ismounted.c (check_mntent_file): Stat all of the entries in

	/etc/mtab and/or /proc/mounts in order to catch dim-witted
	system administrators who might have created alias
	devices.

diff --git a/lib/ext2fs/ChangeLog b/lib/ext2fs/ChangeLog
index 28a3a15f1b4b73be8c440dc26151be664d6e1fe3..7338ee0f02c817f7cd5a501cf56c9d8503dcc2dd 100644 (file)
--- a/lib/ext2fs/ChangeLog
+++ b/lib/ext2fs/ChangeLog
@@ -1,3 +1,10 @@
+2001-12-24  Theodore Tso  <tytso@valinux.com>
+
+       * ismounted.c (check_mntent_file): Stat all of the entries in
+               /etc/mtab and/or /proc/mounts in order to catch dim-witted
+               system administrators who might have created alias
+               devices.
+ 
 2001-12-23  Theodore Tso  <tytso@valinux.com>
 
        * Makefile.in, jfs_user.h: Move linux/jbd.h to

diff --git a/lib/ext2fs/ismounted.c b/lib/ext2fs/ismounted.c
index 1b145c663fefbbe8311993b7e98acd8da63c48b3..8364401f4b6142c7c10506138ec957984e85a6e4 100644 (file)
--- a/lib/ext2fs/ismounted.c
+++ b/lib/ext2fs/ismounted.c
@@ -44,17 +44,29 @@ static errcode_t check_mntent_file(const char *mtab_file, const char *file,
                                   int *mount_flags, char *mtpt, int mtlen)
 {
        struct mntent   *mnt;
-       struct stat     st_mntpnt, st_file;
+       struct stat     st_buf;
        errcode_t       retval = 0;
+       dev_t           file_dev;
        FILE            *f;
        int             fd;
 
        *mount_flags = 0;
        if ((f = setmntent (mtab_file, "r")) == NULL)
                return errno;
-       while ((mnt = getmntent (f)) != NULL)
+       file_dev = 0;
+#ifndef __GNU__ /* The GNU hurd is broken with respect to stat devices */
+       if (stat(file, &st_buf) == 0)
+               file_dev = st_buf.st_rdev;
+#endif 
+       while ((mnt = getmntent (f)) != NULL) {
                if (strcmp(file, mnt->mnt_fsname) == 0)
                        break;
+#ifndef __GNU__
+               if (file_dev && (stat(mnt->mnt_fsname, &st_buf) == 0) &&
+                   file_dev == st_buf.st_rdev)
+                       break;
+#endif
+       }
 
        if (mnt == 0) {
 #ifndef __GNU__ /* The GNU hurd is broken with respect to stat devices */
@@ -65,8 +77,8 @@ static errcode_t check_mntent_file(const char *mtab_file, const char *file,
                 * check if the given device has the same major/minor number
                 * as the device that the root directory is on.
                 */
-               if (stat("/", &st_mntpnt) == 0 && stat(file, &st_file) == 0) {
-                       if (st_mntpnt.st_dev == st_file.st_rdev) {
+               if (file_dev && stat("/", &st_buf) == 0) {
+                       if (st_buf.st_dev == file_dev) {
                                *mount_flags = EXT2_MF_MOUNTED;
                                if (mtpt)
                                        strncpy(mtpt, "/", mtlen);
@@ -83,7 +95,7 @@ static errcode_t check_mntent_file(const char *mtab_file, const char *file,
         * (read: Slackware) don't initialize /etc/mtab before checking
         * all of the non-root filesystems on the disk.
         */
-       if (stat(mnt->mnt_dir, &st_mntpnt) < 0) {
+       if (stat(mnt->mnt_dir, &st_buf) < 0) {
                retval = errno;
                if (retval == ENOENT) {
 #ifdef DEBUG
@@ -94,14 +106,12 @@ static errcode_t check_mntent_file(const char *mtab_file, const char *file,
                }
                goto exit;
        }
-       if (stat(file, &st_file) == 0) {
-               if (st_mntpnt.st_dev != st_file.st_rdev) {
+       if (file_dev && (st_buf.st_dev != file_dev)) {
 #ifdef DEBUG
-                       printf("Bogus entry in %s!  (%s not mounted on %s)\n",
-                              mtab_file, file, mnt->mnt_dir);
+               printf("Bogus entry in %s!  (%s not mounted on %s)\n",
+                      mtab_file, file, mnt->mnt_dir);
 #endif
-                       goto exit;
-               }
+               goto exit;
        }
 #endif
        *mount_flags = EXT2_MF_MOUNTED;
@@ -234,13 +244,16 @@ errcode_t ext2fs_check_if_mounted(const char *file, int *mount_flags)
 int main(int argc, char **argv)
 {
        int     retval, mount_flags;
+       char    mntpt[80];
        
        if (argc < 2) {
                fprintf(stderr, "Usage: %s device\n", argv[0]);
                exit(1);
        }
 
-       retval = ext2fs_check_if_mounted(argv[1], &mount_flags);
+       mntpt[0] = 0;
+       retval = ext2fs_check_mount_point(argv[1], &mount_flags,
+                                         mntpt, sizeof(mntpt));
        if (retval) {
                com_err(argv[0], retval,
                        "while calling ext2fs_check_if_mounted");
@@ -255,6 +268,8 @@ int main(int argc, char **argv)
        
        if (mount_flags & EXT2_MF_ISROOT)
                printf("\t%s is the root filesystem.\n", argv[1]);
+       if (mntpt[0])
+               printf("\t%s is mounted on %s.\n", argv[1], mntpt);
        
        exit(0);
 }