[Bug Report] nvme-cli fails re-formatting NVMe namespace

[Nilay Shroff]

Hi Christoph,

On 3/18/24 07:48, Christoph Hellwig wrote:
> Hi Nilay,
> 
> thanks for the report!
> 
> I'm currently travelling without easy hardware access, but can you try
> the patch below?  This simply rebuilds the limits from scratch.  It
> probably wants a bit of a cleanup if it works, but this should be
> fine for testing:
> 
> diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
> index 00864a63447099..9ef41e65fc83bd 100644
> --- a/drivers/nvme/host/core.c
> +++ b/drivers/nvme/host/core.c
> @@ -2215,10 +2215,13 @@ static int nvme_update_ns_info(struct nvme_ns *ns, struct nvme_ns_info *info)
>  		set_disk_ro(ns->head->disk, nvme_ns_is_readonly(ns, info));
>  		nvme_mpath_revalidate_paths(ns);
>  
> -		lim = queue_limits_start_update(ns->head->disk->queue);
> +		blk_set_stacking_limits(&lim);
> +		lim.dma_alignment = 3;
> +		if (info->ids.csi != NVME_CSI_ZNS)
> +			lim.max_zone_append_sectors = 0;
>  		queue_limits_stack_bdev(&lim, ns->disk->part0, 0,
>  					ns->head->disk->disk_name);
> -		ret = queue_limits_commit_update(ns->head->disk->queue, &lim);
> +		ret = queue_limits_set(ns->head->disk->queue, &lim);
>  		blk_mq_unfreeze_queue(ns->head->disk->queue);
>  	}
>  

I have just tested the above patch and it's working well as expected.
Now I don't see any issue formatting NVMe disk with the block-size of 512.
I think we should commit the above changes.

Feel free to add:

Tested-by: Nilay Shroff<nilay at linux.ibm.com>

Please find below the test result obtained using above patch for reference:
---------------------------------------------------------------------------

# lspci 
0018:01:00.0 Non-Volatile memory controller: Samsung Electronics Co Ltd NVMe SSD Controller PM173X

# nvme list 
Node                  Generic               SN                   Model                                    Namespace  Usage                      Format           FW Rev  
--------------------- --------------------- -------------------- ---------------------------------------- ---------- -------------------------- ---------------- --------
/dev/nvme0n1          /dev/ng0n1            S6EUNA0R500358       1.6TB NVMe Gen4 U.2 SSD                  0x1          1.60  TB /   1.60  TB    512   B +  0 B   REV.SN49

# nvme id-ns /dev/nvme0n1 -H 
NVME Identify Namespace 1:
nsze    : 0xba4d4ab0
ncap    : 0xba4d4ab0
nuse    : 0xba4d4ab0

<snip>
<snip>

nlbaf   : 4
flbas   : 0
  [6:5] : 0	Most significant 2 bits of Current LBA Format Selected
  [4:4] : 0	Metadata Transferred in Separate Contiguous Buffer
  [3:0] : 0	Least significant 4 bits of Current LBA Format Selected
  
<snip>
<snip>  

LBA Format  0 : Metadata Size: 0   bytes - Data Size: 4096 bytes - Relative Performance: 0 Best (in use)
LBA Format  1 : Metadata Size: 8   bytes - Data Size: 4096 bytes - Relative Performance: 0x2 Good 
LBA Format  2 : Metadata Size: 0   bytes - Data Size: 512 bytes - Relative Performance: 0x1 Better 
LBA Format  3 : Metadata Size: 8   bytes - Data Size: 512 bytes - Relative Performance: 0x3 Degraded 
LBA Format  4 : Metadata Size: 64  bytes - Data Size: 4096 bytes - Relative Performance: 0x3 Degraded 

# lsblk -t /dev/nvme0n1 
NAME    ALIGNMENT MIN-IO OPT-IO PHY-SEC LOG-SEC ROTA SCHED RQ-SIZE  RA WSAME
nvme0n1         0   4096      0    4096    4096    0               128    0B
                                   ^^^     ^^^ 	

<<<< The nvme disk has block size of 4096, now format it with block size of 512

# nvme format /dev/nvme0n1 --lbaf=2 --pil=0 --ms=0 --pi=0 -f 
Success formatting namespace:1

>>>> Success formatting; no error seen

# lsblk -t /dev/nvme0n1 
NAME    ALIGNMENT MIN-IO OPT-IO PHY-SEC LOG-SEC ROTA SCHED RQ-SIZE  RA WSAME
nvme0n1         0    512      0     512     512    0               128    0B
                                    ^^^     ^^^
# cat /sys/block/nvme0n1/queue/logical_block_size:512
# cat /sys/block/nvme0n1/queue/physical_block_size:512
# cat /sys/block/nvme0n1/queue/dma_alignment:3

# cat /sys/block/nvme0c0n1/queue/logical_block_size:512
# cat /sys/block/nvme0c0n1/queue/physical_block_size:512
# cat /sys/block/nvme0c0n1/queue/dma_alignment:3

# nvme id-ns /dev/nvme0n1 -H 
NVME Identify Namespace 1:
nsze    : 0xba4d4ab0
ncap    : 0xba4d4ab0
nuse    : 0xba4d4ab0
<snip>
<snip>
nlbaf   : 4
flbas   : 0x2
  [6:5] : 0	Most significant 2 bits of Current LBA Format Selected
  [4:4] : 0	Metadata Transferred in Separate Contiguous Buffer
  [3:0] : 0x2	Least significant 4 bits of Current LBA Format Selected
<snip>
<snip>

LBA Format  0 : Metadata Size: 0   bytes - Data Size: 4096 bytes - Relative Performance: 0 Best 
LBA Format  1 : Metadata Size: 8   bytes - Data Size: 4096 bytes - Relative Performance: 0x2 Good 
LBA Format  2 : Metadata Size: 0   bytes - Data Size: 512 bytes - Relative Performance: 0x1 Better (in use)
LBA Format  3 : Metadata Size: 8   bytes - Data Size: 512 bytes - Relative Performance: 0x3 Degraded 
LBA Format  4 : Metadata Size: 64  bytes - Data Size: 4096 bytes - Relative Performance: 0x3 Degraded 

Thanks,
--Nilay