a/fs/ocfs2/dlm/dlmcommon.h
+++ b/fs/ocfs2/dlm/dlmcommon.h
@@ -1079,11 +1079,9 @@ static inline int dlm_lock_compatible(int existing, int request)
 static inline int dlm_lock_on_list(struct list_head *head,
                                    struct dlm_lock *lock)
 {
-        struct list_head *iter;
         struct dlm_lock *tmplock;
 
-        list_for_each(iter, head) {
-                tmplock = list_entry(iter, struct dlm_lock, list);
+        list_for_each_entry(tmplock, head, list) {
                 if (tmplock == lock)
                         return 1;
         }
diff --git a/fs/ocfs2/dlm/dlmconvert.c b/fs/ocfs2/dlm/dlmconvert.c
index 29a886d1e82c..e36d63ff1783 100644
--- a/fs/ocfs2/dlm/dlmconvert.c
+++ b/fs/ocfs2/dlm/dlmconvert.c
@@ -123,7 +123,6 @@ static enum dlm_status __dlmconvert_master(struct dlm_ctxt *dlm,
                                            int *kick_thread)
 {
         enum dlm_status status = DLM_NORMAL;
-        struct list_head *iter;
         struct dlm_lock *tmplock=NULL;
 
         assert_spin_locked(&res->spinlock);
@@ -185,16 +184,14 @@ static enum dlm_status __dlmconvert_master(struct dlm_ctxt *dlm,
 
         /* upconvert from here on */
         status = DLM_NORMAL;
-        list_for_each(iter, &res->granted) {
-                tmplock = list_entry(iter, struct dlm_lock, list);
+        list_for_each_entry(tmplock, &res->granted, list) {
                 if (tmplock == lock)
                         continue;
                 if (!dlm_lock_compatible(tmplock->ml.type, type))
                         goto switch_queues;
         }
 
-        list_for_each(iter, &res->converting) {
-                tmplock = list_entry(iter, struct dlm_lock, list);
+        list_for_each_entry(tmplock, &res->converting, list) {
                 if (!dlm_lock_compatible(tmplock->ml.type, type))
                         goto switch_queues;
                 /* existing conversion requests take precedence */
@@ -424,8 +421,8 @@ int dlm_convert_lock_handler(struct o2net_msg *msg, u32 len, void *data,
         struct dlm_ctxt *dlm = data;
         struct dlm_convert_lock *cnv = (struct dlm_convert_lock *)msg->buf;
         struct dlm_lock_resource *res = NULL;
-        struct list_head *iter;
         struct dlm_lock *lock = NULL;
+        struct dlm_lock *tmp_lock;
         struct dlm_lockstatus *lksb;
         enum dlm_status status = DLM_NORMAL;
         u32 flags;
@@ -471,14 +468,13 @@ int dlm_convert_lock_handler(struct o2net_msg *msg, u32 len, void *data,
                 dlm_error(status);
                 goto leave;
         }
-        list_for_each(iter, &res->granted) {
-                lock = list_entry(iter, struct dlm_lock, list);
-                if (lock->ml.cookie == cnv->cookie &&
-                    lock->ml.node == cnv->node_idx) {
+        list_for_each_entry(tmp_lock, &res->granted, list) {
+                if (tmp_lock->ml.cookie == cnv->cookie &&
+                    tmp_lock->ml.node == cnv->node_idx) {
+                        lock = tmp_lock;
                         dlm_lock_get(lock);
                         break;
                 }
-                lock = NULL;
         }
         spin_unlock(&res->spinlock);
         if (!lock) {
diff --git a/fs/ocfs2/dlm/dlmdebug.c b/fs/ocfs2/dlm/dlmdebug.c
index 0e28e242226d..e33cd7a3c582 100644
--- a/fs/ocfs2/dlm/dlmdebug.c
+++ b/fs/ocfs2/dlm/dlmdebug.c
@@ -96,7 +96,6 @@ static void __dlm_print_lock(struct dlm_lock *lock)
 
 void __dlm_print_one_lock_resource(struct dlm_lock_resource *res)
 {
-        struct list_head *iter2;
         struct dlm_lock *lock;
         char buf[DLM_LOCKID_NAME_MAX];
 
