[PATCH 6/6 V2]Ext4 journal credits reservation fixes for defrag

[Mingming Cao <cmm@us.ibm.com>]

Same as Version 1, Resend for the completeness of the credit fixes version 2 



This patch should be merged with ext4-online-defrag-alloc-contiguous-blks.patch

It originally came from ext4_journal_credits_fix_for_writepages.patch,
but was split off when this patch was moved into the stable part of
the patch queue.

Cc: Akira Fujita <a-fujita@rs.jp.nec.com>
Cc: Takashi Sato <t-sato@yk.jp.nec.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
---
Index: linux-2.6.27-rc1/fs/ext4/defrag.c
===================================================================
--- linux-2.6.27-rc1.orig/fs/ext4/defrag.c	2008-08-11 17:15:49.000000000 -0700
+++ linux-2.6.27-rc1/fs/ext4/defrag.c	2008-08-11 19:46:59.000000000 -0700
@@ -186,9 +186,9 @@ ext4_defrag_alloc_blocks(handle_t *handl
 	struct buffer_head *bh = NULL;
 	int err, i, credits = 0;
 
-	credits = ext4_ext_calc_credits_for_insert(dest_inode, dest_path);
-	err = ext4_ext_journal_restart(handle,
-				credits + EXT4_TRANS_META_BLOCKS);
+	credits = ext4_ext_calc_credits_for_single_extent(dest_inode,
+							  ar->len, dest_path);
+	err = ext4_ext_journal_restart(handle, credits);
 	if (err)
 		return err;