From mboxrd@z Thu Jan 1 00:00:00 1970 Delivery-date: Wed, 03 Sep 2025 14:16:51 +0200 Received: from metis.whiteo.stw.pengutronix.de ([2a0a:edc0:2:b01:1d::104]) by lore.white.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1utmQ0-007e01-1V for lore@lore.pengutronix.de; Wed, 03 Sep 2025 14:16:51 +0200 Received: from bombadil.infradead.org ([2607:7c80:54:3::133]) by metis.whiteo.stw.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1utmPz-00021G-9j for lore@pengutronix.de; Wed, 03 Sep 2025 14:16:51 +0200 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To: Content-Transfer-Encoding:Content-Type:MIME-Version:References:Message-ID: Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=IyIU0C7kizllHiV6c24rgXXJ/oex2qe+PL0WCzf7cD8=; b=zLJwQ6wpdy4FVPddV9Ulu5CVjo 1kxygtebFfFSvz8lIYJ89adUEp8tbhMCWb78Ww7nlL8V+7U3firf5jdsQvY9uk93lLqotW0oGbU0i zfKBZHi4wFSx5ngfn13WqBZlc+BQRzzZEGSvS3RITDencZa7hVStEukBN/E81J88j3shYpuyCVB0T JlvDGRIrG1vDHincNYL6E+zGiFHmphLP7JRi0EufwVAM+rmSv3x4eiwrzkvLiT3K0ZOTuFwbrUFbB fIQkxDM64dSqTYh5eWIMvqkfBo+mrUPIwOQMIU4HqJguDkM/8ocaS9bS70LR5Xy9YO981UZ2cYn4X m1N9OVQA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1utmPL-00000006MGO-2Jgi; Wed, 03 Sep 2025 12:16:11 +0000 Received: from metis.whiteo.stw.pengutronix.de ([2a0a:edc0:2:b01:1d::104]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1utlJ7-00000006Azs-0GJD for barebox@lists.infradead.org; Wed, 03 Sep 2025 11:05:42 +0000 Received: from drehscheibe.grey.stw.pengutronix.de ([2a0a:edc0:0:c01:1d::a2]) by metis.whiteo.stw.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1utlJ4-0007ZG-HR; Wed, 03 Sep 2025 13:05:38 +0200 Received: from pty.whiteo.stw.pengutronix.de ([2a0a:edc0:2:b01:1d::c5]) by drehscheibe.grey.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1utlJ4-003XyK-0y; Wed, 03 Sep 2025 13:05:38 +0200 Received: from mfe by pty.whiteo.stw.pengutronix.de with local (Exim 4.96) (envelope-from ) id 1utlJ4-00HZQH-0d; Wed, 03 Sep 2025 13:05:38 +0200 Date: Wed, 3 Sep 2025 13:05:38 +0200 From: Marco Felsch To: christian.thiessen@airbus.com Cc: BAREBOX Message-ID: <20250903110538.t6ajvp3xe3v3phdi@pengutronix.de> References: <20250903-mtd-erase-enosys-v1-1-967a95172c4e@airbus.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20250903-mtd-erase-enosys-v1-1-967a95172c4e@airbus.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250903_040541_099716_E497A0DA X-CRM114-Status: GOOD ( 22.65 ) X-BeenThere: barebox@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "barebox" X-SA-Exim-Connect-IP: 2607:7c80:54:3::133 X-SA-Exim-Mail-From: barebox-bounces+lore=pengutronix.de@lists.infradead.org X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on metis.whiteo.stw.pengutronix.de X-Spam-Level: X-Spam-Status: No, score=-5.3 required=4.0 tests=AWL,BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED,SPF_HELO_NONE,SPF_NONE autolearn=unavailable autolearn_force=no version=3.4.2 Subject: Re: [PATCH] mtd: Make mtd_erase fail gracefully if CONFIG_MTD_WRITE is off X-SA-Exim-Version: 4.2.1 (built Wed, 08 May 2019 21:11:16 +0000) X-SA-Exim-Scanned: Yes (on metis.whiteo.stw.pengutronix.de) Hi Christian, thank you for your patch, please see below. On 25-09-03, Christian Thießen via B4 Relay wrote: > From: Christian Thießen > > When CONFIG_MTD_WRITE is unset, the mtd->_erase member of partition > devices does not get initialized, so it remains NULL. > However when running ubiattach on an UBI partition, mtd_erase() still > gets called, tries to call mtd->_erase and crashes. Make it fail > gracefully by returning ENOSYS ("Function not implemented") instead. > > --- > As discussed in https://github.com/barebox/barebox/issues/39 this patch > enables ubiattach-ing a NAND partition even if CONFIG_MTD_WRITE is > turned off, by making mtd_erase fail gracefully. > > Signed-off-by: Christian Thießen > --- > drivers/mtd/core.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/mtd/core.c b/drivers/mtd/core.c > index 6162ec450fc1c3a0fa6339042c4d627e0f9567d0..7ca8fc900af4666070b03ef5f945748d60e6a6e7 100644 > --- a/drivers/mtd/core.c > +++ b/drivers/mtd/core.c > @@ -436,6 +436,7 @@ int mtd_erase(struct mtd_info *mtd, struct erase_info *instr) > { > if (instr->addr >= mtd->size || instr->len > mtd->size - instr->addr) > return -EINVAL; > +#ifdef CONFIG_MTD_WRITE > if (!(mtd->flags & MTD_WRITEABLE)) > return -EROFS; > instr->fail_addr = MTD_FAIL_ADDR_UNKNOWN; > @@ -443,6 +444,9 @@ int mtd_erase(struct mtd_info *mtd, struct erase_info *instr) > return 0; > > return mtd->_erase(mtd, instr); > +#else > + return -ENOSYS; > +#endif Albeit the patch is fine, I wouldn't do it via #ifdef's. Instead could we use something like: if (!IS_ENABLED(CONFIG_MTD_WRITE)) return -ENOSYS; Regards, Marco > } > > int mtd_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops) > > --- > base-commit: b5561f3bdd4845b478e5b35aab04f1d8e71ea93b > change-id: 20250902-mtd-erase-enosys-2d80e4bc77c8 > > Best regards, > -- > Christian Thießen > > > >