[lustre-devel] [PATCH 10/21] lustre: obdclass: use cl_object_for_each where appropriate

[NeilBrown <neilb@suse.com>]

There are various places which have a list_for_each_entry()
where cl_object_for_each (or .._reverse) is more appropriate.

Several of these re-use the 'obj' function parameter as a loop
iterator, which is a little confusing.

Change these to use cl_object_for_each{_reverse}, and where needed,
introduce a new iterator variable 'o'.

Signed-off-by: NeilBrown <neilb@suse.com>
---
 drivers/staging/lustre/lustre/lov/lov_page.c       |    3 -
 drivers/staging/lustre/lustre/obdclass/cl_lock.c   |    3 -
 drivers/staging/lustre/lustre/obdclass/cl_object.c |   82 +++++++++-----------
 drivers/staging/lustre/lustre/obdclass/cl_page.c   |   11 +--
 4 files changed, 44 insertions(+), 55 deletions(-)

diff --git a/drivers/staging/lustre/lustre/lov/lov_page.c b/drivers/staging/lustre/lustre/lov/lov_page.c
index 08485a95ec01..e64b350601d2 100644
--- a/drivers/staging/lustre/lustre/lov/lov_page.c
+++ b/drivers/staging/lustre/lustre/lov/lov_page.c
@@ -103,8 +103,7 @@ int lov_page_init_composite(const struct lu_env *env, struct cl_object *obj,
 		return PTR_ERR(sub);
 
 	subobj = lovsub2cl(r0->lo_sub[stripe]);
-	list_for_each_entry(o, &subobj->co_lu.lo_header->loh_layers,
-			    co_lu.lo_linkage) {
+	cl_object_for_each(o, subobj) {
 		if (o->co_ops->coo_page_init) {
 			rc = o->co_ops->coo_page_init(sub->sub_env, o, page,
 						      cl_index(subobj, suboff));
diff --git a/drivers/staging/lustre/lustre/obdclass/cl_lock.c b/drivers/staging/lustre/lustre/obdclass/cl_lock.c
index 8133d992cc73..fc5976d8b37b 100644
--- a/drivers/staging/lustre/lustre/obdclass/cl_lock.c
+++ b/drivers/staging/lustre/lustre/obdclass/cl_lock.c
@@ -103,8 +103,7 @@ int cl_lock_init(const struct lu_env *env, struct cl_lock *lock,
 	LASSERT(obj);
 
 	INIT_LIST_HEAD(&lock->cll_layers);
-	list_for_each_entry(scan, &obj->co_lu.lo_header->loh_layers,
-			    co_lu.lo_linkage) {
+	cl_object_for_each(scan, obj) {
 		result = scan->co_ops->coo_lock_init(env, scan, lock, io);
 		if (result != 0) {
 			cl_lock_fini(env, lock);
diff --git a/drivers/staging/lustre/lustre/obdclass/cl_object.c b/drivers/staging/lustre/lustre/obdclass/cl_object.c
index f724b2d62df1..d71a680660da 100644
--- a/drivers/staging/lustre/lustre/obdclass/cl_object.c
+++ b/drivers/staging/lustre/lustre/obdclass/cl_object.c
@@ -190,16 +190,15 @@ EXPORT_SYMBOL(cl_object_attr_unlock);
 int cl_object_attr_get(const struct lu_env *env, struct cl_object *obj,
 		       struct cl_attr *attr)
 {
-	struct lu_object_header *top;
+	struct cl_object *o;
 	int result;
 
 	assert_spin_locked(cl_object_attr_guard(obj));
 
-	top = obj->co_lu.lo_header;
 	result = 0;
-	list_for_each_entry(obj, &top->loh_layers, co_lu.lo_linkage) {
-		if (obj->co_ops->coo_attr_get) {
-			result = obj->co_ops->coo_attr_get(env, obj, attr);
+	cl_object_for_each(o, obj) {
+		if (o->co_ops->coo_attr_get) {
+			result = o->co_ops->coo_attr_get(env, o, attr);
 			if (result != 0) {
 				if (result > 0)
 					result = 0;
@@ -221,17 +220,16 @@ EXPORT_SYMBOL(cl_object_attr_get);
 int cl_object_attr_update(const struct lu_env *env, struct cl_object *obj,
 			  const struct cl_attr *attr, unsigned int v)
 {
-	struct lu_object_header *top;
+	struct cl_object *o;
 	int result;
 
 	assert_spin_locked(cl_object_attr_guard(obj));
 
