Re: [PATCH 2/8] imsm: FIX: array size is wrong

[NeilBrown <neilb@suse.de>]

On Tue, 01 Feb 2011 14:49:12 +0100 Adam Kwolek <adam.kwolek@intel.com> wrote:

> Calculation of size is almost ok, except concept of blocks.
> Size for setting in md has to be divided by 2 to be correct.
> 
> Signed-off-by: Adam Kwolek <adam.kwolek@intel.com>
> ---
> 
>  super-intel.c |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
> 
> diff --git a/super-intel.c b/super-intel.c
> index ee0d9c4..42f7065 100644
> --- a/super-intel.c
> +++ b/super-intel.c
> @@ -5187,7 +5187,7 @@ static int imsm_set_array_state(struct active_array *a, int consistent)
>  					<< SECT_PER_MB_SHIFT;
>  				dev->size_low = __cpu_to_le32((__u32) array_blocks);
>  				dev->size_high = __cpu_to_le32((__u32) (array_blocks >> 32));
> -				a->info.custom_array_size = array_blocks;
> +				a->info.custom_array_size = array_blocks/2;
>  				a->check_reshape = 1; /* encourage manager to update
>  						       * array size
>  						       */
> 


I think the original code is correct.
custom_array_size is measured in sectors.
In grow.c we divide by 2 before comparing with the "array_size" sysfs
attribute which is measured in kilobytes.
Also in getinfo_super_imsm_volume, custom_array_size is set from
the same size_low/size_high fields as used here.

However in manage_member custom_array_size is compared directly
with "array_size" which is wrong and is probably causing whatever
problem you experienced.

So I'll change this patch to fix that up instead - see below.

Thanks,
NeilBrown

commit 02eedb57aa0c6f7fdeda1b612f35545ab4eee58f
Author: Adam Kwolek <adam.kwolek@intel.com>
Date:   Thu Feb 3 17:40:18 2011 +1100

    imsm: FIX: array size is wrong
    
    Calculation of size is almost ok, except concept of blocks.
    Size for setting in md has to be divided by 2 to be correct.
    
    Signed-off-by: Adam Kwolek <adam.kwolek@intel.com>
    Signed-off-by: NeilBrown <neilb@suse.de>

diff --git a/managemon.c b/managemon.c
index 63c9705..6001f6a 100644
--- a/managemon.c
+++ b/managemon.c
@@ -549,9 +549,9 @@ static void manage_member(struct mdstat_ent *mdstat,
 			disk_init_and_add(newd, d, newa);
 		}
 		if (sysfs_get_ll(info, NULL, "array_size", &array_size) == 0
-		    && a->info.custom_array_size > array_size) {
+		    && a->info.custom_array_size > array_size*2) {
 			sysfs_set_num(info, NULL, "array_size",
-				      a->info.custom_array_size);
+				      a->info.custom_array_size/2);
 		}
 	out2:
 		sysfs_free(info);