[src/trunk]: src/usr.bin/rump_allserver Use "size=e" as a way say "if the und...

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

details:   https://anonhg.NetBSD.org/src/rev/af8294e21535
branches:  trunk
changeset: 762210:af8294e21535
user:      pooka <pooka%NetBSD.org@localhost>
date:      Thu Feb 17 16:59:46 2011 +0000

description:
Use "size=e" as a way say "if the underlying file is preexisting
regular file, use whatever size it has".

diffstat:

 usr.bin/rump_allserver/rump_allserver.1 |  11 +++++++-
 usr.bin/rump_allserver/rump_allserver.c |  42 +++++++++++++++++++++++++-------
 2 files changed, 42 insertions(+), 11 deletions(-)

diffs (124 lines):

diff -r f0815a46432f -r af8294e21535 usr.bin/rump_allserver/rump_allserver.1
--- a/usr.bin/rump_allserver/rump_allserver.1   Thu Feb 17 16:57:46 2011 +0000
+++ b/usr.bin/rump_allserver/rump_allserver.1   Thu Feb 17 16:59:46 2011 +0000
@@ -1,4 +1,4 @@
-.\"    $NetBSD: rump_allserver.1,v 1.13 2011/02/17 16:03:05 pooka Exp $
+.\"    $NetBSD: rump_allserver.1,v 1.14 2011/02/17 16:59:46 pooka Exp $
 .\"
 .\" Copyright (c) 2010 Antti Kantee.  All rights reserved.
 .\"
@@ -86,10 +86,17 @@
 If the file does not exist, it will be created.
 .It Ar size
 Size of the mapping.
-The host file will be truncated to the size indicated.
 Similar to
 .Xr dd 1 ,
 this argument accepts a suffix as the multiplier for the number.
+The special value
+.Dq e
+indicates that the current size of
+.Ar hostpath
+will be used.
+It is assumed that
+.Ar hostpath
+exists and is a regular file.
 .It OR
 .It Ar disklabel
 Use a disklabel partition identifier to specify the offset and size
diff -r f0815a46432f -r af8294e21535 usr.bin/rump_allserver/rump_allserver.c
--- a/usr.bin/rump_allserver/rump_allserver.c   Thu Feb 17 16:57:46 2011 +0000
+++ b/usr.bin/rump_allserver/rump_allserver.c   Thu Feb 17 16:59:46 2011 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: rump_allserver.c,v 1.17 2011/02/17 16:03:05 pooka Exp $        */
+/*     $NetBSD: rump_allserver.c,v 1.18 2011/02/17 16:59:46 pooka Exp $        */
 
 /*-
  * Copyright (c) 2010, 2011 Antti Kantee.  All Rights Reserved.
@@ -27,7 +27,7 @@
 
 #include <sys/cdefs.h>
 #ifndef lint
-__RCSID("$NetBSD: rump_allserver.c,v 1.17 2011/02/17 16:03:05 pooka Exp $");
+__RCSID("$NetBSD: rump_allserver.c,v 1.18 2011/02/17 16:59:46 pooka Exp $");
 #endif /* !lint */
 
 #include <sys/types.h>
@@ -82,6 +82,7 @@
 #define DFILE 1
        "hostpath",
 #define DSIZE 2
+#define DSIZE_E -1
        "size",
 #define DOFFSET 3
        "offset",
@@ -174,9 +175,20 @@
                                                    "size already given\n");
                                                usage();
                                        }
-                                       /* XXX: off_t max? */
-                                       flen = strsuftoll("-d size", value,
-                                           0, LLONG_MAX);
+                                       if (strcmp(value, "e") == 0) {
+                                               if (foffset != 0) {
+                                                       fprintf(stderr,
+                                                           "cannot specify "
+                                                           "offset with "
+                                                           "size=e\n");
+                                                       usage();
+                                               }
+                                               flen = DSIZE_E;
+                                       } else {
+                                               /* XXX: off_t max? */
+                                               flen = strsuftoll("-d size",
+                                                   value, 0, LLONG_MAX);
+                                       }
                                        break;
                                case DOFFSET:
                                        if (foffset != 0) {
@@ -184,6 +196,12 @@
                                                    "offset already given\n");
                                                usage();
                                        }
+                                       if (flen == DSIZE_E) {
+                                               fprintf(stderr, "cannot "
+                                                   "specify offset with "
+                                                   "size=e\n");
+                                               usage();
+                                       }
                                        /* XXX: off_t max? */
                                        foffset = strsuftoll("-d offset", value,
                                            0, LLONG_MAX);
@@ -330,11 +348,12 @@
                struct disklabel dl;
                struct stat sb;
                off_t foffset, flen, fendoff;
-               int fd;
+               int fd, oflags;
 
-               fd = open(etfs[i].hostpath, O_RDWR | O_CREAT, 0644);
+               oflags = etfs[i].flen == DSIZE_E ? 0 : O_CREAT;
+               fd = open(etfs[i].hostpath, O_RDWR | oflags, 0644);
                if (fd == -1)
-                       die(sflag, errno, "etfs hostpath create");
+                       die(sflag, errno, "etfs hostpath open");
 
                if (etfs[i].partition) {
                        int partition = etfs[i].partition - 'a';
@@ -354,10 +373,15 @@
                        foffset = etfs[i].foffset;
                        flen = etfs[i].flen;
                }
-               fendoff = foffset + flen;
 
                if (fstat(fd, &sb) == -1)
                        die(sflag, errno, "fstat etfs hostpath");
+               if (flen == DSIZE_E) {
+                       if (!S_ISREG(sb.st_mode))
+                               die(sflag, EINVAL, "size=e requires reg file");
+                       flen = sb.st_size;
+               }
+               fendoff = foffset + flen;
                if (S_ISREG(sb.st_mode) && sb.st_size < fendoff) {
                        if (ftruncate(fd, fendoff) == -1)
                                die(sflag, errno, "truncate");