-	top = obj->co_lu.lo_header;
 	result = 0;
-	list_for_each_entry_reverse(obj, &top->loh_layers, co_lu.lo_linkage) {
-		if (obj->co_ops->coo_attr_update) {
-			result = obj->co_ops->coo_attr_update(env, obj, attr,
-							      v);
+	cl_object_for_each_reverse(o, obj) {
+		if (o->co_ops->coo_attr_update) {
+			result = o->co_ops->coo_attr_update(env, o, attr,
+							    v);
 			if (result != 0) {
 				if (result > 0)
 					result = 0;
@@ -254,19 +252,18 @@ EXPORT_SYMBOL(cl_object_attr_update);
 int cl_object_glimpse(const struct lu_env *env, struct cl_object *obj,
 		      struct ost_lvb *lvb)
 {
-	struct lu_object_header *top;
+	struct cl_object *o;
 	int result;
 
-	top = obj->co_lu.lo_header;
 	result = 0;
-	list_for_each_entry_reverse(obj, &top->loh_layers, co_lu.lo_linkage) {
-		if (obj->co_ops->coo_glimpse) {
-			result = obj->co_ops->coo_glimpse(env, obj, lvb);
+	cl_object_for_each_reverse(o, obj) {
+		if (o->co_ops->coo_glimpse) {
+			result = o->co_ops->coo_glimpse(env, o, lvb);
 			if (result != 0)
 				break;
 		}
 	}
-	LU_OBJECT_HEADER(D_DLMTRACE, env, lu_object_top(top),
+	LU_OBJECT_HEADER(D_DLMTRACE, env, lu_object_top(obj->co_lu.lo_header),
 			 "size: %llu mtime: %llu atime: %llu ctime: %llu blocks: %llu\n",
 			 lvb->lvb_size, lvb->lvb_mtime, lvb->lvb_atime,
 			 lvb->lvb_ctime, lvb->lvb_blocks);
@@ -280,14 +277,13 @@ EXPORT_SYMBOL(cl_object_glimpse);
 int cl_conf_set(const struct lu_env *env, struct cl_object *obj,
 		const struct cl_object_conf *conf)
 {
-	struct lu_object_header *top;
+	struct cl_object *o;
 	int result;
 
-	top = obj->co_lu.lo_header;
 	result = 0;
-	list_for_each_entry(obj, &top->loh_layers, co_lu.lo_linkage) {
-		if (obj->co_ops->coo_conf_set) {
-			result = obj->co_ops->coo_conf_set(env, obj, conf);
+	cl_object_for_each(o, obj) {
+		if (o->co_ops->coo_conf_set) {
+			result = o->co_ops->coo_conf_set(env, o, conf);
 			if (result != 0)
 				break;
 		}
@@ -301,13 +297,11 @@ EXPORT_SYMBOL(cl_conf_set);
  */
 int cl_object_prune(const struct lu_env *env, struct cl_object *obj)
 {
-	struct lu_object_header *top;
 	struct cl_object *o;
 	int result;
 
-	top = obj->co_lu.lo_header;
 	result = 0;
-	list_for_each_entry(o, &top->loh_layers, co_lu.lo_linkage) {
+	cl_object_for_each(o, obj) {
 		if (o->co_ops->coo_prune) {
 			result = o->co_ops->coo_prune(env, o);
 			if (result != 0)
@@ -325,14 +319,13 @@ EXPORT_SYMBOL(cl_object_prune);
 int cl_object_getstripe(const struct lu_env *env, struct cl_object *obj,
 			struct lov_user_md __user *uarg, size_t size)
 {
-	struct lu_object_header *top;
+	struct cl_object *o;
 	int result = 0;
 
