From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 44757C25B08 for ; Wed, 17 Aug 2022 13:33:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239708AbiHQNdj (ORCPT ); Wed, 17 Aug 2022 09:33:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50490 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236468AbiHQNdN (ORCPT ); Wed, 17 Aug 2022 09:33:13 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CDA9A520B8; Wed, 17 Aug 2022 06:28:55 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 4555661369; Wed, 17 Aug 2022 13:28:55 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id DAFDFC433D7; Wed, 17 Aug 2022 13:28:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1660742934; bh=6yjNdgODDfvQlP3WEx/1wAUvt0SeFsO8Kkyhby/g+r8=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=buHB4RRG7USSQFiM119COnF6CsdANWo/Cyn5EAUaWP0l/CHpMt3wjfilAs7Lkihz2 Uvwnm2m3UxkfoBMX98Ul5HShNAmCg7XYtgCSOx59s6n/6TAlpN1RNC0G/ivIpoOw15 iqM0HM9NjAV1bmkYtLdzEb6I7vA+uQ2I1QkslgHzJGtAUqGNZNuFU4Ow4D0ppn1lXL k2olxtt3Dc0p5+0Te6slYRkcRlWlQ2mSvZNfhcMBmNIrfTwSIXEPBaRdBdKfqrljFN tKSTE9iQX7YWktVG/6OX99GKjl0h0J+JXWYpwxLp0twKN9RIPyYradj9rHoyVvll6P grd9+g3kpCB/w== Message-ID: <73ef7c1609d9045f7522111b53706ee65b1a253a.camel@kernel.org> Subject: Re: [PATCH] ext4: fix i_version handling in ext4 From: Jeff Layton To: Jan Kara Cc: tytso@mit.edu, adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org, Lukas Czerner , Christian Brauner Date: Wed, 17 Aug 2022 09:28:52 -0400 In-Reply-To: <20220817132533.4xvvkvltmwzudybm@quack3> References: <20220816131522.42467-1-jlayton@kernel.org> <20220817130441.qigqv62wj6lrvxfc@quack3> <20220817132533.4xvvkvltmwzudybm@quack3> Content-Type: text/plain; charset="ISO-8859-15" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.44.4 (3.44.4-1.fc36) MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Wed, 2022-08-17 at 15:25 +0200, Jan Kara wrote: > On Wed 17-08-22 09:09:58, Jeff Layton wrote: > > On Wed, 2022-08-17 at 15:04 +0200, Jan Kara wrote: > > > On Tue 16-08-22 09:15:22, Jeff Layton wrote: > > > > ext4 currently updates the i_version counter when the atime is upda= ted > > > > during a read. This is less than ideal as it can cause unnecessary = cache > > > > invalidations with NFSv4. The increment in ext4_mark_iloc_dirty is = also > > > > problematic since it can also corrupt the i_version counter for > > > > ea_inodes. > > > >=20 > > > > We aren't bumping the file times in ext4_mark_iloc_dirty, so changi= ng > > > > the i_version there seems wrong, and is the cause of both problems. > > > > Remove that callsite and add increments to the setattr and setxattr > > > > codepaths (at the same time that we update the ctime). The i_versio= n > > > > bump that already happens during timestamp updates should take care= of > > > > the rest. > > > >=20 > > > > Cc: Lukas Czerner > > > > Cc: Jan Kara > > > > Cc: Christian Brauner > > > > Signed-off-by: Jeff Layton > > >=20 > > > After some verification (which was not completely trivial e.g. for > > > directories) I agree all cases should be covered. Feel free to add: > > >=20 > > > Reviewed-by: Jan Kara > > >=20 > > > Honza > > >=20 > >=20 > > Thanks. > >=20 > > I think this covers the typical cases, but there are some places I > > missed: > >=20 > > The setacl codepath, for one, and there are a number of places that set > > the ctime explicitly for hole punching and the like. >=20 > Hum, why is