Merge "toolbox: enable mkswap to work on block devices"
diff --git a/toolbox/mkswap.c b/toolbox/mkswap.c
index 0904152..ad66353 100644
--- a/toolbox/mkswap.c
+++ b/toolbox/mkswap.c
@@ -1,11 +1,13 @@
+#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;
@@ -23,71 +25,67 @@
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;
}