--- zzzz-none-000/linux-3.10.107/fs/btrfs/inode-map.c	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/fs/btrfs/inode-map.c	2021-02-04 17:41:59.000000000 +0000
@@ -55,7 +55,7 @@
 	key.type = BTRFS_INODE_ITEM_KEY;
 again:
 	/* need to make sure the commit_root doesn't disappear */
-	mutex_lock(&root->fs_commit_mutex);
+	down_read(&fs_info->commit_root_sem);
 
 	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
 	if (ret < 0)
@@ -78,10 +78,8 @@
 			    btrfs_transaction_in_commit(fs_info)) {
 				leaf = path->nodes[0];
 
-				if (btrfs_header_nritems(leaf) == 0) {
-					WARN_ON(1);
+				if (WARN_ON(btrfs_header_nritems(leaf) == 0))
 					break;
-				}
 
 				/*
 				 * Save the key so we can advances forward
@@ -89,8 +87,8 @@
 				 */
 				btrfs_item_key_to_cpu(leaf, &key, 0);
 				btrfs_release_path(path);
-				root->cache_progress = last;
-				mutex_unlock(&root->fs_commit_mutex);
+				root->ino_cache_progress = last;
+				up_read(&fs_info->commit_root_sem);
 				schedule_timeout(1);
 				goto again;
 			} else
@@ -108,7 +106,7 @@
 		if (last != (u64)-1 && last + 1 != key.objectid) {
 			__btrfs_add_free_space(ctl, last + 1,
 					       key.objectid - last - 1);
-			wake_up(&root->cache_wait);
+			wake_up(&root->ino_cache_wait);
 		}
 
 		last = key.objectid;
@@ -121,15 +119,15 @@
 				       root->highest_objectid - last - 1);
 	}
 
-	spin_lock(&root->cache_lock);
-	root->cached = BTRFS_CACHE_FINISHED;
-	spin_unlock(&root->cache_lock);
+	spin_lock(&root->ino_cache_lock);
+	root->ino_cache_state = BTRFS_CACHE_FINISHED;
+	spin_unlock(&root->ino_cache_lock);
 
-	root->cache_progress = (u64)-1;
+	root->ino_cache_progress = (u64)-1;
 	btrfs_unpin_free_ino(root);
 out:
-	wake_up(&root->cache_wait);
-	mutex_unlock(&root->fs_commit_mutex);
+	wake_up(&root->ino_cache_wait);
+	up_read(&fs_info->commit_root_sem);
 
 	btrfs_free_path(path);
 
@@ -146,20 +144,20 @@
 	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);
+	spin_lock(&root->ino_cache_lock);
+	if (root->ino_cache_state != BTRFS_CACHE_NO) {
+		spin_unlock(&root->ino_cache_lock);
 		return;
 	}
 
-	root->cached = BTRFS_CACHE_STARTED;
-	spin_unlock(&root->cache_lock);
+	root->ino_cache_state = BTRFS_CACHE_STARTED;
+	spin_unlock(&root->ino_cache_lock);
 
 	ret = load_free_ino_cache(root->fs_info, root);
 	if (ret == 1) {
-		spin_lock(&root->cache_lock);
-		root->cached = BTRFS_CACHE_FINISHED;
-		spin_unlock(&root->cache_lock);
+		spin_lock(&root->ino_cache_lock);
+		root->ino_cache_state = BTRFS_CACHE_FINISHED;
+		spin_unlock(&root->ino_cache_lock);
 		return;
 	}
 
@@ -176,9 +174,13 @@
 				       BTRFS_LAST_FREE_OBJECTID - objectid + 1);
 	}
 
-	tsk = kthread_run(caching_kthread, root, "btrfs-ino-cache-%llu\n",
+	tsk = kthread_run(caching_kthread, root, "btrfs-ino-cache-%llu",
 			  root->root_key.objectid);
-	BUG_ON(IS_ERR(tsk)); /* -ENOMEM */
+	if (IS_ERR(tsk)) {
+		btrfs_warn(root->fs_info, "failed to start inode caching task");
+		btrfs_clear_pending_and_info(root->fs_info, INODE_MAP_CACHE,
+				"disabling inode map caching");
+	}
 }
 
 int btrfs_find_free_ino(struct btrfs_root *root, u64 *objectid)
@@ -194,11 +196,11 @@
 
 	start_caching(root);
 
