1 files changed, 261 insertions, 0 deletions

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 591893fe58cb..102ed3143976 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -7478,6 +7478,220 @@ reada:
 	wc->reada_slot = slot;
 }
 
+static int account_leaf_items(struct btrfs_trans_handle *trans,
+			      struct btrfs_root *root,
+			      struct extent_buffer *eb)
+{
+	int nr = btrfs_header_nritems(eb);
+	int i, extent_type, ret;
+	struct btrfs_key key;
+	struct btrfs_file_extent_item *fi;
+	u64 bytenr, num_bytes;
+
+	for (i = 0; i < nr; i++) {
+		btrfs_item_key_to_cpu(eb, &key, i);
+
+		if (key.type != BTRFS_EXTENT_DATA_KEY)
+			continue;
+
+		fi = btrfs_item_ptr(eb, i, struct btrfs_file_extent_item);
+		/* filter out non qgroup-accountable extents  */
+		extent_type = btrfs_file_extent_type(eb, fi);
+
+		if (extent_type == BTRFS_FILE_EXTENT_INLINE)
+			continue;
+
+		bytenr = btrfs_file_extent_disk_bytenr(eb, fi);
+		if (!bytenr)
+			continue;
+
+		num_bytes = btrfs_file_extent_disk_num_bytes(eb, fi);
+
+		ret = btrfs_qgroup_record_ref(trans, root->fs_info,
+					      root->objectid,
+					      bytenr, num_bytes,
+					      BTRFS_QGROUP_OPER_SUB_SUBTREE, 0);
+		if (ret)
+			return ret;
+	}
+	return 0;
+}
+
+/*
+ * Walk up the tree from the bottom, freeing leaves and any interior
+ * nodes which have had all slots visited. If a node (leaf or
+ * interior) is freed, the node above it will have it's slot
+ * incremented. The root node will never be freed.
+ *
+ * At the end of this function, we should have a path which has all
+ * slots incremented to the next position for a search. If we need to
+ * read a new node it will be NULL and the node above it will have the
+ * correct slot selected for a later read.
+ *
+ * If we increment the root nodes slot counter past the number of
+ * elements, 1 is returned to signal completion of the search.
+ */
+static int adjust_slots_upwards(struct btrfs_root *root,
+				struct btrfs_path *path, int root_level)
+{
+	int level = 0;
+	int nr, slot;
+	struct extent_buffer *eb;
+
+	if (root_level == 0)
+		return 1;
+
+	while (level <= root_level) {
+		eb = path->nodes[level];
+		nr = btrfs_header_nritems(eb);
+		path->slots[level]++;
+		slot = path->slots[level];
+		if (slot >= nr || level == 0) {
+			/*
+			 * Don't free the root -  we will detect this
+			 * condition after our loop and return a
+			 * positive value for caller to stop walking the tree.
+			 */
+			if (level != root_level) {
+				btrfs_tree_unlock_rw(eb, path->locks[level]);
+				path->locks[level] = 0;
+
+				free_extent_buffer(eb);
+				path->nodes[level] = NULL;
+				path->slots[level] = 0;
+			}
+		} else {
+			/*
+			 * We have a valid slot to walk back down
+			 * from. Stop here so caller can process these
+			 * new nodes.
+			 */
+			break;
+		}
+
+		level++;
+	}
+
+	eb = path->nodes[root_level];
+	if (path->slots[root_level] >= btrfs_header_nritems(eb))
+		return 1;
+
+	return 0;
+}
+
+/*
+ * root_eb is the subtree root and is locked before this function is called.
+ */
+static int account_shared_subtree(struct btrfs_trans_handle *trans,
+				  struct btrfs_root *root,
+				  struct extent_buffer *root_eb,
+				  u64 root_gen,
+				  int root_level)
+{
+	int ret = 0;
+	int level;
+	struct extent_buffer *eb = root_eb;
+	struct btrfs_path *path = NULL;
+
+	BUG_ON(root_level < 0 || root_level > BTRFS_MAX_LEVEL);
+	BUG_ON(root_eb == NULL);
+
+	if (!root->fs_info->quota_enabled)
+		return 0;
+
+	if (!extent_buffer_uptodate(root_eb)) {
+		ret = btrfs_read_buffer(root_eb, root_gen);
+		if (ret)
+			goto out;
+	}
+
+	if (root_level == 0) {
+		ret = account_leaf_items(trans, root, root_eb);
+		goto out;
+	}
+
+	path = btrfs_alloc_path();
+	if (!path)
+		return -ENOMEM;
+
+	/*
+	 * Walk down the tree.  Missing extent blocks are filled in as
+	 * we go. Metadata is accounted every time we read a new
+	 * extent block.
+	 *
+	 * When we reach a leaf, we account for file extent items in it,
+	 * walk back up the tree (adjusting slot pointers as we go)
+	 * and restart the search process.
+	 */
+	extent_buffer_get(root_eb); /* For path */
+	path->nodes[root_level] = root_eb;
+	path->slots[root_level] = 0;
+	path->locks[root_level] = 0; /* so release_path doesn't try to unlock */
+walk_down:
+	level = root_level;
+	while (level >= 0) {
+		if (path->nodes[level] == NULL) {
+			int child_bsize = root->nodesize;
+			int parent_slot;
+			u64 child_gen;
+			u64 child_bytenr;
+
+			/* We need to get child blockptr/gen from
+			 * parent before we can read it. */
+			eb = path->nodes[level + 1];
+			parent_slot = path->slots[level + 1];
+			child_bytenr = btrfs_node_blockptr(eb, parent_slot);
+			child_gen = btrfs_node_ptr_generation(eb, parent_slot);
+
+			eb = read_tree_block(root, child_bytenr, child_bsize,
+					     child_gen);
+			if (!eb || !extent_buffer_uptodate(eb)) {
+				ret = -EIO;
+				goto out;
+			}
+
+			path->nodes[level] = eb;
+			path->slots[level] = 0;
+
+			btrfs_tree_read_lock(eb);
+			btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK);
+			path->locks[level] = BTRFS_READ_LOCK_BLOCKING;
+
+			ret = btrfs_qgroup_record_ref(trans, root->fs_info,
+						root->objectid,
+						child_bytenr,
+						child_bsize,
+						BTRFS_QGROUP_OPER_SUB_SUBTREE,
+						0);
+			if (ret)
+				goto out;
+
+		}
+
+		if (level == 0) {
+			ret = account_leaf_items(trans, root, path->nodes[level]);
+			if (ret)
+				goto out;
+
+			/* Nonzero return here means we completed our search */
+			ret = adjust_slots_upwards(root, path, root_level);
+			if (ret)
+				break;
+
+			/* Restart search with new slots */
+			goto walk_down;
+		}
+
+		level--;
+	}
+
+	ret = 0;
+out:
+	btrfs_free_path(path);
+
+	return ret;
+}
+
 /*
  * helper to process tree block while walking down the tree.
  *
@@ -7581,6 +7795,7 @@ static noinline int do_walk_down(struct btrfs_trans_handle *trans,
 	int level = wc->level;
 	int reada = 0;
 	int ret = 0;
+	bool need_account = false;
 
