[PATCH] ext3: add extent map support

On disk extents format:
/*
* this is extent on-disk structure
* it's used at the bottom of the tree
*/
struct ext3_extent {
__le32  ee_block;       /* first logical block extent covers */
__le16  ee_len;         /* number of blocks covered by extent */
__le16  ee_start_hi;    /* high 16 bits of physical block */
__le32  ee_start;       /* low 32 bigs of physical block */
};

Signed-off-by: Alex Tomas <alex@clusterfs.com>
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>

1 files changed, 10 insertions, 0 deletions

diff --git a/include/linux/ext4_fs_sb.h b/include/linux/ext4_fs_sb.h
index ce4856d70100..ce7a844d6703 100644
--- a/include/linux/ext4_fs_sb.h
+++ b/include/linux/ext4_fs_sb.h
@@ -78,6 +78,16 @@ struct ext4_sb_info {
         char *s_qf_names[MAXQUOTAS];            /* Names of quota files with journalled quota */
         int s_jquota_fmt;                       /* Format of quota to use */
 #endif
+
+#ifdef EXTENTS_STATS
+        /* ext4 extents stats */
+        unsigned long s_ext_min;
+        unsigned long s_ext_max;
+        unsigned long s_depth_max;
+        spinlock_t s_ext_stats_lock;
+        unsigned long s_ext_blocks;
+        unsigned long s_ext_extents;
+#endif
 };
 
 #endif  /* _LINUX_EXT4_FS_SB */