[PATCH 01/12] btrfs: add helpers for compression type and level

Dennis Zhou
2019-02-04T20:20:37Z

It is very easy to miss places that rely on a certain bitshifting for
decyphering the type_level overloading. Add helpers to do this instead.

Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Cc: Omar Sandoval <osandov@osandov.com>
---
fs/btrfs/compression.c | 2 +-
fs/btrfs/compression.h | 10 ++++++++++
fs/btrfs/zlib.c | 2 +-
3 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index 548057630b69..94a0b0a3a301 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..004db0b3111b 100644
--- a/fs/btrfs/compression.h
+++ b/fs/btrfs/compression.h
@@ -64,6 +64,16 @@ struct compressed_bio {
u32 sums;
};

+static inline unsigned int btrfs_compress_type(unsigned int type_level)
+{
+ return (type_level & 0xF);
+}
+
+static inline unsigned int btrfs_compress_level(unsigned int type_level)
+{
+ return ((type_level & 0xF0) >> 4);
+}
+
void __init btrfs_init_compress(void);
void __cold btrfs_exit_compress(void);

diff --git a/fs/btrfs/zlib.c b/fs/btrfs/zlib.c
index 970ff3e35bb3..2bd655c4f8b4 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