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, 7 insertions, 14 deletions

diff --git a/virt/kvm/eventfd.c b/virt/kvm/eventfd.c
index b6eea5c..adb17f2 100644
--- a/virt/kvm/eventfd.c
+++ b/virt/kvm/eventfd.c
@@ -268,14 +268,13 @@ static void irqfd_update(struct kvm *kvm, struct _irqfd *irqfd,
 			 struct kvm_irq_routing_table *irq_rt)
 {
 	struct kvm_kernel_irq_routing_entry *e;
-	struct hlist_node *n;
 
 	if (irqfd->gsi >= irq_rt->nr_rt_entries) {
 		rcu_assign_pointer(irqfd->irq_entry, NULL);
 		return;
 	}
 
-	hlist_for_each_entry(e, n, &irq_rt->map[irqfd->gsi], link) {
+	hlist_for_each_entry(e, &irq_rt->map[irqfd->gsi], link) {
 		/* Only fast-path MSI. */
 		if (e->type == KVM_IRQ_ROUTING_MSI)
 			rcu_assign_pointer(irqfd->irq_entry, e);
diff --git a/virt/kvm/irq_comm.c b/virt/kvm/irq_comm.c
index ff6d40e..e9073cf 100644
--- a/virt/kvm/irq_comm.c
+++ b/virt/kvm/irq_comm.c
@@ -173,7 +173,6 @@ int kvm_set_irq(struct kvm *kvm, int irq_source_id, u32 irq, int level)
 	struct kvm_kernel_irq_routing_entry *e, irq_set[KVM_NR_IRQCHIPS];
 	int ret = -1, i = 0;
 	struct kvm_irq_routing_table *irq_rt;
-	struct hlist_node *n;
 
 	trace_kvm_set_irq(irq, level, irq_source_id);
 
@@ -184,7 +183,7 @@ int kvm_set_irq(struct kvm *kvm, int irq_source_id, u32 irq, int level)
 	rcu_read_lock();
 	irq_rt = rcu_dereference(kvm->irq_routing);
 	if (irq < irq_rt->nr_rt_entries)
-		hlist_for_each_entry(e, n, &irq_rt->map[irq], link)
+		hlist_for_each_entry(e, &irq_rt->map[irq], link)
 			irq_set[i++] = *e;
 	rcu_read_unlock();
 
@@ -212,7 +211,6 @@ int kvm_set_irq_inatomic(struct kvm *kvm, int irq_source_id, u32 irq, int level)
 	struct kvm_kernel_irq_routing_entry *e;
 	int ret = -EINVAL;
 	struct kvm_irq_routing_table *irq_rt;
-	struct hlist_node *n;
 
 	trace_kvm_set_irq(irq, level, irq_source_id);
 
@@ -227,7 +225,7 @@ int kvm_set_irq_inatomic(struct kvm *kvm, int irq_source_id, u32 irq, int level)
 	rcu_read_lock();
 	irq_rt = rcu_dereference(kvm->irq_routing);
 	if (irq < irq_rt->nr_rt_entries)
-		hlist_for_each_entry(e, n, &irq_rt->map[irq], link) {
+		hlist_for_each_entry(e, &irq_rt->map[irq], link) {
 			if (likely(e->type == KVM_IRQ_ROUTING_MSI))
 				ret = kvm_set_msi_inatomic(e, kvm);
 			else
@@ -241,13 +239,12 @@ int kvm_set_irq_inatomic(struct kvm *kvm, int irq_source_id, u32 irq, int level)
 bool kvm_irq_has_notifier(struct kvm *kvm, unsigned irqchip, unsigned pin)
 {
 	struct kvm_irq_ack_notifier *kian;
-	struct hlist_node *n;
 	int gsi;
 
 	rcu_read_lock();
 	gsi = rcu_dereference(kvm->irq_routing)->chip[irqchip][pin];
 	if (gsi != -1)
-		hlist_for_each_entry_rcu(kian, n, &kvm->irq_ack_notifier_list,
+		hlist_for_each_entry_rcu(kian, &kvm->irq_ack_notifier_list,
 					 link)
 			if (kian->gsi == gsi) {
 				rcu_read_unlock();
@@ -263,7 +260,6 @@ EXPORT_SYMBOL_GPL(kvm_irq_has_notifier);
 void kvm_notify_acked_irq(struct kvm *kvm, unsigned irqchip, unsigned pin)
 {
 	struct kvm_irq_ack_notifier *kian;
-	struct hlist_node *n;
 	int gsi;
 
 	trace_kvm_ack_irq(irqchip, pin);
@@ -271,7 +267,7 @@ void kvm_notify_acked_irq(struct kvm *kvm, unsigned irqchip, unsigned pin)
 	rcu_read_lock();
 	gsi = rcu_dereference(kvm->irq_routing)->chip[irqchip][pin];
 	if (gsi != -1)
-		hlist_for_each_entry_rcu(kian, n, &kvm->irq_ack_notifier_list,
+		hlist_for_each_entry_rcu(kian, &kvm->irq_ack_notifier_list,
 					 link)
 			if (kian->gsi == gsi)
 				kian->irq_acked(kian);
@@ -369,13 +365,12 @@ void kvm_fire_mask_notifiers(struct kvm *kvm, unsigned irqchip, unsigned pin,
 			     bool mask)
 {
 	struct kvm_irq_mask_notifier *kimn;
-	struct hlist_node *n;
 	int gsi;
 
 	rcu_read_lock();
 	gsi = rcu_dereference(kvm->irq_routing)->chip[irqchip][pin];
 	if (gsi != -1)
-		hlist_for_each_entry_rcu(kimn, n, &kvm->mask_notifier_list, link)
+		hlist_for_each_entry_rcu(kimn, &kvm->mask_notifier_list, link)
 			if (kimn->irq == gsi)
 				kimn->func(kimn, mask);
 	rcu_read_unlock();
@@ -396,13 +391,12 @@ static int setup_routing_entry(struct kvm_irq_routing_table *rt,
 	int delta;
 	unsigned max_pin;
 	struct kvm_kernel_irq_routing_entry *ei;
-	struct hlist_node *n;
 
 	/*
 	 * Do not allow GSI to be mapped to the same irqchip more than once.
 	 * Allow only one to one mapping between GSI and MSI.
 	 */
-	hlist_for_each_entry(ei, n, &rt->map[ue->gsi], link)
+	hlist_for_each_entry(ei, &rt->map[ue->gsi], link)
 		if (ei->type == KVM_IRQ_ROUTING_MSI ||
 		    ue->type == KVM_IRQ_ROUTING_MSI ||
 		    ue->u.irqchip.irqchip == ei->irqchip.irqchip)