From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Christian Brauner <christian.brauner@ubuntu.com>
Cc: "David S. Miller" <davem@davemloft.net>,
linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
"Rafael J. Wysocki" <rafael@kernel.org>,
Pavel Machek <pavel@ucw.cz>, Jakub Kicinski <kuba@kernel.org>,
Eric Dumazet <edumazet@google.com>,
Stephen Hemminger <stephen@networkplumber.org>,
linux-pm@vger.kernel.org
Subject: Re: [PATCH net-next 05/10] sysfs: add sysfs_change_owner()
Date: Wed, 12 Feb 2020 05:18:08 -0800 [thread overview]
Message-ID: <20200212131808.GA1789899@kroah.com> (raw)
In-Reply-To: <20200212104321.43570-6-christian.brauner@ubuntu.com>
On Wed, Feb 12, 2020 at 11:43:16AM +0100, Christian Brauner wrote:
> Add a helper to change the owner of sysfs objects.
Seems sane, but:
> The ownership of a sysfs object is determined based on the ownership of
> the corresponding kobject, i.e. only if the ownership of a kobject is
> changed will this function change the ownership of the corresponding
> sysfs entry.
A "sysfs object" is a kobject. So I don't understand this sentance,
sorry.
> This function will be used to correctly account for kobject ownership
> changes, e.g. when moving network devices between network namespaces.
>
> Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
> ---
> fs/sysfs/file.c | 35 +++++++++++++++++++++++++++++++++++
> include/linux/sysfs.h | 6 ++++++
> 2 files changed, 41 insertions(+)
>
> diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c
> index 6239d9584f0b..6a0fe88061fd 100644
> --- a/fs/sysfs/file.c
> +++ b/fs/sysfs/file.c
> @@ -642,3 +642,38 @@ int sysfs_file_change_owner(struct kobject *kobj, const char *name)
> return error;
> }
> EXPORT_SYMBOL_GPL(sysfs_file_change_owner);
> +
> +/**
> + * sysfs_change_owner - change owner of the given object.
> + * @kobj: object.
> + */
> +int sysfs_change_owner(struct kobject *kobj)
What does this change the owner of the given object _to_?
> +{
> + int error;
> + const struct kobj_type *ktype;
> +
> + if (!kobj->state_in_sysfs)
> + return -EINVAL;
> +
> + error = sysfs_file_change_owner(kobj, NULL);
It passes NULL?
> + if (error)
> + return error;
> +
> + ktype = get_ktype(kobj);
> + if (ktype) {
> + struct attribute **kattr;
> +
> + for (kattr = ktype->default_attrs; kattr && *kattr; kattr++) {
> + error = sysfs_file_change_owner(kobj, (*kattr)->name);
> + if (error)
> + return error;
> + }
> +
> + error = sysfs_groups_change_owner(kobj, ktype->default_groups);
> + if (error)
> + return error;
> + }
> +
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(sysfs_change_owner);
I can understand wanting to change owners/groups/whatever of existing
sysfs objects and their files, but I can't figure out how to call this
function to set the attribute I want to change.
With only one parameter, how does this work? It guesses? :)
thanks,
greg k-h
next prev parent reply other threads:[~2020-02-12 13:18 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-12 10:43 [PATCH net-next 00/10] net: fix sysfs permssions when device changes network Christian Brauner
2020-02-12 10:43 ` [PATCH net-next 01/10] sysfs: add sysfs_file_change_owner() Christian Brauner
2020-02-12 13:19 ` Greg Kroah-Hartman
2020-02-12 10:43 ` [PATCH net-next 02/10] sysfs: add sysfs_link_change_owner() Christian Brauner
2020-02-12 10:43 ` [PATCH net-next 03/10] sysfs: add sysfs_group_change_owner() Christian Brauner
2020-02-12 10:43 ` [PATCH net-next 04/10] sysfs: add sysfs_groups_change_owner() Christian Brauner
2020-02-12 10:43 ` [PATCH net-next 05/10] sysfs: add sysfs_change_owner() Christian Brauner
2020-02-12 13:18 ` Greg Kroah-Hartman [this message]
2020-02-12 15:07 ` Christian Brauner
2020-02-12 16:04 ` Greg Kroah-Hartman
2020-02-12 10:43 ` [PATCH net-next 06/10] device: add device_change_owner() Christian Brauner
2020-02-12 10:43 ` [PATCH net-next 07/10] drivers/base/power: add dpm_sysfs_change_owner() Christian Brauner
2020-02-12 10:52 ` Rafael J. Wysocki
2020-02-12 10:43 ` [PATCH net-next 08/10] net-sysfs: add netdev_change_owner() Christian Brauner
2020-02-12 10:43 ` [PATCH net-next 09/10] net-sysfs: add queue_change_owner() Christian Brauner
2020-02-12 10:43 ` [PATCH net-next 10/10] net: fix sysfs permssions when device changes network namespace Christian Brauner
2020-02-12 17:53 ` [PATCH net-next 00/10] net: fix sysfs permssions when device changes network David Miller
2020-02-12 18:00 ` Christian Brauner
2020-02-12 18:16 ` David Miller
2020-02-12 18:20 ` Christian Brauner
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=20200212131808.GA1789899@kroah.com \
--to=gregkh@linuxfoundation.org \
--cc=christian.brauner@ubuntu.com \
--cc=davem@davemloft.net \
--cc=edumazet@google.com \
--cc=kuba@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-pm@vger.kernel.org \
--cc=netdev@vger.kernel.org \
--cc=pavel@ucw.cz \
--cc=rafael@kernel.org \
--cc=stephen@networkplumber.org \
/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).