[PATCH] ext4: allow larger descriptor size
make block group descriptor larger.
Signed-off-by: Alexandre Ratchov <alexandre.ratchov@bull.net>
Signed-off-by: Dave Kleikamp <shaggy@austin.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/include/linux/ext4_fs.h b/include/linux/ext4_fs.h
index 8e5009e..a3df2af 100644
--- a/include/linux/ext4_fs.h
+++ b/include/linux/ext4_fs.h
@@ -142,6 +142,9 @@
/*
* Macro-instructions used to manage group descriptors
*/
+#define EXT4_MIN_DESC_SIZE 32
+#define EXT4_MAX_DESC_SIZE EXT4_MIN_BLOCK_SIZE
+#define EXT4_DESC_SIZE(s) (EXT4_SB(s)->s_desc_size)
#ifdef __KERNEL__
# define EXT4_BLOCKS_PER_GROUP(s) (EXT4_SB(s)->s_blocks_per_group)
# define EXT4_DESC_PER_BLOCK(s) (EXT4_SB(s)->s_desc_per_block)
@@ -149,7 +152,7 @@
# define EXT4_DESC_PER_BLOCK_BITS(s) (EXT4_SB(s)->s_desc_per_block_bits)
#else
# define EXT4_BLOCKS_PER_GROUP(s) ((s)->s_blocks_per_group)
-# define EXT4_DESC_PER_BLOCK(s) (EXT4_BLOCK_SIZE(s) / sizeof (struct ext4_group_desc))
+# define EXT4_DESC_PER_BLOCK(s) (EXT4_BLOCK_SIZE(s) / EXT4_DESC_SIZE(s))
# define EXT4_INODES_PER_GROUP(s) ((s)->s_inodes_per_group)
#endif
@@ -474,7 +477,7 @@
* things it doesn't understand...
*/
__le32 s_first_ino; /* First non-reserved inode */
- __le16 s_inode_size; /* size of inode structure */
+ __le16 s_inode_size; /* size of inode structure */
__le16 s_block_group_nr; /* block group # of this superblock */
__le32 s_feature_compat; /* compatible feature set */
/*60*/ __le32 s_feature_incompat; /* incompatible feature set */
@@ -500,7 +503,7 @@
__le32 s_hash_seed[4]; /* HTREE hash seed */
__u8 s_def_hash_version; /* Default hash version to use */
__u8 s_reserved_char_pad;
- __u16 s_reserved_word_pad;
+ __le16 s_desc_size; /* size of group descriptor */
/*100*/ __le32 s_default_mount_opts;
__le32 s_first_meta_bg; /* First metablock block group */
__le32 s_mkfs_time; /* When the filesystem was created */
diff --git a/include/linux/ext4_fs_sb.h b/include/linux/ext4_fs_sb.h
index ce7a844..691a713 100644
--- a/include/linux/ext4_fs_sb.h
+++ b/include/linux/ext4_fs_sb.h
@@ -29,6 +29,7 @@
*/
struct ext4_sb_info {
unsigned long s_frag_size; /* Size of a fragment in bytes */
+ unsigned long s_desc_size; /* Size of a group descriptor in bytes */
unsigned long s_frags_per_block;/* Number of fragments per block */
unsigned long s_inodes_per_block;/* Number of inodes per block */
unsigned long s_frags_per_group;/* Number of fragments in a group */