am 450c4ad0: am 16068830: Merge "toolbox: enable mkswap to work on block devices"

#include <fcntl.h>

#include <linux/fs.h>

#include <stdio.h>

#include <stdlib.h>

#include <unistd.h>

#include <sys/stat.h>

#include <sys/swap.h>

#include <sys/types.h>

#include <sys/stat.h>

#include <fcntl.h>

/* XXX This needs to be obtained from kernel headers. See b/9336527 */

/* This is not in a uapi header. */

struct linux_swap_header {

    char            bootbits[1024]; /* Space for disklabel etc. */

    uint32_t        version;

int mkswap_main(int argc, char **argv)

{

    int err = 0;

    int fd;

    ssize_t len;

    off_t swap_size;

    int pagesize;

    struct linux_swap_header sw_hdr;

    if (argc != 2) {

        fprintf(stderr, "Usage: %s <filename>\n", argv[0]);

        return -EINVAL;

        return EXIT_FAILURE;

    }

    fd = open(argv[1], O_WRONLY);

    int fd = open(argv[1], O_RDWR);

    if (fd < 0) {

        err = errno;

        fprintf(stderr, "Cannot open %s\n", argv[1]);

        return err;

        fprintf(stderr, "Cannot open %s: %s\n", argv[1], strerror(errno));

        return EXIT_FAILURE;

    }

    pagesize = getpagesize();

    /* Determine the length of the swap file */

    swap_size = lseek(fd, 0, SEEK_END);

    if (swap_size < MIN_PAGES * pagesize) {

        fprintf(stderr, "Swap file needs to be at least %dkB\n",

            (MIN_PAGES * pagesize) >> 10);

        err = -ENOSPC;

        goto err;

    off64_t swap_size;

    struct stat sb;

    if (fstat(fd, &sb)) {

        fprintf(stderr, "Couldn't fstat file: %s\n", strerror(errno));

        return EXIT_FAILURE;

    }

    if (lseek(fd, 0, SEEK_SET)) {

        err = errno;

        fprintf(stderr, "Can't seek to the beginning of the file\n");

        goto err;

    if (S_ISBLK(sb.st_mode)) {

        if (ioctl(fd, BLKGETSIZE64, &swap_size) < 0) {

            fprintf(stderr, "Couldn't determine block device size: %s\n", strerror(errno));

            return EXIT_FAILURE;

        }

    } else {

        swap_size = sb.st_size;

    }

    int pagesize = getpagesize();

    if (swap_size < MIN_PAGES * pagesize) {

        fprintf(stderr, "Swap file needs to be at least %d KiB\n", (MIN_PAGES * pagesize) >> 10);

        return EXIT_FAILURE;

    }

    struct linux_swap_header sw_hdr;

    memset(&sw_hdr, 0, sizeof(sw_hdr));

    sw_hdr.version = 1;

    sw_hdr.last_page = (swap_size / pagesize) - 1;

    len = write(fd, &sw_hdr, sizeof(sw_hdr));

    ssize_t len = write(fd, &sw_hdr, sizeof(sw_hdr));

    if (len != sizeof(sw_hdr)) {

        err = errno;

        fprintf(stderr, "Failed to write swap header into %s\n", argv[1]);

        goto err;

        fprintf(stderr, "Failed to write swap header into %s: %s\n", argv[1], strerror(errno));

        return EXIT_FAILURE;

    }

    /* Write the magic header */

    if (lseek(fd, pagesize - MAGIC_SWAP_HEADER_LEN, SEEK_SET) < 0) {

        err = errno;

        fprintf(stderr, "Failed to seek into %s\n", argv[1]);

        goto err;

        fprintf(stderr, "Failed to seek into %s: %s\n", argv[1], strerror(errno));

        return EXIT_FAILURE;

    }

    len = write(fd, MAGIC_SWAP_HEADER, MAGIC_SWAP_HEADER_LEN);

    if (len != MAGIC_SWAP_HEADER_LEN) {

        err = errno;

        fprintf(stderr, "Failed to write magic swap header into %s\n", argv[1]);

        goto err;

        fprintf(stderr, "Failed to write magic swap header into %s: %s\n", argv[1], strerror(errno));

        return EXIT_FAILURE;

    }

    if (fsync(fd) < 0) {

        err = errno;

        fprintf(stderr, "Failed to sync %s\n", argv[1]);

        goto err;

        fprintf(stderr, "Failed to sync %s: %s\n", argv[1], strerror(errno));

        return EXIT_FAILURE;

    }

err:

    close(fd);

    return err;

    return EXIT_SUCCESS;

}