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/* mkswap.c - Format swap device.
*
* Copyright 2009 Rob Landley <rob@landley.net>
USE_MKSWAP(NEWTOY(mkswap, "<1>1L:", TOYFLAG_SBIN))
config MKSWAP
bool "mkswap"
default y
help
usage: mkswap [-L LABEL] DEVICE
Set up a Linux swap area on a device or file.
*/
#define FOR_mkswap
#include "toys.h"
GLOBALS(
char *L;
)
void mkswap_main(void)
{
int fd = xopen(*toys.optargs, O_RDWR), pagesize = sysconf(_SC_PAGE_SIZE);
off_t len = fdlength(fd);
unsigned int pages = (len/pagesize)-1, *swap = (unsigned int *)toybuf;
char *label = (char *)(swap+7), *uuid = (char *)(swap+3);
// Write header. Note that older kernel versions checked signature
// on disk (not in cache) during swapon, so sync after writing.
swap[0] = 1;
swap[1] = pages;
xlseek(fd, 1024, SEEK_SET);
create_uuid(uuid);
if (TT.L) strncpy(label, TT.L, 15);
xwrite(fd, swap, 129*sizeof(unsigned int));
xlseek(fd, pagesize-10, SEEK_SET);
xwrite(fd, "SWAPSPACE2", 10);
fsync(fd);
if (CFG_TOYBOX_FREE) close(fd);
if (TT.L) sprintf(toybuf, ", LABEL=%s", label);
else *toybuf = 0;
printf("Swapspace size: %luk%s, UUID=%s\n",
pages*(unsigned long)(pagesize/1024),
toybuf, show_uuid(uuid));
}
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