md: use list_for_each_entry macro directly
The rdev_for_each macro defined in <linux/raid/md_k.h> is identical to
list_for_each_entry_safe, from <linux/list.h>, it should be defined to
use list_for_each_entry_safe, instead of reinventing the wheel.
But some calls to each_entry_safe don't really need a safe version,
just a direct list_for_each_entry is enough, this could save a temp
variable (tmp) in every function that used rdev_for_each.
In this patch, most rdev_for_each loops are replaced by list_for_each_entry,
totally save many tmp vars; and only in the other situations that will call
list_del to delete an entry, the safe version is used.
Signed-off-by: Cheng Renquan <crquan@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
diff --git a/include/linux/raid/md_k.h b/include/linux/raid/md_k.h
index 663803e..8f9a54c 100644
--- a/include/linux/raid/md_k.h
+++ b/include/linux/raid/md_k.h
@@ -335,17 +335,14 @@
* iterates through some rdev ringlist. It's safe to remove the
* current 'rdev'. Dont touch 'tmp' though.
*/
-#define rdev_for_each_list(rdev, tmp, list) \
- \
- for ((tmp) = (list).next; \
- (rdev) = (list_entry((tmp), mdk_rdev_t, same_set)), \
- (tmp) = (tmp)->next, (tmp)->prev != &(list) \
- ; )
+#define rdev_for_each_list(rdev, tmp, head) \
+ list_for_each_entry_safe(rdev, tmp, head, same_set)
+
/*
* iterates through the 'same array disks' ringlist
*/
#define rdev_for_each(rdev, tmp, mddev) \
- rdev_for_each_list(rdev, tmp, (mddev)->disks)
+ list_for_each_entry_safe(rdev, tmp, &((mddev)->disks), same_set)
#define rdev_for_each_rcu(rdev, mddev) \
list_for_each_entry_rcu(rdev, &((mddev)->disks), same_set)