Re: [Ext2-devel] [PATCH] fix ext3 mounts at 16T

[Andreas Dilger <adilger@clusterfs.com>]

On Aug 18, 2006  12:39 -0500, Eric Sandeen wrote:
> @@ -168,7 +168,7 @@ goal_in_my_reservation(struct ext3_reser
>  	ext3_fsblk_t group_first_block, group_last_block;
>  
>  	group_first_block = ext3_group_first_block_no(sb, group);
> -	group_last_block = group_first_block + EXT3_BLOCKS_PER_GROUP(sb) - 1;
> +	group_last_block = group_first_block + (EXT3_BLOCKS_PER_GROUP(sb) - 1);
>  
>  	if ((rsv->_rsv_start > group_last_block) ||
>  	    (rsv->_rsv_end < group_first_block))
> @@ -897,7 +897,7 @@ static int alloc_new_reservation(struct 
>  	spinlock_t *rsv_lock = &EXT3_SB(sb)->s_rsv_window_lock;
>  
>  	group_first_block = ext3_group_first_block_no(sb, group);
> -	group_end_block = group_first_block + EXT3_BLOCKS_PER_GROUP(sb) - 1;
> +	group_end_block = group_first_block + (EXT3_BLOCKS_PER_GROUP(sb) - 1);
>  
>  	if (grp_goal < 0)
>  		start_block = group_first_block;

I don't see how these can make a difference?  Surely, if the intermediate
sum overflows it will then underflow when "- 1" is done?  Not that I mind,
per-se, just curious why you think this fixes anything.

Cheers, Andreas
--
Andreas Dilger
Principal Software Engineer
Cluster File Systems, Inc.

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