Re: [RFC][1/4] ext2/3/4: enlarge blocksize

Andreas Dilger
2007-06-21T22:34:47Z

On Sep 08, 2006 13:11 +0900, sho@tnes.nec.co.jp wrote:
> On July 7, 2006, sho wrote:
> These patches support large blocksize up to PAGESIZE (max 64KB).
> NOTE:
> They limit the end of a directory block to 65532(64K - 4)
> to avoid overflow only when using 64KB block.

Takashi, in light of the (very exciting ;-) patches to handle 64kB
PAGE_SIZE on x86 systems, could you please update the large blocksize
patch to the latest ext4 tree?

> diff -upNr -X linux-2.6.18-rc4-mingming/Documentation/dontdiff linux-2.6.18-rc4-mingming/fs/ext2/super.c linux-2.6.18-rc4-mingming-tnes/fs/ext2/super.c
> --- linux-2.6.18-rc4-mingming/fs/ext2/super.c 2006-08-07 03:20:11.000000000 +0900
> +++ linux-2.6.18-rc4-mingming-tnes/fs/ext2/super.c 2006-09-08 09:00:40.000000000 +0900
> @@ -725,7 +725,7 @@ static int ext2_fill_super(struct super_
> brelse(bh);
>
> if (!sb_set_blocksize(sb, blocksize)) {
> - printk(KERN_ERR "EXT2-fs: blocksize too small for device.\n");
> + printk(KERN_ERR "EXT2-fs: bad blocksize %d.\n", blocksize);
> goto failed_sbi;
> }

We need a check in ext2 (like ext3/ext4) to ensure that blocksize <
EXT2_MAX_BLOCK_SIZE. It could be increased to 32768 without danger
I think, only the directory problem prevents it from working with 65536.

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