btrfs: Allow to add new compression algorithm

Make the code aware of compression type, instead of always assuming
zlib compression.

Also make the zlib workspace function as common code for all
compression types.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>

1 files changed, 6 insertions, 4 deletions

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index af52f6d7a4d..e0653443859 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -551,9 +551,10 @@ struct btrfs_timespec {
 } __attribute__ ((__packed__));
 
 enum btrfs_compression_type {
-        BTRFS_COMPRESS_NONE = 0,
-        BTRFS_COMPRESS_ZLIB = 1,
-        BTRFS_COMPRESS_LAST = 2,
+        BTRFS_COMPRESS_NONE  = 0,
+        BTRFS_COMPRESS_ZLIB  = 1,
+        BTRFS_COMPRESS_TYPES = 1,
+        BTRFS_COMPRESS_LAST  = 2,
 };
 
 struct btrfs_inode_item {
@@ -895,7 +896,8 @@ struct btrfs_fs_info {
          */
         u64 last_trans_log_full_commit;
         u64 open_ioctl_trans;
-        unsigned long mount_opt;
+        unsigned long mount_opt:20;
+        unsigned long compress_type:4;
         u64 max_inline;
         u64 alloc_start;
         struct btrfs_transaction *running_transaction;