Re: [PATCH v2 2/2] btrfs: compression: replace set_level callbacks by a common helper

[Anand Jain <anand.jain@oracle.com>]

On 21/8/19 12:17 AM, David Sterba wrote:
> The set_level callbacks do not do anything special and can be replaced
> by a helper that uses the levels defined in the tables.
> 
> Signed-off-by: David Sterba <dsterba@suse.com>
> ---
>   fs/btrfs/compression.c | 20 ++++++++++++++++++--
>   fs/btrfs/compression.h |  9 ++-------
>   fs/btrfs/lzo.c         |  6 ------
>   fs/btrfs/zlib.c        |  9 ---------
>   fs/btrfs/zstd.c        |  9 ---------
>   5 files changed, 20 insertions(+), 33 deletions(-)
> 
> diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
> index 60c47b417a4b..53376c640f61 100644
> --- a/fs/btrfs/compression.c
> +++ b/fs/btrfs/compression.c
> @@ -1039,7 +1039,7 @@ int btrfs_compress_pages(unsigned int type_level, struct address_space *mapping,
>   	struct list_head *workspace;
>   	int ret;
>   
> -	level = btrfs_compress_op[type]->set_level(level);
> +	level = btrfs_compress_set_level(type, level);
>   	workspace = get_workspace(type, level);
>   	ret = btrfs_compress_op[type]->compress_pages(workspace, mapping,
>   						      start, pages,
> @@ -1611,7 +1611,23 @@ unsigned int btrfs_compress_str2level(unsigned int type, const char *str)
>   			level = 0;
>   	}
>   
> -	level = btrfs_compress_op[type]->set_level(level);
> +	level = btrfs_compress_set_level(type, level);
> +
> +	return level;
> +}
> +
> +/*
> + * Adjust @level according to the limits of the compression algorithm or
> + * fallback to default
> + */
> +unsigned int btrfs_compress_get_level(int type, unsigned level)
> +{
> +	const struct btrfs_compress_op *ops = btrfs_compress_op[type];
> +
> +	if (level == 0)
> +		level = ops->default_level;
> +	else
> +		level = min(level, ops->max_level);
>   
>   	return level;
>   }
> diff --git a/fs/btrfs/compression.h b/fs/btrfs/compression.h
> index cffd689adb6e..4cb8be9ff88b 100644
> --- a/fs/btrfs/compression.h
> +++ b/fs/btrfs/compression.h
> @@ -156,13 +156,6 @@ struct btrfs_compress_op {
>   			  unsigned long start_byte,
>   			  size_t srclen, size_t destlen);
>   
> -	/*
> -	 * This bounds the level set by the user to be within range of a
> -	 * particular compression type.  It returns the level that will be used
> -	 * if the level is out of bounds or the default if 0 is passed in.
> -	 */
> -	unsigned int (*set_level)(unsigned int level);
> -
>   	/* Maximum level supported by the compression algorithm */
>   	unsigned int max_level;
>   	unsigned int default_level;
> @@ -179,6 +172,8 @@ extern const struct btrfs_compress_op btrfs_zstd_compress;
>   const char* btrfs_compress_type2str(enum btrfs_compression_type type);
>   bool btrfs_compress_is_valid_type(const char *str, size_t len);
>   
> +unsigned int btrfs_compress_set_level(int type, unsigned level);
> +

    btrfs_compress_set_level() is undefined.

Thanks, Anand




>   int btrfs_compress_heuristic(struct inode *inode, u64 start, u64 end);
>   
>   #endif
> diff --git a/fs/btrfs/lzo.c b/fs/btrfs/lzo.c
> index adac6cb30d65..acad4174f68d 100644
> --- a/fs/btrfs/lzo.c
> +++ b/fs/btrfs/lzo.c
> @@ -507,11 +507,6 @@ static int lzo_decompress(struct list_head *ws, unsigned char *data_in,
>   	return ret;
>   }
>   
> -static unsigned int lzo_set_level(unsigned int level)
> -{
> -	return 0;
> -}
> -
>   const struct btrfs_compress_op btrfs_lzo_compress = {
>   	.init_workspace_manager	= lzo_init_workspace_manager,
>   	.cleanup_workspace_manager = lzo_cleanup_workspace_manager,
> @@ -522,7 +517,6 @@ const struct btrfs_compress_op btrfs_lzo_compress = {
>   	.compress_pages		= lzo_compress_pages,
>   	.decompress_bio		= lzo_decompress_bio,
>   	.decompress		= lzo_decompress,
> -	.set_level		= lzo_set_level,
>   	.max_level		= 1,
>   	.default_level		= 1,
>   };
> diff --git a/fs/btrfs/zlib.c b/fs/btrfs/zlib.c
> index 03d6c3683bd9..df1aace5df50 100644
> --- a/fs/btrfs/zlib.c
> +++ b/fs/btrfs/zlib.c
> @@ -418,14 +418,6 @@ static int zlib_decompress(struct list_head *ws, unsigned char *data_in,
>   	return ret;
>   }
>   
> -static unsigned int zlib_set_level(unsigned int level)
> -{
> -	if (!level)
> -		return BTRFS_ZLIB_DEFAULT_LEVEL;
> -
> -	return min_t(unsigned int, level, 9);
> -}
> -
>   const struct btrfs_compress_op btrfs_zlib_compress = {
>   	.init_workspace_manager	= zlib_init_workspace_manager,
>   	.cleanup_workspace_manager = zlib_cleanup_workspace_manager,
> @@ -436,7 +428,6 @@ const struct btrfs_compress_op btrfs_zlib_compress = {
>   	.compress_pages		= zlib_compress_pages,
>   	.decompress_bio		= zlib_decompress_bio,
>   	.decompress		= zlib_decompress,
> -	.set_level              = zlib_set_level,
>   	.max_level		= 9,
>   	.default_level		= BTRFS_ZLIB_DEFAULT_LEVEL,
>   };
> diff --git a/fs/btrfs/zstd.c b/fs/btrfs/zstd.c
> index b2b23a6a497d..0af4a5cd4313 100644
> --- a/fs/btrfs/zstd.c
> +++ b/fs/btrfs/zstd.c
> @@ -710,14 +710,6 @@ static int zstd_decompress(struct list_head *ws, unsigned char *data_in,
>   	return ret;
>   }
>   
> -static unsigned int zstd_set_level(unsigned int level)
> -{
> -	if (!level)
> -		return ZSTD_BTRFS_DEFAULT_LEVEL;
> -
> -	return min_t(unsigned int, level, ZSTD_BTRFS_MAX_LEVEL);
> -}
> -
>   const struct btrfs_compress_op btrfs_zstd_compress = {
>   	.init_workspace_manager = zstd_init_workspace_manager,
>   	.cleanup_workspace_manager = zstd_cleanup_workspace_manager,
> @@ -728,7 +720,6 @@ const struct btrfs_compress_op btrfs_zstd_compress = {
>   	.compress_pages = zstd_compress_pages,
>   	.decompress_bio = zstd_decompress_bio,
>   	.decompress = zstd_decompress,
> -	.set_level = zstd_set_level,
>   	.max_level	= ZSTD_BTRFS_MAX_LEVEL,
>   	.default_level	= ZSTD_BTRFS_DEFAULT_LEVEL,
>   };
>