Re: Linux... move the Dropbox Folder

MHBoise · ‎12-11-2019

I have been looking but not finding anything... can anyone point me in the right direction for moving the Dropbox folder? I have Ubuntu Server (no Gui) installed and the Dropbox folder (and the two symlinks Dropbox Business created) is located in the home directory. My data is in another directory (seperate hard drive) called Shares. With the receint Dropbox update The symlink I created no longer work and I am dead in the water... Everything I do must be via Command Line...

nullptr · ‎12-17-2019

I just spent 11 days with dropbox support because I recently tried solving the symlink problem by using a bind mount. Putting a bind mount in your dropbox folder will break the dropbox daemon and prevent it from syncing.

Unfortunately, there are no solutions for those of us that relied on symlinks to backup data outside of the dropbox folder.

Здравко · ‎12-17-2019

@nullptr wrote:
...
Unfortunately, there are no solutions for those of us that relied on symlinks to backup data outside of the dropbox folder.

Hi @nullptr,

Your statement isn't true actually! The symbolic link might be most convenient for many users, but isn't the only one.

@nullptr wrote:
... Putting a bind mount in your dropbox folder will break the dropbox daemon and prevent it from syncing.
...

😏 Actually, your statement could be true here (partially). Directory binding is additional layer between underlying file system and users programs. Such a layers interface, on Linux, always have nature of FS interface. In this context - binding falls in FS restrictions of Dropbox (bind interface isn't inside Dropbox "white list"). The truth in your statement is up to here. There is relatively easy way, developed long time ago in context of FS limitation introduction, which just overcome this limitation. Such method could be used and there is example for use here (just change device mount to binding). 😉 That's it.

Enjoy!

nullptr · ‎12-17-2019

@Здравко wrote:
(just change device mount to binding). 😉 That's it.

I looked at the code in that post. It looks like it hard-codes filesystem type to EXT4 for stat calls and passes extra mode parameters in open calls. I don't see how this helps. Since I'm already using a bind mount on an EXT4 filesystem unsuccessfully are you saying that a solution is to change the hard-coded file system type? To what? The magic number for directory binding (does this exist)?

nullptr · ‎12-17-2019

@Здравко wrote:

Or are you saying that when you use a bind mount, that the fs type passed to stat calls is something other than ext4?

Здравко · ‎12-17-2019

@nullptr wrote:
...
I looked at the code in that post. It looks like it hard-codes filesystem type to EXT4 for stat calls and passes extra mode parameters in open calls. I don't see how this helps. ...

Hi @nullptr,

Yes, you are (almost) right. There isn't "extra mode", just parameters forward. I'm not sure what's not clear enough.

@nullptr wrote:
... Since I'm already using a bind mount on an EXT4 filesystem unsuccessfully are you saying that a solution is to change the hard-coded file system type? ...

Yes, exactly!

@nullptr wrote:
...
To what? The magic number for directory binding (does this exist)?

I noted already in previous post. FS-type (and corresponding "magic number"), not directory!

@nullptr wrote:
...
Or are you saying that when you use a bind mount, that the fs type passed to stat calls is something other than ext4?

Yes, exactly!

Hope this adds some clarity.

Midgley · ‎12-17-2019

I suppose it might be worth a try to move the Home folder instead of doing tricky things with symlinks and mounting drives in the dropbox folder. Even so think you would need to uninstall dropbox, move the Home folder, or reinstall Linux and designate a Home partition of your choice. Then install Dropbox and everthing would be hunky dory. I will try that some time but for now I have giving up on Dropbox for my work. Currently I am just running rsync -a Lol.

Здравко · ‎12-17-2019

Hi @Midgley,

😀😃 If that's sounding easier for you... 😉

Midgley · ‎12-17-2019

Lol... I really does! Well maybe not but sometimes it is better than doing too many trix and side steps.

cipherguru · ‎03-10-2020

I guess its my lack of understanding of C++ and Ubuntu but I could not understand what you meant by "(just change device mount to binding)"

Does it require change in the source code? Which line? to what?

I tried ad-hoc fixes based on what I could understand

For example, I tried changing EXT4_SUPER_MAGIC to BINDERFS_SUPER_MAGIC but got the error

<stdin>: In function ‘statfs’:
<stdin>:21:19: error: ‘BINDERFS_SUPER_MAGIC’ undeclared (first use in this function)
<stdin>:21:19: note: each undeclared identifier is reported only once for each function it appears in
<stdin>: In function ‘statfs64’:
<stdin>:32:19: error: ‘BINDERFS_SUPER_MAGIC’ undeclared (first use in this function)

undoing the change says

Your Dropbox is already patched.

So I'm doing something wrong.

Здравко · ‎03-10-2020

@cipherguru wrote:
I guess its my lack of understanding of C++ and Ubuntu but I could not understand what you meant by "(just change device mount to binding)"
...

Hi @cipherguru,

Actually, there isn't any C++ code! Where you see it? API layer functions are C functions, not C++! Other (biggest) part is a shell-script ('bash' - more precise).

@cipherguru wrote:
...
Does it require change in the source code? Which line? to what?
...

No actually. What make you think that any changes are needed?

@cipherguru wrote:
...
For example, I tried changing EXT4_SUPER_MAGIC to BINDERFS_SUPER_MAGIC but got the error
...

I can't see any reason for such change, but if you want see what FS magic numbers are available for your system, take a look on "/usr/include/linux/magic.h". In my case I can't find "BINDERFS_SUPER_MAGIC". Where you find this from (and more important why - isn't Ext4 enough, though)?