Re: [RFC 0/9] Add persistent durable identifier to storage log messages

James Bottomley
2019-12-24T00:50:58Z

On Mon, 2019-12-23 at 16:55 -0600, Tony Asleson wrote:
> Today users have no easy way to correlate kernel log messages for
> storage devices across reboots, device dynamic add/remove, or when
> the device is physically or logically moved from from system to
> system. This is due to the existing log IDs which identify how the
> device is attached and not a unique ID of what is
> attached. Additionally, even when the attachment hasn't changed,
> it's not always obvious which messages belong to the device as the
> different areas in the storage stack use different identifiers, eg.
> (sda, sata1.00, sd 0:0:0:0).
>
> This change addresses this by adding a unique ID to each log
> message. It couples the existing structured key/value logging
> capability and VPD 0x83 device identification.

I understand why, and using the best VPD identifier we have seems fine.
However, we're trying to dump printk in favour of dev_printk and its
ilk, so resurrecting printk_emit instead of using dev_printk_emit looks
a bit retrograde. It does seem that ata_dev_printk should really be
using dev_printk ... not sure about the block case.

You also have a couple of items which could be shorter, but I'll reply
to the individual patches.

James