From mboxrd@z Thu Jan 1 00:00:00 1970 From: "J. Bruce Fields" Subject: Re: [RFC] [PATCH 2/2] Btrfs: move over to use ->update_time Date: Mon, 9 Apr 2012 11:16:05 -0400 Message-ID: <20120409151605.GA6482@fieldses.org> References: <1332771031-3337-1-git-send-email-josef@redhat.com> <1332771031-3337-2-git-send-email-josef@redhat.com> <20120404174300.GB2097@localhost.localdomain> <1333561669.12904.0.camel@falcor> <20120404181622.GC2097@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Cc: "Kasatkin, Dmitry" , Mimi Zohar , linux-fsdevel@vger.kernel.org, viro@zeniv.linux.org.uk, linux-btrfs@vger.kernel.org, hch@infradead.org To: Josef Bacik Return-path: In-Reply-To: <20120404181622.GC2097@localhost.localdomain> List-ID: On Wed, Apr 04, 2012 at 02:16:22PM -0400, Josef Bacik wrote: > On Wed, Apr 04, 2012 at 09:12:57PM +0300, Kasatkin, Dmitry wrote: > > On Wed, Apr 4, 2012 at 8:47 PM, Mimi Zohar wrote: > > > On Wed, 2012-04-04 at 13:43 -0400, Josef Bacik wrote: > > >> On Wed, Apr 04, 2012 at 08:24:19PM +0300, Kasatkin, Dmitry wrote= : > > >> > Hello, > > >> > > > >> > Mimi and I working on IMA/EVM (security/integrity) and it uses > > >> > i_version for checking if file content has been changed. > > >> > extX file systems support i_version updates with mounting file= system > > >> > with "iversion" option or via kernel command line parameter > > >> > "i_version" > > >> > > > >> > It seems iversion option is not recognized when mounting btrfs= =2E > > >> > I see this patchset deals with i_version update as well.. > > >> > Can you please give an advice how to use i_version with btrfs? > > >> > > > >> > > >> Oh good somebody uses this? =C2=A0We actually have a ->sequence = thing we use for > > >> this, the grand idea was to make it smarter about telling nfs wh= en something > > >> changed, but if you guys use i_version we could probably get rid= of our in-core > > >> sequence and use the normal inodes i_version and then just store= it in our > > >> sequence field on disk. =C2=A0I'll do it without a mount option = tho so it just works, > > >> does that sound good to you? =C2=A0Thanks, > >=20 > > Hello, > >=20 > > Thank you for the answer... > > But can you a bit clarify... > >=20 > > Looking to file_update_time() I see that it does: > >=20 > > if (IS_I_VERSION(inode)) > > sync_it |=3D S_VERSION; > >=20 > > Basically it should be (inode->i_sb->s_flags & MS_I_VERSION) > >=20 > > use of i_version is controlled by iversion mount flag. > > for ext4 I see in parse_options(): > >=20 > > case Opt_i_version: > > set_opt(sb, I_VERSION); > > sb->s_flags |=3D MS_I_VERSION; > > break; > >=20 > >=20 > > But who sets MS_I_VERSION in s_flags on btrfs? > >=20 >=20 > Nobody yet, I'm going to send a patch shortly that will support this.= Thanks, Great. It would also be far preferable if it was just always on (at least by default) rather than requiring a mount option. --b. -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" = in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html