From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 1040627BF79; Wed, 28 Jan 2026 15:51:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769615470; cv=none; b=nw142CFKUnD7sqwD9CxysJYp7wGkqSTboTHV1qsWGYxvKIQ4kze7N3RhjqIg+NEv6JBU4949VVac0uZJC35EmZcruqhfrQVFkqYQybhtjTHjTGJ+aPDmiApBBVYE3TmLsn/ts2l8QpFR13yifnLqXC8oW13DLjrf+qBVa8o/UlQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769615470; c=relaxed/simple; bh=LT3+aY8/Yh/m+9tAyh81m6D4X9BnZdkLSFnxg/3kHnU=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=Wq/9UW981Ouxr60LtwPRfnstFKyEwR7tR9egAaCde17/h0ZqkboayOQbQOMZIUg75SihJaplBkqG6Y2nwyd9qd7tBkNX5GAsa6FIieFZ5UTOq0Wy/i4ZyUJSVNwWIxlIyybR8pL/do7ktsQvPHB2hn4FeRIlJMYr0zOtRWMgGz8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=kjcKc3vn; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="kjcKc3vn" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DC104C4CEF1; Wed, 28 Jan 2026 15:51:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1769615469; bh=LT3+aY8/Yh/m+9tAyh81m6D4X9BnZdkLSFnxg/3kHnU=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=kjcKc3vnUfuVg776w84RJMLRpzvvzT0JgKuLgFhY3LOCCLRqlucJePT3Kez7CGI0Y GQl+ACCbW/FQNvukX1d+jXpUYIdVxGNEm2bgRNr3kKINND0vDtzRi8iNATy54C1spu b6HbCpt1FlnkPgf/eO66QFRWWjQ7MPjk5eWCFIcOlx5xw83NjlyYOd0HhR7qhEklW/ HXHI4bbKGcjaTc495tPnQMnP2PVhWOwiVxmjMcPw6UUIMVM35UpAnOOT4r8n4fVMjW ptJ0WQzUM7osnkvnywuxdZAfrrKz+2cVPLvych5sMerGXZ1eMmgikTlWFx/AV/Oxgv vKQ5dwHm5IVow== Message-ID: Subject: Re: [PATCH v3 1/4] open: new O_REGULAR flag support From: Jeff Layton To: Dorjoy Chowdhury Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, viro@zeniv.linux.org.uk, brauner@kernel.org, jack@suse.cz, chuck.lever@oracle.com, alex.aring@gmail.com, arnd@arndb.de, adilger@dilger.ca Date: Wed, 28 Jan 2026 10:51:07 -0500 In-Reply-To: References: <20260127180109.66691-1-dorjoychy111@gmail.com> <20260127180109.66691-2-dorjoychy111@gmail.com> <1c6cccc3e058ef16fa8b296ef6126b76a12db136.camel@kernel.org> Autocrypt: addr=jlayton@kernel.org; prefer-encrypt=mutual; keydata=mQINBE6V0TwBEADXhJg7s8wFDwBMEvn0qyhAnzFLTOCHooMZyx7XO7dAiIhDSi7G1NPxw n8jdFUQMCR/GlpozMFlSFiZXiObE7sef9rTtM68ukUyZM4pJ9l0KjQNgDJ6Fr342Htkjxu/kFV1Wv egyjnSsFt7EGoDjdKqr1TS9syJYFjagYtvWk/UfHlW09X+jOh4vYtfX7iYSx/NfqV3W1D7EDi0PqV T2h6v8i8YqsATFPwO4nuiTmL6I40ZofxVd+9wdRI4Db8yUNA4ZSP2nqLcLtFjClYRBoJvRWvsv4lm 0OX6MYPtv76hka8lW4mnRmZqqx3UtfHX/hF/zH24Gj7A6sYKYLCU3YrI2Ogiu7/ksKcl7goQjpvtV YrOOI5VGLHge0awt7bhMCTM9KAfPc+xL/ZxAMVWd3NCk5SamL2cE99UWgtvNOIYU8m6EjTLhsj8sn VluJH0/RcxEeFbnSaswVChNSGa7mXJrTR22lRL6ZPjdMgS2Km90haWPRc8Wolcz07Y2se0xpGVLEQ cDEsvv5IMmeMe1/qLZ6NaVkNuL3WOXvxaVT9USW1+/SGipO2IpKJjeDZfehlB/kpfF24+RrK+seQf CBYyUE8QJpvTZyfUHNYldXlrjO6n5MdOempLqWpfOmcGkwnyNRBR46g/jf8KnPRwXs509yAqDB6sE