From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 0569E167D83 for ; Mon, 19 Aug 2024 11:59:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724068793; cv=none; b=oTbnAsOzcpkllKxzZq/cMZfvlEKfnaIiQcE/5nhqB3boi3zSJGC4/T0rYalywhSfZwVI5TdB83xfpe1b/6iBwZo4YuMLIOB5wCPVQ0ehL9+fvWdNahFPCUIPshqmlC6BqWNQ81KqM8cSDCX1LMtsRdyXXYZcC4mitymoDWLNDok= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724068793; c=relaxed/simple; bh=QoDrXZXFlLjJRrcfSVsie6OGUkt4QrKIKGi1LCthZaA=; h=From:In-Reply-To:References:Cc:Subject:MIME-Version:Content-Type: Date:Message-ID; b=gJAXxKy9hMBziq00UAKCgTHnMvWsZAvwMdlP6YgeVbh4MV9gUtctk16DQqbcL2R3n5wfmoCb5zd2TOymlpJBy5i42ssDbVk0Wn8Sv5tr1i5FenIlsxQQTmiOH1/bgaLuYyQCIeSWNJXv+m46GfW3zSjejDUzrPMle+zSe2G9Euk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none 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=fcIdoSFc; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none 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="fcIdoSFc" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1724068790; h=from:from:reply-to:subject:subject:date:date:message-id:message-id:to: cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=nSDk9RrUaqqTiS3gE8YAv0OqBuyGmh41yRuUpfpoLP4=; b=fcIdoSFcs5Je/WCbx4Cd0nSI4raS0XCY8LIrHF31HvNoRE7APrAq9Wd/LHbzB9A+l/AbSs 0vmVXYmyK077RxdFPg9GP/HXJihasEquVAnESo2K1gfrAkaT4nwMR1TFb+r54z2UPRwH0h ig0zBdZGA6sT6Mi03OrCcRZdkZCtJdc= Received: from mx-prod-mc-02.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-665-y-oQF2GQOyaLK-9XZ_4nzw-1; Mon, 19 Aug 2024 07:59:43 -0400 X-MC-Unique: y-oQF2GQOyaLK-9XZ_4nzw-1 Received: from mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.15]) (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-02.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 8403F1954B1D; Mon, 19 Aug 2024 11:59:40 +0000 (UTC) Received: from warthog.procyon.org.uk (unknown [10.42.28.30]) by mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id AEB1619773E0; Mon, 19 Aug 2024 11:59:33 +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: <3402933.1724068015@warthog.procyon.org.uk> References: <3402933.1724068015@warthog.procyon.org.uk> <20240818165124.7jrop5sgtv5pjd3g@quentin> <20240815090849.972355-1-kernel@pankajraghav.com> <2924797.1723836663@warthog.procyon.org.uk> Cc: dhowells@redhat.com, "Pankaj Raghav (Samsung)" , brauner@kernel.org, akpm@linux-foundation.org, chandan.babu@oracle.com, linux-fsdevel@vger.kernel.org, djwong@kernel.org, hare@suse.de, gost.dev@samsung.com, linux-xfs@vger.kernel.org, hch@lst.de, david@fromorbit.com, Zi Yan , yang@os.amperecomputing.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, willy@infradead.org, john.g.garry@oracle.com, cl@os.amperecomputing.com, p.raghav@samsung.com, mcgrof@kernel.org, ryan.roberts@arm.com Subject: Re: [PATCH v12 00/10] enable bs > ps in XFS Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <3405742.1724068772.1@warthog.procyon.org.uk> Content-Transfer-Encoding: quoted-printable Date: Mon, 19 Aug 2024 12:59:32 +0100 Message-ID: <3405743.1724068772@warthog.procyon.org.uk> X-Scanned-By: MIMEDefang 3.0 on 10.30.177.15 David Howells wrote: > You can see the invalidate_folio call, with the offset at 0x4 an the len= gth as > 0x1ffc. The data at the beginning of the page is 0x78787878. This look= s > correct. > = > Then second ftruncate() is called to increase the file size to 4096 > (ie. 0x1000): > = > pankaj-5833: netfs_truncate: ni=3D9e isz=3D4 rsz=3D4 zp=3D4 to=3D1000 > pankaj-5833: netfs_inval_folio: pfn=3D116fec i=3D0009e ix=3D00000-00001= o=3D1000 l=3D1000 d=3D78787878 > pankaj-5833: netfs_folio: pfn=3D116fec i=3D0009e ix=3D00000-00001 inval= -part > pankaj-5833: netfs_set_size: ni=3D9e resize-file isz=3D1000 rsz=3D1000 = zp=3D4 > = > And here's the problem: in the invalidate_folio() call, the offset is 0x= 1000 > and the length is 0x1000 (o=3D and l=3D). But that's the wrong half of = the folio! > I'm guessing that the caller thereafter clears the other half of the fol= io - > the bit that should be kept. Actually, I think I'm wrong in my evaluation - I think that's the region t= o be invalidated, not the region to be kept. David