From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-179.mta0.migadu.com (out-179.mta0.migadu.com [91.218.175.179]) (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 99C4D2882CE for ; Wed, 3 Dec 2025 05:57:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.179 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764741445; cv=none; b=WnzDAPuOnHOA3jCvi01IDuDcNySGPl3+wy4XkFtX/g+vtWoXSKpfcCbao710WDAnxoRujF9B50zFASWsWB1xva0i+hvUEf3BfllzCI+q/bsNhRsjhVmo/u5Ij6um9gbwHPTni6cd8GN7zHl6GC1EwdZgAVnibdNmrQ0Wya/1YSc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764741445; c=relaxed/simple; bh=4GCIQG+lt8jY6ue6xWQEXgFjzW+jzKcsDapCJ+7QPKU=; h=Message-ID:Date:MIME-Version:Subject:To:References:From: In-Reply-To:Content-Type; b=V7/4Knw6XTYvGZCJpai9R1IEJbe44bpHlW48YHYrKJL4YkglhFdd8+kYRop5eY1IqXfuzF5XPaQZULKRWoSE4775hRoWb8j31Vj79W/DWlQyOpLZs6Qm1GkNxcX+RmE5gPtlisWgrfFpb1jkXRAnoR44pLJrNheU2q8zcqyY8mY= 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=lZ/dsYrh; arc=none smtp.client-ip=91.218.175.179 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="lZ/dsYrh" Message-ID: <8794c32c-790c-4503-a657-3e66bc541cda@linux.dev> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1764741441; 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=eCvkkXbg15ThEGqxvsHecDKTzDwXwzoFR00iY8d3ftA=; b=lZ/dsYrhRAySm5L7njT09eYtk9mjaneMPMpkwtND+2JVVKmB/KrzEiEOrI1se7ljwN9niR tMhCpaZBRkI1WDb/83solKtUj+uG8+9PKXgVxeBkJZbgfFGDWoxkDKGxqVUWcs7CmoVhld MDumetCX+TUNHdiJ0wHssPBWFuJkpCA= Date: Wed, 3 Dec 2025 13:57:15 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [PATCH 2/2] dm pcache: fix segment info indexing To: Li Chen , dm-devel@lists.linux.dev, linux-kernel@vger.kernel.org, Zheng Gu References: <20251202121158.111092-1-me@linux.beauty> <20251202121158.111092-3-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: <20251202121158.111092-3-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 > > Segment info indexing also used sizeof(struct) instead of the > 4K metadata stride, so info_index could point between slots and > subsequent writes would advance incorrectly. Derive info_index > from the pointer returned by the segment meta search using > PCACHE_SEG_INFO_SIZE and advance to the next slot for future > updates. > > Signed-off-by: Li Chen > --- > drivers/md/dm-pcache/cache_segment.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/drivers/md/dm-pcache/cache_segment.c b/drivers/md/dm-pcache/cache_segment.c > index f0b58980806e..0b4bb08011ce 100644 > --- a/drivers/md/dm-pcache/cache_segment.c > +++ b/drivers/md/dm-pcache/cache_segment.c > @@ -56,7 +56,11 @@ static int cache_seg_info_load(struct pcache_cache_segment *cache_seg) > ret = -EIO; > goto out; > } > - cache_seg->info_index = cache_seg_info_addr - cache_seg_info_addr_base; > + > + cache_seg->info_index = > + ((char *)cache_seg_info_addr - (char *)cache_seg_info_addr_base) / > + PCACHE_SEG_INFO_SIZE; > + cache_seg->info_index = (cache_seg->info_index + 1) % PCACHE_META_INDEX_MAX; Don't advance info_index at init stage. > out: > mutex_unlock(&cache_seg->info_lock); >