Skip calling mount(8) if /etc/mtab doesn't exist...

diff --git a/ChangeLog b/ChangeLog
index 638dd3cb4a11b2e2a27f4a9e487800dea9876134..4f5656685cf23d2921cb317282aa4c869dca4d82 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -3,6 +3,10 @@
        * Fix handling of (no)suid and (no)dev options if filesystem is
        mounted from /etc/fstab or via mount(8).  Reported by Jan Ondrej.
 
+       * Skip calling mount(8) if /etc/mtab doesn't exist or if it's on a
+       read-only filesystem.  This works around issues with certain mount
+       implementations.  Reported by Szabolcs Szakacsits.
+
 2008-06-16  Miklos Szeredi <miklos@szeredi.hu>
 
        * Remove fuse kernel module sources.  Linux 2.6.27 will support

diff --git a/lib/mount_util.c b/lib/mount_util.c
index 7db8060b11d4c07701da4cf4a4ea5a58738a50f1..e78b4820ff38537b6c708270e7ddfa3851778646 100644 (file)
--- a/lib/mount_util.c
+++ b/lib/mount_util.c
@@ -22,6 +22,7 @@
 
 static int mtab_needs_update(const char *mnt)
 {
+       int res;
        struct stat stbuf;
 
        /* If mtab is within new mount, don't touch it */
@@ -29,8 +30,25 @@ static int mtab_needs_update(const char *mnt)
            _PATH_MOUNTED[strlen(mnt)] == '/')
                return 0;
 
-       if (lstat(_PATH_MOUNTED, &stbuf) != -1 && S_ISLNK(stbuf.st_mode))
-               return 0;
+       /*
+        * Skip mtab update if /etc/mtab:
+        *
+        *  - doesn't exist,
+        *  - is a symlink,
+        *  - is on a read-only filesystem.
+        */
+       res = lstat(_PATH_MOUNTED, &stbuf);
+       if (res == -1) {
+               if (errno == ENOENT)
+                       return 0;
+       } else {
+               if (S_ISLNK(stbuf.st_mode))
+                       return 0;
+
+               res = access(_PATH_MOUNTED, W_OK);
+               if (res == -1 && errno == EROFS)
+                       return 0;
+       }
 
        return 1;
 }