[PATCH RFC 14/24] nfsd: wire up GET_DIR_DELEGATION handling

[Jeff Layton <jlayton@kernel.org>]

Add a new routine for acquiring a read delegation on a directory. Since
the same CB_RECALL/DELEGRETURN infrastrure is used for regular and
directory delegations, we can just use a normal nfs4_delegation to
represent it.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
---
 fs/nfsd/nfs4proc.c  | 23 ++++++++++++++++--
 fs/nfsd/nfs4state.c | 69 ++++++++++++++++++++++++++++++++++++++++++++++++++++-
 fs/nfsd/state.h     |  5 ++++
 3 files changed, 94 insertions(+), 3 deletions(-)

diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index 7973fe17bf3c..1a2c90f4ea53 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -2179,9 +2179,28 @@ nfsd4_get_dir_delegation(struct svc_rqst *rqstp,
 			 union nfsd4_op_u *u)
 {
 	struct nfsd4_get_dir_delegation *gdd = &u->get_dir_delegation;
+	struct nfs4_delegation *dd;
+	struct nfsd_file *nf;
+	__be32 status;
+
+	status = nfsd_file_acquire_dir(rqstp, &cstate->current_fh, &nf);
+	if (status != nfs_ok)
+		return status;
+
+	dd = nfsd_get_dir_deleg(cstate, gdd, nf);
+	if (IS_ERR(dd)) {
+		int err = PTR_ERR(dd);
+
+		if (err != -EAGAIN)
+			return nfserrno(err);
+		gdd->nf_status = GDD4_UNAVAIL;
+		return nfs_ok;
+	}
 
-	/* FIXME: actually return a delegation */
-	gdd->nf_status = GDD4_UNAVAIL;
+	gdd->nf_status = GDD4_OK;
+	memcpy(&gdd->stateid, &dd->dl_stid.sc_stateid, sizeof(gdd->stateid));
+	memset(&gdd->cookieverf, '\0', sizeof(gdd->cookieverf));
+	nfs4_put_stid(&dd->dl_stid);
 	return nfs_ok;
 }
 
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 778c1c6e3b54..36574aedc211 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -8874,7 +8874,7 @@ nfsd4_deleg_getattr_conflict(struct svc_rqst *rqstp, struct inode *inode,
 			}
 break_lease:
 			nfsd_stats_wdeleg_getattr_inc(nn);
-			dp = fl->fl_owner;
+			dp = fl->c.flc_owner;
 			ncf = &dp->dl_cb_fattr;
 			nfs4_cb_getattr(&dp->dl_cb_fattr);
 			spin_unlock(&ctx->flc_lock);
@@ -8912,3 +8912,70 @@ nfsd4_deleg_getattr_conflict(struct svc_rqst *rqstp, struct inode *inode,
 	spin_unlock(&ctx->flc_lock);
 	return 0;
 }
+
+struct nfs4_delegation *
+nfsd_get_dir_deleg(struct nfsd4_compound_state *cstate,
+		   struct nfsd4_get_dir_delegation *gdd,
+		   struct nfsd_file *nf)
+{
+	struct nfs4_client *clp = cstate->clp;
+	struct nfs4_delegation *dp;
+	struct file_lease *fl;
+	struct nfs4_file *fp;
+	int status = 0;
+
+	fp = nfsd4_alloc_file();
+	if (!fp)
+		return ERR_PTR(-ENOMEM);
+
+	nfsd4_file_init(&cstate->current_fh, fp);
+	fp->fi_deleg_file = nf;
+	fp->fi_delegees = 1;
+
+	spin_lock(&state_lock);
+	spin_lock(&fp->fi_lock);
+	if (nfs4_delegation_exists(clp, fp))
+		status = -EAGAIN;
+	spin_unlock(&fp->fi_lock);
+	spin_unlock(&state_lock);
+
+	if (status)
+		goto out_delegees;
+
+	status = -ENOMEM;
+	dp = alloc_init_deleg(clp, fp, NULL, NFS4_OPEN_DELEGATE_READ);
+	if (!dp)
+		goto out_delegees;
+
+	fl = nfs4_alloc_init_lease(dp, NFS4_OPEN_DELEGATE_READ);
+	if (!fl)
+		goto out_put_stid;
+
+	status = kernel_setlease(nf->nf_file,
+				 fl->c.flc_type, &fl, NULL);
+	if (fl)
+		locks_free_lease(fl);
+	if (status)
+		goto out_put_stid;
+
+	spin_lock(&state_lock);
+	spin_lock(&clp->cl_lock);
+	spin_lock(&fp->fi_lock);
+	status = hash_delegation_locked(dp, fp);
+	spin_unlock(&fp->fi_lock);
+	spin_unlock(&clp->cl_lock);
+	spin_unlock(&state_lock);
+
+	if (status)
+		goto out_unlock;
+
+	return dp;
+out_unlock:
+	kernel_setlease(fp->fi_deleg_file->nf_file, F_UNLCK, NULL, (void **)&dp);
+out_put_stid:
+	nfs4_put_stid(&dp->dl_stid);
+out_delegees:
+	put_deleg_file(fp);
+	return ERR_PTR(status);
+}
+
diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h
index 01c6f3445646..20551483cc7b 100644
--- a/fs/nfsd/state.h
+++ b/fs/nfsd/state.h
@@ -782,4 +782,9 @@ static inline bool try_to_expire_client(struct nfs4_client *clp)
 
 extern __be32 nfsd4_deleg_getattr_conflict(struct svc_rqst *rqstp,
 		struct inode *inode, bool *file_modified, u64 *size);
+
+struct nfsd4_get_dir_delegation;
+struct nfs4_delegation *nfsd_get_dir_deleg(struct nfsd4_compound_state *cstate,
+						struct nfsd4_get_dir_delegation *gdd,
+						struct nfsd_file *nf);
 #endif   /* NFSD4_STATE_H */

-- 
2.44.0