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> Recently, the proprietary Dropbox Linux client dropped support for all Linux file systems except unencrypted ext4. What the heck. Anyone has more information

by lloeki 8y ago

> Recently, the proprietary Dropbox Linux client dropped support for all Linux file systems except unencrypted ext4. What the heck. Anyone has more information about that? Any announcement? And why would it fail to work on an encrypted (LUKS?) ext4 FS when encryption seemed to me to sit below the filesystem (since AFAIK ext4 doesn't support encryption itself)?

cpach 8y ago
I too was a bit surprised by that statement. But according to Dropbox, full disk encryption should work fine. ”If you received a notification on Linux and you are running ext4, it may be because you are also running ecryptfs. ecrypfts is not supported. However, we support full disk encryption systems, such as LUKS for Linux users.” Source: https://www.dropboxforum.com/t5/Error-messages/Dropbox-client-warns-me-that-it-ll-stop-syncing-in-Nov-why/m-p/290058 https://www.dropboxforum.com/t5/Error-messages/Dropbox-clien...
- lloeki 8y ago
  Oh, I can see why ecryptfs would be a pain to support, but I always considered it to be some kind of an epic-scale hack.
- kgbme 8y ago
  Perfect, thank you for the -forum- link! :)
  - cpach 8y ago
    De nada :)
feb 8y ago
That news hit HN top stories a few months ago: https://news.ycombinator.com/item?id=17732912 https://news.ycombinator.com/item?id=17732912
discordianfish 8y ago
It's FUD. ext4 with LUKS, which is what pretty much everyone is using on a desktop, is still working and the client supported.
- deleted 8y ago
  [deleted]
- pmlnr 8y ago
  No, it's not FUD. encrypted ext4 is encfs and ecryptfs, not xy on LUKs, and yes, they did drop support.
  - geofft 8y ago
    It's potentially misleading phrasing. "Unencrypted ext4" means that the filesystem Dropbox sees has to be actual ext4, not an encryption layer on top. There can be an encryption layer under it, and generally full-disk encryption works that way, by encrypting a block device and letting you run whatever filesystem you want on top. "Unencrypted or decrypted ext4" might be slightly more accurate (although I guess it maybe sounds like you need to remove encryption, not that you just need to decrypt files in memory).
    - cyphar 8y ago
      "Encrypted ext4" most likely refers to ext4's built-in support for file-based encryption.
  - pritambaral 8y ago
    Just FYI: Ext4 has file-level encryption built-in now [1, 2], so 'encrypted ext4' is actually different from encfs and ecryptfs. [1]: https://www.kernel.org/doc/html/v4.19/filesystems/fscrypt.html https://www.kernel.org/doc/html/v4.19/filesystems/fscrypt.ht... [2]: https://wiki.archlinux.org/index.php/ext4#Using_file-based_encryption https://wiki.archlinux.org/index.php/ext4#Using_file-based_e...
    - pmlnr 8y ago
leowoo91 8y ago
I'm not a an active dropbox user but I find this very surprising. Next question is, why wouldn't they open source the client libraries? Supporting many platforms is already a huge task.
- glennpratt 8y ago
  I have Git repos that can't be cloned onto encyptfs, so it's not surprising to me. Make an encrypted partition or just encrypt your entire disk.
qplex 8y ago
Ext4 does support encryption. [0] https://lwn.net/Articles/639427/ https://lwn.net/Articles/639427/
shocks 8y ago
Doesn’t work on ZFS either. I dropped Dropbox because of this.
- monochromatic 8y ago
  Why would an application like this care what file system it’s running on?
  - toomuchtodo 8y ago
    Filesystem primitives the application requires to deliver the desired functionality.
  - hannasanarion 8y ago
    It shouldn't have to. Dropbox ran fine on all filesystems for years. In September they sent everybody an email basically saying "you can't use Dropbox anymore, bye bye"
  - sly010 8y ago
    If I care to guess, because if you go an abstraction lower you can do your job better. Dropbox actually uses kernel drivers on some platforms (not sure on Linux). I guess power users are not the target market.
  - int0x80 8y ago
    In principle I agree with you, and many could argue the the app is broken. But in all fairness it is not so easy. Then there are lots of little details and corner cases where filesystems that implement a POSIX fs have slightly different semantics. This is important for example when dealing with sync'ing files to disk/backend. Encryption is another problem. Error handling. See for an example the annoying details here: https://danluu.com/file-consistency/ https://danluu.com/file-consistency/ http://danluu.com/filesystem-errors/ http://danluu.com/filesystem-errors/
    - userbinator 8y ago
      Encryption is another problem. I thought the whole point of an encrypting filesystem was that applications using it would not need to care about such things? Unless you're going below the FS abstraction and actually accessing blocks of the device directly, it shouldn't matter.

