On Wed, Apr 04, 2012 at 09:12:57PM +0300, Kasatkin, Dmitry wrote: > On Wed, Apr 4, 2012 at 8:47 PM, Mimi Zohar <zohar@xxxxxxxxxxxxxxxxxx> 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. > >> > 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? We actually have a ->sequence thing we use for > >> this, the grand idea was to make it smarter about telling nfs when 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. I'll do it without a mount option tho so it just works, > >> does that sound good to you? Thanks, > > Hello, > > Thank you for the answer... > But can you a bit clarify... > > Looking to file_update_time() I see that it does: > > if (IS_I_VERSION(inode)) > sync_it |= S_VERSION; > > Basically it should be (inode->i_sb->s_flags & MS_I_VERSION) > > use of i_version is controlled by iversion mount flag. > for ext4 I see in parse_options(): > > case Opt_i_version: > set_opt(sb, I_VERSION); > sb->s_flags |= MS_I_VERSION; > break; > > > But who sets MS_I_VERSION in s_flags on btrfs? > Nobody yet, I'm going to send a patch shortly that will support this. Thanks, Josef -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
