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, 36 insertions, 11 deletions

diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 61bd79abb805..f348f2b93164 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -69,9 +69,9 @@ enum {
         Opt_degraded, Opt_subvol, Opt_subvolid, Opt_device, Opt_nodatasum,
         Opt_nodatacow, Opt_max_inline, Opt_alloc_start, Opt_nobarrier, Opt_ssd,
         Opt_nossd, Opt_ssd_spread, Opt_thread_pool, Opt_noacl, Opt_compress,
-        Opt_compress_force, Opt_notreelog, Opt_ratio, Opt_flushoncommit,
-        Opt_discard, Opt_space_cache, Opt_clear_cache, Opt_err,
-        Opt_user_subvol_rm_allowed,
+        Opt_compress_type, Opt_compress_force, Opt_compress_force_type,
+        Opt_notreelog, Opt_ratio, Opt_flushoncommit, Opt_discard,
+        Opt_space_cache, Opt_clear_cache, Opt_user_subvol_rm_allowed, Opt_err,
 };
 
 static match_table_t tokens = {
@@ -86,7 +86,9 @@ static match_table_t tokens = {
         {Opt_alloc_start, "alloc_start=%s"},
         {Opt_thread_pool, "thread_pool=%d"},
         {Opt_compress, "compress"},
+        {Opt_compress_type, "compress=%s"},
         {Opt_compress_force, "compress-force"},
+        {Opt_compress_force_type, "compress-force=%s"},
         {Opt_ssd, "ssd"},
         {Opt_ssd_spread, "ssd_spread"},
         {Opt_nossd, "nossd"},
@@ -112,6 +114,8 @@ int btrfs_parse_options(struct btrfs_root *root, char *options)
         char *p, *num, *orig;
         int intarg;
         int ret = 0;
+        char *compress_type;
+        bool compress_force = false;
 
         if (!options)
                 return 0;
@@ -154,14 +158,29 @@ int btrfs_parse_options(struct btrfs_root *root, char *options)
                         btrfs_set_opt(info->mount_opt, NODATACOW);
                         btrfs_set_opt(info->mount_opt, NODATASUM);
                         break;
-                case Opt_compress:
-                        printk(KERN_INFO "btrfs: use compression\n");
-                        btrfs_set_opt(info->mount_opt, COMPRESS);
-                        break;
                 case Opt_compress_force:
-                        printk(KERN_INFO "btrfs: forcing compression\n");
-                        btrfs_set_opt(info->mount_opt, FORCE_COMPRESS);
+                case Opt_compress_force_type:
+                        compress_force = true;
+                case Opt_compress:
+                case Opt_compress_type:
+                        if (token == Opt_compress ||
+                            token == Opt_compress_force ||
+                            strcmp(args[0].from, "zlib") == 0) {
+                                compress_type = "zlib";
+                                info->compress_type = BTRFS_COMPRESS_ZLIB;
+                        } else {
+                                ret = -EINVAL;
+                                goto out;
+                        }
+
                         btrfs_set_opt(info->mount_opt, COMPRESS);
+                        if (compress_force) {
+                                btrfs_set_opt(info->mount_opt, FORCE_COMPRESS);
+                                pr_info("btrfs: force %s compression\n",
+                                        compress_type);
+                        } else
+                                pr_info("btrfs: use %s compression\n",
+                                        compress_type);
                         break;
                 case Opt_ssd:
                         printk(KERN_INFO "btrfs: use ssd allocation scheme\n");
@@ -898,10 +917,14 @@ static int __init init_btrfs_fs(void)
         if (err)
                 return err;
 
-        err = btrfs_init_cachep();
+        err = btrfs_init_compress();
         if (err)
                 goto free_sysfs;
 
+        err = btrfs_init_cachep();
+        if (err)
+                goto free_compress;
+
         err = extent_io_init();
         if (err)
                 goto free_cachep;
@@ -929,6 +952,8 @@ free_extent_io:
         extent_io_exit();
 free_cachep:
         btrfs_destroy_cachep();
+free_compress:
+        btrfs_exit_compress();
 free_sysfs:
         btrfs_exit_sysfs();
         return err;
@@ -943,7 +968,7 @@ static void __exit exit_btrfs_fs(void)
         unregister_filesystem(&btrfs_fs_type);
         btrfs_exit_sysfs();
         btrfs_cleanup_fs_uuids();
-        btrfs_zlib_exit();
+        btrfs_exit_compress();
 }
 
 module_init(init_btrfs_fs)