Interaction of share modes and file permissions
jra at dp.samba.org
jra at dp.samba.org
Thu Feb 6 17:57:25 GMT 2003
On Thu, Feb 06, 2003 at 02:26:25PM +0000, Neil Hoggarth wrote:
> Consider a file with ownership and mode such that a client has
> read-only permission on that file.
> Suppose that this file is open read-only by second client, with a
> share mode of DENY_WRITE.
> If the first client attempts to open the file read-write then a question
> arises: what is the appropriate response by the server? There are
> multiple reasons why the open should fail ("access denied" and "share
> mode violation"), but the response to the Open AndX request only allows
> for one reason to be communicated back to the client (I think ...).
> I raise this issue because Samba (v2.2.7 on Solaris) appears to respond
> to this circumstance differently than a Windows 2000 system does - Samba
> reports the share mode problem, whereas Windows reports "access denied".
Ok, we treat this as a bug. We need to give the same error codes as
W2K as far ar humanly possible.
> I stumbled across this distinction when trying to diagnose a problem
> with a Windows application called Endnote, which is an academic
> reference manager. The application responds differently depending on
> which error code it gets - as a result, multiple readers can
> simultaneously open an Endnote reference library read-only if it is
> stored on Windows share, but only one reader at a time can open the
> same file if it is stored on a Samba share.
> The fact that the app tries a read-only open on the file if it gets
> "permission denied" but doesn't if it encounters a share mode problem
> is arguably a misfeature of the app, and Samba's choice about how to
> handle the situation seems just as valid as Windows', but I thought
> that I'd highlight the difference in case the team think it is worth
> "correcting" Samba to make it ape a Windows server more closely.
> I have network packet captures which I think illustrate the difference
> between Windows and Samba, which I can provide if anyone is interested
Yes please, I would love to see the ethereal capture traces. If you can
get them to me asap I'll make sure it gets fixed for 2.2.8.
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