Re: [GIT PULL] Squashfs updates for 3.2

[Phillip Lougher <phillip@lougher.demon.co.uk>]

Phillip Lougher wrote:
> NamJae Jeon wrote:
> 
>>
>> I already posted this patch before ([PATCH] squashfs : devblksize set
>> to 4KB intead of BLOCK_SIZE(1KB).).
> 
> No you didn't.  You posted a patch that simply unconditionally changed
> the block size from  1K -> 4K.
> 
> https://lkml.org/lkml/2011/9/18/66
> 
> This is an unacceptable change, Squashfs is used on many devices not only
> NAND, and the default value of 1K is optimal for these other devices, and
> should not be changed.
> 
> Second, if you are going to change long-term existing behaviour you should
> always allow users to "buy-in" to the change, rather than surprising them
> with new unexpected behaviour.
> 
>> It is similar with my patch except option.
> 
> The option *is* the patch.
> 
>> Have you ever seen this patch ? I didn't response about this patch 
>> from you.
> 
> Since 2008 (and probably before) I have had reports that a 1K block size 
> was
> causing performance issues on NAND
> 
> http://old.nabble.com/Default-FS-block-size-td15423970.html
> 
> However, I chose to do nothing at that time because the results were
> inconclusive.
> 
> The impetus for moving to a 1K block on NAND was due to the development
> of the UBIBLK driver for NAND earlier this year
> 
> http://lists.infradead.org/pipermail/linux-mtd/2011-June/036595.html
> 
> where the 1K dev block behaviour of Squashfs was discovered to be the
> reason (in the early V1 driver referenced above) why Squashfs filesystems
> worked, but ext2/3 and vfat filesystems did not.
> 
> Your patch was merely the 3rd or 4th unacceptable patch I have
> received changing the block size unconditionally.
> 
> The month before your patch I received this truly horrible patch, which
> though it is extremely long, does nothing more than change the max dev
> block size to 4K.  I dropped that patch too.
> 

Missing link

https://lkml.org/lkml/2011/8/15/350

oh and the patch was truly horrible because it was
broken, they added a new set of I/O access routines
for the LZO decompressor, but didn't bother with
any of the others (compile error if you were so
audacious as to want to use GZIP, or XZ).

Way to go.

> Phillip
>