Commit 6f9a3da5 authored by Josef Bacik's avatar Josef Bacik Committed by David Sterba
Browse files

btrfs: hold a ref on the root in btrfs_ioctl_send 



We lookup all the clone roots and the parent root for send, so we need
to hold refs on all of these roots while we're processing them.

Signed-off-by: default avatarJosef Bacik <josef@toxicpanda.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent fd79d43b

fs/btrfs/send.c

+24 −4
Original line number Diff line number Diff line
@@ -7201,10 +7201,16 @@ long btrfs_ioctl_send(struct file *mnt_file, struct btrfs_ioctl_send_args *arg) 
				ret = PTR_ERR(clone_root);

				goto out;

			}

			if (!btrfs_grab_fs_root(clone_root)) {

				srcu_read_unlock(&fs_info->subvol_srcu, index);

				ret = -ENOENT;

				goto out;

			}

			spin_lock(&clone_root->root_item_lock);

			if (!btrfs_root_readonly(clone_root) ||

			    btrfs_root_dead(clone_root)) {

				spin_unlock(&clone_root->root_item_lock);

				btrfs_put_fs_root(clone_root);

				srcu_read_unlock(&fs_info->subvol_srcu, index);

				ret = -EPERM;

				goto out;
@@ -7212,6 +7218,7 @@ long btrfs_ioctl_send(struct file *mnt_file, struct btrfs_ioctl_send_args *arg) 
			if (clone_root->dedupe_in_progress) {

				dedupe_in_progress_warn(clone_root);

				spin_unlock(&clone_root->root_item_lock);

				btrfs_put_fs_root(clone_root);

				srcu_read_unlock(&fs_info->subvol_srcu, index);

				ret = -EAGAIN;

				goto out;
@@ -7240,6 +7247,12 @@ long btrfs_ioctl_send(struct file *mnt_file, struct btrfs_ioctl_send_args *arg) 
			ret = PTR_ERR(sctx->parent_root);

			goto out;

		}

		if (!btrfs_grab_fs_root(sctx->parent_root)) {

			srcu_read_unlock(&fs_info->subvol_srcu, index);

			ret = -ENOENT;

			sctx->parent_root = ERR_PTR(ret);

			goto out;

		}



		spin_lock(&sctx->parent_root->root_item_lock);

		sctx->parent_root->send_in_progress++;
@@ -7267,7 +7280,8 @@ long btrfs_ioctl_send(struct file *mnt_file, struct btrfs_ioctl_send_args *arg) 
	 * is behind the current send position. This is checked while searching

	 * for possible clone sources.

	 */

	sctx->clone_roots[sctx->clone_roots_cnt++].root = sctx->send_root;

	sctx->clone_roots[sctx->clone_roots_cnt++].root =

		btrfs_grab_fs_root(sctx->send_root);



	/* We do a bsearch later */

	sort(sctx->clone_roots, sctx->clone_roots_cnt,
@@ -7352,18 +7366,24 @@ long btrfs_ioctl_send(struct file *mnt_file, struct btrfs_ioctl_send_args *arg) 
	}



	if (sort_clone_roots) {

		for (i = 0; i < sctx->clone_roots_cnt; i++)

		for (i = 0; i < sctx->clone_roots_cnt; i++) {

			btrfs_root_dec_send_in_progress(

					sctx->clone_roots[i].root);

			btrfs_put_fs_root(sctx->clone_roots[i].root);

		}

	} else {

		for (i = 0; sctx && i < clone_sources_to_rollback; i++)

		for (i = 0; sctx && i < clone_sources_to_rollback; i++) {

			btrfs_root_dec_send_in_progress(

					sctx->clone_roots[i].root);

			btrfs_put_fs_root(sctx->clone_roots[i].root);

		}



		btrfs_root_dec_send_in_progress(send_root);

	}

	if (sctx && !IS_ERR_OR_NULL(sctx->parent_root))

	if (sctx && !IS_ERR_OR_NULL(sctx->parent_root)) {

		btrfs_root_dec_send_in_progress(sctx->parent_root);

		btrfs_put_fs_root(sctx->parent_root);

	}



	kvfree(clone_sources_tmp);