From: Al Viro <viro@ZenIV.linux.org.uk>
To: Rajat Jain <rajatxjain@gmail.com>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
linux-newbie@vger.kernel.org, Greg Kroah-Hartman <greg@kroah.com>
Subject: Re: debugfs_remove_recursive() while a file is in use by userspace
Date: Mon, 28 Dec 2015 20:30:31 +0000 [thread overview]
Message-ID: <20151228203031.GI20997@ZenIV.linux.org.uk> (raw)
In-Reply-To: <CAA93t1pTkDpaZpQuVu0bQpxsxxUDViKU6-bLbporqkyHCJ0=mw@mail.gmail.com>
On Mon, Dec 28, 2015 at 12:27:22PM -0800, Rajat Jain wrote:
> Hi,
>
> I wanted to understand the behavior taken when a module calls
> debugfs_remove_recursive() on a directory, while files under that
> directory may still be in use by the userspace (for instance an
> ongoing read / write operation).
>
> Does the function wait
>
> (1) until all the currently executing file operation methods
> (read/write/map etc) have returned?
No
> OR
> (2) until the user has given up all references (descriptors) to the
> files under the directory (i.e. until release() method has been
> called)?
... and no. Don't use debugfs for objects that might have a finite
lifetime, or you'll get trouble. And don't use debugfs outside of
well-isolated testing systems.
next prev parent reply other threads:[~2015-12-28 20:30 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-12-28 20:27 debugfs_remove_recursive() while a file is in use by userspace Rajat Jain
2015-12-28 20:30 ` Al Viro [this message]
2015-12-28 20:31 ` Greg Kroah-Hartman
2015-12-28 20:51 ` Rajat Jain
2015-12-28 20:58 ` Greg Kroah-Hartman
2015-12-28 21:11 ` Rajat Jain
2015-12-28 21:17 ` Greg Kroah-Hartman
2015-12-28 20:42 ` Nicolai Stange
2015-12-28 20:56 ` Rajat Jain
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=20151228203031.GI20997@ZenIV.linux.org.uk \
--to=viro@zeniv.linux.org.uk \
--cc=greg@kroah.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-newbie@vger.kernel.org \
--cc=rajatxjain@gmail.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