diff options
| -rw-r--r-- | lib/lib.c | 10 | ||||
| -rw-r--r-- | lib/lib.h | 1 | ||||
| -rw-r--r-- | toys/mkswap.c | 42 |
3 files changed, 53 insertions, 0 deletions
@@ -266,6 +266,16 @@ void xwrite(int fd, void *buf, size_t len) if (len != writeall(fd, buf, len)) perror_exit("xwrite"); } +// Die if lseek fails, probably due to being called on a pipe. + +off_t xlseek(int fd, off_t offset, int whence) +{ + offset = lseek(fd, offset, whence); + if (offset<0) perror_exit("lseek"); + + return offset; +} + char *xgetcwd(void) { char *buf = getcwd(NULL, 0); @@ -73,6 +73,7 @@ ssize_t writeall(int fd, void *buf, size_t len); size_t xread(int fd, void *buf, size_t len); void xreadall(int fd, void *buf, size_t len); void xwrite(int fd, void *buf, size_t len); +off_t xlseek(int fd, off_t offset, int whence); char *readfile(char *name); char *xreadfile(char *name); char *xgetcwd(void); diff --git a/toys/mkswap.c b/toys/mkswap.c new file mode 100644 index 00000000..f902efeb --- /dev/null +++ b/toys/mkswap.c @@ -0,0 +1,42 @@ +/* vi: set sw=4 ts=4: + * + * mkswap.c - Format swap device. + * + * Copyright 2009 Rob Landley <rob@landley.net> + * + * Not in SUSv3. + +USE_MKSWAP(NEWTOY(mkswap, "<1>2", TOYFLAG_SBIN)) + +config MKSWAP + bool "mkswap" + default y + help + usage: mkswap DEVICE + + Format a Linux v1 swap device. +*/ + +#include "toys.h" + +void mkswap_main(void) +{ + int fd = xopen(*toys.optargs, O_RDWR), pagesize = getpagesize(); + off_t len = fdlength(fd); + unsigned int pages = (len/pagesize)-1, *swap = (unsigned int *)toybuf; + + // 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); + 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); + + printf("Swapspace size: %luk\n", pages*(unsigned long)(pagesize/1024)); +} |