Shared My Documents folder not writable by non-root Linux guest

[srackham]

Host: Windows XP Pro SP2, Guest: Xubuntu 8.04

Non-root users can't write to a shared Windows 'My Documents' folder regardless of the 'uid' and 'gid'. Here's a transcript that illustrates the problem (the shared folder named mydocs shares the C:\Documents and Settings\srackham\My Documents folder and the logged on Xubuntu user is 'srackham'):

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$ ls -ld shared/
drwxr-xr-x 2 srackham srackham 4096 2008-09-18 07:59 shared/

$ sudo mount -t vboxsf -o uid=srackham,gid=srackham mydocs shared

$ ls -ld shared/
dr-xr-xr-x 1 srackham srackham 0 2008-09-18 10:15 shared/

$ touch shared/t
touch: cannot touch `shared/t': Permission denied

$ sudo touch shared/t

$ ls shared/t
shared/t

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Note how the user write bit on the mounted directory has been turned off so the user can't write but root can.

The problem seems to be related to the special properties imbued in the 'My Documents' folder by Windows. Same applies to the Windows 'Shared Documents' folder (`C:\Documents and Settings\All Users\Documents`).

[Frank Mehnert]

Recent Linux additions allow you to specify a default mode for files and directories.

[Pello]

It will work if you just create a junction to 'My Documents' folder and ask VirtualBox to share the newly created junction (you may use Mark Russinovich's utility at ​http://live.sysinternals.com to create that junction, name it as you want)