Re: Create file fails on network drives in cygwin-1.7.9-1

[Corinna Vinschen <corinna-cygwin@cygwin.com>]

On Jun 17 12:36, Pete Forman wrote:
> On 17 June 2011 10:53, Corinna Vinschen wrote:
> > Btw., it would be an incredible good idea to change the permissions on
> > the remote drive to allow users to set or change the permissions of
> > files they created themselves.  Otherwise you end up with non-POSIX
> > permissions on the drive anyway, whether or not you're using "acl" or
> > "noacl" mount option.  If the network drives are not under your control,
> > try to persuade the admin.  If the admin is adamant, use the noacl mount
> > option for these drives.  You can also just change the cygdrive prefix
> > to use noacl on all drives.  See the User's Guide for how to do it.
> 
> I've just sat down with the admin and confirmed that I do have Full
> Control on the network drive. Creating and modifying files is working
> fine outside Cygwin.
> 
> chmod is failing with Permission denied in the same places that touch
> fails to create files.

There's still something disallowed.  If creating the file with ACL as
well as changing the ACL via chmod fails, then you don't have WRITE_DAC
permissions.  This has nothing to do with the permission to create
files, it's the permission you need to change permissions (aka to write
the file's DACL).  The error from opening the file in "acl" mode comes
only from this very problem.  If you use the "noacl" mount, then the
only difference when opening the file is that Cygwin does not requests
WRITE_DAC access.  It's not something in Cygwin itself, it's the
underlying Windows function which fails with "Access denied" in this
case.  The reason you can create files outside of Cygwin comes from the
simple fact that 99.999% of the non-Cygwin apps don't care for
permissions.  Cygwin does.


Corinna

-- 
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Project Co-Leader          cygwin AT cygwin DOT com
Red Hat

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