Messages in this thread | | | Date | Fri, 18 Aug 2006 18:56:58 -0500 | From | Eric Sandeen <> | Subject | Re: [Ext2-devel] [PATCH] fix ext3 mounts at 16T |
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Andreas Dilger wrote: > 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.
Well, you're right, if it overflows then it will underflow again. And I've not observed any actual failures, and I don't expect to. But personally I guess I'd rather avoid the whole overflow in the first place... maybe I'm being silly. :)
If you think it's unnecessary code churn then we can not make this change...
-Eric - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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