race condition bugs
Paul_Green at charter.net
Mon Aug 9 19:27:56 GMT 2004
Wayne Davison wrote:
> On Mon, Aug 09, 2004 at 12:12:16PM +0100, Tony Finch wrote:
> > This is because of race conditions in finish_transfer() which mean
> > that it does not update files atomically.
> There is a diff in the "patches" dir named early-chmod.diff
> that changes
> this behavior. It sets the permissions prior to the robust_rename()
> call, and the copy-when-rename-fails logic is extended to ensure that
> these final permissions on the temp file don't interfere with rsync's
> reading of the file for the copy.
> The only reason this patch hasn't already been applied is that I'm not
> 100% sure of the reasons that rsync was written to do the
> chmod() after
> the rename(). For instance, do we need to worry about some strange
> system that drops the setuid bits on rename()? Is there a (relevant)
> system that prevents the rename() if the file is read-only?
> (I seem to
> recall that MS DOS has this behavior, but cygwin probably
> hides it if it does.)
> Any comments on how portable it would be to apply the final
> permissions before calling rename()?
Can we make up a test case that the build farm can execute?
I know of no issues from the POSIX standard that would prevent applying
More information about the rsync