e2fsck: add support for dir_data feature

[tools/e2fsprogs.git] / lib / ext2fs / dirblock.c

diff --git a/lib/ext2fs/dirblock.c b/lib/ext2fs/dirblock.c
index cb3a104..eea6545 100644 (file)
--- a/lib/ext2fs/dirblock.c
+++ b/lib/ext2fs/dirblock.c
@@ -59,6 +59,40 @@ errcode_t ext2fs_read_dir_block3(ext2_filsys fs, blk64_t block,
        return retval;
 }
 
+/*
+ * Compute the total directory entry data length.
+ * This includes the filename and an implicit NUL terminator (always present),
+ * and optional extensions.  Each extension has a bit set in the high 4 bits of
+ * de->file_type, and the extension length is the first byte in each entry.
+ */
+int ext2_get_dirent_dirdata_size(struct ext2_dir_entry_2 *de,
+                                char dirdata_flags)
+{
+       char *len = de->name + de->name_len + 1 /* NUL terminator */;
+       int dlen = 0;
+       __u8 extra_data_flags = (de->file_type & ~EXT2_FT_MASK) >> 4;
+
+       dirdata_flags >>= 4;
+       while ((extra_data_flags & dirdata_flags) != 0) {
+               if (extra_data_flags & 1) {
+                       if (dirdata_flags & 1)
+                               dlen += *len;
+
+                       len += *len;
+               }
+               extra_data_flags >>= 1;
+               dirdata_flags >>= 1;
+       }
+
+       /* add NUL terminator byte to dirdata length */
+       return dlen + (dlen != 0);
+}
+
+int ext2_get_dirent_size(struct ext2_dir_entry_2 *de)
+{
+       return ext2_get_dirent_dirdata_size(de, ~EXT2_FT_MASK);
+}
+
 errcode_t ext2fs_read_dir_block2(ext2_filsys fs, blk_t block,
                                 void *buf, int flags EXT2FS_ATTR((unused)))
 {