kernel support for open share modes
Michael B Allen
mba2000 at ioplex.com
Tue Feb 15 23:31:10 GMT 2005
Jeremy Allison said:
> On Tue, Feb 15, 2005 at 04:30:28AM -0500, Michael B Allen wrote:
>> I believe it's generally accepted that there are certain
>> and limitations between the protocols and the POSIX APIs that prevent
>> proper coordination for many operations. POSIX simply isn't
>> enough to implement a full featured userspace network filesystem in a
>> way that can communicate consistent systemwide state. POSIX was designed
>> to be simple (I guess because it's more secure).
> Slightly off topic I suppose, but it always irks me to see
> people refer to concepts like deny modes as "sophisticated".
> Complex, yes. Sophisticated, no.
Well I don't believe I said that exactly. What I said was that POSIX isn't
sophisticated enough to properly implement a userspace network filesystem.
Specifically, when using only the POSIX APIs, there is a race condition
between examining ACLs, share modes, or other file meta data, and acting
on that information such as opening or deleting the target file.
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