1 files changed, 101 insertions, 55 deletions

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 294e31edec9d..efd5d6e9589e 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -613,6 +613,7 @@ static noinline int create_subvol(struct mnt_idmap *idmap,
 	int ret;
 	dev_t anon_dev;
 	u64 objectid;
+	u64 qgroup_reserved = 0;
 
 	root_item = kzalloc(sizeof(*root_item), GFP_KERNEL);
 	if (!root_item)
@@ -650,19 +651,24 @@ static noinline int create_subvol(struct mnt_idmap *idmap,
 					       trans_num_items, false);
 	if (ret)
 		goto out_new_inode_args;
+	qgroup_reserved = block_rsv.qgroup_rsv_reserved;
 
 	trans = btrfs_start_transaction(root, 0);
 	if (IS_ERR(trans)) {
 		ret = PTR_ERR(trans);
-		btrfs_subvolume_release_metadata(root, &block_rsv);
-		goto out_new_inode_args;
+		goto out_release_rsv;
 	}
+	ret = btrfs_record_root_in_trans(trans, BTRFS_I(dir)->root);
+	if (ret)
+		goto out;
+	btrfs_qgroup_convert_reserved_meta(root, qgroup_reserved);
+	qgroup_reserved = 0;
 	trans->block_rsv = &block_rsv;
 	trans->bytes_reserved = block_rsv.size;
 	/* Tree log can't currently deal with an inode which is a new root. */
 	btrfs_set_log_full_commit(trans);
 
-	ret = btrfs_qgroup_inherit(trans, 0, objectid, root->root_key.objectid, inherit);
+	ret = btrfs_qgroup_inherit(trans, 0, objectid, btrfs_root_id(root), inherit);
 	if (ret)
 		goto out;
 
@@ -767,9 +773,11 @@ static noinline int create_subvol(struct mnt_idmap *idmap,
 out:
 	trans->block_rsv = NULL;
 	trans->bytes_reserved = 0;
-	btrfs_subvolume_release_metadata(root, &block_rsv);
-
 	btrfs_end_transaction(trans);
+out_release_rsv:
+	btrfs_block_rsv_release(fs_info, &block_rsv, (u64)-1, NULL);
+	if (qgroup_reserved)
+		btrfs_qgroup_free_meta_prealloc(root, qgroup_reserved);
 out_new_inode_args:
 	btrfs_new_inode_args_destroy(&new_inode_args);
 out_inode:
@@ -791,6 +799,8 @@ static int create_snapshot(struct btrfs_root *root, struct inode *dir,
 	struct btrfs_pending_snapshot *pending_snapshot;
 	unsigned int trans_num_items;
 	struct btrfs_trans_handle *trans;
+	struct btrfs_block_rsv *block_rsv;
+	u64 qgroup_reserved = 0;
 	int ret;
 
 	/* We do not support snapshotting right now. */
@@ -827,19 +837,19 @@ static int create_snapshot(struct btrfs_root *root, struct inode *dir,
 		goto free_pending;
 	}
 
-	btrfs_init_block_rsv(&pending_snapshot->block_rsv,
-			     BTRFS_BLOCK_RSV_TEMP);
+	block_rsv = &pending_snapshot->block_rsv;
+	btrfs_init_block_rsv(block_rsv, BTRFS_BLOCK_RSV_TEMP);
 	/*
 	 * 1 to add dir item
 	 * 1 to add dir index
 	 * 1 to update parent inode item
 	 */
 	trans_num_items = create_subvol_num_items(inherit) + 3;
-	ret = btrfs_subvolume_reserve_metadata(BTRFS_I(dir)->root,
-					       &pending_snapshot->block_rsv,
+	ret = btrfs_subvolume_reserve_metadata(BTRFS_I(dir)->root, block_rsv,
 					       trans_num_items, false);
 	if (ret)
 		goto free_pending;
+	qgroup_reserved = block_rsv->qgroup_rsv_reserved;
 
 	pending_snapshot->dentry = dentry;
 	pending_snapshot->root = root;
@@ -852,6 +862,13 @@ static int create_snapshot(struct btrfs_root *root, struct inode *dir,
 		ret = PTR_ERR(trans);
 		goto fail;
 	}
+	ret = btrfs_record_root_in_trans(trans, BTRFS_I(dir)->root);
+	if (ret) {
+		btrfs_end_transaction(trans);
+		goto fail;
+	}
+	btrfs_qgroup_convert_reserved_meta(root, qgroup_reserved);
+	qgroup_reserved = 0;
 
 	trans->pending_snapshot = pending_snapshot;
 
