From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from xry111.site (xry111.site [89.208.246.23]) (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 F23E74776A; Mon, 24 Jun 2024 12:19:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=89.208.246.23 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719231589; cv=none; b=Sg2Om7AA2SsqxeaMsOGggQuv7cntMpDXVSqnxhxYuAMJWb5Igd3qC+aBivlj3gTk73p9WQv7b6jn392kNPrHaGuvJ6aSYow42GUhwdnTxHwKSexjYZHrSHrPyAWHYErAZxxx8oIEblzBT+bsflrBVkexSLT62jlXBGl/ZUGyZMc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719231589; c=relaxed/simple; bh=c6fJHiLFxyHf/F2gL1N8M/PRrwGCHjFJaJ3bTOGiUGU=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=qCeyJOPcdVCIyOF7g9DEAxxtpr8r8tVqe7ojBOpT3M6igFeDxxUdCpSxrHPSraZ32+IFPDvtIAdxJ0YsAZbBva/9cENqD6vod7MVgOy8RpydMVBskVQ7Ny3mUINcUwH93JSe/aVKRBabMtAO4DIFYgOM7Zw294pssvTxw+ySS+0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=xry111.site; spf=pass smtp.mailfrom=xry111.site; dkim=pass (1024-bit key) header.d=xry111.site header.i=@xry111.site header.b=BZzQie7w; arc=none smtp.client-ip=89.208.246.23 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=xry111.site Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=xry111.site Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=xry111.site header.i=@xry111.site header.b="BZzQie7w" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=xry111.site; s=default; t=1719231580; bh=c6fJHiLFxyHf/F2gL1N8M/PRrwGCHjFJaJ3bTOGiUGU=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=BZzQie7w1Pj6MR3+WeApxClpW5sMn5UJ5ak9L9c8JNahbSiH/xT6mI0/0ivl970m3 IHTXZOdqO0KtxIpWDrImJ8IBrbiWOC3pePHjiFnZ9lLl4yi04cDF6nDi5OR5SXb8MI KvgzUmBaz+M/lmEwwBB1veZNcaT6g20Fov3x7slU= Received: from [192.168.124.13] (unknown [113.200.174.117]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature ECDSA (P-384) server-digest SHA384) (Client did not present a certificate) (Authenticated sender: xry111@xry111.site) by xry111.site (Postfix) with ESMTPSA id 39A9E675C3; Mon, 24 Jun 2024 08:19:36 -0400 (EDT) Message-ID: Subject: Re: [PATCH v2] vfs: Shortcut AT_EMPTY_PATH early for statx, and add AT_NO_PATH for statx and fstatat From: Xi Ruoyao To: Mateusz Guzik , Linus Torvalds Cc: Christian Brauner , Alexander Viro , Jan Kara , Alejandro Colomar , Arnd Bergmann , Huacai Chen , Xuerui Wang , Jiaxun Yang , Icenowy Zheng , linux-fsdevel@vger.kernel.org, linux-arch@vger.kernel.org, loongarch@lists.linux.dev, linux-kernel@vger.kernel.org Date: Mon, 24 Jun 2024 20:19:33 +0800 In-Reply-To: References: <20240624085037.33442-2-xry111@xry111.site> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.52.2 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 On Mon, 2024-06-24 at 11:04 +0200, Mateusz Guzik wrote: > Below is a diff which compiles but is untested. It adds AT_EMPTY_PATH + > NULL as suggsted by Linus, but it can be adjusted for AT_NO_PATH (which > would be my preffered option, or better yet not do that and add fstatx). >=20 > It does not do the hack to 0-check if a pointer was passed along with > AT_EMPTY_PATH but that again is an easy addition. >=20 > Feel free to take without attribution: I'd still like to make it Co-developed-by: or just From: you. Could you give a S-o-b? And with this change AT_FDCWD with AT_EMPTY_PATH and NULL path does not work. For consistency it'd be better to make it work too: diff --git a/fs/stat.c b/fs/stat.c index b0a4db7b90df..d04f7ba46645 100644 --- a/fs/stat.c +++ b/fs/stat.c @@ -752,10 +752,14 @@ SYSCALL_DEFINE5(statx, int ret; struct filename *name; =20 - if (filename =3D=3D NULL && (flags & AT_EMPTY_PATH)) - return do_statx_fd(dfd, flags, mask, buffer); + if (filename =3D=3D NULL && (flags & AT_EMPTY_PATH)) { + if (dfd >=3D 0) + return do_statx_fd(dfd, flags, mask, buffer); + else + name =3D getname_kernel(""); + } else + name =3D getname_flags(filename, getname_statx_lookup_flags(flags)); =20 - name =3D getname_flags(filename, getname_statx_lookup_flags(flags)); ret =3D do_statx(dfd, name, flags, mask, buffer); putname(name); =20 And should we do it for fstatat() as well? Let's wait for comment from Linus anyway. --=20 Xi Ruoyao School of Aerospace Science and Technology, Xidian University