setacl() not covered by your change to ext4_xattr_set_handle(= )? > ext4_set_acl() ends up calling it... I have checked hole punching (whole > ext4_fallocate()) and it seems to be incrementing iversion where needed. >=20 Oh, ok! I mostly noticed the places I was "missing" by inspection. It's possible that I don't need those changes after all. If you think this patch is sufficient, then I'll plan to just go with this one. > > I'm planning to > > send a v2 once I do a bit more testing. I'll hold off on adding your > > Reviewed-by just yet, since the final patch may be quite a bit > > different. >=20 > OK, thanks! >=20 > Honza >=20 > >=20 > >=20 > > > > --- > > > > fs/ext4/inode.c | 10 +++++----- > > > > fs/ext4/xattr.c | 2 ++ > > > > 2 files changed, 7 insertions(+), 5 deletions(-) > > > >=20 > > > > I think this patch should probably supersede Lukas' patch entitled: > > > >=20 > > > > ext4: don't increase iversion counter for ea_inodes > > > >=20 > > > > This will also mean that we'll need to respin the patch to turn on = the > > > > i_version counter unconditionally in ext4 (though that should be > > > > trivial). > > > >=20 > > > > diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c > > > > index 601214453c3a..a70921df89a5 100644 > > > > --- a/fs/ext4/inode.c > > > > +++ b/fs/ext4/inode.c > > > > @@ -5342,6 +5342,7 @@ int ext4_setattr(struct user_namespace *mnt_u= serns, struct dentry *dentry, > > > > int error, rc =3D 0; > > > > int orphan =3D 0; > > > > const unsigned int ia_valid =3D attr->ia_valid; > > > > + bool inc_ivers =3D IS_IVERSION(inode); > > > > =20 > > > > if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb)))) > > > > return -EIO; > > > > @@ -5425,8 +5426,8 @@ int ext4_setattr(struct user_namespace *mnt_u= serns, struct dentry *dentry, > > > > return -EINVAL; > > > > } > > > > =20 > > > > - if (IS_I_VERSION(inode) && attr->ia_size !=3D inode->i_size) > > > > - inode_inc_iversion(inode); > > > > + if (attr->ia_size =3D=3D inode->i_size) > > > > + inc_ivers =3D false; > > > > =20 > > > > if (shrink) { > > > > if (ext4_should_order_data(inode)) { > > > > @@ -5528,6 +5529,8 @@ int ext4_setattr(struct user_namespace *mnt_u= serns, struct dentry *dentry, > > > > } > > > > =20 > > > > if (!error) { > > > > + if (inc_ivers) > > > > + inode_inc_iversion(inode); > > > > setattr_copy(mnt_userns, inode, attr); > > > > mark_inode_dirty(inode); > > > > } > > > > @@ -5731,9 +5734,6 @@ int ext4_mark_iloc_dirty(handle_t *handle, > > > > } > > > > ext4_fc_track_inode(handle, inode); > > > > =20 > > > > - if (IS_I_VERSION(inode)) > > > > - inode_inc_iversion(inode); > > > > - > > > > /* the do_update_inode consumes one bh->b_count */ > > > > get_bh(iloc->bh); > > > > =20 > > > > diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c > > > > index 533216e80fa2..4d84919d1c9c 100644 > > > > --- a/fs/ext4/xattr.c > > > > +++ b/fs/ext4/xattr.c > > > > @@ -2412,6 +2412,8 @@ ext4_xattr_set_handle(handle_t *handle, struc= t inode *inode, int name_index, > > > > if (!error) { > > > > ext4_xattr_update_super_block(handle, inode->i_sb); > > > > inode->i_ctime =3D current_time(inode); > > > > + if (IS_IVERSION(inode)) > > > > + inode_inc_iversion(inode); > > > > if (!value) > > > > no_expand =3D 0; > > > > error =3D ext4_mark_iloc_dirty(handle, inode, &is.iloc); > > > > --=20 > > > > 2.37.2 > > > >=20 > >=20 > > --=20 > > Jeff Layton --=20 Jeff Layton