pnfs: remove GETDEVICELIST implementation

The current GETDEVICELIST implementation is buggy in that it doesn't handle
cursors correctly, and in that it returns an error if the server returns
NFSERR_NOTSUPP.  Given that there is no actual need for GETDEVICELIST,
it has various issues and might get removed for NFSv4.2 stop using it in
the blocklayout driver, and thus the Linux NFS client as whole.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

fs/nfs/blocklayout/blocklayout.c

@@ -532,7 +532,7 @@ bl_set_layoutdriver(struct nfs_server *server, const struct nfs_fh *fh)
 		return -EINVAL;
 	}
 
-	return nfs4_deviceid_getdevicelist(server, fh);
+	return 0;
 }
 
 static bool

fs/nfs/nfs4proc.c

@@ -7808,54 +7808,6 @@ int nfs4_proc_layoutreturn(struct nfs4_layoutreturn *lrp)
 	return status;
 }
 
-/*
- * Retrieve the list of Data Server devices from the MDS.
- */
-static int _nfs4_getdevicelist(struct nfs_server *server,
-				    const struct nfs_fh *fh,
-				    struct pnfs_devicelist *devlist)
-{
-	struct nfs4_getdevicelist_args args = {
-		.fh = fh,
-		.layoutclass = server->pnfs_curr_ld->id,
-	};
-	struct nfs4_getdevicelist_res res = {
-		.devlist = devlist,
-	};
-	struct rpc_message msg = {
-		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_GETDEVICELIST],
-		.rpc_argp = &args,
-		.rpc_resp = &res,
-	};
-	int status;
-
-	dprintk("--> %s\n", __func__);
-	status = nfs4_call_sync(server->client, server, &msg, &args.seq_args,
-				&res.seq_res, 0);
-	dprintk("<-- %s status=%d\n", __func__, status);
-	return status;
-}
-
-int nfs4_proc_getdevicelist(struct nfs_server *server,
-			    const struct nfs_fh *fh,
-			    struct pnfs_devicelist *devlist)
-{
-	struct nfs4_exception exception = { };
-	int err;
-
-	do {
-		err = nfs4_handle_exception(server,
-				_nfs4_getdevicelist(server, fh, devlist),
-				&exception);
-	} while (exception.retry);
-
-	dprintk("%s: err=%d, num_devs=%u\n", __func__,
-		err, devlist->num_devs);
-
-	return err;
-}
-EXPORT_SYMBOL_GPL(nfs4_proc_getdevicelist);
-
 static int
 _nfs4_proc_getdeviceinfo(struct nfs_server *server,
 		struct pnfs_device *pdev,

fs/nfs/nfs4xdr.c

@@ -362,17 +362,6 @@ static int nfs4_stat_to_errno(int);
 				XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN) + 5)
 #define encode_reclaim_complete_maxsz	(op_encode_hdr_maxsz + 4)
 #define decode_reclaim_complete_maxsz	(op_decode_hdr_maxsz + 4)
-#define encode_getdevicelist_maxsz (op_encode_hdr_maxsz + 4 + \
-				encode_verifier_maxsz)
-#define decode_getdevicelist_maxsz (op_decode_hdr_maxsz + \
-				2 /* nfs_cookie4 gdlr_cookie */ + \
-				decode_verifier_maxsz \
-				  /* verifier4 gdlr_verifier */ + \
-				1 /* gdlr_deviceid_list count */ + \
-				XDR_QUADLEN(NFS4_PNFS_GETDEVLIST_MAXNUM * \
-					    NFS4_DEVICEID4_SIZE) \
-				  /* gdlr_deviceid_list */ + \
-				1 /* bool gdlr_eof */)
 #define encode_getdeviceinfo_maxsz (op_encode_hdr_maxsz + 4 + \
 				XDR_QUADLEN(NFS4_DEVICEID4_SIZE))
 #define decode_getdeviceinfo_maxsz (op_decode_hdr_maxsz + \
@@ -812,14 +801,6 @@ static int nfs4_stat_to_errno(int);
 #define NFS4_dec_reclaim_complete_sz	(compound_decode_hdr_maxsz + \
 					 decode_sequence_maxsz + \
 					 decode_reclaim_complete_maxsz)
-#define NFS4_enc_getdevicelist_sz (compound_encode_hdr_maxsz + \
-				encode_sequence_maxsz + \
-				encode_putfh_maxsz + \
-				encode_getdevicelist_maxsz)
-#define NFS4_dec_getdevicelist_sz (compound_decode_hdr_maxsz + \
-				decode_sequence_maxsz + \
-				decode_putfh_maxsz + \
-				decode_getdevicelist_maxsz)
 #define NFS4_enc_getdeviceinfo_sz (compound_encode_hdr_maxsz +    \
 				encode_sequence_maxsz +\
 				encode_getdeviceinfo_maxsz)
@@ -1929,24 +1910,6 @@ static void encode_sequence(struct xdr_stream *xdr,
 }
 