-	wait_event(root->cache_wait,
-		   root->cached == BTRFS_CACHE_FINISHED ||
+	wait_event(root->ino_cache_wait,
+		   root->ino_cache_state == BTRFS_CACHE_FINISHED ||
 		   root->free_ino_ctl->free_space > 0);
 
-	if (root->cached == BTRFS_CACHE_FINISHED &&
+	if (root->ino_cache_state == BTRFS_CACHE_FINISHED &&
 	    root->free_ino_ctl->free_space == 0)
 		return -ENOSPC;
 	else
@@ -207,57 +209,44 @@
 
 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);
+	if (root->ino_cache_state == BTRFS_CACHE_FINISHED) {
+		__btrfs_add_free_space(pinned, objectid, 1);
 	} else {
-		/*
-		 * If we are in the process of caching free ino chunks,
-		 * to avoid adding the same inode number to the free_ino
-		 * tree twice due to cross transaction, we'll leave it
-		 * in the pinned tree until a transaction is committed
-		 * or the caching work is done.
-		 */
-
-		mutex_lock(&root->fs_commit_mutex);
-		spin_lock(&root->cache_lock);
-		if (root->cached == BTRFS_CACHE_FINISHED) {
-			spin_unlock(&root->cache_lock);
-			mutex_unlock(&root->fs_commit_mutex);
+		down_write(&root->fs_info->commit_root_sem);
+		spin_lock(&root->ino_cache_lock);
+		if (root->ino_cache_state == BTRFS_CACHE_FINISHED) {
+			spin_unlock(&root->ino_cache_lock);
+			up_write(&root->fs_info->commit_root_sem);
 			goto again;
 		}
-		spin_unlock(&root->cache_lock);
+		spin_unlock(&root->ino_cache_lock);
 
 		start_caching(root);
 
-		if (objectid <= root->cache_progress ||
-		    objectid > root->highest_objectid)
-			__btrfs_add_free_space(ctl, objectid, 1);
-		else
-			__btrfs_add_free_space(pinned, objectid, 1);
+		__btrfs_add_free_space(pinned, objectid, 1);
 
-		mutex_unlock(&root->fs_commit_mutex);
+		up_write(&root->fs_info->commit_root_sem);
 	}
 }
 
 /*
- * When a transaction is committed, we'll move those inode numbers which
- * are smaller than root->cache_progress from pinned tree to free_ino tree,
- * and others will just be dropped, because the commit root we were
- * searching has changed.
+ * When a transaction is committed, we'll move those inode numbers which are
+ * smaller than root->ino_cache_progress from pinned tree to free_ino tree, and
+ * others will just be dropped, because the commit root we were searching has
+ * changed.
  *
- * Must be called with root->fs_commit_mutex held
+ * Must be called with root->fs_info->commit_root_sem held
  */
 void btrfs_unpin_free_ino(struct btrfs_root *root)
 {
 	struct btrfs_free_space_ctl *ctl = root->free_ino_ctl;
 	struct rb_root *rbroot = &root->free_ino_pinned->free_space_offset;
+	spinlock_t *rbroot_lock = &root->free_ino_pinned->tree_lock;
 	struct btrfs_free_space *info;
 	struct rb_node *n;
 	u64 count;
@@ -266,23 +255,29 @@
 		return;
 
 	while (1) {
+		bool add_to_ctl = true;
+
+		spin_lock(rbroot_lock);
 		n = rb_first(rbroot);
-		if (!n)
+		if (!n) {
+			spin_unlock(rbroot_lock);
 			break;
+		}
 
 		info = rb_entry(n, struct btrfs_free_space, offset_index);
 		BUG_ON(info->bitmap); /* Logic error */
 
-		if (info->offset > root->cache_progress)
-			goto free;
-		else if (info->offset + info->bytes > root->cache_progress)
-			count = root->cache_progress - info->offset + 1;
+		if (info->offset > root->ino_cache_progress)
+			add_to_ctl = false;
+		else if (info->offset + info->bytes > root->ino_cache_progress)
+			count = root->ino_cache_progress - info->offset + 1;
 		else
 			count = info->bytes;
 
