hlist: drop the node parameter from iterators

I'm not sure why, but the hlist for each entry iterators were conceived

        list_for_each_entry(pos, head, member)

The hlist ones were greedy and wanted an extra parameter:

        hlist_for_each_entry(tpos, pos, head, member)

Why did they need an extra pos parameter? I'm not quite sure. Not only
they don't really need it, it also prevents the iterator from looking
exactly like the list iterator, which is unfortunate.

Besides the semantic patch, there was some manual work required:

 - Fix up the actual hlist iterators in linux/list.h
 - Fix up the declaration of other iterators based on the hlist ones.
 - A very small amount of places were using the 'node' parameter, this
 was modified to use 'obj->member' instead.
 - Coccinelle didn't handle the hlist_for_each_entry_safe iterator
 properly, so those had to be fixed up manually.

The semantic patch which is mostly the work of Peter Senna Tschudin is here:

@@
iterator name hlist_for_each_entry, hlist_for_each_entry_continue, hlist_for_each_entry_from, hlist_for_each_entry_rcu, hlist_for_each_entry_rcu_bh, hlist_for_each_entry_continue_rcu_bh, for_each_busy_worker, ax25_uid_for_each, ax25_for_each, inet_bind_bucket_for_each, sctp_for_each_hentry, sk_for_each, sk_for_each_rcu, sk_for_each_from, sk_for_each_safe, sk_for_each_bound, hlist_for_each_entry_safe, hlist_for_each_entry_continue_rcu, nr_neigh_for_each, nr_neigh_for_each_safe, nr_node_for_each, nr_node_for_each_safe, for_each_gfn_indirect_valid_sp, for_each_gfn_sp, for_each_host;

type T;
expression a,c,d,e;
identifier b;
statement S;
@@

-T b;
    <+... when != b
(
hlist_for_each_entry(a,
- b,
c, d) S
|
hlist_for_each_entry_continue(a,
- b,
c) S
|
hlist_for_each_entry_from(a,
- b,
c) S
|
hlist_for_each_entry_rcu(a,
- b,
c, d) S
|
hlist_for_each_entry_rcu_bh(a,
- b,
c, d) S
|
hlist_for_each_entry_continue_rcu_bh(a,
- b,
c) S
|
for_each_busy_worker(a, c,
- b,
d) S
|
ax25_uid_for_each(a,
- b,
c) S
|
ax25_for_each(a,
- b,
c) S
|
inet_bind_bucket_for_each(a,
- b,
c) S
|
sctp_for_each_hentry(a,
- b,
c) S
|
sk_for_each(a,
- b,
c) S
|
sk_for_each_rcu(a,
- b,
c) S
|
sk_for_each_from
-(a, b)
+(a)
S
+ sk_for_each_from(a) S
|
sk_for_each_safe(a,
- b,
c, d) S
|
sk_for_each_bound(a,
- b,
c) S
|
hlist_for_each_entry_safe(a,
- b,
c, d, e) S
|
hlist_for_each_entry_continue_rcu(a,
- b,
c) S
|
nr_neigh_for_each(a,
- b,
c) S
|
nr_neigh_for_each_safe(a,
- b,
c, d) S
|
nr_node_for_each(a,
- b,
c) S
|
nr_node_for_each_safe(a,
- b,
c, d) S
|
- for_each_gfn_sp(a, c, d, b) S
+ for_each_gfn_sp(a, c, d) S
|
- for_each_gfn_indirect_valid_sp(a, c, d, b) S
+ for_each_gfn_indirect_valid_sp(a, c, d) S
|
for_each_host(a,
- b,
c) S
|
for_each_host_safe(a,
- b,
c, d) S
|
for_each_mesh_entry(a,
- b,
c, d) S
)
    ...+>

[akpm@linux-foundation.org: drop bogus change from net/ipv4/raw.c]
[akpm@linux-foundation.org: drop bogus hunk from net/ipv6/raw.c]
[akpm@linux-foundation.org: checkpatch fixes]
[akpm@linux-foundation.org: fix warnings]
[akpm@linux-foudnation.org: redo intrusive kvm changes]
Tested-by: Peter Senna Tschudin <peter.senna@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 11 insertions, 16 deletions

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 98ca94a41819..ab25b88aae56 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -762,7 +762,6 @@ ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip)
 {
         struct ftrace_profile *rec;
         struct hlist_head *hhd;
-        struct hlist_node *n;
         unsigned long key;
 
         key = hash_long(ip, ftrace_profile_bits);
@@ -771,7 +770,7 @@ ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip)
         if (hlist_empty(hhd))
                 return NULL;
 
