OT: find command permissions: how to exclude dir?

[Rick Stevens]

Dave Burns wrote:
> I have a cron job that runs 'find /' as root, keeps blowing up when
> encountering ~/.gvfs in my home dir. Permissions are set like so:
> 
>  ls -la ~/.gvfs
> total 4
> dr-x------  2 tburns isys    0 2008-10-13 07:43 .
> drwxr-xr-x 73 tburns root 4096 2008-10-24 11:49 ..
> 
> As owner of dir, no problem:
>  find /users/tburns  ! -name .gvfs |grep gvfs
> 
> As root, boom:
> sudo  find /users/tburns  ! -name .gvfs |grep gvfs
> [sudo] password for tburns:
> find: /users/tburns/.gvfs: Permission denied
> 
> When I create another similar directory, same permissions, root has no
> problem with it. But note ***the copy has a different file size
> (original size=0, copy size=4096)***:
> [tburns at cod ~]$ cp -pr .gvfs .gvfscopy
> [tburns at cod ~]$ ls -la .gvfscopy
> total 8
> dr-x------  2 tburns isys 4096 2008-10-13 07:43 .
> drwxr-xr-x 76 tburns root 4096 2008-10-29 10:56 ..
> [tburns at cod ~]$ sudo  find /users/tburns/.gvfscopy
> /users/tburns/.gvfscopy
> 
> 
> .gvfs is using some secret sauce that I don't understand to prevent
> root from accessing it.  Is there some ACL stuff going on here?
> (getfacl results are boring.) File locking? (lsof says it is not
> open.) Corruption? How can it be that root is denied? I wonder what
> would happen if I deleted .gvfs and recreated it manually with
> identical permissions?
> 
> I tried googling gvfs and permissions, got many many irrelevant hits.
> Some hits described a similar problem, but always veer off to a
> workaround for their specific situation, no general solution. Please
> at least give me a hint what to do or what to google for.

.gvfs is a virtual filesystem and doesn't follow normal filesystem
semantics (witness the fact the size of it is zero).  find can't
traverse it if you aren't the owner as the callbacks and such used when
referencing it only exist in the owner's Gnome instance.

Making a copy of it creates a real, honest-to-goodness directory with a
non-zero size, which find can happily traverse even if you aren't the
owner since it's a real file/directory, not a virtual one.

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- Rick Stevens, Systems Engineer                      ricks at nerd.com -
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-                   To err is human, to moo bovine.                  -
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