mkswap: avoid mkswap usage on already mounted device

Signed-off-by: Karel Zak <kzak@redhat.com>

diff --git a/disk-utils/mkswap.c b/disk-utils/mkswap.c
index d53f07ef6db2342f55b34e3259ff3cb7062473d4..1fc18340618164ae3c7b865a35ccd2e35b2406bc 100644 (file)
--- a/disk-utils/mkswap.c
+++ b/disk-utils/mkswap.c
@@ -36,6 +36,7 @@
 #include <string.h>
 #include <fcntl.h>
 #include <stdlib.h>
+#include <mntent.h>
 #include <sys/ioctl.h>         /* for _IO */
 #include <sys/utsname.h>
 #include <sys/stat.h>
@@ -476,6 +477,29 @@ isnzdigit(char c) {
        return (c >= '1' && c <= '9');
 }
 
+
+/*
+ * Check to make certain that our new filesystem won't be created on
+ * an already mounted partition.  Code adapted from mke2fs, Copyright
+ * (C) 1994 Theodore Ts'o.  Also licensed under GPL.
+ * (C) 2006 Karel Zak -- port to mkswap
+ */
+static int
+check_mount(void) {
+       FILE * f;
+       struct mntent * mnt;
+
+       if ((f = setmntent (MOUNTED, "r")) == NULL)
+               return 0;
+       while ((mnt = getmntent (f)) != NULL)
+               if (strcmp (device_name, mnt->mnt_fsname) == 0)
+                       break;
+       endmntent (f);
+       if (!mnt)
+               return 0;
+       return 1;
+}
+
 int
 main(int argc, char ** argv) {
        struct stat statbuf;
@@ -639,8 +663,19 @@ main(int argc, char ** argv) {
        /* Want a block device. Probably not /dev/hda or /dev/hdb. */
        if (!S_ISBLK(statbuf.st_mode))
                check=0;
-       else if (statbuf.st_rdev == 0x0300 || statbuf.st_rdev == 0x0340)
-               die(_("Will not try to make swapdevice on '%s'"));
+       else if (statbuf.st_rdev == 0x0300 || statbuf.st_rdev == 0x0340) {
+               fprintf(stderr,
+                       _("%s: error: "
+                         "will not try to make swapdevice on '%s'\n"),
+                       program_name, device_name);
+               exit(1);
+       } else if (check_mount()) {
+               fprintf(stderr,
+                       _("%s: error: "
+                         "%s is mounted; will not make swapspace.\n"),
+                       program_name, device_name);
+               exit(1);
+       }
 
 #ifdef __sparc__
        if (!force && version == 0) {