Btrfs: update drop progress before stopping snapshot dropping (3c8f2422) · Commits · 戴 / test

Alex pointed out a problem and fix that exists in the drop one snapshot at a time patch. If we decide we need to exit for whatever reason (umount for example) we will just exit the snapshot dropping without updating the drop progress. So the next time we go to resume we will BUG_ON() because we can't find the extent we left off at because we never updated it. This patch fixes the problem. Cc: stable@vger.kernel.org Reported-by:

Alex Lyakas <alex.btrfs@zadarastorage.com> Signed-off-by:

Josef Bacik <jbacik@fusionio.com>

fs/btrfs/extent-tree.c

+8 −6

Original line number	Diff line number	Diff line
		@@ -7552,11 +7552,6 @@ int btrfs_drop_snapshot(struct btrfs_root *root,
		wc->reada_count = BTRFS_NODEPTRS_PER_BLOCK(root);

		while (1) {
		if (!for_reloc && btrfs_need_cleaner_sleep(root)) {
		pr_debug("btrfs: drop snapshot early exit\n");
		err = -EAGAIN;
		goto out_end_trans;
		}

		ret = walk_down_tree(trans, root, path, wc);
		if (ret < 0) {
		@@ -7584,7 +7579,8 @@ int btrfs_drop_snapshot(struct btrfs_root *root,
		}

		BUG_ON(wc->level == 0);
		if (btrfs_should_end_transaction(trans, tree_root)) {
		if (btrfs_should_end_transaction(trans, tree_root) \|\|
		(!for_reloc && btrfs_need_cleaner_sleep(root))) {
		ret = btrfs_update_root(trans, tree_root,
		&root->root_key,
		root_item);
		@@ -7595,6 +7591,12 @@ int btrfs_drop_snapshot(struct btrfs_root *root,
		}

		btrfs_end_transaction_throttle(trans, tree_root);
		if (!for_reloc && btrfs_need_cleaner_sleep(root)) {
		pr_debug("btrfs: drop snapshot early exit\n");
		err = -EAGAIN;
		goto out_free;
		}

		trans = btrfs_start_transaction(tree_root, 0);
		if (IS_ERR(trans)) {
		err = PTR_ERR(trans);

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