LZH+yWr9LQZEwARAQABtCVKZWZmIExheXRvbiA8amxheXRvbkBwb29jaGllcmVkcy5uZXQ+iQI7BB MBAgAlAhsDBgsJCAcDAgYVCAIJCgsEFgIDAQIeAQIXgAUCTpXWPAIZAQAKCRAADmhBGVaCFc65D/4 gBLNMHopQYgG/9RIM3kgFCCQV0pLv0hcg1cjr+bPI5f1PzJoOVi9s0wBDHwp8+vtHgYhM54yt43uI 7Htij0RHFL5eFqoVT4TSfAg2qlvNemJEOY0e4daljjmZM7UtmpGs9NN0r9r50W82eb5Kw5bc/r0km R/arUS2st+ecRsCnwAOj6HiURwIgfDMHGPtSkoPpu3DDp/cjcYUg3HaOJuTjtGHFH963B+f+hyQ2B rQZBBE76ErgTDJ2Db9Ey0kw7VEZ4I2nnVUY9B5dE2pJFVO5HJBMp30fUGKvwaKqYCU2iAKxdmJXRI ONb7dSde8LqZahuunPDMZyMA5+mkQl7kpIpR6kVDIiqmxzRuPeiMP7O2FCUlS2DnJnRVrHmCljLkZ Wf7ZUA22wJpepBligemtSRSbqCyZ3B48zJ8g5B8xLEntPo/NknSJaYRvfEQqGxgk5kkNWMIMDkfQO lDSXZvoxqU9wFH/9jTv1/6p8dHeGM0BsbBLMqQaqnWiVt5mG92E1zkOW69LnoozE6Le+12DsNW7Rj iR5K+27MObjXEYIW7FIvNN/TQ6U1EOsdxwB8o//Yfc3p2QqPr5uS93SDDan5ehH59BnHpguTc27Xi QQZ9EGiieCUx6Zh2ze3X2UW9YNzE15uKwkkuEIj60NvQRmEDfweYfOfPVOueC+iFifbQgSmVmZiBM YXl0b24gPGpsYXl0b25AcmVkaGF0LmNvbT6JAjgEEwECACIFAk6V0q0CGwMGCwkIBwMCBhUIAgkKC wQWAgMBAh4BAheAAAoJEAAOaEEZVoIViKUQALpvsacTMWWOd7SlPFzIYy2/fjvKlfB/Xs4YdNcf9q LqF+lk2RBUHdR/dGwZpvw/OLmnZ8TryDo2zXVJNWEEUFNc7wQpl3i78r6UU/GUY/RQmOgPhs3epQC 3PMJj4xFx+VuVcf/MXgDDdBUHaCTT793hyBeDbQuciARDJAW24Q1RCmjcwWIV/pgrlFa4lAXsmhoa c8UPc82Ijrs6ivlTweFf16VBc4nSLX5FB3ls7S5noRhm5/Zsd4PGPgIHgCZcPgkAnU1S/A/rSqf3F LpU+CbVBDvlVAnOq9gfNF+QiTlOHdZVIe4gEYAU3CUjbleywQqV02BKxPVM0C5/oVjMVx3bri75n1 TkBYGmqAXy9usCkHIsG5CBHmphv9MHmqMZQVsxvCzfnI5IO1+7MoloeeW/lxuyd0pU88dZsV/riHw 87i2GJUJtVlMl5IGBNFpqoNUoqmvRfEMeXhy/kUX4Xc03I1coZIgmwLmCSXwx9MaCPFzV/dOOrju2 xjO+2sYyB5BNtxRqUEyXglpujFZqJxxau7E0eXoYgoY9gtFGsspzFkVNntamVXEWVVgzJJr/EWW0y +jNd54MfPRqH+eCGuqlnNLktSAVz1MvVRY1dxUltSlDZT7P2bUoMorIPu8p7ZCg9dyX1+9T6Muc5d Hxf/BBP/ir+3e8JTFQBFOiLNdFtB9KZWZmIExheXRvbiA8amxheXRvbkBzYW1iYS5vcmc+iQI4BBM BAgAiBQJOldK9AhsDBgsJCAcDAgYVCAIJCgsEFgIDAQIeAQIXgAAKCRAADmhBGVaCFWgWD/0ZRi4h N9FK2BdQs9RwNnFZUr7JidAWfCrs37XrA/56olQl3ojn0fQtrP4DbTmCuh0SfMijB24psy1GnkPep naQ6VRf7Dxg/Y8muZELSOtsv2CKt3/02J1BBitrkkqmHyni5fLLYYg6fub0T/8Kwo1qGPdu1hx2BQ RERYtQ/S5d/T0cACdlzi6w8rs5f09hU9Tu4qV1JLKmBTgUWKN969HPRkxiojLQziHVyM/weR5Reu6 FZVNuVBGqBD+sfk/c98VJHjsQhYJijcsmgMb1NohAzwrBKcSGKOWJToGEO/1RkIN8tqGnYNp2G+aR 685D0chgTl1WzPRM6mFG1+n2b2RR95DxumKVpwBwdLPoCkI24JkeDJ7lXSe3uFWISstFGt0HL8Eew P8RuGC8s5h7Ct91HMNQTbjgA+Vi1foWUVXpEintAKgoywaIDlJfTZIl6Ew8ETN/7DLy8bXYgq0Xzh aKg3CnOUuGQV5/nl4OAX/3jocT5Cz/OtAiNYj5mLPeL5z2ZszjoCAH6caqsF2oLyAnLqRgDgR+wTQ T6gMhr2IRsl+cp8gPHBwQ4uZMb+X00c/Amm9VfviT+BI7B66cnC7Zv6Gvmtu2rEjWDGWPqUgccB7h dMKnKDthkA227/82tYoFiFMb/NwtgGrn5n2vwJyKN6SEoygGrNt0SI84y6hEVbQlSmVmZiBMYXl0b 24gPGpsYXl0b25AcHJpbWFyeWRhdGEuY29tPokCOQQTAQIAIwUCU4xmKQIbAwcLCQgHAwIBBhUIAg kKCwQWAgMBAh4BAheAAAoJEAAOaEEZVoIV1H0P/j4OUTwFd7BBbpoSp695qb6HqCzWMuExsp8nZjr