Clean up error handling in libstand filesystem code to be more consistent:

- bzipfs and gzipfs now properly return errno values directly from their
  read routines rather than returning -1.
- missing errno values on error returns for the seek routines on almost
  all filesystems were added.
- fstat() now returns -1 if an error occurs rather than ignoring it.
- nfs's readdir() routine now reports valid errno values if an error or
  EOF occurs rather than EPERM  (It was just returning 0 for success and
  1 for failure).
- nullfs used the wrong semantics for every function besides close() and
  seek().  Getting it right for close() appears to be an accident at that.
- read() for buffered files no longer returns 0 (EOF) if an error occurs,
  but returns -1 instead.

1 files changed, 2 insertions, 2 deletions

diff --git a/lib/libstand/read.c b/lib/libstand/read.c
index 36f0f22..07401c1 100644
--- a/lib/libstand/read.c
+++ b/lib/libstand/read.c
@@ -115,13 +115,13 @@ read(int fd, void *dest, size_t bcount)
 	if (resid >= SOPEN_RASIZE) {
 	    /* bypass the rest of the request and leave the buffer empty */
 	    if ((errno = (f->f_ops->fo_read)(f, dest, resid, &cresid)))
-		return(bcount - resid);
+		    return (-1);
 	    return(bcount - cresid);
 	}
 
 	/* fetch more data */
 	if ((errno = (f->f_ops->fo_read)(f, f->f_rabuf, SOPEN_RASIZE, &cresid)))
-	    return(bcount - resid);	/* behave like fread() */
+	    return (-1);
 	f->f_raoffset = 0;
 	f->f_ralen = SOPEN_RASIZE - cresid;
 	/* no more data, return what we had */