Return-Path: Received: from mail-pa0-f52.google.com ([209.85.220.52]:36607 "EHLO mail-pa0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752895AbbKZWKX (ORCPT ); Thu, 26 Nov 2015 17:10:23 -0500 Received: by pacdm15 with SMTP id dm15so95362525pac.3 for ; Thu, 26 Nov 2015 14:10:23 -0800 (PST) Subject: Re: [PATCH 02/12] statx: Provide IOC flags for Windows fs attributes Mime-Version: 1.0 (Mac OS X Mail 8.2 \(2104\)) Content-Type: multipart/signed; boundary="Apple-Mail=_11804957-1D5E-42D1-9FC2-1FF410D3FF51"; protocol="application/pgp-signature"; micalg=pgp-sha256 From: Andreas Dilger In-Reply-To: <7976.1448552129@warthog.procyon.org.uk> Date: Thu, 26 Nov 2015 15:10:16 -0700 Cc: "Theodore Ts'o" , arnd@arndb.de, linux-afs@vger.kernel.org, linux-nfs@vger.kernel.org, linux-cifs@vger.kernel.org, samba-technical@lists.samba.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org Message-Id: <591F46C1-DBA1-434A-9BD1-1D45DD94611B@dilger.ca> References: <20151124195256.GB3482@thunk.org> <20151120145422.18930.72662.stgit@warthog.procyon.org.uk> <20151120145447.18930.5308.stgit@warthog.procyon.org.uk> <7976.1448552129@warthog.procyon.org.uk> To: David Howells Sender: linux-nfs-owner@vger.kernel.org List-ID: --Apple-Mail=_11804957-1D5E-42D1-9FC2-1FF410D3FF51 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=us-ascii On Nov 26, 2015, at 8:35 AM, David Howells wrote: >=20 > Theodore Ts'o wrote: >=20 >> As a result, I would suggest that we not try to use the >> FS_IOC_[GS]ETFLAGS number scheme for any new interface, so we're at >> least not making a bad situation worse. >>=20 >> The only reason why some other file systems have chosen to use >> FS_IOC_[GS]ETFLAGS, instead of defining their own ioctl, is so they >> can use lsattr/chattr from e2fsprogs instead of creating their own >> utility. But for statx, there isn't a good reason use the same flags >> number space. At the very least, can we use a new flags field for = the >> Windows file attributes? It's not like lsattr/chattr has the ability >> to set those flags today anyway. So we might as well use a new flags >> field and a new flags numberspace for them. >=20 > Hmmm... I was trying to make it so that these bits would be saved to = disk as > part of the IOC flags so that Samba could make use of them. I guess = they'll > have to be stored in an xattr instead. The flags can be part of the same flags word in the statx() API, and how = they are stored on disk is a filesystem implementation detail. In some = cases, not all of the flags can be stored on disk (e.g. FAT or whatever) and an = error will be returned. In other cases they can be stored efficiently as bits = in the inode, and other filesystems may chose to store them as internal = xattrs. That shouldn't be the concern of the statx() syscall. Cheers, Andreas --Apple-Mail=_11804957-1D5E-42D1-9FC2-1FF410D3FF51 Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename=signature.asc Content-Type: application/pgp-signature; name=signature.asc Content-Description: Message signed with OpenPGP using GPGMail -----BEGIN PGP SIGNATURE----- Comment: GPGTools - http://gpgtools.org iQIVAwUBVleDSHKl2rkXzB/gAQjCNA//Zcdl0r/qkNmEYtHIORP91tJ5V7sEOdlA 89Gj88sPqOMw6KZ3N+yFfe+JXsnJd8lCKcXEJTIwL3bwSGQ07s77x6d78QF9YVwB kvXaY/AwfUHJJjANP6LsIWXlsgIh0t6p4DdXiJinFxEsMeijTbrgsDRhBaQYNRmA fWlAcEuYcrHjc6oBbdvx0qW4zKuFqtyovP3sj3hH01ltgbipRwrkzK9z7aBfl9kg DHqzkopRCwRM6FQVENqHJtyalUiJqo92YjrkTkzN5s7SOpd2fehgW8x7Aw1w9xT/ SgYJKj/Ni/bYQu2tJvYmzfs8oh7DMAklMFedR1c2vkK5RBnTnVBdOJ6nr8QH/rVP 8LX9JzXGfgvPG1mKNd+cSn3OmdbCIeyQFYAWQJrHBibjAHpWuzq4IAxfybYvYGO3 cgL3ie9wFQ0yGwsQqOy1XL56ZnfG4CO9y6hMVxIdggi+N/aEbKEL4q7NWNL/FYOG 77kFAdXnTKAHbr27TCdjtjAY26H868XCeRp3Yo+QzHDjsT8+dCOpSUwPPuwuBf+f aADRTSNgY+spoAUGEBY0r1q6ADfivqmZIQLZoyKDH1N28SINhVuIWOki9TqqkVOA MpCFHm1uIFP0PHKqT/aMzdy9PCAPMzwMqcJwFgRvcMf0pMzVORbbBum0TCDCG7Sd BY4Qo+Yr3lI= =lTnh -----END PGP SIGNATURE----- --Apple-Mail=_11804957-1D5E-42D1-9FC2-1FF410D3FF51--