libmount: FS id and parent ID could be zero

It seems that linux 3.14 is able to produce things like:

  19 0 8:3 / / rw,relatime - ext4 /dev/sda3 rw,data=ordered
     ^

Reported-by: Mantas Mikulėnas <grawity@gmail.com>
Signed-off-by: Karel Zak <kzak@redhat.com>

diff --git a/libmount/src/tab.c b/libmount/src/tab.c
index 4c2f8a4ace5b5013c4b0adb450b1c60c50d7c042..332312b681b998c1cc4afacfd9637d63728f85f5 100644 (file)
--- a/libmount/src/tab.c
+++ b/libmount/src/tab.c
@@ -505,7 +505,7 @@ int mnt_table_get_root_fs(struct libmnt_table *tb, struct libmnt_fs **root)
        assert(tb);
        assert(root);
 
-       if (!tb || !root)
+       if (!tb || !root || !is_mountinfo(tb))
                return -EINVAL;
 
        DBG(TAB, mnt_debug_h(tb, "lookup root fs"));
@@ -515,8 +515,6 @@ int mnt_table_get_root_fs(struct libmnt_table *tb, struct libmnt_fs **root)
        mnt_reset_iter(&itr, MNT_ITER_FORWARD);
        while(mnt_table_next_fs(tb, &itr, &fs) == 0) {
                int id = mnt_fs_get_parent_id(fs);
-               if (!id)
-                       break;          /* @tab is not a mountinfo file? */
 
                if (!*root || id < root_id) {
                        *root = fs;
@@ -524,7 +522,7 @@ int mnt_table_get_root_fs(struct libmnt_table *tb, struct libmnt_fs **root)
                }
        }
 
-       return root_id ? 0 : -EINVAL;
+       return *root ? 0 : -EINVAL;
 }
 
 /**
@@ -545,15 +543,13 @@ int mnt_table_next_child_fs(struct libmnt_table *tb, struct libmnt_iter *itr,
        struct libmnt_fs *fs;
        int parent_id, lastchld_id = 0, chld_id = 0;
 
-       if (!tb || !itr || !parent)
+       if (!tb || !itr || !parent || !is_mountinfo(tb))
                return -EINVAL;
 
        DBG(TAB, mnt_debug_h(tb, "lookup next child of '%s'",
                                mnt_fs_get_target(parent)));
 
        parent_id = mnt_fs_get_id(parent);
-       if (!parent_id)
-               return -EINVAL;
 
        /* get ID of the previously returned child */
        if (itr->head && itr->p != itr->head) {
@@ -584,7 +580,7 @@ int mnt_table_next_child_fs(struct libmnt_table *tb, struct libmnt_iter *itr,
                }
        }
 
-       if (!chld_id)
+       if (!*chld)
                return 1;       /* end of iterator */
 
        /* set the iterator to the @chld for the next call */

diff --git a/misc-utils/findmnt.c b/misc-utils/findmnt.c
index fb21174ef9384e5aaf72d8e6b1e273adf53e9e17..988cd73970853ce3caf41ff19a0faf941cfe8d30 100644 (file)
--- a/misc-utils/findmnt.c
+++ b/misc-utils/findmnt.c
@@ -822,8 +822,9 @@ static int tab_is_tree(struct libmnt_table *tb)
        if (!itr)
                return 0;
 
-       if (mnt_table_next_fs(tb, itr, &fs) == 0)
-               rc = mnt_fs_get_id(fs) > 0 && mnt_fs_get_parent_id(fs) > 0;
+       rc = (mnt_table_next_fs(tb, itr, &fs) == 0 &&
+             mnt_fs_is_kernel(fs) &&
+             mnt_fs_get_root(fs));
 
        mnt_free_iter(itr);
        return rc;