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>

3 files changed, 16 insertions, 20 deletions

diff --git a/net/can/af_can.c b/net/can/af_can.c
index ddac1ee2ed2..c48e5220bba 100644
--- a/net/can/af_can.c
+++ b/net/can/af_can.c
@@ -516,7 +516,6 @@ void can_rx_unregister(struct net_device *dev, canid_t can_id, canid_t mask,
 {
 	struct receiver *r = NULL;
 	struct hlist_head *rl;
-	struct hlist_node *next;
 	struct dev_rcv_lists *d;
 
 	if (dev && dev->type != ARPHRD_CAN)
@@ -540,7 +539,7 @@ void can_rx_unregister(struct net_device *dev, canid_t can_id, canid_t mask,
 	 * been registered before.
 	 */
 
-	hlist_for_each_entry_rcu(r, next, rl, list) {
+	hlist_for_each_entry_rcu(r, rl, list) {
 		if (r->can_id == can_id && r->mask == mask &&
 		    r->func == func && r->data == data)
 			break;
@@ -552,7 +551,7 @@ void can_rx_unregister(struct net_device *dev, canid_t can_id, canid_t mask,
 	 * will be NULL, while r will point to the last item of the list.
 	 */
 
-	if (!next) {
+	if (!r) {
 		printk(KERN_ERR "BUG: receive list entry not found for "
 		       "dev %s, id %03X, mask %03X\n",
 		       DNAME(dev), can_id, mask);
@@ -590,7 +589,6 @@ static inline void deliver(struct sk_buff *skb, struct receiver *r)
 static int can_rcv_filter(struct dev_rcv_lists *d, struct sk_buff *skb)
 {
 	struct receiver *r;
-	struct hlist_node *n;
 	int matches = 0;
 	struct can_frame *cf = (struct can_frame *)skb->data;
 	canid_t can_id = cf->can_id;
@@ -600,7 +598,7 @@ static int can_rcv_filter(struct dev_rcv_lists *d, struct sk_buff *skb)
 
 	if (can_id & CAN_ERR_FLAG) {
 		/* check for error message frame entries only */
-		hlist_for_each_entry_rcu(r, n, &d->rx[RX_ERR], list) {
+		hlist_for_each_entry_rcu(r, &d->rx[RX_ERR], list) {
 			if (can_id & r->mask) {
 				deliver(skb, r);
 				matches++;
@@ -610,13 +608,13 @@ static int can_rcv_filter(struct dev_rcv_lists *d, struct sk_buff *skb)
 	}
 
 	/* check for unfiltered entries */
-	hlist_for_each_entry_rcu(r, n, &d->rx[RX_ALL], list) {
+	hlist_for_each_entry_rcu(r, &d->rx[RX_ALL], list) {
 		deliver(skb, r);
 		matches++;
 	}
 
 	/* check for can_id/mask entries */
-	hlist_for_each_entry_rcu(r, n, &d->rx[RX_FIL], list) {
+	hlist_for_each_entry_rcu(r, &d->rx[RX_FIL], list) {
 		if ((can_id & r->mask) == r->can_id) {
 			deliver(skb, r);
 			matches++;
@@ -624,7 +622,7 @@ static int can_rcv_filter(struct dev_rcv_lists *d, struct sk_buff *skb)
 	}
 
 	/* check for inverted can_id/mask entries */
-	hlist_for_each_entry_rcu(r, n, &d->rx[RX_INV], list) {
+	hlist_for_each_entry_rcu(r, &d->rx[RX_INV], list) {
 		if ((can_id & r->mask) != r->can_id) {
 			deliver(skb, r);
 			matches++;
@@ -636,7 +634,7 @@ static int can_rcv_filter(struct dev_rcv_lists *d, struct sk_buff *skb)
 		return matches;
 