@@ -118,18 +117,15 @@ void __dlm_print_one_lock_resource(struct dlm_lock_resource *res)
                res->inflight_locks, atomic_read(&res->asts_reserved));
         dlm_print_lockres_refmap(res);
         printk("  granted queue:\n");
-        list_for_each(iter2, &res->granted) {
-                lock = list_entry(iter2, struct dlm_lock, list);
+        list_for_each_entry(lock, &res->granted, list) {
                 __dlm_print_lock(lock);
         }
         printk("  converting queue:\n");
-        list_for_each(iter2, &res->converting) {
-                lock = list_entry(iter2, struct dlm_lock, list);
+        list_for_each_entry(lock, &res->converting, list) {
                 __dlm_print_lock(lock);
         }
         printk("  blocked queue:\n");
-        list_for_each(iter2, &res->blocked) {
-                lock = list_entry(iter2, struct dlm_lock, list);
+        list_for_each_entry(lock, &res->blocked, list) {
                 __dlm_print_lock(lock);
         }
 }
@@ -446,7 +442,6 @@ static int debug_mle_print(struct dlm_ctxt *dlm, char *buf, int len)
 {
         struct dlm_master_list_entry *mle;
         struct hlist_head *bucket;
-        struct hlist_node *list;
         int i, out = 0;
         unsigned long total = 0, longest = 0, bucket_count = 0;
 
@@ -456,9 +451,7 @@ static int debug_mle_print(struct dlm_ctxt *dlm, char *buf, int len)
         spin_lock(&dlm->master_lock);
         for (i = 0; i < DLM_HASH_BUCKETS; i++) {
                 bucket = dlm_master_hash(dlm, i);
-                hlist_for_each(list, bucket) {
-                        mle = hlist_entry(list, struct dlm_master_list_entry,
-                                          master_hash_node);
+                hlist_for_each_entry(mle, bucket, master_hash_node) {
                         ++total;
                         ++bucket_count;
                         if (len - out < 200)
diff --git a/fs/ocfs2/dlm/dlmdomain.c b/fs/ocfs2/dlm/dlmdomain.c
index dbb17c07656a..8b3382abf840 100644
--- a/fs/ocfs2/dlm/dlmdomain.c
+++ b/fs/ocfs2/dlm/dlmdomain.c
@@ -193,7 +193,7 @@ struct dlm_lock_resource * __dlm_lookup_lockres_full(struct dlm_ctxt *dlm,
                                                      unsigned int hash)
 {
         struct hlist_head *bucket;
-        struct hlist_node *list;
+        struct dlm_lock_resource *res;
 
         mlog(0, "%.*s\n", len, name);
 
@@ -201,9 +201,7 @@ struct dlm_lock_resource * __dlm_lookup_lockres_full(struct dlm_ctxt *dlm,
 
         bucket = dlm_lockres_hash(dlm, hash);
 
-        hlist_for_each(list, bucket) {
-                struct dlm_lock_resource *res = hlist_entry(list,
-                        struct dlm_lock_resource, hash_node);
+        hlist_for_each_entry(res, bucket, hash_node) {
                 if (res->lockname.name[0] != name[0])
                         continue;
                 if (unlikely(res->lockname.len != len))
@@ -262,22 +260,19 @@ struct dlm_lock_resource * dlm_lookup_lockres(struct dlm_ctxt *dlm,
 
 static struct dlm_ctxt * __dlm_lookup_domain_full(const char *domain, int len)
 {
-        struct dlm_ctxt *tmp = NULL;
-        struct list_head *iter;
+        struct dlm_ctxt *tmp;
 
         assert_spin_locked(&dlm_domain_lock);
 
         /* tmp->name here is always NULL terminated,
          * but domain may not be! */
-        list_for_each(iter, &dlm_domains) {
-                tmp = list_entry (iter, struct dlm_ctxt, list);
+        list_for_each_entry(tmp, &dlm_domains, list) {
                 if (strlen(tmp->name) == len &&
                     memcmp(tmp->name, domain, len)==0)
-                        break;
-                tmp = NULL;
+                        return tmp;
         }
 
-        return tmp;
+        return NULL;
 }
 
 /* For null terminated domain strings ONLY */
@@ -366,25 +361,22 @@ static void __dlm_get(struct dlm_ctxt *dlm)
  * you shouldn't trust your pointer. */
 struct dlm_ctxt *dlm_grab(struct dlm_ctxt *dlm)
 {
-        struct list_head *iter;
-        struct dlm_ctxt *target = NULL;
+        struct dlm_ctxt *target;
+        struct dlm_ctxt *ret = NULL;
 
         spin_lock(&dlm_domain_lock);
 
-        list_for_each(iter, &dlm_domains) {
-                target = list_entry (iter, struct dlm_ctxt, list);
-
+        list_for_each_entry(target, &dlm_domains, list) {
                 if (target == dlm) {
                         __dlm_get(target);
+                        ret = target;
                         break;
                 }
-
-                target = NULL;
         }
 
         spin_unlock(&dlm_domain_lock);
 
