NFSv4: convert fs-locations-components to conform to RFC3530

Use component4-style formats for decoding list of servers and pathnames in
fs_locations.
Signed-off-by: Manoj Naik <manoj@almaden.ibm.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

fs/nfs/nfs4_fs.h

@@ -219,7 +219,7 @@ extern struct dentry *nfs4_atomic_open(struct inode *, struct dentry *, struct n
 extern int nfs4_open_revalidate(struct inode *, struct dentry *, int, struct nameidata *);
 extern int nfs4_server_capabilities(struct nfs_server *server, struct nfs_fh *fhandle);
 extern int nfs4_proc_fs_locations(struct inode *dir, struct dentry *dentry,
-		struct nfs_fs_locations *fs_locations, struct page *page);
+		struct nfs4_fs_locations *fs_locations, struct page *page);
 
 extern struct nfs4_state_recovery_ops nfs4_reboot_recovery_ops;
 extern struct nfs4_state_recovery_ops nfs4_network_partition_recovery_ops;

fs/nfs/nfs4proc.c

@@ -3571,7 +3571,7 @@ ssize_t nfs4_listxattr(struct dentry *dentry, char *buf, size_t buflen)
 }
 
 int nfs4_proc_fs_locations(struct inode *dir, struct dentry *dentry,
-		struct nfs_fs_locations *fs_locations, struct page *page)
+		struct nfs4_fs_locations *fs_locations, struct page *page)
 {
 	struct nfs_server *server = NFS_SERVER(dir);
 	u32 bitmask[2] = {
@@ -3587,7 +3587,7 @@ int nfs4_proc_fs_locations(struct inode *dir, struct dentry *dentry,
 	struct rpc_message msg = {
 		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_FS_LOCATIONS],
 		.rpc_argp = &args,
-		.rpc_resp = &fs_locations,
+		.rpc_resp = fs_locations,
 	};
 	int status;
 

fs/nfs/nfs4xdr.c

@@ -2377,7 +2377,43 @@ static int decode_attr_files_total(struct xdr_stream *xdr, uint32_t *bitmap, uin
 	return status;
 }
 
-static int decode_attr_fs_locations(struct xdr_stream *xdr, uint32_t *bitmap, struct nfs_fs_locations *res)
+static int decode_pathname(struct xdr_stream *xdr, struct nfs4_pathname *path)
+{
+	int n;
+	uint32_t *p;
+	int status = 0;
+
+	READ_BUF(4);
+	READ32(n);
+	if (n <= 0)
+		goto out_eio;
+	dprintk("path ");
+	path->ncomponents = 0;
+	while (path->ncomponents < n) {
+		struct nfs4_string *component = &path->components[path->ncomponents];
+		status = decode_opaque_inline(xdr, &component->len, &component->data);
+		if (unlikely(status != 0))
+			goto out_eio;
+		if (path->ncomponents != n)
+			dprintk("/");
+		dprintk("%s", component->data);
+		if (path->ncomponents < NFS4_PATHNAME_MAXCOMPONENTS)
+			path->ncomponents++;
+		else {
+			dprintk("cannot parse %d components in path\n", n);
+			goto out_eio;
+		}
+	}
+out:
+	dprintk("\n");
+	return status;
+out_eio:
+	dprintk(" status %d", status);
+	status = -EIO;
+	goto out;
+}
+
+static int decode_attr_fs_locations(struct xdr_stream *xdr, uint32_t *bitmap, struct nfs4_fs_locations *res)
 {
 	int n;
 	uint32_t *p;
@@ -2388,7 +2424,8 @@ static int decode_attr_fs_locations(struct xdr_stream *xdr, uint32_t *bitmap, st
 	status = 0;
 	if (unlikely(!(bitmap[0] & FATTR4_WORD0_FS_LOCATIONS)))
 		goto out;
-	status = decode_opaque_inline(xdr, &res->fs_pathlen, &res->fs_path);
+	dprintk("%s: fsroot ", __FUNCTION__);
+	status = decode_pathname(xdr, &res->fs_path);
 	if (unlikely(status != 0))
 		goto out;
 	READ_BUF(4);
@@ -2397,15 +2434,40 @@ static int decode_attr_fs_locations(struct xdr_stream *xdr, uint32_t *bitmap, st
 		goto out_eio;
 	res->nlocations = 0;
 	while (res->nlocations < n) {
-		struct nfs_fs_location *loc = &res->locations[res->nlocations];
+		int m;
+		struct nfs4_fs_location *loc = &res->locations[res->nlocations];
+
+		READ_BUF(4);
+		READ32(m);
+		if (m <= 0)
+			goto out_eio;
 
