1.7.1-1 noacl on samba share has incorrect directory write bit

Raman Gupta rocketraman@fastmail.fm
Thu Jan 7 20:04:00 GMT 2010


On 01/07/2010 02:50 PM, Corinna Vinschen wrote:
> On Jan  7 13:42, Raman Gupta wrote:
>> On 01/07/2010 01:02 PM, Corinna Vinschen wrote:
>>> On Jan  7 00:39, Raman Gupta wrote:
>>>> "Cygwin ignores filesystem ACLs and only fakes a subset of
>>>> permission bits based on the DOS readonly attribute"
>>>
>>> No, it's a bit more tricky.  FAT filesystems, which are the role model
>>> for noacl filesystems don't know something like a R/O directory.  The
>>> DOS R/O bit on a directory does NOT mean the directory is R/O.  Rather,
>>> it only means that the folder is some sort of special folder.  For some
>>> better description, see http://support.microsoft.com/kb/326549.
>>
>> Wow, isn't that just like Microsoft to reuse an existing read-only
>> bit for something that is completely different semantically!
>>
>> In any case, note that the KB article says that attrib *can* be used
>> to see and modify the value -- as I demonstrated in my previous
>> email.
>
> Sure.  That has nothing to do with what I'm talking about.  While you
> can set and reset the R/O bit on a dir, it doesn't have the *meaning* of
> the directory being R/O.  If Cygwin reports such a directory as being
> read-only from the POSIX perspective, certain functions would have
> strange ideas and return EACCES, for instance.

In the case I am speaking of (a Samba share using the default 
settings), the functions *should* return EACCES, since on the 
server-side the directory is indeed non-writable.

>>> Therefore the fault is not on Cygwin's side, but on Samba's side to use
>>> the DOS R/O bit for something different than Windows uses it on
>>> directories.
>>
>> Understood. However, while Samba's use of the read-only bit on
>> directories does differ somewhat from what Windows Explorer expects
>> to use that bit for, it is a valid field and it does provide useful
>> information to the client in the case of noacl Samba mounts.
>>
>> Therefore, what would you think about configuring this via a mount
>> option? For example, a per-mount setting called dro/nodro (directory
>
> That's not the right thing to do, IMHO.  That's what the default "acl"
> mount mode is for.

Unfortunately, acl mode is unusable when in a non-domain environment.

Cheers,
Raman

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