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From: Qu Wenruo <quwenruo.btrfs@gmx.com>
To: Nikolay Borisov <nborisov@suse.com>, Qu Wenruo <wqu@suse.com>,
	linux-btrfs@vger.kernel.org
Subject: Re: [PATCH v2 2/3] btrfs: backref: Implement btrfs_backref_iterator_next()
Date: Fri, 14 Feb 2020 17:35:36 +0800	[thread overview]
Message-ID: <950d7c55-0e18-e710-4d2e-224b7bf054f2@gmx.com> (raw)
In-Reply-To: <4c5cae62-d74e-7ce4-2ed8-4cfc91f19059@suse.com>



On 2020/2/14 下午5:25, Nikolay Borisov wrote:
>
>
> On 14.02.20 г. 10:13 ч., Qu Wenruo wrote:
>> This function will go next inline/keyed backref for
>> btrfs_backref_iterator infrastructure.
>>
>> Signed-off-by: Qu Wenruo <wqu@suse.com>
>> ---
>>  fs/btrfs/backref.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++
>>  1 file changed, 48 insertions(+)
>>
>> diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c
>> index 73c4829609c9..c5f87439f31c 100644
>> --- a/fs/btrfs/backref.c
>> +++ b/fs/btrfs/backref.c
>> @@ -2310,3 +2310,51 @@ int btrfs_backref_iterator_start(struct btrfs_backref_iterator *iterator,
>>  	btrfs_release_path(path);
>>  	return ret;
>>  }
>> +
>> +int btrfs_backref_iterator_next(struct btrfs_backref_iterator *iterator)
>> +{
>
> make it a bool function.

Even when we could hit error in this case?

In the next patch, you would see we handle end of backrefs and error
different.
Thus I don't think it's a good idea to make it bool.

Thanks,
Qu
>
>> +	struct extent_buffer *eb = btrfs_backref_get_eb(iterator);
>> +	struct btrfs_path *path = iterator->path;
>> +	struct btrfs_extent_inline_ref *iref;
>> +	int ret;
>> +	u32 size;
>> +
>> +	if (iterator->cur_key.type == BTRFS_EXTENT_ITEM_KEY ||
>> +	    iterator->cur_key.type == BTRFS_METADATA_ITEM_KEY) {
>> +		/* We're still inside the inline refs */
>> +		if (btrfs_backref_has_tree_block_info(iterator)) {
>> +			/* First tree block info */
>> +			size = sizeof(struct btrfs_tree_block_info);
>> +		} else {
>> +			/* Use inline ref type to determine the size */
>> +			int type;
>> +
>> +			iref = (struct btrfs_extent_inline_ref *)
>> +				(iterator->cur_ptr);
>> +			type = btrfs_extent_inline_ref_type(eb, iref);
>> +
>> +			size = btrfs_extent_inline_ref_size(type);
>> +		}
>> +		iterator->cur_ptr += size;
>> +		if (iterator->cur_ptr < iterator->end_ptr)
>> +			return 0;
>> +
>> +		/* All inline items iterated, fall through */
>> +	}
>> +	/* We're at keyed items, there is no inline item, just go next item */
>> +	ret = btrfs_next_item(iterator->fs_info->extent_root, iterator->path);
>> +	if (ret > 0 || ret < 0)
>> +		return ret;
>> +
>> +	btrfs_item_key_to_cpu(path->nodes[0], &iterator->cur_key,
>> +			      path->slots[0]);
>> +	if (iterator->cur_key.objectid != iterator->bytenr ||
>> +	    (iterator->cur_key.type != BTRFS_TREE_BLOCK_REF_KEY &&
>> +	     iterator->cur_key.type != BTRFS_SHARED_BLOCK_REF_KEY))
>> +		return 1;
>> +	iterator->item_ptr = btrfs_item_ptr_offset(path->nodes[0],
>> +						   path->slots[0]);
>> +	iterator->cur_ptr = iterator->item_ptr;
>> +	iterator->end_ptr = btrfs_item_end_nr(path->nodes[0], path->slots[0]);
>> +	return 0;
>> +}
>>

  parent reply	other threads:[~2020-02-14  9:35 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-14  8:13 [PATCH v2 0/3] Btrfs: relocation: Refactor build_backref_tree() using btrfs_backref_iterator infrastructure Qu Wenruo
2020-02-14  8:13 ` [PATCH v2 1/3] btrfs: backref: Introduce the skeleton of btrfs_backref_iterator Qu Wenruo
2020-02-14  8:53   ` Johannes Thumshirn
2020-02-14  9:19   ` Nikolay Borisov
2020-02-14  9:33     ` Qu Wenruo
2020-02-14  9:36       ` Nikolay Borisov
2020-02-14  9:24   ` Nikolay Borisov
2020-02-14  9:34     ` Qu Wenruo
2020-02-14  8:13 ` [PATCH v2 2/3] btrfs: backref: Implement btrfs_backref_iterator_next() Qu Wenruo
2020-02-14  9:25   ` Nikolay Borisov
2020-02-14  9:28     ` Nikolay Borisov
2020-02-14  9:35     ` Qu Wenruo [this message]
2020-02-14  8:13 ` [PATCH v2 3/3] btrfs: relocation: Use btrfs_backref_iterator infrastructure Qu Wenruo
2020-02-14  9:00   ` Johannes Thumshirn
2020-02-14  9:36     ` Qu Wenruo
2020-02-14  9:29   ` Nikolay Borisov

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