btrfs: add lzo workspace buffer length constants

It makes it more readable for length checking and is be used repeatedly.

Signed-off-by: Dāvis Mosāns <davispuh@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/lzo.c b/fs/btrfs/lzo.c
index e6e28a9..430ad36 100644 (file)
--- a/fs/btrfs/lzo.c
+++ b/fs/btrfs/lzo.c
@@ -55,6 +55,9 @@
  * 0x1000   | SegHdr N+1| Data payload N+1 ...                |
  */
 
+#define WORKSPACE_BUF_LENGTH   (lzo1x_worst_compress(PAGE_SIZE))
+#define WORKSPACE_CBUF_LENGTH  (lzo1x_worst_compress(PAGE_SIZE))
+
 struct workspace {
        void *mem;
        void *buf;      /* where decompressed data goes */
@@ -83,8 +86,8 @@ struct list_head *lzo_alloc_workspace(unsigned int level)
                return ERR_PTR(-ENOMEM);
 
        workspace->mem = kvmalloc(LZO1X_MEM_COMPRESS, GFP_KERNEL);
-       workspace->buf = kvmalloc(lzo1x_worst_compress(PAGE_SIZE), GFP_KERNEL);
-       workspace->cbuf = kvmalloc(lzo1x_worst_compress(PAGE_SIZE), GFP_KERNEL);
+       workspace->buf = kvmalloc(WORKSPACE_BUF_LENGTH, GFP_KERNEL);
+       workspace->cbuf = kvmalloc(WORKSPACE_CBUF_LENGTH, GFP_KERNEL);
        if (!workspace->mem || !workspace->buf || !workspace->cbuf)
                goto fail;
 
@@ -380,7 +383,7 @@ int lzo_decompress_bio(struct list_head *ws, struct compressed_bio *cb)
                kunmap(cur_page);
                cur_in += LZO_LEN;
 
-               if (seg_len > lzo1x_worst_compress(PAGE_SIZE)) {
+               if (seg_len > WORKSPACE_CBUF_LENGTH) {
                        /*
                         * seg_len shouldn't be larger than we have allocated
                         * for workspace->cbuf
@@ -433,7 +436,7 @@ int lzo_decompress(struct list_head *ws, unsigned char *data_in,
        struct workspace *workspace = list_entry(ws, struct workspace, list);
        size_t in_len;
        size_t out_len;
-       size_t max_segment_len = lzo1x_worst_compress(PAGE_SIZE);
+       size_t max_segment_len = WORKSPACE_BUF_LENGTH;
        int ret = 0;
        char *kaddr;
        unsigned long bytes;