This is what was "fdfix2.patch," a fix for fd sharing. It's pretty

far-reaching in fd-land, so you'll want to consult the code for
changes.  The biggest change is that now, you don't use
	fp->f_ops->fo_foo(fp, bar)
but instead
	fo_foo(fp, bar),
which increments and decrements the fp refcount upon entry and exit.
Two new calls, fhold() and fdrop(), are provided.  Each does what it
seems like it should, and if fdrop() brings the refcount to zero, the
fd is freed as well.

Thanks to peter ("to hell with it, it looks ok to me.") for his review.
Thanks to msmith for keeping me from putting locks everywhere :)

Reviewed by:	peter

1 files changed, 4 insertions, 0 deletions

diff --git a/sys/kern/uipc_syscalls.c b/sys/kern/uipc_syscalls.c
index 05fb328..b87114d 100644
--- a/sys/kern/uipc_syscalls.c
+++ b/sys/kern/uipc_syscalls.c
@@ -1420,6 +1420,7 @@ sendfile(struct proc *p, struct sendfile_args *uap)
 	off_t off, xfsize, sbytes = 0;
 	int error = 0, s;
 
+	vp = NULL;
 	/*
 	 * Do argument checking. Must be a regular file in, stream
 	 * type and connected socket out, positive offset.
@@ -1435,6 +1436,7 @@ sendfile(struct proc *p, struct sendfile_args *uap)
 		goto done;
 	}
 	vp = (struct vnode *)fp->f_data;
+	vref(vp);
 	obj = vp->v_object;
 	if (vp->v_type != VREG || obj == NULL) {
 		error = EINVAL;
@@ -1698,5 +1700,7 @@ done:
 	if (uap->sbytes != NULL) {
 		copyout(&sbytes, uap->sbytes, sizeof(off_t));
 	}
+	if (vp)
+		vrele(vp);
 	return (error);
 }