From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.sgi.com (relay1.corp.sgi.com [137.38.102.111]) by oss.sgi.com (Postfix) with ESMTP id 681FB7F56 for ; Mon, 16 Mar 2015 06:35:10 -0500 (CDT) Received: from cuda.sgi.com (cuda2.sgi.com [192.48.176.25]) by relay1.corp.sgi.com (Postfix) with ESMTP id 48A458F8035 for ; Mon, 16 Mar 2015 04:35:07 -0700 (PDT) Received: from mail-pd0-f177.google.com (mail-pd0-f177.google.com [209.85.192.177]) by cuda.sgi.com with ESMTP id QKQKpQ2mVgsmOWUb (version=TLSv1 cipher=RC4-SHA bits=128 verify=NO) for ; Mon, 16 Mar 2015 04:35:05 -0700 (PDT) Received: by pdbcz9 with SMTP id cz9so56061054pdb.3 for ; Mon, 16 Mar 2015 04:35:04 -0700 (PDT) From: Omar Sandoval Subject: [RFC PATCH 0/5] Remove rw parameter from direct_IO() Date: Mon, 16 Mar 2015 04:33:48 -0700 Message-Id: List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: xfs-bounces@oss.sgi.com Sender: xfs-bounces@oss.sgi.com To: Alexander Viro , linux-fsdevel@vger.kernel.org, linux-btrfs@vger.kernel.org, ceph-devel@vger.kernel.org, linux-cifs@vger.kernel.org, osd-dev@open-osd.org, linux-ext4@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, fuse-devel@lists.sourceforge.net, cluster-devel@redhat.com, jfs-discussion@lists.sourceforge.net, HPDD-discuss@lists.01.org, linux-nfs@vger.kernel.org, linux-nilfs@vger.kernel.org, ocfs2-devel@oss.oracle.com, reiserfs-devel@vger.kernel.org, v9fs-developer@lists.sourceforge.net, xfs@oss.sgi.com Cc: Latchesar Ionkov , Dave Kleikamp , Jan Kara , Trond Myklebust , David Sterba , Chris Mason , Andreas Dilger , Ryusuke Konishi , Yan Zheng , Sage Weil , Miklos Szeredi , Changman Lee , Boaz Harrosh , Eric Van Hensbergen , Mark Fasheh , Oleg Drokin , Joel Becker , Jaegeuk Kim , Steven Whitehouse , Theodore Ts'o , Benny Halevy , Josef Bacik , linux-kernel@vger.kernel.org, Steve French , Ron Minnich , Omar Sandoval , Anna Schumaker Hi, Al, here's some cleanup that you mentioned back in December that I got around to (https://lkml.org/lkml/2014/12/15/28). In summary, the rw parameter to a_ops->direct_IO() is redundant with .type in struct iov_iter. Additionally, rw is inconsistently checked for being a WRITE; some filesystems do rw == WRITE, others do rw & WRITE, and others do both within the same function :) The distinction is that swapout may OR in the ITER_BVEC flag in the rw passed to ->direct_IO(), so the two are not equivalent (although this really only happens for swap-over-NFS, but it's scary nonetheless). After looking through all of these, it definitely looks like every check means for ANY write, not just non-kernel writes. So, the solution presented here is: - Add a helper, iov_iter_rw(), which always returns either READ or WRITE, no ITER_.* or REQ_.* nonsense mixed in. For consistency, the return value is always checked for equality - Get rid of all uses of rw in any implementations of direct_IO, starting with the generic code - Nuke the actual parameter and update the documentation I decided to squish all of the filesystems together in patch 4 to avoid inundating the mailing lists with 20+ mostly two-line patches, but I can split those out if that's any better. Additionally, patch 1 pulls fs.h into uio.h, which seems undesirable. These were mostly just compile tested, with a couple of direct I/O xfstests run on btrfs as quick sanity check, so getting some more eyes on is probably a good thing. They should apply on top of v4.0-rc4. Please comment away. Thank you, Omar Sandoval (5): new helper: iov_iter_rw() Remove rw from {,__,do_}blockdev_direct_IO() Remove rw from dax_{do_,}io() direct_IO: use iov_iter_rw() instead of rw everywhere direct_IO: remove rw from a_ops->direct_IO() Documentation/filesystems/Locking | 2 +- Documentation/filesystems/vfs.txt | 2 +- drivers/staging/lustre/lustre/llite/rw26.c | 22 ++++++++--------- fs/9p/vfs_addr.c | 2 +- fs/affs/file.c | 9 +++---- fs/block_dev.c | 8 +++--- fs/btrfs/inode.c | 24 +++++++++--------- fs/ceph/addr.c | 3 +-- fs/cifs/file.c | 3 +-- fs/dax.c | 27 ++++++++++----------- fs/direct-io.c | 39 ++++++++++++++---------------- fs/exofs/inode.c | 4 +-- fs/ext2/inode.c | 11 ++++----- fs/ext3/inode.c | 14 +++++------ fs/ext4/ext4.h | 4 +-- fs/ext4/indirect.c | 25 ++++++++++--------- fs/ext4/inode.c | 28 ++++++++++----------- fs/f2fs/data.c | 22 ++++++++--------- fs/fat/inode.c | 9 +++---- fs/fuse/file.c | 16 ++++++------ fs/gfs2/aops.c | 16 ++++++------ fs/hfs/inode.c | 8 +++--- fs/hfsplus/inode.c | 9 +++---- fs/jfs/inode.c | 8 +++--- fs/nfs/direct.c | 4 +-- fs/nilfs2/inode.c | 10 +++----- fs/ocfs2/aops.c | 22 +++++++---------- fs/reiserfs/inode.c | 8 +++--- fs/udf/file.c | 3 +-- fs/udf/inode.c | 7 +++--- fs/xfs/xfs_aops.c | 12 ++++----- include/linux/fs.h | 24 +++++++++--------- include/linux/nfs_fs.h | 2 +- include/linux/uio.h | 10 ++++++++ mm/filemap.c | 4 +-- mm/page_io.c | 4 +-- 36 files changed, 206 insertions(+), 219 deletions(-) -- 2.3.3 _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs