Ban ecryptfs over ecryptfs

[deliverable/linux.git] / fs / ecryptfs / main.c

diff --git a/fs/ecryptfs/main.c b/fs/ecryptfs/main.c
index 7d3ed6bfcfa55d16c6cb9764aaded383a6a5fff7..cbd4e18adb204438d45b865469d38b7af97a9904 100644 (file)
--- a/fs/ecryptfs/main.c
+++ b/fs/ecryptfs/main.c
@@ -483,6 +483,7 @@ out:
 }
 
 struct kmem_cache *ecryptfs_sb_info_cache;
+static struct file_system_type ecryptfs_fs_type;
 
 /**
  * ecryptfs_read_super
@@ -503,6 +504,13 @@ static int ecryptfs_read_super(struct super_block *sb, const char *dev_name)
                ecryptfs_printk(KERN_WARNING, "path_lookup() failed\n");
                goto out;
        }
+       if (path.dentry->d_sb->s_type == &ecryptfs_fs_type) {
+               rc = -EINVAL;
+               printk(KERN_ERR "Mount on filesystem of type "
+                       "eCryptfs explicitly disallowed due to "
+                       "known incompatibilities\n");
+               goto out_free;
+       }
        ecryptfs_set_superblock_lower(sb, path.dentry->d_sb);
        sb->s_maxbytes = path.dentry->d_sb->s_maxbytes;
        sb->s_blocksize = path.dentry->d_sb->s_blocksize;