Bug 26376

Description Adrian Chadd 2001-04-06 10:50:00 UTC

rsync freezes during execution if it is run over ssh.
If it runs over the tcp rsync protocol everything works ok.
I haven't tested rsh.

When the great s/rsh/ssh/ was done, someone overlooked a bit of
main.c which sets blocking_io if the remote shell command matched
RSYNC_RSH. RSYNC_RSH is either "rsh" or "remsh" depending upon
the target OS (remsh I believe is a HP/UX thing.)

The thing is, ssh doesn't work if blockingio is used. From util.c :

/* this is derived from CVS code
   
   note that in the child STDIN is set to blocking and STDOUT
   is set to non-blocking. This is necessary as rsh relies on stdin being blocki
ng
   and ssh relies on stdout being non-blocking
  
   if blocking_io is set then use blocking io on both fds. That can be
   used to cope with badly broken rsh implementations like the one on
   solaris.
 */

.. if blocking_io is set then ssh breaks since stdout is now blocking.

Fix: Apply the following patch to the port to make this rsh check map to
rsh (I forced it here since under FreeBSD we shouldn't have remsh :-)
and everything works happily again.

How-To-Repeat: 
Run rsync over ssh rather than the rsync protocol.
Watch it hang during a large update. :-)