-		__btrfs_add_free_space(ctl, info->offset, count);
-free:
 		rb_erase(&info->offset_index, rbroot);
+		spin_unlock(rbroot_lock);
+		if (add_to_ctl)
+			__btrfs_add_free_space(ctl, info->offset, count);
 		kmem_cache_free(btrfs_free_space_cachep, info);
 	}
 }
@@ -376,6 +371,8 @@
 	ctl->start = 0;
 	ctl->private = NULL;
 	ctl->op = &free_ino_op;
+	INIT_LIST_HEAD(&ctl->trimming_ranges);
+	mutex_init(&ctl->cache_writeout_mutex);
 
 	/*
 	 * Initially we allow to use 16K of ram to cache chunks of
@@ -412,8 +409,7 @@
 		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)
+	if (btrfs_root_refs(&root->root_item) == 0)
 		return 0;
 
 	if (!btrfs_test_opt(root, INODE_MAP_CACHE))
@@ -467,7 +463,7 @@
 	}
 
 	if (i_size_read(inode) > 0) {
-		ret = btrfs_truncate_free_space_cache(root, trans, path, inode);
+		ret = btrfs_truncate_free_space_cache(root, trans, NULL, inode);
 		if (ret) {
 			if (ret != -ENOSPC)
 				btrfs_abort_transaction(trans, root, ret);
@@ -475,13 +471,13 @@
 		}
 	}
 
-	spin_lock(&root->cache_lock);
-	if (root->cached != BTRFS_CACHE_FINISHED) {
+	spin_lock(&root->ino_cache_lock);
+	if (root->ino_cache_state != BTRFS_CACHE_FINISHED) {
 		ret = -1;
-		spin_unlock(&root->cache_lock);
+		spin_unlock(&root->ino_cache_lock);
 		goto out_put;
 	}
-	spin_unlock(&root->cache_lock);
+	spin_unlock(&root->ino_cache_lock);
 
 	spin_lock(&ctl->tree_lock);
 	prealloc = sizeof(struct btrfs_free_space) * ctl->free_extents;
@@ -492,19 +488,19 @@
 	/* Just to make sure we have enough space */
 	prealloc += 8 * PAGE_CACHE_SIZE;
 
-	ret = btrfs_delalloc_reserve_space(inode, prealloc);
+	ret = btrfs_delalloc_reserve_space(inode, 0, prealloc);
 	if (ret)
 		goto out_put;
 
 	ret = btrfs_prealloc_file_range_trans(inode, trans, 0, 0, prealloc,
 					      prealloc, prealloc, &alloc_hint);
 	if (ret) {
-		btrfs_delalloc_release_space(inode, prealloc);
+		btrfs_delalloc_release_space(inode, 0, prealloc);
 		goto out_put;
 	}
-	btrfs_free_reserved_data_space(inode, prealloc);
+	btrfs_free_reserved_data_space(inode, 0, prealloc);
 
-	ret = btrfs_write_out_ino_cache(root, trans, path);
+	ret = btrfs_write_out_ino_cache(root, trans, path, inode);
 out_put:
 	iput(inode);
 out_release:
@@ -519,7 +515,7 @@
 	return ret;
 }
 
-static int btrfs_find_highest_objectid(struct btrfs_root *root, u64 *objectid)
+int btrfs_find_highest_objectid(struct btrfs_root *root, u64 *objectid)
 {
 	struct btrfs_path *path;
 	int ret;
@@ -559,13 +555,6 @@
 	int ret;
 	mutex_lock(&root->objectid_mutex);
 
-	if (unlikely(root->highest_objectid < BTRFS_FIRST_FREE_OBJECTID)) {
-		ret = btrfs_find_highest_objectid(root,
-						  &root->highest_objectid);
-		if (ret)
-			goto out;
-	}
-
 	if (unlikely(root->highest_objectid >= BTRFS_LAST_FREE_OBJECTID)) {
 		ret = -ENOSPC;
 		goto out;