[PATCH 3/5] fs: squashfs: port zlib compression support from kernel

[Yegor Yefremov]

Hi Enrico,

On Tue, Oct 4, 2016 at 9:40 PM, Sascha Hauer <s.hauer at pengutronix.de> wrote:
> On Tue, Oct 04, 2016 at 12:10:46PM +0200, Enrico Jorns wrote:
>> As this is the default compression method for squashfs, make this the
>> default in kconfig selection, too
>>
>> Signed-off-by: Enrico Jorns <ejo at pengutronix.de>
>> ---
>>  fs/squashfs/Kconfig        |  20 ++++++-
>>  fs/squashfs/Makefile       |   1 +
>>  fs/squashfs/zlib_wrapper.c | 132 +++++++++++++++++++++++++++++++++++++++++++++
>>  3 files changed, 152 insertions(+), 1 deletion(-)
>>  create mode 100644 fs/squashfs/zlib_wrapper.c
>>
>> diff --git a/fs/squashfs/Kconfig b/fs/squashfs/Kconfig
>> index d2de168..1cb1ac5 100644
>> --- a/fs/squashfs/Kconfig
>> +++ b/fs/squashfs/Kconfig
>> @@ -17,6 +17,19 @@ menuconfig FS_SQUASHFS
>>         embedded systems where low overhead is needed.  Further information
>>         and tools are available from http://squashfs.sourceforge.net.
>>
>> +config SQUASHFS_ZLIB
>> +     bool "Include support for ZLIB compressed file systems"
>> +     depends on FS_SQUASHFS
>> +     select ZLIB
>> +     default y
>> +     help
>> +       ZLIB compression is the standard compression used by Squashfs
>> +       file systems.  It offers a good trade-off between compression
>> +       achieved and the amount of CPU time and memory necessary to
>> +       compress and decompress.
>> +
>> +       If unsure, say Y.
>> +
>>  config SQUASHFS_LZ4
>>       bool "Include support for LZ4 compressed file systems"
>>       depends on FS_SQUASHFS
>> @@ -30,9 +43,10 @@ config SQUASHFS_LZ4
>>         LZ4 is not the standard compression used in Squashfs and so most
>>         file systems will be readable without selecting this option.
>>
>> +       If unsure, say N.
>> +
>>  config SQUASHFS_LZO
>>       bool "Include support for LZO compressed file systems"
>> -     default y
>>       depends on FS_SQUASHFS
>>       select LZO_DECOMPRESS
>>       help
>> @@ -44,6 +58,8 @@ config SQUASHFS_LZO
>>         LZO is not the standard compression used in Squashfs and so most
>>         file systems will be readable without selecting this option.
>>
>> +       If unsure, say N.
>> +
>>  config SQUASHFS_XZ
>>       bool "Include support for XZ compressed file systems"
>>       default y
>> @@ -57,3 +73,5 @@ config SQUASHFS_XZ
>>
>>         XZ is not the standard compression used in Squashfs and so most
>>         file systems will be readable without selecting this option.
>> +
>> +       If unsure, say N.
>
> Here unrelated Kconfig entries are changed. Also in the end we get
> "default y" for SQUASHFS_XZ along with the help "If unsure, say N."
> which seems inconsistent.

Care to send v2?

@Sascha what is the plan as to the default compression selection?
Leave XZ or set it to ZLIB? I'm open for both options.

Thanks.

Yegor