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, 5 insertions, 6 deletions

diff --git a/arch/s390/kernel/kprobes.c b/arch/s390/kernel/kprobes.c
index d1c7214e157..3388b2b2a07 100644
--- a/arch/s390/kernel/kprobes.c
+++ b/arch/s390/kernel/kprobes.c
@@ -354,7 +354,7 @@ static int __kprobes trampoline_probe_handler(struct kprobe *p,
 {
         struct kretprobe_instance *ri;
         struct hlist_head *head, empty_rp;
-        struct hlist_node *node, *tmp;
+        struct hlist_node *tmp;
         unsigned long flags, orig_ret_address;
         unsigned long trampoline_address;
         kprobe_opcode_t *correct_ret_addr;
@@ -379,7 +379,7 @@ static int __kprobes trampoline_probe_handler(struct kprobe *p,
         orig_ret_address = 0;
         correct_ret_addr = NULL;
         trampoline_address = (unsigned long) &kretprobe_trampoline;
-        hlist_for_each_entry_safe(ri, node, tmp, head, hlist) {
+        hlist_for_each_entry_safe(ri, tmp, head, hlist) {
                 if (ri->task != current)
                         /* another task is sharing our hash bucket */
                         continue;
@@ -398,7 +398,7 @@ static int __kprobes trampoline_probe_handler(struct kprobe *p,
         kretprobe_assert(ri, orig_ret_address, trampoline_address);
 
         correct_ret_addr = ri->ret_addr;
-        hlist_for_each_entry_safe(ri, node, tmp, head, hlist) {
+        hlist_for_each_entry_safe(ri, tmp, head, hlist) {
                 if (ri->task != current)
                         /* another task is sharing our hash bucket */
                         continue;
@@ -427,7 +427,7 @@ static int __kprobes trampoline_probe_handler(struct kprobe *p,
         kretprobe_hash_unlock(current, &flags);
         preempt_enable_no_resched();
 
-        hlist_for_each_entry_safe(ri, node, tmp, &empty_rp, hlist) {
+        hlist_for_each_entry_safe(ri, tmp, &empty_rp, hlist) {
                 hlist_del(&ri->hlist);
                 kfree(ri);
         }
diff --git a/arch/s390/pci/pci_msi.c b/arch/s390/pci/pci_msi.c
index 90fd3482b9e..0297931335e 100644
--- a/arch/s390/pci/pci_msi.c
+++ b/arch/s390/pci/pci_msi.c
@@ -25,10 +25,9 @@ static DEFINE_SPINLOCK(msi_map_lock);
 
 struct msi_desc *__irq_get_msi_desc(unsigned int irq)
 {
-        struct hlist_node *entry;
         struct msi_map *map;
 
-        hlist_for_each_entry_rcu(map, entry,
+        hlist_for_each_entry_rcu(map,
                         &msi_hash[msi_hashfn(irq)], msi_chain)
                 if (map->irq == irq)
                         return map->msi;