[PATCH 01/11] btrfs: add macros for compression type and level

Dennis Zhou
2019-01-28T21:24:52Z

It is very easy to miss places that rely on a certain bitshifting for
decyphering the type_level overloading. Make macros handle this instead.

Signed-off-by: Dennis Zhou <dennis@kernel.org>
---
fs/btrfs/compression.c | 2 +-
fs/btrfs/compression.h | 3 +++
fs/btrfs/zlib.c | 2 +-
3 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index 548057630b69..586f95ac0aea 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -1036,9 +1036,9 @@ int btrfs_compress_pages(unsigned int type_level, struct address_space *mapping,
unsigned long *total_in,
unsigned long *total_out)
{
+ int type = BTRFS_COMPRESS_TYPE(type_level);
struct list_head *workspace;
int ret;
- int type = type_level & 0xF;

workspace = find_workspace(type);

diff --git a/fs/btrfs/compression.h b/fs/btrfs/compression.h
index ddda9b80bf20..69a9197dadc3 100644
--- a/fs/btrfs/compression.h
+++ b/fs/btrfs/compression.h
@@ -25,6 +25,9 @@

#define BTRFS_ZLIB_DEFAULT_LEVEL 3

+#define BTRFS_COMPRESS_TYPE(type_level) (type_level & 0xF)
+#define BTRFS_COMPRESS_LEVEL(type_level) ((type_level & 0xF0) >> 4)
+
struct compressed_bio {
/* number of bios pending for this compressed extent */
refcount_t pending_bios;
diff --git a/fs/btrfs/zlib.c b/fs/btrfs/zlib.c
index 970ff3e35bb3..1480b3eee306 100644
--- a/fs/btrfs/zlib.c
+++ b/fs/btrfs/zlib.c
@@ -393,7 +393,7 @@ static int zlib_decompress(struct list_head *ws, unsigned char *data_in,
static void zlib_set_level(struct list_head *ws, unsigned int type)
{
struct workspace *workspace = list_entry(ws, struct workspace, list);
- unsigned level = (type & 0xF0) >> 4;
+ unsigned int level = BTRFS_COMPRESS_LEVEL(type);

if (level > 9)
level = 9;
--
2.17.1