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, 15 insertions, 21 deletions

diff --git a/fs/lockd/host.c b/fs/lockd/host.c
index 0e17090c310f..abdd75d44dd4 100644
--- a/fs/lockd/host.c
+++ b/fs/lockd/host.c
@@ -32,15 +32,15 @@
 static struct hlist_head	nlm_server_hosts[NLM_HOST_NRHASH];
 static struct hlist_head	nlm_client_hosts[NLM_HOST_NRHASH];
 
-#define for_each_host(host, pos, chain, table) \
+#define for_each_host(host, chain, table) \
 	for ((chain) = (table); \
 	     (chain) < (table) + NLM_HOST_NRHASH; ++(chain)) \
-		hlist_for_each_entry((host), (pos), (chain), h_hash)
+		hlist_for_each_entry((host), (chain), h_hash)
 
-#define for_each_host_safe(host, pos, next, chain, table) \
+#define for_each_host_safe(host, next, chain, table) \
 	for ((chain) = (table); \
 	     (chain) < (table) + NLM_HOST_NRHASH; ++(chain)) \
-		hlist_for_each_entry_safe((host), (pos), (next), \
+		hlist_for_each_entry_safe((host), (next), \
 						(chain), h_hash)
 
 static unsigned long		nrhosts;
@@ -225,7 +225,6 @@ struct nlm_host *nlmclnt_lookup_host(const struct sockaddr *sap,
 		.net		= net,
 	};
 	struct hlist_head *chain;
-	struct hlist_node *pos;
 	struct nlm_host	*host;
 	struct nsm_handle *nsm = NULL;
 	struct lockd_net *ln = net_generic(net, lockd_net_id);
@@ -237,7 +236,7 @@ struct nlm_host *nlmclnt_lookup_host(const struct sockaddr *sap,
 	mutex_lock(&nlm_host_mutex);
 
 	chain = &nlm_client_hosts[nlm_hash_address(sap)];
-	hlist_for_each_entry(host, pos, chain, h_hash) {
+	hlist_for_each_entry(host, chain, h_hash) {
 		if (host->net != net)
 			continue;
 		if (!rpc_cmp_addr(nlm_addr(host), sap))
@@ -322,7 +321,6 @@ struct nlm_host *nlmsvc_lookup_host(const struct svc_rqst *rqstp,
 				    const size_t hostname_len)
 {
 	struct hlist_head *chain;
-	struct hlist_node *pos;
 	struct nlm_host	*host = NULL;
 	struct nsm_handle *nsm = NULL;
 	struct sockaddr *src_sap = svc_daddr(rqstp);
@@ -350,7 +348,7 @@ struct nlm_host *nlmsvc_lookup_host(const struct svc_rqst *rqstp,
 		nlm_gc_hosts(net);
 
 	chain = &nlm_server_hosts[nlm_hash_address(ni.sap)];
-	hlist_for_each_entry(host, pos, chain, h_hash) {
+	hlist_for_each_entry(host, chain, h_hash) {
 		if (host->net != net)
 			continue;
 		if (!rpc_cmp_addr(nlm_addr(host), ni.sap))
@@ -515,10 +513,9 @@ static struct nlm_host *next_host_state(struct hlist_head *cache,
 {
 	struct nlm_host *host;
 	struct hlist_head *chain;
-	struct hlist_node *pos;
 
 	mutex_lock(&nlm_host_mutex);
-	for_each_host(host, pos, chain, cache) {
+	for_each_host(host, chain, cache) {
 		if (host->h_nsmhandle == nsm
 		    && host->h_nsmstate != info->state) {
 			host->h_nsmstate = info->state;
@@ -570,7 +567,6 @@ void nlm_host_rebooted(const struct nlm_reboot *info)
 static void nlm_complain_hosts(struct net *net)
 {
 	struct hlist_head *chain;
-	struct hlist_node *pos;
 	struct nlm_host	*host;
 
 	if (net) {
@@ -587,7 +583,7 @@ static void nlm_complain_hosts(struct net *net)
 		dprintk("lockd: %lu hosts left:\n", nrhosts);
 	}
 