@@ -881,7 +898,9 @@ fail:
 	if (ret && pending_snapshot->snap)
 		pending_snapshot->snap->anon_dev = 0;
 	btrfs_put_root(pending_snapshot->snap);
-	btrfs_subvolume_release_metadata(root, &pending_snapshot->block_rsv);
+	btrfs_block_rsv_release(fs_info, block_rsv, (u64)-1, NULL);
+	if (qgroup_reserved)
+		btrfs_qgroup_free_meta_prealloc(root, qgroup_reserved);
 free_pending:
 	if (pending_snapshot->anon_dev)
 		free_anon_bdev(pending_snapshot->anon_dev);
@@ -1491,7 +1510,7 @@ static noinline int btrfs_ioctl_subvol_setflags(struct file *file,
 			spin_unlock(&root->root_item_lock);
 			btrfs_warn(fs_info,
 				   "Attempt to set subvolume %llu read-write during send",
-				   root->root_key.objectid);
+				   btrfs_root_id(root));
 			ret = -EPERM;
 			goto out_drop_sem;
 		}
@@ -1900,7 +1919,7 @@ static int btrfs_search_path_in_tree_user(struct mnt_idmap *idmap,
 	struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
 	struct super_block *sb = inode->i_sb;
 	struct btrfs_key upper_limit = BTRFS_I(inode)->location;
-	u64 treeid = BTRFS_I(inode)->root->root_key.objectid;
+	u64 treeid = btrfs_root_id(BTRFS_I(inode)->root);
 	u64 dirid = args->dirid;
 	unsigned long item_off;
 	unsigned long item_len;
@@ -2072,7 +2091,7 @@ static noinline int btrfs_ioctl_ino_lookup(struct btrfs_root *root,
 	 * path is reset so it's consistent with btrfs_search_path_in_tree.
 	 */
 	if (args->treeid == 0)
-		args->treeid = root->root_key.objectid;
+		args->treeid = btrfs_root_id(root);
 
 	if (args->objectid == BTRFS_FIRST_FREE_OBJECTID) {
 		args->name[0] = 0;
@@ -2168,7 +2187,7 @@ static int btrfs_ioctl_get_subvol_info(struct inode *inode, void __user *argp)
 	fs_info = BTRFS_I(inode)->root->fs_info;
 
 	/* Get root_item of inode's subvolume */
-	key.objectid = BTRFS_I(inode)->root->root_key.objectid;
+	key.objectid = btrfs_root_id(BTRFS_I(inode)->root);
 	root = btrfs_get_fs_root(fs_info, key.objectid, true);
 	if (IS_ERR(root)) {
 		ret = PTR_ERR(root);
@@ -2283,7 +2302,7 @@ static int btrfs_ioctl_get_subvol_rootref(struct btrfs_root *root,
 		return PTR_ERR(rootrefs);
 	}
 
-	objectid = root->root_key.objectid;
+	objectid = btrfs_root_id(root);
 	key.objectid = objectid;
 	key.type = BTRFS_ROOT_REF_KEY;
 	key.offset = rootrefs->min_treeid;
@@ -2367,7 +2386,7 @@ static noinline int btrfs_ioctl_snap_destroy(struct file *file,
 	struct mnt_idmap *idmap = file_mnt_idmap(file);
 	char *subvol_name, *subvol_name_ptr = NULL;
 	int subvol_namelen;
-	int err = 0;
+	int ret = 0;
 	bool destroy_parent = false;
 
 	/* We don't support snapshots with extent tree v2 yet. */
@@ -2383,7 +2402,7 @@ static noinline int btrfs_ioctl_snap_destroy(struct file *file,
 			return PTR_ERR(vol_args2);
 
 		if (vol_args2->flags & ~BTRFS_SUBVOL_DELETE_ARGS_MASK) {
-			err = -EOPNOTSUPP;
+			ret = -EOPNOTSUPP;
 			goto out;
 		}
 
@@ -2392,31 +2411,31 @@ static noinline int btrfs_ioctl_snap_destroy(struct file *file,
 		 * name, same as v1 currently does.
 		 */
 		if (!(vol_args2->flags & BTRFS_SUBVOL_SPEC_BY_ID)) {
-			err = btrfs_check_ioctl_vol_args2_subvol_name(vol_args2);
-			if (err < 0)
+			ret = btrfs_check_ioctl_vol_args2_subvol_name(vol_args2);
+			if (ret < 0)
 				goto out;
 			subvol_name = vol_args2->name;
 
-			err = mnt_want_write_file(file);
-			if (err)
+			ret = mnt_want_write_file(file);
+			if (ret)
 				goto out;
 		} else {
 			struct inode *old_dir;
 
 			if (vol_args2->subvolid < BTRFS_FIRST_FREE_OBJECTID) {
-				err = -EINVAL;
+				ret = -EINVAL;
 				goto out;
 			}
 
