From mboxrd@z Thu Jan  1 00:00:00 1970
From: keith.busch@intel.com (Keith Busch)
Date: Mon, 23 Jan 2017 18:08:39 -0500
Subject: crash in sg_alloc_table_chained
In-Reply-To: <8C8F83F9-BDBB-4B59-BA4E-BAA34CB2E20D@cavium.com>
References: <8C8F83F9-BDBB-4B59-BA4E-BAA34CB2E20D@cavium.com>
Message-ID: <20170123230838.GB10771@localhost.localdomain>

On Mon, Jan 23, 2017@10:53:04PM +0000, Trapp, Darren wrote:
> Gents,
> 
> I am using 4.10rc4 kernel with the FC-NVME transport to format a partition on a remote nvme device.  I?ve created a partition on the device, but when I try and create a FS via:
> 
> Mkfs ?t ext3 /dev/nvme0n1p1
> 
> I get a crash in sg_alloc_table_chained at the BUG_ON(!nents).  It is called from nvme_fc_map_data:
> 	        ret = sg_alloc_table_chained(&freq->sg_table, rq->nr_phys_segments,
>                         freq->sg_table.sgl);
> 
>  In this case, rq->nr_phys_segments is 0.  For reference blk_rq_payload_bytes returned 0x10.
> 
> Any ideas what is going on?  

Just to confirm a suspicion, is it successful if you run:

  # mkfs.ext3 /dev/nvme0n1p1 -E nodiscard

?