 	if (can_id & CAN_EFF_FLAG) {
-		hlist_for_each_entry_rcu(r, n, &d->rx[RX_EFF], list) {
+		hlist_for_each_entry_rcu(r, &d->rx[RX_EFF], list) {
 			if (r->can_id == can_id) {
 				deliver(skb, r);
 				matches++;
@@ -644,7 +642,7 @@ static int can_rcv_filter(struct dev_rcv_lists *d, struct sk_buff *skb)
 		}
 	} else {
 		can_id &= CAN_SFF_MASK;
-		hlist_for_each_entry_rcu(r, n, &d->rx_sff[can_id], list) {
+		hlist_for_each_entry_rcu(r, &d->rx_sff[can_id], list) {
 			deliver(skb, r);
 			matches++;
 		}
diff --git a/net/can/gw.c b/net/can/gw.c
index c185fcd5e82..2d117dc5ebe 100644
--- a/net/can/gw.c
+++ b/net/can/gw.c
@@ -457,11 +457,11 @@ static int cgw_notifier(struct notifier_block *nb,
 	if (msg == NETDEV_UNREGISTER) {
 
 		struct cgw_job *gwj = NULL;
-		struct hlist_node *n, *nx;
+		struct hlist_node *nx;
 
 		ASSERT_RTNL();
 
-		hlist_for_each_entry_safe(gwj, n, nx, &cgw_list, list) {
+		hlist_for_each_entry_safe(gwj, nx, &cgw_list, list) {
 
 			if (gwj->src.dev == dev || gwj->dst.dev == dev) {
 				hlist_del(&gwj->list);
@@ -575,12 +575,11 @@ cancel:
 static int cgw_dump_jobs(struct sk_buff *skb, struct netlink_callback *cb)
 {
 	struct cgw_job *gwj = NULL;
-	struct hlist_node *n;
 	int idx = 0;
 	int s_idx = cb->args[0];
 
 	rcu_read_lock();
-	hlist_for_each_entry_rcu(gwj, n, &cgw_list, list) {
+	hlist_for_each_entry_rcu(gwj, &cgw_list, list) {
 		if (idx < s_idx)
 			goto cont;
 
@@ -858,11 +857,11 @@ out:
 static void cgw_remove_all_jobs(void)
 {
 	struct cgw_job *gwj = NULL;
-	struct hlist_node *n, *nx;
+	struct hlist_node *nx;
 
 	ASSERT_RTNL();
 
-	hlist_for_each_entry_safe(gwj, n, nx, &cgw_list, list) {
+	hlist_for_each_entry_safe(gwj, nx, &cgw_list, list) {
 		hlist_del(&gwj->list);
 		cgw_unregister_filter(gwj);
 		kfree(gwj);
@@ -872,7 +871,7 @@ static void cgw_remove_all_jobs(void)
 static int cgw_remove_job(struct sk_buff *skb,  struct nlmsghdr *nlh, void *arg)
 {
 	struct cgw_job *gwj = NULL;
-	struct hlist_node *n, *nx;
+	struct hlist_node *nx;
 	struct rtcanmsg *r;
 	struct cf_mod mod;
 	struct can_can_gw ccgw;
@@ -907,7 +906,7 @@ static int cgw_remove_job(struct sk_buff *skb,  struct nlmsghdr *nlh, void *arg)
 	ASSERT_RTNL();
 
 	/* remove only the first matching entry */
-	hlist_for_each_entry_safe(gwj, n, nx, &cgw_list, list) {
+	hlist_for_each_entry_safe(gwj, nx, &cgw_list, list) {
 
 		if (gwj->flags != r->flags)
 			continue;
diff --git a/net/can/proc.c b/net/can/proc.c
index 49733589214..1ab8c888f10 100644
--- a/net/can/proc.c
+++ b/net/can/proc.c
@@ -195,9 +195,8 @@ static void can_print_rcvlist(struct seq_file *m, struct hlist_head *rx_list,
 			      struct net_device *dev)
 {
 	struct receiver *r;
-	struct hlist_node *n;
 
-	hlist_for_each_entry_rcu(r, n, rx_list, list) {
+	hlist_for_each_entry_rcu(r, rx_list, list) {
 		char *fmt = (r->can_id & CAN_EFF_FLAG)?
 			"   %-5s  %08x  %08x  %pK  %pK  %8ld  %s\n" :
 			"   %-5s     %03x    %08x  %pK  %pK  %8ld  %s\n";