Buffer I/O Errors from Zoned NVME devices

[hch at lst.de]

On Mon, Feb 01, 2021 at 09:53:06AM -0800, Keith Busch wrote:
> On Mon, Feb 01, 2021 at 02:36:12PM +0000, Jeffrey Lien wrote:
> > Christoph, Keith
> > We're seeing a lot of these Buffer I/O errors with our zoned nvme devices.  One of the FW developers looked into it and had the following explanation:
> > All these Reads are from the kernel during enumeration and for LBAs that are in last zone's hole hence expected to return boundary error which is getting logged by kernel.
> > 
> > [65281.936988] Buffer I/O error on dev nvme1n2, logical block 3800039296, async page read
> > [65281.937165] blk_update_request: I/O error, dev nvme1n2, sector 3800039297 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0
> > [65281.937166] Buffer I/O error on dev nvme1n2, logical block 3800039297, async page read
> > [65281.937335] blk_update_request: I/O error, dev nvme1n2, sector 3800039298 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0
> > [65281.937336] Buffer I/O error on dev nvme1n2, logical block 3800039298, async page read
> > [65281.937498] blk_update_request: I/O error, dev nvme1n2, sector 3800039299 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0
> > 
> > Are you aware of this issue and if so, do you have any recommendations on how to avoid or resolve?  
> 
> Is this from the partition scanning? We don't partition zoned devices,
> so I think we can skip it. Does the following resolve the issue?

We already have special zoned device handling in the partitioning code.

But NVMe should make sure to never span a zone boundary as we set the
chunk size to avoid that.

What kernel version is this?  Is CONFIG_BLK_DEV_ZONED enabled?