Btrfs devel - Feb 2013 - [PATCH] btrfs: fix decompress buffer size

lzo1x_1_compress() is unnecessarily used for allocating decompress buffer.

Signed-off-by: Kyungsik Lee <kyungsik.lee@lge.com>
---
 fs/btrfs/lzo.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/btrfs/lzo.c b/fs/btrfs/lzo.c
index 743b86f..223893a 100644
--- a/fs/btrfs/lzo.c
+++ b/fs/btrfs/lzo.c
@@ -55,7 +55,7 @@ static struct list_head *lzo_alloc_workspace(void)
 		return ERR_PTR(-ENOMEM);
 
 	workspace->mem = vmalloc(LZO1X_MEM_COMPRESS);
-	workspace->buf = vmalloc(lzo1x_worst_compress(PAGE_CACHE_SIZE));
+	workspace->buf = vmalloc(PAGE_CACHE_SIZE);
 	workspace->cbuf = vmalloc(lzo1x_worst_compress(PAGE_CACHE_SIZE));
 	if (!workspace->mem || !workspace->buf || !workspace->cbuf)
 		goto fail;
@@ -349,7 +349,7 @@ cont:
 			}
 		}
 
-		out_len = lzo1x_worst_compress(PAGE_CACHE_SIZE);
+		out_len = PAGE_CACHE_SIZE;
 		ret = lzo1x_decompress_safe(buf, in_len, workspace->buf,
 					    &out_len);
 		if (need_unmap)
-- 
1.8.0.3

On Thu, Feb 14, 2013 at 06:12:19PM +0900, Kyungsik Lee
wrote:
> lzo1x_1_compress() is unnecessarily used for allocating decompress buffer.
> 
> --- a/fs/btrfs/lzo.c
> +++ b/fs/btrfs/lzo.c
> @@ -55,7 +55,7 @@ static struct list_head *lzo_alloc_workspace(void)
>  		return ERR_PTR(-ENOMEM);
>  
>  	workspace->mem = vmalloc(LZO1X_MEM_COMPRESS);
> -	workspace->buf = vmalloc(lzo1x_worst_compress(PAGE_CACHE_SIZE));
> +	workspace->buf = vmalloc(PAGE_CACHE_SIZE);
Right, PAGE_CACHE_SIZE is enough in size, but then we don''t even need
vmalloc.

david