Mar 11 2016

staging: lustre: osc_cache: Use list_for_each_entry_safe 

Author: Bhaktipriya Shridhar <bhaktipriya96@gmail.com>

Doubly linked lists which are  iterated  using list_empty
and list_entry macros have been replaced with list_for_each_entry_safe
macro.
This makes the iteration simpler and more readable.

This patch replaces the while loop containing list_empty and list_entry
with list_for_each_entry_safe.

This was done with Coccinelle.

@@
expression E1;
identifier I1, I2;
type T;
iterator name list_for_each_entry_safe;
@@

T *I1;
+ T *tmp;
...
- while (list_empty(&E1) == 0)
+ list_for_each_entry_safe (I1, tmp, &E1, I2)
{
...when != T *I1;
- I1 = list_entry(E1.next, T, I2);
...
}

Signed-off-by: Bhaktipriya Shridhar 
Signed-off-by: Greg Kroah-Hartman 

---
 drivers/staging/lustre/lustre/osc/osc_cache.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)
 
diff --git a/drivers/staging/lustre/lustre/osc/osc_cache.c b/drivers/staging/lustre/lustre/osc/osc_cache.c
index 2e45255..6336311 100644
--- a/drivers/staging/lustre/lustre/osc/osc_cache.c
+++ b/drivers/staging/lustre/lustre/osc/osc_cache.c
@@ -1905,13 +1905,12 @@ static int get_write_extents(struct osc_object *obj, struct list_head *rpclist)
 {
 	struct client_obd *cli = osc_cli(obj);
 	struct osc_extent *ext;
+	struct osc_extent *temp;
 	int page_count = 0;
 	unsigned int max_pages = cli->cl_max_pages_per_rpc;
 
 	LASSERT(osc_object_is_locked(obj));
-	while (!list_empty(&obj->oo_hp_exts)) {
-		ext = list_entry(obj->oo_hp_exts.next, struct osc_extent,
-				 oe_link);
+	list_for_each_entry_safe(ext, temp, &obj->oo_hp_exts, oe_link) {
 		LASSERT(ext->oe_state == OES_CACHE);
 		if (!try_to_add_extent_for_io(cli, ext, rpclist, &page_count,
 					      &max_pages))
@@ -2667,6 +2666,7 @@ int osc_cache_truncate_start(const struct lu_env *env, struct osc_io *oio,
 {
 	struct client_obd *cli = osc_cli(obj);
 	struct osc_extent *ext;
+	struct osc_extent *temp;
 	struct osc_extent *waiting = NULL;
 	pgoff_t index;
 	LIST_HEAD(list);
@@ -2726,10 +2726,9 @@ again:
 
 	osc_list_maint(cli, obj);
 
-	while (!list_empty(&list)) {
+	list_for_each_entry_safe(ext, temp, &list, oe_link) {
 		int rc;
 
-		ext = list_entry(list.next, struct osc_extent, oe_link);
 		list_del_init(&ext->oe_link);
 
 		/* extent may be in OES_ACTIVE state because inode mutex

qlambert