-	for_each_host(host, pos, chain, nlm_server_hosts) {
+	for_each_host(host, chain, nlm_server_hosts) {
 		if (net && host->net != net)
 			continue;
 		dprintk("       %s (cnt %d use %d exp %ld net %p)\n",
@@ -600,14 +596,13 @@ void
 nlm_shutdown_hosts_net(struct net *net)
 {
 	struct hlist_head *chain;
-	struct hlist_node *pos;
 	struct nlm_host	*host;
 
 	mutex_lock(&nlm_host_mutex);
 
 	/* First, make all hosts eligible for gc */
 	dprintk("lockd: nuking all hosts in net %p...\n", net);
-	for_each_host(host, pos, chain, nlm_server_hosts) {
+	for_each_host(host, chain, nlm_server_hosts) {
 		if (net && host->net != net)
 			continue;
 		host->h_expires = jiffies - 1;
@@ -644,11 +639,11 @@ static void
 nlm_gc_hosts(struct net *net)
 {
 	struct hlist_head *chain;
-	struct hlist_node *pos, *next;
+	struct hlist_node *next;
 	struct nlm_host	*host;
 
 	dprintk("lockd: host garbage collection for net %p\n", net);
-	for_each_host(host, pos, chain, nlm_server_hosts) {
+	for_each_host(host, chain, nlm_server_hosts) {
 		if (net && host->net != net)
 			continue;
 		host->h_inuse = 0;
@@ -657,7 +652,7 @@ nlm_gc_hosts(struct net *net)
 	/* Mark all hosts that hold locks, blocks or shares */
 	nlmsvc_mark_resources(net);
 
-	for_each_host_safe(host, pos, next, chain, nlm_server_hosts) {
+	for_each_host_safe(host, next, chain, nlm_server_hosts) {
 		if (net && host->net != net)
 			continue;
 		if (atomic_read(&host->h_count) || host->h_inuse
diff --git a/fs/lockd/svcsubs.c b/fs/lockd/svcsubs.c
index b3a24b07d981..d17bb62b06d6 100644
--- a/fs/lockd/svcsubs.c
+++ b/fs/lockd/svcsubs.c
@@ -84,7 +84,6 @@ __be32
 nlm_lookup_file(struct svc_rqst *rqstp, struct nlm_file **result,
 					struct nfs_fh *f)
 {
-	struct hlist_node *pos;
 	struct nlm_file	*file;
 	unsigned int	hash;
 	__be32		nfserr;
@@ -96,7 +95,7 @@ nlm_lookup_file(struct svc_rqst *rqstp, struct nlm_file **result,
 	/* Lock file table */
 	mutex_lock(&nlm_file_mutex);
 
-	hlist_for_each_entry(file, pos, &nlm_files[hash], f_list)
+	hlist_for_each_entry(file, &nlm_files[hash], f_list)
 		if (!nfs_compare_fh(&file->f_handle, f))
 			goto found;
 
@@ -248,13 +247,13 @@ static int
 nlm_traverse_files(void *data, nlm_host_match_fn_t match,
 		int (*is_failover_file)(void *data, struct nlm_file *file))
 {
-	struct hlist_node *pos, *next;
+	struct hlist_node *next;
 	struct nlm_file	*file;
 	int i, ret = 0;
 
 	mutex_lock(&nlm_file_mutex);
 	for (i = 0; i < FILE_NRHASH; i++) {
-		hlist_for_each_entry_safe(file, pos, next, &nlm_files[i], f_list) {
+		hlist_for_each_entry_safe(file, next, &nlm_files[i], f_list) {
 			if (is_failover_file && !is_failover_file(data, file))
 				continue;
 			file->f_count++;