[PATCH 0/3] ubifs: add lz4hc compression

[Richard Weinberger]

Hyunchul Lee,

Am 28.02.2017 um 06:16 schrieb Hyunchul Lee:
> From: Hyunchul Lee <cheol.lee at lge.com>
> 
> This patch set is for adding support for lz4hc compression.  lz4hc's
> compression ratio is comparable to zlib, but its compression/decompression
> speed is faster than zlib[1].

Do you have performance numbers that show the speedup on a common embedded
system with NAND?

> Another compression type cannot be added any more in respect that type of
> ubifs_inode's compr_type is "unsigned:2" and there are 4 compression
> types.  There may be overflow in assignment to compr_type, and prevision 
> version of ubifs is trying to decompress file with wrong compression type.

As Artem noted this is only an in-memory struct.

What happens when you compress a file with lz4hc and try to access this
UBIFS file with an older kernel?
AFAICT ubifs_iget() will notice and return -EINVAL but please double check.

Thanks,
//richard