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, 3 insertions, 5 deletions

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index a36a7435edf5..a5ba080d303b 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -3998,7 +3998,6 @@ static int run(mddev_t *mddev)
         int raid_disk, memory;
         mdk_rdev_t *rdev;
         struct disk_info *disk;
-        struct list_head *tmp;
         int working_disks = 0;
 
         if (mddev->level != 5 && mddev->level != 4 && mddev->level != 6) {
@@ -4108,7 +4107,7 @@ static int run(mddev_t *mddev)
 
         pr_debug("raid5: run(%s) called.\n", mdname(mddev));
 
-        rdev_for_each(rdev, tmp, mddev) {
+        list_for_each_entry(rdev, &mddev->disks, same_set) {
                 raid_disk = rdev->raid_disk;
                 if (raid_disk >= conf->raid_disks
                     || raid_disk < 0)
@@ -4533,7 +4532,6 @@ static int raid5_start_reshape(mddev_t *mddev)
 {
         raid5_conf_t *conf = mddev_to_conf(mddev);
         mdk_rdev_t *rdev;
-        struct list_head *rtmp;
         int spares = 0;
         int added_devices = 0;
         unsigned long flags;
@@ -4541,7 +4539,7 @@ static int raid5_start_reshape(mddev_t *mddev)
         if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
                 return -EBUSY;
 
-        rdev_for_each(rdev, rtmp, mddev)
+        list_for_each_entry(rdev, &mddev->disks, same_set)
                 if (rdev->raid_disk < 0 &&
                     !test_bit(Faulty, &rdev->flags))
                         spares++;
@@ -4563,7 +4561,7 @@ static int raid5_start_reshape(mddev_t *mddev)
         /* Add some new drives, as many as will fit.
          * We know there are enough to make the newly sized array work.
          */
-        rdev_for_each(rdev, rtmp, mddev)
+        list_for_each_entry(rdev, &mddev->disks, same_set)
                 if (rdev->raid_disk < 0 &&
                     !test_bit(Faulty, &rdev->flags)) {
                         if (raid5_add_disk(mddev, rdev) == 0) {