From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from zeniv.linux.org.uk (zeniv.linux.org.uk [62.89.141.173]) (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 A08DE45014; Thu, 1 Aug 2024 07:24:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=62.89.141.173 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722497099; cv=none; b=tIOysdvAr66FwDIaRbvifdvydOarmDCRxwZiOEuZr42C6jywpprgrwMUIhGz0fGmmqMdy5hDnlLU4Dk4cdVCgqXlMugfZuFxhSwx76z2MVI6Q+ZY2nsxBQlWYY6crg1d3blp7GH7/nco7AHgDv2gfekDP1P6T5DmVAhpusRiKSU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722497099; c=relaxed/simple; bh=2HNoRexbz5ZcFsC1CtZFUw1wgKE76RZOM7uGszyRPCo=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=AD2pPMCb41L25VYW+UWQmf0x/ev6A/Y2woheHI8Yv6LReWBLpD8q+62oF7qF6t+OtZrjaSDxndQrQvdwEuQyTFC0VnTnEiPaHKq+eGEIfzukwWUg08WFgeKhsMym+mdcUZIYH+L61wfOwMEUwE7H+MaEnXsyLaNdm6+cS2uHjZk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zeniv.linux.org.uk; spf=none smtp.mailfrom=ftp.linux.org.uk; dkim=pass (2048-bit key) header.d=linux.org.uk header.i=@linux.org.uk header.b=qBsdv7G/; arc=none smtp.client-ip=62.89.141.173 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zeniv.linux.org.uk Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=ftp.linux.org.uk Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linux.org.uk header.i=@linux.org.uk header.b="qBsdv7G/" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=linux.org.uk; s=zeniv-20220401; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=5gEw2jBq+pJZyxL14pOnd54uIBriCAkLD3oM19s7V3M=; b=qBsdv7G/in+L7XCMrw476taL0Z 9epABP9KZFbkaknuE+wnyXqdFcb8HMKwqAdgl4UhFkfQpwcKbkSZrHHhq1avVhhFGTDbsxLtOq6v/ qkWf/DzOYdo8Rzs+q7FpZtlWk4M1pcP4KcfgOmoJTzXcU0qUbMR9miYrpiDHbd4oEe3e48HzDUNVR txJnFlJK9HAGfzBmyoeX0okDcHRaWpOdw7fKa9VYmpGvKz+z6nwjIjeAeXPKeYH5NEUB56yAaoG0I c7C57IhIFzEUteKOFuUWYMn/cM34UvpqwYFR+BwmuceCF6uwg8FXrg9TQ2ujSOUypB+RikARdJ3Wf qQ9XhQvg==; Received: from viro by zeniv.linux.org.uk with local (Exim 4.98 #2 (Red Hat Linux)) id 1sZQBC-00000000fJT-3J2W; Thu, 01 Aug 2024 07:24:54 +0000 Date: Thu, 1 Aug 2024 08:24:54 +0100 From: Al Viro To: Lizhi Xu Cc: brauner@kernel.org, jack@suse.cz, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, phillip@squashfs.org.uk, squashfs-devel@lists.sourceforge.net, syzbot+24ac24ff58dc5b0d26b9@syzkaller.appspotmail.com, syzkaller-bugs@googlegroups.com Subject: Re: Re: [PATCH] filemap: Init the newly allocated folio memory to 0 for the filemap Message-ID: <20240801072454.GO5334@ZenIV> References: <20240801025842.GM5334@ZenIV> <20240801052837.3388478-1-lizhi.xu@windriver.com> <20240801071016.GN5334@ZenIV> 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-Disposition: inline In-Reply-To: <20240801071016.GN5334@ZenIV> Sender: Al Viro On Thu, Aug 01, 2024 at 08:10:16AM +0100, Al Viro wrote: > Your patch is basically "fill the page with zeroes before reading anything > into it". It makes KMSAM warning STFU, but it does not fix anything > in any of those cases. Incidentally, it does that before it goes ahead and calls filemap_read_folio(), with ->read_folio() as callback. So if it does make it STFU, the case 1 (->read_folio() not called at all) is out of running. Would be interesting to see if that particular ->read_folio() is returning errors and if so - what errors are actually returned.