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From:   Dai Ngo <dai.ngo@oracle.com>
To:     chuck.lever@oracle.com
Cc:     linux-nfs@vger.kernel.org
Subject: [PATCH 1/2] NFSD: add support for sending CB_RECALL_ANY
Date:   Mon, 17 Oct 2022 22:15:38 -0700
Message-Id: <1666070139-18843-2-git-send-email-dai.ngo@oracle.com>
In-Reply-To: <1666070139-18843-1-git-send-email-dai.ngo@oracle.com>
References: <1666070139-18843-1-git-send-email-dai.ngo@oracle.com>
Precedence: bulk

There is only one nfsd4_callback, cl_recall_any, added for each
nfs4_client. Access to it must be serialized. For now it's done
by the cl_recall_any_busy flag since it's used only by the
delegation shrinker. If there is another consumer of CB_RECALL_ANY
then a spinlock must be used.

Signed-off-by: Dai Ngo <dai.ngo@oracle.com>
---
 fs/nfsd/nfs4callback.c | 64 ++++++++++++++++++++++++++++++++++++++++++++++++++
 fs/nfsd/nfs4state.c    | 27 +++++++++++++++++++++
 fs/nfsd/state.h        |  8 +++++++
 fs/nfsd/xdr4cb.h       |  6 +++++
 4 files changed, 105 insertions(+)

diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c
index f0e69edf5f0f..03587e1397f4 100644
--- a/fs/nfsd/nfs4callback.c
+++ b/fs/nfsd/nfs4callback.c
@@ -329,6 +329,29 @@ static void encode_cb_recall4args(struct xdr_stream *xdr,
 }
 
 /*
+ * CB_RECALLANY4args
+ *
+ *	struct CB_RECALLANY4args {
+ *		uint32_t	craa_objects_to_keep;
+ *		bitmap4		craa_type_mask;
+ *	};
+ */
+static void
+encode_cb_recallany4args(struct xdr_stream *xdr,
+			struct nfs4_cb_compound_hdr *hdr, uint32_t bmval)
+{
+	__be32 *p;
+
+	encode_nfs_cb_opnum4(xdr, OP_CB_RECALL_ANY);
+	p = xdr_reserve_space(xdr, 4);
+	*p++ = xdr_zero;	/* craa_objects_to_keep */
+	p = xdr_reserve_space(xdr, 8);
+	*p++ = cpu_to_be32(1);
+	*p++ = cpu_to_be32(bmval);
+	hdr->nops++;
+}
+
+/*
  * CB_SEQUENCE4args
  *
  *	struct CB_SEQUENCE4args {
@@ -482,6 +505,24 @@ static void nfs4_xdr_enc_cb_recall(struct rpc_rqst *req, struct xdr_stream *xdr,
 	encode_cb_nops(&hdr);
 }
 
+/*
+ * 20.6. Operation 8: CB_RECALL_ANY - Keep Any N Recallable Objects
+ */
+static void
+nfs4_xdr_enc_cb_recall_any(struct rpc_rqst *req,
+		struct xdr_stream *xdr, const void *data)
+{
+	const struct nfsd4_callback *cb = data;
+	struct nfs4_cb_compound_hdr hdr = {
+		.ident = cb->cb_clp->cl_cb_ident,
+		.minorversion = cb->cb_clp->cl_minorversion,
+	};
+
+	encode_cb_compound4args(xdr, &hdr);
+	encode_cb_sequence4args(xdr, cb, &hdr);
+	encode_cb_recallany4args(xdr, &hdr, cb->cb_clp->cl_recall_any_bm);
+	encode_cb_nops(&hdr);
+}
 
 /*
  * NFSv4.0 and NFSv4.1 XDR decode functions
@@ -520,6 +561,28 @@ static int nfs4_xdr_dec_cb_recall(struct rpc_rqst *rqstp,
 	return decode_cb_op_status(xdr, OP_CB_RECALL, &cb->cb_status);
 }
 
