ext4: drop ec_type from the ext4_ext_cache structure

We can encode the ec_type information by using ee_len == 0 to denote
EXT4_EXT_CACHE_NO, ee_start == 0 to denote EXT4_EXT_CACHE_GAP, and if
neither is true, then the cache type must be EXT4_EXT_CACHE_EXTENT.
This allows us to reduce the size of ext4_ext_inode by another 8
bytes.  (ec_type is 4 bytes, plus another 4 bytes of padding)

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

1 files changed, 2 insertions, 1 deletions

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 746a59853a07..de937fc10503 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -738,12 +738,13 @@ do {									       \
 
 /*
  * storage for cached extent
+ * If ec_len == 0, then the cache is invalid.
+ * If ec_start == 0, then the cache represents a gap (null mapping)
  */
 struct ext4_ext_cache {
         ext4_fsblk_t    ec_start;
         ext4_lblk_t     ec_block;
         __u32           ec_len; /* must be 32bit to return holes */
-        __u32           ec_type;
 };
 
 /*