-	top = obj->co_lu.lo_header;
-	list_for_each_entry(obj, &top->loh_layers, co_lu.lo_linkage) {
-		if (obj->co_ops->coo_getstripe) {
-			result = obj->co_ops->coo_getstripe(env, obj, uarg,
-							    size);
+	cl_object_for_each(o, obj) {
+		if (o->co_ops->coo_getstripe) {
+			result = o->co_ops->coo_getstripe(env, o, uarg,
+							  size);
 			if (result)
 				break;
 		}
@@ -357,14 +350,13 @@ int cl_object_fiemap(const struct lu_env *env, struct cl_object *obj,
 		     struct ll_fiemap_info_key *key,
 		     struct fiemap *fiemap, size_t *buflen)
 {
-	struct lu_object_header *top;
+	struct cl_object *o;
 	int result = 0;
 
-	top = obj->co_lu.lo_header;
-	list_for_each_entry(obj, &top->loh_layers, co_lu.lo_linkage) {
-		if (obj->co_ops->coo_fiemap) {
-			result = obj->co_ops->coo_fiemap(env, obj, key, fiemap,
-							 buflen);
+	cl_object_for_each(o, obj) {
+		if (o->co_ops->coo_fiemap) {
+			result = o->co_ops->coo_fiemap(env, o, key, fiemap,
+						       buflen);
 			if (result)
 				break;
 		}
@@ -376,11 +368,11 @@ EXPORT_SYMBOL(cl_object_fiemap);
 int cl_object_layout_get(const struct lu_env *env, struct cl_object *obj,
 			 struct cl_layout *cl)
 {
-	struct lu_object_header *top = obj->co_lu.lo_header;
+	struct cl_object *o;
 
-	list_for_each_entry(obj, &top->loh_layers, co_lu.lo_linkage) {
-		if (obj->co_ops->coo_layout_get)
-			return obj->co_ops->coo_layout_get(env, obj, cl);
+	cl_object_for_each(o, obj) {
+		if (o->co_ops->coo_layout_get)
+			return o->co_ops->coo_layout_get(env, o, cl);
 	}
 
 	return -EOPNOTSUPP;
@@ -389,12 +381,12 @@ EXPORT_SYMBOL(cl_object_layout_get);
 
 loff_t cl_object_maxbytes(struct cl_object *obj)
 {
-	struct lu_object_header *top = obj->co_lu.lo_header;
+	struct cl_object *o;
 	loff_t maxbytes = LLONG_MAX;
 
-	list_for_each_entry(obj, &top->loh_layers, co_lu.lo_linkage) {
-		if (obj->co_ops->coo_maxbytes)
-			maxbytes = min_t(loff_t, obj->co_ops->coo_maxbytes(obj),
+	cl_object_for_each(o, obj) {
+		if (o->co_ops->coo_maxbytes)
+			maxbytes = min_t(loff_t, o->co_ops->coo_maxbytes(o),
 					 maxbytes);
 	}
 
diff --git a/drivers/staging/lustre/lustre/obdclass/cl_page.c b/drivers/staging/lustre/lustre/obdclass/cl_page.c
index 057318deaa4e..7d00a9233a3b 100644
--- a/drivers/staging/lustre/lustre/obdclass/cl_page.c
+++ b/drivers/staging/lustre/lustre/obdclass/cl_page.c
@@ -132,7 +132,7 @@ struct cl_page *cl_page_alloc(const struct lu_env *env,
 			      enum cl_page_type type)
 {
 	struct cl_page *page;
-	struct lu_object_header *head;
+	struct cl_object *o2;
 
 	page = kzalloc(cl_object_header(o)->coh_page_bufsize, GFP_NOFS);
 	if (page) {
@@ -149,11 +149,10 @@ struct cl_page *cl_page_alloc(const struct lu_env *env,
 		INIT_LIST_HEAD(&page->cp_layers);
 		INIT_LIST_HEAD(&page->cp_batch);
 		lu_ref_init(&page->cp_reference);
-		head = o->co_lu.lo_header;
-		list_for_each_entry(o, &head->loh_layers, co_lu.lo_linkage) {
-			if (o->co_ops->coo_page_init) {
-				result = o->co_ops->coo_page_init(env, o, page,
-								  ind);
+		cl_object_for_each(o2, o) {
+			if (o2->co_ops->coo_page_init) {
+				result = o2->co_ops->coo_page_init(env, o2, page,
+								   ind);
 				if (result != 0) {
 					__cl_page_delete(env, page);
 					cl_page_free(env, page);