Add fallocate.c to contrib from Eric Sandeen

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

diff --git a/contrib/fallocate.c b/contrib/fallocate.c
new file mode 100644 (file)
index 0000000..23684f3
--- /dev/null
+++ b/contrib/fallocate.c
@@ -0,0 +1,152 @@
+/*
+ * fallocate - utility to use the fallocate system call
+ *
+ * Copyright (C) 2008 Red Hat, Inc. All rights reserved.
+ * Written by Eric Sandeen <sandeen@redhat.com>
+ *
+ * cvtnum routine taken from xfsprogs,
+ * Copyright (c) 2003-2005 Silicon Graphics, Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#define _GNU_SOURCE
+#define _LARGEFILE_SOURCE
+#define _LARGEFILE64_SOURCE
+
+#include <sys/stat.h>
+#include <sys/syscall.h>
+#include <sys/types.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <ctype.h>
+
+// #include <linux/falloc.h>
+#define FALLOC_FL_KEEP_SIZE    0x01
+
+void usage(void)
+{
+       printf("Usage: fallocate [-n] [-o offset] -l length filename\n");
+       exit(EXIT_FAILURE);
+}
+
+#define EXABYTES(x)     ((long long)(x) << 60)
+#define PETABYTES(x)    ((long long)(x) << 50)
+#define TERABYTES(x)    ((long long)(x) << 40)
+#define GIGABYTES(x)    ((long long)(x) << 30)
+#define MEGABYTES(x)    ((long long)(x) << 20)
+#define KILOBYTES(x)    ((long long)(x) << 10)
+
+long long
+cvtnum(char *s)
+{
+       long long       i;
+       char            *sp;
+       int             c;
+
+       i = strtoll(s, &sp, 0);
+       if (i == 0 && sp == s)
+               return -1LL;
+       if (*sp == '\0')
+               return i;
+       if (sp[1] != '\0')
+               return -1LL;
+
+       c = tolower(*sp);
+       switch (c) {
+       case 'k':
+               return KILOBYTES(i);
+       case 'm':
+               return MEGABYTES(i);
+       case 'g':
+               return GIGABYTES(i);
+       case 't':
+               return TERABYTES(i);
+       case 'p':
+               return PETABYTES(i);
+       case 'e':
+               return  EXABYTES(i);
+       }
+
+       return -1LL;
+}
+
+int main(int argc, char **argv)
+{
+       int     fd;
+       char    *fname;
+       int     opt;
+       loff_t  length = -2LL;
+       loff_t  offset = 0;
+       int     falloc_mode = 0;
+       int     error;
+
+       while ((opt = getopt(argc, argv, "nl:o:")) != -1) {
+               switch(opt) {
+               case 'n':
+                       /* do not change filesize */
+                       falloc_mode = FALLOC_FL_KEEP_SIZE;
+                       break;
+               case 'l':
+                       length = cvtnum(optarg);
+                       break;
+               case 'o':
+                       offset = cvtnum(optarg);
+                       break;
+               default:
+                       usage();
+               }
+       }
+
+       if (length == -2LL) {
+               printf("Error: no length argument specified\n");
+               usage();
+       }
+
+       if (length <= 0) {
+               printf("Error: invalid length value specified\n");
+               usage();
+       }
+
+       if (offset < 0) {
+               printf("Error: invalid offset value specified\n");
+               usage();
+       }
+
+       if (optind == argc) {
+               printf("Error: no filename specified\n");
+               usage();
+       }
+
+       fname = argv[optind++];
+
+       /* Should we create the file if it doesn't already exist? */
+       fd = open(fname, O_WRONLY|O_DIRECTORY);
+       if (fd < 0) {
+               perror("Error opening file");
+               exit(EXIT_FAILURE);
+       }
+
+       error = syscall(SYS_fallocate, fd, falloc_mode, offset, length);
+
+       if (error < 0) {
+               perror("fallocate failed");
+               exit(EXIT_FAILURE);
+       }
+
+       close(fd);
+       return 0;
+}