On Wed, Jul 19, 2023 at 09:38:26AM +0200, Paul Menzel wrote:

Dear Xueshi,


Thank you for your patches.

Am 19.07.23 um 09:09 schrieb Xueshi Hu:

quoted

If array size doesn't changed, nothing need to do.

Maybe: … nothing needs to be done.

What a hurry, I'll be cautious next time and check the sentences with
tools.

Do you have a test case to reproduce it?

Userspace command:

	echo 4 > /sys/devices/virtual/block/md10/md/raid_disks

Kernel function calling flow:

md_attr_store()
	raid_disks_store()
		update_raid_disks()
			raid1_reshape()

Maybe I shall provide more information when submit patches, thank you for
reminding me.

Kind regards,

Paul

quoted

Signed-off-by: Xueshi Hu <redacted>
---
  drivers/md/raid1.c | 9 ++++++---
  1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index 62e86b7d1561..5840b8b0f9b7 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c

@@ -3282,9 +3282,6 @@ static int raid1_reshape(struct mddev *mddev)
  	int d, d2;
  	int ret;
-	memset(&newpool, 0, sizeof(newpool));
-	memset(&oldpool, 0, sizeof(oldpool));
-
  	/* Cannot change chunk_size, layout, or level */
  	if (mddev->chunk_sectors != mddev->new_chunk_sectors ||
  	    mddev->layout != mddev->new_layout ||

@@ -3295,6 +3292,12 @@ static int raid1_reshape(struct mddev *mddev)
  		return -EINVAL;
  	}
+	if (mddev->delta_disks == 0)
+		return 0; /* nothing to do */
+
+	memset(&newpool, 0, sizeof(newpool));
+	memset(&oldpool, 0, sizeof(oldpool));
+
  	if (!mddev_is_clustered(mddev))
  		md_allow_write(mddev);