uymMaeZbGr3OWMNEXRI1FWNHMtcMHWLP/RaDqCJil28proO+PQ/yPhsr2QqJcW4nr91tBrv/MqItu AXLYlsgXqp4BxLP67bzRJ1Bd2x0bWXurpEXY//VBOLnODqThGEcL7jouwjmnRh9FTKZfBDpFRaEfD FOXIfAkMKBa/c9TQwRpx2DPsl3eFWVCNuNGKeGsirLqCxUg5kWTxEorROppz9oU4HPicL6rRH22Ce 6nOAON2vHvhkUuO3GbffhrcsPD4DaYup4ic+DxWm+DaSSRJ+e1yJvwi6NmQ9P9UAuLG93S2MdNNbo sZ9P8k2mTOVKMc+GooI9Ve/vH8unwitwo7ORMVXhJeU6Q0X7zf3SjwDq2lBhn1DSuTsn2DbsNTiDv qrAaCvbsTsw+SZRwF85eG67eAwouYk+dnKmp1q57LDKMyzysij2oDKbcBlwB/TeX16p8+LxECv51a sjS9TInnipssssUDrHIvoTTXWcz7Y5wIngxDFwT8rPY3EggzLGfK5Zx2Q5S/N0FfmADmKknG/D8qG IcJE574D956tiUDKN4I+/g125ORR1v7bP+OIaayAvq17RP+qcAqkxc0x8iCYVCYDouDyNvWPGRhbL UO7mlBpjW9jK9e2fvZY9iw3QzIPGKtClKZWZmIExheXRvbiA8amVmZi5sYXl0b25AcHJpbWFyeWRh dGEuY29tPokCOQQTAQIAIwUCU4xmUAIbAwcLCQgHAwIBBhUIAgkKCwQWAgMBAh4BAheAAAoJEAAOa EEZVoIVzJoQALFCS6n/FHQS+hIzHIb56JbokhK0AFqoLVzLKzrnaeXhE5isWcVg0eoV2oTScIwUSU apy94if69tnUo4Q7YNt8/6yFM6hwZAxFjOXR0ciGE3Q+Z1zi49Ox51yjGMQGxlakV9ep4sV/d5a50 M+LFTmYSAFp6HY23JN9PkjVJC4PUv5DYRbOZ6Y1+TfXKBAewMVqtwT1Y+LPlfmI8dbbbuUX/kKZ5d dhV2736fgyfpslvJKYl0YifUOVy4D1G/oSycyHkJG78OvX4JKcf2kKzVvg7/Rnv+AueCfFQ6nGwPn 0P91I7TEOC4XfZ6a1K3uTp4fPPs1Wn75X7K8lzJP/p8lme40uqwAyBjk+IA5VGd+CVRiyJTpGZwA0 jwSYLyXboX+Dqm9pSYzmC9+/AE7lIgpWj+3iNisp1SWtHc4pdtQ5EU2SEz8yKvDbD0lNDbv4ljI7e flPsvN6vOrxz24mCliEco5DwhpaaSnzWnbAPXhQDWb/lUgs/JNk8dtwmvWnqCwRqElMLVisAbJmC0 BhZ/Ab4sph3EaiZfdXKhiQqSGdK4La3OTJOJYZphPdGgnkvDV9Pl1QZ0ijXQrVIy3zd6VCNaKYq7B AKidn5g/2Q8oio9Tf4XfdZ9dtwcB+bwDJFgvvDYaZ5bI3ln4V3EyW5i2NfXazz/GA/I/ZtbsigCFc 8ftCBKZWZmIExheXRvbiA8amxheXRvbkBrZXJuZWwub3JnPokCOAQTAQIAIgUCWe8u6AIbAwYLCQg HAwIGFQgCCQoLBBYCAwECHgECF4AACgkQAA5oQRlWghUuCg/+Lb/xGxZD2Q1oJVAE37uW308UpVSD 2tAMJUvFTdDbfe3zKlPDTuVsyNsALBGclPLagJ5ZTP+Vp2irAN9uwBuacBOTtmOdz4ZN2tdvNgozz uxp4CHBDVzAslUi2idy+xpsp47DWPxYFIRP3M8QG/aNW052LaPc0cedYxp8+9eiVUNpxF4SiU4i9J DfX/sn9XcfoVZIxMpCRE750zvJvcCUz9HojsrMQ1NFc7MFT1z3MOW2/RlzPcog7xvR5ENPH19ojRD CHqumUHRry+RF0lH00clzX/W8OrQJZtoBPXv9ahka/Vp7kEulcBJr1cH5Wz/WprhsIM7U9pse1f1g Yy9YbXtWctUz8uvDR7shsQxAhX3qO7DilMtuGo1v97I/Kx4gXQ52syh/w6EBny71CZrOgD6kJwPVV AaM1LRC28muq91WCFhs/nzHozpbzcheyGtMUI2Ao4K6mnY+3zIuXPygZMFr9KXE6fF7HzKxKuZMJO aEZCiDOq0anx6FmOzs5E6Jqdpo/mtI8beK+BE7Va6ni7YrQlnT0i3vaTVMTiCThbqsB20VrbMjlhp f8lfK1XVNbRq/R7GZ9zHESlsa35ha60yd/j3pu5hT2xyy8krV8vGhHvnJ1XRMJBAB/UYb6FyC7S+m QZIQXVeAA+smfTT0tDrisj1U5x6ZB9b3nBg65kc= Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.58.2 (3.58.2-1.fc43) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 On Wed, 2026-01-28 at 21:36 +0600, Dorjoy Chowdhury wrote: > On Wed, Jan 28, 2026 at 5:52=E2=80=AFAM Jeff Layton = wrote: > >=20 > > On Tue, 2026-01-27 at 23:58 +0600, Dorjoy Chowdhury wrote: > > > This flag indicates the path should be opened if it's a regular file. > > > This is