From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sage Weil Subject: Re: [PATCH] ceph: Don't get layout from mds for regular file which has been written. Date: Fri, 12 Jul 2013 14:06:36 -0700 (PDT) Message-ID: References: <201307111659490192618@gmail.com> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Return-path: Received: from cobra.newdream.net ([66.33.216.30]:57531 "EHLO cobra.newdream.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965359Ab3GLVGg (ORCPT ); Fri, 12 Jul 2013 17:06:36 -0400 In-Reply-To: <201307111659490192618@gmail.com> Sender: ceph-devel-owner@vger.kernel.org List-ID: To: majianpeng Cc: ceph-devel On Thu, 11 Jul 2013, majianpeng wrote: > For regular file which has been written, it can't change layout. > So it can get layout from local rather than mds. > > Signed-off-by: Jianpeng Ma > --- > fs/ceph/ioctl.c | 10 ++++++++-- > 1 file changed, 8 insertions(+), 2 deletions(-) > > diff --git a/fs/ceph/ioctl.c b/fs/ceph/ioctl.c > index e0b4ef3..2b74879 100644 > --- a/fs/ceph/ioctl.c > +++ b/fs/ceph/ioctl.c > @@ -17,10 +17,16 @@ > static long ceph_ioctl_get_layout(struct file *file, void __user *arg) > { > struct ceph_inode_info *ci = ceph_inode(file_inode(file)); > + struct inode *inode = file_inode(file); > struct ceph_ioctl_layout l; > - int err; > + int err = 0; > + > + /*For regular file which has been written,it can't change layout > + * So it don't get layout from mds*/ style nit: space after /* and before */ > + if (!(S_ISREG(inode->i_mode) && (i_size_read(inode) > 0 || > + ci->i_truncate_seq > 1))) > + err = ceph_do_getattr(file_inode(file), CEPH_STAT_CAP_LAYOUT); I think a more defensive approach would be to use the helper to see if we are holding any of the Fcrwbl caps; if so, we can assume the layout is valid. Note that we should be doing the same thing in getxattr when exposing the ceph.file.layout[.*] xattrs.. right now they are blindingly assuming that whatever is in cache is correct, which isn't strictly true. :/ sage > - err = ceph_do_getattr(file_inode(file), CEPH_STAT_CAP_LAYOUT); > if (!err) { > l.stripe_unit = ceph_file_layout_su(ci->i_layout); > l.stripe_count = ceph_file_layout_stripe_count(ci->i_layout); > -- > 1.8.1.2 >