[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, 5 deletions

diff --git a/include/linux/ext4_jbd2.h b/include/linux/ext4_jbd2.h
index 99d37557cbb..aa273f024ad 100644
--- a/include/linux/ext4_jbd2.h
+++ b/include/linux/ext4_jbd2.h
@@ -26,9 +26,14 @@
  *
  * We may have to touch one inode, one bitmap buffer, up to three
  * indirection blocks, the group and superblock summaries, and the data
- * block to complete the transaction.  */
+ * block to complete the transaction.
+ *
+ * For extents-enabled fs we may have to allocate and modify upto
+ * 5 levels of tree + root which is stored in inode. */
 
-#define EXT4_SINGLEDATA_TRANS_BLOCKS    8U
+#define EXT4_SINGLEDATA_TRANS_BLOCKS(sb)                                \
+        (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)   \
+                || test_opt(sb, EXTENTS) ? 27U : 8U)
 
 /* Extended attribute operations touch at most two data buffers,
  * two bitmap buffers, and two group summaries, in addition to the inode
@@ -42,7 +47,7 @@
  * superblock only gets updated once, of course, so don't bother
  * counting that again for the quota updates. */
 
-#define EXT4_DATA_TRANS_BLOCKS(sb)      (EXT4_SINGLEDATA_TRANS_BLOCKS + \
+#define EXT4_DATA_TRANS_BLOCKS(sb)      (EXT4_SINGLEDATA_TRANS_BLOCKS(sb) + \
                                          EXT4_XATTR_TRANS_BLOCKS - 2 + \
                                          2*EXT4_QUOTA_TRANS_BLOCKS(sb))
 
@@ -78,9 +83,9 @@
 /* Amount of blocks needed for quota insert/delete - we do some block writes
  * but inode, sb and group updates are done only once */
 #define EXT4_QUOTA_INIT_BLOCKS(sb) (test_opt(sb, QUOTA) ? (DQUOT_INIT_ALLOC*\
-                (EXT4_SINGLEDATA_TRANS_BLOCKS-3)+3+DQUOT_INIT_REWRITE) : 0)
+                (EXT4_SINGLEDATA_TRANS_BLOCKS(sb)-3)+3+DQUOT_INIT_REWRITE) : 0)
 #define EXT4_QUOTA_DEL_BLOCKS(sb) (test_opt(sb, QUOTA) ? (DQUOT_DEL_ALLOC*\
-                (EXT4_SINGLEDATA_TRANS_BLOCKS-3)+3+DQUOT_DEL_REWRITE) : 0)
+                (EXT4_SINGLEDATA_TRANS_BLOCKS(sb)-3)+3+DQUOT_DEL_REWRITE) : 0)
 #else
 #define EXT4_QUOTA_TRANS_BLOCKS(sb) 0
 #define EXT4_QUOTA_INIT_BLOCKS(sb) 0