useful to write secure programs that want to avoid being tric= ked > > > into opening device nodes with special semantics while thinking they > > > operate on regular files. > > >=20 > > > A corresponding error code ENOTREG has been introduced. For example, = if > > > open is called on path /dev/null with O_REGULAR in the flag param, it > > > will return -ENOTREG. > > >=20 > > > When used in combination with O_CREAT, either the regular file is > > > created, or if the path already exists, it is opened if it's a regula= r > > > file. Otherwise, -ENOTREG is returned. > > >=20 > > > -EINVAL is returned when O_REGULAR is combined with O_DIRECTORY (not > > > part of O_TMPFILE) because it doesn't make sense to open a path that > > > is both a directory and a regular file. > > >=20 > > > Signed-off-by: Dorjoy Chowdhury > > > --- > > > arch/alpha/include/uapi/asm/errno.h | 2 ++ > > > arch/alpha/include/uapi/asm/fcntl.h | 1 + > > > arch/mips/include/uapi/asm/errno.h | 2 ++ > > > arch/parisc/include/uapi/asm/errno.h | 2 ++ > > > arch/parisc/include/uapi/asm/fcntl.h | 1 + > > > arch/sparc/include/uapi/asm/errno.h | 2 ++ > > > arch/sparc/include/uapi/asm/fcntl.h | 1 + > > > fs/fcntl.c | 2 +- > > > fs/namei.c | 6 ++++++ > > > fs/open.c | 4 +++- > > > include/linux/fcntl.h | 2 +- > > > include/uapi/asm-generic/errno.h | 2 ++ > > > include/uapi/asm-generic/fcntl.h | 4 ++++ > > > tools/arch/alpha/include/uapi/asm/errno.h | 2 ++ > > > tools/arch/mips/include/uapi/asm/errno.h | 2 ++ > > > tools/arch/parisc/include/uapi/asm/errno.h | 2 ++ > > > tools/arch/sparc/include/uapi/asm/errno.h | 2 ++ > > > tools/include/uapi/asm-generic/errno.h | 2 ++ > > > 18 files changed, 38 insertions(+), 3 deletions(-) > > >=20 > > > diff --git a/arch/alpha/include/uapi/asm/errno.h b/arch/alpha/include= /uapi/asm/errno.h > > > index 6791f6508632..8bbcaa9024f9 100644 > > > --- a/arch/alpha/include/uapi/asm/errno.h > > > +++ b/arch/alpha/include/uapi/asm/errno.h > > > @@ -127,4 +127,6 @@ > > >=20 > > > #define EHWPOISON 139 /* Memory page has hardware error */ > > >=20 > > > +#define ENOTREG 140 /* Not a regular file */ > > > + > > > #endif > > > diff --git a/arch/alpha/include/uapi/asm/fcntl.h b/arch/alpha/include= /uapi/asm/fcntl.h > > > index 50bdc8e8a271..4da5a64c23bd 100644 > > > --- a/arch/alpha/include/uapi/asm/fcntl.h > > > +++ b/arch/alpha/include/uapi/asm/fcntl.h > > > @@ -34,6 +34,7 @@ > > >=20 > > > #define O_PATH 040000000 > > > #define __O_TMPFILE 0100000000 > > > +#define O_REGULAR 0200000000 > > >=20 > > > #define F_GETLK 7 > > > #define F_SETLK 8 > > > diff --git a/arch/mips/include/uapi/asm/errno.h b/arch/mips/include/u= api/asm/errno.h > > > index c01ed91b1ef4..293c78777254 