From: "Winkler, Tomas" <tomas.winkler@intel.com>
To: Richard Weinberger <richard@nod.at>
Cc: Miquel Raynal <miquel.raynal@bootlin.com>,
Vignesh Raghavendra <vigneshr@ti.com>,
linux-mtd <linux-mtd@lists.infradead.org>,
linux-kernel <linux-kernel@vger.kernel.org>
Subject: RE: [PATCH] mtd: use refcount to prevent corruption
Date: Wed, 27 Jan 2021 20:55:46 +0000 [thread overview]
Message-ID: <c8d0f22c5fdf443cb8dda1f996b148d9@intel.com> (raw)
In-Reply-To: <9732911.325628.1611780400338.JavaMail.zimbra@nod.at>
> Subject: Re: [PATCH] mtd: use refcount to prevent corruption
>
> Tomas,
>
> ----- Ursprüngliche Mail -----
> > Von: "Tomas Winkler" <tomas.winkler@intel.com>
> > An: "Miquel Raynal" <miquel.raynal@bootlin.com>, "richard"
> > <richard@nod.at>, "Vignesh Raghavendra" <vigneshr@ti.com>, "linux-mtd"
> > <linux-mtd@lists.infradead.org>, "linux-kernel"
> > <linux-kernel@vger.kernel.org>
> > CC: "Tomas Winkler" <tomas.winkler@intel.com>
> > Gesendet: Mittwoch, 27. Januar 2021 21:03:19
> > Betreff: [PATCH] mtd: use refcount to prevent corruption
>
> > When underlying device is removed mtd core will crash in case user
> > space is still holding an open handle to a mtd device node.
> > A proper refcounting is needed so device is release only when a
> > partition has no active users. The current simple counter is not
> > sufficient.
>
> Can you please explain a little more what devices are involved?
> Does it implement _get_device() and _put_device()?
No this is not connected to those handlers of the underlying device and those won't help.
I have a spi device provided by MFD framework so it can go away anytime.
My solution tries to replace the current simple partition reference counting. In previous solution it will return -EBUSY on partition that is held but will remove the actual parent device, leading to crash.
Also w/o reference counting there is no process to actually remove the partition that was previously busy.
Thanks
Tomas
>
> Thanks,
> //richard
next prev parent reply other threads:[~2021-01-27 20:57 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-27 20:03 [PATCH] mtd: use refcount to prevent corruption Tomas Winkler
2021-01-27 20:46 ` Richard Weinberger
2021-01-27 20:55 ` Winkler, Tomas [this message]
2021-01-27 21:17 ` Richard Weinberger
2021-01-28 6:33 ` Winkler, Tomas
2021-01-28 7:47 ` Richard Weinberger
2021-01-28 8:53 ` Winkler, Tomas
2021-01-28 9:00 ` Miquel Raynal
2021-01-28 17:57 ` Winkler, Tomas
2021-01-28 20:23 ` Richard Weinberger
2021-02-13 17:09 ` Winkler, Tomas
2021-02-15 13:43 ` Richard Weinberger
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=c8d0f22c5fdf443cb8dda1f996b148d9@intel.com \
--to=tomas.winkler@intel.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mtd@lists.infradead.org \
--cc=miquel.raynal@bootlin.com \
--cc=richard@nod.at \
--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