[PROBLEM] Missing /home mount after system upgrade

[Mike97]

Software
XBian version: 20150408-0
Kodi version: 14.2
Overclock settings: Default

Hardware
Device type and model: Raspberry Pi Model B 512 MB
Power supply rating: 3A (approved powered USB Hub)
SD card size and make/type: 4GB (Rating 10)
Network: Ethernet
Connected devices: TV, ext. USB HDD

Problem description:
After a recent full xbian upgrade (all available packages) I noticed the following during booting: ext. USB HDD with root fs was detected right away (disk activity) as defined in cmdline.txt; this was followed by about a 30 sec disk inactivity at boot message "switching root". Then it proceeded to complete the boot (USB disk activity). However /home, /boot, and /lib/module were not mounted (directories exist). It appears that fstab was not processed. Mount -a produced no error and showed several of duplicate mounts, but did not mount the aforementioned file systems. Mounting them individually worked as expected, e.g. mount -o subvol=home/@ /dev/sda1 /home. Since I couldn't find a thread on my specific problem, I would appreciate any help to resolve the issue.

Relevant Files:
cmdline.txt:
telnet zswap.enabled=1 zswap.compressor=lz4 sdhci-bcm2708.sync_after_dma=0 dwc_otg.lpm_enable=0 console=tty1 root=/dev/sda1 rootflags=subvol=root/@,thread_pool=2,autodefrag,compress=lzo,commit=120 rootfstype=btrfs rootwait=20 smsc95xx.turbo_mode=N logo.nologo noswap loglevel=0 mod_scsi.scan=sync partswap startevent=mountall nohdparm --startup-event mountall

fstab:
/dev/mmcblk0p1 /boot vfat rw 0 1
/dev/sda1 / btrfs noatime 0 0
/dev/sda1 /home btrfs subvol=home/@,noatime 0 0
/dev/sda1 /lib/modules btrfs subvol=modules/@,noatime 0 0
none /run/lock tmpfs noauto 0 0
none /run/shm tmpfs noauto 0 0
none /run/user tmpfs noauto 0 0