-			err = mnt_want_write_file(file);
-			if (err)
+			ret = mnt_want_write_file(file);
+			if (ret)
 				goto out;
 
 			dentry = btrfs_get_dentry(fs_info->sb,
 					BTRFS_FIRST_FREE_OBJECTID,
 					vol_args2->subvolid, 0);
 			if (IS_ERR(dentry)) {
-				err = PTR_ERR(dentry);
+				ret = PTR_ERR(dentry);
 				goto out_drop_write;
 			}
 
@@ -2436,7 +2455,7 @@ static noinline int btrfs_ioctl_snap_destroy(struct file *file,
 			 */
 			dput(dentry);
 			if (IS_ERR(parent)) {
-				err = PTR_ERR(parent);
+				ret = PTR_ERR(parent);
 				goto out_drop_write;
 			}
 			old_dir = dir;
@@ -2460,14 +2479,14 @@ static noinline int btrfs_ioctl_snap_destroy(struct file *file,
 			 * to delete without an idmapped mount.
 			 */
 			if (old_dir != dir && idmap != &nop_mnt_idmap) {
-				err = -EOPNOTSUPP;
+				ret = -EOPNOTSUPP;
 				goto free_parent;
 			}
 
 			subvol_name_ptr = btrfs_get_subvol_name_from_objectid(
 						fs_info, vol_args2->subvolid);
 			if (IS_ERR(subvol_name_ptr)) {
-				err = PTR_ERR(subvol_name_ptr);
+				ret = PTR_ERR(subvol_name_ptr);
 				goto free_parent;
 			}
 			/* subvol_name_ptr is already nul terminated */
@@ -2478,14 +2497,14 @@ static noinline int btrfs_ioctl_snap_destroy(struct file *file,
 		if (IS_ERR(vol_args))
 			return PTR_ERR(vol_args);
 
-		err = btrfs_check_ioctl_vol_args_path(vol_args);
-		if (err < 0)
+		ret = btrfs_check_ioctl_vol_args_path(vol_args);
+		if (ret < 0)
 			goto out;
 
 		subvol_name = vol_args->name;
 
-		err = mnt_want_write_file(file);
-		if (err)
+		ret = mnt_want_write_file(file);
+		if (ret)
 			goto out;
 	}
 
@@ -2493,26 +2512,26 @@ static noinline int btrfs_ioctl_snap_destroy(struct file *file,
 
 	if (strchr(subvol_name, '/') ||
 	    strncmp(subvol_name, "..", subvol_namelen) == 0) {
-		err = -EINVAL;
+		ret = -EINVAL;
 		goto free_subvol_name;
 	}
 
 	if (!S_ISDIR(dir->i_mode)) {
-		err = -ENOTDIR;
+		ret = -ENOTDIR;
 		goto free_subvol_name;
 	}
 
-	err = down_write_killable_nested(&dir->i_rwsem, I_MUTEX_PARENT);
-	if (err == -EINTR)
+	ret = down_write_killable_nested(&dir->i_rwsem, I_MUTEX_PARENT);
+	if (ret == -EINTR)
 		goto free_subvol_name;
 	dentry = lookup_one(idmap, subvol_name, parent, subvol_namelen);
 	if (IS_ERR(dentry)) {
-		err = PTR_ERR(dentry);
+		ret = PTR_ERR(dentry);
 		goto out_unlock_dir;
 	}
 
 	if (d_really_is_negative(dentry)) {
-		err = -ENOENT;
+		ret = -ENOENT;
 		goto out_dput;
 	}
 
@@ -2532,7 +2551,7 @@ static noinline int btrfs_ioctl_snap_destroy(struct file *file,
 		 * Users who want to delete empty subvols should try
 		 * rmdir(2).
 		 */
-		err = -EPERM;
+		ret = -EPERM;
 		if (!btrfs_test_opt(fs_info, USER_SUBVOL_RM_ALLOWED))
 			goto out_dput;
 
@@ -2543,29 +2562,29 @@ static noinline int btrfs_ioctl_snap_destroy(struct file *file,
 		 * of the subvol, not a random directory contained
 		 * within it.
 		 */
-		err = -EINVAL;
+		ret = -EINVAL;
 		if (root == dest)
 			goto out_dput;
 
-		err = inode_permission(idmap, inode, MAY_WRITE | MAY_EXEC);
-		if (err)
+		ret = inode_permission(idmap, inode, MAY_WRITE | MAY_EXEC);
+		if (ret)
 			goto out_dput;
 	}
 
