lz4hc compression in UBIFS?

[Konstantin Tokarev]

04.10.2013, 07:09, "Brent Taylor" <motobud at gmail.com>:
> Here is a patch based on linux-3.12-rc3.  I haven't performed any
> performance testing UBIFS using lz4hc, but I can mount UBIFS volumes
> and haven't seen any problems yet.

Thank you!

Are you planning to implement a patch for mtd-utils (mkfs.ubifs) as well?


>  The only think I know that isn't
> correct about the patch is the description for the Kconfig element for
> select lz4hc as a compression option.  I only copied the description
> from the lzo description.
>
> diff -uN -uNr linux-3.12-rc3.orig/fs/ubifs/compress.c
> linux-3.12-rc3/fs/ubifs/compress.c
> --- linux-3.12-rc3.orig/fs/ubifs/compress.c     2013-09-29
> 17:02:38.000000000 -0500
> +++ linux-3.12-rc3/fs/ubifs/compress.c  2013-07-17 21:57:27.440653860 -0500
> @@ -53,6 +53,22 @@
>  };
>  #endif
>
> +#ifdef CONFIG_UBIFS_FS_LZ4HC
> +static DEFINE_MUTEX(lz4hc_mutex);
> +
> +static struct ubifs_compressor lz4hc_compr = {
> +       .compr_type = UBIFS_COMPR_LZ4HC,
> +       .comp_mutex = &lz4hc_mutex,
> +       .name = "lz4hc",
> +       .capi_name = "lz4hc",
> +};
> +#else
> +static struct ubifs_compressor lz4hc_compr = {
> +       .compr_type = UBIFS_COMPR_LZ4HC,
> +       .name = "lz4hc",
> +};
> +#endif
> +
>  #ifdef CONFIG_UBIFS_FS_ZLIB
>  static DEFINE_MUTEX(deflate_mutex);
>  static DEFINE_MUTEX(inflate_mutex);
> @@ -224,10 +240,14 @@
>  {
>         int err;
>
> -       err = compr_init(&lzo_compr);
> +       err = compr_init(&lz4hc_compr);
>         if (err)
>                 return err;
>
> +       err = compr_init(&lzo_compr);
> +       if (err)
> +               goto out_lz4hc;
> +
>         err = compr_init(&zlib_compr);
>         if (err)
>                 goto out_lzo;
> @@ -237,6 +257,8 @@
>
>  out_lzo:
>         compr_exit(&lzo_compr);
> +out_lz4hc:
> +       compr_exit(&lz4hc_compr);
>         return err;
>  }
>
> @@ -245,6 +267,7 @@
>   */
>  void ubifs_compressors_exit(void)
>  {
> +       compr_exit(&lz4hc_compr);
>         compr_exit(&lzo_compr);
>         compr_exit(&zlib_compr);
>  }
> diff -uN -uNr linux-3.12-rc3.orig/fs/ubifs/Kconfig
> linux-3.12-rc3/fs/ubifs/Kconfig
> --- linux-3.12-rc3.orig/fs/ubifs/Kconfig        2013-09-29
> 17:02:38.000000000 -0500
> +++ linux-3.12-rc3/fs/ubifs/Kconfig     2013-10-03 21:40:39.098747630 -0500
> @@ -29,6 +29,14 @@
>            LZO compressor is generally faster than zlib but compresses worse.
>            Say 'Y' if unsure.
>
> +config UBIFS_FS_LZ4HC
> +       bool "LZ4HC compression support" if UBIFS_FS_ADVANCED_COMPR
> +       depends on UBIFS_FS && CRYPTO_LZ4HC
> +       default y
> +       help
> +          LZ4HC compressor is generally faster than zlib but compresses worse.
> +          Say 'Y' if unsure.
> +
>  config UBIFS_FS_ZLIB
>         bool "ZLIB compression support" if UBIFS_FS_ADVANCED_COMPR
>         depends on UBIFS_FS
> diff -uN -uNr linux-3.12-rc3.orig/fs/ubifs/super.c
> linux-3.12-rc3/fs/ubifs/super.c
> --- linux-3.12-rc3.orig/fs/ubifs/super.c        2013-09-29
> 17:02:38.000000000 -0500
> +++ linux-3.12-rc3/fs/ubifs/super.c     2013-09-30 23:01:06.899526709 -0500
> @@ -1040,6 +1040,8 @@
>                                 return -ENOMEM;
>                         if (!strcmp(name, "none"))
>                                 c->mount_opts.compr_type = UBIFS_COMPR_NONE;
> +                       else if (!strcmp(name, "lz4hc"))
> +                               c->mount_opts.compr_type = UBIFS_COMPR_LZ4HC;
>                         else if (!strcmp(name, "lzo"))
>                                 c->mount_opts.compr_type = UBIFS_COMPR_LZO;
>                         else if (!strcmp(name, "zlib"))
> diff -uN -uNr linux-3.12-rc3.orig/fs/ubifs/ubifs-media.h
> linux-3.12-rc3/fs/ubifs/ubifs-media.h
> --- linux-3.12-rc3.orig/fs/ubifs/ubifs-media.h  2013-09-29
> 17:02:38.000000000 -0500
> +++ linux-3.12-rc3/fs/ubifs/ubifs-media.h       2013-07-16
> 22:56:02.435523610 -0500
> @@ -332,12 +332,14 @@
>   * UBIFS_COMPR_NONE: no compression
>   * UBIFS_COMPR_LZO: LZO compression
>   * UBIFS_COMPR_ZLIB: ZLIB compression
> + * UBIFS_COMPR_LZ4HZ: LZ4HZ compression
>   * UBIFS_COMPR_TYPES_CNT: count of supported compression types
>   */
>  enum {
>         UBIFS_COMPR_NONE,
>         UBIFS_COMPR_LZO,
>         UBIFS_COMPR_ZLIB,
> +       UBIFS_COMPR_LZ4HC,
>         UBIFS_COMPR_TYPES_CNT,
>  };
>
> Enjoy,
> Brent Taylor

-- 
Regards,
Konstantin