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>

1 files changed, 4 insertions, 6 deletions

diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c
index 90f5b24f6e6c..c605ba805586 100644
--- a/drivers/md/raid0.c
+++ b/drivers/md/raid0.c
@@ -57,7 +57,6 @@ static int create_strip_zones (mddev_t *mddev)
         sector_t min_spacing;
         raid0_conf_t *conf = mddev_to_conf(mddev);
         mdk_rdev_t *smallest, *rdev1, *rdev2, *rdev;
-        struct list_head *tmp1, *tmp2;
         struct strip_zone *zone;
         int cnt;
         char b[BDEVNAME_SIZE];
@@ -67,11 +66,11 @@ static int create_strip_zones (mddev_t *mddev)
          */
         conf->nr_strip_zones = 0;
  
-        rdev_for_each(rdev1, tmp1, mddev) {
+        list_for_each_entry(rdev1, &mddev->disks, same_set) {
                 printk(KERN_INFO "raid0: looking at %s\n",
                         bdevname(rdev1->bdev,b));
                 c = 0;
-                rdev_for_each(rdev2, tmp2, mddev) {
+                list_for_each_entry(rdev2, &mddev->disks, same_set) {
                         printk(KERN_INFO "raid0:   comparing %s(%llu)",
                                bdevname(rdev1->bdev,b),
                                (unsigned long long)rdev1->size);
@@ -120,7 +119,7 @@ static int create_strip_zones (mddev_t *mddev)
         cnt = 0;
         smallest = NULL;
         zone->dev = conf->devlist;
-        rdev_for_each(rdev1, tmp1, mddev) {
+        list_for_each_entry(rdev1, &mddev->disks, same_set) {
                 int j = rdev1->raid_disk;
 
                 if (j < 0 || j >= mddev->raid_disks) {
@@ -268,7 +267,6 @@ static int raid0_run (mddev_t *mddev)
         s64 sectors;
         raid0_conf_t *conf;
         mdk_rdev_t *rdev;
-        struct list_head *tmp;
 
         if (mddev->chunk_size == 0) {
                 printk(KERN_ERR "md/raid0: non-zero chunk size required.\n");
@@ -294,7 +292,7 @@ static int raid0_run (mddev_t *mddev)
 
         /* calculate array device size */
         mddev->array_sectors = 0;
-        rdev_for_each(rdev, tmp, mddev)
+        list_for_each_entry(rdev, &mddev->disks, same_set)
                 mddev->array_sectors += rdev->size * 2;
 
         printk(KERN_INFO "raid0 : md_size is %llu sectors.\n",