Btrfs: fix chunk allocation error handling (04487488) · Commits · 戴 / test

If we error out allocating a dev extent we will have already created the block group and such which will cause problems since the allocator may have tried to allocate out of the block group that no longer exists. This will cause BUG_ON()'s in the bio submission path. This also makes a failure to allocate a dev extent a non-abort error, we will just clean up the dev extents we did allocate and exit. Now if we fail to delete the dev extents we will abort since we can't have half of the dev extents hanging around, but this will make us much less likely to abort. Thanks, Signed-off-by:

Josef Bacik <jbacik@fusionio.com>

fs/btrfs/volumes.c

+22 −10

Original line number	Diff line number	Diff line
		@@ -3825,12 +3825,6 @@ static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
		if (ret)
		goto error;

		ret = btrfs_make_block_group(trans, extent_root, 0, type,
		BTRFS_FIRST_CHUNK_TREE_OBJECTID,
		start, num_bytes);
		if (ret)
		goto error;

		for (i = 0; i < map->num_stripes; ++i) {
		struct btrfs_device *device;
		u64 dev_offset;
		@@ -3842,15 +3836,33 @@ static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
		info->chunk_root->root_key.objectid,
		BTRFS_FIRST_CHUNK_TREE_OBJECTID,
		start, dev_offset, stripe_size);
		if (ret) {
		btrfs_abort_transaction(trans, extent_root, ret);
		goto error;
		if (ret)
		goto error_dev_extent;
		}

		ret = btrfs_make_block_group(trans, extent_root, 0, type,
		BTRFS_FIRST_CHUNK_TREE_OBJECTID,
		start, num_bytes);
		if (ret) {
		i = map->num_stripes - 1;
		goto error_dev_extent;
		}

		kfree(devices_info);
		return 0;

		error_dev_extent:
		for (; i >= 0; i--) {
		struct btrfs_device *device;
		int err;

		device = map->stripes[i].dev;
		err = btrfs_free_dev_extent(trans, device, start);
		if (err) {
		btrfs_abort_transaction(trans, extent_root, err);
		break;
		}
		}
		error:
		kfree(map);
		kfree(devices_info);

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