by lloeki 8y ago

cpach 8y ago

I too was a bit surprised by that statement. But according to Dropbox, full disk encryption should work fine. ”If you received a notification on Linux and you are running ext4, it may be because you are also running ecryptfs. ecrypfts is not supported. However, we support full disk encryption systems, such as LUKS for Linux users.” Source: https://www.dropboxforum.com/t5/Error-messages/Dropbox-client-warns-me-that-it-ll-stop-syncing-in-Nov-why/m-p/290058 https://www.dropboxforum.com/t5/Error-messages/Dropbox-clien...

lloeki 8y ago
Oh, I can see why ecryptfs would be a pain to support, but I always considered it to be some kind of an epic-scale hack.
kgbme 8y ago
Perfect, thank you for the -forum- link! :)
- cpach 8y ago
  De nada :)

feb 8y ago

That news hit HN top stories a few months ago: https://news.ycombinator.com/item?id=17732912 https://news.ycombinator.com/item?id=17732912

discordianfish 8y ago

It's FUD. ext4 with LUKS, which is what pretty much everyone is using on a desktop, is still working and the client supported.

deleted 8y ago
[deleted]
pmlnr 8y ago
No, it's not FUD. encrypted ext4 is encfs and ecryptfs, not xy on LUKs, and yes, they did drop support.
- geofft 8y ago
  It's potentially misleading phrasing. "Unencrypted ext4" means that the filesystem Dropbox sees has to be actual ext4, not an encryption layer on top. There can be an encryption layer under it, and generally full-disk encryption works that way, by encrypting a block device and letting you run whatever filesystem you want on top. "Unencrypted or decrypted ext4" might be slightly more accurate (although I guess it maybe sounds like you need to remove encryption, not that you just need to decrypt files in memory).
  - cyphar 8y ago
    "Encrypted ext4" most likely refers to ext4's built-in support for file-based encryption.
- pritambaral 8y ago
  Just FYI: Ext4 has file-level encryption built-in now [1, 2], so 'encrypted ext4' is actually different from encfs and ecryptfs. [1]: https://www.kernel.org/doc/html/v4.19/filesystems/fscrypt.html https://www.kernel.org/doc/html/v4.19/filesystems/fscrypt.ht... [2]: https://wiki.archlinux.org/index.php/ext4#Using_file-based_encryption https://wiki.archlinux.org/index.php/ext4#Using_file-based_e...
  - pmlnr 8y ago

leowoo91 8y ago

I'm not a an active dropbox user but I find this very surprising. Next question is, why wouldn't they open source the client libraries? Supporting many platforms is already a huge task.

glennpratt 8y ago
I have Git repos that can't be cloned onto encyptfs, so it's not surprising to me. Make an encrypted partition or just encrypt your entire disk.

qplex 8y ago

Ext4 does support encryption. [0] https://lwn.net/Articles/639427/ https://lwn.net/Articles/639427/

shocks 8y ago

Doesn’t work on ZFS either. I dropped Dropbox because of this.

monochromatic 8y ago
Why would an application like this care what file system it’s running on?
- toomuchtodo 8y ago
  Filesystem primitives the application requires to deliver the desired functionality.
- hannasanarion 8y ago
  It shouldn't have to. Dropbox ran fine on all filesystems for years. In September they sent everybody an email basically saying "you can't use Dropbox anymore, bye bye"
- sly010 8y ago
  If I care to guess, because if you go an abstraction lower you can do your job better. Dropbox actually uses kernel drivers on some platforms (not sure on Linux). I guess power users are not the target market.
- int0x80 8y ago
  In principle I agree with you, and many could argue the the app is broken. But in all fairness it is not so easy. Then there are lots of little details and corner cases where filesystems that implement a POSIX fs have slightly different semantics. This is important for example when dealing with sync'ing files to disk/backend. Encryption is another problem. Error handling. See for an example the annoying details here: https://danluu.com/file-consistency/ https://danluu.com/file-consistency/ http://danluu.com/filesystem-errors/ http://danluu.com/filesystem-errors/
  - userbinator 8y ago
    Encryption is another problem. I thought the whole point of an encrypting filesystem was that applications using it would not need to care about such things? Unless you're going below the FS abstraction and actually accessing blocks of the device directly, it shouldn't matter.