100644 > > > --- a/arch/mips/include/uapi/asm/errno.h > > > +++ b/arch/mips/include/uapi/asm/errno.h > > > @@ -126,6 +126,8 @@ > > >=20 > > > #define EHWPOISON 168 /* Memory page has hardware error */ > > >=20 > > > +#define ENOTREG 169 /* Not a regular file */ > > > + > > > #define EDQUOT 1133 /* Quota exceeded */ > > >=20 > > >=20 > > > diff --git a/arch/parisc/include/uapi/asm/errno.h b/arch/parisc/inclu= de/uapi/asm/errno.h > > > index 8cbc07c1903e..442917484f99 100644 > > > --- a/arch/parisc/include/uapi/asm/errno.h > > > +++ b/arch/parisc/include/uapi/asm/errno.h > > > @@ -124,4 +124,6 @@ > > >=20 > > > #define EHWPOISON 257 /* Memory page has hardware error */ > > >=20 > > > +#define ENOTREG 258 /* Not a regular file */ > > > + > > > #endif > > > diff --git a/arch/parisc/include/uapi/asm/fcntl.h b/arch/parisc/inclu= de/uapi/asm/fcntl.h > > > index 03dee816cb13..0cc3320fe326 100644 > > > --- a/arch/parisc/include/uapi/asm/fcntl.h > > > +++ b/arch/parisc/include/uapi/asm/fcntl.h > > > @@ -19,6 +19,7 @@ > > >=20 > > > #define O_PATH 020000000 > > > #define __O_TMPFILE 040000000 > > > +#define O_REGULAR 0100000000 > > >=20 > > > #define F_GETLK64 8 > > > #define F_SETLK64 9 > > > diff --git a/arch/sparc/include/uapi/asm/errno.h b/arch/sparc/include= /uapi/asm/errno.h > > > index 4a41e7835fd5..8dce0bfeab74 100644 > > > --- a/arch/sparc/include/uapi/asm/errno.h > > > +++ b/arch/sparc/include/uapi/asm/errno.h > > > @@ -117,4 +117,6 @@ > > >=20 > > > #define EHWPOISON 135 /* Memory page has hardware error */ > > >=20 > > > +#define ENOTREG 136 /* Not a regular file */ > > > + > > > #endif > > > diff --git a/arch/sparc/include/uapi/asm/fcntl.h b/arch/sparc/include= /uapi/asm/fcntl.h > > > index 67dae75e5274..a93d18d2c23e 100644 > > > --- a/arch/sparc/include/uapi/asm/fcntl.h > > > +++ b/arch/sparc/include/uapi/asm/fcntl.h > > > @@ -37,6 +37,7 @@ > > >=20 > > > #define O_PATH 0x1000000 > > > #define __O_TMPFILE 0x2000000 > > > +#define O_REGULAR 0x4000000 > > >=20 > > > #define F_GETOWN 5 /* for sockets. */ > > > #define F_SETOWN 6 /* for sockets. */ > > > diff --git a/fs/fcntl.c b/fs/fcntl.c > > > index f93dbca08435..62ab4ad2b6f5 100644 > > > --- a/fs/fcntl.c > > > +++ b/fs/fcntl.c > > > @@ -1169,7 +1169,7 @@ static int __init fcntl_init(void) > > > * Exceptions: O_NONBLOCK is a two bit define on parisc; O_NDEL= AY > > > * is defined as O_NONBLOCK on some platforms and not on others= . > > > */ > > > - BUILD_BUG_ON(20 - 1 /* for O_RDONLY being 0 */ !=3D > > > + BUILD_BUG_ON(21 - 1 /* for O_RDONLY being 0 */ !