-        return target;
+        return ret;
 }
 
 int dlm_domain_fully_joined(struct dlm_ctxt *dlm)
@@ -2296,13 +2288,10 @@ static DECLARE_RWSEM(dlm_callback_sem);
 void dlm_fire_domain_eviction_callbacks(struct dlm_ctxt *dlm,
                                         int node_num)
 {
-        struct list_head *iter;
         struct dlm_eviction_cb *cb;
 
         down_read(&dlm_callback_sem);
-        list_for_each(iter, &dlm->dlm_eviction_callbacks) {
-                cb = list_entry(iter, struct dlm_eviction_cb, ec_item);
-
+        list_for_each_entry(cb, &dlm->dlm_eviction_callbacks, ec_item) {
                 cb->ec_func(node_num, cb->ec_data);
         }
         up_read(&dlm_callback_sem);
diff --git a/fs/ocfs2/dlm/dlmlock.c b/fs/ocfs2/dlm/dlmlock.c
index 47e67c2d228f..5d32f7511f74 100644
--- a/fs/ocfs2/dlm/dlmlock.c
+++ b/fs/ocfs2/dlm/dlmlock.c
@@ -91,19 +91,14 @@ void dlm_destroy_lock_cache(void)
 static int dlm_can_grant_new_lock(struct dlm_lock_resource *res,
                                   struct dlm_lock *lock)
 {
-        struct list_head *iter;
         struct dlm_lock *tmplock;
 
-        list_for_each(iter, &res->granted) {
-                tmplock = list_entry(iter, struct dlm_lock, list);
-
+        list_for_each_entry(tmplock, &res->granted, list) {
                 if (!dlm_lock_compatible(tmplock->ml.type, lock->ml.type))
                         return 0;
         }
 
-        list_for_each(iter, &res->converting) {
-                tmplock = list_entry(iter, struct dlm_lock, list);
-
+        list_for_each_entry(tmplock, &res->converting, list) {
                 if (!dlm_lock_compatible(tmplock->ml.type, lock->ml.type))
                         return 0;
                 if (!dlm_lock_compatible(tmplock->ml.convert_type,
diff --git a/fs/ocfs2/dlm/dlmmaster.c b/fs/ocfs2/dlm/dlmmaster.c
index 33ecbe0e6734..cf0f103963b1 100644
--- a/fs/ocfs2/dlm/dlmmaster.c
+++ b/fs/ocfs2/dlm/dlmmaster.c
@@ -342,16 +342,13 @@ static int dlm_find_mle(struct dlm_ctxt *dlm,
 {
         struct dlm_master_list_entry *tmpmle;
         struct hlist_head *bucket;
-        struct hlist_node *list;
         unsigned int hash;
 
         assert_spin_locked(&dlm->master_lock);
 
         hash = dlm_lockid_hash(name, namelen);
         bucket = dlm_master_hash(dlm, hash);
-        hlist_for_each(list, bucket) {
-                tmpmle = hlist_entry(list, struct dlm_master_list_entry,
-                                     master_hash_node);
+        hlist_for_each_entry(tmpmle, bucket, master_hash_node) {
                 if (!dlm_mle_equal(dlm, tmpmle, name, namelen))
                         continue;
                 dlm_get_mle(tmpmle);
@@ -3183,7 +3180,7 @@ void dlm_clean_master_list(struct dlm_ctxt *dlm, u8 dead_node)
         struct dlm_master_list_entry *mle;
         struct dlm_lock_resource *res;
         struct hlist_head *bucket;
-        struct hlist_node *list;
+        struct hlist_node *tmp;
         unsigned int i;
 
         mlog(0, "dlm=%s, dead node=%u\n", dlm->name, dead_node);
@@ -3194,10 +3191,7 @@ top:
         spin_lock(&dlm->master_lock);
         for (i = 0; i < DLM_HASH_BUCKETS; i++) {
                 bucket = dlm_master_hash(dlm, i);
-                hlist_for_each(list, bucket) {
-                        mle = hlist_entry(list, struct dlm_master_list_entry,
-                                          master_hash_node);
-
+                hlist_for_each_entry_safe(mle, tmp, bucket, master_hash_node) {
                         BUG_ON(mle->type != DLM_MLE_BLOCK &&
                                mle->type != DLM_MLE_MASTER &&
                                mle->type != DLM_MLE_MIGRATION);
@@ -3378,7 +3372,7 @@ void dlm_force_free_mles(struct dlm_ctxt *dlm)
         int i;
         struct hlist_head *bucket;
         struct dlm_master_list_entry *mle;
-        struct hlist_node *tmp, *list;
+        struct hlist_node *tmp;
 
