Re: [PATCH] mkfs.ubifs: remove the check for UBIFS_MAX_LEB_SZ

[Dongsheng Yang <yangds.fnst@cn.fujitsu.com>]

On 08/18/2015 04:52 PM, Artem Bityutskiy wrote:
> On Tue, 2015-08-18 at 12:52 +0800, Dongsheng Yang wrote:
>> There is a commit 92ed6c0 to increase UBIFS_MAX_LEB_SZ
>> to 2MiB. But recently, as the leb size become larger and
>> larger, 2MiB is not a suitable limit any more.
>>
>> Then remove this check in mkfs.ubifs
>>
>> Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
>> ---
>> NOTE:
>> 	I am not sure the reason why we have to
>> limit the leb size in mkfs.ubifs. Because
>> I did not find any reason for it, I send
>> this patch out. It's very possible I am
>> mising something.
>
> Well, this is sanity check for the user input. If you accidentally
> added few zeroes, we want to spot this and inform you, and you may
> appreciate that we did not just created a bugus image for you. That's
> the idea.

Sorry, Artem, I was trying to understand it, but I did not got the
point. Could you give me some more information about the idea? Maybe
an example?

Thanx a lot
Yang
>
> Another point is that UBIFS and UBI reads eraseblocks entirely into
> memory from time to time, e.g., when scanning the journal (UBIFS) or
> when doing wear-levelling (UBI). Too large eraseblocks will affect the
> UBI/UBIFS drivers negatively - the latency may increase significantly
> (thing reading eraseblock, modifying, writing it), as well as memory
> consumption.
>
> I personally like to be strict, and if I am not sure about something, I
> put limits, assuming that others may later change the limits.
>
> That said, I'd prefer to increase the limit instead of removing it
> altogether. I suggest to make it reasonably large, so that it suits
> your purposes.
>
> Artem.
> .
>