2012-08-17 04:33:40

by Michael wang

Subject: [PATCH 1/3] raid: replace list_for_each_continue_rcu with new interface

From: Michael Wang <[email protected]>

This patch replaces list_for_each_continue_rcu() with
list_for_each_entry_continue_rcu() to save a few lines
of code and allow removing list_for_each_continue_rcu().

Signed-off-by: Michael Wang <[email protected]>
---
drivers/md/bitmap.c | 9 +++------
1 files changed, 3 insertions(+), 6 deletions(-)

diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c
index 15dbe03..b160828 100644
--- a/drivers/md/bitmap.c
+++ b/drivers/md/bitmap.c
@@ -163,20 +163,17 @@ static struct md_rdev *next_active_rdev(struct md_rdev *rdev, struct mddev *mdde
* As devices are only added or removed when raid_disk is < 0 and
* nr_pending is 0 and In_sync is clear, the entries we return will
* still be in the same position on the list when we re-enter
- * list_for_each_continue_rcu.
+ * list_for_each_entry_continue_rcu.
*/
- struct list_head *pos;
rcu_read_lock();
if (rdev == NULL)
/* start at the beginning */
- pos = &mddev->disks;
+ rdev = list_entry_rcu(&mddev->disks, struct md_rdev, same_set);
else {
/* release the previous rdev and start from there. */
rdev_dec_pending(rdev, mddev);
- pos = &rdev->same_set;
}
- list_for_each_continue_rcu(pos, &mddev->disks) {
- rdev = list_entry(pos, struct md_rdev, same_set);
+ list_for_each_entry_continue_rcu(rdev, &mddev->disks, same_set) {
if (rdev->raid_disk >= 0 &&
!test_bit(Faulty, &rdev->flags)) {
/* this is a usable devices */
--
1.7.4.1

2012-08-20 23:42:00

by Paul E. McKenney

Subject: Re: [PATCH 1/3] raid: replace list_for_each_continue_rcu with new interface

On Fri, Aug 17, 2012 at 12:33:29PM +0800, Michael Wang wrote:
> From: Michael Wang <[email protected]>
>
> This patch replaces list_for_each_continue_rcu() with
> list_for_each_entry_continue_rcu() to save a few lines
> of code and allow removing list_for_each_continue_rcu().
>
> Signed-off-by: Michael Wang <[email protected]>

Getting rid of list_for_each_continue_rcu() would indeed be a good thing!

Reviewed-by: Paul E. McKenney <[email protected]>

> ---
> drivers/md/bitmap.c | 9 +++------
> 1 files changed, 3 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c
> index 15dbe03..b160828 100644
> --- a/drivers/md/bitmap.c
> +++ b/drivers/md/bitmap.c
> @@ -163,20 +163,17 @@ static struct md_rdev *next_active_rdev(struct md_rdev *rdev, struct mddev *mdde
> * As devices are only added or removed when raid_disk is < 0 and
> * nr_pending is 0 and In_sync is clear, the entries we return will
> * still be in the same position on the list when we re-enter
> - * list_for_each_continue_rcu.
> + * list_for_each_entry_continue_rcu.
> */
> - struct list_head *pos;
> rcu_read_lock();
> if (rdev == NULL)
> /* start at the beginning */
> - pos = &mddev->disks;
> + rdev = list_entry_rcu(&mddev->disks, struct md_rdev, same_set);
> else {
> /* release the previous rdev and start from there. */
> rdev_dec_pending(rdev, mddev);
> - pos = &rdev->same_set;
> }
> - list_for_each_continue_rcu(pos, &mddev->disks) {
> - rdev = list_entry(pos, struct md_rdev, same_set);
> + list_for_each_entry_continue_rcu(rdev, &mddev->disks, same_set) {
> if (rdev->raid_disk >= 0 &&
> !test_bit(Faulty, &rdev->flags)) {
> /* this is a usable devices */
> --
> 1.7.4.1
>
>

2012-08-24 00:51:38

by Michael wang

Subject: Re: [PATCH 1/3] raid: replace list_for_each_continue_rcu with new interface

On 08/17/2012 12:33 PM, Michael Wang wrote:
> From: Michael Wang <[email protected]>
>
> This patch replaces list_for_each_continue_rcu() with
> list_for_each_entry_continue_rcu() to save a few lines
> of code and allow removing list_for_each_continue_rcu().
>

Hi, Neil

Could I get some comments on this patch?

Regards,
Michael Wang

> Signed-off-by: Michael Wang <[email protected]>
> ---
> drivers/md/bitmap.c | 9 +++------
> 1 files changed, 3 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c
> index 15dbe03..b160828 100644
> --- a/drivers/md/bitmap.c
> +++ b/drivers/md/bitmap.c
> @@ -163,20 +163,17 @@ static struct md_rdev *next_active_rdev(struct md_rdev *rdev, struct mddev *mdde
> * As devices are only added or removed when raid_disk is < 0 and
> * nr_pending is 0 and In_sync is clear, the entries we return will
> * still be in the same position on the list when we re-enter
> - * list_for_each_continue_rcu.
> + * list_for_each_entry_continue_rcu.
> */
> - struct list_head *pos;
> rcu_read_lock();
> if (rdev == NULL)
> /* start at the beginning */
> - pos = &mddev->disks;
> + rdev = list_entry_rcu(&mddev->disks, struct md_rdev, same_set);
> else {
> /* release the previous rdev and start from there. */
> rdev_dec_pending(rdev, mddev);
> - pos = &rdev->same_set;
> }
> - list_for_each_continue_rcu(pos, &mddev->disks) {
> - rdev = list_entry(pos, struct md_rdev, same_set);
> + list_for_each_entry_continue_rcu(rdev, &mddev->disks, same_set) {
> if (rdev->raid_disk >= 0 &&
> !test_bit(Faulty, &rdev->flags)) {
> /* this is a usable devices */
>