=3D > > > HWEIGHT32( > > > (VALID_OPEN_FLAGS & ~(O_NONBLOCK | O_NDELAY)) | > > > __FMODE_EXEC)); > > > diff --git a/fs/namei.c b/fs/namei.c > > > index b28ecb699f32..f5504ae4b03c 100644 > > > --- a/fs/namei.c > > > +++ b/fs/namei.c > > > @@ -4616,6 +4616,10 @@ static int do_open(struct nameidata *nd, > > > if (unlikely(error)) > > > return error; > > > } > > > + > > > + if ((open_flag & O_REGULAR) && !d_is_reg(nd->path.dentry)) > > > + return -ENOTREG; > > > + > > > if ((nd->flags & LOOKUP_DIRECTORY) && !d_can_lookup(nd->path.de= ntry)) > > > return -ENOTDIR; > > >=20 > > > @@ -4765,6 +4769,8 @@ static int do_o_path(struct nameidata *nd, unsi= gned flags, struct file *file) > > > struct path path; > > > int error =3D path_lookupat(nd, flags, &path); > > > if (!error) { > > > + if ((file->f_flags & O_REGULAR) && !d_is_reg(path.dentr= y)) > > > + return -ENOTREG; > > > audit_inode(nd->name, path.dentry, 0); > > > error =3D vfs_open(&path, file); > > > path_put(&path); > > > diff --git a/fs/open.c b/fs/open.c > > > index 74c4c1462b3e..82153e21907e 100644 > > > --- a/fs/open.c > > > +++ b/fs/open.c > > > @@ -1173,7 +1173,7 @@ struct file *kernel_file_open(const struct path= *path, int flags, > > > EXPORT_SYMBOL_GPL(kernel_file_open); > > >=20 > > > #define WILL_CREATE(flags) (flags & (O_CREAT | __O_TMPFILE)) > > > -#define O_PATH_FLAGS (O_DIRECTORY | O_NOFOLLOW | O_PATH | O_= CLOEXEC) > > > +#define O_PATH_FLAGS (O_DIRECTORY | O_NOFOLLOW | O_PATH | O_= CLOEXEC | O_REGULAR) > > >=20 > > > inline struct open_how build_open_how(int flags, umode_t mode) > > > { > > > @@ -1250,6 +1250,8 @@ inline int build_open_flags(const struct open_h= ow *how, struct open_flags *op) > > > return -EINVAL; > > > if (!(acc_mode & MAY_WRITE)) > > > return -EINVAL; > > > + } else if ((flags & O_DIRECTORY) && (flags & O_REGULAR)) { > > > + return -EINVAL; > > > } > > > if (flags & O_PATH) { > > > /* O_PATH only permits certain other flags to be set. *= / > > > diff --git a/include/linux/fcntl.h b/include/linux/fcntl.h > > > index a332e79b3207..4fd07b0e0a17 100644 > > > --- a/include/linux/fcntl.h > > > +++ b/include/linux/fcntl.h > > > @@ -10,7 +10,7 @@ > > > (O_RDONLY | O_WRONLY | O_RDWR | O_CREAT | O_EXCL | O_NOCTTY | O= _TRUNC | \ > > > O_APPEND | O_NDELAY | O_NONBLOCK | __O_SYNC | O_DSYNC | \ > > > FASYNC | O_DIRECT | O_LARGEFILE | O_DIRECTORY | O_NOFOLLOW | \ > > > - O_NOATIME | O_CLOEXEC | O_PATH | __O_TMPFILE) > > > + O_NOATIME | O_CLOEXEC | O_PATH | __O_TMPFILE | O_REGULAR) > > >=20 > > > /* List of all valid flags for the how->resolve argument: */ > > > #define VALID_RESOLVE_FLAGS \ > > > diff --git a/include/uapi/asm-generic/errno.h b/include/uapi/asm-gene= ric/errno.h > > > index 92e7ae493ee3..2216ab9aa32e 100644 > > > --- a/include/uapi/asm-generic/errno.h > > > +++ b/include/uapi/asm-generic/errno.h > > > @@ -122,4 +122,6 @@ > > >=20 > > > #define EHWPOISON 133 /* Memory page has hardware error */ > > >=20 > > > +#define ENOTREG 134 /* Not a regular file */ > > > + > > > #endif > > > diff --git a/include/uapi/asm-generic/fcntl.h b/include/uapi/asm-gene= ric/fcntl.h > > > index 613475285643..3468b352a575 100644 > > > --- a/include/uapi/asm-generic/fcntl.h > > > +++ b/include/uapi/asm-generic/fcntl.h > > > @@ -88,6 +88,10 @@ > > > #define __O_TMPFILE 020000000 > > > #endif > > >=20 > > > +#ifndef O_REGULAR > > > +#define O_REGULAR 040000000 > > > +#endif > > > + > > > /* a horrid kludge trying to make sure that this will fail on old ke= rnels */ > > > #define O_TMPFILE (__O_TMPFILE | O_DIRECTORY) > > >=20 > > > diff --git a/tools/arch/alpha/include/uapi/asm/errno.h b/tools/arch/a= lpha/include/uapi/asm/errno.h > > > index 6791f6508632..8bbcaa9024f9 100644 > > > --- a/tools/arch/alpha/include/uapi/asm/errno.h > > > +++ b/tools/arch/alpha/include/uapi/asm/errno.h > > > @@ -127,4 +127,6 @@ > > >=20 > > > #define EHWPOISON 139 /* Memory page has hardware error */ > > >=20 > > > +#define ENOTREG 140 /* Not a regular file */ > > > + > > > #endif > > > diff --git a/tools/arch/mips/include/uapi/asm/errno.h b/tools/arch/mi= ps/include/uapi/asm/errno.h > > > index c01ed91b1ef4..293c78777254 100644 > > > --- a/tools/arch/mips/include/uapi/asm/errno.h > > > +++ b/tools/arch/mips/include/uapi/asm/errno.h > > > @@ -126,6 +126,8 @@ > > >=20 > > > #define EHWPOISON 168 /* Memory page has hardware error */ > > >=20 > > > +#define ENOTREG 169 /* Not a regular file */ > > > + > > > #define EDQUOT 1133 /* Quota exceeded */ > > >=20 > > >=20 > > > diff --git a/tools/arch/parisc/include/uapi/asm/errno.h b/tools/arch/= parisc/include/uapi/asm/errno.h > > > index 8cbc07c1903e..442917484f99 100644 > > > --- a/tools/arch/parisc/include/uapi/asm/errno.h > > > +++ b/tools/arch/parisc/include/uapi/asm/errno.h > > > @@ -124,4 +124,6 @@ > > >=20 > > > #define EHWPOISON 257 /* Memory page has hardware error */ > > >=20 > > > +#define ENOTREG 258 /* Not a regular file */ > > > + > > > #endif > > > diff --git a/tools/arch/sparc/include/uapi/asm/errno.h b/tools/arch/s= parc/include/uapi/asm/errno.h > > > index 4a41e7835fd5..8dce0bfeab74 100644 > > > --- a/tools/arch/sparc/include/uapi/asm/errno.h > > > +++ b/tools/arch/sparc/include/uapi/asm/errno.h > > > @@ -117,4 +117,6 @@ > > >=20 > > > #define EHWPOISON 135 /* Memory page has hardware error */ > > >=20 > > > +#define ENOTREG 136 /* Not a regular file */ > > > + > > > #endif > > > diff --git a/tools/include/uapi/asm-generic/errno.h b/tools/include/u= api/asm-generic/errno.h > > > index 92e7ae493ee3..2216ab9aa32e 