4 files changed, 8 insertions, 3 deletions

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index b155a0e49eeb..633e559e000e 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -1229,6 +1229,7 @@ struct btrfs_root {
 #define BTRFS_MOUNT_DISCARD             (1 << 10)
 #define BTRFS_MOUNT_FORCE_COMPRESS      (1 << 11)
 #define BTRFS_MOUNT_SPACE_CACHE         (1 << 12)
+#define BTRFS_MOUNT_CLEAR_CACHE         (1 << 13)
 
 #define btrfs_clear_opt(o, opt)         ((o) &= ~BTRFS_MOUNT_##opt)
 #define btrfs_set_opt(o, opt)           ((o) |= BTRFS_MOUNT_##opt)
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 137833e1fc26..1a94ee4c4fbb 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -8198,6 +8198,8 @@ int btrfs_read_block_groups(struct btrfs_root *root)
         if (cache_gen != 0 &&
             btrfs_super_generation(&root->fs_info->super_copy) != cache_gen)
                 need_clear = 1;
+        if (btrfs_test_opt(root, CLEAR_CACHE))
+                need_clear = 1;
 
         while (1) {
                 ret = find_first_block_group(root, path, &key);
diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
index baa193423fb8..22ee0dc2e6b8 100644
--- a/fs/btrfs/free-space-cache.c
+++ b/fs/btrfs/free-space-cache.c
@@ -242,8 +242,6 @@ int load_free_space_cache(struct btrfs_fs_info *fs_info,
          */
         spin_lock(&block_group->lock);
         if (block_group->disk_cache_state != BTRFS_DC_WRITTEN) {
-                printk(KERN_ERR "not reading block group %llu, dcs is %d\n", block_group->key.objectid,
-                       block_group->disk_cache_state);
                 spin_unlock(&block_group->lock);
                 return 0;
         }
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 5c23eb8d6ba3..5f56213908e7 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -68,7 +68,7 @@ enum {
         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_err,
+        Opt_discard, Opt_space_cache, Opt_clear_cache, Opt_err,
 };
 
 static match_table_t tokens = {
@@ -93,6 +93,7 @@ static match_table_t tokens = {
         {Opt_ratio, "metadata_ratio=%d"},
         {Opt_discard, "discard"},
         {Opt_space_cache, "space_cache"},
+        {Opt_clear_cache, "clear_cache"},
         {Opt_err, NULL},
 };
 
@@ -239,6 +240,9 @@ int btrfs_parse_options(struct btrfs_root *root, char *options)
                 case Opt_space_cache:
                         printk(KERN_INFO "btrfs: enabling disk space caching\n");
                         btrfs_set_opt(info->mount_opt, SPACE_CACHE);
+                case Opt_clear_cache:
+                        printk(KERN_INFO "btrfs: force clearing of disk cache\n");
+                        btrfs_set_opt(info->mount_opt, CLEAR_CACHE);
                         break;
                 case Opt_err:
                         printk(KERN_INFO "btrfs: unrecognized mount option "