[Samba] Re: [Possible BUG] Samba v3.0.20b and permissions POSIX/Samba

[Gerald (Jerry) Carter]

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Michael Gasch wrote:
> hi list,
> 
> i experienced a weird behaviour of samba in the latest versions
> (3.0.20[a,b]) on XFS:
> 
> directory:
> 
> /data (owner=iso,group=edv)
> permissions: 2770
> 
> if i put a file in there with permissions 644 (owner=root,group=edv) i
> cannot delete it. windows tells even tells me, that it's readonly (read
> only bit set). and that's the only difference: 3.0.14a doesn't show the
> file as read only.

This has been a debated issues on the technical list.  There's a
new parameter in 3.0.21pre1 called 'map read only'.  Let me summarize
it like this.

In the absence of 'store dos attributes = yes' and the ability
to represent DOS attribute bits separately from permission bits,
we have two choices.

(a) May the read only DOS attrib bit to the inverse of the
user write bit (this is what we did prior to the 3.0.20 series),
or

(b) represent the read only attribute based on whether the
user can actually write to the file.

If the 'R' DOS attribute is set, Windows will not allow you
to delete the file IIRC which is probably what you are hitting.
In 3.0.21pre1 'map read only = yes' should give you 3.0.14a behavior.

The problem in the current 3.0.20 behavior (which might be
considered a bug) is that we do not take the parent directory
permissions into account when determining whether the user
has write  access or not to a given file.  And hence this is
another argument to stay away from user space access checks.
But we have no choice with the changes in WinXP sp2 and file
deletion.

Does this help explain the behavior?





cheers, jerry
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