ecryptfs: make show_options reflect actual mount options

Change ecryptfs_show_options to reflect the actual mount options in use.
Note that this does away with the "dir=" output, which is not a valid mount
option and appears to be unused.

Mount options such as "ecryptfs_verbose" and "ecryptfs_xattr_metadata" are
somewhat indeterminate for a given fs, but in any case the reported mount
options can be used in a new mount command to get the same behavior.

[akpm@linux-foundation.org: fix printk warning]
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Acked-by: Michael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 31 insertions, 21 deletions

diff --git a/fs/ecryptfs/super.c b/fs/ecryptfs/super.c
index 4859c4eecd65..0556604e8dc2 100644
--- a/fs/ecryptfs/super.c
+++ b/fs/ecryptfs/super.c
@@ -156,32 +156,42 @@ static void ecryptfs_clear_inode(struct inode *inode)
 /**
  * ecryptfs_show_options
  *
- * Prints the directory we are currently mounted over.
- * Returns zero on success; non-zero otherwise
+ * Prints the mount options for a given superblock.
+ * Returns zero; does not fail.
  */
 static int ecryptfs_show_options(struct seq_file *m, struct vfsmount *mnt)
 {
         struct super_block *sb = mnt->mnt_sb;
-        struct dentry *lower_root_dentry = ecryptfs_dentry_to_lower(sb->s_root);
-        struct vfsmount *lower_mnt = ecryptfs_dentry_to_lower_mnt(sb->s_root);
-        char *tmp_page;
-        char *path;
-        int rc = 0;
-
-        tmp_page = (char *)__get_free_page(GFP_KERNEL);
-        if (!tmp_page) {
-                rc = -ENOMEM;
-                goto out;
-        }
-        path = d_path(lower_root_dentry, lower_mnt, tmp_page, PAGE_SIZE);
-        if (IS_ERR(path)) {
-                rc = PTR_ERR(path);
-                goto out;
+        struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
+                &ecryptfs_superblock_to_private(sb)->mount_crypt_stat;
+        struct ecryptfs_global_auth_tok *walker;
+
+        mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex);
+        list_for_each_entry(walker,
+                            &mount_crypt_stat->global_auth_tok_list,
+                            mount_crypt_stat_list) {
+                seq_printf(m, ",ecryptfs_sig=%s", walker->sig);
         }
-        seq_printf(m, ",dir=%s", path);
-        free_page((unsigned long)tmp_page);
-out:
-        return rc;
+        mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex);
+
+        /* Note this is global and probably shouldn't be a mount option */
+        if (ecryptfs_verbosity)
+                seq_printf(m, ",ecryptfs_debug=%d\n", ecryptfs_verbosity);
+
+        seq_printf(m, ",ecryptfs_cipher=%s",
+                mount_crypt_stat->global_default_cipher_name);
+
+        if (mount_crypt_stat->global_default_cipher_key_size)
+                seq_printf(m, ",ecryptfs_key_bytes=%zd",
+                           mount_crypt_stat->global_default_cipher_key_size);
+        if (mount_crypt_stat->flags & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED)
+                seq_printf(m, ",ecryptfs_passthrough");
+        if (mount_crypt_stat->flags & ECRYPTFS_XATTR_METADATA_ENABLED)
+                seq_printf(m, ",ecryptfs_xattr_metadata");
+        if (mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED)
+                seq_printf(m, ",ecryptfs_encrypted_view");
+
+        return 0;
 }
 
 const struct super_operations ecryptfs_sops = {