@Devs: Write Access to SD advice, please?
I'm hoping you devs can shed some light on this.
I'm not 100% sure, but pretty close, that beginning with either the 4.4.x builds or the 4.4.4 builds, Titanium backup is no longer able to protect backups. That dev has posted a proposed "fix" which consists of adding the group media_rw to the WRITE_EXTERNAL_STORAGE permission in platform.xml—the same thing as the various "KitKat SD Fix" type apps do. Well, as you know, your ROM already contains this permission group, and yet, Titanium still can't protect backups.
In doing research on this, I discovered one user was able to circumvent this by having his backup folder set to /storage/ExtSDCard/TitaniumBackup (or something similar), and then letting TiBu detect the backup folder. In doing so, TiBu revealed another path to the folder he was using, accessed via /mnt/media_rw/sdcard1/TitaniumBackup. I tried this myself, and TiBu did not reveal that path for me. So I tried navigating to it, and found that TiBu says my /mnt folder is read-only, and my /mnt/media_rw folder, whose permissions are rwx------, "cannot be accessed". I tried some stuff using Root Explorer, and discovered that mounting /mnt as r/w long enough to change /mnt/media_rw permissions to rwxrwx---, and then mounting /mnt as r/o, does the trick—TiBu is able to access the folders under /mnt/media_rw, including sdcard1, and use a folder created under /mnt/media_rw/sdcard1 for backups, AS WELL AS being able to protect backups in that folder. The caveat being that after a reboot, everything is set back to default, meaning TiBu will no longer be able to access the folder.
I figured it would be easy enough to run a shell script or commands at boot to change the permissions on /mnt/media_rw to rwxrwx---. BUT, before that can happen /mnt has to be mounted as r/w, and I'm a little less confident about trying to correctly mount a volume via a shell command.
1. Is it possible and safe to do this (mount r/w; change perms; mount r/o) via boot script/commands? I plan to use Tasker and Secure Settings to accomplish this, but I'm open to other suggestions.
2. Is it safe to keep rwxrwx--- perms on /mnt/media_rw?
3. Is it SO safe, that it's possible (and you'd be willing) to actually build the ROM with those perms on /mnt/media_rw?
I've also tried installing TiBu as a system app, with the understanding that system apps are allowed to set the r/o attribute (essentially what "protecting" a backup does) on SD card files outside of their own designated folders, but that didn't even work. Does that mean that including TiBu in the ROM as a system app (were that appropriate to do) wouldn't work either?
I definitely don't mind the boot script/commands route, as long as I have the correct syntax and parameters for the mount command. But if #3 is doable, that'd be great too!
Thanks in advance for any input, and, once again, for this great ROM! I'm conservative about how often I update it (still on the 7/29 build), but I'm all in.
Have a great weekend!
"In God We Trust"
Hey, y'all...it's a Southern Maryland Thang
Sprint Galaxy S®4 (SPH-L720)
ROM: LiquidSmooth 3.2 7/29/2014
Kernel: PoKernel 2.5
Mini Modular 4.4.4 9/1/2014
Recovery: PhilZ Touch