Re: [PATCH 08/11] btrfs: plumb level through the compression interface

[Nikolay Borisov]

On 28.01.19 Ð. 23:24 Ñ., Dennis Zhou wrote:
> Zlib compression supports multiple levels, but doesn't require changing
> in how a workspace itself is created and managed. Zstd introduces a
> different memory requirement such that higher levels of compression
> require more memory. This requires changes in how the alloc()/get()
> methods work for zstd. This pach plumbs compression level through the
> interface as a parameter in preparation for zstd compression levels.
> This gives the compression types opportunity to create/manage based on
> the compression level.
> 
> Signed-off-by: Dennis Zhou <dennis@xxxxxxxxxx>

Reviewed-by: Nikolay Borisov <nborisov@xxxxxxxx>

> ---
>  fs/btrfs/compression.c | 31 ++++++++++++++++---------------
>  fs/btrfs/compression.h |  7 ++++---
>  fs/btrfs/lzo.c         |  6 +++---
>  fs/btrfs/zlib.c        |  7 ++++---
>  fs/btrfs/zstd.c        |  6 +++---
>  5 files changed, 30 insertions(+), 27 deletions(-)
> 
> diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
> index ab694760ffdb..e509071eaa69 100644
> --- a/fs/btrfs/compression.c
> +++ b/fs/btrfs/compression.c
> @@ -744,9 +744,9 @@ static void heuristic_cleanup_workspace_manager(void)
>  	btrfs_cleanup_workspace_manager(&heuristic_wsm);
>  }
>  
> -static struct list_head *heuristic_get_workspace(void)
> +static struct list_head *heuristic_get_workspace(unsigned int level)
>  {
> -	return btrfs_get_workspace(&heuristic_wsm);
> +	return btrfs_get_workspace(&heuristic_wsm, level);
>  }
>  
>  static void heuristic_put_workspace(struct list_head *ws)
> @@ -766,7 +766,7 @@ static void free_heuristic_ws(struct list_head *ws)
>  	kfree(workspace);
>  }
>  
> -static struct list_head *alloc_heuristic_ws(void)
> +static struct list_head *alloc_heuristic_ws(unsigned int level)
>  {
>  	struct heuristic_ws *ws;
>  
> @@ -825,7 +825,7 @@ void btrfs_init_workspace_manager(struct workspace_manager *wsm,
>  	 * Preallocate one workspace for each compression type so
>  	 * we can guarantee forward progress in the worst case
>  	 */
> -	workspace = wsm->ops->alloc_workspace();
> +	workspace = wsm->ops->alloc_workspace(0);
>  	if (IS_ERR(workspace)) {
>  		pr_warn("BTRFS: cannot preallocate compression workspace, will try later\n");
>  	} else {
> @@ -853,7 +853,8 @@ void btrfs_cleanup_workspace_manager(struct workspace_manager *wsman)
>   * Preallocation makes a forward progress guarantees and we do not return
>   * errors.
>   */
> -struct list_head *btrfs_get_workspace(struct workspace_manager *wsm)
> +struct list_head *btrfs_get_workspace(struct workspace_manager *wsm,
> +				      unsigned int level)
>  {
>  	struct list_head *workspace;
>  	int cpus = num_online_cpus();
> @@ -899,7 +900,7 @@ struct list_head *btrfs_get_workspace(struct workspace_manager *wsm)
>  	 * context of btrfs_compress_bio/btrfs_compress_pages
>  	 */
>  	nofs_flag = memalloc_nofs_save();
> -	workspace = wsm->ops->alloc_workspace();
> +	workspace = wsm->ops->alloc_workspace(level);
>  	memalloc_nofs_restore(nofs_flag);
>  
>  	if (IS_ERR(workspace)) {
> @@ -930,9 +931,9 @@ struct list_head *btrfs_get_workspace(struct workspace_manager *wsm)
>  	return workspace;
>  }
>  
> -static struct list_head *get_workspace(int type)
> +static struct list_head *get_workspace(int type, int level)
>  {
> -	return btrfs_compress_op[type]->get_workspace();
> +	return btrfs_compress_op[type]->get_workspace(level);
>  }
>  
>  /*
> @@ -1003,12 +1004,13 @@ int btrfs_compress_pages(unsigned int type_level, struct address_space *mapping,
>  			 unsigned long *total_out)
>  {
>  	int type = BTRFS_COMPRESS_TYPE(type_level);
> +	int level = BTRFS_COMPRESS_LEVEL(type_level);
>  	struct list_head *workspace;
>  	int ret;
>  
> -	workspace = get_workspace(type);
> +	workspace = get_workspace(type, level);
>  
> -	btrfs_compress_op[type]->set_level(workspace, type_level);
> +	btrfs_compress_op[type]->set_level(workspace, level);
>  	ret = btrfs_compress_op[type]->compress_pages(workspace, mapping,
>  						      start, pages,
>  						      out_pages,
> @@ -1037,7 +1039,7 @@ static int btrfs_decompress_bio(struct compressed_bio *cb)
>  	int ret;
>  	int type = cb->compress_type;
>  
> -	workspace = get_workspace(type);
> +	workspace = get_workspace(type, 0);
>  	ret = btrfs_compress_op[type]->decompress_bio(workspace, cb);
>  	put_workspace(type, workspace);
>  
> @@ -1055,13 +1057,12 @@ int btrfs_decompress(int type, unsigned char *data_in, struct page *dest_page,
>  	struct list_head *workspace;
