ext2fs: Require users to opt-in for xattr-based translator records.

* ext2fs/ext2fs.c (use_xattr_translator_records): New variable.
(X_XATTR_TRANSLATOR_RECORDS): New macro.
(options): New option '--x-xattr-translator-records'.
(parse_opt): Handle new option.
* ext2fs/ext2fs.h (use_xattr_translator_records): New declaration.
* ext2fs/inode.c (diskfs_set_translator): Use new variable.
(diskfs_get_translator): Likewise.

3 files changed, 28 insertions, 2 deletions

diff --git a/ext2fs/ext2fs.c b/ext2fs/ext2fs.c
index 4f38c927..b4c865c8 100644
--- a/ext2fs/ext2fs.c
+++ b/ext2fs/ext2fs.c
@@ -63,6 +63,10 @@ pthread_spinlock_t modified_global_blocks_lock = PTHREAD_SPINLOCK_INITIALIZER;
 int ext2_debug_flag;
 #endif
 
+/* Use extended attribute-based translator records.  */
+int use_xattr_translator_records;
+#define X_XATTR_TRANSLATOR_RECORDS	-1
+
 /* Ext2fs-specific options.  */
 static const struct argp_option
 options[] =
@@ -72,6 +76,8 @@ options[] =
    " (not compiled in)"
 #endif
   },
+  {"x-xattr-translator-records", X_XATTR_TRANSLATOR_RECORDS, 0, 0,
+   "Store translator records in extended attributes (experimental)"},
 #ifdef ALTERNATE_SBLOCK
   /* XXX This is not implemented.  */
   {"sblock", 'S', "BLOCKNO", 0,
@@ -89,6 +95,7 @@ parse_opt (int key, char *arg, struct argp_state *state)
   struct
   {
     int debug_flag;
+    int use_xattr_translator_records;
 #ifdef ALTERNATE_SBLOCK
     unsigned int sb_block;
 #endif
@@ -99,6 +106,9 @@ parse_opt (int key, char *arg, struct argp_state *state)
     case 'D':
       values->debug_flag = 1;
       break;
+    case X_XATTR_TRANSLATOR_RECORDS:
+      values->use_xattr_translator_records = 1;
+      break;
 #ifdef ALTERNATE_SBLOCK
     case 'S':
       values->sb_block = strtoul (arg, &arg, 0);
@@ -134,6 +144,7 @@ parse_opt (int key, char *arg, struct argp_state *state)
 #endif
 	}
 
+      use_xattr_translator_records = values->use_xattr_translator_records;
       break;
 
     default:
@@ -151,6 +162,9 @@ diskfs_append_args (char **argz, size_t *argz_len)
   /* Get the standard things.  */
   err = diskfs_append_std_options (argz, argz_len);
 
+  if (!err && use_xattr_translator_records)
+    err = argz_add (argz, argz_len, "--x-xattr-translator-records");
+
 #ifdef EXT2FS_DEBUG
   if (!err && ext2_debug_flag)
     err = argz_add (argz, argz_len, "--debug");
diff --git a/ext2fs/ext2fs.h b/ext2fs/ext2fs.h
index 2ee97fd0..2104dba3 100644
--- a/ext2fs/ext2fs.h
+++ b/ext2fs/ext2fs.h
@@ -587,4 +587,14 @@ error_t ext2_get_xattr (struct node *np, const char *name, char *value, size_t *
 error_t ext2_set_xattr (struct node *np, const char *name, const char *value, size_t len, int flags);
 error_t ext2_free_xattr_block (struct node *np);
 
+/* Use extended attribute-based translator records.
+ *
+ * This flag allows users to opt-in to the use of extended attributes
+ * for storing translator records.  We will make this the default once
+ * we feel confident that the implementation is fine.
+ *
+ * XXX: Remove this in Hurd 1.0 (or 0.10, or whatever follows 0.9).
+ */
+int use_xattr_translator_records;
+
 #endif
diff --git a/ext2fs/inode.c b/ext2fs/inode.c
index 5109953f..58edb501 100644
--- a/ext2fs/inode.c
+++ b/ext2fs/inode.c
@@ -562,7 +562,8 @@ diskfs_set_translator (struct node *np, const char *name, unsigned namelen,
 
   /* If xattr is supported for this filesystem, use xattr to store translator
      record, otherwise, use legacy translator record */
-  if (EXT2_HAS_COMPAT_FEATURE (sblock, EXT2_FEATURE_COMPAT_EXT_ATTR))
+  if (EXT2_HAS_COMPAT_FEATURE (sblock, EXT2_FEATURE_COMPAT_EXT_ATTR)
+      && use_xattr_translator_records)
     {
       daddr_t blkno;
       struct ext2_inode *di;
@@ -714,7 +715,8 @@ diskfs_get_translator (struct node *np, char **namep, unsigned *namelen)
   if (blkno)
     {
       /* If xattr is no supported by this filesystem, don't report a warning */
-      if (EXT2_HAS_COMPAT_FEATURE (sblock, EXT2_FEATURE_COMPAT_EXT_ATTR))
+      if (EXT2_HAS_COMPAT_FEATURE (sblock, EXT2_FEATURE_COMPAT_EXT_ATTR)
+	  && use_xattr_translator_records)
 	ext2_warning ("This is an old translator record, please update it");
 
       transloc = disk_cache_block_ref (blkno);