 	generation = btrfs_node_ptr_generation(path->nodes[level],
 					       path->slots[level]);
@@ -7626,6 +7841,7 @@ static noinline int do_walk_down(struct btrfs_trans_handle *trans,
 
 	if (wc->stage == DROP_REFERENCE) {
 		if (wc->refs[level - 1] > 1) {
+			need_account = true;
 			if (level == 1 &&
 			    (wc->flags[0] & BTRFS_BLOCK_FLAG_FULL_BACKREF))
 				goto skip;
@@ -7689,6 +7905,16 @@ skip:
 			parent = 0;
 		}
 
+		if (need_account) {
+			ret = account_shared_subtree(trans, root, next,
+						     generation, level - 1);
+			if (ret) {
+				printk_ratelimited(KERN_ERR "BTRFS: %s Error "
+					"%d accounting shared subtree. Quota "
+					"is out of sync, rescan required.\n",
+					root->fs_info->sb->s_id, ret);
+			}
+		}
 		ret = btrfs_free_extent(trans, root, bytenr, blocksize, parent,
 				root->root_key.objectid, level - 1, 0, 0);
 		BUG_ON(ret); /* -ENOMEM */
@@ -7773,6 +7999,13 @@ static noinline int walk_up_proc(struct btrfs_trans_handle *trans,
 			else
 				ret = btrfs_dec_ref(trans, root, eb, 0);
 			BUG_ON(ret); /* -ENOMEM */
+			ret = account_leaf_items(trans, root, eb);
+			if (ret) {
+				printk_ratelimited(KERN_ERR "BTRFS: %s Error "
+					"%d accounting leaf items. Quota "
+					"is out of sync, rescan required.\n",
+					root->fs_info->sb->s_id, ret);
+			}
 		}
 		/* make block locked assertion in clean_tree_block happy */
 		if (!path->locks[level] &&
@@ -7898,6 +8131,8 @@ int btrfs_drop_snapshot(struct btrfs_root *root,
 	int level;
 	bool root_dropped = false;
 
+	btrfs_debug(root->fs_info, "Drop subvolume %llu", root->objectid);
+
 	path = btrfs_alloc_path();
 	if (!path) {
 		err = -ENOMEM;
@@ -8023,6 +8258,24 @@ int btrfs_drop_snapshot(struct btrfs_root *root,
 				goto out_end_trans;
 			}
 
+			/*
+			 * Qgroup update accounting is run from
+			 * delayed ref handling. This usually works
+			 * out because delayed refs are normally the
+			 * only way qgroup updates are added. However,
+			 * we may have added updates during our tree
+			 * walk so run qgroups here to make sure we
+			 * don't lose any updates.
+			 */
+			ret = btrfs_delayed_qgroup_accounting(trans,
+							      root->fs_info);
+			if (ret)
+				printk_ratelimited(KERN_ERR "BTRFS: Failure %d "
+						   "running qgroup updates "
+						   "during snapshot delete. "
+						   "Quota is out of sync, "
+						   "rescan required.\n", ret);
+
 			btrfs_end_transaction_throttle(trans, tree_root);
 			if (!for_reloc && btrfs_need_cleaner_sleep(root)) {
 				pr_debug("BTRFS: drop snapshot early exit\n");
@@ -8076,6 +8329,14 @@ int btrfs_drop_snapshot(struct btrfs_root *root,
 	}
 	root_dropped = true;
 out_end_trans:
+	ret = btrfs_delayed_qgroup_accounting(trans, tree_root->fs_info);
+	if (ret)
+		printk_ratelimited(KERN_ERR "BTRFS: Failure %d "
+				   "running qgroup updates "
+				   "during snapshot delete. "
+				   "Quota is out of sync, "
+				   "rescan required.\n", ret);
+
 	btrfs_end_transaction_throttle(trans, tree_root);
 out_free:
 	kfree(wc);