3 files changed, 14 insertions, 3 deletions

diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index 4a78e5726337..5982c8a71f02 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -1529,5 +1529,5 @@ unsigned int btrfs_compress_str2level(const char *str)
         if (str[4] == ':' && '1' <= str[5] && str[5] <= '9' && str[6] == 0)
                 return str[5] - '0';
 
-        return 0;
+        return BTRFS_ZLIB_DEFAULT_LEVEL;
 }
diff --git a/fs/btrfs/compression.h b/fs/btrfs/compression.h
index 93c5b82ae97e..0868cc554f14 100644
--- a/fs/btrfs/compression.h
+++ b/fs/btrfs/compression.h
@@ -34,6 +34,8 @@
 /* Maximum size of data before compression */
 #define BTRFS_MAX_UNCOMPRESSED          (SZ_128K)
 
+#define BTRFS_ZLIB_DEFAULT_LEVEL                3
+
 struct compressed_bio {
         /* number of bios pending for this compressed extent */
         refcount_t pending_bios;
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 65af029559b5..ff3545e526f5 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -507,9 +507,18 @@ int btrfs_parse_options(struct btrfs_fs_info *info, char *options,
                             token == Opt_compress_force ||
                             strncmp(args[0].from, "zlib", 4) == 0) {
                                 compress_type = "zlib";
+
                                 info->compress_type = BTRFS_COMPRESS_ZLIB;
-                                info->compress_level =
-                                        btrfs_compress_str2level(args[0].from);
+                                info->compress_level = BTRFS_ZLIB_DEFAULT_LEVEL;
+                                /*
+                                 * args[0] contains uninitialized data since
+                                 * for these tokens we don't expect any
+                                 * parameter.
+                                 */
+                                if (token != Opt_compress &&
+                                    token != Opt_compress_force)
+                                        info->compress_level =
+                                          btrfs_compress_str2level(args[0].from);
                                 btrfs_set_opt(info->mount_opt, COMPRESS);
                                 btrfs_clear_opt(info->mount_opt, NODATACOW);
                                 btrfs_clear_opt(info->mount_opt, NODATASUM);