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/* guestfish - the filesystem interactive shell
* Copyright (C) 2009 Red Hat 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; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will 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., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <inttypes.h>
#include <errno.h>
#include "fish.h"
int
do_alloc (const char *cmd, int argc, char *argv[])
{
if (argc != 2) {
fprintf (stderr, _("use 'alloc file size' to create an image\n"));
return -1;
}
if (alloc_disk (argv[0], argv[1], 1, 0) == -1)
return -1;
return 0;
}
int
do_sparse (const char *cmd, int argc, char *argv[])
{
if (argc != 2) {
fprintf (stderr, _("use 'sparse file size' to create a sparse image\n"));
return -1;
}
if (alloc_disk (argv[0], argv[1], 1, 1) == -1)
return -1;
return 0;
}
static int parse_size (const char *str, off_t *size_rtn);
/* This is the underlying allocation function. It's called from
* a few other places in guestfish.
*/
int
alloc_disk (const char *filename, const char *size_str, int add, int sparse)
{
off_t size;
int fd;
char c = 0;
if (parse_size (size_str, &size) == -1)
return -1;
if (!guestfs_is_config (g)) {
fprintf (stderr, _("can't allocate or add disks after launching\n"));
return -1;
}
fd = open (filename, O_WRONLY|O_CREAT|O_NOCTTY|O_TRUNC, 0666);
if (fd == -1) {
perror (filename);
return -1;
}
if (!sparse) { /* Not sparse */
#ifdef HAVE_POSIX_FALLOCATE
int err = posix_fallocate (fd, 0, size);
if (err != 0) {
errno = err;
perror ("fallocate");
close (fd);
unlink (filename);
return -1;
}
#else
/* Slow emulation of posix_fallocate on platforms which don't have it. */
char buffer[BUFSIZ];
memset (buffer, 0, sizeof buffer);
size_t remaining = size;
while (remaining > 0) {
size_t n = remaining > sizeof buffer ? sizeof buffer : remaining;
ssize_t r = write (fd, buffer, n);
if (r == -1) {
perror ("write");
close (fd);
unlink (filename);
return -1;
}
remaining -= r;
}
#endif
} else { /* Sparse */
if (lseek (fd, size-1, SEEK_SET) == (off_t) -1) {
perror ("lseek");
close (fd);
unlink (filename);
return -1;
}
if (write (fd, &c, 1) != 1) {
perror ("write");
close (fd);
unlink (filename);
return -1;
}
}
if (close (fd) == -1) {
perror (filename);
unlink (filename);
return -1;
}
if (add) {
if (guestfs_add_drive (g, filename) == -1) {
unlink (filename);
return -1;
}
}
return 0;
}
static int
parse_size (const char *str, off_t *size_rtn)
{
uint64_t size;
char type;
/* Note that the parsing here is looser than what is specified in the
* help, but we may tighten it up in future so beware.
*/
if (sscanf (str, "%"SCNu64"%c", &size, &type) == 2) {
switch (type) {
case 'k': case 'K': size *= 1024ULL; break;
case 'm': case 'M': size *= 1024ULL * 1024ULL; break;
case 'g': case 'G': size *= 1024ULL * 1024ULL * 1024ULL; break;
case 't': case 'T': size *= 1024ULL * 1024ULL * 1024ULL * 1024ULL; break;
case 'p': case 'P': size *= 1024ULL * 1024ULL * 1024ULL * 1024ULL * 1024ULL; break;
case 'e': case 'E': size *= 1024ULL * 1024ULL * 1024ULL * 1024ULL * 1024ULL * 1024ULL; break;
case 's': size *= 512; break;
default:
fprintf (stderr, _("could not parse size specification '%s'\n"), str);
return -1;
}
}
else if (sscanf (str, "%"SCNu64, &size) == 1)
size *= 1024ULL;
else {
fprintf (stderr, _("could not parse size specification '%s'\n"), str);
return -1;
}
/* XXX 32 bit file offsets, if anyone uses them? GCC should give
* a warning here anyhow.
*/
*size_rtn = size;
return 0;
}
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