>  	int ret;
>  
> -	workspace = get_workspace(type);
> -
> +	workspace = get_workspace(type, 0);
>  	ret = btrfs_compress_op[type]->decompress(workspace, data_in,
>  						  dest_page, start_byte,
>  						  srclen, destlen);
> -
>  	put_workspace(type, workspace);
> +
>  	return ret;
>  }
>  
> @@ -1489,7 +1490,7 @@ static void heuristic_collect_sample(struct inode *inode, u64 start, u64 end,
>   */
>  int btrfs_compress_heuristic(struct inode *inode, u64 start, u64 end)
>  {
> -	struct list_head *ws_list = get_workspace(0);
> +	struct list_head *ws_list = get_workspace(0, 0);
>  	struct heuristic_ws *ws;
>  	u32 i;
>  	u8 byte;
> diff --git a/fs/btrfs/compression.h b/fs/btrfs/compression.h
> index 05342ad081d6..e3627139bc5c 100644
> --- a/fs/btrfs/compression.h
> +++ b/fs/btrfs/compression.h
> @@ -114,7 +114,8 @@ struct workspace_manager {
>  
>  void btrfs_init_workspace_manager(struct workspace_manager *wsm,
>  				  const struct btrfs_compress_op *ops);
> -struct list_head *btrfs_get_workspace(struct workspace_manager *wsm);
> +struct list_head *btrfs_get_workspace(struct workspace_manager *wsm,
> +				      unsigned int level);
>  void btrfs_put_workspace(struct workspace_manager *wsm, struct list_head *ws);
>  void btrfs_cleanup_workspace_manager(struct workspace_manager *wsm);
>  
> @@ -123,11 +124,11 @@ struct btrfs_compress_op {
>  
>  	void (*cleanup_workspace_manager)(void);
>  
> -	struct list_head *(*get_workspace)(void);
> +	struct list_head *(*get_workspace)(unsigned int level);
>  
>  	void (*put_workspace)(struct list_head *ws);
>  
> -	struct list_head *(*alloc_workspace)(void);
> +	struct list_head *(*alloc_workspace)(unsigned int level);
>  
>  	void (*free_workspace)(struct list_head *workspace);
>  
> diff --git a/fs/btrfs/lzo.c b/fs/btrfs/lzo.c
> index f0837b2c8e94..f132af45a924 100644
> --- a/fs/btrfs/lzo.c
> +++ b/fs/btrfs/lzo.c
> @@ -73,9 +73,9 @@ static void lzo_cleanup_workspace_manager(void)
>  	btrfs_cleanup_workspace_manager(&wsm);
>  }
>  
> -static struct list_head *lzo_get_workspace(void)
> +static struct list_head *lzo_get_workspace(unsigned int level)
>  {
> -	return btrfs_get_workspace(&wsm);
> +	return btrfs_get_workspace(&wsm, level);
>  }
>  
>  static void lzo_put_workspace(struct list_head *ws)
> @@ -93,7 +93,7 @@ static void lzo_free_workspace(struct list_head *ws)
>  	kfree(workspace);
>  }
>  
> -static struct list_head *lzo_alloc_workspace(void)
> +static struct list_head *lzo_alloc_workspace(unsigned int level)
>  {
>  	struct workspace *workspace;
>  
> diff --git a/fs/btrfs/zlib.c b/fs/btrfs/zlib.c
> index 04687bf692e3..e2173d0c4fd3 100644
> --- a/fs/btrfs/zlib.c
> +++ b/fs/btrfs/zlib.c
> @@ -39,9 +39,9 @@ static void zlib_cleanup_workspace_manager(void)
>  	btrfs_cleanup_workspace_manager(&wsm);
>  }
>  
> -static struct list_head *zlib_get_workspace(void)
> +static struct list_head *zlib_get_workspace(unsigned int level)
>  {
> -	return btrfs_get_workspace(&wsm);
> +	return btrfs_get_workspace(&wsm, level);
>  }
>  
>  static void zlib_put_workspace(struct list_head *ws)
> @@ -58,7 +58,7 @@ static void zlib_free_workspace(struct list_head *ws)
>  	kfree(workspace);
>  }
>  
> -static struct list_head *zlib_alloc_workspace(void)
> +static struct list_head *zlib_alloc_workspace(unsigned int level)
>  {
>  	struct workspace *workspace;
>  	int workspacesize;
> @@ -71,6 +71,7 @@ static struct list_head *zlib_alloc_workspace(void)
>  			zlib_inflate_workspacesize());
>  	workspace->strm.workspace = kvmalloc(workspacesize, GFP_KERNEL);
>  	workspace->buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
> +	workspace->level = level;
>  	if (!workspace->strm.workspace || !workspace->buf)
>  		goto fail;
>  
> diff --git a/fs/btrfs/zstd.c b/fs/btrfs/zstd.c
> index b06eaf171be7..404101864220 100644
> --- a/fs/btrfs/zstd.c
> +++ b/fs/btrfs/zstd.c
> @@ -53,9 +53,9 @@ static void zstd_cleanup_workspace_manager(void)
>  	btrfs_cleanup_workspace_manager(&wsm);
>  }
>  
> -static struct list_head *zstd_get_workspace(void)
> +static struct list_head *zstd_get_workspace(unsigned int level)
>  {
> -	return btrfs_get_workspace(&wsm);
> +	return btrfs_get_workspace(&wsm, level);
>  }
>  
>  static void zstd_put_workspace(struct list_head *ws)
> @@ -72,7 +72,7 @@ static void zstd_free_workspace(struct list_head *ws)
>  	kfree(workspace);
>  }
>  
> -static struct list_head *zstd_alloc_workspace(void)
> +static struct list_head *zstd_alloc_workspace(unsigned int level)
>  {
>  	ZSTD_parameters params =
>  			zstd_get_btrfs_parameters(ZSTD_BTRFS_MAX_INPUT);
>