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>

1 files changed, 4 insertions, 7 deletions

diff --git a/fs/fscache/cookie.c b/fs/fscache/cookie.c
index 8dcb114758e3..e2cba1f60c21 100644
--- a/fs/fscache/cookie.c
+++ b/fs/fscache/cookie.c
@@ -237,13 +237,12 @@ static int fscache_alloc_object(struct fscache_cache *cache,
 				struct fscache_cookie *cookie)
 {
 	struct fscache_object *object;
-	struct hlist_node *_n;
 	int ret;
 
 	_enter("%p,%p{%s}", cache, cookie, cookie->def->name);
 
 	spin_lock(&cookie->lock);
-	hlist_for_each_entry(object, _n, &cookie->backing_objects,
+	hlist_for_each_entry(object, &cookie->backing_objects,
 			     cookie_link) {
 		if (object->cache == cache)
 			goto object_already_extant;
@@ -311,7 +310,6 @@ static int fscache_attach_object(struct fscache_cookie *cookie,
 {
 	struct fscache_object *p;
 	struct fscache_cache *cache = object->cache;
-	struct hlist_node *_n;
 	int ret;
 
 	_enter("{%s},{OBJ%x}", cookie->def->name, object->debug_id);
@@ -321,7 +319,7 @@ static int fscache_attach_object(struct fscache_cookie *cookie,
 	/* there may be multiple initial creations of this object, but we only
 	 * want one */
 	ret = -EEXIST;
-	hlist_for_each_entry(p, _n, &cookie->backing_objects, cookie_link) {
+	hlist_for_each_entry(p, &cookie->backing_objects, cookie_link) {
 		if (p->cache == object->cache) {
 			if (p->state >= FSCACHE_OBJECT_DYING)
 				ret = -ENOBUFS;
@@ -331,7 +329,7 @@ static int fscache_attach_object(struct fscache_cookie *cookie,
 
 	/* pin the parent object */
 	spin_lock_nested(&cookie->parent->lock, 1);
-	hlist_for_each_entry(p, _n, &cookie->parent->backing_objects,
+	hlist_for_each_entry(p, &cookie->parent->backing_objects,
 			     cookie_link) {
 		if (p->cache == object->cache) {
 			if (p->state >= FSCACHE_OBJECT_DYING) {
@@ -435,7 +433,6 @@ EXPORT_SYMBOL(__fscache_wait_on_invalidate);
 void __fscache_update_cookie(struct fscache_cookie *cookie)
 {
 	struct fscache_object *object;
-	struct hlist_node *_p;
 
 	fscache_stat(&fscache_n_updates);
 
@@ -452,7 +449,7 @@ void __fscache_update_cookie(struct fscache_cookie *cookie)
 	spin_lock(&cookie->lock);
 
 	/* update the index entry on disk in each cache backing this cookie */
-	hlist_for_each_entry(object, _p,
+	hlist_for_each_entry(object,
 			     &cookie->backing_objects, cookie_link) {
 		fscache_raise_event(object, FSCACHE_OBJECT_EV_UPDATE);
 	}