Output of mount -a command (sorry for the long output, but the file attachment function did not work for me):
/dev/sda1 on / type btrfs (rw,noatime)
proc on /proc type proc (rw,noexec,nosuid,nodev)
sysfs on /sys type sysfs (rw,noexec,nosuid,nodev)
udev on /dev type devtmpfs (rw,mode=0755)
devpts on /dev/pts type devpts (rw,noexec,nosuid,gid=5,mode=0620)
tmpfs on /run type tmpfs (rw,noexec,nosuid,size=10%,mode=0755)
fusectl on /sys/fs/fuse/connections type fusectl (rw)
rpc_pipefs on /run/rpc_pipefs type rpc_pipefs (rw)
/dev/sda1 on /xbmc-backup type btrfs (rw,noatime,subvol=data/@)
/dev/sda1 on /home type btrfs (rw,subvolid=264)
/dev/sda1 on /xbmc-backup type btrfs (rw,noatime,subvol=data/@)
/dev/sda1 on /lib/modules type btrfs (rw,noatime,subvol=modules/@)
/dev/sda1 on /home type btrfs (rw,subvolid=264)
fusectl on /sys/fs/fuse/connections type fusectl (rw)
/dev/sda1 on /xbmc-backup type btrfs (rw,noatime,subvol=data/@)
/dev/sda1 on /home type btrfs (rw,subvolid=264)
/dev/sda1 on /lib/modules type btrfs (rw,subvolid=267)
fusectl on /sys/fs/fuse/connections type fusectl (rw)
/dev/sda1 on /xbmc-backup type btrfs (rw,noatime,subvol=data/@)
/dev/sda1 on /xbmc-backup type btrfs (rw,noatime,subvol=data/@)
/dev/sda1 on /xbmc-backup type btrfs (rw,noatime,subvol=data/@)
/dev/sda1 on /xbmc-backup type btrfs (rw,noatime,subvol=data/@)
/dev/sda1 on /home type btrfs (rw,subvolid=264)
/dev/sda1 on /lib/modules type btrfs (rw,subvolid=267)
/dev/sda1 on /xbmc-backup type btrfs (rw,noatime,subvol=data/@)
/dev/sda1 on /home type btrfs (rw,subvolid=264)
/dev/sda1 on /lib/modules type btrfs (rw,subvolid=267)
fusectl on /sys/fs/fuse/connections type fusectl (rw)
/dev/sda1 on /xbmc-backup type btrfs (rw,noatime,subvol=data/@)
/dev/mmcblk0p1 on /boot type vfat (rw)
/dev/sda1 on /run/btrfs-snap type btrfs (rw,subvol=/)
/dev/sda1 on /xbmc-backup type btrfs (rw,noatime,subvol=data/@)
/dev/mmcblk0p1 on /boot type vfat (rw)
/dev/sda1 on /xbmc-backup type btrfs (rw,noatime,subvol=data/@)
/dev/mmcblk0p1 on /boot type vfat (rw)
/dev/sda1 on /xbmc-backup type btrfs (rw,noatime,subvol=data/@)
/dev/sda1 on /xbmc-backup type btrfs (rw,noatime,subvol=data/@)
/dev/sda1 on /xbmc-backup type btrfs (rw,noatime,subvol=data/@)
/dev/mmcblk0p1 on /boot type vfat (rw)
/dev/sda1 on /lib/modules type btrfs (rw,subvolid=267)
/dev/sda1 on /home type btrfs (rw,subvolid=264)
/dev/sda1 on /xbmc-backup type btrfs (rw,noatime,subvol=data/@)
/dev/mmcblk0p1 on /boot type vfat (rw)
/dev/sda1 on /xbmc-backup type btrfs (rw,noatime,subvol=data/@)
/dev/sda1 on /home type btrfs (rw,subvolid=264)
/dev/sda1 on /lib/modules type btrfs (rw,subvolid=267)
fusectl on /sys/fs/fuse/connections type fusectl (rw)
/dev/sda3 on /ntfs-share type fuseblk (rw,nosuid,nodev,allow_other,blksize=4096)
/dev/sda1 on /xbmc-backup type btrfs (rw,noatime,subvol=data/@)
/dev/sda1 on /xbmc-backup type btrfs (rw,noatime,subvol=data/@)
/dev/sda1 on /xbmc-backup type btrfs (rw,noatime,subvol=data/@)
/dev/sda1 on /xbmc-backup type btrfs (rw,noatime,subvol=data/@)
/dev/sda1 on /xbmc-backup type btrfs (rw,noatime,subvol=data/@)
/dev/sda4 on /media/backup-root type btrfs (rw,noexec,nodev,sync,noatime,compress=lzo,subvol=/)
/dev/sda1 on /xbmc-backup type btrfs (rw,noatime,subvol=data/@)
/dev/sda4 on /media/backup-root type btrfs (rw,noexec,nodev,sync,noatime,compress=lzo,subvol=/)
/dev/sda1 on /xbmc-backup type btrfs (rw,noatime,subvol=data/@)
none on /run/lock type tmpfs (rw)
/dev/sda1 on /xbmc-backup type btrfs (rw,noatime,subvol=data/@)
/dev/sda4 on /media/backup-root type btrfs (rw,noexec,nodev,sync,noatime,compress=lzo,subvol=/)
/dev/sda1 on /xbmc-backup type btrfs (rw,noatime,subvol=data/@)
/dev/sda4 on /media/backup-root type btrfs (rw,noexec,nodev,sync,noatime,compress=lzo,subvol=/)
/dev/mmcblk0p1 on /boot type vfat (rw)

[Mike97]

It seems nobody has any ideas how to solve this issue. I also experienced apparently random crashes of kodi. For the time being I'm giving another OS a chance with my particular setup (root on USB drive). Maybe I'll decide to come back in the future to check out an updated version of xbian.