[git commit master] mkswap: add -L LABEL option. closes bug 689.
Denys Vlasenko
vda.linux at googlemail.com
Tue Nov 3 04:51:20 UTC 2009
commit: http://git.busybox.net/busybox/commit/?id=68c67469aabe112cc0ef90bd87700370d96a4085
branch: http://git.busybox.net/busybox/commit/?id=refs/heads/master
Signed-off-by: Denys Vlasenko <vda.linux at googlemail.com>
---
include/usage.h | 14 ++-----
util-linux/mkswap.c | 92 +++++++++++++++++++++++++-------------------------
2 files changed, 50 insertions(+), 56 deletions(-)
diff --git a/include/usage.h b/include/usage.h
index f703e32..0d01577 100644
--- a/include/usage.h
+++ b/include/usage.h
@@ -2815,17 +2815,11 @@
"$ mknod -m 644 /tmp/pipe p\n"
#define mkswap_trivial_usage \
- "DEVICE"
+ "[OPTIONS] BLOCKDEV" /* [SIZE_IN_KB] */
#define mkswap_full_usage "\n\n" \
- "Prepare block device to be used as swap partition"
-#if 0
- "[-c] [-v0|-v1] DEVICE [BLOCKS]"
- "\nOptions:"
- "\n -c Check for readability"
- "\n -v0 Make swap version 0 (max 128M)"
- "\n -v1 Make swap version 1 (default for kernels > 2.1.117)"
- "\n BLOCKS Number of blocks to use (default is entire partition)"
-#endif
+ "Prepare BLOCKDEV to be used as swap partition\n" \
+ "\nOptions:" \
+ "\n -L LBL Label" \
#define mktemp_trivial_usage \
"[-dt] [-p DIR] [TEMPLATE]"
diff --git a/util-linux/mkswap.c b/util-linux/mkswap.c
index 2f7827d..289692d 100644
--- a/util-linux/mkswap.c
+++ b/util-linux/mkswap.c
@@ -50,72 +50,70 @@ static void mkswap_selinux_setcontext(int fd, const char *path)
# define mkswap_selinux_setcontext(fd, path) ((void)0)
#endif
-#if 0 /* from Linux 2.6.23 */
+/* from Linux 2.6.23 */
/*
- * Magic header for a swap area. The first part of the union is
- * what the swap magic looks like for the old (limited to 128MB)
- * swap area format, the second part of the union adds - in the
- * old reserved area - some extra information. Note that the first
- * kilobyte is reserved for boot loader or disk label stuff...
+ * Magic header for a swap area. ... Note that the first
+ * kilobyte is reserved for boot loader or disk label stuff.
*/
-union swap_header {
- struct {
- char reserved[PAGE_SIZE - 10];
- char magic[10]; /* SWAP-SPACE or SWAPSPACE2 */
- } magic;
- struct {
- char bootbits[1024]; /* Space for disklabel etc. */
- __u32 version; /* second kbyte, word 0 */
- __u32 last_page; /* 1 */
- __u32 nr_badpages; /* 2 */
- unsigned char sws_uuid[16]; /* 3,4,5,6 */
- unsigned char sws_volume[16]; /* 7,8,9,10 */
- __u32 padding[117]; /* 11..127 */
- __u32 badpages[1]; /* 128, total 129 32-bit words */
- } info;
+struct swap_header_v1 {
+/* char bootbits[1024]; Space for disklabel etc. */
+ uint32_t version; /* second kbyte, word 0 */
+ uint32_t last_page; /* 1 */
+ uint32_t nr_badpages; /* 2 */
+ char sws_uuid[16]; /* 3,4,5,6 */
+ char sws_volume[16]; /* 7,8,9,10 */
+ uint32_t padding[117]; /* 11..127 */
+ uint32_t badpages[1]; /* 128 */
+ /* total 129 32-bit words in 2nd kilobyte */
};
-#endif
#define NWORDS 129
-#define hdr ((uint32_t*)(&bb_common_bufsiz1))
+#define hdr ((struct swap_header_v1*)bb_common_bufsiz1)
-struct BUG_bufsiz1_is_too_small {
- char BUG_bufsiz1_is_too_small[COMMON_BUFSIZE < (NWORDS * 4) ? -1 : 1];
+struct BUG_sizes {
+ char swap_header_v1_wrong[sizeof(*hdr) != (NWORDS * 4) ? -1 : 1];
+ char bufsiz1_is_too_small[COMMON_BUFSIZE < (NWORDS * 4) ? -1 : 1];
};
/* Stored without terminating NUL */
static const char SWAPSPACE2[sizeof("SWAPSPACE2")-1] ALIGN1 = "SWAPSPACE2";
int mkswap_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
-int mkswap_main(int argc, char **argv)
+int mkswap_main(int argc UNUSED_PARAM, char **argv)
{
- int fd, pagesize;
+ int fd;
+ unsigned pagesize;
off_t len;
+ const char *label = "";
- // No options supported.