 	/* check if subvolume may be deleted by a user */
-	err = btrfs_may_delete(idmap, dir, dentry, 1);
-	if (err)
+	ret = btrfs_may_delete(idmap, dir, dentry, 1);
+	if (ret)
 		goto out_dput;
 
 	if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
-		err = -EINVAL;
+		ret = -EINVAL;
 		goto out_dput;
 	}
 
 	btrfs_inode_lock(BTRFS_I(inode), 0);
-	err = btrfs_delete_subvolume(BTRFS_I(dir), dentry);
+	ret = btrfs_delete_subvolume(BTRFS_I(dir), dentry);
 	btrfs_inode_unlock(BTRFS_I(inode), 0);
-	if (!err)
+	if (!ret)
 		d_delete_notify(dir, dentry);
 
 out_dput:
@@ -2582,7 +2601,7 @@ out_drop_write:
 out:
 	kfree(vol_args2);
 	kfree(vol_args);
-	return err;
+	return ret;
 }
 
 static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
@@ -2962,7 +2981,7 @@ static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
 		ret = PTR_ERR(new_root);
 		goto out;
 	}
-	if (!is_fstree(new_root->root_key.objectid)) {
+	if (!is_fstree(btrfs_root_id(new_root))) {
 		ret = -ENOENT;
 		goto out_free;
 	}
@@ -3739,15 +3758,43 @@ static long btrfs_ioctl_quota_ctl(struct file *file, void __user *arg)
 		goto drop_write;
 	}
 
-	down_write(&fs_info->subvol_sem);
-
 	switch (sa->cmd) {
 	case BTRFS_QUOTA_CTL_ENABLE:
 	case BTRFS_QUOTA_CTL_ENABLE_SIMPLE_QUOTA:
+		down_write(&fs_info->subvol_sem);
 		ret = btrfs_quota_enable(fs_info, sa);
+		up_write(&fs_info->subvol_sem);
 		break;
 	case BTRFS_QUOTA_CTL_DISABLE:
+		/*
+		 * Lock the cleaner mutex to prevent races with concurrent
+		 * relocation, because relocation may be building backrefs for
+		 * blocks of the quota root while we are deleting the root. This
+		 * is like dropping fs roots of deleted snapshots/subvolumes, we
+		 * need the same protection.
+		 *
+		 * This also prevents races between concurrent tasks trying to
+		 * disable quotas, because we will unlock and relock
+		 * qgroup_ioctl_lock across BTRFS_FS_QUOTA_ENABLED changes.
+		 *
+		 * We take this here because we have the dependency of
+		 *
+		 * inode_lock -> subvol_sem
+		 *
+		 * because of rename.  With relocation we can prealloc extents,
+		 * so that makes the dependency chain
+		 *
+		 * cleaner_mutex -> inode_lock -> subvol_sem
+		 *
+		 * so we must take the cleaner_mutex here before we take the
+		 * subvol_sem.  The deadlock can't actually happen, but this
+		 * quiets lockdep.
+		 */
+		mutex_lock(&fs_info->cleaner_mutex);
+		down_write(&fs_info->subvol_sem);
 		ret = btrfs_quota_disable(fs_info);
+		up_write(&fs_info->subvol_sem);
+		mutex_unlock(&fs_info->cleaner_mutex);
 		break;
 	default:
 		ret = -EINVAL;
@@ -3755,7 +3802,6 @@ static long btrfs_ioctl_quota_ctl(struct file *file, void __user *arg)
 	}
 
 	kfree(sa);
-	up_write(&fs_info->subvol_sem);
 drop_write:
 	mnt_drop_write_file(file);
 	return ret;
@@ -3901,7 +3947,7 @@ static long btrfs_ioctl_qgroup_limit(struct file *file, void __user *arg)
 	qgroupid = sa->qgroupid;
 	if (!qgroupid) {
 		/* take the current subvol as qgroup */
-		qgroupid = root->root_key.objectid;
+		qgroupid = btrfs_root_id(root);
 	}
 
 	ret = btrfs_limit_qgroup(trans, qgroupid, &sa->lim);
@@ -4032,7 +4078,7 @@ static long _btrfs_ioctl_set_received_subvol(struct file *file,
 	    !btrfs_is_empty_uuid(root_item->received_uuid)) {
 		ret = btrfs_uuid_tree_remove(trans, root_item->received_uuid,
 					  BTRFS_UUID_KEY_RECEIVED_SUBVOL,
-					  root->root_key.objectid);
+					  btrfs_root_id(root));
 		if (ret && ret != -ENOENT) {
 		        btrfs_abort_transaction(trans, ret);
 		        btrfs_end_transaction(trans);
@@ -4056,7 +4102,7 @@ static long _btrfs_ioctl_set_received_subvol(struct file *file,
 	if (received_uuid_changed && !btrfs_is_empty_uuid(sa->uuid)) {
 		ret = btrfs_uuid_tree_add(trans, sa->uuid,
 					  BTRFS_UUID_KEY_RECEIVED_SUBVOL,
-					  root->root_key.objectid);
+					  btrfs_root_id(root));
 		if (ret < 0 && ret != -EEXIST) {
 			btrfs_abort_transaction(trans, ret);
 			btrfs_end_transaction(trans);