On Sun, May 21, 2023 at 07:08:43PM -0400, Jeff Layton wrote:
> On Sat, 2023-05-20 at 14:36 -0700, Dai Ngo wrote:
> > If the GETATTR request on a file that has write delegation in effect
> > and the request attributes include the change info and size attribute
> > then the write delegation is recalled and NFS4ERR_DELAY is returned
> > for the GETATTR.
> >
> > Signed-off-by: Dai Ngo <dai.ngo@xxxxxxxxxx>
> > ---
> > fs/nfsd/nfs4xdr.c | 45 +++++++++++++++++++++++++++++++++++++++++++++
> > 1 file changed, 45 insertions(+)
> >
> > diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
> > index 76db2fe29624..e069b970f136 100644
> > --- a/fs/nfsd/nfs4xdr.c
> > +++ b/fs/nfsd/nfs4xdr.c
> > @@ -2920,6 +2920,46 @@ nfsd4_encode_bitmap(struct xdr_stream *xdr, u32 bmval0, u32 bmval1, u32 bmval2)
> > return nfserr_resource;
> > }
> >
> > +static struct file_lock *
> > +nfs4_wrdeleg_filelock(struct svc_rqst *rqstp, struct inode *inode)
> > +{
> > + struct file_lock_context *ctx;
> > + struct file_lock *fl;
> > +
> > + ctx = locks_inode_context(inode);
> > + if (!ctx)
> > + return NULL;
> > + spin_lock(&ctx->flc_lock);
> > + if (!list_empty(&ctx->flc_lease)) {
> > + fl = list_first_entry(&ctx->flc_lease,
> > + struct file_lock, fl_list);
> > + if (fl->fl_type == F_WRLCK) {
> > + spin_unlock(&ctx->flc_lock);
> > + return fl;
> > + }
> > + }
> > + spin_unlock(&ctx->flc_lock);
> > + return NULL;
> > +}
> > +
> > +static __be32
> > +nfs4_handle_wrdeleg_conflict(struct svc_rqst *rqstp, struct inode *inode)
> > +{
> > + __be32 status;
> > + struct file_lock *fl;
> > + struct nfs4_delegation *dp;
> > +
> > + fl = nfs4_wrdeleg_filelock(rqstp, inode);
> > + if (!fl)
> > + return 0;
> > + dp = fl->fl_owner;
> > + if (dp->dl_recall.cb_clp == *(rqstp->rq_lease_breaker))
> > + return 0;
> > + refcount_inc(&dp->dl_stid.sc_count);
>
> Another question: Why are you taking a reference here at all? AFAICT,
> you don't even look at the delegation again after that point, so it's
> not clear to me who's responsible for putting that reference.
I had the same thought, but I assumed I was missing something.
> > + status = nfserrno(nfsd_open_break_lease(inode, NFSD_MAY_READ));
> > + return status;
> > +}
> > +
> > /*
> > * Note: @fhp can be NULL; in this case, we might have to compose the filehandle
> > * ourselves.
> > @@ -2966,6 +3006,11 @@ nfsd4_encode_fattr(struct xdr_stream *xdr, struct svc_fh *fhp,
> > if (status)
> > goto out;
> > }
> > + if (bmval0 & (FATTR4_WORD0_CHANGE | FATTR4_WORD0_SIZE)) {
> > + status = nfs4_handle_wrdeleg_conflict(rqstp, d_inode(dentry));
> > + if (status)
> > + goto out;
> > + }
> >
> > err = vfs_getattr(&path, &stat,
> > STATX_BASIC_STATS | STATX_BTIME | STATX_CHANGE_COOKIE,
>
> --
> Jeff Layton <jlayton@xxxxxxxxxx>
