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>

5 files changed, 7 insertions, 12 deletions

diff --git a/drivers/md/dm-bio-prison.c b/drivers/md/dm-bio-prison.c
index aefb78e3cbf..d9d3f1c7b66 100644
--- a/drivers/md/dm-bio-prison.c
+++ b/drivers/md/dm-bio-prison.c
@@ -106,9 +106,8 @@ static struct dm_bio_prison_cell *__search_bucket(struct hlist_head *bucket,
 						  struct dm_cell_key *key)
 {
 	struct dm_bio_prison_cell *cell;
-	struct hlist_node *tmp;
 
-	hlist_for_each_entry(cell, tmp, bucket, list)
+	hlist_for_each_entry(cell, bucket, list)
 		if (keys_equal(&cell->key, key))
 			return cell;
 
diff --git a/drivers/md/dm-bufio.c b/drivers/md/dm-bufio.c
index 651ca79881d..93205e32a00 100644
--- a/drivers/md/dm-bufio.c
+++ b/drivers/md/dm-bufio.c
@@ -859,9 +859,8 @@ static void __check_watermark(struct dm_bufio_client *c)
 static struct dm_buffer *__find(struct dm_bufio_client *c, sector_t block)
 {
 	struct dm_buffer *b;
-	struct hlist_node *hn;
 
-	hlist_for_each_entry(b, hn, &c->cache_hash[DM_BUFIO_HASH(block)],
+	hlist_for_each_entry(b, &c->cache_hash[DM_BUFIO_HASH(block)],
 			     hash_list) {
 		dm_bufio_cond_resched();
 		if (b->block == block)
diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c
index 59fc18ae52c..10079e07edf 100644
--- a/drivers/md/dm-snap.c
+++ b/drivers/md/dm-snap.c
@@ -227,12 +227,11 @@ static void stop_tracking_chunk(struct dm_snapshot *s, struct bio *bio)
 static int __chunk_is_tracked(struct dm_snapshot *s, chunk_t chunk)
 {
 	struct dm_snap_tracked_chunk *c;
-	struct hlist_node *hn;
 	int found = 0;
 
 	spin_lock_irq(&s->tracked_chunk_lock);
 
-	hlist_for_each_entry(c, hn,
+	hlist_for_each_entry(c,
 	    &s->tracked_chunk_hash[DM_TRACKED_CHUNK_HASH(chunk)], node) {
 		if (c->chunk == chunk) {
 			found = 1;
diff --git a/drivers/md/persistent-data/dm-transaction-manager.c b/drivers/md/persistent-data/dm-transaction-manager.c
index 7b17a1fdeaf..81da1a26042 100644
--- a/drivers/md/persistent-data/dm-transaction-manager.c
+++ b/drivers/md/persistent-data/dm-transaction-manager.c
@@ -46,10 +46,9 @@ static int is_shadow(struct dm_transaction_manager *tm, dm_block_t b)
 	int r = 0;
 	unsigned bucket = dm_hash_block(b, DM_HASH_MASK);
 	struct shadow_info *si;
-	struct hlist_node *n;
 
 	spin_lock(&tm->lock);
-	hlist_for_each_entry(si, n, tm->buckets + bucket, hlist)
+	hlist_for_each_entry(si, tm->buckets + bucket, hlist)
 		if (si->where == b) {
 			r = 1;
 			break;
@@ -81,14 +80,14 @@ static void insert_shadow(struct dm_transaction_manager *tm, dm_block_t b)
 static void wipe_shadow_table(struct dm_transaction_manager *tm)
 {
 	struct shadow_info *si;
-	struct hlist_node *n, *tmp;
+	struct hlist_node *tmp;
 	struct hlist_head *bucket;
 	int i;
 
 	spin_lock(&tm->lock);
 	for (i = 0; i < DM_HASH_SIZE; i++) {
 		bucket = tm->buckets + i;
-		hlist_for_each_entry_safe(si, n, tmp, bucket, hlist)
+		hlist_for_each_entry_safe(si, tmp, bucket, hlist)
 			kfree(si);
 
 		INIT_HLIST_HEAD(bucket);
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 19d77a02663..697f026cb31 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -365,10 +365,9 @@ static struct stripe_head *__find_stripe(struct r5conf *conf, sector_t sector,
 					 short generation)
 {
 	struct stripe_head *sh;
-	struct hlist_node *hn;
 
 	pr_debug("__find_stripe, sector %llu\n", (unsigned long long)sector);
-	hlist_for_each_entry(sh, hn, stripe_hash(conf, sector), hash)
+	hlist_for_each_entry(sh, stripe_hash(conf, sector), hash)
 		if (sh->sector == sector && sh->generation == generation)
 			return sh;
 	pr_debug("__stripe %llu not in cache\n", (unsigned long long)sector);