From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-174.mta0.migadu.com (out-174.mta0.migadu.com [91.218.175.174]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1A99A28BAB9 for ; Wed, 3 Dec 2025 05:56:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.174 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764741410; cv=none; b=R0dKmWDOlOxBWNj7vYMlhf9L+QhtJkv7/my1hutB9zv5UNKOPelB0RmBsEAQBFY/ZLbh4mfnWZpbtH++2NMy7caLvlwcfC/muiKCdZSXfgmKhnNlv+c0xs1SZDofSGgnD7kU0u5H2cWFv6KyUIqqy1PvHIIYTqYFoQ35cXLaufQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764741410; c=relaxed/simple; bh=5ZrUUDzqyEBt/iATXAB/q6QU9jtVYshbONnz4kURwvY=; h=Message-ID:Date:MIME-Version:Subject:To:References:From: In-Reply-To:Content-Type; b=nIv97oz/tCwPC8oHIp2CIbO0blHkceBJj2RdhyQNivOc1Ugf51SAQ50UqgzEb0lNRIZXO4tZJH34Kpfx6EyhCfpEO9d9ckym495uVFt07Mq1Ume/YyUGyqLoSvNGy5ZWtF+Rdvkqc489LjLxKAF9ACemjbpKMsbRpGx5cFLtmFQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=DUSEGFhZ; arc=none smtp.client-ip=91.218.175.174 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="DUSEGFhZ" Message-ID: <3222d76f-3710-4238-b90e-cd1deb0d0912@linux.dev> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1764741403; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=N+czyqnIDQE6KDJv0xAhaoeWiZJ0vfby3Nl1tJ+ICKs=; b=DUSEGFhZh86O0eVZk/UQa7G7UZsV6v+CKuItK8aWaBweuEKOQ2IWd9wcwWrOHL/hUCzpMh 2PuYE9hYFz900dXR9vpNtGjRq5ikR1RDd2NkG1spBNiu1obyxjTLXJW63lGFdBzXXuL7G0 DX4cUKZFKCERh1Fo2TPAvc8Buq2CDo8= Date: Wed, 3 Dec 2025 13:56:33 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [PATCH 1/2] dm pcache: fix cache info indexing To: Li Chen , dm-devel@lists.linux.dev, linux-kernel@vger.kernel.org, Zheng Gu References: <20251202121158.111092-1-me@linux.beauty> <20251202121158.111092-2-me@linux.beauty> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Dongsheng Yang In-Reply-To: <20251202121158.111092-2-me@linux.beauty> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT 在 12/2/2025 8:11 PM, Li Chen 写道: > From: Li Chen > > The on-media cache_info index used sizeof(struct) instead of the > 4K metadata stride, so gc_percent updates from dmsetup message > were written between slots and lost after reboot. Use > PCACHE_CACHE_INFO_SIZE in get_cache_info_addr() and align > info_index with the slot returned by pcache_meta_find_latest(). > > Signed-off-by: Li Chen > --- > drivers/md/dm-pcache/cache.c | 13 ++++++++++--- > 1 file changed, 10 insertions(+), 3 deletions(-) > > diff --git a/drivers/md/dm-pcache/cache.c b/drivers/md/dm-pcache/cache.c > index 698697a7a73c..6d5001548628 100644 > --- a/drivers/md/dm-pcache/cache.c > +++ b/drivers/md/dm-pcache/cache.c > @@ -8,9 +8,11 @@ > > struct kmem_cache *key_cache; > > -static inline struct pcache_cache_info *get_cache_info_addr(struct pcache_cache *cache) > +static inline struct pcache_cache_info * > +get_cache_info_addr(struct pcache_cache *cache) > { > - return cache->cache_info_addr + cache->info_index; > + return (struct pcache_cache_info *)((char *)cache->cache_info_addr + > + (size_t)cache->info_index * PCACHE_CACHE_INFO_SIZE); > } > > static void cache_info_write(struct pcache_cache *cache) > @@ -40,7 +42,12 @@ static int cache_info_init(struct pcache_cache *cache, struct pcache_cache_optio > if (IS_ERR(cache_info_addr)) > return PTR_ERR(cache_info_addr); > > - if (cache_info_addr) { > + if (cache_info_addr) { this is unrelated change, and it introduce error in checkpatch.pl # ./scripts/checkpatch.pl drivers/md/dm-pcache/cache.c WARNING: please, no spaces at the start of a line #45: FILE: drivers/md/dm-pcache/cache.c:45: +    if (cache_info_addr) {$ WARNING: suspect code indent for conditional statements (4, 16) #45: FILE: drivers/md/dm-pcache/cache.c:45: +    if (cache_info_addr) { +               int index = ((char *)cache_info_addr - (char *)cache->cache_info_addr) / total: 0 errors, 2 warnings, 452 lines checked > + int index = ((char *)cache_info_addr - (char *)cache->cache_info_addr) / > + PCACHE_CACHE_INFO_SIZE; > + > + cache->info_index = (index + 1) % PCACHE_META_INDEX_MAX; Don't advance info_index at init stage, cache->info_index means the current index, not the next index. It will be advanced in cache_info_write() after write cache_info into next slot. In addition, cache->info_index initialization should be after the data_crc checking. Thanx > + > if (opts->data_crc != > (cache->cache_info.flags & PCACHE_CACHE_FLAGS_DATA_CRC)) { > pcache_dev_err(pcache, "invalid option for data_crc: %s, expected: %s",