From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx.mylinuxtime.de (mx.mylinuxtime.de [46.4.70.188]) (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 E4A9D9461 for ; Tue, 20 May 2025 12:46:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=46.4.70.188 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747745188; cv=none; b=mKmW9qV13J5T44zIKXRB0/FCdQQZd1Ej6WxyMolY8iXzQAcMsjcTgOw1bFJRE1Ep6LoLT5MzCu/S9MH5niF8n6yD/LYe0zMlAAqFa1u5PQDw2ifCteQzzNRJ2mKzBNrHmHWHmoak6CJxuLwm+0GyTiPQ+7USneOZYk7Qfbk1WGA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747745188; c=relaxed/simple; bh=Vgz+W7HUHyTtHeA/lFhxFQ1CaIuoOLy+3QBE7FjmF+M=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=kwHhpY9ucUsqXRZu/Uagjr9YYSELpZnwBlvYVIt9XLNXV7D9+BKJj9B2uTd+b2q+kG3kYv6KAZkSTsGd1/+LY4qbGZyyrDki7ERPAZxA9KAiWxF1P1b5pW3n8UCrhOfeZn4Pvrj85h7Vx6nTE6c1a9f7Ioz2B3uEon60bv+uW8c= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=eworm.de; spf=pass smtp.mailfrom=eworm.de; arc=none smtp.client-ip=46.4.70.188 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=eworm.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=eworm.de Received: from leda.eworm.net (unknown [194.36.25.6]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange x25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mx.mylinuxtime.de (Postfix) with ESMTPSA id 7B44225CBBB; Tue, 20 May 2025 14:46:23 +0200 (CEST) Authentication-Results: mx.mylinuxtime.de; auth=pass smtp.auth=mail@eworm.de smtp.mailfrom=mail@eworm.de Date: Tue, 20 May 2025 14:46:22 +0200 From: Christian Hesse To: "Xu, Lizhi" Cc: "hch@infradead.org" , "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: <20250520144622.3fd9592a@leda.eworm.net> In-Reply-To: References: <20250519175640.2fcac001@leda.eworm.net> <20250520030051.177205-1-lizhi.xu@windriver.com> <20250520073901.6fdfbee4@leda.eworm.net> X-Mailer: Claws Mail 4.3.1 (GTK 3.24.49; x86_64-pc-linux-gnu) X-Face: %O:rCSkHSKf7^4uF|FD$9$I0}g$nbnS1{DYPvs#:,~e`).mzj\$P9]V!WCveE/XdbL,L!{)6v%x4\Bt!b#{;dS&h"7l=ow'^({02!2%XOugod|u*mYBVm-OS:VpZ"ZrRA4[Q&zye,^j;ftj!Hxx\1@;LM)Pz)|B%1#sfF;s;,N?*K*^) Face: 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 Precedence: bulk X-Mailing-List: linux-block@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: multipart/signed; boundary="Sig_/8pW2UZ//kv2J.2flyWDV=A."; protocol="application/pgp-signature"; micalg=pgp-sha512 X-Spamd-Bar: / X-Spamd-Result: default: False [0.00 / 15.00]; TAGGED_RCPT(0.00)[6af973a3b8dfd2faefdc] X-Rspamd-Server: mx X-Rspamd-Queue-Id: 7B44225CBBB X-Stat-Signature: ezmxporh1di5juoau9gmrtmb8gkatif8 X-Rspamd-Action: no action --Sig_/8pW2UZ//kv2J.2flyWDV=A. Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable "Xu, Lizhi" on Tue, 2025/05/20 12:27: > 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, Just tested with an iso file where writable flag from loopback file inside was explicitly removed. No change. > the problem will recur because isofs does not support write_iter. We have two indications here that setup should happen in read-only mode: * The underlaying filesystem is read-only * `losetup` is called with switch `--read-only` I would expect both to make this happy. --=20 Best regards, Chris --Sig_/8pW2UZ//kv2J.2flyWDV=A. 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