         /*
          * We notified all other nodes that we are exiting the domain and
@@ -3394,9 +3388,7 @@ void dlm_force_free_mles(struct dlm_ctxt *dlm)
 
         for (i = 0; i < DLM_HASH_BUCKETS; i++) {
                 bucket = dlm_master_hash(dlm, i);
-                hlist_for_each_safe(list, tmp, bucket) {
-                        mle = hlist_entry(list, struct dlm_master_list_entry,
-                                          master_hash_node);
+                hlist_for_each_entry_safe(mle, tmp, bucket, master_hash_node) {
                         if (mle->type != DLM_MLE_BLOCK) {
                                 mlog(ML_ERROR, "bad mle: %p\n", mle);
                                 dlm_print_one_mle(mle);
diff --git a/fs/ocfs2/dlm/dlmthread.c b/fs/ocfs2/dlm/dlmthread.c
index e73c833fc2a1..9db869de829d 100644
--- a/fs/ocfs2/dlm/dlmthread.c
+++ b/fs/ocfs2/dlm/dlmthread.c
@@ -286,8 +286,6 @@ static void dlm_shuffle_lists(struct dlm_ctxt *dlm,
                               struct dlm_lock_resource *res)
 {
         struct dlm_lock *lock, *target;
-        struct list_head *iter;
-        struct list_head *head;
         int can_grant = 1;
 
         /*
@@ -314,9 +312,7 @@ converting:
                      dlm->name, res->lockname.len, res->lockname.name);
                 BUG();
         }
-        head = &res->granted;
-        list_for_each(iter, head) {
-                lock = list_entry(iter, struct dlm_lock, list);
+        list_for_each_entry(lock, &res->granted, list) {
                 if (lock==target)
                         continue;
                 if (!dlm_lock_compatible(lock->ml.type,
@@ -333,9 +329,8 @@ converting:
                                         target->ml.convert_type;
                 }
         }
-        head = &res->converting;
-        list_for_each(iter, head) {
-                lock = list_entry(iter, struct dlm_lock, list);
+
+        list_for_each_entry(lock, &res->converting, list) {
                 if (lock==target)
                         continue;
                 if (!dlm_lock_compatible(lock->ml.type,
@@ -384,9 +379,7 @@ blocked:
                 goto leave;
         target = list_entry(res->blocked.next, struct dlm_lock, list);
 
-        head = &res->granted;
-        list_for_each(iter, head) {
-                lock = list_entry(iter, struct dlm_lock, list);
+        list_for_each_entry(lock, &res->granted, list) {
                 if (lock==target)
                         continue;
                 if (!dlm_lock_compatible(lock->ml.type, target->ml.type)) {
@@ -400,9 +393,7 @@ blocked:
                 }
         }
 
-        head = &res->converting;
-        list_for_each(iter, head) {
-                lock = list_entry(iter, struct dlm_lock, list);
+        list_for_each_entry(lock, &res->converting, list) {
                 if (lock==target)
                         continue;
                 if (!dlm_lock_compatible(lock->ml.type, target->ml.type)) {
diff --git a/fs/ocfs2/dlm/dlmunlock.c b/fs/ocfs2/dlm/dlmunlock.c
index 850aa7e87537..5698b52cf5c9 100644
--- a/fs/ocfs2/dlm/dlmunlock.c
+++ b/fs/ocfs2/dlm/dlmunlock.c
@@ -388,7 +388,6 @@ int dlm_unlock_lock_handler(struct o2net_msg *msg, u32 len, void *data,
         struct dlm_ctxt *dlm = data;
         struct dlm_unlock_lock *unlock = (struct dlm_unlock_lock *)msg->buf;
         struct dlm_lock_resource *res = NULL;
-        struct list_head *iter;
         struct dlm_lock *lock = NULL;
         enum dlm_status status = DLM_NORMAL;
         int found = 0, i;
@@ -458,8 +457,7 @@ int dlm_unlock_lock_handler(struct o2net_msg *msg, u32 len, void *data,
         }
 
         for (i=0; i<3; i++) {
-                list_for_each(iter, queue) {
-                        lock = list_entry(iter, struct dlm_lock, list);
+                list_for_each_entry(lock, queue, list) {
                         if (lock->ml.cookie == unlock->cookie &&
                             lock->ml.node == unlock->node_idx) {
                                 dlm_lock_get(lock);