Bug: SD card formatted to ext4/btrfs is not mounted automatically [released]

answered 2013-12-25 14:35:30 +0300

hlub
593 ●6 ●16 ●22

updated 2013-12-28 11:22:31 +0300

At boot time the SD card is mounted by (systemd calling) the shell script /usr/sbin/mount-sd.sh.When you have a look at it, you see that it specifies uid and gid:

mount $SDCARD $MNT -o uid=$DEF_UID,gid=$DEF_GID

This makes a lot of sense when mounting a FAT filesystem, but not so much when mounting say btrfs, so the mount command will fail in that case, leaving you with an unmounted SD card. I solved the problem by editing the script, adding a fallback mount command:

 mount $SDCARD $MNT -o uid=$DEF_UID,gid=$DEF_GID || mount -o relatime $SDCARD $MY_MOUNTPOINT

(edit: replace $MY_MOUNTPOINT above by $MNT if you want the SD-card mounted the very same way a FAT-formatted card would - I am using a different mount point)

This works, but whether it is a good idea remains to be seen: trackerd scans the sdcard so putting lots of Linux stuff like say a Gentoo prefix installation on it is not a good idea. I will probably re-partition, putting a vfat system on the first partition and a big btrfs on the second.

answered 2013-12-25 14:38:43 +0300

Kontio
4995 ●58 ●54 ●63

moderator

The /usr/bin/mount-sd.sh script is not smart enough yet (triggered by /etc/udev/rules.d/90-mount-sd.rules), it gives mount options which Ext4 module does not understand (I didn't test btrfs, but I assume it's the same problem), so currently just vFat as a file system is supported:

[  190.490737] EXT4-fs (mmcblk1p1): Unrecognized mount option "uid=100000" or missing value

The script is developed here, you can help to improve it: https://github.com/nemomobile/sd-utils

answered 2014-01-31 00:23:37 +0300

Zombie
121 ●1 ●4 ●4

My solution (prior to stumbling on this report) was the following:

 diff --git a/scripts/mount-sd.sh b/scripts/mount-sd.sh
index 3e42403..5bab959 100755
--- a/scripts/mount-sd.sh
+++ b/scripts/mount-sd.sh
@@ -15,7 +15,11 @@ if [ "$ACTION" = "add" ]; then
                exit $?
        fi      
        su $DEVICEUSER -c "mkdir -p $MNT"
-       mount $SDCARD $MNT -o uid=$DEF_UID,gid=$DEF_GID
+       if /usr/bin/file -Ls $SDCARD | grep ext[234]; then
+               mount $SDCARD $MNT
+       else
+               mount $SDCARD $MNT -o uid=$DEF_UID,gid=$DEF_GID
+       fi
 else
        umount $SDCARD

This works fine for ext4. I guess it can be easily extended to support btrfs.

answered 2014-02-13 18:20:46 +0300

STiAT
596 ●9 ●14 ●19

The proper patch for this can be found here: https://github.com/nemomobile/sd-utils/commit/aac9482cf27ac5d85a854e88c906d6f0040479e3