[src/trunk]: src/sys/fs/tmpfs tmpfs_alloc_node: it is less error-prone to sto...

[rmind <rmind%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/0cb945cef727
branches:  trunk
changeset: 791014:0cb945cef727
user:      rmind <rmind%NetBSD.org@localhost>
date:      Thu Oct 31 00:59:17 2013 +0000

description:
tmpfs_alloc_node: it is less error-prone to store the link path with
the NIL terminator included.  Adjust tmpfs_readlink() to exclude NIL.
Also, remove the check for zero-length and add some asserts.

diffstat:

 sys/fs/tmpfs/tmpfs_subr.c  |  14 +++++++-------
 sys/fs/tmpfs/tmpfs_vnops.c |  11 ++++++-----
 2 files changed, 13 insertions(+), 12 deletions(-)

diffs (76 lines):

diff -r 7555a587a000 -r 0cb945cef727 sys/fs/tmpfs/tmpfs_subr.c
--- a/sys/fs/tmpfs/tmpfs_subr.c Thu Oct 31 00:30:14 2013 +0000
+++ b/sys/fs/tmpfs/tmpfs_subr.c Thu Oct 31 00:59:17 2013 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: tmpfs_subr.c,v 1.80 2013/10/04 15:14:11 rmind Exp $    */
+/*     $NetBSD: tmpfs_subr.c,v 1.81 2013/10/31 00:59:17 rmind Exp $    */
 
 /*
  * Copyright (c) 2005-2011 The NetBSD Foundation, Inc.
@@ -74,7 +74,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: tmpfs_subr.c,v 1.80 2013/10/04 15:14:11 rmind Exp $");
+__KERNEL_RCSID(0, "$NetBSD: tmpfs_subr.c,v 1.81 2013/10/31 00:59:17 rmind Exp $");
 
 #include <sys/param.h>
 #include <sys/dirent.h>
@@ -166,13 +166,13 @@
                break;
        case VLNK:
                /* Symbolic link.  Target specifies the file name. */
-               KASSERT(target && strlen(target) < MAXPATHLEN);
+               KASSERT(target != NULL);
 
                nnode->tn_size = strlen(target);
-               if (nnode->tn_size == 0) {
-                       nnode->tn_spec.tn_lnk.tn_link = NULL;
-                       break;
-               }
+               KASSERT(nnode->tn_size > 0);
+               KASSERT(nnode->tn_size < MAXPATHLEN);
+               nnode->tn_size++; /* include the NIL */
+
                nnode->tn_spec.tn_lnk.tn_link =
                    tmpfs_strname_alloc(tmp, nnode->tn_size);
                if (nnode->tn_spec.tn_lnk.tn_link == NULL) {
diff -r 7555a587a000 -r 0cb945cef727 sys/fs/tmpfs/tmpfs_vnops.c
--- a/sys/fs/tmpfs/tmpfs_vnops.c        Thu Oct 31 00:30:14 2013 +0000
+++ b/sys/fs/tmpfs/tmpfs_vnops.c        Thu Oct 31 00:59:17 2013 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: tmpfs_vnops.c,v 1.103 2013/10/04 15:14:11 rmind Exp $  */
+/*     $NetBSD: tmpfs_vnops.c,v 1.104 2013/10/31 00:59:17 rmind Exp $  */
 
 /*
  * Copyright (c) 2005, 2006, 2007 The NetBSD Foundation, Inc.
@@ -35,7 +35,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: tmpfs_vnops.c,v 1.103 2013/10/04 15:14:11 rmind Exp $");
+__KERNEL_RCSID(0, "$NetBSD: tmpfs_vnops.c,v 1.104 2013/10/31 00:59:17 rmind Exp $");
 
 #include <sys/param.h>
 #include <sys/dirent.h>
@@ -1030,16 +1030,17 @@
        } */ *ap = v;
        vnode_t *vp = ap->a_vp;
        struct uio *uio = ap->a_uio;
-       tmpfs_node_t *node;
+       tmpfs_node_t *node = VP_TO_TMPFS_NODE(vp);
        int error;
 
        KASSERT(VOP_ISLOCKED(vp));
        KASSERT(uio->uio_offset == 0);
        KASSERT(vp->v_type == VLNK);
+       KASSERT(node->tn_size > 0);
 
-       node = VP_TO_TMPFS_NODE(vp);
+       /* Note: readlink(2) returns the path without NIL. */
        error = uiomove(node->tn_spec.tn_lnk.tn_link,
-           MIN(node->tn_size, uio->uio_resid), uio);
+           MIN(node->tn_size - 1, uio->uio_resid), uio);
        node->tn_status |= TMPFS_NODE_ACCESSED;
 
        return error;