NFSv4: Implement the fs_locations function call

NFSv4 allows for the fact that filesystems may be replicated across
several servers or that they may be migrated to a backup server in case of
failure of the primary server.
fs_locations is an NFSv4 operation for retrieving information about the
location of migrated and/or replicated filesystems.

Based on an initial implementation by Jiaying Zhang <jiayingz@citi.umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

2 files changed, 25 insertions, 0 deletions

diff --git a/include/linux/nfs4.h b/include/linux/nfs4.h
index 0c1c306cdaec..1477fc857f6b 100644
--- a/include/linux/nfs4.h
+++ b/include/linux/nfs4.h
@@ -384,6 +384,7 @@ enum {
 	NFSPROC4_CLNT_DELEGRETURN,
 	NFSPROC4_CLNT_GETACL,
 	NFSPROC4_CLNT_SETACL,
+	NFSPROC4_CLNT_FS_LOCATIONS,
 };
 
 #endif
diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
index 95682f7d738a..15a20b815302 100644
--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -679,6 +679,30 @@ struct nfs4_server_caps_res {
 	u32				has_symlinks;
 };
 
+struct nfs_fs_location {
+	unsigned int serverlen;
+	char * server;
+	unsigned int rootpathlen;
+	char * rootpath;
+};
+
+#define NFS_FS_LOCATIONS_MAXENTRIES 10
+struct nfs_fs_locations {
+	struct nfs_fattr fattr;
+	const struct nfs_server *server;
+	unsigned int fs_pathlen;
+	char * fs_path;
+	int nlocations;
+	struct nfs_fs_location locations[NFS_FS_LOCATIONS_MAXENTRIES];
+};
+
+struct nfs4_fs_locations_arg {
+	const struct nfs_fh *dir_fh;
+	const struct qstr *name;
+	struct page *page;
+	const u32 *bitmask;
+};
+
 #endif /* CONFIG_NFS_V4 */
 
 struct nfs_page;