1 files changed, 32 insertions, 2 deletions

diff --git a/fs/btrfs/inode-map.c b/fs/btrfs/inode-map.c
index 3262cd17a12f..b4087e0fa871 100644
--- a/fs/btrfs/inode-map.c
+++ b/fs/btrfs/inode-map.c
@@ -38,6 +38,9 @@ static int caching_kthread(void *data)
         int slot;
         int ret;
 
+        if (!btrfs_test_opt(root, INODE_MAP_CACHE))
+                return 0;
+
         path = btrfs_alloc_path();
         if (!path)
                 return -ENOMEM;
@@ -59,8 +62,7 @@ again:
                 goto out;
 
         while (1) {
-                smp_mb();
-                if (fs_info->closing)
+                if (btrfs_fs_closing(fs_info))
                         goto out;
 
                 leaf = path->nodes[0];
@@ -141,6 +143,9 @@ static void start_caching(struct btrfs_root *root)
         int ret;
         u64 objectid;
 
+        if (!btrfs_test_opt(root, INODE_MAP_CACHE))
+                return;
+
         spin_lock(&root->cache_lock);
         if (root->cached != BTRFS_CACHE_NO) {
                 spin_unlock(&root->cache_lock);
@@ -178,6 +183,9 @@ static void start_caching(struct btrfs_root *root)
 
 int btrfs_find_free_ino(struct btrfs_root *root, u64 *objectid)
 {
+        if (!btrfs_test_opt(root, INODE_MAP_CACHE))
+                return btrfs_find_free_objectid(root, objectid);
+
 again:
         *objectid = btrfs_find_ino_for_alloc(root);
 
@@ -201,6 +209,10 @@ void btrfs_return_ino(struct btrfs_root *root, u64 objectid)
 {
         struct btrfs_free_space_ctl *ctl = root->free_ino_ctl;
         struct btrfs_free_space_ctl *pinned = root->free_ino_pinned;
+
+        if (!btrfs_test_opt(root, INODE_MAP_CACHE))
+                return;
+
 again:
         if (root->cached == BTRFS_CACHE_FINISHED) {
                 __btrfs_add_free_space(ctl, objectid, 1);
@@ -250,6 +262,9 @@ void btrfs_unpin_free_ino(struct btrfs_root *root)
         struct rb_node *n;
         u64 count;
 
+        if (!btrfs_test_opt(root, INODE_MAP_CACHE))
+                return;
+
         while (1) {
                 n = rb_first(rbroot);
                 if (!n)
@@ -388,9 +403,24 @@ int btrfs_save_ino_cache(struct btrfs_root *root,
         int prealloc;
         bool retry = false;
 
+        /* only fs tree and subvol/snap needs ino cache */
+        if (root->root_key.objectid != BTRFS_FS_TREE_OBJECTID &&
+            (root->root_key.objectid < BTRFS_FIRST_FREE_OBJECTID ||
+             root->root_key.objectid > BTRFS_LAST_FREE_OBJECTID))
+                return 0;
+
+        /* Don't save inode cache if we are deleting this root */
+        if (btrfs_root_refs(&root->root_item) == 0 &&
+            root != root->fs_info->tree_root)
+                return 0;
+
+        if (!btrfs_test_opt(root, INODE_MAP_CACHE))
+                return 0;
+
         path = btrfs_alloc_path();
         if (!path)
                 return -ENOMEM;
+
 again:
         inode = lookup_free_ino_inode(root, path);
         if (IS_ERR(inode) && PTR_ERR(inode) != -ENOENT) {