Do not return success and a string "unknown" when vn_fullpath() was unable

to resolve the path of the text vnode of the process. The behaviour is
very confusing for any consumer of the procfs, in particular, java.

Reported and tested by:	bf
MFC after:	2 weeks
Approved by:	re (bz)

1 files changed, 9 insertions, 6 deletions

diff --git a/sys/fs/procfs/procfs.c b/sys/fs/procfs/procfs.c
index 8b69eb1..514e279 100644
--- a/sys/fs/procfs/procfs.c
+++ b/sys/fs/procfs/procfs.c
@@ -67,20 +67,23 @@
 int
 procfs_doprocfile(PFS_FILL_ARGS)
 {
-	char *fullpath = "unknown";
-	char *freepath = NULL;
+	char *fullpath;
+	char *freepath;
 	struct vnode *textvp;
+	int error;
 
+	freepath = NULL;
 	PROC_LOCK(p);
 	textvp = p->p_textvp;
 	vhold(textvp);
 	PROC_UNLOCK(p);
-	vn_fullpath(td, textvp, &fullpath, &freepath);
+	error = vn_fullpath(td, textvp, &fullpath, &freepath);
 	vdrop(textvp);
-	sbuf_printf(sb, "%s", fullpath);
-	if (freepath)
+	if (error == 0)
+		sbuf_printf(sb, "%s", fullpath);
+	if (freepath != NULL)
 		free(freepath, M_TEMP);
-	return (0);
+	return (error);
 }
 
 /*