[OE-core] [PATCH] [RFC] udev-extraconf: update mount.sh to use /run/media instead of /media

[Otavio Salvador]

On Sat, Mar 29, 2014 at 5:59 PM, Denys Dmytriyenko <denis at denix.org> wrote:
> On Sat, Mar 29, 2014 at 12:17:23PM -0300, Otavio Salvador wrote:
>> Hello Denys,
>>
>> On Fri, Mar 28, 2014 at 6:29 PM, Denys Dmytriyenko <denis at denix.org> wrote:
>> > From: Denys Dmytriyenko <denys at ti.com>
>> >
>> > This is done to work around the issue of auto-mounting block devices
>> > (i.e. SD cards) when root filesystem is still in read-only mode and
>> > creating /media/<device> mount-points by udev is not possible. That
>> > is due to udev (/etc/rcS.d/S03udev) getting started earlier than
>> > checkroot (/etc/rcS.d/S10checkroot.sh) gets a chance to re-mount the
>> > rootfs as read-write.
>> >
>> > Although, canonical FHS specifies /media/<device> as a mount point
>> > for removable media devices, the latest 2.3 version was released in
>> > 2004 and since then FreeDesktop/udisks and other tools adopted the
>> > new /run/media/<user>/<device> location. That was done to overcome
>> > read-only rootfs limitation, since /run is usually a tmpfs mounted
>> > partition, plus avoid name-clash between users.
>>
>> Agreed.
>>
>> > For our embedded systems environment we assume single-user operation
>> > and hence simplify mount point to just /run/media/<device>.
>>
>> Please don't. I have customers using multiple users in an embedded
>> device and so I think it is better to adopt udisks standard here
>> instead of diverging from it without a reasoning.
>
> I guess I should have phrased it a bit better...
>
> This part is a system-wide automount. It gets to run even when no user is
> logged in. In order to do per-user mounting, some sort of session management
> is required. For example, udisks, we both mentioned, starts along with the
> session, when a user logs in, hence allowing per-user mounts.
>
> Since this approach uses udev and gets triggered on addition or removal of
> block devices, described in the corresponding rules, it happens on system
> level and is not dependant on a session or logged in user. When a session
> based approach is used with udisks, these rules should be disabled though.
>
> The two approaches are rather mutually exclusive, but both are valid. There
> are cases when this system-level automount is desired (e.g. in industrial use
> cases) since there are no users are ever expected to log in or interact with
> the system.
>
> So, this is not meant to replace or provide session-based mounting...

Agreed; I missed this but I fully agree now :)

>> ...
>> > diff --git a/meta/recipes-core/udev/udev-extraconf/mount.sh b/meta/recipes-core/udev/udev-extraconf/mount.sh
>> > index cb57e47..3e4f21f 100644
>> > --- a/meta/recipes-core/udev/udev-extraconf/mount.sh
>> > +++ b/meta/recipes-core/udev/udev-extraconf/mount.sh
>> > @@ -20,7 +20,7 @@ done
>> >  automount() {
>> >         name="`basename "$DEVNAME"`"
>> >
>> > -       ! test -d "/media/$name" && mkdir -p "/media/$name"
>> > +       ! test -d "/run/media/$name" && mkdir -p "/run/media/$name"
>>
>> Please see above...
>>
>> ...
>>
>> > --- a/meta/recipes-core/udev/udev-extraconf_1.0.bb
>> > +++ b/meta/recipes-core/udev/udev-extraconf_1.0.bb
>> > @@ -4,7 +4,7 @@ LICENSE = "MIT"
>> >  LIC_FILES_CHKSUM = "file://${COREBASE}/LICENSE;md5=4d92cd373abda3937c2bc47fbc49d690 \
>> >                      file://${COREBASE}/meta/COPYING.MIT;md5=3da9cfbcb788c80a0384361b4de20420"
>> >
>> > -PR = "r16"
>> > +PR = "r17"
>>
>> Don't change PR; in fact with this change I'd say to move it to 1.1 and drop PR.
>
> I thought about it - either PV or PR needs to change. But I wasn't sure about
> bumping PV...

I am all for the PV bumping...

-- 
Otavio Salvador                             O.S. Systems
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