From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 0DDE414A4E0; Tue, 20 May 2025 12:46:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.133 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747745221; cv=none; b=ffcaZuiWrYNZgRI+vw+0Zetnh3FGY/4A8RZhcVICg/ON4ooren04OveTBjm7P3TV3ICe5MLgCqCaLyBtGHys+215LhN2AQi+IllsLQng4kChigjTZBC0Q5mawQP4/2rUYr/0LNXKcoF3CkzFtw5ZiDvACuiAKcHJesVgRuMQf6k= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747745221; c=relaxed/simple; bh=ZTVDXCWpd1QEoEKJfvPRMxvirYpRzQgOcYKSupGJ4zw=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=j43AuWZ+G+olXJlI4zpLK2XRlC5pV1MKb7C8EezXUE9tRVfEaM+zw9h9UBhLIHBbuNrRVFe9dINuv0t8tRHj/t4QGWWqXygZZjZozx8Pjh5jSCLLGpxkGe2nDjOhRCg0BzzSfgASrfrrLpPTIMdbsX/LZzWYgbKCFgmR52L4f70= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=2HeBJmdq; arc=none smtp.client-ip=198.137.202.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="2HeBJmdq" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=ZTVDXCWpd1QEoEKJfvPRMxvirYpRzQgOcYKSupGJ4zw=; b=2HeBJmdq+Q8wq6tgF53cu3I9gn UyWXlhaIVFxja+E9NUiyIpYm14biAPbYwvU5FmhWt28cpkRZKve/NF+eUKcLDn7LDoQoPIblMEI3b cYy277h886hzpZscnzSBkEiCV0cFHTWPGAyq8ATjWeF8tVCa8qRvbt5idGeD3IzQjNGi8Tq9cbJKk UYuY5468dxZjz4rv6xMyoM+kEku+sz1WYZutbD97EPd/i+vIWsTd+EGhUQAUPfoOuLsBlvsrylt6t ppubInRIIf0/xCuNEQUkJOTL3+VNVT6gTabweaRYi7Oi/HD0YbIlTtfxZA46xEVG3RB7EyVrsuRQr 2LzOOynw==; Received: from hch by bombadil.infradead.org with local (Exim 4.98.2 #2 (Red Hat Linux)) id 1uHMMx-0000000CutE-1Kj9; Tue, 20 May 2025 12:46:55 +0000 Date: Tue, 20 May 2025 05:46:55 -0700 From: "hch@infradead.org" To: "Xu, Lizhi" Cc: "hch@infradead.org" , Christian Hesse , "axboe@kernel.dk" , "christian@heusel.eu" , "linux-block@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "ming.lei@redhat.com" , "syzbot+6af973a3b8dfd2faefdc@syzkaller.appspotmail.com" , "syzkaller-bugs@googlegroups.com" Subject: Re: [PATCH V5] loop: Add sanity check for read/write_iter Message-ID: References: <20250519175640.2fcac001@leda.eworm.net> <20250520030051.177205-1-lizhi.xu@windriver.com> <20250520073901.6fdfbee4@leda.eworm.net> 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-Disposition: inline In-Reply-To: X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html On Tue, May 20, 2025 at 12:27:44PM +0000, Xu, Lizhi wrote: > isofs does not support read_iter (I used a directory when testing). > If it is a regular file, generic_ro_fops is used. In this case, > isofs supports read_iter. When a regular file has a writable attribute, > the problem will recur because isofs does not support write_iter. All Linux filesystems do (or at least should) point read on directories to generic_read_dir which returns -EISDIR as reading from directories is not supported.