Merge tag 'mvebu-dt-fixes-3.15-2' of git://git.infradead.org/linux-mvebu into fixes

[cascardo/linux.git] / fs / kernfs / mount.c

diff --git a/fs/kernfs/mount.c b/fs/kernfs/mount.c
index 0f4152d..6a5f04a 100644 (file)
--- a/fs/kernfs/mount.c
+++ b/fs/kernfs/mount.c
@@ -19,12 +19,49 @@
 
 struct kmem_cache *kernfs_node_cache;
 
-static const struct super_operations kernfs_sops = {
+static int kernfs_sop_remount_fs(struct super_block *sb, int *flags, char *data)
+{
+       struct kernfs_root *root = kernfs_info(sb)->root;
+       struct kernfs_syscall_ops *scops = root->syscall_ops;
+
+       if (scops && scops->remount_fs)
+               return scops->remount_fs(root, flags, data);
+       return 0;
+}
+
+static int kernfs_sop_show_options(struct seq_file *sf, struct dentry *dentry)
+{
+       struct kernfs_root *root = kernfs_root(dentry->d_fsdata);
+       struct kernfs_syscall_ops *scops = root->syscall_ops;
+
+       if (scops && scops->show_options)
+               return scops->show_options(sf, root);
+       return 0;
+}
+
+const struct super_operations kernfs_sops = {
        .statfs         = simple_statfs,
        .drop_inode     = generic_delete_inode,
        .evict_inode    = kernfs_evict_inode,
+
+       .remount_fs     = kernfs_sop_remount_fs,
+       .show_options   = kernfs_sop_show_options,
 };
 
+/**
+ * kernfs_root_from_sb - determine kernfs_root associated with a super_block
+ * @sb: the super_block in question
+ *
+ * Return the kernfs_root associated with @sb.  If @sb is not a kernfs one,
+ * %NULL is returned.
+ */
+struct kernfs_root *kernfs_root_from_sb(struct super_block *sb)
+{
+       if (sb->s_op == &kernfs_sops)
+               return kernfs_info(sb)->root;
+       return NULL;
+}
+
 static int kernfs_fill_super(struct super_block *sb)
 {
        struct kernfs_super_info *info = kernfs_info(sb);