Conan Troutman · Jan 20, 2013 at 10:30 pm

Fix for Empty App-Mounted Directories in Android 4.2

With the release of Android 4.2 came many new features, one of which was the support for multiple user accounts on the same device. Unfortunately this addition had a rather undesirable effect on a feature that many people found much more useful than being able to create a separate user account. As of version 4.2, apps such as CIFS manager and Mountpoint no longer function as they should, due to changes that prevented Dalvik apps from mounting file systems to be shared with other apps. The directories will appear to be absolutely fine from within the app that initially mounted them. However, when attempting to view the contents from another app, well, you won’t be able to. Certain aspects of this issue have been addressed by XDA Elite Recognized Developer Chainfire‘s Stickmount, which is compatible with 4.2. However, until now there hasn’t yet been a resolution that doesn’t rely on a third party application.

The crux of the issue is that to ensure separation between user accounts, the system mounts everything under “/” (which is everything) as a recursive slave mountspace. In laymans terms, linking between apps across the filesystem is somewhat borked. Fortunately for those of you who would like to rectify this and regain that functionality, XDA Recognized Developer mkasick has come up with not just one but two different methods of remedying this issue. Please note though that these fixes are primarily aimed at developers looking to integrate them into 4.2-based ROMs.

Both fixes are composed of two parts, one of which is a modification to the boot ramdisk init.rc. The preferable method of patching this issue is by applying a change to Dalvik, which restricts the slave mountspace to  “/system” and “/mnt/shell/emulated”. The second option does the same thing at kernel level for ROMs that don’t/can’t use the preferred fix. These commits are in the process of being evaluated for inclusion into CyanogenMod, but at the moment still need to be applied manually.

Check out the original forum thread for a much more technical evaluation of the problem and links to the relevant gerrit/github pages for these patches.


_________
Want something on the XDA Portal? Send us a tip!
TAGS:

Conan Troutman

Conan Troutman is an editor on XDA-Developers, the largest community for Android users. Senior Moderator, Newswriter, Recovering Meme Addict. View Conan Troutman's posts and articles here.
Aamir Siddiqui · Jul 2, 2015 at 11:46 am · no comments

Xiaomi Sold 34.7 Million Phones In 6 Months

2015 has been a phenomenal year for Xiaomi so far. With a stellar rise in 2014, 2015 saw increased success outside of China for Xiaomi along with tremendous consumer interest in the company's smartphone offerings. The company also increased its ventures outside of smartphones touching everything from routers to selfie sticks. The company took to twitter to announce their recent success. Xiaomi's smartphones sales increased 33% year-on-year, with the company having sold 34.7 Million smartphones in the first half of...

XDA NEWS
Aamir Siddiqui · Jul 2, 2015 at 11:30 am · no comments

Sprint Reacts To Jab From T-Mobile

America's cellular network space has always been a battle of the big four: Verizon, AT&T, Sprint and T-Mobile. Together, they serve around 370 million subscribers while the 5th place U.S. Cellular serves 4.7 million subscribers. The battle for the top spot has always been between Verizon (133.5 million) and AT&T (121.8 million), while Sprint and T-Mobile battle it out for the 3rd place with 57.1 million and 56.8 million subscribers respectively. Needless to say, in such a neck-to-neck competition scenario, swords...

XDA NEWS
Jimmy McGee · Jul 2, 2015 at 06:00 am · no comments

Floating Apps with Rovers – XDA App Review

There are a lot of great launchers to help customize your phone. Some Launchers allow you to apply different color themes. Others offer many great automated features. Some make your most used apps easy to locate by putting them in prominent positions. There is a launcher that will let you do just about anything you want. XDA Senior Member roshga offers up a neat little app that allows you to have floating shortcuts to your favorite apps. In this video, XDA TV Producer TK...

XDA NEWS
Share This