Re: [PATCHv5 00/14] dm-zoned: metadata version 2

From: Hannes Reinecke <hare@suse.de>
To: Damien Le Moal <Damien.LeMoal@wdc.com>,
	Mike Snitzer <snitzer@redhat.com>
Cc: Bob Liu <bob.liu@oracle.com>,
	"dm-devel@redhat.com" <dm-devel@redhat.com>
Subject: Re: [PATCHv5 00/14] dm-zoned: metadata version 2
Date: Mon, 11 May 2020 13:24:55 +0200	[thread overview]
Message-ID: <2553e593-795d-6aed-f983-e990a283e2ff@suse.de> (raw)
In-Reply-To: <BY5PR04MB6900C76141ABD428F42C1840E7A10@BY5PR04MB6900.namprd04.prod.outlook.com>

On 5/11/20 12:55 PM, Damien Le Moal wrote:
> On 2020/05/11 11:46, Damien Le Moal wrote:
>> Mike,
>>
>> I am still seeing the warning:
>>
>> [ 1827.839756] device-mapper: table: 253:1: adding target device sdj caused an
>> alignment inconsistency: physical_block_size=4096, logical_block_size=4096,
>> alignment_offset=0, start=0
>> [ 1827.856738] device-mapper: table: 253:1: adding target device sdj caused an
>> alignment inconsistency: physical_block_size=4096, logical_block_size=4096,
>> alignment_offset=0, start=0
>> [ 1827.874031] device-mapper: table: 253:1: adding target device sdj caused an
>> alignment inconsistency: physical_block_size=4096, logical_block_size=4096,
>> alignment_offset=0, start=0
>> [ 1827.891086] device-mapper: table: 253:1: adding target device sdj caused an
>> alignment inconsistency: physical_block_size=4096, logical_block_size=4096,
>> alignment_offset=0, start=0
>>
>> when mixing 512B sector and 4KB sector devices. Investigating now.
> 
> 
> OK. Figured that one out: the 500GB SSD I am using for the regular device is
> 976773168 512B sectors capacity, that is, not a multiple of the 256MB zone size,
> and not even a multiple of 4K. This causes the creation of a 12MB runt zone of
> 24624 sectors, which is ignored. But the start sector of the second device in
> the dm-table remains 976773168, so not aligned on 4K. This causes
> bdev_stack_limits to return an error and the above messages to be printed.
> 
> So I think we need to completely ignore the eventual "runt" zone of the regular
> device so that everything aligns correctly. This will need changes in both
> dmzadm and dm-zoned.
> 
> Hannes, I can hack something on top of your series. Or can you resend with that
> fixed ?
> 
> 
> 
> 
Does this one help?

diff --git a/drivers/md/dm-zoned-target.c b/drivers/md/dm-zoned-target.c
index ea43f6892ced..5daca82b5ec7 100644
--- a/drivers/md/dm-zoned-target.c
+++ b/drivers/md/dm-zoned-target.c
@@ -1041,13 +1041,17 @@ static int dmz_iterate_devices(struct dm_target *ti,
  {
         struct dmz_target *dmz = ti->private;
         unsigned int zone_nr_sectors = dmz_zone_nr_sectors(dmz->metadata);
+       unsigned int nr_zones;
         sector_t capacity;
         int r;

-       capacity = dmz->dev[0].capacity & ~(zone_nr_sectors - 1);
+       nr_zones = DIV_ROUND_DOWN(dmz->dev[0].capacity, zone_nr_sectors);
+       capacity = nr_zones * zone_nr_sectors;
         r = fn(ti, dmz->ddev[0], 0, capacity, data);
         if (!r && dmz->ddev[1]) {
-               capacity = dmz->dev[1].capacity & ~(zone_nr_sectors - 1);
+               nr_zones = DIV_ROUND_DOWN(dmz->dev[1.capacity,
+                                                  zone_nr_sectors));
+               capacity = nr_zones * zone_nr_sectors;
                 r = fn(ti, dmz->ddev[1], 0, capacity, data);
         }
         return r;

Cheers,

Hannes
-- 
Dr. Hannes Reinecke            Teamlead Storage & Networking
hare@suse.de                               +49 911 74053 688
SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), Geschäftsführer: Felix Imendörffer


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