Re: [PATCH v2 3/7] nfsd: use ATTR_CTIME_SET for delegated ctime updates

Jeff Layton
2025-07-26T19:03:55Z

On Sat, 2025-07-26 at 14:48 -0400, Chuck Lever wrote:
> Hi Jeff -
>
> Thanks again for your focus on getting this straightened out!
>
>
> On 7/26/25 10:31 AM, Jeff Layton wrote:
> > Ensure that notify_change() doesn't clobber a delegated ctime update
> > with current_time() by setting ATTR_CTIME_SET for those updates.
> >
> > Also, set the tv_nsec field the nfsd4_decode_fattr4 to the correct
> > value.
>
> I don't yet see the connection of the above tv_nsec fix to the other
> changes in this patch. Wouldn't this be an independent fix?
>

I felt like they were related. Yes, the ia_ctime field is currently
being set wrong, but it's also being clobbered by notify_change(), so
it doesn't matter much. I can break this into a separate patch (with a
Fixes: tag) if you prefer though.

> > Don't bother setting the timestamps in cb_getattr_update_times() in the
> > non-delegated case. notify_change() will do that itself.
> >
> > Signed-off-by: Jeff Layton <jlayton@kernel.org>
>
> General comments:
>
> I don't feel that any of the patches in this series need to be tagged
> for stable, since there is already a Kconfig setting that defaults to
> leaving timestamp delegation disabled. But I would like to see Fixes:
> tags, where that makes sense?
>

I don't think any of these need to go to stable since this is still
under a non-default Kconfig option, and the main effect of the bug is
wonky timestamps. I should be able to add some Fixes: tags though.

> Is this set on top of the set you posted a day or two ago with the new
> trace point? Or does this set replace that one?
>

This set should replace those.

>
> > ---
> > fs/nfsd/nfs4state.c | 6 +++---
> > fs/nfsd/nfs4xdr.c | 5 +++--
> > 2 files changed, 6 insertions(+), 5 deletions(-)
> >
> > diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
> > index 88c347957da5b8f352be63f84f207d2225f81cb9..77eea2ad93cc07939f045fc4b983b1ac00d068b8 100644
> > --- a/fs/nfsd/nfs4state.c
> > +++ b/fs/nfsd/nfs4state.c
> > @@ -9167,7 +9167,6 @@ static bool set_cb_time(struct timespec64 *cb, const struct timespec64 *orig,
> > static int cb_getattr_update_times(struct dentry *dentry, struct nfs4_delegation *dp)
> > {
> > struct inode *inode = d_inode(dentry);
> > - struct timespec64 now = current_time(inode);
> > struct nfs4_cb_fattr *ncf = &dp->dl_cb_fattr;
> > struct iattr attrs = { };
> > int ret;
> > @@ -9175,6 +9174,7 @@ static int cb_getattr_update_times(struct dentry *dentry, struct nfs4_delegation
> > if (deleg_attrs_deleg(dp->dl_type)) {
> > struct timespec64 atime = inode_get_atime(inode);
> > struct timespec64 mtime = inode_get_mtime(inode);
> > + struct timespec64 now = current_time(inode);
> >
> > attrs.ia_atime = ncf->ncf_cb_atime;
> > attrs.ia_mtime = ncf->ncf_cb_mtime;
> > @@ -9183,12 +9183,12 @@ static int cb_getattr_update_times(struct dentry *dentry, struct nfs4_delegation
> > attrs.ia_valid |= ATTR_ATIME | ATTR_ATIME_SET;
> >
> > if (set_cb_time(&attrs.ia_mtime, &mtime, &now)) {
> > - attrs.ia_valid |= ATTR_CTIME | ATTR_MTIME | ATTR_MTIME_SET;
> > + attrs.ia_valid |= ATTR_CTIME | ATTR_CTIME_SET |
> > + ATTR_MTIME | ATTR_MTIME_SET;
> > attrs.ia_ctime = attrs.ia_mtime;
> > }
> > } else {
> > attrs.ia_valid |= ATTR_MTIME | ATTR_CTIME;
> > - attrs.ia_mtime = attrs.ia_ctime = now;
> > }
> >
> > if (!attrs.ia_valid)
> > diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
> > index 8b68f74a8cf08c6aa1305a2a3093467656085e4a..c0a3c6a7c8bb70d62940115c3101e9f897401456 100644
> > --- a/fs/nfsd/nfs4xdr.c
> > +++ b/fs/nfsd/nfs4xdr.c
> > @@ -538,8 +538,9 @@ nfsd4_decode_fattr4(struct nfsd4_compoundargs *argp, u32 *bmval, u32 bmlen,
> > iattr->ia_mtime.tv_sec = modify.seconds;
> > iattr->ia_mtime.tv_nsec = modify.nseconds;
> > iattr->ia_ctime.tv_sec = modify.seconds;
> > - iattr->ia_ctime.tv_nsec = modify.seconds;
> > - iattr->ia_valid |= ATTR_CTIME | ATTR_MTIME | ATTR_MTIME_SET | ATTR_DELEG;
> > + iattr->ia_ctime.tv_nsec = modify.nseconds;
> > + iattr->ia_valid |= ATTR_CTIME | ATTR_CTIME_SET |
> > + ATTR_MTIME | ATTR_MTIME_SET | ATTR_DELEG;
> > }
> >
> > /* request sanity: did attrlist4 contain the expected number of words? */
> >
>
>

--
Jeff Layton <jlayton@kernel.org>