+/*
+ * 20.6. Operation 8: CB_RECALL_ANY - Keep Any N Recallable Objects
+ */
+static int
+nfs4_xdr_dec_cb_recall_any(struct rpc_rqst *rqstp,
+				  struct xdr_stream *xdr,
+				  void *data)
+{
+	struct nfsd4_callback *cb = data;
+	struct nfs4_cb_compound_hdr hdr;
+	int status;
+
+	status = decode_cb_compound4res(xdr, &hdr);
+	if (unlikely(status))
+		return status;
+	status = decode_cb_sequence4res(xdr, cb);
+	if (unlikely(status || cb->cb_seq_status))
+		return status;
+	status =  decode_cb_op_status(xdr, OP_CB_RECALL_ANY, &cb->cb_status);
+	return status;
+}
+
 #ifdef CONFIG_NFSD_PNFS
 /*
  * CB_LAYOUTRECALL4args
@@ -783,6 +846,7 @@ static const struct rpc_procinfo nfs4_cb_procedures[] = {
 #endif
 	PROC(CB_NOTIFY_LOCK,	COMPOUND,	cb_notify_lock,	cb_notify_lock),
 	PROC(CB_OFFLOAD,	COMPOUND,	cb_offload,	cb_offload),
+	PROC(CB_RECALL_ANY,	COMPOUND,	cb_recall_any,	cb_recall_any),
 };
 
 static unsigned int nfs4_cb_counts[ARRAY_SIZE(nfs4_cb_procedures)];
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 4e718500a00c..c60c937dece6 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -2854,6 +2854,31 @@ static const struct tree_descr client_files[] = {
 	[3] = {""},
 };
 
+static int
+nfsd4_cb_recall_any_done(struct nfsd4_callback *cb,
+			struct rpc_task *task)
+{
+	switch (task->tk_status) {
+	case -NFS4ERR_DELAY:
+		rpc_delay(task, 2 * HZ);
+		return 0;
+	default:
+		return 1;
+	}
+}
+
+static void
+nfsd4_cb_recall_any_release(struct nfsd4_callback *cb)
+{
+	cb->cb_clp->cl_recall_any_busy = false;
+	atomic_dec(&cb->cb_clp->cl_rpc_users);
+}
+
+static const struct nfsd4_callback_ops nfsd4_cb_recall_any_ops = {
+	.done		= nfsd4_cb_recall_any_done,
+	.release	= nfsd4_cb_recall_any_release,
+};
+
 static struct nfs4_client *create_client(struct xdr_netobj name,
 		struct svc_rqst *rqstp, nfs4_verifier *verf)
 {
@@ -2891,6 +2916,8 @@ static struct nfs4_client *create_client(struct xdr_netobj name,
 		free_client(clp);
 		return NULL;
 	}
+	nfsd4_init_cb(&clp->cl_recall_any, clp, &nfsd4_cb_recall_any_ops,
+			NFSPROC4_CLNT_CB_RECALL_ANY);
 	return clp;
 }
 
diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h
index e2daef3cc003..49ca06169642 100644
--- a/fs/nfsd/state.h
+++ b/fs/nfsd/state.h
@@ -411,6 +411,10 @@ struct nfs4_client {
 
 	unsigned int		cl_state;
 	atomic_t		cl_delegs_in_recall;
+
+	bool			cl_recall_any_busy;
+	uint32_t		cl_recall_any_bm;
+	struct nfsd4_callback	cl_recall_any;
 };
 
 /* struct nfs4_client_reset
@@ -639,8 +643,12 @@ enum nfsd4_cb_op {
 	NFSPROC4_CLNT_CB_OFFLOAD,
 	NFSPROC4_CLNT_CB_SEQUENCE,
 	NFSPROC4_CLNT_CB_NOTIFY_LOCK,
+	NFSPROC4_CLNT_CB_RECALL_ANY,
 };
 
+#define RCA4_TYPE_MASK_RDATA_DLG	0
+#define RCA4_TYPE_MASK_WDATA_DLG	1
+
 /* Returns true iff a is later than b: */
 static inline bool nfsd4_stateid_generation_after(stateid_t *a, stateid_t *b)
 {
diff --git a/fs/nfsd/xdr4cb.h b/fs/nfsd/xdr4cb.h
index 547cf07cf4e0..0d39af1b00a0 100644
--- a/fs/nfsd/xdr4cb.h
+++ b/fs/nfsd/xdr4cb.h
@@ -48,3 +48,9 @@
 #define NFS4_dec_cb_offload_sz		(cb_compound_dec_hdr_sz  +      \
 					cb_sequence_dec_sz +            \
 					op_dec_sz)
+#define NFS4_enc_cb_recall_any_sz	(cb_compound_enc_hdr_sz +       \
+					cb_sequence_enc_sz +            \
+					1 + 1 + 1)
+#define NFS4_dec_cb_recall_any_sz	(cb_compound_dec_hdr_sz  +      \
+					cb_sequence_dec_sz +            \
+					op_dec_sz)
-- 
2.9.5