100644 > > > --- a/tools/include/uapi/asm-generic/errno.h > > > +++ b/tools/include/uapi/asm-generic/errno.h > > > @@ -122,4 +122,6 @@ > > >=20 > > > #define EHWPOISON 133 /* Memory page has hardware error */ > > >=20 > > > +#define ENOTREG 134 /* Not a regular file */ > > > + > > > #endif > >=20 > > One thing this patch is missing is handling for ->atomic_open(). I > > imagine most of the filesystems that provide that op can't support > > O_REGULAR properly (maybe cifs can? idk). What you probably want to do > > is add in some patches that make all of the atomic_open operations in > > the kernel return -EINVAL if O_REGULAR is set. > >=20 > > Then, once the basic support is in, you or someone else can go back and > > implement support for O_REGULAR where possible. >=20 > Thank you for the feedback. I don't quite understand what I need to > fix. I thought open system calls always create regular files, so > atomic_open probably always creates regular files? Can you please give > me some more details as to where I need to fix this and what the > actual bug here is that is related to atomic_open? I think I had done > some normal testing and when using O_CREAT | O_REGULAR, if the file > doesn't exist, the file gets created and the file that gets created is > a regular file, so it probably makes sense? Or should the behavior be > that if file doesn't exist, -EINVAL is returned and if file exists it > is opened if regular, otherwise -ENOTREG is returned? >=20 atomic_open() is a combination lookup+open for when the dentry isn't present in the dcache. The normal open codepath that you're patching does not get called in this case when ->atomic_open is set for the filesystem. It's mostly used by network filesystems that need to optimize away the lookup since it's wasted round trip, and is often racy anyway. Your patchset doesn't address those filesystems. They will likely end up ignoring O_REGULAR in that case, which is not what you want. What I was suggesting is that, as an interim step, you find all of the atomic_open operations in the kernel (there are maybe a dozen or so), and just make them return -EINVAL if someone sets O_DIRECTORY. Later, you or someone else can then go back and do a proper implementation of O_REGULAR handling on those filesystems, at least on the ones where it's possible. You will probably also need to similarly patch the open() routines for those filesystems too. Otherwise you'll get inconsistent behavior vs. when the dentry is in the cache. One note: I think NFS probably can support O_DIRECTORY, since its OPEN call only works on files. We'll need to change how we handle errors from the server when it's set though. --=20 Jeff Layton