[src/trunk]: src/lib/librt Allow /var/shm to be a symlink to a properly set u...

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

details:   https://anonhg.NetBSD.org/src/rev/5a51a0f4827e
branches:  trunk
changeset: 809301:5a51a0f4827e
user:      martin <martin%NetBSD.org@localhost>
date:      Tue Jun 30 11:46:47 2015 +0000

description:
Allow /var/shm to be a symlink to a properly set up directory.

diffstat:

 lib/librt/shm.c |  20 +++++++++++++++++---
 1 files changed, 17 insertions(+), 3 deletions(-)

diffs (56 lines):

diff -r 5fcbdc6e8089 -r 5a51a0f4827e lib/librt/shm.c
--- a/lib/librt/shm.c   Tue Jun 30 08:31:42 2015 +0000
+++ b/lib/librt/shm.c   Tue Jun 30 11:46:47 2015 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: shm.c,v 1.1 2013/12/19 19:11:50 rmind Exp $    */
+/*     $NetBSD: shm.c,v 1.2 2015/06/30 11:46:47 martin Exp $   */
 
 /*-
  * Copyright (c) 2013 The NetBSD Foundation, Inc.
@@ -34,7 +34,7 @@
  */
 
 #include <sys/cdefs.h>
-__RCSID("$NetBSD: shm.c,v 1.1 2013/12/19 19:11:50 rmind Exp $");
+__RCSID("$NetBSD: shm.c,v 1.2 2015/06/30 11:46:47 martin Exp $");
 
 #include <sys/mman.h>
 #include <sys/mount.h>
@@ -58,6 +58,7 @@
 #define        MOUNT_SHMFS             MOUNT_TMPFS
 
 static const char *            _shmfs_path = NULL;
+static char                    _shmfs_path_buf[PATH_MAX];
 
 static bool
 _shm_check_fs(void)
@@ -65,7 +66,15 @@
        const char *shmfs = SHMFS_DIR_PATH;
        struct statvfs sv;
        struct stat st;
+       char buf[PATH_MAX];
+       ssize_t cnt;
 
+       if ((cnt = readlink(shmfs, buf, sizeof(buf))) > 0) {
+               if ((size_t)cnt >= sizeof(buf))
+                       return false;
+               buf[cnt] = 0;
+               shmfs = buf;
+       }
        if (statvfs1(shmfs, &sv, ST_NOWAIT) == -1) {
                return false;
        }
@@ -80,7 +89,12 @@
                return false;
        }
 
-       _shmfs_path = shmfs;
+       if (shmfs == buf) {
+               strcpy(_shmfs_path_buf, buf);
+               _shmfs_path = _shmfs_path_buf;
+       } else {
+               _shmfs_path = shmfs;
+       }
        return true;
 }