-
- if (argc != 2) bb_show_usage();
+ opt_complementary = "=1";
+ /* TODO: -p PAGESZ, -U UUID,
+ * optional SIZE_IN_KB 2nd param
+ */
+ getopt32(argv, "L:", &label);
+ argv += optind;
- // Figure out how big the device is and announce our intentions.
+ fd = xopen(argv[0], O_WRONLY);
- fd = xopen(argv[1], O_RDWR);
+ /* Figure out how big the device is and announce our intentions */
/* fdlength was reported to be unreliable - use seek */
len = xlseek(fd, 0, SEEK_END);
-#if ENABLE_SELINUX
- xlseek(fd, 0, SEEK_SET);
-#endif
+ if (ENABLE_SELINUX)
+ xlseek(fd, 0, SEEK_SET);
+
pagesize = getpagesize();
- printf("Setting up swapspace version 1, size = %"OFF_FMT"u bytes\n",
- len - pagesize);
- mkswap_selinux_setcontext(fd, argv[1]);
+ len -= pagesize;
+ printf("Setting up swapspace version 1, size = %"OFF_FMT"u bytes\n", len);
+ mkswap_selinux_setcontext(fd, argv[0]);
+
+ /* Make a header. hdr is zero-filled so far... */
+ hdr->version = 1;
+ hdr->last_page = (uoff_t)len / pagesize;
- // Make a header. hdr is zero-filled so far...
- hdr[0] = 1;
- hdr[1] = (len / pagesize) - 1;
if (ENABLE_FEATURE_MKSWAP_UUID) {
char uuid_string[32];
- generate_uuid((void*) &hdr[3]);
- bin2hex(uuid_string, (void*) &hdr[3], 16);
+ generate_uuid((void*)hdr->sws_uuid);
+ bin2hex(uuid_string, hdr->sws_uuid, 16);
/* f.e. UUID=dfd9c173-be52-4d27-99a5-c34c6c2ff55f */
printf("UUID=%.8s" "-%.4s-%.4s-%.4s-%.12s\n",
uuid_string,
@@ -125,16 +123,18 @@ int mkswap_main(int argc, char **argv)
uuid_string+8+4+4+4
);
}
+ safe_strncpy(hdr->sws_volume, label, 16);
- // Write the header. Sync to disk because some kernel versions check
- // signature on disk (not in cache) during swapon.
+ /* Write the header. Sync to disk because some kernel versions check
+ * signature on disk (not in cache) during swapon. */
xlseek(fd, 1024, SEEK_SET);
xwrite(fd, hdr, NWORDS * 4);
xlseek(fd, pagesize - 10, SEEK_SET);
xwrite(fd, SWAPSPACE2, 10);
fsync(fd);
- if (ENABLE_FEATURE_CLEAN_UP) close(fd);
+ if (ENABLE_FEATURE_CLEAN_UP)
+ close(fd);
return 0;
}
--
1.6.3.3
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