[src/trunk]: src/sys/rump/librump/rumpvfs Allocate large struct from heap ins...

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

details:   https://anonhg.NetBSD.org/src/rev/63f88b97b390
branches:  trunk
changeset: 787376:63f88b97b390
user:      pooka <pooka%NetBSD.org@localhost>
date:      Fri Jun 14 05:54:04 2013 +0000

description:
Allocate large struct from heap instead of stack for the benefit of
low-stack environments in which this code can run.

diffstat:

 sys/rump/librump/rumpvfs/rumpfs.c |  31 +++++++++++++++++--------------
 1 files changed, 17 insertions(+), 14 deletions(-)

diffs (84 lines):

diff -r 82f3e15d6a22 -r 63f88b97b390 sys/rump/librump/rumpvfs/rumpfs.c
--- a/sys/rump/librump/rumpvfs/rumpfs.c Fri Jun 14 05:39:28 2013 +0000
+++ b/sys/rump/librump/rumpvfs/rumpfs.c Fri Jun 14 05:54:04 2013 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: rumpfs.c,v 1.116 2013/06/12 12:14:35 pooka Exp $       */
+/*     $NetBSD: rumpfs.c,v 1.117 2013/06/14 05:54:04 pooka Exp $       */
 
 /*
  * Copyright (c) 2009, 2010, 2011 Antti Kantee.  All Rights Reserved.
@@ -26,7 +26,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: rumpfs.c,v 1.116 2013/06/12 12:14:35 pooka Exp $");
+__KERNEL_RCSID(0, "$NetBSD: rumpfs.c,v 1.117 2013/06/14 05:54:04 pooka Exp $");
 
 #include <sys/param.h>
 #include <sys/atomic.h>
@@ -1274,7 +1274,7 @@
        return error;
 }
 
-/* simple readdir.  event omits dotstuff and periods */
+/* simple readdir.  even omits dotstuff and periods */
 static int
 rump_vop_readdir(void *v)
 {
@@ -1290,6 +1290,7 @@
        struct uio *uio = ap->a_uio;
        struct rumpfs_node *rnd = vp->v_data;
        struct rumpfs_dent *rdent;
+       struct dirent *dentp = NULL;
        unsigned i;
        int rv = 0;
 
@@ -1302,35 +1303,37 @@
                goto out;
 
        /* copy entries */
+       dentp = kmem_alloc(sizeof(*dentp), KM_SLEEP);
        for (; rdent && uio->uio_resid > 0;
            rdent = LIST_NEXT(rdent, rd_entries), i++) {
-               struct dirent dent;
-
-               strlcpy(dent.d_name, rdent->rd_name, sizeof(dent.d_name));
-               dent.d_namlen = strlen(dent.d_name);
-               dent.d_reclen = _DIRENT_RECLEN(&dent, dent.d_namlen);
+               strlcpy(dentp->d_name, rdent->rd_name, sizeof(dentp->d_name));
+               dentp->d_namlen = strlen(dentp->d_name);
+               dentp->d_reclen = _DIRENT_RECLEN(dentp, dentp->d_namlen);
 
                if (__predict_false(RDENT_ISWHITEOUT(rdent))) {
-                       dent.d_fileno = INO_WHITEOUT;
-                       dent.d_type = DT_WHT;
+                       dentp->d_fileno = INO_WHITEOUT;
+                       dentp->d_type = DT_WHT;
                } else {
-                       dent.d_fileno = rdent->rd_node->rn_va.va_fileid;
-                       dent.d_type = vtype2dt(rdent->rd_node->rn_va.va_type);
+                       dentp->d_fileno = rdent->rd_node->rn_va.va_fileid;
+                       dentp->d_type = vtype2dt(rdent->rd_node->rn_va.va_type);
                }
 
-               if (uio->uio_resid < dent.d_reclen) {
+               if (uio->uio_resid < dentp->d_reclen) {
                        i--;
                        break;
                }
 
-               rv = uiomove(&dent, dent.d_reclen, uio); 
+               rv = uiomove(dentp, dentp->d_reclen, uio); 
                if (rv) {
                        i--;
                        break;
                }
        }
+       kmem_free(dentp, sizeof(*dentp));
+       dentp = NULL;
 
  out:
+       KASSERT(dentp == NULL);
        if (ap->a_cookies) {
                *ap->a_ncookies = 0;
                *ap->a_cookies = NULL;