From: Christoph Hellwig <hch@lst.de>
To: Dan Williams <dan.j.williams@intel.com>
Cc: linux-nvdimm@lists.01.org, Christoph Hellwig <hch@lst.de>,
Ming Lei <ming.lei@redhat.com>, Hannes Reinecke <hare@suse.de>,
Jens Axboe <axboe@kernel.dk>, kernel test robot <lkp@intel.com>,
linux-kernel@vger.kernel.org, linux-block@vger.kernel.org
Subject: Re: [PATCH] libnvdimm: Let revalidate_disk() revalidate region read-only
Date: Tue, 9 Mar 2021 08:31:10 +0100 [thread overview]
Message-ID: <20210309073110.GA3140@lst.de> (raw)
In-Reply-To: <161527286194.446794.5215036039655765042.stgit@dwillia2-desk3.amr.corp.intel.com>
On Mon, Mar 08, 2021 at 10:54:22PM -0800, Dan Williams wrote:
> Previous kernels allowed the BLKROSET to override the disk's read-only
> status. With that situation fixed the pmem driver needs to rely on
> revalidate_disk() to clear the disk read-only status after the host
> region has been marked read-write.
>
> Recall that when libnvdimm determines that the persistent memory has
> lost persistence (for example lack of energy to flush from DRAM to FLASH
> on an NVDIMM-N device) it marks the region read-only, but that state can
> be overridden by the user via:
>
> echo 0 > /sys/bus/nd/devices/regionX/read_only
>
> ...to date there is no notification that the region has restored
> persistence, so the user override is the only recovery.
I've just resent my series to kill of ->revalidate_disk for good, so this
obvious makes me a little unhappy. Given that ->revalidate_disk
only ends up beeing called from the same path that ->open is called,
why can't you just hook this up from the open method?
Also any reason the sysfs attribute can't just directly propagate the
information to the disk?
_______________________________________________
Linux-nvdimm mailing list -- linux-nvdimm@lists.01.org
To unsubscribe send an email to linux-nvdimm-leave@lists.01.org
next prev parent reply other threads:[~2021-03-09 7:31 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-09 6:54 [PATCH] libnvdimm: Let revalidate_disk() revalidate region read-only Dan Williams
2021-03-09 7:31 ` Christoph Hellwig [this message]
2021-03-09 16:36 ` Dan Williams
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=20210309073110.GA3140@lst.de \
--to=hch@lst.de \
--cc=axboe@kernel.dk \
--cc=dan.j.williams@intel.com \
--cc=hare@suse.de \
--cc=linux-block@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-nvdimm@lists.01.org \
--cc=lkp@intel.com \
--cc=ming.lei@redhat.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).