 #ifdef CONFIG_NFS_V4_1
-static void
-encode_getdevicelist(struct xdr_stream *xdr,
-		     const struct nfs4_getdevicelist_args *args,
-		     struct compound_hdr *hdr)
-{
-	__be32 *p;
-	nfs4_verifier dummy = {
-		.data = "dummmmmy",
-	};
-
-	encode_op_hdr(xdr, OP_GETDEVICELIST, decode_getdevicelist_maxsz, hdr);
-	p = reserve_space(xdr, 16);
-	*p++ = cpu_to_be32(args->layoutclass);
-	*p++ = cpu_to_be32(NFS4_PNFS_GETDEVLIST_MAXNUM);
-	xdr_encode_hyper(p, 0ULL);                          /* cookie */
-	encode_nfs4_verifier(xdr, &dummy);
-}
-
 static void
 encode_getdeviceinfo(struct xdr_stream *xdr,
 		     const struct nfs4_getdeviceinfo_args *args,
@@ -2900,24 +2863,6 @@ static void nfs4_xdr_enc_reclaim_complete(struct rpc_rqst *req,
 	encode_nops(&hdr);
 }
 
-/*
- * Encode GETDEVICELIST request
- */
-static void nfs4_xdr_enc_getdevicelist(struct rpc_rqst *req,
-				       struct xdr_stream *xdr,
-				       struct nfs4_getdevicelist_args *args)
-{
-	struct compound_hdr hdr = {
-		.minorversion = nfs4_xdr_minorversion(&args->seq_args),
-	};
-
-	encode_compound_hdr(xdr, req, &hdr);
-	encode_sequence(xdr, &args->seq_args, &hdr);
-	encode_putfh(xdr, args->fh, &hdr);
-	encode_getdevicelist(xdr, args, &hdr);
-	encode_nops(&hdr);
-}
-
 /*
  * Encode GETDEVICEINFO request
  */
@@ -5773,54 +5718,6 @@ static int decode_sequence(struct xdr_stream *xdr,
 }
 
 #if defined(CONFIG_NFS_V4_1)
-/*
- * TODO: Need to handle case when EOF != true;
- */
-static int decode_getdevicelist(struct xdr_stream *xdr,
-				struct pnfs_devicelist *res)
-{
-	__be32 *p;
-	int status, i;
-	nfs4_verifier verftemp;
-
-	status = decode_op_hdr(xdr, OP_GETDEVICELIST);
-	if (status)
-		return status;
-
-	p = xdr_inline_decode(xdr, 8 + 8 + 4);
-	if (unlikely(!p))
-		goto out_overflow;
-
-	/* TODO: Skip cookie for now */
-	p += 2;
-
-	/* Read verifier */
-	p = xdr_decode_opaque_fixed(p, verftemp.data, NFS4_VERIFIER_SIZE);
-
-	res->num_devs = be32_to_cpup(p);
-
-	dprintk("%s: num_dev %d\n", __func__, res->num_devs);
-
-	if (res->num_devs > NFS4_PNFS_GETDEVLIST_MAXNUM) {
-		printk(KERN_ERR "NFS: %s too many result dev_num %u\n",
-				__func__, res->num_devs);
-		return -EIO;
-	}
-
-	p = xdr_inline_decode(xdr,
-			      res->num_devs * NFS4_DEVICEID4_SIZE + 4);
-	if (unlikely(!p))
-		goto out_overflow;
-	for (i = 0; i < res->num_devs; i++)
-		p = xdr_decode_opaque_fixed(p, res->dev_id[i].data,
-					    NFS4_DEVICEID4_SIZE);
-	res->eof = be32_to_cpup(p);
-	return 0;
-out_overflow:
-	print_overflow_msg(__func__, xdr);
-	return -EIO;
-}
-
 static int decode_getdeviceinfo(struct xdr_stream *xdr,
 				struct pnfs_device *pdev)
 {
@@ -7104,32 +7001,6 @@ static int nfs4_xdr_dec_reclaim_complete(struct rpc_rqst *rqstp,
 	return status;
 }
 
