public inbox for linux-scsi@vger.kernel.org
 help / color / mirror / Atom feed
From: "Martin K. Petersen" <martin.petersen@oracle.com>
To: Kashyap Desai <kashyap.desai@broadcom.com>
Cc: Christoph Hellwig <hch@infradead.org>,
	linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org
Subject: Re: out of range LBA using sg_raw
Date: Wed, 08 Mar 2017 11:32:36 -0500	[thread overview]
Message-ID: <yq1y3wfhgpn.fsf@oracle.com> (raw)
In-Reply-To: <eb88925faa247b2ae6e510fc7fd0cff9@mail.gmail.com> (Kashyap Desai's message of "Wed, 8 Mar 2017 21:29:28 +0530")

>>>>> "Kashyap" == Kashyap Desai <kashyap.desai@broadcom.com> writes:

Kashyap,

Kashyap> I am just curious to know how badly we have to scrutinize each
Kashyap> packet before sending to Fast Path as we are in IO path and
Kashyap> recommend only important checks to be added.

As Christoph pointed out, when the fast path is in use you assume the
role of the SCSI device. And therefore it is your responsibility to
ensure that the VD's capacity and other relevant constraints are being
honored. Just like the MR firmware and any attached disks would.

It is a feature that there is no sanity checking in the sg interface.
The intent is to be able to pass through commands directly to a device
and have the device act upon them. Including fail them if they don't
make any sense.

PS. I'm really no fan of the fast path. It's super messy to have the VD
layout handled in two different places.

-- 
Martin K. Petersen	Oracle Linux Engineering

  parent reply	other threads:[~2017-03-08 16:32 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-03-08 14:21 out of range LBA using sg_raw Kashyap Desai
2017-03-08 15:11 ` Christoph Hellwig
2017-03-08 15:59   ` Kashyap Desai
2017-03-08 16:04     ` Bart Van Assche
2017-03-08 16:15       ` Kashyap Desai
2017-03-08 16:06     ` Christoph Hellwig
2017-03-08 16:11       ` Kashyap Desai
2017-03-08 16:32     ` Martin K. Petersen [this message]
2017-03-08 16:49       ` Kashyap Desai
2017-03-09  0:40         ` Martin K. Petersen

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=yq1y3wfhgpn.fsf@oracle.com \
    --to=martin.petersen@oracle.com \
    --cc=hch@infradead.org \
    --cc=kashyap.desai@broadcom.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-scsi@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox