ext4: Avoid rec_len overflow with 64KB block size

[mirror_ubuntu-zesty-kernel.git] / include / linux / ext4_fs.h

diff --git a/include/linux/ext4_fs.h b/include/linux/ext4_fs.h
index dfe4487fc739ed9e7374d620a4763445696b7ff9..fb31c1aba989e9ca29c1479377ed96780bdd63ae 100644 (file)
--- a/include/linux/ext4_fs.h
+++ b/include/linux/ext4_fs.h
@@ -767,6 +767,26 @@ struct ext4_dir_entry_2 {
 #define EXT4_DIR_ROUND                 (EXT4_DIR_PAD - 1)
 #define EXT4_DIR_REC_LEN(name_len)     (((name_len) + 8 + EXT4_DIR_ROUND) & \
                                         ~EXT4_DIR_ROUND)
+#define EXT4_MAX_REC_LEN               ((1<<16)-1)
+
+static inline unsigned ext4_rec_len_from_disk(__le16 dlen)
+{
+       unsigned len = le16_to_cpu(dlen);
+
+       if (len == EXT4_MAX_REC_LEN)
+               return 1 << 16;
+       return len;
+}
+
+static inline __le16 ext4_rec_len_to_disk(unsigned len)
+{
+       if (len == (1 << 16))
+               return cpu_to_le16(EXT4_MAX_REC_LEN);
+       else if (len > (1 << 16))
+               BUG();
+       return cpu_to_le16(len);
+}
+
 /*
  * Hash Tree Directory indexing
  * (c) Daniel Phillips, 2001