From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 4932E3B5820 for ; Fri, 11 Sep 2026 08:11:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789114272; cv=none; b=cacUhHzyAAR6OYUn1u2n4nixokAlLHXvuesQgPJfA0UZ+RQlQ4xbt7S/pMUNWPRlDObIqDtPcHCVdxEz/WUigQyFr3VMIem4ExsmdPvDp/mcqHbk+psLyGZicU7VZ/bg5aR0puVfHmt1kdJRkNUsPbaOL3WD6WOZaA7sE1j9SWs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789114272; c=relaxed/simple; bh=9EWyKxpvwDuyXTv1d+2e/EeTIXfhXvw4dndst9H/9BE=; h=From:In-Reply-To:References:To:Cc:Subject:MIME-Version: Content-Type:Date:Message-ID; b=M1/JLIltQcA/ewZt0U48DWZ/V7ZR8kd6yyxLaBUMbIbl4ajoc9raG8nWLI7d2XhKOfRI6McpVz007wbClf/JTE/SYG9KfxIEPokvShVSi1ENjmSagjfsEaRhs3NLN+stbNskmTOsFQGT9C3vvCpguTJ5btJgHLmeyZ1XyS4nxb8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=cX+3Brqi; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="cX+3Brqi" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1789114270; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=KM7H7X1d32hwES9HmLQ+a3yj4IwaejBWYAwsQEvzy9Y=; b=cX+3BrqicfU/qzHopEyJDrNVkeNqmoB3/wLFb8S18ea+5RJqLFDjTa6NdJBpOeP7cBSB8x rhBwrNlWbJxDkB/CQ5Vjs+YPEek/oklG8G92IR0ydXqx6JEdDtLi6rx8rsOFbJGt/lg7TY 765G2qO7D85D8XFTD5jY4xd9ytM5ixg= Received: from mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-222-tPEIzxiRNvWbEVqVnvybBw-1; Fri, 11 Sep 2026 04:11:04 -0400 X-MC-Unique: tPEIzxiRNvWbEVqVnvybBw-1 X-Mimecast-MFC-AGG-ID: tPEIzxiRNvWbEVqVnvybBw_1789114262 Received: from mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.12]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id BB9AF1956072; Fri, 11 Sep 2026 08:11:01 +0000 (UTC) Received: from warthog.procyon.org.uk (unknown [10.44.32.54]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 758071956088; Fri, 11 Sep 2026 08:10:57 +0000 (UTC) Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 From: David Howells In-Reply-To: References: To: Michael Mulqueen Cc: dhowells@redhat.com, ericvh@kernel.org, lucho@ionkov.net, asmadeus@codewreck.org, pc@manguebit.org, linux_oss@crudebyte.com, v9fs@lists.linux.dev, netfs@lists.linux.dev, linux-fsdevel@vger.kernel.org, regressions@lists.linux.dev Subject: Re: PROBLEM: [REGRESSION 7.1-rc4 -> 7.1-rc5] 9p: silent NUL corruption of file data on cache modes with CACHE_WRITEBACK Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <2217383.1789114255.1@warthog.procyon.org.uk> Date: Fri, 11 Sep 2026 09:10:55 +0100 Message-ID: <2217384.1789114255@warthog.procyon.org.uk> X-Scanned-By: MIMEDefang 3.0 on 10.30.177.12 Michael Mulqueen wrote: > cache=none read 0/20 write 0/20 [cache=0x0] > cache=readahead read 0/20 write 0/20 [cache=0x1] > cache=mmap read 20/20 write 20/20 [cache=0x5] > cache=loose read 20/20 write 20/20 [cache=0xf] > cache=fscache read 20/20 write 20/20 [cache=0x8f] I presume these should all be 0/20? When I have a cachefiles cache active, I see: cache=none read 0/20 write 0/20 [cache=0x0] cache=readahead read 0/20 write 0/20 [cache=0x1] cache=mmap read 20/20 write 20/20 [cache=0x5] cache=loose read 20/20 write 20/20 [cache=0xf] cache=fscache read 0/20 write 20/20 [cache=0x8f] so I suspect on the last one, the data is drawn from fscache, not from the server. David