On Mon, 18 Apr 2011 11:52:12 +0100 "Kwolek, Adam" [off-list ref]
wrote:

quoted

-----Original Message-----
From: NeilBrown [mailto:neilb@suse.de]
Sent: Monday, April 18, 2011 2:34 AM
To: Kwolek, Adam
Cc: linux-raid@vger.kernel.org; Williams, Dan J; Ciechanowski, Ed;
Neubauer, Wojciech
Subject: Re: [PATCH 0/4] Report new_disks number when migration is
started

On Fri, 15 Apr 2011 14:30:22 +0200 Adam Kwolek [off-list ref]
wrote:

quoted

External metadata handler reports starting disks number during

expansion

quoted

until migration is finished. It is opposite to native metadata

behavior

quoted

where new disks number is reported immediately when expansion is

started.

quoted

This causes problem during expansion restart and causes exception
due to wrong disks number information.

This patch series unifies reported raid disks number. After reshape
is started external metadata handler reports new disks number now.

BR
Adam

---

Adam Kwolek (4):
      FIX: Count correctly added devices
      FIX: Set proper raid disks during migration
      FIX: Fiddle raid_disks number for external metadta
      FIX: Always report new raid_disks during migration

Thanks.  I've applied all this.

I change the second one a bit - please check that it still works for
you.

Unfortunately it doesn't work.
During restart 3-disks raid5 to 5-disks expansion  it stops in reshape_array() on first condition after change (Grow.c:1695)
	reshape.before.raid_disks +reshape.parity != info->array.raid_disks 
where:
	reshape.before.raid_disks = 2
	reshape.parity = 1
	info->array.raid_disks = 5

It is used during restart only (checked for restart flag).

Do not you think that in this condition instead reshape.before.raid_disks, reshape.after.raid_disks should be used?
For both (native and external) metadata formats during reshape restart new raid_disks will be reported so 'after' filed should be used.
Patch for this will follow this post.

BR
Adam

Thanks for testing and for the patch.

However I think I do want to still test before.raid_disk... though it is all
a bit messy.

Anyway I've commited the patch like this...

Thanks.
NeilBrown

From 384e9be1330c29b40559f85dd0e6124bd0dfa535 Mon Sep 17 00:00:00 2001
From: Adam Kwolek <redacted>
Date: Tue, 19 Apr 2011 17:25:43 +1000
Subject: [PATCH] FIX: Check correctly raid disks during reshape restart

During reshape restart info->array.raid_disks contains new raid_disks number
It cannot be compared against old disks number. Such check will always fail.

Check raid disks array field against final disks number for restart.

Signed-off-by: Adam Kwolek <redacted>
Signed-off-by: NeilBrown <redacted>
---
 Grow.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/Grow.c b/Grow.c
index 9c1f096..9c63036 100644
--- a/Grow.c
+++ b/Grow.c

@@ -1692,7 +1692,8 @@ static int reshape_array(char *container, int fd, char *devname,
 	if (restart &&
 	    (reshape.level != info->array.level ||
 	     reshape.before.layout != info->array.layout ||
-	     reshape.before.data_disks + reshape.parity != info->array.raid_disks)) {
+	     reshape.before.data_disks + reshape.parity
+	     != info->array.raid_disks - info->delta_disks)) {
 		fprintf(stderr, Name ": reshape info is not in native format -"
 			" cannot continue.\n");
 		goto release;

-- 
1.7.3.4