-        hlist_for_each_entry_rcu(rec, n, hhd, node) {
+        hlist_for_each_entry_rcu(rec, hhd, node) {
                 if (rec->ip == ip)
                         return rec;
         }
@@ -1133,7 +1132,6 @@ ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip)
         unsigned long key;
         struct ftrace_func_entry *entry;
         struct hlist_head *hhd;
-        struct hlist_node *n;
 
         if (ftrace_hash_empty(hash))
                 return NULL;
@@ -1145,7 +1143,7 @@ ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip)
 
         hhd = &hash->buckets[key];
 
-        hlist_for_each_entry_rcu(entry, n, hhd, hlist) {
+        hlist_for_each_entry_rcu(entry, hhd, hlist) {
                 if (entry->ip == ip)
                         return entry;
         }
@@ -1202,7 +1200,7 @@ remove_hash_entry(struct ftrace_hash *hash,
 static void ftrace_hash_clear(struct ftrace_hash *hash)
 {
         struct hlist_head *hhd;
-        struct hlist_node *tp, *tn;
+        struct hlist_node *tn;
         struct ftrace_func_entry *entry;
         int size = 1 << hash->size_bits;
         int i;
@@ -1212,7 +1210,7 @@ static void ftrace_hash_clear(struct ftrace_hash *hash)
 
         for (i = 0; i < size; i++) {
                 hhd = &hash->buckets[i];
-                hlist_for_each_entry_safe(entry, tp, tn, hhd, hlist)
+                hlist_for_each_entry_safe(entry, tn, hhd, hlist)
                         free_hash_entry(hash, entry);
         }
         FTRACE_WARN_ON(hash->count);
@@ -1275,7 +1273,6 @@ alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash)
 {
         struct ftrace_func_entry *entry;
         struct ftrace_hash *new_hash;
-        struct hlist_node *tp;
         int size;
         int ret;
         int i;
@@ -1290,7 +1287,7 @@ alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash)
 
         size = 1 << hash->size_bits;
         for (i = 0; i < size; i++) {
-                hlist_for_each_entry(entry, tp, &hash->buckets[i], hlist) {
+                hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
                         ret = add_hash_entry(new_hash, entry->ip);
                         if (ret < 0)
                                 goto free_hash;
@@ -1316,7 +1313,7 @@ ftrace_hash_move(struct ftrace_ops *ops, int enable,
                  struct ftrace_hash **dst, struct ftrace_hash *src)
 {
         struct ftrace_func_entry *entry;
-        struct hlist_node *tp, *tn;
+        struct hlist_node *tn;
         struct hlist_head *hhd;
         struct ftrace_hash *old_hash;
         struct ftrace_hash *new_hash;
@@ -1362,7 +1359,7 @@ ftrace_hash_move(struct ftrace_ops *ops, int enable,
         size = 1 << src->size_bits;
         for (i = 0; i < size; i++) {
                 hhd = &src->buckets[i];
-                hlist_for_each_entry_safe(entry, tp, tn, hhd, hlist) {
+                hlist_for_each_entry_safe(entry, tn, hhd, hlist) {
                         if (bits > 0)
                                 key = hash_long(entry->ip, bits);
                         else
@@ -2901,7 +2898,6 @@ static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip,
 {
         struct ftrace_func_probe *entry;
         struct hlist_head *hhd;
-        struct hlist_node *n;
         unsigned long key;
 
         key = hash_long(ip, FTRACE_HASH_BITS);
@@ -2917,7 +2913,7 @@ static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip,
          * on the hash. rcu_read_lock is too dangerous here.
          */
         preempt_disable_notrace();
-        hlist_for_each_entry_rcu(entry, n, hhd, node) {
+        hlist_for_each_entry_rcu(entry, hhd, node) {
                 if (entry->ip == ip)
                         entry->ops->func(ip, parent_ip, &entry->data);
         }
@@ -3068,7 +3064,7 @@ __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
                                   void *data, int flags)
 {
         struct ftrace_func_probe *entry;
-        struct hlist_node *n, *tmp;
+        struct hlist_node *tmp;
         char str[KSYM_SYMBOL_LEN];
         int type = MATCH_FULL;
         int i, len = 0;
@@ -3091,7 +3087,7 @@ __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
         for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
                 struct hlist_head *hhd = &ftrace_func_hash[i];
 
-                hlist_for_each_entry_safe(entry, n, tmp, hhd, node) {
+                hlist_for_each_entry_safe(entry, tmp, hhd, node) {
 
                         /* break up if statements for readability */
                         if ((flags & PROBE_TEST_FUNC) && entry->ops != ops)
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index 194d79602dc7..697e88d13907 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -739,12 +739,11 @@ static int task_state_char(unsigned long state)
 struct trace_event *ftrace_find_event(int type)
 {
         struct trace_event *event;
-        struct hlist_node *n;
         unsigned key;
 
         key = type & (EVENT_HASHSIZE - 1);
 
-        hlist_for_each_entry(event, n, &event_hash[key], node) {
+        hlist_for_each_entry(event, &event_hash[key], node) {
                 if (event->type == type)
                         return event;
         }