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What is the truth behind the sdcard complaints for KitKat

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Default What is the truth behind the sdcard complaints for KitKat

While researching the great N7000/Galaxy-S2 sdcard FUSE deadlock bug, I've come across lots of posts that complain in the strongest possible language about how KitKat has changed the rules for SD cards.

The android police thread named "external-blues-google-has-brought-big-changes-to-sd-cards-in-kitkat-and-even-samsung-may-be-implementing-them" seems to sum things up less emotionally:
  • An app without any permissions has automatic read and write for designated private folders on the primary and secondary storage
  • An app with WRITE_EXTERNAL_STORAGE, also has:
    • Read and write for any public folder on the primary (built-in) storage
    • Read (not write) for any public folder on the secondary (SD card) storage
This implies, as many posts point out, that some of our most useful tools (file managers, backup apps, ...) will no longer work.

But I'm not seeing that - FX, even in non-SU mode, can still create folders and files and copy between cards, for example.

So what IS the (full) truth, and how does this affect Omni?
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Note: Anything here relating to use of the sdcard daemon for anything other than mapping /data/media to /sdcard on devices with unified storage is NEW for 4.4

Also relevant: - this is the one that modified the sdcard fuse daemon to do all the new stuff, and it's somewhere in the set of changes starting here that the problem lies.

It can't simply be reverted out as all of the new KK perms management stuff depends on the new daemon to work properly.
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would it be fair to say that they're killing off the ext card?
(Last edited by jeffsf; 17th March 2014 at 03:13 PM.)
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Google has never had a card slot in their phones. Originally, they wanted you to store everything on their servers.

The changes are needed to provide some level of security on the external card, a gaping hole prior to KK and not a whole lot better now. For a slew of reasons, you don't want any app to be able to arbitrarily read another apps data, even if on the card.
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