mediascanner fails to watch removable devices if /media/$USER doesn't exist when starting

Jussi can you take a look? this is to make SD cards work properly for media playback

This log is from when /media/$USER exists:
https://bugs.launchpad.net/ubuntu/+source/mediascanner2/+bug/1354543/+attachment/4172992/+files/upstart.mediascanner-2.0.log.txt

The core question is why does not /media/$USER exist when Mediascanner is starting? It does exist on the desktop. Could this be a timing issue or is the configuration completely different?

On lunes 11 de agosto de 2014 05h'04:19 ART, Jussi Pakkanen wrote:
> The core question is why does not /media/$USER exist when Mediascanner
> is starting? It does exist on the desktop. Could this be a timing issue
> or is the configuration completely different?

/media is created as a temp filesystem and udisks2 only creates the full
path on first mount.

The desktop has a persistent filesystem, so the rule is probably the same
and would only fail for the first time after a new install. We also don't
have udisks (sans 2) on the phone.

I just tested on desktop by creating a new user and /media/$USER doesn't
exist until I first mount something; of course, this is hidden by the
persistence and long term desktop use.

The way Mediascanner currently gets to know about mounted drives is a bit hacky as it listens to inotify events in that directory. Is there a more reliable way of getting mount/unmount events from the system? Maybe over dbus?

On lunes 11 de agosto de 2014 08h'58:22 ART, Jussi Pakkanen wrote:
> The way Mediascanner currently gets to know about mounted drives is a
> bit hacky as it listens to inotify events in that directory. Is there a
> more reliable way of getting mount/unmount events from the system? Maybe
> over dbus?

I wrote ciborium which interfaces with udisks2, I can create a specific
signal to track or you could watch udisks2 (which is kind of involved IMO,
but already there):

Here's filesystem-mount:

signal sender=:1.58 -> dest=(null destination) serial=30
path=/org/freedesktop/UDisks2;
interface=org.freedesktop.DBus.ObjectManager; member=InterfacesAdded
   object path "/org/freedesktop/UDisks2/jobs/2"
   array [
      dict entry(
         string "org.freedesktop.UDisks2.Job"
         array [
            dict entry(
               string "Operation"
               variant string "filesystem-mount"
            )
            dict entry(
               string "Progress"
               variant double 0
            )
            dict entry(
               string "ProgressValid"
               variant boolean false
            )
            dict entry(
               string "Bytes"
               variant uint64 0
            )
            dict entry(
               string "Rate"
               variant uint64 0
            )
            dict entry(
               string "StartTime"
               variant uint64 1407760864560033
            )
            dict entry(
               string "ExpectedEndTime"
               variant uint64 0
            )
            dict entry(
               string "Objects"
               variant array [
                     object path
"/org/freedesktop/UDisks2/block_devices/mmcblk1p1"
                  ]
            )
            dict entry(
               string "StartedByUID"
               variant uint32 32011
            )
            dict entry(
               string "Cancelable"
               variant boolean true
            )
         ]
      )
   ]
signal sender=:1.58 -> dest=(null destination) serial=31
path=/org/freedesktop/UDisks2/jobs/2;
interface=org.freedesktop.UDisks2.Job; member=Completed
   boolean true
   string ""
signal sender=:1.58 -> dest=(null destination) serial=32
path=/org/freedesktop/UDisks2;
interface=org.freedesktop.DBus.ObjectManager; member=InterfacesRemoved
   object path "/org/freedesktop/UDisks2/jobs/2"
   array [
      string "org.freedesktop.UDisks2.Job"
   ]
signal sender=:1.58 -> dest=(null destination) serial=34
path=/org/freedesktop/UDisks2/block_devices/mmcblk1p1;
interface=org.freedesktop.DBus.Properties; member=PropertiesChanged
   string "org.freedesktop.UDisks2.Filesystem"
   array [
      dict entry(
         string "MountPoints"
         variant array [
               array of bytes [
                  2f 6d 65 64 69 61 2f 70 68 61 62 6c 65 74 2f 4b 69 6e 67
73
                  74 6f 6e 00
               ]
            ]
      )
   ]
   array [
   ]

unmounting is a bit more invo...

This bug was fixed in the package mediascanner2 - 0.103+14.10.20140815.1-0ubuntu1

---------------
mediascanner2 (0.103+14.10.20140815.1-0ubuntu1) utopic; urgency=medium

  [ Dimitri John Ledkov ]
  * Add missing dependencies to libmediascanner-2.0-dev package. (LP:
    #1351358)

  [ James Henstridge ]
  * Automatically update models when the daemon sends the
    InvalidateResults D-Bus signal. Add a status property to models to
    let loading progress be tracked. Rename rowCount property to count,
    keeping the old name around for compatibility. (LP: #1347444)

  [ Jussi Pakkanen ]
  * Minor fixes for libc++.
  * Handle the case when /media/username does not exist when
    Mediascanner first starts up. (LP: #1354543)
 -- Ubuntu daily release <email address hidden> Fri, 15 Aug 2014 11:18:39 +0000