[patch] fix ext3 i_blocks accounting

[Andrew Morton]

This fixes the "i_blocks went wrong when the disk filled up"
problem.

In ext3_new_block() we increment i_blocks early, so the
quota operation can be performed outside lock_super().
But if the block allocation ends up failing, we forget to
undo the allocation.  

This is not a serious bug, and probably does not warrant
an upgrade for production machines.  Its effects are:

1) errors are generated from e2fsck and

2) users could appear to be over quota when they really aren't.

The patch undoes the accounting operation if the allocation
ends up failing.

--- 2.4.19-pre5/fs/ext3/balloc.c~ext3-i_blocks	Tue Apr  2 13:12:34 2002
+++ 2.4.19-pre5-akpm/fs/ext3/balloc.c	Tue Apr  2 13:15:03 2002
@@ -542,6 +542,7 @@ int ext3_new_block (handle_t *handle, st
 	int i, j, k, tmp, alloctmp;
 	int bitmap_nr;
 	int fatal = 0, err;
+	int performed_allocation = 0;
 	struct super_block * sb;
 	struct ext3_group_desc * gdp;
 	struct ext3_super_block * es;
@@ -644,8 +645,7 @@ int ext3_new_block (handle_t *handle, st
 	}
 
 	/* No space left on the device */
-	unlock_super (sb);
-	return 0;
+	goto out;
 
 search_back:
 	/* 
@@ -694,6 +694,7 @@ got_block:
 	J_ASSERT_BH(bh, !ext3_test_bit(j, bh->b_data));
 	BUFFER_TRACE(bh, "setting bitmap bit");
 	ext3_set_bit(j, bh->b_data);
+	performed_allocation = 1;
 
 #ifdef CONFIG_JBD_DEBUG
 	{
@@ -815,6 +816,11 @@ out:
 		ext3_std_error(sb, fatal);
 	}
 	unlock_super (sb);
+	/*
+	 * Undo the block allocation
+	 */
+	if (!performed_allocation)
+		DQUOT_FREE_BLOCK(inode, 1);
 	return 0;
 	
 }

-