Re: [PATCH v1 05/11] dm-pcache: add cache_segment

[Dongsheng Yang <dongsheng.yang@linux.dev>]

在 7/1/2025 10:59 PM, Jonathan Cameron 写道:
> On Tue, 24 Jun 2025 07:33:52 +0000
> Dongsheng Yang <dongsheng.yang@linux.dev> wrote:
>
>> Introduce *cache_segment.c*, the in-memory/on-disk glue that lets a
>> `struct pcache_cache` manage its array of data segments.
>>
>> * Metadata handling
>>    - Loads the most-recent replica of both the segment-info block
>>      (`struct pcache_segment_info`) and per-segment generation counter
>>      (`struct pcache_cache_seg_gen`) using `pcache_meta_find_latest()`.
>>    - Updates those structures atomically with CRC + sequence rollover,
>>      writing alternately to the two metadata slots inside each segment.
>>
>> * Segment initialisation (`cache_seg_init`)
>>    - Builds a `struct pcache_segment` pointing to the segment’s data
>>      area, sets up locks, generation counters, and, when formatting a new
>>      cache, zeroes the on-segment kset header.
>>
>>
>> +
>> +	cache = cache_seg->cache;
>> +	cache_seg_gen_increase(cache_seg);
>> +
>> +	spin_lock(&cache->seg_map_lock);
>> +	if (cache->cache_full)
>> +		cache->cache_full = false;
> Perhaps just write cache->cache_full = false unconditionally?
> If there is a reason to not do the write, then add a comment here.
Hi Jonathan,

When the cache->cache_full is already false, we don't need to write 
cache->cache_full with false.


Thanx

Dongsheng


>
>> +	clear_bit(cache_seg->cache_seg_id, cache->seg_map);
>> +	spin_unlock(&cache->seg_map_lock);
>> +
>> +	pcache_defer_reqs_kick(CACHE_TO_PCACHE(cache));
>> +	/* clean_work will clean the bad key in key_tree*/
>> +	queue_work(cache_get_wq(cache), &cache->clean_work);
>> +}