From: Kees Cook <keescook@chromium.org>
To: WeiXiong Liao <liaoweixiong@allwinnertech.com>
Cc: Rob Herring <robh@kernel.org>, Tony Luck <tony.luck@intel.com>,
Vignesh Raghavendra <vigneshr@ti.com>,
Jonathan Corbet <corbet@lwn.net>,
Richard Weinberger <richard@nod.at>,
Anton Vorontsov <anton@enomsg.org>,
linux-doc@vger.kernel.org,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
linux-kernel@vger.kernel.org, Colin Cross <ccross@android.com>,
linux-mtd@lists.infradead.org,
Jonathan Cameron <Jonathan.Cameron@huawei.com>,
Miquel Raynal <miquel.raynal@bootlin.com>,
Mauro Carvalho Chehab <mchehab+samsung@kernel.org>,
"David S. Miller" <davem@davemloft.net>
Subject: Re: [PATCH v3 02/11] pstore/blk: new support logger for block devices
Date: Thu, 7 May 2020 23:07:16 -0700 [thread overview]
Message-ID: <202005072301.57F73B61CC@keescook> (raw)
In-Reply-To: <1585126506-18635-3-git-send-email-liaoweixiong@allwinnertech.com>
On Wed, Mar 25, 2020 at 04:54:57PM +0800, WeiXiong Liao wrote:
> pstore/blk is similar to pstore/ram, but dump log to block device
> rather than persistent ram.
> [...]
> +int psblk_register_blkdev(unsigned int major, psblk_panic_write_op panic_write)
> +{
> + struct block_device *bdev;
> + struct psblk_device dev = {0};
> + struct bdev_info *binfo;
> + int ret = -ENODEV;
> + void *holder = blkdev;
> +
> + binfo = psblk_get_bdev_info();
> + if (IS_ERR(binfo))
> + return PTR_ERR(binfo);
> +
> + /* only allow driver matching the @blkdev */
> + if (!binfo->devt || MAJOR(binfo->devt) != major) {
> + pr_debug("invalid major %u (expect %u)\n",
> + major, MAJOR(binfo->devt));
> + return -ENODEV;
> + }
> +
> + /* hold bdev exclusively */
> + bdev = psblk_get_bdev(holder);
> + if (IS_ERR(bdev)) {
> + pr_err("failed to open '%s'!\n", blkdev);
> + return PTR_ERR(bdev);
> + }
> +
> + /* psblk_bdev must be assigned before register to pstore/blk */
> + psblk_bdev = bdev;
> + blkdev_panic_write = panic_write;
> +
> + dev.total_size = psblk_bdev_size(bdev);
> + dev.panic_write = panic_write ? psblk_blk_panic_write : NULL;
> + dev.read = psblk_generic_blk_read;
> + dev.write = psblk_generic_blk_write;
> +
> + ret = psblk_register_do(&dev);
> + if (ret)
> + goto err_put_bdev;
> +
> + pr_info("using '%s'\n", blkdev);
> + return 0;
> +
> +err_put_bdev:
> + psblk_bdev = NULL;
> + blkdev_panic_write = NULL;
> + psblk_put_bdev(bdev, holder);
> + return ret;
> +}
> +EXPORT_SYMBOL_GPL(psblk_register_blkdev);
I've gotten this series refactored on top of current pstore, and I've
been making various bikeshed changes to names, etc, and as I went to go
start testing, I realized that nothing actually uses
psblk_register_blkdev().
It seems like it should be possible to just start using this on any
block device of the user's choosing. I assume the idea is to allow for
drivers to register panic_write handlers, but even without that, it'd be
nice to just be able to test this with something like /dev/loop0.
What's your thinking on how this would happen? It seems like if
pstore/blk uses pstore/zone, and mtdpstore uses pstore/blk, there should
be a blkoops that uses pstore/blk too? I guess I need to learn a bit
more about how block device probing works so pstore/blk can notice
devices as they're brought online, etc.
--
Kees Cook
______________________________________________________
Linux MTD discussion mailing list
http://lists.infradead.org/mailman/listinfo/linux-mtd/
next prev parent reply other threads:[~2020-05-08 6:07 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-25 8:54 [PATCH v3 00/11] pstore: mtd: support crash log to block and mtd device WeiXiong Liao
2020-03-25 8:54 ` [PATCH v3 01/11] pstore/zone: a common layer to manage storage as zones WeiXiong Liao
2020-04-14 1:42 ` WeiXiong Liao
2020-03-25 8:54 ` [PATCH v3 02/11] pstore/blk: new support logger for block devices WeiXiong Liao
2020-05-08 6:07 ` Kees Cook [this message]
2020-05-08 12:46 ` WeiXiong Liao
2020-03-25 8:54 ` [PATCH v3 03/11] pstore/blk: respect for driver to pick pstore front-ends WeiXiong Liao
2020-03-25 8:54 ` [PATCH v3 04/11] pstore/blk: pstore/zone: support pmsg recorder WeiXiong Liao
2020-03-25 8:55 ` [PATCH v3 05/11] pstore/blk: blkoops: support console recorder WeiXiong Liao
2020-04-14 2:13 ` WeiXiong Liao
2020-03-25 8:55 ` [PATCH v3 06/11] pstore/blk: blkoops: support ftrace recorder WeiXiong Liao
2020-03-25 8:55 ` [PATCH v3 07/11] Documentation: create document for pstore/blk WeiXiong Liao
2020-03-25 8:55 ` [PATCH v3 08/11] pstore/zone: skip broken zone for MTD device WeiXiong Liao
2020-03-25 8:55 ` [PATCH v3 09/11] pstore/blk: a way to get user configure about pstore front-ends WeiXiong Liao
2020-03-25 8:55 ` [PATCH v3 10/11] pstore/zone: pstore/blk: support non-block devices WeiXiong Liao
2020-03-25 8:55 ` [PATCH v3 11/11] mtd: new support oops logger based on pstore/blk WeiXiong Liao
2020-05-07 19:45 ` [PATCH v3 00/11] pstore: mtd: support crash log to block and mtd device Kees Cook
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=202005072301.57F73B61CC@keescook \
--to=keescook@chromium.org \
--cc=Jonathan.Cameron@huawei.com \
--cc=anton@enomsg.org \
--cc=ccross@android.com \
--cc=corbet@lwn.net \
--cc=davem@davemloft.net \
--cc=gregkh@linuxfoundation.org \
--cc=liaoweixiong@allwinnertech.com \
--cc=linux-doc@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mtd@lists.infradead.org \
--cc=mchehab+samsung@kernel.org \
--cc=miquel.raynal@bootlin.com \
--cc=richard@nod.at \
--cc=robh@kernel.org \
--cc=tony.luck@intel.com \
--cc=vigneshr@ti.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).