-		status = decode_opaque_inline(xdr, &loc->serverlen, &loc->server);
+		loc->nservers = 0;
+		dprintk("%s: servers ", __FUNCTION__);
+		while (loc->nservers < m) {
+			struct nfs4_string *server = &loc->servers[loc->nservers];
+			status = decode_opaque_inline(xdr, &server->len, &server->data);
 			if (unlikely(status != 0))
 				goto out_eio;
-		status = decode_opaque_inline(xdr, &loc->rootpathlen, &loc->rootpath);
+			dprintk("%s ", server->data);
+			if (loc->nservers < NFS4_FS_LOCATION_MAXSERVERS)
+				loc->nservers++;
+			else {
+				int i;
+				dprintk("%s: using first %d of %d servers returned for location %d\n", __FUNCTION__, NFS4_FS_LOCATION_MAXSERVERS, m, res->nlocations);
+				for (i = loc->nservers; i < m; i++) {
+					int len;
+					char *data;
+					status = decode_opaque_inline(xdr, &len, &data);
+					if (unlikely(status != 0))
+						goto out_eio;
+				}
+			}
+		}
+		status = decode_pathname(xdr, &loc->rootpath);
 		if (unlikely(status != 0))
 			goto out_eio;
-		if (res->nlocations < NFS_FS_LOCATIONS_MAXENTRIES)
+		if (res->nlocations < NFS4_FS_LOCATIONS_MAXENTRIES)
 			res->nlocations++;
 	}
 out:
@@ -2948,7 +3010,7 @@ static int decode_getfattr(struct xdr_stream *xdr, struct nfs_fattr *fattr, cons
 	if ((status = decode_attr_fileid(xdr, bitmap, &fattr->fileid)) != 0)
 		goto xdr_error;
 	if ((status = decode_attr_fs_locations(xdr, bitmap, container_of(fattr,
-						struct nfs_fs_locations,
+						struct nfs4_fs_locations,
 						fattr))) != 0)
 		goto xdr_error;
 	if ((status = decode_attr_mode(xdr, bitmap, &fattr->mode)) != 0)
@@ -4297,7 +4359,7 @@ static int nfs4_xdr_dec_delegreturn(struct rpc_rqst *rqstp, uint32_t *p, struct
 /*
  * FS_LOCATIONS request
  */
-static int nfs4_xdr_dec_fs_locations(struct rpc_rqst *req, uint32_t *p, struct nfs_fs_locations *res)
+static int nfs4_xdr_dec_fs_locations(struct rpc_rqst *req, uint32_t *p, struct nfs4_fs_locations *res)
 {
 	struct xdr_stream xdr;
 	struct compound_hdr hdr;

include/linux/nfs_xdr.h

@@ -679,21 +679,31 @@ struct nfs4_server_caps_res {
 	u32				has_symlinks;
 };
 
-struct nfs_fs_location {
-	unsigned int serverlen;
-	char * server;
-	unsigned int rootpathlen;
-	char * rootpath;
+struct nfs4_string {
+	unsigned int len;
+	char *data;
+};
+
+#define NFS4_PATHNAME_MAXCOMPONENTS 512
+struct nfs4_pathname {
+	unsigned int ncomponents;
+	struct nfs4_string components[NFS4_PATHNAME_MAXCOMPONENTS];
+};
+
+#define NFS4_FS_LOCATION_MAXSERVERS 10
+struct nfs4_fs_location {
+	unsigned int nservers;
+	struct nfs4_string servers[NFS4_FS_LOCATION_MAXSERVERS];
+	struct nfs4_pathname rootpath;
 };
 
-#define NFS_FS_LOCATIONS_MAXENTRIES 10
-struct nfs_fs_locations {
+#define NFS4_FS_LOCATIONS_MAXENTRIES 10
+struct nfs4_fs_locations {
 	struct nfs_fattr fattr;
 	const struct nfs_server *server;
-	unsigned int fs_pathlen;
-	char * fs_path;
+	struct nfs4_pathname fs_path;
 	int nlocations;
-	struct nfs_fs_location locations[NFS_FS_LOCATIONS_MAXENTRIES];
+	struct nfs4_fs_location locations[NFS4_FS_LOCATIONS_MAXENTRIES];
 };
 
 struct nfs4_fs_locations_arg {