>Number:         30
>Category:       kern
>Synopsis:       fsync() on pipe fails with EINVAL
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    gnats-admin (Kernel Bug People)
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Mon Nov 29 20:35:02 1993
>Originator:     Bill Sommerfeld
>Organization:
	Self
>Release:        NetBSD 0.9, NetBSD-current
>Environment:
    	i[34]86
System: NetBSD orchard.medford.ma.us 0.9a ORCHARD#11 i386


>Description:
	fsync() on a pipe fails, returning EINVAL.
	This breaks RCS, which expects to fsync all of its I/O before
	closing it.
>How-To-Repeat:
	rlog foo,v | cat
	Note that rlog fails with an "output error"
This problem was first seen with emacs 19 "vc" (version-control) mode, which
runs RCS commands in subprocesses, connected to the main emacs using a pipe.
>Fix:
	Apply following patch to /sys/kern/vfs_syscalls.c
alternatively:
	(more work)
	fix rlog and anything else which might fsync() a pipe/socket
or	(even more work)
	implement fsync() on sockets -> wait until all queued output is drained.

*** 1.1	1993/11/24 22:06:05
--- 1.2	1993/11/28 17:33:35
***************
*** 1565,1572 ****
  	struct file *fp;
  	int error;
  
! 	if (error = getvnode(p->p_fd, uap->fd, &fp))
  		return (error);
  	vp = (struct vnode *)fp->f_data;
  	VOP_LOCK(vp);
  	error = VOP_FSYNC(vp, fp->f_flag, fp->f_cred, MNT_WAIT, p);
--- 1565,1575 ----
  	struct file *fp;
  	int error;
  
! 	if (error = getvnode(p->p_fd, uap->fd, &fp)) {
! 		if (error == EINVAL)
! 			error = 0;
  		return (error);
+ 	}
  	vp = (struct vnode *)fp->f_data;
  	VOP_LOCK(vp);
  	error = VOP_FSYNC(vp, fp->f_flag, fp->f_cred, MNT_WAIT, p);
>Audit-Trail:
>Unformatted:

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