From: James Bottomley <James.Bottomley@HansenPartnership.com>
To: Amit Sahrawat <amit.sahrawat83@gmail.com>
Cc: Nam-Jae Jeon <namjae.jeon@samsung.com>,
linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/1] scsi: retrieve cache mode using ATA_16 if normal routine fails
Date: Mon, 12 Dec 2011 16:51:07 +0400 [thread overview]
Message-ID: <1323694267.20451.5.camel@dabdike> (raw)
In-Reply-To: <1323688722-25400-1-git-send-email-amit.sahrawat83@gmail.com>
On Mon, 2011-12-12 at 16:48 +0530, Amit Sahrawat wrote:
> It has been observed that a number of USB HDD's do not respond correctly
> to SCSI mode sense command(retrieve caching pages) which results in their
> Write Cache being discarded by queue requests i.e., WCE if left set to
> '0'(disabled).
> This results in a number of Filesystem corruptions, when the device
> is unplugged abruptly.
Um, how would knowing the caching type correctly help? If you surprise
unplug the device, we can't send a flush to it anyway ...
> So, in order to identify the devices correctly - give it
> a last try using ATA_16 after failure from normal routine.
> Introduce a mechanism to store write-cache type using /sys/class/
> interface, so that the normal code continues to function without errors.
>
> Signed-off-by: Amit Sahrawat <amit.sahrawat83@gmail.com>
> Signed-off-by: Nam-Jae Jeon <namjae.jeon@samsung.com>
This whole patch looks like a layering violation. Why not just update
the SAT layer to translate the MODE SENSE correctly?
James
next prev parent reply other threads:[~2011-12-12 12:51 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-12-12 11:18 [PATCH 1/1] scsi: retrieve cache mode using ATA_16 if normal routine fails Amit Sahrawat
2011-12-12 12:51 ` James Bottomley [this message]
2011-12-13 0:20 ` Namjae Jeon
2011-12-13 0:20 ` Namjae Jeon
[not found] ` <CADDb1s2SOK5sC3N0OOdkBrPuDKc2d2A4z4yso4jYs=1rbxNmkA@mail.gmail.com>
2011-12-13 4:56 ` Amit Sahrawat
2011-12-13 4:56 ` Amit Sahrawat
2011-12-13 8:53 ` James Bottomley
2011-12-13 12:15 ` Amit Sahrawat
2011-12-13 12:15 ` Amit Sahrawat
2011-12-13 20:38 ` Jeff Garzik
2011-12-14 3:44 ` Amit Sahrawat
2011-12-14 3:44 ` Amit Sahrawat
2011-12-14 7:39 ` James Bottomley
2011-12-15 0:25 ` Namjae Jeon
2011-12-15 0:25 ` Namjae Jeon
2012-01-27 5:20 ` Amit Sahrawat
-- strict thread matches above, loose matches on Subject: below --
2012-02-03 12:59 Amit Sahrawat
2012-02-05 12:05 ` Sergei Shtylyov
2012-02-06 5:40 ` Amit Sahrawat
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=1323694267.20451.5.camel@dabdike \
--to=james.bottomley@hansenpartnership.com \
--cc=amit.sahrawat83@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-scsi@vger.kernel.org \
--cc=namjae.jeon@samsung.com \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.