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

[Eric Sandeen <esandeen@redhat.com>]

Mingming Cao wrote:

> Yes, this isn't being addressed in the current 2.6.18-rc4 kernel. I 
> think this is better than casting to unsigned long long:
> 
> -     if ((my_rsv->rsv_start >= group_first_block + EXT3_BLOCKS_PER_GROUP(sb))
> +     if ((my_rsv->rsv_start > group_first_block - 1 + EXT3_BLOCKS_PER_GROUP(sb))

And there are a few more of these.  The patch I currently have in my stack follows.
(personally I think
	last = first + (count - 1)
is clearer than
	last = first - 1 + count
but that's just my opinion...)

Thanks,

-Eric

Signed-off-by: Eric Sandeen <esandeen@redhat.com>

Index: linux-2.6.17/fs/ext3/balloc.c
===================================================================
--- linux-2.6.17.orig/fs/ext3/balloc.c
+++ linux-2.6.17/fs/ext3/balloc.c
@@ -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;
@@ -1132,7 +1132,7 @@ ext3_try_to_allocate_with_rsv(struct sup
 			try_to_extend_reservation(my_rsv, sb,
 					*count-my_rsv->rsv_end + grp_goal - 1);
 
-		if ((my_rsv->rsv_start >= group_first_block + EXT3_BLOCKS_PER_GROUP(sb))
+		if ((my_rsv->rsv_start > group_first_block + (EXT3_BLOCKS_PER_GROUP(sb) - 1))
 		    || (my_rsv->rsv_end < group_first_block))
 			BUG();
 		ret = ext3_try_to_allocate(sb, handle, group, bitmap_bh, grp_goal,