-/*
- * Decode GETDEVICELIST response
- */
-static int nfs4_xdr_dec_getdevicelist(struct rpc_rqst *rqstp,
-				      struct xdr_stream *xdr,
-				      struct nfs4_getdevicelist_res *res)
-{
-	struct compound_hdr hdr;
-	int status;
-
-	dprintk("encoding getdevicelist!\n");
-
-	status = decode_compound_hdr(xdr, &hdr);
-	if (status != 0)
-		goto out;
-	status = decode_sequence(xdr, &res->seq_res, rqstp);
-	if (status != 0)
-		goto out;
-	status = decode_putfh(xdr);
-	if (status != 0)
-		goto out;
-	status = decode_getdevicelist(xdr, res->devlist);
-out:
-	return status;
-}
-
 /*
  * Decode GETDEVINFO response
  */
@@ -7498,7 +7369,6 @@ struct rpc_procinfo	nfs4_procedures[] = {
 	PROC(SECINFO_NO_NAME,	enc_secinfo_no_name,	dec_secinfo_no_name),
 	PROC(TEST_STATEID,	enc_test_stateid,	dec_test_stateid),
 	PROC(FREE_STATEID,	enc_free_stateid,	dec_free_stateid),
-	PROC(GETDEVICELIST,	enc_getdevicelist,	dec_getdevicelist),
 	PROC(BIND_CONN_TO_SESSION,
 			enc_bind_conn_to_session, dec_bind_conn_to_session),
 	PROC(DESTROY_CLIENTID,	enc_destroy_clientid,	dec_destroy_clientid),

fs/nfs/pnfs.h

@@ -180,9 +180,6 @@ extern int pnfs_register_layoutdriver(struct pnfs_layoutdriver_type *);
 extern void pnfs_unregister_layoutdriver(struct pnfs_layoutdriver_type *);
 
 /* nfs4proc.c */
-extern int nfs4_proc_getdevicelist(struct nfs_server *server,
-				   const struct nfs_fh *fh,
-				   struct pnfs_devicelist *devlist);
 extern int nfs4_proc_getdeviceinfo(struct nfs_server *server,
 				   struct pnfs_device *dev,
 				   struct rpc_cred *cred);
@@ -277,8 +274,6 @@ bool nfs4_put_deviceid_node(struct nfs4_deviceid_node *);
 void nfs4_mark_deviceid_unavailable(struct nfs4_deviceid_node *node);
 bool nfs4_test_deviceid_unavailable(struct nfs4_deviceid_node *node);
 void nfs4_deviceid_purge_client(const struct nfs_client *);
-int nfs4_deviceid_getdevicelist(struct nfs_server *server,
-		const struct nfs_fh *fh);
 
 static inline struct nfs4_deviceid_node *
 nfs4_get_deviceid(struct nfs4_deviceid_node *d)

fs/nfs/pnfs_dev.c

@@ -358,33 +358,3 @@ nfs4_deviceid_mark_client_invalid(struct nfs_client *clp)
 	}
 	rcu_read_unlock();
 }
-
-int
-nfs4_deviceid_getdevicelist(struct nfs_server *server,
-		const struct nfs_fh *fh)
-{
-	struct pnfs_devicelist *dlist;
-	struct nfs4_deviceid_node *d;
-	int error = 0, i;
-
-	dlist = kzalloc(sizeof(struct pnfs_devicelist), GFP_NOFS);
-	if (!dlist)
-		return -ENOMEM;
-
-	while (!dlist->eof) {
-		error = nfs4_proc_getdevicelist(server, fh, dlist);
-		if (error)
-			break;
-
-		for (i = 0; i < dlist->num_devs; i++) {
-			d = nfs4_find_get_deviceid(server, &dlist->dev_id[i],
-					NULL, GFP_NOFS);
-			if (d)
-				nfs4_put_deviceid_node(d);
-		}
-	}
-
-	kfree(dlist);
-	return error;
-}
-EXPORT_SYMBOL_GPL(nfs4_deviceid_getdevicelist);

include/linux/nfs_xdr.h

@@ -252,17 +252,6 @@ struct nfs4_layoutget {
 	gfp_t gfp_flags;
 };
 
-struct nfs4_getdevicelist_args {
-	struct nfs4_sequence_args seq_args;
-	const struct nfs_fh *fh;
-	u32 layoutclass;
-};
-
-struct nfs4_getdevicelist_res {
-	struct nfs4_sequence_res seq_res;
-	struct pnfs_devicelist *devlist;
-};
-
 struct nfs4_getdeviceinfo_args {
 	struct nfs4_sequence_args seq_args;
 	struct pnfs_device *pdev;